| 摘要 |
1,077,318. Photographic shutters. PRONTOR-WERK ALFRED GAUTHIER G.m.b.H. Nov.16, 1965 [Dec.28, 1964], No.48601/65. Heading G2A. A photographic shutter of the kind having blades 4 which are pivoted through 180‹ to open and then close the shutter by rotation of a ring 5, the next exposure being effected by rotating the ring in the opposite direction, thereby causing the blades to take up their original positions, is provided with a lever 12 for reversing the direction of rotation of the ring, the lever having two stops 13, 14 which, for successive exposures, alternately engage with arms 11a, 11b respectively of a rod 11 driven by the shutter tensioning lever 9. To cock the shutter, the lever 9 is rotated about a pivot 7 thereby moving the rod 11 to the right as shown. A cam (18) Fig.4 (not shown) strikes the pin (13) and is pivoted anticlockwise to tension a spring (20). The rod 11 then loses contact with the pin 14 and is rotated about a pin 10 by the spring (20), which rotation brings pin (14) and rod (11) in contact again, Fig.5 (not shown) simultaneously with the lever 9 being latched in its cocked position. To release the shutter, a lever 24 is rotated in a clockwise direction, thereby moving a lever 27 out of the path of a pin 29 on the ring 5 and releasing the latch on the lever 9. The latter then returns to the position of Fig. 1 under spring action, thereby moving rod 11, and hence pin (14) to the left (as seen in Fig. 5). This rotates the lever 12 which carries with it a pin 16 of the ring 5, thus rotating the ring anticlockwise. When the shutter is reclosed, the pins 16, 29 are at the opposite ends of slots 2b, 2c from the position shown. During the next cocking action the lever 9 is rotated as before, but this time a cam (19) (Fig. 4) strikes the pin 14, so that at the end of the cocking movement the rod 11 abuts the pin 13. Releasing the shutter causes an action similar to that described above but modified in that the lever 12 is rotated anticlockwise and the ring 5 clockwise. The blades 4 again assume the position of Fig. 1. |
