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Chapter 6 Continued
 
I. EYEPIECE SKELETON ASSEMBLY
 
6I1. Description of eyepiece skeleton assembly. The eyepiece skeleton assembly (Figure 4-28) is almost identical to the eye piece skeleton assembly used in the Type II periscope. All   parts except the eyepiece prism and the eyepiece lens are identical. Refer to Section L, Chapter 4, following the procedure of Sections 4L1, 2, and 3 for description, disassembly, and reassembly.
 
J. EYEPIECE BOX AND MISCELLANEOUS ASSEMBLIES
 
6J1. Description of eyepiece box and miscellaneous assemblies. This eyepiece box and miscellaneous assemblies (Figure 4-29) are identical   to the eyepiece box and miscellaneous assemblies used in the Type II periscope. Refer to Section 4M1 for its description.
 
K. PACKING GLAND ASSEMBLIES
 
6K1. Description of packing gland assemblies. The packing gland assemblies (Figures 4-30, 31, 32, 33, and 34) ale identical to the packing   gland assemblies used in the Type II periscope. Refer to Sections 4N1 to 4N13 inclusive, for description, disassembly, and reassembly.
 
L. EYEPIECE WINDOW ASSEMBLY
 
6L1. Description of the eyepiece window assembly. The eyepiece window assembly (Figure 4-38) is almost identical to the eyepiece window assembly used in the Type II periscope. All   parts except the eyepiece window are identical. Refer to Section O of Chapter 4, following the procedure stated in Sections 4O1, 2, and 3 for description, disassembly, and reassembly.
 
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M. FOCUSING KNOB ASSEMBLY.
 
6M1. Description of the focusing knob assembly. The focusing knob assembly (Figure 4-39) is identical to the focusing knob assembly used   in the Type II periscope. Refer to Sections 4P1, 2, and 3 for description, disassembly, and reassembly.
 
N. RAYFILTER ASSEMBLY
 
6N1. Description of rayfilter assembly. The rayfilter assembly (Figure 4-40) is identical to the rayfilter assembly used in the Type II   periscope. Refer to Sections 4Q1, 2, and 3 for description, disassembly, and reassembly.
 
O. VARIABLE DENSITY POLAROID FILTER ASSEMBLY
 
6O1. Description of variable density polaroid filter assembly. The variable density polaroid filter assembly (Figure 4-41) is identical to the variable density polaroid filter assembly used   in the Type II periscope. Refer to Section R under Chapter 4 following the procedure stated in Sections 4R1, 2, and 3 for description, disassembly, and reassembly.
 
P. EYE BUFFER AND BLINDER ASSEMBLY
 
6P1. Description of the eye buffer and blinder assembly. The eye buffer and blinder assembly (Figure 4-42) is identical to the eye buffer and blinder assembly used in the Type II   periscope. Refer to Section S under Chapter 4, following the procedure stated in Sections 4S1, 2, and 3 for description, disassembly, and reassembly.
 
Q. TRAINING HANDLE ASSEMBLIES
 
6Q1. Description of the left training handle assembly. This left training handle assembly operates the prism tilt mechanism by the movement of the revolving grip (3, Figure 6-11) and is interconnected, with an appropriate mechanism in the eyepiece skeleton assembly. It is further interconnected by shifting wire tapes (38, Figure 4-28) to the prism tilt mechanism and the skeleton head assembly for elevation and depression of the head prism.

This assembly is similar to the left training handle assembly (Figure 4-43) used in the Type II periscope, except for various deletions, such as the spring detent assembly and its accompanying parts. There is also a variation in the construction of various parts. Several parts of this assembly are used in the right training handle assembly of the Type II periscope the handle hinge (16, Figure 6-11) is the only part of this assembly having a variance in construction. Figure 6-11 shows the left training handle assembly. All bubble numbers in Sections 6Q1, 2, and 3 refer to Figure 6-11 unless otherwise specified.

 
Ill.
No.
Drawing
Number
Num-
ber Re-
quired
Nomenclature
1 P-1069-1 1 Revolving grip end cap
2 P-1069-2 1 Fixed grip
3 P-1069-4 1 Revolving grip
4 P-1069-5 1 Revolving grip outer collar
5 P-1069-7 1 Fixed grip outer collar
6 P-1069-9 1 Revolving grip inner collar
7 P-1069-10 1 Index ring
8 P-1069-11 1 Segment stop
9 P-1069-12 1 Outer bevel gear clutch shaft
10 P-1069-13 1 Revolving grip shaft
11 P-1069-14 1 Outer bevel gear clutch shaft collar
12 P-1069-15 1 Outer bevel gear clutch spring
13 P-1069-16 1 Outer bevel gear clutch spring retaining screw
14 P-1069-18 2 Revolving and fixed grip lockscrews
15 P-1069-21 1 Revolving grip shaft and outer bevel gear clutch shaft locking taper pin
16 P-1157-1 1 Handle hinge
17 P-1157-5 1 Inner bevel gear clutch
 
342

Ill.
No.
Drawing
Number
Num-
ber Re-
quired
Nomenclature
18 P-1157-6 1 Outer bevel gear clutch
19 P-1157-7 1 Handle detent plunger
20 P-1157-8 1 Handle detent plunger spring
21 P-1157-9 1 Handle detent plunger retaining screw
22 P-1161-7 4 Hinge bracket bolts
23 P-1171-6 2 Pivot screws
24 P-1179-39 2 Pivot screw lockscrews
25 P-1179-52 1 Index ring actuating screw
26 P-1179-53 2 Segment stop lockscrews
27 P-1179-191 1 Outer bevel gear clutch shaft collar taper pin
28 P-1310-39 2 Segment stop adjusting screw lockscrews
29 P-1389-7 2 Segment stop adjusting screws
30 P-1408-3 1 Hinge bracket

a. Handle hinge. The handle hinge (16) is identical to the left handle hinge (28, Figure 4-43) used in the left training handle assembly of the Type II periscope. The alignment support section of the handle hinge, however, does not include the two counterbored sections for the main body stop (31, Figure 4-43) used in the left handle hinge (28, Figure 4-43) and the square broached hole and opposite clearance hole.

b. Index ring. The index ring (7) is almost identical to the index ring (6, Figure 4-43) used in the left training handle assembly of the Type II periscope, except for the fact that the periphery is engraved after assembly to indicate 10 degrees depression, 0 degrees line of sight, and 45 degrees elevation.

6Q2. Disassembly. The left training handle assembly is disassembled in the following manner:

1. Remove the lockscrew (14), unscrewing it from the tapped hole in the revolving grip shaft (10), and carrying it out of the clearance holes in the revolving grip (3) and the outer collar (4).

2. Remove the assembled revolving grip (3) sliding it off the revolving grip shaft (10), carrying with it the revolving grip end cap (1), revolving grip outer collar (4), revolving grip inner collar (6), and the index ring actuating screw (25).

  3. Remove the two lockscrews (26) from the segment stop (8), unscrewing them from tapped holes in the revolving grip shaft (10). Remove the segment stop (8).

4. Remove the lockscrew (14) from the fixed grip (2), unscrewing it from tapped holes in the handle hinge (16) alignment support section and the fixed grip.

5. Remove the assembled fixed grip (2) with the index ring (7) on its outer collar (5) sliding it off the handle hinge (16) alignment support section and carrying it off the revolving grip shaft (10).

6. Remove the index ring (7), sliding it off the fixed grip outer collar (5).

7. Remove the two pivot screw lockscrews (24), unscrewing them from their contact with the two pivot screws (23) and the tapped holes in each hinge section side wall of the hinge bracket (30) in its lower counterbored section seat.

8. Swing the handle hinge (16) to the extended position. Only in this position is there sufficient clearance for the removal of the outer bevel gear clutch (18) with the remaining assembly of the handle hinge (16) from the hinge bracket (30).

9. Remove the two pivot screws (23), unscrewing them from the tapped holes in the hinge section side walls of the hinge bracket (30). Remove the hinge bracket.

10. Remove the inner bevel gear clutch (17), sliding it out of the hinge bracket (30).

11. Remove the retaining screw (13), unscrewing it from the tapped hole in the outer bevel gear clutch shaft (9). Remove the outer bevel gear clutch (18), and the outer bevel gear clutch spring (12), sliding them off the square section of the outer bevel gear clutch shaft (9).

12. Rotate the revolving grip shaft (10) until the small end of the taper pin (27) is lined up with the drift clearance hole in the handle hinge wall (16).

13. Place a drift punch of suitable size in the handle hinge clearance hole (16).

 
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Figure 6-11. Left training handle assembly.
Figure 6-11. Left training handle assembly.
14. Drive the taper pin (2I) from the outer bevel gear clutch collar (11) and the outer bevel gear clutch shaft (9).

15. Remove the outer bevel gear clutch collar (11) from the outer bevel gear clutch shaft (9).

16. Remove the revolving grip shaft (10) with the assembled outer, bevel gear clutch shaft (9) from the handle hinge (16).

17. Do not disassemble the outer bevel gear clutch shaft (9) from the revolving grip shaft (10). Leave them secured with the taper pin (15).

  18. Remove the retaining screw (21), unscrewing it from its engagement in the keyway in the handle detent plunger (19) and the tapped hole in the hinge section rear side wall of the handle hinge (16).

19. Remove the handle detent plunger (19) and the handle detent plunger spring (20) from the reamed hole in the hinge section inner circumference wall of the handle hinge (16).

20. The two segment stop adjusting screws (29) and the two lockscrews (28) are not altered during disassembly.

6Q3. Reassembly. The left training handle assembly is reassembled in the following manner:

 
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1. Lubricate lightly all rotating parts with Lubriplate No. 110 as the reassembly procedure is followed.

2. Place the handle detent plunger spring (20) in the reamed clearance holes in the handle detent plunger (19).

3. Place the handle detent plunger (19) and the spring (20) in the reamed hole in the rear inner circumference wall of the handle hinge (16). Rotate the handle detent plunger until its keyway is located to the rear, and its detent point is lying in a horizontal plane, so that the retaining screw (21) engages in the keyway.

4. Insert the retaining screw (21), screwing it into the tapped hole with its undercut shoulder engaging in the keyway in the handle detent plunger (19).

5. Place the assembled outer bevel gear clutch shaft (9) with revolving grip shaft (10) in their respective reamed holes in the handle hinge (16).

6. Place the outer bevel gear clutch collar (11) on the outer bevel gear clutch shaft (9).

7. Align the taper pin holes in the outer bevel gear clutch shaft (9) and the collar (11).

8. Insert and secure the taper pin (27) in these lined up holes from the open hinge section of the handle hinge (16).

9. Place the Outer bevel gear clutch spring (12) on the outer bevel gear clutch shaft (9) and into the counterbored section in the outer bevel gear clutch collar (11).

10. Place the outer bevel gear clutch (18) on the square section of the outer bevel gear clutch shaft (9) with reference marks properly reestablished.

11. Compress the outer bevel gear clutch spring (12) by pressing inward on the outer bevel gear clutch (18) for the insertion of the retaining screw (13). Insert the retaining screw (13), screwing it into the square section tapped axis hole in the outer bevel gear clutch shaft (9).

12. Check the outer bevel gear clutch (18) for free spring movement.

  13. Place the inner bevel gear clutch (17) in the reamed hole in the cored hinge section of the hinge bracket (30).

14. Holding the handle hinge assembly in the extended position, carry the outer bevel gear clutch (18) through the cored clearance hole in the hinge bracket (30).

15. Check the reference marks of the inner bevel gear clutch tooth (17) with its mating reference mark between two teeth of the outer bevel gear clutch (18). Engage the gear teeth of the inner and outer bevel gear clutches, carrying the hinge section of the handle hinge (16) over the hinge section of the hinge bracket (30).

16. Apply downward pressure to the handle hinge (16) and the handle detent plunger (19) resting on the hinge section side wall periphery of the hinge bracket (30). This compresses the handle detent plunger spring fully, for the insertion of the two opposite side pivot screws (23).

17. Insert the two pivot screws (23) into opposite side walls of the handle hinge (16), check their reference marks for proper insertion, and screw them into tapped holes in the hinge section side walls of the hinge bracket (30).

