Drive mechanism for film projectors - has two control cams with gear wheel and sprocket drives for different speeds

摘要

A film projector drive mechanism which can be used to provide drive at speeds blow normal has a powered drive device mounted so that it can be moved between two click stop settings. It is rotated by a toothed drum (14) gear wheel connected to the main drive shaft. A second control arm is provided and the drive engages with one of the gear wheels in both its positions. The control cam engages a lifting device in one of the settings.