Tightening system
US4163310A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1976 |
| Grant date | Aug 7, 1979 |
| Priority date | — |
| Expiry date | Dec 29, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49766
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A tightening and control system is disclosed for automatically tightening a fastener to a predetermined tightened condition in a workpiece, where the fastener is of the type which exhibits more than one installation region on a graph of two tightening characteristics during a complete tightening cycle. Typical of such fasteners are thread tapping fasteners, such as thread-cutting or thread forming types, which first generate a mating thread in a workpiece material and thereafter are tightened in the workpiece to a predetermined load condition. Such fasteners typically exhibit a curve of two related input tightening characteristics, such as torque and rotation, having a thread forming region characterized by a generally linear portion followed by a marked drop off in the slope, an intermediate region having several possible characteristic shapes, and a tightening region having a somewhat similar shape to the thread forming region. Apparatus is generally disclosed for determining the gradient of the torque-rotation curve through which the assembly is being tightened, determining when a first condition indicative of having formed the thread has occurred, and thereafter determining whe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.