JPH09120743A - Push switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a push switch of small and dustproof structure which can be assembled easily, by configuring a switch case with a cover equipped with a detention part and a base mold having an inclined portion provided with a notch and pawl, and installing a dust cover in this switch case. SOLUTION: The space in a push switch concerned 1 is formed from a base mold 7 and a cover 2 having a flat plate part 2A equipped with a through hole for a push button 3. The button 3, a spacer 4, dust cover 5 having resilience, and contact blade 6 are installed in this space one after another. The cover 2 is furnished at the side faces with four detention parts 2A positioned opposingly, while the base mold 7 is equipped with a notch 7B, inclined portion 7A fitted with pawl at the bottom, and a cover locating guide 7D positioned on the outside of the part 7A. This permits the cover 2 to be installed on the base mold 7 easily, and an intended push switch 1 of high reliability can be established in simple configuration and in a dustproof structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounting push switch in which a cover and a base mold are fitted to each other, and in particular, has a simple structure and excellent assembling property, has a small size, has a dustproof structure, and has high reliability. And a push switch.

[0002]

2. Description of the Related Art Conventionally, a small-sized and low-cost push switch which can be surface-mounted on a printed wiring board has been put into practical use and widely used in various fields.

For example, it is mounted as a memory clear reset key in a device having a memory such as an electronic notebook, and is used under various environments.

Further, when the push switch is adopted as a reset switch, after the push switch is once operated and reset, it often happens that the push switch is not used for a long period of time.

[0005]

The conventional push switch is often used for memory reset, and when it is not used for a long period of time, the contact surface of the switch has dust and dirt mixed in from the case of the device. May adhere to cause a contact failure.

In order to prevent contact failure due to the entry of dust and dust, it is sufficient to hermetically seal the contact area of the push switch to have a dust-proof structure. However, in order to make a small push switch a dust-proof structure, the structure is complicated. Therefore, there is a problem that the switch shape becomes large.

Further, the dustproof small push switch has a problem that the number of parts for the dustproof structure is increased and the number of switch assembling steps is increased to increase the product cost.

Further, in the case where the cover is provided with a flat plate portion having a through hole through which the push button penetrates in the center and a plurality of (for example, four) engaging portions facing the side surfaces, the base mold is If the cover is provided with only a sloped part that is formed wide downward, and the bottom part of this sloped part has a tab that locks the locking part, positioning of the cover when mounting the cover on the base mold However, there is a problem that it is difficult to install and it takes time to install.

The present invention has been made to solve such a problem, and an object thereof is to provide a highly reliable push switch having a simple structure, excellent assembling property, small size, and dustproof structure.

[0010]

In order to solve the above-mentioned problems, a push switch according to the present invention is such that a contact blade having a spring property is pushed by a push button through a dust cover for dust protection to bring the contact blade into contact with a contact. In addition to electrically connecting the contact blade, in the push switch that restores the push button by the spring property of the contact blade to electrically disconnect the contact blade and the contact,
A dust cover and a spacer for pressing the dust cover are provided in the space formed by the cover and the base mold, and the spacer is sandwiched and fixed by the cover and the base mold. The cover has a push button penetrating through the center. The base mold is provided with a flat plate portion having a through hole and a plurality of locking portions facing each other on the side surface, and the base mold is formed with a slanted portion formed wide downward, and for a cover located outside the slanted portion. With positioning guide,
The lowermost portion of the inclined portion is formed with a claw that locks the locking portion.

Since the positioning guide for the cover for positioning the cover is provided on the base mold, the cover can be easily attached to the base mold when manufacturing the push switch.

Further, since the dust cover for preventing dust is provided, the contact blade and the contact can be hermetically sealed in the space formed by the cover and the base mold, and the mixture of dust and dust can be prevented.

Further, since the spacer which is sandwiched and fixed by the cover and the base mold is provided, the dust cover can be easily fixed.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external view of a push switch according to the present invention, FIG. 2 is a sectional view of the push switch according to the present invention, and FIG. 3 is an assembly view of the push switch according to the present invention.

1 to 3, the push switch 1
Is a one-circuit normal break contact type switch, and includes a cover 2, a push button 3 for pressing the switch to make a switch, a hollow cylindrical spacer 4, and an elastic disk-shaped dust cover. 5, a contact blade 6 of a good electric conductor having a spring property, and a base mold 7 which is integrally formed with the terminals 8 and 9 and fits with the cover 2 to form the case of the push switch 1. It

The cover 2 is provided with a flat plate portion 2B having a circular through hole for allowing the push button 3 to pass therethrough, and four engaging portions 2A which are opposed to each other on the side surfaces thereof, and the operation portion of the push button 3 is externally provided. The locking portion 2A is projected and the base mold 7
The case of the push switch 1 is formed by engaging with the tabs formed at the lowermost portions of the cutout portion 7B and the inclined portion 7A.

