Patent Document

BACKGROUND OF THE INVENTION 
     The present invention is directed to electrical winding structures that may be employed in electromagnetic devices such as, by way of example and not by way of limitation, transformers, relays, solenoids and similar devices. 
     Prior art electromagnetic devices employ discrete structures for each winding stratum about a central member. The central member may be embodied in a ferrous core, another type of magnetic core, an air core or a mandrel used solely to effect a winding operation. For example, if one wished to provide a device with a primary winding and a secondary winding, each of the primary and secondary windings would be a discrete winding structure unconnected with the other. Such an arrangement is not a problem in a simple winding structure. However, it may be advantageous to employ a more complex winding structure that requires interleaving or otherwise alternating segments of a primary winding and a secondary winding. The effect may result in an A-B-A-B arrangement of windings where A-layers may be a primary winding and B-layers may be a secondary winding. Providing electrical access, such as by connecting termination structures or leads to alternating layers situated in the interior of the winding structure is problematic. The problems associated with such a structure generally result in more difficult manufacture, manual assembly and less stringent operating limits. Such characteristics generally result in a more expensive looser-tolerance product. Individual electrical leads provided for each layer of a respective winding (primary winding or secondary winding) at each interleaved or alternated stratum present can present a virtual “forest” of multiple leads for effecting proper connection of the unit within a host device. Such multiple connection leads present their own problems and attendant costs in effecting assembly of a device employing such a multi-lead electromagnetic unit. 
     There is a need for a method and structure for assembling electrical windings about a central member for an electromagnetic device that does not require multiple leads for terminating with discrete layers of respective windings located within the interior of the device. 
     SUMMARY OF THE INVENTION 
     A method for assembling electrical windings about an axis, the windings being strips and wound in alternating strata with their widths parallel with the axis, includes the steps: (a) Winding a first-wound winding in a winding path about the axis establishing a first stratum. (b) Arranging the first-wound winding to clear the winding path. (c) Winding one or more next windings to establish next-wound windings in the winding path until at least one next stratum is established. (d) Interleaving earlier-wound windings to establish the plurality of strata; the interleaving including the steps of: (1) rearranging a next-to-be-wound winding to realign with the winding path; (2) winding the next-to-be-wound winding in the winding path until a next stratum is established; (3) arranging the next-to-be-wound winding to clear the winding path; and (4) repeating steps (d)(1) through (d)(3) until the assembling is complete. 
     An electrical winding structure configured for use in assembling a plurality of electrical winding structures in an installed orientation wound about a central member includes: a unitary segmented strip. First portions of the unitary strip are oriented about a first axis. Second portions of the unitary strip are oriented about a second axis substantially perpendicular with the first axis. Each of the first portions and the second portions have a thickness, have a width greater than the thickness and have a length at least as great as the width. The first and second portions are oriented to effect arranging the electrical winding structure at predetermined loci during winding to clear the winding path to establish a predetermined plurality of strata in the installed orientation. 
     It is, therefore, an object of the present invention to provide a method and structure for assembling electrical windings about a central member for an electromagnetic device that does not require multiple leads for terminating with discrete layers of respective windings located within the interior of the device. 
     Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a first step in assembling an electrical winding structure using a prior art technique. 
         FIG. 2  illustrates a second step in assembling the electrical winding structure illustrated in  FIG. 1  using a prior art technique. 
         FIG. 3  is a plan view of a structure used in assembling an electrical winding structure according to a first embodiment of the present invention. 
         FIG. 3A  is a plan view of detail of an alternate structure for terminating a winding configured using the structure described in connection with  FIG. 3 . 
         FIG. 4  illustrates a first step in assembling an electrical winding structure using the structure illustrated in  FIG. 3 . 
         FIG. 5  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 4 . 
         FIG. 6  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 5 . 
         FIG. 7  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 6 . 
         FIG. 8  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 7 . 
         FIG. 9  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 8 . 
         FIG. 10  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 9 . 
         FIG. 11  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 10 . 
         FIG. 12  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 11 . 
         FIG. 13  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 12 . 
         FIG. 14  illustrates a first step in assembling an electrical winding structure according to a second embodiment of the present invention. 
         FIG. 15  illustrates a second step in assembling the electrical winding structure illustrated in  FIG. 14 . 
         FIG. 16  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 15 . 
         FIG. 17  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 16 . 
         FIG. 18  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 17 . 
         FIG. 19  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a first step in assembling an electrical winding structure using a prior art technique. In  FIG. 1 , an electrical winding structure  10  is oriented substantially symmetrically about an axis  12 . For ease of reference a plane is illustrated substantially perpendicular with axis  12  having directions “NORTH”, “EAST”, “SOUTH” and “WEST”. Electrical winding structure  10  includes a central structure or member  14  substantially symmetrically oriented about axis  12 . As may be recognized by those skilled in the art of electrical winding structures and as representatively illustrated in  FIG. 1 , central member  14  may be a non-ferrous form for establishing an air core for electrical winding structure  10 . Alternatively, central member  14  may be a solid ferrous core member (not shown in  FIG. 1 ) or a thin-walled ferrous member configured substantially as illustrated in  FIG. 1 . Another alternative embodiment of central member  14  may be a mandrel upon which electrical winding structure  10  is constructed, which mandrel is removed after completion of fabrication of electrical winding structure  10 . 
     In  FIG. 1 , a first step has been effected in constructing electrical winding structure  10  by installing a first winding  16  on central member  14 . First winding  16  may be configured using a strip of electrically conductive material, such as copper, gold, silver or another electrically conductive material. Preferably, the strip is electrically insulated over most or all of its surface area in order to avoid shorting between layers if more than one turn of first winding  16  is installed about central member  14 . In order to simplify this description, only one turn of first winding  16  is installed about central member  14  in  FIG. 1 . First winding  16  is arranged to substantially surround central member  14  so that the NORTH, EAST and SOUTH sides of central member  14  are covered by first winding  16  and substantially all of the WEST side of central member  14  is covered by first winding  16 . A gap  18  is provided between ends of first winding  16  to avoid electrical shorting of winding  16 . Electrical leads  20 ,  22  are provided for electrical connection with first winding  16  from without electrical winding structure  10  after assembly is completed. 
       FIG. 2  illustrates a second step in assembling the electrical winding structure illustrated in  FIG. 1  using a prior art technique. In  FIG. 2 , a second step has been effected in constructing electrical winding structure  10  by installing a second winding  24  on top of first winding  16  about central member  14 . Second winding  24  may be configured similar to first winding  16  employing a strip of electrically conductive material preferably electrically insulated over most or all of its surface area in order to avoid shorting between layers if more than one turn of second winding  24  is installed. In order to simplify this description, only one turn of second winding  24  is installed on top of first winding  16  about central member  14  in  FIG. 2 . Second winding  24  is arranged to substantially surround first winding  16  and central member  14  so that the NORTH, EAST, SOUTH and WEST sides of first winding  16  and central member  14  are covered by second winding  24 . Second winding  24  is illustrated with a remainder portion  26  poised in  FIG. 2  for applying or installing a second turn. Electrical lead  28  is provided for electrical connection with second winding  24  from without electrical winding structure  10  after assembly is completed. As will be understood by those skilled in the art of electrical winding assemblies, another electrical lead (not shown in  FIG. 2 ) would be provided at the end of second winding  24  when second winding  24  is terminated. Other windings (not shown in  FIG. 2 ) may be applied to surround first winding  16 , second winding  24  and central member  14  as desired. For purposes of phase balance, AC (Alternating Current) loss reduction and other design parameter optimization, several alternating layers may be employed in electrical winding structure  10  to establish a primary and a secondary winding arrangement about central member  14 . In such a structure, each respective discrete winding layer must be provided it own discrete electrical leads for effecting electrical connection with the respective winding layer. Such a structure may present a large number of leads for termination with a printed wiring board or other substrate in a host device (not shown in  FIGS. 1-2 ). The provision of leads and their termination for connection within a host device can be problematic and reduce efficiency in manufacture and installation of electrical winding structure  10 . A result may be an increase in cost of any device employing electrical winding structure  10 . 
