JP2003337582A - Keyboard or keyboard instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a keyboard of a keyboard instrument which permits easy and sure attaching of a weight into a weight embedding hole of the keyboard and prevents the weight from rotating, floating and dropping out. <P>SOLUTION: The weight embedding hole 2 is formed at the prescribed point of the keyboard 1 and the weight 11 is fitted and fixed into this hole 2. The hole 2 is formed to a through-hole consisting of a small-diameter hole portion 2A and large-diameter hole portions 2B and 2C disposed in apertures at both ends of the hole portion 2A. The weight 11 comprises a weight body 11A and a pipe 11B formed of a material softer than the material of the weight body 11A. The weight body 11A is inserted into the center within the pipe 11B and these two members are integrally coupled by a pin 12, by which the weight 11 is formed. The weight 11 is thereafter fitted to be inserted into the hole 2 and both ends of the pipe 11 are caulked outward in the radial direction and are respectively engaged with the portions 2B and 2C. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard of a keyboard instrument, and more particularly to a keyboard using a material other than lead as a weight material used for adjusting the weight of a key touch.

[0002]

2. Description of the Related Art In general keyboard instruments such as upright pianos, grand pianos, and electronic pianos, the weight of the keyboard causes the player to feel a slight difference in the touch feeling, and psychologically greatly affects the performance content. Because of the weight of the key,
That is, it is necessary to make the weight of key touch uniform for all keyboards or for each range. The weight of the key touch is basically adjusted according to the taste of each player, but in practice, the weight is set to a standard weight predetermined when the musical instrument is manufactured.

As a method of adjusting the weight of the key touch,
In the case of a grand piano keyboard, it is usually shown in FIGS. 10 and 11.
As shown in FIG. 3, a required number of weight embedding holes 2 having a diameter of about 10 mm are formed in the keyboard 1 at predetermined positions near the front end of the rotation fulcrum O at predetermined positions in the longitudinal direction of the keyboard 1. Then, a cylindrical weight 3 is fitted into the weight burying hole 2.

Wood is used as the material of the keyboard 1, and lead is usually used as the material of the weight 3. The reason for using lead is that it is inexpensive, has a relatively large specific gravity, is rich in flexibility and ductility, and is easy to mount on the keyboard. That is, after the lead weight 3 is inserted into the weight embedding hole 2, the outer peripheral portions of both end surfaces of the weight 3 are plastically deformed outward by the pressurizing means (bit) 4 so as to bite into the inner wall of the weight embedding hole 2. As a result, it is possible to fix without needing any special fixing means such as a set screw, and it is possible to reliably prevent the weight from being dropped from the buried hole 2. Reference numeral 5 is an action mechanism for striking a string. When the capstan screw 6 projecting from the rear end of the upper surface of the keyboard 1 is pushed up at the time of key-pressing operation, the hammer 7 turns upward to rotate the keyboard 1.
Is configured to strike the corresponding string. Reference numeral 8 denotes a cover that covers the upper surface and the front surface of the front end portion of the keyboard 1. Normally, both white keys and black keys are formed of synthetic resin or the like.

[0005]

Lead, which is used as a material for the weight 3, is inexpensive, has the highest specific gravity (11.34) among industrial metals, and has flexibility and ductility, and is easily processed into any shape. Since it is possible and easy to press fit into the weight burying hole 2, it is an essential material for the balancer of the keyboard 1. However, since lead is a heavy metal and a substance harmful to the human body and the natural environment, it is desirable not to use it from the viewpoint of environmental protection.

Therefore, recently, various keyboards using weights made of alternative materials other than lead have been proposed (see Patent Documents 1 to 6). The applicant could not find prior art documents closely related to the present invention by the time of filing, other than the prior art documents specified by the prior art document information described in this specification.

[0007]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-142454

[Patent Document 2] Japanese Patent Laid-Open No. 2001-147685

[Patent Document 3] Japanese Patent Laid-Open No. 2001-154661

[Patent Document 4] Japanese Patent Laid-Open No. 2001-175248

[Patent Document 5] JP 2001-195056 A

[Patent Document 6] Japanese Patent Laid-Open No. 2002-162960

The keyboard described in Japanese Patent Application Laid-Open No. 2001-142454 has a weight formed of an elastic composite material having a predetermined specific gravity in which a material other than lead and an elastic material are mixed with each other in a predetermined mixing ratio.

