Global Patent Index - EP 1839772 A1

EP 1839772 A1 20071003 - Method and apparatus for plastic working of hollow rack bar and hollow rack bar

Title (en)

Method and apparatus for plastic working of hollow rack bar and hollow rack bar

Title (de)

Verfahren und Vorrichtung für die plastische Verarbeitung einer hohlen Zahnstange und hohle Zahnstange

Title (fr)

Procédé et appareil pour la formation plastique d'une crémaillère creuse, et crémaillère creuse

Publication

EP 1839772 A1 20071003 (EN)

Application

EP 07005750 A 20070321

Priority

JP 2006093190 A 20060330

Abstract (en)

A preparatory working device by which a work piece (10) to be fed to a rack bar forging device is obtained. The device is provided with a die sets (22,37,48) for obtaining a diameter reduction at a location of a blank pipe, which becomes a toothed part of a rack bar, while the wall thickness being substantially unchanged or slightly increased. The device is further provided with a die set (32,44) for reducing a wall thickness at a location of the blank pipe, which becomes a connection part of the rack bar. The wall thickness reduction is one half of the initial thickness, which causes the length of the work piece (10) to be elongated. Then a rack bar forging by a die set (12,14) is done.

IPC 8 full level

B21K 1/76 (2006.01)

CPC (source: EP US)

B21K 1/767 (2013.01 - EP US); B21K 1/768 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

DE

Designated extension state (EPC)

AL BA HR MK YU

DOCDB simple family (publication)

EP 1839772 A1 20071003; US 2007204668 A1 20070906

DOCDB simple family (application)

EP 07005750 A 20070321; US 68670507 A 20070315