Patents by Inventor John David Callaghan

John David Callaghan 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: 4109191
    Abstract: An antenna rotator of the type including a first remote drive motor for rotating a remote shaft and a control unit including a second motor for driving an indicator-control member into alignment with a preselect member is described. Self-synchronization and de-energization of the two motors is provided herein when the shaft has been rotated to an end stop position and the indicator-control member is not in alignment with the preselect member. This self-synchronization and de-energization is achieved by sensing the increased current levels caused when the first motor is prevented from rotating by the end stop to apply the energizing potentials being applied to the first motor directly to the second motor whereupon the indicator-control member is aligned with the preselect member and both motors are de-energized.
    Type: Grant
    Filed: June 3, 1977
    Date of Patent: August 22, 1978
    Assignee: RCA Corporation
    Inventor: John David Callaghan
  • Patent number: 3984841
    Abstract: A low cost broadband antenna system particularly suitable for television reception is described wherein the feed line includes a pair of conductors mounted in insulated manner one above the other above a support boom with the conductors having a fixed separation from each other and from the boom, a fixed conductor diameter and boom dimension maintaining a constant impedance along the line. Dipoles extend transverse the longitudinal axis of the boom and are symmetrically disposed about the axis with the dipole half elements on the same side of the axis successively connected alternately to the first and second conductors of the pair.
    Type: Grant
    Filed: October 14, 1975
    Date of Patent: October 5, 1976
    Assignee: RCA Corporation
    Inventors: Peter John Mikulich, Jr., John David Callaghan