JP3195298B2 - 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 push button switch used as a key switch or the like of a keyboard device, and more particularly, to a key top supporting member via a key top holding member in which a pair of link members are connected in an X-shape. The present invention relates to a push button switch that is supported up and down freely.

[0002]

2. Description of the Related Art Conventionally, a push button switch of this type has been proposed in Japanese Utility Model Laid-Open No. 2-5236. In the push button switch disclosed in the publication, a key top is supported on a printed board as a support so as to be able to move up and down via a key top holding body, and a click rubber is provided between the key top and the printed board. I have. The key top holding body is composed of a pair of link members bridging between a pair of parallel leg pieces at a connecting portion, and a central portion of each leg piece of both link members is crossed in an X shape so as to be rotatable. Are linked. An upper holder is fixed to the back surface of the keytop, the upper end of one link member is rotatably engaged with an engagement recess provided in the upper holder, and the upper end of the other link member is provided in the upper holder. It is slidably engaged with the slide groove. Also, a pair of lower holders are fixed on the printed circuit board, the lower end of one link member is rotatably engaged with an engagement recess provided in one lower holder, and the lower end of the other link member is the other. Slidably engaged with a slide groove provided in the lower holder.

When the operator pushes the keytop against the resilience of the click rubber, the two link members rotate in the engagement recess and slide along the slide groove when the operator presses the keytop against the elasticity of the click rubber. Therefore, the crossing angle of each leg connected in an X-shape changes, and the keytop descends accordingly. When the key top is lowered by a predetermined amount, the click rubber buckles to generate a click feeling, and the movable contact provided on the inner top surface of the click rubber comes into contact with the fixed contact provided on the printed circuit board, thereby turning off. Is switched from ON to ON.

[0004]

As described above, in the above-described conventional push button switch, a key top holding member in which a pair of link members are connected in an X-shape is used, and the key top is connected via the key top holding member. Since the key top is supported on the support so as to be able to move up and down, it has the advantage that the key top can be stably pressed without rattling as compared with a push button switch of the type in which the key top moves up and down by sliding the stem and the guide cylinder. .

[0005] However, since the crossing angle of both link members changes as the key top moves up and down, one end of each link member must be slidably engaged with the key top or the support. In the above-described conventional push button switch, a slide protrusion provided at an upper end of one link member is sandwiched between a key top and an upper holder, and a slide protrusion provided at a lower end of the other link member is connected to a support (printed circuit board). Each end of both link members is slidably engaged with the key top and the support by being sandwiched between the lower holders, but the number of parts increases because the upper holder and the lower holder are required. There has been a problem that the assembling work is complicated.

[0006]

In a push button switch according to the present invention, a first link portion in which a pair of leg pieces extend parallel to each other.
Material and a second link in which a pair of leg pieces extend parallel to each other
A member, and the second link inside the first link member.
The center of each leg intersects in an X-shape with the clip members placed
A key top holder rotatably connected to the key top, a key top supported on the support via the key top holder so as to be movable up and down, and an elasticity for urging the key top upward. Switching of the contacts by raising and lowering the member and the key top
And a switch element to be performed , wherein the first and second
A shaft is provided at the center of either leg of the link member
And make a hole in the center of either leg
The two link members of the first link member are elastically deformed outward.
With this, the shaft portion and the hole are snap-in-coupled to each other.
The key top holder and the first link
This is achieved by elastically deforming both legs of the
The slide projection provided on the free end side of these leg pieces is
Snap-in connection was made to the slide groove provided in the holding body .

With this configuration, the second link member
The two leg pieces of the first link member arranged outside
Elastic deformation allows snap-in between shaft and hole
When combined, each leg of the first and second link members
The key top holder whose central part is connected in an X shape can be easily
Can be assembled.

