GB937945A - Photographic shutter unit and camera comprising the same - Google Patents

Abstract

937,945. Shutter mechanisms. AGFA A.G. April 24, 1962 [April 29, 1961; Aug. 9, 1961], No. 15652/62. Class 98 (1). A shutter mechanism, incorporating a delayed action device for optional use, has a blade. Opening and a blade-closing ring which move in the same direction in running down the shutter, with a latching means operable by a moving part of the shutter, which in the setting movement latches, and in the running down movement unlatches, the exposure value setting means. The arrangement is intended for use with cameras having automatic exposure regulation. As shown, the mechanism has a bladeopening ring 3, a blade-closing ring 4, and an aperture/shutter speed control ring 5, all spring- loaded. Rings 3 and 4 can make contact via respective lugs 10, 9. Ring 5 controls the diaphragm leaves 18. Ring 3 also has a pin 23, cooperating with a manual control 26, and a lug 24 co-operating with the escapement 28 of the delayed action mechanism 45-60. Control ring 5 has a ratchet portion 15, in which can engage the tooth 44 of a latch 41 pivoted on a fixed pin 42. The measured exposure value is taken into account by pivoting the arm 13 of ring 5 in the direction of arrow 65, prior to or together with setting the shutter. In addition the delayed action mechanism is set by turning lever 51 in the direction of arrow 67. Lever 26 is now turned in the direction of arrow 66, to set the shutter, causing rings 3 and 4 to turn clockwise, tensioning the springs 6, 7. During this rotation, pawl 41 engages its tooth 44 in ratchet 15, to restrain ring 5. Also, tooth 45 of pawl 46, which has been bearing on the lug of ring 3, falls into a recess 32 therein. Continuing movement of lever 26 causes pin 23 to reach an escape point. Just prior to this, lug 24 engages latch 27, which liberates the escapement- 28 of the delayed action mechanism, and so sets this in action. After pin 23 is released, ring 3, and thus also ring 4, are still held by pawl 46. As the retarding mechanism runs down, tooth 45 eventually lifts out of recess 32, thus releasing ring 3 to return under loading and so open the shutter blades. Running down of ring 4 is further delayed by another retarding arrangement 33-38, in which a pin 33 engages against the periphery of a projection 29 of ring 4. When the delayed action is not set, tooth 45 is retained out of engagement with recess 32. Fig. 2 (not shown) is a modification having a different latching arrangement.