Structure of cross-shaped groove of screw for fit with driver bit
US8757950B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2009 |
| Grant date | Jun 24, 2014 |
| Priority date | — |
| Expiry date | Apr 6, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B23/0061
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A screw has a head with a cross-shaped groove having first to fourth wing grooves, each having bilaterally-formed inner side faces defined by opposing base-end inner side faces, opposing intermediate inner side faces and opposing distal-end inner side faces angled at angles relative to each other so that the first angle of the base-end inner side face<the second angle of the intermediate inner side face<the third angle of the distal-end inner side face. The base-end inner side faces define a trapezoidal base, the distal-end inner side faces define an inverse-trapezoidal distal-end groove, and the intermediate inner side faces define an approximately parallel intermediate groove between each base-end groove and each distal-end groove. Each of the inner side faces is provided with an elevation angle spreading toward an opening face of the cross-shaped groove.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.