AU3261093A - Improved core for wire rope - Google Patents
Improved core for wire ropeInfo
- Publication number
- AU3261093A AU3261093A AU32610/93A AU3261093A AU3261093A AU 3261093 A AU3261093 A AU 3261093A AU 32610/93 A AU32610/93 A AU 32610/93A AU 3261093 A AU3261093 A AU 3261093A AU 3261093 A AU3261093 A AU 3261093A
- Authority
- AU
- Australia
- Prior art keywords
- core
- strands
- central member
- plastics material
- wire rope
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/16—Ropes or cables with an enveloping sheathing or inlays of rubber or plastics
- D07B1/165—Ropes or cables with an enveloping sheathing or inlays of rubber or plastics characterised by a plastic or rubber inlay
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
- D07B1/0673—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core having a rope configuration
- D07B1/0686—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core having a rope configuration characterised by the core design
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/10—Rope or cable structures
- D07B2201/1028—Rope or cable structures characterised by the number of strands
- D07B2201/1032—Rope or cable structures characterised by the number of strands three to eight strands respectively forming a single layer
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2001—Wires or filaments
- D07B2201/2002—Wires or filaments characterised by their cross-sectional shape
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2015—Strands
- D07B2201/2036—Strands characterised by the use of different wires or filaments
- D07B2201/2037—Strands characterised by the use of different wires or filaments regarding the dimension of the wires or filaments
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2048—Cores characterised by their cross-sectional shape
- D07B2201/2049—Cores characterised by their cross-sectional shape having protrusions extending radially functioning as spacer between strands or wires
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2052—Cores characterised by their structure
- D07B2201/2053—Cores characterised by their structure being homogeneous
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2052—Cores characterised by their structure
- D07B2201/2055—Cores characterised by their structure comprising filaments or fibers
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2052—Cores characterised by their structure
- D07B2201/2065—Cores characterised by their structure comprising a coating
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2047—Cores
- D07B2201/2067—Cores characterised by the elongation or tension behaviour
- D07B2201/2068—Cores characterised by the elongation or tension behaviour having a load bearing function
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2201/00—Ropes or cables
- D07B2201/20—Rope or cable components
- D07B2201/2071—Spacers
- D07B2201/2073—Spacers in circumferencial direction
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2205/00—Rope or cable materials
- D07B2205/20—Organic high polymers
- D07B2205/201—Polyolefins
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2205/00—Rope or cable materials
- D07B2205/20—Organic high polymers
- D07B2205/2039—Polyesters
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2205/00—Rope or cable materials
- D07B2205/30—Inorganic materials
- D07B2205/3003—Glass
Abstract
A tubular outer member 1 of plastics material is extruded onto an extruded solid cylindrical central member 3 of plastics material. The outer member 1 has symmetrically spaced helical grooves 2 for receiving respective wire strands 4. Plastics materials are specified, and may incorporate fibres. Member 3 may be lubricated.
Description
Improved Core for Wire Rope
This invention relates to cores for wire ropes, particularly steel wire ropes.
GB-A-2 219 014 describes a core for wire rope comprising a fluted member of polymeric or elastomeric material having helical grooves symmetrically spaced around its outer surface, each groove in cross-section (in a plane normal to the longitudinal axis of the core) having the form of an arc of a ellipse. The properties and control of manufacture of the core may be substantially improved by incorporating within the extrusion a reinforcing member or cord constituted by a fibre core or independent wire rope.
However, the use of conventional types of reinforcing members such as are illustrated in GB-A-2 219 014, has certain drawbacks. Both fibre cores and independent wire rope cores, by the very nature of their helical construction, entrap a quantity of air which has a detrimental effect on the solidity of support that the core is able to provide in the rope. This is especially important in a wire rope, where the core is typically subjected to very high radial pressures; any compressibility of the core results in a reduction in rope diameter with tension and, hence, an increased rope stretch characteristic, which is often undesirable in service. Additionally, any pronounced reduction in rope diameter will result in the outer strands of the rope coming into contact with one another at the wire crowns, with very high stresses at the contact points. In a rope which is working backwards and forwards over sheaves or is otherwise
repetitively flexed, these stresses will cause fretting damage to the outer wires, with a consequent loss of fatigue performance.
Practical experience with the conventional types of reinforcing member disclosed in GB-A-2 219 014 has also revealed that it is possible for the reinforcing member to fail
prematurely, before there has been any significant deterioration of the outer strands of the rope (which are readily inspectable). This mode of failure is not only undesirable from an inspection viewpoint, but can also lead to a loss of load carrying capacity and structural integrity of the wire rope.
