Push button switch

Abstract

A push button switch (1) is configured to comprise: a base (30) which has a plurality of terminals arranged on the same circumference to be separated from each other; a movable contact brush (50) which has a plurality of contact parts arranged on the plurality of terminals; a rotor (90) which has a cam for bringing the plurality of contact parts into contact with, or for separating the same away from, the plurality of terminals and which is supported so as to be rotatable about the axis of the base (30); an actuator (70) which abuts against a gear provided on the rotor (90) and rotates the rotor (90) by moving in a direction orthogonal to the axis of the base (30); and a button (60) which abuts against the actuator (70), moves the actuator (70) by a push-in operation, and elastically returns by a spring force.

Description

Pushbutton Switch

[0001] The present invention relates to a push button switch suitable for use as a switch for operating a seat heater in an automobile, for example.

[0002] A conventional switch of this type is the seesaw switch described in Patent Document 1 listed below. This seesaw switch can switch between a conductive state and a non-conductive state by tilting a knob supported by a case and bringing a contact portion of a movable contact inside the case into contact with or away from a terminal, and is equipped with a locking mechanism that maintains that state. With this switch, pressing the left end of an operating body provided on the top of the case establishes electrical continuity between the power supply Vcc and contact A, locking the conductive state (HIGH setting). On the other hand, pressing the right end of the operating body releases electrical continuity between contact A and power supply Vcc, establishing electrical continuity between contact B and locking the conductive state (LOW setting).

[0003] Japanese Patent Application Laid-Open No. 2017-073215

[0004] With the conventional seesaw switch, for example, when switching the circuit from a HIGH setting to a LOW setting, it is necessary to press the right end of the operating member to release the locked state and switch the power OFF. Then, the right end of the operating member must be pressed again to turn the power ON and then lock the switch, which is a cumbersome operation to release the lock. Furthermore, because the circuit can only be switched between a HIGH setting and a LOW setting, there is also the problem that it cannot be used for seat heaters with fine temperature settings, such as a MID setting.

[0005] The present invention has been made to solve such problems, and its purpose is to provide a push button switch that can switch circuits with a simple operation and can also handle switching between multiple circuits.

[0006] In order to achieve the above-mentioned object, the push button switch of the present invention is characterized by comprising: a base having a plurality of terminals arranged spaced apart on the same circumference; a movable contact brush having a plurality of contact portions arranged on the plurality of terminals; a rotor having a cam that brings the plurality of contact portions into contact with or separates from the plurality of terminals and is rotatably supported around the axis of the base; an actuator that abuts against a gear provided on the rotor and moves in a direction perpendicular to the axis of the base to rotate the rotor; and a button that abuts against the actuator, moves the actuator when pressed, and elastically returns to its original position by spring force.

[0007] In addition, in the push button switch of the present invention, the mechanism for rotating the rotor by the actuator is composed of upper and lower protrusions arranged opposite the actuator, and an upper gear that is stacked in two stages on the rotor, with the upper protrusion abutting and the lower gear abutting, and the upper gear and the lower gear have different rotation radii and the gear teeth are arranged at positions offset from each other in the rotation direction.

[0008] In addition, in the push button switch of the present invention, the mechanism for elastically returning the button is characterized by comprising an inclined surface provided on the base and a spring holder that houses a coil spring compressed by the actuator and is pressed against the inclined surface by the repulsive force of the spring.

[0009] The push button switch according to the present invention employs the above-described configuration, which has the effect of enabling circuits to be switched with a simple operation and also enabling switching of multiple circuits.

[0010] 1 is a perspective view showing the appearance of a push button switch according to the present invention; FIG. 2 is an exploded perspective view showing the internal structure of the switch; FIG. 3 is a plan view showing the structure of a base constituting the switch; FIG. 4 is a plan view showing the structure of a top case constituting the switch; FIG. 5 is a plan view showing the structure of a movable contact brush constituting the switch; FIG. 6 is a plan view showing the structure of a button constituting the switch; FIG. 7 is a plan view showing the structure of an actuator constituting the switch; FIG. 8 is a plan view showing the structure of a spring holder constituting the switch; FIG. 9 is a plan view showing the structure of a rotor constituting the switch; FIG. 10 is a cross-sectional view showing the assembled state of the switch; FIG. 11 is an explanatory diagram showing the rotational movement of the rotor when the button in the switch is pressed; FIG. 12 is an explanatory diagram showing the rotational movement of the rotor when the button in the switch automatically returns; FIG. 13 is an explanatory diagram showing the state of the circuit accompanying the rotational movement of the rotor in the switch; FIG. 14 is an explanatory diagram showing the contact state between the contact portion and the terminal in the switch; FIG. 15 is an explanatory diagram showing the relationship between the spring holder and the base in the switch; FIG. 16 is an explanatory diagram showing the reason for having two gears, upper and lower, in the switch; and FIG. 17 is an explanatory diagram showing the switching timing of each circuit in the switch.

