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:
Dec. 02, 1997
Filed:
Jun. 07, 1995
Raymond P Champagne, Sterling, MA (US);
Neles-Jamesbury, Inc., Worcester, MA (US);
Abstract
The invention attenuates higher frequency vibrations or oscillations which can result in wear and/or less than optimal performance of a valve positioner. The invention provides a low pass mechanical filter which can be realized, for example, in a dash pot like damper device. The damper includes a pair of diaphragms associated with a pair of chambers, which are in communication with one another by an orifice. The chambers associated with each diaphragm are filled with oil or a hydraulic fluid such that the rate of relative motion (for example between a summing beam of the positioner and the location at which a signal force is applied) is controlled by flow of oil through the orifice.