JP2003007167A - Press button switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press button switch of high reliability in contacting where a lower part movable contact point is easily fitted to a housing while the dust and darts are prevented from entering the contact point part. SOLUTION: An annular adhesive sheet 8 comprising a through hole 6a at its center is so provided to a housing part 1a of a housing 1 as to cover the upper surface side of a lower part movable contact point 4. The top part of a swelling part 4a of the lower part movable contact point 4 is exposed from the through hole 6a of the adhesive sheet 6 to allow contacting to an upper part movable contact point 5. The circumferential part of the lower part movable contact point 4 is glued and held, across the entire circumference, by the housing part 1a of the housing 1 using an annular part 6b of the adhesive sheet 6.

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 in which a dome-shaped movable contact is reversed by being pressed to bring the contact into and out of contact, and in particular, a so-called double action type in which the contact is switched in two steps when pressed. The structure of the push button switch of.

[0002]

2. Description of the Related Art The structure of a conventional push button switch is shown in FIGS. FIG. 12 is a plan view of the push button switch, and FIG.
[FIG. 3] is a vertical sectional view of a push button switch.

The conventional push button switch has a rectangular housing 11 having a housing 11a, a central fixed contact 12a, a first peripheral fixed contact 12b and a second peripheral fixed contact arranged in the housing 11a of the housing 11. 12c, a lower movable contact 14 arranged on the central fixed contact 12a and the first peripheral fixed contact 12b, and an upper movable contact 15 arranged on the lower movable contact 14 and the second peripheral fixed contact 12c. , A cover sheet 17 mounted on the upper surface of the housing 11 while covering the storage portion 11a, and a frame 18.

The housing 11 is formed of an insulating material such as synthetic resin into a rectangular box shape, and has a circular storage portion 11a inside. A central fixed contact 12a made of a conductive metal material is disposed at the center of the storage portion 11a so as to be exposed on the inner bottom surface.
A first peripheral fixed contact 12b, which is also made of a conductive metal material, is disposed on the outer side of a so as to project further from the central fixed contact 12a. Further, outside the first peripheral fixed contact 12b, a second peripheral fixed contact 12c, which is also made of a conductive metal material, is arranged so as to project further one step.

The lower movable contact 14 is formed of a conductive metal plate in a circular shape having a small diameter, and is formed in a dome shape having a reversible bulging portion 14a in the center. Also,
The upper movable contact 15 is also formed of a conductive metal plate in the shape of a circular dome having a reversible bulge 15a in the center, and its outer diameter is larger than that of the lower movable contact 14. It is formed to have a diameter.

The lower movable contact 14 is connected to the storage portion 11a.
In the case of accommodating in the above, the center of the bulging portion 14a is arranged so as to face the central fixed contact 12a arranged in the accommodating portion 11a,
The peripheral edge of the lower movable contact 14 is placed in contact with the first peripheral fixed contact 12b. At this time, the annular inner wall 11 protruding along the outer periphery of the lower movable contact 14 is housed in the storage portion 11a.
b is formed. The outer peripheral portion of the lower movable contact 14 is directly caulked and fixed by deforming the inner wall 11b of the housing portion 11a of the housing 11 inward.

The lower movable contact 1 is fixed by caulking the outer peripheral portion of the lower movable contact 14 to the housing 11.
The peripheral portion of 4 is always in contact with the first peripheral fixed contact 12b, and the lower movable contact 14 can be used as a conduction path for switching with the upper movable contact 15. Then, the bulging portion 1 of the upper movable contact 15
5a are arranged so as to oppose each other so as to cover the lower movable contact 14, and the peripheral portion of the upper movable contact 15 is placed in contact with the second peripheral fixed contact 12c so that each contact portion to the storage portion 11a. Storage is completed.

The cover sheet 17 is formed of a substantially rectangular resin sheet, and is used as an abutting portion of an operating portion such as a key top when the upper movable contact 15 is operated, and also the housing. 11 storage part 11a
By being attached to the upper surface of the upper movable contact 15, the upper movable contact 15 is prevented from popping out and foreign matter such as dust is prevented from entering the contact portion.

