GB846222A - Photographic camera pivoted blade shutter - Google Patents

Abstract

846,222. Photographic shutters. AGFA A. G. Dec. 1, 1958 [Dec. 18, 1957], No. 38735/58. Class 98(1) A shutter has two concentric blade rings 2, 3, which rotate in the same direction to cause respective opening and shutting of the shutter blades, the actuating means which effects said rotation being subsequently retractable to its original position, for re-setting the shutter, without causing any further movement of the rings. The two facing edges of the rings have respective teeth 2b, 3b, and notches 2c, 3c in which respective friction springs 6, 5 engage. The rings are driven by a pawl 11, whose rear end is guided by a pin 11 a in a cam slot 12. Its forward end is pivotally attached to a block 7 moving within a recess 8 in the shutter housing. The block forms part of a setting ring 7b having a lever 7c tensioned by a spring 9. In the position shown the shutter is tensioned and set, but prevented from running down by the trigger 10. When this is released, the block is pulled in the direction of the arrow. The nose 11c of the pawl impacts one of the inner teeth 3b, causing the inner ring 3 to rotate, so opening the shutter, until spring 5 re-engages in the next notch. The movement of pin 11 a in the cam slot meanwhile pivots the nose 11c away from ring 3 to ring 2, when it impacts one of the outer teeth 2b, causing ring 2 to rotate and so close the shutter. A lever 7a controls the shutter speed. To re-set the shutter, block 7 is moved by means of lever 7c against the direction of the arrow, so that the pawl 11 is retracted without any further movement of the shutter rings.