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] As shown in Figure 1, the push button switch 1 of this embodiment is used as a switch for operating a seat heater in an automobile. This push button switch 1 is an auto-return type switch in which, when the operating body 3 provided on the top of the case 2 is pressed, the button 60 sinks in the direction of arrow A, and when the finger is released, the button 60 automatically returns in the direction of arrow B. As shown in the circuit diagram, each time the operating body 3 is pressed, the internal circuit switches in the following order: OFF (stop) → LOW (weak: SW1 is ON) → MID (medium: SW2 is ON) → HIGH (strong: SW3 is ON) → OFF (stop).

[0013] 2, the push button switch 1 of this embodiment has a structure in which a movable contact brush 50 is housed inside a case 2, which is made up of a top case 40 placed on a base 30, and an operating body 3 is installed, which is made up of a button 60 for moving the movable contact brush 50, an actuator 70, a spring holder 80, and a rotor 90. The detailed structure of this push button switch 1 will be explained below, with each component disassembled.

[0014] The base 30 shown in FIG. 3 is made of an insulating resin material, and has a rectangular box-shaped base body 31 with locking claws 32, 32, ... formed on the outer wall surface for attaching the top case 40. A circular pedestal 33 is provided inside the base body 31 to house a movable contact brush 50 (see FIG. 5) and a rotor 90 (see FIG. 9). A shaft 34 is provided at the center of the circular pedestal 33 to support the rotor 90 rotatably about its axis, and inclined surfaces 35, 35 are provided on both sides of the circular pedestal 33 against which a spring holder 80 (see FIG. 8) abuts and moves. A fixed contact pattern 10, stamped from a conductive metal plate, is insert-molded into the floor of the circular pedestal 33. The fixed contact pattern 10 includes a first switch terminal 11, a second switch terminal 12, a third switch terminal 13, and a ground terminal 14, which are spaced apart from one another at 90-degree intervals around the circumference of the circular pedestal 33. A printed circuit board 20 (see FIG. 2) is mounted on the top surface of the base 30, and an LED 22 as an indicator light for the switch and a resistor 23 are mounted on a board 21.

[0015] The top case 40 shown in Figure 4 is made of an insulating resin material and is formed with a U-shaped cross section, consisting of a top plate 41 that covers the base 30 and left and right side plates 42, 42. Locking claws 43, 43, ... for attaching the button 60 are formed on the top surface of the top plate 41 and the bottom surfaces of the side plates 42. Mounting pieces 44, 44 for attaching the push button switch 1 inside the vehicle are provided on the upper left and right sides of the side plates 42, and two rows of locking holes 45, 45 are formed on both the left and right side surfaces of the side plates 42. The locking claws 32, 32 are engaged with the locking holes 45, 45 to attach the top case 40 to the base 30, thereby forming the case 2 for accommodating components.

[0016] The movable contact brush 50 shown in Figure 5 is made of a conductive metal plate 51, and four leaf spring pieces 52, 52, ... are formed by cutting each side of the rectangular metal plate 51. Each leaf spring piece 52 has a curved portion 53, 53, ... bent upward at its middle position. Each leaf spring piece 52 has a bifurcated contact portion 54, 54, ... bent at an obtuse angle at its tip to prevent poor contact. The four contact portions 54 are assigned clockwise as a first switch contact portion 55, a second switch contact portion 56, a third switch contact portion 57, and a ground contact portion 58.

[0017] 6 is made of an insulating resin material and includes a square box-shaped button body 61 that covers the case 2, and a flat rectangular operating portion 62 that protrudes from the top surface of the button body 61. The button body 61 has two rows of locking holes 63, 63 on the front and back, and recesses 64, 64 on both the left and right sides to avoid the mounting pieces 44, 44.

[0018] The actuator 70 shown in Figure 7 is made of an insulating resin material, and has a pair of protrusions 72, 72 for mounting the button 60 on the top surface of a flat box-shaped actuator body 71. An upper protrusion 73 and a lower protrusion 74 with acute-angled tips are provided on the back surface of the actuator body 71 as a mechanism for rotating a rotor 90 (see Figure 9). The upper protrusion 73 and the lower protrusion 74 are positioned 180 degrees opposite each other and move back and forth in a direction perpendicular to the axis of the shaft portion 34.

