Coldwork holes with reusable seamless SMA sleeve
US6266991A · kind A · utility
Inventor
Key dates
| Filing date | Apr 3, 2000 |
| Grant date | Jul 31, 2001 |
| Priority date | — |
| Expiry date | Apr 3, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23P9/025
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for coldworking holes using a reusable tubular seamless sleeve made of shape memory alloys. The apparatus uses a pre-lubricated tubular seamless sleeve made of shape memory alloys having a superelasticity property, a mandrel having a major diameter portion, an end-cap with a rough surface, and an adapting-spacer having a rough complementary surface. The preferred coldworking operation includes the steps of placing the sleeve firmly between the rough surfaces of the end-cap and the adapting-spacer which are carried on a mandrel pulling means, passing forward the major diameter portion of the mandrel through the sleeve whose diameter is therefore elastically expanded and thereafter shrinks to a size sufficiently smaller than the diameter of a hole in a workpiece, inserting the sleeve together with the mandrel into said hole, placing the end-cap against the workpiece, retracting the mandrel backward through and out of the sleeve; thereby elastically expanding the sleeve wall against the hole bore and exerting radial outward forces on the sleeve which in turn transmitting the coldworking force to the hole bore; thereafter the sleeve diameter shrinking to a size s…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.