Patent GB-778933-A (GB)
Title: Improvements in or relating to photographic cameras
IPC: G03B9/08
Filed: 1955-06-28
Abstract: 778,933. Photographic cameras. DECKEL, H., and DECKEL, F. W. June 28, 1955 [July 9, 1954], No. 18649/55. Class 98(1) In a photographic camera of the kind in which the shutter is set and released by a single actuating member connected to release means mounted on the camera body, the actuating member is held in tensioned position by a locking device on the camera body, and is additionally influenced by a separate source of potential energy which is adapted to move it from tensioned position to release position. As shown in Fig. 1, the operating member consists of a shaft 14 extending through the shutter casing 10. A drive spring 20 is connected at one end to the shutter casing and at the other end to a drive member 18. A toothed tensioning pinion 16 fast on the shaft 14 has a projection 26 engaging a lug 28 on a member 18, to turn it anticlockwise to tension spring 20. The shutter blades 30 are movable about pivots 32 in the shutter casing and by means of pins 38 engaging slots 36 in a blade ring 40 which has radial arm 42 which co-operates with the driving member 18. A control ring 44, mounted in the casing 10 for rotation about the lens tube, is biased by a spring 46 and has teeth 48 engaging pinion 16. A pin 52 on ring 44 is engageable with the nose 54 of a toothed segment 56 pivoted at 58 in the casing 10 and biased by a spring 60. The teeth of segment 56 engage a known kind of delay mechanism to control preignition of a flash bulb. A projection 62 on segment 56 engages the lug 64 on a lever 66 pivoted at 68 and urged by spring 70 into engagement with segment 56. The parts are normally held against the stop 72. Locking lever 66 has a toe 74 for engagement with a cam 76 on ring 44, and a pawl 78 for engagement with a lug 80 of a main driving member 18 to hold it in its tensioned position. A cam 82 on driving member 18 co-operates with the delay mechanism (not shown). The shutter is set when the film is wound by rotating a knob 94, Fig. 4, geared to a film transport roller 100 by gears 96, 98 and to a shaft 102 by further gears 101, 104. Gear 104, which is fast with shaft 102, has a driving pin 106 engaging a pin 108 on gear wheel 110 freely mounted on shaft 102 and engaging a gear wheel 92 fast on a shaft 90, which is connected by bevel gears 84, 86 to the shutter tensioning shaft 14. The driving member 18 is turned anticlockwise to a tensioned position, wherein it is held by the pawl 78 on locking lever 66. The control ring 44 is turned clockwise against spring 46 by pinion 16, but cannot return because a ratchet 124 and pawl 126 hold the knob 94 against reverse rotation. The shutter is released by pressing the spindle 102 down. This disengages pins 106, 108 to allow the shutter to run down, rotating shaft 90 until a catch 114 on a disc 112 mounted on a shaft 90 engages a lug 116 on a spring arm 118 which has been pressed down by a shoulder on shaft 102. During this movement, cam 76 on control ring 44 engages the toe 74 of lever 66, which rocks so that its pawl 78 releases driving member 18, which rotates under action of spring 20 to operate operate the blade ring 40 through its arm 42. When pressure on shaft 102 is removed, it moves upward under action of spring arm 118 which also withdraws lug 116 from engagement with catch 114 to allow the shutter to continue its running down action. In a modification, Fig. 8, the control ring 44 has an additional cam 200 which, when "bulb" exposures are required, co-operates with a lug 202 on a lever 204 pivoted at 206 and biased by a spring 208. When the shutter is released from the position shown the ring 44 rotates until the catch 114 engages the lug 116, as described above. During this movement the shutter blades open but a lug 210 punched out on lever 204 is engaged by a shoulder 212 formed on the blade ring 40, retaining the blades open. When the release shaft 102 is released, further movement of the control ring 44 rocks lever 204 by means of its cam 200, disengaging shoulder 212 from ring 40 so that the blades may close again. When ordinary exposures are to be made, lever 204 is moved to an inoperative position by a cam 214 on the shutter speed setting ring. Specification 720,847 is referred to.