# US 5,699,763 A · Air intake system for a marine engine

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- Number: US 5,699,763 A
- Document ID: US5699763A
- Status: Granted
- Kind: A
- Application number: 08/733,002
- Filed: 1996-10-16
- Granted: 1997-12-23
- Earliest claimed: 1996-10-16
- Assignees: Brunswick Corporation
- Inventors: George E. Phillips; Wayne M. Jaszewski; John M. Griffiths; Keith W. Gessner
- Web page: https://patentgrep.com/patent/US5699763A

## CPC

- F02M 35/10111: {Substantially V-, C- or U-shaped ducts in direction of the flow path}
- F02M 35/12: Intake silencers {; Sound modulation, transmission or amplification (intake silencers also used as exhaust silencer F01N13/007; filters for compressors F04B39/16)}
- F02M 35/167: {having outboard engines; Jet-skis}
- F02B 61/045: {for marine engines}
- F02B 2075/027: {four}
- F02M 35/10222: {Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission}
- F02M 35/10321: {Plastics; Composites; Rubbers}
- F02M 35/10347: {Moulding, casting or the like}
- F05C 2225/08: Thermoplastics
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)
- F05C: INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES

## Abstract

An air intake box for a four-stroke marine engine. The air box is generally U-shaped in configuration, including a lower section that is connected to the carburetor throat. The lower section extends forwardly from the carburetor and merges into an upper section via a reverse bend. The upper section extends rearwardly above the carburetor and terminates in a distal inlet end that is located at the rear of the engine. The air box reduces air intake noise, and results in cooler air being supplied to the engine, which enhances combustion.

## Claims

### Claim 1

In a four stroke outboard marine engine for a boat, a cylinder block having at least one cylinder bore, said engine block having a forward end facing toward a bow of the boat and having a rear end, a fuel delivery unit mounted on the engine block for supplying a combustible mixture of fuel and air to the cylinder bore, and having an air intake opening facing in a forward direction, and an air intake box having a first end facing in a rearward direction and disposed in communication with said intake opening, said air intake box also having a second end facing in a rearward direction and located to the rear of the fuel delivery unit, whereby air from the rear portion of the engine is drawn into said second end and passes through said air box and is discharged through said first end to said fuel delivery unit.

### Claim 2 (depends on 1)

The engine of claim 1, wherein said air box includes a first section extending forwardly from said first end, and a second section located above said first section, said air box also including a reverse bend section connecting said first and second sections.

### Claim 3 (depends on 1)

The engine of claim 1, wherein said second end is located at the rear of said engine block.

### Claim 4 (depends on 1)

The engine of claim 1, wherein the internal surface of said air box is smooth and substantially free of baffles.

### Claim 5 (depends on 1)

The engine of claim 1, wherein said engine block includes a breather chamber connected to a crankcase of the engine, and conduit means connecting said breather chamber with the interior of said air box.

### Claim 6 (depends on 2)

The engine of claim 2, wherein said second section is disposed above said fuel delivery unit.

### Claim 7 (depends on 2)

The engine of claim 2, wherein said engine block includes a breather chamber connected to a crankcase of the engine, and conduit means connecting the second section of said air box to said breather chamber.

### Claim 8 (depends on 7)

The engine of claim 7, wherein said conduit means comprises a tubular nipple extending outwardly from said second section, and sealing means for connecting said nipple in sealed relation to said breather chamber.

### Claim 9

In a four-stroke outboard marine engine for a boat, an engine block having a plurality of cylinders, said engine block having a forward end facing the bow of the boat and having a rear end, a carburetor mounted on the engine block for supplying a combustible mixture of fuel and air to said cylinders, said carburetor having an air intake opening facing in a forward direction, an air intake box for supplying air to the intake opening of the carburetor, said air box including a first section having a first rearward facing end connected to said air intake opening and further including a second section located generally parallel to said first section and terminating in a second rearward facing end, said air box also including a reverse bend section connecting said first section and said second section, said second end located adjacent the rear of said engine, whereby air is drawn into said second end and flows through said air box and is discharged through said first end to said carburetor.

### Claim 10 (depends on 9)

The engine of claim 9 wherein said air box is composed of a plastic material.

### Claim 11 (depends on 9)

The engine of claim 9, wherein said first section extends upwardly at an acute angle to the horizontal from the carburetor, and said second section extends above the carburetor.

### Claim 12 (depends on 9)

The engine of claim 9, wherein said second end is located rearwardly of said first end.