JPH04319215A - Push button switch - Google Patents

Abstract

PURPOSE:To provide a push button switch which is formed out of parts provided with a structure that does not emit dust which can cause contact failure and for which a stroke from starting pushing down a push button until the electrodes are bridged, is not changed, in obtained a push button switch, which is used for various information input devices and controllers, in particular, a short- stroke type push button switch bridged through a dome-shaped dish spring between electrodes. CONSTITUTION:A cushion member 6 is formed out of elliptic coil spring which is wound almost densely. The cushion member 6 is inserted into a supporting groove 52 provided in the diagonal direction of a terminal plate 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push button switch used in various information input devices and control equipment, and more particularly to a short stroke push button switch in which electrodes are bridged by a dome-shaped disc spring.

A short-stroke push-button switch that bridges a plurality of exposed electrodes by pressing down on a dome-shaped disc spring is constructed of parts that do not emit dust that can cause contact failure between the electrodes. It is required that the process from the start of pressing the push button until the electrodes are bridged does not change as the number of times of use increases.

0003

2. Description of the Related Art FIG. 4 is a perspective view showing the structure of a conventional push-button switch, FIG. 5 is a diagram showing the operating principle of the conventional push-button switch, and FIG. 6 is a diagram showing the pressing characteristics of the conventional push-button switch.

In FIG. 4, a conventional push button switch has a terminal plate 1, a dome-shaped disc spring 2, a buffer member 3, and a push button 4. The terminal plate 1 has a circular recess 12 formed integrally with a lead terminal 11 and opening upward. It includes an electrode 13 exposed at the center, and an electrode 15 integrally formed with the lead terminal 14 and exposed at the periphery of the circular recess 12.

The dome-shaped disc spring 2 fitted into the circular recess 12 of the terminal plate 1 is placed downwardly so as to cover the electrodes 13 and 15.
The push button 4 inserted into the terminal board 1 is connected to the protrusion 1 that the terminal board 1 has.
6 and the hole 41 of the push button 4 so as to be slidable. Furthermore, a rubber sheet or the like is used as a buffer member 3 interposed between the dome-shaped disc spring 2 and the push button 4.

In such a push button switch, when the push button 4 is pressed down, the dome-shaped disc spring 2 is driven via the buffer member 3. Initially, there is a distance between the electrode 13 exposed at the center of the circular recess 12 and the dome-shaped disc spring 2 as shown in FIG.
As shown in the figure, the dome-shaped disc spring 2 is inverted, the dome-shaped disc spring 2 contacts the electrode 13, and the gap between the electrode 13 and the electrode 15 is bridged by the dome-shaped disc spring 2.

As shown by the solid line in FIG. 6(a), the dome-shaped disc spring 2 also has a pressing force that increases as the initial displacement increases;
When a critical point is reached, a reversal occurs and the pressing force decreases as the displacement increases. It increases almost linearly.

That is, a push button switch in which a dome-shaped disc spring 2 and a buffer member 3 are superimposed on a terminal board 1 is shown in FIG. 6(b).
As shown in FIG. 2, the pressing force initially increases as the displacement increases, but when the dome-shaped disc spring 2 reverses, the pressing force decreases, and when the dome-shaped disc spring 2 comes into contact with the electrode 13, the pressing force decreases. It has the characteristic that the pressing force increases again.

[0009]

FIG. 7 is a diagram showing problems in a conventional push button switch. Conventional push-button switches have a buffer member interposed between the push button and the dome-shaped disc spring, so when the push button is pressed, friction occurs between the push button and the buffer member, and between the buffer member and the dome-shaped disc spring, making it difficult to use. As the number of times increases, the cushioning member made of a rubber sheet or the like is scraped, generating shavings and becoming thinner. Furthermore, as the number of uses increases, the buffer member made of a rubber sheet or the like gradually deforms and becomes thinner. Furthermore, there was a problem in that shavings generated when the buffer member was scraped adhered to the electrodes, causing poor contact.

For example, in a push button switch in which a dome-shaped disc spring and a buffer member have composite spring characteristics as shown in FIG. 6, the push button switch is assembled such that the buffer member is compressed by 0.15 mm from the beginning in the thickness direction, As shown by the chain line ■, the force (initial pressure) pushing up the push button at that time was 108 g.
Assuming that the distance from the start of pressing the push button until the electrodes are bridged is 0.21 mm, if the buffer member is shaved or deformed and becomes thinner by 0.1 mm, the starting point of pressing will be at the position indicated by the dashed line ■. The initial pressure at this time decreased to 23g, and the distance until the electrodes were bridged was 0.3g.
Increases to 1mm. Furthermore, the cushioning material has been reduced to 0.15 from the beginning.
If it becomes thinner by mm, the initial pressure becomes 0, causing backlash in the push button and further increasing the stroke.

[0011] An object of the present invention is to provide a push button switch that is constructed of parts having a structure that does not emit dust that may cause contact failure, and that does not change the process from the start of pressing the push button until the electrodes are bridged. There is a particular thing.

0012

[Means for Solving the Problems] FIG. 1 is a perspective view showing the structure of a push button switch according to the present invention. The same objects are represented by the same symbols throughout the figures.

The above problem is solved by having an electrode 13 that is formed integrally with the lead terminal 11 and exposed at the center of the circular recess 12 that opens upward, and an electrode 15 that is formed integrally with the lead terminal 14 and exposed at the periphery of the circular recess 12. A terminal plate 5, a dome-shaped disc spring 2 that is fitted into the circular recess 12 and lies down so as to cover the electrodes 13 and 15, and a push button that is slidably held by the terminal plate 5 and drives the dome-shaped disc spring 2. 4 and
This is a push button switch equipped with a buffer member 6 interposed between a dome-shaped disc spring 2 and a push button 4. The buffer member 6 is made of a substantially elliptical coil spring that is tightly wound, and extends in the diagonal direction of the terminal plate 5. This is achieved by the push button switch of the present invention, which is fitted into a support groove 52 provided in the push button switch.