The frame 18 is formed of a plate-shaped metal plate in a substantially rectangular shape, and a large window hole portion 18a is provided in the center thereof. A pair of vertically bent side plates (not shown) is provided on the side, and the frame 18 is locked by locking the side plates to the side surface of the housing 11.
Is attached to the upper surface of the housing 11. This time,
The cover sheet 17 is exposed from the window portion 18a, and it is possible to press the upper movable contact 15 from above to reverse the operation.

When the cover sheet 17 is pressed from the window portion 18a by an operation portion such as a key top (not shown),
The upper movable contact 15 reverses and comes into contact with the lower movable contact 14 to switch the click feeling and the contact of the first stage switch, and by further pushing, the lower movable contact 14 reverses and comes into contact with the central fixed contact 12a. As a result, the click feeling of the second step and the switching of the contacts are performed, and a double-action push button switch can be obtained.

[0011]

However, in the structure of the conventional push button switch described above, the outer peripheral portion of the lower movable contact 14 is fixed by caulking by deforming the inner wall of the housing 11 inward. Since the lower movable contact 14 may be obliquely floated and fixed with respect to the first peripheral fixed contact 12b, or the operating characteristics of the lower movable contact 14 may change due to variations in the caulking conditions, strict caulking control is required. There was a problem that it was required and the assembly work became complicated.

Further, when the lower movable contact 14 is reversed, there is a problem that dust enters the inside of the contact through the gap between the outer peripheral portion of the lower movable contact 14 and the caulking portion of the housing 11 and the contact becomes unstable. .

Therefore, the present invention solves the above-mentioned problems and provides a push button switch which is easily attached when the lower movable contact is attached to the housing and which prevents dust from entering the contact portion and has high contact reliability. The purpose is to do.

[0014]

In order to solve the above-mentioned problems, as a first means of the present invention, a housing having a housing portion, a central fixed contact disposed on the inner bottom surface of the housing portion of the housing, and a center thereof are provided. A first peripheral fixed contact arranged outside the fixed contact, a second peripheral fixed contact arranged further outside the first peripheral fixed contact, and a center of the bulging portion facing the central fixed contact. A dome-shaped lower movable contact that is disposed and has a peripheral edge that is always in contact with the first peripheral fixed contact, and a swelling center having a diameter larger than the outer shape of the lower movable contact and facing the lower movable contact. And a dome-shaped upper movable contact whose peripheral portion is in constant contact with the second peripheral fixed contact, and an annular adhesive sheet having a through hole in the center is provided in the lower portion of the housing of the housing. Install so that the upper surface of the movable contact is covered. And exposing the top of the bulging portion of the lower movable contact through the through-hole of the adhesive sheet so as to be in contact with the upper movable contact, and the peripheral portion of the lower movable contact is entirely covered by the annular portion of the adhesive sheet. It is characterized in that it is adhered and held in the housing portion of the housing over the circumference.

As a second means, a recessed groove portion is formed in the housing portion of the housing to accommodate the outer peripheral portion of the lower movable contact and positionally regulates the peripheral portion of the lower movable contact and the recessed groove portion. The annular portion of the pressure-sensitive adhesive sheet is adhered over the entire circumference with the edge portion of.

As a third means, the adhesive sheet is formed of a flexible resin sheet having an adhesive layer formed on one surface, so that it can follow the reversing operation of the lower movable contact. The annular portion is bonded to the lower movable contact and the housing.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a push button switch according to the present invention are shown in FIGS. 1 is a plan view of a push button switch, FIG. 2 is a longitudinal sectional view of the same, FIG. 3 is a plan view showing an engaged state of a housing and an upper movable contact, and FIG. 4 is a plan view showing a fixed state of a housing and a lower movable contact. 5 is a plan view of the housing, FIG. 6 is a plan view of the upper movable contact, FIG. 7 is a plan view of the lower movable contact, FIG. 8 is a plan view of the adhesive sheet, and FIG.
Is an operation explanatory diagram when there is no operation, FIG. 10 is an operation explanatory diagram when the first stage is on, and FIG. 11 is an operation explanatory diagram when the second stage is on.

