Spark developing apparatus for internal combustion engines

Claim 1

Apparatus for developing sparks to ignite the combustible mixture in a cylinder of an internal combustion engine comprising, an internal combustion engine having a cylinder, a secondary spark developing unit comprising a spark plug supported by said engine having a pair of electrodes associated with said cylinder, said spark plug having first insulator means for supporting and for electrically insulating said electrodes from each other and having second insulator means extending axially of said first insulator means, said second insulator means having a bore, a core formed of a magnetic material located within said bore, a secondary coil winding carried by said second insulator means and disposed about said core, the opposite ends of said secondary winding being electrically connected respectively to said electrodes, means for causing a voltage to be induced in said secondary winding which is high enough to cause an arc to be developed across said electrodes comprising a primary winding unit that is a part that is separate from said secondary spark developing unit, said primary winding unit having a bore, and means for supporting said primary winding unit relative to said secondary spark developing unit such that said second insulator means, said secondary winding and said core are located within said bore, said primary winding unit having a primary winding disposed about said bore, said primary winding when energized developing a magnetic flux that passes through said core to induce said voltage in said secondary winding, said primary winding unit being completely separable from said secondary spark developing unit.