GB867998A - Improvements in or relating to photographic cameras having coupled exposure meters - Google Patents

Abstract

867,998. Photographic cameras. GAUTHIER G. m. b. H. A. Oct. 31, 1957 [Feb. 5, 1957], No. 34038/57. Class 98(1) In a camera, the diaphragm aperture and shutter speed setting members control the indicating or follower member of an exposure meter by means of two separately rotatable rings or part rings, the first of which, on rotation, carries the second axially along the axis of rotation and the second has an edge cam track for operating the exposure meter member. Preferably, the rings are rotatable on the shutter casing of a camera objective and are connected directly to the diaphragm aperture and shutter speed adjusting rings. One ring may be journalled in a channel formed in the outer surface of the other one, as shown, both may be journalled on the shutter housing 1 and have pins 14 and 15 riding respectively in groove 3b of shutter speed adjusting ring 3 and between forked arms 16 of diaphragm aperture adjusting ring 2. The first ring 7 is moved axially by pin 12 thereon engaging slot 1d in housing 1. Alternatively, the first ring may be moved by a multiple screw-threaded connection with the housing. The first ring 7 is rotatably connected to the second 8 by a locking spring 11. Ring 8 is thus separately adjustable by means of ring 2 and rod 23 which control the indicating or follower member of the exposure meter rides on cam track 8c thereof. The adjusting rings 2, 3 are coupled together on releasing projection 22 and the shutter speed and diaphragm aperture can only then be adjusted by compensating amounts so that the total exposure value remains constant and rod 23 is not displaced. However the coupling arrangement between rings 2 and 3 is optional and when no coupling is provided the camera can have any type of diaphragm and shutter speed scales. Other variation in which for example rod 23 is non-resiliently held against track 8c and in which rings 7 and 8 are resiliently pressed together are referred to. Instead of groove 3b and forked arms 16, the movement of the adjusting rings 2 and 3 may be transmitted to the rings 7 and 8 by toothed pinions rotating on fixed spindles. In another arrangement, rod 23 may provide an abutment to limit the adjustment of rings 2 and 3, the rod being positioned by means of an exposure meter operated feeler lever system as disclosed in Specification 802,020.