Failsafe sensing edge for automatic doors and gates

Claim 1

A sensing edge for a overhead door or gate having a door edge comprising: a. channel means for mounting along the edge of said door or gate, said channel means having a pair of projecting, spaced arms forming a slot-like opening at the free ends thereof for extending the length of said channel means parallel to said door edge; b. outer covering means supported on said channel means enclosing said arms, said outer covering means being made out of a flexible material readily depressed when an obstacle is encountered when said door or gate is closing; c. member means of rigid material within and mounted on said outer covering means extending through said slot-like opening, said member means terminating in an actuating member between said arms and normally spaced from said door edge; d. a light source means mounted on one end of said channel means for directing a light beam down the length of said channel means between said arms and in the space between said actuating member and said channel means when said outer covering means is in its normal, undepressed state, said actuating means blocking said light beam when said outer covering means is depressed by an obstacle in the path of said door or gate when being closed; e. photoswitch means mounted on the other end of said channel means for receiving said light beam so that interruption of said light beam will actuate said photoswitch means; f. said light source means, channel means and photoswitch means forming a rigid structure whereby said light source means and photoswitch means remain in alignment and do not require adjustment once assembled; and g. means sealing the ends of said outer covering means capable of being compressed when said covering means is depressed by an obstacle.