Patent · US Expired

Valve arrangement for closed-loop control system

US4116321A · kind A · utility

23Cited by
6References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 27, 1976
Grant dateSep 26, 1978
Priority date
Expiry dateDec 27, 1996

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16D2500/7109
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A two-stage, four-way valve has fluid input and output connections, and passes a fluid under controlled pressure to an actuator to operate any component. Such operation is sensed and, after comparison with a reference signal, a control signal regulates the duty cycle of a pulse-width modulation (PWM) circuit. The output square-wave signal from the PWM circuit regulates a solenoid incorporated in the valve, to modify its operation and regulate the pressure of the controlled fluid. The valve has a spool which effectively integrates the PWM signal and provides a type 1 servo system when connected in a closed loop system.

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