GB351684A - Improvements in film feed mechanism particularly for soundrecording or reproducing apparatus - Google Patents

Abstract

351,684. Feeding webs. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.- (Pacent Electric Co., Inc. ; 91, 7th Avenue, New York, U.S.A.) May 22, 1930, No. 15821. [Class 100 (i).] Mechanism for driving a film, such as a soundrecord film, at a constant speed, as in sound-recording apparatus, comprises two separately driven inertia members such as flywheels, having a slip coupling, and each being driven through energystoring means such as springs, one of the flywheels or the like being connected to the film-advancing device. In the construction shown, a sprocket 11 which draws a film 7 past the gate 10 of an optical sound reproducer is carried by a shaft 26 on which two flywheels 27, 28 are mounted, the flywheel 27 being keyed to the shaft and the member 28 loose thereon. A slip coupling between the flywheels is provided by an interposed oiled friction washer 44, the pressure thereon of the flywheel 28 being regulated by means of a bowed spring 48 and an adjustable nut 53. Loosely mounted on the shaft 26 are two wheels 24, 25, each being connected to one of the flywheels through spring couplings, each of which in the arrangement shown consists of a pair of intercoiled springs 30, 31, Fig. 4. These are mounted in annular recesses in the outer faces of the flywheels. A shaft 19, driven from a motordriven shaft 14, is geared to the two wheels 24, 25 through two pairs of wheels 20, 22 and 21, 23 respectively, the gear ratios being such that the wheel 25, coupled to the loose flywheel 28, is driven slightly slower than the wheel 24. Thus during normal running, the flywheel 28 exerts a slight drag on the flywheel 27 through which the film sprocket 11 is directly driven. The wheels 24, 25 are adapted to drive the fly-wheels positively when the machine is started, through pairs of opposed pins 38, 40 and 39, 41, so that excessive strain on the springs is avoided, but under normal running conditions the pins are separated, the drive being transmitted only through the springs. The film take-up reel is driven from a pulley 57 on the shaft of the wheel 23. An oil tank 58 is provided, Fig. 1, from which lubricant is supplied to the various shafts and gears through pipes 60.