JPH05128941A - Switch - Google Patents

Abstract

PURPOSE:To provide a detection switch inexpensive and excellent in reliability to be used for the purpose of discrimination of a tape cassette used mainly for video associated equipment. CONSTITUTION:A first and second movable contact pieces 11, 12 are arranged in the same plane and parallel to each other, while a third movable contact piece 17 integrally molded with the lever 16 is arranged at a position opposing to the first and second movable contact pieces 11, 12 in a U-shaped bottom face part of the lever 16. Movable ends 11a, 12a of the first and second movable contact pieces 11, 12 are provided with insulating bodies 13, 14 respectively having plane parts in the same plane as contact point parts 11b, 12b. Even in a state where an oxide film and the like is produced on a surface of a contact point, the oxide film is destroyed by sliding movement of the third movable contact piece 17 provided in the lever 16 on the contact point parts 11b, 12b. A switch can be made inexpensive and excellent in contact reliability by only a silver plating process less expensive in cost in comparison with gold, its alloy or the like. Because of the arrangement of the first and second movable contact pieces 11, 12 in the same plane and parallel to each other, the insulating members can be integrated with the case so as to reduce component parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch mainly used for discriminating tape cassettes used in video tape recorders and related equipment.

[0002]

2. Description of the Related Art FIG. 16 (a), (b),
This will be described with reference to the switch of (c).

As shown in FIG. 1, reference numeral 1 denotes a first movable contact piece made of a belt-shaped conductive member having a spring property. The movable end 1a has a contact portion 1b and the other end has a lead portion 1c. The vicinity of the above is integrally molded with the insulating member 2 and the movable portion 1d is flexed by using the insulating member 2 as a fulcrum. Reference numeral 3 is a second movable contact piece that is substantially similar to the first movable contact piece 1 and is fixed to the insulating member 2 so as to face and be parallel to the first movable contact piece 1. Reference numeral 4 denotes a case made of a molded member for holding the lever 5 integrated with the insulating member 2, and the inner surfaces 4b and 4c facing the opening 4a for the lever 5 to project and rotate on the ceiling. Shafts 4d and 4e are formed so as to face downward from the first movable contact piece 1. Reference numeral 5 denotes a lever formed in a substantially U-shape, and holes 5c and 5d are formed at positions where the respective foot portions 5a and 5b face each other. The holes 5c and 5d are the shafts 4d and 4e of the case 4.
At the same time, they are rotatably inserted and supported, and at the same time, the bottom surface 5e biases the movable portion 1d of the first movable contact piece 1.

Next, the operation of the above switches will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 17 shows the non-operating state of the switch. In this state, the lever 5 is almost upright because the bottom surface 5e is urged by the first movable contact piece 1, and the contact portion of the first movable contact piece 1 is also upright. 1b and the second movable contact piece 3 are separated. In this state, when an external force is applied to the lever 5 from the A direction, the lever 5 moves the shafts 4d, 4 of the case 4
Starting to rotate around e, the first movable contact piece 1 as shown in FIG.
Starts to bend when the movable portion 1d is biased by the bottom surface 5e of the lever 5, and the contact portion 1b of the first movable contact piece 1 and the second movable contact piece 3 are brought into conduction. When the lever 5 continues to rotate, the second movable contact piece 3 is moved to the contact portion 1 of the first movable contact piece 1.
The urging force of b causes the deflection to proceed while maintaining the conduction state, and the state shown in FIG. 19 is obtained.

[0005]

However, in the above-mentioned structure, since the contacts are simply statically pressed against each other for conduction, the wiping effect (contact stability due to mutual contact deviation between contacts) is small and the device does not operate for a long time. If left unattended, it has the drawback of poor contact due to the oxide film that forms on the contact surface.If you try to suppress this drawback, you will need to protect the contact with gold or its alloys, which have stable environmental characteristics. It had to be carried out, resulting in an increase in cost.

Furthermore, since the first and second movable contact pieces 1, 3 are arranged in parallel with each other and in the direction perpendicular to the side surfaces 4c, 4d of the case 4, the first and second movable contact pieces 1 are arranged. , 3 and the insulating member 2 and the case 4 cannot be integrally molded because of the mold structure, and at least the first and second movable contact pieces 1 and 3 are integrally molded, and the insulating member 2 and the case 4 are independent from each other. Had to do. Therefore, there are problems that the cost of materials is increased due to the large number of constituent parts and the cost of assembling the switch is high.

