JPH0668746A - Key button structure for keyboard - Google Patents

Abstract

PURPOSE: To simplify a structure with a small number of constituent members and provide a wide range of a switch setting place. CONSTITUTION: A push button 3 for a keyboard is supported by a flexible film 2 with elasticity and provided at an opening part forming a switch installation place. A base 1 can be constituted, having integral leg parts 4 and integral guide posts 6 for holding the push button 3, so as to be fixed to a printed circuit board 21.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to keyboards for data entry devices such as telephones, calculators and the like, and more particularly to a key button structure for a keyboard incorporating a push button switch arrangement.

[0002]

2. Description of the Related Art Keyboards used for data input devices such as telephones and calculators have been conventionally known, and various push button switch structures incorporated therein are also known.

[0003]

The conventional push-button switch structure of this type has a large number of individual constituent members, and it is desired to improve it.

An object of the present invention is to provide a key button structure for a push button switch structure having a simple structure.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a substrate having an opening forming a switch installation location, and an elastic member arranged integrally with the substrate to provide a return spring action for a push button. A key button structure for a switch structure comprising a flexible membrane.

[0006] Preferably, the substrate has guide means for locating the push button for axial sliding movement towards and away from the substrate.

Conveniently, the guide means is positioned around the periphery of the opening and extends to one side of the substrate for receipt in a recess below the push button.

Conveniently, the guide means comprises a plurality of guide posts which are uniformly spaced around the periphery of the opening in the substrate.

In the preferred construction, there are four guide posts for placement in each corner of the square recess of the push button for engaging adjacent sidewalls along the outer corner edges of the guide posts. .

The push button can be held in the raised inactive or rest position by the biasing of the membrane by engagement with the guide means. For example, the push button may have a retaining arm that can engage the guide post. The retaining arm may also be releasable for removal of the push button.

In a variant, the push button can be held in the raised position by the biasing of the membrane by engagement with the cover or case of the data input device. For example, the push button may extend through the opening in the case of user actuation and be retained by engagement on the underside of the case around the opening.

The board may be adapted to secure a key button structure to a circuit board or similar board to align the switch device with an opening in the board. For example, the board may have resilient legs for engagement within the aligned openings of the circuit board. The legs are preferably releasable to remove the key button structure.

In a variation, the board is adapted to secure the key button structure to the cover or case of the data entry device prior to assembly on a circuit board or the like to align the switch device with the opening in the board. You can For example, the substrate may have resilient tongues for engagement at an opening in the cover or case through which the push button projects for user use.

The switch device is composed of a pair of fixed switch contacts on the circuit board and a movable contact made of a conductive material and fixed to the lower side of the film.

Advantageously, the membrane is arranged to seal the key button structure in relation to the circuit board around the opening to protect the switch device from contaminant ingress.

In the preferred construction, the membrane is cut away with a base seated around the opening on the underside of the substrate and a raised platform at the top engageable with the push button on the opposite side of the substrate. It has a conical shape.

Preferably, the substrate has stop means for elastically limiting the depression of the push button for lowering the movable contact onto the fixed contact. The stopper means is preferably integrally formed with the membrane to permanently fix the membrane and the substrate.

In the preferred construction, the substrate is a molded article made of a substantially rigid plastic such as polyphenylene sulfide, and the membrane is made of an elastomer such as silicone rubber molded onto the substrate so as to be permanently affixed thereto. It is a molded product.

The key button structure can be fitted to one push button by providing a single opening in the substrate.
In a variant, the key button structure can be adapted to several push buttons by providing the substrate with a plurality of openings, each opening having an associated membrane integral with the substrate.

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

[0021]

1 to 4 of the accompanying drawings show a first embodiment of a key button structure in a switch arrangement for a data input device such as a telephone keyboard (not shown).

The key button structure is a plastic substrate 1.
And an elastically flexible elastomeric membrane 2 and a plastic push button 3.

The substrate 1 has a substantially square shape in plan view, and has elastic legs 4 suspended from the respective corners and a circular hole 5 in the center.

Four guide posts 6 stand upright from the substrate 1 adjacent to each corner, and the guide posts 6 are uniformly arranged around the periphery of the hole 5 at regular intervals.

