GB511090A - Improvements in or relating to photographic shutters - Google Patents

Abstract

511,090. Photographic shutters. ZEISS IKON AKT.-GES. May 26, 1938, No. 15807. Convention date, July 17, 1937. [Class 98 (i)] The setting of the delay-action mechanism of the shutter is prevented when the shutter is set to " Bulb," Time " or the highest speed instantaneous exposures, and similarly when the delay-action mechanism is tensioned, the setting to these speeds is also prevented. A locking lever 6, Fig. 4, mounted on a pin 5 on the shutter housing can lock the adjustment ring 1 of the shutter by engaging with one arm 8 in a groove 3 on the ring 1. The other arm 9 of the lever 6 can be moved to a position which prevents movement of the tensioning arm 7. When the shutter is set to " B," the arm 8 lies against the thicker wall of the ring 1, and the arm 7 is then prevented from moving to the delay-action tensioning position. Also when the delay-action mechanism is tensioned, the arm 8 lies in the slot 3, and the member 7 prevents downward movement of the arm 9 so that the adjustment of the ring 1 to " B " &c. is prevented. In a modification, Fig. 6, the locking device is arranged outside the shutter. The time adjustment ring 13 is geared through an intermediate wheel 16 and a gear wheel 18, to an exposure indicating disc 17. A sector 19 is rigidly connected to the shaft of the disc 17 so that when the disc is set to " B" &c., the sector projects into the path of a manually adjustable double armed lever 20. When the disc 17 is set to " I," the lever 20 is moved by the handle 22 to tension the delay-action mechanism by striking the winding lever 11 of the ring 13. In the end position, a projection 23 on the ring 13 is disposed in the path of a pin 24 and prevents an adjustment to " B," " T " &c. The lever 20 may be replaced by a slider.