What is desired is a core which avoids or mitigates these disadvantages.
The present invention provides a core for a wire rope, comprising a tubular outer member made of plastics material and a solid cylindrical central member made of plastics material, the outer member having a cylindrical inner surface in intimate contact with the central member and having a fluted outer surface with symmetrically spaced helical grooves for receiving
respective wire strands of the rope.
Preferred and optional features are set forth in the claims.
The invention will be described further, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a diagrammatic cross-section through a core for a wire rope; and
Figure 2 is a diagrammatic cross-section through a wire rope incorporating the core.
The core illustrated comprises a tubular outer member 1 o f plastics material ana a solid cylindrical central memoer 3 of plastics material. The outer member 1 has a cylindrical inner surface in intimate contact with the central member 3.
Optionally there may be a film of lubricant or release agent at the interface between the members 1,3. The outer member 1 has a fluted outer surface with symmetrically spaced helical grooves 2 for receiving respective steel wire strands 4.
In the illustrated example of a wire rope, shown in Figure 2, there are six strands 4. However, it will be appreciate.: tnat a different number of strands may be used (e.g. 5, 7, or 8). Each strand 4 is a round strand whose circumscribing envelope E - in a cross-section perpendicular to the strand axis - is a circle of diameter d1. Since each strand extends helically, the envelope E appears slightly elliptical in a cross-section in the plane of the drawings, which plane is perpendicular to the axis of the core. Each groove 2 - in a cross-section perpendicular to the groove - is an arc of a circle of diameter d1.
To maximise the area of contact between the wires of the strand 4 and the core, the strand is a Dyform (Trade Mark - Bridon pic) strand which - in cross-section perpendicular to .its axis - has a compacted structure in which the outer wires 6 nave eternal edges 6a which are arcs of a circle of diameter d1.
However, conventional strands made up of round wires may be used instead. Also, non-round strands may be used, with grooves o f suitable cross-section.
The core having a solid cross-section provides good support to the strands 4. By providing the core with a
sufficiently large cross-section with grooves 2 of sufficient iept'n, a working clearance between the adjacent strands 4 can be ensured, even up to the breaking load of the rope. The use of two distinct (outer and central) members 1,3 enables one to select the properties of the members 1,3 to satisfy various requirements for the physical (and chemical) properties of the core as a whole.
In order to define the preferred size of core, reference is made to Figure 1, wherein dimension d1 represents the diameter cf the outer strands 4 of the rope and diameter d2 denotes the root diameter of the fluted member 1, i.e. the minimum distance between the bottoms of any two diametrically opposing grooves. For any given rope type and construction the minimum root diameter d2 may be expressed as a function of the outer strand diameter d1. The exact relationship will depend primarily upon the number of outer strands in the rope and the lay angle (or pitch) at which they are closed together, although additional account may be taken of the strand construction and service duty. For example, different factors will be required for ropes in which the strands are of quasi-triangular shape. For the more common round-strand rope constructions and lays, the following relationships are recommended :
The two members 1,3 may be made of the same type of plastics material or different types. In each case the plastics material may, for example, be selected from the following types:
Polypropylene
Polyethylene (medium to high density)
Polyester (such as Hytrel - Trade Mark of DuPont)
Specific grades of material, and their characteristic physical properties, are shown in the following Table 2 :
The above properties are cited for the purpose of
illustration only. Additional property enhancement may be obtained by going to harder grades of material or incorporating reinforcing fibres (e.g. glass-fibre) into the polymer, albeit with some loss of rope flexibility.
The optimum blend of core properties may be obtained by using two dissimilar materials to produce the core. For example, the outer member 1 may comprise a material with good elongation properties to accept the high bending strains and also be capable of deforming locally to provide close conformance with the
surface geometry of the outer strands of the rope, whereas the central member 3 may be beneficially composed of a harder and more rigid material, perhaps incorporating reinforcing fibres.
Whatever the choice of materials, the core is preferably prepared in two separate extrusion operations, the first of which produces the solid cylindrical member 3. Optionally, a lubricant or a release agent is applied to the solid cylindrical member 3. This is then fed into an extruder for a further operation which produces the fluted member 1, the central member 3 greatly assisting in the control of the second extrusion operation.
