JP2001229765A - Key switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate attachment of a key cap to an upper housing by improving the setting structure of a stabilizer. SOLUTION: A post-shaped part 7 of a key cap 6 is inserted into a guide hole 11 of an upper housing 3 covering a switch circuit board 2 on a back plate 1 of the key switch to close movable contacts of the switch circuit board 2 by deforming a rubber spring 8 according to the push-in of the key cap 6. A U-shaped stabilizer 11 is mounted on the back of the upper housing 3, and clasping parts 31 are mounted on the key cap 6. The clasping parts 31 are inserted into through-holes 22 formed on the upper housing 3 for clasping two leg parts 13 of the stabilizer 11. The key cap 6 is inserted into the upper housing 3, and at the same time, the two leg parts 13 of the stabilizer 11 are clasped by the clasping parts 31 of the key cap 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key switch used for a keyboard input device such as a computer and a word processor.

[0002]

2. Description of the Related Art As shown in FIG. 14, a key switch of this type generally has a boss having a rectangular guide hole 4 on the upper surface of an upper case 3 which covers a switch substrate 2 disposed on a back plate 1. The boss portion 5 is provided.
A hollow columnar portion 7 provided on the key cap 6 is slidably fitted into the guide hole 4 of the key cap 6, and the dome-shaped rubber spring 8 disposed on the switch substrate 2 is compressed in accordance with the pressing of the key cap 6. Deform this rubber spring 8
Of the switch substrate 2 by the pressing projection 8a provided inside the top of the
It is configured to close the movable contact inside. The key cap 6 is normally raised at its raised end by engaging the elastically deformable claw pieces 7a (FIG. 15) provided on the left and right side surfaces of the columnar portion 7 with the step portions 4a provided on the inner surface of the guide hole 4. Is positioned at The upper case 3 and the key cap 6
Is usually made of an injection molded article of a styrene resin.

[0003] By the way, there are various types of key caps provided in the keyboard input device, such as a rectangular shape, a vertically long shape and a horizontally long shape, and the conventional key switch is not limited to the key cap. The columnar portion 7 is provided substantially at the center, and the key cap is slid at only one position at the center. Further, in the conventional key switch, the sliding length L of the inner surface of the guide hole 4 for slidingly guiding the key cap 6 is required to be as low as possible in the entire height.
It is limitedly provided in the boss portion 5. From these facts, as shown in the figure, when the end portion of the vertically or horizontally long key cap 6 is partially pressed, the end is inclined, and it becomes difficult to smoothly slide the columnar portion 7, and the key operation feeling is reduced. Sex will be worse.

Therefore, conventionally, as shown in FIGS. 15 and 16, a steel C-shaped spring member (stabilizer) 9 is prepared, and this stabilizer 9 is provided on the inner surface of the key cap 6 with left and right holding portions 6a. To be rotatable, while
On the upper surface of the upper case 3, there is provided an L-shaped stopper piece 10 for locking the bent pieces 9a at both ends of the stabilizer 9;
The columnar portion 7 of the keycap 6 is fitted into the guide hole 4 while the bent portions 9 a at both ends of the stabilizer 9 are hooked on the stopper pieces 10. When the stabilizer 9 is mounted in this manner, when the key cap 6 is pressed halfway, tension is applied from the stabilizer 9 to the side opposite to the pressed side, and the inclination of the key cap 6 is corrected. Guaranteed.

[0005]

However, according to the key switch provided with the stabilizer 9, when the key cap 6 is mounted on the upper case 3, the stabilizer 9 is used.
It is necessary to engage the bent portions 9a at both ends of the upper case 3 with the stopper pieces 10 on the upper case 3, and the key cap 6 may impede the view behind, so that much time is required for the work. There was such a problem. Recently, it has been attempted to automatically assemble the key cap 6 to the upper case 3 by using an automatic machine. However, the stabilizer 9 becomes an obstacle to the automatic assembling, and requires the stabilizer 9. There was also a problem that the horizontal and vertical keycaps had to rely on manual assembly.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to make it possible to easily attach a key cap to an upper case by improving an installation structure of a stabilizer. It is another object of the present invention to provide a key switch that also contributes to automatic key cap assembly.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides two sub-bosses having a through hole at a point symmetrical position about the boss on the upper surface of the upper case. A support portion for detachably and rotatably supporting the base of the U-shaped stabilizer is provided on the back surface of the case, and the key cap is inserted into each of the through holes to hold both legs of the stabilizer. It is characterized in that it is configured to project two holding portions. In the key switch configured as described above, the stabilizer is supported in advance on the support portion on the back of the upper case,
Inserting the key cap column into the upper case guide hole while inserting the key cap column into the upper case through-hole allows the stabilizer to pinch both legs of the stabilizer. Disappears.

