Figure 7-19. Rayfilter housing and plate assembly.

a. Rayfilter plate. The rayfilter plate (14) is made of cast phosphor-bronze and is rectangular shaped. This plate serves as a foundation for the rayfilter housing (13). The upper part is provided with a center male hinge projection with a reamed hole to accommodate two spring actuated plunger rods (6) of the two female hinge projection sections of the rayfilter housing (13). The upper main inside section has a cast recess, while the remaining wall has a nominal thickness, with side shoulders and a narrow upper shoulder. The side shoulders are provided with recesses that carry the rayfilter plate straps (15) on each side. A rayfilter plate strap (15) is secured to the rayfilter plate (14) on each side with seven lockscrews each (10).

The lower section of the rayfilter plate (14) has a cast inside recess, while the remaining wall has a nominal thickness with side shoulders and a narrow lower shoulder. The left side of the inside recess of the lower section when viewed from the rear is provided with a rectangular boss section for the rayfilter drive actuating gear rack (1), secured with four lockscrews (10), and maintained in alignment with two dowel pins (12) This gear rack meshes with a rayfilter drive actuating gear (9, Figure 7-13) projecting externally from the rayfilter drive packing gland assembly. The rayfilter drive actuating ear (9) is synchronized to carry the rayfilter p fete (14) vertically with the eyepiece drive mechanism for the focusing movement of 1 1/2 plus and 2 minus diopters.

The exteriors of the side shoulders of the lower section are beveled at a 45 degrees angle, with a straight section having two spotted recesses of 120 degrees The spotted recesses allow the ball bearing friction catches (9) to retain the lower swinging part of the rayfilter housing (13). The lower part of the straight section corners are beveled at a 45 degrees angle to allow clearance for the milled concave corners of the inside recess of the rayfilter housing (13). A raised rectangular boss section on the exterior surface of the wall in the lower part serves as a stop when the ball bearing

The main body wall is provided with a 3-inch opening for light transmission with anti-reflection threads in the inner circumference. This opening permits free access to the field of the periscope. The inside recess of the main body wall is provided with sliding vertical clearance over the flat flanges of the eyepiece window frame (7, Figure 4-38). The upper and lower shoulders of the main section serve as stops to restrict the vertical movement of the rayfilter plate (14) which has 1 inch of vertical guided travel over the eyepiece window frame upper and lower rectangular section shoulders (7, Figure 4-38).

b. Rayfilter plate straps. The rayfilter plate straps (15) are 1/8 inch longer than the rayfilter plate straps (3, Figure 4-40) of the Types II and III periscope rayfilter assembly. They are secured to the rayfilter plate (14) with seven lockscrews (10) in the same manner. Refer to Section 4Q1.

c. Rayfilter housing. The rayfilter housing (13) is made of cast phosphor bronze and is shaped rectangular. This housing serves as an apron foundation which can be removed readily during the installation and removal of the periscope. The upper part is provided with two female hinge projection sections, a sliding fit over the center male hinge projection section of the rayfilter plate (14). Both female hinge projection sections have an axis reamed hole to carry the spring actuated plunger rods (6) which are moved axially against spring tension for removal or reassembly to the center male hinge projection section of the rayfilter plate (14). Both female hinge projection sections have a threaded section located in their outer sides to carry two plunger rod spring bushings (5).

The internal part when viewed from the rear has machined recesses allowing a remaining main body wall of nominal thickness with side shoulders. The side shoulders are a sliding fit over the sides of the rayfilter plate (14). The lower part of the internal lower section of each side shoulder has a projecting section with a raised boss section, leaving a narrow lower side wall. The two projecting sections of the side shoulders provide sufficient wall area for the ball bearing friction catch assemblies. The

When the rayfilter housing (13) is swung to the closed position, the ball bearing friction catches (9) engage in the 120 degrees spotted recesses in each shoulder step of the rayfilter plate (14). The raised boss section connecting the two side shoulder projecting sections contacts the raised rectangular boss section of the rayfilter plate (14) upon engagement of the two ball bearing friction catches (9).

The outer face of the main body wall is provided with a large flat raised boss which has a bored hole and shallow counterbored section. The bored hole is provided for light transmission and anti-reflection threads on its inner circumference. The variable density polaroid filter assembly (Figure 4-41), is centered in this shallow counterbored section and rests on the large flat raised boss. Either of the two assemblies is retained by two inserted anchor screw pins (16) located with an appropriate center distance concentric with the bored hole and counterbored shallow section.

In the lower central part of the outer face of the main body wall there is a raised boss with a reamed hole. The inside face of the reamed hole of the boss, when viewed from the rear, is countersunk to allow sufficient space for peening of the pressed in stub shaft section of the housing, knob (2). The housing knob furnishes the observer a provision by which he can pull the lower swinging part of the rayfilter housing (13) free of its friction catch engagement with the rayfilter plate (14).

d. Anchor screw pins. The two anchor screw pins (16) are similar to the anchor screw pins (6, Figure 4-40) of the Types II and III rayfilter assembly. Refer to Section 4Q1.

f. Plunger rod spring bushings. The two plunger rod spring bushings (5) are identical to the plunger rod spring bushings (22, Figure 4-40) used in the Types II and III periscopes. Refer to Section 4Q1.

g. Spring actuated plunger knobs. The two spring actuated plunger knobs (7) with their lockscrews (11) are identical to the spring actuated plunger knobs (24, Figure 4-40) used in the Types II and III periscopes. Refer to Section 4Q1.

7N2. Disassembly. The rayfilter housing and plate assembly is disassembled in the following manner:

1. Lift the lower swinging part of the rayfilter housing (13) by grasping the housing knob (2) and pulling it clear of its engagement in the friction catch spotted recesses in the rayfilter plate (14).

2. Grasp the two spring actuated plunger knobs (7), pulling them outward as far as possible, thus removing the rayfilter housing (13) from the rayfilter plate (14).

3. Remove the rayfilter plate (14) by removing the seven lockscrews (10) and the two rayfilter plate straps (15) from each side. Remove the rayfilter plate (14) and straps (15) from the eyepiece window frame (7, Figure 4-38).

4. Remove the two lockscrews (11), unscrewing them from the hubs of the spring actuated plunger knobs (7).

5. Wrap a piece of emery cloth around the extended part of each spring actuated plunger rod (6). Holding the emery cloth and plunger rod firmly with a pair of parallel pliers, unscrew each spring actuated plunger knob (7) from the threaded periphery of the spring actuated plunger rods (6) one by one.

6. Remove the spring actuated plunger rods (6) and the plunger rod springs (8) one by one

7. Remove the two friction catch spring retainers (3) unscrewing them from the outer two lower sides of the rayfilter housing (13), removing the two friction catch springs (4) and the two ball bearing friction catches (9).

8. Remove the four lockscrews (10) from the front lower right side of the rayfilter plate (14), unscrewing these lockscrews from the tapped holes in the rayfilter drive actuating gear rack (1). Remove the rayfilter drive actuating gear rack with its two dowel pins (12).

7N3. Reassembly. The rayfilter housing and plate assembly is reassembled in the following manner:

1. Place the rayfilter drive actuating gear rack (1) with its two dowel pins (12) on the lower left inner raised boss face of the rayfilter plate (14), when viewed from the rear. Secure the gear rack with our lockscrews (10). These lockscrews are inserted in countersunk clearance holes in the rayfilter plate front lower right side and screwed into tapped holes in the gear rack.

2. Focus the eyepiece prism to the center of the eyepiece window frame (7, Figure 4-38) making certain that the rayfilter drive actuating gear (9, Figure 7-13) is on the projecting square section of the rayfilter drive actuating shaft (8, Figure 7-13) of the rayfilter drive packing gland assembly. This central position is necessary for full focusing travel.

3. The rayfilter plate (14) is mounted only when the eyepiece lens (33, Figure 7-11) is in the center of the eyepiece window frame (7, Figure 4-38) to establish full synchronized movement. Place the rayfilter plate (14) over the flat sides of the eyepiece window frame (7, Figure 4-38). Check the rayfilter drive actuating gear rack (1) to ascertain its engagement with the rayfilter drive actuating gear (9, Figure 7-13).

4. With the rayfilter plate (14) properly centered and the gear rack in mesh with the rayfilter drive actuating gear, place both rayfilter plate straps (15) in each side shoulder recess of the rayfilter plate in the recess groove

5. Place both ball bearing friction catches (9) in clearance holes in the rayfilter housing side shoulders (13) of the lower section with both friction catch springs (4), securing them with both friction catch spring retainers (3).

