Switch device having rubber dome and generating superior click feeling

A switch device is provided with a first rubber dome for small application force, a second rubber dome for heavy application force, and an operation body. The rubber domes are integrally formed with a plate shaped base, and adjacent to each other. Lower ends of the operation body is disposed on the top surface of the first and second rubber domes. The operation body is movably supported in a vertical direction. The base around the second rubber dome is formed with a smaller thickness than the base around the first rubber dome. A preventing part is provided so as to prevent the base of the first rubber dome from deforming. The thick base around the second rubber dome for and the preventing part are disposed around an outer periphery of the base of the first rubber dome.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a switch device for use as a power window switch of, for example, an automobile.

2. Description of the Related Art

As an example of a switch device in the related art, JP-A-2002-334631 discloses a power window switch of an automobile, andFIGS. 11 and 12show the above power window switch.

When a pulling operation is performed on a switch device S2shown inFIG. 11by hooking a finger on an operation side wall of a seesaw knob101so as to be pulled in an arrow direction indicated by C, the operation side wall102of the seesaw knob101is pulled, and then a driving member103integrally mounted on the seesaw knob101moves so as to pivot on a concavity104as a fulcrum, thereby pressing a switch operation part105.

When the switch operation part105is pressed, an operation body106in contact with the switch operation part105and a cam member108in contact with a pressed part107of the operation body106are all pressed. When the cam member108is pressed in this way, movable contacts110inside two rubber domes119of a click rubber109are brought in contact with two fixed contacts (not shown) of a printed wiring substrate111, respectively facing the movable contacts, which leads to becoming the state show inFIG. 12, thereby turning on two of first switches.

Next, when the pulling operation on the operation side wall102of the seesaw knob101is released from the state ofFIG. 12, the movable contacts110are separated from the fixed contacts by a resilient force of the rubber dome119having the two movable contacts110, thereby turning off the first switches. At this time, the cam member108and the operation body106are pushed upward by a resilient force of the rubber dome119having the movable contacts110. with the pushing upward, the driving member103pivots on the concavity104as a fulcrum, so that the switch operation part105is pushed upward, whereby the seesaw knob101returns to its original position shown inFIG. 11.

Reference numeral112indicates a member for mounting the driving member103, reference numeral113indicates a through hole of the mounting member112, reference numeral114indicates a upper wall of the seesaw knob101, reference numeral115indicates a side wall of the seesaw knob101, reference numeral116indicates an outer peripheral wall of the mounting member112, reference numeral117indicates another switch operation part of the driving member103, and reference numeral indicates a cover for covering the bottom.

In the switch device according to the related art, since the switch operation parts105and117should be pressed so as to abut the center of the cam member108corresponding to the middle position between the two rubber domes119, the two rubber domes119are concurrently pressed, as shown inFIG. 12, thereby turning the switches on. In the meantime, a recently developed power window switch provides a two-stage operation; a manual operation is performed in a first-stage operation, an automatic operation is performed in a second-stage operation. In order to perform the two-stage operation with the switch device according to the related art, a position at which the switch operation parts105and117are pressed is eccentrically disposed from the idle position between the two rubber domes so as to make different distances from the rubber domes119to each operation part, whereby the first and second-stage operation is performed. However, since the rubber domes119have the same shape, it is very difficult for the rubber domes to correspond to various application force.

SUMMARY OF THE INVENTION

The present invention has been finalized in view of the drawbacks inherent in the switch device according to the related art, and it is an object of the present invention to provide a switch device which has rubber domes generating superior click feelings, in a two-stage click which smoothly corresponds to various application forces.

According to an aspect of the invention, a switch device includes a rubber dome for small application force, a rubber dome for heavy application force, and an operation body. The rubber domes made of a rubber material are integrally formed with one plate shaped base, respectively and are adjacent to each other. The operation body is disposed on the rubber domes such that one lower end of the operation body is disposed on the top surface of the rubber dome for small application force and the other lower end is disposed on the top surface of the rubber dome for heavy application force. The operation body is movably supported in a vertical direction. The base around the rubber dome for heavy application force is formed with a smaller thickness than the base around the rubber dome for small application force, and a preventing part is provided so as to prevent the base of the rubber dome for small application force from deforming. The thick base around the rubber dome for heavy application force and the preventing part are disposed so as to surround an outer periphery of the base of the rubber dome for small application force.

