JP3779609B2 - Optical plug conversion adapter - Google Patents

Description

[0001]
BACKGROUND 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]
[Prior art]
Optical fibers are widely used in the communication field such as telephones as signal transmission media, and in recent years, they are also widely used in home and personal devices such as digital audio devices and mobile phones.
In such an audio device or a mobile phone, etc., an audio cable (optical fiber cable) is used to connect between audio devices, or other information devices are connected to the mobile phone via an optical cable. 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]
[Problems to be solved by the invention]
By the way, optical jacks provided on the side of such devices are required to be miniaturized in accordance with miniaturization of the devices to which the optical jacks are attached, and in response to this, optical plugs are also being miniaturized and reduced in diameter. A combination of a φ2.5 optical plug having a diameter of 2.5 mm and a φ2.5 optical minijack connected thereto has been used.
However, an optical cable to which a φ3.5 optical plug having a plug diameter of 3.5 mm is attached is popular in the market. For those who have such a conventional (existing) optical cable, the optical cable is used. Therefore, there has been a demand for an inexpensive and high-performance plug diameter conversion adapter that can be used without replacement.
[0004]
In view of such circumstances, an object of the present invention is to provide an optical plug conversion adapter that can be configured at low cost.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in the optical plug conversion adapter having the plug portion having a diameter different from the plug diameter of the optical plug to be inserted and fitted, the optical fiber is inserted and fixed in the center hole to form the plug portion. A cylindrical portion into which the optical plug is inserted is formed integrally with the ferrule. A locking spring for locking the optical plug is inserted into the cylindrical portion, and a sleeve is press-fitted. The locking spring is formed by bending a leaf spring material into a cylindrical shape, and cutting and raising the locking piece so as to protrude toward the inner peripheral surface of the cylindrical portion. .
[0006]
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 facing each other, the locking pieces have a free end on the plug portion side, and a folded portion at the free end. Is supposed to be formed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of the present invention. In this example, an optical plug conversion adapter includes a ferrule 10, a locking spring 20, a sleeve 30, an insulating ring 40, a handle 50, and an optical fiber 60. Yes.
The ferrule 10 is made of metal and includes a plug portion 11 and a cylindrical portion 12 formed integrally with the plug portion 11. A central hole 13 into which the optical fiber 60 is inserted is formed at the center of the plug portion 11. Is formed. In this example, the plug portion 11 has a round optical plug with a diameter of 2.5 mm.
[0008]
The locking spring 20 accommodated in the cylindrical portion 12 is formed by subjecting a leaf spring material such as stainless steel to required cutting and bending.
FIG. 2 shows the detailed shape of the locking spring 20. The leaf spring material is bent so as to form a cylindrical shape, and a pair of locking pieces 22 are formed in the cylindrical portion 21. These locking pieces 22 are formed by being cut and raised so as to protrude toward the inner peripheral surface at positions facing each other of the cylindrical portion 21, and a folded portion 23 is formed at the free end.
The locking spring 20 is fixed in the cylindrical portion 12 by inserting the locking spring 20 into the cylindrical portion 12 and then press-fitting the sleeve 30 into the cylindrical portion 12 as shown in FIG. The cylindrical portion 21 is sandwiched between the step portion 14 provided on the inner end side of the cylindrical portion 12 and the step portion 31 provided on the sleeve 30, whereby the locking spring 20 is connected to the sleeve 30. Therefore, it is prevented from coming off and positioned and fixed.
[0009]
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 on the open end surface of the cylindrical portion 12. The press-fitting position is defined by hitting.
As described above, the internal space (optical plug insertion hole) constituted by the sleeve 30 and the locking spring 20 accommodated in the cylindrical portion 12 is a φ3.5 round optical plug having a plug diameter of 3.5 mm in this example. It shall be compatible.
[0010]
The insulating ring 40 is provided so as to cover the outer peripheral surface excluding the distal end portion of the plug portion 11, 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. Is provided.
The insulating ring 40 is made of synthetic resin, and the handle 50 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.
[0011]
Insertion and fixing of the optical fiber 60 to the plug portion 11 is performed after the locking spring 20 and the sleeve 30 are assembled in the ferrule 10 and the insulating ring 40 and the handle 50 are insert-molded.