[0008] In this way, the key top protection
After assembling the holding body, this time, both legs of the first link member
By elastically deforming the legs inward, the legs
The slide protrusion provided on the end side is provided on the support
If you snap-in the slide groove, you can already snap
Each leg to prevent the hole and the in-joined shaft from coming off
The connected state of the pieces can be reliably maintained .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the internal structure of a push button switch according to an embodiment of the present invention, FIG. 2 is a sectional view of the push button switch in an off state, FIG. 3 is a sectional view of the on state of the push button switch, and FIG. FIG. 5 is an exploded perspective view of the key top holding body incorporated in the push button switch, FIG. 5 is an exploded perspective view of the key top holding body, and FIGS. 6A to 6D are explanatory views of the operation of the key top holding body.

In these figures, reference numeral 15 denotes a base plate made of a hard material such as a metal plate, on which a membrane switch 16 is mounted. The membrane switch 16 has a flexible upper sheet 17.
The movable contact 18 provided on the lower surface of the lower sheet 19 is opposed to the fixed contact 20 provided on the upper surface of the lower sheet 19.
This is a switch element in which a spacer 21 is provided between 7, 7. Reference numeral 22 denotes a synthetic resin housing serving as a support.
8, a pair of inward slide grooves 22b and a pair of outward slide grooves 22c for slidably engaging a slide protrusion of a key top holder described later are provided. It is. further,
Reference numeral 23 denotes a key top made of a synthetic resin held up and down above the housing 22 so as to be able to move up and down.
An engagement recess 23a for rotatably engaging a rotation projection of a key top holder described below is provided on the back surface of the key top holder. Then, on the housing 22, a click rubber 24 which generates a click feeling when the side wall 24a buckles is formed with a skirt-like side wall 24a capable of buckling deformation and is shaped to support the drive unit 24b. The driving portion 24 b of the click rubber 24 is positioned above the movable contact 18.

Reference numeral 25 denotes a key top holder made of a synthetic resin. As is apparent from FIGS. 4 and 5, the key top holder 25 includes a substantially E-shaped link member 26 and a substantially U-shaped link member 27. Are combined. Here, one of the link members 26 has a pair of pivotal projections, each of which has an outward slide projection 29a at the distal end and an inward connection pin 29b at a substantially central portion from both ends of the support shaft 28. An external leg piece 29 is extended in parallel, and an operation piece 30 shorter than the external leg piece 29 is extended from the center of the support shaft 28. The support shaft 28 is provided with an engagement recess 23a of the key top 23. And supports and fixes one side of the back surface of the key top 23. The operation piece 30 is an elastic piece having some flexibility against external force in the thickness direction. When the key top holder 25 is incorporated in the housing 22, the tip of the operation piece 30 is Is always in elastic contact with the top surface of the drive unit 24b. The other link member 27 is parallel to and inwardly crosses the outer leg piece 29 from both ends of the support shaft 31 which is also a rotation protrusion,
A pair of inner leg pieces 32 each having an inward slide projection 32a at a distal end thereof and a substantially heart-shaped elongated hole 32b at a substantially central portion.
The support shaft 31 is rotatably fitted to another engagement recess 23 a of the key top 23, and supports and fixes the other side of the back surface of the key top 23. Then, the connection pins 29b are loosely inserted into the long holes 32b by snap-in using the inclined surface 32c on the upper portion of the long holes 32b, and the corresponding outer leg pieces 29 and inner leg pieces 32 are respectively inserted.
Are connected so that the connecting pin 29b is movable along the long hole 32b, so that both link members 26 and 27 are connected.
Are integrated into a key top holder 25. Therefore, this key top holder 25 is
6 (a) to 6 (c), when a pressing operation force is applied to the support members and the support shafts 28, 31 of the link members 26, 27 are pushed downward.
As shown in (d), the angle at which the outer leg piece 29 and the inner leg piece 32 intersected and connected in a substantially X-shape gradually increases as viewed from the key top 23 side, and the key top holder 25 The two link members 26 and 27 can be folded so that the height dimension of the link members gradually decreases.

However, the key top holder 25 is attached to the support shaft 28 of the outer link member 26 by the inner link member 2.
7 is set so that the inner leg pieces 32 do not abut. Specifically, the distance D from the elongated hole 32b to the support shaft 28 is set to the length from the elongated hole 32b to the tip of the inner leg piece 32. L
(See FIG. 6). Therefore,
Both link members 26, 27 can be folded until the outer leg piece 29 and the inner leg piece 32 fall down to the side.

