Method of forming a hollow fastener from sheet metal
US4928375A · kind A · utility
Inventor
Key dates
| Filing date | Sep 26, 1988 |
| Grant date | May 29, 1990 |
| Priority date | — |
| Expiry date | Sep 26, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49943
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A method of forming an integral fastener such as a rivet on a sheet metal component such as part of a clutch plate assembly. The method involves placing the metal sheet between a pair of dies so that portion of the sheet overlies a cavity in one die. The other die has an annular working face which surrounds the cavity in immediately adjacent relationship. A biased plunger is arranged for movement relative to both dies and is receivable in the die cavity with clearance. That plunger is engaged with the sheet portion on the side thereof opposite the cavity so as to apply a bias force to that portion which acts in the direction of the cavity. The annular working face is then applied to the metal sheet so as to compress an annular zone of that sheet. The combined effect of the bias force and the compression then causes material to yield in the annular zone and to be displaced from that zone to flow into the die cavity to form a hollow fastener in the clearance between the cavity and the plunger.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.