6. Place the two plunger rod spring bushings (5) in the outer threaded parts of the opposite female hinge projection sections of the rayfilter housing (13). Secure them with a screwdriver.

7. Place the plunger rod springs (8) on the spring actuated plunger rods (6). Insert the spring and plunger rod in the reamed axis hole in each female hinge projection section, carrying them in from the center milled out section.

8. Place a piece of fine emery cloth around the stub section of the spring actuated plunger rod; grasp the emery cloth and stub section with a pair of parallel pliers. Compress the spring and attach the spring actuated plunger knobs (7), one by one, screwing them on the threaded part of the plunger rods (6). Secure the knobs when the shoulder section of each plunger rod is flush with the inner face of each female hinge projection section.

9. Insert the two lockscrews (11) in the hub section of each spring actuated plunger rod knob (7), securing the knobs on the two spring actuated plunger rods (6).

10. Grasp both spring actuated plunger knobs (7) and pull them outward as far as possible, and assemble the rayfilter housing female hinge projection sections (13) to the center male hinge projection section of the rayfilter plate (14). Release the outward tension of the spring actuated plunger knobs, as the springs will allow the plunger rods to snap into the reamed axis hole in opposite sides of the center male hinge projection section of the rayfilter plate. Push the lower part of the rayfilter housing down on the rectangular raised boss stop of the rayfilter plate (14); the ball bearing friction catches (9) will engage the spotted recesses of the shoulder stops in the rayfilter plate in this closed position.

The rayfilter and eye buffer and blinder assembly are external to the hermetically sealed part of the periscope, as is also the rayfilter stowage case assembly. The stowage case assembly is secured to the eyepiece box bottom flange plate (13, Figure 7-12) and carries the mounted rayfilters.

Refer to Section 4S1 for the description of the eye buffer and blinder assembly. Figure 7-20 shows the rayfilter, eye buffer, blinder, and stowage case assemblies. All bubble numbers in Sections 7O1, 2, and 3, refer to Figure 7-20 unless otherwise specified.

b. Base plate. The base plate (20) is almost identical to the base plate (2, Figure 4-42) described under Section 4S1. It differs in the center axis bored hole, and has no cylindrical raised boss on the lower face. The lower part of the base plate is counterbored and threaded with a coarse thread to carry the threaded periphery of the rayfilter mounts (21) against its counterbored seat. This counterbored threaded section carries any of the three assembled rayfilter mounts desired by the observer.

c. Finger grip levers. The right and left finger grip levers (2 and 3) are identical to the right and left finger grip levers (1 and 2, Figure 4-41) described under Section 4R1 They serve the same purpose and function along with the following parts: two finger grip lever springs (4), two finger grip lever pivot screw pins (10), and two finger grip lever thrust stop screw ins (9).

d. Blinder plate. The blinder plate (5) is identical to the blinder plate (6, Figure 4-42), described under Section 4S1.

e. Blinder adjusting screw. The blinder adjusting screw (6) is identical to the blinder adjusting screw (7, Figure 4-42) described under Section 4S1.

f. Blinder adjusting screw. The blinder adjusting screw nut (7) together with the blinder adjusting screw nut lockscrew (8) is identical, to the blinder adjusting screw nut (8, Figure 4-42), and lockscrew (7) described under Section 4S1.

g. Rayfilters. The three rayfilters (11) consist simply of cylindrical colored filter glass with parallel surfaces. Three shades are used; red, green, and yellow, which are provided for various conditions of observation. Each rayfilter is mounted in an individual rayfilter mount (21) and secured with a clamp ring (22) which is secured with a lockscrew (12).

h. Rayfilter mounts. The rayfilter mounts (21) are provided for each of the three shades of rayfilters. The rayfilter (11) is carried in the

The external surface of the mount consists of an undercut shoulder with a threaded periphery to engage into the internal threaded section in the base plate (20) with a 3/4 turn. The shoulder section contacts the base plate when in position and has ample clearance in the bored hole of the rayfilter housing (13, Figure 7-19).

The outer beveled surface of the shoulder section has a straight knurl to provide a rough surface, and offers a firm grip for the removal or replacement of any shade of the three mounted rayfilters (11).

i. Rayfilter clamp rings. The three rayfilter clamp rings (22) are cylindrical, and of nominal width. The clamp ring is bored for light transmission and has a nominal remaining wall thickness. The periphery is threaded to engage into the internal threaded section in each rayfilter -mount, and is secured with a lockscrew (12) after clamping the rayfilter (11) sufficiently to prevent it from unscrewing from the mount. Each mounted rayfilter (11) is carried in the rayfilter stowage case assembly (31, Figure 7-12) attached to the eyepiece box bottom flange plate (13, Figure 7-12). The outer face of each clamp ring is provided with opposite slots for the insertion of a special wrench.

j. Stowage case base plate. The stowage case base plate (19) is made of 1/8-inch brass and is 3 1/32 inches in length. The main section is 1 15/16 inch in diameter and forms a concave junction on opposite sides with an arm 7/8 inch in diameter. The arm has a clearance hole in its center axis for attachment to the eyepiece box bottom flange plate (13, Figure 7-12) upon which it rests.

The main section carries the stowage case body (14) secured with three lockscrew (13) which are inserted in clearance holes in the stowage case body (14) and screwed into tapped holes in the stowage case base plate (19).

k. Stowage case body. The stowage case body (14) is made of sheet brass of nominal thickness and is shaped cylindrical. The

The inner face of the stowage case body wall has a felt washer (17) glued to it. The felt washer has three clearance holes for the lockscrew heads (13) which are inserted into three clearance holes in the lower wall of the stowage case body and screwed into tapped holes in the stowage case base plate (19) for the securement of the stowage case body.

1. Stowage case cap. The stowage case cap (15) is made of sheet brass of nominal thickness. The cap is a sliding fit over the stowage case body wall (14). A rivet (16) is secured at an appropriate location in the outer wall of the cap so that its inward projecting part engages in the circumferential slot in the stowage case body wall. The cap when assembled covers the large opposite slotted sections of the stowage case body and the mounted rayfilters (11) to prevent breakage and foreign matter from entering. The assembly, provides an adequate stowage case to prevent the mounted rayfilters from becoming lost.

m. Felt separation washers. The two felt separation washers (18) are made of 1/32-inch felt, having a diameter of 1 3/4 inch. One felt washer is centered and glued in the inner face of the upper wall of the stowage case cap (15), while the other is used to separate the mounted rayfilters in the stowage case body (14). On the outer face of the cap are the engraved letters rayfilters filled with, white monofil to be clearly visible to the observer.

7O2. Disassembly of the rayfilter, eye buffer, and blinder assembly: The rayfilter, eye buffer, and blinder assembly is disassembled in the following manner:

1. Unscrew the mounted rayfilter (11) from the inner face of the base plate (20) (should

2. By pulling outward with two fingers (one on each hand) placed inside near the base of the eyeguard, remove both eyeguards (1), one from the blinder plate (5) and the other from the base plate (20).

3. Using a small screwdriver, remove the two finger grip lever thrust stop screw pins (9) and the two finger grip lever pivot screw pins (10). Unscrew these four screw pins from the lower slotted walls of the base plate (20). Remove the right and left finger grip levers (2 and 3) and their two tension springs (4).

4. Remove the blinder screw nut lockscrew (8), unscrewing it from the tapped hole in the center axis in the blinder adjusting screw (6) and the counterbored recess in the blinder adjusting screw nut (7).

5. Remove the blinder adjusting screw nut (7), unscrewing it from the threaded stub section of the blinder adjusting screw (6).

6. Remove the blinder plate (5) with blinder adjusting screw (6). Remove the blinder adjusting screw (6).from the blinder plate (5).

7O3. Reassembly of the rayfilter, eye buffer, and blander assembly. The rayfilter, eye buffer, and blinder assembly is reassembled in the following manner:

1. Place the blinder adjusting screw (6) in the offset counterbored clearance hole in the blinder plate (5). Line up the flat shoulders of the adjusting screw with the flat shoulders of the blinder plate small projection by turning the adjusting screw.

2. Press the left thumb against the blinder adjusting screw thread (6), and place the raised projection pant of the blinder plate (5) in the wide shallow keyway in the base plate projection boss (20) and the protruding part of the adjusting screw into its elongated axial hole. Check to ascertain that the offset hole in the blinder plate is located outward.

3. Screw the blinder adjusting screw nut (7) on the threaded stub section of the blinder adjusting screw (6), turning it clockwise until tight. The counterbored section side should face inward.