18. Secure both pivot screws (23) with lockscrews (24). Insert these lockscrews in body clearance holes and screw them into the tapped hole section in each of the hinge section side walls of the hinge bracket (30) located in the lower counterbored section seat in its base. The lockscrews contact the pivot screw threaded sections to prevent them from unscrewing.

19. Place the fixed grip (2) on the revolving grip shaft (10), sliding it on over the alignment support section of the handle hinge (16).

20. Align the tapped lockscrew holes and insert the lockscrew (14). This lockscrew is screwed into the tapped hole in the fixed grip (2) and in the alignment support section wall of the handle hinge (16).

21. Place the index ring (7) over the revolving grip shaft (10) and on the undercut shoulder of the fixed grip outer collar (5). It should fit snugly over the shoulder of this collar.

 
345

22. Place the segment stop (8) on the revolving grip shaft (10), secure it opposite the semi-circular projecting section of the fixed grip outer collar (5) to the revolving grip shaft (10) with two lockscrews (26). These lockscrews are inserted in countersunk clearance holes in the segment stop (8) and screwed into tapped holes in the above shaft.

23. Place the assembled revolving grip (3) on the revolving grip shaft (10), carrying with it the outer and inner collars (4 and 6), end cap (1), and index ring actuating screw (25). Engage the actuating screw head in the elongated circumferential recess in the outer side face of the index ring (7).

24. Insert the lockscrew (14), carrying it into the clearance holes of the revolving grip (3) and its outer collar (4), screwing it into the tapped hole in the revolving grip shaft (10).

  25. Rotate the revolving grip (3) until the index ring (7) with its graduated line of 45 degrees is located in the full elevated position. This graduated line on the index ring should coincide with the stationary index line on the fixed grip (2). Correct the insufficient or over-travel of the index ring by means of two segment stop adjusting screws (29). The front adjusting screw corrects for elevation, while the rear adjusting screw corrects for depression. Follow the same procedure for 10 degrees or full depression. To make the necessary adjustments requires the removal of the revolving grip (3).

6Q4. Description of the right training handle assembly. The right training handle assembly (Figure 4-44) is identical to the right training handle assembly used in Type II periscope. Refer to Sections 4T5, 6, and 7 for description, disassembly, and reassembly.

 
R. STADIMETER ILLUMINATOR ASSEMBLY
 
6R1. Description. The stadimeter illuminator assembly may be attached to the anchor screw pins (19, Figure 4-29) in the front or rear sides of the eyepiece box (11). It is adjusted in such position as to illuminate either the front or rear stadimeter housing dials (Figure 4-24)   in an emergency, or when the observer desires the extinguishing of the submarine control tower lighting. The light intensity is adjustable for varying degrees of darkness adaptation in the observer's eye. Figure 6-12 shows the stadimeter illuminator assembly. All bubble numbers
Figure 6-12. Stadimeter illuminator assembly.
Figure 6-12. Stadimeter illuminator assembly.
 
346

in Section 6R1 refer to Figure 6-12 unless otherwise specified.

Ill.
No.
Drawing
Number
Num-
ber Re-
quired
Nomenclature
1 P-1179-26 3 Insulating plate lockscrews
2 P-1179-31 1 Contact strip lockscrew
3 P-1414-3 1 Right finger grip lever
4 P-1414-4 1 Left finger grip lever
5 P-1414-5 2 Finger grip lever springs
6 P-1416-5 2 Finger grip lever thrust stop screw pins
7 P-1416-6 2 Finger grip lever pivot screw pins
8 P-1431-1 1 Illuminator housing
9 P-1431-2 1 Housing base plate
10 P-1431-3 1 Battery cell housing
11 P-1433-1 1 Rheostat assembly
12 P-1433-1A 1 Rheostat hub locknut
13 P-1433-1B 1 Rheostat shaft retaining lock washer
14 P-1433-2 1 Bulb socket assembly
15 P-1433-9 1 Battery single cell
16 P-1433-12 2 Battery bulbs
17 P-1434-1 2 Illuminator housing spacer screws
18 P-1434-2 1 Battery center contact
19 P-1434-3 4 Bulb and rheostat mount plates lockscrews
20 P-1434-5 1 Insulating plate
21 P-1434-6 2 Illuminator housing spacing screw locknuts
22 P-1434-7 1 Stuffing gland
23 P-1434-8 1 Contact spring usher
24 P-1434-9 1 Spare bulb housing
25 P-1435-1 3 Illuminator housing screws
26 P-1435-2 3 Bulb and rheostat mount plate spacers
27 P-1435-3 1 Rheostat mount plate
28 P-1435-4 1 Bulb and rheostat mount plate key spacer
29 P-1435-6 1 Battery cell spring
30 P-1435-7 1 Bulb and rheostat mount knurled retaining ring
31 P-1435-8 1 Contact strip insulator
32 P-1435-9 1 Contact strip
33 P-1436-1 1 Rheostat assembly cover
34 P-1436-2 1 Rheostat operating knob
35 P-1436-2A 1 Rheostat operating knob lockscrew
36 P-1436-3 1 Contact strap aligning Screw.
37 P-1436-4 1 Condenser lens,
38 P-1436-5 1 Rheostat hub lock washer
39 P-1436-6 1 Rheostat assembly cover lead washer
40 P-1436-7 1 Rheostat mount plate lead washer
41 P-1436-8 1 Battery housing lead washer
 

Ill.
No.
Drawing
Number
Num-
ber Re-
quired
Nomenclature
42 P-1436-9 1 Condenser lens mount
43 P-1436-10 1 Rheostat operating knob taper pin
44 P-1436-11 1 Condenser lens clamp ring
45 P-1436-12 1 Red lucite filter
46 P-1-1 1 Rheostat mount plate stop pin

a. Housing base plate. The housing base plate, (9) is made of cast phosphor bronze and is 4.190 inches in length. The upper and lower projecting parts are similar to the base plate (9) used in the variable density polaroid filter assembly of the Type II and III periscopes, for the attachment of two finger grip levers right and left (3 and 4), and the two tension springs (5). Refer to (9), Figure 4-41, Section 4R1, for these upper and lower projecting sections.

The upper and lower projecting sections are separated on opposite sides with rectangular slotted sections, leaving a narrow center section. This narrow center section fits between the rear cylindrical walls of the illuminator housing (8) with an axial adjustment clearance of approximately 1/8 inch. This allows the housing to be adjusted, axially, so that the position of the lamp filament will illuminate the stadimeter housing dials uniformly.

The lower projecting section is provided with two tapped holes to receive two cap screws (25). The narrow section in the center of the connecting section below the upper projecting section is provided with a tapped hole for the third cap screw, (25). These three cap screws (25) inserted in three elongated holes in the three illuminator housing lug sections, secure the housing axially and angularly. Two tapped holes located in opposite recesses in the rear of the illuminator housing cylindrical periphery (8) receive spacer screws (17) fitted with locknuts to adjust the lamp filament angularly as desired for uniform illumination of the stadimeter housing dials.

b. Finger grip levers. The finger grip levers right and left (3 and 4) with their two thrust stop screw pins (6) and the two pivot screw pins (7) are identical to the finger grip levers right and left (1 and 2, Figure 4-41) and

 
347

their thrust stop screw pins (13) and pivot screw pins (14) used in the variable density polaroid filter assembly of the Type II periscope. Refer to Section 4R1.

c. Illuminator housing. The illuminator housing (8) is made of cast phosphor bronze and is 3 1/4 inches in length. The external surfaces of this housing follow an irregular cast design from the main cylindrical body on opposite ends. Its left cylindrical body has a cast projection extending upward sufficiently to serve as a container. This cast projection is drilled a depth of 7/8 inch and is provided with a coarse thread to receive a left-hand housing (24) containing a spare battery bulb (16).

The housing from the cast projection slopes downward to form a hood arrangement between its two cylindrical body sections in the central part. The two cylindrical body sections are separated by a space of 7/8 inch. This hood arrangement leaves a narrow wall with a raised boss in the left side to accommodate an elongated hole for a cap screw (25). The hood arrangement follows a convex contour in a distance of approximately 120 degrees, at which point it slopes inward at an angle of about 24 degrees.

The inward sloping section is spotted with a router in the inner wall section of the hood arrangement, with a counterbored and internal threaded section to receive the condenser lens mount (42). This section is counterbored to receive the large shoulder of the condenser lens mount (42), with the remaining sides of the cylindrical body sections having a cored concave seat. The cored convex seat allows clearance for adequate divergence of the illuminated light beam projecting downward and inward.

Two projecting lugs extend downward on opposite sides of the bored and internal threaded condenser lens mount opening and each cylindrical body section to form the rear flat-wall section extension. Each projecting lug has an elongated hole for insertion of cap screws (25).

The left cylindrical body section is undercut and threaded to receive a lead washer (41) and battery cell housing (10). The inner surface of this left side is provided with two counterbored sections. The small section of shallow depth carries an insulating plate (20) which is secured with three lockscrews (1). These lockscrews are

  inserted in countersunk clearance holes in the insulating plate (20) and screwed into tapped holes in the small counterbored seat. The large counterbored section accommodates sufficient clearance for a single cell battery (15).

The right cylindrical body section is undercut and threaded to receive the bulb and rheostat mount knurled retaining ring (30), which retains the rheostat assembly cover (33) and rheostat mount plate (27). The inner surface of this right side is counterbored with a 45 degrees chamfer in its seat to provide clearance for the bulb socket assembly (14). The inner circumference of the counterbored section is provided with a milled recess for the bulb and rheostat mount key spacer (28), which serves to designate its correct assembly.

The center section between the left and right side counterbored sections in both body sections is cored with a semi-circular section bounded on both ends with narrow raised boss sections located directly opposite. This semi-circular section carries a contact strip insulator (31) to prevent the battery from grounding to the illuminator housing.

The rear part of the housing between the two cylindrical body sections is machined flat as are also the two projecting lug sections. This allows it an axial adjustment on the housing base plate (9) by means of the three elongated holes in the two projecting lug sections and the upper narrow wall and raised boss section above the hood arrangement.

d. Spare bulb housing. The spare bulb housing (24) is made of phosphor bronze and is 1/2 inch in length. The large outer diameter is rough diamond knurled to offer a firm grip to the observer. The outer face has the letters Spare Lamp inscribed on it, and is filled with white monofil, in order to be clearly visible to the observer. The undercut section is threaded with 12 threads per inch and engages into the coarse tapped hole in the upper projecting section of the left cylindrical body section of the illuminator housing (8). The inside axis of the bulb housing has a tapped hole for an American national miniature thread to receive the threaded periphery of the spare bulb.

e. Battery cell housing. The battery cell housing (10) is made of brass rod and is 2 1/32

 
348

inches in length. The outer diameter is uniform its entire length with a knurled band 1/16-inch wide near its outer end. The outer sharp corner is rounded off.

The inner part is bored to carry the battery cell (15) of a loose fit. It is provided with a counterbored section 1 3/16 inch long to reduce its weight, and is provided, with an undercut trap 1/16 inch in width to retain the battery cell spring (29) within 1/8 inch of the outer side wall.

The inner end is counterbored a depth of 1/8 inch and is threaded to engage on the threaded periphery of the illuminator housing (8) left side against a lead washer (41).

f. Insulating plate. The insulating plate (20) is made of 1/8-inch Bakelite and is shaped cylindrical. It is a sliding fit in the small shallow counterbored section in the left side of the illuminator housing (8) and is secured with three lockscrews (1). These lockscrews are inserted in countersunk clearance holes in the outer face of this insulating-plate and screwed into tapped holes in the counterbored seat.

It carries the battery center contact (18) mounted in its axis. The inner face of this plate carries the contact strip (32) secured with an aligning screw (36), contact strip washer (23), and lockscrew (2). The lockscrew (2) inserted in a hole in the contact strip (32) extends into the axis tapped hole in the battery center contact.

