Tamper-resistant fastener
US4258596A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1979 |
| Grant date | Mar 31, 1981 |
| Priority date | — |
| Expiry date | Apr 23, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S411/911
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A tamper-resistant fastener is disclosed, having a head which tends to prevent the removal of the fastener by conventional tools. The fastener head is provided with three sockets, at least one of which is eccentrically disposed with respect to the other two. The fastener may be attached and removed only with the application of a special driving tool having a male portion adapted for matable engagement with the fastener head. The eccentricity of at least one of the sockets permits the turning of the fastener upon the application of torque by the driving tool. The three-socket arrangement substantially eliminates the tendency of the driving tool to tilt when torque is applied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.