GB667829A - Improvements in or relating to photographic shutters - Google Patents

Abstract

667,829. Photographic shutters. KODAK, Ltd. (Eastman Kodak Co., and Fox, A. B.). March 17, 1950, No. 6726/50. Class 98 (i). An everset shutter in which the exposuremaking shutter blade 3 having a slot aperture 10 and a cover-blade 21, which may have an aperture 22 and which carries a trigger 24, are pivoted at 4 and 23 respectively on a plate 1 apertured at 2, has a gear sector 12 mounted on a shaft 13 and meshing with a pinion 5 on the shutter blade, the shaft 13 also carrying an arm 14 to which is secured one end of a hairpin spring 18 secured at its other end to the coverblade 21. The shaft 13 may extend through the plate 1, the gear sector may be mounted on one side, of the plate, and the cover-blade and the arm. 14 may be mounted on the other side, as shown. Preferably the shutter blade is arranged on the same side of the support as the gear sector, and comprises a disc of moulded plastic material such as opaque nylon tapering in thickness from the centre to the periphery and the pinion and shutter blade are integrally moulded. On depressing the trigger 24, the cover-blade moves anticlockwise against its return-spring 25 to engage a stop 32, thereby tensioning the hairpin spring until the end 19 thereof passes the arm 14, when the arm through gear sector 12 drives the shutter blade to make an exposure, the lug 8 on the nylon blade being arrested by a stop 30 without appreciable rebound. On releasing the trigger, the cover-blade closes the aperture Z, and the shutter is then driven back to its rest position shown against the stop formed by the shaft 13. For bulb exposures, a stop 34 is moved into the path of the lug 8 by an external member 33.