JP2010267440A - Push-button switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a push-button switch improving contact performance between a fixed contact and a movable contact through restraint of deposition of dust on a peripheral fixed contact, and capable of smoothing air flow in and out of an elastic spring. <P>SOLUTION: The push-button switch is provided with a housing 2 having a storing part 11, a center fixed contact 5 fitted on an inner bottom surface of the housing 2 as well as a peripheral fixed contact 6 fitted around the center fixed contact 5, a movable contact 7 loaded on the peripheral fixed contact 6 and capable of separating and contacting to the center fixed contact 5, and a rubber spring 3 formed in swelling in free reversing by pushing, and making the movable contact 7 contact to the center fixed contact 5 at reversing. The peripheral fixed contact 6 forms a groove part 18 made in contact with the movable contact 7 by a plurality of contact parts 17a, 17b protruded on the movable contact 7 side, and communicating inside and outside of the rubber spring 3 between the plurality of contact parts 17a, 17b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pushbutton switch incorporated in an electronic device or the like, and more particularly, to a pushbutton switch that performs switching by inverting an dome-shaped elastic spring such as a rubber spring.

  In general, in a pushbutton switch that switches by inverting a dome-shaped elastic spring, a flow path is formed to allow air inside to escape when the elastic spring is reversed. As such a pushbutton switch having an air flow path, a rubber elastic spring having a flow path is known (for example, see Patent Document 1). The elastic spring of this pushbutton switch is configured to have an annular leg portion and a bulging portion that rises from the leg portion and bulges in a dome shape, and is placed so as to cover a fixed contact provided on the substrate. The

  The legs of the elastic spring are formed with a plurality of grooves as flow paths in the lower surface placed on the substrate, and each groove extends in a direction obliquely intersecting with the radial direction toward the fixed contact and fixed. The flow path is formed in a direction that avoids the contact. The push button switch is pressed to discharge the air inside the elastic spring to the outside through the plurality of grooves when the elastic spring is reversed, and from the outside to the inside of the elastic spring through the plurality of grooves when the elastic spring is restored. Air is inhaled. Even when dust is sucked together with air when the elastic spring is restored, accumulation of dust near the fixed contact is prevented because the plurality of grooves extend in a direction avoiding the fixed contact.

  Further, as a pushbutton switch in which an air flow path is formed, a switch in which a plurality of protrusions are arranged radially on a substrate and an elastic spring is arranged on the plurality of protrusions is known (for example, Patent Document 2). reference). In this pushbutton switch, the gap between the upper surface of the substrate formed by a plurality of protrusions and the lower surface of the elastic spring is an air flow path, and the flow path is formed with a simple configuration.

JP 2003-281968 A No. 5-9786

  By the way, as the contact structure of the pushbutton switch, the fixed contact is composed of the central fixed contact and the peripheral fixed contact arranged around the central fixed contact, and the movable contact is mounted on the peripheral fixed contact with respect to the central fixed contact. The one configured to be separable can be considered. When the elastic spring described in Patent Document 1 described above is applied to this contact structure, dust can be prevented from accumulating at the central fixed contact, but dust can accumulate at the peripheral fixed contact, and the peripheral fixed contact and the movable contact can be prevented. There was a possibility that the contact property with would decrease.

  Further, in the pushbutton switch described in Patent Document 1, since the elastic spring is made of rubber, it is difficult to secure a predetermined groove width by collapsing the groove when the elastic spring is reversed, and smooth air entry / exit is hindered. There was a risk of being. Furthermore, in the pushbutton switch described in Patent Document 2, although a flow path is formed with a simple configuration, it has not been possible to prevent dust from accumulating on the peripheral fixed contact and the central fixed contact.

  The present invention has been made in view of such circumstances, and suppresses the accumulation of dust on the peripheral fixed contacts to improve the contact between the fixed contacts and the movable contacts, and also allows air to enter and exit the elastic springs. It is an object to provide a push button switch that can be smoothly operated.

  The pushbutton switch of the present invention is mounted on a housing having a housing portion, a central fixed contact provided on the inner bottom surface of the housing, a peripheral fixed contact provided around the central fixed contact, and the peripheral fixed contact A movable contact that is separable with respect to the central fixed contact; and an elastic spring that is formed to bulge so as to be reversible when pressed, and that makes the movable contact contact the central fixed contact when reversed. Has a flow path that connects the inside and the outside of the elastic spring at the contact portion that contacts the movable contact.

