Electronic ignition system with encapsulated reed device and conducting sleeve thereabout forming a flux filter

Claim 1

A SWITCHING STRUCTURE FOR USE IN AN ELECTRICAL SYSTEM WHICH MAY BE SUBJECTED TO THE INFLUENCE OF MAGNETIC FIELDS EXHIBITING VARIATIONS IN FLUX, SAID SWITCHING STRUCTURE INCLUDING IN COMBINATION, A REED SWITCH COMPRISING A PAIR OF MAGNETIC REEDS ENCAPSULATED WITHIN A GLASS TUBE AND OPERABLE TO CONTROL A FUNCTION OF THE ELECTRICAL SYSTEM, A COPPER SLEEVE DIRECTLY SURROUNDING SAID GLASS TUBE, MOVABLE MAGNETIC MEANS OPERABLE TO PROVIDE A MAGNETIC FLUX THROUGH SAID REEDS VARYING IN A GIVEN FREQUENCY RANGE TO OPEN AND CLOSE SAID REED SWITCH, SAID REED SWITCH HAVING A NATURAL RESONANCE FREQUENCY WHICH IS SUBSTANTIALLY HIGHER THAN THE GIVEN FREQUENCY RANGE, SAID COPPER SLEEVE FORMING A SHORTED TURN ABOUT SAID REEDS AND BEING OF A THICKNESS OF PROVIDE A SUFFICIENTLY LOW INDUCTANCE TO HAVE A NEGLIGIBLE EFFECT OF MAGNETIC FLUX VARIATIONS WITHIN THE GIVEN FREQUENCY RANGE, AND ACTING TO FILTER OUT MAGNETIC FLUX VARIATIONS AT FREQUENCIES OF THE ORDER OF SAID NATURAL RESONANCE FREQUENCY.