Patent GB-1396137-A (GB)
Title: Camera shutter device
IPC: G03B9/58
Filed: 1972-11-02
Abstract: 1396137 Camera shutter device SEIKO KOKI K K 2 Nov 1972 [4 Nov 1971 J 50578/72 Heading G2A A camera shutter device, shown reset and shutter closed in Fig. 1 includes a switch S for controlling an electrical circuit which controls the timing of the closing movement of the shutter, a switch activating member 20 which is biased by a spring 23 to an inoperative position, and means for rendering the spring 23 operative and inoperative during the opening and closing movements of a shutter operating member 2. Operation of a shutter release member 16 by depression of the arm 16C in the direction of arrow B causes pivotal rotation of the switch actuating member 20 in the direction of arrow C through the interaction of arms 18, 21 against the action of spring 23 whereupon the two biased-apart spring contact blades 25, 26 of the switch S are brought into engagement and arm 22 of the actuating member 20 becomes detented in a recess formed in contact blade 26 to hold the contacts closed. Operation of the shutter release member 16 also frees a rotatable drive member 1, spring urged in direction of arrow A, to engage a driving pin 11 and to rotate the shutter operating member 2 anti-clockwise against the action of a restoring spring acting in the direction of arrow F whereupon a plurality of shutter blades 3 (one only shown) pivoted at 4 open by movement of pin 6 attached to the shutter operating member 2 within slot 5 of each blade. As the shutter operating member 2 rotates a projection support 2a for end 23a of spring 23 is removed thus making the spring inoperative and also a pin 9, acting on arm 15 of a pivotally rotatable member 8 and spring urged into engagement with the pin, moves a further arm 14 of member 8 into the prospective path of an abutment 13 of the drive member 1 which, in the shutter open position of Fig. 3 (not shown) is temporarily held against a pivotal stop member 28. At the end of the exposure time a control circuit 24 controlled by switch S and which includes an electromagnet acts on stop member 28 via link 27 to move it clockwise to allow rotation of the drive member 1 to continue, and subsequent engagement with the arm 14 causes the shutter operating member 2 (via arm 15 of member 8 acting on the pin 9) to move to the shutter closed position of Fig. 4 (not shown). During the shutter closure movement the projection 2a returns to the reset position so that the spring 23 again becomes operative on the switch actuating member 20, the detent restraint is removed, and the switch contacts open to deenergize the control circuit 24. Manually operated means are used to restore the driving member 1 to the reset position of Fig. 1. In another embodiment Fig. 5 (not shown) the spring 23 is dispensed with and is replaced by a spring 123 acting between a pin 51 on arm 21 of the member 20 and a pin 54 on arm 53 of an additional two-armed lever 52 the other arm 55 of which coacts with the projection 2a on the shutter operating member 2. In a further embodiment Fig. 6 (not shown) the switch S' is of the biased closed type and is held open by the actuating member 20 when the shutter is in the closed position. Instead of the projection 2a another part of the shutter operating mechanism may be used to render springs 23 or 123 inoperative.