TM 11-6720-242-35
4-19. Removal and Disassembly of the Carriage
4-16. Removal and Replacement of Focal Plane
Assembly Components
Plate
(fig. 34 (1))
a. Removal.
a. Removal. Remove four screws (2) securing focal
(1) Remove the setscrew (6) securing the shaft of the
plate (1) to the housing (129). Remove two locating
shaft and bushing assembly (5) to housing (129).
pins (3) from housing (129).
b. Replacement.
Remove the shaft. The two bushings will remain in the
carriage.
(1) When installed, the focal plane plate (1) must
(2) Remove the two setscrews (8) securing the shaft (7)
conform to the following precise dimensions with
in the carriage (4). Remove the shaft (7) with are to
relation to the shutter blade.
prevent damaging the lens assembly (9).
(a) With shutter blade (121) (fig. 3-3 (4)) closed to the
b. Disassembly.
limit of its mechanical stop and the phasing hole in
(1) Remove the cam follower arm (para 417).
housing (129) concentric within 0.001 inch with the
(2) Remove the retainer ring (31) and spacers (32-34)
phasing hole in the cam of cam-shaft assembly (82) (fig.
from the shaft of the pivot plate assembly (25). Restrain
the spring (26) and withdraw the shaft of the pivot plate
of the shutter blade (121) must be parallel with the focal
assembly (25) from the carriage (4). Withdraw the
plane slit within 0.0005 inch. The clearance between
upper and lower diaphragm blades (23 and 24) from the
the ends of the shutter blade and focal plane slit must
diaphragm blade guide (21).
be a minimum of 0.001 inch. The minimum opening
(3)
Remove the three screws (22) securing the
must be 0.020 + 0.001 inch.
diaphragm blade guide (21) to the carriage (4).
(2) Position the focal plane plate (1) (fig 33 (1)) on
(4) Remove the four screws (10) securing the lens
housing (129) and adjust for the dimensions stipulated in
assembly (9) to the carriage (4). Remove the lens
(1) (b) above (3) Secure with the four screws (2).
assembly (9) and the shims (1114).
4-17. Removal and Disassembly of Cam Follower
4-20.
Reassembly and Installation of Carriage
Arm (IMC)
Assembly
(fig. 33 (1))
(fig. 3-3 (1))
a. Removal.
a. Reassembly.
(1) Remove the aec assembly from the camera body
(1) The distance from the top surface of the focal plate
(2) Remove the shoulder screw (16) securing the cam
(1) to the surface of the lens mounting flange (9), which
follower arm (15) to the carriage assembly (4).
mates with the carriage assembly (4), must be held to
(3) Remove the spring (19).
2.8750.001 inches with the lens assembly mounted in
b. Disassembly. Remove the retaining ring (20),
the carriage assembly (4). Use the shims (11-14) to
bearings (18), and cam follower (17) from the cam
establish this measurement, then secure the lens
follower arm (15).
assembly with the four screws (10).
(2) Coat about three-sixteenths inch of the top and
4-18. Reassembly and Installation of Cam Follower
bottom outer surfaces of the both dial phragm blades
Arm
with solid film lubricant.
(3) Insert the lower diaphragm blade (24) first and the
a. Reassembly. Replace the cam follower arm (15) and
upper diaphragm blade (23) next in the diaphragm blade
guide (21). Secure the blade guide to the carriage (4)
reassemble the parts in reverse of the disassembly
with the three screws (22).
procedures (b above).
(4) Insert the shaft of the pivot plate assembly (25)
b. Installation. Position the cam follower arm (15) and
through the spring (26), and on through the hole in the
the assembled parts on the carriage assembly (4) and
diaphragm blade guide (21) and the hole in the carriage
secure with a replacement shoulder screw (16).
assembly (4). The two
Change 3 4-16