5. Insert the right and left finger grip levers (2 and 3) with their two tension springs (4) in the upper and lower slotted sections in the base plate (20). Compress the tension springs (4) sufficiently to line up the outer pivot hole in each finger grip lever with the pivot hole in the base plate for the insertion of the two finger grip lever pivot screw pins (10) one by one.

6. Grasp both finger grip levers (2 and 3) and compress them together, until near the limit of their travel. Insert the two finger grip lever thrust stop screw pins (9), and screw them into the tapped holes of the lower slotted base plate walls (20) one by one.

7. Reassemble the two eyeguards (1), one to the blinder plate (5), and the other to the base plate (20). Rotate the two lower portions of the outer flared out sections of the eyeguards so that they line up centrally.

Clean all three shades of the mounted rayfilters (11) and place them in the rayfilter stowage case assembly (31, Figure 7-12) attached to the eyepiece box bottom flange plate (13).

Ill. No.	Drawing Number	Num- ber Re- quired	Nomenclature
1	P-1069-15	1	Outer bevel gear clutch spring
2	P-1069-16	1	Outer bevel gear clutch retaining screw
3	P-1157-5	1	Inner bevel gear clutch
4	P-1157-6	1	Outer bevel gear clutch
5	P-1161-7	4	Hinge bracket bolts
6	P-1171-6	2	Pivot screws
7	P-1420-6	1	Detent plunger
8	P-1420-8	1	Detent plunger release knob
9	P-1421-1	1	Detent plunger spring retaining bushing
10	P-1421-2	1	Detent plunger retaining cap
11	P-1421-3	1	Detent plunger spring
12	P-1421-5	1	Detent plunger release knob lockscrew
13	P-1421-6	1	Detent plunger retaining cap lockscrew
14	P-1486-3	1	Upper leather cushion
15	P-1486-4	1	Lower leather cushion
16	P-1505-9	1	Detent plunger housing
17	P-1506-21	4	Leather cushion lockscrews
18	P-1506-30	2	Segment adjusting screw lockscrews
19	P-1506-55	1	Spring barrel lockscrew
20	P-1506-56	4	Pivot screw lockscrews, and segment adjusting screws
21	P-1506-107	2	Plunger roller
22	P-1506-115	1	Outer bevel gear clutch collar and revolving grip shaft taper pin
23	P-1509-1	1	Hinge bracket
24	P-1509-2	1	Handle hinge and fixed grip
25	P-1509-3	1	Spring barrel
26	P-1509-4	1	Revolving grip
27	P-1509-6	1	Spring barrel washer
28	P-1510-1	1	Revolving grip shaft
29	P-1510-2	1	Revolving grip shaft key
30	P-1510-3	2	Revolving grip lock nuts
31	P-1510-4	1	Index ring
32	P-1510-5	1	Revolving grip segment stop screw

Ill. No.	Drawing Number	Num- ber Re- quired	Nomenclature
1	P-1069-15	1	Outer bevel gear clutch spring
2	P-1069-16	1	Outer bevel gear clutch retaining screw
3	P-1157-5	1	Inner bevel gear clutch
4	P-1157-6	1	Outer bevel gear clutch
5	P-1161-7	4	Hinge bracket bolts
6	P-1171-6	2	Pivot screws
7	P-1486-3	1	Upper leather cushion
8	P-1486-4	1	Lower leather cushion
9	P-1506-21	4	Leather cushion lockscrews
10	P-1506-30	2	Segment adjusting screw lockscrews
11	P-1506-54	2	Power indicating screws
12	P-1506-55	1	Spring barrel lockscrew
13	P-1506-56	4	Pivot screw lockscrews, and segment adjusting screws
14	P-1506-107	2	Plunger roller pins
15	P-1506-115	1	Outer bevel gear clutch collar and revolving grip shaft taper pin
16	P-1509-1	1	Hinge bracket
17	P-1509-2	1	Handle hinge and fixed grip
18	P-1509-3	1	Spring barrel
19	P-1509-5	1	Revolving grip
20	P-1509-6	1	Spring barrel washer
21	P-1510-1	1	Revolving grip shaft
22	P-1510-2	1	Revolving grip shaft key
23	P-1510-3	2	Revolving grip lock nuts
24	P-1510-5	1	Revolving grip segment stop screw
25	P-1510-6	1	Outer bevel gear clutch collar
26	P-1510-7	1	Bearing plate
27	P-1510-8	2	Plungers
28	P-1510-9	2	Plunger rollers
29	P-1510-10	1	Coil plunger spring
30	P-1523-6	1	Power index ring

a. Revolving grips. The two revolving grips, left and right (26 and 19, Figures 7-21 and 7-22 respectively) are made of phosphor-bronze material with the same over-all length. The outer section of each grip is rough diamond knurled on its periphery. The internal part of this outer section is counterbored with a wall

Both grips have a short undercut shoulder next to the inner art of the knurled section. The graduated index ring (31, Figure 7-21) is a sliding fit on the shoulder section of the left revolving grip (26) and is carried by the inserted actuating screw (28) placed through the elongated slot and in the tapped hole in the shoulder section. The power index ring (30, Figure 7-22) is a sliding fit on the shoulder section of the right revolving grip (19) and is secured with a power indicating screw (11).

Both grips are provided with bearing shoulder sections which are a sliding fit in the inner fixed grips of the training handle hinges (24 or 17).

The segment section of the left revolving grip (26) consists of a narrow section with 275 degrees of the cylindrical shoulder wall section removed. The removed section allows the revolving grip free rotation for operation of the prism tilt mechanism. The segment section is provided with two tapped holes to carry the headless adjusting screws (20) and two perpendicular tapped holes in the face of the segment for the adjusting screw lockscrews (18). These lockscrews are headless screws, which secure the adjusting screws and maintain the adjustment. The adjusting screws project into the cutaway section sufficiently to permit the revolving grip to be adjusted. Adjustments are made to set the graduated index ring (31) to 10 degrees depression and 45 degrees elevation, with the coinciding stationary

The right revolving grip (19) is provided with a narrow segment section with 117 degrees of the cylindrical section removed. The removed section allows the revolving grip free rotation for operation of the change of power mechanism. The segment section is provided with adjusting screws (13) and adjusting screw lockscrews (10) similar to the left revolving grip (19, Figure 7-21). Adjustments are made to set the power index ring (30) to high and low power, with the coinciding stationary index line on the fixed grip (17) and the segment stop screw (24).

b. Handle hinge and fixed grips. The two handle hinge and fixed grips deft and right (24 and 17) are made of cast phosphor-bronze material, with the same over-all length. The outer parts of both are rough diamond knurled, and when in the extended position provide the revolving grip sufficient length for leverage to turn the periscope through azimuth. The inner part of each fixed grip has a cast filleted section between the grip and the hinge sections. The hinge section is shaped similarly to an apron, with the contour of the main wall uniform with the inner circumference wall of 150 degrees. The side walls of each hinge angle section have projecting bosses on the inner and outer faces, with a reamed hole through the center axis of each boss, offset from the main centerline of the fixed grip section. The inner bosses of each are a sliding fit over the side walls of the cam projection section of the hinge brackets (23 or 16). The reamed holes of each side wall of the hinge section carry, a pivot screw (6), thus serving as hinge pivots to carry the fixed grip and its hinge through 90 degrees of rotation.

Both fixed grip sections, have two narrow undercut shoulder sections on their outer part. The small shoulder of the left fixed grip (24) carries half of the graduated index ring (31), a drag fit on this half, while on the right fixed grip (17) it carries half of the power index ring (30), a sliding fit on this half. The next larger shoulders of both fixed grips are each provided with a

The inside of both fixed grip sections has two counterbored sections. The small counterbored section provides clearance for the vertical movement of the bearing plate (34 or 26) with the outer part provided with a narrow threaded section. The internal threaded section carries the external threaded section of the spring barrel (25 or 18), secured with a lockscrew (19 or 12). The lockscrew extends into the tapped hole in the center of the threaded section from the tapped hole in the outer circumference of the knurled fixed grips (24 or 17).

