Nv Bekaert Sa

Ghislain Doornaert

Wei Shen

Rik Mullebrouck

Erwin Vereecken

Bart Vanlandeghem

Tom Gommers

Lei Gu

Tiehong Yang

Zhigao Yu

Jan Gallet

Liu Zhou

A steel cord for reinforcing a breaker or belt ply in a rubber tire having a core group and a sheath group. The core group consists of two to four core steel filaments with a first diameter dc and the sheath group consists of one to six sheath steel filaments with a second diameter ds. The ratio dc/ds of the first diameter dc to the second diameter ds ranges from 1.10 to 1.70. The two core steel filaments are untwisted or have a twisting step greater than 300 mm. The sheath group is twisted around the core group with a cord twisting step in a cord twisting direction. The ratio of the difference in residual torsions of the core group and the sheath group to the difference in saturation level between the core group and the sheath group ranges from 0.10 to 0.65, preferably from 0.10 to 0.60.

Steel cord with reduced residual torsions

An apparatus () and a method for measuring residual torsions of an elongated structure () such as a steel cord use a pivot head (). The pivot head () comprises a wheel () adapted to guide an elongated structure (). The wheel () is mounted in the pivot head () to transmit torques exercised by the elongated structure () on the wheel () to the pivot head (). The pivot head () is mounted along a pivotal axis (). This pivotal axis () lies in a plane of the wheel () and comprises the center of the wheel (). Sensors () measure the torque on the pivot head (). The pivotal movement of the pivot head () around the pivotal axis () is limited to an angle range of &#xb1;5&#xb0;, preferably &#xb1;3&#xb0; in order to reach an improved accuracy of the torque measurement.

Apparatus and method for measuring residual torsions on an elongated element

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OSA Peninsula, Costa Rica

Ghislain Doornaert