JP3296666B2 - Detection switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for detecting the type of a detected object such as a cassette tape or the like and the presence or absence of an erroneous erasure preventing claw piece in a mechanism for mounting the detected object. It relates to a detection switch.

[0002]

2. Description of the Related Art FIG. 5 is a plan view of a conventional detection switch of this type, and FIG. 6 is a sectional view of the detection switch shown in FIG.

The detection switch shown in FIGS. 5 and 6 has a base end buried in an insulating base 1 and protrudes from the insulating base 1 in a substantially parallel manner. Contact portions 2a and 3a are provided so as to be able to contact and separate from each other.
An actuator 4 is fixed to one contact spring piece 2,
A cover 6 is attached to the other contact spring piece 3 via a connector 5. The cover 6 has a guide surface 6a for guiding a loaded detection object (not shown), and a notch for projecting the actuator 4 and obtaining necessary flexibility when the connector 5 is mounted. 6b is provided,
When an object to be detected such as a cassette tape is loaded, a specific portion of the object to be detected (for example, an erroneous erasure preventing claw) is projected from the notch 6b onto the guide surface 6a.
The presence / absence of the specific portion is detected by whether or not the contact portions 2a and 3a are brought into contact with each other via the contact, that is, by whether or not the movable contact portion 2a following the actuator 4 abuts on the fixed contact portion 3a. I can do it. FIG.
Reference numerals 7 and 8 in the drawing denote terminals extending from the base ends of the contact spring pieces 2 and 3, respectively, and reference numerals 9 and 10 in FIG. 6 denote spacers fixed to the contact spring pieces 2 and 3, respectively. .

The detection switch thus configured can absorb a dimensional error of the cassette half or the mechanism due to the flexibility of the contact spring pieces 2 and 3 and the swinging movement allowed for the cover 6. Therefore, for example, even if the dimensions of the cassette half vary depending on the manufacturer, the variation can be absorbed without increasing the size of the switch mechanism and stable detection can be performed, which is advantageous for reducing the size of the mechanism.

[0005] As related to this kind of prior art, there is, for example, one described in Japanese Patent Publication No. Hei 2-26330.

[0006]

By the way, in the above-mentioned conventional detection switch, if the contact spring pieces 2 and 3 are bent by some external force, for example, vibration during conveyance, and the actuator 4 is excessively pushed into the cover 6, , Actue
The contact spring piece 2 to which the motor 4 is attached
Since the cover 6 also rotates, the actuator 4 gets into the cover 6, and as a result, even if the above-mentioned force is removed, the actuator 4 does not return to the initial position shown in FIG. There was a problem of becoming. In the conventional detection switch described above, the cover
6 is supported by only one contact spring piece 3,
When the cover 6 is pushed in strongly during handling, the contact spring
There was also a problem that a few plastic deformations occurred.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to ensure that when the force applied to the actuator is removed, the spring force of the contact member ensures that the actuator is initially actuated. It is restored to the position
And reliably prevent plastic deformation of the contact members.
And to provide a detection switch which can and.

[0008]

In order to achieve the above object, the present invention provides a pair of resilient contact members having a base end portion embedded in an insulating base and a contact portion provided on a distal end side. Each of the contact portions is protruded substantially in parallel from the insulating base so as to oppose each other so that the contact portions can be separated from and separated from each other, and at least a part of the actuator attached to one of the contact members is formed of a cover having a guide surface for a detection target. A detection switch for projecting from the window hole and detecting the presence / absence of the specific portion by determining whether or not the specific portion of the object to be detected makes contact between the contact portions via the actuator; A support means for movably supporting is provided, and a stopper portion which comes into contact with the insulating base when the cover rotates beyond a predetermined angle is formed on the opposite side of the guide surface of the cover, and Up Inwardly of the window opening facing the cover
A receiving surface is provided, and the pair of contact members is bent beyond a predetermined amount.
When bent, at least one end of the contact member is
The actuator is configured to prevent the actuator from penetrating into the window hole of the cover by contacting the receiving surface .

Further , in order to achieve the above object, the present invention
Buried the base end in an insulating base and provided a contact on the tip side
A pair of contact members having a spring property are substantially separated from the insulating base.
Protruding in parallel, each contact point can be connected and separated
To the contacts and to the contacts attached to one of the contact members.
At least a part of the actuator is provided with a guide surface for the object to be detected.
Protruding from a window hole of a cover having
The specified part of the object to be detected contacts
Detection switch that detects the presence or absence of the specific part
, The cover is rotatably supported on the insulating base.
And supporting means for supporting the cover.
On the opposite side of the surface, the cover has rotated beyond a predetermined angle
The stopper that comes into contact with the insulating base
A contact portion on at least one end side of the contact member.
When the contact member is bent beyond a predetermined amount,
Abuts the inner surface of the cover opposite the window hole
This allows the actuator to
Structured to prevent it from getting inside the above window hole
It is characterized by having done.

[0010]

In the detection switch configured as described above, when a force is applied to the actuator protruding from the window of the cover, the pair of contact members are driven via the actuator. The cover bends to the side facing the window hole. When a large external force acts on the actuator and the contact member is bent beyond a predetermined amount with the rotation of the cover, the contact member is provided inside the cover facing the window hole.
The tip of the contact member against the receiving surface
Provided on the inner surface facing the window of the bar, at the tip of the contact member
By contacting the contact portion, the actuator is prevented from getting into the inside of the cover, and excessive movement of the distal end side of the contact member is regulated, so that when the force applied to the actuator is removed, The actuator can be reliably returned to the initial position by the spring force of the contact member.

In addition, the cover is mounted on the insulating base by supporting means.
To support the guide surface of the cover.
Make sure that the stopper protruding from the opposite side contacts the insulating base.
Because the excessive rotation of the cover is regulated by
Even if a large force is applied to the cover during handling, the contact
It is possible to reliably prevent plastic deformation of the material .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the detection switch according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a detection switch according to an embodiment of the present invention, partially cut away, FIG. 2 is an exploded perspective view of the detection switch, and FIG. 3 is a cross-sectional view of a main part for explaining the operation of the detection switch. is there.

The detection switch shown in these figures has a pair of spring wires 11 and 12 made of phosphor bronze as a base material by applying tin to the base, coating carbon at one end, bending and crushing the end. An insulating base 13 in which a part of the spring wires 11 and 12 is embedded, an actuator 14 fixed at a predetermined position of one of the spring wires 11, and a loaded object to be detected, for example, a cassette tape 15. And a cover 16 having a window hole 16b for projecting the actuator 14 on the guide surface 16a. In addition, the two spring wires 11, 12
Among them, the long portion whose base end is buried in the insulating base 13 and protrudes upward in FIG. 2 is opposed to the movable contact portion 17a and the fixed contact portion 18a to which carbon is attached so as to be able to contact and separate. No contact members 17, 18 and both spring wires 1
Short portions protruding downward from the insulating base 13 in FIG.

A receiving surface 21 is provided on the inner side of the cover 16 facing the window hole 16b.
When the contact members 7 and 18 are bent beyond a predetermined amount, the contact member 1
The distal ends of 7, 8 abut against the receiving surface 21. A support means for rotatably supporting the cover 16, for example, a pair of support shafts 22 is provided on the upper portion 13 a of the insulating base 13, and the pair of support shafts 22 are provided for the contact members 17 and 18, respectively. It protrudes from the upper part 13a in a direction orthogonal to the direction of bending. Further, an insertion hole 23 into which the support shaft 22 is inserted is provided at a base end portion of the cover 16, and a side opposite to the guide surface 16a of the cover 16, that is, an outer side surface on the right side in FIG. A stopper 24 is provided which comes into contact with the upper surface of the base 13b of the insulating base 13 when the cover 16 rotates beyond a predetermined angle.

A plate-like portion 17b is provided at an appropriate position of the one contact member 17 made of a spring wire by crushing, and the plate-like portion 17b is inclined toward the window hole 16b. The contact member 17 is easily bent in the cover 16 when pushed in the direction of being buried therein, and the cover 1 is bent by the pair of contact members 17, 18 when the guide surface 16a of the cover 16 is directly pushed in.
6 rotates around the support shaft 22.
Furthermore, since the contact member 18 is bent at a substantially right angle in the vicinity of the fixed contact portion 18a, and the tips of the two contact members 17, 18 intersect each other at the contact portions 17a, 18a, the actuator 14 Are pushed into the window hole 16b by a predetermined amount, and the contact portions 17a, 1
8a come into point contact with each other.

In this embodiment, after applying carbon using the spring wires 11 and 12 having a diameter of 0.4 mm, the contact portions 17a and 18a are fired at a firing temperature of 140 to 160 ° C. and a firing time of 30 minutes. After the insulating base 13 is integrated with the spring wires 11 and 12 by insert molding, the base end of the cover 16 is mounted on the upper portion 13a of the insulating base 13 and the support shaft 22 is inserted into the insertion hole 23. By snap-in, the cover 16 is attached to the insulating base 13.

