Classifications

• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
• • 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
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/2006—Wires or filaments characterised by a value or range of the dimension given
• • 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
  • D07B2201/2015—Strands
  • D07B2201/2036—Strands characterised by the use of different 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
  • D07B2201/2051—Cores characterised by a value or range of the dimension given
• • 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
  • D07B2201/206—Cores characterised by their structure comprising wires arranged parallel to the axis
• • 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
  • D07B2201/2066—Cores characterised by the materials used
• • 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
  • D07B2207/207—Sequential double twisting devices
  • D07B2207/208—Sequential double twisting devices characterised by at least partially unwinding the twist of the upstream double twisting step
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B3/00—General-purpose machines or apparatus for producing twisted ropes or cables from component strands of the same or different material
  • D07B3/08—General-purpose machines or apparatus for producing twisted ropes or cables from component strands of the same or different material in which the take-up reel rotates about the axis of the rope or cable or in which a guide member rotates about the axis of the rope or cable to guide the rope or cable on the take-up reel in fixed position and the supply reels are fixed in position
  • D07B3/10—General-purpose machines or apparatus for producing twisted ropes or cables from component strands of the same or different material in which the take-up reel rotates about the axis of the rope or cable or in which a guide member rotates about the axis of the rope or cable to guide the rope or cable on the take-up reel in fixed position and the supply reels are fixed in position with provision for imparting more than one complete twist to the ropes or cables for each revolution of the take-up reel or of the guide member
  • D07B3/106—General-purpose machines or apparatus for producing twisted ropes or cables from component strands of the same or different material in which the take-up reel rotates about the axis of the rope or cable or in which a guide member rotates about the axis of the rope or cable to guide the rope or cable on the take-up reel in fixed position and the supply reels are fixed in position with provision for imparting more than one complete twist to the ropes or cables for each revolution of the take-up reel or of the guide member characterised by comprising two bows, both guiding the same bundle to impart a twist

