JP2003185885A - Optical plug conversion adaptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical plug conversion adaptor that is assembled easily and structured at a low cost. <P>SOLUTION: In the optical plug conversion adaptor having a plug diameter different from that of an optical plug to be inserted and fitted, a cylindrical part 12 for the optical plug to be inserted is integrally formed with the ferrule 10 in which an optical fiber 60 is fixedly inserted into the center hole 13 to form a plug 11. In this cylindrical part 12, a locking spring 20 is inserted for restraining the optical plug, with a sleeve 30 force-fitted, and with the locking spring 20 fixed by the sleeve 30 to prevent the fall-off. The locking spring 20 is formed by cylindrically bending a plate spring material and by cutting/ raising restraining pieces 22 projectingly to the inner circumferential face of the cylindrical part 21. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical plug conversion adapter that enables an optical plug to be connected to an optical jack that is not compatible with the optical plug.

[0002]

2. Description of the Related Art Optical fibers have been widely used as a signal transmission medium in the field of communication such as telephones, and in recent years, they have also come to be widely used in household and personal devices such as digital audio devices and mobile phones. . In such audio devices and mobile phones, optical cables (optical fiber cables) are used to connect audio devices, and other information devices are connected to mobile phones via optical cables. The connection is made by inserting an optical plug attached to the end of the optical cable into an optical jack provided on the device side.

[0003]

By the way, the optical jack provided on such a device side is required to be downsized as the device to which it is attached is downsized, and in response to this, the optical plug is also downsized. -As the diameter has been reduced, for example, a combination of a φ2.5 optical plug having a plug diameter of 2.5 mm and a φ2.5 optical minijack connected to the plug has come to be used. However, an optical cable to which a φ3.5 optical plug having a plug diameter of 3.5 mm is attached is widely used in the market, and for those who have such a conventional (existing) optical cable, the optical cable is There has been a demand for an inexpensive and high-performance plug diameter conversion adapter that can be used without replacement.

In view of such a situation, an object of the present invention is to
It is to provide an optical plug conversion adapter that can be configured at low cost.

[0005]

According to the invention of claim 1, an optical plug conversion adapter having a plug portion having a diameter different from a plug diameter of an optical plug to be inserted and fitted has an optical fiber in a center hole. A tubular portion into which the optical plug is inserted is integrally formed with a ferrule that is inserted and fixed to form a plug portion, a locking spring that locks the optical plug is inserted into the tubular portion, and a sleeve is press-fitted. Then, the locking spring is retained and fixed by the sleeve, the leaf spring material of the locking spring is bent into a cylindrical shape, and the locking piece is cut and raised in the cylindrical portion so as to project to the inner peripheral surface side. It is supposed to be formed.

According to a second aspect of the present invention, in the first aspect of the present invention, the locking spring has a pair of locking pieces opposed to each other, and the free ends of the locking pieces are on the plug portion side, and the free ends thereof. It is assumed that the folded-back portion is formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described by way of examples with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In this embodiment, an optical plug conversion adapter comprises a ferrule 10, a locking spring 20, a sleeve 30, an insulating ring 40, a handle 50 and an optical fiber 60. There is. The ferrule 10 is made of metal, and includes a plug portion 11 and a tubular portion 12 that is integrally formed following the plug portion 11. A center hole 13 into which the optical fiber 60 is inserted is formed at the center of the plug portion 11. Has been formed.
The shape and size of the plug portion 11 is a round optical plug of φ2.5 mm in this example.

Locking spring 20 housed in the cylindrical portion 12
Is formed by subjecting a leaf spring material such as stainless steel to required cutting and bending processes. FIG. 2 shows a detailed shape of the locking spring 20, in which a leaf spring material is bent into a cylindrical shape, and a pair of locking pieces 22 is formed on the cylindrical portion 21. These locking pieces 22 are formed by being cut and raised at positions facing each other of the cylindrical portion 21 so as to project toward the inner peripheral surface side, and the folded portion 2 is provided at the free end.
3 is formed. The locking spring 20 is fixed in the tubular portion 12 by inserting the locking spring 20 into the tubular portion 12 and then press-fitting the sleeve 30 into the tubular portion 12 to fix the locking spring 20 as shown in FIG. Both end surfaces of the cylindrical portion 21 are provided with a step portion 14 provided on the inner end side of the tubular portion 12 and a step portion 3 provided with the sleeve 30.
It is carried out by sandwiching the locking spring 20 with the locking spring 1 and the locking spring 20 is prevented from coming off by the sleeve 30 and positioned and fixed.

The locking spring 20 is inserted so that the free end of the locking piece 22 faces the plug portion 11 side, and the sleeve 30 has a flange portion 32 provided on the outer peripheral surface thereof of the tubular portion 12. The press-fitting position is defined by hitting the open end surface. As described above, the tubular portion 12
In this example, the internal space (optical plug insertion hole) formed by the sleeve 30 and the locking spring 20 accommodated in is adapted to a φ3.5 round optical plug having a plug diameter of 3.5 mm.

