EP0092696B1 - Reinforcing cord for rubber products - Google Patents

Abstract

Reinforcement cable of metal wire for elastomeric conduits are disclosed, containing at least two corded-together strands which each have two or more wires and at least one outerlying of which strands is composed from two or more core wires wrapped by at least one spiral-shaped strand winding wire. Particular embodiments include wrapping with strands; use of three to seven thereof; enveloping the strands with preferably up to four cable winding wires; arranging various of the combination sets of core wires, strands and cables to be of equal pitch, pitch angle and rotary direction, mainly in-phase; and staggering the cores wires to define a reciprocal contact curve parallel thereto.

Description

The invention relates to a reinforcement rope made of metal wires, preferably steel wires, for elastomeric products, consisting of at least two strands stranded together, each consisting of two or more wires, at least one outer strand consisting of two or more core wires wound helically by at least one strand loop wire.

Such a reinforcement rope is known from BE-A-655 590. In this reinforcement rope, several non-preformed metal wires are laid parallel to strands and helically wrapped by a strand loop wire. Several of these strands can be combined to form a reinforcement rope.

Such reinforcement ropes, which consist of several strands, are always used in elastomeric products when the elastomeric products are to be subjected to an increased load capacity. The individual wire diameters are usually 0.12 to 0.5 mm. The reinforcement ropes, which consist of several strands, are used when the embedding of the individual strands in the elastomeric product becomes very labor-intensive.

The known reinforcement rope has the advantage that when it is embedded in the elastomeric material, it can also get into the core areas of the ropes, so that no capillaries can be formed from the wires, which lead to undesirable corrosion if the surface of the composite material is damaged up to the rope position would. However, it has the disadvantage that the strand wrap wires do not contribute to the strength of the rope.

It is therefore an object of the present invention to provide a reinforcement rope which likewise has good behavior against corrosion, but in which at least the strand-wrapping wires also contribute to the strength of the rope.

According to the invention, this object is achieved by a reinforcement rope of the type mentioned above, which is characterized in that the strands are helically wrapped by at least one rope wrapping wire and / or at least one rope wrapping strand, and in the strands and / or in the rope wrapping strands the core wires and the Strands wrapping wires have a helical shape of the same pitch, the same pitch angle and the same direction of rotation, and the core wires of a strand are arranged bundled almost in phase.

Rope wrap wires for reinforcement ropes per se are known for example from DE-PS 803 801. These have the task of preventing the reinforcement rope from splicing. In this respect, the rope wrap wire must be tightly wrapped around the reinforcement rope. In this respect, the loop wire usually acts against penetration of the elastomeric product.

The metal wires should bond well with the elastomeric material. However, they can also be coated with a second metal, plastic or another material, with a good tendency to bind between the metal wire and the coating material on the one hand and the coating material and elastomeric material on the other hand. Wires made of steel, usually made of carbon steel, are also particularly suitable, but also made of other types of steel, for example made of alloyed or high-alloyed steel with a low Fe content. Steel wires coated with brass are preferred.

External strands are understood to be the strands that are visibly on the outside of the finished reinforcement rope.

It is particularly expedient if the core wires of the strands and / or the rope wrap strands are arranged next to one another and against one another such that each of the core wires is in parallel linear contact with at least one other core wire. The contact line therefore runs parallel to the direction of the core wires.

These strands are known as reinforcement ropes in simple stranding from DE-OS 26 19 086. The reinforcement ropes have been found to be particularly favorable for use as reinforcement ropes in elastomeric products, since the loop wire also has a supporting function and, moreover, the elastomeric material also penetrates particularly well into the core area of the rope when the rope is embedded, and thus also corrosion of the wires is largely prevented in the case of severe damage.

Surprisingly, it turns out that a renewed stranding of these ropes as strands creates a reinforcement rope for elastomeric products, which comes close to the favorable properties of the individual rope mentioned above.

It is very particularly advantageous if the strands and the rope wrapping wires and / or rope wrapping strands are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the strands are arranged bundled almost in phase.

