Safety device for a sheet-fed rotary press

摘要

A safety device has pivotally mounted rails for guarding impression cylinder nips in a sheet-fed rotary printing press. The guard rails are pivoted from a guard or safety position during maintenance to a second position away from the impression cylinder during printing to insure that the printed sheets are not smeared by the edges of the guard rails. The guard rails, however, also sense operator contact during maintenance to cause the inching drive of the press to shut off immediately. A hinged access cover or door on the press shields the impression cylinder and cooperating cylinder during printing, and is opened to perform maintenance. Opening of the access cover operates an electrical switch for shutting off the main drive of the press, and the access cover is mechanically connected to the guard rails by a resilient linkage which in turn causes pivoting of the guard rails toward their safety positions. A second electrical switch is operated by the pivoting of the guard rails and shuts off the inching drive in response to operator contact and pivoting of the guard rails in either direction from their safety positions. The resilient linkage also includes abutments limiting the range of pivoting due to operator contact.