Action of upright piano

An action of an upright piano having strings, the action comprising a regulating rail, a jack stop rail, a main action rail, a damper stop rail, a wippen, a jack, a hammer butt, and a hammer, the action further comprising a jack spring between the wippen and a jack tail of the jack, the action being adapted to operate, when a piano player depresses a key, in such a manner that the wippen moves up with rotating, a protruding end of a pushing-up portion of the jack pushes up a pushed-up portion of the hammer butt from below, the hammer pivots and hits a corresponding string, the jack tail of the jack strikes a regulating button, and that a protruding end of the pushing-up portion slips out from under the pushed-up portion, wherein

• either one member of said regulating rail and said jack stop rail serves as a first rail;
• either one member of said first rail and said pushing-up portion has a first spring;
• the other member of said first rail and said pushing-up portion that does not have said first spring has a first spring rest adapted to come into contact with said first spring;
• either one member of said main action rail and said damper stop rail serves as a second rail;
• one member of said second rail, a hammer core of said hammer, a hammer shank of said hammer, and said hammer butt has a second spring;
• if one member of said hammer core, said hammer shank, and said hammer butt has said second spring, then said second rail has a second spring rest adapted to come into contact with said second spring, and
• if said second rail has said second spring, then one member of said hammer core, said hammer shank, and said hammer butt has the second spring rest adapted to come into contact with said second spring;
• said action being adapted to produce a first force and a second force, the first force being applied by said first spring that has been bent between the member having said first spring and said first spring rest to said pushing-up portion when the piano player releases said key, said wippen moves down with rotating, and said jack tail escapes from said regulating button, the second force being applied by said second spring that has been bent between the member having said second spring and said second spring rest to said hammer when said first spring forces said pushing-up portion under said pushed-up portion and said hammer pivots towards said string by the force applied from said pushing-up portion to said pushed-up portion, the first force having magnitude and direction that press the protruding end of said pushing-up portion to a surface located in front of and above said pushed-up portion of said hammer butt and the force having magnitude and direction that force said pushing-up portion under said pushed-up portion, the second force having magnitude and direction that stop the pivot motion of said hammer before said hammer hits said string.

A method of controlling touch of keys of an upright piano having strings by means of modifying an action of the upright piano, the action comprising a regulating rail, a jack stop rail, a main action rail, a damper stop rail, a wippen, a jack, a hammer butt, and a hammer, the action further comprising a jack spring between the wippen and a jack tail of the jack, the action being adapted to operate, when a piano player depresses a key, in such a manner that the wippen moves up with rotating, a protruding end of a pushing-up portion of the jack pushes up a pushed-up portion of the hammer butt from below, the hammer pivots and hits a corresponding string, the jack tail of the jack strikes a regulating button, and that a protruding end of the pushing-up portion slips out from under the pushed-up portion, said method comprising the steps of:

• attaching a first spring to either one member of said regulating rail, said jack stop rail, and said pushing-up portion, and attaching a first spring rest to the other member of said pushing-up portion and a first rail that does not have said first spring, the first rail being consisted of either one member of said regulating rail and said jack stop rail, the first spring rest being adapted to come into contact with said first spring;
• attaching a second spring to one member of said main action rail, said damper stop rail, a hammer core of said hammer, a hammer shank of said hammer, and said hammer butt, and attaching a second spring rest to either one of said hammer core, said hammer shank, and said hammer butt if a second rail has the second spring out of the second rail, said hammer core, said hammer shank, and said hammer butt, the second rail being consisted of either one member of said main action rail and said damper stop rail, while attaching the second spring rest to said second rail if either one of said hammer core, said hammer shank, and said hammer butt has said second spring, the second spring rest being adapted to come into contact with said second spring;
• making a force applied by said first spring that has been bent between the member having said first spring and said first spring rest to said pushing-up portion when the piano player releases said key, said wippen moves down with rotating, and said jack tail escapes from said regulating button, have magnitude and direction that press the protruding end of said pushing-up portion to a surface located in front of and above said pushed-up portion of said hammer butt, and have magnitude and direction that force said pushing-up portion under said pushed-up portion;
• and
• making a force applied by said second spring that has been bent between the member having said second spring and said second spring rest to said hammer when said first spring forces said pushing-up portion under said pushed-up portion and said hammer pivots towards said string by the force applied from said pushing-up portion to said pushed-up portion, have magnitude and direction that stop the pivot motion of said hammer before said hammer hits said string.

An action of an upright piano having strings, the action including a hammer that pivots and strikes a string when a piano player depresses a key;

• a jack that moves up with rotating when the piano player depresses said key;
• and a hammer butt that is pushed up by said jack to pivot said hammer when said jack moves up with rotating, said jack having a pushing-up portion to push up said hammer butt, said hammer butt having a pushed-up portion that is pushed up by said jack;
• said action comprising:
• a first elastic body adapted to apply such a force to said jack that forcefully returns said pushed-up portion of said jack under said pushing-up portion of said hammer butt after said hammer butt has been pushed up;
• and
• a second elastic body adapted to apply such a force to said hammer that does not interfere with said hammer hitting said string when the hammer is in the course of a first pivot motion towards said string in response to depression of the key by the piano player, and that interferes with said hammer hitting said string when the hammer is in the course of a second pivot motion towards said string by said hammer butt that has moved up, if said pushed-up portion of said jack is forcefully returned under said pushing-up portion of said hammer butt by the force applied by said first elastic body.