Keys for cylinder locks
US5615565A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T70/7881
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A key with a blade portion which is bitted for actuating the tumbler pins of a cylinder lock has improved cross-sectional strength despite deep cut bittings which extend well into the thickness of the blade. The key is generally flat with upper and lower surfaces and opposite short side edges. The bittings are cut across at least one of the surfaces so as to extend arcuately through the thickness of the blade and one of the side edges. The volume of key blank material which is adjacent the deep cut bittings after the key is cut is substantially more than conventional keys and provides the key blade with increased strength to prevent breakage. The bittings are cut into the key blade by a rotary cutter wheel which is dimensioned to form an arcuate bitting surface rather than a flat surface. A cylinder lock includes a rotatable plug having a tenon with a plurality of corner portions, and a keyway passing through the plug and tenon is configured to permit all of the tenon corners to remain intact, thereby providing secure seating of a tailcam on the tenon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.