(19)
(11) EP 0 936 357 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
10.01.2001 Bulletin 2001/02

(43) Date of publication A2:
18.08.1999 Bulletin 1999/33

(21) Application number: 99301044.6

(22) Date of filing: 12.02.1999
(51) International Patent Classification (IPC)7: F04D 27/02, F01D 17/10
(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: 13.02.1998 US 23217
13.02.1998 CA 2229352

(71) Applicant: PRATT & WHITNEY CANADA CORP.
Longueuil, Quebec J4G 1A1 (CA)

(72) Inventor:
  • Liu, Xiaoliu
    Mississauga, Ontario L5M 4K7 (CA)

(74) Representative: Johnson, Terence Leslie 
Edward Evans & Co., Clifford's Inn, Fetter Lane
London EC4A 1BX
London EC4A 1BX (GB)

   


(54) Compressor bleed valve


(57) A bleed valve 110 is in fluid communication with the compressor fluid flow path and the bypass fluid flow path 112 whereby a piston 126 extends radially of the valve 110 and includes a piston head 134 radially remote from the compressor fluid flow path. A pneumatic chamber 132 surrounds a portion of the piston head 134, and air from a source downstream of the impeller is introduced into the chamber. The piston including a valving member 136 and a rigid sleeve 130 connecting the piston head 134 to the valving means opens or closes the communication between the compressor flow path and the bypass flow path 112. A precompressed spring 144 is associated with the piston to normally urge the piston 120 radially outwardly relative to the compressor fluid flow path to a valve open position, and when the pneumatic pressure in the chamber surrounding the piston head overcomes the precompressed spring, the valve is closed.






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