| 摘要 |
<p>A latch lock comprising a latch bolt (10) adapted for movement between a latching and a retracted position, a first part including a boss (30) adapted in use to be rotated by a door handle, and a second part (40) adapted in use to drive the latch bolt (10) between one of the positions and the other. Clutch means when engaged transmit drive from the first part to the second (40) and when disengaged allow free rotation of the first part by the door handle. The clutch means comprise a lever (34) pivotally connected to the second part (40) and the lever (34) is provided with a spur (33) which can be engaged by pivotal movement of the lever (34) with a recess (32) in the boss (30) of the first part. The lever (34) is biased toward engagement of the spur (33) and recess (32) and is operated to disengage the first and second parts by a locking means (50). In the locked configuration the locking means (50) can also operate to prevent movement of the latch bolt (10) by abutment with the second part.</p> |
