Constant Power Patents (Class 84/16)
  • Patent number: 7678989
    Abstract: An electronic keyboard that includes a plurality of keys including a first key. The keyboard further includes a key support supporting the first key for movement between a rest position and a depressed position. The keyboard also includes a first key return spring configured to apply a return force to the first key to bias the first key toward the rest position. In the keyboard, the first key return spring is configured such that the return force has a substantially constant magnitude throughout the movement of the first key between the rest position and the depressed position.
    Type: Grant
    Filed: October 30, 2006
    Date of Patent: March 16, 2010
    Assignee: Magnekey
    Inventor: Van S. Chandler
  • Patent number: 7019201
    Abstract: A key actuation system that is designed for use with a keyboard instrument of the type having multiple keys. Each key is pivotally supported and has a front end that is depressed by a player to play a note. The actuation system includes multiple actuators that are operable to move at least some of the keys. The actuators together include a block of ferromagnetic material with a surface with multiple bores defined in the surface. Each of the bores has a diameter. A winding is positioned in each of the bores. Each of the windings has a hole. A piston is provided at least partially in each of the holes, with each piston being in mechanical communication with one of the keys such that movement of the piston causes movement of the key. Each piston has a width. A ferromagnetic flux plate with multiple openings is positioned on the surface of the block of ferromagnetic material with the openings aligned with the bores.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: March 28, 2006
    Inventor: David Meisel
  • Patent number: 6891092
    Abstract: A key actuation system that is designed for use with a keyboard instrument of the type having multiple keys. Each key is pivotally supported and has a front end that is depressed by a player to play a note. The actuation system includes multiple actuators that are operable to move at least some of the keys. The actuators together include a block of ferromagnetic material with a surface with multiple bores defined in the surface. Each of the bores has a diameter. A winding is positioned in each of the bores. Each of the windings has a hole. A piston is provided at least partially in each of the holes, with each piston being in mechanical communication with one of the keys such that movement of the piston causes movement of the key. Each piston has a width. A ferromagnetic flux plate with multiple openings is positioned on the surface of the block of ferromagnetic material with the openings aligned with the bores.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: May 10, 2005
    Inventor: David Meisel
  • Patent number: 6888052
    Abstract: A key actuation system that is designed for use with a keyboard instrument of the type having multiple keys. Each key is pivotally supported and has a front end that is depressed by a player to play a note. The actuation system includes multiple actuators that are operable to move at least some of the keys. The actuators together include a block of ferromagnetic material with a surface with multiple bores defined in the surface. Each of the bores has a diameter. A winding is positioned in each of the bores. Each of the windings has a hole. A piston is provided at least partially in each of the holes, with each piston being in mechanical communication with one of the keys such that movement of the piston causes movement of the key. Each piston has a width. A ferromagnetic flux plate with multiple openings is positioned on the surface of the block of ferromagnetic material with the openings aligned with the bores.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: May 3, 2005
    Inventor: David Meisel
  • Patent number: 6444885
    Abstract: The key actuation system is designed for use with a keyboard instrument of the type that has a key fulcrum which pivotally supports multiple keys. Each key has a front end forward of the fulcrum which is to be depressed by a player, and a rear portion which is positioned rearward of the fulcrum and it pivots upwardly when the front end is depressed. The key actuation system includes a pull solenoid with a coil portion and a piston. When the coil portion of the solenoid is energized, the piston is drawn into the coil portion. The solenoid is mounted such that the coil portion is above one of the keys and behind the key fulcrum. The piston is in mechanical communication with the rear portion of the key so that when the coil portion is energized and the piston is drawn into the coil portion, the rear portion of the key is lifted upwardly.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: September 3, 2002
    Inventor: David Meisel