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, 2000
Filed:
Mar. 25, 1999
Charles F Drexel, Rancho Palos Verdes, CA (US);
DXL USA Inc., Torrance, CA (US);
Abstract
A fluid valve assembly including a ball valve within a central hole in a resilient disc-shaped spring. The spring has additional openings to minimize resistance to fluid flow from inlet to outlet. Clearance between the spring and side walls of the cavity within which it is mounted allows the ball to center itself in its seat. The central hole diameter, ball diameter and separation between the spring and seat are selected to create an upward force on the ball over its entire stroke which provides a frictional force between the spring and a supporting lip to minimize radial motion of the spring to keep the ball aligned. The force also overcomes the weight of the ball in applications where the inlet pressure is very low, and also overcomes adhesion of the ball to the seat. The assembly is incorporated in a mass flow controller typically used with semiconductor fabrication processes.