Global Patent Index - EP 0882526 B1

EP 0882526 B1 20031001 - Method and device for preventing or reducing trumpet-shaped widenings on a pipe end by skew rolling of thin-walled pipes

Title (en)

Method and device for preventing or reducing trumpet-shaped widenings on a pipe end by skew rolling of thin-walled pipes

Title (de)

Verfahren und Vorrichtung zur Vermeidung oder Verminderung trompetenförmiger Aufweitungen am Rohrende beim Schrägwalzen von dünnwandigen Rohren

Title (fr)

Procédé et dispositif pour éviter ou réduire des évasements en forme de trompette à l'extrémité d'un tube lors du laminage oblique de tubes à parois minces

Publication

EP 0882526 B1 20031001 (DE)

Application

EP 98250181 A 19980526

Priority

DE 19724233 A 19970603

Abstract (en)

[origin: EP0882526A2] The prevention or reduction of the trumpet like expansion of the pipe end during rolling of thin walled pipes on an Assel mill comprises reducing the degree of radial forming of the blank as the front end of the hollow blank enters into the mill, in comparison to the stationary state of rolling, and/or increasing the resistance torque of the blank cross section at the front end by reduction of the tangential material flow. At least one roll and preferably all rolls (A) are provided quick acting hydraulic closing and opening units which allow the rolls to be set radially against the rolled material (C, D), in a short time interval and also against the rolling force. The maximum closure distance of each movable roll is equal to the corresponding shoulder height or to the maximum wall thickness reduction.

IPC 1-7

B21B 19/06

IPC 8 full level

B21B 19/06 (2006.01)

CPC (source: EP)

B21B 19/06 (2013.01)

Designated contracting state (EPC)

AT DE ES FR IT SE

DOCDB simple family (publication)

EP 0882526 A2 19981209; EP 0882526 A3 20020206; EP 0882526 B1 20031001; AT E250990 T1 20031015; DE 19724233 A1 19981210; DE 19724233 C2 20031016; DE 59809767 D1 20031106

DOCDB simple family (application)

EP 98250181 A 19980526; AT 98250181 T 19980526; DE 19724233 A 19970603; DE 59809767 T 19980526