In the present invention, it is preferable that a projection for lifting the stabilizer from the switch board is provided on both legs of the stabilizer or on the switch board. This makes it possible to reduce the holding depth of the stabilizer with respect to the holding section of the key cap. It can be as deep as possible and the pinching of the stabilizer is more reliable. Further, it is preferable that the holding portion of the key cap for holding both legs of the stabilizer is configured to make a point or line contact with the outer peripheral surface of the stabilizer,
As a result, the stabilizer follows the pressing operation of the keycap without great resistance, and the feeling of the key operation is not hindered by the stabilizer.

In the present invention, the material of the keycap and the stabilizer is not particularly limited. However, when a general-purpose styrene-based resin molded body is used as the keycap, an acetal-based resin molded body is used as the stabilizer. It is desirable to use Styrene-based resin and acetal-based resin are compatible with each other in terms of sliding characteristics, so it is not necessary to supply lubricant such as grease to the contact portion between the key cap holding portion and the stabilizer, and noise is reduced. I do.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 12 show an embodiment of a key switch according to the present invention. In this embodiment, the horizontally long (capacity: about 1.5 to 2) key cap 6 shown in FIG. 14 is used as a constituent element, and its basic structure is as shown in FIG. Therefore, here, the same reference numerals are given to the same parts. In the present embodiment, a U-shaped stabilizer 11 is prepared in place of the C-shaped stabilizer 9 (FIGS. 14 to 16), and this stabilizer 11 is arranged on the rear side of the upper case 3. . As shown in FIGS. 8 to 10, the stabilizer 11 has protrusions 14 that are narrower than the legs 12 and protrude in the vertical direction at the distal ends of the legs 13 on both sides of the base 12. The stabilizer 11 is made of an injection-molded product of an acetal resin.

On the upper surface of the upper case 3, the key cap 6 is mounted around a boss 5 having the guide hole 4.
Two sub-bosses 2 at positions that are point-symmetric in the longitudinal direction
1 and 21 are provided, and a through hole 22 is formed in each sub boss 21. Also, on the back surface of the upper case 3, two support bases 23 for supporting two right and left portions of the base 12 of the stabilizer 11, and the two support bases 23.
Are provided with two pressing blocks 24 for pressing the base portion 12 of the stabilizer 11 (see FIGS. 2, 3,
5). The stabilizer 11 includes the two support bases 23 described above.
And the two holding blocks 24 and the (supporting portion) are detachably and rotatably supported on the rear surface of the upper case 3, and in this state, both legs 13 extend transversely to the through hole 22. It is made to let.

On the other hand, on the back surface of the key cap 6, two positions which can be inserted into the through-holes 22 provided in the upper case 3 at positions symmetrical with respect to the longitudinal direction with respect to the columnar portion 7. The holding parts 31 are protruded. Each of the holding portions 31 is composed of a pair of holding pieces 32 for holding both legs 13 of the stabilizer 11 and a bridge piece 33 for connecting the base sides of the pair of holding pieces 32. The portions are resiliently deformable in the opening direction. Engaging portions 34 (FIGS. 6, 7, and 12) capable of engaging with the legs 13 of the stabilizer 11 are formed on opposing surfaces of the distal ends of the pair of holding pieces 32. The portion 13 is elastically held between the engaging portions 34 of the holding pieces 32.

