JPH0448591Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a contact rubber for switching in push buttons of telephone extension transfer buttons, calculators, various audio products, measuring instruments, and the like.

[Prior Art] The contact rubber has a conductive part 24 provided at the lower end of the push key pressurized and brought into contact with the electrodes 22, 22' provided on the printed circuit board 21.
The two electrodes 22, 22' are electrically connected. (5th
figure).

However, in the conventional contact rubber, in order to continue the conduction state, pressure must be continuously applied to the push key part 23, and when the pressure is released, the thin skirt part 25 (indicated by the dotted line) that has been buckled be)
However, due to its own elasticity, it returns to its original state, that is, from the on state to the off state. Therefore, in order to maintain the on state, pressurization must be continued, which is inconvenient.

That is, conventional rubber contacts have the disadvantage that only pulse signals can be passed through them.

[Means for solving the problem] In the present invention, the conductive part contacts the electrode of the printed circuit board during the first pressurization and turns on, and even when the pressure is removed, the conductive part continues to be on. The purpose of the present invention is to provide a contact rubber in which the spring portion has a special structure so that it is restored to the initial state, that is, the off state, by the second pressurization.

[Example] A description will be given according to an embodiment shown in the drawings.

Figure 1 shows the plane of the contact rubber of the present invention;
The figure shows its cross section.

The overall shape is a dome shape with a hollow interior and a thick ceiling.This thickened part is the key top part 3, and this key top part has a downward convex shape inside the cavity. The conductive portion 4 is fixed to the distal end surface of the conductive portion 6. The key top part 3 and the base part 7 are connected by a spring part 5,
The key top part 3 is lifted and supported from the base part 7. Connection portions 5a and 5b of this spring portion 5 with the key top portion 3 and the base portion 7, respectively.
is thin, and the central portion 8 is thickened and reinforced. 1 is a printed circuit board with electrodes 2,
2'.

[Function] Since the present invention is configured as described above, when the upper surface 9 of the key top portion 3 is pressurized, the spring portion 5 is deformed as shown in FIG. contacts the electrodes 2 and 2' of the printed circuit board 1, and conduction occurs between the two electrodes. The center 8 of this spring part 5
Since it is reinforced with a thick wall, it can only bend at the upper and lower thin spring parts 5a and 5b that are continuous with this thick wall, so even if the pressing force is removed, it will not return to its original state and will be in a buckled state. . This is because when the spring part 5 passes through the horizontal position from the initial upwardly inclined position (FIG. 1) and moves to the downwardly inclined position, that is, the buckled position in FIG. Since the distance from the key top part 3 is the minimum distance, the spring part 5 is once bent in this horizontal position, and then buckled to the downwardly inclined position (FIG. 3). In this buckled position, the base 7 and the key top part 3 are connected again.
This is because the main spring part 5 is expanded into a flat plate shape rather than a curved state, and the thick reinforcement part 8 is provided to press the entire key top part 3 downward. Therefore, unless force is applied again, the spring portion 5 will not restore its shape, that is, will not curve again, and the key top portion 3 will continue to be pressurized, and will be fixed to the tip of the convex portion 6 within the cavity a. The conductive portion 4 is pressed onto the electrodes 2, 2' of the printed circuit board 1, and the conductive state between the electrodes 2, 2' is continued.

Next, as shown in FIG. 3, when one side end portion 9a of the upper surface 9 of the key top portion 3 is pressurized, the edge 6a of the inner convex portion 6 of the key top portion 3 close to the pressure side
serves as a fulcrum and by this principle, the other side edge 6b
is lifted, and the buckling on the opposite side of the spring portion 5 is released, resulting in an inclined state as shown in FIG. When this second pressurizing force is released, the overall balance is disrupted, and the restoring force of the spring section 5 continuous to the periphery of the key top section 3 releases the entire buckling, resulting in the lift shown in Fig. 1 at the beginning. It will be restored to its original state.

Therefore, the pressure bond between the conductive portion 4 and the electrodes 2, 2' is released and they are separated, so that the conduction between the electrodes 2, 2' is interrupted and turned off.

In this way, it is turned on by the first application of pressure, continues to be in the on state even if the application of pressure is stopped, and is then turned off by the second application of pressure.

[Effects of the invention] The contact rubber of the present invention can maintain a conductive state, compared to conventional contact rubbers that can only send pulse signals, so it can be used in various power switches. It also becomes a simple electrical circuit as a switch.

Furthermore, the contact rubber of the present invention has different external shapes in the switch-on and switch-off states, that is, when it is on, the key top part 3 is low and the spring part 5 is recessed downward, and when it is off, the shape is different. Since the main spring part 5 is exposed upward and to the outside, and the key top part 3 is also lifted into a dome shape and has a raised shape, it is easy to visually confirm whether the switch is in the on state or the off state.

Therefore, it also has the advantage that a verification element such as a pilot lamp is not required.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the contact rubber of the present invention. FIG. 2 is a sectional view of the same. FIG. 3 is a sectional view showing the switch-on state after the first pressurization. Figure 4 shows the second
A sectional view showing the moment when pressurization is applied for the first time. Figure 5 shows
The same sectional view of the conventional contact rubber. 1...Printed circuit board, 2, 2'...electrode, 3...
...Key top part, 4...Conductive part, 5...Spring part,
8... Reinforced thick part.

Claims (1)

[Scope of utility model registration request] The interior is hollow and the ceiling is dome-shaped with a thick wall. Inside the thick upper key top part 3, a protruding part 6 is provided, and a conductive part is provided on the tip surface of the protruding part 6. 4 is fixed, and the key top part 3
A spring portion 5 is formed around the periphery of the key top portion to lift and support the entire key top portion from the base portion 7, and the center portion of this spring portion 5 is configured as a reinforced thick wall portion 8 to prevent buckling. When the key top part 3 is pressurized, the conductive part 4 fixed to the tip of the inner convex part 6 comes into contact with the electrodes 2, 2' of the printed circuit board 1, and when further pressure is applied, the conductive part 4 and the convex Spring part 5 supporting key top part 3 having part 6
buckles, passes through a horizontal position from the initial upwardly inclined position, buckles to the downwardly inclined position and maintains that state, and furthermore, one side end 9a of the upper surface 9 of the key top portion 3 When pressure is applied, the edge 6a on the pressurizing side of the inner convex portion 6 serves as a fulcrum, and the other edge 6b is lifted to release the buckling of the spring portion 5. Contact rubber.