JPH037802Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a drum chuck for tensile testing of optical fibers.

(B) Prior art and its problems As a means for holding the optical fiber when performing a tensile test on the optical fiber, in consideration of the fragility of the fiber, as shown in Fig. 1, a cushion material 1 such as rubber is held on the clamping surface. Generally, the fiber a is held between a flat plate 2 attached to the fiber a, and the fiber a is wound around a drum 3 as shown in FIG.

However, the former has problems such as the fiber a not having enough clamping force and slipping, and conversely, the fiber a breaking if the clamping force is too strong. It is necessary to wrap the fiber a three or four times around the coil, which requires a long sample to be wound, which results in a lot of wasted sample, and it is necessary to be careful not to overlap the fiber a when wrapping. , there is a problem in terms of workability.

(c) Problems that this invention aims to solve This invention proposes that in a holding means by winding around a drum, most of the holding force is provided by the first winding around the drum, and the subsequent windings serve as supplements. The purpose of this invention is to solve the above-mentioned conventional problems by focusing on the fact that it is not related to the winding diameter.

(d) Means for solving the problem In order to achieve the above object, in the drum chuck of this invention, the outer diameter of the drum on which the tensile test sample is first wound is increased, and the outer diameter of the drum on which the tensile test sample is wound subsequently is increased. It has a smaller diameter.

With this structure, the tensile test sample is first wound around the large diameter side of the drum's outer surface, then wound around the small diameter side, and the sample is held by the drum.

Hereinafter, embodiments of this invention will be described based on the accompanying drawings, FIGS. 3 and 4.

(E) Example 1 In the example shown in FIG. 3, the drum 3 is composed of two drums 3a and 3b having different outer diameters, and these drums 3a and 3b are arranged side by side and their outer peripheral surfaces are inscribed. It is something that

When the fiber a is held by this drum 3, the fiber a is first held on the large diameter drum 3.
After wrapping the first round around a, the small diameter drum 3b
Wrap the second to fourth turns around and hold.

The outer diameter of the conventional drum 3 is generally 120mmφ.
Usually, it is held by wrapping it four times, and the required length of the fiber a for this holding is approximately 3014 mm, including the length of the upper and lower drum chucks.

In the case of the drum 3 according to the invention of the present invention, when the outer diameter of the large diameter drum 3a is 120 mmφ and the outer diameter of the small diameter drum 3b is 60 mmφ and the fiber a is wound around it, sufficient holding force can be obtained and no slipping can be achieved. No disconnection occurred. The required length of the holding fiber a in this case is approximately 1883 mm, which is approximately 2/2 of the conventional length.
It was 3 in length.

In the above embodiment, the drum 3 is composed of the drums 3a and 3b, but if the number of drums is increased and the diameter is made smaller in turn, and the fiber a is wound only once around each drum, the fiber a during winding can be There is no overlap of a.

Furthermore, even if grooves 4 for guiding the fiber a are formed on the outer peripheral surfaces of the drums 3a, 3b, etc., the fiber a
Overlapping can be prevented.

(F) Example 2 In the example shown in FIG. 4, the drum 3 is shaped like a truncated cone and has a spiral groove 4 formed on its outer peripheral surface.

To hold the fiber in this embodiment, it is sufficient to wrap the fiber a along the groove 4 from the large diameter to the small diameter, and as in the above embodiment, sufficient holding force can be obtained even if the wrapping length is short. can.

Note that the outer peripheral surface of the drum 3 may be coated with an elastic material such as rubber for cushioning and resistance.

(g) Effects As described above, according to this invention, the diameter of the winding around the drum is made smaller from the second round, so the winding length is shorter than with conventional means, making it economical. be.

In addition, there is little overlapping of the fibers during winding, and workability is good.

Furthermore, since the drum itself is lightweight, it has the effect of reducing the load on the testing machine.

[Brief explanation of the drawing]

1 and 2 are schematic views of examples of conventional holding means, and FIGS. 3 and 4 are front views of examples of the drum chuck of this invention. a...Optical fiber, 3, 3a, 3b...Drum, 4...Groove.

Claims (1)

[Claims for Utility Model Registration] (1) A drum chuck for tensile testing, which is constructed by increasing the outer diameter of the drum on which the tensile test sample is first wound, and reducing the outer diameter of the drum on which it is subsequently wound. (2) The scope of the utility model registration claim, characterized in that the drum is composed of two or more drums with different outer diameters, and the drums are arranged side by side in order of diameter, and their outer peripheral surfaces are inscribed. A drum chuck for tensile testing as described in paragraph (1). (3) The drum chuck for tensile testing as set forth in claim (1) of the utility model registration claim, wherein the drum is shaped like a truncated cone and has a spiral groove formed on its outer peripheral surface. .