Global Patent Index - EP 0811444 B1

EP 0811444 B1 20020227 - Method of wall-thickening metal pipes

Title (en)

Method of wall-thickening metal pipes

Title (de)

Verfahren zur Erhöhung der Wanddicke von Metallrohren

Title (fr)

Méthode pour augmenter l'épaisseur de paroie de tubes métalliques

Publication

EP 0811444 B1 20020227 (EN)

Application

EP 97109237 A 19970606

Priority

JP 14531696 A 19960607

Abstract (en)

[origin: EP0811444A1] To produce a metal pipe which has a desired region of increased thickness with an outer diameter identical to or substantially identical to the outer diameter of the remaining portion by means of cold working with utmost ease and saved cost, a method of processing metal pipes into a thick-walled structure is comprised of a first stage in which a punch (3) provided with a tapered portion is inserted into a starting metal pipe (1) at one of both ends thereof, thereby forming a diametrically expanded region thereat, and a second stage in which the expanded region of the pipe is inserted into a contracting die (5) provided with a tapered portion (5b), thereby contracting the expanded region at a given outer diameter. <IMAGE>

IPC 1-7

B21J 5/08; B21K 21/12

IPC 8 full level

F01N 13/08 (2010.01); B21C 37/15 (2006.01); B21C 37/16 (2006.01); B21D 39/04 (2006.01); B21D 41/02 (2006.01); B21J 5/08 (2006.01); B21K 21/12 (2006.01); F16L 13/14 (2006.01)

CPC (source: EP)

B21C 37/16 (2013.01); B21J 5/08 (2013.01); B21K 21/12 (2013.01)

Designated contracting state (EPC)

DE FR GB

DOCDB simple family (publication)

EP 0811444 A1 19971210; EP 0811444 B1 20020227; DE 69710640 D1 20020404; DE 69710640 T2 20020808; JP 2776796 B2 19980716; JP H09327723 A 19971222

DOCDB simple family (application)

EP 97109237 A 19970606; DE 69710640 T 19970606; JP 14531696 A 19960607