US4337734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-cycle engine
Assignee: Yamaha Motor Co Ltd
•
Filing: 1980-09-29
•
Granted: 1982-07-06
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Expires: 2000-09-29
Abstract
Abstract In a two cycle internal combustion engine having a cylinder, a piston, and an exhaust port, the improvement comprising tapering the edge of the exhaust port farthest into the cylinder where it intersects the cylinder wall as an isosceles triangle.
Inventors
- 👤 Toshimitsu Iio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:04
CPC Classifications
F; F02; F02D; F02D13/00; F02D13/02; F02D13/028; F02D13/0284; F02B; F02B25/00; F02B25/14; F02F; F02F1/00; F02F1/18; F02F1/22; F02B75/00; F02B75/02; F02B2075/022; F02B2075/025; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
106 words
In a two cycle engine of the type having a cylinder with an axis, a piston slidably disposed in said cylinder, and an exhaust port through the wall of said cylinder, the closed and opened condition of said exhaust port being a function of the axial position of said piston in said cylinder, said exhaust ports having generally axial side walls and an upper edge extending into the cylinder and away from the piston when said piston is in a lower position, said upper edge at its intersection with the inside cylinder wall, viewed toward said exhaust port, forming the upper portion of an isosceles triangle.
Claim 2
Dependent Claim
106 words
In a two cycle engine of the type having a cylinder with an axis, a piston slidably disposed in said cylinder, and an exhaust port through the wall of said cylinder, the closed and opened condition of said exhaust port being a function of the axial position of said piston in said cylinder, said exhaust ports having generally axial side walls and an upper edge extending into the cylinder and away from the piston when said piston is in a lower position, said upper edge at its intersection with the inside cylinder wall, viewed toward said exhaust port, forming the upper portion of an isosceles triangle.
Claim 3
Dependent Claim
12 words
Apparatus according to claim 1 in which said triangle is also equilateral.
Claim 4
Dependent Claim
33 words
Apparatus according to claim 1 in which said exhaust port at the outside wall of said cylinder is generally rectangular, said exhaust port merging smoothly from said outside wall to said inside wall.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 3 in which said merging occurs at a chamferred angle with said axis between about 30° and about 45°.
Claim 6
Dependent Claim
12 words
Apparatus according to claim 3 in which said triangle is also equilateral.
Claim 7
Dependent Claim
12 words
Apparatus according to claim 4 in which said triangle is also equilateral.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-05 | 1986-01-04 | 1986-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-05 | 1990-01-04 | 1990-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-05 | 1994-01-04 | 1994-07-06 | $7700.00 | Window Closed / Lapsed |