The inside of the sub-boss 21 having the through hole 22 is defined as a large cavity 25 which allows the legs 13 of the stabilizer 11 to swing vertically (FIGS. 6 and 7). A part of the ceiling of the cavity 25 is defined by the inclined wall 21a of the sub-boss portion 21, and the legs 13 of the stabilizer 11 swing upward so that the upper edge thereof comes into contact with the back surface of the inclined wall 21a. Is at the end.
Therefore, when the key cap 6 is lifted greatly in a state where both legs 13 of the stabilizer 11 are held between the holding portions 31 of the key cap 6, both legs 13 of the stabilizer 11 are attached to the inclined wall 21 a. As a result, the upward swing is restricted, and as a result, the two leg portions 13 are detached from the pair of holding pieces 32 of the holding portion 31 of the key cap 6, and the key cap 6 and the stabilizer 11 are separated. As described above, the key cap 6 normally receives the spring force of the rubber spring 8 and the stepped portion 4 a provided on the inner surface of the guide hole 4 with the claw pieces 6 a provided on the left and right side surfaces of the columnar portion 7. At the rising end of the keycap 6, as shown in FIG. 6, the leg 13 of the stabilizer 11 is in an inclined state separated from the inclined wall 21a of the sub-boss 21. Is positioned.

On the other hand, both legs 13 of the stabilizer 11
The position at which the tip 14 contacts the switch substrate 2 is the downward swinging end, and in this state, a considerable gap S (FIG. 7) is formed between the leg 13 and the switch substrate 2.
The upper case 3 is configured such that the stabilizer 11 is previously attached to the support portion (the support base 23, the holding block 24), and then assembled and integrated with the back plate 1. In this assembled state, the stabilizer is 11 is positioned at the above-mentioned downward swing end. Therefore, with the upper case 3 attached to the back plate 1, the holding portion 31 of the keycap 6 is now attached to the upper case 3.
When inserted into the through hole 22, the leg 13 of the stabilizer 11 is pushed between the pair of holding pieces 32 of the holding section 31, and the stabilizer 11 is inserted between the opposed engaging portions 34 of the pair of holding pieces 32. Become pinched.

Here, the engaging portions 34 of the holding pieces 32 constituting the holding portion 31 of the key cap 6 are shown in FIGS.
As shown in FIG. 2, the center position in the width direction is configured as a middle-high curved ridgeline 35, and the curved ridgeline 35 has a flared flank 36 on both sides of the curved ridgeline 35. On the other hand, as shown in FIG. 11, the leg portion 13 of the stabilizer 11 has an irregular cross-section having a stepped flat surface 13a on both sides thereof and a semi-circular surface 13b on the upper and lower portions thereof. The semi-circular surface 13b of the leg 13 of the stabilizer 11
Is smaller than the arc radius of the curved ridgeline 35 of the holding piece 32. Therefore, the stabilizer 1
In a state where 1 is positioned substantially horizontally, the curved ridgeline 35 of the holding piece 32 comes into point contact with the semicircular surface 13b of the leg 13 of the stabilizer 11, as shown by a contact point P in FIG. On the other hand, when the keycap 5 moves up and down from this state, the leg 13 of the stabilizer 11 tilts while sliding on the curved ridgeline 35 as shown in FIG. A line contact is made along the vertical inclined side edge of 36 (the contact portion is hatched). The inclined position of the leg 13 of the stabilizer 11 shown in FIG. 12 represents the rising end of the key cap 6 described above.
In this state, the transmission of the force from the stabilizer 11 to the key cap 6 is also ensured by the line contact.

The reason that the legs 13 of the stabilizer 11 have an irregular cross section is due to the design convenience of the injection molding die, and has no special meaning in function. Also,
The portion of the base portion 12 of the stabilizer 11 held by the holding portion 31 of the keycap 6 and the central portion of the base portion 12 also have irregular cross sections as shown in FIG. It has no special meaning in function. The columnar portion 7 of the keycap 6 has an escape portion 7b formed on the wall surface thereof so that only four corners are in sliding contact with the guide hole 4 (FIG. 3).