       FIG. 3  is a plan view of a structure used in assembling an electrical winding structure according to a first embodiment of the present invention. In  FIG. 3 , an electrical winding component or structure  30  is embodied in a unitary segmented strip  32  of electrically conductive material such as copper, gold, silver or another electrically conductive material. Portions  60 ,  70 ,  100  of strip  32  include segments that are delimited by fold structures. Portion  60  of strip  32  has a first edge  61  and a second edge  63  and includes a first segment  34  extending generally symmetrically with respect to an axis  33  a length L 1  from an end  35  to a fold structure  50 . Fold structure  50  has a length Δ 1 . A segment  36  extends generally symmetrically with respect to axis  33  a length L 2  from fold structure  50  to a fold structure  52 . Fold structure  52  has a length Δ 2 . A segment  38  extends generally symmetrically with respect to axis  33  a length L 3  from fold structure  52  to a fold structure  54 . Fold structure  54  has a length Δ 3 . A segment  40  extends generally symmetrically with respect to axis  33  a length L 4  from fold structure  54  to a fold structure  56 . Fold structure  56  has a length Δ 4 . A segment  42  extends generally symmetrically with respect to axis  33  a length L 5  from fold structure  56  to an end  37 . Lengths L 1 , L 2 , L 3 , L 4 , L 5 , Δ 1 , Δ 2 , Δ 3 , Δ 4  are established appropriately for providing a smooth transition as strip  32  is wound around a central member (not shown in  FIG. 3 ; see  FIGS. 4-13 ). 
     Portion  70  of strip  32  has a first edge  71  and a second edge  73  and includes a first segment  82  extending generally symmetrically with respect to an axis  43  a length L 10  from an end  81  to a fold structure  92 . Fold structure  92  has a length Δ 10 . A segment  84  extends generally symmetrically with respect to axis  43  a length L 11  from fold structure  92  to a fold structure  94 . Fold structure  94  has a length Δ 11 . A segment  86  extends generally symmetrically with respect to axis  43  a length L 12  from fold structure  94  to a fold structure  96 . Fold structure  96  has a length Δ 12 . A segment  88  extends generally symmetrically with respect to axis  43  a length L 13  from fold structure  96  to a fold structure  98 . Fold structure  98  has a length Δ 13 . A segment  89  extends generally symmetrically with respect to axis  43  a length L 14  from fold structure  98  to an end  83 . Lengths L 10 , L 11 , L 12 , L 13 , L 14 , Δ 10 , Δ 11 , Δ 12 , Δ 13  are established appropriately for providing a smooth transition as strip  32  is wound around a central member (not shown in  FIG. 3 ; see  FIGS. 4-13 ). 
     Portion  100  of strip  32  has a first edge  101  and a second edge  103  and includes a first segment  110  extending generally symmetrically with respect to an axis  53  a length L 20  from an end  109  to a fold structure  120 . Fold structure  120  has a length Δ 20 . A segment  112  extends generally symmetrically with respect to axis  53  a length L 22  from fold structure  120  to a fold structure  122 . Fold structure  122  has a length Δ 22 . A segment  114  extends generally symmetrically with respect to axis  53  a length L 24  from fold structure  122  to a fold structure  124 . Fold structure  124  has a length Δ 24 . A segment  126  extends generally symmetrically with respect to axis  53  a length L 26  from fold structure  124  to a fold structure  126 . Fold structure  126  has a length Δ 26 . A segment  118  extends generally symmetrically with respect to axis  53  a length L 28  from fold structure  126  to an end  111 . Lengths L 20 , L 22 , L 24 , L 26 , L 28 , Δ 20 , Δ 22 , Δ 24 , Δ 26  are established appropriately for providing a smooth transition as strip  32  is wound around a central member (not shown in  FIG. 3 ; see  FIGS. 4-13 ). 
     A transition structure  44  joins segments  42 ,  82 . Transition structure  44  includes fold structures  58 ,  59 . Fold structure  58  has a length Δ 5 . Fold structure  59  has a length Δ 5 . Fold structures  58 ,  59  and lengths Δ 5 , Δ 6  are positioned and proportioned within transition structure  44  to accommodate a folding-straddle relationship with another wrap-layer applied in a substantially abutting relation with strip  32  in an installed orientation about a central member (not shown in  FIG. 3 ; see  FIGS. 4-13 ). 
     A transition structure  99  joins segments  89 ,  110 . Transition structure  99  includes fold structures  95 ,  105 . Fold structure  95  has a length Δ 14 . Fold structure  105  has a length Δ 15 . Fold structures  95 ,  105  and lengths Δ 14 , Δ 15  are positioned and proportioned within transition structure  99  to accommodate a folding-straddle relationship with another wrap-layer applied in a substantially abutting relation with strip  32  in an installed orientation about a central member (not shown in  FIG. 3 ; see  FIGS. 4-13 ). 
     Electrical connection leads  130 ,  132  are coupled with strip  32  at segments  34 ,  118 . Multiple leads are indicated in  FIG. 3  in recognition that such multiple leads are sometimes required in order to meet current carrying requirements for an electrical winding device. Connection between leads  130 ,  132  and strip  32  may be established by soldering, conductive adhesive, sonic welding or another connection process or technique that preserves electrical connectivity between strip  32  and leads  103 ,  132 . 
       FIG. 3A  is a plan view of detail of an alternate structure for terminating a winding configured using the structure described in connection with  FIG. 3 . In  FIG. 3A , an integral uninsulated tab is formed in an end segment of strip  32  ( FIG. 3 ). In order to avoid prolixity, only one end segment  34  will be described. One skilled in the art of electrical winding structures will recognize how one may apply the illustrated alternate embodiment in either of end segments  34 ,  118 . In  FIG. 3A , end segment  34  of strip  32  is separated from segment  36  by fold structure  50 . A connection tab  131  is integrally formed in end segment  34 . Connection tab  131  may be dimensioned and configured for connecting insertion with a slot in a printed wiring board or other receiving structure or substrate in a host device (not shown on  FIG. 3A ). A serrated edge or sawtooth edge  133  or another structure (not shown in  FIG. 3A ) may be provided for easing or enhancing connection of strip  32  with a host device using integral connection tab  131 . 
       FIG. 4  illustrates a first step in assembling an electrical winding structure using the structure illustrated in  FIG. 3 . In  FIG. 4 , an electrical winding structure  140  is oriented substantially symmetrically about an axis  142 . For ease of reference a plane is illustrated substantially perpendicular with axis  142  having directions “NORTH”, “EAST”, “SOUTH” and “WEST”. Electrical winding structure  140  includes a central structure or member  144  substantially symmetrically oriented about axis  142 . As may be recognized by those skilled in the art of electrical winding structures and as representatively illustrated in  FIG. 4 , central member  144  may be a non-ferrous form for establishing an air core for electrical winding structure  140 . Alternatively, central member  144  may be a solid ferrous core member (not shown in  FIG. 4 ) or a thin-walled ferrous member configured substantially as illustrated in  FIG. 4 . Another alternative embodiment of central member  144  may be a mandrel upon which electrical winding structure  140  is constructed, which mandrel is removed after completion of fabrication of electrical winding structure  140 . 
     In  FIG. 4 , a winding strip  146  is applied around a central member  144  along a winding path  182  for establishing windings about central member  144 . Strip  146  is substantially similar with strip  32  ( FIG. 3 ). Strip  146  has a segment  150  extending from an end  148  to a fold structure  152 . Segment  150  has a length appropriate to span eastern face  180  of central member  144 . Electrical lead  151  is affixed or connected with strip  146  at segment  150 . Fold structure  152  is configured to have an appropriate length to accommodate curving about central member  144  at a southeast corner  181 . Strip  146  has a segment  154  extending from fold structure  152  to a fold structure  156 . Segment  154  has a length appropriate to span a southern face of central member  144  (obscured in  FIG. 4  by strip  146 ). Fold structure  156  is configured to have an appropriate length to accommodate curving about central member  144  at a southwest corner  183 . Strip  146  has a segment  158  extending from fold structure  156  to a fold structure  160 . Segment  158  has a length appropriate to span a western face of central member  144  (obscured in  FIG. 4  by strip  146 ). Fold structure  160  is configured to have an appropriate length to accommodate curving about central member  144  at a northwest corner  184 . Strip  146  has a segment  162  extending from fold structure  160  to a fold structure obscured by electrical lead  151 . Segment  162  has a length appropriate to span a northern face of central member  144  (not visible in  FIG. 4 ). Strip  146  has a segment  164  extending to span eastern face  180 . Segment  164  extends beyond central member  144  to clear strip  146  from winding path  182  so that another layer may be applied over top of strip  146 . Segment  164  is illustrated in  FIG. 4  as departing upward to clear winding path  182 . Segment  164  could just as well depart downward. 
     Comparing electrical winding structure  140  with strip  146  installed with portion  100  of strip  32  ( FIG. 3 ) one may observe a correspondence between strips  32 ,  146 . Segment  150  substantially corresponds with segment  118  of strip  32 . Similarly, there is substantial correspondence between folding structures  126 ,  152 , segments  116 ,  154 , folding structures  124 ,  156 , segments  114 ,  158 , folding structures  122 ,  160 , segments  112 ,  162 , and segments  110 ,  164 . Correspondence also is substantial between folding structure  120  and the folding structure obscured by electrical lead  151  ( FIG. 4 ). 
