Push button switch component

Abstract

To provide a push button switch component that can maintain reliable grounding even after a pusher portion is grounded and a dome portion connected to the pusher portion has completed deformation, thereby realizing normal switch operation.SOLUTION: A push button switch component 1 includes a base portion 10, a first dome portion 11, a key top 12, a second dome portion 14, and a pusher portion 15. The second dome portion 14 extends from a connection portion 21 with the pusher portion 15 toward the outside in the radial direction of the pusher portion 15 and is connected to the key top 12. The second dome portion 14 is connected to the inner surface of the key top 12 and is formed such that an upper portion 14c of the second dome portion 14 faces the inner surface with a gap 22 therebetween. The second dome portion 14 is formed such that the upper portion 14c is most easily deformed between the key top 12 and the pusher portion 15.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a member for a push-button switch.

Background Art

[0002] Conventionally, as a switch for various devices such as in-vehicle devices, communication devices, audio devices, and household electrical appliances, a member for a push-button switch including a pressing portion, a dome portion, and a base portion has been known (see, for example, Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] FIG. 4 shows a longitudinal sectional view and a plan view seen from above of a member for a push-button switch prototyped by the inventor of the present applicant prior to the present invention.

[0005] The member 100 for a push-button switch includes an annular base portion 110, a key top 112 disposed inside the base portion 110 in the radial direction, and a first dome portion 111 connected to the base portion 110 from a position in the middle of the key top 112 in the vertical direction. The member 100 for a push-button switch is made of a conductive rubber-like elastic body. The rubber-like elastic body has a conductive filler such as graphite kneaded therein. The first dome portion 111 is a dome-shaped member protruding outward. The key top 112 is a cylindrical member penetrating downward from its top surface. The member 100 for a push-button switch includes a thin second dome portion 114 extending downward from the bottom peripheral edge of the key top 112 inside the first dome portion 111 in the radial direction. The second dome portion 114 is located below the key top 112 and is a straight dome portion in a longitudinal sectional view. The member 100 for a push-button switch includes a pusher portion (contact portion) 115 below the second dome portion 114. The pusher portion 115 is disposed above the bottom surface of the base portion 110. That is, the second dome portion 114 and the pusher portion 115 are in a state of being suspended downward from the key top 112. The key top 112 is held above the inside of the base portion 110 in the radial direction by the first dome portion 111. According to the member 100 for a push-button switch having such a structure, when the key top 112 is pressed downward from its top surface, the pusher portion 115 descends and contacts a plurality of contacts (not shown) on a substrate disposed below the pusher portion 115 to turn the switch on or off.

[0006] FIG. 5 shows the change of the push-button switch member when pressed downward from the top surface side of the key top of the push-button switch member in FIG. 4. FIG. 5(a) is a longitudinal sectional view of the state of the push-button switch member when not pressed downward from the top surface side of the key top (the state of P1 in FIG. 6). FIG. 5(b) is a longitudinal sectional view of the state of the push-button switch member during downward pressing from the top surface side of the key top (the state of P2 in FIG. 6). FIG. 5(c) is a longitudinal sectional view of the state of the push-button switch member at the final stage of downward pressing from the top surface side of the key top (the state of P3 in FIG. 6). FIG. 6 shows a graph in which an F-S curve representing the relationship between the stroke (the displacement of the upper surface of the key top after pressing with reference to the upper surface of the key top before pressing) and the dome load when the key top in the push-button switch member in FIG. 4 is pressed, and an F-S curve representing the relationship between the stroke and the contact pressure load generated when grounded to a substrate or the like are superimposed.

[0007] As shown in FIG. 6, in the push-button switch member 100, as the key top 112 is pressed downward from its top surface, the outer first dome portion 111 gradually deforms and moves the pusher portion 115 downward. Thereafter, the bottom surface of the pusher portion 115 contacts the substrate (P1→P2). Since the first dome portion 111 does not undergo buckling deformation, no click feeling is generated for the user. When further pressed after the pusher portion 115 contacts the substrate, the second dome portion 114 withstands the pressing and undergoes buckling deformation when reaching a certain load (also referred to as the peak load) (between P2 and P3). This buckling deformation generates a click feeling for the user. After the deformation of the first dome portion 111 and the second dome portion 114 is almost completed, as the stroke increases due to pressing, the dome load rapidly increases (after P3).

