FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION Improved Air Intake system for automobiles
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr.Sudhakara Naidu, Mr.Pramodkumar Mhaske and Dr. Milind Ambardekar, all Indian nationals
of TATA MOTORS LIMITED
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention
and the manner in which it is to be performed.

Field of invention:
This invention is relates to air intake system for automobiles and more particularly relates to an air-intake system for noise reduction of a passenger carrier.
Background of Invention:
Air intake system is one of the important systems in automobile, which supplies desired quantity of air to engine. In conventional air intake system the air-intake snorkel is provided on top of vehicle body in a cavity provided on B- Pillar to supply fresh air to the duct which is connected to an air filter. From filter this air goes to engine. Because the fresh air is made to pass through a cavity of the B-pillar of the vehicle body, it creates higher noise at Driver's Ear Level due to drumming effect of air impinging on walls of cabin because of air-column in the B-pillar creating standing waves at low frequencies like 250 Hz and 500 Hz. Due to these standing waves, there was found higher In-cab noise throughout engine speeds. Exterior level of the vehicle noise was also found increased.
1. "The design and Development of Intake and Exhaust Silencers for high performance motorcycle engines "by Roe, G. E., published in I. Mech. E. Paper No. C 135/ 78, in 1978 teaches a concept of annular discharge type intake silencer to reduce noise level at a particular frequency only. The drawbacks associated with this technique are that there is a requirement of very large volume silencers and they are tuned to a particular frequency of noise and are not much effective for a wide band noise.
2. "Reduction of Exhaust and Air-induction System noise by a Predictive method" by Parsons J. W. published in SAE Paper No. 931338 in 1993 teaches use of a
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Helmholtz resonator and provisions of tuning holes at intake duct for noise reduction. The drawback associated with this technique is said resonators are tuned to a particular frequency of noise and are not much effective for a wide band noise. 3. "Rapid Predictions of vehicle Intake/exhaust radiated noise" by Harrison, M. F. published in I. Mech. E. Paper No. C 487/019/94 in 1994 teaches use of computational method to predict noise radiated from vehicle intake systems. The drawback associated with this method is it gives only a computational method and utility to seek a technical solution to a vehicle level noise problem is limited.
Objects of this invention:
The main object of this invention is to provide an air intake system with minimum noise inside an automobile.
Another object of this invention is to provide an air intake system with grills at the inlet to prevent entry of dirt, rain water etc. without affecting aesthetics of the automobile. Yet another object of this invention is to provide air intake system having simple in construction and cost effective.
Statement of Invention:
Improved air intake system for automobiles comprises of an intake snorkel, grill and a duct, wherein said snorkel is fitted at the bottom side of the cabin; air inlet end of said snorkel is fitted with grill, said grill have outer surface and inclined multiple louvers integral with said outer surface, and outer surface of said grill is provided with two or more snaps to snap fit on the outer panel of an automobile, other end of said snorkel is
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fitted in to one end of duct which is supported on inner panel of an automobile and other end of said duct is fitted to an air filter.
Improved air intake system for automobiles wherein said grill is fitted to snorkel by using suitable adhesives.
Improved air intake system for automobiles wherein lower most position of said snorkel is provided with opening to drain water.
Improved air intake system for automobiles wherein one end of said duct is supported on inner panel by means of fasteners.
Brief description of Invention:
An air intake system in accordance with this invention basically comprises of an intake snorkel, a duct and grills wherein said intake snorkel is fitted at the bottom side of the vehicle cabin. Air inlet end of said snorkel is fitted with grill and the intake duct is fitted between said snorkel and the Air-filter. With this arrangement, standing waves are eliminated as the B- pillar cavity is completely isolated from the intake system. Due to routing of air-flow through an intake duct, the sound waves will not strike the cabin wall and the in-cab noise will not increase.
Detailed description of invention:
Referring now to the drawings wherein the showings are for the purpose of illustrating a
preferred embodiment of the invention only, and not for the purpose of limiting the same,
Fig. 1 - Shows an Air intake system in accordance with this invention
Fig. 2 - Shows isometric view of an air intake system provided on automobile body
Fig. 3- Shows isometric view of air intake system fitted on inner panel
Fig. 4 - Shows a graph of Noise level Vs Engine RPM
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Referring to figures 1 to 3 an air intake system (A) basically comprises of an intake snorkel (1), grill (2) and a duct (3) wherein said snorkel (1) is fitted at the bottom side of the vehicle cabin (not shown). Air inlet end of said snorkel (1) is fitted with grill (2), said grill (2) have inclined integral multiple louvers (4) and outer periphery of said grill is provided with two or more snaps (6) to snap fit on the outer panel (7) of automobile. Grill (2) is fitted to snorkel (1) by using suitable adhesives. Lower most position of said snorkel (1) is provided with opening (5) to drain water. Other end of snorkel (1) is inserted in to one end of duct (3) and said duct (3) is supported on inner panel (8) of an automobile. Other end of said duct (3) is fitted to air filter. With this new arrangement, standing waves are eliminated as the B- pillar cavity is completely isolated from the intake system. Due to routing of air-flow through a horizontal intake duct, the sound waves will not strike the cabin wall and the in-cab noise will not increase.
Fig. 4 shows a graph plotted noise level Vs Engine RPM, from graph it is clear that overall noise level at Driver's ear is reduced across the whole speed band in 3rd gear wide-open-throttle running of the vehicle.
By using air intake system in accordance with this invention clean air-flows to the engine via a filter. The desired engine performance is achieved with this system without adding noise to driver's compartment.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
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We claim:
1. Improved air intake system for automobiles comprises of an intake snorkel, grill and a duct, wherein said snorkel is fitted at the bottom side of the cabin; air inlet end of said snorkel is fitted with grill, said grill have outer surface and inclined multiple louvers integral with said outer surface, and outer surface of said grill is provided with two or more snaps to snap fit on the outer panel of an automobile, other end of said snorkel is fitted in to one end of duct which is supported on inner panel of an automobile and other end of said duct is fitted to an air filter.
2. Improved air intake system for automobiles as claimed in claim 1 wherein said grill is fitted to snorkel by using suitable adhesives.
3. Improved air intake system for automobiles as claimed in claim 1 and 2 wherein lower most position of said snorkel is provided with opening to drain water.
4. Improved air intake system for automobiles as claimed in claim 1 and 3 wherein one end of said duct is supported on inner panel by means of fasteners.
5. Improved air intake system for automobiles substantially as herein described with reference to accompanying drawings.
Dated this 22nd day of June 2007.

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ABSTRACT
Improved Air Intake system for automobiles
This invention relates to an air intake system for automobiles comprising of an intake snorkel, a duct and grill, wherein said intake snorkel is fitted at the bottom side of the vehicle cabin. Air inlet end of said snorkel is fitted with grill and the intake duct is fitted between said snorkel and the Air-filter. With this arrangement, standing waves are eliminated as the B- pillar cavity is completely isolated from the intake system. Due to routing of air-flow through an intake duct, the sound waves will not strike the cabin wall and the in-cab noise will not increase. Fig.l