Patent ID: 8319153

Claim:
A glow plug assembly of the type for assisting cold start combustion in a combustion chamber, said assembly comprising: a generally tubular metal shell defining an axially extending bore; a transition zone associated with said shell, said transition zone having a circular seat concentric with said bore and adapted to establish a seal against an opening in the combustion chamber, a generally annular membrane extending radially inwardly from said seat, and a hollow tube portion extending axially from said membrane; an elongated heater probe axially aligned with said bore of said shell, said heater probe including a generally tubular metallic sheath extending between open first and closed second ends, said sheath having a generally cylindrical outer body surface; and said sheath including a reduced diameter pilot section at said open first end thereof, said pilot section having a reduced diameter relative to said outer body surface and separated from said outer body surface by a shoulder, said reduced diameter pilot section and said shoulder forming a joint area in direct abutting contact with said tube portion of said transition zone.