Tightening apparatus
US4185701A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1977 |
| Grant date | Jan 29, 1980 |
| Priority date | — |
| Expiry date | Jul 25, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/1453
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An impact wrench having an adaptive control system for determining the yield point or some similarly significant point of a fastener assembly by detecting a signal representative of the peak deceleration of the hammer, one embodiment of which is the peak recoil value of the hammer after impacting with the anvil of the wrench, and a signal representative of the angular displacement of the output shaft of the wrench. Yield of the fastener is determined when the respective magnitudes of successive deceleration signals do not exceed the magnitude of a previously stored maximum deceleration signal by a predetermined fixed amount. Upon attaining the yield point or other similarly significant point, the wrench may be allowed to rotate the fastener an additional preselected number of degrees before shutting off.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.