Compression test instrument

Abstract

This compression test instrument (100) for an optical cable (20) having two opposite side surfaces (20a, 20b) comprises: a fixed flat plate (1) on which the optical cable (20) is placed; a pair of support members (4, 5) that support the two side surfaces (20a, 20b) while the optical cable (20) is placed on the fixed flat plate (1); and a movable flat plate (2) that applies a load on the optical cable (20) in the direction of the fixed flat plate (1).

Description

Compression Test Equipment

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a compression testing instrument for use in compression testing cables.

[0002] Cables such as optical fiber cables are required to have a certain level of compressive strength, and so compression tests are conducted. For example, as specified in "JIS6870 1-21," a compression test is conducted by placing the cable on a fixed plate and applying a vertical load from above the cable using a movable plate.

[0003] Recently, optical fiber cables having a flattened elliptical or rectangular cross section have been put to practical use, as disclosed in Patent Documents 1 to 3.

[0004] JP 2003-227977 A JP 2012-32572 A JP 2022-504791 A

[0005] However, conventional cable compression testing methods assume that the cable has a circular cross section. Therefore, it is difficult to perform a longitudinal compression test on cables with non-circular cross sections, such as the aforementioned flattened oval or rectangular cross sections. That is, when a cable has a cross section with both a longitudinal and a lateral direction and a compression test is performed by applying a load in the longitudinal direction, the cable may collapse due to the load. In such cases, the cable must be repositioned, which increases the time and effort required for the compression test.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a compression test device that can easily perform compression tests on cables that do not have a circular cross section.

[0007] One embodiment of the compression test apparatus disclosed herein is an apparatus for compressing a cable having two opposing sides, and comprises a fixed plate on which the cable is placed, a pair of support members that support the two sides while the cable is placed on the fixed plate, and a movable plate that applies a load to the cable toward the fixed plate.

[0008] According to the present disclosure, it is possible to easily perform a compression test on a cable having a non-circular cross section.

[0009] Fig. 1 is a cross-sectional view showing the configuration of a compression test instrument according to a first embodiment, Fig. 2 is a cross-sectional view showing the configuration of a compression test instrument according to a second embodiment, and Fig. 3 is a cross-sectional view showing the configuration of a compression test instrument according to a third embodiment.

[0010] [Description of First Embodiment] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing the configuration of a compression test fixture according to a first embodiment. As shown in Fig. 1, a compression test fixture 100 includes a fixed plate 1, a movable plate 2, a compression member 3, and support members 4 and 5. The compression test fixture 100 is a fixture for fixing an optical cable 20 (an optical cable having a rectangular cross section) to be tested and applying a load to the optical cable 20. Note that, in this embodiment, an optical cable will be used as an example of the cable to be tested, but the present invention can also be applied to other cables.

[0011] The fixed plate 1 has a flat plate shape. The fixed plate 1 is installed, for example, so that its upper surface is horizontal. Hereinafter, the left and right of the cross-sectional view shown in Fig. 1 will be referred to as the leftward and rightward directions, and the top and bottom will be referred to as the upward and downward directions. The left-right direction and the up-down direction are the left-right direction and the up-down direction, respectively, in the cross section of the optical cable 20 (a plane perpendicular to the longitudinal direction of the optical cable 20).

[0012] An optical cable 20 to be tested is placed on the fixed plate 1. The optical cable 20 has a cross section that is different in length and width, such as a flattened ellipse or rectangle. In other words, the cross section of the optical cable 20 is not circular. In the example shown in Fig. 1, the short side of the optical cable 20 having a rectangular cross section is placed on the fixed plate 1.

[0013] As shown in Fig. 1, the optical cable 20 includes two tension members 21, an outer jacket 22, and a plurality of optical fibers 23. In the cross section of the optical cable 20, side surfaces 20a and 20b in the longitudinal direction are parallel to each other. That is, the optical cable 20 has two opposing sides (side surfaces 20a and 20b). As shown in Fig. 1, when the optical cable 20 is placed on the fixed flat plate 1 so that the short side faces thereof are in contact with each other, the direction along the side surfaces 20a and 20b is the up-down direction (the direction perpendicular to the fixed flat plate 1).

