GB887222A - Improvements in or relating to roll film photographic cameras - Google Patents

Abstract

887,222. Screw-and-nut gearing. KAMEKAUND KINOWERKE DRESDEN VEB. Feb. 25, 1960, No. 6650/60. Class 80 (3). [Also in Group XX] A screw-and-nut mechanism coupling the setting members for exposure value and exposure time with the diaphragm in a photographic camera comprises a rotatably and axially movably mounted spindle 2a, axial displacements of which are arranged to adjust the diaphragm blades 7 (only one shown) against the tension of a spring 22, said spindle carrying fixedly thereon a pinion 3a in toothed engagement with the exposure value setting-ring 4a and being screw-threaded into a bushing 12, axial movement of which under loading of spring 22 is limited by a shoulder of the housing la and which bushing bears a pinion 13 in toothed engagement with an exposure timesetting ring 14a. When, during adjustment of the exposure-value setting-ring 4a, the end of diaphragm aperture scale 19a comes opposite index 17a, a lug 15a on said ring 4a engages one of the stops 30, 30a, or 30b in ring 14a and both rings are then adjusted together for effecting changes in the exposure value setting. Which of the stops 30a or 30b is engaged by the lug 15a depends on the diaphragm adjustment range of the interchangeable objective 27, collar 26 and spring 24 co-operating to position said lug accordingly.