Rolling flat die for manufacturing a screw with groove for self-locking
US4782688A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1987 |
| Grant date | Nov 8, 1988 |
| Priority date | — |
| Expiry date | Jul 24, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B39/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A rolling flat die operable on a blank to produce a threaded element having self-locking threads includes a flat die moveable in a forward direction to engage the blank and form the self-locking threads on the blank. The flat die has a first section and a second section, the first section having a first plurality of first thread-forming parts having a first outer crest and a first inner root, the second section having a plurality of second thread-forming parts parallel to one another and parallel to the first thread-forming parts, each of the second thread-forming parts having a second outer crest and a second inner root. The first section of the flat die is operable to form a helical first groove on the blank and the second section of the flat die is operable to superimpose a second deeper groove over alternate first grooves such that the second deeper groove defines the flanks of a thread with the second deeper groove having a second groove pitch which is greater than that of the first groove pitch and with the outer crests of the thread having a self-locking center groove defined by the first groove.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.