In the switch according to another aspect of the invention, four rubber domes are provided to correspond to one seesaw switch, and the four rubber domes are disposed such that the rubber dome for small application force and the rubber dome for heavy application force are diagonally arranged.

In the switch according to another aspect of the invention, the preventing part, for preventing the base of the rubber dome for small application force from deforming, is formed such that the preventing part is in contact with an internal wall face of a switch case of the switch device and sides of the base.

In the invention, since the outer periphery of the base to be affected by pressing the rubber dome for small application force is prevented from unnecessarily bending by the base of the rubber dome for heavy application force and the preventing part, the rubber dome for small application force is normally buckling, so that clear click feelings can be obtained. Further, since the base of the rubber dome for heavy application force can replace the preventing part, the preventing part for deformation does not need to be separately disposed in the base, which makes it possible to lessen the dimensions and even to simplify the structure. Further, since deformation can be prevented by using the switch case having high rigidity, in a region where the base around the rubber dome for heavy application force cannot be used as a preventing part for deformation, the switch case can be made smaller, compared to the switch case having the preventing part disposed in the click rubber.

Even though the rubber dome for small application force can be prevented from deforming by making thick the base of the rubber dome for heavy application force, click feelings do not deteriorate, because the base around the rubber dome for heavy application force is thick so that the base can be prevented from deforming.

In this way, it is possible to make smaller and simpler switches for small application force and heavy application force, and generate clear click feelings.

In the invention, since the rubber dome for small application force and the rubber dome for heavy application force are diagonally arranged, it is possible to make the best use of the base of the rubber dome for heavy application force.

In the invention, when heavily pressing the click rubber so as to prevent deformation, the amount of deformation of the base depends on differences of pressed loads on the base, which may cause different click feelings. However, since the preventing part is in contact with the internal wall face of the switch case and the side of the base, the amount of deformation of the base never changes, thereby ensuring stable click feelings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1is a plan view of a power window switch device to which a switch device according to the embodiment of the invention is applied;FIG. 2is a cross-sectional view of the power window switch device taken from the line2—2ofFIG. 1;FIG. 3is a cross-sectional view of the power window switch device taken from the line3—3ofFIG. 1;FIG. 4is a cross-sectional view showing a state in which the power window switch device is pressed;FIG. 5is a cross-sectional view of the power window switch device taken from the line5—5ofFIG. 4;FIG. 6is a cross-sectional view showing a state in which the power window switch device is further pressed;FIG. 7is a cross-sectional view of the power window switch device taken from the line7—7ofFIG. 6;FIG. 8is a cross-sectional view of a click rubber accommodated in a switch case;FIG. 9is a perspective view of the click rubber; andFIG. 10is an explanatory view showing the dimensional relationship of a rubber dome of a click rubber.

Next, the constitution of the switch device according to the embodiment of the invention will be described with reference toFIGS. 1 to 10.

A switch device S is deposed on sides of a door on the driver's side for the driver's convenience in operating the switch device, and four seesaw switches1serving as power window switches are disposed individually corresponding to respective windows for opening/closing windows of respective seats. Since the four seesaw switches basically share one structure, only two of them are illustrated. Switches indicated by2are other operation switches.

As shown inFIG. 2, the switch device S has a circuit board3having a plurality of sets of fixed contacts (not shown), a switch case4is mounted on the circuit board3, and the switch case4is provided with a panel5thereabove and with the switch case4therebelow, respectively, so as to form a basic structure. The seesaw switch1is mounted on the basic structure.

Next, the constitution of the seesaw switch1will be described.

