Music – Instruments – General features
Reexamination Certificate
1999-09-07
2001-06-19
Nappi, Robert E. (Department: 2837)
Music
Instruments
General features
C084S433000, C084S434000
Reexamination Certificate
active
06248943
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a keyboard musical instrument and, more particularly, to a keyboard musical instrument like an acoustic upright piano and equipped with dummy hammers allowing a player to finger a piece of music without acoustic sound.
DESCRIPTION OF THE RELATED ART
A typical example of the keyboard musical instrument has a keyboard, which has black keys and white keys laid out on the pattern of the acoustic piano. The black keys and the white keys are linked with key action mechanisms, and hammers are respectively driven for rotation by the key action mechanisms as similar to the acoustic piano. Key sensors respectively monitor the motions of the black/white keys, and send pieces of positional information representative of the variation of the keys to a tone generator. The tone generator determines the notes of the scale to be generated and the timings for the sound generation on the basis of the pieces of positional information. The sound generator supplies a sound signal to a speaker system or a headphone at the appropriate timings, and the speaker system or the headphone converts the sound signal to the acoustic piano sound.
FIG. 1
illustrates the essential parts of the prior art keyboard musical instrument. Though not shown, the prior art keyboard musical instrument has a case like that of an acoustic upright piano. The essential parts form key action mechanisms
1
, hammers
2
, damper mechanisms
3
and a receiving member
4
, and the key action mechanisms
1
, the hammers
2
, the damper mechanisms
3
and the receiving member
4
are installed inside the case. Black keys
5
a
and white keys
5
b
are laid out on the patter of the acoustic upright piano, and form in combination a keyboard
5
. The keyboard
5
is placed on a key bed
6
a,
which forms a part of the case. The black keys
5
a
and the white keys
5
b
turn around a balance rail
6
b
like a seesaw.
Each of the key action mechanisms
1
is associated with one of the black/white keys
5
a
/
5
b,
and is placed over the rear end portion of the associated black/white key
5
a
/
5
b.
The key action mechanism
1
has a jack
1
a
turnably supported by a whippen assembly
1
b.
The whippen assembly
1
b
and a butt
1
c
are turnably supported by a center rail
7
. The jack
1
a
is moved together with the whippen assembly
1
b,
and turns with respect to the whippen assembly
1
b.
A regulating button
1
d
is provided on a trajectory of the jack moved together with the whippen assembly
1
b.
A capstan button
5
c
upwardly projects from the rear end portion of each black/white key
5
a
/
5
b,
and is held in contact with the whippen assembly
1
b.
A hammer shank
2
a
and a hammer head
2
b
form in combination the hammer
2
, and the hammer shank
2
a
is fixed to the butt
1
c.
The hammer head
2
b
is corresponding to the hammer top felt of the hammer incorporated in the acoustic upright piano. However, the hammer head
2
b
is shaped into a different configuration from the hammer top felt used in the acoustic upright piano. The hammer head
2
b
is like a column, and has a center of gravity on an extension of the center line of the hammer shank
2
a.
While the associated black/white key
5
a
/
5
b
is staying in the rest position, the jack
1
a
is held in contact with the lower surface of the butt
1
c,
and the hammer head
2
b
is spaced from the receiving member
4
.
The receiving member
4
does not have any string, and is beaten by the hammer head
2
b.
The receiving member
4
does not vibrate like the strings, nor generate the acoustic piano sound. The damper mechanism
3
is also supported by the center rail
7
, and has a damper lever
3
a
driven for rotation by a damper spoon
3
b
fixed to the whippen assembly
1
b.
Thus, the damper mechanism
3
is like the damper mechanism of the acoustic upright piano. However, the damper mechanism
3
does not have any damper head. This is because of the fact that the prior art keyboard musical instrument does not have any string to vibrate upon strike with the hammer head
2
b.
When a player depresses one of the black/white keys
5
a
/
5
b,
the black/white key
5
a
/
5
b
is moved from the rest position toward the end position, and the capstan button
5
c
upwardly pushes the whippen assembly
1
b.
The whippen assembly
1
b
turns in the counter clockwise direction, and the jack is moved together with the whippen assembly
1
b.
The toe of the jack
1
a
is getting closer and closer to a regulating button
1
d.
When the toe is brought into contact with the regulating button
1
d,
the reaction makes the jack
1
a
turn in the clockwise direction with respect to the whippen assembly
1
b,
and the other end of the jack
1
a
kicks the butt
1
c.
The butt
1
c
is rotated in the counter clockwise direction, and escapes from the jack
1
a.
The hammer head
2
b
strikes the receiving member
4
, and rebounds. When the butt
1
c
escapes from the jack
1
a,
the player feels the black/white key
5
a
/
5
b
lighter, and the change is unique like the touch on the keyboard of the acoustic upright piano. The key motion is monitored by the key sensors, and the tone generator and the speaker system generate electronic sound.
The hammers
2
are simpler than the hammers incorporated in the acoustic upright piano, and the manufacturer produces the hammers
2
at a low cost. The key action mechanisms
1
, the damper mechanisms
3
and the keyboard
5
are smaller and simpler than those of a grand piano, and, accordingly, the manufacturer can produce the essential parts at a lower cost. The manufacturer assembles the key action mechanisms
1
with the simple hammers
2
, and offers the prior art keyboard musical instrument to users at a low price. For this reason, the prior art keyboard musical instrument is spread over the market. However, some users do not satisfy the prior art keyboard musical instrument. They express their dissatisfaction at the key touch.
SUMMARY OF THE INVENTION
It is therefore an important object of the present invention to provide a keyboard musical instrument, which offers a key touch identical with the key touch of an acoustic upright piano.
The present inventor contemplated the key touch different from that of the acoustic upright piano, and noticed that the hammer head
2
b
was different in center of gravity from a hammer head, i.e., a hammer felt
8
assembled with a hammer wood
10
of the acoustic upright piano (see FIG.
2
). Although the hammer head
2
b
had the center of gravity on the extension of the center line of the hammer shank
2
a,
the hammer felt
8
and the hammer wood
10
of the acoustic upright piano had the center of gravity offset from the center line of the hammer shank
9
. The hammer head
2
b
exerted a moment on the butt
1
c
around the butt flange, and the hammer felt
8
and the hammer wood
10
also exerted a moment on the associated butt around the butt flange. If the center of gravity in the hammer head
2
b
was offset from the center of gravity in the hammer felt
8
and the hammer wood
10
, the moments were different in magnitude, and differently offered the load against the jack. Thus, the difference in the center of gravity affected the escaping, and made the key touch different between the prior art keyboard musical instrument and the acoustic upright piano. The present inventor concluded that the simple hammer head was to have the center of gravity at the right position corresponding to that of the hammer felt
8
and the hammer wood
10
.
To accomplish the object, the present invention proposes to offset the center of gravity in a weight from the center line of a hammer shank toward a hammer receiver.
In accordance with one aspect of the present invention, there is provided a keyboard musical instrument comprising a keyboard including plural keys independently turnable between respective rest positions and respective end positions and assigned notes of a scale, respectively, plural key action mechanisms similar to key action mechanisms of an acoustic
Lockett Kim
Morrison & Foerster
Nappi Robert E.
Yamaha Corporation
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