Action for upright piano

In an upright piano action in which each note element of the action comprises a substantially horizontal key in the form of a lever pivotally connected to a frame member of the piano such that the back of the key is raised when the front playing portion of the key is depressed, a back check lever pivotally connected to a frame member and positioned above the back of said key to be raised by upward movement of the back of the key, at least one substantially vertically-oriented piano string installed on a frame member, a hammer-carrying shank pivotally installed on a main action rail about a horizontal axis for moving said hammer towards and away from said at least one piano string, and hammer action means arranged between said back check lever and said hammer shank for actuating said hammer in response to the upward movement of said back check lever, the improvement in which said hammer action means for each note element is installed on a key frame of the piano capable of lateral movement with respect to said piano strings, and in which said hammer action means for each note element comprises:

• a catcher arm integrally connected with said hammer shank at a substantial angle such that substantially upward movement of said catcher arm produces essentially rearward movement of said hammer towards said piano string, said catcher arm including a knuckle on its lower surface and further including a catcher at its forward end for engagement with a back check provided on said back check lever when said key has been fully depressed and said hammer has rebounded from said piano string;
• a grand whippen disposed above said back check lever, said grand whippen comprising:
• a whippen arm pivotally connected near its front end to a whippen rail;
• a repetition lever pivotally connected to a pivot support arm protruding upwardly from an intermediate point of said whippen arm;
• a jack pivotally connected to said whippen arm near the rear end of said whippen arm, said jack comprising an upwardly-directed attack arm passing through a slot provided in said repetition lever and a rearwardly-directed bell-crank arm integral with said attack arm;
• and spring means for biasing said attack arm of said jack forwardly against a stop for positioning directly under said knuckle and for biasing said repetition lever upwardly and against a stop such that said repetition lever does not ordinarily lie below the end of said attack arm in the area of the knuckle, said stops being attached above said whippen arm;
• a regulating button positioned below said main action rail and positioned above said bell-crank arm of said jack for engaging said bell-crank arm just prior to said hammer contacting said piano string;
• and
• a drop screw fixed with respect to said main action rail and positioned for engaging said repetition lever just prior to said hammer contacting said piano string.