JPH0441538Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Field of the invention This invention relates to a small switch used, for example, as a detection switch for VCR cassettes, floppy disks, etc. More specifically, it relates to a small switch that is small but can be pressed sufficiently. This invention relates to a small switch that can adjust the stroke length.

(b) Background of the invention Conventionally, this type of small switch has been designed by pushing down a plunger 62 slidably supported by a switch case 61 against a return spring 63, as shown in FIGS. 6 and 7. By operating, a switching operation is performed via the fixed contact piece 64 and the movable contact piece 65 which corresponds to the contact/separation.

However, in this type of switch structure, as the switch is made smaller, the length of expansion and contraction of the return spring 63 is restricted, and the downward stroke of the plunger 62 is only small, and as a result, it is not suitable for making the switch smaller. It had a unique structure.

Further, the relationship between the pressing stroke of the plunger and the operating force depends on the spring characteristics of the return spring, and the operating force increases in proportion to the length of the pressing stroke. Therefore, in order to suppress the operating force, the initial load must be set small, and as a result, by setting the initial load small,
This may cause failure to return to the plunger.

Furthermore, during assembly, the coiled return spring is inconvenient to handle, and automatic assembly is particularly difficult, and the number of parts and assembly man-hours are large, resulting in high costs.

(c) Purpose of the invention The purpose of this invention is to provide a small switch that is small but can have a long pressing stroke.

(d) Structure of the device In this device, the conductive movable spring is fixed to one side wall of the switch base, and its free end is elastically bent to form a pressure receiving piece extending to the other side wall intersecting the direction in which the plunger is pressed down. The pressure-receiving piece protrudes from the pressure-receiving piece toward one side wall of the switch base so as to be elastically displaceable;
The small switch is characterized by being provided with a movable contact piece whose protruding tip is positioned at a position facing away from and into contact with a fixed contact surface based on a pressing operation of the plunger.

(e) Function of the device In this device, the movable contact piece of the conductive movable spring that is linked to the pressing operation of the plunger comes into contact with the fixed contact surface and turns ON, and when the plunger is released from the pressing operation, the movable contact piece contacts the fixed contact surface. It becomes OFF when separated.

(f) Effects of the invention According to this invention, the pressure-receiving piece of the conductive movable spring is disposed at a lateral position that intersects with the direction in which the plunger is pressed down, so that the lateral space inside the switch can be effectively utilized. The conductive movable spring can be provided.

Therefore, even if the switch is miniaturized, a long press-down stroke can be obtained by utilizing the leaf spring properties of the conductive movable spring, and there is no restriction on miniaturization due to the intervention of a coiled return spring as is currently the case. It disappears.

In addition, since a single conductive movable spring is provided with a pressure receiving piece that is linked to the pressing operation of the plunger and a movable contact piece that is formed on this pressure receiving piece and contacts and separates from the fixed contact surface, this single conductive movable The spring can perform both the elastic action for returning the plunger and the movable contact action for opening and closing between the contact parts, and by providing one conductive movable spring,
The number of parts is reduced, and based on this, it is possible to simplify the structure, facilitate automatic assembly, save space in the switch parts mounting section, and certainly reduce costs.

Furthermore, when the plunger is pressed down, the protruding tip of the movable contact piece comes into contact with and separates from the fixed contact surface, and the contact action at this time is such that the movable contact piece elastically displaces and slides on the fixed contact surface, causing the contact to A wiping effect for cleaning the surface can be obtained at the same time.

(g) Example of the invention An example of the invention will be described below in detail based on the drawings.

The drawings show a small switch, and in FIGS. 1 to 4, this small switch 11 is formed into a rectangular body by a switch cover 12 made of synthetic resin and a switch base 13, and the upper surface in the longitudinal direction A pair of plungers 14, 14 for performing a switching operation are protruded, and a common terminal 15 is provided on one side of the switch base 13 in the transverse direction, and a first terminal 16a and a second terminal 16b are provided on both sides of the common terminal 15.
is extended outward, and a switch mechanism 1 is provided inside.
7 is formed.

The switch cover 12 described above has an L-shape having an upper wall and a long side wall, and furthermore, both engaging protrusions 18, 18 extending from both sides of the side walls are formed on both sides of the lower part of the switch base 13. Engagement groove 19,1
By being engaged with 9, they are integrated.

The above-mentioned switch base 13 has a long side wall, both short side walls, and a bottom wall, and corresponds to the switch cover 12, and has terminals 15, 16a, 1 on the long side walls.
Each inner end of the switch base 13 is insert-molded so as to be exposed horizontally on the inner surface of the switch base 13,
These inner end portions are provided as the common contact portion 20, the first fixed contact portion 21a, and the second fixed contact portion 21b.

The above-mentioned switch mechanism 17 includes a plunger 14
, each contact portion 20, 21a, 21b, and a conductive movable spring 22.
is provided by punching out a conductive flat plate, and a pair of caulking holes 23, 2 for fixing are provided in the punched center part.
3, the conductive movable spring 22 is fixed in a conductive state to the caulking shafts 20a, 20a of the common contact portion 20 exposed on the side surface through the caulking holes 23, 23, and the conductive movable spring 22 is connected to the switch base. 1
Located along the inside wall of 3.

In addition, pressure receiving pieces 24, 2 are provided on both fixed end sides.
4 and the movable contact pieces 25, 25 at the elastic bending part 2.
6 and 26, respectively.

