GB616547A - Improvements in ignition systems for internal combustion engines - Google Patents

Abstract

616,547. Ignition systems. EITEL-McCULLOUGH, Inc. April 1, 1946, No. 10063. Convention date, Oct. 11, 1943. [Class 7 (iv)] An ignition system comprises a source of high-frequency electric oscillations, a keying means for the source causing intermittent operation thereof in synchronism with the engine and means conducting the intermittent oscillations thus produced to energize ignition means for producing a spark within the combustion chamber, the ignition means being adapted when energized to resonate at the frequency of the oscillations to produce a spark within the combustion chamber and a potential node adjacent the wall of the chamber. The term high-frequency is intended to denote frequencies of the order of 300 megacycles or higher. Fig. 1 shows a high-frequency oscillator 8 supplying oscillations by a transmission line 14 comprising an inner conductor 17 and tubular conductor 16 to a quarter-wave line comprising two parallel metallic rods 9 in the engine combustion chamber. The oscillator is operated in timed relation to the engine by means of a switch 21 driven by the engine. Each time the switch closes, a condenser 19 is discharged into the oscillator to set it working. The discharge takes place at the potential antinode at the end of the rods 9. The condenser is charged by a suitable D.C. source such as by a full wave rectifier 23. In a modification, a tuned transmission line comprising two parallel insulated conductors in place of the rods 9 is employed. In a further modification, Fig. 4, the combustion chamber is formed as a resonant cavity having a gap 28 therein. The high-frequency oscillations are supplied to a line 16, 17 ending in a loop 29. Specification 583,802 is referred to.