Patents by Inventor Lau Wai Keung

Lau Wai Keung 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: 6125498
    Abstract: A handheld liquid extraction cleaner includes a recovery tank mounted to the forward end of a cleaner housing with a suction nozzle and conduit on a front face of the recovery tank connected to an inlet opening in the recovery tank. A vacuum source is connected to the recovery tank through an exhaust conduit, integrally formed in the recovery tank, for drawing liquid and debris through the suction nozzle and the suction conduit and into the recovery tank A removable cleaning fluid supply tank is mounted to a rear portion of the cleaner housing, an adjustable spray nozzle is mounted to the suction conduit and a pump is positioned in a supply conduit between the spray nozzle and the cleaning fluid supply tank for supplying pressurized cleaning fluid from the cleaning fluid supply tank to the spray nozzle The pump includes an impeller which is positioned in an outlet opening of a reservoir in which the cleaning fluid is deposited from the cleaning fluid supply tank.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: October 3, 2000
    Assignee: Bissell Homecare, Inc.
    Inventors: Kenneth L. Roberts, Diane M. Simek, Jeffrey A. Hall, Eric C. Huffman, Charles A. Reed, Jr., Steven K. Meek, Lau Wai Keung, Ng Tat Shing