EP 0331613 A3 19900919 - METHOD AND APPARATUS FOR PRODUCING A CORRUGATED TUBE
Title (en)
METHOD AND APPARATUS FOR PRODUCING A CORRUGATED TUBE
Publication
Application
Priority
DE 3807002 A 19880301
Abstract (en)
[origin: EP0331613A2] The invention relates to a method for producing a helically profiled hollow body from a metallic material, in which a rotatably mounted drawing die having obliquely cut grooves is made to act on a cold hollow body with a smooth cylinder wall and the cross-section of the hollow body is reduced in the process. In order to provide a method and a device with which it is possible to produce in a simple and economical manner a thin-walled tube having a twisted profile over the entire wall thickness, it is proposed that to produce a tube which, in cross-section, has a corrugated profile over the entire wall thickness, a smooth tube with an s/D ratio in the range from 0.015 to 0.080 is drawn to a smaller diameter through the rotatably mounted drawing ring having obliquely cut grooves, the length of the envelope curve of the outer profile of the profiled tube being approximately equal to the circumference of the smooth tube and the wall thickness remaining virtually unaltered.
IPC 1-7
IPC 8 full level
B21C 37/20 (2006.01)
CPC (source: EP)
B21C 37/207 (2013.01)
Citation (search report)
- GB 1131585 A 19681023 - CALUMET & HECLA
- CH 588311 A5 19770531 - JANSEN AG
- FR 2156707 A1 19730601 - PHELPS DODGE IND INC
- GB 321017 A 19291031 - BROMFORD TUBE COMPANY LTD, et al
- US 2852835 A 19580923 - HERBERT HARVEY, et al
- FR 2477917 A1 19810918 - MANSFELD KOMBINAT W PIECK VEB [DD]
- FR 2477971 A1 19810918 - CII HONEYWELL BULL [FR]
Designated contracting state (EPC)
AT BE FR GB IT NL SE
DOCDB simple family (publication)
DE 3807002 C1 19890427; EP 0331613 A2 19890906; EP 0331613 A3 19900919
DOCDB simple family (application)
DE 3807002 A 19880301; EP 89730016 A 19890124