The pressure-receiving piece 24 extends substantially horizontally toward the other side wall intersecting the pressing direction of the plunger 14 that slides in the vertical direction, and is bent downward into a substantially U-shape with the extended pressure-receiving piece 24. elastic bending section 26
The inclined curved portion 24a continues between the lower end corner portion 29 of the plunger 14 and the inclined curved surface 24a.
The plunger 1 is brought into contact with the upward biasing action of the elastic bending portion 26, and is pressed down by this upward biasing action.
It has a restoring effect on 4.

The inclined curved surface 24a of the pressure receiving piece 24 is pressed down by a predetermined amount at the lower end corner portion 29 of the plungers 14, 14, which are normally vertically passed through the sliding holes 28, 28 on the upper surface of the switch cover 12 and are allowed to move up and down. is in a state of

On the other hand, the movable contact piece 25 is formed with a notch in the center of the extended tip of the pressure receiving piece 24, and protrudes horizontally toward the side wall surface of the switch base 13 so as to be elastically displaceable, and these protruding tips are movable. Contact part 2
7 and 27 are provided in close proximity to and away from the first fixed contact portion 21a and the second fixed contact portion 21b, respectively, so as to be spaced apart from each other.

In the figure, 30 is a vertical guide groove for the plunger, 31
is the elevation guide protrusion, and the switch base 1
3 is provided with an attachment hole 32 to the main body,
A mounting shaft 33 is provided on the other side.

The small switch configured in this way is configured such that when the plunger 14 is pressed down, the plunger 14
Since the lower end corner portion 29 presses down the inclined curved surface 24a of the conductive movable spring 22, the elastic bent portion 26 of the spring 22 is contracted and retreated.

Based on this elastic displacement, the movable contact piece 25 moves downward, and the movable contact portion 27 at the tip thereof is displaced laterally, and finally, the movable contact portion 27 at the tip thereof is displaced laterally, and finally becomes connected to the first or second fixed contact portion 21a, 21b opposite to the side. Touch to turn on.

Thereby, between the common contact part 20 and one fixed contact part 21a or 21b, the movable contact piece 2
5, conduction is established, and the state is closed.

In this case, when the plunger 14 is pressed down, the contact action when the movable contact portion 27 of the movable contact piece 25 comes into contact with the first or second fixed contact portion 21a, 21b is caused by the elastic displacement of the movable contact piece 25. By slidingly contacting the surfaces of the first or second fixed contact portions 21a and 21b, a wiping effect of cleaning the contact surfaces can be obtained at the same time.

Then, when the plunger 14 is released, the plunger 14 returns due to the upward biasing action of the inclined curved surface 24a, and the pressure receiving piece 24 and the movable contact piece 25
also returns to its original upward movement position.

As a result, the movable contact section 27 also moves upward and separates from the first or second fixed contact section 21a, 21b.
Returns to original open state.

Figure 5 shows the relationship between the operating force and the stroke length of the small switch of this invention. This figure shows that the pressure receiving piece sufficiently elastically displaces and absorbs the operating force through the plunger, resulting in a long stroke. It is recognized that the switch can be removed, and a switch suitable for miniaturization can be obtained. On the other hand, for reference, in the case of conventional small switches, the operating force increases rapidly in proportion to the stroke, as shown by the imaginary line, and as a result, the stroke length is limited, making it unsuitable for miniaturization. It is recognized that

As mentioned above, the pressure-receiving piece of the conductive movable spring is placed at a lateral position that intersects with the direction in which the plunger is pressed down, and the inclined curved surface is brought into contact with the pressure-receiving piece, making effective use of the lateral space inside the switch. , the conductive movable spring can be provided.

Therefore, even if the switch is miniaturized, a long press-down stroke can be obtained by utilizing the leaf spring properties of the conductive movable spring, and there is no restriction on miniaturization due to the intervention of a coiled return spring as is currently the case. It disappears.

In addition, a single conductive movable spring is provided with a pressure receiving piece that is continuous with an elastic curved surface that is linked to the pressing operation of the plunger, and a movable contact piece that is formed on this pressure receiving piece and that makes contact with and separates from the fixed contact part. With this one conductive movable spring, it is possible to perform both the elastic action for returning the plunger and the movable contact action for opening and closing between the contact parts, and by providing this one conductive movable spring, The number of parts is reduced, and based on this, it is possible to simplify the structure, facilitate automatic assembly, save space in the switch parts mounting section, and certainly reduce costs.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, and FIG. 1 is an exploded perspective view of a small switch, FIG. 2 is a partially cross-sectional plan view of the small switch, FIG. 3 is a partially vertical front view of the small switch, and FIG. The figure is a longitudinal side view of a small switch, Fig. 5 is a chart showing the relationship between plunger operating force and stroke length, Fig. 6 is a partial longitudinal side view of a conventional small switch, and Fig. 7 is a conventional small switch. FIG. DESCRIPTION OF SYMBOLS 11...Small switch, 13...Switch base, 14...Plunger, 17...Switch mechanism, 21a, 21b...Fixed contact part, 22...Conductive movable spring, 24...Pressure receiving piece, 25...Movable contact Piece 27...Movable contact part.

Claims (1)

[Scope of Claim for Utility Model Registration] A small switch that is operated via a conductive movable spring that is elastically displaced in conjunction with the pressing operation of a plunger, and the conductive movable spring is fixed to one side wall of the switch base and A pressure-receiving piece is formed by elastically bending the end side and extending to the other side wall intersecting the direction in which the plunger is pressed down, and the pressure-receiving piece protrudes from this to the one side wall of the switch base so as to be elastically displaceable. A small switch provided with a movable contact piece whose protruding tip is positioned at a position facing away from and into contact with a fixed contact surface based on a pressing operation of the plunger.