Spiral windings

Claim 1

In an ignition coil assembly adapted for use with an ignition system in an internal combustion engine, said ignition coil assembly having an ignition coil including a secondary winding assembly and an electromagnetically-coupled primary winding assembly which receives periodic energy pulses at least in part in accordance with an operating position of said engine so as to thereby induce a relatively high voltage in said secondary winding which is adapted to cause a spark generating device partially disposed within a combustion chamber of said engine to ignite an air fuel mixture therein, the improvement wherein said secondary winding assembly comprises: a core which provides a closed magnetic circuit; an electrically non-conductive bobbin support assembly mounted on a portion of said core, said support assembly having individual and separate winding and transition discs of different shapes which are directly connected together in an alternating coaxial nested relationship to form a unitary structure, sad discs being formed to provide a plurality of axially separated annular winding recesses and transition recesses, with at least one of said discs being formed with an inwardly extending slot; and a single continuous electrically-conductive wire being wound without severances or splices on said unitary structure so as to form a plurality of spaced apart spiral coils, each of said spiral coils having a plurality of layers, each of said spiral coils having only one turn per radial layer in each of said winding recesses, said wire passing through each of said transition recesses and through said slot to traverse from a major spiral coil diameter to a minor spiral coil diameter of the next adjacent spiral coil, said winding recesses having a width less than twice the diameter of said wire.