Patent GB-769086-A (GB)
Title: Photographic shutter of the objective type
IPC: G03B9/08
Filed: 1955-05-19
Abstract: 769,086. Photographic shutters. DECKEL, H., and DECKEL. F. W. May 19.1955 [May 28. 1954], No. 14475/55. Class 98(1) In a shutter of the between-lens type having a built-in diaphragm and a master member controlling the shutter blades, a control 'member supported within the shutter case and driven by the master member during the setting movement of the latter operates to open the blades and the diaphragm during the setting movement. As shown in Fig. 1, a setting gear 16 carried on the shaft 14 engaged by suitable drive means at the rear of the shutter casing 10 has a lug 26 co-operating with a lug 28 on the master member 18 rotatable about the shaft 14. The member 18 is surrounded by a spring 20 attached at the end 22 to the casing 10 and at the end 24 to the member 18. The blades 30 have pivots 32 engaging in openings in a rotatable ring 34 and have slots 36 engaged by pins 38 on a blade ring 40 having an arm 42 co-operating with two driving pegs carried by the member 18 which, when released, first rotates the blade ring 40 anticlockwise to open the blades and then rotates it clockwise to close the blades. The ring 34 has an arm 44 extending through an opening in the wall of the shutter casing and is urged counterclockwise by the spring 46, and also carries a pin 48 extending through the slot 50 in the casing to limit, its movement. Operation of the arm 44 opens the blades. The diaphragm comprises blades 52 having pivots 54 and pins 56 engaging in slots 58 in the diaphragm setting ring 60 having a radial operating arm 62 extending through an opening 'in the shutter casing. The ring 60 is urged counterclockwise by the spring 64 against a lug 66 on a stop selector ring 63 having a pointer 70 co-operating with the stop scale 72. A ring 76 rotatable about the front lens tube and urged counterclockwise by the spring 84 carries an arm 80 which can engage the arms 44 and 62 and has teeth-88 meshing with the teeth 90 on the rear 16 so that tensioning the master member 18 rotates the ring 76 clockwise until engaged by the spring-urged latch 92. A peg 96 on the ring 76' engages. during the clockwise movement of the ring 76, a lug 98, to rotate the toothed segment 100 anticlockwise against the action of a spring 104. A cam 106 on the segment 100 engages a lug 108 of. a locking lever 110 pivoted at 112, the lug 108 being acted on by a spring 114 to maintain it in engagement with the segment 100. The lever 110 has a lug 118 co-operating with the cam 120 on the ring 76 and a tooth 122 adapted to engage with a lug 124 on the master member 18 to retain it in tensioned position. The segment 100 engages an escapement mechanism retarding its clockwise movement -and the cam portion 126 of the master member co-operates with an escapement mechanism tending to retard its running down movement, the period of retardation being controlled by adjustment of the shutter speed selector ring: When the shaft 14 is rotated counterclockwise to set the shutter, the ring 76 is rotated clockwise to cause the arm 80 to engage first the arm 62 to open the diaphragm and then the arm 44 to open the shutter blades 30, and is held in cocked position by the latch 92. As the segment. 100 is rocked by the peg 96, the lever 110 is rocked counterclockwise by the spring 114 to bring its tooth 122 into position to lock the master member 18 and to engage its lug 118 with the periphery of the ring 76. When the shutter is released by depressing the lever 94, the ring 76 rotates anticlockwise to allow first arm 44 to move to close the shutter blades and then the arm 62 to allow the diaphragm blades 52 to assume their pre-selected position. Finally, the cam 120 on the ring 76 rocks the lever 110 to disengage the tooth 122 from the lug 124 of the master member 18 and allow the latter to effect the exposure movement of the shutter blades and the segment 100 completes its movement to urge the lever 110 against the stop 116. The shutter may be used in a reflex camera.