| 摘要 |
<p>THE SAFETY LOCK A safety lock for a door provided with a standard dead-bolt lock having an inside handle for turning the lock between a locking position and an unlocked position. The safety lock includes a retaining bar mounted on the inside surface of the door and movable to a position engaging the dead-bolt lock handle to prevent rotation thereof and to a position releasing said handle. A locking pin swingably mounted on an end of the retaining bar extends through the door when the bar is engaging the handle, and a secondary lock mounted on the outer surface of the door receives this pin and is operable to grip and release the pin. A switch in the circuit of an electrical alarm is opened when the retaining bar is moved to engage the lock handle to render the alarm inoperative, and when the bar is moved away from the handle, the switch closes to cause the alarm to operate.</p> |
