Method of improving repetitive striking performance, jack and action mechanism of piano
AssigneeKabushiki Kaisha Kawai Gakki Seisakusho
InventorKousuke Tanaka
Life of this patent
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Abstract
A jack used in an action mechanism of a piano has substantially an L-shape, composed of a big jack portion and a small jack portion. The thickness of the small jack portion is made smaller than that of the big jack portion in a direction of key arrangement in a state of the jack being fitted in the piano. By reducing the weight of the small jack portion as above, the time required for the jack to return to a position capable of pushing up a part of a striking member can be shortened. Accordingly, more frequent repetitive striking is allowed within a predetermined period.
Claims3
A method of improving repetitive striking performance of a piano comprising an action mechanism in which a substantially L-shaped jack pushes up a part of a striking member in response to key depression in order to cause the striking member to strike a string,
- the jack being composed of elongated portions comprising:
- a big jack portion for pushing up the striking member, and
- a small jack portion integrated almost perpendicular to the big jack portion,
- wherein the small jack portion is lightened by at least one of the following steps:
- forming the lightened small jack portion from a material with a higher strength versus weight ratio than a material from which the big jack portion is manufactured,
- incorporating voids into the small jack portion,
- providing the small jack portion with a thickness less than that of the big jack portion,
- manufacturing the small jack portion from a material less dense than a material from which the big jack portion is manufactured, and
- curving an upper side of the small jack portion into a concave shape.
A jack for use in an action mechanism of a piano, that is formed into substantially an L-shape and pushes up a part of a striking member in response to key depression in order to cause the striking member to strike a string,
- the jack being composed of:
- an elongated big jack portion for pushing up the part of the striking member, and
- a lightened small jack portion integrated almost perpendicular to the big jack portion, wherein a weight of the lightened small jack portion is decreased by at least one of:
- the lightened small jack portion has a curved concave upper side,
- the lightened small jack portion is thinner than the big jack portion,
- the lightened small jack portion is manufactured from a material less dense than a material from which the big jack portion is manufactured,
- the lightened small jack portion is formed from a material with a higher strength versus weight ratio than a material from which the big jack portion is manufactured, and
- the lightened small jack portion contains voids therein.
An action mechanism of a piano, comprising a substantially L-shaped jack that pushes up a part of a striking member in response to key depression in order to cause the striking member to strike a string,
- the jack being composed of:
- an elongated big jack portion for pushing up the part of the striking member, and
- a lightened small jack portion integrated almost perpendicular to the big jack portion wherein a weight of the lightened small jack portion is decreased by at least one of:
- the lightened small jack portion has a curved concave upper side,
- the lightened small jack portion is thinner than the big jack portion,
- the lightened small jack portion is manufactured from a material less dense than a material from which the big jack portion is manufactured,
- the lightened small jack portion is formed from a material with a higher strength versus weight ratio than a material from which the big jack portion is manufactured, and
- the lightened small jack portion contains voids therein.
Dependencies are inferred from the claim text.