Demand drive component

DETAILED DESCRIPTION Accordingly, the above problems and difficulties are obviated by the present invention which provides a novel drive puck for use in driving a film roller in a positive demand drive system in which the film roller is resiliently centered on a rotating drive shaft whereby the tension of a film length carried thereon selectively causes engagement of the film roller with the drive puck.
The drive puck is secured to the drive shaft so as to rotate therewith and is provided with an external tread means which projects into a lateral cavity of the film roller so as to engage with the underside of the film roller in response to the resilient centering movement of the film roller.
Therefore, it is among the primary objects of the present invention to provide a novel drive puck in a positive demand drive system which provides more torque than conventional drive pucks in such systems.
Another object of the present invention is to provide a novel drive puck in a positive drive system for processing photographic film which includes an irregular surface for selectively engaging with a regular surface on a film roller whereby greater torque is achieved.
Still a further object of the present invention is to provide a novel drive puck used in combination with a film roller which creates a "fluid drive" action by means of an irregular or tread surface on the drive puck which is intended to engage with a smooth surface on the film roller.
Yet a further object of the present invention is to provide a novel drive puck which may be used or employed in situations requiring greater torque than can be handled by conventional pucks.