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:
Sep. 12, 1995
Filed:
Jun. 24, 1994
Giampaolo Levi, Turin, IT;
John C Helmer, Menlo Park, CA (US);
Varian Associates, Inc., Palo Alto, CA (US);
Abstract
The present invention relates to turbomolecular pumps comprising one or more tangential flow pumping stages in addition to axial flow pumping stages, so as to raise the pump exhaust pressure up to the atmospheric pressure, wherein at least one tangential flow pumping stage having a tangential flow pumping channel of improved design. The channel is located between the lateral surface of the rotor disk and the annular inner wall of stator and comprises an upper closure plate provided with suction port and a lower closure plate provided with diskharge port wherein these ports operably coupled to the tangential flow pumping channel. The cross-section area of the channel is enlarged from its periphery portion defined by the lateral surface of the rotor disk to a central portion defined by the upper and lower closure plates.