LU84435A1 - COMPOUND CABLE FOR REPLACEMENT OF ELASTOMERS - Google Patents

Description

WBV / cd / 1927

COMPOSITE GLUE FOR REINFORCEMENT OF ELASTOMERS

· Η · ΒΒ "Ηβα9ΒΒΒ => Κ" ΒΒΤ ··· ηΚΒ · *> Β · Βα · 8 ···· Μ · ΒΒ ·· The invention relates to a steel cable for the reinforcement of a material elastomer, such as rubber, comprising several strands. These strands can be arranged in the cable, for example as a certain number n of strands which are twisted together all around one another to form helices of substantially equal diameter and pitch. These strands can also be arranged in the form of a straight strand forming a core and a layer of strands running helically around the strand-core.

So far we have used as a strand a group of m lines twisted together which form helices of diameter and not equal, such as the strands 3 x 0.15 (3 lines of 0.15 in diameter), 4 x 0.175 "4 x 0.22, having a step of 15 to. 25 millimeters. These strands are then stranded to form a cable, for example forming a core strand with 6 strands around (7 strands of 3 or 4 wires, ie a 7 x 3 or 4 cable) or else forming three strands which are stranded around each other (3 x 3 or 4 cable)

In some cases of cable application, it is desirable to have a variant of those of the type mentioned above, having roughly a similar structure of the same number of strands and the same tensile strength, but having d 'other physical characteristics, for example where the stiffness is greater.

According to the invention, this is obtained by using a strand of a special type, the structure of which is sufficiently round and compact to allow itself to be used as strand forming a cable of roundness and of acceptable diameter.

> - * '· ΐ # - ~' Μ * ·. . ·. , Γ. · ** · -. * Λν ”, i-ia * ·. - fZ- ‘'Λ * 1." Vi. * ·,. * \: ΐ.' ‘'· ... -, Κ.Λ 2.

According to the invention each ioron has two groups of wires, these grouped being twisted one around the other so as to form helices which have approximately the same shape, the wires of the first group having a pitch of a greater size. at 300 mm, and the wires of the second group having a pitch of twist in the same direction and of the same value as the pae of said propellers.

Preferably, the number of yarns in the second group is equal to the number of yarns in the first group and is between two and four, preferably two. The torsion pitch of the first group will preferably have an infinite value, so as to form in the strand a bundle of parallel wires. The lines generally have a diameter of 0.10 to 0.40 mm.

The characteristics and advantages of the invention will emerge from the description which follows given by way of nonlimiting example and with reference to the appended drawings in which 2 Figure 1 shows a cable used as a strand in the cable according to the invention.

Figure 2 shows a section of a cable according to the invention and more specifically the way in which the strands join to form the cable.

The strand used in the tests which will be explained above is shown in detail in Figure 1. It comprises a first group of two strands 1 and a second group of two wires 2. The two groups are twisted together, one around on the other in helices with a pitch q. Figure 1 shows a side view and four sectional views taken a quarter of a step apart from each other. The wires 1 of the first group have no twist around each other, while the wires 2 of the second group have a twist around each other and in the same direction and with the same no twist p. Instead of a group of parallel wires 1, it is also possible to use a group of twisted wires with a very large pitch, eg greater than 300 mm. Such a strand is then indicated by the symbol "2 + 2".

3.

Seven strands 2 + 2 of the type shown in Figure 1 are then used in a cable 7 1 (2 + 2), as shown in Figure 2, where the pitch q of the strands in the cable is in the opposite direction to the direction of not p for leading groups in the strands. With the strand shown in Figure 1 (having a pitch "Z"), we therefore obtain a structure "S / z". The pitch q of the strands along the cable is to be determined * with respect to a direction AA which remains fixed along the cable · The pitches p and q generally have a value between 5 and 30 mm, preferably around 10 mm and p about 20 mm. We are talking about a 7 x (2 + 2) cable having the steps "10/20".

We can make other cables of the same kind, for example 3 x (2 + 2) or others. TJn conventional 7 x 4 or 5 x 4 cable is generally still wrapped by a helical running wire around the cable with a fairly short pitch of about a half or one. third of the pitch of the strands and in the opposite direction of the pitch of the strands. This can also be done in the cable according to the invention, and we then speak of a cable 7 1 (2 + 2) + 1 or a cable 3 x (2 + 2) + 1 having a pitch " q / p / r ", r being the pitch, in millimeters of the envelope wire.

For the purpose of testing the qualities of the cable according to the invention, the following samples were taken t

No. Sample Diameter Construction Pitch ___ thread____

A (conventional) 0.22 7χ4 + 1 1θ / 2θ / 3.5 S / z / S

B 0.22 7 x (2 + 2) + 1 10/20 / 3.5 S / z / S

C 0.22 7 x (2 + 2) + 1 12.5 / 20 / 3.5 S / z / S

D 0.22 7 x (2 + 2) + 1 14/20 / 3.5 S / Z / S

The stiffness was measured on a 70 mm section. We measure by Mq the bending moment Mq necessary to cause the section to flex 15 * along its length. We then measure by M 'the bending moment necessary to return the sample to straight form.

. The measurement is made according to the Taber method and the moments are 4.

With these samples we made the following observations:

Sample Resistance to Cable Diameter (mm) Stiffness (TSU) Tensile (excluding enclosure wire) - (N / mm2) Mo [I 2,633 1,563 139 40 B 2,553 1,660 204.5 71.5 C 2,596 1,681 218 79 , 5 D 2.619 1.677 222 90 * v

It can be concluded that the use of the strand "2 + 2" does not remarkably increase the diameter of the cable, while remarkably increasing the stiffness.

t! !

Claims (5)

5. EETBHDICITIONS t 1. Steel cable for the reinforcement of an elastomeric material, such as rubber, comprising several strands, characterized in that each strand comprises two groups of wires, these groups being stranded around one another so as to forming helices which have approximately the same shape, the wires of the first group having a pitch of a value greater than 300 mm, and Ιθβ wires of the second group having a pitch of twist in the same direction and of the same value as the pitch of said propellers * 2. Cable according to claim 1, characterized in that the number of son of the second group is equal to the number of son of the first group and is between two and four. 3 * Cable according to claim 2, characterized in that the pitch of the first group has an infinite value. 4 · Cable according to claim 3 "characterized in that each group comprises two wires * 5 * Cable according to any one of claims 1 to 4 "characterized in that it comprises a first strand forming ome and six strands running helically around the first with a pitch opposite to the pitch of the strands. j. '/