JPH0684641U - Tactile switch - Google Patents

Abstract

(57) [Summary] [Purpose] The switch itself has a normally closed function. [Structure] Pusher 1 during normal operation without switch operation
Is pushed up by the dome contact 2, and at that time, the fixed contacts 5 and 6 provided on the covers 51 and 61 respectively come into contact with the movable contact 7 to short-circuit and become conductive, resulting in a normally closed state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tactile switch which is a switch with an operation feeling used for OA equipment, FA equipment, HA equipment and the like.

[0002]

[Prior art]

 As shown in the half cross-sectional view of FIG. 6, a conventional tactile switch includes a pusher 101, a dome contact 102 that is a movable contact pressed by the pusher, a cover 103 that houses them, an insulator 104, and an insulator. The insulator 104 is composed of fixed contacts 105 and 106 on the inner bottom surface of which the contact portions 105a and 106a are located. The outer peripheral portion of the dome contact 102 is in constant contact with the contact portion 106a of the fixed contact 106 from its upper surface. Further, the contact portion 105a of the fixed contact 105 is located below the central portion of the dome contact that is bent upward as shown in the figure, in a state of being separated from the central portion. The circuit diagram of this tactile switch is as shown in FIG. 7. Terminal numbers T1 and T2 correspond to the fixed contact 106, and terminal numbers T3 and T4 correspond to the fixed contact 105, respectively.

When the tactile switch having the conventional structure is operated (ON operation), the external pressure F is applied and the pusher 101 is pushed down. Then, the central portion of the dome contact 102 is pushed by the pusher 101, is inverted, and is bent downward, and the bent central portion is brought into contact with the contact portion 105a of the fixed contact 105, whereby the fixed contacts 105 and 106 are brought into contact with each other. Conducts through. When the external pressure F is released, the central portion of the dome contact 102 returns to the upper side again due to its elasticity, and the fixed contacts 105 and 106 become non-conductive.

[0004]

[Problems to be solved by the device]

 By the way, the above-mentioned conventional tactile switch is generally a so-called normally open type in which the fixed contacts are off in a steady state when the pusher 101 is not pressed down (that is, the tactile switch is not operated). Therefore, when using this type of tactile switch as a so-called normally closed type in which the fixed contacts are turned on in the steady state, for example, a flip-flop circuit mounted on the same substrate as this tactile switch It is necessary to adjust the state on the circuit such as maintaining the ON state. As a result, there is a problem that the circuit configuration becomes complicated and the cost increases.

Therefore, a technical problem of the present invention is to provide a tactile switch that can solve the above-mentioned conventional drawbacks and can make the switch itself have a normally closed function.

[0006]

[Means for Solving the Problems]

 According to the present invention, it is provided with a pusher, a dome contact that is elastically returned to a position before being pressed when the pusher is pressed and released, and a cover having a locking surface that locks the pusher. In the tactile switch, at least two fixed contacts are provided on the locking surface, and a movable contact that short-circuits the fixed contacts is provided at a portion of the pusher facing the locking surface. Is obtained.

[0007]

[Action]

 In the tactile switch of the present invention, the pusher is pushed up by the dome contact in the steady state when the switch is not operated. At this time, the pair of fixed contacts on the locking surface of the cover come into contact with the movable contacts at the opposite parts of the pusher, causing a short circuit and a conduction state. For this reason, the tactile switch is normally closed in the steady state. Then, when the pusher is pushed down, the short circuit due to the movable contact is released and the fixed contact becomes non-conducting open state.

[0008]

【Example】

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

FIG. 1 is a partial sectional view of a tactile switch according to an embodiment of the present invention. Referring to FIG. 1, a tactile switch according to an embodiment of the present invention includes a pair of covers 51 and 61 having an opening 65, a central protrusion 11 protruding from the opening 65 at one end, and a protrusion at the other end. The pusher 1 having the portion 13 and having the outer peripheral surface locked to the pair of covers 51 and 61, the movable contact 7 formed around the pusher 1, and the pushers of the pair of covers 51 and 61 are locked. It is provided with fixed contacts 5 and 6 formed on the surface, and a dome contact 2 which is convexly curved to come into contact with the protruding portion 13 of the pusher 1.

In the tactile switch of FIG. 1, the pusher 1 is pushed up by the dome contact 2 in a steady state when the switch is not operated. At this time, the pair of fixed contacts 5 and 6 on the engaging surfaces of the covers 51 and 61 respectively come into contact with the movable contacts 7 on the opposing portions of the pusher 1 to short-circuit and become conductive. For this reason, the tactile switch is normally closed in the steady state. Then, when the pusher 1 is pushed down, the short circuit due to the movable contact 7 is released and the fixed contacts 5 and 6 are brought into a non-conductive open state.

FIG. 2 is an exploded perspective view showing the overall structure of the tactile switch of FIG. 1, FIG. 3 (a) is a plan view showing the assembled state of the tactile switch of FIG. 1, and FIG. 1 is a sectional view showing the assembled state of the tactile switch of FIG. 1, FIG. 3 (c) is a diagram showing an equivalent circuit of the tactile switch of FIG. 1, and FIG. 4 is a sectional view showing a state where the pusher is pushed from the state of FIG. is there.

The tactile switch according to the embodiment of the present invention will be described in more detail with reference to FIGS. 2 to 4. The tactile switch according to the embodiment of the present invention comprises a pusher 1, a dome contact 2, an insulator 4, a first cover 51, a second cover 61, and a movable contact 7.

