JPH0544977Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a switch, particularly a detection switch suitable for application to a VTR cassette, a floppy disk drive device, etc.

<Summary of the invention> This is a switch in which a single torsion coil spring serves as both the spring for returning the push button and the movable piece.The torsion coil spring constantly presses the push button and fixes one end to one of the terminals. The other end is brought into selective contact with another terminal by pressing the push button.

<Prior Art> In a conventional detection switch, for example, as shown in FIG. 8, a common terminal 2 and a normally open terminal 3 are fixed on a base 1. is fixed. A cover 5 covering the base 1 supports a push button 6 so as to be movable in its axial direction, and its lower end is in contact with the free end of a lever 7 whose base end is fixed to the cover 5.

The movable piece 4 has a spring property, and its contact 4a is always urged away from the normally open terminal 3, and its free end comes into contact with the lever 7, so that the lever 7 also pushes the push button 6 upward at all times. energized. When push button 6 is pressed downward, lever 7 moves movable piece 4
is pressed, the contact point 4a contacts the normally open terminal 3, the common terminal 2 and the normally open terminal 3 are brought into conduction, the circuit is closed, and the object to be detected is detected.

<Problems to be solved by the invention> However, in such a conventional structure, since the movable piece 4 and the lever 7 are formed of thin plate springs, it is difficult to manage the load and the stroker in terms of operating force and contact pressure. There were also other problems, such as bending during assembly and the possibility of only being configured as a normally open type.

Therefore, the purpose of this invention is to provide an improved switch that can easily manage load and stroke and can be configured into various types.

<Means for Solving the Problems> The slide switch according to this invention has a common terminal, a normally closed terminal, and a normally open terminal provided on a case or base, and is movably supported by a cover covering the case or base. a push button; pressing and urging the push button toward the cover;
A torsion whose one end is fixed to the common terminal and whose other end selectively contacts the contact portions of the normally closed terminal and the normally open terminal by a pressing operation of the push button along a guide groove formed in the case or base. A coil spring is provided, and the contact portions of the normally closed terminal and the normally open terminal are visible from the bottom of the guide groove.

<Example> An example of this invention is shown in FIGS. 1 to 3. In the case 11 made of resin, an L-shaped common terminal 12, a normally closed terminal 13, and a normally open terminal 14 are arranged in a row by insert molding, each facing downward. The common terminal 12 and the normally closed and normally open terminals 13 and 14 are connected to the case 1 so that a part of their horizontal parts are separated in a direction perpendicular to the arrangement direction, and the horizontal part of the common terminal 12 is located one step higher.
1 and constitute contact portions 12a, 13a, and 14a. The contact portion 12a of the common terminal 12 is
A locking protrusion 15 is provided on the upper surface of the contact portion 13a, 14a of the normally closed and normally open terminals 13, 14.
is peeking out from the bottom of the guide groove 16.

The conductive torsion coil spring 17 has end portions 17a and 17b extending from both sides forming a V-shape. One end 17a is bent in the horizontal direction and is locked to the locking protrusion 15 of the common terminal 12, and the other end 17b is bent upward and its lower part is the contact part of the normally closed terminal 13. 13a.

The top of the coil portion 17c of the torsion coil spring 17 is in contact with the bottom of the lower flange portion 18a of the push button 18. The push button 18 is inserted from below into a guide hole 20 provided in a cover 19 fixed to the upper opening of the case 11 so as to be movable up and down.
9 is attached to the case 11, the flange portion 18 of the torsion coil spring 17 is restored.
The upper surface of a is brought into pressure contact with the lower surface of the cover 19. The guide hole 20 is formed in a shaft portion 19a that is formed upright on the upper surface of the cover 19 to ensure vertical movement of the push button 18.

When the push button 18 is pressed downward, its bottom presses down the coil portion 17c of the torsion coil spring 17. Since one end 17a of the torsion coil spring 17 is locked to the locking protrusion 15 of the common terminal 12, the pressed coil spring 17 is locked to the other end 17.
b moves outward in the guide groove 16 from above the contact portion 13a of the normally closed terminal 13 and is positioned above the contact portion 14a of the normally open terminal 14. When the pressure on the push button 18 is released, the push button 18 rises due to the return force of the torsion coil spring 17, and the coil spring 1
The other end 17b of 7 moves from above the contact portion 14a of the normally open terminal 14 to above the contact portion 13a of the normally closed terminal 13.
In this way, the normally closed terminal 13 and the normally open terminal 14 are alternately switched, and a double-throw switch is realized.

