Coil constructions for improved inductive energy transfer

Abstract

An inductor coil for an inductive energy transfer system includes multiple layers of a single wire having windings that are interlaced within at least two of the multiple layers such that both an input end and an output end of the wire enter and exit the coil on a same side of the coil. The input end and the output end of the wire may abut one another at the location where the input and output wires enter and exit the inductor coil. The wire can include one or more bundles of strands and the strands in each bundle are twisted around an axis extending along a length of the wire, and when there are at least two bundles, the bundles may be twisted around the axis. At least one edge of the inductor coil can be formed into a variety of shapes, such as in a curved shape.

We claim: 
     
         1 . An inductor coil for use in an inductive energy transfer system, wherein the inductor coil is included in a portable electronic device, the inductor coil comprising three or more layers of a single wire having windings that are interlaced within at least two of the three or more layers such that both an input end and an output end of the wire enter and exit the coil on a same side of the coil. 
     
     
         2 . The inductor coil as in  claim 1 , wherein the input end and the output end of the wire abut one another. 
     
     
         3 . The inductor coil as in  claim 1 , wherein the wire comprises one or more bundles of strands and the strands in each bundle are twisted around an axis extending along a length of the wire. 
     
     
         4 . The inductor coil as in  claim 3 , wherein the wire comprises four bundles twisted around the axis. 
     
     
         5 . The inductor coil as in  claim 1 , wherein a shape of at least one edge of the inductor coil complements a surface of the electronic device. 
     
     
         6 . The inductor coil as in  claim 5 , wherein the inductor coil is arranged in a trapezoid shape and a shape of one edge of the inductor coil complements a curved surface. 
     
     
         7 . The inductor coil as in  claim 1 , wherein the coil comprises three layers and twelve windings. 
     
     
         8 . The inductor coil as in  claim 1 , wherein each layer in the inductor coil has an equal number of columns as the other layers. 
     
     
         9 . An inductor coil for use in an inductive energy transfer system, wherein the inductor coil is included in a portable electronic device, the inductor coil comprising three or more layers of a single wire having windings arranged in an interlace pattern such that both an input end and an output end of the wire enter and exit the coil at substantially one location and abut one another, wherein a shape of at least one edge of the inductor coil complements a surface of the electronic device. 
     
     
         10 . The inductor coil as in  claim 9 , wherein the wire comprises one or more bundles of strands and the strands in each bundle are twisted around an axis extending along a length of the wire. 
     
     
         11 . The inductor coil as in  claim 10 , wherein the wire comprises four bundles twisted around the axis. 
     
     
         12 . The inductor coil as in  claim 9 , wherein the inductor coil is arranged in a trapezoid shape and a shape of one edge of the inductor coil complements a curved surface. 
     
     
         13 . The inductor coil as in  claim 9 , wherein the coil comprises three layers and twelve windings. 
     
     
         14 . The inductor coil as in  claim 13 , wherein the interlace pattern of windings is: 
       
         
           
                 
                 
                 
                 
                 
               
                     
                     
                 
                     
                   11 
                   10  
                   7 
                   6 
                 
                     
                   12 
                   9 
                   8 
                   5 
                 
                     
                   1 
                   2 
                   3 
                   4 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
               
            
           
         
         and windings  1  and  12  comprise the input and output ends. 
       
     
     
         15 . The inductor coil as in  claim 9 , wherein each layer in the inductor coil has an equal number of columns as the other layers. 
     
     
         16 . A method for providing an inductor coil for a portable electronic device, the method comprising:
 providing three or more layers of a single wire in the inductor coil, the inductor coil having windings that are interlaced within at least two of the three or more layers such that both an input end and an output end of the wire enter and exit the coil on a same side of the coil, wherein a shape of at least one edge of the inductor coil complements a surface of the electronic device.   
     
     
         17 . The method as in  claim 16 , wherein the input end and the output end of the wire abut one another. 
     
     
         18 . A method for forming an inductor coil having multiple layers of a single wire, the method comprising:
 heating the inductor coil to produce a malleable bonding agent, wherein the inductor coil is configured in a first inductor coil structure; and   shaping at least one edge of the inductor coil on a mold to produce a second inductor coil structure that is different from the first inductor coil structure.   
     
     
         19 . The method as in  claim 18 , further comprising forming the inductor coil on a mandrel to produce the first inductor coil structure. 
     
     
         20 . The method as in  claim 18 , wherein the mold comprises a curved surface.