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:
Jan. 10, 1989
Filed:
May. 18, 1987
James H Ewing, Brockton, MA (US);
MKS Instruments, Inc., Andover, MA (US);
Abstract
A proportional-control solenoid-actuated fluid valve, capable of governing relatively large volumes and rates of flow swiftly and accurately with expenditure of relatively little electrical power, includes a movable valving member positioned by an armature having a substantially frictionless spring suspension, the armature being under influence of a special force-counterbalancer in the form of a bellows proportioned and disposed to exert upon it, automatically, neutralizing forces which are substantially equal and opposite to unavoidable pressure-induced imbalances afflicting the valving member. The same pressures which tend to unbalance the valve member are impressed upon opposite sides of the bellows, one through an enabling bleed port, and resulting forces developed by the bellows over a defined area are exerted upon the armature mechanically in a counterbalancing sense.