US4972809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power unit of inboard/outboard
Assignee: Yamaha Marine Co Ltd
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Filing: 1989-04-13
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Granted: 1990-11-27
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Expires: 2009-04-13
Abstract
Abstract An improved propulsion unit for a watercraft embodying a reciprocating internal combustion engine having horizontally disposed cylinders so as to provide a compact assembly. The engine operates on the two-stroke principle and the exhaust manifold for the engine is disposed beneath the engine to achieve further silencing.
Inventors
- 👤 Takeshi Hirasawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 05:44
CPC Classifications
F; F02; F02B; F02B61/00; F02B61/04; F02B61/045; B; B63; B63H; B63H20/00; B63H20/24; B63H20/245; F02B75/00; F02B75/16; F02B75/18; F02B75/24; F02B75/243; F02B75/02; F02B2075/022; F02B2075/025
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
67 words
In a propulsion unit for a watercraft having a transom, an internal combustion engine adapted to be positioned immediately forwardly of said transom and driving a propulsion device to the rear of said transom, said propulsion device rotating about a longitudinal extending axis, the improvement comprising said engine comprising a reciprocating engine with its cylinders extending in a horizontal plane and perpendicular to the longitudinal extending axis.
Claim 2
Dependent Claim
67 words
In a propulsion unit for a watercraft having a transom, an internal combustion engine adapted to be positioned immediately forwardly of said transom and driving a propulsion device to the rear of said transom, said propulsion device rotating about a longitudinal extending axis, the improvement comprising said engine comprising a reciprocating engine with its cylinders extending in a horizontal plane and perpendicular to the longitudinal extending axis.
Claim 3
Dependent Claim
20 words
In a propulsion unit as set forth in claim 1 wherein the engine has a plurality of horizontally extending cylinders.
Claim 4
Dependent Claim
23 words
In a propulsion unit as set forth in claim 2 wherein the engine has opposed cylinder banks in which the cylinders are formed.
Claim 5
Dependent Claim
20 words
In a propulsion unit as set forth in claim 3 wherein there are a plurality of cylinders in each bank.
Claim 6
Dependent Claim
20 words
In a propulsion unit as set forth in claim 4 wherein the engine is of the two-cycle, crankcase compression type.
Claim 7
Dependent Claim
29 words
In a propulsion unit as set forth in claim 5 further including an induction system for delivering a charge to the crankcase of the engine from above the engine.
Claim 8
Dependent Claim
25 words
In a propulsion unit as set forth in claim 6 wherein the induction system includes an intake device disposed above one of the cylinder banks.
Claim 9
Dependent Claim
34 words
In a propulsion unit as set forth in claim 7 further including an exhaust system for the engine comprising a plurality of downwardly extending exhaust ports formed in the lower sides of the cylinders.
Claim 10
Dependent Claim
27 words
In a propulsion unit as set forth in claim 8 wherein there is provided an exhaust manifold for each cylinder bank extending beneath the respective cylinder banks.
Claim 11
Dependent Claim
29 words
In a propulsion unit as set forth in claim 9 wherein the exhaust manifolds each communicate with a muffler positioned beneath the crankcase and discharging rearwardly through the transom.
Claim 12
Dependent Claim
25 words
In a propulsion unit as set forth in claim 10 further including a trap section extending from the muffler to an underwater exhaust gas discharge.
Claim 13
Dependent Claim
26 words
In a propulsion unit as set forth in claim 1 wherein each of the cylinders has a downwardly discharging exhaust port positioned beneath the respective cylinder.
Claim 14
Dependent Claim
27 words
In a propulsion unit as set forth in claim 12 wherein there are a plurality of cylinders discharging into a common exhaust manifold positioned beneath the cylinders.
Claim 15
Dependent Claim
32 words
In a propulsion unit as set forth in claim 13 wherein there are a pair of opposed cylinder banks each discharging into a respective exhaust manifold positioned beneath the respective cylinder bank.
Claim 16
Dependent Claim
29 words
In a propulsion unit as set forth in claim 14 wherein the exhaust manifolds each communicate with a muffler positioned beneath the crankcase and discharging rearwardly through the transom.
Claim 17
Dependent Claim
25 words
In a propulsion unit as set forth ]n claim 15 further including a trap section extending from the muffler to an underwater exhaust gas discharge.
