GB773280A - Photographic lens shutter with an additional opening device - Google Patents

Abstract

773,280. Photographic shutters. VEB ZEISS IKON DRESDEN. Aug. 18, 1955, No. 23842/55. Class 98(1) In a multiple-blade shutter, the blades, pivoted on a ring, movable to-and-fro for the purpose of additional opening of the shutter for focusing are opened for focusing by the operation of the shutter means and close again on or after the operation of the shutter release member. As shown, the shutter, which is in the set position, comprises a setting ring 2 having an arm 5 and spring urged counterclockwise by the spring 23, a blade-operating ring 8 urged counterclockwise by the spring 14 and having a pin 21 engaged by the nose 20 on the ring 2, and a blade-pivot ring 3 to which the blades 11 are pivoted, which has an arm 7 and which is urged counterclockwise by the spring 4. In setting, the ring 2 is turned clockwise by the arm 5 and is held by the latch 17, the ring 8 being turned by the nose 20 until the projection 15 thereon is held by the lug 16 of the latch 13. During the last part of the setting movement, the lug 6 on the lever 5 engages the arm 7 and rotates the ring 3 to open the shutter for focusing. Operation of the trigger 18 engages the latch 17 to free the ring 2, and the arm 7 follows the arm 5 until, arrested by the pin 22, in which position the shutter is again closed. The cam surface 19 on the ring 2 then releases the catch 13 to free the ring 8 for normal exposure movement. In a modification, the ring 3 may be held in set position by the lever 17 in such a manner that operation of the trigger 18 - releases the ring 3 first and then the ring 3 releases the setting ring 2 by means of a pawl.