The first and second covers 51 and 61 are made of a conductive material, and the opposite ends (fitting surfaces) of the first and second covers 51 and 61 are provided with recesses 53 and 63 each having a half-moon cutout. Together, the opening 65 is formed. In FIG. 2, a plurality of fixed contacts 5 and 6 are formed along the recesses 53 and 63 on the surface of the first and second covers 51 and 61 on which the pusher 1 is abutted on the rear surface side. These fixed contacts 5 and 6 are made of, for example, a silver clad material. In addition, terminals 52 and 62 are formed at the lower ends of the first and second covers 51 and 61, respectively. These terminals 52 and 62 are inserted into the terminal holes 81 of the printed circuit board 8 as shown in FIG. 3 (b) and soldered or the like. Further, on both side surfaces of the first and second covers 51, 61, there are formed locking holes 54, 64 which are locked to the convex portions 41 provided on both side surfaces of the insulator 4 at the time of assembly. There is.

The movable contact 7 is ring-shaped, and its outer end face is plated with, for example, silver to improve conductivity. Further, the pusher 1 is composed of a central convex portion 11 which is a portion pressed down when the switch is operated, an outer peripheral portion 12 on which the movable contact 7 is mounted, and a protruding portion 13 which protrudes to the lower end side. The dome contact 2 is made of a conductive material such as a metal thin plate, or an elastic synthetic resin thin plate. Further, the central portion 21 of the dome contact 2 is formed in a convex shape on the pusher side as shown in the figure, which gives a feeling of operation when operating the switch and necessary elasticity. Further, the insulator 4 is formed with a concave portion 42 for accommodating the pusher 1, the dome contact 2 and the like, and the above-mentioned convex portions 41 for locking the cover are provided on both side surfaces.

In the switch of the embodiment having such a configuration, during normal operation without operating the switch shown in FIGS. 3A and 3B, the elasticity of the dome contact 2 pushes the pusher 1 upward, The movable contact 7 is pressed against the lower surfaces of the first and second covers 51 and 61 and locked, and thus the movable contact 7 mounted on the outer peripheral portion 12 of the pusher 1 is provided on the lower surfaces of the first and second covers 51 and 61. Touch the fixed contacts 5 and 6 respectively. Therefore, these fixed contacts 5 and 6 are short-circuited. The circuit diagram of the tactile switch at this time is as shown in FIG. 3 (c). The terminal number T1 corresponds to the fixed contact 5 and the terminal number T2 corresponds to the fixed contact 6, and the switch is normally closed.

FIG. 4 shows a state where the pusher 1 is pushed down from the state of FIG. That is, by pressing the pusher 1 against the elasticity of the dome contact 2 by the external force F, the contact between the fixed contacts 5 and 6 and the movable contact 7 is cut off, and the fixed contacts 5 and 6 are brought into the open state. Almost at the same time, the dome contact 2 is inverted, which gives the switch operator who presses the pusher 1 a feeling of operation. When the external force F is removed, the pusher is pushed up by the elasticity of the dome contact 2 and returns to the state shown in FIG.

Although the case where the tactile switch of the present invention is used alone has been described above, the tactile switch of the present invention can be used together with a conventional tactile switch. In this case, the conventional normally open type tactile switch includes, as described above, the pusher 101, the dome contact 102 pushed by the pusher 101, and the pair of fixed contacts 105, 106 which are conducted by the pushed dome contact 102. There is. Then, by using the conventional normally open type tactile switch and the normally closed type tactile switch of the present invention together and shorting their common terminals, they can be used as single pole, double throw tactile switches.

To explain this with reference to FIG. 5, in the two tactile switches used together, the fixed contact 5 and the fixed contact 106 respectively corresponding to the terminal number T1 are short-circuited to form the common terminal COM. As a result, the normally closed output is generated by the common terminal COM and the fixed contact 6 corresponding to the terminal number T2, and the normally open output is generated by the common terminal COM and the fixed contact 105 corresponding to the terminal numbers T3 to T4. Can be obtained.

[0019]

[Effect of device]

 As described above, in the tactile switch of the present invention, since the movable contact that short-circuits the fixed contacts provided on the cover is provided at the portion facing the fixed contact of the pusher, it has a normally closed function during steady operation. be able to. As a result, there is no need to make adjustments on the circuit for normally closed circuits as in the past, preventing the circuit configuration from becoming complicated and reducing costs.

[Brief description of drawings]

FIG. 1 is a partial half sectional view of a tactile switch according to an embodiment of the present invention.

2 is an exploded perspective view of the tactile switch of FIG. 1. FIG.

3A is a plan view of the tactile switch of FIG. 1 assembled, FIG. 3B is a sectional view of the same, and FIG. 3C is an equivalent circuit diagram thereof.

FIG. 4 is a cross-sectional view of an operation state in which a pusher is pushed down from the state of FIG.

FIG. 5 is a circuit diagram showing an example in which the tactile switch according to the embodiment of the present invention is used as a single-pole double-throw switch in combination with a conventional switch.

FIG. 6 is a sectional view of a conventional tactile switch.

FIG. 7 is a circuit diagram of the switch shown in FIG.

[Explanation of symbols]

 1,101 Pusher 2,102 Dome contact 4,104 Insulator 5,6,105,106 Fixed contact 7 Moving contact 51 First cover 51,52 Terminal 61 Second cover

Claims (1)

[Scope of utility model registration request] 1. A tactile comprising a pusher, a dome contact that is elastically returned to a position before the depression when the pusher is pressed and released, and a cover having a locking surface that locks the pusher. In the switch, at least two fixed contacts are provided on the locking surface, and a movable contact that short-circuits the fixed contacts is provided at a portion of the pusher facing the locking surface.