Abstract: A universal piano action having a minimum number of identical parts interchangeable in upright and grand pianos, under and above the tensioned strings and effecting rapid repetition in upright and grand pianos, this universal piano action responds to every strenght of touch evoking sounds from a whisper to thunder. In this universal piano action the hammers can be positioned to any at rest position, to any proximity in respect to the tensioned strings for a sensitive control of sound, permitting practice playing with a normal strenght of piano key touch without disturbing.

Abstract: Within each action of a grand piano there are certain wood surfaces which rub against other surfaces. These interfaces create friction, which adversely affects the playability of the piano. In order to reduce and overcome this friction, strips of fluorocarbon resin, having an extremely low coefficient of friction, are adhered to those wooden surfaces within the action which come into contact with other surfaces.