JPH0519752A - Key driving device of player piano - Google Patents

Abstract

PURPOSE:To simplify the structure of the key driving device used for the player piano. CONSTITUTION:A rotatable shaft 11 and an electromagnet 12 mounted on a key 13 are provided and a current is supplied to the electromagnet 12 to drive the key 13 by attracting it to the shaft 11. Thus, the key driving device in simple structure for the player piano is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key driving device for an automatic playing piano in which an electromagnet is attracted to a rotating shaft.

[0002]

2. Description of the Related Art A conventional key driving device for an automatic playing piano will be described below.

FIG. 2 is a perspective view of a conventional key driving device for an automatic playing piano. In FIG. 2, 21 is a solenoid, 22 is a plunger, and 23 is a key. The plunger 22 is driven by the excitation of the solenoid 21, and pushes down the key 23. The key 23 rotates about a rotation shaft 24.

The operation of the key driving device of the automatic playing piano constructed as described above will be described below.

When a current is applied to the solenoid 21, the plunger 22 moves downward and pushes down the key 23. When the current to the solenoid 21 is stopped, the plunger 22 returns to its original position and the key 23 also returns to its original position.

[0006]

However, in the above-mentioned conventional structure, the number of plungers has to be arranged in the same number as the keys, so that there is a drawback that the structure becomes large.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a key driving device for an automatic playing piano with a relatively simple structure.

[0008]

In order to achieve this object, a key driving device for an automatic playing piano according to the present invention comprises a plurality of keys equipped with electromagnets and a rotatable shaft arranged so as to penetrate each key. Is arranged.

[0009]

With this structure, the key can be driven by attracting the electromagnet to the rotating shaft.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a key driving device for an automatic playing piano according to an embodiment of the present invention. Figure 1
In FIG. 11, 11 is a shaft made of a magnetic material, 12 is an electromagnet attached to the key, 13 is a key, and 14 and 15 are stoppers that limit the moving range of the key 13. The key 13 is not fixed to the shaft 11, and the rotation of the shaft 11 does not affect the key 13 unless a current is passed through the electromagnet 12. The key 13 rotates around the shaft 11.

An XYZ coordinate system is set in order to describe the movement of each part. Shaft 11 is Z axis, shaft 11 and key 1
The X and Y axes are set so that the point where 3 intersects is the origin O and the position of the electromagnet 12 is (X, Y, Z) = (R, 0, 0) where R is an arbitrary positive constant. The electromagnet 12 is attached to the key 13 so as to be movable only in the X direction.

The operation of the key driving device of the automatic playing piano constructed as described above will be described below.

When the shaft 11 is rotated clockwise when viewed from the positive direction of the Z axis and a current is applied to the electromagnet 12, the electromagnet 12 receives a force in the negative direction of X and moves in the negative direction of X. Adsorb to the shaft 11. Then, due to the frictional force between the electromagnet 12 and the shaft 11, the electromagnet 12 receives a force in the negative Y direction. Since the electromagnet 12 is immovable in the Y-axis direction, the key 13 is dragged by the electromagnet 12 and rotates clockwise around the shaft 11 when viewed from the positive direction of the Z-axis, and comes into contact with the stopper 14 to stop. ..

When the current to the electromagnet 12 is stopped, the electromagnet 1
2 is no longer attracted to the shaft 11, and the electromagnet 1
The frictional force between 2 and the shaft 11 also disappears. Then,
Due to the action mechanism of the key 13, the key 13 is the shaft 11.
When viewed from the positive direction of the Z-axis, it rotates counterclockwise about the center of the arrow and contacts the stopper 15 to stop.

As described above, according to this embodiment, by providing the electromagnet mounted on the key and the rotatable shaft, the key driving device can be constructed with a relatively simple device.

Although the shaft 11 is made of a magnetic material in the embodiment, the shaft 11 may be a shaft which is not a magnetic material and is provided with a magnetic material in the vicinity of the electromagnet 12.

[0018]

As described above, the present invention can realize a key driving device for an automatic playing piano with a relatively simple structure by providing an electromagnet equipped on a key and a rotatable shaft.

[Brief description of drawings]

FIG. 1 is a sectional view of a key driving device of an automatic playing piano according to an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional key driving device for an automatic playing piano.

[Explanation of symbols]

 11 Shaft 12 Electromagnet 13 Key 14 Stopper 15 Stopper 21 Solenoid 22 Plunger 23 Key 24 Rotation axis

Claims (1)

Claim: What is claimed is: 1. A key driving device for an automatic playing piano, comprising: a plurality of keys equipped with electromagnets; and a rotatable shaft arranged so as to penetrate each key.