Patents by Inventor Douglas D. Lau

Douglas D. Lau 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).

  • Escrow device for coin-operated systems
    Patent number: 4782937
    Abstract: A coin escrow device includes a housing for receiving coins, and first and second gates for selectively discharging coins to a coin return chute or to a coin collection chute. Actuating mechanisms are provided to selectively unlatch the gates and to bias the gates to their latched positions.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: November 8, 1988
    Assignee: Tatung Telecom Corp.
    Inventors: Abraham Y. Chen, Douglas D. Lau