JPH0831254A - Push-button switch - Google Patents

Abstract

PURPOSE:To surely perform switching operation even in case that a user presses the periphery of a stem. CONSTITUTION:A round line material 3 having roughly circular cross section is used as the metallic member constituting a fixed contact 5, and also a mobile contact 12 in the shape of an elastic thin plate is provided between the dome- shaped spring member 11 driven by the stem 7 and the fixed contact 5. By pushing in the stem 7, resisting the spring member 11, the mobile contact 12 contacts with a pair of fixed contacts 5 and performs switching. The mobile contact has freedom, being provided separately from the spring member, so that mobile contact contacts with both a pair of fixed contacts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small push button switch suitable for taping packaging and automatic mounting.

[0002]

2. Description of the Related Art As a conventional example of this kind, Japanese Patent Laid-Open No. 5-32
As described in Japanese Patent No. 5710, the applicant of the present invention has proposed a fixed contact made of a part of a round wire.

FIG. 5 is a cross-sectional view showing a push button switch of this type. The push button switch has an opening 1 at the upper end, an insulating case 2 made of a synthetic resin material, and an insulating case 2 inserted at the time of molding. A pair of fixed contacts 5 formed by exposing a part of the round wire 3 to the inner bottom portion 4 of the insulating case 2, and a terminal formed by projecting another part of the round wire 3 to the outside of the insulating case 2. (Not shown) and a dome-shaped spring member 6 facing the fixed contact 5 in the insulating case 2 and forming a movable contact.
Then, a part is exposed from the opening 1, and the spring member 6 is fixed to the fixed contact 5
A stem 7 that can be pressed in the direction of, and a lid 8 that is attached to the upper end of the insulating case 2 and that prevents the stem 7 from coming off are provided.

In the push button switch thus constructed, when the operator presses the stem 7 downward in FIG. 5, the conductive dome-shaped spring member 6 is buckled and deformed, and the pair of fixed contacts 5 of the fixed contact 5 is pushed. The contact from both causes switching from off to on. Further, when the operator removes the pressing operation force on the stem 7 in the ON state, the stem 7 reaches the initial position as the spring member 6 returns to the initial state by the elastic force of the spring member 6 itself. By being pushed up, the spring member 6 separates from the fixed contact 5 and returns to the off state. In such a push button switch, since the round wire 3 constituting the fixed contacts 5 and the like can be cut with a relatively small shearing force, abrasion of the blade for cutting the terminal is suppressed, and the use of the round wire 3 reduces the material cost. It's cheap.

[0005]

By the way, in the above-mentioned conventional push button switch, when the operator presses the peripheral portion of the stem 7 (so-called end push operation) as shown by an arrow 9 in FIG. The spring member 6 is pressed in a state where the stem 7 is tilted, and the spring member 6 is pressed in an oblique direction, so that the spring member 6 is not buckled and deformed into a predetermined shape. There is a problem that the switching operation from off to on is unstable because the contact is made with only one of them.

The present invention has been made in view of the actual situation in the prior art as described above, and an object thereof is to provide a push button switch capable of surely performing a switching operation even when a peripheral portion of a stem is pressed. To provide.

[0007]

In order to achieve the above object, the present invention provides an insulating case made of a synthetic resin material and a part of a metal member inserted at the time of molding the insulating case in the insulating case. A pair of fixed contacts exposed on the bottom surface, a terminal formed by protruding a part of the metal member to the outside of the insulating case, a movable contact facing the fixed contact in the insulating case, and the movable contact. In a push button switch having a stem for bringing a contact into contact with the fixed contact, a round wire having a substantially circular cross-section is used as the metal member, and a thin plate having elasticity is used as the movable contact, and A dome-shaped spring member is provided between the stem and the movable contact, and the stem is pressed against the spring member so that the movable contact comes into contact with the fixed contact and slides. By being configured to perform the etching, and the most important features.

