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:
Oct. 25, 1994
Filed:
Sep. 01, 1993
Anders Haegermarck, Tr.ang.ngsund, SE;
Abstract
This invention relates to a vacuum pump. The pump includes a pump housing (10) having upper and lower cylindrical, partly liquid filled, compression chambers (11 and 12 respectively) which are separated from each other and in which an upper and a lower part (14, 15) of a piston (12) is movable. The piston has a passage (21) which is provided with a check valve and which provides communication between the upper and the lower chamber (11 and 12 respectively). The upper chamber communicates, via an opening (26) which is provided with a check valve, with a liquid filled de-aeration receptacle (27). The lower chamber (12), during a part of the movement of the piston, via an inlet (33), communicates with the space being evacuated.