The flexible membrane 2 is in the form of a truncated cone, and has an annular base 7 that sits around the hole 5 in the countersink 5a below the substrate 1 and a guide post 6 on the opposite side of the substrate 1. It has a plateform 8 at the top centered between.

The film 2 is formed on the substrate 1, and the film 2 and the substrate 1 are formed.
4 pads 9 connected to the base 7 of the membrane 2 through the respective openings 10 formed in the substrate 1 in order to permanently fix them are integrally formed on the upper surface of the substrate 1 at each corner. is there.

The button 3 has a square shape in a plan view, and comprises a top wall 11 and a suspended side wall 12 forming a square recess 13 which is open downwardly for accommodating the guide post 6.

Each guide post 6 is positioned adjacent a respective corner of the recess 13 and positions the button 3 for axial sliding movement relative to the substrate 1, as best shown in FIG. And a rounded outer corner edge 6 that is engageable with the adjacent side wall 12 of the button 3 to prevent tilting or rocking of the button 3 on the guide post 6.
a.

The line contact between the corner edge 6a of the guide post 6 and the side wall 12 of the button 3 facilitates axial sliding movement with minimal frictional resistance. Its frictional resistance can be further reduced by the choice of plastic material for the substrate 1 and the button 3.

A central post 14 having an X-shaped cross section, which is seated on the platform 8 from the top wall 11 of the button 3, is suspended in the recess 13, and similarly inside the guide post 6, around the central post 14. Four holding arms 15 that are evenly arranged at regular intervals are suspended.

The guide post 6 and the holding arm 15 have facing inner and outer chamfers 16 and 17, respectively.
6 and 17 extend from the free end and are notched door contact portions 18 and 1
It ends at 9.

The chamfered parts 16 and 17 are door stop parts 18 and 19, respectively.
To press fit the button 3 onto the guide post 6 until it engages by a snap action to hold the button 3 on the guide post 6 in the inoperative or rest position raised by the recoil of the flexible membrane 2. Guide post 6 in radial direction
Cooperate with the movement of the holding arm 15.

The side wall 12 of the button 3 is formed with a notch portion 20 at a position between the adjacent guide posts 6, and the notch portion 20 removes the button 3 when necessary for repair, replacement or the like. Therefore, an appropriate tool (not shown) can be inserted to release the holding arm 15.

The key button structure described above is configured to be fixed to a flat substrate such as the printed circuit board 21 by inserting the suspension legs 4 of the board 1 through the aligned openings 22 of the printed circuit board 21. Provide the body.

Each leg 4 has a foot 2 with an outer sloping surface 24.
3, the outer inclined surface 24 has the foot portion 23 on the substrate 21.
It cooperates with the perimeter of the opening 22 to move the legs 4 radially until they engage the underside of the base plate 21 by a snap action to hold the key button structure thereon.

The key button structure releases the legs 23 and opens the legs 4 into the openings 22 if necessary for repair, replacement, etc.
It can be removed from the substrate 21 by retracting through.

A switch device is arranged in the hole 5 of the substrate 1, and the switch device is fixed above the fixed contact 25 on the pair of fixed contacts 25 on the substrate 21 and in the non-actuated or rest position of the button 3. Movable contacts 26 made of a conductive material on the lower side of the plate foam 8 which are arranged at intervals.
It consists of

The movable contact 26 is attached to the membrane 2 by the push button 3
By engaging the fixed contacts 25 by means of a manual depression and being lowered to make an electrical connection, the membrane 2 is provided with a spring action to return the button 3 to the inoperative or rest position when the button 3 is released. .

The base 7 of the membrane 2 seals the key button structure against the substrate 21 around the hole 5 to protect the switch device from the ingress of contaminants and the pad 9 acts to comfortably depress the user. Can be performed and elastically limits the depression of the button 3 in order to protect the switch device from excessive user pressure exerted on the push button 3.

The data input device is a circuit board as described above for performing various functions with each button 3 arranged to project through the opening 27 of the outer case 28 for user contact. It has a plurality of individual key button structures fixed to 21. The various functions can be identified by the appropriate display on the exposed surface of each button 3, for example the top wall 11.

The number and location of key button structures is adapted to various applications as desired in a simple manner that facilitates assembly of a wide range of keyboards having various button arrangements using a common key button structure. be able to.

