Method for tightening a screw connection and screw driving tool
US8025106B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 24, 2007 |
| Grant date | Sep 27, 2011 |
| Priority date | — |
| Expiry date | May 24, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B21/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method for screwing in and tightening a screw connection (1) to a predetermined tightened level (2), especially a predetermined torque level (2) or a predetermined pretension level, with the aid of a hand-held screwing tool (3) comprising a regulated drive unit (4) and/or control functionality, particularly an electric nut runner (3). A tightening phase (B-C-D), during which the screw head rests against the supporting surface (6) of the screw connection (1), starts following a screwing phase (A). In order to improve said method, the speed (N) of the screwing tool (3) is increased to an output speed (7) for the tightening phase (B-C-D) within an acceleration time (8) in the tightening phase (B-C-D) and is lowered within a delay time (9) prior to or until reaching the predetermined tightened level (2). The combined acceleration time (8) and delay time (9) represents the predominant part of the entire tightening phase (B-C-D), especially in relation to the traveled angle of twist (W) of the screw connection (1), the acceleration time (8) being shorter than the delay time (9).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.