In the figure, the housing 1 is formed of an insulating material such as synthetic resin into a box shape having an accommodating portion 1a inside and a square outer shape with an open upper surface. This storage 1
a is formed of a substantially circular base portion 1b formed in a concave shape in the center of the housing 1, and a substantially rectangular accommodation recess 1c that is connected to the base portion 1b and extends to a diagonal square portion of the housing 1. Has been done. Further, the side wall portion of the accommodating recessed portion 1c is formed by an inclined portion 1d having a narrow width toward the front wall portion in a continuous portion with the base portion 1b, and a parallel portion 1e extending in parallel from the inclined portion 1d. ing. Also, the base 1
In the center of b, a groove portion 1 having a substantially circular shape is provided at a position lowered by one step.
f is formed. A lower movable contact 4, which will be described later, is accommodated in the groove portion 1f, and the base portion 1 covers the upper surface thereof.
The upper movable contact 5, which will be described later, is housed in the housing b and the housing recess 1c.

A central fixed contact 2a made of a conductive metal material is formed at the center of the inner bottom surface of the housing portion 1a of the housing 1.
The upper surface side is arranged so as to be exposed, and at a position facing each other with the central fixed contact 2a sandwiched therebetween, the first fixed contact 2a is made of a conductive metal material so as to project further from the central fixed contact 2a. Peripheral fixed contacts 2b are provided. Further, at a position outside the first peripheral fixed contact 2b, one pair of the accommodating recesses 1c on the diagonal line of the housing 1 is provided.
Is provided with a second peripheral fixed contact 2c, which is also made of a conductive metal material, in a state where it is further projected. Then, the bottom surfaces of the other pair of accommodating recesses 1c intersecting with this are formed to be lower than the contact surface of the second peripheral fixed contact 2c.

In addition, on the opposing outer surfaces of the housing 1, to the circuit board of equipment or the like, which is led out from the central fixed contact 2a and the first and second peripheral fixed contacts 2b and 2c, and is projected outward. Connection terminals 3a, 3b, 3c for connection are formed.

The lower movable contact 4 is formed of a conductive metal plate in a circular shape having a small diameter, and has a bulging portion 4 which can be inverted in the center.
It is formed in a dome shape having a. The lower surface of the top of the bulging portion 4a serves as a central contact portion that contacts the central fixed contact 2a.

The upper movable contact 5 is also formed of a conductive metal plate in the shape of a dome having a reversible bulge 5a in the center, and a plurality of arms extending continuously in the cross direction from the bulge 5a. 5b is formed and has a cross shape as a whole. In addition, the outer diameter connecting the arms 5b is formed to be larger than the outer diameter of the lower movable contact 4. The side portion of the arm portion 5b is formed with an inclined surface 5c that becomes narrower from the base end portion toward the distal end portion, and the inclined surface 5c and the inclined portion 1d of the accommodating recess 1c are not aligned with each other. It is formed as follows.

When the lower movable contact 4 is stored in the storage portion 1a, the center of the storage portion 1 is the dome-shaped bulging portion 4a.
a While facing the central fixed contact 2a arranged in the center of a, the peripheral edge of the lower movable contact 4 is placed in contact with the pair of first peripheral fixed contacts 2b. This time,
A substantially circular recessed groove portion 1f is formed along the outer peripheral portion of the lower movable contact 4 at a position lowered by one step in the storage portion 1a, and the lower movable contact 4 is accommodated in the recessed groove portion 1f to form an outer peripheral portion. Will be positionally regulated.

On the upper surface side of the lower movable contact 4, an annular adhesive sheet 6 having a through hole 6a formed in the center is attached so as to cover the upper surface side of the lower movable contact 4, and By bonding the annular portion 6b of the sheet 6 over the entire circumference of the peripheral edge portion of the lower movable contact 4 and the edge portion of the concave groove portion 1f, the lower movable contact 4 is attached to the concave groove portion 1.
It is designed to be held at f.

