Air-cooled ignition lead

A fluid-cooled ignition lead, comprising:

• a center conductor;
• an insulating sleeve covering said center conductor and having an outer surface;
• a non-collapsible conduit surrounding said insulating sleeve, said conduit having an inner surface and being spaced from said insulating sleeve, whereby said inner surface of said conduit and said outer surface of said insulating sleeve together define a fluid passage therebetween, said fluid passage extending radially from said insulating sleeve to said conduit and extending axially along a length of said insulating sleeve, whereby fluid flowing through said fluid passage is in direct contact with said insulating sleeve and said conduit;
• a return path conductor located radially outwardly of said conduit;
• and
• an outerbraid covering said return path conductor and providing an abrasion-resistant outer surface of said ignition lead, wherein said return path conductor has a lower electrical resistance than said outerbraid.

An air-cooled ignition lead for use with an ignition system and a sparking device, comprising:

• an elongated center conductor for conducting high voltage ignition pulses between the ignition system and sparking device;
• an insulation jacket coaxially surrounding said center conductor and having an outer cylindrical surface;
• a flexible conduit coaxially surrounding said insulation jacket and having an inner cylindrical surface;
• an airflow passage for allowing air to flow within said ignition lead, said airflow passage being located coaxially between said insulation jacket and said flexible conduit, with said airflow passage having an annular cross-sectional shape and extending radially from said insulation jacket for a distance of between 2 mm and 11 mm;
• a copper-cored innerbraid coaxially surrounding said flexible conduit;
• and
• a nickel-based outerbraid coaxially surrounding said innerbraid;
• wherein said airflow passage is bounded on a radially-inward side by said insulation jacket outer cylindrical surface and on a radially-outward side by said flexible conduit inner cylindrical surface, such that air flowing in said airflow passage is in direct contact with said insulation jacket outer cylindrical surface to thereby remove heat from said insulation jacket.