Patents by Inventor Ernest D. Hoffman

Ernest D. Hoffman 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: 4817132
    Abstract: A multiline access module for connection of a number of telephone lines to a station set. The station set is controlled by a microprocessor and communicates with the access module through a communications channel to select one telephone line for connection to the station and to read the line status, ringing, on-hook, seized, no connection, or hold, for each line; the microprocessor controlling audible and visual indicators accordingly. The access module monitors voltage levels on each line to determine the line status. Each access module includes apparatus for connection to first and second groups of telephone lines and when two modules are interconnected by an appropriately polarized cable each will activate a different connection apparatus, allowing two modules to be connected in parallel for greater line capacity.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: March 28, 1989
    Assignee: Dictaphone Corporation
    Inventors: David B. Chamberlin, Nicholas A. D'Agosto, III, Ernest D. Hoffman