EP0635597A1 - Steel cord construction - Google Patents
Steel cord construction Download PDFInfo
- Publication number
- EP0635597A1 EP0635597A1 EP94202020A EP94202020A EP0635597A1 EP 0635597 A1 EP0635597 A1 EP 0635597A1 EP 94202020 A EP94202020 A EP 94202020A EP 94202020 A EP94202020 A EP 94202020A EP 0635597 A1 EP0635597 A1 EP 0635597A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- filaments
- steel
- steel cord
- cord
- core
- 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.)
- Ceased
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Classifications
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B5/00—Making ropes or cables from special materials or of particular form
- D07B5/12—Making ropes or cables from special materials or of particular form of low twist or low tension by processes comprising setting or straightening treatments
-
- 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
- D07B1/0606—Reinforcing cords for rubber or plastic articles
- D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B7/00—Details of, or auxiliary devices incorporated in, rope- or cable-making machines; Auxiliary apparatus associated with such machines
- D07B7/02—Machine details; Auxiliary devices
- D07B7/022—Measuring or adjusting the lay or torque in the rope
-
- 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
- D07B2201/2023—Strands with core
-
- 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
- D07B2201/2059—Cores characterised by their structure comprising wires
-
- 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
- D07B2205/3021—Metals
- D07B2205/3025—Steel
- D07B2205/3046—Steel characterised by the carbon content
- D07B2205/3057—Steel characterised by the carbon content having a high carbon content, e.g. greater than 0,8 percent respectively SHT or UHT wires
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2207/00—Rope or cable making machines
- D07B2207/20—Type of machine
- D07B2207/204—Double twist winding
- D07B2207/206—Double twist winding with means for providing less than double twist, e.g. counter rotating means
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2207/00—Rope or cable making machines
- D07B2207/40—Machine components
- D07B2207/4072—Means for mechanically reducing serpentining or mechanically killing of rope
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2401/00—Aspects related to the problem to be solved or advantage
- D07B2401/20—Aspects related to the problem to be solved or advantage related to ropes or cables
- D07B2401/2015—Killing or avoiding twist
Definitions
- the present invention relates to a steel cord adapted for the reinforcement of elastomers such as rubber or plastic products.
- elastomers reinforced by means of steel cords are conveyor belts, timing belts, rubber hoses and radial tyres where the carcass plies and/or the breaker plies can comprise steel cords.
- a steel cord adapted for the reinforcement of elastomers.
- a steel cord 'adapted for the reinforcement of elastomers' means that the steel cord has the proper features to reinforce elastomers such as rubber tyres, conveyor belts, hoses and timing belts. This means particularly, either alone or in combination, that :
- the steel cord of the present invention comprises individual steel filaments. Some of these steel filaments have a difference in torsion saturation level in comparison with other of these steel filaments. All of the individual steel filaments have a predetermined number of residual torsions per filament, e.g. no residual torsions per filament, or in another embodiment where the cord consists of a core of one or more core filaments and a layer of layer filaments, residual torsions of the core filament which tend to open the cord and residual torsions of the layer filaments which tend to close the cord.
- the inventors have discovered that it was not sufficient that the steel cord, taken as a whole, was free of residual torsions in order to avoid processability problems, but that it was necessary to control the residual torsions of the individual steel filaments in order to further enhance the processability and to obtain reinforced elastomeric plies with a sufficient flatness.
- the 'number of residual torsions' is herein defined as the number of revolutions made by a specific length of cord or filament (conveniently 6 meter) when one end is held in a fixed position and the other end is allowed to turn freely. It is conveniently expressed in turns per six meters.
- the individual steel filaments have been twisted individually around their longitudinal axes, which means that the steel cord has been manufactured by means of a double-twister or single-twister.
- Individual filaments which have been twisted around their longitudinal axes can be distinguished from filaments which have not been twisted around their longitudinal axes by the inspection of the drawing lines which are a secondary result of the necessarily imperfect final wet drawing steps : these drawing lines form a helicoid in case the filaments have been twisted around their longitudinal axes and are substantially parallel to their longitudinal axes in case the filaments have not been twisted around their longitudinal axes.
- the torsion saturation level of an individual steel filament is dependent upon : the material of the steel filament, and, especially, upon the diameter of the steel filament and upon the tensile strength of the steel filament.
- the inventors have discovered that the reason why control of the number of residual torsions of the global steel cord was not sufficient to obtain the required processability was due to a difference in torsion saturation level of individual steel filaments and that it was necessary to take care of this difference.
- steel cords according to the invention are wrapless compact cords, i.e. cords having filaments which all have the same twist pitch and the same twist direction and having no wrapping filament, and where some of the filaments have a filament diameter or a filament tensile strength or both which is different from the filament diameter or the filament tensile strength of the other filaments in the cord.
- This difference in filament diameter and/or filament tensile strength results in a difference in torsion saturation level between the individual steel filaments of the cord.
- Some specific examples are : - 1 x 0.20
- Figure 1 shows the cross-section of a 1 + 6 -cord 10 according to the prior art.
- the cord 10 has one core filament 12 and six layer filaments 14 surrounding and contacting the core filament 12.
- the steel cord has been twisted into the Z-direction.
- the steel cord 10 taken as a whole, is free of residual torsions, the individual steel filaments have residual torsions : the layer filaments 14 have residual torsions in the S-direction while the core filament has residual torsions in the Z-direction.
- Figure 2 shows an end of an elastomeric ply reinforced with a steel cord according to the prior art.
- the ends of the filaments, and particularly the end of the core filament start to rotate in case the elastomeric material 16 has not completely filled up the interstices between the core filament 12 and the layer filaments 14.
- the layer filaments 14 no longer contact the core filament at the place of cutting.
- disadvantages are the result.
- the steel cord 10 has a larger diameter than designed.
- the interstices between the filaments 12, 14 have become much greater allowing moisture to penetrate more easily into the cord.
- the elastomeric ply no longer has its desired flatness over its complete surface, which results in a worse processability.
- Figure 3 shows an end of an elastomeric ply reinforced with steel cord 10 according to the present invention.
- the individual steel filaments 12, 14 are free from residual torsions.
- the individual steel filaments 12, 14 do not rotate and contact between the core filament 12 and the layer filaments 14 is maintained.
- the diameter of the cord 10 does not increase, the interstices between the filaments 12, 14 do not increase and the elastomeric ply remains flat.
- Figure 4 illustrates schematically the way of manufacturing a steel cord 10 according to the present invention.
- the core filament 12 and the layer filaments 14 are drawn from the supply spools 18 on the left side of the Figure and are led to a distributing disc 20 and to a cord forming die 22 where the cord 10 is at least partially formed.
- the thus formed cord 10 is further guided over a guiding pulley 24, a rotating flyer 25 and over a reversing pulley 26.
- the cord 10 has reached its final twist pitch.
- the cord 10 is now further overtwisted by means of a first false twister 28, i.e. twisted to a twist pitch smaller than the final twist pitch of the cord 10 and untwisted until the final twist pitch of the cord 10.
- the cord 10 is untwisted by means of a second false twister 30, i.e. untwisted to a twist pitch greater than the twist pitch of the cord 10 and twisted again to the final twist pitch of the cord 10. Finally, the cord 10 is wound on spool 32.
- a second false twister 30 i.e. untwisted to a twist pitch greater than the twist pitch of the cord 10 and twisted again to the final twist pitch of the cord 10.
- Figure 5 shows torsion diagrams of steel filaments of a 1 x 0.20 + 6 x 0.175 -cord according to the prior art manufactured in the convenient way, i.e. by making use of one single false twister in order to make the steel cord as a whole free of residual torsions.
- the abscissa (horizontal axis) n a is the number of applied torsions
- the ordinate (vertical axis) n r is the number of residual torsions.
- the torsion curve of the core filament 12 is designated by 34
- the torsion curve of the layer filaments 14 is designated by 36. While being twisted by means of a double-twister to the final twist pitch, core filament 12 follows curve OA, while layer filaments 14 follow curve OA' to a higher level of residual torsions, since the torsion saturation level of a layer filament 14 with a diameter of 0.175 mm is higher than for a core filament 12 with a diameter of 0.20 mm.
- the number of torsions n LL applied by means of the double-twister corresponds to the final twist pitch.
- a false twister the only one
- the cord 10 is further overtwisted to a number n FT1 of applied torsions.
- the core filament 12 follows curve AB while the layer filaments follow curve A'B'. Subsequently the cord is untwisted to the same number n FT1 of torsions in order to reach again the final twist pitch of the cord.
