Fastening of sheet material
US6725521B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 2001 |
| Grant date | Apr 27, 2004 |
| Priority date | — |
| Expiry date | Aug 22, 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 (1) is inserted into sheet material (19) without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material (19). The sheet material (19) is clamped between a nose (17) and a die (16) of a riveting machine. Once the sheet material (19) is clamped, the distance between the nose (17) and the die (16) is controlled during the riveting operation by a restraint device (20, 23). This technique ensures that reaction forces generated in the joint between the nose (17) and the die (16) during riveting are absorbed in the joint as compressive stresses during the riveting operation so that the resulting joint has improved fatigue life. Furthermore, the rivet insertion load imparted into the C frame as a reaction force is applied back into the joint as a post rivet-insertion clamping load. Alternatively, a separate clamping force is applied after the rivet (1) has been inserted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.