GB390452A - Improved film driving mechanism for film sound recording and reproducing apparatus - Google Patents

Abstract

390,452. Driving sound-films. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.- (Assignees of Elmer, L. A. ; 102, Riggs Place, West Orange, and MacDougall, H. W. ; 514, North Maple Avenue, East Orange, both in New Jersey, U.S.A.) Oct. 31, 1932, No. 30579. Convention date, Jan. 7. [Class 40 (ii).] A sound-film driving mechanism comprises a film-feeding roller driven through a floating or frictional coupling and a film-driving sprocket driven through a resilient member. As shown, separate shafts 37, 18 are extended from the gear-box of a combined motion picture and sound-reproducing apparatus to drive a friction roller 3 and a sprocket 4, respectively, which feed the film 1 past the sound-reproducing head 43. The drive to the roller 3 is transmitted through a fluid coupling 40 consisting of an outer member 34 driven from the shaft 37 and an inner member 33 driven through the medium of a fluid 39 which may be oil. A flywheel 5 is provided on the shaft 4 of the roller 3 and, in order that a strain may not be imposed upon the film at starting, the roller 3 is coupled to its shaft through a clutch comprising a friction disc 8 maintained against the roller 3 by a spring 9, washer 10 and nut 11. The sprocket 14 is driven from the shaft 18 through gears 16, 17 and is held against appreciable longitudinal displacement by bearings 23. The drive is transmitted through a spring 20 which allows the sprocket 14 to rotate somewhat on the shaft 19 depending upon the load and so prevents noise and irregularity of film movement due to any misalignment of the film perforations with the sprocket teeth. In place of the floating coupling 40, an electromagnetic coupling or a coupling acting on the principle of a turbine may be employed.