Abstract: An electromagnetic coil which may be employed as an ignition coil for an internal combustion engine is disclosed. The electromagnetic coil includes a lower voltage winding portion and a higher voltage winding portion. The lower voltage winding portion is wound around a spool and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a leading portion of wire. The higher voltage winding portion is wound around the spool adjacent the lower voltage winding portion and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a trailing portion of the wire.

Abstract: A stick-type ignition coil have a central core, a cylindrical member, primary spool, primary coil, secondary spool, secondary coil, outer core and a resin insulator. The two longitudinal end corners and faces of the core are covered by respective buffer members. The inner circumferential corners of the outer core is supported by ring members. Some of the members disposed radially inside and other members disposed radially outside of the inside members are held slidably to each other in the ignition coil. The spools are made of resin containing a rubber in excess of 5 weight percent and reinforcing materials. The resin insulator contains a flexible material.

Abstract: An electromagnetic coil which may be employed as an ignition coil for an internal combustion engine is disclosed. The electromagnetic coil includes a lower voltage winding portion and a higher voltage winding portion. The lower voltage winding portion is wound around a spool and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a leading portion of wire. The higher voltage winding portion is wound around the spool adjacent the lower voltage winding portion and includes a plurality of winding layers overlapped with each other and inclined at a given angle to the length of the spool. Each of the winding layers includes a collection of turns made up of a trailing portion of the wire.

Abstract: An ignition coil unit which is capable of mounting in a relatively small space between opposed cylinder head covers of an internal combustion engine is disclosed, wherein a pair of separate coil assemblies received in a single insulating-resin case is firmly embedded in the case by a cured casting resin such as a thermosetting resin filled in the case in such a manner that the pair of coil assemblies can be directly connected to each pair of adjacent spark plugs provided one for each cylinder of the internal combustion engine.