GB319644A - Improvements in and relating to cinematographs - Google Patents

Abstract

319,644. Smith, W. June 25, 1928. Kinematograph apparatus. - In kinematograph apparatus of the type in which reversal of the feeding mechanism is automatically produced in the course of travel of the film, a pair of feeders and the film gate are moved relatively to each other so as to bring the film into engagement with the feeder alternately. The invention may be applied to the feeding of a film with the picture series on each side of a central row of apertures, or to a feeding arrangement in which alternate pictures are stepped over in one direction and exhibited on reversal. One arrangement of the apparatus is shown in Fig. 1 and comprises a film gate 34 pivoted on a post 36 and provided with lateral wings making a large obtuse angle with each other, and two feed claws 28, 29 continuously operated in opposite directions by cam-actuated plates 33 driven through gearing from the main shaft. The gate is held in a position to cause one or other of the claws to engage the film by means of a latch, which is carried by a spring controlled lever pivoted on the gate and co-acting with the film to release the latch at the desired time. A slotted arm 35 is thereupon moved by a crank pin 21 on a spring-actuated disc 22 into the alternative position in which the other claw engages the film. Two reels 3, 4, act alternately as winding and un-winding reels and are driven by a flexible belt 14 passing round a pulley 10 on the main shaft and pulleys 12, 13 on a carriage 11 which is pivoted on the shaft and is thrown into position to cause the belt to drive one or other of the reels by a slotted lever 19 actuated by the crank-pin 21 when the reversal of the feed device takes place. Fig. 7 shows another construction in which the feed claws 56 are operated by crank and link connections 57, 58 and slide on an angled member 61 which is held in one or other of its two operative positions by latches the release of which is controlled by the film. The member 61 is thrown over from one position to the other by the spring- controlled crank disc 22 acting on the slotted arm 62. A further modification is described in which one driving device is provided for an angled bracket carrying both feed claws. Means may be provided for laterally shifting the lens or a screen in the condenser or covering the source of illumination, when a film with two sets of pictures side by side is used, and a trigger may be set to stop the action at will, when a clockwork, electric or other motor is used as the prime mover.