Patents by Inventor Wai Y. C. Chan

Wai Y. C. 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: 5500050
    Abstract: A detergent dispenser controller for use with a washing device, such as a dishwasher, that measures detergent concentration in a water tank by measuring the conductivity of the detergent solution in the water tank. The detergent controller automatically learns the feed rate of the detergent dispenser used, regardless of the type of detergent dispenser being used. For each detergent feed cycle, the controller computes a Feed Factor equal to the amount of detergent feed on time required for each unit increase in the detergent concentration, which is the inverse of the detergent feed rate. The controller stores the computed Feed Factor for the last N feed cycles in a non-volatile memory, and computes a running average of the N feed factors stored in the non-volatile memory. Whenever the detergent dispenser is powered on, it determines the difference between the measured wash tank detergent concentration and a specified detergent concentration set point value.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: March 19, 1996
    Assignee: Diversey Corporation
    Inventors: Wai Y. C. Chan, James W. Livingston
  • Patent number: 5494061
    Abstract: A liquid chemical dispensing system for dispensing a plurality of liquid chemicals into a dishwasher includes at least a detergent pump and a rinse agent pump, a first switch indicating whether the dishwasher is a door type or a conveyor type dishwasher, a second switch indicating whether the controller is in training mode or in run mode, a non-volatile memory and a data processor. The liquid chemical dispensing system is powered on whenever the dishwasher is spraying rinse water. In the training mode, the data processor enables a user to set values for a rinse run time parameter, a detergent run time parameter, and a rinse delay time, and stores those parameters in the non-volatile memory.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 27, 1996
    Assignee: Diversey Corporation
    Inventors: Wai Y. C. Chan, James W. Livingston
  • Patent number: 5453131
    Abstract: A liquid chemical dispensing system for dispensing a plurality of liquid chemicals into a dishwasher includes at least a detergent pump and a rinse agent pump, a first switch indicating whether the dishwasher is a door type or a conveyor type dishwasher, a second switch indicating whether said controller is in training mode or in run mode, a non-volatile memory and a data processor. The liquid chemical dispensing system is powered on whenever the dishwasher is spraying rinse water. In the training mode, the data processor enables a user to set values for a rinse run time parameter, a detergent run time parameter, and a rinse delay time, and stores those parameters in the non-volatile memory.
    Type: Grant
    Filed: June 23, 1994
    Date of Patent: September 26, 1995
    Assignee: Diversey Corporation
    Inventors: Wai Y. C. Chan, James W. Livingston