Patents by Inventor David E. Goodrich

David E. Goodrich 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: 4062056
    Abstract: The electronic combination door lock has three codes, each of which if properly actuated will allow the door to open. Signal switches are connected in parallel with two sets of resettable multiposition switches. The multiposition switches enable setting the first and second codes and transmit the signals generated by the signal switches selected to a logic circuit or sequence detector that detects the sequence of the signals. If the sequence is correct, the sequence detector provides an output to solenoid circuitry to release the lock. A third code circuit is in parallel with the first and second codes and also provides a connection from selected signal switches to the sequence detector. An error detecting circuit counts all actuations of the signal switches and resets the sequence detector if the generated signals exceed the number of digits in the code.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: December 6, 1977
    Inventor: David E. Goodrich