Patents by Inventor Thomas A. Hollfelder

Thomas A. Hollfelder 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).

  • Telephone protector module having flag indicator
    Patent number: 4335416
    Abstract: A heat sensitive telephone protector module of a type having visual indicator means to indicate the actuation of heat sensitive means upon the occurrence of excessive current flow. The module includes dual heat sensitive units for protecting the tip and ring circuits of an individual subscriber pair, and a single indicator unit which is outwardly projected from the module housing by action of either heat sensitive element.
    Type: Grant
    Filed: February 13, 1981
    Date of Patent: June 15, 1982
    Assignee: Porta Systems Corp.
    Inventors: Thomas A. Hollfelder, Paul V. De Luca
  • Telephone digital office cutover system
    Patent number: 4334129
    Abstract: A system for automated pre-testing of subscriber pairs prior to final transfer from an old telephone office to a new digital central office. The system combines a known line verification tester, a trunk transition system, and an optional line ringing tester interconnected through a novel micro computer based interface. The interface controls the tests performed by the line verification tester and line ringing tester prior to transfer of tested circuits to the central office.
    Type: Grant
    Filed: October 17, 1980
    Date of Patent: June 8, 1982
    Assignee: Porta Systems Corp.
    Inventors: Paul V. De Luca, John J. Gazzo, Thomas A. Hollfelder
  • Telephone connector block
    Patent number: D271100
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: October 25, 1983
    Assignee: Porta Systems Corp.
    Inventor: Thomas A. Hollfelder
  • Combined telephone connector block and circuit protector
    Patent number: D271295
    Type: Grant
    Filed: August 4, 1980
    Date of Patent: November 8, 1983
    Assignee: Porta Systems, Corp.
    Inventors: Paul V. De Luca, Thomas A. Hollfelder
  • Telephone terminal block or similar article
    Patent number: D271965
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: December 27, 1983
    Inventor: Thomas A. Hollfelder
  • Telephone connector block
    Patent number: D273289
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: April 3, 1984
    Assignee: Porta Systems Corp.
    Inventor: Thomas A. Hollfelder
  • Telephone connector block
    Patent number: D273290
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: April 3, 1984
    Assignee: Porta Systems Corp.
    Inventor: Thomas A. Hollfelder