Patent GB-932428-A (GB)
Title: Improvements in or relating to a between-lens camera shutter and diaphragm mechanism
IPC: G03B7/00
Filed: 1959-12-02
Abstract: 932,428. Photographic cameras. H. DECKEL, and F. W. DECKEL. Dec. 2, 1959 [Dec. 5, 1958], No. 41022/59. Class 98 (1). A between-lens camera shutter and diaphragm mechanism comprises a common housing, a shutter speed control ring and a diaphragm control ring mounted within said common housing, both control rings being connected with setting rings radially guided on the periphery of said common housing, said setting rings being located by spring rings sprung into recesses in said housing and formed with radial arms which act as springs in the axial direction of the housing to press the setting rings axially against shoulders on the housing. As shown, a diaphragm control ring 44 coupled to blades 52 is connected to a diaphragm setting ring 36 by way of an arm 42. A shutter speed-control ring 10 coupled to a conventional shutter mechanism (not shown) mounted on the base-plate 6 and surrounded by a housing 2 is connected to a shutter speedsetting ring 22 by way of a projection 10a. Ring 10 and a further coaxial ring 12 spaced therefrom by a spacing ring 14 are held in position by means of a spring 16 which is sprung into a recess in the housing 2 and has arms 16a extending through openings 16b in said housing 2 for holding ring 22 and a further ring 18 normally coupled therewith against a shoulder of the housing 2. Ring 36 is similarly located against a further shoulder of the housing 2 by means of a spring 40 having radial arms 38. For coupling the shutter and diaphragm setting rings to a follow-up pointer (not shown) of an exposure meter, a differential mechanism may be provided comprising a pinion wheel 74 mounted on a rotatable carrier ring 76 and engaging on the one hand with external teeth on the diaphragm control ring 44 and on the other hand with internal teeth on a transmission ring 72 which is coupled with the shutter speed-setting ring 22 by way of a pinion 68, a shaft 66, a further pinion 64, the ring 12, and the ring 18. The arrangement is such that on rotation of the setting rings 22 and 36 together the shutter speed-diaphragm aperture combination as indicated respectively by scales 24, 34 is changed at constant exposure value and on rotation of one of said setting rings relative to the other the said exposure valve is altered and the carrier ring 76 becomes rotated to adjust the follow-up pointer by way of a shaft 78 coaxial with the pinion 74, a cam ring 84 engaging therewith and a spring-urged follower lever 90 pivoted on a shaft 92. Ring 18 may be rotated relative to the ring 22, on release of a locking catch 28, to allow for different film sensitivities, a film sensitivity scale 26 on the ring 22 being provided for cooperation with an index mark 20 on the ring 18, and the ring 22 being held fixed during such film sensitivity setting by the frictional engagement of the inner end of a release catch 32 with the housing 2. Pinion 64 is releasably secured on a tapering end of shaft 66 by a screw 66a so that final adjustments of the mechanism to the exposure meter may be made after assembly. In modifications, the cam arrangement 84, 90 may be replaced either by an axially displaceable cam-follower co-operating with a cam-shaped flange on the ring 84, or by a cam lever 90a (Fig. 4, not shown), directly engaging with the shaft 78.