GB704918A - Improvements in or relating to motion-picture projectors - Google Patents

Abstract

704,918. Kinematograph projectors. PAILLARD SOC. ANON. Dec. 12, 1951 [Feb. 10, 1951], No. 29060/51. Class 97(1) In stereoscopic projection, particularly, the film moves horizontally past two projection apertures separated vertically by half the film width and provided with separate projection lenses and projection light beams, which latter are intercepted simultaneously 'by a shutter having two blades and rotated through one and a half revolutions for each film feed cycle. One form is shown in plan in Fig. 1 and in vertical sections at II-II and III-III in Figs. 2 and 3. The mechanism is carried by plates 3 and 4, spaced by pillars 6, the plate 3 forming the top of a housing 5. Lamps, shutter and claw feed are contained in a further housing 46. The motor M drives, through a belt 8, a ventilating fan 9 and a spindle 10 carrying the cam 12 of a claw feed mechanism of the kind described in Specification 674,205. The shaft 10 drives a horizontal shaft 17 through gears 15, 16 and this drives through gears 16, 18, a shaft 19 carrying a shutter 20. The shaft 17 also drives through gears 33, 34, 35, 40, 43, 44 a number of shafts on some of which are carried film sprockets 32, 41 and pulleys 29, 37, driven by ratchets 31, 39, connected by belts to pulleys 24, 26 connected to the spool spindles through friction drives. Each friction drive consists of a number of discs, alternate discs having driving connection respectively with a squared portion of the spindle and with pins upstanding from the driving pulley. The weight of the spooled film provides the pressure between the friction discs. Separate projection lamps 51 have reflectors 53 and condensers 54. The objectives 55, 56 are carried in eccentric sleeves rotatable by knobs 70 to provide adjustment of the objective axes, one horizontally and one vertically. The objectives are simultaneously axially adjustable by a device 73. Both objectives are mounted on a plate 58 with an upstanding vertical wall adjacent the front wall 45 of the housing 46. The vertical wall contains the projection apertures 1, 2, Fig. 3, against which the film is retained by apertured pressure plates, not shown, carried on a spring blade secured to the wall 45. The plate 58 can be slid forward, under control of a spring detent, into a film threading position. In a modification a single central light source is used with inclined mirrors or prisms to reflect the light along the projection axes. A transverse shaft carries shutters between the lamp and the reflectors. Specification 704,919 also is referred to.