Patent GB-520814-A (GB)
Title: Improvements in or relating to photographic cameras
IPC: G03B17/42
Filed: 1939-03-29
Abstract: 520,814. Photographic cameras. LEITZ GES., E. March 29, 1939, No. 9763. Convention date, May 12, 1938. [Class 98 (i)] In a camera of the kind having a spring for automatically re-winding the shutter and advancing the film, the spring is brought into action by a relay which is tripped as the shutter completes the exposure. A mechanical relay may also be provided between the shutter release and its' operating member, the relay being re-set during the automatic re-winding of the shutter. In the camera shown, the film is advanced and the shutter set and released by a motor comprising a casing 7 secured to the underside of the camera and containing springs 8, 9 which are connected by gears, one of which is mounted on a master shaft 16 carrying the winding handle 62. On the shaft 16 is a gear wheel 17 which drives a speed regulator of known type and carries a stop 28 which may be engaged by the hooked end of a lever 51 and a latching member, comprising a spring strip 58 bearing a hook 59 which engages over the edge 40 of a slot formed in the inner wall of the camera, holds the lever 51 in position to engage the stop 28 against the action of a spring 55. When an exposure is completed a projection 63 on the lower edge of the trailing blind of the focal-plane shutter pushes the hook 59 from the edge 40, the spring 55 then moving the lever 51 to the position shown to release the gear 17, which then rotates a gear 22 on the shaft of which is a pinion 24 which turns the film past roller 2 to advance the film. The pinion 24 also rotates a sleeve 26 freely mounted on the spindle 25 of the shutter blind rollers and coupled by a dog clutch to the roller 3 thus rewinding the shutter. A cut-away portion 27 of the wheel 17 prevents rotation of the gear 22 and sleeve 26 before the latter has re-engaged the roller 5. During the rotation of the shaft 16 a pin 30 on a disc 29 carried by the shaft bears on the lever 51 and turns it so that the hooked end engages the stop 28, thus arresting the rotation of the wheel 17 when it has made a single turn and resetting the relay formed by the lever 51 and spring 55 in readiness for the next operation by the stop 63 on the blind shutter. The shutter release also operates through a relay, which is formed by a pivoted lever 37 having a projection 35 on which bears a rod 33 pivoted at 32 and pressed downwardly by a spring 39, the rod having a bent portion 38 engaging in a groove in the sleeve 26. Pressure on the shutter release 48 causes it to disengage the hooked end of a bell-crank lever 46 from the lever 37, which then turns to the position shown in Fig. 4 under the action of the spring 39 and rod 33. As the rod 33 moves downwardly, the bent portion 38 lowers the sleeve 26 and thus releases the shutter. The relay is reset by the rotation of the disc 29, which forces a hook 41 on the end of the lever 37 out of a notch 31 on the lower side of the disc and turns the lever until it is re-latched by the bell-crank lever 46. In a modification, the projection 63 on the trailing blind of the shutter which causes the actuation of the relay lever 54 is replaced by a projection on a gear wheel driven through an intermediate gear from a gear wheel on the blind roller spindle.