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:
Jun. 19, 1990
Filed:
Apr. 11, 1989
Applicant:
Inventors:
David A Turrell, Burgess Hill, GB;
Nigel T Dennis, Crawley, GB;
Assignee:
The BOC Group, PLC, Windlesham, GB;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04C / ;
U.S. Cl.
CPC ...
418-9 ; 418 88 ; 418 95 ;
Abstract
A vacuum pump system comprising a first vacuum pump having at least one pumping chamber with port means for communication with an enclosure to be evacuated and having mechanical pumping means mounted on at least one shaft whose bearings and/or gears are contained in a housing and a second vacuum pump having a first pumping chamber with means for communication with the chamber of the first pump and at least one further pumping chamber wherein means are provided for communication between the housing of the first pump and a further pumping chamber of the second pump.