The contact, strip (32), which is 1 5/16 inches long and extends the entire length of the center axis section in the illuminator housing (8), is properly insulated from grounding with the illuminator housing by means of the contact strip insulator (31). The contact strip is chromium plated and serves as a reflector.

g. Bulb socket assembly. The bulb socket assembly (14) is directly connected electrically with the rheostat assembly (11). It is a commercial product consisting of a bulb socket and finger contact attached to a 1/8-inch Bakelite insulating plate. The insulating plate is supported by the rheostat mount plate (27) and is separated from it by three bulb and rheostat mount plate spacers (26) and a bulb and rheostat mount plate key spacer (28). It is secured with four lockscrews (19). These lockscrews are inserted in countersunk clearance holes in the rheostat mount plate (27), and extend through

  clearance holes in each of the three bulb and rheostat mount plate spacers (26) and one bulb and rheostat mount plate key spacer (28) to screw in the insulating plate of this bulb socket assembly. The rheostat assembly (11) axis section fits through the axis clearance hole in the rheostat mount plate (27). This plate is provided with a stop pin (46) which is a drive fit in a reamed hole located 15 degrees from the vertical centerline and an appropriate distance from its center axis. This stop pin (46) extends through a clearance hole in the rheostat coil plate of the rheostat assembly, and restricts the rheostat resistance contact finger from further rotation for a known OFF position inscribed on the rheostat assembly cover (33) with a reference line on the rheostat operating knob (34).

h. Rheostat assembly cover. The rheostat assembly cover (33) is made of brass and is 27/32 inch in width. It is provided with three external shoulder sections. The large diameter shoulder is counterbored a shallow depth to carry a lead washer (39) in its outer face to provide a negative ground for the battery, and contacts the inner counterbored seat of the knurled retaining ring (30). The medium diameter shoulder section is a sliding fit in the bored opening of the retaining ring, while the small diameter shoulder section is chamfered to a diameter which is coincident with the large diameter of the rheostat operating knob (34). The chamfered shoulder periphery is inscribed with the letters OFF and filled with white monofil to designate to the observer the OFF position of the illuminator as indicated by the rheostat operating knob reference line.

The center axis is provided with a clearance hole which is a sliding fit over the rheostat hub threaded periphery, and has a counterbored and threaded section in the outer part. This counterbored section allows sufficient clearance for the attachment of the rheostat hub lock washer (38) and rheostat hub locknut (12). This cover is secured to the rheostat mount plate (27) in direct relation to its inscribed OFF designation with the rheostat operating knob (34) reference line. The internal threaded section receives a stuffing gland (22) which locks the rheostat hub lock nut (12).

i. Stuffing gland. The stuffing gland (22) is made of phosphor bronze and is shaped

 
349

cylindrical. Its outer periphery is threaded to engage in the internal threaded section in the rheostat assembly cover (33). Its center axis is provided with a reamed clearance hole, a sliding fit over the projecting section of the rheostat assembly shaft. The inner face is countersunk to provide clearance over the rheostat shaft retaining lock washer (13). The outer face is provided with two opposite drilled holes for the insertion of a special wrench. This stuffing gland serves to prevent moisture from entering the rheostat assembly, and also serves to lock the rheostat hub locknut (12).

j. Rheostat operating knob. The rheostat operating knob (34) is made of black bakelite with a clearance hole in its inner axis, and is a sliding fit on the rheostat assembly shaft secured with a taper pin (43) and lockscrew (35). The knob has two shoulder sections, the large shoulder coincides with the chamfered shoulder section of the rheostat assembly cover (33) and is filleted with the octagon shoulder section.

k. Bulb and rheostat mount knurled retaining rings. The bulb and rheostat mount knurled retaining ring (30) is made of brass and is 0.570 inch in width. It is shaped cylindrical, with the periphery rough diamond knurled to offer the observer a firm grip. The outer 1/16 inch of the periphery is undercut, with the sharp corner rounded off.

It is bored a sliding fit over the medium shoulder section of the rheostat assembly cover (33), and is provided with two counterbored sections. The small counterbored shoulder section is provided with clearance over the large diameter of the rheostat assembly cover (33) while the large counterbored and threaded section fits over the rheostat mount plate (27) and engages on the threaded periphery section on the right side of the illuminator housing (8) to secure the rheostat assembly with a good negative battery ground against the lead washer (39).

l. Condenser lens mount and lens. 1. Condenser lens mount. The condenser lens mount (42) is made of brass and is 1 3/64 inch wide. It has an undercut shoulder section which serves as an alignment support section for its entry in the internal threaded section in the illuminator housing (8). Its large diameter has

  a threaded periphery to engage in the internal threaded section in the illuminator housing, and rests, against the counterbored seat.

The mount is bored for the illuminated light transmission and is counterbored, leaving a narrow shoulder seat. The smooth part of this counterbored section carries the red lucite-filter (45) and the condenser lens (37), while the internal threaded section carries the threaded clamp ring (44). The outer face of the mount is provided with opposite slots for the insertion of a special wrench.

2. Condenser lens. The condenser lens (37) is made of one optical element consisting of a plano convex crown element. It is mounted in the condenser lens mount (42) with the plano side resting against the red Lucite filter (45), and is secured with a clamp ring (44).

m. Red Lucite filter. The red lucite filter (45) is shaped cylindrical with parallel faces and is placed in the condenser lens mount (42) below the condenser lens (37). This red filter presents a red beam of light to the stadimeter housing dials. The light intensity is adjustable by counterclockwise rotation of the rheostat operating knob from maximum intensity to minimum intensity as desired by the observer.

n. Clamp ring. The clamp ring (44) is made of brass and has a nominal thickness and width. The periphery is threaded and engages in the internal threaded section in the condenser lens mount (42) to secure the red lucite filter (45) and condenser lens in the seat of the mount. The inner face is chamfered at 30 degrees and rests against the convex surface of the condenser lens (37). The outer face is provided with two opposite slots for the insertion of a special wrench.

o. Electrical circuit. The negative side of the battery cell (15) is grounded to the battery cell housing (10) by a battery cell spring (29) and the illuminator housing (8) with a lead washer (41). The positive battery terminal feeds through the center contact (18), contact strip (32), and contact finger of the bulb socket assembly (14) to one side of the bulb (16). The other side of the bulb feeds through the rheostat assembly (11) and grounds to the illuminator housing (8) completing the circuit.

 
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S. OPTICAL SYSTEM
 
6S1. Principles of periscopic systems. The principles discussed in Section 4U1 apply equally well to the Type III periscope except as noted below:

1. Magnifying power. While the over-all power of the Type II and III is the same, the Type III has a different arrangement of telescopes for obtaining the high and low powers (6X and 1.5X). Omit, therefore, the list of component telescopes in section 4U2-b, and substitute the following list:

Type III Periscope Low
Power
High
Power
Galilean telescope 1/4 X Out
Upper main telescope 1/4.7 X 1/4.7 X
Lower main telescope 28 X 28 X
PERISCOPE (Combined product) 1.5 X 6 X

2. Field of view. The apparent field of view and the true field of view are the same in the two types discussed so far; however, the head prism in the Type III can be elevated only far enough to raise the line of sight 45 degrees above horizontal, thus, the limits of the field are different in the present instrument. Refer to section 6S1-4 for complete data. Also, since the Type III periscope does not have the two one-power auxiliary telescopes, omit Section 4U1-c.

3. Image brightness. Omit Section 4U4 and substitute the following details. Since there are five fewer lenses in the Type III, we may expect this periscope to transmit more light than the Type II. Less light is lost by absorption and reflection.

a. Absorption-reflection losses. The reflection loss at the successive air-glass surfaces may be calculated approximately on the basis of the Fresnel theory, by assuming that about 4.1 percent of the incident light is lost at each air-crown glass surface and about 5.6 percent at each air-flint glass surface. The number of such surfaces are shown in the following table. A further reflection loss occurs at each of the two silvered glass surfaces (head prism and eyepiece prism), and this amounts to about 6 percent at each, or 11.64 percent for the two (=1.0000 - 0.8836).

In addition, there is the light lost due to absorption by the glass, the total axial thickness of

  which in the Type III is 222 mm in low power and 213 mm in high power. Assuming that about 0.1,percent of the incident light is absorbed by each millimeter of glass path, we arrive at the absorption loss shown in the table.

By multiplying the transmission (= 100 percent minus the percent of loss) values together, we find that the overall theoretical transmission of the periscope is 19.2 percent in low power and 24.4 percent in high power. These values may also be called the transmission efficiencies, since the incident light was taken as 100 percent.

Type III Periscope Low
Power
High
Power
Total axial thickness, glass 222mm 213mm
No. of air-crown surfaces 14 14
No. of air-flint surfaces 12 8
No. of silvered surfaces 2 2
TRANSMISSION that would result if loss were due to:
Absorption by glass 77.80% * 78.70%
Reflection, air-glass 27.87% ** 35.09%
Reflection, silvered-glass 88.36% *** 88.36%
Uncoated theoretical TRANSMISSION 19.2% **** 24.4%
Uncoated Measured TRANSMISSION 19.5% 25.2%
Measured TRANSMISSION (Coated optics) 43.6% 50.9%

* 100 % - (222 mm X 0.001) = 0.778 = 77.80% (absorption loss).
** (1.000 - 0.041)14 X (1.000 - 0.056)12 = 0.2787 = 27.87%.
*** (1.00 - 0.06)2 = 0.8836 = 88.36%.
**** (0.7780) X (0.2787) X (0.8836) = 0.192 = 19.2%.

The actual measurements of transmission for coated and uncoated optical elements were compiled from the measurements of several trained technicians using a Lummer-Brodhun type photometer. The measured values above are the averages of their results.

b. Effect of pupillary size. Since the exit pupil of the Type III periscope is also 4 mm (either low or high power), refer to Section 4U1, b.

c. Central and oblique brightness. Essentially the same considerations are involved here as in the Type II. Refer to Section 4U4, c. A comparison of the ray tracing diagram for

 
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each type, however, will disclose that the objective lens of the upper main telescope is filled with ray-bundles in the Type III periscope (Figure 6-13, page 288), while in the case of the Type II only the central area (112 mm diameter) of the free aperture (144 mm) is used. The reasons for this situation are discussed in the following.

It must be realized that the classification of submarine periscopes into Types I (now obsolete), II, III, and IV occurred some time after the periscopes were actually designed and built. For instance, the periscope (88KA40/1.99) now known as the Type III was actually in use before the Type II periscope (91KA40T/ 1.414HA) was designed. Hence, since the optical arrangement of the Type III is simpler than that of the Type II, and since much of the optical design of the Type II is actually a carry-over from the Type III, it might be easier for some students to study the Type III before investigating the principles of the Type II.

As mentioned in Section 4U3,c, the over-all length of a submarine periscope is a most important part of the design. Thus, when the Type III was modified to arrive at the design of the Type II (which carries the two one-power auxiliary telescopes in order to achieve the ultra-narrow upper reduced tube section), it was necessary to reduce the distance between the two main telescopic systems so that there would lie room for the reduced-tube optics. A comparison of the optical assembly drawings for the two instruments shows that this inter-objective distance was 7300.5 mm in the Type III and is only 6091.8 min in the Type II, a decrease of over 1200 mm or about 4 feet.

Shifting the upper main telescope system down the tube, however, would produce an undesirable reduction of the exit pupil of the periscope as follows: Shortening the inter-objective distance causes the oblique ray-bundles traveling down the tube from the upper main objective to meet the lower main objective before they are far enough from the optical axis to fill the free aperture of the latter lens. If the entire aperture of the lower-main objective is not filled with light, its image (the exit pupil of the periscope) will not be filled with light, causing a smaller exit pupil and a dimmer image.

  During the design of the Type II, then, it was necessary to change the direction of these oblique bundles so that the lower-main objective's free aperture would be fully illuminated. This was accomplished by modifying the curvature of the collective of the eyepiece system of the upper main telescope. In the Type II, this particular lens has a focal length that is shorter than that of its counterpart in the Type III, hence the Type II collective produces more deviation in the ray bundles it receives from its eye lens and sends down the tube to the upper-main objective lens. These oblique bundles, which have been bent more by the collective, strike the upper-main objective closer to the optical axis than they otherwise would and, hence, are deviated less than they otherwise would be. The result of this change in the focal length of the collective (change from Type III to Type II) is that the oblique bundles are sent down the tube with just enough inclination to the optical axis so that they completely fill the free aperture of the lower-main objective lens. Of course, it would be possible in the Type II periscope to reduce the diameter of the upper-main objective so that its free aperture is just 112 mm (the same as that of the lower-main objective), however, it is more practicable from the standpoint of mechanical mounting to retain the 144-mm aperture for this lens.

