Global Patent Index - EP 0356743 A2

EP 0356743 A2 19900307 - Mandrel rod for tube rolling mills.

Title (en)

Mandrel rod for tube rolling mills.

Title (de)

Dornstange für Rohrwalzwerke.

Title (fr)

Barre de mandrin pour laminoir de tubes.

Publication

EP 0356743 A2 19900307 (DE)

Application

EP 89114240 A 19890802

Priority

CH 325488 A 19880831

Abstract (en)

[origin: JPH02104406A] PURPOSE: To obtain a mandrel rod free from strain, light weighted and stable by making a mandrel rod for pipe rolling mill to roll a hollow stock consist of at least two inner and outer pipes. CONSTITUTION: A mandrel rod 1 consists of an outer pipe 2 and a inner pipe 3 coaxial with the outer pipe 2. Between both the pipes 2 and 3, there is an annular clearance 4, into which plastic material is poured. The outer pipe 2 is a rolled pipe made of a high alloy steel, preferably of a chromium alloy, and the outer surface of the pipe is chromium plated so as to be as hard as possible and smooth. The inner pipe 3 is also a rolled pipe made of a plain steel. The inner pipe 3 supports the outer pipe 2 through plastics as a force transmission medium in the annular clearance 4. The annular clearance 4 is completely filled with a thermosetting material which stiffly adheres to the inner surface of the outer pipe 2 and the outer surface of the inner pipe 3.

Abstract (de)

Die Dornstange (1) für Rohrwalzwerke, bei denen die Luppe (5) auf der Dornstange (1) gewalzt wird, besteht aus zwei ineinandergesteckten Rohren (2, 3). Der Ringspalt (4) zwischen den Rohren (2, 3) ist mit einem Duroplast ausgefüllt, dessen Ausdehnungskoeffizient so groß gewählt ist, daß der Duroplast auch bei Temperaturdifferenzen zwischen den Rohren (2, 3) den Ringspalt (4) vollständig ausfüllt.

IPC 1-7

B21B 25/00

IPC 8 full level

B21B 25/00 (2006.01)

CPC (source: EP US)

B21B 25/00 (2013.01 - EP US)

Designated contracting state (EPC)

BE CH DE ES FR GB IT LI NL

DOCDB simple family (publication)

EP 0356743 A2 19900307; EP 0356743 A3 19910327; BR 8904379 A 19900417; CH 679462 A5 19920228; CN 1040747 A 19900328; JP H02104406 A 19900417; US 4956988 A 19900918

DOCDB simple family (application)

EP 89114240 A 19890802; BR 8904379 A 19890831; CH 325488 A 19880831; CN 89106963 A 19890825; JP 21765889 A 19890825; US 39691789 A 19890822