Night Latch Function， 夜功能锁体

Lockcase:   1   latch   bolt   plus1 guard latch, no deadbolt. 单斜舌加一个防撬
舌。没有方舌。
Outside trim: Dummy handle or no handle, single cylinder.外部假把手或没有把
手， 单边锁芯。
Inside   trim:   Lever   handle   only, no cylinder, no turn.内部仅有执手，没锁
芯，没旋钮。
Lock   and   unlock:   Door can be unlocked with key. Once the door is closed,
the latch bolt is locked by the guard latch. 钥匙开门，门一旦关上，防撬舌锁
住斜舌。
Get in: First turn with key withdraws the latch bolt and door can be opened
then.开门时，旋转钥匙收回斜舌，然后开门。
Exit:   One can leave by turning the inside lever.   出门时，转动执手然后可以
出门。