The size of the central member 3 in relation to the size of the core may vary, so that one size of central member can be used for a range of core sizes, thereby achieving an economy in manufacturing costs. However, the cross-sectional area of the central member 3 is preferably at least 40% (more preferably at least 45%) and preferably at most 60% (more preferably at most 55%) of the cross-sectional area of the core, a convenient ratio being about 50% (enabling extrusion speeds to be equalised). Accordingly, the central member 3 preferably has a circular cross-section whose diameter d1 is at least 70% (more preferably at least 75%) of the root diameter d preferably d3 is at most 90% (more preferably 85%) of d2, a convenient ratio being about
Claims (13)
1. A core for a wire rope, comprising a tubular outer member (1) made of plastics material and a solid cylindrical central member (3) made of plastics material, the outer member
( 1 ) having a cylindrical inner surface in intimate contact with the central member (3) and having a fluted outer surface with symmetrically spaced helical grooves (2) for receiving respective wire strands (4) of the rope.
2. A core as claimed in claim 1, in which the outer member (1) is longitudinally slidable relative to the central member (3).
3. A core as claimed in claim 1, in which the plastics material of the central member (3) is harder and/or stiffer than the plastics material of the outer member (1).
4. A core as claimed in claim 1, in which the plastics material of the central member (8) and/or of the outer member (1) contains discontinuous reinforcing fibres.
5. A core as claimed in claim 1, in which the plastics material of the central member (3) and the plastics material of the outer member (1) are of the same type.
6. A core as claimed in claim 1, in which the
cross-sectional area of the central member (3) is at least 40% of that of the core.
7. A core as claimed in claim 1, in which the central member (3) has a circular cross-section whose diameter (d3) is at least 70% of the root diameter (d2) of the fluted outer surface.
8. A core as claimed in claim 1, for a wire rope comprising round strands (4) each having a circumscribing circle, in which each groove (2) - in a cross-section perpendicular to the groove - describes a substantially circular arc.
9. A core as claimed in claim 8, which is of sufficient size to prevent contact between the strands (4) in the rope when the radius of the said circumscribing circle is equal to the radius of the said arc.
10. A method of manufacturing a core according to claim 1, in which the core is formed by two separate successive extrusion operations, the first of which forms the central member (3), and the second of which forms the outer member (1) around the central member (3).
11. A wire rope comprising a core according to claim 1, and wire strands (4) received in the respective grooves (2).
12. A wire rope as claimed in claim 11, in which the core prevents contact between the strands (4).
13. A wire rope as claimed in claim 11, in which the strands (4) are round strands each having a circumscribing circle.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9216482A GB2269400B (en) | 1992-08-03 | 1992-08-03 | Core for wire rope |
GB9216482 | 1992-08-03 | ||
PCT/GB1993/000008 WO1994003672A1 (en) | 1992-08-03 | 1993-01-06 | Improved core for wire rope |
Publications (2)
Publication Number | Publication Date |
---|---|
AU3261093A true AU3261093A (en) | 1994-03-03 |
AU674295B2 AU674295B2 (en) | 1996-12-19 |
Family
ID=10719754
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU32610/93A Ceased AU674295B2 (en) | 1992-08-03 | 1993-01-06 | Improved core for wire rope |
Country Status (12)
Country | Link |
---|---|
EP (1) | EP0652989B1 (en) |
JP (1) | JP3229055B2 (en) |
KR (1) | KR100250193B1 (en) |
AT (1) | ATE168148T1 (en) |
AU (1) | AU674295B2 (en) |
BR (1) | BR9306801A (en) |
CA (1) | CA2140937A1 (en) |
