(19)
(11) EP 0 428 355 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
03.07.1991 Bulletin 1991/27

(43) Date of publication A2:
22.05.1991 Bulletin 1991/21

(21) Application number: 90312319.8

(22) Date of filing: 12.11.1990
(51) International Patent Classification (IPC)5: B21D 15/02
(84) Designated Contracting States:
AT BE CH DE DK ES FR GB GR IT LI LU NL SE

(30) Priority: 14.11.1989 GB 8925669

(71) Applicant: WEST (IPSWICH) LIMITED
Ipswich, Suffolk (GB)

(72) Inventors:
  • Van den Burgh, Jack Malcolm Bruce
    Felixstowe, Suffolk, IP10 0JD (GB)
  • Hall, Peter
    Ipswich, Suffolk (GB)

(74) Representative: Dummett, Thomas Ian Peter et al
Dummett Copp & Co. 25 The Square
Martlesham Heath, Ipswich, Suffolk IP5 7SL
Martlesham Heath, Ipswich, Suffolk IP5 7SL (GB)


(56) References cited: : 
   
       


    (54) Method and apparatus for forming ducting


    (57) The present invention provides a method for forming polygonal ducting from an intially circular cross-section duct by radially expanding a mandrel within the duct so as to cause radial deformation of the duct into the desired shape. The invention also provides a mandrel for use in the method of the invention.







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