JPH0256771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an overcurrent automatic device that automatically cuts off the overcurrent when an overcurrent exceeding the allowable range flows through an electronic device or device, and can easily release the set state of the switch contact manually. This invention relates to an alternating cut-off push button switch.

Conventional switches of this type, such as so-called circuit breakers, have had problems in that they are not only complex in structure but also large in size.

The present invention has been made in view of the above-mentioned problems, and therefore, an object of the present invention is to create a new compact and highly reliable overcurrent system by simplifying the internal structure as much as possible. The purpose of the present invention is to provide an automatic shut-off device.

In order to achieve the above object, the overcurrent automatic cutoff alternating push button switch according to the present invention has a movable contact piece made of a material that warps when heated, with the center or one end of the movable contact piece as a fulcrum. A heart cam is disposed on the side surface of the push rod, a return spring is disposed below the heart cam, and the heart cam is provided with a return spring in the groove of the heart cam. The tip of one bent portion of a hook pin is engaged with the tip of the other bent portion as a fulcrum, and when the movable contact piece is heated, a tongue piece provided on one of the movable contact pieces holds the hook pin. By displacing the heart cam in a direction away from the groove, the push rod is unlocked and the movable contact piece is released from contact with the fixed contact.

Next, preferred embodiments of the present invention will be specifically explained with reference to the drawings.

Figures 1 to 7 show one embodiment of the present invention, of which Figure 1 is a partial sectional view with the cover removed to show the internal state of the switch in the OFF position, and Figure 2 is a partial cross-sectional view of the switch in the OFF position. FIG. 3 is a partially exploded perspective view, FIG. 4 and FIG. 5 are perspective views of essential parts showing each embodiment of the movable contact piece, and FIG.
FIG. 7 is an explanatory diagram of the operation.

In FIGS. 1 to 7, reference number 1 indicates a switch body, and inside the switch body 1 there is a fixed contact piece 2 having a fixed contact 2 ¹ and a terminal 2 ² led out to the outside, and a fixed A fixed contact piece 3 having a contact point 3 ¹ and a terminal 3 ² led out to the outside is provided. A hole ¹¹ is formed in a stepped portion provided approximately in the center of the switch body 1, and a shaft (rivet) 5 that rotatably supports a movable contact piece 4 is inserted into the hole ¹¹ . .

The movable contact piece 4 is a metal plate (e.g., bimetal, etc.) that warps when heat is applied.
fixed contacts 2 ¹ and 3 ¹ at both ends.
Movable contact pieces 4 ¹ and 4 ² selectively contact each other.
is provided. The movable contact piece 4 also has a cutout 4 ³ formed in the longitudinal direction, and a hole 4 ⁴ into which the shaft 5 is fitted is provided in the center of the cutout 4 3 . Movable contact 4 ²
is provided with a tongue piece ⁴⁵ for displacing the hook pin 6 outward when the movable contact piece 4 is heated and curved outward. The movable contact piece 4 is bent slightly inward as shown in FIG. 3 to increase the contact pressure between the movable contacts 4 ¹ , 4 ² and the fixed contacts 2 ¹ , 3 ¹ . This is desirable.

A sleeve ¹² projects from the upper part of the switch body 1, and a push rod (plunger) 7 is inserted through the sleeve ¹² so as to be movable up and down. The lower part of the push rod 7 is provided with two protrusions 7 ¹ that engage with a part of the movable contact piece 4 in order to rotate the movable contact piece 4 about the shaft 5 by moving it up and down. Further, a heart cam ⁷² is formed on the side surface of the push rod 7 near the protrusion ⁷¹ , with which the upper end of the hook pin 6 engages. Instead of providing the projection ⁷¹ on the push rod 7, as a modification, a leg piece (not shown) is provided on the movable contact piece 4,
The push rod 7 may be provided with an engaging portion (not shown) that engages with the leg piece so that the two are interlocked, and various other modifications of this connection method are conceivable. A return spring 8 for returning the push rod 7 is interposed between the lower end of the push rod 7 and the inner bottom of the main body 1. As the return spring 8, a coil spring or a bent spring plate is used. The hook pin 6 is supported with its bent lower end as a fulcrum on the inner bottom of the switch body 1, and its approximately middle portion is engaged with the tongue piece ⁴⁵ , and its bent upper end is connected to the heart cam ^72. The movable contact piece 4 is engaged with the cam groove of the cam groove, and is interlocked with the vertical movement of the push rod 7 and the rotation and outward displacement of the movable contact piece 4 due to heating.
While moving according to the cam groove of heart cam 7 ² ,
Displaces outward. Although the fulcrum of the hook pin 6 is provided below the heart cam ⁷² in this embodiment, it may be placed above the heart cam ⁷² .