- Core filament 12 follows curve BC resulting finally in residual torsions which tend to close the cord.
- Layer filaments 14 follow curve B'C' resulting in residual torsions which tend to open the cord.
- Figure 6 shows torsion diagrams of steel filaments of a 1 x 0.20 + 6 x 0.175 -cord according to the present invention manufactured in the way illustrated in Figure 4, i.e. by making use of two false twisters in order to make not only the steel cord as a whole free of residual torsions but also the individual steel filaments.
- the first false twister 28 has a rotation speed which is higher than the rotation speed of the only false twister of Figure 5, which means that the number n FT1 of torsions applied by the first false twister is higher than in the case of Figure 5.
- Core filament 12 follows curve ABC and layer filaments 14 follow curves A'B'C' while being false twisted in the first false twister 28.
- a second false twister 30 untwists the cord 10 to a number n FT2 of applied torsions and again twists the cord 10 to its predetermined final twist pitch.
- the revolution speed of the second false twister 30, and hence the number n FT2 of applied torsions, are so chosen that they correspond always to the point where both torsions curves 34 and 36 cross each other.
- Core filament 12 follows curve CDE while layer filaments 14 follow curve C'DE, resulting in a steel cord consisting only of filaments which are free of residual torsions.
- both false twisters 28 and 30 must be so tuned that the point where the both torsion curves 34 and 36 cross each other is such that it is reached after the untwisting stage of the second false twister 30 and that the twisting of the second false twister results in zero residual torsions on both kind of filaments. Too low a revolution speed of the first false twister 28 will result in residual torsions on the filaments which will open the steel cord 10, too high a revolution speed of the first false twister will result in residual torsions on the filaments which will close the steel cord 10.
Abstract
A steel cord (10) adapted for the reinforcement of elastomers, comprises individual steel filaments (12, 14). Some of these steel filaments (12) have a difference in torsion saturation level in comparison with other steel filaments (14). All of the individual steel filaments have a predetermined number of residual torsions and are preferably free of residual torsions. Such a steel cord is manufactured by making use of two false twisters.
Description
- The present invention relates to a steel cord adapted for the reinforcement of elastomers such as rubber or plastic products. Examples of elastomers reinforced by means of steel cords are conveyor belts, timing belts, rubber hoses and radial tyres where the carcass plies and/or the breaker plies can comprise steel cords.
- It is well known in the prior art to remove residual torsions from steel cords by means of a false twister or to set the amount of residual torsions of a steel cord to a predetermined value by means of a false twister. This is done to increase the processability of the steel cords and to give to elastomeric plies reinforced with steel cords a desired flatness.
Despite the removal of residual torsions, however, some steel cords still remain difficult to be processed and the reinforced elastomeric plies do not show the required flatness. This is especially the case with compact cords, i.e. steel cords where all the filaments have been twisted in the same direction and to the same step, and with steel cords without a wrapping filament.
Supplemental mechanical processing steps of the steel cord, such as preforming or straightening, have not proved to be always sufficient to solve the above problems. - It is an object of the present invention to solve the disadvantages of the prior art.
It is a further object of the present invention to provide a steel cord with enhanced processability properties. - According to the present invention, there is provided a steel cord adapted for the reinforcement of elastomers.
- A steel cord 'adapted for the reinforcement of elastomers' means that the steel cord has the proper features to reinforce elastomers such as rubber tyres, conveyor belts, hoses and timing belts. This means particularly, either alone or in combination, that :
- the steel cord comprises steel filaments with a diameter ranging from 0.05 mm to 0.80 mm, and preferably from 0.05 mm to 0.50 mm ;
- the steel filaments are coated with a layer that promotes the adhesion to the elastomer ; in the case of a rubber elastomer, copper alloy coatings such as brass (either low - 63.5 % Cu - or high copper - 67.5 % Cu) or a complex brass coating (Ni + brass, brass + Co ...) are particularly suitable ;
- the steel filaments have a composition which is along the following lines : a carbon content ranging from 0.70 to 0.98 %, a manganese content ranging from .10 to 1.10 %, a silicon content ranging from .10 to 0.90 %, sulphur and phosphorous contents being limited below 0.15 %, preferably below 0.010 %, additional elements such as chromium (up to 0.20-0.40 %), copper (up to 0.20 %), cobalt (up to 0.30 %) and nickel (up to 0.40 %) may be added either alone or in combination ;
- the steel filaments have a tensile strength which is higher than 2000 MPa (Mega-Pascal = N/mm²), and preferably higher than 2500 MPa ; the tensile strength is dependent upon the filament diameter : the smaller the filament diameter, the higher the final tensile strength, for 0.20 mm filaments the tensile strengths can reach 3800 MPa and higher, for 0.30 mm filaments the tensile strengths can reach 3500 MPa and higher.
- The steel cord of the present invention comprises individual steel filaments. Some of these steel filaments have a difference in torsion saturation level in comparison with other of these steel filaments. All of the individual steel filaments have a predetermined number of residual torsions per filament, e.g. no residual torsions per filament, or in another embodiment where the cord consists of a core of one or more core filaments and a layer of layer filaments, residual torsions of the core filament which tend to open the cord and residual torsions of the layer filaments which tend to close the cord.
- The inventors have discovered that it was not sufficient that the steel cord, taken as a whole, was free of residual torsions in order to avoid processability problems, but that it was necessary to control the residual torsions of the individual steel filaments in order to further enhance the processability and to obtain reinforced elastomeric plies with a sufficient flatness.
- The 'number of residual torsions' is herein defined as the number of revolutions made by a specific length of cord or filament (conveniently 6 meter) when one end is held in a fixed position and the other end is allowed to turn freely. It is conveniently expressed in turns per six meters.
- Preferably, the individual steel filaments have been twisted individually around their longitudinal axes, which means that the steel cord has been manufactured by means of a double-twister or single-twister. Individual filaments which have been twisted around their longitudinal axes can be distinguished from filaments which have not been twisted around their longitudinal axes by the inspection of the drawing lines which are a secondary result of the necessarily imperfect final wet drawing steps : these drawing lines form a helicoid in case the filaments have been twisted around their longitudinal axes and are substantially parallel to their longitudinal axes in case the filaments have not been twisted around their longitudinal axes.
- In this respect and in order to understand the present invention, a distinction must be made between applied twists to a filament (or cord), on the one hand, and residual torsions of a filament (or cord), on the other hand.
If twists are applied to an individual steel filament, the drawing lines on the steel filament form a helicoid. The pitch of this helicoid is inversely proportional to the number of applied twists. The greater the number of applied twists the smaller the pitch of the helicoid.
The relationship between the applied twists to a steel filament and the residual torsions of this steel filament is as follows : As long as the steel filament remains in the elastic region due to the applied twists, the number of residual torsions is equal to the number of applied twists, i.e. when one end of the steel filament is held in a fixed position, the other end will turn freely as much turns as the number of applied twists. When the number of applied twists, however, is that high that the steel filament is plastically deformed, the number of residual torsions becomes smaller than the number of applied twists. A typical saturation phenomenon can be observed : After the number of applied twists has passed a determined value, the number of residual torsions even no longer increases, i.e. the 'torsion saturation level' has been reached. - The torsion saturation level of an individual steel filament is dependent upon : the material of the steel filament, and, especially, upon the diameter of the steel filament and upon the tensile strength of the steel filament. The inventors have discovered that the reason why control of the number of residual torsions of the global steel cord was not sufficient to obtain the required processability was due to a difference in torsion saturation level of individual steel filaments and that it was necessary to take care of this difference.
- Particular examples of steel cords according to the invention are wrapless compact cords, i.e. cords having filaments which all have the same twist pitch and the same twist direction and having no wrapping filament, and where some of the filaments have a filament diameter or a filament tensile strength or both which is different from the filament diameter or the filament tensile strength of the other filaments in the cord. This difference in filament diameter and/or filament tensile strength results in a difference in torsion saturation level between the individual steel filaments of the cord.