With this reinforcement rope, all wires in the rope bond contribute to the strength of the rope; So they all have a supporting function.

It is advantageous if the strand wrap wires are arranged out of phase with the core wires, preferably shifted by half a pitch length. The preferred lay length for the second stranding is 10 to 30 mm.

In this embodiment, preference is given to producing the rope during the second stranding the method known from DE-OS 26 19 086 applied, wherein instead of the core wires core strands and instead of the wrapping wires, rope wrapping wires and / or rope wrapping strands are used.

It was surprising that with such a reinforcement rope, despite its generally considerably larger number of wires and thus its larger cross section, the equally good properties described above of the rope described in DE-OS 26 19 086 can be achieved.

The technical terms used here about rope constructions are taken from the book "Steel wire products", Verlag Stahleisen, 1956, Volume I.

In addition to the strands, one or more individual wires can also be installed in the reinforcement rope.

As a rule, the reinforcement rope according to the invention consists of three to seven strands, up to four rope wrap wires and / or up to four rope wrap strands.

According to the invention, strands are understood to be strands in the reinforcement rope, which are generally present in a larger number than the rope-wrapping strands. However, there can also be the same number of strands and rope-wrapping strands, one group of strands and the other group of rope-wrapping strands being named for distinction.

As a rule, the strands and / or the rope wrapping strands contain two to eight core wires; however, more core wires are also possible.

Likewise, the strands and / or the rope wrapping strands generally contain up to four strand wrapping wires, a larger number also being possible here.

Core wires are understood to be those wires in the strand or rope wrap strand which are generally in the majority.

Strand wrap wires are understood to be those wires in the strand or rope wrap strand which are generally in fewer numbers.

The strands or the rope wrapping strands can, for example, contain 3 + 1, 5 + 2, 6 + 3, 7 + 2, or generally n, + n ₂ wires, the first number or n, the number of core wires and the second number or n ₂ indicates the number of strand wrap wires.

However, the same number of core wires and also strand-wrapping wires can also be contained in the strands or in the rope-wrapping strands. Such strands or rope wrapping strands then contain 2 + 2, 3 + 3.4 + 4 or n, + n ₂ , where n, = n ₂ , wires, the first number or n, as core wires and the second number or n _{2 are to} be understood as strand wrap wires.

The reinforcing ropes according to the invention are preferably used in the manufacture of pneumatic vehicle tires, in particular pneumatic tires for trucks or earth moving machines.

The invention is explained in more detail with reference to the attached figures and examples.

• Figur 1 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles mit vier Litzen und einem Seilumschlingungsdraht der Konstruktion 4 x (5 + 2) + 1
• Figur 2 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles mit sieben Litzen und einem Seilumschlingungsdraht der Konstruktion 7 x (3 + 1) + 1
• Figur 3 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles mit sieben Litzen und einem Seilumschlingungsdraht der Konstruktion 7 x (2 + 2) + 1
• Figur 4 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles gemäß Anspruch 3 mit fünf Litzen und zwei Seilumschlingungsdrähten der Konstruktion 5 x (4 + 1) +
• Figur 5 den prinzipiellen Aufbau eines erfindurgsgemäßen Verstärkungsseiles gemäß Anspruch 3 mit drei Litzen und einer Umschlingungslitze der Konstruktion (3 + 1) x (5 + 2)
• Figur 6 schematisch den Versuchsaufbau beim Korrosionsversuch
• Figur 7 schematisch den Versuchsaufbau bei der Bestimmung der Luftdurchlässigkeit des eingebetteten Verstärkungsseiles
• Figur 8 einen Schnitt durch den Prüfkörper, welcher bei der Bestimmung der Luftdurchlässigkeit eingesetzt wird
• Figur 9 schematisch den Aufbau eines Reifens, in welchen erfindungsgemäße Verstärkungsseile eingebettet sind.

