Heating Unit for Rollers Employing Magnetic Inductance

Abstract

Heating units for heating hair rollers are provided, as well as rollers for use therewith. An exemplary heating unit includes a housing having a lid and a lower portion, with a first magnetic core disposed within the lower portion and a second magnetic core disposed within the lid. The first magnetic core includes two parallel legs, and a plurality of conductive windings wound around one of the two legs. When the housing is closed the first and second magnetic cores together form a square closed core. When energized, the windings generate a magnetic field within the square closed core that induces an electric current in a roller disposed around the second of the two legs. An exemplary roller for use with the heating unit comprises a conductive cylinder, such as aluminum, having a diameter of at least two inches and including bristles protruding perpendicular to the exterior surface.

What is claimed is: 
     
         1 . A heating unit for rollers, comprising:
 a housing comprising a lid and a lower portion;   a first magnetic core disposed within the lower portion and a second magnetic core disposed within the lid, wherein when the lid is engaged with the lower portion the first and second magnetic cores together form a square closed core, and wherein the first magnetic core includes two parallel legs;   a plurality of conductive windings wound around one of the two legs, wherein a second of the two legs is configure to receive a roller.   
     
     
         2 . The heating unit of  claim 1  wherein the lid and the lower portion are connected by a hinge. 
     
     
         3 . The heating unit of  claim 1  wherein the first magnetic core comprises a U-shape or a C-shape. 
     
     
         4 . The heating unit of  claim 1  wherein the first magnetic core comprises an E-shape. 
     
     
         5 . The heating unit of  claim 1  wherein the first and second magnetic cores comprise grain-oriented laminated silicon steel. 
     
     
         6 . The heating unit of  claim 1  wherein the plurality of conductive windings includes 350 turns of 12GA enameled copper wire. 
     
     
         7 . The heating unit of  claim 1  further comprising a thermal sensor disposed proximate to the second leg and configured to produce an analog signal in response to a temperature of the roller. 
     
     
         8 . The heating unit of  claim 7  further comprising a microcontroller configured to control the flow of alternating current to the windings and to turn off the alternating current in response to the thermal sensor. 
     
     
         9 . The heating unit of  claim 1  further comprising the roller disposed on the second of the two legs. 
     
     
         10 . A roller for use in conjunction with a heating unit, the roller comprising:
 a cylinder of an electrically conductive material having an inside diameter of at least two inches and including a plurality of bristles protruding perpendicular to the exterior surface.   
     
     
         11 . The roller of  claim 10  wherein the electrically conductive material comprises aluminum.