JPS6137148Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key switch mechanism used in keyboard devices in typewriters, desktop calculators, processing units of electronic computers, and the like.

In general, portable computers etc.
A substantially bowl-shaped or mortar-shaped elastic member made of rubber or the like presses and urges the key top in a predetermined direction, and the key switch is switched as the elastic member deforms.
However, in a data entry keyboard device, the operating stroke of the key top must be relatively long (for example, about 4 mm), so special components are used in this type of key switch mechanism.

FIG. 1 shows this type of conventional key switch mechanism, in which a printed circuit board 3 is screwed to a post 1a of a base 1, and on the upper surface of this printed circuit board 3, that is, on the component mounting surface 3a, for example. A large number of key housings 4 are arranged in a row in all directions. That is, a pair of terminals 5 attached to this key housing 4 are connected to the through hole 3 of the printed circuit board 3.
c and is soldered to a predetermined wiring pattern 2, whereby the key housing 4 is mounted and fixed on the printed circuit board 3. Also, inside this key housing 4 is an elastic member 6 having a truncated conical shape.
is incorporated, and a conductive rubber member 7 is attached as a contact to the upper surface of the inside thereof.

On the other hand, an operating shaft 9 is integrally attached to the lower surface 8a of the key top 8, and this operating shaft 9 is supported by a bearing portion 4a of the key housing 4.
A compression coil spring 11 is attached to the operating shaft 9 between the key top 8 and the key housing 4, and when the key top 8 is pressed downward against the biasing force of the compression coil spring 11, the elastic The member 6 is elastically deformed and the conductive rubber member 7 comes into contact with the pair of terminals 5.
are short-circuited to perform a predetermined switching operation. In addition, in Figure 1, 12
is the operating shaft 9 in order to prevent the key top 8 and the operating shaft 9 from moving back due to the biasing force of the compression coil spring 11.
It is a retaining ring fixed to the tip of the

However, the key switch mechanism constructed in this way is constructed so that a sufficient movement stroke of the key top 8 and the operating shaft 9 can be obtained by using special members such as the key housing 4 and the compression coil spring 11. The disadvantage is that the number of parts and the number of assembly steps increase, resulting in higher costs. Moreover, since the above-mentioned special members are used, there is a disadvantage that the key switch mechanism inevitably becomes larger despite the progress in miniaturization of various electric circuit components. In addition, since the operating shaft 9 tends to rattle against the bearing 4a of the key housing 4, especially when the movement stroke of the key top 8 is lengthened, the pressing operation of the key top 8 cannot be performed smoothly, resulting in a poor operating feel. .

The present invention was devised in view of the above-mentioned circumstances, and allows for extremely smooth pressing operation without impairing the feeling of pressing the key top even when the key top movement stroke is long, and is inexpensive and compact. The present invention is intended to provide a structured key switch mechanism.

Next, an embodiment in which the present invention is applied to a key switch mechanism in a data entry keyboard device will be described with reference to FIGS. 2 to 7.

As shown in FIGS. 2 and 3, the keyboard device 15 has a large number of keytops 16 arranged at equal intervals in a line vertically and horizontally.
6 has two guide shafts 17 integrally attached to a pair of opposite corners of its lower surface 16a. Further, in the printed circuit board 18 screwed to the post 1a of the base body 1, through holes 20a and 20b for attaching guide members are arranged in a row in a row in correspondence with the key top 16, as shown in FIG. A guide member 23 is press-fitted into these through holes 20a, 20b as will be described in detail later.
A pair of guide shafts 17, which are integrally attached to mutually adjacent key tops 16 and are closest to each other, are respectively supported by a pair of guide holes 23a provided in this guide member 23 in the axial direction. It is becoming more and more guided by.

Further, an elastic member 26 is formed by providing elastic parts 24 having a substantially truncated cone shape (mortar shape) in a row in a vertical and horizontal manner corresponding to the key top 16, and integrally connected to each other by a connecting part 25. It is disposed between the upper surface of the key top 18, that is, the wiring pattern surface 18a, and the lower surface 16a of the key top 16. and a tapered upper surface portion 24 of the elastic portion 24.
The key top 16 is placed on the bottom surface 16a of the key top 16.
is in contact with this upper surface portion 24a, and the key top 16 and guide shaft 17 are constantly pressed upward in FIG. 3 by the elastic restoring force of this elastic portion 24. Note that this upward movement of the key top 16 is prevented by a retaining ring 27 fixed to the lower end of the guide shaft 17. Also, guide member 2
3 is fitted into an opening 25a provided in the connecting portion 25 of the elastic member 26.