The large counterbored section carries the inner moving part of the revolving grip shoulder bearing sections (26 or 19). In the bottom of each knurled fixed grip a clearance hole with a tapped section is provided near the inner depth of the large counterbored section for the revolving grip segment stop screws (32 or 24). The left fixed grip (24) is provided with a tapped hole near the center of the knurled section for a spring detent assembly to hold the line of sight at zero degree, and is located in the front centerline. Refer to the spring detent assembly of the Type II periscope,

The inside of the inner hinge section, from the small counterbored section, is provided with three equally spaced reamed holes. One is in the center axis to carry the stem section of the revolving grip shaft (28 or 21), while the other two reamed hole of the same size are located on opposite sides of the center reamed hole and are parallel. The two outer reamed holes are located in a perpendicular plane to the inner face of the projecting bosses of the side walls of the hinge section. Each outer reamed hole is counterbored a sufficient depth from the hinge section to carry the shoulder section of each plunger (35 or 27). The center reamed hole is counterbored sufficiently in the inside 150 degrees radius of the apron wall section to allow a flat surface for

c. Index ring. The index ring (31, Figure 7-21) is made of brass tubing material of nominal wall thickness. The bore is a sliding fit over the shoulder section of the revolving grip (26) and is a drag fit over the shoulder section of the fixed grip shoulder section (24). The periphery is engraved after assembly to indicate specifically 10 degree depression, 0 degree line of sight, 45 degree elevation, and individual 1 degree graduations between the designed limits. A plus and minus indication is engraved above and below the 0 degree graduation. It is provided with a circumferential slot, located for the insertion of an actuating screw (38) in the tapped hole in the center of the shoulder section of the revolving grip. The circumferential slot has 3/32-inch angular movement to coordinate with the correction made with the adjusting screws (13) in the segment section of the revolving grip.

d. Power index ring. The power index ring (30, Figure 7-22) is made of brass tubing material of nominal wall thickness. The bore is a sliding fit over the shoulder, section of both the revolving grip (19) and lie fixed grip (17). The periphery has index marks: and the engraved letters of hp and lp above each index mark, located at assembly. The power index ring is secured to the shoulder section of the revolving grip (19) with a power indicating screw (11).

e. Hinge brackets. The two hinge brackets (23 and 16, (Figures 7-21 and 7-22 respectively) are made of cast phosphor-bronze material of duplicate design, with the base flange section shaped rectangular. A cam section projects upward from each base flange section. Both of these sections form the fixed half of the training handle hinge. Four raised bosses are provided in each corner of each base flange section, and each boss has a clearance hole in which the hinge bracket bolts (5) are inserted. The bolts extend into the tapped holes in each side of the eyepiece box to retain each hinge bracket. The lower face of each base flange section is provided with a counterbored

The center cored section of each cam section is provided with a cylindrical raised boss, to carry the shoulder of the inner bevel gear clutches (3). Sufficient radius clearance is provided for assembly and removal of the inner and outer bevel gear clutches (3 and 4) and clearance inside the side walls for the 90 degrees rotation of the outer bevel gear clutch collar (33 or 25, Figures 7-21 and 7-22 respectively). The concave recesses are located for the folded position only, with the heavy tension on the set of plunger rollers retaining the handle beyond the high point of the cam. In the folded position, the spring pressure is at a minimum, and with the handle hinge swung downward in the extended position, the tension is increased, with the maximum tension reached at the highest point of the cams. Each set of rollers rides on the cams constantly because of heavy spring tension. When they pass the high point of the cam, the handle hinge and fixed grip of each will be returned to the folded position by the heavy recoil of the spring. The upper and lower part of the outer face of the base flange section is provided with leather cushions (14 and 15, Figure 7-21) or (7 and 8, Figure 7-22) secured with two lockscrews (17 or 9, Figures 7-21 and 7-22 respectively). The outer face of each cam section side wall is a snug fit between the apron side wall bosses of the hinge section of each handle hinge and fixed grip. Two tapped holes located in each side wall and in the main horizontal centerline are offset slightly, and carry hinge bracket pivot screws (6).

f. Training handle and hinge recoil principle. This recoil is provided as a safety device to return each training handle to the folded position when lowering the periscope in the well of the submarine. It also prevents damage to each

g. Leather cushions. The two leather cushions (14 and 15, Figure 7-21) or (7 and 8, Figure 7-22) are attached on the upper and lower part of the outer base flange section of the hinge brackets (23 or 16, Figures 7-21 or 7-22 respectively) next to the cam section. Two lockscrews (17 or 9) secure each leather cushion to its hinge bracket. They provide a cushion to absorb the heavy shock of the spring recoil of the hinge when in the folded and extended positions.

h. Pivot screws. The two pivot screws (6, Figures 7-21 and 7-22) are made of phosphor-bronze rod material. They form hinge pins on which the hinge section of the fixed grip can be swung through 90 degrees of rotation. Each screw has a head section, with the main body section a snug sliding fit in each of the hinge section pivot holes in each handle hinge and fixed grips (24 or 17, Figures 7-21 or 7-22, respectively). The stub section is threaded and engages into a tapped hole in each side wall of each set of cam sections. The lockscrews (20 or 13, Figures 7-21 or 7-22 respectively) prevent the threaded section of each pivot screw from unscrewing.

i. Spring barrels. The two spring, barrels (25 or 13, Figures 7-21 or 7-22 respectively) are made of brass rod material. They consist of an enclosed cylinder with a uniform wall thickness, and a reamed clearance hole in the load end shoulder center axis for the revolving grip shafts (28 or 21). The opposite end has a threaded flange section with uniform wall thickness. The coil plunger spring (37 or 29) is stabilized by the side walls of each spring barrel. The threaded flange section of each engages into the small counterbored threaded section in the handle hinge and fixed grips (24 or 17, Figures 7-21 or 7-22 respectively), after compressing 2 inches of coil plunger spring. It is secured with a lock Screw (19 or 12). Two opposite holes are provided in the outer load shoulder part of each spring barrel for the insertion of a special wrench to tighten the spring barrel against the heavy tension of the coil plunger spring.

k. Bearing plates. The two bearing plates (34 or 26, Figures 7-21 or 7-22 respectively) are made of phosphor-bronze rod material. They consist of a cylindrical plate with a clearance hole in the center axis that moves axially over the revolving shaft (28 or 21). Under spring tension each plate distributes equal pressure to their plungers (35 or 27). Two square broached holes are provided in the outer body for the square stub section of the plungers. The square section of the plungers and the square broached holes in the bearing plate maintain proper alignment for the plungers and rollers (35 and 36, Figure 7-21) or (27 and 28, Figure 7-22), preventing angular movement. The counterbored recess in each bearing plate centers the plunger springs (37 or 29) at the lower load end.

l. Plungers. The two plungers (35 or 27, Figures 7-21 or 7-22 respectively), are made of corrosion-resisting steel material. Both the main body sections are a close axial sliding fit in both reamed holes in the handle hinge and fixed grips (24 or 17). The hub section is slotted to carry a plunger roller (36 or 28) with a reamed hole perpendicular to the slotted section to carry each plunger roller pin (21 or 14). The pin provides a bearing for the plunger rollers and is riveted over at assembly. The large section of each plunger is milled on one side sufficiently to allow it to clear the inside boss of the hinge section side wall of each handle hinge and fixed grip. The square section of the plunger is cut parallel with the pivot pin hole and the slotted section.

m. Revolving grip shafts. The two revolving grip shafts (28 or 21, Figures 7-21 or 7-22 respectively) are made of corrosion-resisting steel material. The shaft forms the connection between each revolving grip (26 or 19) through the spring barrels (25 or 18), plunger springs (37 or 29), bearing plates (34 or 26), handle hinge, and fixed grips (24 or 17) to connect with the outer bevel gear clutch collars (33 or 25) and each outer bevel gear clutch (4) at the opposite end. The outer bevel gear clutch collars (33 or 25) are secured to the stem section of each shaft with a taper pin (22 or 15) in the hinge section of the fixed grips. The square section of each shaft carries each outer bevel gear clutch (4) against the spring tension of each gear clutch spring (1) by means of each retaining screw (2). The retaining screw extends into a tapped hole in the square section of each shaft.

n. Outer bevel gear clutch collars. The outer bevel gear clutch collars (33 or 25, Figures 7-21 or 7-22 respectively) are made of phosphor-bronze material of short length. They provide a container in which each gear clutch spring (1) is carried. The collar has a reamed hole in its center axis with a counterbored section, and is secured to the stem section of each revolving grip shaft with a taper pin (22 or 15). Each gear clutch spring (1) is carried over part of the stem section and the square section of the revolving grip shafts (28 or 21). The spring places a constant pressure against the hub face of each outer bevel gear clutch (4).

o. Inner and outer bevel gear clutches. The two sets of inner and outer bevel gear clutches (3 and 4, Figures 7-21 and 7-22 respectively) are made of phosphor-bronze material. Both the bevel gear sections have the same diameter and number of teeth. Each is provided with a square broached hole. The square broached hole and the hub sections of the outer bevel gear clutch (4) move axially in the gear clutch collar (33 or 25) against each gear clutch

The hub section of the inner bevel gear clutch fits in the reamed hole in each hinge bracket (23 or 16), and further extends on the square section of the right and left training handle actuating shafts (8 or 4, Figures 7-15 or 7-16, respectively) of the training handle packing gland assemblies. It extends simultaneously over the square section of the shaft and in the counterbored recess in each packing retainer (6 or 8).