The keyboard described in Japanese Patent Laid-Open No. 2001-147685 has a cylindrical weight body formed of a composite material in which a plurality of kinds of materials other than lead are mixed in a predetermined mixing ratio so as to have a predetermined specific gravity. It is detachably fitted into a tubular body made of an elastic material, and these two members constitute a weight.

The keyboard described in Japanese Patent Laid-Open No. 2001-154661 has a weight formed by a composite material in which a metal other than lead and a plastic are mixed in a predetermined mixing ratio,
A large number of small protrusions are provided on the outer peripheral surface.

The keyboard described in Japanese Patent Laid-Open No. 2001-175248 mixes a fluid material with a metal other than lead, mercury and a light metal, and pours it into a weight embedding hole of the keyboard to solidify the fluid material. The weight is formed by making it. Copper, brass, iron, tungsten, etc. are used as the metal material, and thermosetting resin, thermoplastic resin, low melting point alloy, organic adhesive, low melting point alloy, etc. are used as the fluid material. .

The keyboard disclosed in Japanese Unexamined Patent Publication No. 2001-195056 is a sleeve-shaped cylindrical body made of heat-shrinkable plastic, and a weight main body formed in a cylindrical shape by a metal other than lead and housed in the cylindrical body. The two members make up the weight.

The keyboard disclosed in Japanese Patent Laid-Open No. 2002-162960 is formed of a material other than lead into a cylindrical shape, has a press-fitting hole penetrating through the center thereof, and has a slit-shaped gap extending in the radial direction from the press-fitting hole. The weight is inserted into the embedding hole of the keyboard, and the mounting member is press-fitted into the press-fitting hole, whereby the outer dimension of the weight is enlarged and pressed against the peripheral surface of the embedding hole.

[0014]

However, all the above-mentioned conventional keyboards have the following problems, and there is still room for improvement. That is, Japanese Patent Laid-Open No. 2001-2001
In the keyboard described in Japanese Patent Publication No. 142454, since a weight is formed into a cylindrical shape by an elastic composite material made of a material other than lead and an elastic material and is press-fitted into an embedded hole of the keyboard, a certain fixing force is secured. However, if there is a large dimensional tolerance between the inner diameter of the weight embedding hole and the outer diameter of the weight due to manufacturing errors, the weight will rotate or loosen (rattle), and it will not be possible to secure it in a stable state. There is a risk of causing noise or dropping from the weight burial hole. Further, if the inner diameter of the weight burying hole becomes large due to a change in humidity, the weight may loosen, fall off, or, conversely, the keyboard may crack. Furthermore, since the elasticity of the weight changes depending on the filling rate of the elastic material, the holding force of the weight on the keyboard changes and stable quality cannot be obtained.

In the keyboard described in Japanese Unexamined Patent Publication No. 2001-147685, if the dimensional tolerance between the cylinder body and the weight body is large, the weight body may move and cause noise, or the weight body may drop off from the cylinder body. is there.

In the keyboard described in Japanese Patent Laid-Open No. 2001-154661, a large number of small protrusions are provided on the outer circumference of the weight so that the strength of the connection with the keyboard can be secured to some extent. Has a hemispherical shape that is symmetric in the axial direction of the weight, so that there is a problem in that it is not easily caught by the inner wall of the weight-embedded hole and is easily removed in both the insertion and anti-insertion directions.

The keyboard disclosed in Japanese Patent Laid-Open No. 2001-175248 has a large amount of fluid material because a material having fluidity is poured together with a metal other than lead into the weight embedding hole of the keyboard to be solidified. If it is too small, the strength of the metal joint will be low and the metal may loosen or fall off, making it difficult to control the amount of fluid material used.

In the keyboard described in Japanese Patent Laid-Open No. 2001-195056, when the dimensional tolerance between the inner diameter of the weight burying hole and the outer diameter of the cylindrical body is large, the weight rotates like the above-mentioned Japanese Patent Laid-Open No. 2001-142454. There is a risk that it may loosen or loosen, causing noise, or falling off the weight embedded hole.

