The principle

Umlauf Bridles consist of two crawler-type units covered with an elastic coating. One unit is arranged above and one below the strip. They guide and transport the strip linearly, i.e. without any deflection, at different positions within strip processing lines.

By applying the force over an area – and not concentrated in one point – any local concentrations of forces or relative movements between the crawler unit and the strip surface are avoided. Therefore, the risk of surface damage is ruled out, making this technology highly suitable for delicate strip surfaces.

Virtually any desired strip back-tension

The crawler units apply back-tensions of up to 2,000 kN or more to the strip - uniformly over its entire width.

Umlauf Bridles can be pivoted through their vertical axis in a precisely controlled way. This feature allows them, for example, to properly guide the strip during side trimming or place the strip in an exact perpendicular position below the cut-to-length shear.

One Umlauf Bridle – for strip pulling or braking

Arranged as single units, Umlauf Bridles can be used to actively pull the strip through a processing unit or to reduce the strip speed in a controlled manner. Umlauf Bridles apply very large forces to the strip, for example, in order to pull it through side trimmers or levelers – a feature that is particularly important when processing thick strips.

Ahead of a coiler, a single Umlauf Bridle can be used to brake the strip in a controlled manner so as to ensure exact coiling.

It can also reduce strip back-tension to zero in order to eliminate any effects that may interfere with optical strip flatness measurements.

Two Umlauf Bridles – precise strip tension control for many processes

Two Umlauf Bridle units, one arranged ahead and one after, let’s say, a leveler or a rolling stand, can generate virtually any tension in the strip. Thus it is possible to precisely set any desired ratio of compressive and tensile forces.

A possible application is continuous stretch-leveling, in which the Umlauf Bridles make it possible to level the strip in a continuous rather than a discontinuous operation -  without the use of conventional bridle rolls or, in certain applications, even without leveling rollers..