Method for determining the installed torque in a screw joint at impulse tightening and a torque impulse tool for tightening a screw joint to a predetermined torque level
US6134973A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 26, 1998 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Oct 26, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/1405
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A basic method is provided for determining the installed torque in a screw joint which is being tightened by a series of repeated torque impulses. The rotational movement of the screw joint is detected during each impulse. The point in which the screw joint ceases to rotate is detected. And the actually applied torque is indicated at the very instance the screw joint ceases to rotate. In a tightening process control application of the above described basic method, the per impulse increasing value of the installed torque is compared to a predetermined target value in a way known per se, and the tightening process is interrupted as the target value is reached. In a tightening process quality check application of the above described basic method, the accomplished angular displacements of the joint at repeated impulses are indicated and added, and high and low limit values for the final installed torque and the total angle of rotation are provided and compared to the actually obtained values. A torque impulse delivering power tool employing the above-described basic method, moreover, includes an impulse generator (12) with an output shaft (13) having a torque transducer (23) and a rota…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.