Abstract: An improvement in the action for a harpsichord type of keyboard musical instrument which uses a pneumatic piston to provide a variable pluck loudness. The improvement comprises a new pick-body design which allows several strings to be plucked at once for any single note or key, thus increasing the loudness of the instrument. The invention involves the use of a crank arm which, being restrained by a pneumatic piston, tilts the pick-body and the picks into the strings, the loudness resulting therefrom being proportional to the key-lever velocity.

Abstract: An improvement in the action for that type of plectrum piano which uses a pneumatic piston to provide a variable pluck loudness. The pneumatic piston is joined by a connecting rod to a crank arm on a rotatable pick body, the latter being driven vertically past a vibratable element when the instrument is played. The plectrum is mounted below the center of rotation of the pick body and describes both a lateral and a vertical motion during the pluck stroke, the pluck loudness being proportional to stroke velocity. The improvement includes the use of a gravity acting ball valve joint between the connecting rod and the piston to provide the repeat function.

Abstract: An action for a piano type musical instrument in which the hammer striking force is produced by the reaction of a pneumatic piston. For the grand piano embodiment, the hammer pivot is carried by the key-lever and the piston is connected to the hammer butt such that when the instrument is played the resistance of the piston raises the hammer into the musical string. A similar action is shown for the upright piano. In each case the hammer is propelled into the string with a velocity proportional to key-lever velocity and the escape, check and repetition parts of conventional actions are made unnecessary by the inherent properties of the pneumatic piston.

Abstract: An improvement in the action for a plectrum piano in which a pneumatic piston and cylinder are used to produce a variable pluck loudness, the reaction of the piston urging the plectrum toward the musical string in proportion to key-lever velocity. A rotatable pick-rod is used to carry the plectrum, the pick-rod being connected to the piston by means of a crank arm such that the plectrum is also rotated into the string during the pluck.