In the keyboard described in Japanese Patent Application Laid-Open No. 2002-162960, it is necessary to machine and form the press-fitting hole and the slit-shaped gap in the weight, so that the manufacturing cost of the weight becomes high. Also, when the weight is caulked and fixed, the mounting member is press-fitted into the press-fit hole of the weight to expand the diameter of the entire weight, and the force that uniformly spreads the embedded hole of the keyboard works, and the wood layer of the keyboard is removed. The peeling force acted, sometimes destroying the xylem of the keyboard.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to enable a weight made of a material other than lead to be easily and surely attached to a keyboard. (EN) It is an object to provide a keyboard of a keyboard musical instrument in which a weight does not rotate, loosen, or destroy the xylem of the keyboard.

[0021]

In order to achieve the above object, a first invention is a keyboard of a keyboard instrument in which a weight embedding hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted into the weight embedding hole to be fixed. , The weight is composed of a weight main body arranged inside the weight burying hole, and a thin-walled end portion extending from the weight main body in an outward direction of the weight burying hole, and the weight main body is embedded in the weight burying body. It is fitted in the hole and both ends thereof are caulked outward in the radial direction so as to be engaged with the weight embedding hole.

In the first aspect of the present invention, both ends of the thin wall provided in the weight main body are caulked outward in the radial direction to engage with the weight embedding hole, whereby the weight can be fixed in the weight embedding hole. The rotation, looseness, and dropout of the are prevented.

According to a second aspect of the present invention, in a keyboard of a keyboard musical instrument in which a weight embedding hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted and fixed in the weight embedding hole, the weight embedding hole is formed as a straight through hole. The weight is a cylindrical weight body,
The weight main body is housed in the center of the inside, and the pipe is inserted into the weight embedding hole. The pipe and the weight main body are integrally connected by a coupling means, and the weight is inserted into the weight embedding hole. The weight is fixed to the weight embedding hole by caulking both ends of the pipe radially outward so as to bite into the inner peripheral surface of the opening end of the weight embedding hole.

In the second aspect of the invention, only the openings at both ends of the pipe are crimped outward in the radial direction so as to bite into the inner peripheral surface near the openings at both ends of the weight embedding hole. It can be prevented from falling off, and no force is exerted on the entire inner peripheral surface of the weight embedding hole to peel off the wood grain layer of the keyboard, and there is no risk of breaking the keyboard.

A third invention is the same as the above-mentioned second invention.
The connecting means is composed of a pipe and a pin driven in the radial direction of the weight body.

In the third aspect of the invention, the pin mechanically connects the weight main body and the pipe to prevent the weight main body from rotating, loosening or falling off.

In a fourth aspect of the present invention, in the second aspect of the present invention, the connecting means is formed by a protrusion that is formed on the inner surface side by recessing the front surface side of the pipe and that bites into the weight body.

In the fourth invention, when the front surface side of the pipe is dented by a punch or the like, a protrusion is formed on the inner surface side of the pipe, and the weight main body and the pipe are formed by biting the protrusion into the weight main body. It can be joined together. Therefore, no special member is required as the connecting means.

According to a fifth aspect of the present invention, in a keyboard of a keyboard instrument in which a weight embedding hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted and fixed in the weight embedding hole, the weight is formed into a columnar shape at one end side. Forming divided pieces facing each other by a slit passing through the center and forming irregularities on the outer surface,
The weight is fitted into the weight-embedded hole, and the divided pieces are plastically deformed in a direction in which they are separated from each other, so that they are pressed against the hole wall of the weight-embedded hole.

In the fifth aspect of the invention, since the weight division piece is plastically deformed in the opening direction (radial expansion direction) and pressed against the inner peripheral surface of the weight embedding hole, no special member is required at all, and the unevenness is obtained. The weight can be fixed securely with the rotation of the weight, free movement,
It can be prevented from falling off.

In a sixth aspect based on the fifth aspect, a through hole is further formed in the center of the weight, and a tapered pin having a large diameter portion larger than the hole diameter is driven into the through hole to separate the divided pieces from each other. It is fixed to the keyboard by opening it in the direction.

In the sixth invention, when the taper pin is driven into the through hole, the divided piece is plastically deformed in the opening direction and pressed against the inner peripheral surface of the weight embedded hole.

