EP 0072891 B1 19851113 - METHOD OF AND DEVICE FOR CONICALLY WIDENING METAL TUBES BY COMPRESSED AIR
Title (en)
METHOD OF AND DEVICE FOR CONICALLY WIDENING METAL TUBES BY COMPRESSED AIR
Publication
Application
Priority
DE 3133257 A 19810822
Abstract (en)
[origin: EP0072891A1] 1. Process for the conical widening of metal tubes (16), wherein the cylindrical metal tube, which is to be shaped into conical form and is closed at one end and open at the other end, is sealed in an airtight manner at the open end, the interior space is placed under pressure by means of a pneumatic medium. And the cylindrical metal tube is pressed onto the interior wall of the matrix (5) designed with a conical recess, characterised in that, due to the linear pressing of the outer edge of the open end of the cylindrical metal tube (16), the metal tube is sealed in an airtight manner against the chamfered sealing surface (2) of the metallic sealing ring (1) which is under spring pressure, and, during the conification process, in order to permit the further build-up of pressure, an inward-directed sealing chamfer (6) is produced at the open edge of the metal tube (16) by means of the axial movement of the sealing ring (1) in the direction of the tube.
IPC 1-7
IPC 8 full level
B21D 26/02 (2006.01); B21D 51/36 (2006.01)
CPC (source: EP)
B21D 51/36 (2013.01)
Designated contracting state (EPC)
CH DE FR IT LI
DOCDB simple family (publication)
EP 0072891 A1 19830302; EP 0072891 B1 19851113; DE 3133257 A1 19830303; DE 3267377 D1 19851219
DOCDB simple family (application)
EP 82104100 A 19820512; DE 3133257 A 19810822; DE 3267377 T 19820512