By the way, when the cassette tape 15 is loaded into the mechanism having the detection switch, as shown in FIG. 3B, the erroneous erasure preventing claw 15a as a specific portion of the cassette tape 15 is moved. In this case, the claw 15a contacts the contact portions 17a and 18a via the actuator 14 projecting from the window 16b onto the guide surface 16a.
The contact of the movable contact 17a following the contact with the fixed contact 18a makes it possible to detect the presence of the claw 15a. On the other hand, as shown in FIG. 3A, when the claw piece 15a is removed from the cassette tape 15, the actuator 14 is moved from the window hole 16b to the guide surface 16a.
The upwardly protruding state is maintained, and the contact portions 17a and 18a do not contact each other, that is, the movable contact portion 17a following the actuator 14 does not contact the fixed contact portion 18a. Can be detected.

When an external force acts via the actuator 14 and the pair of contact members 17 and 18 are bent beyond a predetermined amount, as shown in FIG. 3B, the pair of contact members 17 and 18 are bent. Since the tip of 18 contacts the receiving surface 21 in the cover 16, the movement of the contact members 17, 18 on the tip side is restricted. Further, when an excessive force is applied to the guide surface 16a of the cover 16 and the cover 16 rotates beyond a predetermined angle to the opposite side of the guide surface 16a, as shown by a two-dot chain line in FIG. When the stopper 24 at the base end is the insulating base 1
Since the cover 16 is in contact with the upper surface of the base 13b, the rotation of the cover 16 is restricted.

In the embodiment constructed as described above, when the pair of contact members 17 and 18 are bent beyond a predetermined amount, the movement of the distal end side is regulated by the receiving surface 21, so that the actuator 14 remains under the position. Therefore, when the force applied to the actuator 14 is removed, the actuator 14 is reliably returned to the initial position shown in FIG. 3A by the spring force of the contact members 17 and 18. be able to. In addition, the detection switch can absorb a dimensional error of the cassette half or the mechanism side by the flexibility of the contact members 17 and 18 and the pivoting operation permitted to the cover 16. Therefore, even if the dimensions of the cassette half vary, the variation can be absorbed without increasing the size of the switch mechanism, and stable detection can be performed, which is advantageous for reducing the size of the mechanism.

Further, in the above embodiment, the cover 16 is rotatably supported by the insulating base 13 and
The stopper 24 at the base end of the cover 16 is
Since the rotation of the cover 16 is restricted by contacting the upper surface of the base 13b, there is no possibility that the contact members 17, 18 will be plastically deformed even if a large force is applied to the cover 16 during handling. In other words, in the case of the above-described conventional example, the cover is supported only by one of the contact spring pieces and has no stopper function.
The contact spring piece may be plastically deformed. However, in the above embodiment, there is no fear that the contact spring piece is easily handled.

In addition, the pair of contact members 17, 18 used in the detection switch include contact portions 17a, 18a.
Because the wire is a spring wire coated with carbon, the material cost is low and the material is hardly wasted, making it extremely inexpensive to manufacture. In the above embodiment, the manufacturing cost can be significantly reduced as compared with the above-described conventional example. Since the contact members 17 and 18 cross each other contact portions 17a and 18a, when the actuator 14 is pressed by the claw 15a of the cassette tape 15, the opposing contact portions 17a and 18a are turned on. The contact portions 17a and 18a formed by applying carbon can be brought into contact with each other to prevent poor contact.
Thus, high reliability can be ensured.

In the above embodiment, the contact member 17 made of a spring wire is crushed by using a wire crushing machine at an appropriate position to form a plate-like portion 17b. Although the flexibility is ensured, when the operating point and the contact pressure are changed, the squeezing amount and the squeezing range may be appropriately changed. Therefore, in comparison with the conventional example in which the stamping die of the press machine and the plate thickness of the contact spring are changed to correspond to various operating points and contact pressures, the above embodiment is simple and inexpensive in terms of operating force and contact pressure. For example, the operating force can be increased by shortening the crushing range of the plate-like portion 17b of the contact member 17, or the contact member 1 can be changed.
The contact pressure can be reduced by forming a plate-shaped portion also in FIG.

Further, in the above embodiment, the contact portions 17a and 18a of the contact members 17 and 18 are substantially sealed by the cover 16, and the cassette tape 15 is loaded in the window hole 16b from which the actuator 14 projects. When it is not, since it is closed by the actuator 14, it is excellent in dustproofness, and conduction failure due to the intrusion of dust is prevented beforehand.