[0008]

When the operator pushes the stem against the elastic force of the dome-shaped spring member, the spring member buckles and deforms to press the thin plate-shaped movable contact, and this movable contact also elastically deforms. Then, the pair of fixed contacts are contacted, and switching from off to on is performed. Further, when the operator removes the pressing operation force on the stem in such an ON state, the spring member returns to the initial state by the elastic force of the spring member and pushes up the stem to the initial position, and the movable contact also has its own elasticity. The force separates from the fixed contact and returns to the off state.

Further, when the operator pushes the peripheral portion of the stem, the spring member is pushed in an oblique direction with the stem tilted, but the movable contact is provided separately from the spring member to provide a degree of freedom. Because of this, the movable contact elastically deforms in a stable state and contacts both the pair of fixed contacts. Therefore, the switching operation can be reliably performed even when the peripheral portion of the stem is pressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a push button switch according to an embodiment of the present invention, FIG. 2 is a sectional view showing the push button switch in an ON state, and FIG. 3 is a plan view showing a state in which a stem, a spring member and the like are removed from the push button switch. 4 and 5 are diagrams for explaining the operation of the movable contact provided in the push button switch. In these figures, the parts corresponding to those in FIGS. 5 and 6 are designated by the same reference numerals.
That is, 1 is an opening, 2 is an insulating case, 3 is a round wire rod, 4
Is an inner bottom portion, 5 is a fixed contact, 7 is a stem, and 8 is a lid.

The push button switch of the present embodiment is shown in FIG.
The difference from the conventional push button switch shown in FIG. 6 is that a dome-shaped spring member 11 facing the pair of fixed contacts 5 in the insulating case 2 is provided, and a phosphorus member is provided between these spring members 11 and the fixed contacts 5. There is a thin flat plate-like movable contact 12 having elasticity such as bronze or stainless steel,
Other configurations are basically the same.

In FIGS. 1 to 3, the insulating case 2 of the push button switch is formed by molding a synthetic resin material into a bottomed cylindrical shape. When the insulating case 2 is molded, two pre-pressed pieces are formed. After the round wire rods 3 are inserted in parallel and molded, and after molding, the terminal forming portion of each round wire rod 3 which protrudes to the outside of the insulating case 2 is bent and an unnecessary portion is cut off, a fixed contact is made from each round wire rod 3. 5 and terminals not shown are obtained. Although not shown in the drawing when the round wire rod 3 is preliminarily pressed, the round wire rod 3 is bent by pressing a die having a groove along the extending direction of the round wire rod 3 from below. Only the portion of the fixed contact 5 is projected upward from the other portions, and the groove forms the protrusion 5a at the lower portion of the fixed contact 5. As a result of such press working, after the insulating case 2 is molded, as shown in FIG. 3, the fixed contact 5 is exposed in the concave portion 4a and is arranged at the same diameter as the fixed contact 5 and at a lower position. The other part of the round wire 3 is also exposed to some extent.

At the upper end of the insulating case 2, as shown in FIG. 3, a plurality of mounting holes 2a for mounting the lid 8 are provided. The inner bottom portion 4 of the insulating case 2 has a fixed contact 5
And a step portion 4b provided around the recess 4a and located above the recess 4a. On the step portion 4b, both ends of the movable contact 12 on the short side are formed. While being placed, the peripheral portion of the dome-shaped spring member 11 is placed on the movable contact 12. Furthermore, since the stepped portion 4b receives both ends of the movable contact 12 having a rectangular shape as shown by the chain double-dashed line in FIG. 3, it projects in the same direction as the extending direction of the round wire rod 3 at two places, The wall thickness of the side wall of the insulating case 2 is thinner than the other portions at these two locations. As a result, the long side of the movable contact 12 is the round wire 3
The movable contact 12 is provided so as to extend in the same direction as the wire extension direction of the, and the movable contact 12 is provided so as to straddle the recess 4a so that the movable contact 12 is separated from the fixed contact 5 when the stem 7 is not operated. It has become.

