Patents by Inventor Charles Stevenson

Charles Stevenson 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: 5953438
    Abstract: An electromagnetic transducer diaphragm having an electrical conductor layer, with a conductor pattern, positioned between two insulating layers of a flexible, electrically-insulating material bonded together to protect the diaphragm. An electrical current can flow through the conductors to produce magnetic and electrostatic fields around said conductors which interact with an electromagnetic field to produce mechanical displacement of the diaphragm which in turn produces an audio signal. Non-ferrous supports can be used to support the diaphragm. A magnet or magnets may be used to create the electromagnetic field. The magnets can be bonded to the cross arms of the non-ferrous support.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: September 14, 1999
    Assignee: Chain Reactions, Inc.
    Inventors: Charles Stevenson, Edward M. Porrazzo
  • Patent number: 5720639
    Abstract: A method of manufacturing EL lamp systems is available which incorporates some of the processes used in manufacturing flexible, printed circuit boards with surface mounted components along with those used to form multilayered EL lamps. The EL lamp system produced by this method is suitable for a variety of graphics and low-cost consumer applications.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 24, 1998
    Assignee: American International Pacific Industries, Corp.
    Inventor: William Charles Stevenson
  • Patent number: 5430805
    Abstract: An electromagnetic transducer diaphragm having an electrical conductor layer, with a conductor pattern, positioned between two insulating layers of a flexible, electrically-insulating material bonded together to protect the diaphragm. An electrical current can flow through the conductors to produce magnetic and electrostatic fields around said conductors which interact with an electromagnetic field to produce mechanical displacement of the diaphragm which in turn produces an audio signal. Non-ferrous supports can be used to support the diaphragm. A magnet or magnets may be used to create the electromagnetic field. The magnets can be bonded to the cross arms of the non-ferrous support.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: July 4, 1995
    Assignee: Chain Reactions, Inc.
    Inventors: Charles Stevenson, Edward Porrazzo
  • Patent number: 5167297
    Abstract: A safety device for a stairway or other inclined surface includes a rail and a safety belt. The safety belt is wrapped around the rail to form a noose. The noose allows the safety belt to move freely along the rail when a person is not falling and prevents the safety belt from moving along the rail when a person is falling.
    Type: Grant
    Filed: May 10, 1991
    Date of Patent: December 1, 1992
    Inventor: Charles Stevenson