Each set of inner and outer portion bevel gear clutches is in mesh in either the folded or extended position by means of each gear clutch spring (1). In the folded position both sets of bevel gears are in relation to each other at 90 degrees, with both 45 degrees pitch cone line angles. In the extended position both sets of bevel gears act as universal jaw clutches with all teeth engaged for the operation of the prism tilt or the change of power mechanisms.

p. Detent plunger housing. The detent plunger housing (16, Figure 7-21) is made of brass-rod material, with an over-all length of 0.812-inch. It differs from the Type II periscope detent plunger housing (34, Figure 4-43) in several ways. It is 3/16 inch longer in order to provide a sufficient shoulder section. The shoulder section is provided with a square broached hole to accommodate the square section of the detent plunger (7, Figure 7-21). In the Type II periscope, this square hole provision was made in the training handle hinge (28, Figure 4-43).

7O2. Disassembly. The left or right training handle assembly is disassembled in the following manner:

1. Remove the two pivot screw lockscrews (20 or 13, Figures 7-21 or 7-22 respectively) from the counterbored section seat in the hinge bracket (23 or 16). These lockscrews are unscrewed from tapped holes in the base of the hinge bracket.

2. Place either training handle in the folded position before removing the two training handle pivot screws (6). This prevents damage to the outer bevel gear clutch (4) and reduces the spring pressure. The spring pressure in the folded position is at a minimum.

4. Remove the inner bevel gear clutch . (3) from the hinge bracket (23 or 16). It will slide out easily from the outer side.

5. Remove the detent plunger retaining bushing lockscrew (13, Figure 7-21) from the detent plunger retaining bushing (10). This lock screw is unscrewed from a tapped hole in the detent plunger retaining bushing and spotted recess in the detent plunger (7).

6. Remove the detent plunger retaining bushing (10) from the detent plunger (7).

7. Remove the plunger release knob (8) from the detent plunger housing (16) and detent plunger (7).

9. Remove the detent plunger spring (11) and the detent plunger (7) from the detent plunger housing (16).

10. Remove the two revolving grip lock nuts (30 or 23) from the outer part of the revolving grip (26 or 19). Unscrew the first lock nut using a special wrench (Figure 7-23), then unscrew the second lock nut from the threaded periphery of the revolving grip shaft (28 or 21).

11. Remove the revolving grip (26 or 19) from the handle hinge and fixed grip (24 or 17) and the revolving grip shaft (28 or 21). Remove the graduated index ring (31) or power index ring (30) with the revolving grip (26 or 19). The two segment adjusting screws (20 or 13) and the segment adjusting screw lockscrews (18 or 13) should not be removed unless they are damaged.

13. Remove either of the gear clutch retaining screws (2) from either of the outer portion bevel gear clutches (4) and the revolving grip shafts (28 or 21). The retaining screw is unscrewed from a tapped hole in either revolving grip shaft.

14. Remove either of the outer bevel gear clutches (4) and the gear clutch springs (1). Check either of the outer bevel gear clutches for reference marks with the square section of the revolving grip shafts (28 or 21). Should observations indicate that there are no reference marks, the repairman should mark the parts as they are disassembled for proper reassembly alignment.

15. Remove the taper pins (22 or 15) after rotating the revolving grip shaft (28 or 21) until the small end of the taper pin (22 or 15) is lined up with a drift clearance hole in its respective wall of the handle hinge and fixed grip (24 or 17).

16. Place a drift punch of suitable size in either small clearance hole in the fixed grip and handle hinge (24 or 17).

17. Drive either taper pin (22 or 15) from its gear clutch collar (33 or 25) and the revolving grip shaft (28 or 21).

18. Remove the bevel gear clutch collar (33 or 25) from the evolving grip shaft (28 or 21).

19. Remove the revolving grip shaft (28 or 21) with its inserted key (29 or 22) from the handle hinge and fixed grip (24, or 17).

20. Remove the spring barrel lockscrew (19 or 12) from the fixed grip of the handle hinge (24 or 17) and from its contact with the spring barrel (25 or 18). This lock screw is unscrewed from the tapped hole is the handle hinge and fixed grip.

21. Remove the revolving grip segment stop screw (32 or 24) from the fixed grip of the handle hinge (24 or 17). The stop screw is unscrewed

22. Remove the spring barrel (25 or 18) from the fixed grip of the handle hinge (24 or 17). Unscrew the spring barrel from the fixed grip of the handle hinge, using a special guide bushing and wrench in the load end. Figure 7-24 shows the guide bushing while Figure 7-25 shows the spring barrel wrench. Remove the spring barrel (25 or 18) coil plunger spring (37 or 29), and spring barrel washer (27 or 20).

23. Remove the two assembled plungers (35 or 27) consisting of the plungers, plunger rollers (36 or 28) and plunger roller pins (21 or 14) from the lower reamed holes in the handle hinge and fixed grip (24 or 17). Check reference marks of both plungers to insure proper reassembly alignment. Should observations indicate that there are no factory reference marks, the repairman should make reference marks at appropriate places at disassembly to provide for proper reassembly alignment.

24. It is not necessary to disassemble the plunger roller pins (21 or 14) and rollers (36 or 28).

25. Remove the bearing plate (34 or 26) from the fixed grip of the handle hinge (24 or 17).

26. It is not necessary to remove the detent plunger housing (16, Figure 7-21), and the detent plunger release knob lockscrew (12) from the inner grip of the handle hinge (24).

27. It is not necessary to remove the leather cushions (14 and 15) or (7 and 8) and lockscrews (17 or 9) from the hinge bracket (23 or 16).

7Q3. Reassembly. The left or right training handle assembly is reassembled in the following manner:

1. Check the factory reference marks on each plunger (35 or 27). The plunger should be replaced in the proper reamed hole in the handle hinge (24 or 17).

2. Reassemble the bearing plate (34 or 26) into the fixed grip of the handle hinge (24 or 17). Place the shallow counterbored section seat facing the plunger spring (37 or 29). Align the bearing plate so that its square broached holes fit on the square section of the plungers (35 or 27). The plungers should move freely with the bearing plate, as any tendency of tightening

3. Reassemble the spring barrel washer (27 or 20) into the bottom of the spring barrel (25 or 18) and place the coil plunger spring (37 or 29) on its spring barrel washer.

4. Reassemble the spring barrel (25 or 18) in the fixed grip of the handle hinge (24 or 17). The plunger spring should be compressed sufficiently for the spring barrel to engage into the internal threaded part of the fixed grip of the handle hinge. Screw the spring barrel in until it rests on the shoulder of the fixed grip of the handle hinge, using a special guide bushing and wrench (Figures 7-24 and 7-25). The plunger spring is compressed approximately 1 1/8 inch.

5. Insert the spring barrel lockscrew (19 or 12), screwing it into a tapped hole in the fixed grip of the handle hinge (24 or 17) and further into the threads in the spring barrel (25 or 18).

6. Insert the revolving grip segment stop screw (32 or 24) into the fixed grip of the handle hinge (24 or 17). The segment stop screw extends into a tapped hole in the fixed grip of the handle hinge and projects further to allow the adjusting screws of the revolving grip segment to contact it for full elevation and depression as a stop screw and for high and low power magnification.

7. Reassemble the revolving grip shaft (28 or 21), with its inserted hey (29 or 22) into the spring barrel, (25 or 18), spring barrel washer (27 or 20), coil plunger spring (37 or 29), bearing plate (34 or 26), and handle hinge aid fixed grip (24 or 17).

8. Check the large taper pin hole in the revolving grip shaft (28 or 21) and the outer bevel gear clutch collar (33 or 25) for proper assembly of the collar on the shaft. Tap the collar on the revolving grip shaft (28 or 21) and insert a taper pin (22 or 15). The taper pin should not be drive into the collar and shaft excessively, as it will spread them.

9. Reassemble the outer bevel gear clutch spring (1) over the square section end of the revolving grip shaft (28 or 21) acid assemble the outer bevel gear clutch. (4) compressing the gear

10. Reassemble the graduated index ring (31, Figure 7-21) on the inner shoulder of the revolving grip (26). Align the elongated circumferential slot over the tapped hole in the revolving grip.