  According to this configuration, since the flow path that connects the inside and the outside of the elastic spring is provided in the contact portion of the peripheral fixed contact, the dust around the contact portion of the peripheral fixed contact is caused by the entry and exit of air by the pressing operation of the pushbutton switch. Is washed away. Therefore, dust does not accumulate on the contact portion of the peripheral fixed contact, and the contact between the peripheral fixed contact and the movable contact is improved. In addition, since the flow path is formed at the peripheral fixed contact, the flow path is not crushed when the elastic spring is reversed, and the air can enter and exit smoothly.

  In the pushbutton switch according to the present invention, a plurality of contact portions of the peripheral fixed contact are formed to protrude toward the movable contact, and the flow path is a groove formed between the plurality of contact portions. It is characterized by being.

  According to this configuration, since the contact portion is formed to protrude, the peripheral fixed contact and the movable contact are brought into contact with each other above the groove portion through which air enters and exits, and dust that intrudes due to the entry and exit of air adheres to the contact portion. Is prevented. In addition, when fixing the external terminal connected to the peripheral fixed contact by soldering, the contact portion that is the contact position between the peripheral fixed contact and the movable contact is contacted with a position higher than the groove portion. It is possible to suppress the flux from rising up to the point of contact, and it is possible to prevent poor contact at the contact portion due to the flux rising.

  In the push button switch according to the present invention, the flow path extends in a direction avoiding the center fixed contact.

  Further, the present invention is characterized in that, in the pushbutton switch, an end portion on the inner side of the elastic spring of the flow path is formed so as to suck and discharge in a direction avoiding the central fixed contact.

  According to these configurations, even if dust is inhaled together with air when the elastic spring is restored, the dust is scattered in a direction avoiding the center fixed contact, so that accumulation of dust at the center fixed contact can be prevented. .

  Further, the present invention provides the pushbutton switch, further comprising a stem provided in the housing portion of the housing and pressing the elastic spring, wherein the stem has a gap between the inner peripheral surface of the housing and the outer peripheral surface of the stem. The gap is formed wider on the corner side of the housing than the side surface of the housing, and the flow path is in the vicinity of an intermediate position between adjacent corners on the side surface of the housing. The end of the flow path outside the elastic spring is formed so as to face the side surface.

  According to this configuration, air can smoothly enter and exit during the pressing operation of the stem by the gap formed between the housing and the stem. In addition, since air is sucked into the flow path through the side surface of the housing with the narrow gap at a position separated from the corner side of the housing with the wide gap, large dust flows directly from the gap on the corner side of the housing. Inhalation can be prevented.

  According to the present invention, dust accumulation on the peripheral fixed contacts can be suppressed to improve the contact between the fixed contact and the movable contact, and air can smoothly enter and exit the elastic spring.

It is a figure which shows embodiment of the pushbutton switch which concerns on this invention, and is a whole perspective view of a pushbutton switch. It is a figure which shows embodiment of the pushbutton switch which concerns on this invention, and is an exploded perspective view of a pushbutton switch. It is a figure which shows embodiment of the pushbutton switch which concerns on this invention, and is explanatory drawing of the flow path formed in the pushbutton switch. It is a figure which shows embodiment of the pushbutton switch which concerns on this invention, and is explanatory drawing of pressing operation of a pushbutton switch.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an overall perspective view of a pushbutton switch according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the pushbutton switch according to the embodiment of the present invention.

  As shown in FIGS. 1 and 2, the pushbutton switch 1 is used as an operation switch for various electric devices, and has a movable contact provided in a housing 2 provided with a central fixed contact 5 and a pair of peripheral fixed contacts 6. 7 and a rubber spring 3 as an elastic spring are accommodated, and the housing 4 is assembled by mounting the stem 4 from above. The assembled push button switch 1 has improved operational feeling due to the reversing operation of the rubber spring 3 during the pressing operation.

