JPH0350575Y2 - - 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, it is necessary to continue pressurizing the push key part 23, and when the pressure is released, the thin skirt part 25 (indicated by the dotted line) which had been buckled. ) returns to its original state, that is, from on to off, due to its own elasticity. 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.

FIG. 1A shows a plan view of the contact rubber of the present invention, and FIG. 1B shows its cross section.

The overall shape is a dome shape with a hollow interior a and a thick ceiling.The thick upper key top part 3 has two symmetrically spaced recesses b and c. is provided, and convex portions 10 and 10' are provided at a distance from each other through thin auxiliary spring portions 9 and 9', respectively, and protrude from the inside of this concave portion, and at least one of the protrusions 10 and 10' On the tip surface of
Conductive parts 4, 4' are fixed to each. A main spring part 5 is continuously formed on the periphery of the key top part 3 so as to be inclined downwardly and outwardly.
More lift and support. This main spring part 5 is
Both ends, that is, the joint parts 5a and 5b with the key top part 3 and the base part 11 are thin parts,
The central portion 6 is configured as a reinforced thick wall portion to prevent buckling. Reference numeral 1 denotes a printed circuit board having electrodes 2 and 2'.

[Function] Since the present invention is configured as described above, when the key top portion 3 is pressurized, the inner cylinder portions 10, 1
The conductive parts 4, 4' fixed to the tip of 0' contact the corresponding electrodes 2, 2' of the substrate 1, respectively,
When further pressure is applied, the auxiliary spring parts 9, 9' that support the conductive parts 4, 4' and the convex parts 10, 10' buckle, and the main spring part 5 that supports the key top part 3 also buckles. It will be in the state shown in Figure 2. Since this main spring portion 5 is reinforced in the shape of a leaf spring, it passes through a horizontal position from the initial upwardly inclined position (FIG. 1B),
The base portion 11 in the horizontal position when moving to the downwardly inclined position in FIG.
and the end 8 of the key top part 3 is the minimum distance k.
Therefore, in this horizontal position, the main spring portion 5 is once curved, and then buckled to the downwardly inclined position (FIG. 2). In this position, the distance between the base 11 and the key top end 8 becomes wider again, so the main spring part 5 is expanded from a curved state to a flat plate shape, and the reinforcement thick part 6 is provided, so that the key top Press the entire section 3 downward. Therefore, unless a strong force is applied again, the main spring section will not bend again, so the key top section 3 continues to be pressurized, and within the cavity a, the convex sections 10, 1
The conductive parts 4, 4' fixed to the ends of the electrodes 0' are pressed against the electrodes 2, 2' of the printed circuit board 1, and conduction is established between the electrodes 2, 2', and this conductive state continues.

Next, as shown in FIG. 3, when pressure is applied to the end 7 of the key top part 3, the lower end 7a of this end 7 or the adjacent inner protrusion 10' serves as a fulcrum and according to this principle, , the other end 8 is lifted,
Accordingly, the buckling of the main spring portion 5 is also released. Then, by releasing the pressing force on the pressurized end 7, the restoring force of the main spring section 5 continuous to the periphery of the key top section 3 releases the entire buckling, and the first
Restored to the lifted state shown in the figure.

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 the first
It is turned on by applying pressure for the second time, remains on even if pressurization is stopped, and is then turned off by applying pressure again for the second time.

In order to more reliably restore the whole body by applying pressure to the end portion 7 in the second time, a convex portion 12 is further provided inside the center as shown in FIG. It would be more advantageous to make this principle work more strongly.

[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, since the contact rubber of the present invention has different external shapes in the switch on and off states, that is, when the switch is on, the key top part 3 is low and the main spring part 5 is recessed downward.
When the switch is off, the main spring section 5 is exposed upward and outward, and the key top section 3 is also lifted into a dome shape and assumes a high shape, so that it is easy to visually confirm whether the switch is in the on state or the off state.

Therefore, a confirmation element such as a pilot lamp is also unnecessary.

[Brief explanation of the drawing]

Figure 1 A is a plan view of the contact rubber of the present invention, and B is a
The same cross-sectional view. FIG. 2 is a sectional view showing the switch-on state after the first pressurization. FIG. 3 is a sectional view showing the moment when the second pressurization is applied. FIG. 4 is a sectional view showing another embodiment. FIG. 5 is a sectional view of a conventional contact rubber. 1...Printed circuit board, 2, 2'...electrode, 3...
...Key top part, 4...Conductive part, 5...Main spring part, 6...Reinforcement thick part, 9...Reinforcement spring part, 1
0,10'...Protrusion.

Claims (1)

[Scope of utility model registration request] The interior is hollow and the ceiling is dome-shaped with a thick wall.The thick upper key top part 3 is provided with two recesses spaced apart from each other. Inside, there are convex portions 10, 10'.
A conductive part 4 is fixed to at least one end surface of the thin-walled auxiliary spring parts 9 and 9', and a main part is attached to the periphery of the key top part 3. The spring portion 5 is formed to be inclined downwardly and outwardly, and the main spring portion 5 lifts and supports the entire key top portion from the base portion 11, and the central portion of the main spring portion 5 is attached to the seat. When the key top portion 3 is pressurized, the conductive portions 4 fixed to the tips of the inner convex portions 10 and 10' are connected to the corresponding printed circuit board 1. When it comes into contact with the electrodes 2, 2' and further pressure is applied, the auxiliary spring parts 9, 9' that support the conductive parts and the convex parts 10, 10' buckle, and the spring part 5 that supports the key top part 3 also buckles. It is designed to buckle, pass through a horizontal position from the initial upwardly inclined position, buckle to the downwardly inclined position and maintain that state, and when further pressure is applied to the end 7 of the key top part 3. A contact rubber characterized in that the buckling of the main spring portion 5 is released by lifting the other side end a by using the adjacent inner protrusion 10' as a fulcrum.