Patent · US Expired

Method of making screws and dies therefor

US4561277A · kind A · utility

9Cited by

9References

9Claims

0Family size

Assignee

Conti Fasteners · CH

Inventors

Hubert Taubert · Neuwied, DE
Rudolf Webendoerfer · Neuwied, DE

Key dates

Filing date	Aug 29, 1984
Grant date	Dec 31, 1985
Priority date	—
Expiry date	Aug 29, 2004

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB21H3/025
WIPO fieldMachine tools
WIPO sectorMechanical engineering

Abstract

Method and dies for threading a screw comprises providing a screw blank with a portion of its length of lobular cross section and an adjacent portion of the blank of circular cross section. The blank is rolled between roll dies so as to roll the thread on the circular portion and simultaneously roll the thread at the lobes only on the lobular portion. Thereafter, the blank is rolled to additional regions of the dies wherein the thread is rolled to form on the lobular section, while the cylindrical section passes through regions of clearance or relief on the dies.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.