Reference numeral7indicates a seesaw finger grip having a case shape whose bottom is opened, a pair of shaft support holes8are formed at a lower portion of both side plates of the seesaw finger grip7. Both sides of the shaft support hole8are provided with switch operation parts9aand9b. On the left side of the shaft support hole8, a protrusion, which is protrudingly formed on a lower end surface of a left side wall inFIG. 2, serves as the switch operation part9a. On the right side of the shaft support hole8, a protrusion, which is protrudingly formed on a lower surface of a wall drawn to the right inFIG. 2, serves as the switch operation part9b.

The switch case4is surrounded by an ascent wall part10so that an aperture11is formed. A pair of shaft support protrusions12is integrally formed at both sides of the ascent wall part11to be inserted in the shaft support hole8. Both side plates and the ascent wall part10of the seesaw finger grip7made of synthetic resin bend, so that the seesaw finger grip7is swingably mounted on the switch case4. An insertion through hole13is disposed in a lower portion inside the aperture11. A guide hole14is formed on an upper plate of the switch case4, and an operation body15is inserted in the guide hole14so as to be vertically movable therein. Lower ends of these operation bodies15are in contact with rubber domes17A and17B of the click dome16. An upper end of one of the operation bodies15is in contact with a switch operation part9bof the seesaw finger grip7, and an upper end of the other operation body15is in contact with a switch operation part9bof the seesaw finger grip7. To be described later, the rubber dome17A is a rubber dome which needs a heavy application force, the rubber dome17B is a rubber dome which can generate click feelings with a small application force.

The click rubber16is electrically conductive to the rubber domes17A and17B, respectively, is provided with a movable contact17A1facing the fixed contact, so that a push switch18is formed by these fixed contacts and movable contacts. Both lower ends of the operation body15are provided with protrusions19protruding therefrom, these protrusions19are individually fitted in fitting concavities20provided on a upper surface of the rubber domes17A and17B of the click rubber16. Two push switches18are provided for each operation body15. As shown inFIG. 3, the switch operation parts9aand9babutting the upper ends of the operation bodies15are disposed in a position closer to the right push switch18(rubber dome17B) rather than in a middle position between both push switches18(rubber domes17A and17B). With this structure, a two-stage switch operation is performed while generating two-stage click feelings, as to be described later. A rectangular base27A (from the top view) is formed around the rubber dome17A for heavy application force, and the base27A is formed thicker than a base27B formed around the rubber dome17B for small application force. As shown inFIG. 9, the rubber dome17A for heavy application force and the rubber dome17B for small application force are adjacently disposed to the plate shaped base27A and27B and alternately disposed on the click rubber16.

An upper part of one end in a formation direction of the seesaw finger grip7is a contacted part A where a finger contacts the seesaw finger grip7. A tapered part21is disposed in a direction away from the seesaw finger grip7, over at least the range of a gap a, so as to face the contacted part A and to decline as it goes away from the seesaw finger grip7. A space22is provided above the tapered part21.

The panel5covers the switch case4so as to have a cosmetic surface, a concave wall part23is formed in an arc, and a storage opening24is formed opened. The seesaw finger grip7is disposed in the storage opening24of the panel5, a left end edge of the arc shaped concave wall part23is disposed to face a right outside wall face25(inFIG. 2) of the seesaw finger grip7with a gap a. The seesaw finger grip7swings about the shaft support hole8and the shaft support protrusion12. Therefore, when the seesaw finger grip7is pressed at the contacted part A, the seesaw finger grip7swings in a clockwise direction about the shaft support hole8and the shaft support protrusion12, the right outside wall face25swings along a locus B indicated by a one-dot chain line.

When the seesaw finger grip7is pressed, the right outside wall face25of the seesaw finger grip7abuts a right wall part26of the switch case4, so that the right wall part26functions as a stopper for the seesaw finger grip7, the tapered part21is continuously formed to the stopper.

These tapered parts21and spaces22are provided in the formation direction of the seesaw finger grip7, that is, in a transverse direction ofFIG. 2. With this structure, a plurality of seesaw switches1functioning as a switch for driving power windows can be compactly arranged in a direction (orthogonal to the page ofFIG. 2) orthogonal to the formation direction of the seesaw finger grip7.

First, the two-stage switch operation according to the present embodiment will be described.

