GB533270A - Improvements in or relating to photographic shutters - Google Patents

Abstract

533,270. Photographic shutters. KODAK, Ltd. Oct. 26, 1939, No. 28727. Convention date, Oct. 26, 1938. [Class 98 (i)] A photographic shutter comprises a blade pivotally mounted on a pivoted oscillatable member, the blade upon release moving about the axis of this member and at the same time rotating about its own pivot to uncover and cover the exposure aperture. In the form shown, a two-lobed blade 24 is pivoted at 23 on a member 20 oscillatably mounted on a central upstanding flange 22 of the shutter casing. A hairpin spring 17 is attached to an arm 19 on the member 20 and to the trigger 5, which is pivoted at 12 and urged in a clockwise direction by a spring 13. Fig. 2 shows the parts towards the end of the operating stroke of the trigger. Slight further anti-clockwise movement of the trigger causes the ends of the spring 17 to snap over the dead-centre position in which they are shown, the spring then opening and swinging the member 20 to the position shown in Fig. 5. During this movement the blade 24 is caused to make a semi-rotation by means of a gear segment 25 secured to it and meshing with an internal fixed gear segment 26, thus uncovering and covering the exposure aperture. At the end of the return stroke of the trigger, effected by the spring 13, the spring 17 again snaps over, and the parts come to the position of rest as shown in Fig. 7, in which the exposure aperture is covered by a plate 14 forming part of the trigger 5. Time exposures are effected by turning a stop 33 so that it arrests the member 20 when the exposure aperture is uncovered.