Method for determining the replacement state of wear of a rope made of a textile fibre material

{
  "publication_number": "US11008703B2",
  "country": "US",
  "kind": "B2",
  "title": "Method for determining the replacement state of wear of a rope made of a textile fibre material",
  "abstract": "The invention relates to a method for determining the replacement state of wear of a rope made of a textile fibre material, wherein, in the course of using the rope, the elongation of the rope is monitored over its entire length and the rope is discarded if the elongation of the rope over the entire length exceeds a predetermined maximum value (%). The method according to the invention is characterized in that also the local elongation of a discrete rope section is monitored and the rope is discarded if the local elongation of the rope section exceeds a predetermined maximum value (%), with the maximum value of the local elongation of the rope section being greater than the maximum value of the elongation of the rope over the entire length.",
  "claims": [
    "1. A method for determining a replacement state of wear of a rope made of a textile fibre material, comprising: monitoring, during use of the rope, an elongation of the rope over its entire length and discarding the rope if the elongation of the rope over its entire length exceeds a first predetermined maximum value (%), and also monitoring local elongation of a discrete rope section and discarding the rope if the local elongation of the discrete rope section exceeds a second predetermined maximum value (%), wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section is greater than the first predetermined maximum value (%) of the elongation of the rope over its entire length, and wherein the first predetermined maximum value (%) of the elongation of the rope over its entire length and the second predetermined maximum value (%) of the local elongation of the discrete rope section are established based on a type of textile fibre material used and a structure of the rope.",
    "2. A method according to claim 1, wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section is higher than the first predetermined maximum value (%) of the elongation of the rope over its entire length by a factor ranging from 1.2 to 20.",
    "3. A method according to claim 2, wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section is higher than the first predetermined maximum value (%) of the elongation of the rope over the entire length by a factor ranging from 3.0 to 15.",
    "4. A method according to claim 1, wherein the method is applied to a rope which is a core/sheath rope.",
    "5. A method according to claim 4, wherein the monitoring of the elongation of the rope over its entire length or, respectively, the discrete rope section occurs within a core of the rope.",
    "6. A method according to claim 4, wherein the monitoring of the elongation of the rope over its entire length or, respectively, the discrete rope section occurs within a sheath of the rope.",
    "7. A method according to claim 1, the method comprising monitoring a rope section as a discrete rope section which ends up lying in a bending zone when the rope is used.",
    "8. A method according to claim 1, wherein the rope is a load rope.",
    "9. A method according to claim 8, wherein the use of the rope is with a Koepe-sheave or drum drive.",
    "10. A method according to claim 1, wherein the determination of the elongation of the rope over its entire length or, respectively, the discrete rope section occurs by means of indicator fibres present within the rope.",
    "11. A method according to claim 1, wherein the rope to which the method is applied consists essentially of the textile fibre material, both in terms of load-bearing and non-load-bearing components.",
    "12. A method according to claim 1, wherein a load-bearing fibre material of the rope to which the method is applied consists of high-strength synthetic fibres.",
    "13. A method according to claim 12, wherein the high-strength synthetic fibres are at least partially UHMWPE fibres.",
    "14. A method according to claim 12, wherein the rope on which the method is performed has the following properties: a) the load-bearing fibre material consists of high-strength synthetic fibres, b) the rope is provided in the form of a spiral strand rope, c) the rope comprises at least two concentric load-bearing strand layers, d) the individual strands of the strand layers are movable against each other, e) the rope has a degree of filling with a textile fibre material of ≥75%, and e) the outermost layer of the rope has a coefficient of friction μ, in comparison to steel of μ<0.15.",
    "15. A method according to claim 14, wherein the degree of filling with a textile fibre material is ≥85%.",
    "16. A method according to claim 14, wherein the rope comprises at least three concentric load-bearing strand layers.",
    "17. A method for determining a replacement state of wear of a rope made of a textile fibre material, comprising: monitoring, during use of the rope, an elongation of the rope over its entire length and discarding the rope if the elongation of the rope over its entire length exceeds a first predetermined maximum value (%), and also monitoring local elongation of a discrete rope section and discarding the rope if the local elongation of the discrete rope section exceeds a second predetermined maximum value (%), wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section is greater than the first predetermined maximum value (%) of the elongation of the rope over its entire length; and wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section exceeds the first predetermined maximum value (%) of the elongation of the rope over its entire length by a factor ranging from 1.2 to 20.",
    "18. A method for determining a replacement state of wear of a rope made of a textile fibre material, comprising: monitoring, during use of the rope, an elongation of the rope over its entire length and discarding the rope if the elongation of the rope over its entire length exceeds a first predetermined maximum value (%), and also monitoring local elongation of a discrete rope section and discarding the rope if the local elongation of the discrete rope section exceeds a second predetermined maximum value (%), wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section is greater than the first predetermined maximum value (%) of the elongation of the rope over its entire length; and wherein the discrete rope section ends up lying in a bending zone when the rope is used.",
    "19. A method according to claim 18, wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section exceeds the first predetermined maximum value (%) of the elongation of the rope over the entire length by a factor ranging from 1.2 to 20.",
    "20. A method according to claim 18, wherein the second predetermined maximum value (%) of the local elongation of the discrete rope section exceeds the first predetermined maximum value (%) of the elongation of the rope over the entire length by a factor ranging from 3.0 to 15."
