JPH0981120A - Earthquake-resistant device for grand piano - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the breakage of legs in the event of an earthquake by constituting an earthquake-resistant device of a moving plate in which plural recessed parts for engagement which are respectively engageable with the bottom ends of the plural legs of a grand piano are formed. SOLUTION: The earthquake-resistant device 1 is composed of the moving plate 3 installed between the grand piano 2 and a floor F. The moving plate 3 is composed of a metallic plate, such as iron plate, and wooden plate and is constituted by connecting three sheets of forked engaging plates and three sheets of rectangular intermediate plates to each other by means of screws 22, thereby forming a triangular shape blanked in the middle. The recessed parts 12 for engagement having a partially spherical shape are formed in the positions corresponding to the legs 5 of the grand piano 2 on the upper surface of the engaging plates in the state after the connection so that the rollers 8 of casters 6 engage therewith. Then, the entire part of the grand piano moves horizontally together with the moving plate when the lateral load by the earthquake increases to some extent to absorb the lateral load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-proof device for a grand piano for preventing damage or excessive movement of the grand piano during an earthquake, and especially for preventing breakage of legs.

[0002]

2. Description of the Related Art Since the Great Hanshin Earthquake, attention has been paid to the importance of safety measures against earthquakes, one of which is prevention of collapse or movement of furniture in a room. Such earthquake countermeasures have been conventionally performed even for acoustic pianos with a large weight, and in the case of grand pianos,
Since there is little risk of falling like an upright piano, emphasis is placed on preventing slippage. For this reason, the conventional earthquake-proof device for grand pianos is one in which the lower end of each leg made of wood material is fixed to the floor with a fixing metal fitting, or the lower end of each leg is retained in the metal fitting fixed to the floor. The mainstream is something to combine.

[0003]

However, in this conventional seismic resistant device, the lower ends of the legs are fixed to the floor and their displacements are constrained. Therefore, when a lateral load acts on the grand piano due to an earthquake, There is a problem that the stress is increased and the leg weak in strength is easily broken due to shear failure. In fact,
Most of the causes of breakage of grand pianos due to earthquakes are due to breakage of legs, and it is an important issue for earthquake countermeasures to solve this.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a seismic resistant device for a grand piano capable of reliably preventing damage to the legs during an earthquake. .

[0005]

In order to achieve the above object, the seismic resistant device for a grand piano of the present invention is a movable structure in which a plurality of engaging recesses are formed so that the lower ends of a plurality of legs of the grand piano can engage with each other. It is characterized by being composed of a plate.

In this grand piano earthquake-proof device, a movable plate is placed on a floor surface, then the grand piano is placed on the movable plate, and the lower end portions of the legs of the grand piano are engaged with the engaging recesses. Installed. When an earthquake occurs, the lateral load acting on the grand piano acts on the movable plate via the lower ends of the legs. Then, when this lateral load exceeds the maximum frictional force between the movable plate and the floor surface, the movable plate slides on the floor surface, and the grand piano placed on it slides horizontally along with the movable plate. Move to. As described above, in the earthquake-resistant device of the present invention, when the lateral load due to an earthquake increases to some extent, the entire grand piano horizontally moves together with the movable plate, and the lateral load is absorbed. Therefore, excessive shear stress is applied to the legs. Since it does not occur, it is possible to reliably prevent breakage of the leg.

In this case, it is preferable that each of the plurality of legs has a caster at a lower end thereof, and the engaging recess is formed so that the caster can be engaged. According to this configuration, the existing caster normally provided on the leg of the grand piano is used as it is, and is engaged and fixed in the engaging recess of the movable plate, so that it is not necessary to perform any processing on the grand piano. Since only the movable plate needs to be prepared, it can be constructed inexpensively and easily. Further, the position of the caster and the engagement recess can be easily adjusted while rolling the caster.

Further, in this case, it is preferable that the movable plate is provided with a caster retainer for preventing the caster from being separated from the engaging recess. According to this configuration, the caster is prevented from coming off during an earthquake, and the integrity of the grand piano and the movable plate is ensured, so that the movable plate slides reliably and only the grand piano moves significantly. Such a situation can be reliably avoided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an installation situation of a seismic resistant device to which the present invention is applied. As shown in the figure, the earthquake-resistant device 1 is composed of a movable plate 3 installed between a grand piano 2 and a floor F.

The grand piano 2 is provided with a piano body 4 and three legs 5, 5, 5 extending downward from a predetermined position on the lower surface of the piano body 4, and the legs 5 are made of wood material. There is. Casters 6 are provided at the lower ends of the legs 5 as usual. As shown in FIG. 4, the caster 6 includes a support fitting 7 rotatably attached to the lower surface of the leg 5 about a vertical axis, and a short cylindrical shape rotatably supported by the support fitting 7 via a shaft 7a. And roller 8 of.

On the other hand, the movable plate 3 is composed of a metal plate such as an iron plate or a wooden plate, and as shown in FIG. 2, three bifurcated engagement plates 9, 9, 9 and three rectangular intermediate plates. By connecting the screws 10, 10 and 10 to each other with screws 11, they are formed in a hollow triangular shape. Further, the thickness of both plates 9 and 10 may be the same as shown in FIG. 3A or different as shown in FIG. 3B, but in any case, at least the lower surfaces of both are flush with each other. Be connected.

On the upper surface of the engagement plate 9, a partially spherical engagement recess 12 is formed at a position corresponding to the leg 5 of the grand piano 2 in the state after connection, and the caster 6 is formed.
Roller 8 is engaged. Reference numeral 13 in FIG. 4 is a caster retainer fixed to the engaging plate 9 with a screw 14 so as to press the roller 8 in order to prevent the caster 6 from being separated from the engaging recess 12. .

In the seismic resistant device 1 having the above-described structure, first, the assembled movable plate 3 is placed at a predetermined position on the floor F, and then
It is installed by placing the grand piano 2 on the movable plate 3, engaging the rollers 8 of the casters 6 with the engaging recesses 12, and finally attaching the caster retainer 13.

Next, the operation of the seismic resistant device 1 will be described. When an earthquake occurs, the lateral load acting on the grand piano 2
It acts on the movable plate 3 via the rollers 8 of the casters 6. Then, when this lateral load exceeds the maximum frictional force between the movable plate 3 and the floor F, the movable plate 3 moves to the floor F.
The grand piano 2 that slides on and is placed on it also moves horizontally along with the movable plate 3. Since the lateral movement is absorbed by the horizontal movement of the grand piano 2, even if a large earthquake occurs, the shear stress generated in the leg 5 can be suppressed to be equal to or less than the allowable stress, and therefore the leg 5 is reliably broken. Can be prevented.

In this case, it is preferable to surely slide the movable plate 3 in the horizontal direction and prevent the sliding too much to suppress the movement amount of the grand piano 2 as much as possible. It is important to make the friction coefficient between F to be an appropriate size. For this reason,
Actually, the type of floor F (wooden floor, carpet, tatami, etc.)
Depending on the situation, the material of the movable plate 3, the width D and the thickness H
Will be decided.

The caster retainer 13 prevents the caster 6 from coming off during an earthquake and ensures the integrity of the grand piano 2 and the movable plate 3, so that the movable plate 3 can be slid reliably. In addition, it is possible to surely avoid the situation where only the grand piano 2 moves greatly.

Further, in the seismic resistant device 1 of the present embodiment, the existing casters 6 usually provided on the legs of the grand piano are used as they are to engage and fix the engaging recesses 12 of the movable plate 3. Since it is not necessary to process the piano 2 and only the movable plate 3 needs to be prepared, the piano 2 can be constructed inexpensively and easily.
In addition, alignment of the caster 6 and the engaging recess 12 is
This can be easily done while rolling the casters 6. Furthermore, since the movable plate 3 is formed in a hollow triangular shape by assembling the engaging plate 9 and the intermediate plate 10, it is possible to reduce the weight and reduce the manufacturing cost by improving the material yield.

The present invention is not limited to the embodiments described above, but can be implemented in various modes.
For example, the movable plate is not limited to the illustrated one, and may be integrally formed in advance, may be solid instead of hollow, or may have a shape other than a triangle. Further, in order to adjust the friction coefficient of the movable plate, an adjustment mat may be attached to the back surface of the movable plate or the front surface of the floor F, if necessary.

Further, in the embodiment described above, the casters of the legs are engaged and fixed in the engaging recesses of the movable plate. However, when the casters are not provided, the lower ends of the legs are engaged and fixed. You may In addition, the configuration of the details can be appropriately changed without departing from the spirit of the present invention.

[0020]

As described in detail above, in the seismic resistant device of the present invention, when the lateral load due to an earthquake increases to a certain extent, the entire grand piano moves horizontally together with the movable plate, so that the lateral load is absorbed. Even when a large earthquake occurs, the shear stress generated in the legs can be suppressed to be equal to or lower than the allowable stress, and therefore, the legs can be reliably prevented from being broken.

[Brief description of drawings]

FIG. 1 is a perspective view showing an installation situation of an earthquake-proof device for a grand piano to which the present invention is applied.

FIG. 2 is a plan view of the movable plate shown in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is an enlarged cross-sectional view showing a main part of the seismic resistance device of FIG.

[Explanation of symbols]

 1 Earthquake-proof device 2 Grand piano 3 Movable plate 5 Legs 6 Casters 12 Engagement recesses 13 Caster foot

Claims (3)

[Claims] 1. An earthquake-proof device for a grand piano, characterized in that the lower ends of a plurality of legs of the grand piano are constituted by a movable plate having a plurality of engaging recesses capable of engaging with each other. 2. The grand piano according to claim 1, wherein each of the plurality of legs has a caster at a lower end thereof, and the engaging recess is formed so that the caster can be engaged with the grand piano. Anti-seismic device. 3. The seismic resistant device for a grand piano according to claim 2, wherein a caster retainer for preventing the caster from being separated from the engagement recess is attached to the movable plate.