Patents by Inventor Leung Wai Tat Raymond

Leung Wai Tat Raymond 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).

  • Differential pressure switch
    Patent number: 7855345
    Abstract: The invention relates to a field adjustable pressure switch that incorporates a manually adjustable differential to set the pressure level for the trip point for the pressure switch used in conjunction with a submersible sump pump system requiring trip levels corresponding to the desired water level in the sump well for operation of the pump motor.
    Type: Grant
    Filed: November 19, 2007
    Date of Patent: December 21, 2010
    Assignee: Stevens Pump Company
    Inventors: James E. Stevens, Geoffrey M. Stevens, Bill Irwin, Leung Wai Tat Raymond
  • Differential pressure switch
    Publication number: 20090129940
    Abstract: The invention relates to a field adjustable pressure switch that incorporates a manually adjustable differential to set the pressure level for the trip point for the pressure switch used in conjunction with a submersible sump pump system requiring trip levels corresponding to the desired water level in the sump well for operation of the pump motor.
    Type: Application
    Filed: November 19, 2007
    Publication date: May 21, 2009
    Inventors: James E. Stevens, Geoffrey M. Stevens, Bill Irwin, Leung Wai Tat Raymond