11. Insert the index ring actuating screw (38) through the elongated circumferential slot in the graduated index ring (31) and screw it into a tapped hole in the revolving grip (26).

12. Reassemble the power index ring (30, Figure 7-22) on the inner end shoulder of the revolving grip (19). Align the tapped holes in the power index ring and the revolving grip and insert the power indicating screw (11) for the securement of the power index ring.

13. The segment adjusting screws (20 or 13) and the segment adjusting screw lockscrews (18 or 10) were not removed during disassembly. Therefore, it may be necessary to release the segment adjusting screw lockscrews (18 or 10) and make fine adjustments with the segment adjusting screws (20 or 13) to permit full elevation and depression of the head prism, the necessary slack allowance, and a positive engagement of the change of power mechanism.

14. Reassemble the revolving grip (26 or 19) with the assembled graduated index ring (31) or the power index ring (30) and the index ring actuating screw (38) or the power indicating screw (11) over the spring barrel (25 or 18) and the revolving grip shaft (28 or 21). Align the inserted key (29 or 22) in the revolving shaft with the keyseat in the revolving grip. Carry the revolving grip into the fixed grip of the handle hinge (24 or 17).

15. Reassemble both revolving grip lock nuts (30 or 23) on the threaded part of the revolving grip shaft (28 or 21). Secure each lock nut in turn with the special wrench (Figure 7-23).

16. Rotate the revolving grip (26, Figure 7-21) to carry the graduated index ring (31) so that the full elevation and depression position index lines coincide with a stationary index line on the fixed grip of the handle hinge (25). Insufficient or over-travel of the index ring can be corrected by the segment adjusting screws (20). The front adjusting screw provides correction for elevation

17. Rotate the revolving grip (19, Figure 7-22) to carry the power index ring (30) so that the high- and low-power index lines coincide with the stationary index line on the fixed grip of the handle hinge (17). Insufficient or excessive travel of the power index ring is described in Steps 7, 8, and 9 of Section 7V4.

18. Reassemble the detent plunger (7, Figure 7-21) into the square hole in the detent plunger housing (16). Check the detent plunger for proper reference marks so that the plunger 90 degrees angle point is placed in proper mesh to engage into a 90 degrees groove on the inner shoulder of the revolving grip (26).

19. Reassemble the detent plunger spring (11) and the detent plunger spring bushing (9) over the detent plunger shaft (7) and place them in the detent plunger housing (16). Using a special wrench, screw the detent plunger spring bushing into the internal threaded section in the detent plunger housing down to the shoulder. Check the detent plunger to insure that it moves freely.

20. Reassemble the plunger release knob (8) over the detent plunger shaft (7) and the detent plunger housing (16).

21. Reassemble the detent plunger retaining bushing (10) on the detent plunger shaft (7) and secure the above plunger retaining bushing with a lockscrew (13).

22. Reassemble the inner bevel gear clutch (3) into the reamed hole in the hinge bracket (23 or 16).

23. Reassemble the handle hinge (24 or 17) over the side walls of the hinge section of the hinge bracket (23 or 16). Carry the handle hinge in a sufficiently tilted position to allow the outer bevel gear clutch (4) to slide into the center clearance recesses in the inner hinge section

24. The hinge bracket (23 or 16) should be held in a vise to enable the repairman to apply sufficient pressure on the two plungers (35 or 27) and the coil plunger spring (37 or 29). Reassemble both pivot screws (6) into the walls of the hinge section. The pivot screws extend into the tapped holes in the walls of the hinge bracket hinge section (23 or 16).

25. Reassemble the two lockscrews (20 or 13) into the counterbored section seat in the base of the hinge bracket (23 or 16). The lockscrews extend into the body clearance holes and tapped holes in the counterbored section seat in the base of the hinge bracket (23 or 16).

26. Rotate the knurled plunger release knob (8, Figure 7-21) to the observing position.

27. Turn the revolving grip (26) slowly to observe the detent action. The detent should engage at 0 degree elevation.

28. Insufficient or over travel of the zero graduation can be corrected by the two adjusting screws located in the segment section of the revolving grip (26).

29. To make the necessary adjustments to either training handle assembly requires the disassembly of both revolving grip locknuts (30 or 23) and the removal of the revolving grip (26 or 19).

30. The correction of the detent of the left training handle assembly cannot be made until its graduated index ring (31, Figure 7-21) has been corrected for elevation and depression.

31. Both training handle assemblies are adjusted during the procedure outlined in Section 7V4.

The alteration of the hoisting yoke used with the electric hoisting system for use in the

The electric and hydraulic hoisting yoke assemblies are described in the sections discussing their use. Figure 7-26 shows the electric and hydraulic hoisting yoke assemblies. All bubble numbers in Section 7R1 refer to Figure 7-26 unless otherwise specified.

Ill. No.	Drawing Number	Num- ber Re- quired	Nomenclature
1	P-1326-1	1	Hoisting yoke body (electric and hydraulic)
2	P-1326-2	1	Cover ring (electric)
3	P-1326-3	2	Split ring halves (electric)
4	P-1326-4	3	Cover ring lockscrews (electric and hydraulic)
5	P-1326-5	4	Spherical movement and guide stop lockscrews (electric)
6	P-1327-1	2	a. Upper ball bearing race (electric and hydraulic)
7	P-1327-1	2	b. Ball bearings by retainer (electric and hydraulic)
8	P-1327-1	1	c. Lower ball bearing race (electric)
9	P-1327-1	1	d. Phosphor-bronze locating collar (electric)
10	P-1327-2	2	Adjusting nuts for wire rope and hydraulic bracket connectors (electric and by hydraulic
11	P-1327-3	2	7/16 inch wire rope sleeves (electric).
12	P-1327-4	2	Adjusting nut lockscrews (electric)
13	P-1327-5	2	Spherical movement guide stops (electric).
14	P-1327-6	2	Spherical movement stops (electric)
15	P-1448-7	1	Zerk grease fitting (electric and hydraulic)
16	P-1519-1	1	Cover ring (hydraulic)
17	P-1519-2	2	Split ring halves (hydraulic)
18	P-1519-3	1	Lower ball bearing race (hydraulic)
19	P-1520-1	2	Bracket connectors (hydraulic)
20	P-1520-2	2	Plunger rod locknuts (hydraulic)
21	P-1520-3	2	Bracket 11 connector locknuts (hydraulic)
22	P-1520-4	1	Limit stop (hydraulic)
23	P-1520-5	4	Limit stop lockscrews (hydraulic)
24	P-0-0	2	Plunger rods (hydraulic)

The internal part is bored with sufficient clearance for assembly around the body tube of the periscope. The lower face is beveled outward at 30 degrees to allow the spherical movement required with the self-aligning thrust bearing of the electric hoisting yoke. Four equally spaced recesses are provided in the bottom face for assembly of the spherical movement and guide stops (14 and 13) with each stop secured with two lockscrews (5).

The small counterbored section carries the phosphor-bronze locating collar (9) for the electric hoisting yoke, and the lower ball bearing race (18) for the hydraulic hoisting yoke. The large counterbored Section area directly above the small counterbored section, serves as clearance to allow the lower spherical face of the lower ball bearing race sufficient spherical alignment. The lower face of the large counterbored section is beveled at a 45 degrees angle, to permit sufficient clearance for the electric hoisting yoke thrust bearing. This large counterbored section area has no special purpose for the hydraulic hoisting yoke other than serving to utilize the same hoisting yoke body. The small counterbored section and the large counterbored section area carry the upper ball bearing race (6), ball bearings and retainer (7), lower ball bearing,

The small counterbored and threaded section above the large counterbored section area provides a sufficient threaded section to carry the cover ring (2) of the electric hoisting yoke. The outer tapered wall of the hoisting yoke body

The upper face is provided with two tapped holes spotted at assembly to carry the cover ring lock-screws (4).

The outer wall is provided with a drilled clearance hole and a larger tapped hole section for the insertion of a Zerk grease fitting (15).

1. Upper ball bearing race. The upper ball bearing race (6) is one part of four component parts which constitute the self-aligning thrust bearing. It is made of SAE 52100 steel material, hardened and ground. (Refer to the factory detail drawing.) This race is cylindrical in shape, with a bored hole and counterbored section. The bored hole has nominal clearance over the outer tube (2, Figures 4-15, 6-2, and 7-2). The periphery is beveled at a 35 degrees angle to allow sufficient clearance inside the yoke for self-alignment, with a narrow shoulder section of the periphery remaining to maintain sufficient wall strength. The counterbored section carries both halves of the assembled split ring (3) which fits in the undercut groove in the lower part of the outer tube body. The lower face of the race has a cylindrical concave groove 1/16 inch deep and a pitch diameter of 8.470 inches. All sharp corners are stoned off to prevent cracking and chipping the cylindrical concave groove in its lower face rests on the 38 half-inch ball bearings in the retainer (7).

