Prefastenable torque-shear bolt
US4659267A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 29, 1985 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Nov 29, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B35/045
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A prefastenable torque-shear bolt has a bolt cut with a thread adapted to engage a nut, and full-fastening and prefastening grips each having wrench-engaging surfaces. One end of the bolt continues to a first transition portion that is tapered like a truncated cone. The full-fastening grip extends from the first transition portion and a full-fastening break-off groove. One end of the full-fastening grip continues to a second transition portion tapered like a truncated cone. The prefastening grip extends from the second transition portion and a prefastening break-off groove. The effective area of the fracture surface of the prefastening break-off groove is smaller than that of the full-fastening break-off groove. A first burr that arises on the threaded portion side when the full-fastening break-off groove is formed by rolling is formed on the first transition portion, and the outside diameter of the first burr is smaller than the diameter of the thread bottom in the threaded portion. A second burr that arises on the full-fastening grip side when the prefastening break-off groove is formed by rolling is formed on the second transition portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.