| 摘要 |
A lock comprises a casing 10, 11, 12, 13a, 13b, 14 containing a deadbolt 21 moveable between extended and retracted positions by movement of a drive plate 34. The drive plate 34 is operated by the rotation of an external handle through a boss 24a. A key operated internal bolt 100 is moveable to a position in which the internal bolt 100 blocks movement of drive plate 34 and so prevents the deadblot 21 from being extracted. |
