Method of rolling a screw with groove for self-locking
US4782681A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 27, 1987 |
| Grant date | Nov 8, 1988 |
| Priority date | — |
| Expiry date | Jul 27, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B39/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing a self-locking threaded element includes the steps of disposing a blank element in which the self-locking threads are to be formed between two spaced rolling dies, contacting the start ends of each die with the blank element such that one die extends from its start end to its finish end in one direction and the other die extends from its start end to its finish end in an opposite direction, applying a pressure to the rolling dies, moving the two rolling dies in opposite directions a first distance, rotating the blank element a first amount as the two dies are moved the first distance causing the two oppositely moving dies to form a helical first groove in the rotating blank element, moving the dies in such opposite direction a second distance, rotating the blank element a second amount as the two dies are moved such second distance causing the two oppositely moving dies to superimpose a second deeper groove over alternate first grooves such that the deeper grooves define the flanks of a thread having a pitch which is twice that of the first pitch and with the outer radial crest ends of the thread having a self-locking center groove defined by the first gro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.