WO2019207590A1

WO2019207590A1 - A break indication rope

Info

Publication number: WO2019207590A1
Application number: PCT/IN2019/050062
Authority: WO
Inventors: Kishor Jayantilal DARDA; Neeraj Shrivastava; Sanjay Vasudeo RAUT
Original assignee: Garware Technical Fibres Ltd.
Priority date: 2018-04-26
Filing date: 2019-01-28
Publication date: 2019-10-31

Abstract

The present invention discloses a break indication rope (10,30) for simple visual detection of wear and tear and end of service life of the rope (10,30). The examination of the rope using sophisticated instrumental techniques is time consuming and complex. Therefore, a rope of the present invention provides a faster & simple monitoring and detection, leading to saving of time and cost. The rope 10 of invention comprises plurality of strands, each strand comprises a core layer 12a, at least one intermediate layer 12b,12c, and a sheath or cover layer 12d, wherein any of the intermediate layer comprises a break indication element 13. The break indication element 13 is present in one or more strands of a rope.

Description

A BREAK INDICATION ROPE

FIELD OF INVENTION:

The present invention in general relates to ropes that include a wear & tear detection mechanism and thus detect end of its service life. More particularly, the present invention relates to ropes that provide a visual indication of such a wear & tear and end of service life when its outer surface degrades over a time period or due to stress or any other operational factors that are responsible for its wear & tear.

BACKGROUND & PRIOR ARTS:

A rope is often defined as a long, flexible assembly of fibers, laid, braided, or bundled together, to serve as a tensile strength member. There are different types of ropes such as braided rope, which is formed by braiding or plaiting the strands together; cable laid ropes, which is formed by three or more strands or ropes twisted to form a helix around the same central axis; combined rope, which has outer fibrous strands around a central steel wire; double braided ropes etc. These ropes are used for variety of applications. Some of the applications are found in mooring lines in commercial vessels, fishing, climbing and mountaineering, for a support while working on buildings, lifting and load handing in cranes, electrical utility services and power line stringing, recreation etc. These ropes are manufactured from various natural and synthetic fibers.

The outer layer of yarns in the ropes degrades due to abrasion, environmental exposure etc. Such degradation exposes internal layers of yarns to further degradation resulting in loss of tensile strength and thereby causing the rope to fail during its service/operation, which may lead to loss of life, property etc. It is, therefore, a mandatory practice to check the health of the rope before every operation, especially in the applications where loss of life and property are involved. However, it may be difficult and time consuming to physically examine the rope before every operation. Also the process of examining and retiring rope in general is subjective in nature and the retirement criteria is based on the judgement of the user based on his experience and assessment of the state of the rope. There is no mechanism present in the rope for the user to help him to arrive at a decision on either continue using the same rope or to retire it based on the amount of wear and tear of the rope. Therefore, in order to indicate the user that the rope in service has undergone enough wear and tear and is likely to fail, a detection system is required in the rope itself. It has also been observed that out of fear of failure of the rope during operation, the rope is prematurely discarded leading to economic losses to the user. US6999641 describes measurement of the accumulating strain in the rope to provide a reliable structural health monitoring method for ropes. A plastic optical fiber in which reflective surfaces are placed inside it and plastic optical fiber is integrated in the rope itself such that it experiences the same strain as the rope during its operation. An optical instrumentation is used for measuring time of flight through said plastic optical fiber and reflective surfaces placed in the said plastic optical fiber to find the strength in the entire length or in discrete segments along the length of the rope. However, such complex detection system cannot be commonly available at every site for a wear & tear detection since such system requires a technical expertise. The additional investment for such project may also be high.

Another patent application 2883/CHE/2007 relates to a synthetic fiber rope consisting of plurality of synthetic yarns and at least one indicator fiber for supporting an elevator car in an elevator installation. The said synthetic rope has outer strand layer having lower tensile strength than that of inner strand layer. The outer strand layer is provided with electrically conducting wires. When the outer layer starts abrading, a voltage source may be utilised to find out number of snapped electrical conducting wires so that the residual load bearing capacity can be assured. However, the weaker tensile strength of the outer strand layer of rope claimed in said patent application may create operational problems as the outer layers are more exposed to the abrasion as well as environmental degradation and hence may lead to premature failure of the rope. Such rope cannot be used for outside application.

W02015109079 relates to a system having wired, RFID, fiber optic based warning indicators when a rope is about to fail. However, WO’079 does not cover break indication based on wear & tear of the rope.

The present invention visually detects a wear & tear of the rope in a simpler manner when the outer surface of the rope degrades. None of the above prior art provides a simple facility as in the present invention. The ropes of the present invention provide an economic and time saving approach for physical examination of rope.

