Lockable gate mechanism with automatic reindexing feature
AssigneeMinnesota Mining and Manufacturing Company
InventorRoland W. Rubertus
Life of this patent
Estimating the term…
Abstract
A gate for controllably inhibiting passage through a controlled zone which includes a rotating arm, the rotation of which may be prevented by a solenoid-coupled pawl which engages a gear-like multiposition detent member coupled to a shaft on which the arm is mounted. In the event excessive force is applied to the arm when thus locked to enable emergency egress, a clutch allows rotation of the shaft, and of the arm, with respect to the detent member. The arm may be automatically repositioned to enable a new position about the periphery of the detent member to become engageable by the pawl.
Claims8
A gate for inhibiting passage through a controlled zone, comprising
- (a) support means adapted to be secured to a base proximate said controlled zone,
- (b) barrier means including a passage blocking member secured to a shaft pivotally mounted on said support means,
- (c) locking means positioned within said support means for controllably locking said shaft in a first angular position at which said blocking member inhibits passage through said zone, including a rotatable multiposition detent member coupled to said shaft, a pawl for engaging and locking the detent member for preventing rotation thereof and hence of said shaft and passage blocking member, and means for controllably moving said pawl to a locked or unlocked position,
- (d) means for biasing said shaft to said first angular position, and
- (e) clutch means coupled to said shaft for enabling rotation of said shaft from said first angular position by the application of an angular force to said shaft causing slipping of said clutch means,
- whereby emergency passage through said zone is permitted by forcible rotation of the shaft to a different angular position with respect to said detent member when locked by said pawl such that said passage blocking member is moved to permit passage thereby, and when said shaft is returned to said first angular position at which said blocking member inhibits passage, a different one of said multipositions of the detent member may be engaged by the pawl.
Dependencies are inferred from the claim text.