Patents Assigned to HNL Instruments & Controls Limited
  • Flow sensing devices
    Patent number: 4397195
    Abstract: A flow sensing device comprises a shaft which is axially movable, and extends across a flow passageway, and carries an angled vane in the passageway. At each side of the passageway, the shaft is supported by a diaphragm which also prevents the leakage of fluid from the passageway beside the shaft. The two diaphragms are of equal area, so that any static pressure within the passageway does not result in a net pressure force tending to move the shaft axially. No other support is provided for the shaft.
    Type: Grant
    Filed: July 16, 1981
    Date of Patent: August 9, 1983
    Assignee: HNL Instruments & Controls Limited
    Inventor: Terence J. Hayward
  • Valves
    Patent number: 4204553
    Abstract: A fluid control valve, especially intended as a pilot valve in pneumatic control systems, in which the controlled flow path is provided by the gaps between adjacent coils of a helical spring. The flow direction is from the outside to the inside of the spring; this allows the valve to seal against high pressures, since the spring will be helped to remain closed by the pressure forces acting thereon.
    Type: Grant
    Filed: June 14, 1978
    Date of Patent: May 27, 1980
    Assignee: HNL Instruments & Controls Limited
    Inventors: Terence J. Hayward, Alan H. T. Berrecloth