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US5755606A Expired / Lapsed US ⏱️ 0.0 years remaining

Four-cam outboard motor

Assignee: Yamaha Marine Co Ltd
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Filing: 1996-07-31
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Granted: 1998-05-26
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Expires: 2016-07-31
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Abstract

Abstract A high-performance outboard motor embodying a V-type four overhead camshaft four-cycle internal combustion engine. A compact cam driving arrangement is provided for driving the camshafts from the crankshaft of the engine at the upper end. A flywheel is mounted to the lower end of the crankshaft and is driven by a starter motor for starting of the engine. Another engine accessory is driven off the upper end of the crankshaft so as to maintain a compact and yet highly serviceable arrangement.

Inventors

  • 👤 Masanori Takahashi
  • 👤 Hitoshi Watanabe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 21:11
CPC Classifications
F; F02; F02B; F02B75/00; F02B75/16; F02B75/18; F02B75/22; F02B61/00; F02B61/04; F02B61/045; F02B2075/1804; F02B2075/1824; F02B2275/00; F02B2275/18

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 183 words
An internal combustion engine comprised of a cylinder block having a pair of angularly disposed cylinder banks, each being formed with at least one cylinder bore therein, a crankshaft journaled for rotation at one end of said cylinder block and driven by pistons reciprocating in said cylinder bores, a pair of cylinder heads, each affixed to a respective one of said cylinder banks and closing the respective cylinder bores formed therein, said cylinder heads and said cylinder banks forming a valley there between, a first and second pair of camshafts, each of said pairs being rotatably journaled in a respective one of said cylinder heads for operating the valves therein, a first flexible transmitter for driving one of said camshafts of each of said pairs from said crankshaft, an idler sprocket journaled for rotation contiguous to said valley and engaged with said first flexible transmitter for maintaining engagement of said first flexible transmitter with said one camshaft of each of said pairs, and a pair of second flexible transmitters for driving the remaining camshaft of each of said pairs from the crankshaft-driven camshaft.
Claim 2
Dependent Claim 183 words
An internal combustion engine comprised of a cylinder block having a pair of angularly disposed cylinder banks, each being formed with at least one cylinder bore therein, a crankshaft journaled for rotation at one end of said cylinder block and driven by pistons reciprocating in said cylinder bores, a pair of cylinder heads, each affixed to a respective one of said cylinder banks and closing the respective cylinder bores formed therein, said cylinder heads and said cylinder banks forming a valley there between, a first and second pair of camshafts, each of said pairs being rotatably journaled in a respective one of said cylinder heads for operating the valves therein, a first flexible transmitter for driving one of said camshafts of each of said pairs from said crankshaft, an idler sprocket journaled for rotation contiguous to said valley and engaged with said first flexible transmitter for maintaining engagement of said first flexible transmitter with said one camshaft of each of said pairs, and a pair of second flexible transmitters for driving the remaining camshaft of each of said pairs from the crankshaft-driven camshaft.
Claim 3
Dependent Claim 28 words
An internal combustion engine as set forth in claim 1, wherein at least one of the camshafts driven by the first flexible transmitter is disposed adjacent the valley.
Claim 4
Dependent Claim 26 words
An internal combustion engine as set forth in claim 2, wherein both of the camshafts driven by the first flexible transmitter are disposed adjacent the valley.
Claim 5
Dependent Claim 35 words
An internal combustion engine as set forth in claim 2, wherein the other of the camshafts driven by the first flexible transmitter is on the side of the respective cylinder head spaced from the valley.
Claim 6
Dependent Claim 29 words
An internal combustion engine as set forth in claim 1, wherein the idler sprocket has a smaller diameter than sprockets driving the one camshafts by the first flexible transmitter.
Claim 7
Dependent Claim 26 words
An internal combustion engine as set forth in claim 5, wherein the idler sprocket is journalled upon a shaft that is journalled in the cylinder block.
Claim 8
Dependent Claim 28 words
An internal combustion engine as set forth in claim 6, wherein at least one of the camshafts driven by the first flexible transmitter is disposed adjacent the valley.
Claim 9
Dependent Claim 26 words
An internal combustion engine as set forth in claim 7, wherein both of the camshafts driven by the first flexible transmitter are disposed adjacent the valley.
Claim 10
Dependent Claim 35 words
An internal combustion engine as set forth in claim 7, wherein the other of the camshafts driven by the first flexible transmitter is on the side of the respective cylinder head spaced from the valley.
Claim 11
Dependent Claim 104 words
An internal combustion engine as set forth in claim 1 in combination with an outboard motor having a power head containing said engine and a protective cowling encircling said power head, said engine being mounted in said power head so that said crankshaft rotates about a vertically disposed axis, a drive shaft housing and lower unit depending from said power head and containing a drive shaft rotatably journaled about a vertically extending axis, means for coupling said crankshaft to said drive shaft for driving said drive shaft from said crankshaft, and a propulsion device driven by said drive shaft for propelling an associated watercraft.
Claim 12
Dependent Claim 28 words
An internal combustion engine as set forth in claim 10, wherein at least one of the camshafts driven by the first flexible transmitter is disposed adjacent the valley.
