JPS635311A - Relaying adaptor for optical fiber - Google Patents

Abstract

PURPOSE:To easily make highly accurate center-alignment, by using a cylindrical rod, with which a highly accurate shape and dimensions can easily be obtained. CONSTITUTION:A relaying adaptor 10 for optical fiber is provided with two terminals 10 and a metallic split sleeve 14 having an almost triangular shape and an optical fiber core 18 and optical fiber strand 20 are firmly fixed to each of the terminals 11 by means of a holder 17. The fiber strand 12 is extended through the path formed by three cylindrical rods 12. Since the cylindrical rods can easily be formed of a metal to have accurate shapes and dimensions, the fiber strand 12 can be positioned accurately to the three cylindrical rods 12 by a easy technique and two fiber strands 20 facing each other can be aligned.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a relay adapter for optical fibers, and more particularly to a relay adapter for optical fibers of a type in which the end faces of bare fibers are brought into contact with each other.

BACKGROUND ART Conventionally, as an optical fiber relay adapter, a type in which the end surfaces of a fiber cable are brought into contact with each other is known. In this type of optical fiber relay adapter, only the two end faces are in contact, so in order to minimize splice loss, it is necessary to align the center of the end of the fiber with particular precision. be.

In order to accurately align the center, an optical fiber relay adapter is known in which a minute hole is provided in the central axis of a cylindrical rod, and the end of the optical fiber strand is disposed within the minute hole. In this optical fiber relay adapter,
Two cylindrical rods, each having an end portion of a fiber strand arranged thereon, are held by a cylindrical split sleeve or the like so that their central axes coincide.

According to this type of optical fiber relay adapter, the central axes of the two fiber wires can be made to match accurately. However, in this type of optical fiber relay adapter, it is extremely difficult to manufacture because it is necessary to form a microhole precisely on the central axis of the cylindrical rod.

On the other hand, there is also known an optical fiber or eyeglass relay adapter in which a 3 or 111 IAiI ball or cylindrical rod is arranged in a cylindrical ferrule and a fiber core wire is arranged at the center of the ball or cylindrical rod.

However, since this type of optical fiber relay adapter uses three or four balls or cylindrical rods, the relative positions of the balls or rods are not uniquely determined, and the There is a problem that the fiber core wires cannot be accurately centered because their mutual positions are shifted or because the cylindrical ferrule is aligned based on the outer periphery of the cylindrical ferrule.

Means for Solving the Problems According to the present invention, in order to solve the above problems, the outer peripheries of a plurality of cylindrical rods are held in contact with each other, and three of the cylindrical rods , two terminals in which passages for the fiber strands are defined, and a split sleeve that contacts the exposed outer peripheral surfaces of the plurality of cylindrical rods to center the passages of the two terminals. Provided is an optical fiber relay adapter comprising:

Embodiment Referring to FIGS. 1 to 3, an optical fiber relay adapter according to a preferred embodiment of the present invention will be described.

This optical fiber relay adapter 10 has two terminals 11
and a substantially triangular metal split sleeve 14.

Each of the two terminals 11 is connected by a holder 17 to the optical fiber core &! 18 and the optical fiber wire 20 are firmly fixed.

A fiber strand 12 extends through a passage formed between three cylindrical rods 12.

If the radius of the three cylindrical rods 12 is R, and the radius of the fiber wire 20 that is in contact with the outer periphery of the three cylindrical rods 12 and is arranged in the passage formed between them is r,
R and r satisfy the following formula.

R= (R+ r) cos30° Therefore, r is expressed as follows.

r = (2/, /j −1>
・R=0.1547・R Conversely, if the radius of the fiber wire 20 is a specific value, if three cylindrical rods 12 having a radius R that satisfies the above formula are used, these circles The columnar rod 12 allows accurate positioning.

The cylindrical rod 12 can be made of metal such as stainless steel, ceramic, or the like.

It is relatively easy to form cylinders with precise shapes and dimensions, for example from metal. Therefore, using a relatively easy technique, the fiber wire 20 is connected to the three cylindrical rods 1.
2, thereby making it possible to center the two opposing fiber strands 20.

