Spark plug with increased durability and carbon fouling...

Details Spark plug with increased durability and carbon fouling... Spark plug with increased durability and carbon fouling...

2005-09-13

2009-06-30

Roy, Sikha (Department: 2879)

Electric lamp and discharge devices

Spark plugs

Particular electrode structure or spacing

C313S137000, C445S007000, C269S012000

Reexamination Certificate

active

07554253

ABSTRACT:
A spark plug for an internal combustion engine is provided which includes a metal shell, a porcelain insulator, a center electrode, a main ground electrode, and auxiliary ground electrodes. Each of the auxiliary ground electrodes has an end face facing the insulator to define an auxiliary spark gap. The end face includes an increasing-radial distance surface which is located at a distance from a longitudinal center line of the spark plug in a radial direction thereof which increases as approaching to the metal shell. The insulator nose has a wall thickness T meeting a relation of 0.3 mm≦T≦0.7 mm. This avoids a great local increase in electrical field strength on the auxiliary ground electrode to minimize excessive discharge within the auxiliary spark gap to enhance carbon fouling resistance and durability of the spark plug.

REFERENCES:
patent: 3870918 (1975-03-01), Senda et al.
patent: 4092558 (1978-05-01), Yamada
patent: 5693999 (1997-12-01), Osamura et al.
patent: 5929556 (1999-07-01), Matsubara et al.
patent: 6064143 (2000-05-01), Kagawa
patent: 6091185 (2000-07-01), Matsubara et al.
patent: 6095124 (2000-08-01), Matsubara et al.
patent: 6316868 (2001-11-01), Ishino et al.
patent: 6552476 (2003-04-01), Hanashi et al.
patent: 6831397 (2004-12-01), Kanao et al.
patent: 2002/0067110 (2002-06-01), Nishikawa et al.
patent: 2002/0094743 (2002-07-01), Harada
patent: 2002/0109447 (2002-08-01), Hanashi et al.
patent: 2003/0062815 (2003-04-01), Kanao et al.
patent: 2004/0080252 (2004-04-01), Ito et al.
patent: A-UM-S52-131528 (1977-10-01), None
patent: 6-260261 (1994-09-01), None
patent: H11-135229 (1999-05-01), None
patent: 3140006 (2000-12-01), None
patent: A-2001-068251 (2001-03-01), None
patent: 2001-093645 (2001-04-01), None
patent: 2001-160475 (2001-06-01), None
patent: 2002-313524 (2002-10-01), None
patent: 2004-200137 (2004-07-01), None
Information Offer Form dated May 14, 2008 submitted in counterpart Japanese Application 2005-136162 with English translation.
Japanese Office Action, dated Aug. 26, 2008, issued in corresponding Japanese Application No. 2005-136162 with English translation.

Affiliated with

Also associated with

Rating

Spark plug with increased durability and carbon fouling... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Spark plug with increased durability and carbon fouling..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spark plug with increased durability and carbon fouling... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4109221