Patent GB-849870-A (GB)
Title: Improvements in and relating to cameras
IPC: G03B19/04
Filed: 1958-12-22
Abstract: 849,870. Photographic magazine cameras. WEDEMEYER, E. Dec. 22, 1958. No. 41328/58. Class 98(1.) In a camera having an exchangeable film magazine, the magazine has a spring-loaded shutter slidable in one of its walls to cover a picture gate therein, said magazine being insertable into the camera in a direction parallel to the focal plane and the plane of the said shutter, the camera having a stop which engages and holds the shutter in the magazine as it is inserted so that the picture gate is opened. The magazine 5 contains the film-carrying spool 6, winding spool 7 and feed sprocket 8. The rear wall 12 of the magazine itself is removeable, for replacement of the film. The front wall of the magazine is hollow (Fig. 8), and contains within it a sliding shutter 15, loaded by zig-zag spring 16 to slide over and cover the picture aperture 9. The slide is locked in this closed position by a catch 19, so as to ensure that the shutter is closed when the magazine is removed from the camera. When the magazine is inserted into the camera, a stop 24 on the latter disengages the catch 19, and holds the shutter, so that as the magazine is pushed fully home, the shutter is then held completely open to uncover the picture aperture. The upper wall of the magazine has a groove 30, shaped as shown, in which engages the end 35 of a locking lever 34 loaded by a spring 37. When fully home, this end 35 engages in a widened portion 31 of the groove 30 against a step 38 to lock the magazine in position. To remove the magazine the lever 34 is pressed, against the action of spring 37, to disengage the end 35 from the step 38, so that the compressed spring 16 pushes the magazine out of the camera, at the same time closing shutter 15. The magazine may be held in a partly removed position by engagement of the lever end 35 in a widened part 39 of the groove 30, which also can accommodate a key for rewinding on to spool 6. The film feed sprocket 8 has an upper journal 41 contaning a slot 42 which coincides with the groove 30 at the end of each feed movement, so allowing unimpeded movement along the groove of lever end 35. The feed movement is operated by a swing lever which drives a train of gear wheels 46, 48, 49 (Fig. 12) which are secured in the camera casing. The last is fast with a coupling journal which has a tooth projecting into the camera which slides along groove 30 as the magazine is inserted, finally engaging in the slot 42, so that now the final wheel 49 of the gear train, and consequently the swing lever, is in direct engagement with the feed sprocket 8. A slide 57 is provided which is loaded by a spring 60, and which can shift a limited distance between two extreme positions permitted by slots 59 in which pins 58 engage. In one extreme position, when spring 60 is under tension (Fig. 12), it is held thus by a catch 62, and blocks a nose 56 of a disc 55 on the shaft of the feed sprocket 8, so that the film feed cannot operate. On pressing the trigger 63 to make an exposure, the catch 62 is pivoted to release the slide 57 to take up its other extreme position, in which it blocks the locking lever 34 (so preventing the magazine from being withdrawn from the camera), and also, by means of a locking tongue 68, prevents the trigger from being pressed again (so preventing a double exposure). The slide is moved back again into its first extreme position during the film feed operation, an entrainment pin 69 on the disc 55 engaging a tongue 70 on the slide. The magazine can therefore not be withdrawn from the camera until after a film feed operation, thus leaving an unexposed frame ready in position when the magazine is re-inserted into the camera.