[0007]

In order to solve the above-mentioned problems, a switch according to the present invention has first and second movable contact pieces arranged in the same plane and parallel to each other, and has a first U-shaped bottom portion of a lever. An insulating member, in which a third movable contact piece is mounted at a position facing the first and second movable contact pieces, and which has a flat portion which is flush with the contact portion at the movable ends of the first and second movable contact pieces. It has a configuration provided.

[0008]

With the above structure, the third movable contact piece mounted on the lever slides on the contact portions of the first and second movable contact pieces, so that an oxide film or the like is formed on the contact surface. Since it has the effect of destroying the oxide film, it can be made inexpensive and have excellent contact reliability only by silver plating, which is cheaper than gold or its alloys. Since the insulating members and the case can be integrated by arranging the components in the same plane and parallel to each other, the number of constituent parts can be reduced and the assembling cost can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the switch of the present invention will be described with reference to FIGS. 1, 2 (a) and 2 (b). In the figure, reference numerals 11 and 12 denote first and second movable contact pieces made of a strip-shaped conductive member having the same shape and having a spring property, respectively.
1a and 12a have silver-plated contacts 11b and 12
b and the contact portions on the same plane as the flat portions 13a and 1a, respectively.
While integrally molding the insulators 13 and 14 having 4a,
The first and second movable contact pieces are integrally molded in the case 15 in the vicinity of the lead portions 11c and 12c at the other ends so that the first and second movable contact pieces are on the same plane and parallel to each other. The case 15 is a case made of a molded member and is formed in a rectangular frame shape having an opening 15a at the center.
A pair of shafts 15d and 15e for pivotally holding the lever 16 are formed so as to be opposed to each other at a position substantially on the boundary with a and below the plane portions 13a and 14a. The lever 16 is formed in a substantially U-shape, and each foot 16
A pair of holes 16c and 16d are provided to face a and 16b.
A third movable contact piece 17 made of a silver-plated round wire is integrally formed on the lower part of the span portion 16e. This third movable contact piece 17 is the flat surface portion 1 of the insulators 13 and 14.
3a, 14a so as to be urged across the hole 16c,
16d is rotatably locked to the shafts 15d and 15e of the case 15.

The operation of the above switch will be described with reference to FIGS. FIG. 3 shows a non-operating state of the switch. In this state, the spring reaction force of the first and second movable contact pieces 11, 12 acts on the third movable contact piece 17, so that the movable contact piece 17 is insulated. The lever 16 is stationary on the plane portions 13a and 14a of the bodies 13 and 14 and in a state substantially perpendicular to the first and second movable contact pieces. In this state, when an external force B is applied to the lever 16 from the direction A, the lever 16 rotates about the shafts 15d and 15e of the case 15, and the third movable contact piece 17 moves to the first and second movable contact pieces 11. , 12 are curved, and at the same time, they slide on the surfaces of the flat parts 13a, 14a of the insulators 13, 14, and the third movable contact piece 17 is attached to the contact parts 11b, 12b as shown in FIG. The first movable contact piece 11 and the second movable contact piece 12 are brought into conduction with each other almost at the same time. When the lever 16 is further rotated, the third movable contact piece 17 remains on the first and second movable contact pieces 11 and 12 while maintaining the electrical connection with the first and second movable contact pieces 11 and 12. Slide, and the lever 16 is fully rotated as shown in FIG. When the rotation operation of the lever 16 is stopped in this state, the first and second movable contact pieces 1
Due to the restoring forces of 1 and 12, the lever 16 returns to the initial state of FIG. 3 and a series of operations is completed.

As described above, according to the above embodiment, the third movable contact piece 17 provided on the lever 16 has the first and second movable contact pieces 1.
By sliding while contacting the contact portions 11b and 12b of 1 and 12 under pressure, even if an oxide film or the like is formed on the contact surface, the oxide film is destroyed (wiping effect), so that the cost is higher than that of gold or its alloys. It is possible to make the contact reliability excellent by using only a relatively inexpensive silver plating process, and at the same time, by arranging the first and second movable contact pieces 11 and 12 in the same plane and parallel to each other, the first and second movable pieces can be moved. Contact pieces 11, 12 and case 15
The shafts 15d and 15e having a function of holding the lever 16 can be easily formed in the case 15 and can be easily formed in the case 15.

In the above embodiment, the flat surface portion 13 of the first and second movable contact pieces 11 and 12 is vertically above the shaft 15e.
a and 14a are located, and the first and second movable contact pieces are in the off state in the non-operating state of FIG. 3, but the third movable contact piece 17 has the flat surface portions 13a and 14a in the above state.
If it is in contact with any one of a, the first and second movable contact pieces 1
It is a good thing that the off state between 1 and 12 can be secured.