Show it:

• Figure 1 shows the basic structure of a reinforcement rope according to the invention with four strands and a rope wrap wire of the construction 4 x (5 + 2) + 1
• Figure 2 shows the basic structure of a reinforcement rope according to the invention with seven strands and a rope wrap wire of construction 7 x (3 + 1) + 1
• Figure 3 shows the basic structure of a reinforcement rope according to the invention with seven strands and a rope wrap wire of construction 7 x (2 + 2) + 1
• Figure 4 shows the basic structure of a reinforcement rope according to the invention according to claim 3 with five strands and two rope wrap wires of the construction 5 x (4 + 1) +
• 5 shows the basic structure of a reinforcement rope according to the invention according to claim 3 with three strands and a looping strand of the construction (3 + 1) x (5 + 2)
• Figure 6 schematically shows the test setup in the corrosion test
• Figure 7 schematically shows the experimental setup when determining the air permeability of the embedded reinforcement rope
• Figure 8 shows a section through the test specimen, which is used in determining the air permeability
• Figure 9 schematically shows the structure of a tire in which reinforcing ropes according to the invention are embedded.

FIG. 1 shows the basic structure of a reinforcement rope I according to the invention with four strands 2, which consist of five core wires 3 and two strand strands 4 each, and a rope strapping wire 5. In general, the construction is given as 4 x (5 + 2) + 1. The strands 2 are stranded in a cross lay. The strands 2 are constructed in such a way that the core wires 3 and the strand wrapping wires 4 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires 3 of a strand 2 are arranged in almost the same phase. The core wires 3 and strand wrap wires 4 are only shown in the upper half of FIG. 1. For better clarity, only the strand 2 is shown as a thick cable without stranded wire 4 in the rope network.

Figure 2 shows the basic structure of a reinforcement rope 6 according to the invention with seven strands 7, which consist of three core wires 8 and a strand loop wire 9, and a rope loop wire 10. In general, the construction with 7 x (3 + 1) + 1 specified. Here, too, the strands are stranded in a cross lay. The form of representation corresponds to that of FIG. 1.

FIG. 3 shows the basic structure of a reinforcement rope 11 according to the invention with seven strands 12, which each consist of two core wires 13 and two strand wrap wires 14, and a rope wrap wire 15. In general, the construction is given as 7 x (2 + 2) + 1. The additional information given in FIG. 1 also applies analogously to FIG. 3.

FIG. 4 shows the basic structure of a reinforcement rope 16 according to the invention, in which five strands 17 and two rope wrapping wires 20 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the strands are bundled almost in phase, the rope wrapping wires 20 being around half a pitch length are arranged out of phase with respect to the strands 17. The strands 17 each consist of four core wires 18, each strand 17 being helically wrapped with a strand wrap wire 19. In the stranded wires, the core wires 18 and the strand wrapping wires 19 have a helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires 18 of a strand 17 are arranged bundled almost in phase.

FIG. 5 shows the basic structure of a reinforcement rope 21 according to the invention, in which three strands 22 and one rope wrap strand 25 of helical shape are of the same pitch, same pitch angle and same direction of rotation, and the strands 22 are bundled in almost the same phase, the rope wrap strands 25 is arranged out of phase by half a pitch length with respect to the strands 22. The strands 22 each consist of five core wires 23 and two strand wrapping wires 24. The rope wrapping strand 25 also consists of five core wires 26 and two strand wrapping wires 27. In the strands 22 and also in the rope wrapping strand 25, the core wires 23 and 26 and the strand wrapping wires 24 and 24, respectively 27 helical shape of the same pitch, the same pitch angle and the same direction of rotation, and the core wires 23 and 26 of a stranded wire 22 and 25 are arranged bundled almost in phase. It is particularly favorable here if the strand wrap wires 24 and 27 are arranged out of phase by half a pitch length with respect to the core wires 23 and 26.

Example 1 Corrosion Tests

To demonstrate the good properties of the reinforcement ropes according to the invention, corrosion tests were carried out in accordance with an experimental setup shown schematically in FIG. 6, the results of the reinforcement ropes according to the invention being compared with previously used reinforcement ropes.

