JPS643141Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention provides a tension coil spring that is mounted between an actuating piece and a movable contact piece, and presses the actuating piece by applying an external force. Regarding the improvement of a switch switching mechanism that switches the switch by reversing the movable contact piece through the The tension coil spring is brought into contact with a fixed fulcrum for the tension coil spring formed on the upper surface, and the tension coil spring is bent into an arched shape around this fulcrum, thereby causing the tension coil spring to return to its straight state (normal state). This invention relates to a switching mechanism for a switch that uses force to make the switching operation of the switch more reliable.

According to the switch switching mechanism according to the present invention, it is possible to roughly set the position at which the actuating piece stops being pressed by an external force, and the stroke of the pressing operation can be increased. This is an extremely advantageous switch switching mechanism for practical use.

[Prior Art] A conventional switch switching mechanism utilizes the principle of a snap action, and simply includes an actuating piece and a movable contact piece with a tension coil spring mounted between the actuating piece. By pressing the operating piece, the movable contact piece is reversed and the switch is switched.

[Problems to be solved by the invention] In the conventional switch switching mechanism, sufficient care must be taken in setting the pressure stopper of the actuating piece. There was a drawback that the traction force of the spring sometimes did not work sufficiently. For example, when the actuating piece is pressed, the axial center line (hereinafter referred to as the line of action) of the tension coil spring installed between the actuating piece and the movable contact piece may exceed the pivot point of the actuating piece even slightly due to wear of the stopper, etc. Once this happens, the actuating piece will no longer be able to return to its original state due to the traction force of the tension coil spring, and the switch switching mechanism will no longer function.

Furthermore, in the conventional mechanism, as mentioned above, it is difficult to take a large stroke of the push rod that presses the actuating piece in order to prevent the line of action of the tension coil spring from exceeding the pivot point of the actuating piece. It would be mechanically unreasonable to apply this to a small switch that employs a heart cam type push button lock mechanism, for example, where the stroke is relatively large.

Therefore, an object of the present invention is to provide a switch switching mechanism that overcomes the above-mentioned drawbacks, in which when the actuating piece is pressed down, the tension coil spring mounted between the actuating piece and the movable contact piece is activated. , forcibly collides with a fixed fulcrum for the spring formed at a suitable location within the switch, thereby bending the tension coil spring into an arched shape, and causing the curved tension coil spring to return to its normal straight state. To provide a switch switching mechanism which uses force to always apply a restoring force to an actuating piece and ensures reliable switching.

Another purpose of the present invention is that the pressing stop position of the actuating piece can be roughly set and the pressing operation stroke can be relatively large, so that the press rod or operating plate that presses the actuating piece can be locked. It is an object of the present invention to provide a switch switching mechanism that is extremely advantageous in putting into practical use a small switch equipped with, for example, a heart cam type locking mechanism that requires a relatively large stroke.

Still another object of the present invention is that even if the stopper of the temporary actuating piece or the contact part of the movable contact piece is worn out due to repeated switching operations, the stopper or contact part is To provide a switch switching mechanism capable of smoothly switching a switch almost unchanged from an initial state in which the switch is not worn out.

[Means for Solving the Problem] The present invention provides a pair of support pieces integrally formed with a common terminal on the upper surface of the switch base, and a pair of support pieces formed integrally with the common terminal on both sides of the support pieces in a direction orthogonal to the plate thickness direction. An actuating piece is provided with a notch with a step, and pivots both ends of a movable contact piece formed in a U-shape with one of the notches as a pivot point, and the other notch is formed in a U-shape with the other notch as a pivot point. A tension coil spring having hook portions at both ends is mounted on each locking portion of the movable contact piece and the actuating piece, and the end portions of the movable contact piece and the actuating piece are pivoted to face the movable contact piece and the actuating piece. By pressing the piece,
In the switch mechanism that reverses the movable contact piece via the tension coil spring to switch between fixed contacts disposed above and below the movable contact piece, the switch base is located between the movable contact piece and the operating piece. A raised part is formed on the upper surface, and the raised part is in a position where, when the actuating piece is pressed, the raised part comes into contact with a substantially central portion in the longitudinal direction of the tension coil spring, causing the tension coil spring to curve. This is a switch switching mechanism characterized by serving as a fixed fulcrum for a hot spring.

[Embodiment] An embodiment of the present invention will be described below along with an example of a small illuminated push button switch equipped with the switch switching mechanism.

FIG. 1 is a schematic partially cut away cross-sectional view showing the main parts of an illuminated push button switch constructed by applying an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the main parts of the switch.
FIG. 3 is an enlarged central sectional view thereof. In these figures, numeral 1 indicates a switch housing;
The housing 1 has an open end face 1a, and is partitioned into an upper space in which the operating shaft 3 slides up and down and a lower space in which the switch member 2 is housed, by a flat part 1b provided approximately at the center. ing. Inside the housing 1 from the direction of the open end surface 1a of the housing 1, there are a push button 6, a converter 4, and a support frame 5.
An operating shaft 3 composed of the above is inserted and is slidably arranged. On the other hand, the base end 1c of the housing 1
A switch base 2A on which a switch member 2, which will be described later, is arranged is attached to the switch base 2A. The housing 1 and the switch base 2A have a plurality of recesses 1d, 1d... formed in the base end 1c of the housing 1, and a plurality of engagement holes formed in the side faces 2a, 2a of the switch base 2A. The mating convex portions 2b, 2b, . . . are engaged with each other to be attached.

Now, to first explain the switch member 2 used in this embodiment, on the switch base 2A are the NC fixing piece 20 that constitutes the switch member 2, and the NO.
A fixed piece 21 and a supporting piece 22 having a pair of rising portions 22a, 22a are respectively provided.
The NC fixing piece 20 and the NO fixing piece 21 serve as an NC contact terminal 23 and an NO contact terminal 24, respectively, which penetrate the bottom wall of the switch base 2A, and the support piece 22 is attached to the bottom of the switch base 2A. It also serves as a common terminal 25 that penetrates the wall. Notches 26a, 26b (shown in FIG. 1) with steps are formed on both sides of each rising portion 22a, 22a of this support piece 22, and the notches 26a, 26b (shown in FIG. Contact 27a
An actuating piece 29 is pressed by an operating plate 28, which will be described later, as a push rod, using the side end 27b of the movable contact piece 27 and the notch 26b as a pivot point.
The side end portions 29a of each are rotatably supported. Then, one end of the tension coil spring 30 is locked to the movable contact piece 27 and the other end is locked to the actuation piece 29, and when the operation plate 28 presses the actuation piece 29, the tension coil spring 3
The line of action on the movable contact piece 27 side of the movable contact piece 27 crosses the pivot point of the movable contact piece 27, thereby imparting reversibility so that the movable contact piece 27 can be reversed. In this embodiment, an operation plate designated by the reference numeral 28 functions to transmit the operation of the push button 6 to the switch member 2. That is, the operation plate 28 is guided by the inner wall surface 1e of the housing 1 and the vertical pieces 2e, 2e of the pair of upright pieces 2d, 2d provided on the switch base 2A, so that it can freely slide in the vertical direction. The converter 4 is connected to the operating shaft 3 by engaging the engaging claw 4b of the converter 4 with the downward step portion 28 formed on the inner upper end thereof. By coming into contact with the downward step portion 1f (shown in FIG. 3) formed on the inner wall surface 1e,
It is designed to prevent it from slipping upward. Housing 1
A heart cam 31 is formed on one surface of the operation plate 28 facing the inner wall surface 1e of the switch base 2A.
The free end 32b of the pin 32 is slidably engaged with the pin 32.

To further explain the switch switching mechanism, as shown in FIG. It is housed within the open space formed by the notch 29b and on the protrusion 2B formed on the upper surface of the switch base 2A. This raised part 2
At position B, when the operating piece 29 is pushed down by the operation plate 28, the tension coil spring 30 comes into contact with this protrusion 2B, as shown in FIG. 30 is forcibly curved. Before the tension coil spring 30 comes into contact with the raised portion 2B, the line of action of the tension coil spring 30 on the movable contact piece 27 side crosses the pivot point (notch 26a) of the movable contact piece 27, and the above-mentioned The movable contact piece 27 is configured to be reversed.

That is, the horizontal portion 28 extending from the operation plate 28
At the time when the lower end surfaces 28c, 28 of b, 28b collide with the actuating piece 29 and a downward pressing force begins to be applied, the movable contact piece 27a is in a state of contacting the NC contact 20a (see Fig. 1). When a sufficient pressing force is applied to the actuating piece 29 and the axis of the spring 30 crosses the pivot point of the movable contact piece 27, the movable contact piece 27 is turned around the pivot point to the NO contact 21a side. The switch changes from the NC contact 20a to the NO contact 21a (see Figure 5).

On the other hand, regarding the actuation piece 29, since the tension coil spring 30 collides with the protrusion 2B and is curved, a bending restoring force is generated in the tension coil spring 30 to return to the straight state, and the actuation piece 29
The bending restoring force always applies a force that tries to return to the original state.

Furthermore, by selecting the position of the raised portion 2B, which is a fixed fulcrum for the spring, with respect to the pivot point of the actuating piece 29, in addition to the bending restoring force of the tension coil spring 30 described above, the spring force along the line of action is It is possible to further add restoring force through tension (traction force).

That is, as for the position of the raised portion, the line of action of the curved tension coil spring 30 on the movable contact piece 27 side exceeds the pivot point of the movable contact piece 27, and the line of action on the side of the actuating piece 29 crosses the pivot point of the movable contact piece 27. If the position is selected so that it does not exceed the pivot point of , 26b), as shown in FIG.
9 is pressed down and the movable contact piece 27 is inverted, the movable contact piece 27 of the tension coil spring 30
The line of action on the side is the fulcrum A of the movable contact piece 27 (notch 26
a), but there is a step at the pivot point (fulcrum A).
and B) and the spring 3 on the switch base 2A.
By providing the raised portion 2B, which is a fixed fulcrum at 0, the line of action of the tension coil spring 30 on the actuating piece 29 side does not exceed the pivot point B (notch 26b) of the actuating piece 29, and the actuating piece 29 An upward restoring force due to the tension of the tension coil spring 30 is always acting.

In this way, in addition to the restoring force due to the bending of the tension coil spring 30 described above, the restoring force due to this spring tension (traction force) is added, making it possible to provide an even stronger restoring force.

Further, a lamp terminal 9 for a light emitting body is provided at the center of the switch base 2A, and is provided through the bottom wall of the switch base 2A.

Now, the operating shaft 3 includes a converter 4 for opening and closing the switch member 2, and is molded separately from the converter 4, is attached to the converter 4, and has a light emitter 7.
The support frame 5 includes a support frame 5 having a through hole 3a for inserting and locking the support frame 5 from below, and a push button 6 that is attached to the support frame 5. Of these, the converter 4 is formed with two left and right engaging claw pieces 4b, 4b having elasticity hanging from the lower end surface 4a, as described above.
One of the engaging claw pieces 4b is elastically engaged with the downward stepped portion 28a of the operation plate 28, as described above.
The other engaging claw piece 4b is attached to the sliding plate 3 as shown in FIG.
It is elastically engaged with the downward step portion 33a of No.3. Therefore, the operation plate 28 is connected to the inner wall surface 1e of the housing 1.
Not only that, but it is further guided by the side surfaces 2e, 2e of the pair of upright pieces 2d, 2d that stand up from the switch base 2A, and slides smoothly up and down. Then, the free end 32b of the hook pin 32, whose one end bent portion 32a is attached to the side hole 2c of the switch base 2A, slides within the heart cam 31 provided on the operation plate 28, and It is designed to lock vertical movement. on the other hand,
A compression spring 33b is mounted between the sliding plate 33 and the switch base 2A, and the sliding plate 33 is adapted to slide along a guide provided in the housing 1.

In this way, the operation plate 28 is connected to the tension coil spring 3.
0 and the sliding plate 3 disposed on the opposite surface of the operation plate 28 in the housing 1.
Due to the upward biasing force of the compression spring 33b on the switch 3, the converter 4 is biased upward with an average force, and as a result, the push button 6 slides smoothly within the housing 1.

Now, returning to FIGS. 1 to 3, the operating shaft 3
The push button 6 that constitutes a part of the leg pieces 6a, 6a, .
b, 6b, . . . are attached to the converter 4 by being elastically attached to grooves 4c, 4c, . . . provided in the converter 4. Then, the light is effectively emitted upward from the light emitting body 7 from, for example, the top surface of the push button 6 through a lens 11 disposed inside the push button 6.

The light-emitting body indicated by the reference numeral 7 has a light-emitting portion 7a protruding from the upper end surface 5a of the support frame 5, and an annular portion 7c having a stepped portion 7b formed of an insulator through the through hole formed in the support frame 5. By inserting it into the hole 3a, it is locked to the support frame 5, and the light emitting body 7
Two pin terminals 7d, 7d are housed in the housing 1 so as to protrude from the lower end surface of the support frame 5. The light emitting body 7 may be a light emitting diode, a miniature light bulb having a filament, a neon bulb, or the like, as long as it has a pin terminal.

