JPS6217944Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a switch using a cup-shaped elastic body.

Generally, in the case of a cup-shaped elastic body used in a switch, there is a specific relationship between the stress or external force and the amount of displacement when the head is pressed. That is, as long as the amount of displacement is small, Hook's law is roughly followed, but when the amount of displacement exceeds a certain value, a phenomenon similar to yielding occurs, and the stress rapidly decreases.

Such a relationship is indicative of the preferred operation of the switch piece, and a preferred push button switch can be achieved by attaching a conductive material to the inner surface of the head of the cup-shaped elastic body so that the cup-shaped elastic body is lowered onto the surface on which the conductor is provided. can be formed.

Figure 1 is a cross-sectional view of a conventional switch.
A plurality of conductors 7 are arranged on the bottom inner surface of the housing 3 attached to the substrate 6, and the ends 7 of the conductors 7
After being pulled out to the outside of the housing 3, the portion a is bent at a substantially right angle, passes through the hole 6a of the substrate 6, and protrudes to the back side thereof. Further, a cup-shaped elastic body 4 made of rubber is hung down on the surface on which the conductor 7 is disposed, and the key stem 2 guided by the inner surface of the housing 3 is attached to the head of the cup-shaped elastic body 4. A key top 1 is engaged with the key stem 2, and the cup-shaped elastic body 4 is bent by pressing the key top 1. Note that the key top 1 and the key stem 2 constitute a pressing operation body.

Further, a conductive rubber chip 5 is attached to the inner surface of the head of the cup-shaped elastic body 4, and when the key top 1 is pressed, the conductive rubber chip 5 comes into contact with a plurality of conductors 7 and electrically connects these conductors. I'm starting to let them do it.

By the way, if you try to bring the conductive rubber chip 5 into contact with the conductor 7 by bending the cup-shaped elastic body 4 in a state where the space surrounded by the conductor placement surface and the cup-shaped elastic body 4 is isolated from the outside, the conductor placement The air pressure in the space surrounded by the surface and the cup-shaped elastic body 4, that is, the compressed air pressure, increases, and a large force must be applied to the key top 1. In order to eliminate such a problem, a groove 4a is provided at the edge of the cup-shaped elastic body 4 that is in contact with the conductor installation surface.
This allows air to freely flow in and out.

In such a conventional switch, a groove 4a is provided in the cup-shaped elastic body 4 to facilitate its deformation. This dust is conductor 7
The conductive rubber chip 5 may be interposed between the conductive rubber chip 5 and the conductive rubber chip 5, causing poor contact.

The present invention has been made in view of the above points, and includes a tank that isolates the internal space of the cup-shaped elastic body from the outside and introduces the internal air of the cup-shaped elastic body, thereby preventing dust from entering the cup-shaped elastic body. It is an object of the present invention to provide a switch which prevents the intrusion of a cup-shaped elastic body by a key top and which allows a cup-shaped elastic body to be easily deformed by a key top.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view showing the structure of the first embodiment of the switch according to the present invention, in which the same reference numerals and affixes as in FIG. 1 indicate components having the same effect. The second feature is that a hole 5b is provided in the center of the conductive rubber chip 5 provided in the cup-shaped elastic body 4, and a tank 4b is connected to the head of the cup-shaped elastic body 4, and that the groove on the edge of the cup-shaped elastic body 4 is eliminated. It is different from Figure 1.

In this case, the tank 4b is formed integrally with the cup-shaped elastic body 4, penetrates the key stem 2, and is fitted into the space 1a of the key top 1.

Thus, the surface on which the conductor 7 is disposed and the cup-shaped elastic body 4
A space enclosed by
Since the air flows into the space _V1 of b, the compressed air pressure at the time of switch operation can be kept low. In this case, if the capacity of the space V ₁ is appropriately determined according to the amount of deformation of the cup-shaped elastic body 4, the key top 1 will be reduced due to the increase in compressed air pressure caused by isolating the inside of the cup-shaped elastic body 4 from the outside. The adverse effect of an increase in pressing force can be reduced to an almost negligible level, so that the key top 1 can be operated smoothly and dust can be prevented from entering.

In the above embodiment, the tank 4b, which is integrally formed with the cup-shaped elastic body 4, passes through the key stem 2, but if the capacity of the tank 4b is small, it can be fitted into the key stem 2. You can.

Next, FIG. 3 is a sectional view showing the structure of a second embodiment of the switch according to the present invention, in which the same reference numerals as in FIG. 2 indicate components having the same effect. In this embodiment, there is a hole 5b in the center of the conductive rubber chip 5.
The head of the cup-shaped elastic body 4 is fitted into a hole formed in the key stem 2, and a tank communicating with this hole is pressed to form the key top 1 constituting the operating body. Further, an O-ring 8 is provided between the key top 1 and the key stem 2.

Thus, the space _V2 of the key top 1 and the internal space of the cup-shaped elastic body 4 communicate with the inside of the cup-shaped elastic body 4 through the hole 5b, so that the key top 1 has a tank.

By adopting such a configuration, the space _V2 into which air can flow inside the cup-shaped elastic body 4 is significantly expanded, which contributes to reducing the compressed air pressure and allows the key top 1 to be operated more smoothly.

In the second embodiment, the tank is provided on the key top 1, but even if the tank is provided on the key stem 2 as shown in FIG. 4, substantially the same effect can be obtained. That is, a tank is provided in the key stem 2 constituting a pressing operation body that presses against the outer surface of the head of the cup-shaped elastic body 4 to deform it, and a hole 5b for guiding the internal air of the cup-shaped elastic body 4 is provided in the head. Therefore, effects greater than those of the first embodiment can be obtained.

As is clear from the above description, according to the switch of the present invention, it is possible to prevent dust from entering the inside of the cup-shaped elastic body, and the cup-shaped elastic body can be easily deformed by the key top. This will further improve the reliability of the switch.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the configuration of a conventional switch.
FIG. 2 is a sectional view showing the construction of one embodiment of the switch according to the present invention, and FIGS. 3 and 4 are sectional views showing the construction of other embodiments of the switch according to the invention. 1...Key top, 2...Key stem, 3...
Housing, 4...Cup-shaped elastic body, 5...Conductive rubber chip, 6...Substrate, 7...Conductor, 8...O
ring.

Claims (1)

[Claims for Utility Model Registration] (1) A cup-shaped elastic body provided with a conductor on the inner surface of the head is placed down on the conductor-arranged surface, and the outer surface of the head of the cup-shaped elastic body is pressed by a pressing operation body to generate the conductive material. A switch for bringing an object into contact with a plurality of conductors, characterized in that a tank is airtightly connected to the head communicating with the inside of the cup-shaped elastic body in order to isolate the inside of the cup-shaped elastic body from outside air space. A switch to do. (2) The switch according to claim 1, wherein the tank is integrally formed with the head of the cup-shaped elastic body. (3) The switch according to claim 1, wherein the key top is formed with a tank connected to the head part communicating with the inside of the cup-shaped elastic body. (4) The switch according to claim 1, wherein the tank is formed in a key stem.