With reference to FIGS. 5 and 6, there is shown a modification of the key button structure in which the same reference numerals are used to indicate the parts corresponding to the first embodiment.

The key button structure comprises sub-structures for fixing to the outer case 28 by means of four elastic tongues 29 which stand upright from the peripheral edge of the substrate 1 on each side. Tongue 2
Reference numeral 9 denotes a push fit, which frictionally engages with the inner end of the opening 27 of the case 28 for positioning and holding the key button structure for continuously assembling the case 28 on the printed circuit board 21.

When assembled, the key button structure is loaded against the substrate 21 by the engagement of the corner pads 9 and the case 28 at the inner ends of the openings 27, so that the base 7 of the membrane 2 has holes 5. A key button structure is hermetically sealed to the base plate 21 around the tongue 2 when the button 3 is pushed down so that the notch 20 in the side wall of the button 3 operates the switch device.
Clearance for 9 is provided.

By fixing the key button structure to the case 28, the area of the circuit board 21 that can be used for circuit connection is smaller than that in the first embodiment in which the key button structure is fixed to the board 21. Increase.

In addition, as shown in FIG. 5, the base 7 of the membrane 2 is arranged on the substrate 21 so as to raise the lower side of the substrate 1 so as to provide the clearance space 30. The solder contacts 31 are arranged thereby further increasing the area for making electrical contacts.
This is advantageous if the space available is limited, for example for the production of small keyboards with a plurality of closely arranged pushbuttons.

Another modification of the key button structure is shown in FIG. 7, in which the same reference numerals are used to indicate the parts corresponding to the first embodiment.

The key button structure is composed of a substrate 1 and a membrane 2 which is detachably fixed to a circuit board 21 by a suspension leg portion 4 of the substrate 1, and a push button 3 slides in an opening 27 of an outer case 28. It is movably attached. Push button 3
Is held in the raised position by the reaction of the membrane 2 by the engagement of the outer projection 32 in the guide slot 33 in the axial direction of the opening 27.

Referring to FIGS. 8 and 9, there is shown a second embodiment of a key button structure incorporating a switch arrangement, in which the portions of the second embodiment corresponding to the first embodiment are designated by the reference numeral of the first embodiment. Is denoted by 100.

The substrate 101 has an open lattice structure consisting of a square array of 16 uniformly spaced circular holes 105 formed by a ring member 134 having an interconnecting web 135. .

The substrate 10 is provided around the periphery of each hole 105.
Four guide posts 106 standing upright from 1 are arranged at regular intervals, and each push button 10 is arranged on the substrate 101.
3 are arranged for sliding movement in the axial direction.

Each button 3 has a square shape in plan view, and has a top wall 111 and a suspended side wall 112 forming a square recess 113 opened downward, and the recess 113 has a guide post 106. Is housed.

Each guide post 106 is positioned adjacent to a corner of the recess 113, and a button 103 is arranged so as to be slidable in the axial direction with respect to the substrate 101, and the button 103 is inclined on the guide post 106. Alternatively, it has a rounded outer corner edge 106a that can engage an adjacent sidewall 112 of the button 103 to prevent it from rocking.

Each hole 105 is located under the substrate 101 and is a countersink 10
Annular base 1 seated around hole 105 at 5a
07 and at the top centered between the guide posts 106 on the opposite side of the substrate 101.
And a resiliently flexible elastomeric membrane 102 in the form of a truncated cone.

Each membrane 102 is molded onto the substrate 101 and surrounds the associated guide post 106 and the membrane 102 and the substrate 1.
01 is fixed to the base 101 of the film 102 through the opening 110 of the substrate 101 so as to be fixed to the base 101, and an annular pad 109 is integrally formed on the upper surface of the substrate 101.

Outer case 128 having an aligned array of 16 openings 127 aligned with button 103.
Four pedestals 1 for placing and fixing the substrate 101 on the
36 are upright from the substrate 101 adjacent to each corner.

Each button 103 has an opening 127 aligned by the reaction of the associated membrane 102 by the engagement of the outer flange 137 with the underside of the case 128 around the opening 127.
It is retained on the guide post 106 in an elevated, non-actuated or rest position projecting therethrough. In a modification, each button can be held in the raised position by engagement with a guide post, for example by a holding arm similar to the first and second embodiments.

