Patents by Inventor Daniel J. Hargrove

Daniel J. Hargrove 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).

  • Asynchronous digital locking system
    Patent number: 4104694
    Abstract: An asynchronous digital electronic combination locking system including a hand-held transmitter means for providing timed and coded transmission data, and a receiver for providing timed and coded receiver data and comparing the receiver data with the incoming transmission data. The door locking apparatus is opened only when said timed and coded data matches.
    Type: Grant
    Filed: October 28, 1976
    Date of Patent: August 1, 1978
    Inventor: Daniel J. Hargrove