GB990942A - An exposure device for cameras - Google Patents

Abstract

990,942. Camera exposure control. PENTAGON DRESDEN KAMERA-UND KINOWERKE VEB. Jan. 29, 1963, No. 3606/63. Heading G2A. In a camera shutter comprising two blinds which run down one after the other, the release mechanism has two cams in fixed relation to each other, the first releasing one blind and the second the other, the exposure-regulating means comprising two escapement levers, either of which, according to the exposure time selected, retards the release of the second blind. In the form shown, the two time-setting discs 2, 3 have mounted beneath them corresponding cams 4, 5, against the edges of which bear respective levers 12, 7. Lever 7, biased by spring 6, has a toothed segment 8 engaging a gear train 10 having an anchor 9. Lever 12, biased by spring 11, has a movable weight 30 fixed to an arm 28. The release member 16 is wound and tenssioned by means not shown, and held against running down by a nose part 17 which latches behind a hooked lever 18. This 'set' position is shown in Fig. 1. The member 16 has an opening 13 into which extends part of either lever 7 or lever 12, according to the setting of the time discs 2, 3; in Fig. 1 it is part of lever 7 which enters into opening 13. Spring-biased into contact with member 16 are two levers 26, 27, which respectively control the release of the two shutter blinds. These are actuated one after the other by two cams 22, 23 fixed to member 16. When the release knob 20 is pressed, lever 18 is disengaged from nose 17, allowing member 16 to run down (anticlockwise). Cam 22 strikes lever 26, so releasing the first shutter blind. After this action, the edge of opening 13 makes contact with the end of lever 7 and begins to turn it clockwise on its pivot, so that its end is being pushed out of the opening 13 (Fig. 2, not shown). During this period the run-down is being retarded by the action of the gear train 10, with which lever 7 engages. After lever 7 has been moved completely out of opening 13 (Fig. 3, not shown) the second cam 23 strikes lever 27 to release the second shutter blind to terminate the exposure. The same manner of operation occurs if the other lever 12 extends into opening 13, except that since this is not engaged with a gear train, it has a slidable weight 30 which acts as an escapement force.