[0019] 8 is made of an insulating resin material, and has a cylindrical housing 82 on the top surface of a flat box-shaped holder main body 81 as a mechanism for elastically returning the button 60. A coil spring 83 made of a spirally wound metal wire is housed in this housing 82. Click pieces 84, 84 are formed on the bottom surface of the holder main body 81 to provide a clicking sensation when the button 60 is pressed and when it automatically returns.

[0020] The rotor 90 shown in FIG. 9 is made of an insulating resin material and includes an upper gear 92 and a lower gear 93 stacked vertically on the front surface of a disk-shaped rotor body 91. In this embodiment, the upper gear 92 has 12 teeth and a pressure angle of 18 degrees, while the lower gear 93 has 12 teeth and a pressure angle of 12 degrees. The upper gear 92 and the lower gear 93 have different rotation radii, and the gear teeth are positioned at predetermined angles in the circumferential direction (rotational direction). A cylindrical bearing 94 is provided at the center of the back surface of the rotor body 91. Three arc cams 95, 96, and 97 are formed at equal intervals on the same circumference around the bearing 94, contacting the first switch contact 55, the second switch contact 56, and the third switch contact 57 within predetermined ranges. A circular cam 98 that is in constant contact with the ground contact portion 58 is formed in a continuous protruding manner on the inner circumference of the bearing 94 .

[0021] The components that make up the push button switch 1 are as described above. During assembly, the movable contact brush 50 is first placed on the circular seat 33 of the base 30 as shown in FIG. 10A. This positions the first switch contact 55, the second switch contact 56, and the third switch contact 57 in a non-contact state above the first switch terminal 11, the second switch terminal 12, and the third switch terminal 13 of the fixed contact pattern 10, respectively. Next, as shown in FIG. 10B, the rotor 90 is placed over the movable contact brush 50, and the bearing 94 (see FIG. 9) of the rotor 90 is fitted into the shaft 34 (see FIG. 3) of the base 30. Next, as shown in FIG. 10C, the spring holder 80 containing the coil spring 83 is attached to the actuator 70, and the actuator 70 is placed on the base 30. The top case 40 is then placed over the actuator 70 and attached to the base 30. Finally, the button 60 is fixed to the actuator 70 , and the latching claws 43 (see FIG. 4) of the top case 40 are fitted into the latching holes 63 (see FIG. 6) of the button 60 to attach the button 60 to the top case 40 .

[0022] In this manner, the operating body 3 is formed, consisting of the button 60, actuator 70, spring holder 80, and rotor 90. As a result, in the push button switch 1, when the operating body 3 is pressed with a finger, the button 60 sinks, and the rotor 90, pressed by the actuator 70, rotates a predetermined angle about the shaft 34 of the base 30, operating the movable contact brush 50 and switching the contacts. On the other hand, when the finger is released from the operating body 3 and the force pressing the button 60 is released, the spring force of the coil spring 83 housed in the spring holder 80 causes the button 60 to elastically return to its original position.

[0023] The structure of the push button switch 1 of this embodiment has been described above. Next, we will explain the rotation of the rotor 90 in response to the operation of the button 60. FIG. 11A shows the interior of the case 2 when the button 60 is in the free position. At this time, the lower protrusion 74 of the actuator 70 is in contact with the lower gear 93 of the rotor 90, but the upper protrusion 73 is not in contact with the upper gear 92. When the operating portion 62 of the button 60 is pressed in the direction of arrow A as shown in FIG. 11B, the protrusion 72 in contact with the button body 61 is pressed, causing the actuator 70 to move in a direction perpendicular to the axis, and the upper protrusion 73 collides with the upper gear 92, causing the rotor 90 to begin rotating counterclockwise. Furthermore, when the operating portion 62 of the button 60 is further pressed in the direction of arrow A as shown in FIG. 11C, the upper protrusion 73 contacts the upper gear 92, further rotating the rotor 90. At this time, the actuator 70 remains in a moving state, so the lower gear 93 of the rotor 90 and the lower protrusion 74 do not come into contact with each other during rotation.