To carry out the corrosion test, test specimens 28 are produced in which two layers 29, each with fourteen ropes per 32 mm, are vulcanized into two different types of rubber in such a way that the two layers 29 are vulcanized together within a region B of 25.4 mm of the test specimen length. The area limits are 12.5 mm (area A) from one end and 50 mm (area C) from the other end face of the test specimen 28, the cable cross sections being visible on both end faces 30 and 31. The ropes within the rope layers 20 and the two rope layers one below the other lie at a constant distance from one another in the longitudinal direction of the sample.

The finished test specimens 28 are immersed on the flat side with the shorter, non-vulcanized side in a 20% NaCl solution 32 in a container at an angle of 45 ° to the bath surface in such a way that the immersion length D of the vulcanized area is 12.5 mm. Several samples of the different types of rope were produced, which were either not at all (immersion time 0 days) or immersed in the 20% NaCl solution for several days.

Here two different, common types of rubber were used. After the immersion time, the rope layers of the test specimens were torn apart after the two longer, non-vulcanized sides 30 had been clamped in place. The degree of rubber coverage was assessed within the previously vulcanized area of both torn test specimen halves 29, a distinction being made between immersed (area D) and non-immersed area. 100% coverage means that neither rope nor rope parts are visible on both halves of the test specimen 29.

• Seil I: ein erfindungsgemäßes Verstärkungsseil gemäß Anspruch 4 und Figur 1, welches aus vier Litzen 2, bei welchen fünf Kerndrähte 3 und zwei Litzenumschlingungsdrähte 4 von schraubenförmiger Gestalt gleicher Steigung, gleichen Steigungswinkels und gleicher Drehrichtung sind, und die Kerndrähte 3 einer Litze 2 nahezu phasengleich gebündelt angeordnet sind, und einem Seilumschlingungsdraht 5. Die Litzenumschlingungsdrähte 4 waren gegenüber den Kerndrähten 3 um eine halbe Steigungslänge phasenverschoben angeordnet. Die Kerndrähte 3 und die Litzenumschlingungsdrähte 4 hatten einen Drahtdurchmesser von 0,22 mm, während der Seilumschlingungsdraht 5 einen Durchmesser von 0,15 mm hatte. Die Verseilung der Litzen erfolgte im Kreuzschlag. Die Konstruktion wird üblicherweise wie folgt angegeben
  • 4 x (5 + 2 x 0,22) + 0,15
• Seil II: Aufbau wie Seil I, jedoch andere Drahtzahlen der Konstruktion
  • 3 x (7 + 2 x 0,22) + 0,15
• Seil III: Aufbau wie Seil I, jedoch andere Drahtzahlen, wie in Figur 2 dargestellt, der Konstruktion
  • 7 x (3 ₊ 1 x 0,22) ₊ 0,15
• Seil IV: Aufbau wie Seil 1, jedoch andere Drahtzahlen, wie in Figur 3 dargestellt, der Konstruktion
  • 7 x (2 + 2 x 0,22) + 0,15
• Seil V: Aufbau wie Seil I, wobei anstatt des Seilumschlingungsdrahtes eine Seilumschlingungslitze um das Seil gewickelt war. Das Verstärkungsseil bestand aus drei Litzen und einer Seilumschlingungslitze, welche Litzen jeweils aus fünf Kerndrähten und zwei Litzenumschlingungsdrähten bestanden, der Konstruktion:
  • 3 + 1 x (5 + 2 x 0,22)
• Seil VI: ein Vergleichsseil, welches zweifach im Kreuzschlag verseilt ist, der Konstruktion
  • 7x4x0,22+0,15
• Seil VII: ein Vergleichsseil, welches einfach verseilt ist, der Konstruktion:
  • 3+9+15x0,22+0,15

The following were used as ropes:

• Rope I: a reinforcement rope according to the invention as claimed in claim 4 and FIG. 1, which consists of four strands 2, in which five core wires 3 and two strand wrapping wires 4 are of helical shape with the same pitch, same pitch angle and same direction of rotation, and the core wires 3 of a strand 2 are almost in phase are arranged bundled, and a rope wrap wire 5. The strand wrap wires 4 were arranged out of phase with the core wires 3 by half a pitch length. The core wires 3 and the strand wrap wire 4 had a wire diameter of 0.22 mm, while the rope wrap wire 5 had a diameter of 0.15 mm. The strands were stranded in a cross lay. The construction is usually given as follows
  • 4 x (5 + 2 x 0.22) + 0.15
• Rope II: Construction like rope I, but different numbers of wires in the construction
  • 3 x (7 + 2 x 0.22) + 0.15
• Rope III: Construction like rope I, but different numbers of wires, as shown in Figure 2, the construction
  • 7 x (3 ₊ 1 x 0.22) ₊ 0.15
• Rope IV: Construction like rope 1, but different numbers of wires, as shown in Figure 3, the construction
  • 7 x (2 + 2 x 0.22) + 0.15
• Rope V: Construction like rope I, whereby instead of the rope wrap wire a rope wrap was wrapped around the rope. The reinforcement rope consisted of three strands and a rope wrap wire, which strands each consisted of five core wires and two wire wrap wires, the construction:
  • 3 + 1 x (5 + 2 x 0.22)
• Rope VI: a comparison rope, which is twisted twice in the cross lay of the construction
  • 7x4x0.22 + 0.15
• Rope VII: a comparison rope, which is simply stranded, the construction:
  • 3 + 9 + 15x0.22 + 0.15

The degrees of rubber coverage in% of the torn apart samples in which the inventive or comparative reinforcement ropes were embedded are shown in Tables I and II as a function of the immersion time.

The test specimens with reinforcement ropes according to the invention thus behave more corrosion-resistant than the test specimens with comparison ropes.

example

In order to check what the quality of the embedding of a reinforcement rope according to the invention in the rubber is in comparison to the usual reinforcement ropes, the air permeability was determined in accordance with FIG. 7, a test specimen in accordance with FIG. 8 being used.

For this purpose, a 7.5 cm long reinforcement rope 36 is embedded in rubber 35, the reinforcement rope 36 being visible on both end faces of the test specimen 34. At the same time, a sealing washer 37 and a pipe stop piece 38 are embedded in the rubber 35 in each test specimen 34.

With the union nut 40, the test body 34 is connected gas-tight with a compressed air connection piece 41. The compressed air connector 41 is connected via a transition piece 42, a pressure reducing valve 43 and a compressed air line 44 to a compressed air source (not shown).

At the pipe connector 38, a pipe 39 is connected in a gastight manner, the free end of which is immersed in a tub 45 filled with water 46. The free end is bent upwards and is located under the opening of a measuring cylinder 47 filled with water at the beginning of the experiment, which is also immersed in the water bath 45, 46. With the valve 48, the height of the water column in the measuring cylinder 47 can be adjusted.

At the beginning of the air permeability determination, a pressure of 1 bar is set via the pressure reducing valve 43. If air can penetrate through the test grains into the rubber mass 35 as a result of incomplete embedding of the reinforcement cable 36, the air bubbles that arise rise in the measuring cylinder 47. The amount of air accumulating in the measuring cylinder 47 per unit of time is measured.

• Die erfindungsgemäßen Verstärkungsseile I und V gemäß Beispiel 1.
• Außerdem wurde ein weiteres erfindungsgemäßes Seil VIII eingebettet, welches wie Seil I aufgebaut ist, jedoch zwei Seilumschlingungsdrähte hat, der Konstruktion:
  • 5 x (4 + 1 x 0,22) + 2 x 0,22
• Als Vergleichsseile wurden die Seile VI und VII aus Beispiel 1 gewählt.

