Patent ID: 6128934
Filing Date: 2000-10-10
Classification: B21B

Abstract:
A system that monitors and controls the roll speed of each roll stand in a plurality of roll stands in a tube reducing mill, comprising:a plurality of roll stands;at least one AC electric motor for driving said roll stands;a plurality of drives, one of each said plurality of drives coupling said at least one AC motor to one of each said roll stands;a master controller, said master controller coupled to each individual roll stand of said plurality of roll stands, that monitors and controls the roll speed of said individual roll stands of said purality of roll stands;a computer that calculates a desired roll speed for each said roll stand of said plurality of roll stands and transmits to said master controller a signal corresponding to said desired roll speed;a plurality of speed control motors, each speed control motor of said plurality of speed control motors coupled to a single drive and coupled to said master controller;a plurality of speed pickups, one of each speed pickup of said plurality of said speed pickups coupled to a single roll stand, wherein said speed pickups measure the roll speed of each roll stand and transmit a signal corresponding to said measured roll speed to said master controller; anda plurality of stand controllers, each stand controller of said plurality of stand controllers coupled to said speed control motor and said master controller, each said stand controller receives a reference signal from said master controller, said reference signal corresponds to a desired motor speed.