[0024] FIG. 12A shows the interior of the case 2 when the button 60 moves a full stroke (S in the figure). At this time, the rotor 90 rotates until the upper protrusion 73 contacts the bottom of the teeth of the upper gear 92, causing the rotor 90 to rotate from the free position shown in FIG. 11A by an angle equal to the pressure angle of the upper gear 92 (18 degrees). When the force pressing the button 60 is released, the button 60 automatically returns to its original position due to the spring force of the coil spring 83. At this time, as shown in FIG. 12B, the actuator 70 pushes the button 60 upward in the direction of arrow B, causing the lower protrusion 74 to collide with the lower gear 93, causing the rotor 90 to begin rotating counterclockwise. Then, as shown in FIG. 12C, when the button 60 returns to the free position, the rotor 90 rotates from the full stroke position shown in FIG. 12A by an angle equal to the pressure angle of the lower gear 93 (12 degrees). That is, each time the button 60 is pressed, the rotor 90 rotates 18 degrees before the button 60 moves to the full stroke position and 12 degrees before the button 60 returns to the free position, for a total of 30 degrees.

[0025] Next, the switching of the circuit associated with the rotation of the rotor 90 will be described. To facilitate understanding of the relative positions of the contacts, the top case 40, button 60, and actuator 70 are omitted from FIG. 13 , and the positions of the arc cams 95, 96, and 97 on the back side of the rotor 90 are indicated by hatching. FIG. 13A shows the state inside the case 2 when the button 60 is in the free position. At this time, the circular cam 98 of the rotor 90 constantly presses against the curved portion 53 of the movable contact brush 50, and the depressed ground contact 58 constantly contacts the ground terminal 14. In contrast, none of the three arc cams 95, 96, and 97 press against the curved portion 53 of the movable contact brush 50, so the first switch contact 55, the second switch contact 56, and the third switch contact 57 are separated from and not in contact with the first switch terminal 11, the second switch terminal 12, and the third switch terminal 13 (see FIG. 14A ). This is the circuit OFF state.

[0026] Here, when button 60 is pressed once, rotor 90 rotates 30 degrees counterclockwise as described in Figure 12, and the cam position also rotates 30 degrees. Then, as shown in Figure 13(B), one arc cam 95 presses against curved portion 53 of movable contact brush 50, and the depressed first switch contact portion 55 contacts first switch terminal 11. At this time, ground contact portion 58 is always in contact with ground terminal 14, but neither second switch contact portion 56 nor third switch contact portion 57 contacts second switch terminal 12 or third switch terminal 13. This is the ON state of SW1.

[0027] Here, if button 60 is pressed once more, rotor 90 rotates another 30 degrees counterclockwise, and the cam position also rotates another 30 degrees. Then, as shown in Figure 13 (C), arc cam 95, which had been in contact with curved portion 53, separates from curved portion 53, and the next arc cam 96 presses against curved portion 53, causing second switch contact 56, which has been pressed down, to contact second switch terminal 12. At this time, ground contact 58 is always in contact with ground terminal 14, but neither first switch contact 55 nor third switch contact 57 is in contact with first switch terminal 11 or third switch terminal 13. This is the ON state of SW2.

[0028] Here, if the button 60 is pressed once more, the rotor 90 rotates another 30 degrees counterclockwise, and the cam position also rotates another 30 degrees. Then, as shown in FIG. 13(D), the arc cam 96 that had been in contact with the curved portion 53 separates from it, and the next arc cam 97 presses against the curved portion 53, causing the depressed third switch contact 57 to contact the third switch terminal 13 (see FIG. 14(B)). At this time, the ground contact 58 is always in contact with the ground terminal 14, but neither the first switch contact 55 nor the second switch contact 56 contacts the first switch terminal 11 or the second switch terminal 12. This is the ON state of SW3. Finally, if the button 60 is pressed once more, the rotor 90 rotates another 30 degrees counterclockwise, returning to the circuit OFF state shown in FIG. 13(A).

[0029] Next, the return operation of the button 60 will be described. As shown in FIG. 15 , when the button 60 is in the free position, the coil spring 83 housed in the spring holder 80 is compressed against the actuator 70, and the repulsive force of this spring presses the click piece 84 against the base 30. When the button 60 is pressed in the direction of arrow A, the actuator 70 and spring holder 80 are pressed in, and the click piece 84 climbs up the inclined surface 35 of the base 30 against the spring force of the coil spring 83. As shown in the enlarged view, the inclined surface 35 initially has an inclination angle of 30 degrees but changes to 15 degrees midway. This changes the resistance force when the click piece 84 crosses the boundary of this inclination angle, providing a clicking sensation in the fingertip. Meanwhile, when the finger is released and the pressure applied to the button 60 is released, the click piece 84, which is pushed downward by the spring force of the coil spring 83, moves down the inclined surface 35 in the opposite direction. Accordingly, the button 60, which has been pressed by the actuator 70, automatically returns to its original free position.