According to a seventh aspect of the present invention, in a keyboard of a keyboard musical instrument in which a weight embedding hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted and fixed in the weight embedding hole, the weight is formed in a columnar shape, and the weight is substantially formed from both ends thereof. By forming the slits passing through the center so as to be orthogonal to each other, the divided pieces facing each other are formed at both ends, and the weight is inserted into the weight embedding hole to plastically deform the divided pieces in a direction in which they are separated from each other. As a result, the weight embedding hole is pressed against the hole wall.

In the seventh aspect of the invention, since the divided pieces of the weight are plastically deformed and pressed against the inner peripheral surface of the hole for embedding the weight, no special member is required at all and the weight can be securely fixed and the weight can be securely fixed. It is possible to prevent rotation, looseness, dropping, and the like.

An eighth invention is the above-mentioned seventh invention, wherein
A through hole is further formed at the center of the weight, a taper pin having a large diameter portion larger than the hole diameter is driven into the through hole, and the divided pieces are opened in a direction in which they are separated from each other, thereby fixing to the keyboard.

In the eighth invention, when the tapered pin is press-fitted into the through hole, the divided piece is plastically deformed in the opening direction and the weight is fixed in the weight embedded hole.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is an exploded perspective view showing a first embodiment in which the present invention is applied to a piano keyboard,
FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a view showing how the weight is mounted in the weight burying hole. The same members as those shown in the section of the prior art are designated by the same reference numerals and the description thereof will be omitted as appropriate. In these figures, 1 is a keyboard made of wood such as Ezo pine, and two weight embedding holes 2 that open to both sides are formed at predetermined locations near the front end, and these weight embedding holes 2 A weight 11 for key touch adjustment is fitted and fixed.

The weight-embedded hole 2 is formed of a through-hole having a different diameter and having large-diameter holes at both end openings. More specifically, the weight embedding hole 2 is a straight small-diameter hole portion 2A.
And two large diameter holes 2B and 2C respectively provided at both ends of the small diameter hole 2A. The inner diameter and the depth of the two large diameter holes 2B and 2C are substantially equal.

The weight 11 is composed of a weight body 11A and a pipe 11B for accommodating the weight body 11A,
These two members are integrally connected by a pin 12 as a connecting means. The weight main body 11A is formed in a cylindrical shape, and has a length substantially equal to the small diameter hole portion 2A of the weight embedding hole 2 and an outer diameter smaller than this. The pipe 11
B has a length substantially equal to that of the weight-embedded hole 2, and the small-diameter hole portion 2
The weight main body 11A has an outer diameter substantially equal to the inner diameter of A and an inner diameter substantially equal to or slightly larger than the outer diameter of the weight main body 11A, and the weight main body 11A is housed in the center of the inside. The pin 12 is
The weight body 11A and the pipe 11B are integrally coupled by being press-fitted into the radial hole 13 formed in the center of the weight body 11A and the pipe 11B.

The pin 12 is press-fitted into the hole 13 by previously forming in the center of the weight body 11A and the pipe 11B a pin hole 13 having an inner diameter substantially equal to or smaller than the outer diameter of the pin 12 by a drill. , The weight main body 11 is fitted into the pipe 11B so as to be positioned at the center of the inside, and the pin holes 13 of these two members are aligned with each other and the pin 12 is driven into the pin hole 13 so that the weight main body 11A and the pipe 11B are integrated. Combined or weight body 1
1 is housed in the center of the pipe 11B, pin holes 13 are formed in these members by a drill or the like, and then the pin 12 is driven into the pin hole 13 to integrate the weight main body 11A and the pipe 11B. They can be combined with each other.

The material of the weight body 11A is not a harmful substance other than lead or mercury but has a relatively large specific gravity, such as iron (specific gravity 7.86), brass (specific gravity 8.3),
Copper (specific gravity 8.96), tungsten (specific gravity 19.3),
A sintered metal, or a composite material in which powder of at least one of these metals and a synthetic resin are mixed at a predetermined ratio is used. Particularly, in the case of tungsten, the specific gravity is heavier than that of lead. Therefore, depending on the mixing ratio with the synthetic resin, the specific gravity can be the same as that of lead. In the case of a composite material, it is desirable that the hardness at room temperature be set sufficiently higher than the hardness of the keyboard 1. As the synthetic resin, urethane resin, polyester resin, epoxy resin, phenol resin, urea resin, melamine resin or other thermosetting resin, or ABS resin, acrylic resin or other thermoplastic resin is used. Regarding the mixing ratio of the metal and the synthetic resin, it is generally desirable to increase the amount of the metal material in order to increase the density of the weight 11. Further, when the weight main body 11A is formed of iron, it is desirable to apply rustproofing treatment to the surface.

The material of the pipe 11B is a material other than lead or mercury, which is easily plastically deformed, such as copper, brass, or a composite of powder of any one of these metals and plastic mixed in a predetermined mixing ratio. Material or the like is used.

Such a weight 11 is inserted into the weight embedding hole 2 of the keyboard 1 and then the protrusions 14a of the caulking bit 14 are pushed into the openings at both ends of the pipe 11B as shown in FIG. As shown in FIG. 11, the plastically deformed portion 15 is plastically deformed radially outward so as to be substantially orthogonal to the axis of the pipe 11B.
Is fixed to the weight embedding hole 2 by engaging or pressing the bottom surfaces of the large diameter hole portions 2B and 2C.

In the keyboard 1 having such a weight 11, since the weight body 11A and the pipe 11B are integrally connected by the pin 12, the weight body 11A rotates or floats inside the pipe 11B. It can be securely fixed without falling or falling off. Further, since it is sufficient to drive the pin 12 into the pin hole 13 formed at the center of the weight body 11A and the pipe 11B, the weight 11 can be easily assembled and can be manufactured at low cost.

Further, since both ends of the pipe 11B are plastically deformed outward in the radial direction so as to engage with the large-diameter hole portion 2B of the weight embedding hole 2, the weight 11 is surely inserted in the weight embedding hole 2. It can be fixed, the weight 11 itself can move, rotate,
It can be prevented from falling off.

Since it is not necessary to press the weight 11 into the weight burial hole 2, it is possible to prevent the keyboard 1 from cracking. In particular, when both ends of the pipe 11B are plastically deformed outward, almost no force is applied to the inner peripheral surface of the weight embedding hole 2, so there is no risk of peeling off the wood grain layer of the keyboard, and It is possible to prevent destruction.

Furthermore, since no lead harmful to the human body or the natural environment is used as the weight 11, the problem of environmental pollution can be solved.

FIG. 4 is a sectional view showing a second embodiment of the present invention. In this embodiment, instead of using the pin 12 as a coupling means for integrally coupling the weight main body 11A and the pipe 11B, the protrusion 2 provided on the inner peripheral surface of the pipe 11B.
2 is used. That is, when a small conical recess 21 is formed on the outer periphery of the pipe 11B having the weight body 11A housed in the center by a tool such as the punch 20, a conical protrusion 22 is bulged on the inner side of the pipe 11B. The weight main body 11A, and the weight main body 11A and the pipe 11B are integrally connected. Other configurations and mounting of the keyboard 1 into the weight embedding hole 2 are the same as those in the above-described first embodiment.

In the weight 11 having such a structure, the weight body 11A and the pipe 11B are integrally coupled by simply projecting the protrusion 22 projecting inside the pipe 11B and biting into the weight body 11A. Because you can
It is possible to reduce the number of parts without using any connecting means made of other members.

FIGS. 5A and 5B are a sectional view showing a third embodiment of the present invention and a sectional view showing a state before caulking. In this embodiment, the weight embedding hole 2 of the keyboard 1 is a straight through hole (hole diameter is constant over the entire length), and the weight 11 shown in the first embodiment is inserted into the weight embedding hole 2 to form a pipe. The both ends of 11B are plastically deformed outward in the radial direction by the convex portions 14a of the caulking bit 14 so as to bite into the inner peripheral surface of the opening end of the weight embedding hole 2 so that the weight 11 is fixed to the weight embedding hole 2. It was done.

Even in such a structure, the pipe 11B
When plastically deforming both ends of the, the force is applied only to the inner peripheral surface of the opening end of the weight embedding hole 2, and the force is not applied to the entire inner peripheral surface. It is possible to prevent the keyboard 1 from being broken.

FIG. 6 is a sectional view showing a fourth embodiment of the present invention. In this embodiment, the weight embedding hole 2 of the keyboard 1 is used.
Is straight (a through hole having a constant hole diameter over the entire length, and a weight 25 is inserted into the weight embedding hole 2 and both ends thereof are plastically deformed outward in the radial direction as in the third embodiment described above. The weight 25 is fixed to the weight embedded hole 2.

