JPH0731471Y2 - Push button switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a push button switch which is operated by pressing a push button.

[Prior Art] A conventional push button switch has a case 1 and a contact member 3, as shown in FIG. The contact member 3 is supported by the case 1 via the dome portion 5. The contact member 3 and the dome portion 5 are integrally made of an elastic member such as a rubber material. As a result, the contact member 3 can move up and down due to the elastic bending of the dome portion 5. The dome portion 5 projects upward toward the opening 1a formed in the upper part of the case 1. The upper surface and the lower surface of the contact member 3 are flat. A plate-shaped movable contact 7 is provided on the lower surface of the contact member 3, that is, one surface inside the dome portion 5.

Further, the end of the actuator 9 is supported by the end of the case 1.
It is rotatably connected via 11. Actuator 9
A dowel part 15 is formed in the central part of the. The dowel part 15 extends downward toward the opening 1a of the case 1. A key top 17 is provided on the upper surface of the actuator 9. Here, the actuator 9 and the key top 17 are collectively referred to as an operation member.

The case 1 and the actuator 9 are engaged with each other on the opposite side of the support shaft 11. That is, the hook portion 9a formed on one side of the actuator 9 is engaged with the protrusion 1b formed on one side of the case 1. This hook 9a and protrusion 1b
With, the upward rotation of the actuator 9 is prevented. In this state, the tip of the dowel portion 15 is in contact with the upper surface of the contact member 3.

Further, a board 19 such as a printed circuit board is provided below the case 1. The substrate 19 has a fixed contact 21 on the upper surface. The lower portion of the dome portion 5 is clamped between the end portion of the substrate 19 and the lower portion of the case 1 at its lower edge. In this way, the movable contact 7 is opposed to the fixed contact 21 with a space.

To connect the contact 7 and the fixed contact 21 to each other, first, the key top 17 is pressed downward. Then, the actuator 9 rotates about the support shaft 11 as a fulcrum. As a result, the actuator 9
Since the dowel part 15 of the above presses the dome part 5 downward, the dome part 5 is compressed. At this time, the dome portion 5 buckles so as to be crushed by the dowel portion 11.

[Problems to be Solved by the Invention] In the push button switch of FIG. 3, when the key top 17 is pressed, the movable contact 7 is moved against the fixed contact 21 as shown in FIG.
The contact is started in a tilted state. Ie fixed contacts
The movable contact 7 starts to gradually contact 21 from one side. As a result, there is a problem that it takes a long time from the time when the fixed contact 21 and the movable contact 7 start contacting until the contact becomes stable, and the rising characteristic at the time of switch operation deteriorates.

Further, since the dome portion 5 is largely buckled to one side by the pressing of the dowel portion 15, the compressive force is partially different, so that the mechanical life of the contact member 5 is shortened.

Therefore, an object of the present invention is to provide a push button switch that has a good start-up characteristic until the contact between the contact and the fixed contact becomes stable and has a good mechanical life characteristic.

[Means for Solving the Problems] According to the present invention, a case, a movable contact member elastically supported by the case, and having a contact on one surface, and a part of the case are rotatably coupled to the case. In a push button switch including an operating member, wherein the contact member is moved by operating the operating member, a driven element facing the surface opposite to the one surface of the contact member and driven by the contact member, The guide member is fixed to the case and includes a guide portion that linearly guides the movement of the driven element, and the operation member has a dowel portion that extends in a direction of pressing the driven element,
A push button switch is obtained in which a spherical portion that contacts the driven element is formed at the tip of the dowel portion.

[Embodiment] FIG. 1 shows a push button switch according to an embodiment of the present invention. In this embodiment, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

With reference to FIG. 1, this push button switch has a driven element 25 that moves following the movable contact 7 of the contact member 3. The driven element 25 faces the dome portion 5 on the opposite surface of the movable contact 7. On the upper part of the case 1, a tubular guide portion 27 is formed which linearly guides the movement of the driven element 25 only in the vertical direction. A driven element 25 is slidably fitted in the opening 1a of the case 1 formed by the guide portion 27. Further, the operation member has an actuator 9 and a key top 17 similar to the operation member described in FIG.
A dowel portion 15 is formed in the central portion of the actuator 9. The driven element 25 is interposed between the tip of the dowel portion 15 and the contact member 5. A spherical surface portion (semi-cylindrical portion) 29 is formed at the tip of the dowel portion 15. The spherical portion 29 projects in a direction in which it comes into contact with one surface of the driven element 25.

To operate the push button switch, as shown in FIG. 2, first, the key top 17 is pressed downward. On this occasion,
The actuator 9 rotates downward about the support shaft 11 as a fulcrum. Therefore, a part of the spherical surface portion 29 presses the driven element 25. Then, the driven element 25 linearly guides the movement of the contact member 3 along the guide portion 27, so that the dome portion 5 starts to buckle with a uniform compressive force. Due to the buckling of the dome portion 5, the entire movable contact 7 also starts contacting with uniform pressure.
If you further press down the key top 17, the dowel part continues.
Since the driven element 25 is pushed down uniformly by 15, the dome portion 5 also buckles so as to be crushed uniformly, and the movable contact 7 comes into contact with the fixed contact 21.

Thus, after the fixed contact 21 and the movable contact 7 are conducted,
When the pressing of the key top 17 is released, the dome portion 5 returns to the original state by the elastic force, and the contact state between the movable contact 7 and the fixed contact 21 is released.

[Effects of the Invention] As described above with reference to the embodiments, according to the push button switch of the present invention, the contact point of the contact member starts contact with a uniform compression force over the entire surface, so that the rising characteristic until the contact becomes stable. Will get better. Further, since the dome portion of the contact member buckles uniformly over the entire circumference, mechanical life characteristics can be improved rather than uneven buckling such as pushing down while tilting.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the push button switch of the present invention, FIG. 2 is a sectional view showing a state when the push button switch of FIG. 1 is operated, and FIG. 3 is a conventional push button switch. FIG. 4 is a sectional view showing the state of the push button switch of FIG. 3 during operation. 1; case, 3; contact member, 5; dome part, 7; movable contact, 9; actuator, 11; support shaft, 15; dowel part, 17; key top, 19;
Substrate, 21; fixed contact, 25; driven element, 27; guide part.

Claims (1)

[Scope of utility model registration request] 1. An operating member including a case, a movable contact member elastically supported by the case and having a contact on one surface, and an operating member partially rotatably coupled to the case. In a push button switch configured to move the contact member by an operation, a driven element facing the surface opposite to the one surface of the contact member and driven by the contact member, and the driven element fixed to the case. And a guide portion for linearly guiding the movement of the driven member, the operating member has a dowel portion extending in a direction for pressing the driven element, and a spherical portion contacting the driven element is provided at a tip of the dowel portion. A push button switch characterized by being formed.