  ],
  "description_excerpt": "The present invention relates to a method for determining the replacement state of wear of a rope made of a textile fibre material.\n\nRopes made of a textile fibre material, e.g., synthetic fibre ropes, are used for numerous applications. Especially in the field of materials handling, high-strength fibre ropes are now superior to steel ropes, which previously were used and, respectively, available exclusively, because of several advantages.\n\nDuring their use, ropes are exposed to various stresses, which, in particular, are mechanical. A person skilled in the art will understand that the “replacement state of wear” (“point of discard”) is the point at which the rope can no longer be used or, respectively, can no longer be used to a sufficiently safe extent due to the wear caused by those stresses and, therefore, must be taken out of use.\n\nOf course, the determination of the replacement state of wear is particularly important especially in applications such as, e.g., crane ropes or ropes in lifts.\n\nVarious methods are known for detecting the replacement state of wear of a rope made of a textile fibre material.\n\nSo far, none of those methods have prevailed on the market. The previously inexistent possibility of safely identifying the replacement state of wear of fibre ropes may be regarded as one of the main reasons as to why, so far, fibre ropes have not yet become accepted for industrial use.\n\nIt is inherent to most of the published methods that they detect only one characteristic of the rope at a time (e.g., diameter, elongation or the like).",
  "cpc": [
    "D07B 1/145",
    "B66C 13/16",
    "B66C 15/00",
    "B66C 15/06",
    "B66D 1/54",
    "D07B 2205/2014",
    "D07B 2301/259",
    "D07B 2301/45",
    "D07B 2801/10",
    "G01N 2203/0017",
    "G01N 2203/0023",
    "G01N 2203/0026",
    "G01N 2203/0028",
    "G01N 2203/028",
    "G01N 2291/02854",
    "G01N 2291/2626",
    "G01N 3/00",
    "G01N 3/56",
    "G01N 33/367"
  ],
  "ipc": [
    "B66C 13/16",
    "B66C 15/00",
    "B66C 15/06",
    "B66D 1/54",
    "D07B 1/14",
    "G01N 3/00",
    "G01N 3/56",
    "G01N 33/36"
  ],
  "assignees": [
    "Teufelberger Fiber Rope GmbH"
  ],
  "inventors": [
    "Björn Ernst",
    "Erich Rührnössl",
    "Rudolf Kirth",
    "Peter Baldinger",
    "Robert Traxl",
    "Gunter Kaiser"
  ],
  "filing_date": "2016-12-14",
  "publication_date": "2021-05-18",
  "grant_date": "2021-05-18",
  "priority_date": "2015-12-16",
  "application_number": "US-201616060380-A",
  "family_id": "55024815",
  "cited_by_count": 1,
  "citations": [
    "US5461925A",
    "JP2001192183A",
    "US20030111298A1",
    "US20050226584A1",
    "WO2004029343A1",
    "EP1530040A1",
    "EP1905892A2",
    "US20140027401A1",
    "US20140109682A1",
    "WO2015139842A1",
    "US20180238815A1",
    "US20180011044A1"
  ]
}