       FIG. 5  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 4 . The arrangement of central member  144 , axis  142  and directions NORTH, EAST, SOUTH and WEST (Abbreviated N, E, S and W in  FIGS. 5-13 ) is similar in  FIGS. 4-13 . In order to avoid prolixity description of that arrangement will not be repeated in connection with  FIGS. 5-13 ). In  FIG. 5 , a winding strip  246  is applied around winding strip  146  wound about central member  144  along a winding path  182  for establishing windings about winding strip  146  wound about central member  144 . Strip  246  is substantially similar with portion  100  of strip  32  ( FIG. 3 ) and strip  146 . Strip  246  has a first segment  250  (obscured in  FIG. 5 ; partially visible in  FIGS. 8-13 ) in substantially abutting relation with segment  158  of strip  146  ( FIG. 4 ). Segment  250  has a length appropriate to span segment  158  ( FIG. 4 ). An electrical lead  251  (obscured in  FIG. 5 ; visible in  FIGS. 8-13 ) is affixed or connected with strip  246  at segment  250 . A fold structure  252  (obscured in  FIG. 5 ; visible in  FIGS. 8-13 ) is configured to have an appropriate length to accommodate curving about winding strip  146  wound about central member  144  at northwest corner  184 . Strip  246  has a segment  254  extending from fold structure  252  to a fold structure (obscured in  FIGS. 5-13 ). Segment  254  has a length appropriate to span the northern face of winding strip  146  wound about central member  144 . Strip  246  has a segment  258  extending from the fold structure obscured at northeast corner  185  to a fold structure  260 . Segment  258  has a length appropriate to span the eastern face of winding strip  146  wound about central member  144 . Fold structure  260  is configured to have an appropriate length to accommodate curving about winding strip  146  wound about central member  144  at a southeast corner  181 . Strip  246  has a segment  262  extending from fold structure  260  to a fold structure  264 . Segment  262  has a length appropriate to span the southern face of winding strip  146  wound about central member  144 . Strip  246  has a segment  266  extending to span the western face of winding strip  146  wound about central member  144 . Segment  266  extends beyond strip  146  and central member  144  to clear strip  246  from winding path  182  so that another layer may be applied over top of strip  246 . Segment  266  is illustrated in  FIG. 5  as departing upward to clear winding path  182 . Segment  266  could just as well depart downward. 
     Comparing strip  246  with strip  32  ( FIG. 3 ) one may observe a correspondence between strips  32 ,  246  substantially similar with the correspondence between strip  146  and portion  100  of strip  32 . One may observe that each succeeding winding about previous windings about central member  144  will require greater-length segments and greater-length folding structures to accommodate ever increasing widths presented for covering with each succeeding winding layer. This is manifested in strip  32  ( FIG. 3 ) where portions  100 ,  70 ,  60  have increasingly longer lengths for corresponding segments. That is, segment length L 5 &gt;(is greater than) length L 14 &gt;Length L 28 . Similarly, L 4 &gt;L 13 &gt;L 26 ; L 3 &gt;L 12 &gt;L 24 ; L 2 &gt;L 11 &gt;L 22 ; L 1 &gt;L 10 &gt;L 20 . Folding structure lengths are also varied in size to accommodate greater circumferential dimensions with increasing winding layers. While not as obvious as differences n segment lengths in  FIG. 3 , folding structure lengths vary also so that Δ 4 &gt;Δ 13 &gt;Δ 26 ; Δ 3 &gt;Δ 12 &gt;Δ 24 ; Δ 2 &gt;Δ 11 &gt;Δ 22  Δ 1 &gt;Δ 10 &gt;Δ 20 . 
       FIG. 6  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 5 . In  FIG. 6 , a transition structure  170  of winding strip  146  includes folding structures  171 ,  173  separated by a distance d 1 . Folding structures  171 ,  173  are flexed or folded to return strip  146  to winding path  182  for applying further winding using strip  146 . Distance d 1  is of sufficient length to span one or more layers of strip  246  (one layer is illustrated in  FIG. 6 ) and permit proper positioning of strip  146  with respect to winding path  182  for applying new windings in substantially abutting relationship with strip  246  using a new portion of strip  146  (see, e.g., portions  100 ,  70 ,  60 ; strip  32 ;  FIG. 3 ). Winding of strip  146  about strip  246  is effected in a manner substantially as described in connection with  FIGS. 4-5 . One skilled in the art of electrical winding structures will recognize the similarities among  FIGS. 4-6  and understand their applicability to establishing additional winding by strip  146  about strip  246 . In order to avoid prolixity a detailed description will not be repeated here. 
