JPH0224925A - Push-button device - Google Patents

Abstract

PURPOSE:To hold key caps orderly on key tops provided on a key sheet by forcedly fitting the square key caps on the square key tops provided on the key sheet consisting of an elastic material in such a manner that respective projecting ribs and a cylindrical recessed hole of the key top are elastically deformed in the fitting process. CONSTITUTION:A key sheet 1 consists of an elastic material such as rubber, and is integrally provided with square key tops 2. On the four side faces of the key top 2 there are provided projecting ribs 3 in both side parts thereof, and the outer extremity portion of the rib 3 is formed to have a curved surface 3a becoming narrower when approaching the extremity. Further, a cylindrical recessed hole 2a is provided in the top surface of the key top 2 in the axial direction, and a cylindrical projection 2b is provided on the bottom surface with its central axis being same with that of the key top 2. On the other hand, the key cap 4 consists of plastic, etc., and is formed in a square shape in accordance with the key top 2. The key cap 4 is forcedly fitted on the key top 2 by elastically deforming the projecting ribs 3 and the recessed hole 2a thereof in a compressed state. Thus, the key caps are held orderly on the key tops provided on the key sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a 1773-type button device, and particularly to a structure for fitting and holding a keycap on a keypad 7 placed on a key sheet.

2. Description of the Related Art Conventionally, the configuration shown in FIGS. 5 and 6 has been known in order to completely retain a keycap on the key top of a key sheet.

In the conventional example shown in FIG. 5, a key cap 53 is fitted onto a key top 52 of a key sheet 51 made of an elastic material such as rubber, and a key is inserted into a recessed hole 54 formed in the center of the key top 52. The protrusion 55 of the cap 53 is press-fitted, and the key camp 53 is held on the key top 52.

In the conventional example shown in FIG. 6, a key camp 53 is forcibly fitted to a key top 52 of a key sheet 51 by fully utilizing the elastic deformation of the key top 52, and the key cap 53 is held by the key top 52. .

Problems to be Solved by the Invention However, among the conventional examples described above, in the configuration shown in FIG. 5, the key cap 53 can be held on the key top 52 relatively smoothly, When illuminating from the back of the cap 53, the effect is weakened by the projections provided on the inside, and the key cap 53 is painted. :, f) There are problems such as the inability to perform masking treatment on the inner surface of the key camp 53 during plating. Further, in the configuration shown in FIG. 6, dimensional accuracy between the key top 52 of the key sheet 51 and the key cap 53 is required, and even small variations in manufacturing may make it impossible for the key cap 53 to fit into the key top 52. Or, conversely, Keycamp 5
There was a problem that the fitting of No. 3 to the key top 52 was loose, and the key camp 53 could come off from the key top 52.

To solve the above problem, the key cap 53 may be loosely fitted into the key top 52 of the key sheet 51 as shown in FIG. 7, but in this configuration, the gap between the key cap 53 and the key top 52 is large. , the center of the key cap 53 tends to shift from the center of the key top 52 in various directions, and
As shown in the figure, it becomes irregular with respect to the case 56, resulting in a very unsightly appearance. Furthermore, since the key tops 52 and key caps 53 of the key sheet 51 cannot be integrated, there are problems such as poor workability during assembly.

In addition, in order to solve the above problem, as shown in FIG. 9, a protrusion 56 may be provided on the key top 52 of the key sheet 51, and the key top 52 of the key sheet 51 may be elastically deformed to be forcibly fitted.
In this configuration, when the key cap 53 is fitted, the stress is concentrated in one direction of the key top 52, that is, on the 17 surfaces that are not covered by the key camp 53, so as shown in FIG. This is directly transmitted to the switch 57 located under the seat 51, resulting in a phenomenon in which the switch 57 malfunctions. This requires extremely high dimensional accuracy for various component parts and workability during assembly, which cannot be fully grasped in the design, so a cut-and-try type of work is required, resulting in loss to the design. The problem was that it was big.

The present invention solves one or more of the conventional problems, and can easily be attached to the key top of all key camp key sheets.
It can be held reliably and orderly, and it also absorbs small variations in manufacturing and assembly work, eliminating design losses.
In addition, masking processing during painting, plating, etc. can be easily performed, and the key cap is integrated with the key top of the key sheet, making the assembly process easier. The entire purpose is to do so.

Means for Solving the Problems In order to achieve all of the above objects, the present invention provides a key sheet made of an elastic material such as rubber, in which a rectangular key top is integrally provided with protrusions extending along the axial direction on four sides thereof, and A cylindrical recessed hole is provided in the axial direction on the top surface of the key top, and a cylindrical protrusion is provided on the top bottom surface of the same center axis with respect to the key top of the key sheet, and a rectangular key cap is provided on the key top. Each protrusion, recessed hole, and cylindrical protrusion are all elastically deformed and forcibly fitted.

Effects The present invention has the following effects due to the above configuration. In other words, by forcibly fitting the entire keycap to the keytop of the key sheet, a protrusion is formed along the axial direction on the four sides of the keytop, and a cylindrical column is formed on the top surface of the keytop in the axial direction. The recesses are elastically deformed into a compressed state, and the keycap can be held integrally with the key top due to their repulsive elasticity. The contact area between the protrusion and the keycap is narrow, and the cylindrical recessed hole allows the stress during fitting to be absorbed by the recessed hole, which allows the keycap to almost align with the center of the key top and prevent it from shifting. By making use of the elastic deformation of the cylindrical protrusion on the bottom of the cylindrical recessed hole, the operating stroke of the keycap can be lengthened, creating extra length for vertical dimensional changes during assembly, and completely preventing switch malfunctions. I can do it. Also, protrusions from the inner surface of the key camp can be eliminated.