The behavior of the central bundle, it will be noted, is essentially identical in both types, since the collective has little effect on it.

4. Head prism. Omit Section 4U6. The head prism of the Type III periscope may be elevated only to 45 degrees above horizontal and depressed to 10 degrees below horizontal; therefore, the limits of the field are somewhat different from the Type II. It should be noted that the field of view of both types covers 32 degrees in low and 8 degrees in high power. The limits of the field of view in both powers are shown in the following table.

Type III Periscope Low
Power
High
Power
Line of sight
elevated to 45 deg
Upper edge of the field
Lower edge of the field
61 deg
29 deg
49 deg
41 deg
Line of sight
depressed to -10 deg
Upper edge of the field
Lower edge of the field
6 deg
-26deg
-6 deg
-14deg
 
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a. Target ranging devices. Refer to Section 4U7.

6S2. Optical Maintenance. For method of tracing rays read Section 4U8, c, concerning the four rules of ray tracing until these rules are thoroughly

Arrangement of Optical Elements
Arrange-
ment of
Elements
(in direction
of rays)
Use in
Instrument
Type of
Telescope
Magni-
fying
Power
Head
 window
Head prism
Gas&water
seal
Deviates op-
tical axis
   
Negative
 doublet
Positive
 doublet
Eyepiece

Objective
GALI-
LEAN
*
1/4X
Positive
 doublet
Telemeter
 lens
Air-space
 doublet
Eye-lens

Collective
 ocular**
Objective
UPPER MAIN 1/4.7X
Air-space
 doublet
Split-lens
objective
***
   
Dioptric
 prism
Positive
 doublet
Collective
****
Eye-lens
 ocular
LOWER MAIN 28X
Eyepiece
 window
Rayfilters

Polaroids
*****
Gas seal

Visibility
 aids
Variable
 density
   

* In the system for low power only.
** Telemeter lens reticle is etched on the plane side of this piano-convex lens and is thus located in the first real image plane of the periscope so that the reticle will vibrate in unison with the image-forming lenses preceding it.
*** The plane of the split lens also contains the -optical axis of the system. The two halves moue in a plane normal to the axis to produce a double image for use in the stadimeter.
**** Refer to section 4U8 (a, Note "e") and also section 4U9-a-21.
***** The fixed polaroid filter must be lined up with its index marks vertical when the variable density polaroid filter assembly is in place on the periscope.
  understood. Then referring to Section 6S2, and to the ray tracing diagram in Figure 6-13, page 288, consider the action of the various optical elements on these bundles (which are cylindrical upon entering the periscope, since they have come from infinitely distant object-points).

UPPER MAIN TELESCOPE

1. Since the head window is piano-parallel, it does not affect the direction of the ray-bundles or the parallelism of rays in any one bundle.

2. Since the head prism has plane faces (entrance, reflecting, and exit), it produces no convergence or divergence in the cylindrical bundles. The head prism does, however, deviate the line of sight so that it travels along the optical axis down the tube.

3. If the Type III periscope is in high power, the Galilean system is swung out of the field, and the cylindrical bundles next meet the upper eyepiece eye lens, which converges each bundle to a point in its back focal plane.

4. If the parallax has been removed from the periscope, the plane surface (containing the reticle) of the telemeter lens will lie in the back focal plane of the eye lens. Thus, the target image is superimposed on the telemeter lens and the rays continue down the tube as though they originated at each image-point in the plane of the telemeter lens.

By virtue of the fact that these ray bundles seem to originate in the plane surface of the telemeter lens, that lens has practically no converging effect on the diverging bundles; however, it does perform a collective action by deviating the course of each bundle. It produces zero deviation in the one bundle which meets it at the axis, and produces its maximum deviation in those bundles which meet it farthest from the optical axis. In other words, because of its unique position in the system (that is, with one of its surfaces lying in an image plane), this collective lens acts like a thin prism but not like a lens.

5. The objective lens of the upper main telescope is so placed (one focal length from the telemeter lens) in the periscope that the

 
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above ray bundles diverging from the plane of the telemeter lens are converged by the objective to form cylindrical bundles that travel on down the tube until they meet the next lens.

LOWER MAIN TELESCOPE

6. The above cylindrical bundles are converged by the lower-main-telescope objective lens (assume that it acts as a single lens, that is, the two halves have not been shifted) to the back focal plane of the objective, which is the next real image plane in the system. Thus, the rays in any one bundle are converged to a point (not necessarily on the optical axis) in this image plane where they cross each other at this image-point, and they proceed as a diverging bundle to enter the dioptric prism.

7. The dioptric prism, acts as the collective lens of the lower eyepiece. This collective is very thick, and since the image plane from which it receives the diverging ray bundles is some distance in front of its first surface, the dioptric prism deviates the bundles and also produces convergence in them. The image plane, however, is less than one focal length in front of the collective and, therefore, the dioptric prism is unable to converge the bundles enough to make them cylindrical. Thus, they leave the collective and enter the eye lens of the lower eyepiece still diverging a slight amount.

8. These slightly diverging bundles are converge by the eyepiece lens of the eyepiece system so that they emerge from that lens as cylindrical bundles. In other Fords, the equivalent focal length of the eyepiece system (collective and eye lens) is such that the front focal plane of the system coincides with the back focal plane of the objective.

9. The eyepiece window is plano-parallel, hence it does not deviate the raybundles or cause them to converge or diverge.

10. The rayfilters and polaroids are also plano-parallel and do not deviate the ray bundles or cause them to converge or diverge. They do, however, absorb all rays of colors different than their own and thus provide the observer with some control over the visual contrast between various parts of the image.

 
GALILEAN TELESCOPE

11. When the periscope is in low power, the reversed Galilean telescope is included in the system, following the head prism and preceding the eyepiece lens of the upper main telescope. Since this component is a telescope, we know that cylindrical bundles will emerge from it if cylindrical bundles enter it.

For the action of a reversed Galilean telescope, refer to Section 4U8-c-17.

6S3. Method of removing parallax caused by gas pressure. Read Section 4V7 concerning the basic principles of the Kollmorgen universal collimator, and also Section 4U8, 18, omitting only the data regarding pre-gassing setting of the eyepiece lens and eyepiece prism on the Type II and the data regarding target distances used for the Type II.

Since the introduction of nitrogen at the specified pressure (7.5 lbs. above atmospheric) will invariably introduce parallax in the periscope system, so adjust the spacing of the various lens elements before gassing that they will produce no parallax (between the image and the telemeter lens) after gassing.

This is accomplished by considering one, all the lenses that

the telemeter lens and two, all the lenses that precede the telemeter lens.

1. Lenses that follow the telemeter lens. To compensate for the effect of the nitrogen in both high and low power, before gassing, the eyepiece must be set at -0.4 diopters (or shifted toward objective 2.1 mm) while the telemeter lens is brought into sharp focus (using an auxiliary telescope correctly focused for the observer's eye). Then when the gas is introduced and the eyepiece returned to its zero diopter position, there will be no parallax in that part of the periscope system following the telemeter lens.

2. Lenses that precede the telemeter lens. With the periscope in high power, there is only one lens that precedes the telemeter lens, namely, the upper eyepiece eye lens. Since the nitrogen under pressure will reduce the relative index of refraction of this glass or speed of light transmission (actually it increases the

 
354

index of refraction of the surrounding medium), it will cause the focal length of this eye lens to be lengthened slightly.

Now with the system in air, we can choose a target that is not at infinity but at some finite distance so that the upper eyepiece lens will form its image in a plane which is slightly more than one focal length behind the upper eyepiece lens. In the case of the particular lens in question, this particular distance equals 3,110 feet. Thus, if we remove the parallax for lenses preceding the telemeter lens while the system is in air, by using the above object-distance of 3,110 feet, when the gas has been introduced and the

  periscope sealed, all infinitely distant objects will be imaged exactly in the plane of the telemeter lens.

When the periscope is in low power, there are three lenses which precede the telemeter lens, namely, the upper eyepiece lens of the upper main telescope and the two lenses of the Galilean telescope. If a target distance of 47 feet is used and if the position of the eye lens is not disturbed, there will be no parallax in low power for infinitely distant objects after gassing.

Type III PeriscopeTarget
Distance
Periscope in high power3,100 feet
Periscope in low power47 feet
 
T. REASSEMBLY OF THE UPPER AND LOWER TELESCOPE SYSTEMS AND SKELETON HEAD
 
6T1. Reassembly of the upper telescope system. The upper telescope system is reassembled in the following manner:

1. Screw the threaded periphery of the upper part of the fourth inner tube section upper end coupling (4, Figure 6-6) into the internal threaded section in the lower part of the fifth inner tube section (41, Figure 6-5) of the upper telescope system Part I.

2. Insert and secure the four lockscrews (42) in countersunk clearance holes in the lower part of the fifth inner tube section, (41), screwing them into tapped holes in the upper alignment support section of the fourth inner tube section upper end coupling (4, Figure 6-6). This secures the upper telescope system Part I and Part II together.

6T2. Reassembly of the lower telescope system. The lower telescope system is reassembled in the following manner:

1. Connection of the eyepiece skeleton assembly to the lower part of the first inner tube section assembly, proceeds as follows:

2. Screw the internal threaded section in the upper part of the eyepiece skeleton (42, Figure 4-28) on the threaded periphery of the spider bearing (3, Figure 6-10).

3. Insert and secure the four lockscrews (37, Figure 4-28) in countersunk clearance holes in the counterweight bearing section of the eyepiece skeleton (42), screwing them into

  tapped holes in the lower alignment support section of the spider bearing (3, Figure 6-10).

4. Connection of the objective operating mechanism assembly to the first inner tube section assembly proceeds as follows:

5. Screw the internal threaded section located in the lower part of the track sleeve (18, Figure 6-7) on the threaded periphery of the upper part of the first inner tube section upper end coupling (23, Figure 6-10).

6. Insert and secure the four lockscrews (9, Figure 6-7) in countersunk clearance holes in the lower part of the track sleeve (18), screwing them into tapped holes in the upper part of the first inner tube section upper end coupling (23, Figure 6-10).

7. Place the stadimeter transmission shaft coupling (3 Figure 6-7) on the lower part of the operating gear pinion shaft (20) and secure it to the shaft with a taper pin (15).

8. Place the objective operating mechanism assembly and the eyepiece skeleton assembly attached to the first inner tube section assembly in two V-blocks on the optical I-beam bench.

9. The four coiled shifting wire tapes (38, Figure 4-28) for the prism tilt and change of power mechanisms are unwound sufficiently for their attachment to their respective sides of the eyepiece skeleton assembly.

10. Loosen the two shifting wire clamp nuts (3) of the prism tilt mechanism side sufficiently

 
355

to allow the phosphor-bronze wire extensions of the tapes to enter snugly in each shifting wire clamp (2). The wires extend downward from the rectangular slot in the large shoulder flange of the eyepiece skeleton (42). Each wire will extend equally beyond the lower end of each shifting wire spindle (1).

11. Secure the two shifting wire clamp nuts (3) temporarily and secure each coiled up shifting wire tape to the first inner tube section (1, Figure 6-10) with friction tape.

12. Follow the procedure described under Steps 10 and 11 for the change of power mechanism side.

13. Unscrew the assembled eyepiece lens mount (19, Figure 4-22), carrying with it the eyepiece lens (9a, Figure 6-13), eyepiece lens clamp ring (16, Figure 4-28) and its lockscrew (41). The removal of the above outward projecting assembly is necessary for the assembly of the eyepiece box (11, Figure 4-29) to the eyepiece skeleton (42, Figure 4-28).

14. Check the base of the eyepiece box (11, Figure 4-29) to ascertain that the eyepiece skeleton centering screw (12) is not secured in place.

15. Reassemble the outer tube and eyepiece box rubber gasket (8) on the upper alignment support section of the eyepiece box (11), resting it against the sealing shoulder located preceding the threaded periphery. Check the eyepiece box and eyepiece skeleton assembly to ascertain the removal of all inward and external parts to make sure that nothing restricts the assembly of the eyepiece box (11).

16. Place the eyepiece box (11) over the eyepiece skeleton assembly, guiding it on slowly and carefully. It is carried on the narrow alignment shoulder of the large shoulder flange of the eyepiece skeleton (42, Figure 4-28). Engage the reamed dowel pin holes of the eyepiece box upper face over the downward protruding dowel pins (36) in the eyepiece, skeleton large shoulder flange. This reestablishes the factory alignment.

