Screw for composite/plastic materials
US8616816B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2009 |
| Grant date | Dec 31, 2013 |
| Priority date | — |
| Expiry date | Aug 2, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B2033/025
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fastener for composite or plastic material having a dense composition employs a head which has a socket and a recessed underside and a lower rim. In one embodiment, the shank has an upper portion with an enlarged diameter and a left hand thread while the lower portion has a tri-lobed configuration and is traversed by a right hand thread. The right hand thread may have a plurality of notches which, in one embodiment, are arranged in a spiral array. One embodiment of a fastener has longitudinally spaced rings which project from an enlarged diameter portion of the shank. The lower portion of the shank has a thread with a plurality of notches. The rings have a major diameter and spacing greater than the major diameter and spacing of the thread.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.