- Some specific examples are :
- 1 x 0.20 | 6 x 0.175 pitch 10 mmS - 1 x 0.22 | 6 x 0.20 pitch 12 mmS - 1 x 0.25 | 6 x 0.23 pitch 12 mmS - 1 x 0.28 | 6 x 0.25 pitch 14 mmZ - 1 x 0.32 | 6 x 0.30 pitch 16 mmZ - 1 x 0.36 | 6 x 0.32 pitch 18 mmS - 1 x 0.38 | 6 x 0.35 pitch 20 mmZ - 3 x 0.22 | 9 x 0.20 pitch 12 mmS - The invention will now be described into more detail with reference to the accompanying drawings wherein
- Figure 1 shows a cross-section of a steel cord according to the prior art ;
- Figure 2 shows an end of an elastomeric ply reinforced with a steel cord according to the prior art ;
- Figure 3 shows an end of an elastomeric ply reinforced with a steel cord according to the present invention ;
- Figure 4 illustrates schematically a method of manufacturing a steel cord according to the present invention ;
- Figure 5 shows torsion diagrams of steel filaments of a steel cord according to the prior art ;
- Figure 6 shows torsion diagrams of steel filaments of a steel cord according to the present invention.
- Figure 1 shows the cross-section of a 1 + 6 -
cord 10 according to the prior art. Thecord 10 has onecore filament 12 and sixlayer filaments 14 surrounding and contacting thecore filament 12. Suppose that the steel cord has been twisted into the Z-direction. Despite the fact that thesteel cord 10, taken as a whole, is free of residual torsions, the individual steel filaments have residual torsions : thelayer filaments 14 have residual torsions in the S-direction while the core filament has residual torsions in the Z-direction. - Figure 2 shows an end of an elastomeric ply reinforced with a steel cord according to the prior art. As soon as the elastomeric ply is cut, the ends of the filaments, and particularly the end of the core filament, start to rotate in case the
elastomeric material 16 has not completely filled up the interstices between thecore filament 12 and thelayer filaments 14. In a cross-section of thesteel cord 10 thelayer filaments 14 no longer contact the core filament at the place of cutting. Following disadvantages are the result. At the place of cutting thesteel cord 10 has a larger diameter than designed. The interstices between thefilaments - Figure 3 shows an end of an elastomeric ply reinforced with
steel cord 10 according to the present invention. In asteel cord 10 according to the present invention theindividual steel filaments individual steel filaments core filament 12 and thelayer filaments 14 is maintained. The diameter of thecord 10 does not increase, the interstices between thefilaments - Figure 4 illustrates schematically the way of manufacturing a
steel cord 10 according to the present invention. Thecore filament 12 and thelayer filaments 14 are drawn from thesupply spools 18 on the left side of the Figure and are led to a distributingdisc 20 and to a cord forming die 22 where thecord 10 is at least partially formed. The thus formedcord 10 is further guided over a guidingpulley 24, a rotatingflyer 25 and over a reversingpulley 26. At the level of reversingpulley 26 thecord 10 has reached its final twist pitch. Thecord 10 is now further overtwisted by means of a firstfalse twister 28, i.e. twisted to a twist pitch smaller than the final twist pitch of thecord 10 and untwisted until the final twist pitch of thecord 10. Thereafter thecord 10 is untwisted by means of a secondfalse twister 30, i.e. untwisted to a twist pitch greater than the twist pitch of thecord 10 and twisted again to the final twist pitch of thecord 10. Finally, thecord 10 is wound onspool 32. As will be explained hereafter, correct tuning of the rotation speeds of bothfalse twisters - Figure 5 shows torsion diagrams of steel filaments of a 1 x 0.20 + 6 x 0.175 -cord according to the prior art manufactured in the convenient way, i.e. by making use of one single false twister in order to make the steel cord as a whole free of residual torsions.
- The abscissa (horizontal axis) na is the number of applied torsions, the ordinate (vertical axis) nr is the number of residual torsions. The torsion curve of the
core filament 12 is designated by 34, the torsion curve of thelayer filaments 14 is designated by 36.
While being twisted by means of a double-twister to the final twist pitch,core filament 12 follows curve OA, whilelayer filaments 14 follow curve OA' to a higher level of residual torsions, since the torsion saturation level of alayer filament 14 with a diameter of 0.175 mm is higher than for acore filament 12 with a diameter of 0.20 mm. The number of torsions nLL applied by means of the double-twister corresponds to the final twist pitch.
