(under the class definition) Device wherein an element of a closure moving means has provision for discontinuing, reversing or preventing the application of a moving force to the closure if the closure meets abnormal resistance or is subjected to a force in a different direction.
(1) Note. Included in this subclass are closures having a moving means which includes an overload responsive coupling which continues to urge the closure to a closed position, and which moves the closure in this direction upon the removal of the obstruction.
SEE OR SEARCH THIS CLASS, SUBCLASS:
141, for a closure having means to permit its emergency release.
192, for a crossing gate movable vertically to block a passageway, and additionally yieldably movable horizontally when struck by a vehicle using the passageway.