Patent GB-729888-A (GB)
Title: Improvements in or relating to roll film photographic cameras
IPC: G03B17/42
Filed: 1953-09-23
Abstract: 729,888. Photographic roll-film cameras. KODAK, Ltd. Sept. 23, 1953 [Sept. 24, 1952], No. 26218/53. Class 98 (1). In a camera in which an interlock is provided between the film winding and shutterreleasing mechanisms to ensure alternate operation thereof, a shifting member is mounted on the camera body for movement into engagement with said interlock to disengage it from the film winding mechanism independently of the shutter-releasing mechanism. As shown, the interlock comprises a lever 20 pivoted at 19 and spring-urged anticlockwise to bring its pawl arm 21 into engagement with a ratchet wheel 18 on the manually rotatable take-up spool shaft 17 when its other arm 35 moves into the path of a conical portion of a shutter-tripping button 30, and a concentrically pivoted lever 45 urged clockwise by a spring 39 between it and the pawl arm 21 of the lever 20 capable of engaging beneath the shutter trigger-operated plate 56 which is carried by a spring arm 52 engaging in a slot in a downturned lug 49 about which the plate can rock vertically in a depression in the mechanism supporting plate 13 (Fig. 3, not shown) to trip the button 30. With the parts as shown after an exposure, on rotating the shaft 17 the film is wound on until first the nose 38 on a pawl pivoted at 37 and urged clockwise by the engagement of the spring 39 with the lug 41 thereon and then a lug 36 on the lever 20 fall into a recess 16 in a film driven metering disc 15 when the ratchet and pawl 18, 21 re-engage to lock the shaft 17 and simultaneously a lug 24 on the lever 20 moves the lever 45 anticlockwise to free the plate 56 for a further exposure. On depressing the shutter trigger the plate 56 depresses the button 30 to trip the shutter and on release of the trigger the plate 56 is locked by an upturned lug 60 on the lever 45 moving beneath it, the lever 45 engaging the lug 24 on the lever 20 and rotating it clockwise to free the take-up spool shaft, the lock being held disengaged by the nose 38 moving clockwise so as to ride on the periphery of the metering disc 15 as shown. An intentional double exposure may be made by manually rocking anticlockwise the arm 62 when the nose 38 and lug 36 re-enter the recess 16 relocking the film wind and freeing the plate 56. After the last exposure, to wind off the trailing strip of the film without interruption, an arm 76 of a pivoted lever 71 is manually depressed to an extent limited by engagement with the shaft 14 of the metering disc when a nose 72 on it moves the lever 20 to free the film winding lock while maintaining the nose 38 and lug 36 in the recess 16 in the metering disc a friction clutch being provided between the disc and the film driven shaft 14 so that a setting adjustment of the disc is not necessary when a new film is inserted. To do this and to avoid having to hold the arm 76 depressed during the initial winding with the camera back open, a further lever 77 pivoted coaxially with the lever 71 has an arm 80 projecting through the casing and spring-urged clockwise so that a lug 78 on it moves the lever 71 to disengage the film winding lock. On closing the camera back, this moves the arm 80 to the position shown freeing the lever 71 which must then be manually depressed by the arm 76 until the numeral "1" on the backing paper has been wound into the window in the camera back.