In the key switch constructed as described above, prior to assembling and integrating the upper case 3 with the back plate 1, its support 23 and holding block 24 are provided.
And the stabilizer (support portion). The stabilizer 11 is mounted on the upper case 3
Is turned upside down so that the rear side faces upward. Therefore, the opening operation is performed from above, so that the stabilizer 11 can be easily mounted on the rear surface of the upper case 11.

Then, the upper case 3 to which the stabilizer 11 has been attached is assembled to the back plate 1 and integrated.
Thereafter, while inserting the columnar portion 7 of the key cap 6 into the guide hole 4 of the upper case 3, the left and right holding portions 31 are inserted into the through holes 22 in the left and right sub-boss portions 21 of the upper case 3. At this time, both legs 13 of the stabilizer 11
The protrusion 14 at the tip is brought into contact with the switch board 2 to maintain a state of floating from the switch board 2 (FIG. 7), and the holding portion 31 of the key cap 6 is sufficiently deep into the through hole 22 of the upper case 3. When pushed in, the leg 13 of the stabilizer 11 is pushed between the pair of holding pieces 32 of the holding section 31, and the stabilizer 11 is held between the opposed engaging portions 34 of the pair of holding pieces 32.

On the other hand, the columnar portion 7 of the key cap 6 compresses and deforms the dome-shaped rubber spring 8 in the guide hole 4, and when the pressing force is released from the key cap 6 by the completion of the sandwiching of the stabilizer 11, the rubber is released. When the spring 8 expands and the columnar portion 12 is lifted, the columnar portion 12 rises until the claw pieces 13 on the left and right sides engage with the step portion 14 on the inner surface of the guide hole 11, and the key cap 6 is moved to the rising end. The key switch is positioned, and the assembly of the key switch is completed. In this assembled state, the leg 13 of the stabilizer 11 is positioned in an inclined state separated from the inclined wall 21a of the sub-boss 21 (FIG. 6). And
When the key cap 6 is pressed down from this state, the columnar portion 12 is lowered while being slidably guided by the four corners in the guide hole 4 in the holder 5 of the upper case 3, whereby the dome-shaped rubber spring 8 is moved. Is compressed and deformed, and the movable contact in the switch board 2 is closed by the pressing protrusion 8 a provided inside the top of the rubber spring 8. At this time, when the keycap 6 is pressed one-sidedly, a tension acts on the side opposite to the pressed side from the stabilizer 11, thereby correcting the inclination of the keycap 6.

Thus, the holding portion 31 of the keycap 6
When the key cap 6 is lifted, the engaging portion 34 is in line contact with the leg 13 of the stabilizer 11, so that the transmission of the force from the stabilizer 11 to the key cap 6 is also ensured. When pressed halfway, a large reaction force acts on the keycap 6 to reliably correct its inclination. On the other hand, in response to the pressing of the keycap 6, the holding portion 31 and the leg portion 13 of the stabilizer 11 change from line contact to point contact, and from point contact to line contact. Since it is slight, the stabilizer 11 follows the pressing operation of the keycap 6 without great resistance, and the feeling of the key operation is not hindered by the stabilizer 11. In particular, in the present embodiment, since the molded body of the acetal resin is used as the stabilizer, the compatibility in terms of the sliding characteristics with the keycap 6 using the molded body of the styrene resin is good. In addition, it is not necessary to supply lubricant such as grease to the contact portion between the holding portion of the keycap and the stabilizer, and noise is reduced.

In the above embodiment, the projections 14 are provided at the ends of the legs 3 of the stabilizer 11 in order to float the stabilizer 11 from the switch substrate 1.
The means for floating the stabilizer 11 from the switch substrate 1 is arbitrary. For example, a protrusion having the same function as the protrusion 14 may be provided on the switch substrate 1 side.

