3.6.1 Shield assembly.- With the plunger depressed (disengaged),
maximum operation of the handle shall operate the shield through full
operation; open for viewing and closed for protection. When the shield is
fully open and when the shield is fully closed the plunger shall engage
and lock the handle when the plunger is released.
3.6.2 Holding features. - A medium which incorporates the critical
mounting surfaces of a Periscope M31 shall be utilized for insertion and
removal on the mount to determine the following functional requirements.
18.104.22.168 Release grip. - When the medium is inserted into the
periscope mount, the mount shall automatically latch the medium in the
fully inserted position so that it cannot be removed without actuating
the release grip. When applying an upward force of 15 to 20 pounds on the
medium, a direct pull of not more than 12 pounds on the release grip shall
actuate the grip to it's full disengaged position. Full diengagement of
the grip shall allow removal of the medium from the periscope mount with-
out restrictions. The recorded pull on the grip shall not change by more
than 3 pounds when the mount is subjected to the temperatures specified
22.214.171.124 Lever. - When the plunger of the Level Assembly 8298434 is
depressed and lever pushed to its fullest forward position and locked
by releasing the plunger, the medium shall be secured in the mount. sub-
sequent to the application of a 10 pound pressure applied horizontally to
the front and rear of the medium at its lowest point, the medium shall be
within .0005 inch of its original location when measured horizontally at
that point. This requirement shall be met following the release of each
of the pressures applied.
3.6.3 Headrest travel.
126.96.36.199 Headrest, horizontal travel. - Plunger 8262113 shall engage
in the detent at each end of the slide and firmly secure the headrest
in each position. When the plunger is freed from the detent, the head-
rest shall slide smoothly without interference when pushed right and left
between the detent positions.
188.8.131.52 Headrest, rotational travel.- The headrest assembly shall
provide full movement without interference when rotated through the maximum
travel range permitted by Bracket 8229065, and shall not move when left
in any position within the rotational travel range.
3.6.4 Adjustment range. - Each Screw Assembly B7639274 shall be
loosened and the headrest assembly shall be adjustable through maximum
movement permitted by the elongated slots in the assembly without
restriction or force.