Fuel ignition device and method of assembling same
 A fuel ignition plug (10) includes an outer electrode (12) defined by a conductive shell which surrounds a central electrode (28) and an insulator body (22) between the central electrode (28) and outer electrode (12). Fused glass powder seals (40,42) between the shell and the insulator body (22), and between the insulator body (22) and the central electrode (28), prevent combustion gasses from passing through the interior of the device (10). The device (10) is assembled by holding the electrodes (12,28) and insulator body (22) in fixed, concentric relationship with each other while the seals (40,42) are heated and extruded into sealing position against a shoulder (38,52) of the insulator body (22). The seals (40,42) are extruded into sealing position by applying force to push rings (44,46) which are respectively sleeved over the insulator body (22) and central electrode (28) and bear against the seals (40,42). 
Allied Corporation
H
H01T
inventional
Helmut P.
Meyer