The key button structure fixed to the case 128 is assembled on the printed circuit board 121 to form the board 1.
Each hole 105 of No. 01 is aligned with its respective switch device, and each switch device is disposed at a fixed distance above the fixed contact in the rest position of the associated button 103 and a pair of fixed switch contacts 125 on the substrate 121. It consists of a movable contact 126 which is fixed to the underside of the plating foam 108.

The switch device can be selectively actuated by depressing a suitable push button 103 to lower the movable contact 126 onto the fixed contact 125 relative to the membrane 102, which when the button 103 is released. A spring action is provided to return the button to the inoperative position.

The key button structure is sealed against the substrate 121 around the hole 105 by the associated membrane base 107 to prevent the ingress of contaminants, and the excessive pressing force is for the comfort of the user and To prevent damage to switch contacts 125 and 126, pad 109 and button 10
It is tempered by the engagement with 3.

By using a common substrate for multiple buttons, the key button structure can be adapted to different applications by changing the buttons. It will be appreciated that the number and location of openings in the substrate can be varied to provide the desired button array for a given application.

In the embodiment described above, the substrates 1, 101
Is a molded article made of substantially solid plastic such as polyphenylene sulfide, and buttons 3,103 are formed on the substrate.
Elastomer membranes 2, 102 are molded to form a unitary spring unit for use. Suitable elastomers for the membranes 2,102 include silicone rubber, and each pushbutton 3,10
For convenience, 3 is a molded article made of substantially rigid plastic such as acrylonitrile butadiene styrene.

The invention is not limited to the embodiments described above. For example, the actuating portion of each push button can be rectangular or circular or any other shape desired such as an oval. Thus, in the above embodiments, the actuated portion of the desired shape can be provided by an upright on the top wall of the button arranged to project through the opening in the case.

The substrate may be rectangular or any other suitable shape and the openings may be circular or formed of any other suitable shape as desired for a given application.

The substrate is provided with a plurality of guide posts or other suitable apertures associated with each aperture for axially positioning the push button by any cooperating structure to hold the push button in the raised position due to the associated membrane bias. Can have different guiding means. If the substrate comprises guide posts, the number and arrangement can be chosen to suit the size and shape of the openings in the substrate and / or the recesses in the buttons.

The substrate may be adapted for fixing to the circuit board or case by any suitable means. If the substrate comprises elastic legs, tongues or similar structures, the number and arrangement can be chosen to suit the size and shape of the substrate. The structure can hold the board by self-locking or by frictional engagement with the circuit board or case as desired.

The membrane may be permanently affixed to the substrate by any suitable structure that provides mechanical engagement between the membrane and the substrate. Alternatively, or alternatively, the shaping of the film on the substrate may be controlled so that the film bonds to the substrate.

The key button structure may be arranged for actuation of a suitable switching device which is aligned with the hole in the substrate and the invention is not limited to the exemplary switching device described above.

The integral spring unit formed by the substrate and the membrane is convenient for manufacturing a keyboard incorporating the key button structure of the present invention. Thus, the number of individual components for assembly is reduced and a common spring unit can be used with different pushbuttons. The inner guide means, if provided, precisely positions the push button during its travel, and a compact construction suitable for a wide range of applications due to the optional retention of the push button on the guide means providing further assembly benefits. The overall height can be reduced to the minimum height that the body produces.

Other benefits and advantages of the invention will be apparent to those skilled in the art, and the invention encompasses all modifications and variations within the scope of the appended claims.

[0071]

As described above, the present invention is a flexible substrate which is arranged to have a base plate having an opening for forming a switch installation location and which is integral with the base plate and has a return spring action for a push button. Since it is configured with a flexible membrane, it is possible to provide a key button structure for a switch structure, which can reduce the number of components for individual assembling to make a compact structure.

[Brief description of drawings]

1 is a cross-sectional view of a first embodiment of a key button structure incorporating a switch arrangement according to the present invention.

2 is a cross-sectional view taken along line 2-2 of FIG.

FIG. 3 is a plan view showing a substrate of the key button structure shown in FIG.

4 is a cross-sectional view taken along the line 4-4 of FIG.