In this manner, the concave groove portion 1f facilitates the positioning of the lower movable contact 4 to be attached and fixed by the adhesive sheet 6, and the gap between the concave groove portion 1f and the outer peripheral edge of the lower movable contact 4 is adhered to the adhesive sheet. Since it is covered with 6, it is possible to reduce the intrusion of dust. Further, when the adhesive sheet 6 is formed of a flexible resin sheet having an adhesive layer formed on one surface, and the dome-shaped bulging portion 4a of the lower movable contact 4 is inverted by a pressing operation. Also in the above, the annular portion 6b is adhered to the lower movable contact 4 and the storage portion 1a so as to be able to follow the reversing operation.

Further, since the top of the bulging portion 4a of the lower movable contact 4 is exposed from the through hole 6a of the adhesive sheet 6, it is possible to make contact with the upper movable contact 5 and The peripheral edge of the movable contact 4 is attached to the adhesive sheet 6
The peripheral portion of the lower movable contact 4 is always in contact with the first peripheral fixed contact 2b by being adhesively held in the storage portion 1a by the annular portion 6b of the lower movable contact 4
Can be used as a conduction path for switching with the upper movable contact 5.

When accommodating the upper movable contact 5 in the accommodating portion 1a, the center of the bulging portion 5a of the upper movable contact 5 is arranged so as to face the upper surface of the lower movable contact 4 and face each other. , The arm portion 5b of the movable contact 5 is positioned in the accommodating recess 1c of the accommodating portion 1a, and the arm portion 5b is
The peripheral edge portion of the above is placed in contact with the second peripheral fixed contact 2c. At this time, the side portion of the arm portion 5b is formed with an inclined surface 5c that becomes narrower from the base end portion toward the tip portion, and the inclined surface 5c of the arm portion 5b and the side wall portion of the accommodation recess 1c. Since the inclined portion 1d and the inclined portion 1d are formed so as to line up with each other, the upper movable contact 5 is formed by the inclined surface 5c and the inclined portion 1d.
Is regulated.

In this way, the position regulation of the upper movable contact 5
Since the inclined surface 5c on the side of the arm portion 5b and the inclined portion 1d of the side wall portion of the accommodating recess 1c for accommodating the arm portion 5b are used, the side wall portion and the arm portion 5b side And a gap G1 formed by the front wall of the accommodation recess 1c and the tip of the arm 5b.
By forming the front wall portion and the side wall portion so as to be narrower than 2, the gap G2 between the front wall portion of the accommodation recess 1c and the tip portion of the arm portion 5b can be set to be wide. When the upper movable contact 5 is pressed, the front end of the arm 5b does not collide with and is restrained from the front wall, so that the operation feeling at the time of reversal is not affected and accurate positioning is performed. Will be possible.

The side portion of the arm portion 5b is formed with an inclined surface 5c which becomes narrower from the base end portion toward the tip end portion, and the inclined surface 5c and the side wall portion of the accommodation recess 1c are inclined. Since the portion 1d and the portion 1d are formed so as to be aligned with each other, the arm portion 5b and the accommodating recess 1 due to the operation of the upper movable contact 5 are formed.
Since shaving with c can be reduced, contact failure due to the influence of shavings or the like can be prevented, and contact reliability can be improved.

Further, another pair of accommodating recesses 1c intersecting with one pair of accommodating recesses 1c on the diagonal line of the housing 1 in which the second peripheral fixed contact 2c is disposed.
Since the bottom surface of the second peripheral fixed contact 2c is formed lower than the contact surface of the second peripheral fixed contact 2c with the arm portion 5b, the second peripheral fixed contact 2c and the arm portion 5b surely contact each other and the other arm Part 5
It is possible to prevent the contact of b from coming into contact with the bottom of the accommodating recess 1c and making the contact unstable.

Further, the lower movable contact 4 placed below the upper movable contact 5 is formed in a substantially circular dome shape in outer diameter and has a plurality of crosses extending in the cross direction of the upper movable contact 5. Since the diameter is smaller than the outer diameter connecting the arms 5b, the layout can be performed without interfering with the arms 5b of the upper movable contact 5, and the positioning in the rotation direction is unnecessary. Therefore, it can be easily incorporated.