17. Insert and secure the eight lockscrews (31). These lockscrews can be inserted only with the counterweight (25) at its extreme upward

  position. The lockscrews are inserted in clearance holes in the eyepiece skeleton (42) large shoulder flange and screwed into tapped holes in the upper face of the eyepiece box (11, Figure 4-29).

18. Place the stadimeter transmission shaft (12, Figure 6-10) in the stuffing box section in the eyepiece box base. Guide the shaft as it is carried upward slowly through the clearance hole in the large shoulder flange of the eyepiece skeleton (42, Figure 4-28) and the counterweight (25).

19. Place the lower thrust collar (4, Figure 6-10) on the stadimeter transmission shaft (12) and carry the shaft through the bearing hole in the spider (2).

20. Place the upper thrust collar (4) on the stadimeter transmission shaft (12), and carry the shaft upward through the clearance hole in the soldered bracket (21) located on the central part of the first inner tube section periphery (1).

21. Disengage the operating gear pinion (2, Figure 6-7) from its engagement with the gear teeth of the operating gear (22) in the observing position. Check the male tang section of the stadimeter transmission shaft (12) to ascertain that it faces outward and toward the left face of the eyepiece box (11, Figure 4-29). This places the male tang section of the shaft in correct position for proper engagement with the female tang coupling (68, Figure 4-24) of the stadimeter housing assembly for its reassembly.

22. Check the dowel pin holes of the stadimeter transmission shaft (12, Figure 6-10) in the above position for proper entry in the stadimeter transmission shaft coupling (3, Figure 6-7) and for proper coincidence of dowel pin holes. Insert and secure two temporary lockscrews in tapped holes in the coupling until completion of collimation.

23. Reengage the operating gear pinion (2) into mesh with the gear teeth of the operating gear (22) checking the position of the male tang section of the stadimeter transmission shaft (12, Figure 6-10) following the procedure described in Step 21 of this section.

 
356

24. Place the two thrust collars (4) next to the side faces of the cast bearing projection of the spider (2) and secure them with two taper pins (10).

25. Place the counterweight (25, Figure 4-28) at the extreme upward limit of its travel (the plus position).

26. Place the female coupling section (3, Figure 4-39) of the focusing knob assembly on the square section of the eyepiece drive actuating shaft (12, Figure 4-35) of the eyepiece drive packing gland assembly. Check the reference punch mark on the eyepiece drive actuating shaft (12) and the corresponding reference mark on the female coupling section (3, Figure 4-39) of the focusing knob assembly for proper alignment.

27. Check the 1 1/2 diopter setting with the stationary zero reference line of the knob bracket hub (7). The 1 1/2 diopter setting should be turned to a slight over-travel of the stationary reference line.

28. Place the eyepiece drive packing gland assembly with its rubber gasket (11, Figure 4-35) and the attached focusing knob assembly in its opening in the eyepiece box (11, Figure 4-29). Align the rectangular base of the knob bracket (7, Figure 4-39) with the rectangular recess face on the eyepiece box.

29. The eyepiece drive mechanism bevel gear (1, Figure, 4-35) attached to the eyepiece drive actuating shaft (12) should mesh with the eyepiece prism shift bevel gear (11, Figure 4-28) of the eyepiece skeleton assembly correctly.

30. Remove the focusing knob assembly from the eyepiece drive packing gland assembly.

31. Rotate the stuffing box body (6, Figure 4-35) of the eyepiece drive packing gland assembly so that the-reference numerals on the stuffing box body flange coincide with the reference numerals on the eyepiece box recess face.

32. Insert and secure the six lockscrews (3), inserting them in countersunk clearance holes in the stuffing box body flange (6) and screwing them into tapped holes in the eyepiece box counterbored section seat.

33. Replace the focusing knob assembly on the square section of the eyepiece drive actuating

  shaft (12) in the same manner as described in Step 26.

34. Check the rectangular flange of the knob bracket (7, Figure 4-39) to ascertain that the two dowel pins (8) engage in the dowel pin holes in the eyepiece box recess face.

35. Insert and secure the four lockscrews (10) in countersunk clearance holes in the knob bracket (7), screwing them into tapped holes in the eyepiece box (11, Figure 4-29).

36. Place the eyepiece skeleton centering screw lead washer (13) on the centering screw shoulder (12), inserting the centering screw in the base of the eyepiece box (11). The centering screw extends into the reamed hole in the eyepiece skeleton base (42, Figure 4-28), and is screwed into the tapped hole section in the eyepiece box base. Secure the centering screw with a large screwdriver blade, using a small wrench attached to the blade to insure the hermetical seal of this opening.

37. Reassembly of the stadimeter transmission shaft packing gland assembly (modified hycar type) proceeds as follows: Place the gland filler piece (3, Figure 4-31) over the shaft, placing the chamfered side upward.

38. The hycar packing spacers (4) are soaked in Lubriplate No. 210 for a week. Before assembly all Lubriplate is wiped off, and Glydag is applied to the shaft and hycar packing spacers. Place each of the hycar packing spacers (4) over the stadimeter transmission shaft (12, Figure 6-10), separating each packing spacer with a brass spacer washer (5, Figure 4-31) and finishing with the insertion of the retainer brass washer (6).

39. Place the packing retainer (2) over the above shaft and engage it in the internal threads in the stuffing box section of the eyepiece box.

40. Use a special wrench with the projecting pins inserted in the four holes in the face of the packing retainer (2). Screw the packing retainer upward, compressing the hycar packing spacers, and continue compressing the packing spacers until the packing retainer face is flush with the lower face of the eyepiece box (11, Figure 4-29).

 
357

41. Insert the lockscrew (1, Figure 4-31) in the tapped hole in the face of the slotted section of the packing retainer (2), screwing it tight to secure the packing retainer (2).

42. Place a special wrench on the male tang section of the stadimeter transmission shaft (12, Figure 6-10) and rotate the shaft in alternate directions for one half hour to work in the packing. This should eliminate the freezing of the shaft, as the hycar packing spacers take a permanent set because of compression.

43. Assemble the rayfilter drive packing gland assembly stuffing box body rubber gasket (9, Figure 4-32) to the square recess seat in the front of the eyepiece box.

44. Check the reference marks on the rayfilter drive packing gland assembly female coupling section (2) with the corresponding reference mark of the male coupling section (40, Figure 4-28) of the eyepiece skeleton assembly for proper alignment. Check the stamped numeral of the rayfilter drive stuffing box body (4, Figure 4-32) to coincide with a similar stamped numeral on the eyepiece box. It may be necessary to rotate the female coupling section (2) for both corresponding reference marks. Place the rayfilter drive packing gland assembly in the bored hole and on the rubber gasket located in the square recess seat in the eyepiece box. Remove the rayfilter drive actuating gear (11) if necessary, from the square section of the rayfilter drive actuating shaft (10) for the application of a pair of parallel pliers, juggle the female coupling section (2) with the pliers for proper engagement.

45. Secure the rayfilter drive packing gland assembly stuffing box body (4) with four lockscrews (13). These lockscrews are inserted in countersunk clearance holes in the stuffing box body and screwed into tapped holes in the square recess seat in the eyepiece box.

46. Assemble the left and right training handle packing gland assembly rubber gaskets (10, Figure 4-36) in the counterbored section seats in opposite sides of the eyepiece box.

47. Check the left and right training handle packing gland assemblies for their proper sides

  of the eyepiece box. Check the reference marks of each female coupling section (3, Figure 4-36) one by one and properly engage them in their respective male coupling sections of the training handle rack gears and shafts (39, Figure 4-28), simultaneously carrying the assemblies in the bored holes and on the assembled rubber gaskets (10, Figure 4-36) in the counterbored section seats.

48. Rotate each training handle stuffing box body (5) until the stamped figures coincide with their mating figures on the eyepiece box (11, Figure 4-29).

49. Secure both packing gland assemblies with six lockscrews each (1, Figure 4-36). These lockscrews are inserted in countersunk clearance holes in each stuffing box body (5) and screwed into tapped holes in the counterbored section seats in the eyepiece box (11, Figure 4-29).

50. Assemble the lower (split) objective lens and mount assembly (Figure 4-22) to the objective operating mechanism assembly.

51. Place each assembled mount half on its respective mounting plate (1, Figure 6-7) and secure each temporarily with two stadimeter collimating screws (13, Figure 4-22) and washers (14). The collimating screws are inserted in the washers and elongated slots in each mount half (1 and 2) and screwed in tapped holes in each mounting plate half (1, Figure 6-7).

6T3. Reassembly of the skeleton head assembly to the upper telescope system Part I assembly. The skeleton head assembly is reassembled in the following manner:

1. Screw the skeleton head assembly on the upper threaded periphery of the fifth reduced tube section (1, Figure 6-5) until the lockscrew holes coincide.

2. Insert and secure the two lockscrews (55, Figure 6-4) in opposite countersunk clearance holes in the skeleton head (1), screwing them into tapped holes in the upper alignment support section of the fifth reduced tube section (1, Figure 6-5). This secures the skeleton head assembly to the upper part of the upper telescope system Part I assembly.

 
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U. FINAL COLLIMATION
 
6U1. Collimation of the upper and lower telescope systems in high power. The upper and lower telescope systems are collimated in the following manner:

1. Check the height of the Sperry-Kollmorgen collimator by using the boresight and grooved crossline disks having a diameter of 6.495 inches for the inner tube axis. Refer to the procedure described under Section 4V10 for the setting of the azimuth disk plate (6, Figure 4-69) to 90 degrees.

2. Loosen the wedge lock bolt (11) and wedge lock (10) sufficiently to swing the index line of the collimator base plate (7) into coincidence with the 0 degree numeral graduation of the azimuth disk plate (6). Secure the wedge lock (10) with the wedge lock bolt (11). Check the collimator reticle; it should be located at the infinity setting (Figure 4-71).

3. Place the assembled upper telescope system and skeleton head assembly in V-blocks on the optical I-beam bench, resting the bearing sections of the various couplings in the V-blocks.

4. Slide the assembly axially with the V-blocks toward the Sperry-Kollmorgen collimator until the head prism is spotted centrally over the collimator axis. Place the head prism at zero line of sight, placing the front face parallel to the skeleton head frame by eye.

5. Place the lower telescope system assembly of Section 6T1 in two V-blocks, resting the bearing flange periphery of the track sleeve (18, Figure 6-7) in one, and the large shoulder flange periphery of the eyepiece skeleton (42, Figure 4-28,) and upper alignment support section periphery of the eyepiece box in the other.

6. Rotate the lower telescope in the two V-blocks for vertical collimation, with the eyepiece end of the eyepiece box facing upward.

7. Slide the lower telescope system with the two V-blocks axially until near the upper telescope system assembly.

8. Line up the reference marks of the second inner tube section lower end coupling (26, Figure 6-6) checking it by the coupling sleeve

  (17, Figure 6-7) in its proper coincidence relationship with the reference marks of the track sleeve (18).

9. Holding the coupling sleeve (17) on the undercut alignment support sections of the track sleeve (18) and the second inner tube section lower end coupling (26, Figure 6-6), slide the lower telescope system with the V-blocks snugly against the coupling sleeve. This permits the coupling sleeve to fit snugly between the bearing shoulders of the track sleeve (18, Figure 6-7) and the second inner tube section lower end coupling (26, Figure 6-6). Remove the coupling sleeve and place it in a convenient place until it is required again for distance measurement or for reassembly.

10. Place the threaded periphery of the special eyepiece alignment jig (Figure 4-50) in the threaded bore of the eyepiece prism front retaining plate (24, Figure 4-28) of the eyepiece skeleton assembly. Screw the jig into this front retaining plate until the shoulder of the jig is a metal to metal contact with the projecting cylindrical shoulder of this retaining plate.

11. Rotate the lower telescope system in the two V-blocks for vertical Collimation, with the eyepiece end of the eyepiece box facing upward.

12. Follow the procedure described under Section 4V4, Steps 5 to 9 inclusive for the vertical position of the eyepiece end of the eyepiece box.

