Method for producing male conical threads
US4689984A · kind A · utility
Inventor
Key dates
| Filing date | Dec 23, 1985 |
| Grant date | Sep 1, 1987 |
| Priority date | — |
| Expiry date | Dec 23, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21K1/56
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A male conical thread of an elongated steel structure, e.g. a steel rod or wire of the type employed as reinforcement in pre-stressed concrete, for use in engagement with a matching female conical thread provided in a fixing sleeve or other nut means is formed by first shaping an end portion of the wire or rod, e.g. by grinding or hammering, into a cone that tapers down towards the end of the rod or wire and has a generally truncated smooth outer surface; then, the cone's surface is deformed by cold-pressing such that the thread is formed. Further, a press-die appartus is disclosed for use in such cold-pressing, e.g. at a construction site where steel reinforcements are mounted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.