As stated above, the process of examining the rope using instrumental techniques is time consuming and complex. Therefore, a rope of the present invention provides a faster monitoring and detection, leading to saving of time and cost. The present invention also avoids premature retiring of the rope out of fear of failure during operation.

SUMMARY OF INVENTION:

The present invention provides a simple, cost-effective facility of the visual indication to indicate the end of service life of the rope.

Accordingly, the present invention discloses a break indication rope for simple visual detection of wear and tear and end of service life of the rope. It comprises a plurality of strands, wherein each strand comprises a core layer, at least one intermediate layer, and a sheath or cover layer. Further, any of the intermediate layer comprises a break indication element.

In an embodiment, break indication element are selected from electroluminescent wire, optical fiber, luminous yarn, photochromic yarn and combination thereof. Further, in a rope having plurality of strands, any one or more strands may contain a break indication element.

In an embodiment, luminous yam element is selected from phosphorescent yarn, fluorescent yam or a combination thereof. The phosphorescent yarn is prepared by using a phosphorescent material selected from self-excited, organic dyes or non radioactive material. The self-excited phosphorescent material is radium or any other suitable material. The non-radioactive material is either a material having short after-glow time and a material having long after-glow time. The material having short after-glow time may be copper sulphides, silver sulphides, bismuth activated (zinc) sulphides or combination thereof, whereas the material having long after-glow time may be rare earth doped alkaline earth aluminates, alkaline earth sulphides, alkaline earth silicates, or combination thereof.

In another embodiment, optical fiber element is a side glow optical fiber.

In another embodiment, the photochromic yam is produced by using photochromic dyes or inorganic materials exhibiting photochromic effects. Photochromic dyes used could belong to various classes such as triarylmethanes, stilbenes, azastilbenes, nitrones, fulgides, spiropyrans, naphthopyrans, spiro-oxazines, quinones and others. Inorganic substances exhibiting photochromism could be silver halide, zinc halide and others.

In an embodiment, the rope is twisted, laid, braided, combined rope etc.

In another embodiment, yarns other than break indication element are selected from polyolefins, polyamides, polyesters, aramids or a combination thereof.

Further, the present invention discloses a simple visual detection method of wear tear of a rope using break indication element by observing illumination of the wire, the illumination being stimulated by incident ambient light (as in case of luminous yarn or photochromic yarn used as break indication element), or the break indication connected to a power source (as in case of Electroluminescent wire used as break indication element), or a light passed through the break indication element (as in case of Optical fiber used as break indication element).

BRIEF DESCRIPTION OF DRAWINGS:

Figure 1 illustrates a three-strand laid rope, which is a preferred embodiment.

Figure 2 illustrates a cross sectional view of an exemplary embodiment of three- strand laid rope.

Figure 3 illustrates a cross-sectional view of a three-strand laid rope, one of the embodiment of the present invention.

Figure 4 illustrates working of the present invention.

DETAILED DESCRIPTION OF INVENTION:

Accordingly, the present invention discloses a break indication rope to help in detecting wear and tear and end of service life of the rope. The rope provides a simple, cost-effective provision for the visual detection to indicate the end of service life of the rope.

In a preferred embodiment, the break indication rope comprises plurality of strands, each strand comprises multiple layers of yams, wherein any of the inner layer comprises a break indication element.

The break indication element may be selected from, but not limited to, electroluminescent wire, optical fiber, luminous yam, photochromic yarn and combination thereof. In an embodiment, the break indication element may be one or more luminous yarns. The luminous yarns are produced by extruding one or mixture of polymers, and a phosphorescent or fluorescent additive containing phosphorescent and/or fluorescent material respectively. The luminous yarn is also be produced by applying any coating containing phosphorescent and/or fluorescent material on synthetic fiber/yarn.

The phosphorescent material is selected from self-excited, organic dyes or non radioactive material. The self-excited phosphorescent material is radium or any other suitable material. The non-radioactive material may be a material having short after-glow time or a material having long after-glow time. The material having short after-glow time may be copper sulphides, silver sulphides, bismuth activated (zinc) sulfides or combination thereof, whereas the material having long after-glow time may be rare earth doped alkaline earth aluminates, alkaline earth sulfides, alkaline earth silicates, or combination thereof.

In another embodiment, the break indication element may be an Electroluminescent (EL) wire. During inspection of the rope, the break indication element having EL wire is connected to the power source. If the user observes any glowing EL wire at one or more places during its inspection, it indicates that the outer layer of the rope has undergone wear and tear and therefore it is time to retire the rope.

In yet another embodiment, the break indication element may be an optical fiber. A light source has to be connected during visual assessment of the rope. When the light passed through the optical fiber is visible behind a degraded outer layer, it indicates the end of service life of the rope.