Definitions

• the invention relates to a steel cord for the reinforcement of elastomers, comprising two strands of at least two fila- ments each so as to form an m + n -structure, where m is the number of filaments of the first strand and n the number of filaments of the second strand, m and n being greater than or equal to two.
• the steel cord according to the invention is particularly suitable for use as a reinforcement of rubber articles such as tires, and more particularly for use as a reinforcement of breaker layers in a tire.
• Steel cords for use as a reinforcement of breaker layers in a tire conveniently comprise steel filaments having a diameter between 0.05 mm and 0.60mm, preferably between 0.15 and 0.45 mm.
• a conventional steel composition for such steel cords is a carbon content above 0.65 %, preferably above 0.80 %, e.g. 0.83 % or 0.85 %, a manganese content between 0.40 and 0.70 %, a silicon content between 0.15 and 0.30 %, and maxi ⁇ mum sulphur and phosphorus contents of 0.03 %.
• the invention is not limited to such a steel composition.
• Other elements such as chromium, nickel or boron may also be added.
• the steel cord usually has a rubber adherable layer such as a copper, zinc, or brass alloy.
• n x 1 -constructions occupy a special place. These are. . ,constructions with n filaments twisted together with the same twist pitch and in the same twist sense, n is an integer number between 3 and 5.
• the problem with these constructions is that they have a central void where rubber cannot penetrate during vulcanisation and where moisture may easily enter and cause corrosion.
• a solution to this problem has been given by the open n x 1 -constructions.
• These are constructions where one or more filaments are kept apart from each other by giving them a specified prefor ation during the twisting process. However, this preformation must exceed a certain limit in order to avoid closing the steel cord when this is put under tension during the vulcanisation process. The problem is then that too high a preformation may cause an irregular cord aspect and instability.
• a steel cord for the reinforcement of elastomers which comprises two strands of at least two filaments each. These strands are twisted around each other and form helicoids of a same pitch.
• the filaments of the first strand have a pitch differing from the pitch of said helicoids and have a value of more than 300 mm.
• the filaments of the second strand have the same pitch as the helicoids and are twisted in the same sense as the helicoids. All the filaments of both strands have a diameter between 0.08 and 0.45 mm.
• the diameter of the filaments of one of the strands is at least 0.02 mm greater than the diameter of the filaments of the other of the strands.
• the diameter of the filaments of the second strand is at least 0.02 mm greater than the diameter of the filaments of the first strand, and preferably up to 0.12 mm greater than the diameter of the filaments of the first strand.
• m + n -construction is provided, where m is the number of filaments of the first strand and n the number of filaments of the second strand.
• the filaments conveniently have a circular cross-section, but this is not necessary. In cases where the filaments don't have a circular cross-section, "diameter" means the diameter of. a circular cross-section with the same surface as the cross-section of the filaments.
• the filaments within one strand conveniently have the same diameter, but small differences in the range of 0.01 mm - 0.02 mm may occur.
• the fatigue limit of the cord according to the invention is much higher than the fatigue limit of a conventional m + n -construction with the same cross-sectional surface. This is surprising because the diameter of the filaments of one strand has been decreased with respect to the conventional m + n -construction and the diameter of the filaments of the other strand has been increased with respect to the conven- tional m + n -construction in order to obtain about the same cross-sectional surface and hence reinforcing effect. It is hereby understood that, as is generally known in the art, decreasing the diameter of filaments increases the fatigue limit and increasing the diameter of filaments decreases the fatigue limit.
• the number of steel filaments in the first strand is equal to the number of steel filaments in the second strand and most preferably this number is equal to two.
• the steel filaments in both strands may have a normal tensile strength,, i.e. a tensile strength below the value of
• d is the diameter expressed in mm, or they may have a high tensile strength, i.e. a tensile strength above the value of formula (I).
• the filaments of one strand have a normal tensile strength and the fila ⁇ ments of the other strength have a high tensile strength. If the filaments of the first strand have the smaller diameter and have a high tensile strength and the filaments of the second strand have the greater diameter and have a normal tensile strength then the loss in reinforcing strength of the first strand with regard to the second strength due to the smaller diameters may be compensated so that both strands equally contribute to the tensile strength of the whole cord.
• the filaments of the first strand having the smaller diameter may also have a normal tensile strength while the filaments of the second strand having the greater diameter have a high tensile strength. It is further clear that by using filaments with a high ten ⁇ sile strength, the overall diameter of the cord may be decreased without loss of tensile strength with regard to m + n-cords with all filaments having a normal tensile strength.
• FIGURE 1 represents a side view and subsequent cross-sections of a cord according to the present inven ⁇ tion
• FIGURE 2 represents an apparatus for manufacturing a cord according to the present invention.
• FIGURE 1 represents a cord 1 according to the present inven ⁇ tion.
• the cord consists of a first strand having two fila ⁇ ments 11 and a second strand also having two filaments 12.
• the cross-section of the filaments 11 of the first strand is shaded.
• the filaments 11 have a diameter of 0.24 mm and the filaments 12 have a diameter of 0.28 mm.
• the two strands are twisted around each other with a twist pitch p of 15 mm.
• the twist pitch p conveniently lies between 30 and 100 times the average diameter of the filaments and preferably between 40 and 80 times the average diameter of the filaments.
• the fila- ments 12 of the second strand are twisted in the same sense with the same twist pitch p while the filaments 11 of the first strand remain substantially parallel to each other, i.e. they have an infinite twist pitch.
• FIGURE 2 represents a double-twisting apparatus 2 for manufac ⁇ turing a cord according to the present invention.
• the fila ⁇ ments 11 of the first strand are drawn from bobbins 21 and pass through the holes 231 of a guiding plate 23 and come together at a first guiding pulley 24 of the double-twister 2 where they are provisionally twisted together. They pass fur ⁇ ther over a flyer 25 and over a reversing pulley 26.
• Two bob ⁇ bins 27 are stationarily mounted inside the rotor of the double-twister 2.
• the filaments 12 of the second strand are drawn from these bobbins 27 and pass through the holes 281 of a guiding plate 28 and come together with the provisionally twisted filaments 11 at the cabling die 29.
• the filaments 11 and 12 pass over reversing pulley 210, flyer 211 and guiding pulley 212 to the winding unit 213.
• the filaments 11 are untwisted so as to form a first strand consisting of substantially parallel filaments 11, while the filaments 12 are twisted with the same pitch and in the same direction as the two strands.
• NT normal tensile, i.e. a tensile strength below the value of formula (I);
• HT high tensile, i.e. a tensile strength above the value of formula (I)) :
• a second test reveals an additional advantage of the cord according to the invention, namely a better behaviour under compression.
• the buckling stress is a measure for the maximum compression force taken up by the steel cord when embedded in rubber. The greater the buckling stress the greater this maximum compres ⁇ sion force.
• the deformation is the deformation of the cord in rubber when subjected to this maximum compression.
• a high Young's modulus in compression means a cord which does not allow high deformations under compression whereas a low
• a third test has evaluated the influence of the diameter dif- ference between the two strands on the cord properties. Following cords have been evaluated :
• invention cord 2 x 0.22 HT + 2 x 0.25 HT pitch : 14 mm
• invention cord 2 x 0.25 NT + 2 x 0.28 HT pitch : 14 mm 3.
• invention cord 2 x 0.20 HT + 2 x 0.25 HT pitch 14 mm
• invention cord 2 x 0.22 NT + 2 x 0.28 HT pitch 14 mm
• Table 3 summarizes the results of the P.L.E. values and of the fatigue properties of these cords.
• P.L.E. means here part load elongation. It is defined as the increase in length of a gauge length between a tension of 2.5 N and a tension of 50 N and may be expressed as a percentage of the original gauge length. It is a measure of the openness of the steel cord.

Landscapes

• Ropes Or Cables (AREA)
• Tires In General (AREA)
• Reinforced Plastic Materials (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8202353

Family Applications (1)

Country Status (12)

Cited By (1)

Families Citing this family (2)

Citations (4)

Family Cites Families (2)

• 1990
  • 1990-03-02 ZA ZA901611A patent/ZA901611B/xx unknown
  • 1990-03-22 CA CA002050922A patent/CA2050922A1/en not_active Abandoned
  • 1990-03-22 AU AU52788/90A patent/AU630940B2/en not_active Ceased
  • 1990-03-22 WO PCT/EP1990/000493 patent/WO1990012145A1/en active IP Right Grant
  • 1990-03-22 JP JP2504932A patent/JPH04506235A/ja active Pending
  • 1990-03-22 KR KR1019910700854A patent/KR920701564A/ko not_active Application Discontinuation
  • 1990-03-22 BR BR909007261A patent/BR9007261A/pt not_active IP Right Cessation
  • 1990-03-22 EP EP90904817A patent/EP0466720B1/de not_active Expired - Lifetime
  • 1990-03-22 ES ES90904817T patent/ES2049026T3/es not_active Expired - Lifetime
  • 1990-03-22 DE DE90904817T patent/DE69004795T2/de not_active Expired - Fee Related
  • 1990-03-28 MX MX020073A patent/MX173016B/es unknown
  • 1990-04-03 TR TR90/0338A patent/TR25281A/xx unknown

Patent Citations (4)

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