As shown in FIGS. 3 and 4, below the light emitting body 7, it is inserted and guided into a cylindrical portion 1g that is a movement guide for the illumination unit formed in the housing 1, and is pushed upward by a conductive compression spring 10, which will be described later. It is provided with a biased socket 8 (see FIG. 4). In the longitudinal direction of this socket 8, two of the light emitters 7 are arranged.
A pair of through holes 8a, 8a are provided for inserting and holding the main pin terminals 7d, 7d, and each of the through holes 8a, 8a has a downward step portion pressed against the upper end of the compression spring 10. 8b, 8b are formed. This socket 8 is made of an insulator, and the terminal 7 of the light emitter 7 is located near the stepped portions 8b, 8b in the respective through holes 8a, 8a.
A socket fitting 8c is inserted which comes into contact with the pin terminals 7d, 7d of the light emitting body 7 and the spring 10 when the terminals d, 7d are inserted from above. As shown in FIG. 3, the socket 8 is connected to the lamp terminals 9, 9 for the light emitter, one end of which is located inside the housing 1 and the other end of which protrudes outward from the base 2A. , the upper end is the stepped portion 8 of the socket 8.
The spring 10 is mounted with the lower ends of the lamp terminals 9 and 9 in pressure contact with the ends 9a and 9a of the lamp terminals 9, 9, and thereby the light emitting body 7 and the lamp terminal 9 are connected to each other. electrically connected.

Thus, in this embodiment, when the push button 6 is pressed, the converter 4, the support frame 5, the light emitter 7 and the socket 8 below the push button 6 can simultaneously move downward. In addition, in order to apply a pressing force to the push button 6 to complete the switch switching operation and to prevent the push button 6 from further lowering, for example, a step (not shown) is formed on the inner wall surface 1e of the housing 1, and the A protrusion that comes into contact with the stepped portion may be formed on the outer wall of the push button 6, converter 4, etc. that constitute the operation shaft 3, for example, 3b.

Reference numeral 12 denotes holes 12a, 12a that fit into protrusions 1i, 1i, . . . provided on the outer periphery of the housing 1.
This elastic plate 12 and the flange 1j of the housing are members used to attach this switch to a panel (not shown).

[Effect of the idea] The present invention has the following effects.

(1) After the movable contact piece is reversed, the raised part becomes a fixed fulcrum for the spring, and the tension coil spring is bent by the pressure of the actuation piece, so it is activated by the bending restoring force that causes the curved tension coil spring to return to its straight state. A large return force can be obtained for the piece, and therefore a switch switching mechanism with high return safety can be obtained.

(2) Even if the pressing stroke of the actuating piece is increased, the bending restoring force of the tension coil spring increases accordingly, so the pressing stroke can be increased without worrying that the restoring force will disappear. Therefore, this is an extremely advantageous switch switching mechanism for putting into practical use a switch that employs a heart cam type push button locking mechanism, for example.

Furthermore, the end position of the pressing stroke can be roughly set.

(3) The return force of the actuating piece is given by the bending restoring force of the tension coil spring, and is hardly affected by wear of the stopper of the actuating piece, wear of the contacts, wear of the pivot point, etc., so it is always in the initial state. Similarly, the switch can be switched smoothly and reliably.

[Brief explanation of the drawing]

Fig. 1 is a partially cut away sectional view showing the main parts of an example in which the switch switching mechanism according to the present invention is applied to an illuminated push button switch, Fig. 2 is an exploded perspective view of the main parts of the component, and Fig. 3 is Fig. 1 is an enlarged central cross-sectional view, Fig. 4 is a schematic view of the pin terminal socket of the light emitter inserted into the cylindrical part provided in the switch housing, as seen from the direction of the switch base, and Fig. 5 is the present invention. 6 is an explanatory diagram of the switch switching mechanism related to
A top view of the figure is shown.

Claims (1)

[Claims for Utility Model Registration] 1. A pair of support pieces integrally formed with a common terminal are disposed on the upper surface of the switch base, and the support pieces have steps on both sides in a direction perpendicular to the plate thickness direction. A notch is provided, and both ends of a movable contact piece formed in a U-shape are pivoted with one of the notches as a pivot point, and both ends of an actuating piece are formed in a U-shape with the other notch as a pivot point. The movable contact piece and the actuating piece are pivoted so that the movable contact piece and the actuating piece face each other, and a tension coil spring having hook portions at both ends is mounted on each locking part of the movable contact piece and the actuating piece, and the actuating piece is pressed. In this switch mechanism, the movable contact piece is reversed via the tension coil spring and the fixed contacts disposed above and below the movable contact piece are switched. A raised part is formed on the upper surface of the switch base, and when the actuating piece is pressed, the raised part
A switch switching mechanism characterized in that the protrusion comes into contact with a substantially central portion in the longitudinal direction of the tension coil spring, is in a position to curve the tension coil spring, and serves as a fixed fulcrum for the spring. 2. The position of the raised portion is such that the line of action of the movable contact side of the curved tension coil spring does not exceed the pivot point of the movable contact piece, and the line of action of the actuation side does not exceed the pivot point of the actuation piece. The switch switching mechanism according to claim 1 of the utility model registration claim, which is located in such a position.