The following were embedded in rubber type 2 as reinforcement ropes:

• The reinforcement ropes I and V according to the invention as in Example 1.
• In addition, another rope VIII according to the invention was embedded, which is constructed like rope I, but has two rope wrap wires, of the construction:
  • 5 x (4 + 1 x 0.22) + 2 x 0.22
• Ropes VI and VII from Example 1 were chosen as comparison ropes.

The results are shown in Table III.

The reinforcing ropes according to the invention are therefore completely embedded in the rubber mass.

FIG. 9 schematically shows the structure of a tire in which reinforcing ropes according to the invention are embedded. With 47 the tread of the tire is designated, which is constructed here as a radial tire. In the tread 47 two layers 48 and 49 of reinforcing ropes according to the invention are embedded, which run at a certain angle to the circumferential direction. This angle depends on the area of application of the tire. Reinforcement ropes 50 according to the invention are likewise embedded in a carcass 51 perpendicular to the circumferential direction of the tire - in the circumferential direction of the tire cross section. The reinforcing ropes according to the invention can also be embedded in the bead 57.

Claims (11)

1. A reinforcing cable of metal wires, preferably steel wires, for elastomeric products, consisting of at least two strands (2, 7, 12,17, 22) twisted together of two or more wires each, at least one outer strand consisting of two or more core wires (3, 8,13, 18,12) around which at least one strand wrapping wire (4, 9, 14, 19, 24) is helically wound, characterized in that in all at least one cable wrapping wire (5, 10, 15, 20) and/or at least one cable wrapping strand (25) is/are wound helically around the strands (2, 7, 12,17,22) and in the strands (2, 7,12, 17, 22) and/or in the cable wrapping strands (25) the core wires (3, 8, 13, 18, 23, 26) and the strand wrapping wires (4, 9, 14, 19, 24, 27) are of helical configuration with the same pitch, the same helix angle and the same direction of twist and the core wires (3, 8,13,18, 23, 26) of a strand (2, 7,12, 17, 22, 25) are bundled in substantially the same phase.

2. A reinforcing cable as claimed in Claim 1, characterized in that the core wires (3, 8, 13, 18, 23, 26) of the strands (2, 7, 12, 17, 22) and/or the cable wrapping strands (25) are arranged adjacent and against one another and each of the core wires is in parallel linear contact with at least one other core wire.

3. A reinforcing cable as claimed in Claim 1 or 2, characterized in that the strands (17, 22) and the cable wrapping wires (20) and/or cable wrapping strands (25) are of helical configuration with the same pitch, the same helix angle and the same direction of twist and the strands (17, 22) are bundled in substantially the same phase.

4. A reinforcing cable as claimed in Claim 1, 2 or 3, characterized in that the reinforcing cable (1, 6, 11, 16, 21) consists of three to seven strands (2, 7, 12, 17, 22).

5. A reinforcing cable as claimed in at least one of Claims 1 to 4, characterized in that up to four cable wrapping wires (5,10,15,20) are wound helically around the strands (2, 7, 12, 17, 22).

6. A reinforcing cable as claimed in any of Claims 1 to 5, characterized in that up to four cable wrapping strands (25) are wound helically around the strands (22).

7. A reinforcing cable as claimed in any of Claims 1 to 6, characterized in that the strands (2, 7,12,17,22) and/or the cable wrapping strands (25) each contain from two to eight core wires (3, 8, 13, 18, 23, 26).

8. A reinforcing cable as claimed in any of Claims 1 to 7, characterized in that the strands (2, 7, 12, 17, 22) and/or the cable wrapping strands (25) each contain up to four strand wrapping wires (3, 9, 14, 19, 24, 27).

9. The use of the reinforcing cables claimed in any of Claims 1 to 8 for the production of pneumatic tyres for motor vehicles.

10. The use of the reinforcing cables claimed in any of Claims 1 to 8 for the production of pneumatic tyres for heavy goods vehicles.

11. The use of the reinforcing cables claimed in any of Claims 1 to 8 for the production of pneumatic tyres for earth-moving machines.

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