FIG. 5 is a sectional view similar to FIG. 1, showing a modification of the key button structure.

6 is a plan view of a substrate of the key button structure shown in FIG.

FIG. 7 is a sectional view similar to FIG. 1, showing another modification of the key button structure.

FIG. 8 is a cross-sectional view showing a second embodiment of a key button structure incorporating a switch structure according to the present invention.

9 is a plan view showing a substrate and an integral film of the key button structure shown in FIG.

[Explanation of symbols]

1 Substrate 2 Membrane 3 Push Button 4 Leg (Elastic Structure) 5 Opening (Hole) 6 Guide Means (Guide Post) 6a Outer Corner Edge 7 Membrane Base 8 Membrane Platform 12 Sidewall 13 Recess 15 Retaining Means 21 Support Body (printed circuit board) 25 Switch 26 Switch 29 Integrated mounting means 101 A molded product made of an elastomer such as a substrate recon rubber. 102 Membrane 103 Push Button 105 Hole (Opening) 106 Guide Means (Guide Post) 107 Membrane Base 108 Membrane Platform 112 Sidewall 113 Recess 125 125 Switch 126 Switch

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Claims (10)

[Claims] 1. A substrate (1; 101) having an opening (5; 105) forming a switch installation site, and a push button (3; 103) integral with the substrate (1; 101).
And a resiliently flexible membrane (2; 102) arranged to provide a return spring action for the switch. 2. The substrate (1; 101) is provided on the substrate (1; 1).
Switch arrangement according to claim 1, characterized in that it comprises guide means (6; 106) for arranging a push button (3; 103) for axial sliding movement towards and away from (01). Key button structure. 3. The push button (3; 103) has a membrane (2;
Holding means (15; 11) engageable with the guiding means (6; 106) for holding the push button (3; 103) in the inactivated or rest position raised by the reaction of (102).
The key button structure for a switch structure according to claim 2, further comprising 5). 4. Outer corner edges (6a; 106) which engage the guiding means (6; 106) with the adjacent side walls (12; 112) of the recess (13; 113) of the push button (3; 103).
Key switch structure for a switch arrangement according to claim 2 or 3, characterized in that it comprises a guide post (6; 106) housed in the recess (13; 113) by a). 5. The substrate (1; 101) has a support (21;
Key structure for a switch arrangement according to any one of the preceding claims, characterized in that it comprises an integral mounting means (4; 29; 136) for fixing it to a (28; 128). 6. A plurality of elastic structures (4; 2), the attachment means preferably being self-locking and / or releasable.
9. The key button structure for a switch structure according to claim 5, which is composed of 9). 7. A substrate (1; 10) on the membrane (2; 102).
1) a base (7; 107) for sealing around the opening (5; 105) on the underside, and a raised platform (8; 108) on the opposite side of the substrate (1; 101). A push button for actuating a switch (25, 26; 125, 126) aligned with the opening (5; 105) of the substrate (1; 101) which comprises the platform (8; 108). The key button structure for a switch structure according to any one of claims 1 to 6, which can be pushed down by (83; 103). 8. The substrate (101) is provided with a plurality of openings (105) forming switch setting locations for a plurality of push buttons (103), the openings (105) for the push buttons (103). In order to provide a return spring action, the substrate (10
Key switch structure for a switch arrangement according to any one of claims 1 to 7, characterized in that it comprises a respective elastically flexible membrane (102) integral with 1). 9. A substrate (1; 101) having an opening (5; 105) forming a switch setting place, and a substrate (1; 101) integral with the substrate (1; 101) and at a peripheral portion of the opening (5; 105). Guide means (6; 10) extending around one side thereof
6), a push button (3; 103) arranged and held on the guide means (6; 106) for axial movement towards and away from the opening (5; 105), and the substrate (1; 10).
An elastically flexible membrane (2; 102) integral with 1) and urging the push button (3; 103) to the raised inoperative position.
And a substrate (1; 101) having an integral mounting means (4; 29; 136) for fixing to a support (21; 28; 128), a push button of a keyboard of a data input device. Key button structure for switch. 10. The substrate (101) has a plurality of openings (105) forming a plurality of switch setting locations for a plurality of push buttons (103).
The key button structure for the push button switch described in.