[0030] In this embodiment, the rotor 90 is provided with an upper gear 92 and a lower gear 93. The reason for providing two upper and lower gears is as follows. As shown in FIG. 16A , if a single gear (12 teeth, 15-degree rotation angle) were provided, the gear would have point symmetry. Therefore, when the lower protrusion 74 is positioned in the free position as shown in the figure, the rotor 90 would interfere with the rotating gear teeth. To avoid this, the rotor 90 must be rotated an additional 15 degrees when the lower protrusion 74 is positioned. Therefore, in this embodiment, as shown in FIG. 16B , the rotor 90 has two upper and lower gears with different rotation radii, and the gear teeth are offset in the circumferential direction (rotational direction). This prevents interference between the gear teeth and the protrusions at 180-degree opposing positions when the button 60 is pressed and when it automatically returns to its original position.

[0031] In this embodiment, the pressure angle of the upper gear 92 is set to 18 degrees, and the pressure angle of the lower gear 93 is set to 12 degrees. The reason for the different pressure angles of the upper and lower gears is as follows. Each time the button 60 is pressed, the internal circuits of the push button switch 1 are switched in the following order: OFF → SW1 is ON → SW2 is ON → SW3 is ON → OFF. Figure 17 shows the switching timing of each circuit, with the ON contacts indicated by hatching. As shown in the figure, the switching timing of each circuit occurs while the button 60 is being pressed, and each circuit is OFF when switching. This is because narrowing the switching timing requires precision of components. Therefore, since a larger rotation angle of the rotor 90 when the button 60 is pressed is advantageous because a larger switching angle can be achieved, the rotation angle when the button 60 is pressed is set larger than the rotation angle when the button is automatically reset (18 degrees when pressed, 12 degrees when automatically reset).

[0032] In the embodiment described above, the number of contacts that turn the circuit on and off is three (SW1, SW2, SW3), but the number of contacts is not limited to this. For example, by increasing the number of switch terminals of the fixed contact pattern 10, the number of contact portions of the movable contact brush 50, and the number of arc cams of the rotor 90, it is possible to set the number of contacts that turn on and off to four or more (SW1, SW2, SW3, SW4, ...). In other words, the present invention is not limited to the above embodiment, and can be modified as appropriate within the technical scope of the present invention using the ordinary creative ability of a person skilled in the art.

[0033] DESCRIPTION OF SYMBOLS 1: Push button switch 2: Case 3: Operating body 10: Fixed contact pattern 11: First switch terminal 12: Second switch terminal 13: Third switch terminal 14: Ground terminal 20: Printed circuit board 21: Circuit board 22: LED 23: Resistor 30: Base 31: Base body 32: Locking claw 33: Circular base 34: Shaft 35: Inclined surface 40: Top case 41: Top plate 42: Side plate 43: Locking claw 44: Mounting piece 45: Locking hole 50: Movable contact brush 51: Metal plate 52: Leaf spring piece 53: Curved portion 54: Contact portion 55: First switch contact portion 56: Second switch contact portion 57: Third switch contact portion 58: Ground contact portion 60: Button 61: Button body 62: Operating portion 63: Locking hole 64: Recess 70: Actuator 71: Actuator body 72: Convex portion 73: Upper projection 74: Lower projection 80: Spring holder 81: Holder body 82: Container 83: Coil spring 84: Click piece 90: Rotor 91: Rotor body 92: Upper gear 93: Lower gear 94: Bearing 95: Arc cam 96: Arc cam 97: Arc cam 98: Circular cam

Claims

1. A push button switch comprising: a base having a plurality of terminals arranged spaced apart on the same circumference; a movable contact brush having a plurality of contact portions arranged on the plurality of terminals; a rotor having a cam for bringing the plurality of contact portions into contact with or separating them from the plurality of terminals and supported rotatably around the axis of the base; an actuator that abuts against a gear provided on the rotor and moves in a direction perpendicular to the axis of the base to rotate the rotor; and a button that abuts against the actuator, moves the actuator when pressed, and returns elastically to its original position due to a spring force.

2. The push button switch described in claim 1, characterized in that the mechanism for rotating the rotor by the actuator is composed of upper and lower protrusions arranged opposite the actuator, and an upper gear that is stacked in two stages on the rotor, with the upper protrusion abutting against it and a lower gear that abuts against the lower protrusion, and the upper gear and the lower gear have different rotation radii and their gear teeth are positioned offset from each other in the rotation direction.

3. A push button switch as claimed in claim 1 or 2, characterized in that the mechanism for elastically returning the button comprises an inclined surface provided on the base, and a spring holder which houses a coil spring compressed by the actuator and is pressed against the inclined surface by the repulsive force of the spring.

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