Patents by Inventor Ka Ki Chan

Ka Ki Chan 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).

  • Patent number: 8303449
    Abstract: A transmission assembly is powered by an electric motor and includes a transmission having an outer ring gear, a connector moveable relative to the outer ring gear between a first position, in which the connector is rotatable with the transmission in response to torque received from the motor, and a second position, in which the connector and the outer ring gear are non-rotatable, and a control mechanism operable to detect the operating current of the motor and compare the operating current to a threshold current. The control mechanism is operable to move the connector from the first position to the second position in response to the motor operating current exceeding the threshold current.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: November 6, 2012
    Assignee: Techtronic Power Tools Technology Limited
    Inventors: Chi Hong Ho, Ka Ki Chan, Wing Fung Yip
  • Publication number: 20090098971
    Abstract: A transmission assembly is powered by an electric motor and includes a transmission having an outer ring gear, a connector moveable relative to the outer ring gear between a first position, in which the connector is rotatable with the transmission in response to torque received from the motor, and a second position, in which the connector and the outer ring gear are non-rotatable, and a control mechanism operable to detect the operating current of the motor and compare the operating current to a threshold current. The control mechanism is operable to move the connector from the first position to the second position in response to the motor operating current exceeding the threshold current.
    Type: Application
    Filed: December 16, 2008
    Publication date: April 16, 2009
    Inventors: Chi Hong Ho, Ka Ki Chan, Wing Fung Yip
  • Publication number: 20090094838
    Abstract: A storable blade for use with a saw, such as a jigsaw. The blade has stored and operative positions. In the stored position, the blade is disposed in the housing, and in the operative position, the blade is in the cutting position. In either the operative or the stored positions, the saw blade is coupled with the jigsaw.
    Type: Application
    Filed: October 10, 2007
    Publication date: April 16, 2009
    Inventors: Ka Ki Chan, Chi Hong Ho, Dan Larson
  • Publication number: 20080252726
    Abstract: A work device is disclosed that comprises a body and a drive portion attached with the body for working on a workpiece. At least one camera is attached with the body, and at least one video display device is operatively connected with the at least one camera. The camera is positioned on the body at an angle that is not perpendicular to the workpiece when the workpiece is positioned to be worked on by the drive portion. The at least one camera transmits images to the at least one video display.
    Type: Application
    Filed: March 7, 2008
    Publication date: October 16, 2008
    Inventors: Ka Ki Chan, Kwok Ting Mok, Siu Yan Lau
  • Patent number: 7159497
    Abstract: A saw such as a chop saw, a circular saw, a compound miter saw or a sliding compound miter saw having a rotatable saw blade is provided with a laser arbor alignment system. The laser arbor may include a power generator that generates power as the saw blade and the laser arbor are rotated by a spindle. The generator may include a stator comprising an electrical magnet or a permanent magnet mounted on a fixed portion of the saw. The other portion of the generator is a rotor comprising a coil that is rotated with the laser arbor to generate power for the laser. Power may also be provided to the laser by slip ring contacts from a stationary source to the laser arbor.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: January 9, 2007
    Assignee: Eastway Fair Company Ltd.
    Inventors: Gerhard Josef Karl Weusthof, John Ka Ki Chan
  • Patent number: 6753106
    Abstract: A method and apparatus are provided for distributing water produced by the electrochemical reaction to ion-exchange membranes in an array comprising a plurality of electrochemical fuel cell stacks. Water distribution within individual fuel cell stacks within the array is improved to reduce membrane dryness near the oxidant stream inlet and to also reduce saturation of the oxidant stream near the oxidant stream outlet, thereby reducing electrode flooding. The method comprises periodically reversing the oxidant stream flow direction within at least one of the plurality of fuel cell stacks. The apparatus comprises an oxidant stream flow switching device for periodically switching the flow direction of an oxidant stream through an individual fuel cell stack. In one embodiment the apparatus further comprises a water recycler for capturing water from the oxidant exhaust stream and returning the captured water to the oxidant stream when the flow direction is reversed.
    Type: Grant
    Filed: October 31, 2001
    Date of Patent: June 22, 2004
    Assignee: Ballard Power Systems Inc.
