US3791482A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Noise supression air duct assembly for air cooled internal combustion engines in vehicle installations
Assignee: Coleman Co Inc
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Filing: 1973-05-14
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Granted: 1974-02-12
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Expires: 1993-05-14
Abstract
Abstract The noise emitted by an air cooled internal combustion engine in a vehicle installation is suppressed by an air duct assembly which is light weight and easily removable to permit access to the engine and related components for routine adjustments and servicing. The duct assembly includes relatively rigid air intake and air exhaust ducts, each of which is integrally molded from plastic with sound absorbing qualities. For axial fan cooled engines, the fan and cylinder cooling fins are enclosed by a shroud provided with air intake and exhaust openings. The cowl of the vehicle which encloses the engine is also provided with air intake and exhaust openings. The intake duct extends between the air intake opening of the vehicle cowl and the air intake opening in the engine shroud, and the exhaust duct extends between the exhaust opening of the engine shroud and the exhaust opening in the vehicle cowl. Each duct provides a baffled or tortuous air passage so that noise cannot escape through the duct without being reflected from the walls of the duct, and each duct is removably secured to either the engine shroud or the cowl by spring latches which permit quick removal of the ducts when desired. The duct assembly also supplies combustion air through a baffled path to a carburetor plenum chamber.
Inventors
- 👤 H Sykora
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:43
CPC Classifications
F; F01; F01P; F01P1/00; F01P1/02; F01N; F01N1/00; F01N1/08; F02; F02B; F02B77/00; F02B77/11; F02B77/13
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
185 words
A noise suppression duct assembly for a vehicle having an engine cowl and an air cooled engine comprising shroud means on the engine providing an air cooling chamber, the shroud means having an air intake opening and an air exhaust opening, the vehicle cowl having an air intake opening and an air exhaust opening, an air intake duct extending between the air intake opening of the cowl and the air intake opening of the shroud means and being removably secured to at least one of the cowl and the engine shroud means, and an air exhaust duct extending between the air exhaust opening of the engine shroud means and the air exhaust opening in the cowl and being removably secured to at least one of the engine shroud means and the cowl, each of the ducts providing a tortuous air passage therethrough whereby air cannot travel in a straight path from the air intake opening in the cowl to the air intake opening of the shroud means and from the air exhaust opening of the shroud means to the air exhaust opening in the cowl.
Claim 2
Dependent Claim
185 words
A noise suppression duct assembly for a vehicle having an engine cowl and an air cooled engine comprising shroud means on the engine providing an air cooling chamber, the shroud means having an air intake opening and an air exhaust opening, the vehicle cowl having an air intake opening and an air exhaust opening, an air intake duct extending between the air intake opening of the cowl and the air intake opening of the shroud means and being removably secured to at least one of the cowl and the engine shroud means, and an air exhaust duct extending between the air exhaust opening of the engine shroud means and the air exhaust opening in the cowl and being removably secured to at least one of the engine shroud means and the cowl, each of the ducts providing a tortuous air passage therethrough whereby air cannot travel in a straight path from the air intake opening in the cowl to the air intake opening of the shroud means and from the air exhaust opening of the shroud means to the air exhaust opening in the cowl.
Claim 3
Dependent Claim
25 words
The structure of claim 1 in which each of the ducts is integrally molded from plastic and is light weight, and relatively rigid and self-supporting.
Claim 4
Dependent Claim
37 words
The structure of claim 1 in which each of the ducts includes flexible sealing means attached thereto and engaging the cowl around the associated opening therein to restrain leakage of noise between the cowl and the duct.
Claim 5
Dependent Claim
61 words
The structure of claim 1 including attachment means for each duct for removably securing each duct to at least one of the cowl and the engine shroud means, each attachment means including a resilient spring secured to one of the cowl and the engine shroud means and hook means secured to one of the ducts and being engaged by the spring.
Claim 6
Dependent Claim
120 words
The structure of claim 1 in which the cowl includes a hood extending rearwardly from the front end of the vehicle over the engine and a console closing the rear end of the cowl, the air intake and air exhaust opening in the cowl being provided through the console on opposite sides thereof and below the air intake and air exhaust openings, respectively, of the engine shroud means, the air intake duct extending forwardly and upwardly from the air intake opening in the console to the air intake opening of the engine shroud means, and the air exhaust duct extending downwardly and rearwardly from the air exhaust opening of the shroud means to the air exhaust opening in the console.
Claim 7
Dependent Claim
120 words
The structure of claim 5 including a carburetor mounted on the engine and extending rearwardly therefrom, the console including a rear wall and partition means positioned forwardly of the rear wall and having an opening therein, a carburetor box secured to the engine and extending rearwardly therefrom around the carburetor, and resilient seal means between the rear end of the carburetor box and the partition means and extending around the opening in the partition means, the carburetor box and the partition means and the rear wall of the console providing a carburetor plenum chamber, the console being provided with an air intake opening for the carburetor plenum chamber for supplying air to the carburetor plenum chamber and to the carburetor.
Claim 8
Dependent Claim
27 words
The structure of claim 6 in which the rear wall of the console includes a door portion for providing access to the carburetor through the plenum chamber.
Claim 9
Dependent Claim
26 words
The structure of claim 6 in which each of the ducts is formed of integrally molded plastic and is light weight, and relatively rigid and self-supporting.
Claim 10
Dependent Claim
44 words
The structure of claim 1 in which the cowl includes a hood extending rearwardly from the front end of the vehicle and over the engine, the air intake and air exhaust openings in the cowl being provided through the hood on opposite sides thereof.
Claim 11
Dependent Claim
126 words
The structure of claim 9 including a carburetor mounted on the engine, a carburetor box secured to the engine and extending around the carburetor, the air intake duct including an intake portion extending laterally inwardly from the intake opening in the hood, a first branch portion extending from the intake portion to the air inlet opening of the engine shroud means, and a second branch portion extending from the intake portion to the carburetor box, the second branch portion and the carburetor box having mating peRipheries whereby a carburetor plenum chamber is formed by the second branch portion and the carburetor box, the first branch portion being removably secured to the engine shroud means and the second branch portion being removably secured to the carburetor box.
Claim 12
Dependent Claim
26 words
The structure of claim 10 in which each of the ducts is formed of integrally molded plastic and is light weight, and relatively rigid and self-supporting.
Claim 13
Dependent Claim
66 words
The structure of claim 10 in which each of the ducts is formed of integrally molded plastic and is relatively rigid and self-supporting, attachment means for each duct for removably securing each duct to the engine shroud means, each attaching means including a resilient spring secured to the engine shroud means and hook means secured to one of the ducts and being engaged by the spring.
References Cited (Backward Citations)
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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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |