Patents by Inventor Per Winfeld

Per Winfeld 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: 4884262
    Abstract: In a stereo pick-up having movable coils (14) and an SmCo magnet (22) with a high energy content, with the coil system (14, 15, 18) arranged in front of one pole face of said magnet, a yoke plate (23) of a magnetic soft material is arranged in front of said system to increase the magnetic induction in the coils. The great coercive force of the magnet is utilized for simplifying and reducing the costs of the mechanical structure in that the yoke plate is formed with two legs (26) which extend rearwardly, engage and are secured to two opposite sides of the magnet. The short-circuit of the magnet established by these legs has no noticeable impact on the induction in the air gap because of the high coercive force of the magnet.
    Type: Grant
    Filed: July 17, 1987
    Date of Patent: November 28, 1989
    Assignee: Ortofon Manufacturing A/S
    Inventors: Jan Larsen, Robert Gudmandsen, Per Winfeld