Method and system for tightening joint assembly
US4104780A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1976 |
| Grant date | Aug 8, 1978 |
| Priority date | — |
| Expiry date | Dec 29, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49767
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The preferred embodiment of the invention disclosed herein relates to a method of and a tightening system for tightening a joint assembly including a fastener system to a yield point of one of the members in the assembly. According to the method torque is applied and rotation is imparted to a fastener member and the instantaneous slope of the Torque-Rotation curve which could be plotted is determined between successive increments of rotation of the fastener member. Each instantaneous slope is compared with the preceding instantaneous slope to determine the change in the slope of the curve. When the instantaneous slope of the curve decreases a predetermined consecutive number of times equal to a predetermined span of rotation divided by the interval between successive increments of rotation, tightening is discontinued. The tightening system includes a wrench and a control system associated with the wrench including gradient calculating means for determining the instantaneous slope between successive increments of rotation of the Torque-Rotation curve and for determining an instantaneous gradient signal representative thereof. Comparator means responsive to the instantaneous gradient…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.