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

1 to 4 show the entire punch type button device in one embodiment of the present invention, FIG. 1 is a perspective view, FIG. 2-1,
FIG. 2-2 is a sectional view, FIG. 3 is a perspective view of the key sheet, and FIG. 4 is a plan view of an example of the overall arrangement.

In this embodiment, the key sheet 1 is made of an elastic material such as rubber, and a rectangular key top 2 is integrally provided, and the key sheet 1 is made of an elastic material such as rubber. Projections are integrally provided along the axial direction on both sides of the west side surface of the 7p2. The outer tip of each protrusion is formed into a curved surface 3a that gradually becomes narrower toward the tip. Further, a recessed hole 2a is provided in the upper surface of the key top 2 in a cylindrical shape in the axial direction. Recessed hole 2a
As shown in Fig. 2-1 and Fig. 2-2, a through hole or a hole stopping in the middle can be considered. Furthermore, a cylindrical projection is provided on the bottom surface of the key top 2 and the same center axis.

On the other hand, as shown in Figures 2 and 3, the key camp 4
is made of plastic or the like and is formed into a rectangular shape corresponding to the key top 2. As shown in FIGS. 2 and 3, this key camp 4 is forcibly fitted by elastically deforming the protrusion 3 and the recessed hole 2a of the key top 2 into a fully compressed state, and the protrusion 3 and the recessed hole 2a are forcibly fitted together. The keycap 4 is held on the key top 2 by the repulsion. At this time, the keycap 4 comes into contact with the protrusion 3, so the contact area is small, and it is easily elastically deformed by the recessed hole 2a, and as described above, the keycap 4 gradually becomes narrower as it reaches the outside of the tip of the protrusion 3. Since the curved surface 3a is formed in such a manner that the key cap 4 can be easily fitted to the key top 2.

Then, as described above, the elastic deformation of the protrusion 3 and the recessed hole 2a
Since the keycap 4 is fully retained by making full use of its elastic deformation,
The key cap 4 can be held securely, and since the protrusions 3 are provided on the west side of the key top 2, the center of the key cap 4 is almost aligned with the center of all key tops 2, preventing it from shifting. As shown in FIG. 4, each keycap 4 can be arranged in an orderly manner on the case 5. In addition, as shown in Fig. 11, variations in the dimensions of the inner surface of the keycap 4 that fits into the key top 2 and variations in assembly work are absorbed by the elastic deformation of the recessed hole 2a and the cylindrical protrusion 2b. So switch 5
7 malfunctions can be prevented. Further, since no protrusions are required on the inner surface of the key camp 4, masking processing during painting, plating, etc. can be easily performed. Furthermore, since the key cap 4 is integrated with the key top 2 of the key sheet 1, when assembling these to the case 5,
All the work can be done easily.

Effects of the Invention As described above, according to the present invention, protrusions extending along the axial direction are provided on all four sides of the rectangular key top of the key sheet made of an elastic material such as rubber; A cylindrical recessed hole is provided along the axial direction, and the rectangular keycap is elastically deformed by the above-mentioned protrusions and recessed hole to forcibly fit into the keycap. Moreover, the center of the key camp can be made to almost coincide with the center of all the key tops to prevent them from shifting, and the keys can be held in an orderly manner. In addition, the contact area between the keycap and the protrusion is small,
Since there is a cylindrical recessed hole, it can be easily held on all key tops of the key camp. In addition, dimensional variations in the keycap and variations in assembly work can be absorbed by elastic deformation in the cylindrical recessed hole and the cylindrical protrusion, thereby preventing malfunction of the switch. Furthermore, when lighting is performed using a key sheet, since there are no protrusions inside the key cap, masking processing during painting, plating, etc. can be easily performed. Furthermore, since the key cap can be held integrally with the key top of the key sheet, assembly work efficiency can be improved.

[Brief explanation of the drawing]

1 to 4 show a push-button device according to an embodiment of the present invention, in which FIG. 1 is a perspective view, FIG.
Figure 2 is a sectional view, Figure 3 is a perspective view of the key sheet, Figure 4 is a plan view of the overall arrangement, and Figures 5, 6, and 7 each show a conventional push button device. Sectional view, No. 8
The figure is a plan view of the overall arrangement example according to the conventional example shown in Fig. 7.
9 and 10 are cross-sectional views showing the arrangement relationship with the switch in a conventional example, and FIG. 11 is a cross-sectional view showing how the key top absorbs variations in parts and work in the above-mentioned embodiment of the present invention. It is a diagram. 1...Key sheet, 2...Key top, 2a...Cylindrical recessed hole, 2b...Cylindrical protrusion, 3... Projection, 4... Name of keycap agent Patent attorney Shige Takashi Awano and one other person Figure B No. 8

Claims (1)

[Claims] A rectangular key top placed on a key sheet made of an elastic material is integrally formed with protrusions along the axial direction on the four sides thereof, a cylindrical recessed hole is provided in the top surface of the key top, and a cylindrical recessed hole is provided in the bottom surface of the key top. A push button device characterized in that a cylindrical projection is provided in the same axial direction, and a rectangular keycap is forcibly fitted to the key top by elastically deforming each of the projections and the cylindrical recess.