  The housing 2 has a box shape with an open upper surface, and a housing portion 11 in which the movable contact 7 and the rubber spring 3 are housed is formed. At the four corners of the accommodating portion 11, arc-shaped wall portions 13 are formed so as to protrude upward from the bottom wall, and the movable contact 7 and the leg of the rubber spring 3 are formed on the inner peripheral surface of each arc-shaped wall portion 13. The part 31 is held. Further, the outer peripheral surface of each arcuate wall portion 13 forms a guide hole portion 14 together with the inner peripheral surface of the side wall of the housing 2, and the stem 4 is guided to the back of the accommodating portion 11 by the guide hole portion 14.

  The central fixed contact 5 and the pair of peripheral fixed contacts 6 are formed of a metal plate and are integrally disposed on the bottom wall of the housing 2 by insert molding or the like. The central fixed contact 5 is disposed at the center of the bottom wall of the housing 2, and the pair of peripheral fixed contacts 6 are disposed at positions facing each other with the central fixed contact 5 interposed therebetween. The center fixed contact 5 has a contact portion 16 protruding upward from the flat plate portion, and the contact portion 16 has a substantially circular outer shape with a part cut away.

  The pair of peripheral fixed contacts 6 each have a pair of contact portions 17a and 17b protruding upward from the flat plate portion, and a groove portion 18 as a flow path is formed between the contact portions 17a and 17b. Further, external terminals 19 are connected to the central fixed contact 5 and the pair of peripheral fixed contacts 6, respectively, and each external terminal 19 extends outward from the four corners of the housing 2. The details of the groove portion 18 of the pair of peripheral fixed contacts 6 will be described later.

  The movable contact 7 is formed of a phosphor bronze plate or the like having a spring property, and includes an annular plate portion 21 having an opening at the center and a contact piece 23 that is cantilevered inside the annular plate portion 21. Yes. The annular plate portion 21 has positioning pieces 24 for positioning in four directions and is formed in a substantially annular shape, and each positioning piece 24 is aligned with an empty space between adjacent arcuate wall portions 13, thereby housing 2. Positioned and placed on the front, rear, left and right. The annular plate portion 21 is placed on the projecting end surfaces of the contact portions 17 a and 17 b of the peripheral fixed contact 6, and forms a flow path together with the peripheral fixed contact 6.

  The contact piece 23 extends from a part of the annular plate portion 21 toward the center of the opening 22 of the annular plate portion 21, and the free end side is positioned above the central fixed contact 5. Further, the contact piece 23 is configured to swing around the connecting portion of the annular plate portion 21 as a fulcrum and to be able to be separated from and connected to the central fixed contact 5. A plurality of contact portions 25 that come into contact with the central fixed contact 5 and a pressed portion 26 that is pressed by the rubber spring 3 are formed on the free end side of the contact piece 23.

  The plurality of contact portions 25 are formed to protrude downward at three locations surrounding the pressed portion 26, and are brought into contact with the contact portion 16 of the central fixed contact 5 at three points when the contact piece 23 moves downward. Thus, since the movable contact 7 is brought into contact with the central fixed contact 5 at three points, even if dust or the like adheres to the central fixed contact 5, it is reliably contacted with the central fixed contact 5. The The pressed portion 26 is formed to protrude upward at the center of the movable contact 7, and the pressing of the rubber spring 3 is concentrated.

  The rubber spring 3 is formed in a dome shape whose bottom surface is opened by a flexible resin such as an elastomer or silicone rubber, and is configured to be reversed by a pressing operation. The rubber spring 3 has a leg portion 31 formed in an annular shape, a skirt portion 32 that rises radially inward from the leg portion 31 at a predetermined angle, and a columnar head portion 33 that continues to the skirt portion 32. is doing. The head 33 of the rubber spring 3 is provided with an operating projection 34 that projects downward from the lower surface (see FIG. 4).

  The rubber spring 3 is positioned on the housing 2 by holding the leg portion 31 on the inner peripheral surface of the plurality of arcuate wall portions 13, and the center of the operating projection 34 is the pressed portion 26 of the movable contact 7. Located above. The operating protrusion 34 is configured to be able to press the pressed portion 26 of the movable contact 7 when the rubber spring 3 is reversed, and brings the contact portion 25 of the movable contact 7 into contact with the contact portion 16 of the central fixed contact 5.