When the lever 16 is in the non-operating state, the third movable contact piece 17 and the contact portions 12a and 13a of the first and second movable contact pieces 11 and 12 are brought into contact with each other to be turned on, and the lever 1
6 in the operating state, the third movable contact piece 17 and the flat surface portion 13a
Alternatively, the flat portion 14a can be brought into contact with each other to be turned off by changing the mounting positions of the flat portions 13a and 14a on the first and second movable contact pieces.

FIGS. 6 and 7 show another embodiment of the switch of the present invention. The same parts as those of the embodiment of FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. , 13
d and 14d are flat portions 13 of the insulators 13 and 14, respectively.
a, 14a provided with inclined surfaces 13b, 13c, 14
It is a V groove composed of b and 14c.

V-grooves 13d and 14 are formed in the insulators 13 and 14, respectively.
The operation of the switch provided with d will be described with reference to FIGS. 8 to 10. FIG. 8 shows the non-operating state of the switch. In this state, the spring restoring force of the first and second movable contact pieces 11, 12 is V. The third movable contact piece 17 is inserted through the grooves 13d and 14d.
By acting on the lever 16, the lever 16 moves the first and second movable contact pieces 1.
It is stationary at a right angle to 1,12. In this state, if an external force is applied to the lever 16 from the B direction, the lever 1
6 rotates around the shafts 15d and 15e of the case 15, and the third movable contact piece 17 bends the first and second movable contact pieces 11 and 12, and at the same time, the inclined surfaces of the insulators 13 and 14. Thirteen
b, 14b and the plane portions 13a, 14a, and when they come into contact with the contact portions 11b, 12b as shown in FIG. 9, the first movable contact piece 11 and the second movable contact piece 12 become the third movable contact piece. The circuit is short-circuited via 17. When the lever 16 is further rotated, the third movable contact piece 17 maintains the state in which the third movable contact piece 17 is electrically connected to the first and second movable contact pieces 11, 12. Sliding on the contact points 11b and 12b, the lever 16 is fully rotated as shown in FIG. When the rotation operation of the lever 16 is stopped in this state, the lever 16 begins to recover due to the restoring force of the first and second movable contact pieces 11 and 12 acting on the third movable contact piece 17, and the initial state of FIG. When the state is reached, a series of operations is completed.

As described above, according to the above-described embodiment, the V grooves 13d and 14d provided in the insulators 13 and 14 contact so as to sandwich the third movable contact piece 17, and the return position of the lever 16 is stabilized. Therefore, the insulating distance between the third movable contact piece 17 and the first and second movable contact pieces 11, 12 is stabilized, and the insulation reliability is improved.

FIGS. 11 and 12 also show another embodiment of the switch of the present invention. The same parts as those of the embodiment of FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted. Then, 16 is a lever formed in a substantially U shape, the foot 16
Shafts 16e and 16f are formed substantially in the center inside a and 16b. Reference numeral 18 denotes a slider having a third movable contact piece 19, which is formed in a substantially square shape having a necessary and sufficient area for covering the insulators 13 and 14 and the contact portions 11b and 12b. The lever 16 is provided on the upper surface 18a. Axes 16e and 16f
Recesses 18b and 18c into which are inserted are formed. 1
Reference numeral 9 is a contact portion 11b, 1 of the first and second movable contact pieces 11, 12.
A third movable contact piece for short-circuiting between 2b and having silver-plated contact portions 19a, 19b,
It is integrally molded into.

The operation of the switch provided with the slider 18 will be described with reference to FIGS. 13 to 15. FIG. 13 shows the non-operating state of the switch. In this state, the first and second movable contact pieces 11, 12 are Since the spring reaction force acts on the contact points 19a and 19b of the third movable contact piece 19, the lever 16 is substantially perpendicular to the first and second movable contact pieces 11 and 12 via the recesses 18b and 18c of the slider 18. It is stationary in the state of. At this time, the contact portion 19 of the third movable contact piece 19
a and 19b are flat portions 13a and 13b of the insulators 13 and 14, respectively.
It is above. In this state, when an external force is applied to the lever 16 from the B direction, the slider 1 rotates with the rotation of the lever 16.
8 and the third movable contact piece 19 are the first and second movable contact pieces 11, 1.
When the lever 16 begins to move in the rotation direction of the lever 16 while curving 2, and the rotation is continued, the third movable contact piece 19 as shown in FIG.
Contacts 19a, 19b of the first and second movable contact pieces 11, 12
The first movable contact piece 11 and the second movable contact piece 12 are short-circuited by contacting the contact portions 11b and 12b. When the lever 16 further continues to rotate, the contact portions 19a, 1 of the third movable contact piece 19
9b is a contact portion 11b of the first and second movable contact pieces 11 and 12,
The movement (wiping) is continued while maintaining the conductive state with 12b, and the full rotation state of FIG. 15 is obtained. Lever 16 in this state
When the rotational movement of the first and second movable contact pieces 11, 12 is stopped.
The restoring force causes the lever 16 to return to the initial state shown in FIG. 13 to complete a series of operations.