The push button 3 has an operating portion at the top, a cylindrical stopper at the middle, and a conical protrusion at the bottom,
The upper limit position of the operating portion is determined by the stopper while the operating portion is projected through the through hole of the cover 2.

Further, the conical projection of the push button 3 is positioned so as to contact the upper surface of the dust cover 5 as shown in FIG. 2, and the contact blade 6 of the contact blade 6 which contacts the lower surface of the dust cover 5 in the normal state. Pushed upward by spring force.

The spacer 4 is formed of a hollow cylindrical resin or the like, the outer peripheral portion thereof is brought into contact with the inner peripheral portion of the base mold 7, and the dust cover 5 is sandwiched between steps provided in the lower portion of the base mold 7. And cover the top 2
It is fixed by pressing. In addition, the hollow diameter is the push button 3
The cylindrical stopper is formed to be slightly larger than the cylindrical diameter of the push button 3 so that it can be moved in the vertical direction without friction.

The dust cover 5 is made of a disc-shaped material having elasticity and is fixed to the base mold 7 by the spacer 4. The dust cover 5 and the inside of the base mold 7 in which the contact blade 6 is arranged are hermetically sealed. A space is formed to prevent the contact blade 6 and the contact point 8A in this closed space from being mixed with dust and dust from the upper portion of the dust cover 5.

The bottom surface of the dust cover 5 contacts the curved upper surface of the contact blade 6 to support the contact blade 6 on the base mold 7.

Further, when the push button 3 is pushed, the elasticity of the material forming the dust cover 5 causes the pushing force of the push button 3 to push the contact blade 6 through the dust cover 5, and the contact blade 6 is pushed. And the contact 8A come into contact with each other to generate electrical conduction (make state).

The contact blade 6 is made of a good conductive material having a small electric resistance and is formed into a disc shape. The contact blade 6 is curved so that the vicinity of the center of the disc has the maximum size. The springiness of the curved portion causes the push button 3 in a normal state. It is formed so as to obtain the restoring force when fixing the push button 3 and restoring the push button 3. Further, since the switch pressing force when the push button 3 is operated is also set by the springiness of the bending portion, the material of the contact blade 6 and the size of the bending portion are determined so that the optimum pressing force and restoring force can be obtained.

The base mold 7 is made of a molding material, and integrally forms a terminal 8, a contact 8A having continuity with the terminal 8 and a terminal 9 having continuity with the contact blade 6.
The inclined portion 7A, the cutout portion 7B, the positioning projection 7C when mounted on the printed wiring board, and the cover positioning guide 7D located outside the inclined portion 7A are provided.

The inclined portion 7A is located above the cutout portion 7B and formed wide below the base mold 7. The inclined portion 7A and the positioning guide 7D for the cover attach the cover 2 to the final stage of assembly of the push switch 1. When the cover 2 is attached and covered, the locking portion 2A is expanded outward while guiding the locking portion 2A of the cover 2, so that the cover 2 is covered with the base mold 7 by the spring force acting on the inside of the four locking portions 2A facing each other. The cutout portion 7B and the inclined portion 7A are locked and fixed to the tabs formed at the lowermost portion. The height of the bottom of the inclined portion 7A is also the locking portion 2.
Helps to lock A. 4 to 7 are respectively a plan view of the push switch when the cover is attached to the base mold, a front view of the push switch viewed from the BB direction of FIG. 4 with the terminal 9 facing forward, and a view of the AA direction of FIG. FIG. 3 is a left side view and a perspective view.

The terminal 8 is formed of a good electric conductor material that is electrically connected to the contact 8A of the good electric conductor formed on the inner bottom surface of the base mold 7, and is taken out of the base mold 7 for external attachment of the push switch 1. The terminals are formed and surface-mounted by soldering on the land pattern of the printed wiring board.

The terminal 9 is formed on the inner bottom surface of the base mold 7 and is made of a good electric conductor material which is electrically connected to the contact blade 6 at all times. 7 is formed outside to form an external mounting terminal of the push switch 1 and is surface-mounted by soldering to a land pattern of a printed wiring board.

The contact 8A forms a disk-shaped contact and is arranged in the center of the inner bottom surface of the base mold 7. When the push button 3 is pressed down and the curved upper surface of the contact blade 6 is pressed down and comes into contact, the terminal 9A. -> Contact blade 6-> contact 8A-> terminal 8 is in an electrically conductive state, push switch 1 is in a make state, and terminals 8 and 9 are in an electrically conductive state.

As described above, since the push switch 1 is provided with the dust cover 5 for dust prevention, the contact blade 6 and the contact 8A can be hermetically sealed in the space formed by the cover 2 and the base mold 7. It is possible to prevent dust from mixing in.

Since the spacer 4 which is sandwiched and fixed by the cover 2 and the base mold 7 is provided, the dust cover 5 can be easily fixed.

Further, since the dust cover 5 supports the contact blade 6 on the base mold 7 and transmits the pressing force of the push button 3 to the contact blade 6 via the dust cover 5, it affects the operation of the switch. It is possible to separate the push button 3 side from the contact blade 6 and the contact 8A sides without giving the above, and to provide a dustproof structure with a simple configuration.

