Patent GB-463540-A (GB)
Title: Improvements in cinematograph cameras and projector apparatus
IPC: G03B15/08
Filed: 1935-06-25
Abstract: 463,540. Kinematograph apparatus. ABBOTT, F. F. M. June 25, 1935, Nos. 12242/35 and 20739/36. [Class 97 (i)] In apparatus in which images are taken in ranks by moving the lens system transversely of the film and reversing the direction of feed after the exposure or projection of each rank, these movements are automatically effected by a shaft having two film-engaging members permitting partial rotation of the shaft after the 'film has been completely fed in one or other direction. As shown, the film is fed between plates 2, 3, and is engaged by one of two members 25 on a shaft 28, Fig. 4, the members being shaped as in Fig. 6, and being relatively displaced through 45‹ on the shaft. The lens system 40, Figs. 1 and 2, is carried in a tube 39 and extends through helical slots 38 in a rotatable tube 35 and through longitudinal slots 37 in a fixed tube 36. The tube 35 carries a skew gear 34 engaging a gear 33 on the shaft 28, so that, on rotation of the shaft, the tube 35 rotates and moves the lens system along the slots 37 by means of the helical slots 38. A milled head 47 facilitates manual rotation of the tube 35 to move the lens system to its initial position and to wind up a spring 39 for rotating the shaft 28. The film is fed by the claws 9a on one or other of two pawls 9, Figs. 1 and 2, pivoted to levers 6 which are mounted on a shaft 7 and are reciprocated by the pins 5a of cranks on a driven shaft 5 which engage slots 6a. Each pawl 9 carries a pin 8 which is guided by the bent ends 73a, 12a of two members 73, 12, Fig. 4, pivoted to the shaft 5 and connected together by a spring 13, the members being urged into the position shown in Fig. 4, by a spring 11. The shaft 28 carries a cam 14 engaging an extension 10 of the member 73 so that, on rotation of the shaft, the members 73, 12 pivot together about the shaft 5, and bring the other feed pawl into engagement with the film thus reversing the direction of the feed. A sliding shutter 42, Fig. 6, is pivoted at 43 to a lever 44 pivoted to the shaft 7 and reciprocated by a pin 45 driven by the shaft 5. The shaft 5 is operated through a gear train driven by motor or by a handle 72 on a rod 67, Fig. 2; the rod is provided with a pin 69 engaging a recess 70 in its inoperative position and with a recess 71 in its operative position, and is held in these positions by a spring 71<1>. The gate comprises a lower fixed plate 3, Fig. 1, having a series of apertures 41, and an upper plate 2, having a long aperture 60, pivoted on the shaft 28 and held away from the plate 3 by a spring 31, Fig. 2, the gate being held closed by a catch 59. The operation of the apparatus is as follows: The spring 30 is wound by rotating the head 47 to bring the lens system into its initial position, and a film is placed in the chamber 50. The plate 2 is then rotated about the shaft 28 and the film is threaded so that its end lies between the members 25, the shaft 28 being held meanwhile by engagement of a catch 48, Fig. 4, with one of the members 25. Closing of the gate releases the catch 48 and allows the film to be fed by one of the pawls 9, and exposed through the shutter 42. When the other end of the film has passed the left-hand member 25, this member is released and allows the shaft 28 to rotate until the other member 25 engages the film, such rotation moving the lens 40 and rocking the members 12, 73 to reverse the direction of feed. In a modification, the lens system is carried on a flexible black strip having one end wrapped round the shaft 28, and the other end held by spring pressure so that when the shaft rotates the strip is unrolled and the lens system moved across the film. For projection, the back of the casing is removed and, a projection lamp and lens are fitted to the inner end of a pivoted bell-crank lever 27, Fig. 4, having a pin 32 engaging a helical groove in a boss 26 on the shaft 28 ; rotation of the shaft moves the lever and lamp along the apertures 60 and 41. For colour photography, the lens system 40 may comprise two lenses each having a colour filter so that two images are taken simultaneously, the feed of the film being modified by lengthening the throw of the cranks or by other means to feed two image areas at a time.