Patent · US Expired

Digitally controllable flow rate valve

US5887847A · kind A · utility

47Cited by
5References
1Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 18, 1997
Grant dateMar 30, 1999
Priority date
Expiry dateSep 18, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05D16/2095
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A digitally controllable valve has a main valve member mounted on a diaphragm for movement sealing and exposing a main valve seat. A flow restriction on the main valve member varies the flow rate as a function of displacement of the main valve member from the main valve seat. Pressure in a reservoir above the diaphragm is controlled by two pilot valves respectively connected to the inlet and outlet ports of the main valve, one of which has fluid passageway with a larger minimum cross sectional area than the other. Both pilots communicate with the reservoir through a single common bleed opening which has an area less than the minimum cross sectional areas of pilot valve flow passageways.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.