Failsafe sensing edge for automatic doors and gates having a U-shaped outer covering and an elongated actuating member
AssigneeLink Controls, Inc.
InventorCharles G. Strand
Life of this patent
Estimating the term…
Abstract
A failsafe or self-monitoring sensing edge for an overhead door includes a channel mounted on the bottom edge of the door having a pair of downwardly extending arms which are spaced apart. An outer covering of soft material is attached to the channel for enclosing the arms. The covering supports within a rigid, separate free-floating actuating member extending upwardly through the arms. On one end of the channel is a light source and the other end is a photoswitch. When the covering is depressed upwardly as a result of an obstacle in the path of the door, the actuating member blocks the light beam and the photoswitch gives off a signal, which can be used to terminate or reverse motion of the door.
Claims10
A sensing edge for an 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-apart arms forming a generally U-shaped, slot-like opening therebetween, extending the length of said channel means, generally 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) a free-floating, relatively rigid, elongated actuating member enclosed by said outer covering means and said channel means which member is normally spaced from said door edge between said arms of said channel;
- (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 member 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;
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- (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.
Dependencies are inferred from the claim text.