2. 38 half-inch ball bearings and retainer. The 38 half-inch ball bearings and retainer (7) are a part of the self-aligning thrust bearing made of stainless steel material and are located in a bronze retainer with 38 equally spaced ground spherical seats. The ball bearings roll between the cylindrical concave grooves in both the upper and lower ball bearing races (6 and 8) in the electric hoisting yoke, to carry the weight of the periscope. The bronze retainer is cylindrical with a bored hole. It has a nominal clearance over the outer tube, and a nominal wall thickness, with all sharp corners beveled.

3. Lower ball bearing race. The lower ball bearing race (8) is a part of the self-aligning thrust bearing and is made of the same material as the upper race. It is shaped cylindrically with a spherical convex face.

4. Phosphor-bronze locating collar. The phosphor-bronze locating collar (9) is a part of the self-aligning thrust bearing. It is cylindrical in shape and is bored with sufficient clearance to allow approximately 3/8 inch self-alignment on each side. The periphery is a sliding fit in the small counterbored section in the hoisting yoke body (1). The collar has a spherical concave seat to carry the thrust bearing parts (6, 7, and 8).

The self-aligning thrust bearing assembled in the hoisting yoke body serves to carry the weight of the periscope plus the downward force created by the water pressure acting on the periscope. It also allows the periscope to turn easily through azimuth. The self-alignment principle serves to provide a means for equalizing any difference of the wire rope cable lengths which would otherwise result in the binding of the thrust bearing. The self-alignment bearing and clearance provided allow for a shortening or lengthening of each cable of 0.218 inch or a cable differential of 0.437 inch.

c. Thrust bearing. The thrust bearing of the hydraulic hoisting yoke is similar to the self-alignment thrust bearing, as it utilizes the upper ball bearing race (6) and 38 half inch ball bearings and retainer (7). The lower ball bearing race (8) and phosphor-bronze locating collar (9) are omitted. A new lower ball bearing race (18) is made of the same material as the upper race (6). The race is cylindrical, with a bored hole having sufficient wall thickness to carry the weight of the periscope. All corners are chamfered to strengthen the race, thus preventing it from cracking as a result of the shock created by the hydraulic hoist system. The upper face is provided with a cylindrical concave groove similar to the lower face of the upper ball bearing race (6). This race fits into the small counterbored

d. Split ring. The split ring (3) for the electric hoisting yoke is made of phosphor-bronze material. It is shaped cylindrically, with the flange section undercut a tap fit in the counterbored section in the upper ball bearing race. The bore conforms to the undercut diameter of the outer tube undercut groove, with the width of the inner shoulder a tap fit in the above groove.

The flange section is counterbored with a spherical concave seat with an additional filleted cylindrical recess. The spherical concave seat allows the split ring sufficient clearance inside of the counterbored spherical overlapping guide section of the cover ring (2). The split ring carries the weight of the periscope in the counterbored section in the upper ball bearing race (6).

e. Split ring. The split ring (17) for the hydraulic hoisting yoke is made of phosphor-bronze material of nominal wall thickness. It is made cylindrical with the bore conforming to the undercut diameter of the outer tube undercut groove, and the width of the split ring a tap fit in the above groove. The ring is slotted through its center axis, for assembly to the outer tube. Both halves of the split ring serve the same purpose as the split ring (3) of the electric hoisting yoke, that of carrying the weight of the periscope. The counterbored section of the upper ball bearing race (6) is a tap fir over both assembled halves of the split ring.

f. Cover ring. The cove ring (2) for the electric hoisting yoke is made of phosphor-bronze material add is shaped cylindrically. The periphery is provided with a narrow flange section in which two clearance holes are countersunk for the lockscrews (4). These lockscrews secure the cover ring after adjustments have been made for the proper clearance. The undercut threaded, section of the cover ring engages in the internal threaded section in the hoisting yoke body (1) the upper part has a raised overlapping guide section bored with sufficient clearance around the outer tube for self-alignment. The inside is counterbored at an angle of 16 degrees to the depth of the filleted section, with an additional counterbored section beveled at 37 degrees.

The spherical overlapping guide section is provided with a spherical convex shoulder that rests snugly on the spherical flange section of the split ring (3). The upper face is provided with eight equally spaced holes of shallow depth on an 8 1/2-inch diameter circle for the insertion of projecting pins of a spanner wrench used in the assembly or removal of the cover ring. The cover ring secures the hoisting yoke together, thus retaining the thrust bearing against the split ring halves with sufficient clearance for free rotation.

g. Cover ring. The cover ring (16) for the hydraulic hoisting yoke is made of phosphor-bronze material and is shaped cylindrical. The periphery is provided with a flange section with an undercut threaded section. The threaded section engages into the internal threaded section in the hoisting yoke body (1). The ring is bored with sufficient clearance over the outer tube, with a counterbored section to allow sufficient wall thickness. A small cylindrical shoulder is provided for the adjustment of the thrust bearing, so that it has sufficient free rotation. The upper face is beveled at a 45 degrees angle toward its bore, allowing a narrow shoulder section. The upper face of the ring has eight equally spaced holes of shallow depth for the projecting pins of a spanner wrench, to assemble or remove the cover ring.

h. 7/16-inch wire rope sleeve. The two 7/16-inch wire rope sleeves (11) are made of corrosion-resisting steel material. The body section of each has the periphery threaded to carry adjusting nuts (10). Two opposite vertical slots are provided 180 degrees apart in the threaded section, the entire length and are cut to a depth below the root of the threads. The recess slot on each side receives the inserted adjusting nut lockscrew (12) which extends inward from the adjusting nut. Each half turn for adjustment of the adjusting nut can be secured by the lockscrew to maintain its adjustment.

The square section located in the lower part provides a means for attaching a wrench, thus restricting the sleeve from turning while taking up the adjusting nut, and preventing any twist in the wire rope. A narrow undercut radius

The center axis of each has a reamed guide hole of short length for the wire rope, with the lower part tapered. The wire rope is inserted through the reamed hole and extends a sufficient length for spreading. The strands are back spliced, and separated after splicing, to provide an enlargement in the tapered section. The wire rope is now carried back with the built-up section in the tapered part of the sleeve. The sleeve is heated and filled with molten lead, which adheres to the separated wire rope strands and fills up the tapered section. It also adheres to the bored tapered walls of the sleeve. The lead prevents the wire rope strands from unraveling and provides a positive means of supporting the weight of the periscope. The sleeves are assembled in the cable projections of the hoisting yoke body (1) with the weight of the periscope carried on the convex face of the adjusting nuts in contact with the lower concave seat in each opposite cable projection.

i. Adjusting nuts. The two adjusting nuts (10) are made of corrosion-resisting steel material of hexagon design. The upper face of each nut is provided with a convex face and fits into the lower seat in each cable projection of the hoisting yoke body (1). The center axis is provided with a bored and tapped hole, and engages on the threaded periphery of the 7/16-inch wire rope sleeves (11). The adjusting nut provides the adjustment to the wire rope with a tapped hole in one of the hexagon flats for the insertion of an adjusting nut lockscrew (12). This lockscrew maintains each half turn of adjustment, thus preventing slack in the wire rope. The adjusting nuts are used for the hydraulic brackets by not using the lockscrews (12) but using two additional locknuts (21).

j. Spherical movement guide stops. The two spherical guide stops (13) are made of corrosion-resisting steel material of nominal thickness, width, and length. Two clearance holes with counterbored recesses are provided for lockscrews (5). Two corners of the stop are rounded for assembly in recesses 180 degrees apart in the lower face of the hoisting yoke body (1). The guide stops

k. Spherical movement stops. The two spherical movement stops (14) are similar to the spherical movement guide stops (13) in length and thickness. The clearance holes and counterbored recesses are similar, and are attached to the recesses 180 degrees apart and perpendicular to the recesses for the spherical movement guide stops (13). The movement stops are narrower in width, and are provided with a concave seat conforming to the contour of the outer tube. The spherical movement stops when assembled project inward toward the axis of the outer tube of the periscope to restrict the self-alignment of the thrust bearing to 3/8-inch movement.

l. Bracket connectors. The two bracket connectors (19) for the hydraulic hoisting yoke are made of corrosion-resisting steel material. Each bracket connector has an offset section for connection to the plunger rods of the hydraulic hoist. By utilizing the electric hoisting yoke body (1) and using both cable projections, it was necessary to design an offset bracket to accommodate the greater center distance of both hydraulic hoist plunger rods (24).

