Method of manufacturing long dual layer metal pipe

(19)

(11)

EP 0 950 441 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	02.05.2001 Bulletin 2001/18

(43)	Date of publication A2:
	20.10.1999 Bulletin 1999/42

(21)	Application number: 99106946.9

(22)	Date of filing: 08.04.1999

(51)	International Patent Classification (IPC)⁷: B21C 37/06, B21C 37/15

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

08.04.1998 JP 9552998

(71)	Applicant: DAIDO TOKUSHUKO KABUSHIKI KAISHA
	Naka-ku Nagoya-shi Aichi-ken (JP)

(72)	Inventors:
	Shimizu, Takao, Yagoto Sanhaitsu 501, Nagoya-shi, Aichi (JP) Horio, Hirotsugu Toukai-shi, Aichi (JP) Yamamoto, Noboru Nagoya-shi, Aichi (JP) Inagaki, Shigeyuki Nagoya-shi, Aichi (JP)

(74)	Representative: Diehl, Hermann, Dr. et al
	DIEHL, GLÄSER, HILTL & PARTNER, Augustenstrasse 46 80333 München 80333 München (DE)

(54)	Method of manufacturing long dual layer metal pipe

(57) The present invention relates to a method for manufacturing a long dual layer metal pipe (50) which comprises the following steps. Namely, a joined body (30) of inner metal pipes is inserted into a joined body (10) of outer metal pipes. The joined body (30) of inner metal pipes has an outer diameter smaller than an inner diameter of the joined body (10) of outer metal pipes. The joined body (30) of inner metal pipes has one or more joining portions. The joined body of outer metal pipes has one or more joining or clamping portions. Then the joined body of inner metal pipes is expanded to manufacture a dual layer metal pipe (50).

Search report