When the key top holder 25 is attached to the housing 22, the outward slide projections 29a of the outer leg pieces 29 are respectively turned inward by snap-in using the inclined surface 22d shown in FIG. And the inward slide protrusions 32a of the respective inner leg pieces 32 are loosely inserted into the outward slide grooves 22c by snap-in using the inclined surface 22e shown in FIG. . That is, each outer leg piece 29
It is elastically deformed inward and the outward slide projection 29a is moved inward.
While snapping into the slide groove 22b of the orientation,
Each inner leg piece 32 is elastically deformed outward and slides in the direction
Snap the projection 32a into the outward slide groove 22c.
On. As a result, the slide projections 29a and 32a are slidably engaged with the slide grooves 22b and 22c, respectively, so that the position of the outside of each of the external leg pieces 29 and the inside of each of the internal leg pieces 32 is regulated by the housing 22. Become. When the key top holder 25 is incorporated in the housing 22 in this manner, the driving portion 24b of the click rubber 24 previously incorporated in the housing 22 elastically contacts the distal end of the operation piece 30. Member 26
Of the link member 27 is urged upward, and the inner link member 27 is
Is also urged upward.

As shown in FIG. 1, the housing 22 has a protrusion 22 at a position obliquely opposed to the slide groove 22b.
f is provided, and the key top holding body 25 is
2, the rear side of the slide projection 29 a at the tip of the outer leg piece 29 is close to the projection 22 f, so that the slide projection 29 a comes off the slide groove 22 b even when a strong external force such as an impact is applied. It has become difficult.

The push button switch configured as described above is
The support shafts 28, 31 of both link members 26, 27 of the key top holder 25 receive the resilience of the click rubber 24 to support both sides of the back surface of the key top 23. Since the outer leg piece 29 and the inner leg piece 32 of 26 and 27 are connected so that the angle at which they intersect with each other can be changed, and the position of each leg piece 29 and 32 is regulated by the housing 22, As a result, the key top 23 is held above the housing 22 so as to be able to move up and down.

Therefore, when the operator applies a pressing operation force to the key top 23 and pushes both support shafts 28 and 31 against the resilience of the click rubber 24, the two support shafts 28 and 31 are pressed.
Is rotated on the spot with the engaging recess 23a of the key top 23 as a fulcrum, and the respective slide protrusions 29a and 32a slide within the slide grooves 22b and 22c of the housing 22, and are connected in a substantially X-shaped cross. External leg piece 2
9 and the inner leg piece 32 gradually increase the angle of intersection when viewed from the key top 23 side, and the operating piece 30 pushes the drive part 24b of the click rubber 24 downward accordingly. At the time of lowering, the side wall portion 24a buckles to generate a click feeling, and the driving portion 24b is pushed in vigorously and collides with the upper sheet 17 of the membrane switch 16, and as a result, the upper sheet 17 is The movable contact 18 is bent downward and contacts the fixed contact 20, and the switching from the off state shown in FIG. 2 to the on state shown in FIG. 3 is performed.

When the operator removes the pressing force on the key top 23 in the ON state, the buckled click rubber 24 returns to its original shape due to its own elasticity. The operation piece 30 is pushed up, and the two link members 2 thus folded are folded.
The key tops 23 are raised and the key tops 23 are pushed up to the initial position, the bending of the upper sheet 17 is eliminated, the movable contact 18 is separated from the fixed contact 20, and returns to the off state.

As described above, in the above-described embodiment, the key top holding member 25 formed by combining the pair of link members 26 and 27 is used.
The key top 23 is supported so as to be able to move up and down by using the key top 23, and the leg pieces 29, 32 of both link members 26, 27 whose crossing angle can be changed according to the height position of the key top 23 are mounted on the housing 2.
Because the position is regulated by 2, the key top 23 can be moved up and down straight and stably, and the parts that hinder the elevating operation of the key top 23 are less likely to be caught by each other. The push button switch has been greatly reduced in thickness without deteriorating its reliability.