       FIG. 7  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 6 . In  FIG. 7 , winding strip  146  proceeds along winding path  182  from transition structure  170  substantially around electrical winding structure  140  to return to a position adjacent to transition structure  170 . More than one layer of strip  146  may be applied, but only one layer is illustrated here. Layers  146 ,  246  and central member  144  are preferably oriented in substantially abutting relation when electrical winding structure  140  is in its assembled or installed orientation. Loose windings with gaps between layers are illustrated here to aid in understanding the invention. In its winding about strip  246 , strip  146  proceeds along winding path  182  past southeast corner  181 , southwest corner  183 , northwest corner  185  and northeast corner  187  to return to the position illustrated in  FIG. 7 . One may notice that strip  146  has now ( FIG. 7 ) established two turns about electrical winding structure  140  and electrical lead  151  is electrically coupled with the entire length of strip  146 . Strip  146  is configured with a segment  172  extending beyond central member  144  to clear strip  146  from winding path  182  so that another layer may be applied over top of strip  146 . Segment  172  is illustrated in  FIG. 7  as departing downward to clear winding path  182 . Segment  172  could just as well depart upward. 
       FIG. 8  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 7 . In  FIG. 8 , a transition structure  270  of winding strip  246  includes folding structures  271 ,  273  separated by a distance d 2 . Folding structures  271 ,  273  are flexed or folded to return strip  246  to winding path  182  for applying further winding using strip  246 . Distance d 2  is of sufficient length to span one or more layers of strip  146  (one layer is illustrated in  FIG. 8 ) and permit proper positioning of strip  246  with respect to winding path  182  for applying new windings in substantially abutting relationship with strip  146  using a new portion of strip  246  (see, e.g., portions  100 ,  70 ,  60 ; strip  32 ;  FIG. 3 ). Winding of strip  246  about strip  146  is effected in a manner substantially as described in connection with  FIGS. 4-7 . One skilled in the art of electrical winding structures will recognize the similarities among  FIGS. 4-7  and understand their applicability to establishing additional winding by strip  246  about strip  146 . In order to avoid prolixity a detailed description will not be repeated here. 
       FIG. 9  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 8 . In  FIG. 9 , winding strip  246  proceeds along winding path  182  from transition structure  270  substantially around electrical winding structure  140  to return to a position adjacent to transition structure  270 . More than one layer of strip  246  may be applied, but only one layer is illustrated here. Layers  146 ,  246  and central member  144  are preferably oriented in substantially abutting relation when electrical winding structure  140  is in its assembled or installed orientation. Loose windings with gaps between layers are illustrated here to aid in understanding the invention. In its winding about strip  146 , strip  246  proceeds along winding path  182  past northwest corner  185 , northeast corner  187 , southeast corner  181  and southwest corner  183  to return to the position illustrated in  FIG. 9 . One may notice that strip  246  has now ( FIG. 9 ) established two turns about electrical winding structure  140  and electrical lead  251  is electrically coupled with the entire length of strip  246 . Strip  246  is configured with a segment  272  extending beyond central member  144  to clear strip  246  from winding path  182  so that another layer may be applied over top of strip  246 . Segment  272  is illustrated in  FIG. 9  as departing downward to clear winding path  182 . Segment  272  could just as well depart upward. 
       FIG. 10  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 9 . In  FIG. 10 , a transition structure (not visible in  FIG. 10 ) of winding strip  246  is configured and flexed in a manner similar to configuration and flexing of transition structure  170  ( FIG. 6 ) to return strip  146  to span one or more layers of strip  246  (one layer is illustrated in  FIG. 10 ) and permit proper positioning of strip  146  with respect to winding path  182  for applying new windings in substantially abutting relationship with strip  246  using a new portion of strip  146  (see, e.g., portions  100 ,  70 ,  60 ; strip  32 ;  FIG. 3 ). Winding of strip  146  about strip  246  is effected in a manner substantially as described in connection with  FIGS. 4-9 . One skilled in the art of electrical winding structures will recognize the similarities among  FIGS. 4-9  and understand their applicability to establishing additional winding by strip  146  about strip  246 . In order to avoid prolixity a detailed description will not be repeated here. 