The weight 25 has an outer diameter of the weight embedded hole 2
A small-diameter cylinder is hollowed out at both ends of a metal cylinder having an outer diameter substantially equal to the inner diameter of the circular recess 26.
By forming the weight main body 25A in the central portion,
The weight main body 25A is composed of thin-walled cylindrical end portions 25B provided at both ends of the weight main body 25A so as to extend to the outside of the weight embedded hole 2. Then, these end portions 25B are caulked to the outside so as to bite into the inner circumferential surface of the weight burying hole, whereby the weight 2 is fixed in the weight burying hole 2.

In such a structure, since the weight 25 can be manufactured by one member, the connecting member is not required, the weight 25 can be manufactured easily, and the number of parts can be reduced.

FIG. 7 is an exploded perspective view showing the fifth embodiment of the present invention. In this embodiment, the weight embedding hole 2 of the keyboard 1 is a straight through hole, the weight 30 is formed of a material having a large specific gravity other than lead in a cylindrical shape, and a slit 31 passing through substantially the center is formed on one end surface thereof. As a result, one end side is made into two plastically deformable divided pieces 30a and 30b that are opposed to each other with the slit 31 interposed therebetween, and the other end side is made into a connecting portion 30c of the two divided pieces 30a and 30b. Further, a small-diameter through hole 33 is formed in the center of the weight 3 so as to overlap with the slit 31 and a taper pin 32 as a tool is inserted therein. Therefore, each divided piece 30
A semicircular groove is formed at the center of the surfaces of a and 30b that face each other. The taper pin 32 has a large diameter portion larger than the hole diameter of the through hole 33. Furthermore, small irregularities 35 are formed on the outer peripheral surface of the weight 30. Unevenness 35
Can be formed by mechanically surface-treating the surface, or by forming projections in a scattered manner, or by partially or wholly forming a groove.

As the material of the weight 30, the above-mentioned first and
Similar to the weight main body 11A of the weight 11 in the second embodiment, a metal other than lead or mercury, which has a relatively large specific gravity and is not harmful, such as iron, brass, tungsten, sintered metal, or at least one of these metals. A composite material or the like in which one powder and a synthetic resin are mixed at a predetermined ratio is used.

Such a weight 30 is inserted into the weight embedding hole 2 and then the taper pin 32 is inserted into the through hole 33 to form the weight 2.
The two divided pieces 30a and 30b are spread by a wedge action to be plastically deformed and pressed against the inner peripheral surface of the weight embedded hole 2 to be fixed. In assembling the weight 30 into the weight burial hole 2, in order to prevent damage to the keyboard 1, the divided pieces 30a,
It is desirable to insert so that the direction of plastic deformation of 30b (direction of arrow A) matches the grain direction of keyboard 1 (direction of arrow B). After the weight 30 is incorporated in the weight embedded hole 2, the taper pin 32 is extracted from the through hole 33.

Even in the weight 30 having such a structure, the weight 30 can be easily and easily attached to the weight burying hole 2 and can be fixed in a stable state even if the dimensional tolerance between the weight burying hole 2 and the weight 30 is large. In particular, the unevenness 35 provided on the outer peripheral surface is effective in preventing the weight 30 from rotating, loosening, falling off, or the like. Further, since the weight 30 is composed of one member, it can be manufactured at low cost.

FIG. 8 is a perspective view of a weight and a taper pin showing a sixth embodiment of the present invention. In this embodiment, the tapered pin 40 is driven into the through hole 33 of the weight 30 in the fifth embodiment, and the left and right divided pieces 3 are formed.
0a, 30b are opened and pressed against the inner peripheral surface of the weight burying hole 2. The taper pin 40 remains in the through hole 3 even after the weight 30 is incorporated into the weight embedded hole 2.
It remains within 3.

In the mounting structure of the weight 30 having such a structure, since the taper pin 40 remains in the through hole 33, there is no possibility that the divided pieces 30a and 30b return to their original shapes, and the fixing is performed more reliably. can do.

