| 摘要 |
<p>To prevent costly damage to door frames and door bolting mechanisms caused by slamming of doors with security bolts projecting, a bolt immobilizing device automatic in its operation and biased toward the immobilizing position is installed on the door adjacent to the bolt. The device is moved to a bolt release position when the door is closed by engagement of an operator with the opposing stop surface of the door jamb. When the door is opened with the locking bolt retracted, the device returns automatically to the bolt immobilizing position. The device includes a shiftable blocking plate across the end face of the bolt in a plane perpendicular to the bolt axis.</p> |