By means of a false twister (the only one) thecord 10 is further overtwisted to a number nFT1 of applied torsions. Thecore filament 12 follows curve AB while the layer filaments follow curve A'B'. Subsequently the cord is untwisted to the same number nFT1 of torsions in order to reach again the final twist pitch of the cord.Core filament 12 follows curve BC resulting finally in residual torsions which tend to close the cord.Layer filaments 14 follow curve B'C' resulting in residual torsions which tend to open the cord. Tuning of the revolution speed of the false twister, and, as a consequence, of the number nFT1, is only done in order to obtain a cord which is free of residual torsions when taken as a whole. Care is not taken of the residual torsions of the individual filaments. - Figure 6 shows torsion diagrams of steel filaments of a 1 x 0.20 + 6 x 0.175 -cord according to the present invention manufactured in the way illustrated in Figure 4, i.e. by making use of two false twisters in order to make not only the steel cord as a whole free of residual torsions but also the individual steel filaments.
The firstfalse twister 28 has a rotation speed which is higher than the rotation speed of the only false twister of Figure 5, which means that the number nFT1 of torsions applied by the first false twister is higher than in the case of Figure 5.Core filament 12 follows curve ABC andlayer filaments 14 follow curves A'B'C' while being false twisted in the firstfalse twister 28. Thereafter, a secondfalse twister 30 untwists thecord 10 to a number nFT2 of applied torsions and again twists thecord 10 to its predetermined final twist pitch. The revolution speed of the secondfalse twister 30, and hence the number nFT2 of applied torsions, are so chosen that they correspond always to the point where both torsions curves 34 and 36 cross each other.Core filament 12 follows curve CDE whilelayer filaments 14 follow curve C'DE, resulting in a steel cord consisting only of filaments which are free of residual torsions.
The revolutions speeds of bothfalse twisters false twister 30 and that the twisting of the second false twister results in zero residual torsions on both kind of filaments. Too low a revolution speed of the firstfalse twister 28 will result in residual torsions on the filaments which will open thesteel cord 10, too high a revolution speed of the first false twister will result in residual torsions on the filaments which will close thesteel cord 10.
Claims (14)
- A steel cord adapted for the reinforcement of elastomers, said steel cord comprising individual steel filaments, some of these steel filaments having a difference in torsion saturation level in comparison with other steel filaments, the cord as a whole having a predetermined number of residual torsions and each of the individual steel filaments having a (not necesarily equal) predetermined number of residual torsions.
- A steel cord according to claim 1 wherein the difference in torsion saturation level of the steel filaments is due to a difference in filament diameter.
- A steel cord according to any of the preceding claims wherein the difference in torsion saturation level of the steel filaments is due to a difference in filament tensile strength.
- A steel cord according to any of the preceding claims wherein each of the individual steel filaments has no residual torsions.
- A steel cord according to any of claims 1 to 3 wherein said steel cord comprises a core of one or more core filaments and a layer of one or more layer filaments surrounding said core.
- A steel cord according to claim 5 wherein the core filaments have a difference in torsion saturation level in comparison to the layer filaments.
- A steel cord according to claim 6 wherein the torsion saturation level of the layer filaments is higher than the torsion saturation level of the core filaments.
- A steel cord according to claim 7 wherein the core filaments have residual torsions which tend to open the cord and the layer filaments have residual torsions which tend to close the cord.
- A steel cord according to claim 7 wherein both the core filaments and the layer filaments have substantially no residual torsions.
- A steel cord according to any of the preceding claims wherein the individual steel filaments have been twisted individually around their longitudinal axes.
- A steel cord according to any of the preceding claims wherein all the individual steel filaments have been twisted in the same direction and to the same twist pitch in order to form said steel cord.
- A steel cord according to any of the preceding claims said steel cord having no wrapping filament.
- A steel cord according to any of claims 5 to 12 wherein the core consists of three core filaments and the layer consists of nine layer filaments.
