Electromagnetic brake in a slitter

摘要

An idler roll brake in a paper handing machine employs an electromagnet positioned close to the periphery all of the idler roll which interacts with and induces eddy currents a conducive roll and a gear shaped steel ring fitted within the conducive roll. The electromagnet is arranged transverse to the axis of the roll and has three poles. The gear-shaped steel ring forms opposite poles which are attracted to the poles of the electromagnet which bring the roll to complete stop. An alternative embodiment roll brake employs a brake shoe mounted to the roll end bearing. The brake shoe slides forward to bring the brake shoe against the interior surface of the roll. An electromagnet positioned beneath the roll attracts a ferromagnetic armature or permanent magnet mounted to the brake to pull the brake shoe into engagement with the inner surface of the roll.