Magnetic Liquid Patents (Class 381/415)
  • Shock resistant electroacoustic transducer
    Patent number: 6041131
    Abstract: The present invention relates to a hearing aid receiver (10) having a coil (12) with a tunnel (14) therethrough, a magnetic structure (16) having a central magnetic gap (18), an armature (20), and a fluid (30, 32) with a viscosity greater than air to provide shock protection to the receiver (10). The tunnel (14) and the magnetic gap (18) collectively form an armature aperture (28). The armature (20) extends through the armature aperture (28). The fluid (30, 32) lies within the armature aperture (28).
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: March 21, 2000
    Assignee: Knowles Electronics, Inc.
    Inventors: Dennis Ray Kirchhoefer, Thomas Edward Miller, Paris Tsangaris
  • High power tweeter
    Patent number: 5894524
    Abstract: A high power compact tweeter which includes a high energy magnet sandwiched between the base of a yoke and top plate which form the magnetic path, the magnet and top plate being spaced from side walls of the yoke by a predetermined gap. A voice coil is positioned in the gap. A heat sink is in thermal contact with the yoke to facilitate, preferably in conjunction with heat transfer management from the speaker.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: April 13, 1999
    Assignee: Boston Acoustics, Inc.
    Inventors: Andrew G. Kotsatos, Moses A. Gabbay