JPH03194811A - Push-button switch - Google Patents

Abstract

PURPOSE:To make a device compact and thin without degradation of the operation feeling of a key top by relatively moving an actuator to a guide cylinder and a stem respectively at the time of pushing operation of the key top. CONSTITUTION:An actuator 7, which can slide freely to a stem 4b of a key top 4 and a guide cylinder 3a of a housing 3, is interposed between the stem 4 and the guide cylinder 3a. Consequently, a sliding distance can be made nearly two times, and a height dimension of a push button switch can be shortened, maintaining the sliding feeling at a degree as same as the conventional one. Since a contact of a membrane switch 2 is pushed by an elastic pushing piece 7c formed integrally with the actuator 7, diameter dimensions of the stem 4b and the guide cylinder 3a can be reduced. A space, in which a click rubber 8 can be housed, is thereby secured outside of the guide cylinder 3a to make the push button switch compact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] 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 relates to a push button switch suitable for thinning.

[Conventional technology]

FIG. 11 is a sectional view showing a conventional example of this type of push button switch. In the figure, 1 indicates a reinforcing plate made of a hard material such as metal, and a membrane switch 2 is placed on this reinforcing plate 1. has been done. This membrane switch 2 includes an upper sheet 2b having a movable contact 2a, a lower sheet 2d having a fixed contact 2c, and these upper and lower sheets 2b, 2d.
It is composed of a spacer 2e laminated in between. A housing 3 made of synthetic resin is placed on the membrane switch 2, and a guide cylinder 3a of a ring rod and a protrusion 3b located outside the housing 3 are integrally molded. A stem 4a hanging vertically from the top surface of a key top 4 made of synthetic resin is slidably inserted into the inner wall 3c of the guide tube 3a, and a coil spring 5 is tightly fitted into the stem 4a. It is installed by Furthermore, a flat surface 3d is formed between the guide cylinder 3a and the protrusion 3b of the housing 3, and a return spring 6 is interposed between the flat surface 3d and the top surface of the key top 4. It is set up. Although not shown, cutout grooves are formed in the protruding portion 3b in the direction perpendicular to the paper surface of FIG. 11, and the key top 4 moves up and down within these cutout grooves. An engaging claw is provided, and when this engaging claw comes into contact with the upper end of the notch groove, the housing 3 of the key top 4
Prevents it from falling off.

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

In the non-operating state shown in FIG. 11, the key top 4 is located at the highest stroke point where the engaging pawl (not shown) comes into contact with the upper end of the notch groove due to the elastic force of the return spring 6. Since the lower end of the spring 5 is spaced apart 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 with each other.

From this state, the operator returns the key top 4 to the spring 6.
When the key top 4 is pushed in against the elastic force, the outer wall of the stem 4a descends along the inner wall 3C of the guide cylinder 3a, and the key top 4 is moved to the lowest stroke point. In this case, stem 4a
The coil spring 5 held by the coil spring 5 comes into contact with the upper sheath 2b and is gradually compressed, so the elastic force of the coil spring 5 causes the upper sheath 2b to bend, causing the movable contact 2a to contact the fixed contact 2C.
The membrane switch 2 is switched from OFF to ON state by contacting .

When the pressing operation force on the key top 4 is removed in this ON state, the key top 4 rises to the highest stroke point shown in FIG. 11 due to 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.

[Problem to be solved by the invention]

By the way, in this type of push button switch, stem 4
By inserting the key top 4 into the inner wall 3c of the guide tube 3a and making it slide into contact with the inner wall 3c of the guide tube 3a, the key top 4 is held in the housing 3 so as to be able to move up and down. Attempts have been made to reduce the height dimension of the guide tube 3a, but in that case, the amount of insertion of the stem 4a into the guide tube 3a inevitably becomes smaller, and the distance between the two required during sliding is reduced. Due to the small clearance between the key top 4 and the housing 3,
In particular, when the operator presses the edge of the key top 4 into a so-called end push, the stem 4a gets caught in the guide tube 3a, resulting in an extremely poor operating feel.

The present invention was made in view of the above circumstances, and its purpose is to provide a key top without deteriorating the operating feel of the key top.
An object of the present invention is to provide a push button switch that can be made smaller and thinner.

[Means to solve the problem]

To achieve the above object, the present invention includes a housing having a guide tube, a key top having a stem, and a return spring interposed between the housing and the key top, and the stem is connected to the guide tube. In a push-button switch that switches contacts by moving up and down along It is characterized by the following structure.

[Effect]

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

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are cross-sections V of a push-button switch according to the first embodiment of the present invention viewed from different directions, FIG. 3 is a cross-section showing the press operation state of the push-button switch, and FIG. 4 is an exploded perspective view of the push button switch, and the first button switch described above is
Components corresponding to those in FIG. 1 are given the same reference numerals.

In these figures, 7 indicates an actuator, and the actuator 7 includes a hollow cylindrical portion 7a, a connecting portion 7b extending horizontally from the bottom of the cylindrical portion 72, and a flat surface integrally formed at one end of the connecting portion 7b. A projection 7d for pressing the contact point 6B of the non-blind switch 2 is formed in a part of the elastic pressing piece 7C. The cylindrical portion 7a is a guide tube 3a of the housing 3.
The connecting portion 7b is inserted into a guide groove 3e formed in the housing 3 so as to cross the guide cylinder 3a, and the elastic pressing piece 7C
is arranged in a space defined between the housing 3 and the membrane switch 2.

On the other hand, the top surface of the key top 4 has a solid stem 4b,
Engagement 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 tough, and the engaging claw 4C
The key top 4 is prevented from falling off from the housing 3 by coming into contact with the upper end of the notched groove 3f formed in the protrusion 3b. Further, a click rubber 8 is interposed between the housing 3 and the key top 4. This click rubber 8 is formed in the shape of an inverted dome 12, 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 periphery of the guide tube 3a.

The remaining structures such as the reinforcing plate 1 and the membrane switch are the same as those of the conventional example described above.

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

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

From this state, when the operator pushes the key top 4 against the elastic force of the click rubber 8, the click rubber 8 is reversed with a click sensation, and the key top 4 is lowered, as shown in FIG. In this case, first, the stem 4b descends inside the cylindrical portion 7a, and when the top surface of the key top 4 comes into contact with the upper end of the cylindrical portion 7a, the cylindrical portion 7a moves against the inner wall of the guide tube 3a.
Descend along C. When the cylindrical part 7a descends in this way, the elastic pressing piece 7C moves along with the descending of the connecting part 7b.
is gradually bent, and the contact portion of the membrane switch 2 is pressed by the protrusion 7d, thereby switching from the off state to the on state.

When the pressing operation force on the key top 4 is removed, the key top 4 rises to the highest stroke point shown in FIG. 2 due to the elastic force of the click rubber 8 and the elastic pressing piece 7C, so that the membrane switch 2 changes from the on state to the off state. Switched to.

As described above, in the above embodiment, the actuator 7 is provided between the stem 4b of the key top 4 and the guide tube 3a of the housing 3, and is slidable with respect to the stem 4b and the guide tube 3a, respectively. As a result, compared to conventional products in which the stem slides directly onto the guide tube, the sliding distance can be approximately doubled.In other words, while maintaining the same sliding feel as conventional products, The height of the push button switch can be shortened. In addition, since the contact part of the membrane switch 2 is pressed by the elastic pressing piece 7C integrally molded on the actuator tough, the diameter of the stem 4b and guide tube 3a can be reduced compared to conventional products that use coil springs. Can be made smaller. Therefore, a space is secured outside the guide tube 3a in which the click rubber 8 can be stored, and the push button switch can be made smaller.

FIG. 5 is a sectional view showing a non-operating state of a push button switch according to a 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 parts are given the same reference numerals.

This embodiment differs from the first embodiment described above in that the actuator 7 is constructed by outserts an elastic pressing piece 7C made of an elastic metal plate into a connecting portion 7b made of synthetic resin, and the rest of the structure is The operation is similar.

7 and 8 are cross-sectional views of a push-button switch according to a third embodiment of the present invention viewed from different directions, FIG. 9 is a cross-sectional view showing the push-button switch in a pressed state, and FIG. It is a perspective view of an actuator provided in the push button switch, and parts corresponding to those in FIGS. 1 to 4 are given the same reference numerals.

In the case of this embodiment, the actuator 7 has a protrusion 7d on the lower end.
a hollow cylindrical portion 7a having a hollow cylindrical portion 7a, first and second leg pieces 7e and 7f extending in crank shapes in opposite directions from the upper end of the cylindrical portion 7d, and these first and second leg pieces 7e and 7.
It is provided with retaining parts 7g and 7h provided at the tips of f, and a stopper protrusion 71 provided vertically on a part of the second leg piece 7f. The click rubber 8 is attached to the housing 3 and both leg pieces 7e and 7f.
The retaining portions 7g and 7h are interposed between the key top 4 and the top surface of the key top 4. Further, the stopper protrusion 7N
is adapted to move up and down within a stopper groove 3g provided in the housing 3, and prevents the actuator tough from falling off from the housing 3. The rest of the configuration of this embodiment is the same as that of the first embodiment, and the explanation thereof will be omitted.

In the push button switch configured in this way, No. 7.8
When the operator presses the key top 4 from the non-operating state shown in the figure, the cylindrical part 7a first descends on the inner wall of the guide tube 3a, the click rubber 8 is reversed, and then the stem 4b moves down as shown in FIG. The first and second leg pieces 7e and 7f bend as they descend on the inner wall of the cylindrical part 7a, and the contact part of the membrane switch 2 is pressed against the protrusion 7d by the reaction force, thereby switching from the off state to the on state. When the pressing force on the key top 4 is removed, the elastic force of the click rubber 8 and the leg pieces 7e and 7f causes the key top 4 to rise to the highest stroke point shown in FIG. 8, and the membrane switch 2 is turned from on to on. state.

In this third embodiment, in addition to the effects of the first embodiment described above, since the protrusion 7d integrally formed at the lower end of the cylindrical portion 7a presses the contact portion of the member play switch 2, dimensional errors, deformation, etc. This has the effect of preventing contact malfunctions caused by. In addition, since a stopper protrusion 71 is formed on the actuator tough to prevent it from falling off from the housing 3,
Housing 3, actuator 7 and click rubber 8
These three parts can be made into semi-finished products, and assembly work efficiency can be improved.

In each of the above embodiments, a case has been described in which the click rubber 8 is used to return the key top 4, but it is also possible to use a coil spring instead and use it as a non-click push button switch.

〔Effect of the invention〕

As explained above, according to the present invention, the height can be shortened without reducing the swinging distance, and the diameter of the guide tube and stem can be reduced, thereby creating a push button switch suitable for downsizing and thinning. Can be provided.

[Brief explanation of drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention.
2 and 2 are cross-sectional views of the push-button switch in the non-operated state, respectively, viewed from different directions, FIG. 3 is a cross-sectional view showing the push-button switch in the pressed operation state, FIG. 4 is an exploded perspective view of the push-button switch, and FIG. The figure 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 to 10 are according to a third embodiment of the present invention. 7 and 8 are cross-sectional views of the push-button switch in the non-operated state, viewed from different directions, FIG. 9 is a cross-sectional view showing the push-button switch in the pressed-operated state, FIG. 10 is a perspective view of the actuator, and FIG. The figure is a sectional view of a conventional push button switch. 2... Membrane switch, 3...
...Housing, 3a...Guide tube, 4...Key top, 4b...
...Stem, 7...Actuator, 7a...Cylindrical portion, 7b...
...Connection part, 7c......Elastic pressure piece, 7d
・・・・・・Protrusion, 7e・・・・・・1st
Leg piece, 7f...Second leg piece, 7g, 7
h......Engaging part, 71......
Stopper protrusion, 8... River... Click rubber (return spring). Figure d b a e Figure Figure 7 Figure ia Figure e 0 to ia tc la ■

Claims (2)

[Claims] (1) A housing having a guide tube, a key top having a stem, and a return spring interposed between the housing and the key top, and by moving the stem up and down along the guide tube, the contact point can be adjusted. In the push-button switch for switching, an actuator is provided between the guide tube and the stem, and the actuator is slidable with respect to both, one end of the actuator is opposed to the key top, and the other end of the actuator is arranged to face the key top. A push button switch characterized in that an elastic pressing piece is provided for pressing the contact. (2) A housing having a guide tube, a key top having a stem, and a return spring interposed between the housing and the key top, and by moving the stem up and down along the guide tube, the contact point can be adjusted. In the push-button switch for switching, an actuator is provided between the guide tube and the stem, and the actuator is slidable with respect to both, and a pressing part for pressing the contact is provided at one end of the actuator. A push button switch characterized in that an elastic leg piece is provided at the other end to come into contact with the key top.