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US 2003/0155849 A1Published application
Spark plug
AssigneeDenso Corporation
InventorTsunenobu Hori
Life of this patent
Estimating the term…
Abstract
A noble metallic tip of a ground electrode protrudes from an opposed surface of the ground electrode by a protrusion amount ‘t’ not less than 0.3 mm. The noble metallic tip of the ground electrode possesses excellent oxidative and volatile resistance compared with a noble metallic tip of a center electrode.
Claims12
A spark plug comprising:
- a center electrode;
- a ground electrode disposed in an opposed relationship with said center electrode via a discharge gap;
- a noble metallic tip fixed to an opposed surface of said center electrode;
- and
- a noble metallic tip fixed to an opposed surface of said ground electrode, wherein
- said noble metallic tip of said ground electrode protrudes from said opposed surface of said ground electrode by a protrusion amount ‘t’ not less than 0.3 mm, and
- said noble metallic tip of said ground electrode possesses excellent oxidative and volatile resistance compared with said noble metallic tip of said center electrode.
4 more elements
A spark plug comprising:
- a center electrode;
- a ground electrode disposed in an opposed relationship with said center electrode via a discharge gap;
- a noble metallic tip fixed to an opposed surface of said center electrode;
- and
- a noble metallic tip fixed to an opposed surface of said ground electrode, wherein
- said noble metallic tip of said ground electrode protrudes from said opposed surface of said ground electrode by a protrusion amount ‘t’ not less than 0.3 mm,
- each of said noble metallic tip of said center electrode and said noble metallic tip of said ground electrode is made of an iridium alloy which contains iridium whose content exceeds 50% by weight and also contains at least one kind of additive, and
- a total amount of all additives contained in said noble metallic tip of said ground electrode is not less than 15% by weight.
5 more elements
A spark plug comprising:
- a center electrode;
- a ground electrode disposed in an opposed relationship with said center electrode via a discharge gap;
- a noble metallic tip fixed to an opposed surface of said center electrode;
- and
- a noble metallic tip fixed to an opposed surface of said ground electrode, wherein
- said noble metallic tip of said ground electrode protrudes from said opposed source of said ground electrode by a protrusion amount ‘t’ not less than 0.3 mm,
- said noble metallic tip of said center electrode is made of an iridium alloy which contains iridium whose content exceeds 50% by weight and also contains at least one kind of additive, and
- said noble metallic tip of said ground electrode is made of a platinum alloy which contains platinum whose content exceeds 50% by weight and also contains at least one kind of additive.
5 more elements
Dependencies are inferred from the claim text.