GB629549A - Improvements in or relating to cinematograph film shutter mechanism - Google Patents

Abstract

629,549. Kinematograph apparatus. AMPRO CORPORATION. Jan. 10, 1947, No. 948. Convention date, Jan. 12, 1946. [Class 97 (i)] A shutter mechanism comprises a pair of parallel overlying shutter blades, mounted for simultaneous reciprocation in opposite phase in their own planes to move apertures in said blades into and out of register to expose a film, and a pair of cams for actuating the blades by engagement with cam tracks thereon, the cams being shaped so that the blades remain stationary during a period of cam rotation at either end of the stroke and being disposed on a cam - shaft between sepatator plates arranged both to position the cams and align the shutter blades. In the form shown the shutter mechanism is mounted between a partition 21 and the front camera wall 22. The apertured shutter plates 23, 24 are oscillated by cams 26, 27. of the " triangular " shape normally used for feed-claw mechanism. The cams are mounted on a hub 63 on the shaft 29 driven through a pinion 74. Another cam 28 oscillates a further blade 25 carrying a feedclaw 41 operating in a slot in the wall 21. The cams are separated by discs 64, 65, 66, 67 of larger diameter by which the oscillating blades are guided. The shutter blades are slotted at their upper ends to-embrace a guiding member 50. The blades are of thin sheet metal carrying thickened rims in the apertures in which the cams operate. The cams and separator discs are secured by a nut 68. They are kept in proper angular relationship by interlocking tongues and notches formed in them. A masking member 37 occupies that part of the space between the walls 21 and 22 not filled by the shutter blades.