[0014]

[Operation] As shown in Fig. 1, a nearly tightly wound approximately elliptical coil spring is used as a buffer member, and by inserting and holding the buffer member into the support groove provided in the diagonal direction of the terminal plate, contact failure is prevented. It is possible to realize a push button switch that is configured using parts having a structure that does not emit dust and that does not change the process from the start of pressing the push button until the electrodes are bridged.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings. 2 is a diagram showing the operating principle of the push button switch according to the present invention, and FIG. 3 is a perspective view showing the main parts in another embodiment.

In FIG. 1, the push button switch according to the present invention has a terminal plate 5, a dome-shaped disc spring 2, a buffer member 6, and a push button 4, and the terminal plate 5 has a circular recess formed integrally with a lead terminal 11 and opening upward. Electrode 13 exposed at the center of 12
, and a support groove 52 which is integrally formed with the lead terminal 14 and has an electrode 15 exposed at the peripheral edge of the circular recess 12, and into which the buffer member 6 is inserted diagonally and held so as not to fall.
is formed on the top surface.

The dome-shaped disc spring 2 fitted into the circular recess 12 of the terminal plate 5 is placed downwardly so as to cover the electrodes 13 and 15.
The push button 4 inserted into the terminal board 5 is connected to the protrusion 1 that the terminal board 5 has.
6 and the hole 41 of the push button 4 so as to be slidable. In the case of a push button switch in which the distance from the start of pressing the push button to the time when the electrodes are bridged is long, a normal coil spring, for example, can be interposed between the dome-shaped disc spring and the push button as a buffer member.

However, in the case of a short-stroke push button switch, a normal coil spring cannot be used. Therefore, as shown in the figure, a substantially elliptical coil spring wound almost tightly is interposed as a buffer member 6 between the dome-shaped disc spring 2 and the push button 4, and is held by the support groove 52 of the terminal plate 5 to prevent it from falling. .

In such a push button switch, when the push button 4 is pressed down, the dome-shaped disc spring 2 is driven via the buffer member 6. That is, the electrode 13 exposed at the center of the circular recess 12 and the dome-shaped disc spring 2 are initially separated from each other as shown in FIG. It descends toward the dome-shaped disc spring 2 along
When the force for pressing the push button 4 reaches a critical point, as shown in Fig. 2(b)
The dome-shaped disc spring 2 is reversed as shown in FIG. As a result, the dome-shaped disc spring 2 comes into contact with the electrode 13, and the electrode 13 and the electrode 1
5 is bridged by a dome-shaped disc spring 2.

[0020] As described above, a coil spring which has excellent wear resistance and does not deform even when pressed repeatedly is used as a buffer member, and the buffer member is inserted into the support groove provided diagonally on the terminal plate to hold it so that it does not fall. By doing this, it is possible to realize a push button switch that is constructed using parts with a structure that does not emit dust that can cause contact failure, and that does not change the process from the start of pressing the push button until the electrodes are bridged. can.

Further, the buffer member 6 is supported by the support groove 52 of the terminal plate 5 so as not to fall, but for further safety, it is placed in contact with the buffer member 6 of the push button 4 as shown in FIG. 3(a), for example. A groove 42 may be provided on the surface, or a groove 42 may be provided on the surface, or
), reinforcement can be achieved by providing a protrusion 61 protruding from the lower side of the buffer member 6 and at the same time providing a hole 21 in the dome-shaped disc spring 2 and inserting the protrusion 61 thereinto.

[0022]

Effects of the Invention As described above, according to the present invention, the parts are constructed with a structure that does not emit dust that can cause contact failure, and the process from the start of pressing the push button until the electrodes are bridged does not change. A push button switch can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of a push button switch according to the present invention.

FIG. 2 is a diagram showing the operating principle of the push button switch according to the present invention.

FIG. 3 is a perspective view showing main parts in another embodiment.

FIG. 4 is a perspective view showing the structure of a conventional push button switch.

FIG. 5 is a diagram showing the operating principle of a conventional push button switch.

FIG. 6 is a diagram showing switching characteristics of a conventional pushbutton switch.

FIG. 7 is a diagram showing problems in a conventional push button switch.

[Explanation of symbols]

2 Dome-shaped disc spring 4
Push button 5 terminal board
6 Buffer member 11, 14 Lead terminal 12 Circular recess 13, 15 Electrode
16, 61 protrusion 21, 41 hole
42 Groove 52
support groove

Claims (1)

[Claims] 1. An electrode (13) exposed at the center of a circular recess (12) that is integrally formed with the lead terminal (11) and opens upward; and an electrode (13) that is integrally formed with the lead terminal (14) and that is exposed at the center of the circular recess (12). The electrode (15
), a dome-shaped disc spring (2) fitted into the circular recess (12) and placed downward so as to cover the electrodes (13, 15), and the terminal plate (5). a push button (4) that is slidably held by the dome-shaped disc spring (2) and drives the dome-shaped disc spring (2);
4) A push button switch comprising a buffer member (6) interposed between the buffer member (6), the buffer member (6) consisting of a substantially elliptical coil spring wound substantially tightly;
A support groove (5) provided in a diagonal direction of the terminal plate (5)
2) A push button switch characterized by being fitted into the switch.