Abstract: A spark gap assembly includes a sealed chamber, at least two discharge electrodes, and a non-radioactive gas fill within the sealed chamber. The sealed chamber includes first and second end plugs and a vitreous tube having opposite ends, each end being sealed by one of said end plugs. The discharge electrodes extend through the first and second end plugs, respectively, from an exposed portion outside of the sealed chamber to an enclosed portion inside the sealed chamber. The discharge electrodes each have a discharge portion that includes a surface from which electrons of a spark discharge exit or are received, with the discharge surfaces of the discharge portions facing each other to thereby define a spark discharge gap between the discharge surfaces of the two discharge electrodes. The gas fill within the sealed chamber includes one or more non-radioactive isotopes of one or more noble gases.

Abstract: An air-cooled ignition lead for use with aircraft engines to conduct high voltage ignition pulses between an exciter and an igniter. The ignition lead includes a center conductor covered by an insulation jacket for electrical isolation. Radially spaced outwardly from the insulation jacket is a flexible conduit that has sufficient structural integrity to resist collapsing inwardly. The insulation jacket and conduit define an airflow path therebetween that is used for conducting air through the lead. An innerbraid is located over and supported by an outer surface of the flexible conduit, and this location of the innerbraid prevents it from collapsing over time and obstructing the airflow passage that extends on the inner side of the flexible conduit. The innerbraid can be used as a return path conductor that provides a return current path and/or EMI shielding. Covering the innerbraid is an outerbraid to protect the lead against external damage.

Abstract: An ignition lead that includes at least one terminal assembly having a replaceable terminal contact that provides a simple means of replacing worn contacts without removal and replacement of the entire ignition lead. The terminal assembly includes the replaceable contact which threads onto a contact body located within a tubular insulator. A retaining ring attaches to the contact to hold the insulator in place over the contact body. The contact can include a groove that extends around the contact to receive the retaining ring. Replacement of the contact involves removing the retaining ring from the groove in the contact, sliding the insulator off the terminal assembly, unthreading the worn contact, threading on a replacement contact, reassembling the insulator onto the assembly, and then securing the insulator in place by snapping the retaining ring back into the groove on the replacement contact.

Abstract: An igniter having a two-piece center electrode assembly that includes an upper electrode member and an iridium lower electrode member. The two electrode members are assembled together by insertion of an expanded head section of the iridium electrode into a blind hole within the upper electrode. The upper electrode is then swaged over the expanded head section to provide a positive mechanical interlock of the two electrode members together. Thereafter, the two components are brazed together by heating of a brazing compound that is pre-loaded into the blind hole prior to insertion of the expanded head section. This assembly results in both a mechanical and metallurgical bond between the two components without subjecting the iridium electrode to deformation that could otherwise result in axial cracking of the iridium material.

Abstract: An igniter having a two-piece center electrode assembly that includes an upper electrode member and an iridium lower electrode member. The two electrode members are assembled together by insertion of an expanded head section of the iridium electrode into a blind hole within the upper electrode. The upper electrode is then swaged over the expanded head section to provide a positive mechanical interlock of the two electrode members together. Thereafter, the two components are brazed together by heating of a brazing compound that is pre-loaded into the blind hole prior to insertion of the expanded head section. This assembly results in both a mechanical and metallurgical bond between the two components without subjecting the iridium electrode to deformation that could otherwise result in axial cracking of the iridium material.

Abstract: Igniter and spark plugs according to the invention include a tubular insulator having an axially extending passage and axially opposed sealing shoulders within the passage spaced from the ends of the insulator. A multi-part electrode assembly is disposed within the insulator, including an upper electrode joined by resistance welding to a lower electrode. A heat-expandable sleeve is carried about the upper electrode and a lower end thereof confronts a compressible gasket and the upper sealing shoulder. An enlarged head of the lower electrode confronts a sealing gasket on the lower sealing shoulder. During resistance welding, the upper and lower electrodes are displaced toward one another causing the gaskets to be compressed against the sealing shoulders of the insulator to form a gas-tight seal therebetween.