As described above, according to the above-described embodiment, by disposing the slider 18 covering at least the contact portions 11b and 12b, it is possible to eliminate the contact failure due to foreign matter such as dust and dust due to the dustproof effect. I have.

[0020]

As described above, according to the present invention, the first and second movable contact pieces are arranged in the same plane and parallel to each other, and face the first and second movable contact pieces of the U-shaped bottom portion of the lever. Since the third movable contact piece is disposed at a position where the contact point is arranged, and the movable end of the first and second movable contact pieces is provided with an insulating member having a flat surface portion on the same plane as the contact portion, wiping of the contact portion is performed. The same effect or higher contact reliability can be obtained only by the surface treatment with silver without performing the surface treatment of the contact with expensive gold or its alloy. It is possible to easily manufacture a die integrally molded with the case and realize an excellent switch that can reduce the cost of parts.

[Brief description of drawings]

FIG. 1 is an exploded perspective view in which a part of a case, which is a main part of an embodiment of a switch of the present invention, is cut away.

FIG. 2A is a top view of the same, and FIG.

FIG. 3 is a side sectional view for explaining the same operation.

FIG. 4 is a side sectional view for explaining the same operation.

FIG. 5 is a side sectional view for explaining the same operation.

FIG. 6 is an exploded perspective view in which a part of a case, which is a main part of the other embodiment, is cut away.

FIG. 7 is a partially enlarged side sectional view for explaining an engagement state between the second movable contact piece and the lever according to the embodiment of FIG.

FIG. 8 is a side sectional view for explaining the same operating state.

FIG. 9 is a side sectional view for explaining the same operating state.

FIG. 10 is a side sectional view for explaining the same operating state.

FIG. 11 is an exploded perspective view of another embodiment of the switch of the present invention.

12A is a front sectional view of the same, and FIG. 12B is a sectional view of the same side.

FIG. 13 is a side sectional view for explaining the same operating state.

FIG. 14 is a side sectional view for explaining the same operating state.

FIG. 15 is a side sectional view for explaining the same operating state.

16A is a front sectional view of a conventional switch, FIG. 16B is a top view thereof, and FIG. 16C is a sectional view of the same side.

FIG. 17 is a side sectional view for explaining the same operation.

FIG. 18 is a side sectional view for explaining the same operation.

FIG. 19 is a side sectional view for explaining the same operation.

[Explanation of symbols]

 11 First movable contact piece 12 Second movable contact piece 13 Insulator 13d V groove 14 Insulator 14d V groove 15 Case 16 Lever 17 Third movable contact piece 18 Slider 19 Third movable contact piece

Claims (4)

[Claims] 1. A first and a second movable contact piece integrally molded in parallel on the same plane with one end of the molded member, and a rotation center near the movable end of the first and second movable contact piece. The U-shaped lever, the third movable contact piece mounted on the bottom surface side of the substantially U-shaped lever and straddling the first and second movable contact pieces, and the lever are rotated. At least the first and second movable contact pieces are turned on and off when the third movable contact piece slides on the first and second movable contact pieces. A switch including an insulating member mounted on a sliding contact portion with any of the third movable contact pieces. 2. An insulating member mounted on at least one of the first and second movable contact pieces, and a contact portion of the movable contact piece mounted with the insulating member on the same plane on which a third movable contact piece slides. The switch according to claim 1, which forms a switch. 3. The switch according to claim 1 or 2, wherein a V groove having a valley portion is provided in a portion on a vertical plane of a rotation center of the lever of the first and second movable contact pieces. 4. A slider in which a third movable contact piece is mounted on the bottom portion covering the contact portions of the first and second movable contact pieces, and which slides on the first and second movable contact pieces as the lever rotates. The switch according to claim 1, wherein the switch is provided.