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US 4,709,950 AGranted
Crash bar door locking device
AssigneeAmerican Device Manufacturing Company
InventorZedekiah Z. Zortman
Life of this patent
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AssigneeAmerican Device Manufacturing Company
InventorZedekiah Z. Zortman
Estimating the term…
A crash bar door locking device is provided, suited for mounting on the inside of a swinging door. The crash bar is mounted horizontally across the door providing ready access by movement in the outside direction. The crash bar activates a pivotal lever which causes a latch bolt to rotate inwardly and disengage from a door strike. The pivotal lever provides a deadbolt feature by preventing the rotation of the latch bolt. A release is incorporated in the latch bolt and allows the latch bolt to rotate when the release engages the door strike as the door closes. An additional unlocking mechanism may be provided for retracting the latch bolt from the outside of the door independently of the crossbar. A firelocking mechanism may be incorporated in the latch bolt to secure the latch bolt when a fire occurs. Two pins with a spring between them are retained by fusible plugs at either end of a bore in the latch bolt, so that the latch bolt operates as a normal lock on the door. When a fire occurs, the fusible plugs will melt and the pins will go to an extended position in which they interact with a bracket mounted on the door and prevent the latch bolt from disengaging the door strike so that the door will remain closed.
A door latch having a fire safety locking mechanism, to secure the latch in a locked position upon release of said safety lock mechanism, wherein the door latch has a latch bolt and a mounting bracket, the latch bolt having a transverse bore and the bracket having two transverse holes therein, the bracket being located on the door latch with the bore opening in alignment with the holes in the bracket, the latch bolt having two slidably received in the bore, each pin being biased against the other pin by a means for biasing located between the pins, the pins and the biasing means being retained in a compressed position by two plugs of fusible material frictionally engaged at either end of the bore to restrain the pins and biasing means in a compressed position out of engagement with the holes, whereby when the locking mechanism is exposed to heat sufficient to melt the fusible plugs, the pins are released and engage the holes in the bracket, securing the latch bolt in the locked condition.
A door latch adapted to be mounted on a door for selective engagement with a door strike, the door latch comprising a frame, a latch bolt supported on the frame for selective, pivotal movement outwardly to engage a door strike and inwardly to disengage the door strike, the latch bolt, when extended outwardly, substantially engaging the cooperating door strike to retain a door on which the latch is mounted in a locked position, the door latch having a release within the latch bolt, means for biasing the release outwardly from the latch bolt, and a deadlocking means having a first position preventing inward movement of the latch bolt and a second position at which the latch bolt is permitted to pivot inwardly and clear the deadlocking means, whereby when the latch is mounted on a door, the release will engage the strike on closing, causing the release to move inwardly, forcing the disengagement of the deadlocking means and forcing inward pivotal movement of the latch bolt by the release permitting the latch bolt to clear the door strike.
A door latch adapted to be mounted on a door for selective engagement with a door strike, the door latch comprising a frame, a latching means supported on the frame for selective pivotal movement outwardly to engage a door strike and inwardly to disengage the door strike, the latching means having an extendable pivotal latch bolt which, when extended outwardly, substantially engages the cooperating door strike to retain a door on which the latch is mounted in a locked position, the latch bolt having an opening therein, a release inserted in the opening in the latch bolt, means for biasing the release outwardly from the latch bolt, a lever pivotally supported on the frame and engaging the latch bolt, the lever having a normal position at which the lever prevents inward movement of the latch bolt and a depressed position at which the latch bolt is forced inwardly by the lever to clear the strike, the lever having a means for biasing the lever to the normal position, the release engaging the strike on closing of a door on which the door latch is mounted, moving the release inwardly to engage the lever, forcing the lever out of the normal position, allowing inward pivotal movement of the latch bolt and permitting the latch bolt to clear the door strike.
Dependencies are inferred from the claim text.