Method of producing a sheet metal fan, and fan produced thereby

(19)

(11)

EP 0 857 528 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	23.06.1999 Bulletin 1999/25

(43)	Date of publication A2:
	12.08.1998 Bulletin 1998/33

(21)	Application number: 98101839.3

(22)	Date of filing: 03.02.1998

(51)	International Patent Classification (IPC)⁶: B21D 53/78

(84)	Designated Contracting States:
	AT BE CH 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:

04.02.1997 IT TO970082

(71)	Applicant: CORAL S.p.A.
	10040 Leini (Torino) (IT)

(72)	Inventor:
	Coral, Erminio 10040 Leini (IT)

(74)	Representative: Cerbaro, Elena et al
	STUDIO TORTA S.r.l., Via Viotti, 9 10121 Torino 10121 Torino (IT)

(54)	Method of producing a sheet metal fan, and fan produced thereby

(57) The method includes the steps of: preparing a sheet metal disk (28) with a central hole (29) coaxial with an axis (8); subjecting the disk (28) to at least a first drawing operation to form an undulated body (36) having at least a first number of radial undulations (34) defining a first number of blades (7) of the fan (6); and subjecting the undulated body (36) to a second drawing operation to vary the transverse dimension of each of the blades (7) and so obtain the fan (6). More specifically, the first drawing step forms blades (7) tapering axially, and each having a pair of facing converging lateral walls (11), and a connecting wall (12) connecting the lateral walls (11). And the blades (7) are formed by deforming portions of the disk (28) in the same direction.

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