[0014] The support members 4 and 5 have a rectangular shape in a side view and are disposed on the left and right sides of the optical cable 20. A side surface 4a on the right side (optical cable 20 side) of the support member 4 is flat. A side surface 5a on the left side (optical cable 20 side) of the support member 5 is also flat. Therefore, when the optical cable 20 and the two support members 4 and 5 are placed on the fixed flat plate 1, the side surface 20a of the optical cable 20 and the side surface 4a of the support member 4 come into surface contact, and the side surface 20b of the optical cable 20 and the side surface 5a of the support member 5 come into surface contact.

[0015] The upper surfaces 4b, 5b of the support members 4, 5 are flat. The upper surfaces 4b, 5b of the support members 4, 5 are at the same height in the vertical direction as the upper surface 20c of the optical cable 20. That is, the optical cable 20 and the support members 4, 5 have the same thickness. The support members 4, 5 are preferably formed from a material that is less hard (more flexible) than the material of the jacket 22 of the optical cable 20.

[0016] The movable platen 2 is placed above the support members 4 and 5. A compression member 3 is placed on the upper surface of the movable platen 2. The movable platen 2 is arranged parallel to the fixed platen 1. A pressure device (not shown) is connected to the compression member 3, which makes it possible to apply a desired load downward.

[0017] Next, a description will be given of the procedure for a compression test using the above-mentioned compression test instrument 100. First, the optical cable 20 to be tested is placed on the upper surface of the fixed plate 1 shown in Fig. 1. At this time, the optical cable 20 is placed so that the direction along the longitudinal side surfaces 20a, 20b in the cross section of the optical cable 20 is the up-down direction.

[0018] Next, the support members 4 and 5 are installed on the sides of the two side surfaces 20a and 20b of the optical cable 20. At this time, the side surface 4a of the support member 4 faces the side surface 20a of the optical cable 20, and the side surface 5a of the support member 5 faces the side surface 20b of the optical cable 20.

[0019] Thereafter, a downward load F1 is applied to the compression member 3. The movable plate 2 connected to the compression member 3 descends, applying a load to the upper surface 20c of the optical cable 20 and the upper surfaces 4b, 5b of each support member 4, 5. As described above, the material of the support members 4, 5 is less hard and more flexible than the jacket 22 of the optical cable 20, so almost all of the load applied to the movable plate 2 is applied to the upper surface 20c of the optical cable 20. Furthermore, because the two side surfaces 20a, 20b of the optical cable 20 are pressed by the support members 4, 5, the optical cable 20 can be prevented from tipping over even if stress acts in the left-right direction due to the load applied to the optical cable 20. This makes it possible to avoid problems such as the need to retest the optical cable 20 due to tipping over.

[0020] As such, the compression test instrument 100 of this embodiment is an instrument for compression test of an optical cable 20 (cable) having two opposing sides (e.g., side surfaces 20a and 20b), and comprises a fixed plate 1 on which the optical cable 20 is placed, a pair of support members 4 and 5 that support the two sides when the optical cable 20 is placed on the fixed plate 1, and a movable plate 2 that applies a load to the optical cable 20 toward the fixed plate 1.

[0021] The compression test instrument 100 according to this embodiment can prevent the optical cable 20 from tipping over when a test is performed in which a load is applied in the longitudinal direction (direction along the side surfaces 20a, 20b) of the optical cable 20 to be tested. This can solve problems such as having to redo the compression test due to the optical cable 20 tipping over, and can reduce the effort required by the user.

[0022] In this embodiment, the support members 4 and 5 are made of a material that is lower in hardness than the jacket 22 of the optical cable 20, so that the support members 4 and 5 deform first when a load is applied. This makes it possible for the support members 4 and 5 to more firmly fix the side surfaces 20 a and 20 b of the optical cable 20.

[0023] [Description of Second Embodiment] Next, a second embodiment will be described. Fig. 2 is a cross-sectional view showing the configuration of a compression test device 101 according to the second embodiment. The compression test device 101 according to the second embodiment differs from the compression test device 100 shown in Fig. 1 in that fixing devices 6 and 7 are installed on the sides of the support members 4 and 5.

[0024] 2 , the fixtures 6 and 7 have a rectangular shape in side view. The fixtures 6 and 7 are formed of, for example, metal and are fixed to the fixed flat plate 1. The right side surface 6a of the fixture 6 contacts the left side surface 4c of the support member 4 and the left side surface 2a of the movable flat plate 2. The left side surface 7a of the fixture 7 contacts the right side surface 5c of the support member 5 and the right side surface 2b of the movable flat plate 2. In other words, the pair of fixtures 6 and 7 fix the surfaces of each support member 4 and 5 that are opposite to the surfaces that support the optical cable 20.

