GB438849A - Improvements in method of and device for the rewinding of photographic films - Google Patents

Abstract

438,849. Kinematograph projectors. DEHN, F. B., 103, Kingsway, London.- (Automotion Pictures, Inc. ; 14, West 40th Street, New York, U.S.A.) April 18, 1935, No. 12032. [Class 97 (i)] In apparatus for feeding films to the projector from the interior of a coil and simultaneously rewinding the used film on the exterior, the film is fed to a positive feed device by frictional means with a slight excess of speed, the consequent slack in the film resulting in slip of the frictional drive. The coiled film 14 is rotatably mounted outside a circle of rollers 20, 20A and is led off from the interior over a conical roller 23 to a positively driven wheel 15 and thence to the projector 12. The used film is led over a wheel mounted coaxially with the wheel 15 and then to the outside of the coil. The film is rotated and fed frictionally by an endless belt 24 running over a driving sprocket 25 and between the rollers 20 and the film. The frictional grip of the endless belt between the rollers 20 and the film and hence the rate of frictional feed depends upon the tension of the film between the guide pulley 23 and the positive feed pulley 15. As the film rotates, adjacent turns slip slightly over one another so that the dimensions of the coil are unchanged.