  The stem 4 has a box shape with an open lower surface, and is held by the housing 2 so as to cover the rubber spring 3. A pair of sliding protrusions 36 are formed on the side walls of the stem 4 so as to slightly protrude from the outer surface to the side, and are slidably held on the housing 2 by the sliding protrusions 36 (see FIG. 3). . Further, guide protrusions 37 protrude downward from the side walls at the four corners of the stem 4, and each guide protrusion 37 is inserted into the guide hole 14 of the housing 2 during a pressing operation to guide the sliding of the stem 4.

  In the pushbutton switch 1 configured as described above, when the stem 4 is pressed, the movable contact 7 and the central fixed contact 5 are brought into contact with each other by the reversal of the rubber spring 3, and the peripheral fixed contact 6 and the central fixed contact 5 are Is conducted through the movable contact 7. At this time, the air inside the rubber spring 3 is discharged to the outside when the rubber spring 3 is reversed, and the air is sucked into the inside of the rubber spring 3 from the outside when the rubber spring 3 is returned.

  Here, with reference to FIG. 3, the flow path through which the air at the time of reversal and return of the rubber spring 3 enters and exits will be described. FIG. 3 is an explanatory diagram of the flow path formed in the pushbutton switch according to the embodiment of the present invention. In FIG. 3, for convenience of explanation, the movable contact is omitted, and the outer shapes of the rubber spring and the stem are indicated by broken lines.

  As shown in FIG. 3, the stem 4 is held by the housing 2 such that a gap is formed between the outer peripheral surface of the stem 4 and the outer peripheral surface of the housing 2 by a plurality of sliding protrusions 36. In this case, the gap 41 on the corner side of the housing 2 is formed wider than the gap 42 on the side surface side of the housing 2, and the stem 4 is suppressed by suppressing the contact area when the housing 2 and the stem 4 slide. Improves the operational feel. The gaps 41 and 42 function as a flow path in the operation direction (vertical direction) connecting the outside of the push button switch 1 and the bottom wall side of the housing 2.

  Peripheral fixed contacts 6 are provided in the vicinity of the left and right intermediate positions of the pair of opposing side walls of the housing 2, and each peripheral fixed contact 6 is provided with a pair of contact portions 17 a and 17 b. The pair of contact portions 17 a and 17 b are formed so as to protrude from the plate-like portion, and a gap is generated between each peripheral fixed contact 6 and the movable contact 7. Further, the pair of contact portions 17a and 17b are formed in a trapezoidal shape when viewed from above, and are arranged so that the trapezoidal slopes face each other. A groove portion 18 is formed in each peripheral fixed contact 6 by the inclined surfaces of the pair of contact portions 17a and 17b facing each other.

  One end of each groove portion 18 communicates with the inside of the rubber spring 3 through the opening 22 of the movable contact 7, and the other end communicates with a gap 42 on the side surface side of the housing 2. Each groove 18 functions as a planar flow path that connects the gaps 41 and 42 and the inside of the rubber spring 3 on the bottom wall side of the housing 2 together with the periphery of the pair of contact portions 17a and 17b.

  Each groove 18 extends in a direction that obliquely intersects the radial direction toward the central fixed contact 5. The extending direction of the groove portion 18 faces the direction in which the central fixed contact 5 is removed from the extension line L of the groove portion 18. In this case, each groove portion 18 is a point object centered on the central fixed contact 5, and air is sucked so as to vortex inside the rubber spring 3 when the rubber spring 3 is restored. Therefore, even if dust is inhaled together with air when the rubber spring 3 is restored, the dust is scattered in a direction away from the center fixed contact 5, so that accumulation of dust on the center fixed contact 5 is suppressed.

  The groove width of each groove portion 18 is formed such that the acute angle portions of the pair of contact portions 17 a and 17 b overlap in the radial direction toward the central fixed contact 5. With this configuration, since the inclined surfaces of the pair of contact portions 17 a and 17 b (side surfaces of the groove portion 18) obstruct the flow from the other end of each groove portion 18 toward the central fixed contact 5, Dust is not scattered and the accumulation of dust at the center fixed contact 5 is further suppressed.

  Moreover, since the flow path in the pushbutton switch 1 is narrowed in each groove part 18, the pressure in each groove part 18 is reduced. Therefore, the dust around the pair of contact portions 17a and 17b is attracted and pushed away by the air due to the entry and exit of the air in each groove portion 18, so that the accumulation of dust around the contact portions 17a and 17b is suppressed. Further, since the contact portions 17a and 17b are in contact with the movable contact 7 at a position higher than the groove portion 18, contact failure due to adhesion of dust to the contact portions 17a and 17b and increase in flux at the time of soldering of the external terminals 19 occurs. Is prevented.