       FIG. 11  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 10 . In  FIG. 11 , winding strip  146  proceeds along winding path  182  substantially around electrical winding structure  140  to return to a position between corners  181 ,  187 . More than one layer of strip  146  may be applied, but only one layer is illustrated here. Layers  146 ,  246  and central member  144  are preferably oriented in substantially abutting relation when electrical winding structure  140  is in its assembled or installed orientation. Loose windings with gaps between layers are illustrated here to aid in understanding the invention. In its winding about strip  246 , strip  146  proceeds along winding path  182  past southeast corner  181 , southwest corner  183 , northwest corner  185  and northeast corner  187  to return to the position illustrated in  FIG. 11 . Strip  146  has now ( FIG. 11 ) established three turns about electrical winding structure  140 . An electrical lead  191  is affixed with strip  146  to establish electrical contact with strip  146 . One may observe that strip  146  is electrically continuous along its entire length among various winding layers. Electrical leads  151 ,  191  electrically terminate each end of strip  146 . 
       FIG. 12  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 11 . In  FIG. 12 , a transition structure  275  of winding strip  246  includes folding structures  277 ,  279  separated by a distance d 3 . Folding structures  277 ,  279  are flexed or folded to return strip  246  to winding path  182  for applying further winding using strip  246 . Distance d 3  is of sufficient length to span one or more layers of strip  146  (one layer is illustrated in  FIG. 12 ) and permit proper positioning of strip  246  with respect to winding path  182  for applying new windings in substantially abutting relationship with strip  146  using a new portion of strip  246  (see, e.g., portions  100 ,  70 ,  60 ; strip  32 ;  FIG. 3 ). Winding of strip  246  about strip  146  is effected in a manner substantially as described in connection with  FIGS. 4-11 . One skilled in the art of electrical winding structures will recognize the similarities among  FIGS. 4-11  and understand their applicability to establishing additional winding by strip  246  about strip  146 . In order to avoid prolixity a detailed description will not be repeated here. 
       FIG. 13  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 12 . In  FIG. 13 , winding strip  246  proceeds along winding path  182  substantially around electrical winding structure  140  to return to a position between corners  183 ,  185 . More than one layer of strip  246  may be applied, but only one layer is illustrated here. Layers  146 ,  246  and central member  144  are preferably oriented in substantially abutting relation when electrical winding structure  140  is in its assembled or installed orientation. Loose windings with gaps between layers are illustrated here to aid in understanding the invention. In its winding about strip  146 , strip  246  proceeds along winding path  182  past northwest corner  185 , northeast corner  187 , southeast corner  181  and southwest corner  183  to return to the position illustrated in  FIG. 13 . Strip  246  has now ( FIG. 13 ) established three turns about electrical winding structure  140 . An electrical lead  291  is affixed with strip  246  to establish electrical contact with strip  246 . One may observe that strip  246  is electrically continuous along its entire length among various winding layers. Electrical leads  251 ,  291  electrically terminate each end of strip  246 . 
       FIG. 14  illustrates a first step in assembling an electrical winding structure according to a second embodiment of the present invention. In  FIG. 14 , a winding strip  300  is wound oriented substantially symmetrically about an axis  342 . For ease of reference a plane is illustrated substantially perpendicular with axis  342  having directions “NORTH”, “EAST”, “SOUTH” and “WEST”. Winding strip  300  is wound about a central area  344 . Central area  344  may contain a central structure or member (not shown in  FIG. 14 ) substantially symmetrically oriented about axis  342  and configured, by way of example and not by way of limitation, as described in connection with  FIG. 4  above. As may be recognized by those skilled in the art of electrical winding structures a central member may be a non-ferrous form for establishing an air core, may be a solid ferrous core member, may be a thin-walled ferrous member or may be a mandrel upon which winding strip  300  is wound, which mandrel may be removed after completion of winding. 
     Winding strip  300  is configured as a substantially linear strip having a thickness t, a width or breadth B greater than thickness t and a length greater than width B. Length is not indicated in  FIG. 14  because length of strip  300  may be as great or as long as is desired to establish a desired number of turns about a central member (not shown in  FIG. 14 ; see  FIGS. 4-13 ). Winding strip  300  is applied along a winding path  382  for establishing windings about central area  344 . Strip  300  may be configured similar to one portion  60 ,  70 ,  100  of strip  32  ( FIG. 3 ) with fold structures provided to accommodate southeast corner  381 , southwest corner  383 , northwest corner  385  and northeast corner  387  during winding. If strip  300  is sufficiently thin and flexible no fold structures are requires. By way of example and not by way of limitation, a sufficiently thin winding strip not to require fold structures may have a thickness t of approximately 0.010 inches. 
