Patent GB-442763-A (GB)
Title: Improvements in or relating to optical sound reproducing apparatus for kinematographic film projectors
IPC: G03B31/00
Filed: 1935-03-26
Abstract: 442,763. Combined optical sound-reproducing and kinematograph apparatus. DEBRIE, A. L. V. C., 111, Rue St. Maur, Paris. March 26, 1935, No. 9413. Convention date, Oct. 27, 1934. [Class 40 (ii)] In a portable combined optical sound-reproducing apparatus and kinematograph projector, all the parts of the sound-reproducing device are fixed on a single easily removable support which is secured like a lid over an aperture in a lateral wall of the machine frame, a part of the device extending within the frame, so that it is thus protected from damage, and the overall size of the machine remains small. The support also forms a shield for the photoelectric cell. Additional features of the invention relate to means for connecting the cell to an amplifier, means for ensuring uniformity of motion of the film, the construction and arrangement of a pressure shoe adapted to engage with the film at the sound-gate, and means for adjusting the optical system which projects a light beam through the soundtrack. In the apparatus shown, the soundreproducing device is made as a readily detachable unit by mounting it on a support 8 which fits over an aperture in the frame 9. A cylindrical metal part 12 of the support 8 forms a shielding enclosure for the photo-electric cell 5. A removable cap 13 is provided. A recessed portion 15 of the support 8 extends within the frame 9, and houses contact pins 16, 16<1>, which are held between insulating plates 17, 18. These pins, which are adapted to engage in sockets (not shown), on the frame, for connection with the loud-speaker amplifier, are connected to sockets which receive the contact-pins 19 of the photo-electric cell. Between a lug 21 and a bracket 22 on the support 8, Fig. 3, a spindle 23 is fixed, on which are provided bearings for a sleeve 26<1> carrying at one end a roller 4 over which the film passes and at the other end a flywheel 24 which ensures uniformity of movement of the film. The sound-gate comprises a curved channel 2 in which the film is held by a shoe 28, pressed down by springs surrounding screws 29, Fig. 1, which allow the shoe to rock in all directions. The shoe bears only on the margins of the film, with a pressure that can be adjusted. The screws 29 are attached to a lever 31, which can be rocked, indirectly, against the action of a spring (not shown), by pressure on a lever 51, to raise the shoe 28 from the film channel 2. The lever 31, which is connected by a ball catch to a member intermediate between it and the lever 51, may be readily removed from its support merely by withdrawing it forwardly. In order that the apparatus may be used with either the emulsion - coated or the uncoated face in contact with the channel 2, the objective lens is adapted to be focused into either of two definite positions by mounting it in a carrier tube 57, Fig. 2, which screws into a tube 56 arranged in a support 55. Focusing is effected by rotating the tube 57 into either of two positions, determined by stops, by means of a collar 58. Angular adjustment of the optical system around its axis, for correct positioning of the light slit relatively to the sound-track, is effected by rotating the tube 56 in its support 55 by means of an eccentric projection on a screw 66, Fig. 1. A second screw 68 prevents vertical movement of the tube 56.