Music – Instruments – General features
Reexamination Certificate
2001-12-21
2003-11-18
Lockett, Kimberly (Department: 2837)
Music
Instruments
General features
C084S427000, C084S424000
Reexamination Certificate
active
06649821
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to keyboard musical instrument and, more particularly, to a keyboard musical instrument equipped with a key-touch generator for giving appropriate key-touch to the player.
DESCRIPTION OF THE RELATED ART
The “key-touch” is an important factor to players. When a pianist initiates depressing a key of an acoustic piano, the pianist feels the key heavy. The pianist soon notices the key becoming light on the way to the end position. The change of resistance is called as “key-touch”. While a pianist is playing a piece of music on the acoustic piano, he or she delicately controls the force exerted on the keys for his or her artificial expression. If an acoustic piano to be played gives a key-touch different from that of the acoustic piano familiar to a player, he or she would be puzzled how to play with expression, because the key motion is unusual. Thus, the key-touch directly concerns his or her performance, and pianists desire acoustic pianos to give the same key touch as the acoustic piano familiar to them does. Nevertheless, pianists sometimes feel the acoustic pianos different from that of the acoustic piano familiar to him or her.
A piano manufacturer has his own specifications to be applied to the manufactured pianos. When the manufacturer completes products of an acoustic piano, the manufacturer inspects the products to see whether or not the products satisfy the specification. In the inspection, the manufacturer uniformly applies the standards in the specification to the products. In the inspection, the inspector checks the products for the standard key-touch, and a tuner uniformly regulates the key touch in accordance with the specifications, if necessary. Thus, the products of the acoustic piano are expected to give the standard key-touch to pianists. However, the key-touch is to be varied with time. For this reason, the pianists usually feel other pianos different in key-touch from the piano familiar to him or her.
The grand piano is a typical example of the keyboard musical instrument.
FIG. 1
shows a key forming a part of the keyboard incorporated in the standard grand piano. In the following description, term “front” is indicative of a position closer to a pianist sitting in front of a piano than a position modified with “rear”. Term “longitudinal” is indicative of a direction passing through a front point and a corresponding rear point, and “lateral direction” is perpendicular to the longitudinal direction.
Reference numeral
1
designates the key. Through-holes
2
are formed in the key
1
at intervals in the longitudinal direction, and weights
3
are snugly received in the through-holes
2
. The weights
3
are formed of lead. The reason why the manufacturer uses the lead weights
3
is that the lead is deformable and easy to fill the through-holes. Another reason is the large specific weight. The key
1
is put on a balance rail
4
a
, and a balance pin
4
b
is upright on the balance rail
4
a
. The balance pin
4
b
passes through the central portion of the key
1
, and the key
1
is rotatable about an axis perpendicular to the balance pin
4
b
. A front rail
6
a
laterally extends under the front portion of the key
1
, and a rear rail
6
b
also laterally extends under the rear portion of the key
1
. The front rail
6
a
sets a limit to the rotation of the key
1
in the counter clockwise direction, and the rear rail
6
b
sets a limit to the rotation of the key
1
in the clockwise direction.
An action
5
is rotatably supported by a whippen rail
9
, which in turn is supported by action brackets
6
c
. The key
1
is held in contact with the action
5
through a capstan screw
7
, and a hammer
8
is engaged with the action
5
. The action is broken down into a whippen assembly
11
a
, a repletion lever assembly
11
b
and a jack
11
c
. The whippen assembly
11
a
is rotatably connected at the right end thereof to a whippen flange
11
d
, which in turn is fixed to the whippen rail
9
. The repetition lever assembly
11
b
is provided on the intermediate portion of the whippen assembly
11
a
, and a through-hole is formed in the left portion of the repetition lever assembly
11
b
. The jack
11
c
is rotatably connected to the left portion of the whippen assembly
11
a
, and has a leg portion, a foot portion and a toe. The leg portion projects into the through-hole, and the hammer
8
is engaged with the leg portion. On the other hand, the toe is opposed to a regulating button
11
e.
The hammer
8
is rotatably supported by a shank flange rail
6
d
under an associated set of strings, and the shank flange rail
6
d
is supported by the action brackets
6
c
. The hammer
8
pushes down the whippen assembly
11
a
due to the self-weight, and the whippen assembly
11
a
in turn pushes down the capstan screw
7
. The force due to the total self-weight of the hammer and whippen assembly
8
/
11
a
is exerted on the rear portion of the key
1
through the capstan screw
7
, and gives rise to the rotation of the key
1
in the clockwise direction. For this reason, the rear portion is in contact with the rear rail
6
b
, and the front portion is spaced from the front rail
6
a.
When a pianist depresses the front portion of the key
1
, the force gives rise to the rotation of the key
1
in the counter clockwise direction against the total self-weight of the hammer and whippen assembly
8
/
11
a
, and the depressed key
1
actuates the action
5
. In detail, the capstan screw
7
upwardly pushes the whippen assembly
11
a
, and gives rise to rotation of the whippen assembly
11
a
about the whippen flange
11
d
. The jack
11
c
is rotated together with the whippen assembly
11
a
, and the toe is getting closer and closer to the regulating button
11
e
. When the toe is brought into contact with the regulating button
11
e
, the jack
11
c
turns about the left end of the whippen assembly
11
a
, and escapes from the hammer
8
. When the jack
11
c
escapes from the hammer
8
, the hammer
8
starts free rotation. Although the pianist further rotates the key
1
, he or she exerts the force on the front portion of the key
1
against only the self-weight of the whippen assembly
11
a
. The self-weight never serves as the resistance. For this reason, the pianist feels the key
1
light.
Thus, the key
1
is moved at the balance between the moment due to the self-weight of the hammer and whippen assembly
8
/
11
a
and the moment due to the force exerted on the front portion by the pianist. The larger the difference between the moments is, the heavier the pianist feels the key
1
. The weights
3
partially cancel the moment due to the total self-weight of the hammer and whippen assembly
8
/
11
a
, and render the key-touch light. However, it is difficult for the user to change the original weights
3
to other weights. Thus, only the manufacturer regulates the keys
1
to the standard key-touch by using the weights
3
.
The manufacturer encounters a problem in that the lead is detrimental to health and harmful to the environment. The manufacturer tries to change the lead to another kind of metal such as iron and brass. However, these kinds of metal make the regulating work and assembling work difficult. This is because of the fact that the iron and brass are less deformable rather than the lead. In order to snugly insert the iron weights into the through-holes
2
, a force fitting system is required for the iron or brass weights. However, the keys
1
are liable to be broken in the force fitting, and the force fitting is undesirable for the wooden keys
1
. Otherwise, the iron or brass weights are loosely inserted into the through-holes
2
, and are adhered to the wooden keys
1
. The wooden keys
1
are free from the breakage. However, the adhesive compound is less reliable. Moreover, the workers keep the iron or brass weights inside of the through-holes until the adhesive compound is solidified. If the worker supplies the adhesive compound too much, the adhesive compound flows out from the through-holes, and the w
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