EP 0225262 B1 19901003 - METHOD OF CREATING HELICAL THREADS WITH ZERO OR NEGATIVE SIDE INCLINATION
Title (en)
METHOD OF CREATING HELICAL THREADS WITH ZERO OR NEGATIVE SIDE INCLINATION
Publication
Application
Priority
FR 8516324 A 19851028
Abstract (en)
[origin: US4799372A] A process for forming a helical screw thread comprising a flank with negative inclination on the wall of a rotationally symmetrical body (19) such as a metal pipe or tube. A first phase involves producing a screw thread having flanks with a positive inclination and then a second phase involves modifying the inclination of one of the flanks (24) by plastic deformation to make it negative (32). For that purpose, use is made of a roller (26) mounted on an inclined axis (X2-X2), which rolls against the flank of the thread.
IPC 1-7
IPC 8 full level
B21H 3/04 (2006.01); B23G 1/02 (2006.01); F16L 15/00 (2006.01)
CPC (source: EP US)
B21H 3/04 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE DE GB IT NL SE
DOCDB simple family (publication)
EP 0225262 A1 19870610; EP 0225262 B1 19901003; AT E57116 T1 19901015; DE 3674737 D1 19901108; FR 2589092 A1 19870430; FR 2589092 B1 19871113; JP S62104640 A 19870515; US 4799372 A 19890124
DOCDB simple family (application)
EP 86420265 A 19861027; AT 86420265 T 19861027; DE 3674737 T 19861027; FR 8516324 A 19851028; JP 25670386 A 19861028; US 92321586 A 19861027