US4671219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-stroke internal combustion engine
Assignee: Honda Motor Co Ltd
•
Filing: 1983-09-09
•
Granted: 1987-06-09
•
Expires: 2003-09-09
Abstract
Abstract A two-cycle internal combustion engine having an oblong cylinder and an oblong piston therein. The engine includes two sets of scavenging ports at either end of the oblong cylinder having at least three ports each. Scavenging passages extending to the scavenging ports may be directed at sequentially increasing angles of inclination to the local normal with the cylinder away from the exhaust porting. In this way, flow may be directed across the piston head away from the exhaust porting and then upwardly to return toward the exhaust porting. A domed piston is also disclosed having discrete guide surfaces on the domed surface of the piston to specifically direct incoming air/fuel mixture upwardly from each of the scavenging ports. An element of the cylinder midway in the long dimension of the cylinder extends in the direction of piston movement without porting so as to provide a smooth wall surface. An oblong piston ring mounted within a groove in the piston has a break in the ring coincide with the unported cylinder element to reduce stress and friction.
Inventors
- 👤 Kazuo Ooyama
- 👤 Yasuhiko Nakano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:39
CPC Classifications
F; F02; F02F; F02F1/00; F02F1/18; F02F1/183; F02B; F02B25/00; F02B25/14; F02B25/18; F02B33/00; F02B33/02; F02B33/04; F02B75/00; F02B75/02; F02B2075/022; F02B2075/025
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
146 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; a piston, oblong in cross section and having a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a brake at the element of said cylinder without porting.
Claim 2
Dependent Claim
146 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; a piston, oblong in cross section and having a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a brake at the element of said cylinder without porting.
Claim 3
Dependent Claim
87 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-setional axis and a minor cross-sectional axis; a piston, oblong in cross section and having a peripheral groove; porting in said cylinder, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston; and an oblong piston ring in said peripheral groove, said piston ring having a break at the element of said cylinder without porting.
Claim 4
Dependent Claim
87 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-setional axis and a minor cross-sectional axis; a piston, oblong in cross section and having a peripheral groove; porting in said cylinder, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston; and an oblong piston ring in said peripheral groove, said piston ring having a break at the element of said cylinder without porting.
Claim 5
Dependent Claim
195 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; and scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; scavenging passages extending to said scavenging ports, each said scavenging passage terminating at a said scavenging port and defining an angle of inclination with the normal to said cylinder at said scavenging port, each successive scavenging passage progressively increasing in angle of inclination away from said exhaust porting; a piston, oblong in cross section and having a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a brake at the element of said cylinder without porting.
Claim 6
Dependent Claim
195 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; and scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; scavenging passages extending to said scavenging ports, each said scavenging passage terminating at a said scavenging port and defining an angle of inclination with the normal to said cylinder at said scavenging port, each successive scavenging passage progressively increasing in angle of inclination away from said exhaust porting; a piston, oblong in cross section and having a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a brake at the element of said cylinder without porting.
Claim 7
Dependent Claim
43 words
The two-stroke internal combustion engine of claim 3 further comprising an auxiliary scavenging passage extending to said cylinder and defining an angle of inclination with the normal to said cylinder at said cylinder greater than the angles of inclination of said scavenging passages.
Claim 8
Dependent Claim
28 words
The two-stroke internal combustion engine of claim 3 further comprising a piston, oblong in cross section and positioned within said cylinder, said piston including a domed piston head.
Claim 9
Dependent Claim
157 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; a piston oblong in cross section and positioned within said cylinder, said piston including a domed piston head and a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a break at the element of said cylinder without porting.
Claim 10
Dependent Claim
157 words
A two-stroke internal combustion engine comprising a cylinder, oblong in cross section with a major cross-sectional axis and a minor cross-sectional axis; intake porting in said cylinder; exhaust porting in said cylinder, said intake porting and said exhaust porting being centered at said minor axis and opposed in said cylinder; scavenging porting extending in said cylinder from adjacent said intake porting to adjacent said exhaust porting and including two sets of at least three scavenging ports each, said sets being opposed in said cylinder; a piston oblong in cross section and positioned within said cylinder, said piston including a domed piston head and a peripheral groove; and an oblong piston ring in said peripheral groove, said cylinder being without porting along an element of said cylinder at said minor axis, said element being parallel to the direction of motion of said piston and said piston ring having a break at the element of said cylinder without porting.
Claim 11
Dependent Claim
47 words
The two-stroke internal combustion engine of claim 6 wherein said domed piston head has a plurality of guide surfaces thereon, each said guide surface being adjacent a said scavenging port and being generally concave to direct flow from the adjacent said scavenging port upwardly above said piston.
Claim 12
Dependent Claim
21 words
The two-stroke internal combustion engine of claim 6 wherein said sets of scavenging ports include at least three scavenging ports each.
References Cited (Backward Citations)
US1632988A
Cited
GB478959A
Cited
US2190011A
Cited
US2760469A
Cited
GB2027795A
Cited
US4174685A
Cited
US4287860A
Cited
US4329948A
Cited
US4306730A
Cited
JPS569616A
Cited
JPS5632036A
Cited
JPS5773826A
Cited
US4373474A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |