JPS59204992A - Steel cord for reinforcing elastomer material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel cord for reinforcing a diostomeric material such as rubber, having at least two strands. To date, strands have been used in the form of groups of m wires, which are twisted together to form a helix with the same diameter and pitch. Examples of these are 3X0.15 (0,15+m diameter) 3 wire) strands, 4X0.175 strands, and 4X0.22 strands, which are 15 to 2
It has a pitch of 5 mm. These strands are then twisted to form a single cord. For example, 6 strands wrapped around one core strand (7 strands of 3 or 4 wires each, i.e. 7x3 or 4 cord) or 3 strands twisted together. There is a code (3x3 or 4 code) with Depending on the cord application, cords of similar construction may be used with the same number of wires and the same tension, but with different physical properties, eg, higher stiffness.

The present invention provides a steel cord with high stiffness without increasing the diameter by using specially shaped strands that are sufficiently rounded and have a compact structure.

The steel cord of the present invention comprises at least two strands, each strand consisting of two strands of wire, the groups being twisted around each other to form a generally uniform helix; The first wire has a pitch of more than 300, and the second
The Gruzo wires have the same orientation and pitch as the pitch of the helix.

Preferably the number of wires in the second group is equal to the number of wires in the first group and ranges from 2 to 4, preferably 2. The thread severity of the wires in the first groove preferably has an infinite value (1nfinitevalve) so as to form a bundle of parallel wires in the strand.

Each wire typically has a diameter of 0.10-0.40 mm.

Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, the strand consists of a first group of two wires 1 and a second group of two wires 2. The above two groups are screwed together with a pitch p
form a spiral body with FIG. 1 shows a side view and four cross sections.

The first group of wires 1 are not twisted together and the second
It is also possible to use a group of wires twisted with a very high pitch, e.g. 300 or more, for the group of parallel wires 1, which have the same orientation and the same thread pitch p. be. This type of strand is designated by the symbol "2+2".

7 strands (2+2) of the type shown in Figure 1
is used in a 7 x (2+2) code as shown in FIG. 2, in which the pitch q of the strands is opposite to the pitch p of the groups of wires in the strand. The "'SA" structure is obtained from the strands shown in FIG. 1 (with a pitch in the "z" direction). The pitch q of the strands along the cord is determined relative to the direction of the AA force being fixed along the cable. pitch p and q
is usually a value of 5 to 30IIIi, preferably q is about 10
Kaku, and p is about 20m+. Such a code P is called a 7x(2+2) code r having a pitch of "10/20". For example, 3X (2+2
) Codes etc. may be made.

Conventional 7x4 or 3x4 cords are generally further coated with wire that spirals the cable in short pitches of about half or two of the strand pitch and in a direction opposite to the strand pitch. Run. This wire coating method is also implemented in the present invention (7) code, which is a code 7X(2+2) having a pitch "'q/p/r" (where r is the pitch of the coated wire)
+1, or code 3X(2+2)+1.

Characteristic testing of the cord of the invention was performed as follows.

Stiffness was measured on 70 length sections.

Required bending moment) Mo was measured by bending the length section inward by 15°. The required bending moment was then measured by straightening the specimen. The measurements are carried out based on the Taber method and the bending moment is Taber
Measured in er units (T, S, U). If a 70-fold sample piece is used, the Taber unit of 1 is 98. IX
Corresponds to 10-”Nym.

As is clear from the table above, the use of (2+2) strands increases the stiffness of the cord without increasing its diameter.

[Brief explanation of the drawing]

FIG. 1 is a side view of the strands used to form the cord of the present invention, and FIG. 2 is a drawing showing the state in which the strands are assembled to form the cord. 1... Wire of the first groover, 2... Wire of the second groover. Applicant's agent Patent attorney Takehiko Suzue, Director of the Japan Patent Office'g
Wakasugi Oro Daidono 1. Display of the case Patent application No. 197485 2, Title of the invention Steel cord for reinforcing elastomer materials 3, Person making the amendment Relationship to the case Patent application Artificial Nuvi Bekaert Dennisuei 4, Agent 11B Kazu 59 May 29th

Claims (5)

[Claims] (1) comprising at least two strands, each strand consisting of two groups of wire, each group twisted into its own turn to form a substantially conical helix; 1 group of wires is 300m5+
Reinforcement of a rubber-like nidistomer material, characterized in that the wires of the second group have the same pitch as the pitch of the helix and have a pitch of the same value. steel cord. (2) The steel cord of claim 1, wherein the number of wires in the second group is equal to the number of wires in the first group and is in the range from 2 to 4. (3) The steel cord according to claim 2, wherein the pitch of the first group is an indefinite value. (4) A steel cord according to claim 3, wherein each group has two wires. (5) The steel cord is composed of one core strand and six strands running spirally around the core strand, and the steel cord has a pitch opposite to that of the strands. The steel cord according to any one of Items 1 to 4.