GB373751A - Improvements in or relating to combined motion picture and sound reproducing apparatus - Google Patents

Abstract

373,751. Sound reproducing apparatus associated with kinematographs. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.-(Assignees of Pfannenstiehl, H.; 80, Boulevard West, Mountain Lakes, New Jersey, U.S.A.) May 1, 1931, No. 12877. Convention date, May 31, 1930. [Class 40 (ii).] Comprises a combined motion-picture and sound-reproducing apparatus having driving means designed to ensure constancy of speed of the photographic sound record past the soundreproducing point. Pivoted on a pedestal 10 is a bracket 11 which supports a lamp housing 12, a picture-projector head 14, and a casing 21 containing optical sound-reproducing apparatus. The casing 21 contains a light source 24, Fig. 2, an optical system 26, a photoelectric cell 27 and driving and guiding means for the film 32, which comprise a pressure-foot 31 and sprockets 33, 34, 35. The output from the photo-electric cell 27 is taken to an amplifier 28.and, to reduce the length of the connection, the amplifier 28 is mounted on an adjustable pedestal 29. The sprocket 34 is mounted on a shaft 36, Fig. 3, to which is secured a flywheel 37 driven from a motor 18 through a flexible belt 38. To transmit power to the projector driving-mechanism, a gear wheel 41, rotatably mounted on the shaft 36, has a series of holes 42 adapted to register with projections 40 on a spider .39 secured to the shaft 36. Resilient sleeves 43 are fitted into the holes 42 so that any vibrations transmitted to the gear 41 will be prevented from affecting the constancy of speed of the shaft 36, the uniform rotation of which is further ensured by the combination of the flexible belt 38 and heavy flywheel 37. The gear 41 drives through an idler gear 44 a gear 45 on the shaft of the sprocket 33, and through a second idler gear 46 a gear 47 which rotates the hold-back sprocket 35. A gear 50 meshes with the gear 45 to drive,the picture-projector mechanism.