JPH0334018Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a push button switch used in terminal keyboards, typewriter keyboards, and the like.

(Prior Art) Some push button switches perform opening and closing operations by pressing a contact piece made of empty metal material with a protrusion of a stem made of resin material.

In this type of push button switch, the force required to open and close the contact piece varies depending on the size and shape of the contact piece. The piece is formed into a rectangular shape, one longitudinal end of which is fixed, and a contact point is formed at the other end.

The contact piece is generally arranged so that its longitudinal direction coincides with the advancing and retreating direction of the stem.

(Problem to be solved by the invention) By the way, the thickness of the push button switch as a whole can be made thinner by arranging the contact pieces perpendicularly to the advancing and retracting directions of the stem, rather than arranging them in the same direction as the advancing and retracting direction of the stem. There are advantages.

However, when the contact piece is arranged in a direction perpendicular to the advancing and retracting direction of the stem, the protrusion of the stem made of a resin material slides into contact with and presses the contact piece from the short side direction, which has high rigidity. The protrusions are prone to wear, and the abrasion of these protrusions causes fine particles to adhere to the contact points, resulting in poor contact and changes in the pressure sensation of the stem.

For this reason, push-button switches in which the contact pieces are arranged in a direction perpendicular to the forward and backward direction of the stem have not been applied to keyboards and the like that are operated frequently, although they have the above-mentioned advantages.

This invention was developed based on these circumstances, and it solves the above-mentioned problems by reducing the wear on the protrusion of the stem in a push button switch in which the contact piece is arranged in a direction perpendicular to the forward and backward direction of the stem. The purpose is to suppress the occurrence of such problems and to enable practical use of thin push button switches.

(Means for solving the problem) In order to achieve this object, this invention arranges a stem having a protrusion on its side so that it can move forward and backward in the case, fixes one end to the case side, and fixes the other end to the case. A push button switch is provided with a contact piece having a contact point, and the contact piece is pressed and displaced by the displacement of the protrusion as the stem advances and retreats to open and close the contact. An actuator made of a leaf spring material and having a pressing part for pressing the contact piece at its free end is installed in the case and extends in a direction perpendicular to the contact piece and the protrusion of the stem. The contact piece is moved toward and away from the contact piece by pressing the actuator with the protrusion.

(Function) According to this invention, the contact piece is made of a leaf spring material between the protrusion of the stem and the contact piece extending in a direction perpendicular to the direction of forward and backward movement of the stem, and the contact piece is provided at the free end of the contact piece. An actuator having a pressing part for pressing is interposed between the cases by standing upright, and the contact piece is moved toward and away from the contact piece by pressing the actuator with the protrusion. Since direct pressure from a high direction can be avoided and pressure can be applied via the actuator, it is possible to reduce the occurrence of wear on the protrusion of the stem.

Furthermore, even if the stem wears out, the fine particles caused by the wear are on the opposite side of the actuator from the contact piece, so it is difficult to enter between the contacts and cause poor contact.

Therefore, this actuator suppresses the conventional inconveniences that this type of push-button switch has, and allows application of thin push-button switches to keyboards and the like.

(Example) This invention will be explained below based on the drawings.

FIGS. 1 to 3 are diagrams illustrating an embodiment of this invention. In the figure, 1 is a case integrally molded from resin, and a stem storage part 2 formed in the center of this case 1 has a spring 3.
A stem 4 is disposed so as to be able to move forward and backward in the vertical direction.

Further, a protrusion 4a is formed on one side of the stem 4, and the protrusion 4a is vertically slidable in a guide groove 2a formed vertically so as to face the stem storage portion 2.

Further, a contact storage section 5 is formed between the stem storage section 2 and one side wall of the case 1, and by storing a contact member 6 in this contact storage section 5, each contact piece described below is placed on the case side. Fixed.

This contact member 6 has a frame 6A formed in a substantially U-shape, and an L-shaped fixed contact piece 6a and a movable contact piece 6b made of a conductive elastic material, which are provided by insert molding.

In this embodiment, these fixed contact pieces 6a
Terminals t ₁ and t ₂ are integrally formed on the movable contact piece 6b, and these terminals t ₁ and t ₂ are connected to the case 1.
It is made to extend outside of the .

In these fixed contact pieces 6a and movable contact pieces 6b, the original contact pieces other than the terminals t ₁ and t ₂ are formed in a rectangular shape horizontally inside the U-shape of the frame 6A. The tips of these parts are considered free ends.

At these free end portions, a contact S ₁ of the fixed contact piece 6a and a contact S ₂ of the movable contact piece 6b are provided facing each other, and these contacts S ₁ , S ₂
, the contacts S ₁ and S ₂ are in contact with each other when not pressed.

Note that the original contact piece portion of the movable contact piece 6b extending inside the U-shape of the frame 6A corresponds to the contact piece in this invention.

A pressed protrusion P is provided near the contact point _S2 of the movable contact piece 6b, and the pressed protrusion P has a width wider than the pressed protrusion P, which is formed at the free end of the pressing piece 7A that constitutes the actuator 7. Formed pressing part 7
a is in sliding contact.

That is, this actuator 7 is made of a corrosion-resistant leaf spring material such as phosphor bronze or stainless steel, and holes C formed on both sides of the lower end of the actuator 7 engage with protrusions (not shown) formed on the frame 6A of the contact member 6. The contact member 6 is supported by the case 1 through a contact member 6 supported by the case 1.

