JP2641779B2 - Push button switch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push button switch used as a key switch of an input device such as a personal computer or a word processor, and particularly to a push button switch suitable for thinning.

[Conventional technology]

FIG. 11 is a cross-sectional view showing a conventional example of this type of push button switch. In the figure, reference numeral 1 denotes a reinforcing plate made of a hard material such as a metal, and a membrane switch 2 is mounted on the reinforcing plate 1. Is placed. The membrane switch 2 includes an upper sheet 2b having a movable contact 2a, a lower sheet 2d having a fixed contact 2c, and a spacer 2e laminated between the upper and lower sheets 2b, 2d. A housing 3 made of a synthetic resin is mounted on the membrane switch 2, and an annular guide cylinder 3a and a protruding portion 3b located outside thereof are integrally formed on the housing 3. On the inner wall 3c of the guide cylinder 3a, a stem 4a suspended from the top surface of the synthetic resin key top 4 is slidably inserted.
A coil spring 5 is mounted in the stem 4a by strong fitting. Further, a flat surface 3d is formed between the guide tube 3a and the projecting portion 3b of the housing 3, and a return spring 6 is provided between the flat surface 3d and the top surface of the key top 4.
Is interposed. Although not shown, the eleventh
A cutout groove is formed in the protruding portion 3b in a direction perpendicular to the plane of the drawing, while the key top 4 is provided with an engagement claw that moves up and down in the notch groove. By contacting the upper end of the notch groove, the dropping of the key top 4 from the housing 3 is prevented.

Next, the operation of the push button switch configured as described above will be described.

In the non-operation state shown in FIG. 11, the key top 4 is located at the highest point of the stroke where the not-shown engaging claw abuts on the upper end of the notch groove due to the elastic force of the return spring 6. Since the lower end of the coil spring 5 is separated from the upper sheet 2b, the membrane switch 2 is in an off state in which the movable contact 2a and the fixed contact 2c are not in contact.

In this state, when the operator pushes the key top 4 against the elastic force of the return spring 6, the outer wall of the stem 4a descends along the inner wall 3c of the guide tube 3a, and the key top 4 is moved to the lowest stroke point. . In this case, since the coil spring 5 held by the stem 4a abuts on the upper sheet 2b and is gradually compressed, the upper sheet 2b is bent by the elastic force of the coil spring 5, and the movable contact 2a is connected to the fixed contact 2c. Upon contact, the membrane switch 2 is switched from the off state to the on state.

When the pressing operation force on the key top 4 is removed in the on state, the key top 4 is raised to the highest point of the stroke shown in FIG. 11 by the elastic force of the return spring 6, so that the bent upper sheet 2b is restored. Accordingly, the movable contact 2a is separated from the fixed contact 2c, and the membrane switch 2 is switched from the on state to the off state.

[Problems to be solved by the invention]

By the way, for this type of push button switch, the stem
By inserting the 4a into the inner wall 3c of the guide cylinder 3a and slidingly contacting the same, the key top 4 is held in the housing 3 so as to be able to move up and down, so that the push button switch can be made thin while securing a desired operation stroke. Attempts have been made to reduce the height dimension of the guide cylinder 3a, but in that case, the amount of insertion of the stem 4a into the guide cylinder 3a is necessarily reduced, and between the two required during sliding. Due to the minute clearance, the key top 4 is easily inclined with respect to the housing 3. In particular, if the operator
When the so-called end pushing that pushes the edge of the stem is performed, the stem 4a
However, there is an inconvenience that the user gets caught on the guide cylinder 3a and the operation feeling becomes extremely poor.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a push-button switch that can be reduced in size and thickness without deteriorating the operation feeling of a key top.

[Means for solving the problem]

In order to achieve the above object, the present invention includes a housing having a guide cylinder, a key top having a stem, and a return spring interposed between the housing and the key top. In the push-button switch for switching the contacts by moving up and down, an actuator slidably interposed between the guide cylinder and the stem is provided between the guide cylinder and the stem, and the contacts are pressed by the actuator. It is characterized by having comprised.

[Action]

According to the above means, when the key top is pressed, the actuator moves relative to the guide cylinder and the stem, so that the height dimension of the guide cylinder can be shortened without reducing the sliding distance. Is pressed, the diameter of the guide cylinder can be reduced.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 are cross-sectional views of the pushbutton switch according to the first embodiment of the present invention as viewed from different directions, FIG. 3 is a cross-sectional view showing a pressing operation state of the pushbutton switch, and FIG. FIG. 3 is an exploded perspective view of a push button switch,
Parts corresponding to those in FIG. 11 are denoted by the same reference numerals.

In these figures, reference numeral 7 denotes an actuator. The actuator 7 has a hollow cylindrical portion 7a, a connecting portion 7b extending horizontally from a lower portion of the cylindrical portion 7a, and a planar view D formed integrally with one end of the connecting portion 7b. Having a U-shaped elastic pressing piece 7c,
A projection 7d for pressing the contact portion of the membrane switch 2 is formed on a part of the elastic pressing piece 7c. The cylindrical part
7a is slidably inserted into the inner wall 3c of the guide tube 3a of the housing 3, and the connecting portion 7b is inserted into a guide groove 3e formed in the housing 3 so as to cross the guide tube 3a. The piece 7c is disposed in a space defined between the housing 3 and the main switch 2.

On the other hand, a solid stem 4b is provided on the top of the key top 4,
Engaging claws 4c facing each other via the stem 4b are vertically provided. The stem 4b is slidably inserted into the cylindrical portion 7a of the actuator 7, and the engaging claw 4c is
By contacting the upper end of the notch groove 3f formed in the
The dropping of the key top 4 from the housing 3 is prevented. Further, a click rubber 8 is interposed between the housing 3 and the key top 4. The click rubber 8 is formed in an inverted dome shape. The large diameter portion at the upper end is in contact with the top surface of the key top 4, and the small diameter portion at the lower end is inserted into the outer peripheral portion of the guide cylinder 3a. Other configurations such as the reinforcing plate 1 and the membrane switch are the same as those of the above-described conventional example.

Next, the operation of the pressing switch configured as described above will be described.

In the non-operating state shown in FIGS. 1 and 2, the key top 4 is positioned at the highest point of the stroke where each engaging claw 4c abuts the upper end of the corresponding notch groove 3f by the elastic force of the click rubber 8. At this time, the cylindrical portion of the actuator 7
Since 7a is not pressed by the key top 4, the membrane switch 2 is in the off state.

When the operator pushes the key top 4 against the elastic force of the click rubber 8 from this state, the click rubber 8 is inverted with a click feeling as shown in FIG. 3, and the key top 4 descends. In this case, first, the stem 4b descends in the cylindrical portion 7a, and when the top surface of the key top 4 contacts the upper end of the cylindrical portion 7a, the cylindrical portion 7a descends along the inner wall 3c of the guide cylinder 3a. And when the cylindrical portion 7a descends in this way,
The elastic pressing piece 7c is gradually bent with the lowering of the connecting portion 7b, and the contact portion of the membrane switch 2 is pressed by the projection 7d to be switched from OFF to ON.

When the above pressing force on the key top 4 is removed,
The key top 4 is raised to the uppermost point of the stroke shown in FIG. 2 by the elastic force of the click rubber 8 and the elastic pressing piece 7c, so that the membrane switch 2 is switched from the on state to the off state.

Thus, in the above-mentioned embodiment, the key top 4
Since the actuator 7 slidable with respect to the stem 4b and the guide cylinder 3a is interposed between the stem 4b of the housing 3 and the guide cylinder 3a of the housing 3, the stem is slid directly on the guide cylinder. The sliding distance can be approximately doubled as compared with the above, in other words, the height dimension of the push button switch can be shortened while maintaining the same sliding feeling as the conventional product. Also, an elastic pressing piece integrally formed with the actuator 7
Since the contact portion of the membrane switch 2 is pressed by 7c, the diameter of the stem 4b and the guide cylinder 3a can be reduced as compared with the conventional product using a coil spring.
For this reason, a space for storing the click rubber 8 is secured outside the guide cylinder 3a, and the push button switch can be downsized.

FIG. 5 is a sectional view showing a non-operation state of the push button switch according to the second embodiment of the present invention, and FIG. 6 is a perspective view of an actuator provided in the push button switch, corresponding to FIGS. 1 to 4. The same reference numerals are given to the same parts.

This embodiment differs from the first embodiment in that the actuator 7 is formed by outsert an elastic pressing piece 7c made of a metal elastic plate to a connecting portion 7b made of a synthetic resin. And the operation is the same.

7 and 8 are cross-sectional views of the push-button switch according to the third embodiment of the present invention as viewed from different directions, FIG. 9 is a cross-sectional view showing a pressing operation state of the push-button switch, and FIG. FIG. 5 is a perspective view of an actuator provided in the push button switch, and portions corresponding to FIGS. 1 to 4 are denoted by the same reference numerals.

In the case of this embodiment, the actuator 7 has a projection 7d at the lower end.
And a first and second leg 7 extending in a crank shape in opposite directions from the upper end of the cylindrical portion 7d.
e, 7f, engaging portions 7g, 7h provided at the distal ends of the first and second leg pieces 7e, 7f, and a stopper projecting piece 7i vertically provided on a part of the second leg piece 7f. It has. The click rubber 8 is interposed between the housing 3 and the two leg pieces 7e and 7f.
g and 7h are elastically urged to the top of the key top 4. Also,
The stopper projecting piece 7i moves up and down in a stopper groove 3g provided in the housing 3 to prevent the actuator 7 from dropping out of the housing 3. The remaining configuration of this embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

In the pushbutton switch configured as described above,
When the operator pushes down the key top 4 from the non-operation state shown in the figure, first, the cylindrical portion 7a descends on the inner wall of the guide tube 3a, and the click rubber 8 is inverted. Then, as shown in FIG. The first and second leg pieces 7e and 7f bend down the inner wall of 7a, and the contact force of the membrane switch 2 is pressed by the projection 7d by the reaction force, and is switched from off to on. When the pressing force on the key top 4 is removed, the click rubber 8 and both end pieces 7e and 7f are removed.
Due to the resilient force, the key top 4 rises to the uppermost point of the stroke shown in FIG. 8, and the membrane switch 2 is switched from the on state to the off state.

In the third embodiment, in addition to the effects of the above-described first embodiment, since the projection 7d integrally formed at the lower end of the cylindrical portion 7a presses the contact portion of the membrane switch 2, dimensional errors and deformations are caused. This brings about an effect that a malfunction of the contact caused by this can be prevented. Further, since the stopper 7 is formed on the actuator 7 to prevent the housing 3 from dropping off the housing 3, the housing 3, the actuator 7 and the click rubber 8 can be made into a semi-finished product, and the assembling workability can be improved.

In each of the above-described embodiments, the case where the click rubber 8 is used for returning the key top 4 has been described. However, a coil spring may be used instead, and the click rubber 8 may be used as a non-click push button switch.

〔The invention's effect〕

As described above, according to the present invention, it is possible to shorten the height without reducing the swinging distance and to reduce the diameter of the guide cylinder and the stem, and to provide a push button switch suitable for miniaturization and thinning. it can.

[Brief description of the drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention.
FIGS. 2 and 3 are cross-sectional views of the push-button switch in a non-operating state viewed from different directions. FIG. 3 is a cross-sectional view showing a pressing operation state of the push-button switch. FIG. FIG. 6 is a sectional view of a push button switch according to a second embodiment of the present invention, FIG. 6 is a perspective view of an actuator provided in the push button switch, and FIGS.
7 and 8 are cross-sectional views of the push-button switch in a non-operating state viewed from different directions, FIG. 9 is a cross-sectional view showing a pressing operation state of the push-button switch, and FIG. 10 is a view of the actuator. FIG. 11 is a perspective view, and FIG. 11 is a sectional view of a conventional push button switch. 2 ... Membrane switch, 3 ... Housing, 3a ...
Guide cylinder, 4 ... top, 4b ... stem, 7 ... actuator, 7a ... cylindrical part, 7b ... connecting part, 7c ... elastic pressing piece, 7d ... projection, 7e ... first leg piece , 7f ... second
7g, 7h ... engaging part, 7i ... stop projection, 8 ...
... Click rubber (return spring).

Claims (2)

(57) [Claims] A housing having a guide cylinder, a key top having a stem, and a return spring interposed between the housing and the key top, wherein the stem is moved up and down along the guide cylinder to form a contact. In a push button switch for performing switching, an actuator slidably interposed between the guide cylinder and the stem is provided between the guide cylinder and the stem, one end of the actuator is opposed to the key top, and the other end of the actuator is connected to the other end of the actuator. A push button switch comprising an elastic pressing piece for pressing a contact. 2. A housing having a guide cylinder, a key top having a stem, and a return spring interposed between the housing and the key top, wherein the stem is moved up and down along the guide cylinder to form a contact. In the push button switch for performing switching, an actuator slidably interposed between the guide cylinder and the stem is provided between the guide cylinder and the stem, and a pressing portion for pressing the contact is provided at one end of the actuator, and A push button switch comprising an elastic leg piece provided at the other end for contacting the key top.