| 摘要 |
<p>Rigid with a plate mounted on a door jamb is an inward extension, on the free end of which is pivoted a latch which swings between door-blocking and door-unblocking positions. The latch is releasably retained in door-blocking position by a flat strip having one end pivoted to the latch and a free end engageable between the door and the door jamb. The latch also has an intermediate position which permits the door to be cracked open.</p> |
