Global patent index - EP 1006281 A1

EP 1006281 A1 2000-06-07 - Multi-stage roots pump

Title (en)

Multi-stage roots pump

Title (de)

Mehrstufige Roots-Pumpe

Title (fr)

Pompe Roots multiétagée

Publication

EP 1006281 A1 (EN)

Application

EP 99123818 A

Priority

JP 34501198 A

Abstract (en)

A multi-stage Roots pump has a plurality of parallel pump chambers formed in the casing thereof. Each pump chamber has a pair of rotors arranged therein for rotation to effect a pumping action, an intake port and an exhaust port. Exhaust ports of pump chambers of the preceding stages are connected to intake ports of pump chambers of the succeeding stages through communication holes, one after another, in series. The communication hole extends across an imaginary plane that include the axes of shafts and is perforated in the casing between the shafts so that the communication hole does not contact the shafts. <IMAGE>

IPC 1-7 (main, further and additional classification)

F04C 18/12; F04C 23/00

IPC 8 full level (invention and additional information)

F04C 18/18 (2006.01); F04C 2/08 (2006.01); F04C 18/12 (2006.01); F04C 23/00 (2006.01); F04C 25/02 (2006.01); F04C 29/00 (2006.01); F04C 29/12 (2006.01)

CPC (invention and additional information)

F04C 18/126 (2013.01); F04C 23/001 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR NL

EPO simple patent family

EP 1006281 A1 20000607; JP 2000170679 A 20000620; KR 20000047492 A 20000725; TW 436585 B 20010528

INPADOC legal status

2001-07-11 [18W] WITHDRAWN

- Ref Legal Event Code: 18W

- Date of withdrawal: 20010519

2001-02-21 [AKX] PAYMENT OF DESIGNATION FEES

- Ref Legal Event Code: AKX

- Free Format Text: DE FR NL

2000-06-07 [17P] REQUEST FOR EXAMINATION FILED

- Ref Legal Event Code: 17P

- Effective date: 19991201

2000-06-07 [AK] DESIGNATED CONTRACTING STATES:

- Ref Legal Event Code: AK

- Designated State(s): DE FR NL

2000-06-07 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

- Ref Legal Event Code: AX

- Free Format Text: AL;LT;LV;MK;RO;SI