JPS6210910Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a key switch for an electronic musical instrument or the like.

In the conventional key switch of an electronic musical instrument, as shown in FIG. 1, a keyboard 2 is attached to the tip of a key channel 1 that can swing freely about a fulcrum plate 11, and is normally biased upward by a key spring 8. There is. key 2
A stopper 12 provided vertically on the lower surface defines the upper limit of the key 2 at the front end of a frame 13 provided on the lower surface of the key 2 and the key channel 1.
Elastic body 1 such as rubber or felt stuck on top
4 is the lower limit for pressing key 2.

FIG. 2 is an exploded perspective view of the switch part shown in FIG.
A movable contact support hole 41 (41a, 41b, 41c) for inserting and supporting (6a, 6b, 6c) is drilled, and a coil spring 5 is wound around the lower part 43 of the actuator 4, so that the key 2 can be pressed down. Normally, the switch is in the OFF state. On the other hand, the upper part 42 of the actuator 4 is placed in contact with the lower surface of the drive rod 3. When the key 2 is pressed down, the drive rod 3 protruding from the lower surface of the key channel 1 moves the actuator 4 downward, and the movable contacts 6 (6a, 6b, 6
c) is the fixed contact 7 (7a, 7
b, 7c) and the switch turns ON.

However, as shown in FIG. 6, the relationship between the weight of the key touched by the conventional key switch and the depression depth (stroke) of the key 2 is such that after the switch is turned on, the repulsive force of the coil spring 5 and the movable contact 6 is multiplied by the key spring 8. That is, even after the movable contact 6 contacts the fixed contact 7, the movable contact 6 is still pressed by the actuator 4, so the movable contact 6 bends and its repulsive force is transmitted to the key 2, causing the key to be touched. The weight increases rapidly, resulting in what is called a two-step upward touch.
This two-step upward touch is very uncomfortable for the player, as opposed to the comfortable two-step downward touch, and is extremely difficult to play.

As a way to somewhat overcome this drawback, it is possible to consider a method in which the movable contact 6 is a self-contact type contact.
However, this method still requires actuator 4
Since there is a coil spring 5 in , the upward direction 2
Dantatsuchi occurs.

The present invention solves the above drawbacks by making the movable contact 6 a self-pressure contact type, removing the coil spring 5 used in the actuator 4, and removably connecting the actuator 4 and the drive rod 3. death,
In addition, the movable contact support holes 41 (41a, 41b, 41c) in the actuator 4 are made large in the vertical direction, and the movable contact 6 and the fixed contact 7 contact each other from the time when the movable contact 6 and the fixed contact 7 contact each other until the point at which the actuator 4 completes its downward movement. The actuator 4 is configured to be mechanically separated from the actuator 4.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 schematically shows the structure of the key switch of the present invention, and FIG. 4 shows an exploded perspective view of the structure of the key switch shown in FIG. As shown in FIG. 4, a notch with a width a is provided at the tip of the drive rod 3 with a thickness b. On the other hand, a notch with a width b is provided on both sides of the upper portion 42 of the actuator 4, and the width of the actuator 4 at this notch portion is a, and the drive rod 3 is tightly fitted into the actuator 4. Also, the lower part 4 of the actuator 4
3 is a hole 9 drilled in the bottom of the switch box 9
It is supported so that it can freely slide up and down. In addition, the movable contact support hole 41 (41a,
41b, 41c) are simply movable contacts 6 as in the conventional case.
The holes are not large enough to simply insert and support (6a, 6b, 6c), but are made larger in the vertical direction. Therefore, under normal conditions when the key 2 is not pressed down, the movable contact 6a is lifted upward to abut against the lower edge _41a1 of the movable contact support hole 41a of the actuator 4, and when the key 2 is pressed down, the movable contact 6a 4 moves downward, and movable contact 6 follows this downward movement.
a also moves downward. From the time when the movable contact 6a contacts the fixed contact 7a with its own pressure to the point at which the actuator 4 completes its downward movement, the movable contact support hole 41a of the actuator 4 is enlarged in the vertical direction. The movable contact 6a is mechanically separated from the movable contact 6a, and the movable contact 6a continues to contact the fixed contact 7a with its own pressure, and the repulsive force of the movable contact 6a as in the conventional case is not generated. The movable contact support hole 41a is made large in the vertical direction so that the actuator 4 does not come into contact with the upper edge _41a2 of the movable contact support hole 41a even if the actuator 4 moves downward to the maximum extent.

As described above, according to the present invention, the movable contact is a self-pressure contact type, the coil spring used in the actuator is removed, the actuator and the drive rod are removably connected, and the actuator is movable. The contact support hole is made larger in the vertical direction so that the movable contact and the actuator are mechanically separated from the time when the movable contact and the fixed contact come into contact until the point at which the actuator completes its downward movement. As shown in FIG. 7, the weight and stroke characteristics become a downward two-step touch, making the key touch comfortable.

In addition, FIG. 5 shows another embodiment of the present invention in which the drive rod 3 and the actuator 4 are connected, and the actuator 4 is provided with a cylindrical body A, and a screw B is connected to this via the drive rod 3. The actuator 4 and the drive rod 3 are connected by screwing them together.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional key switch, Fig. 2 is an exploded perspective view of a conventional key switch, Fig. 3 is a cross-sectional view of a key switch according to an embodiment of the present invention, and Fig. 4 is a cross-sectional view of a key switch according to an embodiment of the present invention. FIG. 5 is an exploded perspective view of the main parts of a key switch according to another embodiment of the present invention, and FIG. 6 shows the key touch weight and weight of the conventional key switch shown in FIG. 1. FIG. 7 is a characteristic graph showing the relationship between the key touch weight and the key depression depth (stroke) of the keyboard switch of the present invention shown in FIG. 1... Key channel, 2... Key, 3... Drive rod, 4... Actuator, 41... Movable contact support hole, 6 (6a, 6b, 6c)... Movable contact, 7
(7a, 7b, 7c)... Fixed contact, 8... Key spring.

Claims (1)

[Scope of utility model registration request] The driving rod 3 protruding from the lower surface of the key channel 1 biased by the key spring 8 or the lower surface of the key 2 attached to the key channel 1 and the actuator 4 that moves the movable contact 6 downward when the key is pressed are removed and removed. The movable contact 6 is of a self-pressure contact type, and when the key is not pressed, the movable contact 6 is inserted into a movable contact support hole 41 provided in the actuator 4 and supported; When the key is pressed, the movable contact 6 moves downward following the downward movement of the actuator 4, and from the time when the movable contact 6 contacts the fixed contact 7 placed opposite to it until the actuator 4 completes its downward movement. A key switch structure characterized in that the movable contact support hole 41 is made larger in the vertical direction so that the movable contact 6 and the actuator 4 are mechanically separated.