Further, a conductive rubber member 29 is attached to the inner surface of the upper surface portion 24a of the elastic member 24, and a conductive rubber member 29 is mounted on the wiring pattern surface 18a of the printed circuit board 18 at a position opposite to this rubber member 29 as shown in FIG. A pair of comb-like wiring patterns 30 and 31 are provided, respectively.

Next, the through holes 20a, 20 of the printed circuit board 18
The state of attachment of the guide member 23 to b will be described in detail. First, as shown in FIG. 4, the above-mentioned through hole 20
Numerals a and 20b are elongated holes extending longitudinally along the direction connecting the guide shafts 17 adjacent to each other, and are arranged at equal intervals and on a straight line in the longitudinal direction. Here, to describe the dimensional relationship between the through holes 20a arranged horizontally in a row in FIG. The outer peripheral dimensions of 23 are configured to be equal to each other. Therefore, when the guide member 23 is fitted into the through hole 20a, there is no clearance between them. In addition, the dimensional relationship between the other through holes 20b and the guide member 23 is as follows.
As clearly shown in FIG. 5, the length L ₁ of the through hole 20b in the longitudinal direction is the length L ₁ of the guide member 23 in the longitudinal direction.
The length _L2 of the through hole 20b in the direction perpendicular to the longitudinal direction is equal to the length _l2 of the guide member 23. Therefore, while the surfaces 21 and 22 extending in the longitudinal direction of the through hole 20b and the guide member 23 are pressed against each other, a clearance 36 is created between them in the longitudinal direction.

Next, the jig 32 for fitting and fixing the guide member 23 into the through holes 20a, 20b of the printed circuit board 18 will be explained with reference to FIG. In this jig 32, a large number of guide members 23 are positioned and placed at predetermined positions on the jig 32 so that a large number of guide members 23 can be attached to the printed circuit board 18 in one operation. ing. That is, as shown in FIG. 6, a large number of recesses 33 for accommodating a part of the guide member 23 are provided at predetermined positions on the upper surface of the jig 32. A pair of protrusions 34 corresponding to the holes 23a are integrally molded.

The guide member 23 is inserted into the through hole 2 of the printed circuit board 18.
0a, 20b, when installing the guide member 23
This guide member 23 is inserted into the pair of protrusions 34 of the jig 32, respectively, through the guide holes 23a of the
is placed in the recess 33 of the jig 32. As a result, a large number of bearing members 23 placed on this jig 32 are positioned at predetermined intervals from each other. Thereafter, in this state, the guide member 23 is moved along with the jig 32 in the direction indicated by the arrow A in FIG.
direction, the guide member 23 is inserted into the through holes 20a and 2 of the printed circuit board 18 as shown by the imaginary line.
0b, respectively. At this time, a pair of click engagement pieces 2 provided on the side surface of the guide member 23
3b (see FIG. 5B) is elastically deformed, and the claw portion 23c of this engaging piece 23b clicks into the wiring pattern surface 18a of the printed circuit board 18. Further, as described above, since the through hole 20a of the printed circuit board 18 is configured to have the same dimensions as the guide member 23, the guide member 23 is press-fitted with the through hole 20a with no clearance at all. .

On the other hand, in the other through holes 20b, the guide member 23 has a clearance 36 at its longitudinal end within the through hole 20b of the printed circuit board 18.
(See Figure 6). Therefore, even if the printed circuit board 18 is deformed due to warpage or the like, or there is a dimensional error in the through hole 20b, the guide member 23 can fully absorb this by the above-mentioned clearance 36. It is press-fitted into the hole 20b. As a result, the guide hole 23a of the guide member 23 attached to the through hole 20b of the printed circuit board 18 is accurately positioned with reference to the guide hole 23a of the guide member 23 attached to the through hole 20a of the printed circuit board 18. It will be placed in

To roughly describe an example of the procedure for assembling the key switch mechanism, the elastic member 26 is placed on the wiring pattern surface 18a of the printed circuit board 18, and then the printed circuit board 1 is assembled using the jig 32 as described above.
The guide member 23 is fitted and fixed in the through holes 20a and 20b of the guide member 23, and then the pair of guide shafts 17 are inserted into the guide holes 23a of the guide member 23.Then, the key top 16 is attached to the tips of the pair of guide shafts 17. .

According to the key switch mechanism configured in this manner, the key top 16 is supported movably in the vertical direction by the two guide shafts 17, and the elastic restoring force of the elastic portion 24 of the elastic member 26 is used as an auxiliary force for returning the key top. By doing so, the compression coil spring 11 as shown in FIG. 1 can be omitted.
The height h (see FIG. 3) of the key switch mechanism can be made low. Moreover, since the movement stroke of the guide shaft 17 is absorbed by the space between the base 1 and the printed circuit board 18, this is advantageous in terms of space factor, and the key switch mechanism can be made thinner and smaller. becomes possible.

Furthermore, when fitting the guide member 23 into the through hole 20b of the printed circuit board 18, the presence of the clearance 36 as described above allows flexibility in the fitting position of the guide member 23 within the through hole 20b. The guide members 23 can be attached to the printed circuit board 18 by a simple attachment operation using the jig 32 while being accurately positioned relative to each other. As a result, the distance between the guide shafts 17 is determined extremely accurately without any variation, so even if the movement stroke l (see FIG. 3) of the key top 16 is relatively long, the guide shafts 17
7 can be moved up and down smoothly. Therefore, the key top 16 can be pressed with a good operational feel.

Although the present invention has been described above with reference to one embodiment, the present invention is not limited to this embodiment, and various modifications can be made based on the technical idea of the present invention.

For example, in this embodiment, the through hole 20a is provided in the printed circuit board 18 as a reference hole, but instead of providing this hole, all of the guide member mounting through holes provided in the printed circuit board 18 are replaced by the through hole 20b as described above. You can also use it as As described above, the present invention includes (a) a plurality of key tops arranged in a row in a row and a row, (b) a pair of guide shafts integrally attached to each of the key tops, and (c) a pair of guide shafts integrally attached to mutually adjacent key tops. (d) a plurality of guide members provided with a pair of guide holes for respectively guiding a pair of guide shafts that are attached to the key tops and are closest to each other; (e) a printed circuit board having a printed circuit board with the guide shafts attached to the through holes, respectively; (f) a conductive member disposed so as to be able to contact at least two or more wiring patterns provided on the printed circuit board and short-circuit them as the key top is pressed and moved; and at least some of the guide members have a clearance in a direction connecting the pair of guide holes with respect to the through hole of the printed circuit board, and have no clearance in a direction perpendicular to this direction. It is fitted and fixed within the through hole of the printed circuit board. Therefore, according to the present invention, there is no need for a key housing, a spring for reciprocating the key top, etc., so that the key switch mechanism can be made thinner and smaller, and it is also possible to reduce costs. Further, since the guide members are attached to the printed circuit board in a state where they are accurately positioned relative to each other as described above, the distance between the guide shafts can be accurately determined. As a result, even if the movement stroke of the key top is made sufficiently long, the guide shaft can be moved extremely smoothly, so that the key top can be pressed with a good feeling.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the key switch mechanism in a conventional data entry keyboard device;
7 to 7 show an embodiment in which the present invention is applied to the above-mentioned key switch mechanism.
The figure is a plan view of the key switch mechanism, Figure 3 is a longitudinal sectional view of the key switch mechanism, Figure 4 is a plan view showing the guide member attached to the printed circuit board, and Figure 5A is the through hole of the printed circuit board and the guide. An enlarged plan view for explaining the dimensional relationship with the members, FIG. 5B is a sectional view taken along line A-A in FIG. 5A, and FIG.
The figure is a sectional view showing the operation of press-fitting and fixing the guide member into the through hole of the printed circuit board using a jig, and FIG. 7 is a plan view of the wiring pattern on the printed circuit board. In addition, in the symbols used in the drawings, 16
...Key top, 17...Guide shaft, 18...Printed circuit board, 20a, 20b...Through hole, 23...
...Guide member, 23a...Guide hole, 26...Elastic member, 29...Conductive rubber member, 30, 31...
. . . wiring pattern, 32 . . . jig, 36 . . . clearance.

Claims (1)

[Claims for Utility Model Registration] (a) A plurality of key tops arranged in a row and a row, (b) A pair of guide shafts integrally attached to each of the key tops, (c) A pair of guide shafts integrally attached to each of the key tops adjacent to each other. (d) a plurality of guide members provided with a pair of guide holes for respectively guiding a pair of guide shafts that are attached to the key top and are closest to each other; (e) a printed circuit board with the guide shafts attached to these through holes, respectively; (f) a conductive member disposed so as to be able to contact at least two or more wiring patterns provided on the printed circuit board and short-circuit them as the key top is pressed and moved; a state in which at least some of the guide members have a clearance in a direction connecting the pair of guide holes with respect to the through hole of the printed circuit board, and have no clearance in a direction perpendicular to this direction. A key switch mechanism in a keyboard device, characterized in that the key switch mechanism is fitted and fixed in a through hole of the printed circuit board.