| 摘要 |
<p>A lock (1) combining security with safety has cylinders (2,3) operable by keys (4,5) respectively from opposite sides of a closure such as a final exit door from a building. The key (4) for operating the lock (1) from the inside is arranged to be held captive when locking the closure from the inside so as to be available to unlock the closure in an emergency.</p> |
