Expression Mechanism Patents (Class 84/33)
  • Patent number: 7935875
    Abstract: In order to improve a touch of a key of a keyboard musical instrument by using a key actuating apparatus which actuates the key supported so as to be rotationally movable with regard to a frame of the keyboard musical apparatus, a key actuating apparatus (1) includes: a plunger (15) which is moved on an arc or curved line in correspondence with a rotational motion of a key (3); and a solenoid (7) including electro magnets (17 and 19) which are fixed to the frame and which are substantially in a cylindrical shape into which the plunger is inserted. The plunger (15) is formed in an arc or curved shape extended in a direction of a rotational motion of the plunger (15). A head end (15b) arranged on the plunger (15) in a lengthwise direction is made from a magnetic body.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: May 3, 2011
    Assignee: Yamaha Corporation
    Inventor: Akihiko Komatsu
  • Patent number: 5905220
    Abstract: A piano pedal optical sensor apparatus and method for accurately measuring, recording and reproducing the pedal expression generated during piano performances. A plurality of optical emitter/sensors are mounted on the pedal support assembly of a piano, and a plurality of corresponding optical reflectors are mounted on the moving connecting rods associated with piano pedals on the piano. Output voltage signals from the optical emitter sensors, which vary according to pedal movement, are monitored and used to generate and record pedal position values. The recorded pedal position values are then used to recreate the original pedal expression of the piano performance by generation of pulse width modulation signals which are used to drive solenoids associated with piano pedals.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: May 18, 1999
    Assignee: Burgett, Inc.
    Inventors: Charles R. Lee, Pamela K. Clift, Alana J. Yorba
  • Patent number: 5545839
    Abstract: A keyboard musical instrument lowers a key bed together with a keyboard, key action mechanisms and hammer mechanisms in a silent mode, and a stopper mechanism and a make-up mechanism cause the depressed keys to actuate the key action mechanisms and damper mechanisms as similar to an acoustic sound mode, thereby allowing a player to feel the key touch usual in a performance without an acoustic sound.
    Type: Grant
    Filed: November 22, 1994
    Date of Patent: August 13, 1996
    Assignee: Yamaha Corporation
    Inventors: Kiyoshi Kawamura, Toshio Tajima, Shinya Koseki