In the vicinity of each of the fixed contacts 2 ¹ , 3 ¹ , stepped portions 9 ¹ , 9 ² having the same height as the fixed contacts 2 ¹ , 3 ¹ are provided, so that the movable contacts 4 ₁ , 4 This prevents the side surface of the movable contact from getting caught on the fixed contact when the ^switch rotates up and down, preventing the switch from turning on.

The inner surface ⁷³ of the push rod ⁷ surrounded by the cam groove of the heart cam 72 is formed lower than the outer peripheral surface ⁷⁴ . Therefore, the movable contact piece 4 caused by heating
When the hook pin 6 is removed from the heart cam 7 ² due to the force of outward warping, the bent portion of the upper end of the hook pin 6 is prevented from deviating from the cam groove of the heart cam 7 ² (the edge of the outer circumferential surface 7 ⁴ ). part becomes a stop).

Note that the hole ¹³ formed in the switch body 1 is a lip hole for attaching a cover (not shown), and the hole ¹⁴ is a hole for attaching a cover (not shown).
indicates the switch mounting hole. The switch according to the present invention may be mounted on a panel by using nuts on the screws of the sleeve ¹² , or by inserting screws into the mounting holes ¹⁴ provided on the side of the main body. The good news is obvious.

Next, to explain the operation, assume that the switch is currently in the "OFF" state as shown in FIG.
In this state, the upper bent portion of the hook pin 6 is at a rest position below the cam groove of the heart cam ⁷² , as seen in FIG. At this time, when the push rod 7 is pressed in the direction of arrow ^A and moved downward as shown in FIG. As a result, the movable contacts 4 ¹ and 4 ² are rotated, respectively, and the fixed contacts 2
¹ and 3 ² and the switch turns "ON". In this state, the upper bent portion of the hook pin 6 is at a resting position above the cam groove of the heart cam ⁷² , as seen in FIG.

In the state shown in FIG. 2, if an overcurrent flows through the switch circuit including the movable contact piece 4, the movable contact piece 4
is bent outward by the heat generated at that time, and as a result, it is reversed in the direction away from the fixed contacts 2 ¹ and 3 ¹ (in the direction of arrow C in FIG. 7). At the same time, the hook pin 6 is connected to the tongue piece 4 fixed to the movable contact piece 4 ^.
Similarly, the heart cam 72 is pulled in the direction of the arrow C and separated from the cam groove of the heart cam ⁷² . As a result, the lower position of the push rod is unlocked, and the push rod 7 is pressed in the direction of arrow B, that is, upward, by the return spring 8, and is returned to the state shown in FIG. At the same time, the movable contact piece 4 is rotated counterclockwise about the shaft 5 in conjunction with the upward movement of the push rod 7, returning to the state shown in FIG. 1, and the switch is turned "OFF".

Furthermore, when the movable contact piece 4 is cooled by heat radiation, it returns to its original shape, and accordingly, the hook pin 7 also returns to its original position, that is, the upper bent end of the hook pin 6 returns to the lower resting position of the heart cam 7 ² . engaged,
Return to the state seen in FIG.

Note that the switch according to the present invention is turned "ON" by pressing the push rod 7, but if it is desired to cancel this "ON" state as necessary, the switch may be pressed once again. At that time, the push rod is returned to the position shown in Fig. 1 by the engagement mechanism between the heart cam ⁷² and the hook pin 6, and the switch is turned "OFF".
becomes. In other words, each time the push rod 7 is pressed, the "ON" and "OFF" states are alternately repeated.

FIG. 5 is a perspective view of main parts showing another embodiment of the movable contact piece. In this modification, instead of using tongue pieces 4 ⁵ ,
A tongue piece ⁴⁵ ' is integrally formed at the end of the movable contact piece 4, and is functionally almost the same as the embodiment shown in FIG. 4, but it is necessary to change the mounting position of the push rod 7. There will be.

FIG. 8 is a partial sectional view similar to FIG. 1 showing another embodiment of the present invention, and FIG. 9 is a schematic exploded perspective view of a movable contact piece and its surrounding parts used in this other embodiment. . In this embodiment, the movable contact piece 14 is rotatably supported on a shaft (rivet 14 ¹ ) so that one end of the movable contact piece 14 is always in contact with the contact point of one of the fixed contacts 12 , and the movable contact piece 14 is mounted around the shaft 14 ¹ . By rotating in an arc shape as ^shown in ^FIG . It is configured as follows.