In a non operation state, as shown inFIGS. 2 and 3, when an operator presses the seesaw finger grip7at the right upper side (inFIG. 2) of the seesaw finger grip7, since the seesaw finger grip7is swingably supported about the shaft support hole8and the shaft support protrusion12, the seesaw finger grip7swings in the clockwise direction ofFIG. 2about the shaft support protrusion12, the pressed side (right side) of the seesaw finger grip7descends. Operation force applied on the seesaw finger grip7presses down the operation body15through the switch operation part9bdisposed at the rear side of the seesaw finger grip7, and then is transmitted to the right and left rubber domes17A and17B (inFIG. 3) of the click rubber16(inFIG. 3). Since the switch operation part9bis located in a position closer to the right rubber dome17B (inFIG. 3) than to the left rubber dome17A, if distances from the switch operation part9bto the rubber domes17A and17B are the same, the right rubber dome17B can be operated by only small load, so that the right rubber dome17B first starts buckling deformation. As shown inFIGS. 4 and 5, at a time point when the seesaw finger grip7slightly swings, for example, in the clockwise direction inFIG. 4, the right rubber dome17B (inFIG. 5) is buckling-deformed by pressing the seesaw finger grip7and thus generates click feelings, and the movable contacts (not shown) disposed in the rubber dome17B are brought into contact with the fixed contacts (not shown) facing the movable contacts, so that the corresponding fixed contact is made electrically continuous via the movable contact. Therefore, the corresponding push switch18outputs a first-stage electric signal according to the swinging of the seesaw finger grip7.

When the seesaw finger grip7is further pressed in the state shown inFIGS. 4 and 5, since the deformation of the right rubber dome17B has been finished, the operation body15swings in a counter-clockwise direction ofFIG. 5about the right rubber dome17B for small application force as a fulcrum, a sufficient force is applied on the left rubber dome17A inFIG. 5. As shown inFIGS. 6 and 7, when the corresponding seesaw finger grip7further swings, the left rubber dome17A inFIG. 7is buckling-deformed and thus a second click feeling is generated, and the movable contacts (not shown) disposed in the rubber dome17A are brought into contact with the fixed contacts (not shown) facing the movable contacts, and the corresponding fixed contact becomes conducting (on) by way of the movable contact. Therefore, the push switch18outputs a second-stage electric signal according to the swinging of the seesaw finger grip7. The rubber dome17A for generating a second-stage click feeling may be operated with a heavy application force.

If the tilted seesaw finger grip7is released from a finger, resilient force of the pair of rubber domes17A and17B pushes the tilted side of the seesaw finger grip7up by way of the operation body9b, the seesaw finger grip7returns to the non operation state shown inFIGS. 2 and 3. At this time, the movable contacts in contact with the fixed contacts are respectively separated from the fixed contacts, so as to return the set of two push switches18to a non conducting state (off).

When an operator pulls down the right end of the seesaw finger grip7which is in the non operation state shown inFIGS. 2 and 3, the corresponding seesaw finger grip7swings in the counter-clockwise direction ofFIG. 2so as to press the switch operation part9a. In the same manner as pressing the switch operation part9b, the set of two push switches18output first and second electric signals corresponding to swing angles.

Therefore, two operation bodies15operate with respect to one seesaw finger grip7, two rubber domes17A and17B face one operation body15, and all the four rubber domes17A and17B shown inFIGS. 8 and 9are operated by one seesaw finger grip7.

Next, the operation of the tapered part21and the space22will be described.

In the non operation state ofFIG. 2, the gap a is provided between the right outside wall face25of the seesaw finger grip7and the end edge of the concave wall part23of the panel5. Therefore, even though extraneous materials, such as a small stone sand on the arc shaped concave wall part23of the panel5, extraneous materials having a larger size than the gap a are prevented from intruding thereinto. However, when an extraneous material is smaller than the gap a, the extraneous material intrudes into the gap a and drops on the tapered part21disposed below the gap a, and slips and falls to the right (inFIG. 2) due to the inclination of the tapered part21. The tapered part21is disposed over at least the length of the gap a, from a swing locus B of the right outside wall face25, and the space22having extraneous materials therein, forming the tapered part21, is disposed above the tapered part21. Therefore, the dropped extraneous materials are smoothly ejected from the swing locus B of the right outside wall face25of the seesaw finger grip7, as shown inFIG. 6, the extraneous materials do not hinder the operation of pressing the seesaw finger grip7to the lowest position. Accordingly, it is possible to reliably output the first and second electric signals.

