Importance

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Abstract

In the upright piano action, the wire protruding up from the damper lever leaning or biased towards the string contacts and slides back to and forth along a pin fixed and protruding straight out from the hammer spring rail towards the string. On the sostenuto rod, attached and moveable horizontally on top of the hammer spring rail, is fixed a thin wire arm with a hooked end extending straight towards the space between the strings, reaching just long enough to clear the damper lever wire as it travels horizontally back and forth when the damper is on the string. When the damper moves off the string after depression of the key, the damper wire slides back along the side of pin in hammer spring rail and is hooked by wire arm on sostenuto rod when it moves horizontally towards the damper wire clamping it securely back, even after release of the depressed key. So long as the sostenuto rod is held in that position, thus allowing the string, after being struck by hammer to continue to vibrate sustaining the tone. A plurality of such sostenuto wire spring arms and hammer spring rail pins for a plurality of damper levers are fixed to the transversely extending hammer spring rail and sostenuto rod which moves the spring arms in unison toward the damper lever wires catching those that are off the string against the hammer spring rail pins and ignoring those that are on the strings allowing all of the piano action to function normally by moving the spring arms beyond the reach of the damper lever wires.

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First Claim