The movable contact piece 14, as shown in FIG.
The part where ² is fixed is a defect (or gap) 14 ⁴ that follows the defect 14 ³ , and by pressing it with an auxiliary plate provided with a tongue piece 14 ⁵ to eliminate this defect 14 ⁴ , it can be moved. The contact piece 14 is bent slightly inward (ie, in the direction of the fixed contact). By bending in this way, the contact pressure with the fixed contact can be increased. As a modification, the contact pressure can be similarly increased by simply bending the movable contact piece slightly toward the fixed contact without providing the cutout ¹⁴⁴ at the tip of the movable contact piece 14. The operation of this embodiment is almost the same as that of the first embodiment described above, so the explanation thereof will be omitted.

The present invention is constructed and operates as described above, and the following effects are produced according to the present invention.

First of all, the present invention forms a heart cam on the side surface of the push rod and uses a locking mechanism by engaging a movable contact piece made of bimetal with a hook pin, which makes it easier to interrupt overcurrent than the conventional setting of the contact state by pressing the push rod. It is possible to provide an alternating push button switch which has a novel function of manually canceling a set state, which was conventionally impossible.

Second, by minimizing the number of components and arranging the movable contact piece with its plate thickness facing vertically, it is thin and compact, yet operates accurately and has high reliability. I was able to get an automatic shut off switch.

Thirdly, we use a metal plate (e.g. bimetal) that warps due to heat as the movable contact piece, and the effect of warping, which is a characteristic of the material, can be controlled not only by turning the switch contact "ON" or "OFF", but also by using a heart cam. This type of switch is skillfully used to remove the hook pin of the locking mechanism using a combination of hook pins, which minimizes the number of parts, has a low failure rate, and is not only highly safe and reliable, but also has a simple structure, making this type of switch more popular than ever. I was able to get it at an extremely low price, about 1/2 of the price of.

Fourth, since the inner surface of the heart cam provided on the lower side of the push rod is formed lower than the outer peripheral side,
The locking mechanism using the heart cam and hook pin operates extremely smoothly, resulting in extremely high safety and reliability.

Although the present invention has been described above with respect to each of its preferred embodiments, these are merely illustrative, and the present invention is not limited only by the embodiments described herein, and all within the scope thereof. Of course, it includes modifications and changes.

[Brief explanation of the drawing]

Figures 1 to 7 show one embodiment of the present invention, of which Figure 1 is a partial sectional view with the cover removed to show the internal state of the switch in the OFF position, and Figure 2 is a partial cross-sectional view of the switch in the OFF position. Figure 3 is a partially exploded perspective view showing the internal state, Figure 4 is a perspective view of the main parts of the movable contact piece and its surroundings, and Figure 5 is the movable contact piece and its surroundings. Fig. 6 is a sectional view of the main part for explaining the state in which the push rod is located upward, and Fig. 7 is a perspective view of the main part showing other embodiments of the part. FIG. 8 is a partial sectional view similar to FIG. 1 showing another embodiment of the present invention; FIG. FIG. 7 is an exploded perspective view showing an example of a movable contact piece and its peripheral portion used in another embodiment. 1... Switch body, 2, 3... Fixed contact piece, 2
¹ , 3 ¹ ... Fixed contact, 2 ² , 3 ² , 12 ² ... Terminal,
4, 14... Movable contact piece, 4 ¹ , 4 ² , 14 ² ... Movable contact, 4 ³ , 14 ³ , 14 ⁴ ... Defect, 4 ⁵ , 14 ⁵
...Tongue, 5,14 ¹ ...Shaft (rivet), 6...
Hook pin, 7...Push bar, 7 ¹ ...Protrusion, 7 ² ...
Heart cam, 7 ³ ...Inner surface, 7 ⁴ ...Outer surface, 8
... Return spring, 9 ¹ , 9 ² ... Stepped section.

Claims (1)

[Scope of Claims] 1. A movable contact piece made of a material that warps when heated is engaged with a push rod in an uneven relationship with the center or one end of the movable contact piece as a fulcrum, thereby changing the operating direction of the push rod. At the same time, a heart cam is provided on the side surface of the push rod, and a return spring is provided below, and one bent of the hook pin is placed in the groove of the heart cam with the tip of the other bending portion as a fulcrum. At the same time, when the fixed contact provided on the switch body and the movable contact piece are brought into contact with each other, and the movable contact piece is heated, the tongue piece serving as the engagement portion provided on one of the movable contact pieces is brought into contact with the fixed contact provided on the switch body. By displacing the hook pin in a direction away from the groove of the heart cam, the lock of the push rod is released and the movable contact piece is removed from contact with the fixed contact piece, and the movable contact piece is removed from contact with the fixed contact piece provided in the switch body. 1. An overcurrent automatic cut-off alternating push button switch, characterized in that the movable contact piece is disposed on a stepped portion of approximately the same height. 2. The overcurrent automatic cutoff alternating push button switch according to claim 1, further characterized in that the outer peripheral surface of the heart cam is higher than the inner surface of the heart cam.