BERNELL DELANO SHOFF
Engineers in Bittersville, PA

4508014, Apr 2, 1985

Jun 8, 1982

6/386270

Bernell D. Shoff - Windsor PA

U.S. Truck Cranes, Inc. - York PA

F15B 1308

91527

Disclosed is control apparatus for a machine such as crane which includes a remote control assembly fluid-coupled to the machine by a substantially electrically non-conducting tube assembly. The machine can be operated remotely from the remote control assembly or from an electrical control assembly disposed at the machine. Apparatus is provided for automatically shutting down all or selected machine functions in response to a blockage in one or more of the fluid lines extending between the remote control apparatus and the machine. In a preferred embodiment, the remote control assembly includes pneumatic switches coupled by the fluid lines to electric pressure switches disposed at the machine. The pressure switches are in turn coupled to electro-mechanical devices for controlling the machine functions. The apparatus for shutting down one or more machine functions comprises one or more pneumatic valves connected to the inlet of one or more respective pressure switches which causes the respective pressure switch to change state in response to said blockage and thereby shut down one or more machine functions.