[0025] Furthermore, the distance between the right side surface 6a of the fixing device 6 and the left side surface 7a of the fixing device 7 is approximately the same as the left-right length L1 of the movable flat plate 2. Note that the left-right length L1 of the movable flat plate 2 may be shorter than the distance between the side surfaces 6a and 7a. In other words, the left-right length L1 of the movable flat plate 2 (the length in the direction perpendicular to the longitudinal direction of the cable) is set to be equal to or less than the distance between the pair of fixing devices 6, 7.

[0026] In the second embodiment, similarly to the first embodiment described above, the optical cable 20 to be tested can be prevented from falling over when a load is applied. Furthermore, in the second embodiment, by installing the fixing members 6 and 7 on the outer sides of the support members 4 and 5, the support members 4 and 5 can be prevented from sliding in the left-right direction when a load is applied.

[0027] Furthermore, the length of the movable plate 2 in the direction perpendicular to the longitudinal direction of the optical cable 20 is set to be equal to or less than the distance between the fixtures 6 and 7, which has the effect of not restricting the height (vertical length) of the fixtures 6 and 7.

[0028] [Description of Third Embodiment] Next, a third embodiment will be described. Fig. 3 is a cross-sectional view showing the configuration of a compression test fixture 102 according to the third embodiment. The compression test fixture 102 differs from the compression test fixture 101 according to the second embodiment in that the height of the fixture is lower and the length of the movable platen 2 in the left-right direction is longer.

[0029] As shown in Figure 3, the compression test apparatus 102 according to the third embodiment includes fixtures 8 and 9. The fixtures 8 and 9 are rectangular in side view. The right side surface 8a of the fixture 8 contacts the left side surface 4c of the support member 4. The left side surface 9a of the fixture 9 contacts the right side surface 5c of the support member 5. In other words, the pair of fixtures 8 and 9 fix the surfaces of the support members 4 and 5 opposite to the surfaces that support the optical cable 20.

[0030] The upper surface 8b of the fixture 8 is lower than the upper surface 4b of the support member 4. The upper surface 9b of the fixture 9 is lower than the upper surface 5b of the support member 5. That is, the heights of the upper surfaces 8b and 9b of the fixtures 8 and 9 are lower than the upper surfaces 4b and 5b of the support members 4 and 5. In addition, the length of the movable platen 2 in the left-right direction is longer than the distance from the left end of the support member 4 to the right end of the support member 5.

[0031] In the third embodiment, as in the first and second embodiments, the optical cable 20 to be tested can be prevented from falling over when a load is applied. Furthermore, in the third embodiment, by installing the fixing members 8 and 9 on the outer sides of the support members 4 and 5, the support members 4 and 5 can be prevented from sliding in the left-right direction when a load is applied.

[0032] In the compression test fixture 102 according to the third embodiment, the upper surfaces 8b, 9b of the fixtures 8, 9 are positioned lower than the upper surface 20c of the optical cable 20, which prevents the movable plate 2 from interfering with the fixtures 8, 9. This makes it possible to increase the length of the movable plate 2 in the left-right direction.

[0033] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0034] REFERENCE SIGNS LIST 1 Fixed plate 2 Movable plate 3 Compression member 4, 5 Support member (pair of support members) 4b, 5b Upper surface (upper surface of support member) 6, 7, 8, 9 Fixture 20 Optical cable (cable) 20a, 20b Side surface (two opposing sides of optical cable) 20c Upper surface 21 Tension member 22 Jacket 23 Optical fiber 100, 101, 102 Compression test fixture

Claims

1. An apparatus for a compression test of a cable having two opposing side portions, comprising: a fixed flat plate on which the cable is placed; a pair of support members that support the two side portions with the cable placed on the fixed flat plate; and a movable flat plate that applies a load to the cable toward the fixed flat plate.

2. The apparatus for a compression test according to claim 1, wherein the support member and the cable have the same thickness, and the support member has a lower hardness than the cable.

3. The apparatus for a compression test according to claim 1 or 2, further comprising a pair of fixtures that fix the surfaces of each support member on the side opposite to the surface that supports the cable, and wherein the length of the movable flat plate in a direction orthogonal to the longitudinal direction of the cable is equal to or less than the distance between the pair of fixtures.

4. The apparatus for a compression test according to claim 1 or 2, further comprising a pair of fixtures that fix the surfaces of each support member on the side opposite to the surface that supports the cable, and wherein the height of the fixture is lower than that of the support member.

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