Device for tightening threaded joints
US5245747A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 1992 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Feb 4, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53061
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention concerns a device for tightening threaded joints in two subsequent steps, namely a first step during which a joint is tightened to a predetermined torque snug level and a second step during which the joint is further tightened up to a final predetermined pretension level. During the second tightening step the angle speed of the power tool (10) is gradually increased at a predetermined rate. The power tool (10) comprises an electric brushless motor which is supplied with power from a variable frequency output inverter (11), and the gradual increase in angle speed of the power tool (10) is accomplished by a gradually increased output frequency and voltage from the power supply means (11).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.