Apparatus for assembling a screw and compressible washer
US3981170A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1975 |
| Grant date | Sep 21, 1976 |
| Priority date | — |
| Expiry date | May 8, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23P19/08
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for assembling a screw and an axially compressible washer and rolling threads on the screw blank in a single operation that results in a shank configuration immediately beneath the head of the screw that allows complete compression of the washer. The method involves assembling a washer on the blank and retaining it thereon while the washer and screw assembly are subjected to swaging forces from opposing reciprocating thread rolling dies. The washer is retained on the blank in such a manner as to allow the thread rolling dies to swage an upper section of the blank and thereafter move the washer upwardly directly adjacent the head in a single thread rolling pass.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.