13. Remove the eyepiece alignment jig and replace the assembled eyepiece lens mount (19, Figure 4-28) by screwing it into the eyepiece prism front retaining plate (24). Check the inner and outer surface of the eyepiece lens (9a, Figure 6-13) for cleanliness before replacement.

14. The position of the upper objective lens mount (45, Figure 6-5) in the fifth inner tube section (41) and the upper eyepiece lens mount (3) in the fourth reduced tube section (2) should be that of their original settings unless a lens is replaced because of damage. A renewal of any one or both lenses requires a resetting of the lockscrew holes in both mounts in their reduced tube and inner tube sections.

 
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15. Release the temporary securement of the upper eyepiece lens mount (3) and the upper objective lens mount (45), by the removal of the two lockscrews (5) and our lockscrews (43) from their respective mounts.

16. The collimation of the lower telescope system is accomplished by the axial movement of the upper objective lens mount. This brings the eyepiece prism mount arrangement into focus with the telemeter lens (15) within the prescribed limits of -3 and +1 1/2 diopters.

17. In checking the essential travel of the eyepiece prism mount (20, Figure 4-28) which should be 25 mm, diopter lenses are used. Minus and plus lenses must be inserted in the auxiliary telescope adapter (Figure 4-57) attached in the interval threads in the objective end of the auxiliary telescope to obtain the minus and plus diopter settings.

18. Insert a -1 1/2 diopter lens in the auxiliary telescope adapter, moving the counterweight up to its stop for full travel; the stop is the spider bearing. This causes the eyepiece prism mount to move downward. Check the definition of the telemeter lens to ascertain that it will fade slightly at the end of the prism travel. It is necessary to move the upper objective lens axially for make this definition check.

19. Insert the +3 diopter lens in the auxiliary telescope adapter, and bring the counterweight downward to the lower stop with the two lockscrews opposite each other in the eyepiece skeleton flange. These lockscrew heads are longer than the other six lockscrews in the eyepiece skeleton large shoulder flange. The downward movement of the counterweight carries the eyepiece prism mount to the upward position. Check the definition of the telemeter lens to be sure that it will fade slightly at the end of the prism travel. It may be necessary to move the upper objective lens axially to make this definition check.

20. Continue the procedure stated in Steps 18 and 19 until a setting is obtained at which a slight over-travel is observed at -3 and +1 1/2 diopters.

21. Upon completion of the collimation of the lower telescope system, secure the upper objective

  lens mount (45, Figure 6-5) to the fifth inner tube section (41) with four lockscrews (43).

22. Now obtain the true zero diopter reading of the diopter ring of the focusing knob assembly. Using the auxiliary telescope minus the adapter, focus the eyepiece prism mount until sharp definition of the telemeter lens is detected. The diopter ring should read -0.4 diopter at atmospheric pressure. This allowance is compensated for when nitrogen of 7 1/2 psi is introduced; refer to Section 6S3-1.

23. With the auxiliary telescope at the eyepiece end set for -0.4 diopter at atmospheric pressure, proceed to check the upper and lower telescope systems on the collimator reticle at the infinity setting. Move the upper eyepiece lens mount axially until a clear, well-defined image is apparent. The upper eyepiece lens mount is not secured until the completion of the orientation of the telemeter lens, and collimation for parallax elimination on the distance target of the collimator reticle set to 3,110 feet. 24. Temporary squaring of the telemeter lens is required for the collimation of the lower (split) objective lens with the Kollmorgen universal collimator range function and the telemeter lens.

25. Using a special wrench attached to the male tang section of the stadimeter transmission shaft (12, Figure 6-10), rotate the shaft, displacing the lower (split) objective lens to the maximum displacement. In this maximum displacement, the telemeter lens line should appear to the observer as a solid line. If it appears double or faded, it is necessary to release the angular alignment lockscrew (12, Figure 6-5) slightly and tap the telemeter lens mount angularly. Continue until the telemeter lens line appears as a solid line, and secure the angular alignment lockscrew (12). Using the above special wrench, return the lens halves, placing them and the objective operating mechanism at the observing position and removing the special wrench. Refer to Figure 4-81 for the incorrect and correct orientation of the telemeter lens line.

6U2. Collimation of the lower (split) objective lens to the stadimeter dials, using the telemeter lens and Sperry-Kollmorgen collimator. This procedure is performed in the following manner:

 
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1. Check the stadimeter dials to determine that the observing position of the dials is correct.

2. Check the objective operating mechanism assembly to determine that the lower (split) objective lens mounts are located in the observing position.

3. Place the stadimeter housing assembly at the base of the eyepiece box (11, Figure 4-29). Check the entrance of the female tang coupling (68, Figure 4-24) to determine that it engages on the male tang section of the stadimeter transmission shaft (12 Figure 6-10). Insert the four housing bolts (30, Figure 4-24) in clearance holes in the stadimeter housing (8, Figure 6-8), screwing the bolts into tapped holes in the eyepiece box base (11, Figure 4-29), and securing them snugly.

4. Remove the operating gear stop (23, Figure 6-7) from the operating gear (22) by removing four lockscrews (29). The two factory scribed lines can be seen approximately. 27/32 inch apart on the operating gear shoulder and the retaining ring (21). This distance represents 10 degrees on the periphery of the operating gear (22). When the operating gear is rotated 10 degrees counterclockwise, viewing it from the lower end, the right scribe line of the operating gear (22) coincides with the left scribe line on the retaining ring (21). At this position the mounting plates (1) are displaced on amount equal to 2 minutes and 4 seconds of arc, and corresponding scribed lines are in coincidence to the right of the above scribed lines.

5. With the operating gear in this position, the range scale dials (14, Figure 6-8) should read 11,000 yards opposite the value 20-foot height indication on the height scale dials (13). The collimator reticle should show the horizontal crossline in one image superimposed over the first small horizontal graduated line of the reticle in the other image.

6. If the horizontal crossline of one imago shows that the horizontal crossline of the reticle is not superimposed over the first small line of the other image, the parallel sliding half of the lower (split) objective lens and mount assembly is moved so that the horizontal crossline of one image is superimposed over the first small horizontal line of the collimator reticle

  in the other, or the 11,000/20 graduation. It is necessary to use an offset screwdriver to loosen the stadimeter collimating screws (13, Figure 4-22) sufficiently to tap the mount lightly with a small rawhide mallet. Figure 4-79 shows the six positions for collimating the stadimeter dials as indicated by the displacement of the lower (split) objective lens.

7. The stadimeter transmission shaft coupling (3, Figure 6-7) has previously been secured temporarily to the stadimeter transmission shaft (12, Figure 6-10) with two special setscrews inserted for collimation use and with the taper pin holes aligned. Using the offset screwdriver, secure the stadimeter collimating screws (13, Figure 4-22), securing the vertical sliding half of the lower (split) objective lens and mount assembly.

8. Turn the handwheel (12, Figure 4-24) clockwise until the horizontal crossline of the collimator reticle in one image superimposes over the second horizontal graduated line of the collimator reticle in the other image. The range scale dials (14, Figure 6-8) should read 7,500 yards opposite the value 20-foot height indication on the height scale dials (13).

9. Continue turning the handwheel (12, Figure 4-24) clockwise until the horizontal crossline of the collimator reticle in one image superimposes over the third horizontal graduated line of the collimator reticle in the other image. The range scale dials should read 2,500 yards opposite the value 20-foot height indication on the height scale dials.

10. Continue in like manner with the fourth horizontal line at 1,000 yards opposite the value 20-foot height indication, the fifth horizontal line at 500 yards opposite the value 20-foot height indication, and the sixth horizontal line at 400 yards opposite the value 20-foot height indication.

11. If an error, as much as the thickness of a dial line, is noticed in the reading of the range scale dials, the handwheel (12) is turned to remove half the error. Release the two setscrews in the tapped holes in the stadimeter transmission shaft coupling (3, Figure 6-7) and turn the handwheel (12, Figure 4-24) setting the range scale dial indication of 400 yards opposite the

 
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value 20-foot height indication on the height scale dials. Then secure the two setscrews. Correct the remaining error by loosening the stadimeter collimating screws (13, Figure 4-22) with an offset screwdriver. Tap the vertical moving half of the lower (split) objective lens and mount assembly with a rawhide mallet to make the horizontal crossline of the collimator reticle in one image superimpose over the sixth horizontal graduated line of the collimator reticle in the other image at 400/20, and secure the stadimeter collimating screws (13).

12. Return the displacement of the lower (split) objective lens images so that the horizontal crossline of the collimator reticle in one image superimposes over the first horizontal graduated line of the collimator reticle in the other image. The range scale dials should read 11,000 yards opposite the value 20-foot height indication on the height scale dials. Check the complete series of ranges, 11,000/20, 7,500/20, 1,000/20, 500/20, and 400/20, noting any error and correcting in the same manner as before.

13. When the range scale dials read correctly, the operating gear stop (23, Figure 6-7) is reassembled to the operating gear (22) and is secured with four lockscrews (29). The observation position is determined by slowly turning the handwheel (12, Figure 4-24) counterclockwise until the duplicate images almost close to one image.

14. Rotate the operating gear (22, Figure 6-7) and its stop (23) from the observation position stop (24) to the maximum displacement stop (25) with sufficient impact to determine any misalignment which may take place. Check for a double image in the observing position; if one is observed when the operating gear stop (23) is in contact with the observation position stop (24), it will be necessary to manufacture a new operating gear stop (23) or build up the present one and grind it down. If the stop is built up, it must be ground down in a series of steps, taking off small amounts until no double image is observed, or until duplicate images become one.

15. Upon completion of the stadimeter collimation, secure the stadimeter transmission shaft coupling (3) to the stadimeter transmission shaft (12, Figure 6-10) with a taper

  pin (15, Figure 6-7). It is seldom necessary to redrill and ream a taper pin hole in the coupling and the shaft for a new position of the taper pin (15). Remove the two temporary setscrews from the stadimeter transmission shaft coupling (3).

16. After securing the stadimeter collimating screws (13, Figure 4-22), the parallel moving half of the lower (split) objective lens and mount assembly is secured with two straight dowel pins (15); the dowel pins are also replaced in their original holes in the left mount half and its corresponding mounting plate (1, Figure 6-7).

17. With the optical focus of the instrument at infinity, the etched lines on the telemeter lens should be coincident, or of duplicate height. If it is noted that they are not in correct adjustment, the stadimeter collimating screws (13) are loosened sufficiently with an offset screwdriver to tap the perpendicular sliding half of the lower (split) objective lens and mount assembly using a rawhide mallet until the coincident or duplicate height of the etched lines of the telemeter lens is correct. The clockwise rotation of the handwheel (12) displaces the lens halves sufficiently to distinguish this adjustment. When corrections have been made, tighten the stadimeter collimating screws (13) and insert the two straight dowel pins (15) in their original holes in the same manner as stated in Step 16 of this section. Figure 4-80 shows the collimation of the lower (split) objective line perpendicular moving half.

18. The range scale dial readings in the observing position should be 220 yards opposite the value 15-foot height indication on the height scale dials, as indicated by numerals stamped on the stadimeter housing (8, Figure 6-8).

19. After collimation of the lower (split) objective lens and mount assembly to the stadimeter dials and telemeter lens, screw the coupling sleeve (17, Figure 6-7) on the threaded periphery of the second inner tube section lower end coupling (26, Figure 6-6). It is first necessary to slide the lower telescope system and the V-blocks clear for the assembly of the coupling sleeve.

20. Secure the upper part of the coupling (17, Figure 6-7) with four lockscrews (8).

 
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These lockscrews are inserted from countersunk clearance holes in the coupling sleeve (17) and screwed into tapped holes in the second inner tube section lower end coupling alignment support section (26, Figure 6-6).

21. Connection of the assembled coupling sleeve (17, Figure 6-7) to the track sleeve (18) of the objective operating mechanism assembly proceeds as follows (take precautions to see that the operating gear pinion (2) is carried axially with the lower telescope system in the correct alignment position in the coupling sleeve (17) internal recess):

22. The track sleeve (18) alignment support section is carried into the coupling sleeve (17) until its bearing shoulder is a metal to metal contact with the lower face of the coupling sleeve. It is secured with 15 lockscrews (11) inserted in countersunk clearance holes in the coupling sleeve (17) and screwed into tapped holes in the track sleeve (18) alignment support section.

23. Check the stadimeter dials and turn the handwheel (12, Figure 4-24) until the dials are in the observing position; the figure 15 on the height scale dial should appear approximately opposite the value 220 on the range scale dial.

6U3. Orientation of the telemeter lens by the maximum displacement of the lower (split) objective lens. This procedure is performed in the following manner:

1. Slide the inner tube axial with the V-blocks toward the Sperry-Kollmorgen collimator until the head prism is spotted centrally over the collimator axis. Place the head prism at zero link of sight, lacing the front face parallel to the skeleton head frame by eye.

2. Recheck the inner tube, following the procedure stated in Section 6U1, Steps 12 and 13 for the vertical position of the eyepiece end of the eyepiece box.

3. Turn the stadimeter handwheel. (12, Figure 4-24), clockwise until the lower (split) objective lens halves are displaced to maximum displacement.

4. The telemeter lens line should appear as one solid line. If it appears double or faded, it

  is necessary to release the angular alignment lockscrew (12, Figure 6-5) sufficiently to rotate the telemeter lens mount (10) angularly. This procedure is continued until the telemeter lens line appears as one solid line. Figure 4-81 shows the incorrect and correct orientation of the telemeter lens by means of the lower (split) objective lens maximum displacement.

5. Secure the telemeter lens mount (10, Figure 6-5) with the circumferential recess and slot in the third reduced tube section (9) and screw into the tapped hole in the mount.

6. Recheck the telemeter lens line, noting whether any change has taken place during the tightening of the lockscrew (12).

7. Turn the handwheel (12, Figure 4-24) counterclockwise, and return the lower (split) objective lens halves back to the observing position.

Figure 6-14. Collimator reticle lens set at 3110-foot target distance.
Figure 6-14. Collimator reticle lens set at 3110-foot target distance.

6U4. Collimation of the high power system free of parallax on the Kollmorgen distance collimator function at atmospheric pressure. This procedure is performed in the following manner:

1. Release the lock ring (51, Figure 4-69) and turn the reticle lens mount actuating sleeve (53) clockwise 10 graduations as indicated by the micrometer graduation and the micrometer vernier arm (57), securing the lock ring (51) snugly against the reticle lens mount end bushing (52). This places the reticle lens (60) and mount (42) at the 3,110-foot distance target position. Figure 6-14 shows the correct position of the reticle lens mount actuating sleeve in relation to the micrometer vernier arm and the range table in Section 4V8 in the first function

 
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for the proper position of the reticle lens of the 3,110-foot distance.

2. Place the auxiliary telescope at the eyepiece of the periscope. Set the diopter reading of the auxiliary telescope at infinity for the observer (this should be based on at least five observations of an infinity target which give consistent readings). Move out the upper eyepiece lens mount (3, Figure 6-5), carrying the upper eyepiece lens (8) until the image of the collimator reticle is apparent on the telemeter lens. The axial movement of the upper eyepiece lens mount focuses the upper eyepiece lens on the collimator reticle.

3. At the above setting, the auxiliary telescope is focused from plus diopter to the observer's diopter reading, as a check to prove that the telemeter lens and the collimator reticle are in sharp definition. At this reading, no parallax should be apparent on the telemeter lens.

4. Secure the upper eyepiece lens mount (3) with two lockscrews (5). These lockscrews are inserted in countersunk clearance holes in the fourth reduced tube section (2) and screwed into tapped holes in the upper eyepiece lens mount (3).

6U5. Collimation of the Galilean telescope system to the high power system, and free of parallax on the Kollmorgen distance collimator function at atmospheric pressure. This procedure is performed in the following manner:

1. Place the auxiliary telescope at the eyepiece of the periscope. Set the diopter reading of the telescope at infinity for the observer, and place the periscope in low power.

2. Focus the periscope to zero setting at atmospheric pressure or -0.4 diopter. Using the 3,100-foot distance target of the collimator, move the, Galilean eyepiece lens mount (36, Figure 6-4) in its housing internal threads (37) until the image of the target is apparent on the telemeter lens. At this setting, the auxiliary telescope is focused from plus diopter to the observer's diopter reading to ascertain that the telemeter lens and the collimator reticle are in sharp definition. At this reading, no parallax should be apparent on the telemeter lens. Secure the Galilean eyepiece lens mount (36) temporarily with the lockscrew (52).

  3. The Galilean telescope system lenses move through 90 degrees for change of power and therefore must be collimated to the fixed high power magnification series of telescope systems.

4. The Galilean eyepiece lens mount housing (37) is provided with an adjustment allowance to correct the mechanical axis of the Galilean telescope system by means of the optical axis movement of the Galilean eyepiece lens (63).

5. Loosen the three lockscrews (38) sufficiently to adjust the Galilean eyepiece lens mount housing (37). The optical axis of the Galilean telescope system is collimated to the optical axis of the high power system with a minimum of vertical and horizontal displacement tolerance allowance.

6. The horizontal displacement of the collimator reticle crossline image of low power is collimated to superimpose with the telemeter lens line of high power system to within a tolerance of 2 minutes of arc. The collimator reticle crossline is superimposed with the telemeter lens line in high power; therefore, it is necessary to change to power in determining the proper relationship of the low power system with the securement of the three lockscrews (38) each time.

7. The vertical displacement of the centerline of sight of low power is collimated to superimpose with the centerline of sight of the high power system to within a tolerance of 30 minutes of arc. Use the collimator reticle crossline as a reference in changing power to determine the proper relationship of the low power system and the securement of the three lockscrews (38) each time.

8. Repeat the procedure stated in Steps 6 and 7, making any adjustments that may be necessary.

9. Release the lock ring (51, Figure 4-69) and turn the reticle lens mount actuating sleeve (53) clockwise 19 complete turns and 24 graduations, as indicated by the micrometer 0 graduation of the actuating sleeve (53) and the micrometer vernier arm (57) from the infinity setting. Secure the lock ring (51) snugly against the reticle lens mount end bushing (52). This places the reticle lens (60) and its mount (42) at the 47-foot distance target position. Figure

 
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6-15 shows the correct position of the reticle lens mount actuating sleeve in relation to the micrometer vernier arm and the range table in Section 4V8 in the first function for the proper position of the reticle lens of this 47-foot distance.

10. Loosen the lockscrew (52, Figure 6-4) and move the Galilean eyepiece lens mount (36) in its housing internal threads (37). Screw it outward until the image of the collimator reticle is apparent on the telemeter lens. The Galilean eyepiece lens mount (36) focuses the Galilean eyepiece lens (63) on the collimator reticle.

11. At the above setting, the auxiliary telescope is focused from plus diopter to the observer's diopter reading, as a check to make certain that the telemeter lens and collimator reticle are in sharp definition. At this reading,

  no parallax should be apparent on the telemeter lens.

12. Secure the Galilean eyepiece lens mount (36) with its lockscrew (52).

Figure 6-15. Collimator reticle lens set at 47-foot
target distance.
Figure 6-15. Collimator reticle lens set at 47-foot target distance.

 
V. FINAL ASSEMBLIES AND CHECKING
 
6V1. Reassembly of shifting wire tapes and air lines to the inner tube sections and skeleton head assembly. This procedure is performed in the following manner:

1. Remove the friction tape from the coiled up prism tilt mechanism shifting wire tapes (38, Figure 4-28) and place them through the various guides and straps of the inner tube sections and reduced tube sections.

2. Remove the four 1ockscrews (49, Figure 6-4) and two clamp blocks (11). Attach each tape to its respective head prism shifting racks (14 and 15), individually securing them with one clamp block (11) and two lockscrews (49) each. Loosen the two shifting wire clamp nuts (3, Figure 4-28) sufficiently to allow the phosphor-bronze wire extensions of the tapes to be carried upward as necessary for the attachment of the tapes to the head prism shifting racks (14 and 15, Figure 6-4). The shifting wire tapes should be secured by the clamp nuts (3, Figure 4-28) so that an equal amount of adjustment of both shifting wire spindles (1) at half throw of both prism shifting racks (43 and 44) is provided for the shifting wire spindle adjusting nuts (4).

3. Remove the friction tape from the coiled up change of power shifting wire tapes (38) and place them through the various guides and

  straps of the inner tube sections and reduced tube sections.

4. Remove the four lockscrews (49, Figure 6-4) and two clamp blocks (11). Attach each tape to its respective cube shifting racks (12 and 13) individually, securing them with one clamp block (11) and two lockscrews (49) each. Loosen the two shifting wire clamp nuts (3, Figure 4-28) sufficiently to allow the phosphor-bronze wire extensions of the tapes to be carried upward as necessary for the attachment of the tapes to the cube shifting racks (12 and 13, Figure 6-4). The shifting wire tapes should be secured by the clamp nuts (3, Figure 4-28) so that an {equal amount of adjustment of both shifting wire spindles (1) at half throw of the power shifting rack (45 and 46) is provided for the shifting wire spindle adjusting nuts (4).

5. Slide the upper end of the air line section (22, Figure 6-5) and its continuations (25 and 35) through the two soldered air line straps (39) of the sixth inner tube section (28), carrying it upward through the soldered air line strap (21) and connecting it in the air line adapter (20) of the second reduced tube section (17). The air line section continuation (25) of the first reduced tube section (23) is secured to its periphery wall by the removable air line strap (26) and its two lockscrews (27). The air line

 
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section continuation (35) of the air line section (22) carries the soldered air line coupling (36) at its lower end in the lower part of the sixth inner tube section (28).

6. Slide the upper end of the air line section (37) through the two soldered air line straps (22, Figure 6-6) in the upper part of the third inner tube section (11), carrying it upward through the seven soldered air line straps (10) of the fourth inner tube section (1) and connecting it to the air line coupling (36, Figure 6-5) at, the lower part of the sixth inner tube section (28). The air line section continuations (21 and 9, Figure 6-6), and (47, Figure 6-5), of the air line section (37) of the sixth inner tube section (28), adhere to their respective inner tube sections, third, fourth, fifth, and sixth inner tube sections. The air line section (37) is secured to the lower part of the sixth inner tube section (28) periphery wall with a removable air line strap (38) which is secured with two lockscrews (40). The air line section continuation (21, Figure 6-6) of the third inner tube section (11) carries the soldered air line coupling (20) at its lower end in the upper part of the third inner tube section (11).

7. Slide the upper end of the air line section (19) through the six soldered air line straps (32) of the second inner tube section (23), carrying it upward through the four soldered air line straps of the third inner tube section (11) and connecting it in the air line coupling (20) in the upper part of the third inner tube section (11). The air line-section continuations, (30 and 16, Figure 6-7) of the air line section (19, Figure 6-6) of the third inner tube section (11) adhere to their respective inner tube sections and the coupling sleeve (17, Figure 6-7).

8. Insert the long air line coupling section (13, Figure 6-10) in the clearance hole in the spider (2), and extend it farther into the tapped hole in the eyepiece skeleton large shoulder flange, screwing it tight.

9. Place the short, bent, round air line section (14) on the upper end of the long air line coupling section (13), rotating it against the first inner tube section (1), attaching the removable air line strap (20) over the bent air line section (14) to the lower periphery wall

  of the first inner tube section (1), and securing it with two lockscrews (22).

10. Slide the air line section (16) downward through the soldered air line strap (19) and connect its soldered air line coupling (15) at its lower end in the short bent round air line section (14) of the first inner tube section.

11. Pull the air line section continuations (16, Figure 6-7) of the coupling sleeve (17) and the continuation (17, Figure 6-10) of the first inner tube section (1) outward sufficiently for the connection of the air line coupling (15) in the upper end of the air line section (16) of the first inner tube section (1).

12. Place the removable air line strap (31, Figure 6-6) over the air line section continuation (30) and secure it to the lower periphery wall of the second inner tube section (1) with its two lockscrews (33).

13. Place the removable air line strap (18, Figure 6-10) over the air line section continuation (17) and secure it to the upper periphery wall of the first inner tube section (1) with its two lockscrews (22).

6V2. Orientation check of the head prism using the Sperry-Kollmorgen collimator. This procedure is performed in the following manner:

1. Recheck the head prism to ascertain that it is spotted centrally over the collimator axis.

2. Recheck the inner tube following the procedure stated in Section 6U1, Steps 12 and 13 for the vertical position of the eyepiece end of the eyepiece box.

