The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 22, 2014
Filed:
Sep. 01, 2011
Applicants:
Nigel Paul Schofield, Horsham, GB;
Peter Hugh Birch, Horsham, GB;
Inventors:
Nigel Paul Schofield, Horsham, GB;
Peter Hugh Birch, Horsham, GB;
Assignee:
Edwards Limited, West Sussex, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F03C 2/00 (2006.01); F03C 4/00 (2006.01); F04C 2/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A multistage vacuum pump includes a stator housing a multistage rotor assembly, each stage having intermeshing Roots rotor components, wherein the tip radius of the rotor components at an inlet stage of the pump is larger than the tip radius of the rotor components at an exhaust stage of the pump, wherein a meshing clearance between the rotor components at the inlet stage of the pump is greater than a meshing clearance between the rotor components at the exhaust stage of the pump.