GB727446A - Improvements in or relating to motion picture projectors - Google Patents

Abstract

727,446. Kinematograph apparatus. KODAK, Ltd. April 1, 1953 [April 1, 1952], No. 9040/53. Class 97 (1). The Specification describes two arrangements of clutches and slipping and free-wheel drives for providing forward and reverse winding and rewinding. In the form shown the drive through the belt 23 and pulley 22 rotates, through the worm 21, the worm-wheel 20, anticlockwise for forward film feed, to drive, through a pawl 29 and ratchet 28, the slipping belt driving the lower, take-up spool. When the direction of the drive is reversed, for reverse winding, the pawl rides over the ratchet and allows the spool drive to free-wheel. A pulley 50; however is rigidly secured to the spindle of the worm-wheel 20 and drives a pulley 52 through a belt 53 which provides a slipping drive to the upper spool, when acting as take-up spool during reverse winding, through a ratchet wheel 55 driving a ratchet 56, carried by a pulley 35 driving the spool through a non-slipping belt 36, the rotation being clockwise. Meanwhile the spindle 15<SP>1</SP> on which the pulleys 35 and 52 are loosely mounted is being rotated in the opposite direction by a wormwheel 19 engaging the worm 21. For rewinding the direction of the main drive is the same as for forward winding, the assembly of pulleys 35 and 52 being slid along the spindle 15<SP>1</SP> by operating means, not shown, until clutch members thereon engage the wormwheel 19 and provide a positive drive therefrom to the take-up spool through the belt 36. The pawl and ratchet 55, 56 free-wheel but a drive is provided to the lower spool,- as in forward winding, to tension the film. In a modification the wheels 19 and 20 are spur wheels driven in the same direction through an idler pinion. In this form reverse winding and rewinding are secured with the same direction of the main drive. The changes in relative directions of rotation, as compared with the embodiment shown, result in there being no forward drive applied to the lower spool during rewinding. There is, however, a tendency for the spool to rotate at such a speed that the ratchet 29 would need to rotate faster than the ratchet 28 and, being restrained by the ratchet, a frictional retardation is provided by the belt 27 slipping. The spindles 15<SP>1</SP> and 18<SP>1</SP> carrying the wheels 19 and 20 also carry the top and bottom feed sprockets, not shown. The operating lever for the clutch member which engages the wheel 19 for rewinding carries an indicator member which projects in the rewind position, into the threaded film path as a reminder that the film should not be so threaded during rewinding.