Patents by Inventor Henry M. Robbins, Jr.

Henry M. Robbins, Jr. 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: 4312003
    Abstract: A ferrite antenna assembly comprising a ferrite rod surrounded by a first coil and positioned within a surrounding ferrite or the like cylinder provided with a second coil. A signal which is 180.degree. out of phase with the signal on the first coil is applied to the second coil to induce a radio-frequency magnetic field in opposition to the field produced by the ferrite rod antenna. The opposing field creates a high reluctance return path for the magnetic flux emitted from the ferrite antenna at angles deviating from the axis of the rod. This forces the magnetic flux from the rod further out from the axis of the antenna, thus increasing the efficiency and range of the antenna.
    Type: Grant
    Filed: September 15, 1980
    Date of Patent: January 19, 1982
    Assignee: Mine Safety Appliances Company
    Inventor: Henry M. Robbins, Jr.