Patent GB-1509690-A (GB)
Title: Film winding and shutter actuating mechanism suitable for a cartridge film type camera
IPC: G03B17/42
Filed: 1975-09-29
Abstract: 1509690 Winding and shutter mechanism RICOH CO Ltd 29 Sept 1975 [30 Sept 1974] 39704/75 Heading G2A A camera has a film winding member consisting of a slidable drive bar 12, a shutter cocking member consisting of a slidable bar 16 which moves with bar 12, and a sensing means 35 which can engage in a film perforation to sense the film position, and accordingly locks the film transport against further movement. Fig. 1 shows the position after shutter release, and before film winding. Bar 12 is biased into its lowest position by a spring 15, and bar 16 is also in its lowest position, urged upwards by a spring 18 so that a lug 12c thereon abuts against a lower edge portion of bar 12. Release of the shutter has caused the cocking pin 19 to move downwards into contact with a lug 16a on bar 16. A pawl arm 20a is spring urged anticlockwise into contact with a serrated edge portion 12b of bar 12, so allowing only upward movement of bar 12. The shutter release member (47) Fig. 2 (not shown) is spring urged to the left, and locked against movement by a stop lever (52'a). Initially the film leader portion, which has no perforations, has to be wound on to take-up spool 3. Rotation of the film winding lever causes bar 12 to be moved upwards (direction A), which draws bar 16 up with it. Lug 16a moves pin 19 upwards to cock the shutter. When bar 16 reaches the limit of its travel, bar 12 can still move further, tensioning the spring 18. A slanted edge 12d of bar 12 engages and pivots a latching lever 41 clockwise. This actuates a reset lever 39 which allows the sensing lever to be pivoted so that its arm 35a engages against the film 2a. Upward movement of bar 12 also causes a rocker arm 7 to pivot clockwise, so that a pawl 8a thereon engages in the teeth of a gear 5, which in turn drives a gear 4 and hence the take-up spool 3, the film moving in direction C. Pin 12c pivots pawl arm 20a out of engagement with the serrated edge 12b, so that when the film winding lever is released, bars 12 and 16 can be pulled down again to their original position. This operation is repeated a number of times until the first frame of the film is positioned in front of the exposure window (56) (Fig. 2). At this point the sensing arm 35a drops into a film projection. Slight additional movement of the film pivots the sensing lever clockwise, so that, via a latch lever 37, a pawl lever 29 is released, to be spring urged clockwise. A pawl 29a of lever 29 engages in a ratchet wheel 26, so stopping the film wind. To release the shutter and effect an exposure, the release member (47) is released and moves to the right, bar 12 being now in such a position that this is not prevented. The reset lever 39 pivots clockwise, which causes the sensing arm 35a to be retracted from the film perforation, and pawl 29a is pivoted out of engagement from ratchet wheel 26, so that the film can now again be wound. All the parts of the mechanism are now restored to the Fig. 1 position. In winding on the film to bring the next frame into the exposure position, only a single winding stroke is necessary.