[0008] However, as shown in FIG. 6, after P3, even when the dome load rapidly increases, there is a situation where the contact pressure load does not increase but decreases. This is due to the following reasons. The second dome portion 114 has a shape with a decreasing wall thickness in the downward direction. Therefore, when the second dome portion 114 buckles, the second dome portion 114 bends outward from the thin-walled portion near the pusher portion 115 and becomes more likely to contact the substrate. As a result, the pressing force from the key top 112 is dispersed to the contact portion between the pusher portion 115 and the substrate and the contact portion between the second dome portion 114 and the substrate.

[0009] As a result, after the key top 112 is pressed downward to generate a click feeling, the contact pressure load from the pusher portion 115 to the substrate becomes weak, increasing the possibility of conduction failure. Such a decrease in the contact pressure load leads to switch failure and is not preferable.

[0010] An object of the present invention is to provide a member for a push-button switch that can maintain reliable grounding even after the deformation of the dome portion connected to the pusher portion is completed after the grounding of the pusher portion, thereby realizing a normal switch operation to solve the above problems.

Means for Solving the Problems

[0011] (1) A member for a push-button switch according to an embodiment for achieving the above object includes a base portion, a key top disposed inside the base portion in a plan view and above the bottom surface of the base portion, a thin-walled first dome portion connecting the side surface of the key top and the base portion, a pusher portion disposed inside the first dome portion, below the key top and floating above the base portion, a thin-walled second dome portion connecting the key top and the pusher portion inside the first dome portion, and is a member for a push-button switch. The first dome portion and the second dome portion are deformable in response to downward pressing from the key top and are elastically recoverable upon release of the pressing. The key top is a cylindrical member that penetrates from its top surface to its bottom surface, or a member having a recess at least on the bottom surface side. The second dome portion extends radially outward of the pusher portion from the connection portion with the pusher portion and is connected to the key top. The second dome portion is connected to the inner surface on the bottom surface side of the key top and is formed so as to face the upper portion of the second dome portion with a gap interposed between the inner surface and the second dome portion. The second dome portion is formed such that the upper portion is most easily deformable between the key top and the pusher portion. (2) In the member for a push-button switch according to another embodiment, preferably, the second dome portion may have a shape in which the wall thickness increases in a tapered shape between the connection portion with the key top and the connection portion with the pusher portion. (3) In the member for a push-button switch according to another embodiment, preferably, the second dome portion may be configured to undergo buckling deformation after the pusher portion makes contact, due to downward pressing from the top surface of the key top.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a member for a push-button switch that can maintain reliable contact even after deformation of the dome portion connected to the pusher portion is completed after the pusher portion makes contact, thereby enabling a normal switch operation.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Explanation of Reference Numerals

[0014] 1... Member for push-button switch, 10... Base portion, 11... First dome portion, 12... Key top, 14... Second dome portion, 14c... Upper portion, 15... Pusher portion, 20, 21... Connection portions, 22... Gap.

Mode for Carrying Out the Invention

[0015] Next, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are essential for the solution means of the present invention.

[0016] FIG. 1 shows a longitudinal sectional view (a) and a plan view (b) seen from above of a member for a push-button switch according to an embodiment of the present invention. FIG. 2 shows a change in the member for a push-button switch when it is pressed downward from the top surface side of the key top of the member for a push-button switch of FIG. 1. FIG. 2(a) is a longitudinal sectional view of the state of the member for a push-button switch when not pressed downward from the top surface side of the key top (the state of P1 in FIG. 3). FIG. 2(b) is a longitudinal sectional view of the state of the member for a push-button switch during pressing downward from the top surface side of the key top (the state of P2 in FIG. 3). FIG. 2(c) is a longitudinal sectional view of the state of the member for a push-button switch at the final stage of pressing downward from the top surface side of the key top (the state of P3 in FIG. 3).

[0017] The member 1 for a push-button switch according to this embodiment includes a base portion 10, a key top 12, a first dome portion 11, a second dome portion 14, and a pusher portion 15. In this embodiment, the base portion 10 is an annular plate-like member in plan view, but is not limited to such a shape. The base portion 10 may be, for example, a square frame-like member in plan view. The key top 12 is disposed inside the base portion 10 in plan view and above the bottom surface of the base portion 10. In this embodiment, the key top 12 is a cylindrical member penetrating from the top surface to the bottom surface. However, the key top 12 may be a member having at least a concave portion on the bottom surface side. Therefore, the key top 12 may have a shape opening to the bottom surface side or a shape opening to both the bottom surface side and the top surface side. The first dome portion 11 is a thin dome portion connecting the side surface (preferably the outer surface) of the key top 12 and the base portion 10. In this embodiment, the first dome portion 11 is a dome-shaped member curved so as to protrude radially outward of the member 1 for a push-button switch in a longitudinal sectional view. The pusher portion 15 is disposed below the key top 12 and floating above the base portion 10 inside the first dome portion 11 in the radial direction.

[0018] The key top 12 is connected to a thin second dome portion 14 sandwiched between an outer wall 14a and an inner wall 14b inside the first dome portion 11 in the radial direction. The second dome portion 14 is configured to connect the key top 12 and the pusher portion 15. By providing the second dome portion 14 inside the first dome portion 11, the size of the member 1 for a push-button switch in plan view can be made compact. In this way, by disposing the second dome portion 14 in the space inside the first dome portion 11, a small-sized member 1 for a push-button switch that effectively utilizes the space can be constructed.

[0019] The second dome portion 14 extends radially outward from the connection portion 21 with the pusher portion 15 and is connected to the key top 12. More specifically, the second dome portion 14 extends radially outward from the connection portion (the connection portion between the second dome portion 14 and the pusher portion 15) 21 with the pusher portion 15 and is connected to the key top 12. The connection portion 20 between the second dome portion 14 and the key top 12 is present on the inner surface of the cylindrical key top 12. Further, the second dome portion 14 is formed such that the upper portion 14c of the second dome portion 14 faces the inner surface of the key top 12 with a gap 22 therebetween. In addition, the second dome portion 14 is formed such that the upper portion 14c is most easily deformable between the key top 12 and the pusher portion 15. More specifically, the upper portion 14c that is above the second dome portion 14 and faces the inner surface of the key top 12 with the gap 22 therebetween is formed to be the thinnest between the connection portion 20 and the connection portion 21 of the second dome portion 14. However, the connection portion 20 itself does not necessarily have to be the thinnest.

[0020] The upper portion 14c of the second dome portion 14 is a region that faces the inner surface of the cylindrical or concave key top 12. It is not necessary for the thickness of the upper portion 14c to be the smallest among the thicknesses of the second dome 14 over its entire region. It is sufficient that only a part of the region of the upper portion 14c is the smallest among the thicknesses of the second dome 14.

[0021] Also, the connection portion 21 between the second dome portion 14 and the pusher portion 15 is preferably the thickest among all regions of the second dome portion 14. After the pusher portion 15 comes into contact with the ground due to the pressing from the top surface of the key top 12, the second dome portion 14 tries to deform but cannot withstand the pressing. At this time, if the thickness of the connection portion 21 is large, the risk of the second dome portion 14 bending from the vicinity of the connection portion 21 is greatly reduced. As a result, the second dome portion 14 starts to deform above the connection portion 21. Such deformation effectively prevents the second dome portion 14 from coming into contact with the substrate.

[0022] The second dome portion 14 preferably has a shape in which the wall thickness increases in a tapered shape between the connection portion 20 with the key top 12 and the connection portion 21 with the pusher portion 15. That is, in a longitudinal sectional view, the second dome portion 14 has a shape that flares out so that the thickness T2 on the base portion 10 side (i.e., the downward direction when the push-button switch member 1 is fixed on the substrate) is larger than the thickness T1 on the top surface side of the key top 12 (i.e., the upward direction when the push-button switch member 1 is fixed on the substrate) (see FIG. 1). Here, the thickness T1 and the thickness T2 are the distances from the outer wall 14a perpendicular to the outer wall 14a to the inner wall 14b. The recess 13 formed by the upper opening 13b of the through-hole of the cylindrical key top 12, passing through the second dome portion 14, and the top surface 13a of the pusher portion 15 has a shape in which the inner diameter decreases from the upper opening 13b toward the top surface 13a. In this embodiment, the shape of the recess 13 is a substantially frustum shape with the top surface 13a being circular (small circle) and the upper opening 13b being circular (large circle). The outer wall 14a and the inner wall 14b of the second dome portion 14 are straight (flat or nearly flat) and inclined with respect to the vertical direction. The second dome portion 14 is a so-called straight dome. In the present application, the shape of the "dome" does not matter whether it is curved or linear in a longitudinal sectional view of the push-button switch member 1. Therefore, both the first dome portion 11 and the second dome portion 14 are dome-shaped members.

[0023] The upper portion 14c of the second dome portion 14 (i.e., the upper portion on the top surface side when the push-button switch member 1 is fixed on the substrate) is preferably located above the upper portion 11a of the first dome portion 11 (i.e., the upper portion on the top surface side when the push-button switch member 1 is fixed on the substrate).

[0024] With such a configuration, when the top surface of the key top 12 is pressed, the second dome portion 14 deforms a part of it radially inward (see Fig. 2(c)). When the upper portion 14c of the second dome portion 14 can no longer withstand the pressure, it may deform so as to move radially outward of the second dome portion 14. However, the inner surface of the key top 12 facing the upper portion 14c with a gap 22 therebetween functions as a stopper for the outward movement of the upper portion 14c. For this reason, the upper portion 14c does not bulge outward beyond the inner surface. As a result, after deformation, the second dome portion 14 becomes less likely to come into contact with the ground. Further, since the second dome portion 14 in this embodiment is a straight dome as described above, it buckles suddenly when the pressure from the top surface of the key top 12 exceeds a predetermined magnitude. The second dome portion 14 has a thickness such that it is difficult to deform in the vicinity of the connection portion 21 while making it easy to deform the upper portion 14c. Therefore, even when the second dome portion 14 buckles, it can concentrate the pressure on the pusher portion 15 without a part of it coming into contact with the ground. Moreover, the buckled second dome portion 14 contacts a pusher (= a member that presses the top surface of the key top 12) that presses down the key top 12 (see Fig. 2(c)). Thereby, the contact pressure from the pusher portion 15 to the substrate increases. As a result, the contact pressure between the pusher portion 15 and the substrate can be maintained, contributing to the stabilization of the switch operation.

[0025] In this embodiment, the first dome portion 11 is a dome portion that gradually deforms by the pressure from the top surface of the key top 12 and can elastically return to its original shape by releasing the pressure. Also, in this embodiment, the second dome portion 14 is a dome portion that buckles by the downward pressure from the top surface of the key top 12 following the deformation of the first dome portion 11 and can elastically return to its original shape by releasing the pressure.

[0026] In this embodiment, the member 1 for the push-button switch is preferably entirely made of a rubber-like elastic body. Examples of the rubber-like elastic body preferably include thermosetting elastomers such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR), or styrene butadiene rubber (SBR), thermoplastic elastomers such as urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, fluorine-based elastomers, or composites of the above. Among these exemplified rubber-like elastic bodies, silicone rubber is particularly preferred. Further, in order to make the rubber-like elastic body itself a member with high conductivity, it preferably contains a graphite filler or a filler of a metal with excellent conductivity such as aluminum or SUS. Such a filler with high conductivity occupies, for example, 5 to 50% by volume, preferably 10 to 30% by volume, based on the volume of the member for the push-button switch.

[0027] When not containing a filler with high conductivity in the rubber-like elastic body, it is preferable to fix a plate made of graphite, metal, etc. as a contact point (contact point for the switch) to the bottom surface of the pusher portion 15. Thereby, the contact point for the switch fixed to the pusher portion 15 contacts a plurality of contact points (contact points for the substrate) on the substrate. In this way, the switch can be turned on or off.

[0028] (Method and Results of Measuring Dome Load and Contact Pressure) After embedding the measurement tip terminal (contact part) into the through-hole of the measurement plate, a test object equipped with a push-button switch member (measurement KEY) was placed on the measurement plate (not shown), a dome load measurement load cell (not shown) was arranged above the test object, and a contact pressure measurement load cell (not shown) was arranged below the test object. As the measurement conditions, the ambient temperature was 25 °C, and the measurement speed of the dome load measurement load cell (the lowering speed of the push-pull gauge) was set to 1 mm / sec. The stroke (displacement) when the key top 12 was pressed from above the push-button switch member 1,100 by the dome load measurement load cell, the dome load generated on the upper surface of the key top 12 of the push-button switch member 1, and the contact pressure load generated on the pusher part (contact part) 15 when grounded to the substrate or the like were measured.

[0029] Figure 3 shows a graph in which the F-S curve representing the relationship between the stroke (displacement) and the dome load when the key top 12 of the push-button switch member 1 in FIG. 1 was pressed by implementing the above measurement method, and the F-S curve representing the relationship between the stroke and the contact pressure load generated when grounded to the substrate or the like are superimposed. In FIG. 3, as a comparative example, the F-S curve of the push-button switch member 100 prototyped by the inventor of the present applicant prior to the present invention (represented as "conventional" in FIG. 3) is also shown. In the graph of FIG. 3, "dome F-S (solid line)" indicates the behavior of the dome load of the push-button switch member 1. "Contact pressure F-S (dashed line)" indicates the behavior of the contact pressure load of the push-button switch member 1. "Conventional dome F-S (dash-dotted line)" indicates the behavior of the dome load of the push-button switch member 100. "Conventional contact pressure F-S (double dash-dotted line)" indicates the behavior of the contact pressure load of the push-button switch member 100.

[0030] In the present application, "dome peak" indicates the maximum value of the load immediately before the second dome part 14 of the push-button switch member 1 buckles and deforms. "Contact pressure peak" indicates the maximum value of the contact pressure load before the second dome part 14 buckles in the state where the pusher part 15 of the push-button switch member 1 is grounded. Here, "dome load" means the load applied to the top surface of the key top in the switch pressing operation. Also, "contact pressure load" means the load applied to the lower surface of the grounded pusher part 15 in the switch pressing operation.

[0031] (Operation of the member 1 for the push-button switch) The operation of the member 1 for the push-button switch will be described below with reference to FIGS. 1 to 3. When the key top 12 in the non-pressed state P1 (see FIG. 2(a)) is pressed from its top surface, first, the first dome portion 11 is gradually deformed, and the bottom surface of the pusher portion 15 comes into contact (grounds) with the substrate that fixes the member 1 for the push-button switch, resulting in the state P2 (see FIG. 2(b)). Between P1 and P2, since the increase in the dome load with respect to the stroke is small, the pressing operation can be performed with a small pushing resistance. After the bottom surface of the pusher portion 15 comes into contact with the substrate, the second dome portion 14 resists the continuous downward pressing. When a predetermined pressing force (about 1.6 N in this embodiment) is exceeded, a part of it buckles and deforms so as to be located radially inward of the second dome portion 14 (between P2 and P3). This buckling deformation gives the operator a click feeling. After the deformations of the first dome portion 11 and the second dome portion 14 occur, as the pushing stroke increases (after P3: see FIG. 2(c)), the dome load rapidly increases.

[0032] On the other hand, when comparing the member 1 for push-button switch according to this embodiment with the member 100 for push-button switch developed previously (see FIG. 4), a significant difference is observed in the behavior of the contact pressure load. As shown in FIG. 3, when comparing the two contact pressure F-S curves of the contact pressure load of the member 1 for push-button switch and the contact pressure load of the member 100 for push-button switch, as the dome load decreases after the second dome portion 14 undergoes buckling deformation (after the dome peak in FIG. 3), the contact pressure loads of the member 1 for push-button switch and the member 100 for push-button switch also decrease (between the dome peak in FIG. 3 and P3). When the dome load of the member 1 for push-button switch rapidly increases after P3, the contact pressure load of the member 1 for push-button switch increases. This is because until the second dome portion 14 completes buckling deformation, the second dome portion 14 begins to bend in the region of the upper portion 14c of the pusher portion 15 and becomes in a state where it is difficult to move radially outward of the pusher portion 15. As a result, the second dome portion 14 deforms so as not to contact the substrate. In particular, since the vicinity of the connection portion 21 where the second dome portion 14 is connected to the pusher portion 15 has a relatively large thickness among the second dome portion 14, it is possible to hold the second dome portion 14 upright against pressing.

[0033] On the other hand, for the member 100 for push-button switch, even when the dome load of the member 100 for push-button switch rapidly increases after P3, the contact pressure load decreases. This is because the second dome portion 114 contacts the ground after undergoing buckling deformation, preventing the pressing force from the key top 12 from concentrating on the pusher portion 115 (see FIG. 5(c)).

[0034] When the dome load rises rapidly after P3, the contact pressure load of the member 1 for the push button switch is higher than that of the member 100 for the push button switch (L is the difference in contact pressure load after P3 between the member 1 for the push button switch and the member 100 for the push button switch: refer to the double-headed arrow in Fig. 3). More specifically, in the member 1 for the push button switch, the contact pressure load at the time of P3 is about 0.4 N and then rises to about 0.8 N. On the other hand, in the member 100 for the push button switch, the contact pressure load at the time of P3 is about 0.4 N, but then it drops to about 0.3 N. Thus, even when the dome load rises rapidly after buckling deformation, the member 1 for the push button switch shows a contact pressure load (0.4 - 0.8 N) higher than the contact pressure (0.3 - 0.4) of the member 100 for the push button switch. By designing the form of the second dome portion 14 as described above, a sufficient contact pressure load can be obtained even after P3, and the risk of contact failure can be reduced or eliminated.

[0035] (Other Embodiments) As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited thereto and can be implemented with various modifications.

[0036] In the above embodiment, the shape of the key top 12 is cylindrical. However, the shape of the key top 12 may be a concave shape with its top surface closed and opening downward. Also, the top surface 13a of the pusher portion 15 is flat at the center, but it may be formed in a non-planar shape (for example, convex upward or convex downward). The first dome portion 11 is a dome portion that gradually deforms by the pressing from the top surface of the key top 12, but it may also be a buckling deformation type dome portion that linearly inclines in a cross-sectional view. However, it is preferable to make the first dome portion 11 a dome portion that gradually deforms by the pressing from the top surface of the key top 12 in terms of lengthening the pushing stroke and obtaining a click feeling thereafter.

[0037] In the above-described embodiment, the second dome portion 14 has a shape in which the wall thickness increases in a tapered shape from the connection portion 20 with the key top 12 to the connection portion 21 with the pusher portion 15. However, the shape of the second dome portion 14 is not limited to a shape in which the wall thickness increases in a tapered shape. The shape of the second dome portion 14 may be a shape that draws a curve like a rafter from the connection portion 20 with the key top 12 to the connection portion 21 with the pusher portion 15. More preferably, the shape of the second dome portion 14 is a rafter shape that draws an arc toward the inner side in the radial direction of the second dome portion 14. Such a rafter-shaped second dome portion 14 is not buckled under the pressure from the top surface of the key top 12 and is easily deformed so as to gradually bend from the upper portion 14c located in the vicinity of the connection portion 20 with the key top 12.

[0038] Each component of the push-button switch member 1 described above can be arbitrarily combined. In particular, with respect to the push-button switch member 1 of claim 1, one or any two or more components among the components described in the claims subordinate to claim 1 can be added.

Industrial Applicability

[0039] The present invention can be used in industries that use switches.

Claims

1. A base portion, A key top disposed inside the base portion in a plan view and above the bottom surface of the base portion, A thin-walled first dome portion connecting a side surface of the key top and the base portion, Inside the first dome portion, a pusher portion that is disposed below the key top and floats above the base portion, A thin-walled second dome portion inside the first dome portion that connects the key top and the pusher portion, A member for a push button switch comprising: The first dome portion and the second dome portion are deformed in response to downward pressing from the key top and are elastically recoverable when the pressing is released, The key top is a cylindrical member that opens from its top surface to its bottom surface, or a member having at least a recess on the bottom surface side, The second dome portion extends radially outward of the pusher portion from a connection portion with the pusher portion and is connected to the key top, The second dome portion is connected to an inner surface on the bottom surface side of the key top and is formed so as to face an upper portion of the second dome portion with a gap interposed between the inner surface and the second dome portion, The second dome portion is formed such that an upper portion thereof is most easily deformed between the key top and the pusher portion. A member for a push button switch, characterized by this.

2. The second dome portion has a shape in which the wall thickness increases in a tapered shape between a connection portion with the key top and a connection portion with the pusher portion. The member for a push button switch according to claim 1, characterized by this.

3. The second dome portion is configured to undergo buckling deformation after the pusher portion makes contact with the ground when pressed downward from the top surface of the key top. The member for a push button switch according to claim 1 or 2, characterized by this.

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