Patent GB-760221-A (GB)
Title: Improvements in or relating to photographic roll film cameras
IPC: G03B17/42
Filed: 1952-12-12
Abstract: 760,221. Photographic roll-film cameras. HEIDECKE, R., [trading as FRANKE & HEIDECKE]. Dec. 12, 1952 [Jan. 31, 1952], No. 31562/52. Class 98(1) In a roll-film camera having a setting- type shutter and film-winding mechanism including a ratchet wheel and a locking pawl engageable with the wheel under the control of a notched metering disc rotated by means driven from the film, a manually actuable member having a co-operating latching pawl is movable in opposite directions for setting and releasing the shutter,' the latching pawl and the locking pawl being coupled together in such a manner that with either pawl in operative position the other is inoperative, the latching pawl thus holding the actuating member against movement to set the shutter until the film has been advanced, following an exposure. to a new exposure position and locked therein, and thereafter the latching pawl, following setting and release of the shutter, re-engaging with the actuating member and causing the locking pawl to release the film winding mechanism. A manually operable cam may be provided to move the latching pawl out of latching position independently of the film winding mechanism. As shown, the film metering, film wind locking, and exposure counting. mechanisms are closely similar to those described in Specification 709,981. The shutter, which has means preventing actuation of the trigger unless the shutter has been set, is provided with an actuatorring 36 having lugs 38, 39 and a handle 37, movements in opposite directions causing. lug 38 to set the shutter by means of lever 33 and lug 39 to release the shutter by means of trigger 34. With the parts as shown, operation of the shutter is prevented since an exposure has been made so that the shutter is not set and the nose 42 of a anti-clockwise urged pivoted latch 41 engages in a recess 43 in the ring 36 and prevents the clockwise setting movement, while the film-winding shaft 3 is free. When one frame has been wound on, thefinger 25 on the anti-clockwise urged threearmed lever 22 falls into a recess 29 in a metering disc 20 rotated by the film movement, so that the pawl 23 on the lever engages a ratchet wheel 24 on the shaft 3 to latch it. Simultaneously, the forked end 26 of another arm of the lever embracing a pin 27 on a slide 28 moves the latch clockwise, the tail 49 of the latch resting in a cut-out 50 in the ring 36. The shutter may then be set and thereafter released, the film wind being locked until during the anti-clockwise trigger tripping movement of the ring, the tail 49 of the latch 41 is cammed outwardly by the end 150 of the ring 36 when the latch moves the slide 28 downwardly and so removes the pawl 23 from the film wind ratchet 24 and the finger 25 from the notch 29 in the metering disc 20 which thereupon by virtue of a spring tensioning lost-motion device between it and the film driven gearing rotates sufficiently under the action of the tensioned spring to prevent the finger 25 reentering the notch 29.. In a modification, provision is made for also operating the shutter independently of the film winding mechanism. To this end, the actuator ring latching nose is not formed on the lever 41 but on an anti-clockwise urged bellcrank lever having a pin engageable by an eccentric on the lever 41 which may be turned to move the bell-crank lever clear of the recess 43 in the ring 36. By this means, the camera may be used with cutfilm and plate adapters or roll-film slides: having their own winding means.