DE (1) | DE69319600D1 (en) |
GB (1) | GB2269400B (en) |
NO (1) | NO950264D0 (en) |
WO (1) | WO1994003672A1 (en) |
ZA (1) | ZA93896B (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2320933B (en) * | 1997-01-03 | 1999-04-07 | Bridon Plc | Manufacture of wire rope |
CA2269017A1 (en) * | 1998-04-20 | 1999-10-20 | Paul Ormon Sullivan | Lariat, lariat rope body, method and apparatus |
FR2783585B1 (en) * | 1998-09-23 | 2000-11-17 | Trefileurope | MIXED CABLE WITH SYNTHETIC CORE FOR LIFTING OR PULLING |
KR100318184B1 (en) * | 1999-11-26 | 2001-12-24 | 홍영철 | Method for making a wire rope having a plastic coated independant wire rope core and its apparatus for making the same |
DE102007024020A1 (en) | 2007-05-18 | 2008-11-20 | Casar Drahtseilwerk Saar Gmbh | Rope, combined rope of synthetic fibers and steel wire strands, as well as combined strand of synthetic fibers and steel wires |
KR101065787B1 (en) | 2011-03-14 | 2011-09-19 | (주)신흥이앤지 | Wire rope which having membrane for seperating strands |
CH708244B1 (en) * | 2013-06-28 | 2016-10-14 | Fatzer Ag | Wire rope as well as a method for producing the same. |
JP6417362B2 (en) * | 2016-05-30 | 2018-11-07 | 株式会社テザックワイヤロープ | Wire rope for moving cable |
WO2018051395A1 (en) * | 2016-09-13 | 2018-03-22 | 東京製綱株式会社 | Wire rope for use as running wire, and method for producing same |
US11578458B2 (en) | 2018-03-06 | 2023-02-14 | Bridon International Limited | Synthetic rope |
CN109295780A (en) * | 2018-09-17 | 2019-02-01 | 江苏普乐菲塑料有限公司 | A kind of PP plastic ties of high tenacity |
ES2960882T3 (en) | 2018-10-23 | 2024-03-07 | Bekaert Advanced Cords Aalter Nv | Steel wire rope and method of producing it |
JP7248502B2 (en) * | 2019-05-28 | 2023-03-29 | 東京製綱株式会社 | Core material for wire rope, wire rope and manufacturing method thereof |
JP2021075824A (en) * | 2019-11-12 | 2021-05-20 | 東京製綱株式会社 | Wire rope core and wire rope |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA570733A (en) * | 1959-02-17 | Columbian Rope Company | Plastic covered wire rope center | |
GB408291A (en) * | 1932-10-06 | 1934-04-06 | William Cormack Robertson | Improvements in or relating to trawl ropes |
DE2703670C2 (en) * | 1977-01-29 | 1983-11-10 | Drahtseilwerk Saar GmbH, 6654 Kirkel | Wire rope with a rope core encased in foamed plastic |
GB2219014B (en) * | 1988-05-19 | 1991-12-18 | Bridon Plc | Cores for wire ropes |
-
1992
- 1992-08-03 GB GB9216482A patent/GB2269400B/en not_active Expired - Fee Related
-
1993
- 1993-01-06 AT AT93901057T patent/ATE168148T1/en not_active IP Right Cessation
- 1993-01-06 DE DE69319600T patent/DE69319600D1/en not_active Expired - Lifetime
- 1993-01-06 WO PCT/GB1993/000008 patent/WO1994003672A1/en active IP Right Grant
- 1993-01-06 CA CA002140937A patent/CA2140937A1/en not_active Abandoned
- 1993-01-06 EP EP93901057A patent/EP0652989B1/en not_active Expired - Lifetime
- 1993-01-06 BR BR9306801A patent/BR9306801A/en not_active Application Discontinuation
- 1993-01-06 AU AU32610/93A patent/AU674295B2/en not_active Ceased
- 1993-01-06 KR KR1019950700302A patent/KR100250193B1/en not_active IP Right Cessation
- 1993-01-21 JP JP02609793A patent/JP3229055B2/en not_active Expired - Fee Related
- 1993-02-09 ZA ZA93896A patent/ZA93896B/en unknown
-
1995
- 1995-01-24 NO NO950264A patent/NO950264D0/en unknown
Also Published As
Publication number | Publication date |
---|---|
GB2269400A (en) | 1994-02-09 |
WO1994003672A1 (en) | 1994-02-17 |
GB9216482D0 (en) | 1992-09-16 |
KR100250193B1 (en) | 2000-05-01 |
JP3229055B2 (en) | 2001-11-12 |
EP0652989A1 (en) | 1995-05-17 |
JPH06257078A (en) | 1994-09-13 |
NO950264L (en) | 1995-01-24 |
BR9306801A (en) | 1998-12-08 |
ATE168148T1 (en) | 1998-07-15 |
CA2140937A1 (en) | 1994-02-04 |
NO950264D0 (en) | 1995-01-24 |
ZA93896B (en) | 1993-09-13 |
GB2269400B (en) | 1995-09-27 |
AU674295B2 (en) | 1996-12-19 |
DE69319600D1 (en) | 1998-08-13 |
EP0652989B1 (en) | 1998-07-08 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |