EP 0133245 A3 19850724 - A METHOD FOR FORMING AN ELECTRIC RESISTANCE WELDED STEEL PIPE
Title (en)
A METHOD FOR FORMING AN ELECTRIC RESISTANCE WELDED STEEL PIPE
Publication
Application
Priority
- IN 376CA1989 A 19890515
- JP 13193883 A 19830721
Abstract (en)
[origin: EP0133245A2] The invention provides an improvement in the method of forming a skelp into a rounded tubular form in the preparation of an electric resistance welded steel pipe. Different from conventional methods, the skelp in bent in the initial and intermediate forming stages within a limited region alone along the centerline thereof to have a U-shaped forming flower. Thereafter, the edge portions of the bent skelp are bent in the upstream fin pass rolls to have a curvature of at least 80% of the final curvature with simultaneous overbending in the boundary regions on both sides of the side portions of the rounded skelp. Finally, the rounded skelp is pressed down in the direction to decrease the vertical diameter to bulge out in the transverse direction with simultaneous unbending the overbent portions into the final curvature.
IPC 1-7
IPC 8 full level
B21C 37/08 (2006.01); B21D 5/12 (2006.01)
CPC (source: EP)
B21C 37/08 (2013.01); B21D 5/12 (2013.01)
Citation (search report)
- [AD] US 4339938 A 19820720 - NAKAGAWA MAKOTO, et al
- [X] US 2234450 A 19410311 - QUARNSTROM BERT L
- [A] US 2563214 A 19510807 - CROSON CLYDE R
- [A] US 2998047 A 19610829 - MALLY GEORGE G, et al
- [A] US 2948324 A 19600809 - RONALD PENROSE JAMES
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0133245 A2 19850220; EP 0133245 A3 19850724; EP 0133245 B1 19880928; IN 172377 B 19930710; JP H0372366 B2 19911118; JP S6024220 A 19850206
DOCDB simple family (application)
EP 84108542 A 19840719; IN 376CA1989 A 19890515; JP 13193883 A 19830721