Hierarchical cylinder lock and key system
US5419168A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 1993 |
| Grant date | May 30, 1995 |
| Priority date | — |
| Expiry date | Dec 7, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/7881
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hierarchical lock and key system includes a plurality of locks and keys wherein each key is provided with at least one unique bitting surface that engages a complementarily shaped tumbler pin tip to cause the tumbler pin to rotate and be positioned at a predetermined location. In one system, one key is provided with bittings to rotate the tumbler pins in a lock that is able to determine the rotational position of the tumbler pins. The one key may also operate a lock which does not determine the rotational position of the tumbler pins by positioning a tumbler pin at its proper elevation in the cylinder. Another key which has at least one different bitting from the one key will operate the latter lock (in which the tumblers do not have to be rotated). However, the other key will not operate the former lock because the bitting does not, properly rotate the tumbler pin to its unlocking location. The complementarily shaped contacting surfaces of the tumbler pin and key are generally sloped from one edge to an opposite edge in tapered form and may be flat, concave, convex, or a combination thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.