A notch 7b is formed approximately in the center of the actuator 7, so that the pressing piece 7A is provided in an upright manner, and the pressing portion 7a is formed at the upper end of the pressing piece 7A.

Therefore, the actuator 7 is interposed between the stem 4 and the contact member 6, and the protrusion 4a of the stem 4 presses or releases the pressure on the movable contact 6b via the pressing portion 7a according to the forward and backward movement of the stem 4. As a result, the fixed contact 6a and the movable contact 6b perform contact and separation operations.

In this case, the movable contact piece 6b moves in a direction perpendicular to the advancing and retreating direction of the stem 4, and the electrical circuit connected to the terminals _t1 and _t2 is opened and closed by the movement of the fixed contact _S1 and the movable contact _S2 . It is designed to ensure that

In this way, the protrusion 4a of the stem 4 is connected to the movable contact piece 6 by way of the actuator 7.
Since the contacts S ₁ and S ₂ are brought into contact and separated by pressing b, the protrusion 4a does not need to come into direct contact with the direction of the movable contact piece 6b in which the rigidity is higher, and wear on the protrusion 4a can be reduced. can.

Then, this actuator 7 has both contact pieces 6
Since it is installed between a, 6b and stem 4,
The structure is such that fine particles due to wear of the stem 4 do not easily enter one side of the contact, making it difficult to cause contact failure.

In addition, since the actuator 7 is made of a leaf spring material, it can follow the movement of the movable contact piece 6b well.
This has the advantage of being less likely to cause fatigue of the movable contact piece 6b.

In addition, in the figure, 8 is a holding plate attached to the case 1, and a stem 4 is installed in the center of this holding plate 8.
An insertion hole 8a is formed through which the upper part of the case 1 passes, and claws 8c of leg pieces 8b extending on both sides of the insertion hole 8a are engaged with engagement portions 1a formed on both sides of the case 1.

Further, the protrusion 4a of the stem 4 comes into contact with the edge of the through hole 8a of the holding plate 8, thereby preventing the stem 4 from slipping out upward.

Furthermore, 9 is a key top that fits into the head of the stem 4, and the stem 4 is moved forward and backward by pressing the key top 9.

With this structure, when the stem 4 is moved downward against the biasing force of the spring 3 as shown in FIG. 3, the pressing portion 7a of the pressing piece 7A and the protrusion 4a of the stem 4 are separated. However, the pressing piece 7A stands almost vertically due to its own restoring force.

Therefore, the pressing portion 7a of the pressing piece 7A does not apply a pressing force to the pressed projection P of the movable contact piece 6b, and S ₁ and S ₂ come into contact with each other due to the biasing force of the movable contact piece 6b itself.

On the other hand, when the downward pressure on the stem 4 is released, the stem 4 moves upward due to the biasing force of the spring 3, and the protrusion 4a of the stem 4 comes into sliding contact with the pressing portion 7a, thereby bending the pressing piece 7A.

As a result, the pressing portion 7a presses the pressed projection P, acts to move the movable contact piece 6b away from the fixed contact piece 6a, and separates the contacts S ₁ and S ₂ .

(Effects of the invention) As explained above, according to this invention, a plate spring material is formed between the contact piece extending in a direction perpendicular to the direction of forward and backward movement of the stem and the protrusion of the stem. , an actuator having a pressing part that presses the contact piece at its free end is installed upright in the case, and the contact piece is moved into and out of contact by pressing the actuator with the protrusion, so that the stem Since the protrusion can avoid direct pressure from the direction of the contact piece having high rigidity and can be pressed via the actuator, it is possible to reduce the occurrence of wear on the protrusion of the stem.

Furthermore, even if the stem wears out, the fine powder caused by the wear is difficult to enter between the contacts because it is on the opposite side of the actuator from the contact piece, and is unlikely to cause contact failure.

Therefore, this actuator suppresses the conventional inconveniences that this type of push-button switch has, and allows application of thin push-button switches to keyboards and the like.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view illustrating the push button switch according to this invention, Fig. 2 is a perspective view of the assembled state shown in Fig. 1 excluding the key top, and Fig. 3 is a side sectional view of the main part illustrating the action of the stem on the actuator. It is a diagram. DESCRIPTION OF SYMBOLS 1... Case, 4... Stem, 6a... Fixed contact piece, 6b... Movable contact piece, 7... Actuator, 7a... Pressing part.

Claims (1)

[Claim for Utility Model Registration] A stem with a protrusion formed on its side is arranged in a case so that it can move forward and backward, one end is fixed to the case side, and a contact piece having a contact point is provided at the other end, so that the stem can move forward and backward. The push button switch opens and closes the contact by pressing and displacing the contact piece by displacement of the protrusion caused by the displacement of the protrusion, wherein the contact piece extends in a direction perpendicular to the forward and backward movement direction of the stem, and the plate An actuator made of a spring material and having a pressing part that presses a contact piece at its free end is erected in the case, and is interposed between the contact piece and a protrusion of the stem, and the protrusion presses the actuator. A push-button switch characterized in that the contact piece is moved toward and away from the contact point by moving the contact piece toward and away from the contact point.