EP 0049372 B1 19840222 - SPARK PLUG FOR INTERNAL-COMBUSTION ENGINES
Title (en)
SPARK PLUG FOR INTERNAL-COMBUSTION ENGINES
Publication
Application
Priority
DE 3038720 A 19801014
Abstract (en)
[origin: US4406968A] A sparkplug for internal combustion engines which has a central electrode extending to the ignition end. The central electrode has an electrically non-conductive core pin with an electrically conductive outer layer on the cylindrical surface of the core pin. The central electrode is positioned in the lengthwise bore of the sparkplug insulator portion, preferably without any clearance between the insulator and the ignition end portion of the central electrode. The core pin is preferably made of a material which has shrinkage characteristics and a thermal coefficient of expansion substantially the same as those of the insulator. Most preferably the same material is used for both components. The electrically conductive coating layer of the central electrode is preferably a conductive metal-ceramic mixture. The coating layer may be in the form of a resistance element and/or contain a pre-ignition discharge gap. The sparkplug may also be formed with a recessed electrically conductive coating portion of the central electrode to form a surface gap sparkplug.
IPC 1-7
IPC 8 full level
H01T 13/20 (2006.01); H01T 13/34 (2006.01); H01T 21/02 (2006.01)
CPC (source: EP US)
H01T 13/34 (2013.01 - EP US); H01T 21/02 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0049372 A1 19820414; EP 0049372 B1 19840222; DE 3038720 A1 19820603; DE 3162383 D1 19840329; JP S5796483 A 19820615; JP S633424 B2 19880123; US 4406968 A 19830927
DOCDB simple family (application)
EP 81106944 A 19810904; DE 3038720 A 19801014; DE 3162383 T 19810904; JP 16108181 A 19811012; US 29735381 A 19810828