The photochromic yarns are produced by extruding one or mixture of polymers, and a photochromic material masterbatch containing photochromic dyes or inorganic material exhibiting photochromism. The photochromic yarn is also produced by applying any coating containing photochromic dyes or inorganic material exhibiting photochromism on any synthetic fiber/yarn. The embodiments of the invention may be understood by referring to appended figures. However, the figures are intended to illustrate the various embodiments of the present invention and do not restrict the scope of the invention. Any minor variations in the embodiment will fall within the ambit of the invention. Figure 1 illustrates a preferred embodiment of three-strand laid rope 10, wherein the said rope 10 comprises of plurality of strands l0a,l0b,l0c. Each strand contains plurality of yarns 11.

Figure 2 shows a cross-sectional view of the rope illustrated in Figure 1. As seen, the three-strand laid rope 10 comprises of a plurality of strands l0a,l0b,l0c, each strand comprises a core layer l2a, an intermediate layer l2b, l2c, and a sheath or cover layer l2d. The intermediate layer l2b or 12 c may comprise of a break indication element 13. As stated before, break indication element 13 may be selected from, but not limited to, electroluminescent wire, optical fiber, luminous yarn, photochromic yarn and combination thereof.

The rationale for choosing the break indication element hidden by the outer strand is that the wear & tear of the rope may be indicated visually when the said outer strand is degraded /abraded during usage. In an embodiment in which the break indication element 13 is an electroluminescent wire, the break indication element 13 is connected to the power source. During inspection of the rope, the break indication element having EL wire is connected to the power source. If the user observes any glowing EL wire at one or more places during its inspection, it indicates that the outer layer of the rope has undergone wear and tear and therefore it is time to retire the rope.

In an embodiment in which the break indication element 13 is an optical fiber, a light source has to be connected during visual assessment of the rope 10. When the light passed through the optical fiber is visible behind a degraded outer layer l2c, it indicates the end of service life of the rope 10.

In an embodiment in which the break indication element 13 is one or more luminous yarns, Figure 1 may be referred as an example of this embodiment. In the said embodiment, yarns 11 may be luminous yams present in the inner layers of any one or more of the strands lOa, lOb or lOc. The luminous yarn may be selected from phosphorescent yarn, fluorescent yarn or a combination thereof. The luminous yarns are produced by extruding one or mixture of polymers, and a phosphorescent or fluorescent additive containing phosphorescent and/or fluorescent material respectively. The luminous yam can also be produced by applying any coating containing phosphorescent and/or fluorescent material on synthetic fiber/yam. The said embodiment disclosing the luminous yam as the break indication element 13 is the preferred embodiment of the invention.

In the said embodiment in which the break indication element is/are luminous yarn/s, an incident light (i.e. sunlight, uv light etc.) may be utilised as the source of illumination. The illuminated inner strand, which is visible to observer from outside, indicates wear & tear of the rope and end of service life of the rope.

In an embodiment in which the break indication element 13 is one or more photochromic yarns, Figure 1 may be referred as an example of this embodiment. In the said embodiment, yarns 11 present in the inner layers of one of the strands lOa, lOb or lOc may be photochromic yarn.

In the said embodiment in which the break indication element is/are photochromic yarn/s, the sight of the colour of this photochromic yarn placed in the inner layer when any user views the rope in presence of sunlight or uv light indicates wear & tear of the rope.

In an another embodiment illustrated in Figure 3, the rope may be any rope with three layers of yams used in each strand wherein the middle layer 32b includes the break indication element 33.

The invention further describes a simple visual detection method by which wear & tear of the rope (10,30) may be detected. The method uses a break indication element (13,33) by observing illumination of the wire, the illumination being stimulated by incident ambient light, or the break indication connected to a power source, or a light passed through the break indication element.

The rope (10,30) comprises of a plurality of strands, each strand comprises a core layer (l2a,32a), at least one intermediate layer (l2b, l2c, 32b), and a sheath or cover layer (l2d,32c), wherein any of the intermediate layer comprises a break indication element (13,33).

In another example, Fig. 4 illustrates the working of a break indication rope. The rope (10,30) which has undergone degradation due to various reasons stated in this patent is being observed for the end of service life. In this case, a luminous yam is used as break indication element. The rope is subjected to sunlight for few minutes and is observed in dark thereafter. The afterglow of the luminous yarn in the rope to the observer indicates the end of the service life of the rope. The said glow may be present at one or more places in the rope. The invention has certain advantages over prior arts. The method and the rope claimed in the present invention provides a simple, faster monitoring and detection, leading to saving of time and cost. In the absence of any complex detection system, any workman, who is not adapt at technicalities of the complex system, is visually able to detect the wear and tear using the present invention. This effectively saves cost and time by considerable margin. The present invention also avoids premature retiring of the rope out of fear of failure during operation.

