JPH06103613B2 - Key top of push button switch - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key top of a push button switch, which has a small number of parts and is suitable for thinning and miniaturization.
Further, the present invention relates to a key top suitable for a push button switch having a drip-proof structure, which can be used as a key top with a display and can prevent moisture or water from the outside from entering the contact portion.

[0002]

2. Description of the Related Art In recent years, along with the miniaturization of electronic devices, there has been a demand for miniaturization and thinning of push button switches used in their operating parts. Many of these electronic devices are used in various environments, and there is a demand for a push button switch having a so-called drip-proof structure in which moisture or water is prevented from entering the contact portion from the outside.

To meet these demands, FIG.
There was a structure shown in. In FIG. 11, 61,6
Reference numeral 2 is a sheet on which a contact pattern is formed. The sheets 61 and 62 are arranged vertically with a spacer 63 interposed therebetween.
The contact pattern (movable contact) formed on the sheet 61 was formed on the sheet 62 via the click spring 68 by pressing the hinge-type key top 64 integrally formed with the panel 65 arranged on the upper portion of the sheet 61. The push button switch is configured so as to come into contact with the contact pattern (fixed contact).

In the push button switch having the above structure,
A drip-proof sheet 66 is provided between the sheet 61 and the key top 64 in order to prevent moisture and water that mainly enter the cabinet 65 from the key top side from permeating the switch contact portion. Seat 66 and cabinet 6 for drops
A rubber packing 67 is interposed between the 5 to form a drip-proof structure. FIG. 12 shows a rubber packing 67 and a drip-proof sheet 66.
It is a plan view showing the shape of.

[0005]

The push-button switch having the above-mentioned structure has a so-called drip-proof structure which prevents moisture and water from entering the contact portion from the outside. Since it requires a stroke, it is not suitable for slimming down, and because the key top 64 has a hinge mechanism with a predetermined length, it is not suitable for downsizing, and it is also a contact point for moisture or water entering from the outside. It was not perfect in terms of so-called drip-proof property of blocking penetration into the part.

The present invention has been made in view of the above points, has a small number of parts, is suitable for thinning and miniaturization, and can also be used as a key top with a display, and the structure of the key top itself is protected from moisture. It is an object of the present invention to provide a key top having a structure in which moisture and moisture do not easily enter.

[0007]

In order to solve the above-mentioned problems, the present invention provides a fixed contact, a movable contact, and a key top, which is arranged on the movable contact and which presses the movable contact. A key top of a push button switch provided, wherein a key top portion is located on an upper surface of a predetermined position of a resin film, and a loop-shaped holding portion is located on a lower surface, and the key top portion and the loop-shaped holding portion are formed on the resin film. In addition, it is integrally formed by resin molding through a plurality of holes provided along the loop-shaped holding portion, and the resin film is sandwiched between the key top portion and the loop-shaped holding portion in a watertight state.

[0008]

As described above, the key top portion and the loop-shaped pressing portion are integrally formed by resin molding through the resin film through a plurality of holes provided in the resin film along the loop-shaped pressing portion. Since the resin film is sandwiched in a watertight state by the loop-shaped pressing part, the number of parts is small, and the structure is thin and compact, and furthermore, the penetration of moisture and water from the outside through the space between the key top part and the resin film. Can be shut off.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are views showing a structure of a key top of a push button switch according to the present invention. FIG. 1A is a plan view and FIG.
-A sectional drawing and FIG.1 (c) are bottom views.

As shown in FIG. 1, the key top 12 has a key top portion 12b on the upper surface of the resin film 10 and a loop-shaped holding portion 12c on the lower surface. The loop-shaped pressing portion 12c is concentric with the outer periphery of the bottom surface of the key top portion 12b and is located directly below the key top portion 12b. As will be described in detail later, the key top portion 12b and the loop-shaped pressing portion 12c are integrally formed by resin molding through a plurality of holes provided in the resin film 10 along the loop-shaped pressing portion 12c. And loop-shaped foot 1
The resin film 10 is sandwiched by 2c in a watertight state. As the material of the key top 12, a polycarbonate resin or an acrylic resin which is a thermoplastic resin is used.

The pressing projection 12a for pressing the movable contact of the key top 12 is integrally provided with a loop-shaped pressing portion 12c which is separated from the center of the bottom surface of the key top 12. Since the pressing protrusion 12a that presses the movable contact is provided at a position apart from the core of the bottom surface of the key top portion 12 in this manner, it is necessary to dispose the contact portion below the center of the bottom surface of the pressing protrusion 12a. There is no. Therefore, if the light emitting element is disposed below the center of the bottom surface of the pressing protrusion 12a by using a material that allows light to pass through the key top, the surface of the key top can be made to stand out by the light from the light emitting element. That is, by printing a number, a symbol, or various symbols on the portion of the resin film 10 where the key top portion 12b is located, the number, symbol, or various symbols can be clearly seen from the key top portion 12b. Will be excellent. Further, in the above embodiment, the key top 12
The material was used as a translucent resin and was made to shine by the light emitting element, but it can be easily seen from the outside without making it shine by the issuing element.

FIG. 2 is a view showing a structural example of a push button switch using the key top 12 having the above structure. In the figure,
Reference numerals 16 and 17 denote sheets on which a movable contact pattern 16a and a fixed contact pattern 17a are formed, respectively, and the sheets 16 and 17 are stacked with the contact patterns 16a and 17a facing each other and a spacer 18 interposed therebetween. It is fixed to the lower part of the drop frame 11. Further, the click spring 1 is provided on the upper surface of the seat 16 where the contact pattern 16a is located.
9 is provided, and the protrusion 12a of the key top 12 is located on the upper portion thereof. A light emitting element 23 such as a light emitting diode is arranged below the center of the key top portion 12b.

Reference numeral 11 is a drip-proof frame 11 surrounding a plurality of key tops 12 in a watertight state with a resin film, as will be described later in detail. The key top 12 and the drip-proof frame 1
The assembly of 1 and the seats 16 and 17 is housed in a housing 15. The panel 14 is disposed on the top of the housing 15. The panel 14 is provided with a long protrusion 14a, and the long protrusion 14a is formed in the long groove 11 of the drip-proof frame 11.
It is fitted in a in a watertight state. As the material for the drip-proof frame 11, a thermoplastic or thermosetting synthetic resin is used. Further, in order to enhance the fitting in the watertight state, the material of the drip-proof frame 11 may be formed of an elastic styrene elastomer or polyester elastomer.

With the push button switch having the above structure, moisture and water permeating through the gap between the key top 12 and the panel 14 are fixed to the resin film 10 in a watertight state because the key top 12 and the drip-proof frame 11 are fixed in a watertight state. , Does not penetrate into the switch contact. Further, since the long groove 11a and the long projection 14a of the drip-proof frame 11 and the panel 14 are fitted in a watertight state as described above, the drip-proof frame 11 and the panel 14 are fitted together.
Water does not penetrate through the spaces. Therefore, this push button switch has a structure excellent in drip-proof property.

3 to 5 are views showing the structure of the operating portion 1 of the push button switch in which the drip-proof frame 11 and the key top 12 are resin-molded in a resin film. FIG. 3 is a plan view and FIG.
Is a sectional view taken along line AA of FIG. 3, and FIG. 5 is a sectional view taken along line BB of FIG. The drip-proof frame 11 has a plurality of key tops 1 as shown.
It is provided in a watertight state on the resin film 10 so as to surround 2 (six in the figure). More specifically, as shown in FIG. 5, the upper portion 11b and the lower portion 11 are sandwiched with the resin film 10 interposed therebetween.
c is formed, and a long groove 11a having a rectangular cross section is formed on the upper surface of the upper portion 11b. Further, a fixing member 13 for fixing to a substrate or the like is integrally formed on the lower surface of the drip-proof frame 11. Here, the drip-proof frame 11 is a loop-shaped upper part 1
The resin film 10 is sandwiched between 1b and the loop-shaped lower portion 11c, and the upper portion 11b and the lower portion 11c are only connected through the holes 20 shown in FIGS. It does not penetrate through between the resin films 10. That is, a watertight structure in which moisture and water do not penetrate between the resin film 10 and the drip-proof frame 11.

Next, a method of manufacturing the switch operating body 1 in which the drip-proof frame 11 and the key top 12 are integrally formed on the resin film 10 by resin molding will be described. FIG. 6 is a plan view showing the outer shape of the resin film 10. As shown in the figure, the resin film 10 has a rectangular shape, and a large number of holes 20 through which the molten resin passes at the time of molding are provided in the portion forming the drip-proof frame 11 at predetermined intervals. Further, in the portion forming the key top 12, a large number of holes 21 through which the molten resin passes are provided at predetermined intervals. Also, this key top 12
As shown in FIG. 7, a large number of small holes 21a and one large hole 21b are provided in a ring shape for forming the holes 21. The small hole 21a is located on the rib 12d of the key top 12, and the large hole 21b is located on the protrusion 12a of the key top 12. Further, a number or symbol or various symbols 24 are printed on the portion of the resin film 10 where the key top portion 12b is located. Further, in this printing, whether on the upper surface or the back surface of the resin film 10 on the key top side, the numbers or symbols or various symbols 24 can be clearly seen.

The key top 12 is formed by forming a gap 11 having the same shape as the key top portion 12b (see FIG. 1) as shown in FIG.
The upper die 105 having 0 and the annular holding portion 12c (see FIG.
(Refer to FIG. 3) and the lower die 106 having a gap 111 of the same shape, the resin film 10 is sandwiched between the protrusions 12 of the key top 12.
Pin gate 107 provided at a position located above a
By injecting the molten resin from the molten resin, the molten resin flows into the cavity (void) 110 of the upper mold 105, and
Lower mold 1 passing through holes 21b and 21a of resin film 10
It flows into the cavity 111 of 06. When the upper mold 105 and the lower mold 106 are removed while the resin is cured, the key top 12 is formed.

As shown in FIG. 9, the drip-proof frame 11 is formed in the same shape as the upper mold 101 and the lower frame 11c (see FIG. 5) having a gap 112 of the same shape as the upper frame 11b (see FIG. 5). By sandwiching the resin film 10 with the lower die 102 having the cavity 113 and injecting the molten resin from the pin gate 103, the molten resin passes through the resin reservoir 22 and the upper die 1
01 into the cavity 112, and then the resin film 1
It passes through the hole 20 of 0 and flows into the gap 113 of the lower mold 102. The upper mold 111 and the lower mold 102 with the resin being cured
By removing the, the drip-proof frame 11 is formed so as to surround a predetermined range of the resin film.

FIG. 10 is a view showing the structure of another key top of the push button switch of the present invention, FIG. 10 (a) is a plan view,
10B is a cross-sectional view (cross section AA), and FIG. 1C is a bottom view. The key top 12 of FIG. 10 differs from the key top 12 of FIG. 1 in that the key top 12 of FIG.
The pressing protrusion 12a for pressing the movable contact of the above is separated from the center of the lower portion of the key top portion 12b, and the loop-shaped pressing portion 12c is formed.
In contrast to the key top of FIG. 10, in the key top of FIG. is there. Since the pressing protrusion 12a is formed, the resin film 10 at the central portion of the key top 12 is cut out in a circular shape. The other points are the same.

The key top portion 12 of the key top 12
The shape of b is not limited to the above example, and it is needless to say that the plane does not have to be circular and may be rectangular or polygonal, for example. And in this case, the pressing portion 12
It is preferable that c is also a rectangular or polygonal loop in accordance with it. The shape of the drip-proof frame 11 is an example, and the shape is not limited to this. For example, drip-proof frame 1
If 1 is an elastic elastomer, the panel 14 may be flat, the surface of the drip-proof frame 11 may be a semi-cylindrical curved surface, and both may be pressed together. Panel 14 and drip-proof frame 11
However, the point is that a loop-shaped drip-proof frame may be resin-molded on the resin film so as to surround a predetermined range of the resin film to form a watertight state with the resin film.

[0021]

As described above, according to the present invention, the key top portion and the loop-shaped pressing portion are integrally formed by resin molding through a plurality of holes provided in the resin film along the loop-shaped pressing portion, Since the resin film is sandwiched between the key top and the loop-shaped retainer in a watertight state, it is possible to completely block the penetration of moisture and water from the outside through the space between the key top and the resin film, and a drip-proof push button switch. It is possible to provide a suitable key top. Further, it has an excellent effect that it has a small number of parts, is suitable for thinning and miniaturization, and can be used as a key top with a display.

[Brief description of drawings]

1A and 1B are views showing the structure of a key top of a push button switch of the present invention, FIG. 1A is a plan view, and FIG. 1B is A of FIG.
-A sectional drawing, FIG. 1 (c) is a bottom view.

FIG. 2 is a partial cross-sectional view showing the structure of a push button switch using the key top of the present invention.

FIG. 3 is a plan view of an operation portion of a push button switch including a resin film, a key top, and a drip-proof frame.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is a plan view of a drip-proof resin film.

FIG. 7 is a diagram showing a hole shape of a resin film in a key top forming portion.

FIG. 8 is a diagram for explaining a resin mold of a key top.

FIG. 9 is a diagram for explaining the resin mold of the drip-proof frame.

10A and 10B are views showing the structure of another key top of the push button switch of the present invention, FIG. 10A is a plan view, FIG. 10B is a sectional view taken along line AA of FIG. 10A, and FIG. ) Is a bottom view.

FIG. 11 is a cross-sectional view showing a structure example of a conventional push button switch having a drip-proof structure.

FIG. 12 is a plan view showing the shapes of a conventional rubber packing and a drip-proof sheet.

[Explanation of symbols]

 1 Switch operation body 10 Resin film 11 Drip-proof frame 12 Key top 13 Fixing member 14 Panel 15 Housing 16 Sheet 17 Sheet 18 Spacer 19 Click spring

Claims (4)

[Claims] 1. A key top of a push-button switch, comprising: a fixed contact, a movable contact, and a key top arranged on the movable contact and facing each other, the fixed contact and the movable contact facing each other. The key top portion is located on the upper surface of the predetermined position, the loop-shaped pressing portion is located on the lower surface, and the key top portion and the loop-shaped pressing portion are provided on the resin film along the loop-shaped pressing portion. A key top for a push button switch, wherein the key top portion and the loop-shaped holding portion sandwich the resin film in a watertight state by integrally forming the resin film through the hole. 2. The key top of the push button switch according to claim 1, wherein the pressing protrusion for pressing the movable contact of the key top is separated from the center of the lower part of the key top. A key top of a push button switch characterized by being integrally provided with. 3. The key top of the push button switch according to claim 2, wherein a number, a symbol, a symbol mark or the like is printed on a surface of the resin film on which the key top is located, and the key top is A key top of a push button switch, which is made of a translucent resin. 4. The key top of the push button switch according to claim 1, wherein a pressing protrusion that presses a movable contact of the key top penetrates the resin film in a substantially central portion below the key top portion. A key top of a push button switch characterized by being provided.