Patent GB-909488-A (GB)
Title: Improvements in or relating to photographic cameras
Inventor: HINTZE KLAUS
IPC: G03B17/42
Filed: 1960-09-20
Abstract: 909,488. Photographic cameras. KAMERAUND KINOWERKE DRESDEN VEB. Sept. 20, 1960, No. 32272/60. Class 98 (1). A photographic camera comprises a shutter device including a shutter cocking member and a release mechanism therefor, a film-drive sprocket drivable from an electric motor through a gear mechanism, means drivable by said gear mechanism and co-operable with said shutter cocking member to move the latter to its cocked position, a switch device in the motor circuit operable at the end of each cocking and winding on operation to open circuit the motor, and operable after each running down of the shutter device to energize the motor, a counting mechanism which is moved step-by-step by said gear mechanism as each picture frame is advanced, and a control device which is settable according to the number of exposures to be taken on the film and operable by said counting mechanism when the set number has been reached, said control device when operated effecting decoupling of a coupling device connected between the film-drive sprocket-andgear mechanism, and also actuation of the switch device in such a manner as to break the motor circuit to prevent further cocking of the shutter and winding-on. As shown, a take-up spool 3 is coupled to an electric motor 2- housed within the spool and powered by a battery 1-by way of a shaft 4 coaxial with the spool 3, gear-wheels 5-10, and a friction clutch 11. Also coupled to the motor 2 by way of shaft 4, gear-wheels 5-9 and 12-14, a shaft 15 and a releasable dog-coupling 17, 18 is a filmfeed sprocket 21, one rotation of which advances the film (shown in chain line) by one image frame. A counting disc 48 is provided which is constantly urged towards its initial position by a spring 52, is advanced-one tooth for each frame advance-by a pin 47 on the gear-wheel 14 and is prevented from returning to said initial position when the camera rear wall is closed by a spring catch 50. When said rear wall is opened and moves out of engagement with a projecting pin 51 on said spring catch 50, this catch is released and the disc 48 is allowed to return to its initial position. The camera operates as follows. On depression of a body release 33, firstly, by means of a cone 36, a locking lever 38 is pivoted out of engagement with a detent recess in a disc 40 on the shaft 15 into a position in which a pin 41 thereon engages with a lip 42 of a latch lever 43, and then the shutter release 32 is actuated by means of a lug 35. When the shutter has run down, a cocking lever 30 abuts against contacts 69, 70 of the switch device and connects the motor 2 to the battery 1 by way of closed contacts 66a, 65. During the ensuing operation of the film feed mechanism (described above), by means of a lever 23 pivoted at 24 and having a slot engaged by a control pin 22 on the gear-wheel 13, and further by means of a slide 26 coupled to said lever 23 at 25 having a pin 27 sliding in a slot 28 and having a projection 29 extending into the path of the cocking lever 30, said cocking lever is returned to its cocked position. The current supply to motor 2 is maintained after contacts 69, 70 have re-opened by way of contacts 66 and 66a which become closed after gear-wheel 14 has rotated and kidney-shaped recess 68 has moved away from a pin 67 on the contact 66. At the end of the film-feed operation, a control disc 46 on the shaft 15 releases latch 43 for return of the locking lever 38 into its detent recess, and the current supply to the motor 2 is broken when recess 68 again comes opposite pin 67. The camera is then ready for a further exposure. At the end of a predetermied number of exposures-in this case either 20 or 36 according to the position of a slider 55 as set by means of a pin 58 on a rotatable and externally settable disc 59 and as indicated by an externally visible slider 60 also controlled by said pin 58-either a pin 54 or a pin 53 on the counter disc 48 engages with the slider 55 and moves it to the left. At the same time, by means of a bent-over end 56 of the slider 55, a further slider 61 is moved towards the shaft 15 for simultaneously raising a pin 16 (slidable in hollow shaft 15) which breaks the coupling 17, 18 ready for re-winding of the film and for depressing the contact 65 for breaking the current connection to the motor 2.