GB793179A - Improvements in or relating to photographic cameras having interchangeable lens units - Google Patents

Abstract

793,179. Photographic cameras DECKEL. H., and DECKEL, F. W. Jan. 13, 1956 [Jan. 14, 1955], No. 1214/56. Class 98(1) In a photographic camera with an interchangeable lens unit, means providing the focusing movement of the lens are mounted on the camera body, and the focusing scale is carried on the lens unit. As shown, a rotatable internally-threaded ring 20 is retained in a recess 22 in the camera body, and engages a threaded bush 24 which is held against rotation by a fixed lug 26, so that when ring 20 is rotated bush 24 moves axially. Bush 24 receives a bayonet ring 32 fixed to a mount 34 which carries a shutter casing 42 in which the lens components 64, 66 are mounted. A ring 38 carrying a focusing scale is rotatable on the mount 34, and carries a pin 120 spring-urged into a slot 126 in ring 20, so that ring 20 rotates with ring 38. A groove 128 on the stem of pin 120 projects beyond the surface of the focusing ring if the pin 6 is not properly engaged, and may have a patch of bright paint. The, focusing scale is differently constructed for each lens; it may be carried on a fixed part of the mount and read by means of a mark on ring 38. A ring 48 controls the diaphragm aperture and also operates two pointers 70, 72 of a depth of focus indicator of the kind described in Specification 793,178, and is connected to a coupling ring 58 bearing the diaphragm aperture scale. The shutter speed is adjusted by ring 50, the skirt 52 of which carries the shutter speed scale, and which can be adjustably coupled to the diaphragm setting ring 48 through coupling ring 58, in accordance with the light value set on a scale on ring 58. Specification 744,962 also is referred to.