Hammer stoppers for pianos having acoustic and silent modes

A piano playable in an acoustic mode and a silent mode, the piano comprising:

• a series of keys;
• a series of key actions, each key action actuated by depression of a corresponding key;
• a series of rotatable hammers, each defining a forward throw direction and having at least one corresponding string, the hammers being driven by corresponding key actions transferring forces from corresponding keys;
• and
• a hammer stopper system comprising:
• a stopper rail set comprising a first stopper rail member and a second stopper rail member, each movable between a respective first position, allowing unobstructed movement of associated piano hammers, and a respective second position, stopping at least one associated piano hammer from striking any corresponding strings;
• and
• at least one rail actuator assembly coupled to at least one of the first stopper rail member and the second stopper rail member of the stopper rail set, the at least one rail actuator assembly comprising:
• at least one drive shaft rotatably coupled to one or both of said first and second stopper rail members of the stopper rail set;
• a drive arm attached to the at least one drive shaft and engaging a drive fulcrum;
• and
• at least one travel guide directing movement of one or both of the stopper rail members of the stopper rail set between its respective first and second position;
• wherein rotation of the at least one drive shaft rotates the drive arm to engage the drive fulcrum for moving one or both of the stopper rail members of the stopper rail set between its respective first and second position.

A method for adjusting stopper rail position in a hybrid upright piano having selectable silent play mode and acoustic play mode, comprising the steps of:

• selecting silent play mode to place a stopper rail in silent play stopper position;
• with one hand, holding a piano hammer against the stopper rail;
• using the other hand to turn a screwdriver in engagement with a screw head an axially fixed, rotatable adjustment screw in threaded engagement with the stopper rail and associated locknut mounted thereto;
• watching as spacing between the held piano hammer and the piano strings changes while the adjustment screw is turned;
• continuing to turn the screwdriver in either direction until desired spacing is achieved;
• and
• completing adjustment by discontinuing screw turning.