Further, in the above embodiment, the horizontal /
Although the case where the key cap 6 whose aspect ratio is not so large (approximately 1.5 to 2) is included as a constituent element has been described, the present invention relates to an elongated keycap having an extremely large aspect ratio (approximately 5 to 6). Of course, it is effective even if applied to. FIG. 13 shows such an elongated keycap 6 '.
In this case, a U-shaped stabilizer 11 ′ is provided on the back surface of the upper case 3 ′ in the same manner as the above-described embodiment, and the key cap 6 ′ is attached to the key cap 6 ′. A holding portion 31 'for holding both legs 13' of the stabilizer 11 'is provided. However, in this case, an external force is applied to the keycap 6 'carelessly,
Since there is a risk that the key cap 6 ′ may come off or roll over from the upper case 3 ′, as shown, the key cap 6 ′ and the upper case 3 ′ cooperate to prevent the key cap 6 ′ from coming off. It is desirable to provide a stopper means 40 and a rocking stopper 41 for preventing the key cap 6 'from rolling. In FIG. 13, parts having the same functions as the parts shown in FIG. 1 are indicated by the same reference numerals with dashes (').

The present invention is not limited to the one having the back plate 1, but may be replaced with a bottom case.

[0024]

As described above, according to the key switch of the present invention, the stabilizer is disposed on the back side of the upper case, and the holding portion provided on the key cap is inserted into the through hole provided on the upper case. Since the stabilizer is held between the holding portions, a horizontally or vertically long key cap can be simply and efficiently attached to the outer case simply by working from the front side, thereby improving productivity. In addition to making a significant contribution, automatic assembly by an automatic machine becomes possible, and its utility value is great.

[Brief description of the drawings]

FIG. 1 shows a structure of a key switch according to one embodiment of the present invention, and is a cross-sectional view taken along the line AA of FIG.

FIG. 2 is a plan view showing an upper case constituting the key switch from above.

FIG. 3 is a plan view showing the key switch from below.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a cross-sectional view taken along line CC of FIG. 3;

FIG. 6 is a cross-sectional view taken along line DD of FIG. 3;

FIG. 7 is a cross-sectional view showing the same cross-section as FIG. 6 and showing a state before the stabilizer is sandwiched by the key cap.

FIG. 8 is a plan view showing the shape of a stabilizer used in the present invention.

FIG. 9 is a side view showing a shape of a stabilizer used in the present invention.

FIG. 10 is a sectional view taken along arrows aa, bb, and cc in FIG. 8;

FIG. 11 is a front view showing a state in which the stabilizer is held by a holding portion provided in the keycap.

FIG. 12 is a schematic view showing a state in which the stabilizer is held by the holding portion of the key cap and an operating state thereof is partially opened;

FIG. 13 is a cross-sectional view illustrating a structure of a key switch according to another embodiment of the present invention.

FIG. 14 is a sectional view showing the structure of a conventional key switch.

FIG. 15 is a perspective view showing a structure of a back side of a key cap in a conventional key switch.

FIG. 16 is a perspective view showing the structure of an upper case in a conventional key switch.

[Explanation of symbols]

 1 Back Plate 2 Switch Board 3 Upper Case 5 Upper Case Boss 6 Key Cap 8 Rubber Spring 11 Stabilizer 12 Stabilizer Base 13 Stabilizer Leg 14 Stabilizer Projection 21 Sub Boss of Upper Case 22 Through Hole 31 Key Cap Clamping section

Claims (4)

[Claims] A columnar portion provided on a horizontally or vertically long key cap is slidably fitted into a guide hole in a boss provided on an upper surface of an upper case covering a switch board, and the key is pressed when the key cap is pressed. In the key switch for closing the movable contact in the switch board by compressing and deforming the dome-shaped rubber spring disposed on the switch board, a point symmetry of the upper surface of the upper case about the boss portion is provided. In addition to providing two sub-boss portions having through holes at positions, a support portion for detachably and rotatably supporting a base portion of a U-shaped stabilizer is provided on a back surface of the upper case, and the key cap is provided on the key cap. A key switch, characterized in that two holding portions, which are inserted into the respective through holes and hold both legs of the stabilizer, protrude therefrom. 2. The key switch according to claim 1, wherein projections for floating the stabilizer from the switch board are provided on both legs of the stabilizer or on the switch board. 3. The key cap according to claim 1, wherein the holding portion of the key cap for holding both legs of the stabilizer is in point or line contact with the outer peripheral surface of the stabilizer. 4. The key switch according to claim 1, wherein the key cap is formed of a styrene resin molded body, and the stabilizer is formed of an acetal resin molded body.