3. Recheck the stadimeter dials to ascertain that the lower (split) objective lens is in the observing position.

4. Reassemble the left and right training handle assemblies to their respective sides of the eyepiece box. Check reference punch marks of the connecting couplings for proper alignment. Secure both training handle assemblies with four hinge bracket bolts each (22 and 21, Figures 6-11 and 4-44 respectively).

5. Check the movement of the right training handle assembly as described under Section 4T7, Steps 24 to 27 inclusive. When no positive

 
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engagement is apparent, check as described under Section 4W2.

6. Check the movement of the left training handle assembly. The correct tension of the prism tilt shifting wire tapes can be noted after the revolving grip has been rotated the necessary 3/32 inch. The head prism should elevate or depress at opposite positions of the 3/32-inch lost motion positions of the index ring (7, Figure 6-11). If observations indicate incorrect indexing, adjust the shifting wire adjusting nuts (4, Figure 4-28) of the eyepiece skeleton assembly to enable the head prism to be oriented correctly.

7. Judgment of the tape tension is detected by the spring-back of the shifting wire adjusting nuts (4) when a light tension is applied. This requires extensive practice. A staggered movement or jumping of the head prism is observed more readily with the periscope in the observing position, since adjustments made in the horizontal position will not have the same reaction when the periscope is in the vertical position.

8. Release the lock ring (51, Figure 4-69) and return the reticle lens mount actuating sleeve (53) to the position described under Section 6U4, Step 1, using the 3,110-foot distance target position. Secure the lock ring (51) snugly against the reticle lens mount end bushing (52).

9. Loosen the wedge lock bolt (11) and wedge lock (10). Elevate the head prism and Sperry-Kollmorgen collimator to 45 degrees elevation, and secure the wedge lock (10) with the wedge lock bolt (11). The observer at the eyepiece end of the periscope should now check the centerline of sight in high power magnification. The centerline of sight should be superimposed with the reticle crossline of the collimator.

10. Loosen the wedge lock bolt (11) and the wedge lock (10). Dress the head prism and Sperry-Kollmorgen collimator to 10 degrees depression, so that the centerline of sight is superimposed with the reticle crossline of the collimator. Secure the wedge lock (10) with the wedge lock bolt (11).

11. After all degrees of elevation and depression have checked correctly, the repairman is assured that the head prism travel is correct.

  Should the centerline of sight show an incorrect reading, it will be necessary to disconnect the gear train bracket (30, Figure 6-4) of the skeleton head assembly and shift the eccentric accordingly.

12. The telemeter lens line is now checked with the Sperry-Kollmorgen collimator reticle vertical crossline. Loosen the wedge lock bolt (11, Figure 4-69) and wedge lock (10) sufficiently to carry the collimator through 20 degrees with the head prism simultaneously from 10 degrees depression to 10 degrees elevation. The telemeter lens line should be carried within 10 minutes of arc through azimuth of 20 degrees. This is checked by observing the telemeter lens line and its relation to the collimator reticle vertical crossline while traveling in azimuth, and also observing the centerline of sight at 10 degrees depression and 10 degrees elevation.

13. Swing the index line of the collimator base plate (7) into coincidence with the 0 degree numeral graduation of the azimuth disk plate (6).

6V3. Reassembly of the inner tube sections in the outer tube. This procedure is performed in the following manner:

1. Check the head prism, the Galilean eyepiece, and objective lenses for cleanliness. Clean all lenses and head prism surfaces with clean lens tissue. Remove any surface dust with a camel's hair brush or vacuum brush used with ether.

2. Rotate the revolving grip (3, Figure 6-11) of the left training handle assembly so that the zero line of sight graduation on the index ring corresponds to the stationary index line graduation on the fixed grip (2). This places the head prism at zero line of sight and offers no obstruction for the entry of the inner tube. Check the right training handle for change of power; it should be set for low power.

3. Follow the procedure described under Section 6B1, Steps 4 to 6 inclusive, for the removal of the stadimeter housing assembly, training handle assemblies, and focusing knob assembly.

4. Rotate the inner tube sections in the V-blocks, placing the eyepiece end facing downward.

 
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5. Attach the special lifting plate (Figure 4-9) at the base of the eyepiece box; insert the four special bolts in the clearance holes of this plate and screw them into the tapped holes in the eyepiece box base securing the lifting plate.

6. Assemble the special hinged clamp over the coupling sleeve (17, Figure 6-7) covering the objective operating mechanism (Figure 4-11).

7. Connect the upper part of the lifting spreader bar (Figure 4-13) to the lifting projection of the hinged clamp. This projection slides between the center slot section of the upper end of the lifting spreader bar and a bolt is placed through the clearance holes in the above projection and the spreader bar secured with a locknut. The lifting plate projection slides into the center slot section of the lower part, and is held in similar manner to the upper part.

8. Assemble the special hinged clamp over the lower part of the fifth inner tube section (41, Figure 6-5) and attach a shackle to the hinged clamp projection clearance hole.

9. Follow the procedure described under Section 4V17, Steps 7 to 14 inclusive,

10. Place the hook of the chain hoist in the shackle of the special hinged clamp attached to the fifth inner tube section (1) and the hook of the second chain hoist in the center pad clearance hole of the spreader bar (Figure 4-14).

11. Lift the inner tube sections evenly with both chain hoists and transport them to the lower end of the outer tube. Check the inner tube sections to ascertain that they are parallel and properly centered for entry in the outer tube.

12. Recheck the skeleton head lenses and head prism for cleanliness. The skeleton head, reduced, and inner tube sections are slowly pushed in the outer tube, guiding them parallel and properly centered.

13. When the fifth inner tube section contacts the attached main coupling (2, Figure 4-29) remove the chain hoist hook and hinged clamp.

14. Slowly resume the inward pushing movement of the remaining inner tube sections until

  the hinged clamp secured to the coupling sleeve (17, Figure 6-7) almost touches the edge of the main coupling (2, Figure 4-29). Place an adjustable roller stand under the eyepiece box, adjusting it until the rollers touch the eyepiece box. Release the load of the chain hoist to the roller stand as shown in Figure 4-11.

15. Follow the procedure described under Section 4V17, Steps 21 to 27 inclusive.

16. Remove the eyepiece box and outer tube alignment guides.

17. Reassemble the side plate and pressure gage rubber gaskets (10, Figure 4-29) to opposite sides of the eyepiece box (11) in the rectangular recess seats. Assemble the side plate (9) in the rectangular opening to the rubber gasket, securing the side plate with 10 lockscrews (5) to the left side of the eyepiece box.

18. Reassemble the pressure gage assembly to the right side of the eyepiece box, securing it in similar manner to that stated under Step 17 above.

19. Clean off all fingerprints and surface dust from the eyepiece lens with clean lens tissue. Use a camel's hair brush to remove any surface dust.

20. Clean the inner surface of the eyepiece window (9, Figure 4-38) in similar manner. Blow off any surface dust with an air bulb. Reassemble the eyepiece window frame rubber gasket (8) to the counterbored section seat in the eyepiece box. Reassemble the eyepiece window assembly in the counterbored section and rest it on the rubber gasket (8). Secure the assembly with four short and eight long lockscrews (2 and 3). These lockscrews are inserted in countersunk clearance holes in the eyepiece window frame (7) and screwed into tapped holes in the counterbored section seat in the eyepiece box.

6V4. Pressure testing and cycling of the periscope. This procedure is performed in the following manner:

1. Follow the procedure described under Section 2C3, and omit Steps 1 to 12 inclusive.

2. The 25th step of 2C3 is followed by transporting the periscope to the built-in water

 
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tank in the deck with two chain hoist hooks and slings, resting the periscope in two roller brackets. The periscope is rotated during this test, and returned to the optical I-beam bench after blowing off all water and wiping it dry.

3. Follow the procedure described under Section 2C5.

4. Follow the 15 safety precautions stated in Section 2C6.

6V5. Reassembly of all external projections and final checks of the instrument. This procedure is performed in the following manner:

1. Follow the procedure described under Section 4V19, Steps 1 to 11 inclusive, for the reassembly of the hoisting yoke assembly.

2. Reassemble the focusing knob assembly to the eyepiece box. Align the corresponding reference marks of the female coupling section (3, Figure 4-39) and the eyepiece drive actuating shaft (12, Figure 4-33) of the eyepiece drive packing gland assembly. Secure the knob bracket (7, Figure 4-39) after proper engagement of dowel pins (8) with four lockscrews (10).

3. Check the instrument; it should be in the observing position. Check the stadimeter dials; they should be locked at infinity, or single image position.

4. Reassemble the stadimeter housing assembly to the base of the eyepiece box. Check the entrance of the female tang coupling (68, Figure 4-24) to ascertain that it engages on the male tang section of the stadimeter transmission shaft (12, Figure 6-10). Insert the four housing bolts (30, Figure 4-24) in clearance holes in the stadimeter housing (8, Figure 6-8), screwing the bolts into tapped holes in the eyepiece box base (11, Figure 4-29) and securing them snugly.

5. Reassemble the left and right training handle assemblies to their respective sides of the eyepiece box. Check reference marks of the connecting couplings for proper alignment. Secure both training handle assemblies with four hinge bracket bolts each (22 and 21, Figures 6-11,and 4-44 respectively).

6. Focus the eyepiece lens to the center of the eyepiece window frame (7, Figure 4-38)

  making certain that the rayfilter drive actuating gear (11, Figure 4-32) is on the protruding square section of the rayfilter drive actuating shaft (10) of the rayfilter drive packing gland assembly. This central position is necessary for full focusing travel.

7. The rayfilter plate (2, Figure 4-40) is mounted only when the eyepiece lens is in the center of the eyepiece window frame to establish full synchronized movement. Place the rayfilter plate (2) over the flat sides of the eyepiece window frame (7, Figure 4-38); check the rayfilter drive actuating gear rack (8, Figure 4-40) to ascertain its engagement with the rayfilter drive actuating gear (11, Figure 4-32).

8. With the rayfilter plate (2, Figure 4-40) properly centered, and the gear rack in mesh with the rayfilter drive actuating gear, place both rayfilter plate straps (3) in each side shoulder recess of the rayfilter plate and recess groove section of the eyepiece window frame (7, Figure 4-38). Secure the straps with seven lockscrews (19, Figure 4-40). These lockscrews are inserted in countersunk clearance holes in the rayfilter plate (2) and screwed into tapped holes in the straps.

9. Check the zero reading of the diopter index ring (9, Figure 4-39). Place the auxiliary telescope at the eyepiece end of the periscope. Focus the eyepiece lens until sharp definition of the telemeter lens is apparent on an infinity target or collimator.

10. Check the field. It must be free of internal and external fogging.

11. Check the instrument in high and low power for cleanliness. If particles of dirt are present, they will clearly show on the telemeter lens which lies on the focal plane of the instrument.

12. Check the high- and low-power system on an infinity target or collimator. No parallax should be apparent on the telemeter lens in either power.

13. Turn the handwheel (12, Figure 4-24) clockwise to the limit of its travel, and turn it counterclockwise back to the observing position (single image or whole lens position). There should be no signs of double image.

 
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14. Check the stadimeter dials on special targets of known height and distance or the collimator reticle set at infinity.

15. Check the operation of the left and right training handles, noting particularly their limit of travel stops by corresponding stationary reference index lines.

16. Grasp both spring actuated plunger knobs (24, Figure 4-40), pull them outward as far as possible, and assemble the rayfilter housing (21) female hinge projection sections to the center male hinge projection section of the rayfilter plate (2). The spring actuated plunger rods (23) will snap into place under spring tension. Push the lower part of the rayfilter

  housing down to the rectangular stops of the rayfilter plate (2); the ball bearing friction catches (26) will engage in the spotted recesses of the shoulder stops of the rayfilter plate in the closed position.

17. Place the eye buffer and blinder assembly on the anchor screw pins (6) of the rayfilter housing (21), snapping it in place.

18. Place the variable density polaroid filter assembly on the anchor screw pins (19, Figure 4-29) in the front wall of the eyepiece box (11) snapping it in place.

19. Place the stadimeter illuminator assembly on the anchor screw pins (19) in the rear wall of the eyepiece box (11), snapping it in place.

 
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