Claims

We Claim,

1. A break indication rope (10,30) for simple visual detection of wear and tear and end of service life of the rope comprising ,

A plurality of strands (l0a,l0b,l0c;30a,30b,30c), each strand comprises a core layer (l2a, 32a), at least one intermediate layer (l2b, l2c, 32b), and a sheath or cover layer (l2d,32c),

wherein any of the intermediate layer comprises a break indication element (13,33).

2. The break indication rope (10,30) according to claim 1, wherein said break indication element (13,33) are selected from electroluminescent wire, optical fiber, luminous yarn, photochromic yarn and combination thereof.

3. The break indication rope (10,30) according to claim 2, wherein said optical fiber element is side glow optical fiber.

4. The break indication rope (10,30) according to claim 2, wherein said luminous yarn element is selected from phosphorescent yarn, fluorescent yarn or a combination thereof.

5. The break indication rope (10,30) according to claim 4, wherein said phosphorescent yam is prepared by using a phosphorescent material selected from self-excited, organic dyes or non-radioactive material.

6. The break indication rope (10,30) according to claim 5, wherein said self- excited phosphorescent material is radium or any other suitable material.

7. The break indication rope (10,30) according to claim 5, wherein said non- radioactive material is selected from a material having short after-glow time and a material having long after-glow time.

8. The break indication rope (10,30) according to claim 7, wherein a material having short after-glow time is selected from copper sulphides, silver sulphides, bismuth activated (zinc) sulfides or combination thereof.

9. The break indication rope (10,30) according to claim 7, wherein a material having long after-glow time is selected from rare earth doped alkaline earth aluminates, alkaline earth sulfides, alkaline earth silicates, or combination thereof.

10. The break indication rope (10,30) according to claim 2, wherein the photochromic yam is prepared by using photochromic dyes or any inorganic material exhibiting photochromism.

11. The break indication rope (10,30) according to claim 1, wherein said rope (10,30) is twisted, laid, braided, combined rope or any other rope.

12. The break indication rope (10,30) according to claim 1, wherein yams other than break indication element (13,33) are selected from polyolefins, polyamides, polyesters, aramids or a combination thereof or any other material used in rope manufacturing.

13. The break indication rope (10,30) according to any of the preceding claims, wherein the break indication element (13,33) is present in at least one of the strand (l0a-c;30a-c) of the break indication rope (10,30).

14. A simple visual detection method of wear tear of a rope (10,30) using break indication element (13,33) by observing illumination of the wire, the illumination being stimulated by incident ambient light, or the break indication connected to a power source, or a light passed through the break indication element, as claimed in claim 1.

15. The method according to claim 12, wherein the rope (10,30) comprises,

A plurality of strands (l0a-c,l la-c), each strand comprises a core layer (l2a,32a), at least one intermediate layer (l2b,l2c,32b), and a sheath or cover layer (l2d,32c),

16. The method according to claim 13, wherein said break indication element (13,33) are selected from electroluminescent wire, optical fiber, luminous yam, photochromic yarn and combination thereof.

17. The method according to claim 15, wherein said optical fiber element is side glow optical fiber.

18. The method according to claim 15, wherein said luminous yarn element is selected from phosphorescent yam, fluorescent yarn or a combination thereof.

19. The method according to claim 17, wherein said phosphorescent yarn is prepared by using a phosphorescent material selected from self-excited, organic dyes or non-radioactive material.

20. The method according to claim 18, wherein said self-excited phosphorescent material is radium or any other suitable material.

21. The method according to claim 18, wherein said non-radioactive material is selected from a material having short after-glow time and a material having long after-glow time.

22. The method according to claim 20, wherein a material having short after-glow time is selected from copper sulphides, silver sulphides, bismuth activated (zinc) sulfides or combination thereof.

23. The method according to claim 20, wherein a material having long after-glow time is selected from rare earth doped alkaline earth aluminates, alkaline earth sulfides, alkaline earth silicates, or combination thereof.

24. The method according to claim 15, wherein the photochromic yarn is prepared by using photochromic dyes or any inorganic material exhibiting photochromism.

25. The method according to claim 14, wherein said rope (10,30) is twisted, laid, braided, combined rope.

26. The method according to claim 14, wherein yams other than break indication element (13,33) are selected from polyolefins, polyamides, polyesters, aramids or a combination thereof or any other material used in rope manufacturing.

27. The method according to any of the preceding claims, wherein the break indication element (13,33) is present in at least one of the strand (l0a-c;30a- c) of the break indication rope (10,30)