Fastener screw having improved installation and self-locking characteristics
US5199839A · kind A · utility
67Cited by
19References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 9, 1991 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | Oct 9, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S411/919
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fastener screw includes a head portion, an elongated shank and a multiple-lead thread formed on the shank opposite the head portion. The head portion has a generally planar end surface having a polygonal drive recess therein. A generally longitudinal chip relief slot is formed along the thread and defines a longitudinal thread profile cutting edge. The underside of the head portion is defined by a generally concave annular surface having a plurality of outwardly projecting serrations formed about its periphery which burr into the workpiece and effect a self-locking action therewith as the screw is threaded into the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.