GB597090A - Improvements in and relating to continuous feed kinematographic apparatus - Google Patents

Abstract

597,090. Kinematograph apparatus. MAYTUM, J. A., and SMITH, L. Oct. 4, 1944, No. 19036. [Class 97 (i)] Continuous feed apparatus includes a square section compensating prism surrounded by a shutter rotating therewith and enclosing its corners so as to confine the scanning of the light-beam by the prism to one facet at a time. In the projector shown in Figs. 2 and 3, a casing 34 contains the compensating prism 21 and a concentric feed sprocket 26. The prism 21 is enclosed between four shutter blades 23 driven from the main shaft 10. One margin of the film is driven by the sprocket. The other runs on a member 66 on a bearing 65. The film is held in place by a pressure member 45. The sprocket is driven at one quarter the speed of the prism by an epicyclic friction drive consisting of a sun-wheel 27 on shaft 10 and planets 28 rotating on spindles 30 carried on the sprocket and running in an outer race 29. To maintain the timing of the projector, the members 27 and 29 and one of the planets 28 are provided with toothed gearing. The member 45 has a projection aperture which may be longer than a single frame. In this case there is provided a frusto-conical shutter 50 with blades 51 arranged to prevent light from more than one frame of the film reaching the prism 21 at any time. This shutter is driven at the same speed as the film sprocket by bevel gears 54, 55 and spur gears 56, 57. The bevel-wheel 55 is attached to the bush 58 secured to the ends of the shutter blades 23. A fly-wheel 73 is provided on the shaft 10 and pulleys 13, 14 carry belts for the drive from a motor and to the take-up film spool. One element 43 of the objective lens combination is placed between the film and the compensating prism. In the camera shown in Fig. 12, the compensating and film feed arrangements are similar to those in the projector. A shutter 79 driven by mitre wheels 82, 83 has radial exposure slots. A fixed mask 78 surrounding the prism has diametrically opposite slots to pass the light beam.