Multi-stage hydraulic stretcher for elongated fasteners
US4074890A · kind A · utility
9Cited by
2References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1976 |
| Grant date | Feb 21, 1978 |
| Priority date | — |
| Expiry date | Oct 26, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Hydraulic device for exerting a pre-stressing traction on bolts or pins comprises three stages, with each stage comprising a piston within a chamber. The thickness of the skirts of the piston increases from stage to stage in proportion to the pressure to which the piston of that stage is subjected during a stretching operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.