Tightening system
US3974883A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 19, 1975 |
| Grant date | Aug 17, 1976 |
| Priority date | — |
| Expiry date | May 19, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D17/02
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention disclosed herein relates to a tightening system including a wrench for applying torque and imparting rotation to a fastener system. Associated with the wrench is a control system including measuring systems for developing a first signal representative of the torque applied to the fastener being tightened and a second signal representative of the rotation of the fastener, both of which are fed to a gradient calculating system for developing a signal representative of the slope of a Torque-Rotation curve which can be plotted for the particular fastener being tightened. The gradient signal is used to develop a signal representative of a theoretical curve which is processed with one of the previously developed signals to develop a control signal when the fastener has been tightened to its yield point or some similarly significant point. In one embodiment of the invention, the theoretical curve signal is representative of a curve which ultimately becomes parallel to the linear portion of the Torque-Rotation curve and whose linearity is maintained when the Torque-Rotation curve deviates. The difference between the theoretical torque signal and the instantaneous torque signa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.