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. 31, 1995
Filed:
Aug. 31, 1993
Richard W Plavidal, Los Gatos, CA (US);
Petru N Nitescu, Milpitas, CA (US);
Greg Mudwilder, San Jose, CA (US);
Richard Crockett, Milpitas, CA (US);
Applied Materials, Inc., Santa Clara, CA (US);
Abstract
A two piece throttling valve is disclosed. The valve assembly includes a stationary outer housing with an inner removable operable assembly. In this configuration the piping (pump stack) does not have to disassembled to remove, clean or replace the internal valve pieces or the in-line screen. The inner assembly can be quickly removed for cleaning. The entire valve assembly is heated to reduce deposition of volatile process byproducts on the internal valve surfaces and reduce the cleaning frequency. A wedge plate is provided in the outer stationary valve housing to mate with a sloped bottom surface of the inner valve housing such that when the inner assembly is in position in the outer valve housing there is a tight fit between adjacent sealing surfaces around the valve bore. A single flat surface seal provides vacuum sealing between the inner assembly and outer housing. A dual valve stem (shaft) seal seals the valve shaft. The seal includes an inner O-ring made of a chemically resistant material and an outer O-ring that is less chemically resistant, but has a dual-quad profile to prevent vacuum leakage. A screen in the fluid passage adjacent to and supported by the outer housing can easily be accessed from the inside of the outer housing.