- A steel cord according to any of claims 5 to 12 wherein the core consists of one core filament and the layer consists of six layer filaments.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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EP94202020A EP0635597A1 (en) | 1993-07-20 | 1994-07-12 | Steel cord construction |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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EP93202122 | 1993-07-20 | ||
EP93202122 | 1993-07-20 | ||
EP94202020A EP0635597A1 (en) | 1993-07-20 | 1994-07-12 | Steel cord construction |
Publications (1)
Publication Number | Publication Date |
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EP0635597A1 true EP0635597A1 (en) | 1995-01-25 |
Family
ID=26133923
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP94202020A Ceased EP0635597A1 (en) | 1993-07-20 | 1994-07-12 | Steel cord construction |
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EP (1) | EP0635597A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997012092A1 (en) * | 1995-09-25 | 1997-04-03 | Drahtcord Saar Gmbh & Co. Kg | Wire filament, especially for reinforcing rubber of plastic items, process for its production and device for implementing the process |
WO1998013546A1 (en) * | 1996-09-23 | 1998-04-02 | Drahtcord Saar Gmbh & Co. Kg | Steel cord and method for its production |
FR2943691A1 (en) * | 2009-03-31 | 2010-10-01 | Michelin Soc Tech | METHOD AND DEVICE FOR MANUFACTURING A THREE-LAYER CABLE OF THE TYPE IN SITU GUM |
FR2943690A1 (en) * | 2009-03-31 | 2010-10-01 | Michelin Soc Tech | METHOD AND DEVICE FOR MANUFACTURING A THREE LAYER CABLE OF THE TYPE GUM A SITU |
WO2015169521A1 (en) * | 2014-05-08 | 2015-11-12 | Nv Bekaert Sa | Steel cord with reduced residual torsions |
WO2022135850A1 (en) * | 2020-12-21 | 2022-06-30 | Nv Bekaert Sa | A steel cord for rubber reinforcement |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0143767A1 (en) * | 1983-09-02 | 1985-06-05 | N.V. Bekaert S.A. | Steel cord for rubber articles |
EP0387803A1 (en) * | 1989-03-15 | 1990-09-19 | Sumitomo Electric Industries, Ltd. | Steel cord for reinforcing rubber |
-
1994
- 1994-07-12 EP EP94202020A patent/EP0635597A1/en not_active Ceased
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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EP0143767A1 (en) * | 1983-09-02 | 1985-06-05 | N.V. Bekaert S.A. | Steel cord for rubber articles |
EP0387803A1 (en) * | 1989-03-15 | 1990-09-19 | Sumitomo Electric Industries, Ltd. | Steel cord for reinforcing rubber |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997012092A1 (en) * | 1995-09-25 | 1997-04-03 | Drahtcord Saar Gmbh & Co. Kg | Wire filament, especially for reinforcing rubber of plastic items, process for its production and device for implementing the process |
US6151879A (en) * | 1995-09-25 | 2000-11-28 | Drahtcord Saar Gmbh & Co. Kg | Wire filament, especially for reinforcing rubber of plastic items, process for its production and device for implementing the process |
CN1079863C (en) * | 1995-09-25 | 2002-02-27 | 德拉特科德萨尔股份有限两合公司 | Wire filament, especially for reinforcing rubber of plastic items, process for its production and device for implementing the process |
WO1998013546A1 (en) * | 1996-09-23 | 1998-04-02 | Drahtcord Saar Gmbh & Co. Kg | Steel cord and method for its production |
WO2010112444A1 (en) * | 2009-03-31 | 2010-10-07 | Societe De Technologie Michelin | Method and device for producing a three-layer cord |
FR2943690A1 (en) * | 2009-03-31 | 2010-10-01 | Michelin Soc Tech | METHOD AND DEVICE FOR MANUFACTURING A THREE LAYER CABLE OF THE TYPE GUM A SITU |
FR2943691A1 (en) * | 2009-03-31 | 2010-10-01 | Michelin Soc Tech | METHOD AND DEVICE FOR MANUFACTURING A THREE-LAYER CABLE OF THE TYPE IN SITU GUM |
WO2010112445A1 (en) * | 2009-03-31 | 2010-10-07 | Societe De Technologie Michelin | Method and device for producing a three-layer cord |
US8720177B2 (en) | 2009-03-31 | 2014-05-13 | Michelin Recherche Et Technique S.A. | Method and device for producing a three-layer cord |
US8720176B2 (en) | 2009-03-31 | 2014-05-13 | Michelin Recherche Et Technique S.A. | Method and device for producing a three-layer cord |
WO2015169521A1 (en) * | 2014-05-08 | 2015-11-12 | Nv Bekaert Sa | Steel cord with reduced residual torsions |
EA031220B1 (en) * | 2014-05-08 | 2018-12-28 | Нв Бекаэрт Са | Steel cord with reduced residual torsions |
US10487448B2 (en) | 2014-05-08 | 2019-11-26 | Nv Bekaert Sa | Steel cord with reduced residual torsions |
WO2022135850A1 (en) * | 2020-12-21 | 2022-06-30 | Nv Bekaert Sa | A steel cord for rubber reinforcement |
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