JPS5821458Y2 - Capacitive key switch assembly equipment - Google Patents

Description

[Detailed Description of the Invention] Conventionally, as shown in FIG. 1, there is a device of this type in which a return spring 19 is provided between the housing 2 and the push button 20. Unless they are attached, the housing 2, plunger 4, and spring 19 cannot be sub-assembled.

In addition, in the case shown in FIG. 2, the electrode plate 11 is first attached to the inside of the diaphragm 22 on the printed circuit board 1, and this is fixed on the printed circuit board 1. Meanwhile, the plunger 4 is inserted from below the housing 2, and the plunger 4 is inserted into the housing 2. The printed circuit board 1
A button 20 is fixed on the top of the plunger 4.
However, without the printed circuit board 1, the parts cannot be sub-assembled, and as shown in FIG.

This idea attempts to eliminate these shortcomings.
In particular, the switch can be sub-assembled without the pushbutton being attached to the plunger, and one embodiment of this invention will be described below with reference to the drawings.

That is, a guide cylinder 3 is integrally molded into a housing 2 attached to a panel 21 on the printed circuit board 1, and a plunger 4 is slidably inserted into this guide cylinder.

This plunger has a pair of elastic legs 5, 5.
The leg consists of retainers 6, 6 that protrude outside the lower end of the leg and engage with the lower end of the guide tube 3, and engaging portions 7, 7 provided at the lower end of the guide tube 3. Recesses 8, 8 are formed on opposite sides of the parts.

Further, a collar 9 is fixed to one end of the plunger 4, that is, to the upper side.

On the other hand, a fixed electrode 10.10 is provided on the printed circuit board 1, and a movable electrode 11 faces this electrode.

This movable electrode is made up of a metal plate 12 made of a rigid material such as brass or aluminum, a cushion 13 made of sponge rubber or the like adhered to the lower part of the metal plate 12, and a plastic film 14 adhered to the lower surface of the cushion. This film is made of a material with a high dielectric constant, such as a Mylar sheet, to be very thin, and a conductive metal is vapor-deposited on the surface that contacts the cushion 13.

Further, a pair of holes 15, 15 are provided in the metal plate 12 at a predetermined distance from each other, that is, in this embodiment, at a distance approximately equal to the distance between the recesses 8, 8. With the bridge part 16 formed and the retaining parts 7, 7 inserted into the holes 15.15, the edges of the bridge part 16 are in the recess 8.
, 8.

A circular bank 17 is formed on the upper surface of the housing 2, and a groove 18 is formed between this bank and the guide tube 3.

A return spring 19 is accommodated in this groove, one end of which abuts against the upper surface of the housing 2, and the other end abuts against the lower surface of the collar 9, respectively.

A push button 20 is provided at one end, that is, the upper end of the plunger 4.
are fitted.

The above configuration can be assembled in the following manner.

First, with the spring 19 fitted into the plunger 4, the legs 5.5 of the plunger 4 are bent so as to approach each other, and the plunger 4 is inserted into the guide cylinder 3 from above the housing 2.

When the retainers 6, 6 protrude below the guide cylinder 3, the legs 5.5 expand outward due to their elasticity, and at the same time, the plunger 4 is pushed upward by the biasing force of the spring 19, thereby preventing the retainer from coming out. The pins 6, 6 abut against the lower end of the guide tube 3, and the plunger 4 is prevented from coming off upward.

Next, when the plunger 4 is pressed downward, the legs 5, 5 protrude from the guide cylinder.

This state means that when a force is applied to the legs 5, 5 in a direction away from each other, that is, outwardly, they can open against the elasticity of the legs.

Therefore, in this state, when the retaining parts 7, 7 are inserted into the holes 15.15 of the movable electrode 11 below the housing 2, the bridge parts 16 are moved into the recesses 8, 8 by the elasticity of the legs 5, 5.
engage with.

In this state, the legs 5, 5 can no longer bend inward due to the presence of the bridge portion 16, and there is no risk that the plunger 4 will come off from the housing 2.
By removing the pressing force, the housing 2, plunger 4, movable electrode 11, and spring 19 are finely assembled to each other.

When this assembly is completed, the movable electrode 11 is set to be placed at a position higher than the lower end of the housing 2 by a predetermined distance because it is necessary to secure a predetermined movable range.

Note that the detailed assembly described above is performed on the movable electrode 11 in the process of mass production.
is placed on a table having a predetermined thickness, and the housing 2 is placed on this so as to cover the electrode.
This is done by placing a spring 19 on top, and then inserting the plunger 4 through the spring 19 and pushing it into the guide cylinder 3 from above.

Further, when the thin assembly assembled in this manner is assembled as a keyboard, a necessary button 20 is fitted to the head of the plunger 4, and this is attached to a panel 21.

This idea connects the spring 19 to the housing 2 as described above.
and the plunger 4, insert the plunger 4 into the housing 2, prevent the plunger 4 from coming out, and engage the electrode plate 11 with the retaining parts 7, 7 below the housing 2. By combining the housing 2, plunger 4, spring 19 and electrode plate 11
Since the buttons 20 are assembled in detail in advance, the assembly process is as easy as an elbow, and the button 20 can be easily replaced.

[Brief explanation of drawings]

Figures 1 and 2 are front sectional views showing a conventional switch;
FIG. 3 is a front sectional view showing an embodiment of this invention, and FIG. 4 is an exploded perspective view. 2... Housing, 3... Guide tube, 4
...Plunger, 7...Engagement part, 1
1...Movable electrode, 19...Spring, 20...Button, 6...Removal retainer.

Claims (1)

[Scope of utility model registration request] A guide tube 3 formed in the housing 2, a plunger 4 slidably inserted into the guide tube and provided with a pair of elastic legs 5.5, and a plunger 4 provided with a pair of elastic legs 5.5, which protrude outside the ends of the legs 5. the retainers 6, 6 that engage with the lower end of the guide tube 3, the push button 20 that is attached to one end of the plunger 4, the movable electrode 11 that faces the fixed electrode 10, and the plunger 4. A retaining part 7 is provided at the other end and engages with a hole 15 provided in the movable electrode 11 to attach the movable electrode to the plunger 4, and one end is attached to the housing 2 and the other end is attached to the A spring 19 is provided which is engaged with a collar 9 provided at one end of the plunger 4, and the other end of the plunger 4 is guided while the spring 19 is positioned between the housing 2 and the collar 9. Tube 3
After that, the plunger 4 is prevented from being removed by the engagement between the stopper 6 and the guide cylinder 3, and the retaining part 7 is inserted into the hole 1 below the housing 2.
5, the housing 2, plunger 4, spring 19, and electrode 11 can be sub-assembled in advance.