A taper groove may be formed continuous to the tapered part21so as to reach the end of the switch case4. With this structure, extraneous materials continuously intrude into the gap a, since the extraneous materials of the tapered part21are ejected through the taper groove continuously formed to the tapered part21, the next extraneous materials intruding thereinto are also ejected through the taper groove from the tapered part21. Accordingly, the seesaw finger grip7is not hindered by the intruding extraneous materials, the seesaw finger grip7can keep the swing operation at the end device thereof, so that it is possible to output the first and second electric signals.

The tapered part21also functions as a container containing extraneous materials. Moreover, the tapered part21also has a function of drawing out water. Even though the tapered part21is replaced by a flat part (without inclination), when an extraneous material consists of a small stone or water, there is no fear that the stroke of the seesaw finger grip7is changed. However, when the water is evaporated leaving the small stone alone, or when the extraneous material is initially a small stone alone, if the tapered part21is replaced by a flat part, the extraneous material may stay on the surface of the flat part and become hindrance, so that the stroke of the seesaw finger grip7may be changed. For this reason, the tapered part has inclination in the invention.

The range in which the tapered part21is formed is set from a position corresponding to a neutral position of the seesaw finger grip7to a position corresponding to the gap a which becomes the largest by pushing and pulling the seesaw finger grip7from the neutral position. Therefore, with any operation of the seesaw finger grip7, the above-described effect can be achieved. For example, in terms of operating position, if the gap a is made small, the shape of the seesaw finger grip7has limitation. On the other hand, by changing the range in which the tapered part21is formed, extraneous materials can be prevented from affecting the operation of the seesaw finger grip.

In the above-described present embodiment, the rubber dome17B for small application force is prevented from unnecessarily bending in the two-stage click operation. However, hereinafter, characterizing parts of the invention will be described in detail.

First, the dimension of the rubber domes17A and17B according to the embodiment and the relationship between the heavy application force and the small application force will be described.

When the rubber domes17A and17B are pressed down, the rubber domes17A and17B are pressed and deformed against resilient force of rubber, and then buckled so as to generate click feelings. At this time, application force varies according to the thickness of the rubber domes.

FIG. 10is a cross-sectional view of the rubber dome17A(17B), reference numeral H indicates the thickness of the base27A(17B), reference numeral h indicates the thickness of a conical part28of the rubber dome17A, reference numeral L indicates the length (span) of the conical part28of the rubber dome17A, and reference numeral R indicates a diameter of a head part29of the rubber dome17A.

The rubber dome17A for heavy application force has a diameter R larger than the rubber dome17B for small application force. In the present embodiment, the rubber domes17A and17B have the same diameter of the root portion thereof, which makes short the span L contributed to the application force as a folded part of the dome (the conical part28) during buckling. Therefore, the application force of the rubber dome increases.

The rubber dome17A for heavy application force has a slightly thick thickness h of the conical part28. When the rubber dome is pressed, the dome part is buckling-deformed. At this time, even though the base27A which is provided around the rubber dome and continuous to the root portion of the rubber dome is deformed so as to widen to the outside, the root portion of the rubber dome can be prevented from spreading by making thick the thickness H of the base27A so as to deform only the dome portion thereof. Therefore, heavy application can be facilitated, and the click feelings can be smooth.

Next, the click rubber will be described.

As shown inFIGS. 8 and 9, the click rubber16is formed such that the rubber dome17A for heavy application force and the rubber dome17B for small application force are alternately disposed. The rubber dome17A for heavy application force especially has the thick base27A therearound, and the rubber dome17B for small application force has the base27B therearound which is thicker than the base27A. That is, the side of the base27A of the rubber dome17A for heavy application force faces the side of the rectangular base27B of the rubber dome17B for small application force. Therefore, three sides or two adjacent sides of the base27B of the rubber dome17B for small application force face the thick base27A of the rubber dome17A for heavy application force.

