US4844025A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual spark plug combustion chamber
Assignee: Brunswick Corp
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Filing: 1988-09-29
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Granted: 1989-07-04
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Expires: 2008-09-29
Abstract
Abstract In a two stroke internal combustion engine (2) having a pair of spark plugs (28, 30) for each cylinder (6), a particular height and spacing ratio of the spark gaps (32,34) have been found to produce misfire-free running during idle. The ratio h/H should be less than 0.5, where h is the height of the spark gaps (32, 34) above the squish surface (20) or the top (60) of the cylinder sidewalls, and H is the height of the top (36) of the combustion chamber above such surface. The ratio d/D should be in the range of about 0.25 to 0.35, where d is the distance between the spark gaps (32, 34), and D is the inner diameter of the cylinder (6).
Inventors
- 👤 Benjamin L. Sheaffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:46
CPC Classifications
F; F02; F02B; F02B23/00; F02B23/08; F02B23/10; F02B23/101; F02P; F02P15/00; F02P15/02; F02B2023/085; F02B2023/102; F02B2275/00; F02B2275/14; F02B2275/40; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A two stroke internal combustion engine having a piston reciprocal in a cylinder having cylindrical sidewalls meeting an upper head at a squish surface, said head and the upper portion of said cylinder defining a combustion chamber above said piston, said combustion chamber having a height H above said squish surface, a pair of spark plugs in said head and extending into said combustion chamber and having spark gaps at a height h above said squish surface, wherein the ratio h/H is less than about 0.5.
Claim 2
Dependent Claim
86 words
A two stroke internal combustion engine having a piston reciprocal in a cylinder having cylindrical sidewalls meeting an upper head at a squish surface, said head and the upper portion of said cylinder defining a combustion chamber above said piston, said combustion chamber having a height H above said squish surface, a pair of spark plugs in said head and extending into said combustion chamber and having spark gaps at a height h above said squish surface, wherein the ratio h/H is less than about 0.5.
Claim 3
Dependent Claim
42 words
The invention according to claim 1 wherein said cylinder has an inner diameter D, said spark gaps are spaced from each other by a distance d, and wherein in combination the ratio d/D is in the range of about 0.25 to 0.35.
Claim 4
Dependent Claim
79 words
The invention according to claim 2 wherein said spark plugs are on opposite sides of the central axis of said cylinder defining the direction of reciprocation of said piston, and wherein each spark plug extends along a direction at about a 35° angle relative to said axis, and wherein each of said spark plugs has inner electrodes extending downwardly and inwardly towards each other in said combustion chamber, each at an angle of about 35° relative to said axis.
Claim 5
Dependent Claim
79 words
The invention according to claim 3 comprising a fuel injector in said head between said spark plugs and having a spray angle of about 60° to provide an outer spray edge at an angle of about 30° relative to said axis on each side of said axis, wherein the outer edge of said spray extends along a line intersecting the centerline of each of said spark plugs at a point slightly below and inwardly of respective said spark gaps.
Claim 6
Dependent Claim
93 words
A two stroke internal combustion engine comprising a piston reciprocal in a cylinder having cylindrical sidewalls extending upwardly to an upper dome portion thereabove, said dome portion and the upper portion of said cylinder defining a combustion chamber above said piston, said combustion chamber having a height H above the top of said cylindrical sidewalls, a pair of spark plugs in said dome portion and extending into said combustion chamber and having spark gaps at a height above the top of said cylindrical sidewalls, where the ratio h/H is less than about 0.5.
Claim 7
Dependent Claim
93 words
A two stroke internal combustion engine comprising a piston reciprocal in a cylinder having cylindrical sidewalls extending upwardly to an upper dome portion thereabove, said dome portion and the upper portion of said cylinder defining a combustion chamber above said piston, said combustion chamber having a height H above the top of said cylindrical sidewalls, a pair of spark plugs in said dome portion and extending into said combustion chamber and having spark gaps at a height above the top of said cylindrical sidewalls, where the ratio h/H is less than about 0.5.
Claim 8
Dependent Claim
42 words
The invention according to claim 5 wherein said cylinder has an inner diameter D, said spark gaps are spaced from each other by a distance d, and wherein in combination the ratio d/D is in the range of about 0.25 to 0.35.
References Cited (Backward Citations)
US4116179A
Cited
CA1075106A
Cited
US4538568A
Cited
US4481911A
Cited
US4481910A
Cited
US4635591A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |