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US4401915A
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US
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Ignition plug for an internal combustion engine
Assignee: Individual
•
Filing: 1981-04-06
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Granted: 1983-08-30
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Expires: 2001-04-06
Abstract
Abstract A spark plug for internal combustion engines is provided with a ground electrode which terminates below the center electrode and is provided with one or more vertical openings to facilitate the passage of ignited gases from the area of the spark to the area of the piston. A single elongated opening may be provided or there may be one or more small openings spaced along the length of the electrode. The area adjacent the opening may be outwardly and downwardly tapered to concentrate and speed the flow of gases.
Inventors
- 👤 Takeaki Kashiwara
- 👤 Ryohei Kashiwara
- 👤 Hideaki Kashiwara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
H; H01; H01T; H01T13/00; H01T13/20; H01T13/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
A spark plug for an internal combustion engine having a grounded outer cylindrical shell and an axially extending centrally positioned insulated electrode, an elongated ground electrode extending radially inwardly from said outer shell with its free end positioned at a location spaced a short axial distance away from the end of said insulated electrode, the width of the ground electrode along its length in a direction at right angles to the axis of the shell being substantially greater than its thickness in the axial direction and being provided with at least one opening extending axially therethrough, the surface of said ground electrode on the side facing away from the end of said insulated electrode being generally concave in transverse cross section along the length thereof.
Claim 2
Dependent Claim
125 words
A spark plug for an internal combustion engine having a grounded outer cylindrical shell and an axially extending centrally positioned insulated electrode, an elongated ground electrode extending radially inwardly from said outer shell with its free end positioned at a location spaced a short axial distance away from the end of said insulated electrode, the width of the ground electrode along its length in a direction at right angles to the axis of the shell being substantially greater than its thickness in the axial direction and being provided with at least one opening extending axially therethrough, the surface of said ground electrode on the side facing away from the end of said insulated electrode being generally concave in transverse cross section along the length thereof.
Claim 3
Dependent Claim
20 words
The spark plug as defined in claim 1, wherein said opening in elongated along the length of the ground electrode.
Claim 4
Dependent Claim
26 words
The spark plug as defined in claim 2, wherein said ground electrode is L-shaped and said opening extends upwardly along the vertical portion of the electrode.
Claim 5
Dependent Claim
26 words
The spark plug as defined in either claim 2 or 5, wherein said opening extends through the end margin of the free end of the electrode.
Claim 6
Dependent Claim
25 words
The spark plug as defined in claim 1, wherein said ground electrode is formed from relatively thin metal having an arcuate downwardly concave transverse cross-section.
Claim 7
Dependent Claim
22 words
The spark plug as defined in claim 1, wherein said opening is circular and is disposed in alignment with said central electrode.
Claim 8
Dependent Claim
29 words
The spark plug as defined in claim 1, wherein said ground electrode is provided with a plurality of openings spaced from each other along the length of the electrode.
References Cited (Backward Citations)
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Cited
GB187501A
Cited
US2129003A
Cited
US2391459A
Cited
US2944178A
Cited
US3970885A
Cited
US4023058A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |