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. 16, 2004
Filed:
Apr. 10, 2002
Applicant:
Inventor:
Albert Cacard, Groisy, FR;
Assignee:
Alcatel, Paris, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B 3/900 ; F16K 4/702 ;
U.S. Cl.
CPC ...
F04B 3/900 ; F16K 4/702 ;
Abstract
According to the invention, discharge noise from rotary vacuum machines having complementary profiles is attenuated by interposing between the discharge from the primary pump and the outlet to the atmosphere, a transfer device having independent cavities, e.g. cavities on a rotor rotated on a shaft, the cavities moving sequentially from the discharge to the outlet while simultaneously providing isolation between the discharge and the outlet. This achieves dynamic attenuation of the noise in a manner that is particularly simple and low cost, while also being very effective in suppressing discharge noise.