Patent GB-764930-A (GB)
Title: Improvements in and relating to photographic cameras
IPC: G03B9/08
Filed: 1955-01-11
Abstract: 764,930. Photographic cameras. VOIGTLANDER AKT.-GES. Jan. 11, 1955 [Jan. 13, 1954], No. 856/55 Class 98(1) In a photographic camera, a group of press-buttons or similar operating members is provided as the adjusting means for at least one of the adjustments of the camera necessary in preparation for an exposure, each of which when actuated is automatically locked and is under the action of a return spring, the number of actuating members in the group corresponding to the number of values or steps of the corresponding camera setting, each member being connected on the one hand with the other members of the same group and on the other hand with the camera adjusting member belonging to the group, which adjusting member is also under the action of a return spring, so that by actuating one of the operating members of the group any other member of the group which had previously been actuated and held locked up to this instant is unlocked and springs back while the necessary setting of the camera is effected by the member last actuated: In one form of the camera, there are three groups of press buttons for adjusting respectively the diaphragm aperture, the exposure time, and the distance to which the camera is focussed. In a preferred form, however, there are four groups of press buttons 3, 4, 10, 11, as shown in Fig. 2. The buttons in groups 3, 4 are for adjusting exposure time and focusing distance respectively, while those in group 10 are operated according to the brightness of the sky and those in group 11 are operated according to the brightness of the subject. Fig. 3 shows one button 16 of each group slidably mounted in a wall 13 of a casing 14 forming part of the camera. Each button has a shank terminating in two conical surfaces 19, 20 with a groove 18 between them, and projections 21, 22, 24, 25. A rod 32, slidable in the wall of casing 14, and normally urged by a spring 30 to a position wherein a stop 31 abuts casing 14, carries a doublearmed lever 33, 34. One arm 34 carries a strip 35 extending under the projections 24 of the buttons in group 11. The other arm 33 carries another double-armed lever 37 carrying other strips 35 extending under the projections 21, 22 of the buttons of groups 3, 10. When a button is depressed, e.g. in group 11, the conical surface 19 enters a hole 26 in a spring-loaded strip 28, Fig. 5, and is retained by the edge of hole 26 entering groove 18. Prior to engagement, however, conical surface 20 bears on the side of hole 26 to move the strip 28 against spring action to release any button in the group which may previously have been depressed and retained. The buttons in groups 10, 11, 3 which have been depressed in accordance with the brightness of the sky and the subject, and with the exposure time required, press down the strips 35, so depressing rod 32 by. a distance equal to the sum of the distances by which the strips 35 have been depressed. This movement is applied to a lever 39 which sets the diaphragm to the required aperture for the conditions indicated by the depressed push-buttons. A second projection 23 carried by the button 16 in group 3 engages a strip 49 connected through a rod 50 to an exposure-setting member 51. The buttons 16 in group 4 act through a strip 54 and a rod 53 on an arm 55 carrying supplementary lenses 56, one or neither of which, according to which button is pressed, is positioned behind the objective 59. To avoid damage should the settings require lever 39 to be moved beyond the limits set by its stops 38, the rod 32 is connected to the lever through a spring coupling 41. If excess movement is taken up in this coupling, the fact is indicated by marks 42, 43 thereon which become misaligned. A ring 44, to which the diaphragm blades are secured, is rotatable with respect to a scale 46 in accordance with film speed. Scale 46 is itself movable to bring one of the indicia S, W into alignment with a fixed mark 48 for use in summer or winter. A button 12 (Fig. 2), mounted in line with the buttons of group 11, serves to release all the buttons so that the controls may be set manually. As shown in Fig. 5, it has a conical end 60 which bears against a strip 61 mounted on a lever 63 pivoted at 62. Strip 61 is moved back against abutments 64 on strips 28, which are thereby moved to release any buttons which may have been depressed and retained. A release button 8, mounted in line with the buttons of group 4, is connected to the shutter releasing member. In a modification, the buttons are replaced by members which slide along the camera wall.