In a piano action, a damper lever, pivoted intermediate thereof and with its damper biased toward the string, has a tab portion extending in the side opposite to the damper side. A sostenuto block, rotatably supported beside the tab portion, has a lip portion rotatable against a biasing force and resting on a stop. The rotation of the block causes the lip portion to come near and away from the tab portion. When the block is rotated while the damper is brought away from the string upon depression of the key, the lip portion catches the tab portion and prevents the damper from coming into contact with the string even after release of the depressed key so long as the block is in a rotated position, thus permitting the string struck by the hammer to continue its vibration so that a sustaining tone is obtained. A plurality of such sustenuto blocks for a plurality of damper levers are fixed to a transversely extending rockable rail, so that the rail rotates all of the blocks at one time. When the damper levers other than the one which the lip portion has caught are to be rotated while all of the blocks are in rotated position, the damper levers to be rotated are permitted their rotation by their tab portions pushing and rotating the corresponding lip portions against the biasing force imparted thereto.
A piano includes an underlever assembly having an underlever arm and an underlever support joining the underlever arm to a string damper. The underlever arm is mounted to move between an at-rest position and a second position. A latch is mounted to a latch mount for movement between non-latching and latching positions. In latching position, the latch engages a latch surface of the underlever support to maintain the string damper spaced from a corresponding piano string. A stop mounted to the latch mount limits movement of the underlever arm toward its second position. A method for controlling a piano string damper includes contacting the underlever arm with the latch to maintain the string damper spaced from the string, and contacting the underlever arm with the stop to limit movement of the underlever arm.
A sostenuto piano action is provided for upright pianos. Each damper is provided at the top rear thereof with a rubber fitting having a catcher flange or tab thereon. A pivoted sostenuto knife similar to that in a grand piano has a blade thereon which, upon pivoting of the sostenuto knife, will catch or engage the catcher tab or flange of each fitting to retain retracted such dampers as are in retracted position. With the knife pivoted to sostenuto position and additional notes played thereafter the flanges will bump the backside of the knife, but will not be caught. Spring biased elbows or hinges are provided in the damper levers to allow "breaking" of the levers at such time so as to avoid providing a strange feel to the pianist. The rubber nature of the fitting prevents any noise at such time.