FIG. 4 is a sectional view showing a main part of a detection switch according to another embodiment of the present invention. FIG. 4 (a) shows a state in which a cassette tape having no claw piece for preventing erroneous erasure is loaded. FIG. 4B is a view showing a state in which a cassette tape having an erroneous erasure preventing claw piece is loaded. In FIGS. 4A and 4B, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals. That is, 14
Is an actuator, 15 is a cassette tape, 15a is a claw piece for preventing erroneous erasure, 16 is a cover, 16a is a guide surface, 16
b is a window hole, 17 and 18 are contact members, 17a is a movable contact portion, and 18a is a fixed contact portion.

In the detection switch shown in FIGS. 4A and 4B, the distal end of the contact member 17 is attached to the inner surface 1 of the cover 16.
The contact portion 17c is provided at the tip of the contact member 17 by bending the contact member 17 at a substantially right angle toward 6c. When the contact member 17 is bent beyond a predetermined amount, the contact member 17 faces the window 16b of the cover 16. The contact portion 17c abuts on the inner side surface 16c, thereby restricting the movement of the contact members 17, 18 on the distal end side. In the other embodiment configured as described above, the same effects as those of the embodiment shown in FIGS. 1 to 3 can be obtained.

[0026]

As described above, according to the present invention,
A receiving surface provided on the inside facing the window hole of the cover, or
A contact portion provided on at least one end side of the contact member
Therefore , the actuator is prevented from getting into the inside of the cover, and excessive rotation of the cover is restricted by the stopper portion protruding from the cover, so that the actuator remains in the cover. Accidents are prevented, and the spring force of the contact members not only ensures that the actuator can return to its initial position, but also ensures that the contact members undergo plastic deformation even if a large force is applied to the cover during handling. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing a detection switch according to an embodiment of the present invention, partially cut away.

FIG. 2 is an exploded perspective view of the detection switch.

FIG. 3 is a sectional view of an essential part for explaining the operation of the detection switch.

FIG. 4 is a sectional view of a main part showing a detection switch according to another embodiment of the present invention.

FIG. 5 is a plan view of a conventional detection switch.

FIG. 6 is a cross-sectional view of the detection switch of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 Insulation base 14 Actuator 15 Cassette tape (detected body) 15a Erroneous erasure prevention claw piece (specific part) 16 Cover 16a Guide surface 16b Window hole 16c Inner side surface 17, 18 Contact member 17a, 18a Contact portion 17c Contact portion Reference Signs List 21 receiving surface 22 support shaft (support means) 23 insertion hole 24 stopper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-82623 (JP, A) JP-A-61-82618 (JP, A) JP-A-58-204426 (JP, A) JP-B-42 24089 (JP, B1) Jiko 60-10034 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 13/18

Claims (2)

(57) [Claims] 1. A pair of contact members having a spring property and having a base end portion buried in an insulating base and a contact portion provided on a distal end side thereof are protruded substantially in parallel from the insulating base to connect the contact portions to each other. And at least a part of an actuator attached to one of the contact members is made to protrude from a window hole of a cover having a guide surface for the object to be detected, and the object to be detected is identified via the actuator. A detection switch for detecting the presence or absence of the specific portion based on whether or not the contact portions make contact with each other, wherein a support means for rotatably supporting the cover on the insulating base is provided, and the guide of the cover is provided. the opposite face, the cover is protruded abutting stopper to the insulating base when pivoted beyond a predetermined angle, and the mosquito
A receiving surface is provided inside the bar facing the window hole, and
When the pair of contact members bend beyond a predetermined amount, the contact portion
At least one end of the material should be in contact with the receiving surface.
Detection switches a result, the actuator is characterized by being configured to prevent submerges inside of the window hole of the cover. 2. The base end is buried in an insulating base and connected to the front end side.
A pair of contact members having a spring property provided with a point portion are
Protrude almost parallel from the base and
And the other side of the contact member
At least a part of the attached actuator is
Protruding from the window hole of the cover having a guide surface for
Check that the specified part of the object to be detected is
The presence or absence of the specific part is detected depending on whether or not the contact is made.
In the detection switch, a support hand for rotatably supporting the cover on the insulating base.
A step is provided and the cover is opposite to the guide surface.
When the cover is rotated beyond a predetermined angle,
A stopper portion that comes into contact with the base is formed so as to protrude, and
A contact portion is provided on at least one end side of the point member,
When the point member is bent beyond a predetermined amount,
Abut the inner surface of the cover facing the window hole
With the above, the actuator is positioned in the window hole of the cover.
A detection switch characterized in that the detection switch is configured to be prevented from getting inside .