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:
Mar. 02, 1999
Filed:
Dec. 05, 1996
Arthur Spring, Flawil, CH;
Buchi Labortechnik AG, Flawil, CH;
Abstract
A vacuum membrane pump includes a housing, a membrane and a head portion having a sealing surface which engages with a sealing edge of the membrane to form a seal. A pump chamber is formed between the head portion and the membrane. The head portion is cast from glass, and has at least one penetrating opening for accommodating a valve element on the side away from the pump chamber. The membrane rests with its sealing edge on a shoulder of the housing and, with the sealing edge, engages with the sealing surface of the head. The valve element is in turn engaged with the inside of the openings of the head. A closure connected to the housing delivers an axial force to the valve element. The valve element, the head, and the membrane are pressed together to form a sealed assembly.