Patents Assigned to Colin F. Norton
  • Patent number: RE32579
    Abstract: A motor operated valve, typically a butterfly valve driven by .[.a synchronous.]. .Iadd.asynchronous .Iaddend.electric motor (16), is provided with a torque sensing arrangement wherein an cyclic electrical signal representative of the rotational speed of the motor is produced by magnets (22) on disc driven by the motor and Hall effect switches (23,24). The frequency of this signal is compared in a circuit (43) with the frequency of current supplied to the motor to provide an indication of motor torque. Switches (46,47) define preset torque limits for the valve. If the limits are exceeded, a signal is fed to control logic (41) which operates switches (18) to control the supply current to the motor. The speed signal from the Hall effect switches is also fed to a counter (31) to develop a count representative of movement of the valve. The output of counter (31) is compared with preset valves defined by switch circuits (37,38) to define limits of travel for the valve.
    Type: Grant
    Filed: February 12, 1986
    Date of Patent: January 19, 1988
    Assignee: Colin F. Norton
    Inventors: Raymond G. A. Harvey, David S. Evans