| 摘要 |
<p>A locking device, which mounts a user key (the first key) and a manager key (the second key) separatedly, places a first lock and a second lock unitedly in an outer cylinder. The first lock is opened or rotated by the first key. After the first lock is open, the first key cannot be pulled out of the locking device. If the second lock is open by the second key, the first key can be pulled out together with the second key.</p> |
