Patents by Inventor Gerald Duncan

Gerald Duncan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070101772
    Abstract: A laundry machine configured to supply a first amount of water to the wash tub wherein a wash plate can be oscillated such that clothes items directly above and in contact with the impeller are frictionally dragged in a oscillatory manner with the wash chamber while continuing to oscillate said wash plate, an additional supply of water is added to said wash tub such that as cloth items lost frictional engagement with the wash plate, the cloth items continue to move along an inverse toroidal rollover path at higher water levels.
    Type: Application
    Filed: September 7, 2006
    Publication date: May 10, 2007
    Inventors: Anna Duncan, Erin Hall, Geoffrey Walker, Gerald Duncan, Flavio Bernardino, Mary Zeitler, David Carr
  • Publication number: 20060171822
    Abstract: A linear compressor comprising has a cylinder part including a cylinder bore. A piston disposed in, and is slidable within, the bore. A main spring connects the cylinder part directly or indirectly the piston. A connecting rod connects between the main spring and the piston. A stator has an air gap, and the connecting rod passes through the air gap. At least one armature pole is located along the connecting rod. Other inventions are also set forth.
    Type: Application
    Filed: March 31, 2006
    Publication date: August 3, 2006
    Inventors: Neville Seagar, Ian McGill, Gerald Duncan, Upesh Patel, Andrew Taylor, Geoffrey Lee
  • Publication number: 20050158193
    Abstract: A linear compressor includes a cylinder part and a piston part. A spring connects the cylinder part and the piston part and operates in the direction of reciprocation of the piston part relative to the cylinder part. The piston part includes a radially compliant but axially stiff linkage and piston. The cylinder part includes a cylinder and a cylinder liner therewithin. A bore runs through the cylinder liner and the piston reciprocates in the bore. Gas bearing passages are formed between the cylinder and the cylinder liner leading to opening through the wall of the cylinder liner to the bore. A gas bearing manifold receives compressed gases and supplies the compressed gases to the gas bearing passages. The gas bearing passages follow a tortuous path to the openings.
    Type: Application
    Filed: January 25, 2005
    Publication date: July 21, 2005
    Inventors: Lindsey Roke, Ian McGill, Gerald Duncan, William Ferguson, Andrew Taylor
  • Patent number: 6034493
    Abstract: An electronically commutated brushless DC motor primarily for fractional horsepower applications of the type where at any instant one motor winding is unpowered and used to detect back EMF zero-crossings which information is used to initiate winding commutations. The duration of the pulse produced in this winding due to dissipation of stored energy by free-wheel diodes in parallel with the commutation devices after supply of current has been removed from this winding is used to provide a measure of motor current. This allows for simplified commutation device current limiting circuits and is available for control purposes which are a function of motor torque. There is also disclosed a method for maximizing useful power output by reducing the phase angle between the motor current and the back EMF. This is accomplished by introducing a delay in commutating the motor windings beyond the occurrence of each back EMF zero-crossing, with the delay being a function of the time between commutations.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: March 7, 2000
    Assignee: Fisher & Paykel Limited
    Inventors: John H. Boyd, Gerald Duncan, Michael Thomas George Perry
  • Patent number: 5067333
    Abstract: A specific physical characteristic (temperature) of a mixture of two liquids in a mixing chamber (14) is controlled by progressively opening a valve member (35) of a selected valve (10,11) through which one of the liquids flows while the other liquid flows through the other valve, and if the temperature of the mixed liquids has not reached a desired level, the selected valve is left fully open while the other valve is progressively closed to adjust the temperature to that desired. The opening and closing of the valves is controlled in response to signals from a sensor in the mixing chamber.
    Type: Grant
    Filed: October 19, 1990
    Date of Patent: November 26, 1991
    Assignee: Fisher & Paykel Limited
    Inventors: Gerald Duncan, Frank W. Shacklock, Murray Greenman
  • Patent number: 4978058
    Abstract: A specific physical characteristic (temperature) of a mixture of two liquids in a mixing chamber (14) is controlled by progressively opening a valve member (35) of a selected valve (10,11) through which one of the liquids flows while the other liquid flows through the other valve, and if the temperature of the mixed liquids has not reached a desired level, the selected valve is left fully open while the other valve is progressively closed to adjust the temperature to that desired. The opening and closing of the valves is controlled in response to signals from a sensor in the mixing chamber.
    Type: Grant
    Filed: February 7, 1989
    Date of Patent: December 18, 1990
    Assignee: Fisher & Paykel Limited
    Inventors: Gerald Duncan, Frank W. Shacklock, Murray Greenman