As shown in FIG. 3, the push switch 1 is assembled by setting the base mold 7, placing the contact blade 6 inside the base mold 7, and then placing the dust cover 5 on the step inside the base mold 7. , The spacer 4 is stacked on the dust cover 5, the push button 3 is inserted into the inner circumference of the spacer 4, and the cover 2 is pushed in while being guided by the cover positioning guide 7D, and is locked to the base mold 7 to complete the process.

As described above, the push switch having a small number of parts, simple assembling in one direction, and a dustproof structure can be constructed.

Next, the operation of the push switch will be described with reference to FIG. FIG. 2 shows the push switch 1 in a normal state. In the normal state, the contact blade 6
Although the upward spring force acts on the dust cover 5 and the push button 3 due to the spring property of the, the stopper of the push button 3 presses against the cover 2 for balance. In addition,
In this balance state, the dust cover 5 is kept substantially horizontal.

Then, when the push button 3 is pushed down,
The protrusion of the push button 3 pushes down the central portion of the dust cover 5 downward, but the outer periphery of the dust cover 5 is fixed by the spacer 4 and the dust cover 5 itself also has elasticity, so the dustproof property is impaired. Instead, the displacement caused by the protrusion of the push button 3 is directly transmitted to the central portion of the contact blade 6.

Since the contact blade 6 is formed of a good electric conductor having a spring property, the center portion of the contact blade 6 is deformed downward to contact the contact 8A arranged on the inner bottom surface of the base mold 7, and the contact blade 6 Since the contact 8A is electrically conducted, the terminal 9 which is electrically connected to the contact blade 6
Then, the contact 8A and the terminal 8 having electrical continuity are electrically conducted, and the make state of the push switch 1 is formed. In addition,
The make state is maintained while the push button 3 is pressed and the contact blade 6 and the contact 8A are in contact with each other.

Next, when the pushing force is removed from the push button 3,
Due to the resilient restoring force of the deformed contact blade 6, the dust cover 5 and the push button 3 are lifted upward, and the stopper of the push button 3 is in contact with the cover 2 to reach a balanced state.

The push switch 1 is electrically disconnected when the contact blade 6 and the contact 8A are no longer in contact with each other to be in a break state.

The base mold 7 may be constructed without providing the cutout 7B. Further, the above embodiment is one embodiment of the present invention, and the present invention is not limited to the above embodiment.

[0040]

As described above, in the push switch according to the present invention, the cover positioning guide for positioning the cover is provided on the base mold. Therefore, the cover can be easily mounted on the base mold at the time of manufacturing the push switch, and Can be installed quickly.

Further, since a dust cover for dust prevention is provided and the contact blade and the contact can be sealed in the space formed by the cover and the base mold, it is possible to prevent the entry of dust and dust, so the push switch The reliability of can be improved.

Further, since the dust cover can be easily fixed by providing the spacer which is sandwiched and fixed by the cover and the base mold, the dustproof structure can be realized with a simple structure.

Therefore, it is possible to provide a highly reliable push switch having a simple structure, excellent assembling property, small size, and a dustproof structure.

[Brief description of the drawings]

FIG. 1 is an external view of a push switch according to the present invention.

FIG. 2 is a sectional view of a push switch according to the present invention.

FIG. 3 is an assembly diagram of a push switch according to the present invention.

FIG. 4 is a plan view of the push switch when the cover is attached to the base mold.

FIG. 5 is a front view of the push switch when the cover is attached to the base mold.

FIG. 6 is a left side view of the push switch when the cover is attached to the base mold.

FIG. 7 is a perspective view of a push switch when the cover is attached to the base mold.

[Explanation of symbols]

1 ... Push switch, 2 ... Cover, 2A ... Locking part, 2
B ... Flat plate portion, 3 ... Push button, 4 ... Spacer, 5 ... Dust cover, 6 ... Contact blade, 7 ... Base mold, 7A ... Inclined portion, 7B ... Notch portion, 7C ... Positioning protrusion, 7D ... Cover positioning Guide, 8, 9 ... Terminal, 8
A ... contact point.

Claims (1)

[Claims] 1. A contact blade having a spring property is pushed by a push button through a dust cover for dust prevention to bring the contact blade into contact with a contact for electrical connection, and due to the spring property of the contact blade, In a push switch that restores a push button to electrically disconnect the contact blade and the contact, the dust cover and a spacer that holds the dust cover are provided in a space formed by a cover and a base mold. Is sandwiched between the cover and the base mold to be fixed, and the cover has a flat plate portion having a through hole for allowing the push button to penetrate therethrough, and a plurality of locking portions facing side surfaces, respectively. The base mold has a sloped portion formed wide downwardly, A push switch comprising: a positioning guide for a cover located outside the inclined portion, wherein a lowermost portion of the inclined portion is formed with a tab for locking the locking portion.