  Further, the other end of the groove portion 18 communicates with the gap 42 on the side surface side of the housing 2, and air is sucked into the groove portion 18 through the narrow gap 42 on the side surface side of the housing 2. Large dust is prevented from being directly sucked from the wide gap 41. Further, the corner-side gap 41 of the housing 2 communicates with the guide hole portion 14 of the housing 2, so that large dust is difficult to be sucked into the rubber spring 3. Thus, in the pushbutton switch 1 according to the present embodiment, the accumulation of dust at the central fixed contact 5 and the peripheral fixed contact 6 is suppressed, and the contact with the movable contact 7 is improved.

  In the present embodiment, the groove portion 18 extends in a direction that obliquely intersects the radial direction toward the central fixed contact 5, but is not limited to this configuration. At least one end of the groove portion 18 on the inner side of the rubber spring 3 may be configured to suck and discharge air in a direction avoiding the center fixed contact 5. For example, the groove portion 18 may be curved and extend in a top view. Good.

  With reference to FIG. 4, the pressing operation of the pushbutton switch 1 will be described. 4A and 4B are explanatory diagrams of the pressing operation of the push button switch according to the embodiment of the present invention. FIG. 4A shows the initial state of the push button switch, and FIG. 4B shows the pressing state of the push button switch.

  As shown in FIG. 4A, in the initial state where the stem 4 is not pressed, the stem 4 is pushed upward by the elastic force of the rubber spring 3. In this case, the annular plate portion 21 of the movable contact 7 contacts the contact portions 17 a and 17 b of the pair of peripheral fixed contacts 6, and the contact piece 23 is separated from the central fixed contact 5. When the stem 4 is pressed from this initial state, the skirt portion 32 of the rubber spring 3 starts to bend, and the air inside the rubber spring 3 is pushed out.

  The air inside the rubber spring 3 includes an opening 22 formed in the annular plate portion 21 of the movable contact 7, the periphery of the contact portions 17 a and 17 b of the peripheral fixed contact 6 and the groove portion 18, and gaps 41 and 42 between the housing 2 and the stem 4. Is discharged to the outside of the push button switch 1. At this time, as the air is discharged, dust adhering to the periphery of the contact portions 17a and 17b of the peripheral fixed contact 6 is pushed away by the air, and the peripheral fixed contact 6 is cleaned.

  Further, when the load applied to the rubber spring 3 becomes a predetermined load or more, the rubber spring 3 is reversed and the contact piece 23 of the movable contact 7 is pressed by the operating protrusion 34. 4B, when the reversal of the rubber spring 3 is completed, the plurality of contact portions 25 provided on the contact piece 23 are brought into contact with the contact portion 16 of the central fixed contact 5, and the central fixed contact 5 And the peripheral fixed contact 6 are conducted through the movable contact 7.

  When the pressing force is removed from the pressed state in which the stem 4 is pressed, the stem 4 is pushed up by the restoring force of the rubber spring 3, the operating protrusion 34 is separated from the contact piece 23, and the contact piece 23 and the central fixed contact 5 are separated. The conduction state with is released. Then, air is sucked into the rubber spring 3 as the rubber spring 3 returns. The air outside the pushbutton switch 1 has openings 41 formed in the gaps 41 and 42 between the housing 2 and the stem 4, the periphery of the contact portions 17 a and 17 b of the peripheral fixed contact 6 and the groove portion 18, and the annular plate portion 21 of the movable contact 7. Is sucked into the rubber spring 3.

  At this time, even if dust is sucked into the rubber spring 3 together with the air, the dust is swept away from the periphery of the contact portions 17a and 17b by the air, and the dust is scattered at a position disengaged from the central fixed contact 5. Accumulation of dust at the fixed contact 5 and the pair of peripheral fixed contacts 6 is suppressed. Further, since the groove portion 18 communicates with the narrow gap 42 on the side surface side of the housing 2, large dust is prevented from entering from the wide gap 41 on the corner side of the housing 2.

  As described above, according to the pushbutton switch 1 according to the present embodiment, the groove portion 18 that communicates the inside and the outside of the rubber spring 3 is provided in the contact portion 16 of the peripheral fixed contact 6. Due to the entry and exit of air by operation, dust around the contact portion 16 of the peripheral fixed contact 6 is pushed away. Therefore, dust does not accumulate on the contact portion 16 of the peripheral fixed contact 6, and the contact between the peripheral fixed contact 6 and the movable contact 7 is improved. In addition, since the flow path is formed in the peripheral fixed contact 6, the groove portion 18 is not crushed when the rubber spring 3 is reversed, so that air can enter and exit smoothly.

  In the above-described embodiment, the flow path is provided by projecting the pair of contact portions at the peripheral fixed contact. However, the present invention is not limited to this configuration. Any configuration may be used as long as the flow path is provided in the contact portion of the peripheral fixed contact. For example, a shallow groove may be provided in one contact portion.

  In the above-described embodiment, the groove portions of the pair of peripheral fixed contacts are provided so as to be pointed around the central fixed contact. However, the present invention is not limited to this configuration. Any groove portion may be provided as long as the groove portion is provided so that air is sucked in a vortex inside the rubber spring.

  Further, in the above-described embodiment, the extending direction of the groove portion of the pair of peripheral fixed contacts is configured to face the direction in which the central fixed contact is removed from the extended line of the groove portion. However, the configuration is limited to this configuration. is not. If the contact between the contact piece of the movable contact and the contact portion of the central fixed contact can be ensured, for example, the groove portion may extend in the radial direction toward the central fixed contact.

  In the above-described embodiment, the pair of peripheral fixed contacts are disposed at the opposing positions with the central fixed contact in between. However, the present invention is not limited to this configuration. The pair of peripheral fixed contacts may be one or three or more. Moreover, as long as it can contact a movable contact around the center fixed contact, it may be arranged at any position.

  In the above-described embodiment, the rubber spring is exemplified as the elastic spring. However, the present invention is not limited to this. Any structure may be used as long as the movable contact is driven by reversal. For example, a metallic reversing spring may be used.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

  As described above, the present invention has the effect that the accumulation of dust on the peripheral fixed contacts is suppressed to improve the contact between the fixed contacts and the movable contacts, and that the air can smoothly enter and exit the elastic springs. In particular, it is useful for a pushbutton switch that performs switching by reversing a dome-shaped elastic spring such as a rubber spring.

1 Pushbutton switch 2 Housing 3 Rubber spring (elastic spring)
4 Stem 5 Center Fixed Contact 6 Peripheral Fixed Contact 7 Movable Contact 11 Housing Part 16 Contact Part 17a, 17b Contact Part 18 Groove (Flow Channel)
21 annular plate part 22 opening 23 contact piece 25 contact part 41, 42 clearance

Claims (5)

A housing having a receiving portion;
A central fixed contact provided on the inner bottom surface of the housing and a peripheral fixed contact provided around the central fixed contact;
A movable contact mounted on the peripheral fixed contact and separable from the central fixed contact;
An elastic spring formed to bulge so as to be reversible by pressing, and to bring the movable contact into contact with the central fixed contact at the time of reversal;
The push button switch according to claim 1, wherein the peripheral fixed contact has a flow path that connects the inside and the outside of the elastic spring at a contact portion that contacts the movable contact. A plurality of contact portions of the peripheral fixed contacts are formed to protrude toward the movable contact side,
The pushbutton switch according to claim 1, wherein the flow path is a groove formed between the plurality of contact portions.   The pushbutton switch according to claim 1 or 2, wherein the flow path extends in a direction avoiding the central fixed contact.   3. The pushbutton switch according to claim 1, wherein an end portion on the inner side of the elastic spring of the flow path is formed so as to suck and discharge in a direction avoiding the central fixed contact. 4. . A stem that is provided in the housing portion of the housing and presses the elastic spring;
The stem is guided by the housing so as to form a gap between the inner peripheral surface of the housing and the outer peripheral surface of the stem,
The gap is formed wider on the corner side of the housing than the side surface side of the housing,
The flow path is located in the vicinity of an intermediate position between adjacent corners on the side surface of the housing, and the end of the flow path on the outer side of the elastic spring is formed to face the side surface. The pushbutton switch according to any one of claims 1 to 4.

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