JPH0532802Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to an optical fiber cable holding device for an optical fiber cable connector.

<Prior art> In order to attach an optical fiber cable to a connector, the end of the optical fiber cable is held by a ferrule member, and the holding method is as follows.
One method is to use adhesive to secure the cable inserted into the ferrule member, and the other is to attach a thick ring to the ferrule member into which the cable is inserted without using adhesive, and apply pressure to this ring to deform it. A method is often used in which the ferrule member and cable are tightened and fixed. In this case, a ring with a thin wall is not used because the clamping force becomes weak due to the creep phenomenon. The fixing method of tightening with a ring is described in detail in Japanese Patent Publication No. 58-49846 by the present applicant.

<Problems that the invention aims to solve> However, when using adhesive, there is a problem that the number of assembly steps increases due to applying and drying the adhesive. When tightening and fixing the ferrule member and cable, the pressure applied to the ring
There were problems in that the core of the cable was deformed, causing optical transmission loss, and the outer diameter of each pole became large due to the thickness of the ring, making multipolarization difficult.

In order to solve these problems, the present invention is an optical fiber cable that is easy to assemble, can fix the ferrule member and cable without damaging the core, and can have multiple connectors or miniaturize the connector. The purpose is to provide a holding device.

Another object of the present invention is to provide an optical fiber cable holding device that does not reduce cable holding power.

<Means for Solving the Problems> The optical fiber cable holding device of the present invention includes a ferrule into which the core exposed from the end of the optical fiber cable is inserted, and a ferrule that connects the ferrule and the end of the optical fiber cable to the end. A fiber optic cable holding device comprising: a crimp barrel for crimp-holding along a portion of the fiber optic cable, the crimp barrel having a coil spring;
A substantially cylindrical lance held in the connector and a substantially annular cover ring are each mounted on the connector, and the lance holds the coil spring between the ferrule and is slidable on the crimp barrel. , the cover ring is fixed on the crimp barrel to restrict rearward movement of the lance.

<Example> Hereinafter, an example of the holding device according to the present invention will be described with reference to the drawings.

FIG. 1 shows a holding device 10 used for attaching an optical fiber cable 12a to a plug connector,
and the above cable 12 to the receptacle connector.
A holding device 50 used for attaching the optical fiber cable 12b connected to the fiber optic cable 12b is shown. However, the combination of the connector and the holding device is not fixed, and it is possible to freely use the holding device 50 for the plug connector and the holding device 10 for the receptacle connector.

The holding device 10 includes a ferrule 16 into which the exposed core 14 from which the coating 13 at the end of the optical fiber cable 12a has been removed is inserted, a crimp barrel 18 for fixing the ferrule 16 to the cable 12a, and the crimp barrel 18. It is provided with a substantially annular cover ring 28 for holding. Ferrule 1
6 is a cable 12 made of plastic or metal material.
It is formed into a cylinder having the same external dimensions as the external shape of a, and has a through hole 20 in the axial direction into which the core 14 is inserted in the center, and a large diameter part 22 at one end. There is. The crimp barrel 18 is formed into a U-shape by bending a plate-like member into a shape that follows the outer shape of the cable 12a.
8a and a curved surface portion 18b. Both plane parts 18
a, 18a, as shown in FIG. 4, a V-shaped notch is provided with the acute angle portion facing sideways,
The acute angle portion of this V-shaped notch is bent inward to form an inwardly standing claw 24, and when this claw 24 engages with the sheath 13 of the cable 12a, the crimp barrel 18
will hold. Therefore, the length of the upright claw 24 is configured to be smaller than the thickness of the sheath 13 of the cable 12a. Additionally, both flat surfaces 18 at one end of the crimp barrel 18
A, 18a are each formed with a notch 26 for avoiding the large diameter portion 22 of the ferrule 16, and a curved surface 18b between the notches 26.
is expanded outward along the outer periphery of the large diameter portion of the ferrule 16. The cover ring 28 has a through hole 30 in close contact with the crimp barrel 18;
The flat part 18a of the crimp barrel 18 is prevented from opening when the crimp barrel 18 is fitted around the crimp barrel. Further, a movable substantially cylindrical lance 32 is provided between the ferrule 16 and the cover ring 28. The lance 32 is formed in a cylindrical shape, and one end is attached to the outer circumferential surface of the lance 32 in order to provide elasticity. It has a retained protrusion 32a' which, when the retaining device 10 is inserted into the connector, engages a protrusion within the connector and serves to secure the retaining device 10 to the connector. The crimp barrel 18 between the ferrule 16 and the lance 32 further includes a lance 3.
A coil spring 34 having the same diameter as the connector 2 is mounted around the connector, and the coil spring 34 provides a certain degree of freedom in the movement of the cable in the axial direction within the connector. However, in the mated multi-pole connector, this coil spring 34 equalizes uneven contact pressure on the joint surface of the core between each pole, and also serves as a buffer to absorb shock and vibration caused by external force. Since it works particularly effectively as a material, it is not necessarily necessary when used in a connector with a small number of pins.