As shown inFIG. 8, the click rubber16is accommodated in a switch case5, the peripheral edge of the click rubber16is in contact with an internal wall face30of the switch case5, the internal wall face30functions as a preventing part that prevents the base27B of the rubber dome17B for small operation force from deforming.

Since the rubber dome17B for small application force is regulated such that an outer periphery of the base27B is prevented from unnecessarily bending by the thick base27A of the rubber dome17A for heavy application force or the internal wall face30of the switch case5, the rubber dome17B can generate clear click feelings.

The base27A of the rubber dome17A for heavy application force can replace the preventing part in a region where a preventing part is not provided, by providing a connection member disposed in the switch case5. Accordingly, replacing the preventing part with the base makes it possible to lessen the dimensions and even to simplify the structure, compared to separately providing a preventing part for deformation in the base. Further, since the base27B of the rubber dome17B for small application force can be prevented from deforming by using a switch case5having high rigidity, in a region where the connection member is not disturbed, the switch case can be made smaller, compared to a switch case having the preventing part disposed in the click rubber16.

In the present embodiment, the internal wall face30is in contact with the entire periphery of the click rubber16so as to function as a preventing part and to regulate the movement of the base27B in a face direction caused by pressing the rubber dome17B. However, the application of the present invention is not limited to this structure. In other words, the entire periphery of the click rubber16does not need to be regulated by the preventing part. For example, when the thick base27A or a preventing part is provided in a region facing the outer periphery of the base27B, the base27B is prevented from deforming toward the thick base27aor the preventing part, which may achieve the above-described effect. To be more specific, for example, two sides facing the click rubber16do not need to be disposed in contact with the internal wall face30at least when the base27B is rectangular. This is because a pair of facing sides of the base27B is provided with the thick base27A or the preventing part (the internal wall face30in contact). This effect can be achieved as well when the external periphery is circular.

In the present embodiment, the operation body15is designed to swing by pressing down the seesaw finger grip7. However, the application of the invention is not limited to the above-described embodiment. For example, the guide hole14is formed such that the operation body15moves only in a vertical direction without inclination, the switch is pressed while varying stroke until a load is applied on the rubber dome. In this way, since the operation body15is vertically pressed, it is difficult to apply a load on the rubber domes17A and17B in an oblique direction, thereby preventing damage.

In the present embodiment having the above-described structure, since the outer periphery of the base27B of the rubber dome17B for small application force is prevented from unnecessarily bending by the thick base27A of the rubber dome17A for heavy application force and the internal wall face30of the switch case5, the rubber dome17B for small application force can generate clear click feelings. Further, since the base27A of the rubber dome17A for heavy application force can replace the preventing part, the preventing part for deformation does not need to be separately disposed in the base, which makes it possible to lessen the dimensions and even to simplify the structure. Further, since deformation can be prevented by using the switch case5having high rigidity, the switch case can be made smaller, compared to the switch case having the preventing part disposed in the click rubber16.

By making thick the base27A of the rubber dome17A for heavy application force, the base27B of the rubber dome17B for small application force can be prevented from deforming. This is possible because the rubber dome17A for heavy application force is designed to bear with heavy application force.

Therefore, the rubber dome17B (switch) for small application force and the rubber dome17A (switch) for heavy application force can be formed into a simple and small structure, and generate clear click feelings.

In the present embodiment, since the rubber dome17B for small application force and the rubber dome17A for heavy application force are diagonally arranged, it is possible to make the best use of the base27A of the rubber dome17A for heavy application force in preventing the base27B of the rubber dome17B for small application force from deforming.

In the present embodiment, when the base is heavily pressed, the amount of deformation of the base depends on differences of pressed loads on the base, which may cause different click feelings. However, since the preventing part is in contact with the internal wall face30of the switch case5and the side of the base27B, the amount of deformation of the base never changes, thereby ensuring stable click feelings.