Patent GB-872428-A (GB)
Title: Improvements in or relating to photographic cameras having focal plane shutters
IPC: G03B9/34
Filed: 1957-09-25
Abstract: 872,428. Photographic cameras. KAMERAWERKE, NEIDERSEDLITZ VEB. Sept. 25, 1957 [Sept. 28, 1956; March 28, 1957], No. 30031/57. Class 98(1) In a photographic camera having a focal plane shutter, the exposure timing mechanism is arranged on one side of the camera overlying the film supply spool chamber and the coupled film feed and shutter winding mechanism is arranged on the other side of the camera overlying the film take-up spool chamber. Preferably, a pivoted lever 34 (Fig. 6) is provided for transmitting the exposure terminating impulse from the timing mechanism to the shutter mechanism. As shown in Figs. 14 and 15, the mirror 85 of a reflex camera has an abutment 93 which strikes an arm 94 of a lever 17 as the mirror is turned to the horizontal position by spring 87, lever 17 is thus turned to release arm 15 which rotates with gear wheel 10 as the first blind of the shutter opens the exposure aperture. Presumably an anchor escapement is simultaneously released and the second blind follows when lever 34 receives the exposure terminating impulse from the escapement and frees wheel 14. Successive ranges of faster shutter speeds are obtained by disconnecting parts of the retard mechanism. Thus for 1/50th to 1/125th second the anchor is moved away from the escape wheel and faster speeds are obtained by disconnecting the escape wheel drive. For the fastest speed lever 34 is held clear of wheel 14 and the shutter blinds move simultaneously. The mirror remains in the horizontal position as long as the shutter is not re-set. Shutter setting lever 19 is connected by gearing to lug 24 which brings arm 15 back to lever 17 to set the shutter, to wind the film take-up spool through a friction clutch and, through gear wheels 73 and 74, Fig. 8, to the mirror 85. On turning lever 19 pin 119 returns mirror 85 to the lowered position where it is retained by catch 81. To set the second blind, wheel 10 picks up and turns wheel 14 by means of pin 13 on the latter. When abutment 93 is removed from arm 94 of lever 17 the latter turns about pivot 16 and brings a catch 126 (Figs. 17 and 18, not shown) into operation. This engages setting lever 19 to prevent any further actuation thereof until the shutter has been released. The release of the shutter is effected by turning lever 67, Fig. 6, about pivot 68. The " bulb setting is obtained on turning shaft 50 so that lever 62 can be turned to allow hook 65 to trap lever 34 and thus prevent wheel 14 from turning as long as lever 67 is held. Lever 76, Fig. 6 and 8, is freed by lever 67 and turns about pivot 77 under spring 78, to release catch 81 and to turn lever 90 about pivot 89 and so release a pre-set lens diaphragm by means of rod 92. Lever 67 may alternatively be retained before release of mirror 85 (and initiation of the exposure thereby) by a delayed action self timer 95, Fig. 12, having a gear retard 108, 109 locked by lever 114 and driven by spring 101 through rack 104. Initial movement of lever 76 along incline 117 turns lever 110 about a pivot 111 to move lever 114 to free the gear retard. When the mechanism runs down striker 116 turns lever 110 to release lever 76 and effect the exposure. On setting the shutter, lever 76 is returned to its original position by pin 118 on gear wheel 73. A non-reflex camera in which levers 76 and 17 are combined into a single lever or coupled together is referred to.