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US5037340A Expired / Lapsed US ⏱️ 0.0 years remaining

Lubricating device for four stroke outboard motor

Assignee: Yamaha Marine Co Ltd
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Filing: 1990-03-29
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Granted: 1991-08-06
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Expires: 2010-03-29
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Abstract

Abstract A number of embodiments of outboard motors powered by four cycle internal combustion engines having a dry sump lubrication system wherein the external oil reservoir is positioned externally of the engine. In some embodiments, the reservoir is contained directly in the power head and in another embodiment, the reservoir is contained externally of the outboard motor. The use of such external positioning of the lubricant reservoirs from the drive shaft housing permits the use of a large expansion chamber for the exhaust system in the drive shaft housing. In one embodiment, a pair of expansion chambers are provided therein.

Inventors

  • 👤 Tasuhiko Shibata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 11:39
CPC Classifications
F; F01; F01M; F01M1/00; F01M1/12; B; B63; B63H; B63H20/00; B63H20/001; B63H20/002; F01M11/00; F02; F02B; F02B61/00; F02B61/04; F02B61/045; F02B75/00; F02B75/007; F02B75/16; F02B75/18; F02B75/20; F01M2001/126; F01M11/0004; F01M2011/0083; F02B75/02; F02B2075/022; F02B2075/027; F02B2075/1804; F02B2075/1816

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 161 words
An outboard motor comprised of a power head including an internal combustion engine and a surrounding protective cowling, a drive shaft housing and lower unit depending from said power head and affixed thereto, a drive shaft driven by said internal combustion engine and journaled in said drive shaft housing and lower unit, and a propulsion unit in said lower unit driven by said drive shaft, the improvement comprising said internal combustion engine operating on a four stroke cycle and having a lubricating system, a lubricant reservoir contained externally of said engine and externally of said drive shaft housing and lower unit, means including a pressure pump for circulating lubricant from said lubricant reservoir to said engine lubricating system, a scavenge pump for returning lubricant from said engine lubricating system to said lubricant reservoir, and vent conduit means communicate said engine lubricating system with said lubricant reservoir at points above the lubricant level in both said lubricating system and said lubricant reservoir.
Claim 2
Dependent Claim 161 words
An outboard motor comprised of a power head including an internal combustion engine and a surrounding protective cowling, a drive shaft housing and lower unit depending from said power head and affixed thereto, a drive shaft driven by said internal combustion engine and journaled in said drive shaft housing and lower unit, and a propulsion unit in said lower unit driven by said drive shaft, the improvement comprising said internal combustion engine operating on a four stroke cycle and having a lubricating system, a lubricant reservoir contained externally of said engine and externally of said drive shaft housing and lower unit, means including a pressure pump for circulating lubricant from said lubricant reservoir to said engine lubricating system, a scavenge pump for returning lubricant from said engine lubricating system to said lubricant reservoir, and vent conduit means communicate said engine lubricating system with said lubricant reservoir at points above the lubricant level in both said lubricating system and said lubricant reservoir.
Claim 3
Dependent Claim 65 words
An outboard motor as set forth in claim 1 wherein the means for circulating lubricant between the lubricant reservoir and the engine lubricating system comprises a supply conduit for delivering lubricant pumped by the pressure pump from the reservoir to the engine lubricating system and a return conduit for returning the lubricant pumped from the lubricating system by the scavenge pump to the lubricant reservoir.
Claim 4
Dependent Claim 30 words
An outboard motor as set forth in claim 2 wherein the engine has a crankshaft rotatably journaled within a crankcase and the lubricant reservoir is positioned externally of the crankcase.
Claim 5
Dependent Claim 19 words
An outboard motor as set forth in claim 3 wherein the engine crankshaft rotates about a vertically extending axis.
Claim 6
Dependent Claim 30 words
An outboard motor as set forth in claim 4 wherein the lubricant reservoir is contained within the protective cowling of the power head but externally of the internal combustion engine.
Claim 7
Dependent Claim 20 words
An outboard motor as set forth in claim 4 wherein the lubricant reservoir is positioned externally of the outboard motor.
Claim 8
Dependent Claim 30 words
An outboard motor as set forth in claim 1 wherein the lubricant reservoir is positioned within the protective cowling of the power head but externally of the internal combustion engine.
Claim 9
Dependent Claim 20 words
An outboard motor as set forth in claim 1 wherein the lubricant reservoir is positioned externally of the outboard motor.
Claim 10
Dependent Claim 31 words
An outboard motor as set forth in claim 1 further including an exhaust expansion chamber formed within the drive shaft housing and lower unit and receiving exhaust gases from the engine.
Claim 11
Dependent Claim 65 words
An outboard motor as set forth in claim 9 wherein the means for circulating lubricant between the lubricant reservoir and the engine lubricating system comprises a supply conduit for delivering lubricant pumped by the pressure pump from the reservoir to the engine lubricating system and a return conduit for returning the lubricant pumped by the scavenge pump from the lubricating system to the lubricant reservoir.
Claim 12
Dependent Claim 30 words
An outboard motor as set forth in claim 10 wherein the engine has a crankshaft rotatably journaled within a crankcase and the lubricant reservoir is positioned externally of the crankcase.
Claim 13
Dependent Claim 19 words
An outboard motor as set forth in claim 11 wherein the engine crankshaft rotates about a vertically extending axis.
Claim 14
Dependent Claim 30 words
An outboard motor as set forth in claim 12 wherein the lubricant reservoir is contained within the protective cowling of the power head but externally of the internal combustion engine.
Claim 15
Dependent Claim 20 words
An outboard motor as set forth in claim 12 wherein the lubricant reservoir is positioned externally of the outboard motor.
Claim 16
Dependent Claim 30 words
An outboard motor as set forth in claim 9 wherein the lubricant reservoir is contained within the protective cowling of the power head but externally of the internal combustion engine.
Claim 17
Dependent Claim 20 words
An outboard motor as set forth in claim 9 wherein the lubricant reservoir is positioned externally of the outboard motor.
Claim 18
Dependent Claim 56 words
An outboard motor as set forth in claim 5 wherein the vent conduit is positioned above the lubricant level in the lubricant reservoir and the lubricating system when the outboard motor is affixed to a transom of the watercraft and also when the outboard motor is removed from a watercraft and is laid on its side.
Claim 19
Dependent Claim 56 words
An outboard motor as set forth in claim 7 wherein the vent conduit is positioned above the lubricant level in the lubricant reservoir and the lubricating system when the outboard motor is affixed to a transom of the watercraft and also when the outboard motor is removed from a watercraft and is laid on its side.
Claim 20
Dependent Claim 56 words
An outboard motor as set forth in claim 13 wherein the vent conduit is positioned above the lubricant level in the lubricant reservoir and the lubricating system when the outboard motor is affixed to a transom of the watercraft and also when the outboard motor is removed from a watercraft and is laid on its side.

References Cited (Backward Citations)

US4588385A Cited
US4588385B1 Cited
US4692123A Cited
JPS60261797A Cited
US4735590A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-08-05 1995-02-04 1995-08-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-08-05 1999-02-04 1999-08-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-08-05 2003-02-04 2003-08-06 $7700.00 Window Closed / Lapsed

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