In the above embodiment, the key top holder
When assembling the link member 25, the link member 26 arranged outside
By elastically deforming the two leg pieces 29 outward,
The pin 29b is snap-fitted into the slot 32b,
After assembling the key top holder 25 as described above,
Moves both leg pieces 29 of the link member 26 arranged outside
By elastically deforming the legs 29, these legs 29
The slide protrusion 29a provided on the end side is
At this time, snap-in connection was made to the groove 22b.
Pin 29b and long hole 32b snap-in
The connection state of each leg piece 29, 32 is confirmed.
Can be maintained indeed. Furthermore, each leg piece 29 , 32
When engaging the slide projections 29a, 32a of the outer leg 29 with the slide grooves 22b, 22c of the housing 22 ,
Together it is elastically deformed inwardly, because you so that <br/> is elastically deformed each inner leg 32 outwardly, the each leg piece 29, 32 X
The snap-in connection can be easily performed while maintaining the connection in the shape of a letter , and the slide grooves 22b, 22
The c to the housing 22 is a support Ru can be simplified the structure integrally provided.

Further, in the above-described embodiment, the connecting pin 29b provided on the outer leg piece 29 of one link member 26 is snapped into the elongated hole 32b provided on the inner leg piece 32 of the other link member 27. X of both link members 26 and 27
Since the key-top holder 25 can be formed in a letter shape, the assembling workability can be improved from this point as well.

In the above embodiment, the case where the membrane switch 16 is used as the switching element has been described. However, the switching element is formed by the movable contact provided inside the click rubber 24 and the fixed contact provided on the printed board. It may be configured.

[0022]

The present invention is embodied in the form described above, and has the following effects.

As a key-top holder for supporting the key-top on the support so as to be able to move up and down, slide protrusions are provided on the free ends of the legs of the first and second link members connected in an X-shape.
Part of the first link member disposed outside
By elastically deforming the outside, the center of each leg
Snap-in connection between the provided shaft and hole
Then, the two leg pieces of the first link member arranged on the outside are
By elastically deforming the leg
Snap-in part to slide groove provided in support
Then, the slide protrusion is snap-in connected to the slide groove
When you do, snap the shaft and hole that were previously connected in an X-shape
Since the connection can be prevented from being disconnected, the connection state of each leg piece
Can be reliably maintained .

[0024]

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the push button switch in an off state.

FIG. 3 is a cross-sectional view of the on state of the push button switch.

FIG. 4 is a perspective view of a key top holder incorporated in the push button switch.

FIG. 5 is an exploded perspective view of the key top holder.

FIG. 6 is an explanatory view of the operation of the key top holder.

[Explanation of symbols]

 Reference Signs List 16 Membrane switch (switch element) 22 Housing (support) 22b, 22c Sliding groove 23 Key top 23a Engaging recess 24 Click rubber (elastic member) 25 Key top holder 26 Link member (first link member) 27 Link member (Second link member) 28, 31 Support shaft (rotating protrusion) 29, 32 Leg piece 29a, 32a Sliding protrusion 29b Connecting pin (shaft) 32b Slot (hole)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-7441 (JP, A) JP-A-63-285828 (JP, A) JP-A-4-4531 (JP, A) 76224 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01H 13/14 H01H 13/20 H01H 13/70

Claims (1)

(57) [Claims] A first pair of leg pieces extending in parallel with each other;
Link member and a pair of leg pieces extending in parallel with each other.
2 and a link member inside the first link member.
With the second link member arranged, the center of each leg is
Key top holder rotatably connected by crossing in a letter shape
A key top supported on the support via the key top holding body so as to be able to move up and down, an elastic member for urging the key top upward, and contact of the contact by raising and lowering the key top.
A switch element for performing switching , wherein one of the first and second link members has a leg piece
A shaft is provided at the center of the
A hole is provided in the center, and both leg pieces of the first link member are removed.
The shaft portion and the hole are elastically deformed to the side.
Snap-in connection with the key top holder and without
In addition, both leg pieces of the first link member are elastically deformed inward.
By providing the free ends of these legs
A push button switch , wherein a slide projection is snap- fitted to a slide groove provided in the support .