Cylinder lock device resistible against unauthorized unlocking
US5428978A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 1994 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Mar 29, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/7751
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A cylinder lock device (10) includes a lever (15) rotatably disposed between a casing (11) and a key cylinder (13), and a blocking member (17) disposed within a notch (16) formed in the lever (15). A concavity (18) are formed on an inner wall of the casing (11), and a chamfer (19) is formed on the key cylinder (13). When the lever (15) is in the locked position and the key cylinder (13) is further rotated to the dead-locked position over the locked position, the blocking member (17) moves away from the chamfer (19) of the key cylinder (13) and into the concavity (18) of the casing (11). When the key is pulled out from the key cylinder in the dead-locked position, the locking device is forcibly maintained in the locked position to prevent unauthorized unlocking.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.