Music – Instruments – General features
Reexamination Certificate
2001-09-20
2003-09-09
Lockett, Kimberly (Department: 2837)
Music
Instruments
General features
C084S435000, C084S434000, C084S438000
Reexamination Certificate
active
06617502
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a keyboard device for an electronic keyboard musical instrument such as an electronic piano which has keys and hammers each pivotally movable in response to depression on an associated key.
2. Description of the Prior Art
FIGS. 1 through 3
illustrate an exemplary keyboard device of a conventional electronic piano. The illustrated keyboard device
51
comprises a chassis
2
; a large number of keys
3
(one each of white key
3
a
and black key
3
b
are illustrated) arranged side by side in the lateral direction (in the depth direction in
FIG. 10
) on the chassis
2
; a large number of hammers
4
(only one of which is illustrated) each pivotally movable in response to depression of an associated key
3
. The chassis
2
is made of a steel plate or the like which is punched out and bent through a press work. Each of the keys
3
is pivotably supported at the center thereof by a balance pin
6
implanted on the chassis
2
.
The hammer
4
is supported by a hammer rail
52
coupled to a rear end portion of the chassis
2
through a fulcrum member
53
. The hammer rail
52
is made of a press-worked steel plate or the like, as is the case with the chassis
2
. The hammer rail
52
extends in the lateral direction to cover all the hammers
4
, and fixed to the chassis
2
at a plurality of locations with screws
61
, and also fixed to a keybed
5
with screws
62
. Also, as illustrated in
FIG. 3
, the hammer rail
52
is formed with a large number of vertical mounting holes
52
a,
52
b
arranged side by side in the lateral direction for mounting the fulcrum members
53
.
A large number of fulcrum members
53
are provided one for each hammer
4
. The fulcrum members
53
are made, for example, of synthetic resin moldings by injection molding. As illustrated in
FIG. 2
, each of the fulcrum members
53
comprises a body
53
a
in the shape of inverted C in cross-section, which has an opened front surface; an upper and a lower engaging protrusion
53
b,
53
c
(see
FIG. 3
) formed on the back surface of the body
53
a;
shaft holes
53
d
formed in a left and a right wide wall of the body
53
a
such that they are open to the front face each other; a key switch mount
53
f
formed on the top surface of the body
53
a
and having an engaging recess
53
e.
Then, as illustrated in
FIG. 3
, each of the fulcrum members
53
is mounted on the hammer rail
52
by fitting the upper and lower protrusions
53
b,
53
c
into the upper and lower mounting holes
52
a,
52
b
of the hammer rail
52
, respectively. Also, as illustrated in
FIG. 2
, engaged protrusions
4
a
(only one of which is illustrated) protruding on both sides of the hammer
4
are fitted into the shaft holes
53
d
of the fulcrum member
53
mounted on the hammer rail
52
in the foregoing manner, thereby pivotably supporting the hammer
4
by the fulcrum member
53
. In this structure, both side walls of the fulcrum member
53
define a space for allowing pivotal movements of the hammer
4
, and serve to prevent the hammer
4
from shifting in lateral directions. In addition, the hammer
4
is carried on a rear end portion of the associated key
3
, so that depression on the key
3
causes the hammer
4
to pivotally move to apply the key
3
with a touch weight similar to that of an acoustic piano.
A plurality of action ribs
54
, for example, arranged in octaves, are attached to the hammer rail
52
with a large number of screws
63
(only two of which are illustrated) at predetermined intervals in the lateral direction. Stopper rails
55
are attached to the leading ends of the action ribs
54
with a large number of screws
64
(only two of which are illustrated). The stopper rails
55
extend in the lateral direction to cover all the hammers
4
. These action ribs and stopper rails
55
are made of press-worked steel plates or the like, as is the case with the hammer rail
52
.
Each of the stopper rails
55
comprises a stopper
14
for restricting the associated hammer
4
from pivotally moving upward; and a key switch
15
for detecting information on depression on the associated key
3
. The stopper
14
extends in the lateral direction to cover the whole length of the hammer
4
, and is made of foamed urethane or the like. The key switch
15
is mounted to the stopper rail
55
with screws (not illustrated), with its printed board
16
having a rear end portion inserted into the engaging recess
53
e
of the fulcrum member
53
.
The conventional keyboard device
51
described above requires a large number of parts because the hammer rail
52
, action ribs
54
and stopper rails
55
are individually assembled into the keyboard device
51
, and these components must be coupled to one another with a large number of screws
63
,
64
. Also, the supporting members
53
for supporting a large number of hammers
4
are required in a number equal to the number of hammers
4
, resulting in the need for a quite large number of parts. In addition, such a large number of supporting members
53
must be manually mounted to the hammer rail
52
one by one. Consequently, the conventional keyboard device
51
requires a quite large number of parts as well as assembling steps, causing an increased manufacturing cost.
Furthermore, the hammer rail
52
, action ribs
54
and stopper rails
55
are all made of press-worked steel plates or the like, making it difficult to achieve a high assembly accuracy, due to a low dimensional accuracy of each component and an additional assembly errors. As a result, the hammers
4
, stoppers
14
, key switches
15
and so on, attached to these components, are also susceptible to large mounting errors, and therefore require a delay for adjustments, contributing to an increased manufacturing cost as well. Moreover, the supporting member
53
is mounted to the hammer rail
52
by fitting the engaging protrusions
53
b,
53
c
of the supporting member
53
into the mounting holes
52
a,
52
b
of the hammer rail
52
, while the supporting member
53
is made of a synthetic resin molding. This inevitably causes variations, to some degree, in dimensional accuracy of the engaging protrusions
53
b,
53
c,
and therefore in a positional relationship and a dimensional relationship between the engaging protrusions
53
b,
53
c
and the mounting holes
52
a,
52
b
among the fulcrum members
53
, leading as well to a lower mounting accuracy of the hammers
4
.
Also, since the stopper
14
is attached to the stopper rail
55
supported over a plurality of action ribs
54
arranged at intervals, the action ribs
54
are susceptible to vibrations due to collision of the hammer
4
with the stopper
14
, possibly causing noise.
SUMMARY OF THE INVENTION
The present invention has been made to solve the problems as mentioned above, and it is an object to provide a keyboard device for an electronic keyboard musical instrument which permits a significant reduction in the number of parts constituting hammer supporting members and the number of assembling steps required therefor, thereby reducing a manufacturing cost, and also permits hammers to be mounted in a high mounting accuracy to eliminate noise.
To achieve the above object, a keyboard device for an electronic keyboard musical instrument according to a first aspect of the present invention includes a chassis; a hammer rail made of an aluminum extrudate, and coupled to the chassis; a plurality of keys pivotably supported by the chassis; a plurality of hammers each provided for each of the plurality of keys, wherein each hammer is pivotably supported by the hammer rail and configured to pivot in response to depression on a key associated therewith; and a stopper mounted to the hammer rail for restricting a pivotal movement of a hammer caused by depression on a key associated with the hammer.
According to this keyboard device for an electronic keyboard musical instrument, the hammers are supported by the hammer rail made of an aluminum extrudate, to which the stopper is m
Shimoda Yoshiaki
Suzuki Akihiro
Crowell & Moring LLP
Kabushiki Kaisha Kawai Gakki Seisakusho
Lockett Kimberly
LandOfFree
Keyboard device for electronic keyboard musical instrument does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Keyboard device for electronic keyboard musical instrument, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Keyboard device for electronic keyboard musical instrument will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3075157