In this case, when the lower movable contact 4 is stored in the storage portion 1a, the peripheral portion of the lower movable contact 4 is formed on the upper surface of the first peripheral fixed contact 2b arranged in the storage portion 1a. Although it is placed in abutting state, since the first peripheral fixed contact 2b is formed one step higher than the central fixed contact 2a, the lower movable contact 4 on the first peripheral fixed contact 2b is Good sitting and dome-shaped bulge 4a
Since the operation stroke at the time of reversing is secured, the operation feeling becomes good.

Similarly, the second peripheral fixed contact 2c and the upper movable contact 5 are also formed so that the second peripheral fixed contact 2c is one step higher than the first peripheral fixed contact 2b. The upper movable contact 5 sits well on the peripheral fixed contact 2c, and the operation stroke for reversing the dome-shaped bulging portion 5a is secured, so that the operation feeling is also good.

A cover sheet 7 made of a substantially rectangular resin sheet is attached to the opening of the storage portion 1a so as to cover the upper surface of the upper movable contact 5. The cover sheet 7 is fixed to the upper surface of the dome-shaped swelling portion 5a of the upper movable contact 5 so that the peripheral edge of the upper movable contact 5 is brought into contact with the second peripheral fixed contact 2c, and is pressed. In this case, the sheet acts as an operation sheet, and covers the storage portion 1a and is attached to the upper surface to prevent the upper movable contact 5 from popping out and dust or the like from entering the contact portion. ing.

The frame 8 is a plate-shaped metal plate formed in a substantially rectangular shape, and a large window hole portion 8a is provided in the center thereof. Further, a pair of vertically bent side plates (not shown) is provided on the side, and by locking the side plates to a locking portion (not shown) provided on the side surface of the housing 1, The frame 8 is attached to the upper surface of the housing 1. At this time, the cover sheet 7 is interposed between the frame 8 and the housing 1, and a part of the cover sheet 7 is exposed from the window hole portion 8a.

Next, the operation of the push button switch having the above structure will be described with reference to FIGS. As shown in FIG. 9, when the switch is in the non-pressing operation state, the peripheral portion of the upper movable contact 5 is in contact with the second peripheral fixed contact 2c, but the dome-shaped bulge portion 5a is the lower movable contact. 4 is separated from the lower movable contact 4, and the peripheral edge of the lower movable contact 4 is the first
Although in contact with the peripheral fixed contact 2b, the dome-shaped bulging portion 4a is separated from the central fixed contact 2a, and the upper and lower two stages of the switch are off.

From this state, as shown in FIG. 10, when the cover sheet 7 is pressed from the window portion 8a of the frame 8 by the operation portion such as the key top 9, it is fixed to the lower surface side of the cover sheet 7. The upper surface of the bulged portion 5a of the upper movable contact 5 thus pressed is pressed to push the bulged portion 5a downward.

At this time, the bulging portion 5a of the upper movable contact 5 is
Is pressed downward, the bulging portion 5a of the upper movable contact 5 is inverted downward. For this reason,
The lower surface of the bulging portion 5a is the bulging portion 4 of the lower movable contact 4.
a. The second peripheral fixed contact 2c and the first fixed contact 2 which are in contact with the upper surface of the second movable contact 4 and the upper and lower movable contacts 4 and 5 are conductive paths.
It is electrically connected to b, and the first stage (upper) switch is turned on.

From this state, as shown in FIG. 11, when the key top 9 is further pressed, the bulging portion 5a lower surface of the upper movable contact 5 causes the bulging portion 4a upper surface of the lower movable contact 4 to move upward. When pushed, the bulging portion 4a is pushed downward.

At this time, the bulging portion 4a of the lower movable contact 4 is
Is pressed downward, the bulging portion 4a of the lower movable contact 4 is inverted downward. For this reason,
The lower surface of the bulged portion 4a contacts the central fixed contact 2a, and the first peripheral fixed contact 2b via the lower movable contact 4.
And the central fixed contact 2a are electrically connected to each other to form a second stage (lower part).
Switch turns on.

