Die for forming self-tapping fastener blank
US6089986A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1999 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Nov 30, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B25/0078
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A header die for forming a self-tapping fastener blank provides die forming zones within which the blank is formed, the blank therby defining an odd number of lobes along a cross section taken perpendicular to its axis of rotation. The lobes define a relatively high out-of-round cross section along a tapered thread-forming zone, and a relatively low out-of-round cross section along the main body taken in a direction toward the drive head. Between the main body and tapered thread-forming zone is located an additional thread forming zone having an axial length of approximately one thread pitch and a cross section that conforms to the high out-of-round of the tapered zone. The maximum diameter (at the lobes) of the additional thread-forming section approximately matches that of the full-diameter main body section. A lower-diameter stabilizing section can be provided ahead of the tapered zone, adjacent the tip of the fastener.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.