FIG. 3 shows this state. The optical fiber 60 is a plastic fiber and has a predetermined length, and its one end 61 is preliminarily mirror-finished. The mirror finish is performed by heating and softening in a state where the end portion of the optical fiber is held by a jig, and pressing the jig having a mirror surface against the end face. One end 61 having the mirror finish is shown in FIG. In this way, it has a flaky shape and is slightly expanded in diameter.
[0012]
The optical fiber 60 is inserted into the center hole 13 from the sleeve 30 side. At this time, the optical fiber 60 is centered by the tapered surface 15 formed from the step 14 at the inner end of the cylindrical portion 12 toward the center hole 13. 13 is invited and inserted.
The optical fiber 60 inserted into the center hole 13 has one end 61 having a flat shape abutting against the tapered surface 15 and the other end 62 slightly protruding from the tip of the plug portion 11. The mirror finish of the other end 62 is obtained by softening the other end 62 while pressing one end 61 in the ferrule 10 with, for example, a rod-shaped jig and pressing a jig having a mirror surface on the end face. In the same manner, the optical fiber 60 is fixed to the center hole 13 of the plug portion 11 as shown in FIG. 1 to complete the optical plug conversion adapter.
[0013]
According to the optical plug conversion adapter configured as described above, the locking spring 20 can be easily placed in a predetermined position simply by inserting the locking spring 20 into the cylindrical portion 12 of the ferrule 10 and simply press-fitting the sleeve 30. Therefore, the assembling work of the locking spring 20 can be performed very easily.
As described above, the optical fiber 60 can be inserted into and fixed to the ferrule 10 after the locking spring 20 and the sleeve 30 are assembled into the ferrule 10 and the insulating ring 40 and the handle 50 are formed. Since it can be performed in the process, there is no problem that the optical fiber 60 is damaged and deteriorated when the locking spring 20 or the sleeve 30 is assembled or molded.
[0014]
Therefore, from these points, according to this example, an optical plug conversion adapter that is extremely easy to assemble and has a simplified structure can be obtained.
FIG. 4 shows a state in which a φ3.5 round optical plug having a plug diameter of 3.5 mm is inserted and fitted to the optical plug conversion adapter shown in FIG. 1, and the optical plug 70 is shown in the drawing. In this manner, the optical plug conversion adapter 80 is inserted into the optical plug insertion hole 81, and its tip is locked by the locking spring 20.
In this example, the locking spring 20 has a structure in which the distal end portion of the optical plug 70 is sandwiched between a pair of locking pieces 22, and the folded portion 23 is in good pressure contact as shown in FIG. Therefore, the optical plug 80 can be held stably and satisfactorily.
[0015]
The optical plug conversion adapter that reduces the diameter of the φ3.5 mm round optical plug to φ2.5 mm has been described as an example. However, the optical plug conversion adapter is, for example, a φ2.5 mm round optical plug. The diameter may be increased to φ3.5 mm, or a diameter conversion different from these may be performed.
[0016]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain an optical plug conversion adapter that has a small number of parts, has a simplified structure, is easy to assemble, and can be configured in a small size and at low cost.
[Brief description of the 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 cross-sectional view thereof. FIG.
FIG. 3 is a view for explaining an optical fiber insertion step (assembly step) in the embodiment shown in FIG. 1;
4 is a view for explaining a state in which an optical plug is inserted and fitted into the optical plug conversion adapter shown in FIG. 1; FIG.

Claims (2)

An optical plug conversion adapter comprising a plug portion having a diameter different from the plug diameter of the optical plug to be inserted and fitted,
Central hole a tubular portion in which the plug portion is an optical fiber is inserted and fixed and the upper Symbol optical plug is inserted is formed integrally following its plug portion,
A taper surface is formed from the step provided on the inner end side of the cylindrical portion toward the central hole ,
A locking spring for locking the optical plug is inserted into the cylindrical portion, and a sleeve is press-fitted ,
The locking spring is formed by bending a leaf spring material into a cylindrical shape and cutting and raising the locking piece so as to protrude to the inner peripheral surface side of the cylindrical portion .
The light characterized in that both ends of the locking spring are sandwiched between the step portion of the cylindrical portion and a step portion provided inside the sleeve, and the locking spring is fixed to prevent the locking spring from coming off. Plug conversion adapter. The optical plug conversion adapter according to claim 1,
The locking spring has a pair of locking pieces facing each other, the locking pieces having a free end on the plug part side, and a folded part formed on the free end. Optical plug conversion adapter.

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