GB863703A - Improvements in or relating to cinematograph projectors having substantially or approximately constant speed driving motors - Google Patents

Abstract

863,703. Kinematograph projectors. BAUER G.m.b.H., E. April 25, 1957 [April 26, 1956], No. 13152/57. Class 97(1) A projector has a driving motor of at least approximately constant speed, a driving shaft for a rotating shutter and another for a claw frame, the driving shafts being interconnected by a continuously and uniformly acting gear mechanism of exchangeable ratio, whereby different film speeds can be obtained for the same shutter speed. In the form shown in Fig. 1 the motor 1 is detachably secured by an end flange unit which contains gears 13, 14 and, when in place, drives, through a clutch, a shaft carrying a gear 16 meshing with a gear 17 on the shaft 18 carrying the shutter 58. The shaft 18 drives a vertical shaft 24 through gearing in a housing 19. An integral pair of gears 20, 21 is slidable on the shaft 18 and may be secured by a pin 221 in a position where one of them meshes with a similarly selected gear of a pair 22, 23 secured by a pin 201. 1. The shaft 24 carries a flywheel 30 and drives, through sets of helical gears, the shafts 32, 34 of upper and lower film sprockets and a shaft 36 which drives the shaft 41 of an additional sprocket and the shaft 44 of the intermittent feed mechanism. The shaft 44 carries a pair of detachable cam discs 48, 55, Fig. 3. The disc 48 produces the engaging movements of the feed claw and is engaged, under pressure of the spring 52 by a bell crank 53 to which is pivoted the claw arm 5 held in contact, by a spring 54, with the disc 55 which produces the feed movements. Each cam disc has two lobes which may be spaced equally, or, for certain television film scanning applications, unequally at 144 degrees separation. The speed of the whole mechanism may be changed by changing the gears 13, 14.