The large flange section of the bracket connector is concentric with the part attached to the cable projections of the hoisting yoke body (1). The large flange section is sufficiently thick with the connector section offset from the center axis a distance of 5/8-inch. The offset connector section is cylindrical, with a tapped hole in its axis of sufficient depth to carry the threaded part of the plunger rods (24) of the hydraulic hoist. The large flange section rests on the face of the cable projection, with a concave section of the shoulder removed to allow sufficient clearance for the removal of the cover ring (16). The removed section is located opposite the offset connector section, and has a concave seat to conform to the contour of the cover ring.

The taper section below the large flange section fits in the tapered hole in each cable projection of the hoisting yoke body (1) with a threaded section that carries an adjusting nut (10) and a locknut (21). The plunger rods (24)

m. Limit stop. The limit stop (22) for the hydraulic hoisting yoke (1) is made of phosphor-bronze material. The stop is made from a section of a large cylindrical ring having a flange section. The ring is bored and counterbored with a 14 degrees 2' wall to conform to the periphery of the hoisting yoke. The counterbored section has a stepped shoulder that rests on the upper face of the hoisting yoke body. Four clearance holes are provided in the wall to secure the stop to the periphery of the hoisting yoke body, by means of four tapped holes spotted at assembly for lockscrews (23). Refer to the hoisting yoke body plan for the correct location of the limit stop. The cylindrical ring will produce 21 full limit stop pieces which are cut at approximately an angle of 16 degrees 28' width. The flange section is finished with a 7-inch radius located from a 12.250-inch diameter circle.

The limit stop of the hoisting yoke body serves to restrict the elevation of the periscope at the observing position. When the periscope is elevated to the observing position by means of the TO RAISE position of the ship's hydraulic system control valve, the limit stop contacts the operating linkage of the control valve. The linkage shifts the control valve to the NEUTRAL position, closing the supply and return ports. The trapped oil in the lower part of the plunger pistons in the cylinders will hold the periscope in the elevated position.

7R2. Operation of hydraulic control valve of the hydraulic hoist system. The control valve of this

1. The NEUTRAL position of the control valve allows the supply and return ports to remain closed.

2. The TO RAISE position of the control valve allows the supply port to open to the high-pressure side of the ship's hydraulic system. The high-pressure system supplies sufficient oil volume below the plunger pistons for elevation. This volume of oil below the pistons is under an approximate pressure of 600 psi.

3. The TO LOWER position of the control valve closes the supply port, and the return port is open to the low-pressure side of the hydraulic system. The weight of the periscope action on the volume of oil below the plunger pistons allows the periscope to be lowered into the well against the oil in the cylinders at a slightly faster rate of speed than for elevation.

There is no limit stop in the well to restrict the lowering of the periscope. The bumper is the only stop and when contacting the bumper, the periscope has an approximate bounce of 3/8-inch. Elevation of the periscope is accomplished in approximately eleven seconds, while it is lowered in approximately seven seconds.

The pressure on the return side of the hydraulic system, plus whatever friction exists in the return piping, is the resistance pressure on which the plunger pistons allow the periscope to be lowered of its own weight.

a. Magnifying power. While both, powers are the same as those of the Type II or Type III, the arrangement of telescopes in the Type IV for obtaining the 6X and 1.5X magnifications is different; therefore, omit the list of component telescopes in Section 4U1, 2 and substitute the following list:

b. Field of view. Same as Type III.

c. Image brightness.

Type IV Periscope	Low Power	High Power
Total of axial thicknesses	248 mm	233 mm
No. of air-crown surfaces	15	14
No. of air-flint surfaces	11	8
No. of silvered-glass surfaces	2	2

Sources of loss and the transmission resulting therefrom are:

Absorption, by glass	73.20%	76.70%
Reflection, by glass-air	28.31%	35.09%
Reflection, silver-glass	88.36%	88.36%
Theoretical TRANSMISSION (not coated)	18.8%	23.8%

No figures are available for actual measurements of the Type IV with optics uncoated and coated; however, approximately double the above percentages of incident light would be transmitted if the optical elements have the magnesium fluoride coating.

2. Effect of pupillary size. In respect to the effect of pupillary size, see Section 4U4, b. The Type IV periscope is designed for night use and, consequently, differs from the preceding two types in that it has an exit pupil of 7-mm diameter, whereas the exit pupil of the two day periscopes is 4 mm in diameter. If the same amount of light were to enter, for example, the Type II and the Type IV, the latter would permit about 3 times as much light (49/16) to emerge because of the larger area of it exit pupil. It must bet remembered, however, that at night there is usually a great deal less light at the target.

Also, the exit pupil of the Type IV is not quite a full circle inasmuch as the two main objectives have a minor chord segment ground off each to permit space in the instrument for the waveguide. The area then of the actual exit pupil is only 99.5 percent of what it would be if the two objectives were full circles. Actually, the, deformity of the exit pupil is not apparent at the eye point.

3. Central and oblique brightness. This is essentially the same as that in the Type II.

d. Head prism. The head prism is identical to that in the Type III, except that it is larger, thus allowing a 42-mm entrance pupil.

7S2. Principles of target ranging devices. For principles of the telemeter, refer to Section 4U7-a. Omit Section 4U7, b, because the Type IV periscope is not equipped with a lower (split) objective lens or stadimeter.

The ranging in the Type IV is accomplished by means of an ST electronic device, which is attached to the base of the periscope.

7S3. Optical maintenance. a. Arrangement of optical elements. See Figure 7-27, page 378.

b. Method of tracing rays. This section is similar to the Type III. See Figure 7-27, page 378.

c. Method of removing parallax caused by gas pressure. This section is identical to the Type III except for the distances the various lenses must be shifted:

1. For all the lenses following the telemeter lens, the periscope eyepiece lens, before gassing, must be shifted toward the lower objective lens an amount equal to 1.25 mm. This is accomplished by setting the eyepiece lens to -0.25 diopters. Then, after the instrument is gassed and the eyepiece shifted back to its zero setting, it will be found that there is no parallax in that part of the system following the telemeter lens.

2. To compensate 1for lenses preceding the telemeter lens, the following target distances are used:

Type IV Periscope	Target Distance
Periscope in high power	4,800 feet
Periscope in low power	62 feet

The setting of the image-forming optics must first be performed for the system in high power. This setting of the upper-main-telescope eyepiece lens must not be disturbed when the low power compensation is undertaken.

2. Reassembly of the lower telescope system Part I together with the upper telescope system Part II. Reassemble the upper part of the third inner tube section (1, Figure 7-10) on the lower part of the fourth inner tube section lower end coupling (40, Figure 7-7). Check reference marks in similar manner to Step 1. Secure them together by the insertion of 24 lockscrews (10, Figure 7-10). These lockscrews are inserted in countersunk clearance holes in the upper part of the third inner tube section an screwed into the tapped holes in the lower alignment support section of the fourth inner tube section lower end coupling.

3. Reassembly of the lower, telescope system Part II eyepiece skeleton assembly together with the lower telescope system Part I. Reassemble the eyepiece skeleton (42, Figure 77-11) to the lower flange of the first inner tube section Figure 7-10). The alignment dowel pin (37, Figure 7-10) in the lower flange of the first inner tube section engages in a reamed hole in the upper small shoulder flange of the eyepiece skeleton to reestablish the factory alignment. Secure both flanges together by the insertion of seven lockscrews (40, Figure 7-11). These lockscrews are inserted in clearance holes in the upper flange of the eyepiece skeleton and screwed into the tapped holes in the lower flange of the first inner tube section.

5. Reassembly of the head prism drive shaft and its continuations. Reassemble the head prism drive shaft (33, Figure 7-10) and its continuation (48, Figure 7-11) with the assembled head prism drive shaft universal coupling (34, Figure 7-10) to the connection point located at the upper part of the first inner tube section. The lower stub end of the shaft continuation (48, Figure, 7-11) with the inserted woodruff key (46) is carried downward through the elongated holes in the lower flange of the first inner tube section (31, Figure 7-10) and the small and large flanges of the eyepiece skeleton (42, Figure 7-11). Check the alignment of the inside keyway of the universal coupling, turning the shaft continuation for proper engagement of the inserted woodruff key.

6. Reassembly of the lower end of the long head prism drive shaft section to head prism drive shaft universal coupling. The stub end of the head prism drive shaft section continuation (15, Figure 7-10) should be slid clear of the upper flange of the first inner tube section to allow the upper part of the head prism drive sha