Patent GB-1468701-A (GB)
Title: Still cameras
IPC: G03B17/00
Filed: 1974-03-20
Abstract: 1468701 Film transport mechanism AGFAGEVAERT AG 20 March 1974 [27 March 1973] 12295/74 Heading G2A A camera for film having one perforation per frame has a reciprocable film transport member 1, a member 10 arranged to move during film transport, a feeler 11 arranged to drop into a perforation and control a locking member 12 which terminates film transport by engaging member 10, but is brought out of engagement therewith during the return of member 1 to its rest position after completion of film transport. As shown, the film transport member 1 is formed as a spring-loaded slider, having two rack portions 1a and 1b. Rack 1a meshes with a member 3 which, via a gear-wheel 5, drives the take-up spool 2 to wind on the film. At the same time, via a cam portion 3a and cam follower lever 8, a flash-cube socket 7 is rotated. The slider 1 has to be operated twice to perform a complete film transport movement, and does not return fully to its rest position after the first stroke, no further rotation of socket 7 occurring on the second stroke. The feeler 11, and a feeler slider 13, are mounted on a spindle 108, and feeler 11 is coupled by a spring 113 to a locking member 12. Member 12 is mounted on a spindle 109, together with a lever 16, to which it is coupled by a spring 110 and spaced by a lug 12g. A pawl 14 is pivoted on a spindle 111, and has a tooth 14a which can be urged into locking engagement with a toothed portion of wheel member 10 by a spring 112. Fig. 1 shows the position after film transport. After shutter release, pawl 14 moves from the position in full line to the position in broken line, so locking wheel 10 against clockwise, but not anti-clockwise, rotation. At this time the feeler 11 is in a perforation, but a lug 12a on member 12 is in engagement with a lug 13b on slider 13 so that feeler 11 is kept away from the edges of the perforation, and exerts no pressure on the film. During the first slider movement, in the direction of arrow 104, the rack portion 1b drives wheel 10 anti-clockwise. The film is transported a certain distance, and the feeler 11 moves with it until lifted out of the perforation by a member 18, and then springs back the other way as far as a stop 19. The anti-clockwise movement of wheel 10 brings a pin 10a thereon out of engagement with locking member 12, which is thus released for clockwise movement. It is arrested first by lug 14b of pawl 14, and then, as that is displaced back to its full line position by member 15 during tensioning, by a lug 13a on slider 13 position of Fig. 2 (not shown). The slider 1 is now released to return towards its rest position, but does not reach this completely because pin 10a comes up against the edge 16a of lever 16. Slider 1 is now moved a second time in direction 104, and after completion of one picture step, feeler 11 drops once more into a perforation, and is carried along by the film until lug 13a slides into a recess 12b in member 12, which is thus now able to pivot clockwise, and engage and lock wheel 10 by means of a tooth 12c position of Fig. 3 (not shown). Lever 16 pivots with member 12, and so is out of the path of pin 10a. When slider 1 is released, it now runs back completely into its rest position, wheel 10 also running back clockwise into its rest position. Pin 10a meets a lug 12h on member 12, and pivots the member out of engagement with wheel 10. The lug 12a of member 12 also moves away from the feeler 11, leaving it in the perforation, but lifted away from the edges thereof. The full line position of Fig. 1 is thus reached again.