Another embodiment of this invention is shown in FIGS. 4-6. The difference from the above embodiment is that a double type torsion coil spring 17 is used, and the terminals 12, 13, 14 are arranged in two rows on both sides. That is, the torsion coil spring 17 is made by connecting two symmetrical coil springs 17c and 17d, each having one end 17a common to the other at the middle part, and having one extending common end 17a and the other outer end 17b. forms a V-shape. The common terminal 12 is continuous in a U-shape and is connected to the case 11.
It has a locking protrusion 15 in its middle part exposed to the .
Each normally closed and normally open terminal 13, 14 is connected to the case 11.
The contact portions 13 are arranged on both sides of the inner
a, 14a are peeking out from the bottom of the guide groove 16 inside the case 11.

In this embodiment as well, when the push button 18 is pressed down, the two coil parts 17c and 17d of the torsion coil spring 17 are pushed down at the bottom, and the other ends 17b on both sides move inside the guide groove 16 into contact with the normally closed terminal 13. It moves from above the part 13a to above the contact part 14a of the normally open terminal 14. When the push button 18 is released,
The push button 18 is pushed up by the return force of the coil spring 17, and the other end 1 of the coil spring 17
7b returns onto the contact portion 13a of the normally closed terminal 13. In the case of this embodiment, the common terminal 12, the normally closed terminal 13,
Since there are two normally open terminals 14, the circuit on one terminal side is conductive, so the reliability of the switch can be improved.

In yet another embodiment of the invention shown in FIG. 7, the contact portion of the lower surface of the push button 18 with the torsion coil spring 17 is inclined at an angle α in the direction of movement of the coil. Due to the presence of this slope 18b, the stroke of the pusher holder 18 becomes large, and the margin becomes large.

Each of the above embodiments has a structure in which a box-shaped case in which terminals etc. are provided is covered with a plate-shaped cover, but the structure is such that the terminals etc. are provided in a plate-shaped or block-shaped base and this is covered with a box-shaped cover. It may be. In addition, the push button is not limited to the one shown in the figure, but may have various shapes,
structure can be used.

<Effects of the invention> As described above, the switch according to this invention has a common terminal, a normally closed terminal and a normally open terminal, and these normally closed terminals and normally open terminals are connected to a torsion terminal that constitutes a movable contact piece. As a result of the selective contact of the coil springs, the normally closed and normally open terminals are alternately switched by the torsion coil spring to provide a double throw type switch.

In addition, in this invention, one end side of the torsion coil spring selectively contacts the contact portions of the normally closed terminal and the normally open terminal along the guide groove formed in the case or the base, and also contacts the normally closed terminal and the normally open terminal. As a result of installing the torsion coil spring so that it is visible from the bottom of the guide groove, one end of the torsion coil spring is reliably guided by the guide groove, preventing lateral vibration and deformation, and preventing normally closed terminals and normally open terminals. This stabilizes the contact pressure with the contact parts, resulting in a long-life switch.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a switch showing an embodiment of this invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 shows the cover and pushbutton of the switch shown in Fig. 1. The plan view, Figure 4, with .
A sectional view of a switch showing another embodiment of this invention,
Figure 5 is a cross-sectional view taken along line V-V in Figure 4;
8 is a plan view of the switch shown in FIG. 4 with the cover and push button removed; FIG. 7 is a sectional view of the switch showing yet another embodiment of the invention;
The figure is a sectional view showing an example of a conventional switch. 11...Case, 12...Common terminal, 13...
Normally closed terminal, 14... Normally open terminal, 16... Guide groove, 17... Torsion coil spring, 18... Push button, 19... Cover.

Claims (1)

[Scope of utility model registration request] A common terminal, a normally closed terminal, and a normally open terminal provided on a case or base, a push button movably supported by a cover that covers the case or base, and a push button that is biased toward the cover. One end is fixed to the common terminal, and the other end is selectively attached to the contact portion of the normally closed terminal and the normally open terminal by a pressing operation of the push button along a guide groove formed in the case or base. 1. A switch comprising a torsion coil spring in contact with the switch, and wherein the contact portions of the normally closed terminal and the normally open terminal are visible from the bottom of the guide groove.