Non-Contact Magnetic Steering

Abstract

A non-contact steering device includes one or more magnetic rotors positioned near a metal strip. Each rotor includes one or more permanent magnets and rotates to impart a changing magnetic field on the metal strip passing nearby. The magnetic rotors can rotate around an axis of rotation that is parallel to the longitudinal direction of travel of the metal strip. The magnetic rotors can be positioned to impart forces on the strip in any combination of laterally, vertically, or longitudinally. A control mechanism can control the rotor speed, rotor direction, vertical position of the rotors, vertical spacing between rotors, and/or lateral position of the rotors. In some cases, the control mechanism can be coupled to sensors, such as a light curtain and a laser distance sensor, in order to provide closed loop feedback control of a metal strip passing through the non-contact magnetic rotor steering device.

What is claimed is: 
     
         1 . A method of modifying processing equipment for magnetic rotor steering, the method comprising:
 removing a section of outer wall from the processing equipment;   replacing the section of outer wall with a recessed section having a horizontal wall and at least one vertical wall; and   positioning a magnetic rotor of a magnetic rotor steering device within the recessed section such that the magnetic rotor is opposite the horizontal wall from an interior of the processing equipment.   
     
     
         2 . The method of  claim 1 , further comprising:
 rotating the magnetic rotor to induce a changing magnetic field within the interior of the processing equipment, wherein the changing magnetic field is sufficient to generate a force in a metal strip moving through the interior of the processing equipment.   
     
     
         3 . The method of  claim 1 , wherein the horizontal wall has a smaller thickness than a thickness of a vertical wall. 
     
     
         4 . The method of  claim 1 , further comprising identifying the section of the outer wall, wherein identifying the section includes determining a distance of outer wall longitudinally offset from one or more adjacent nozzles. 
     
     
         5 . An applied-current magnetic steering apparatus, comprising:
 a current source for applying a direct current to a metal strip;   a pair of electrodes coupled to the current source and biased towards a surface of the metal strip to apply the direct current through the metal strip; and   a permanent magnet positioned proximate the metal strip to induce a magnetic field through the metal strip in a direction perpendicular the direction of the direct current passing through the metal strip.   
     
     
         6 . The apparatus of  claim 5 , further comprising:
 a second current source for applying a second direct current to the metal strip;   a second pair of electrodes coupled to the second current source and biased towards a second edge of the metal strip to apply the second direct current through the metal strip, wherein the pair of electrodes is biased towards a first edge of the metal strip opposite the second edge of the metal strip; and   a second permanent magnet positioned proximate the metal strip to induce a second magnetic field through the metal strip in a direction perpendicular a direction of the second direct current passing through the metal strip.   
     
     
         7 . The apparatus of  claim 5 , further comprising:
 a second current source for applying a second direct current to the metal strip; and   a second pair of electrodes coupled to the second current source and biased towards a second edge of the metal strip to apply the second direct current through the metal strip, wherein the pair of electrodes is biased towards a first edge of the metal strip opposite the second edge of the metal strip, and wherein the permanent magnet extends laterally across a width of the metal strip such that the magnetic field is induced in a direction perpendicular the direction of the second direct current passing through the metal strip.   
     
     
         8 . A method of steering metal, comprising:
 applying direct current along edges of a moving metal strip in a direction parallel a direction of travel of the moving metal strip; and   applying at least one magnetic field along the edges of the moving metal strip such that the at least one applied magnetic field perpendicularly intersects the applied direct current.   
     
     
         9 . The method of  claim 8 , wherein applying at least one magnetic field comprises applying a first magnetic field along a first edge of the moving metal strip and applying a second magnetic field along a second edge of the moving metal strip. 
     
     
         10 . The method of  claim 8 , wherein applying the direct current along the edges of the moving metal strip comprises:
 completing a first circuit between a first set of electrodes, a first current source, and a first edge of the moving metal strip; and   completing a second circuit between a second set of electrodes, a second current source, and a second edge of the moving metal strip.