As described above, when the cover sheet 7 is pressed by the key top 9, the upper movable contact 5 is inverted and comes into contact with the lower movable contact 4, thereby performing a click feeling of the first stage switch and switching of the contact. By further pushing, the lower movable contact 4 is inverted and comes into contact with the central fixed contact 2a, so that the click feeling of the second stage and the switching of the contact are performed, and a double-action push button switch is obtained.

When the pressing force on the key top 9 is released from this state, the bulging portions 4a, 5a of the upper and lower movable contacts 4, 5 are reversed by their own elasticity to return to the initial state. The key top 9 is pressed upward by the urging force at this time and returns to the initial position. At this time, as the bulging portions 4a, 5a of the upper and lower movable contacts 4, 5 are reversed, the bulging portions 4a, 5
The lower surface of a is separated from the upper surface of the lower movable contact 4 and the central fixed contact 2a, and the first-stage and second-stage switches are turned off.

According to the above construction, the annular pressure-sensitive adhesive sheet 6 having the through hole 6a in the center thereof is provided in the housing portion 1a of the housing 1 so as to cover the upper surface side of the lower movable contact 4, and the pressure-sensitive adhesive sheet is formed. 6, the bulging portion 5a of the lower movable contact 5 is exposed from the through hole 6a, and the upper movable contact 5 is arranged so as to be in contact therewith, and the annular portion 6b of the adhesive sheet 6 surrounds the lower movable contact 4. Since the portion is adhered to and held in the storage portion 1a of the housing 1 over the entire circumference, the upper movable contact 5 and the lower movable contact 4 can be arranged so as to be able to contact each other through the through hole 6a of the adhesive sheet 6. At the same time, the lower movable contact 4 can be easily attached to the housing portion 1a of the housing 1.

Since the adhesive sheet 6 can cover the outer peripheral portion of the lower movable contact 4 and the housing 1 over the entire circumference so as to follow the reversing operation of the lower movable contact 4. In addition, the intrusion of dust can be reduced and the contact reliability can be improved.

Further, according to the above construction, the upper movable contact 5 is provided with a plurality of the arm portions 5b extending in the cross direction in succession to the reversible bulging portion 5a, and on the diagonal line of the housing 1. The square portion is formed with a housing recess 1c that is connected to the housing 1a and houses each arm 5b of the upper movable contact 5 in a bendable and expandable manner, and at least one arm 5b is housed in the housing recess 1c. Since the second peripheral fixed contact 2c, which is always in contact with the above, is provided, the operation stroke of the upper movable contact 5 can be secured by the arm portion 5b, and the arm portion 5b is fixed to the square portion of the housing 1. By arranging in the above, the width of the outer shape of the rectangular housing can be reduced as compared with the case where the circular dome-shaped movable contact is used.

[0046]

As described above, the push button switch of the present invention has a housing having a housing portion, a central fixed contact disposed on the inner bottom surface of the housing portion of the housing, and a central fixed contact disposed outside the central fixed contact. The first peripheral fixed contact, the second peripheral fixed contact arranged further outside the first peripheral fixed contact, the center of the bulging portion is arranged to face the central fixed contact, and the peripheral portion is 1 a dome-shaped lower movable contact that is in constant contact with the peripheral fixed contact, a dome-shaped lower movable contact having a larger diameter than the outer shape of the lower movable contact, and the bulging portions are arranged to face each other so as to cover the lower movable contact. 2 A dome-shaped upper movable contact that constantly contacts the peripheral fixed contacts,
An annular adhesive sheet with a through hole in the center is provided to cover the upper surface side of the lower movable contact, and the top of the bulge of the lower movable contact is exposed from the through hole of the adhesive sheet so that it can contact the upper movable contact. In addition, since the peripheral portion of the lower movable contact is adhesively held in the housing of the housing over the entire circumference by the annular portion of the adhesive sheet, it is possible to contact the upper movable contact and the lower movable contact through the through hole of the adhesive sheet. It can be arranged and the lower movable contact can be easily attached to the housing of the housing. Further, the peripheral portion of the lower movable contact is always in contact with the first peripheral fixed contact, and the lower movable contact can be used as a conduction path for switching with the upper movable contact.

Further, a recessed groove portion for accommodating the outer peripheral portion of the lower movable contact and regulating the position is formed in the accommodating portion of the housing,
Since the annular portion of the adhesive sheet is adhered over the entire circumference of the peripheral portion of the lower movable contact and the edge portion of the concave groove portion, the concave groove portion can easily perform the positioning of the adhesive fixing of the lower movable contact by the adhesive sheet, and Since the gap between the concave groove portion and the outer peripheral edge of the lower movable contact is covered with the adhesive sheet, the intrusion of dust can be reduced.

Further, the adhesive sheet is formed of a flexible resin sheet having an adhesive layer formed on one surface, and the annular portion serves as the lower movable contact so as to follow the reversing operation of the lower movable contact. Since it is adhered to the housing, the adhesive sheet that can follow the reversing operation of the lower movable contact can cover the entire circumference between the outer peripheral portion of the lower movable contact and the housing, so that intrusion of dust can be reduced. The contact reliability can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a push button switch according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view showing the same push button switch of the present invention.

FIG. 3 is a plan view showing an engaged state of the housing and the upper movable contact of the present invention.

FIG. 4 is a plan view showing a fixed state of a housing and a lower movable contact of the present invention.

FIG. 5 is a plan view showing a housing of the present invention.

FIG. 6 is a plan view showing an upper movable contact of the present invention.

FIG. 7 is a plan view showing a lower movable contact of the present invention.

FIG. 8 is a plan view showing an adhesive sheet of the present invention.

FIG. 9 is an operation explanatory view showing a state when the push button switch of the present invention is not operated.

FIG. 10 is an operation explanatory view showing a state when the first stage of the push button switch of the present invention is turned on.

FIG. 11 is an operation explanatory view showing a state of the push button switch of the present invention when the second stage is on.

FIG. 12 is a plan view showing a conventional push button switch.

FIG. 13 is a vertical sectional view showing a conventional push button switch.

[Explanation of symbols]

1 housing 1a Storage section 1b base 1c storage recess 1d slope 1e Parallel part 1f concave groove 2a Central fixed contact 2b 1st peripheral fixed contact 2c Second peripheral fixed contact 3a, 3b, 3c connection terminals 4 Lower movable contact 4a bulge 5 Upper movable contact 5a bulge 5b arm 5c slope 6 Adhesive sheet 6a through hole 6b Ring part 7 cover sheet 8 frames 8a window hole 9 key tops G1, G2 void

Claims (3)

[Claims] 1. A housing having an accommodating portion, a central fixed contact disposed on a bottom surface inside the accommodating portion of the housing, a first peripheral fixed contact disposed outside the central fixed contact, and a first peripheral portion of the housing. A second one disposed outside the fixed contact
A peripheral fixed contact, a dome-shaped lower movable contact whose central part of the bulging portion is disposed so as to face the central fixed contact, and whose peripheral edge is in constant contact with the first peripheral fixed contact, and an outer shape of the lower movable contact. Also has a dome-shaped upper movable contact having a large diameter, the center of the bulging portion thereof being opposed to cover the lower movable contact, and the peripheral portion of the dome-shaped upper movable contact constantly contacting the second peripheral fixed contact. An annular adhesive sheet having a through hole in the center is provided in the storage portion so as to cover the upper surface side of the lower movable contact, and the bulging portion top of the lower movable contact is exposed from the through hole of the adhesive sheet. A push button switch, wherein the push button switch is arranged so as to be in contact with the upper movable contact, and the peripheral portion of the lower movable contact is adhesively held in the housing portion of the housing over the entire circumference by the annular portion of the adhesive sheet. 2. The housing portion of the housing is formed with a groove portion for accommodating the outer peripheral portion of the lower movable contact and restricting the position thereof, and the entire peripheral portion of the lower movable contact and the edge portion of the groove portion. 2. The push button switch according to claim 1, wherein an annular portion of the adhesive sheet is adhered over the circumference. 3. The pressure-sensitive adhesive sheet is formed of a flexible resin sheet having a pressure-sensitive adhesive layer formed on one surface thereof, and the annular portion is formed so as to follow the reversing operation of the lower movable contact. The push button switch according to claim 1 or 2, wherein a lower movable contact is adhered to the housing.