Locking fastener
US4220188A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1978 |
| Grant date | Sep 2, 1980 |
| Priority date | — |
| Expiry date | Jul 10, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B39/282
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A self locking threaded fastener is disclosed wherein the self locking system includes a plurality of bearing surfaces contained within a bearing plane and positioned in an annulus around the thread means. Extending inwardly from each bearing surface is a ramp surface which is inclined inwardly and back from the bearing plane. An axially extending shoulder joins one edge of each ramp surface. When the fastener is tightened against a mating part to clamp such part, the engagement causes sufficient pressure to displace material of the mating part by cold flow or other type of displacement into the recesses between the ramp surfaces and shoulders. Continued tightening rotation does not encounter excessive torque since the ramp surfaces provide a camming action but loosening rotation is resisted by the interference between the displaced material and the shoulders. As displacement occurs, additional portions of the ramp surface engages displaced material to increase the effective bearing area and locking interference and provide a self limiting action with respect to the extent the fastener embeds in the mating surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.