TM 11-6720-239-35
pressed, the following actions pertinent to the
shutter release occur:
a. General. The camera focusing mechanism is
(1) Force exerted on shutter release button
operated by the use of focus button 1 (right) and
2, transmitted through the cable assembly to the
focus button 1 (left). The two buttons are at-
shutter release tip, forces the shutter release tip
tached to opposite sides of the focus bar assembly.
up.
The focus bar assembly is connected to the inner
frame (top) by a detent slide. The inner frame
(2) As the shutter release tip travels upward,
(top), in turn, is connected by a shutter shaft
it forces normally open battery switch S1 to close,
sleeve to the shutter assembly. The inner frame
and trips the slide latch.
(bottom) is attached to the camera body and the
(3) Closing battery switch S1 completes a
shutter assembly by track guides. The U-frame
circuit which energizes the electromagnet. The
assembly attaches both the top and bottom inner
electromagnet now holds the closing blade in its
frames by means of link pivots. The three compo-
cocked position.
nents in turn serve to hold the shutter assembly in
(4) When the slide latch is tripped, the
cocking slide is released and snaps back to its
original position.
(5) As the cocking slide returns to its origi-
nal position, a roller on the slide strikes a tab on
the blade latch, forcing the blade latch down.
(6) As the blade latch is forced down, it re-
leases the opening blade, allowing it to snap for-
ward. Light now passes through the aperture and
the hole in the opening blade to expose the nega-
tive.
(7) As the blade latch releases the opening
blade, it also opens timing switch S2. The timing
circuit now begins to operate.
(8) When the average scene light has allowed
the photocell to pass the correct amount of cur-
rent through the timing circuit, the electromagnet
is deenergized and the closing blade snaps shut.
Figure 14. Focusing mechanism.