FIG. 9 is a perspective view of a weight and a taper pin showing a seventh embodiment of the present invention. In this embodiment, the slits 31 are formed on both end surfaces of the weight 30 and pass through substantially the center.
By forming a and 31b toward the other end face and by shifting the phase by 90 ° so as to be orthogonal to each other, split pieces 30a and 30b facing each other with the slits 31a and 31b sandwiched therebetween are formed. , A small-diameter through hole 33 is formed at the center, and a tapered tool 32 (see FIG. 7) or a taper pin 40 as a part of the weight 30 is driven into the through hole 33 to divide the divided piece 30a,
30b is opened and pressed against the inner peripheral surface of the weight-embedded hole 2. When the tapered tool 32 is used, the weight 30 is inserted into the weight embedded hole 2 and then extracted from the through hole 33, and when the tapered pin 40 is used, it is left inside the through hole 33.

In the mounting structure of the weight 30 having such a structure, the slits 3 orthogonal to both ends of the weight 30 are provided.
Since the divided pieces 30a and 30b are formed by forming 1a and 31b, respectively, and these divided pieces are plastically deformed in a direction in which they are separated from each other and pressed against the inner peripheral surface of the weight embedded hole, both ends of the weight 30 are substantially formed. The weight 30 can be fixed in the same state, and the stability of the weight 30 when fixed to the keyboard can be further increased.

In the above-described embodiments, the example applied to the keyboard of the piano is shown, but the present invention is not limited to this, and the keyboard of keyboard musical instruments such as electric pianos and electronic pianos. Can also be applied to. Further, in the embodiment shown in FIGS. 7 to 9, the weight 3
In order to more securely fix 0, it is preferable to form knurls on the outer peripheral surface of the weight 30 by knurling. Furthermore, although the pin 12 or the protrusion 22 is used as the connecting means of the weight body 11A and the pipe 11B, the present invention is not limited to this, and an adhesive may be used.

[0064]

As described above, the weight is attached to the weight main body,
In the invention, which is constituted by the thin-walled end portions on both ends of the weight body, and the end portions are caulked outward in the radial direction so as to engage with the weight embedded hole, the weight can be formed by one member, It is possible to prevent the weight from rotating, loosening, falling, and the like.

In the keyboard of the keyboard musical instrument according to the present invention, in which the weight is composed of the weight main body and the pipe, the weight main body and the pipe are integrally connected by a connecting means such as a pin or a protrusion. The work is easy, the weight main body and the pipe can be securely fixed, and the weight main body can be prevented from rotating, loosening, or falling off in the pipe. In addition, since both ends of the pipe are crimped outward in the radial direction to engage with the weight embedding hole, there is no need to press the weight into the weight embedding hole, and it is possible to prevent the weight itself from rotating, loosening, or falling. Moreover, when the pipe is crimped, no force is applied to the entire inner peripheral surface of the weight embedding hole, and it is possible to prevent the keyboard from being broken.

Further, in the invention in which the connecting means is formed by the protrusion formed on the inner surface of the pipe, the connecting means which is a separate member is not required, and the number of parts can be reduced.

In the invention in which the weight is formed in a columnar shape, and the divided pieces facing each other are provided on one end side by the slits passing through substantially the center, the weight is fitted into the weight embedding hole, and then a tapered tool or Since it suffices to insert the taper pin, plastically deform the divided pieces in the direction in which they are separated from each other, and press them against the weight embedding hole, the work for attaching the weight is simple and easy. Further, since both ends of the pipe are caulked outward in the radial direction, the weight can be reliably fixed to the weight burying hole, and it is possible to prevent loosening, rotation, dropping, and the like. In particular, if the taper pin is left to be driven into the through hole of the weight, the divided piece of the weight does not return to its original shape, and reliable fixing can be obtained. Further, in the invention in which the divided pieces are provided by forming the slits at both ends of the weight, both ends of the weight can be fixed in substantially the same state, so that the stability of the weight can be further improved. Furthermore, if unevenness is provided on the outer circumference of the weight, it is possible to more reliably prevent the weight from moving, rotating, falling, and the like.

Further, in the present invention, since the weight made of a material other than lead is used, there is no fear of causing environmental problems.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment in which the present invention is applied to a piano keyboard.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a diagram showing how a weight is attached to a weight burying hole.

FIG. 4 is a cross-sectional view showing a second embodiment of the present invention.

5 (a) and 5 (b) are a sectional view showing a third embodiment of the present invention and a sectional view showing a state before caulking.