In the push button switch constructed as described above, when the operator pushes the stem 7 against the elastic force of the spring member 11, the spring member 11 buckles and deforms, as shown in FIG. In order to press the movable contact 12,
2 also elastically deforms and comes into contact with the pair of fixed contacts 5, and switching from off to on is performed. Further, when the operator removes the pressing operation force on the stem 7 in the ON state, the spring member 11 returns to the initial state by its own elastic force, and the stem 7 is pushed up to the initial position in conjunction with the spring member 11. At the same time, the movable contact 12 is separated from the fixed contact 5 by its own elastic force and returns to the off state.

Further, when the operator presses the peripheral portion of the stem 7, the spring member 11 with the stem 7 tilted.
However, since the movable contact 12 is provided separately from the spring member 11 and has a degree of freedom, the movable contact 12 elastically deforms in a stable state and contacts both of the pair of fixed contacts 5. At this time, a force in the vertical direction (Z-axis direction) is applied to the movable contact 12 at a position deviated from the center of the movable contact 12 in the short side direction (X-axis direction), as shown in FIG. Since the movable contact 12 has a rectangular shape and the rigidity in the short side direction (X-axis direction) is greater than the rigidity in the long side direction (Y-axis direction), the movable contact 12 hardly bends in the short side direction (X-axis direction). The movable contact 12 is bent only in the (Y-axis direction), and as a result, the movable contact 12 is elastically deformed in a state of being substantially horizontal in the short-side direction (X-axis direction) and contacts both the pair of fixed contacts 5 as described above. It has become.

As described above, in the above embodiment, even when the peripheral portion of the stem 7 is pressed, the movable contact 12 is elastically deformed in a stable state in which the movable contact 12 is substantially horizontal in the short side direction. Since it contacts both of the pair of fixed contacts 5, the switching operation can be reliably performed. In addition, by embedding the protrusion 5a formed in the lower portion of the fixed contact 5 in the insulating case 2, the anti-rotation effect can be enhanced.

[0017]

As described above, according to the present invention,
When the peripheral part of the stem is pressed, the spring member is pressed diagonally with the stem tilted, but the movable contact is stable because the movable contact is provided separately from the spring member. In this state, the pair of fixed contacts can be brought into contact with each other to reliably perform the switching operation, so that the push button switch with good operability can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a push button switch according to an embodiment of the present invention.

FIG. 2 is a sectional view of the push button switch in an ON state.

FIG. 3 is a plan view showing a state in which a stem, a spring member and the like have been removed from the push button switch.

FIG. 4 is an operation explanatory view of a movable contact provided in the push button switch.

FIG. 5 is a sectional view showing a conventional example of a push button switch.

FIG. 6 is a cross-sectional view showing a state where a peripheral portion of a stem included in the push button switch is pressed.

[Explanation of symbols]

 1 Opening 2 Insulation Case 3 Round Wire (Metal Member) 4 Inner Bottom 4a Recess 4b Step 5 Fixed Contact 7 Stem 11 Spring Member 12 Moving Contact

Claims (3)

[Claims] 1. An insulating case made of a synthetic resin material, a pair of fixed contacts formed by exposing a part of a metal member inserted during molding of the insulating case to an inner bottom surface of the insulating case, and the metal member. A pushbutton switch comprising: a terminal, a part of which protrudes outward of the insulating case, a movable contact facing the fixed contact in the insulating case, and a stem for bringing the movable contact into contact with the fixed contact. A round wire having a substantially circular cross-sectional shape is used as the metal member, an elastic thin plate is used as the movable contact, and a dome-shaped spring member is provided between the stem and the movable contact. A push button characterized in that the movable contact comes into contact with the fixed contact to perform switching by pushing the stem against the spring member. switch. 2. The method according to claim 1, wherein a recess is provided in an inner bottom portion of the insulating case, the fixed contact is disposed in the recess, and the movable contact is disposed so as to straddle the recess. Push button switch characterized by being 3. The movable contact according to claim 1 or 2, wherein the movable contact has a rectangular shape, and its long side is arranged in the same direction as the extending direction of the metal member. Push button switch.