    Inventors: Clarence Y.F. Chow, John Ka Ki Chan, Adrian James Corless
  • Publication number: 20030140758
    Abstract: A saw such as a chop saw, a circular saw, a compound miter saw or a sliding compound miter saw having a rotatable saw blade is provided with a laser arbor alignment system. The laser arbor may include a power generator that generates power as the saw blade and the laser arbor are rotated by a spindle. The generator may include a stator comprising an electrical magnet or a permanent magnet mounted on a fixed portion of the saw. The other portion of the generator is a rotor comprising a coil that is rotated with the laser arbor to generate power for the laser. Power may also be provided to the laser by slip ring contacts from a stationary source to the laser arbor.
    Type: Application
    Filed: January 25, 2002
    Publication date: July 31, 2003
    Applicant: One World Technologies Limited
    Inventors: Gerhard Josef Karl Weusthof, John Ka Ki Chan
  • Publication number: 20020041984
    Abstract: A method and apparatus are provided for distributing water produced by the electrochemical reaction to ion-exchange membranes in an array comprising a plurality of electrochemical fuel cell stacks. Water distribution within individual fuel cell stacks within the array is improved to reduce membrane dryness near the oxidant stream inlet and to also reduce saturation of the oxidant stream near the oxidant stream outlet, thereby reducing electrode flooding. The method comprises periodically reversing the oxidant stream flow direction within at least one of the plurality of fuel cell stacks. The apparatus comprises an oxidant stream flow switching device for periodically switching the flow direction of an oxidant stream through an individual fuel cell stack. In one embodiment the apparatus further comprises a water recycler for capturing water from the oxidant exhaust stream and returning the captured water to the oxidant stream when the flow direction is reversed.
    Type: Application
    Filed: October 31, 2001
    Publication date: April 11, 2002
    Inventors: Clarence Y.F. Chow, John Ka Ki Chan, Adrian James Corless
  • Patent number: 6322914
    Abstract: A method and apparatus are provided for distributing water produced by the electrochemical reaction to ion-exchange membranes in an array comprising a plurality of electrochemical fuel cell stacks. Water distribution within individual fuel cell stacks within the array is improved to reduce membrane dryness near the oxidant stream inlet and to also reduce saturation of the oxidant stream near the oxidant stream outlet, thereby reducing electrode flooding. The method comprises periodically reversing the oxidant stream flow direction within at least one of the plurality of fuel cell stacks. The apparatus comprises an oxidant stream flow switching device for periodically switching the flow direction of an oxidant stream through an individual fuel cell stack.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: November 27, 2001
    Assignee: Ballard Power Systems Inc.
    Inventors: Clarence Y. F. Chow, John Ka Ki Chan, Adrian James Corless
  • Patent number: 5935726
    Abstract: A method and apparatus are provided for distributing water produced by the electrochemical reaction to an ion-exchange membrane in a electrochemical fuel cell. Water distribution within a fuel cell is improved to reduce membrane dryness near the oxidant stream inlet and to also reduce saturation of the oxidant stream near the oxidant stream outlet, thereby reducing electrode flooding. The method comprises periodically reversing the flow direction of an oxidant stream through a fuel cell flow field. The apparatus comprises an oxidant stream flow switching device for periodically switching the flow direction of an oxidant stream through a fuel cell flow field. In one embodiment the apparatus further comprises a water recycler for capturing water from the oxidant exhaust stream and returning the captured water to the oxidant supply stream when the flow direction is reversed.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: August 10, 1999
    Assignee: Ballard Power Systems Inc.
    Inventors: Clarence Y. F. Chow, John Ka Ki Chan, Adrian James Corless
  • Patent number: 5804326
    Abstract: An electrochemical fuel cell assembly comprises a pair of separator layers and a membrane electrode assembly interposed between the separator layers. The membrane electrode assembly comprises a pair of electrodes and an ion exchange membrane interposed therebetween, the electrodes having electrocatalyst associated therewith defining an electrochemically active area. Each of the separator layers comprises one or more reactant stream passages in fluid communication with one of the electrodes. At least one of the separator layers further comprises one or more coolant stream passages which do not superpose the electrochemically active area of the adjacent membrane electrode assembly, and are fluidly isolated from the reactant stream passages.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: September 8, 1998
    Assignee: Ballard Power Systems Inc.
    Inventors: Clarence Y. Chow, Boguslaw Wozniczka, John Ka Ki Chan