FIG. 6 is an exploded perspective view showing a fourth embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a fifth embodiment of the present invention.

FIG. 8 is a perspective view of a weight and a taper pin showing a sixth embodiment of the present invention.

FIG. 9 is a perspective view of a weight and a taper pin showing a seventh embodiment of the present invention.

FIG. 10 is a side view showing a keyboard of a conventional piano having a weight.

FIG. 11 is a sectional view of a keyboard.

[Explanation of symbols]

1 ... Keyboard, 2 ... Weight embedding hole, 2A ... Small diameter hole portion, 2B, 2
C ... Large-diameter hole portion, 3 ... weight, 11 ... weight, 11A ... weight body, 11B ... pipe, 12 ... pin, 21 ... dent, 22 ...
Mouth, 25 ... weight, 25A ... weight body, 25B ... end,
30 ... Weight, 30a, 30b ... Dividing piece, 30c ... Connection part, 31, 31a, 31b ... Slit, 32 ... Tapered tool, 33 ... Through hole, 40 ... Tapered pin.

Claims (8)

[Claims] 1. A keyboard of a keyboard instrument, wherein a weight embedding hole is formed at a predetermined position on a side surface of the keyboard, and a weight is fitted and fixed in the weight embedding hole, wherein the weight is arranged inside the weight embedding hole. And a thin-walled end portion extending from the weight main body to the outer side of the weight embedding hole, and the weight main body is fitted into the weight embedding hole and both ends thereof are caulked outward in the radial direction to form the weight. A keyboard of a keyboard instrument characterized by being engaged with a buried hole. 2. A keyboard of a keyboard musical instrument, wherein a weight embedded hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted and fixed in the weight embedded hole, wherein the weight embedded hole is a straight through hole, and the weight is a circle. It is composed of a columnar weight main body and a pipe which is housed in the center of the weight and is inserted into the weight burying hole. The pipe and the weight main body are integrally coupled by a coupling means, and the weight is weighted. A keyboard for a keyboard instrument, characterized in that a weight is fixed to the embedded hole by inserting the pipe into the embedded hole and caulking both ends of the pipe outward in the radial direction so as to bite into the inner peripheral surface of the opening end of the embedded hole. . 3. The keyboard of a keyboard instrument according to claim 2, wherein the connecting means is a pin driven in the radial direction of the pipe and the weight main body. 4. The keyboard of the keyboard instrument according to claim 2, wherein the coupling means is a protrusion that is formed on the inner surface side by recessing the front surface side of the pipe and bites into the weight main body. keyboard. 5. A keyboard of a keyboard instrument, wherein a weight embedding hole is formed at a predetermined position on a side surface of a keyboard, and a weight is fitted and fixed in the weight embedding hole, wherein the weight is formed in a cylindrical shape and a slit passing through the center at one end side. By forming divided pieces facing each other by forming concaves and convexes on the outer surface, and by inserting the weight into the weight embedded hole and plastically deforming the divided pieces in the direction of separating from each other, the hole wall of the weight embedded hole The keyboard of a keyboard instrument characterized by being pressed against. 6. The keyboard of the keyboard musical instrument according to claim 5, wherein a through hole is further formed at the center of the weight, and a taper pin having a large diameter portion larger than the hole diameter is driven into the through hole to separate the divided pieces from each other. A keyboard of a keyboard instrument characterized by being fixed to the keyboard by opening in the direction of separation. 7. A keyboard of a keyboard instrument having a weight embedding hole formed at a predetermined position on a side surface of a keyboard and having a weight fitted and fixed in the weight embedding hole, wherein the weight is formed in a columnar shape and a slit passing through substantially the center from both ends thereof. Are formed so as to be orthogonal to each other, thereby forming divided pieces facing each other at both ends, and by inserting the weights into the weight embedding holes and plastically deforming the divided pieces in a direction in which they are separated from each other, the weights are formed. A keyboard of a keyboard instrument characterized by being pressed against the wall of the buried hole. 8. The keyboard of the keyboard musical instrument according to claim 7, wherein a through hole is further formed at the center of the weight, and a tapered pin having a large diameter portion larger than the hole diameter is driven into the through hole to separate the divided pieces from each other. A keyboard of a keyboard instrument characterized by being fixed to the keyboard by opening in the direction of separation.