On the other hand, the holding device 50 is constructed of the same members as the above-described holding device 10, and the same members are indicated with a prime mark '. However, a dummy ring 52 is attached to the holding device 10 at the position where the coil spring 34 is attached. The dummy ring 52 is a cylinder having the same diameter as the lance 32' extending between the ferrule 16' and the lance 32', and fixes the lance 32' at a fixed position between the ferrule 16' and the cover ring 28'. Further, as shown in FIG. 1, a splice bushing 54 having a through hole is provided at the tip of the ferrule 16'.
The core is aligned by receiving the ferrule 16 through the other opening in the splice bushing 54.

Figures 2A, B and C show the general procedure for assembling the holding device. First, as shown in FIG. 2A, the cover ring 28 is inserted in advance into the fiber cable 12a in which the core 14 is exposed by peeling off the covering 13 of a predetermined length, and the exposed core 14 is inserted into the through hole 20 of the ferrule 16. Insert into. Next, the ferrule 16 is inserted into the notch 26 of the crimp barrel 18.
While aligning the large diameter portion 22 of the cable 12a
is press-fitted into the U-shaped space of the crimp barrel 18, and the crimp barrel 18 is further crimped onto the outer periphery of the cable. At this time, since the claws 24 projecting inwardly of the crimp barrel 18 are configured with surfaces that stand up along the press-fitting direction, they easily bite into the sheath 13 of the cable 12a and hold the cable 12a.
At the same time, the large diameter portion 22 of the ferrule 16 engages with the periphery defining the notch 26 of the crimp barrel, thereby fixing the ferrule 16 (see FIG. 2B).
After the crimp barrel 18 retains the cable 12, the cover ring 2
8 is moved and attached to the crimp barrel 18, the crimp barrel 18 can be prevented from opening, and the fixed state between the cable 12a and the ferrule 16 can be maintained (see FIG. 2C).

When used as a plug connector, the cover ring 28, the lance 32 and the coil spring 34 may be inserted into the cable 12a in advance, and then assembled using the above procedure. In addition, when used in a receptacle connector, the coil spring 3
A dummy ring 52 is inserted in place of the lance 32' to fix the lance 32' in a fixed position.

FIG. 5 shows a multipolar connector plug connector 60 and a receptacle connector 70, each incorporating a plurality of holding devices 10 and 50. Both connectors 60 and 70 have retaining devices 10 and 50.
A through cavity 62 (not shown in the receptacle connector 70) is formed into which the lance 32 is attached to a protrusion (not shown) in the cavity 62 when the holding device 10 is inserted into the cavity. Upon engagement, the retaining device 10 is secured within the cavity 62. Further, the holding device 50 is similarly fixed to the cavity of the receptacle connector 70.

The cables 12a and 12b are connected by fitting the plug connector 60 and the receptacle connector 70 together and tightening them with the coupling ring 80. At this time, the ferrule 16 of the holding device 10 is inserted into the splice bushing 54 of the holding device 50, and the end surfaces of the cores 14 of the cables 12a and 12b collide, but the elastic force of the coil spring 34 aligns both end surfaces. is done properly.

<Effects of the invention> The optical fiber cable holding device of the invention includes a coil spring on a crimp barrel crimped to the ferrule and the end of the optical fiber cable, a substantially cylindrical lance held in the connector, and a substantially annular cover. The ring is crowned, the lance holds the coil spring between it and the ferrule, and is slidable between the ferrule and the cover ring, and the cover ring is fixed to the crimp barrel to restrict rearward movement of the lance. This configuration provides the following effects.

That is, when the ferrule holding the core is connected to a mating connector, the end faces of the core collide, but the elastic force of the coil spring ensures proper alignment of both end faces.

Furthermore, since the cover ring is fixed onto the crimp barrel after it is crimped, the crimp barrel will not open and the optical fiber will not come out. Crimp barrels are thin-walled, easy to process, and do not damage optical fiber cables.

The entire structure can be made compact and can be placed in a high-density connector.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a holding device according to an embodiment of the present invention, illustrating a holding device used for a plug connector and a holding device used for a receptacle connector, and FIGS. 2A to 2C show the assembly order of the holding device. Figure 3 is a sectional view taken along the line 3-3 in Figure 2B, Figure 4 is an exploded perspective view of both holding devices shown in Figure 1, and Figure 5 is a perspective view for explaining the structure. It is a perspective view showing a multi-pole plug connector and a receptacle connector. 12a...Optical fiber cable, 14...Core, 16...Ferrule, 18...Crimp barrel, 28...Covering, 32...Lance, 3
4... Coil spring, 50... Optical fiber cable holding device, 60... Connector.

Claims (1)

[Claims for Utility Model Registration] A ferrule into which a core exposed from an end of an optical fiber cable is inserted, and a crimp barrel that crimply holds the ferrule and the end of the optical fiber cable along the end. In the optical fiber cable holding device, the crimp barrel includes a coil spring,
A substantially cylindrical lance held in the connector and a substantially annular cover ring are each mounted on the connector, and the lance holds the coil spring between the ferrule and is slidable on the crimp barrel. . The optical fiber cable holding device, wherein the cover ring is fixed on the crimp barrel to restrict rearward movement of the lance.