The insulating ring 40 is provided so as to cover the outer peripheral surface of the plug portion 11 excluding the tip end portion, and the handle 50, together with the tubular portion 12, covers a part of the insulating ring 40 and the flange portion 32 of the sleeve 30. It is provided to cover. The insulating ring 40 is made of synthetic resin and has a handle 5
0 is made of soft synthetic resin or synthetic rubber (elastomer). The insulating ring 40 and the handle 50 are both formed by insert molding, the insulating ring 40 is formed by primary molding, and the handle 50 is formed by secondary molding.

The insertion and fixing of the optical fiber 60 into the plug portion 11 is performed after the locking spring 20 and the sleeve 30 are incorporated in the ferrule 10 and the insulating ring 40 and the handle 50 are insert-molded. FIG. 3 shows this state, in which the optical fiber 60 is a plastic fiber and has a predetermined length, and one end 61 thereof is preliminarily mirror-finished.
The mirror-finishing is performed by heating and softening the end portion of the optical fiber held by a jig, and pressing a jig having a mirror surface on the end surface. The mirror-finished one end 61 is shown in FIG. As shown in the figure, it has a slightly expanded shape.

The optical fiber 60 is inserted into the central hole 13 from the sleeve 30 side, and at this time, the optical fiber 60 is inserted into the tubular portion 1.
The taper surface 15 formed from the step portion 14 at the inner end of 2 toward the central hole 13 is guided and inserted into the central hole 13. One end 61 of the optical fiber 60 inserted into the center hole 13 comes into contact with the tapered surface 15, and the other end 62 is slightly projected from the tip of the plug portion 11. While mirror-finishing the other end 62 while holding one end 61 in the ferrule 10 with a rod-shaped jig,
The other end 62 is heated and softened, and a jig having a mirror surface is pressed against the end face, so that the same operation as the one end 61 side is performed.
As a result, the optical fiber 60 is fixed in the center hole 13 of the plug portion 11 as shown in FIG. 1, and the optical plug conversion adapter is completed.

According to the optical plug conversion adapter configured as described above, the locking spring 20 is provided with the locking spring 20 in the tubular portion 12 of the ferrule 10 and the sleeve 30 is simply press-fitted. Since it is easily fixed to the position, the work of assembling the locking spring 20 can be performed very easily. In addition, as described above, when the optical fiber 60 is inserted and fixed in the ferrule 10, the locking spring 20 and the sleeve 30 are incorporated into the ferrule 10,
In addition, since it can be performed after the insulating ring 40 and the handle 50 are molded, that is, can be performed in the final step, there is a problem that the optical fiber 60 is damaged and deteriorated when the locking spring 20 and the sleeve 30 are assembled or molded. It will not be done.

Therefore, from these points, according to this example, the optical plug conversion adapter which is extremely easy to assemble and whose structure is simplified can be obtained. FIG. 4 shows the optical plug conversion adapter shown in FIG.
3.5 shows a state in which a round optical plug is inserted and fitted, and the optical plug 70 is inserted into the optical plug insertion hole 81 of the optical plug conversion adapter 80 as shown in the figure, and its tip is It is locked by the locking spring 20. In this example, the locking spring 20 has a structure in which the front end of the optical plug 70 is sandwiched by a pair of locking pieces 22, and the folded-back portion 23 makes a good pressure contact as shown in FIG. Therefore, the optical plug 80 is stable and good.
Can be held.

As mentioned above, the φ3.5 mm round optical plug is φ
The optical plug conversion adapter that reduces the diameter to 2.5 mm has been described as an example, but the optical plug conversion adapter is, for example, the one that increases the diameter of a round optical plug of φ2.5 mm to φ3.5 mm. Alternatively, a diameter conversion different from these may be performed.

[0016]

As described above, according to the present invention, it is possible to obtain an optical plug conversion adapter which has a small number of parts, has a simple structure, is easy to assemble, and can be constructed in a small size and at a low cost. it can.

[Brief description of drawings]

FIG. 1A is a front view showing an embodiment of the present invention, B is a sectional view thereof, and C is a side view thereof.

2A is a plan view of the locking spring in FIG. 1, B is a side view thereof, and C is a sectional view thereof.

FIG. 3 is a diagram for explaining an optical fiber insertion step (assembly step) in the embodiment shown in FIG.

FIG. 4 is a view for explaining a state in which an optical plug is inserted and fitted in the optical plug conversion adapter shown in FIG.

Claims (2)

[Claims] 1. An optical plug conversion adapter having a plug portion having a diameter different from the plug diameter of an optical plug to be inserted and fitted, wherein an optical fiber is inserted and fixed in a center hole to form the plug portion. , A cylindrical portion into which the optical plug is inserted is integrally formed, a locking spring that locks the optical plug is inserted into the cylindrical portion, and a sleeve is press-fitted so that the sleeve causes the locking spring. The locking spring is formed by bending the leaf spring material into a cylindrical shape and cutting and raising the locking piece so as to project to the inner peripheral surface side in the cylindrical portion of the locking spring. Optical plug conversion adapter characterized in that 2. The optical plug conversion adapter according to claim 1, wherein the locking spring has a pair of the locking pieces facing each other, and the free ends of the locking pieces are on the plug portion side. An optical plug conversion adapter characterized in that a folded portion is formed at its free end.