     Strip  300  is wound along winding path  382  beginning from about southwest corner  383  and windingly passing corners  381 ,  387 ,  385 ,  383 . Strip  300  may continue winding along winding path  382  past corner  381  if more than one turn about central area  344  is desired. 
       FIG. 15  illustrates a second step in assembling the electrical winding structure illustrated in  FIG. 14 . The arrangement of central area  344 , axis  342  and directions NORTH, EAST, SOUTH and WEST (Abbreviated N, E, S and W in  FIGS. 15-19 ) is similar in  FIGS. 14-19 . In order to avoid prolixity description of that arrangement will not be repeated in connection with  FIGS. 15-19 ). In  FIG. 15 , winding strip  300  is arranged to clear winding path  382  so that another strip (not shown in  FIGS. 5-19 ) may be wound over top of winding strip  300 . When winding strip  300  is sufficiently thin, no transition structure is required as was described in connection with strip  32  ( FIG. 3 ). By way of example and not by way of limitation, a sufficiently thin winding strip not to require fold structures may have a thickness of approximately 0.010 inches. Strip  300  is foldingly arranged at a folding angle θ to clear winding path  382  for application of another winding strip (not shown). A preferred value for folding angle θ is approximately 45 degrees. However, any angle θ that clears winding path  382  for another strip to be wound over strip  300  is within the intended scope of this invention. 
       FIG. 16  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 15 . In  FIG. 16 , winding strip  300  is initially positioned for rearranging toward an orientation permitting continuation of winding along winding path  382 . Strip  300  is oriented a first return angle α 1  to clear a second winding strip (not shown in  FIG. 16 ). A preferred value for first return angle α 1  is approximately 90 degrees. However, any first return angle α 1  that positions strip  300  for rearranging toward an orientation permitting continuation of winding along winding path  382  is within the intended scope of this invention. 
       FIG. 17  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 16 . In  FIG. 17 , winding strip  300  is further positioned for rearranging toward an orientation permitting continuation of winding along winding path  382 . Strip  300  is oriented a second return angle α 2  to further clear a second winding strip (not shown in  FIG. 17 ).  FIG. 17  illustrates strip  300  as establishing a transition structure  400  having fold structures  402 ,  404  separated by a distance d 5 . Distance d 5  is intended to be sufficient to span another winding applied over strip  300  (not shown in  FIG. 17 ). When strip  300  and a second-wound strip wound over top of strip  300  are sufficiently thin, no transition structure  400  need actually be formed in strip  300  for spanning a second-wound strip. By way of example and not by way of limitation, a sufficiently thin winding strip not to require fold structures may have a thickness of approximately 0.010 inches. A preferred value for second return angle α 2  is approximately 90 degrees. However, any second return angle α 2  that positions strip  300  for rearranging toward an orientation permitting continuation of winding along winding path  382  is within the intended scope of this invention. 
       FIG. 18  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 17 . In  FIG. 18 , winding strip  300  is finally positioned for rearranging toward an orientation permitting continuation of winding along winding path  382 . Strip  300  is oriented a third return angle α 3  to further clear a second winding strip (not shown in  FIG. 18 ).  FIG. 18  illustrates strip  300  as establishing a transition structure  406  configured similar to transition structure  400  ( FIG. 17 ) to span another winding applied over strip  300  (not shown in  FIG. 18 ). When strip  300  and a second-wound strip wound over top of strip  300  are sufficiently thin, no transition structure  406  need actually be formed in strip  300  for spanning a second-wound strip. By way of example and not by way of limitation, a sufficiently thin winding strip not to require fold structures may have a thickness of approximately 0.010 inches. A preferred value for third return angle α 3  is approximately 45 degrees. However, any third return angle α 3  that positions strip  300  for rearranging toward an orientation permitting continuation of winding along winding path  382  is within the intended scope of this invention. 
       FIG. 19  illustrates a next step in assembling the electrical winding structure illustrated in  FIG. 18 . In  FIG. 19 , winding strip  300  is wound along winding path  382  about central area  344  substantially symmetrically about axis  342 . Strip  300  is wound along winding path  382  beginning from about southwest corner  383  and windingly passing corners  381 ,  387 ,  385 . Strip  300  may continue winding along winding path  382  past corner  381  if more than one turn about central area  344  is desired. 
     It is to be understood that, while the detailed drawings and specific examples given describe preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus and method of the invention are not limited to the precise details and conditions disclosed and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims:

Technology Category: h