JPS59121305A - Covering method of flexible optical fiber bundle or the like - Google Patents

Abstract

PURPOSE:To apply covering on an optical fiber without damaging the same by winding spirally a shape memory alloy formed to a tape shape having a suitable width to form said alloy into a coiled tube, and heat-treating the tube then deforming plastically the tube at an ordinary temp. to develop the tube, winding the alloy around the outside circumference of a flexible optical fiber bundle or the like and heat-treating the bundle wound around said tape. CONSTITUTION:A shape memory alloy 1 which is formed to a suitable width and inside thickness according to an intended application is formed to a coiled tube 2 having the same inside diameter as the outside diameter of a covering material 3 such as a flexible optical fiber bundle or the like. The tube is then heat-treated to store the coil shape and thereafter the tube 2 is plastically deformed at an ordinery temp. and is coiled or stretched straightly. The shape memorized tape is wound around the outside circumference of the material 3 and is then heat- treated to restore the alloy 1 into the tube 2. The covering in tight contact with the material 3 is thus applied on the outside circumference of said material without using any special installation and jig and without damaging said material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of coating a flexible optical fiber bundle used in C1, such as an image guide, for the purpose of reinforcement, etc., and uses a shape memory alloy as the coating material.

This kind of flexible optical fiber bundle is covered with a thin tube made of silicone rubber or the like for protection, and further reinforcement may be applied thereon depending on the environment and conditions in which the image guide is used. This reinforcement method is
There are two methods: forming a coiled tube in advance with a thin, narrow strip and inserting the optical fiber bundle into the coiled tube, and forming a coiled tube around the outer periphery of a flexible optical fiber bundle while covering the same fiber bundle. There is a way to do this.

However, in the former method, the first diameter of the flexible optical fiber bundle,
If the inner diameter of the coiled tube is made equal, the outer peripheral surface of the flexible optical fiber bundle may be damaged when inserted into the coiled tube, and the frictional resistance will increase, making it difficult to insert the fiber bundle. Become. Therefore, the inner diameter of the coiled tube is actually larger than the outer diameter of the flexible optical fiber bundle (1), but if this is the case, the distance between the optical fiber bundle and the coiled tube is C.
There is a problem that two gaps are formed and the reinforcement of the optical fiber bundle is not sufficient.

Although the latter method does not have the disadvantages of the former, it requires more complicated equipment than simply forming a coiled tube, and also requires a special jig. Furthermore, troubles such as breakage may occur during the manufacture of the coiled duplex, and in that case, there is a problem in that the coiled tube must be connected in some way or the process must be restarted from the beginning.

In order to eliminate the above-mentioned various drawbacks, the present invention has been developed by forming a coiled tube 2 by spirally winding a shape memory alloy I formed into a tape as a material for a coiled tube, and by heat-treating this coiled tube 2. The shape is memorized, and then the tube 2 is plastically deformed at room temperature, expanded, and rolled up or stretched linearly as shown in Figure 2, for example.
As shown in FIG. 3, this shape memory alloy is paid out around the outer periphery of a coated object 3 such as an optical fiber bundle that is paid out separately and is heated to return it to the previously memorized coiled tube. It is C2 coated so as to cover it. The width, wall thickness, etc. of the shape memory alloy 1 are appropriately selected depending on the application.

The helical pitch of the coiled tube 2 made of a shape memory alloy is also appropriately selected depending on the application. coiled tube 2
If the inner diameter of is made the same as the outer diameter of the covered object 3, the covered object 3
When it is fed out to the outer periphery of the object 3 and returned to its shape, it comes into close contact with the outer periphery of the covered object 3.

In the present invention, as shown in the above, the coiled tube 2 is formed in advance from a shape memory alloy, so its inner diameter can be freely selected, and therefore it can be matched to an optical fiber bundle of any outer diameter. be able to.

Moreover, since the coiled tube can be formed by any well-known conventional method, and only heating is required to restore the shape memory alloy, special equipment and treatment are not required to carry out the present invention. It is easy to put into practical use because no tools are required.

Furthermore, since it is wrapped around the outer periphery of the optical fiber bundle simply by heat treatment, there is no need to pressurize and fix it with tools, so there is no chance of the outer periphery of the optical fiber bundle being damaged or the optical fiber bundle breaking. .

[Brief explanation of the drawing]

Figure 1 is an illustration of a coiled Chicove made of shape memory alloy, Figure 2 is an illustration of the same tube being plastically deformed and wound up, and Figure 3 is an illustration of the coiled tube being wound around the outer periphery of an optical fiber bundle. It is an explanatory diagram of a state. 1 is a shape memory alloy 2 is a coiled tube 3 is a covered object Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Claims] A shape memory alloy formed into a tape shape of an appropriate width is spirally wound to form a coiled tube, this coiled tube is heat treated to memorize its shape, and then the tube is left at room temperature (and then subjected to plastic deformation). The shape memory alloy is then unrolled onto the outer periphery of a coated object such as a flexible optical fiber bundle that is separately unwound, and heated to return the shape memory alloy to the coiled tube in which it was previously memorized. ,
A method of coating a flexible optical fiber bundle, etc., in which a coated object is coated with the coiled tube.