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. 01, 1996
Filed:
May. 16, 1995
Yoshiki Aruga, Tama, JP;
Naoyuki Suzuki, Fussa, JP;
Anelva Corporation, , JP;
Abstract
A bridge-type main valve located at a connecting outlet between a vacuum chamber and a main vacuum pump, and having a rod of an electric cylinder driven by a stepper motor connected to a valve seat for opening and dosing the connecting outlet so that the driving direction and a closing surface of the valve seat form a right angle. A piston may be attached to the rod, and a cylindrical housing fitted in the piston so that the piston and the cylindrical housing form a pressurized air pumping chamber for moving the rod and the valve seat in the outlet closing direction. The valve can achieve fine pressure adjustment without any variable orifice by stopping a valve seat at an arbitrary (not stepwise) position.