Claim 13
Dependent Claim 26 words
An internal combustion engine as set forth in claim 11, wherein both of the camshafts driven by the first flexible transmitter are disposed adjacent the valley.
Claim 14
Dependent Claim 35 words
An internal combustion engine as set forth in claim 11, wherein the other of the camshafts driven by the first flexible transmitter is on the side of the respective cylinder head spaced from the valley.
Claim 15
Dependent Claim 29 words
An internal combustion engine as set forth in claim 10, wherein the idler sprocket has a smaller diameter than sprockets driving the one camshafts by the first flexible transmitter.
Claim 16
Dependent Claim 26 words
An internal combustion engine as set forth in claim 14, wherein the idler sprocket is journalled upon a shaft that is journalled in the cylinder block.
Claim 17
Dependent Claim 28 words
An internal combustion engine as set forth in claim 15, wherein at least one of the camshafts driven by the first flexible transmitter is disposed adjacent the valley.
Claim 18
Dependent Claim 26 words
An internal combustion engine as set forth in claim 16, wherein both of the camshafts driven by the first flexible transmitter are disposed adjacent the valley.
Claim 19
Dependent Claim 35 words
An internal combustion engine as set forth in claim 16, wherein the other of the camshafts driven by the first flexible transmitter is on the side of the respective cylinder head spaced from the valley.
Claim 20
Dependent Claim 55 words
An internal combustion engine as set forth in claim 10, further including a flywheel fixed for rotation with the lower end of said crankshaft, a starter gear fixed for rotation with said flywheel, and a starter motor carried by said engine and having a pinion gear engaged with said starter gear for starting said engine.
Claim 21
Dependent Claim 29 words
An internal combustion engine as set forth in claim 19, further including a drive pulley affixed to the upper end of said crankshaft and another engine accessory driven thereby.
Claim 22
Dependent Claim 18 words
An internal combustion engine as set forth in claim 20, wherein the further accessory comprises an electrical generator.
Claim 23
Dependent Claim 47 words
An internal combustion engine as set forth in claim 19, wherein the crankshaft is journalled within a crankcase chamber formed in part by a crankcase member affixed to the cylinder block and wherein the crankcase member is formed with a recess into which the starter motor extends.
Claim 24
Dependent Claim 35 words
An internal combustion engine as set forth in claim 22, further including a drive pulley affixed to the upper end of said crankshaft and another engine accessory driven thereby and supported upon said crankcase member.
Claim 25
Dependent Claim 18 words
An internal combustion engine as set forth in claim 23, wherein the further accessory comprises an electrical generator.
Claim 26
Dependent Claim 165 words
An outboard motor adapted to be affixed to the transom of a watercraft for powering the watercraft, said outboard motor being comprised of a power head consisting of an internal combustion engine and a surrounding protective cowling, said engine being mounted in said power head so that its crankshaft rotates about a vertically extending axis, a drive shaft housing and lower unit depending from said power head and containing a drive shaft journaled for rotation about a vertically extending axis, means for coupling said engine crankshaft to said drive shaft for driving said drive shaft, a propulsion device driven by said drive shaft for propelling the associated watercraft, a flywheel fixed for rotation with the lower end of said crankshaft, a starter gear fixed for rotation with said flywheel, and a starter motor carried by said engine at the front of said powerhead and forwardly of said crankshaft axis, said starter motor having a pinion gear engaged with said starter gear for starting said engine.
Claim 27
Dependent Claim 165 words
An outboard motor adapted to be affixed to the transom of a watercraft for powering the watercraft, said outboard motor being comprised of a power head consisting of an internal combustion engine and a surrounding protective cowling, said engine being mounted in said power head so that its crankshaft rotates about a vertically extending axis, a drive shaft housing and lower unit depending from said power head and containing a drive shaft journaled for rotation about a vertically extending axis, means for coupling said engine crankshaft to said drive shaft for driving said drive shaft, a propulsion device driven by said drive shaft for propelling the associated watercraft, a flywheel fixed for rotation with the lower end of said crankshaft, a starter gear fixed for rotation with said flywheel, and a starter motor carried by said engine at the front of said powerhead and forwardly of said crankshaft axis, said starter motor having a pinion gear engaged with said starter gear for starting said engine.
Claim 28
Dependent Claim 51 words
An outboard motor as set forth in claim 25, wherein the crankshaft is journalled within a crankcase chamber formed in part by a crankcase member affixed to the cylinder block and wherein the crankcase member is formed with a recess in its forward face and into which the starter motor extends.
Claim 29
Dependent Claim 34 words
An outboard motor as set forth in claim 26, further including a drive pulley affixed to the upper end of said crankshaft and another engine accessory driven thereby and supported upon said crankcase member.
Claim 30
Dependent Claim 17 words
An outboard motor as set forth in claim 27, wherein the further accessory comprises an electrical generator.

References Cited (Backward Citations)

US5370563A Cited
US5553586A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-05-25 2001-11-24 2002-05-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-05-25 2005-11-24 2006-05-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-05-25 2009-11-24 2010-05-26 $7700.00 Window Closed / Lapsed

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