Fastening of sheet material
US6742235B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2001 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Aug 8, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/5377
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A fastener such as a self piercing rivet is inserted into sheet material without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material. The sheet material is disposed between a nose and a die of fastening apparatus. The rivet is inserted into the sheet material by means of a plunger that is reciprocal relative to the nose. Prior to rivet insertion no significant clamping force is applied to the sheet material and material immediately around the rivet insertion location is allowed to flow towards the rivet as to rivet is inserted. Thereafter during a second stage (being after said first stage) of rivet insertion a clamping force of sufficient magnitude is applied between the nose and the die in the region around the rivet insertion location so as substantially to prevent flow of displaced sheet material away from the rivet. The invention may also be applied to panel clinching. The resulting joints are of improved mechanical strength and fatigue life. Certain components of the apparatus of the present invention have an improved life expectancy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.