Method and apparatus for tightening threaded fastener assemblies
US4375122A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 7, 1980 |
| Grant date | Mar 1, 1983 |
| Priority date | — |
| Expiry date | Apr 7, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53687
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Apparatus and method for tightening assemblies held together by threaded fasteners. The desired tightened condition is achieved by calculating the tightening torque required to induce a preload in a fastener equal to or approximating a predetermined preload and comparing this calculated torque with the torque being imparted to the fastener to tighten the assembly. When the two torques are equal, the torque imparted to the fastener is stopped. The tightening torque is calculated by identifying properly the relationship between the actual torque-rotation curve through which the assembly is taken as it is being tightened and the theoretical torque-rotation curve for the assembly from which a theoretical tightening torque required to induce the predetermined preload is established.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.