In the embodiment described above, the three cylindrical rods 12 have the same radius, but rods with different radii can also be used.

A metal split sleeve 14 is arranged to surround the exposed portions of the three cylindrical rods 12 on both ends 11 (FIG. 3).The metal split sleeve 14 is shown in FIG. Since the cross section is approximately triangular and extends linearly in the axial direction, the three
The central axes of the pair of cylindrical rods 12 coincide with each other, and thereby the central axes of the fiber strands 20 coincide with each other.

Since the sleeve is constituted by a metal split sleeve 14, when connecting two terminals 11, this metal split sleeve 14 is elastically expanded slightly, and as shown in FIGS.
As shown in the figure, three cylindrical rods 12 holding the fiber strands 20 are inserted from both sides, and the fiber strands 20 are inserted.
0 is positioned so that the end faces are in contact with each other.

As noted above, an axially straight metal split sleeve, as described above, is used to create and maintain a high degree of axial alignment. Further, if desired, locking means (not shown) can be provided for restricting the longitudinal movement of the terminal 11 and maintaining the end faces of the fiber cable 20 in contact with each other.

The optical fiber relay adapter according to this embodiment uses three cylindrical rods 12, but instead uses a terminal having four cylindrical rods 12, so that the outer peripheral surfaces of the cylindrical rods 12 are mutually connected. As shown in FIG. It is also possible to use a split sleeve 24 having a substantially trapezoidal cross section that aligns the ends 22 of the columnar rods in a substantially trapezoidal arrangement.

Furthermore, the plurality of cylindrical rods at the terminals are arranged in two or more rows so that their outer peripheries are in contact with each other, and passages for the plurality of fiber strands are defined between them. You can also.

Further, as illustrated in FIG. 5, 6, 10, 15, etc. cylindrical rods are arranged so that their outer peripheries are in contact with each other and the overall cross-sectional shape is approximately triangular. a terminal 26 defining a passageway for a plurality of fiber cables therebetween;
It is also possible to use a centering split sleeve 28 having a substantially triangular cross section.

Effects The optical fiber relay adapter according to the present invention uses a cylindrical rod whose shape and dimensions are relatively easy to obtain, and can be relatively easily and accurately centered.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an optical fiber relay adapter according to a preferred embodiment of the present invention, before a rod is attached to a sleeve. FIG. 2 is a perspective view of the optical fiber relay adapter of FIG. 1 in the middle of fitting the rod into the sleeve. FIG. 3 is a sectional view of a main part of the optical fiber relay adapter shown in FIG. 2. FIG. 4 is a perspective view of an optical fiber relay adapter according to another embodiment of the present invention, in the middle of attaching a rod to a sleeve. FIG. 5 is a perspective view of an optical fiber relay adapter according to still another embodiment of the present invention, in the middle of attaching a rod to a sleeve. 10... Optical fiber relay adapter 11.22.26... Terminal 12... Cylindrical rod 14.24.28... Metal split sleeve 17... Holder 18... Optical fiber core wire 20 ...Fiber wire (1 other person)

Claims (1)

[Claims] 1. The outer circumferences of a plurality of cylindrical rods are held so as to be in contact with each other, and three of the cylindrical rods:
Two terminals defining passages for the fiber strands, and a split sleeve that contacts the exposed outer peripheral surfaces of the plurality of cylindrical rods to center the passages of the two terminals. An optical fiber relay adapter comprising: 2. The optical fiber relay adapter according to claim 1, which includes three cylindrical rods and defines a passage for one fiber wire. 3. The optical fiber relay adapter according to claim 1, which includes four cylindrical rods and defines passages for two fiber wires. 4. Claim 1, comprising six cylindrical rods, arranged so as to have an approximately triangular cross section as a whole, and defining passages for four fiber strands.
Optical fiber relay adapter described in section. 5. The optical fiber relay adapter according to any one of claims 1 to 4, wherein the cylindrical rods have substantially the same radius. 6. The optical fiber relay adapter according to any one of claims 1 to 4, wherein the cylindrical rods have different radii.