Patents by Inventor Arthur Laurence Barbrook

Arthur Laurence Barbrook 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).

  • Electro-magnetic devices
    Patent number: 3993972
    Abstract: An electro-magnet includes a pole-piece having a portion of reduced cross-section. The shape of the reduced portion provides a restriction in the magnetic circuit such that the distance moved, against a biasing force, by an armature of the electro-magnet is proportional to the current in the electro-magnet winding. The pole piece comprises aligned parts of nickel-iron alloy joined by a soft iron part whose cross-section is less than that of the nickel-iron alloy parts.
    Type: Grant
    Filed: July 2, 1975
    Date of Patent: November 23, 1976
    Assignee: Lucas Industries, Limited
    Inventor: Arthur Laurence Barbrook