Platen cover for copying machine

Claim 1

In a copying machine in which document material to be reproduced is positioned on a transparent platen, an improved cover apparatus for holding the document material in copying position comprising a machine frame, contiguous walls forming a top housing with an opened bottom overlying a transparent platen on the machine frame, a diaphragm assembly including a diaphragm member stretched over a diaphragm frame coextensive with the opened bottom of said top housing, and clamping means arranged on the periphery of the diaphragm frame for securing said diaphragm assembly along the periphery of said top housing to affect a lighttight relationship of the platen area when said top housing is in operative copying position, said top housing including hook means engageable with an actuatable member on the machine frame, said actuatable member being actuated in response to a signal from machine control means indicating a copying cycle is completed, and a platen release switch located on the top housing coupled to the machine control means for disengaging said hook means from the actuatable member at a predetermined time when the machine is not in copying operation.