Claim 18
Dependent Claim
46 words
In a propulsion unit as set forth in claim 1 wherein the propulsion unit comprises an outboard drive unit mounted to the rear of the transom and supported for steering movement about a vertically extending axis and tilt and trim movement about a horizontally disposed axis.
Claim 19
Dependent Claim
20 words
In a propulsion unit as set forth in claim 17 wherein the engine has a plurality of horizontally extending cylinders.
Claim 20
Dependent Claim
23 words
In a propulsion unit as set forth in claim 18 wherein the engine has opposed cylinder banks in which the cylinders are formed.
Claim 21
Dependent Claim
20 words
In a propulsion unit as set forth in claim 19 wherein there are a plurality of cylinders in each bank.
Claim 22
Dependent Claim
20 words
In a propulsion unit as set forth in claim 20 wherein the engine is of the two-cycle, crankcase compression type.
Claim 23
Dependent Claim
29 words
In a propulsion unit as set forth in claim 21 further including an induction system for delivering a charge to the crankcase of the engine from above the engine.
Claim 24
Dependent Claim
25 words
In a propulsion unit as set forth in claim 22 wherein the induction system includes an intake device disposed above one of the cylinder banks.
Claim 25
Dependent Claim
34 words
In a propulsion unit as set forth in claim 23 further including an exhaust system for the engine comprising a plurality of downwardly extending exhaust ports formed in the lower sides of the cylinders.
Claim 26
Dependent Claim
27 words
In a propulsion unit as set forth in claim 24 wherein there is provided an exhaust manifold for each cylinder bank extending beneath the respective cylinder banks.
Claim 27
Dependent Claim
29 words
In a propulsion unit as set forth in claim 25 wherein the exhaust manifolds each communicate with a muffler positioned beneath the crankcase and discharging rearwardly through the transom.
Claim 28
Dependent Claim
25 words
In a propulsion unit as set forth in claim 26 further including a trap section extending from the muffler to an underwater exhaust gas discharge.
Claim 29
Dependent Claim
24 words
In a propulsion unit as set forth in claim 17 wherein the cylinder has a downwardly discharging exhaust port port positioned beneath the cylinder.
Claim 30
Dependent Claim
28 words
In a propulsion unit as set forth in claim 28 wherein there are a plurality of cylinders discharging into a common exhaust manifold positioned beneath the cylinder assembly.
Claim 31
Dependent Claim
32 words
In a propulsion unit as set forth in claim 29 wherein there are a pair of opposed cylinder banks each discharging into a respective exhaust manifold positioned beneath the respective cylinder bank.
Claim 32
Dependent Claim
29 words
In a propulsion unit as set forth in claim 30 wherein the exhaust manifolds each communicate with a muffler positioned beneath the crankcase and discharging rearwardly through the transom.
Claim 33
Dependent Claim
25 words
In a propulsion unit as set forth in claim 31 further including a trap section extending from the muffler to an underwater exhaust gas discharge.
Claim 34
Dependent Claim
66 words
In a propulsion unit for a watercraft having a transom, an internal combustion engine adapted to be positioned immediately forwardly of said transom and driving a propulsion device to the rear of said transom, the improvement comprising said engine having an exhaust manifold for receiving exhaust gases from said engine, said exhaust manifold being separated from the passenger compartment by the cylinder block of said engine.
Claim 35
Dependent Claim
66 words
In a propulsion unit for a watercraft having a transom, an internal combustion engine adapted to be positioned immediately forwardly of said transom and driving a propulsion device to the rear of said transom, the improvement comprising said engine having an exhaust manifold for receiving exhaust gases from said engine, said exhaust manifold being separated from the passenger compartment by the cylinder block of said engine.
Claim 36
Dependent Claim
23 words
In a propulsion unit as set forth in claim 33 wherein the engine has opposed cylinder banks in which the cylinders are formed.
Claim 37
Dependent Claim
34 words
In a propulsion unit as set forth in claim 34 further including an exhaust system for the engine comprising a plurality of downwardly extending exhaust ports formed in the lower sides of the cylinders.
Claim 38
Dependent Claim
27 words
In a propulsion unit as set forth in claim 35 wherein there is provided an exhaust manifold for each cylinder bank extending beneath the respective cylinder banks.
Claim 39
Dependent Claim
29 words
In a propulsion unit as set forth in claim 36 wherein the exhaust manifolds each communicate with a muffler positioned beneath the crankcase and discharging rearwardly through the transom.
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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) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |