FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
A RELEASABLE COVER ASSEMBLY FOR INFLATABLE AIR BAG IN
VEHICLE
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,s
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. Sreekesh K. S Nair
Mr. Sandip B Patil
An 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
The present invention relates to cover assembly for vehicle air bag and more particularly to releasable cover assembly for inflatable air bag of vehicle that opens at three sides to avoid the flaps from hitting the windscreen and passenger during accident.
BACKGROUND OF INVENTION
A restraint system like airbag, seat belt etc are employed in the automobiles to ensure the safety of passengers in vehicles. The driver and front passenger airbags are provided as a supplement to the seat belts to help reduce the shocks applied to the head and chest of the driver or front passenger in the event of frontal impact collision. The air bags are usually provided at different locations in vehicles, as shown in figure-01. The driver airbag 1 is provided for protecting the driver, and passenger airbag 2 is provided for protecting an occupant in a front passenger seat. The side airbag 3 is also used for coping with a side impact in an automobile if necessary. In such an airbag system, the driver airbag 1 is mainly installed in the center of a steering wheel, while the passenger airbag 2 is installed by placing an airbag module on the instrument panel. Generally the air bags are packaged out of sight, thereby reducing the potential for intentional and unintentional tampering therewith. Thus, an additional door is constructed by forming an incision line in the instrument panel so that the door can be easily opened upon operation of the passenger airbag 2.
In the event of a crash, the front passenger airbag expands and blows open the cover, shearing the trim material along the inner shear line. The first requirement is that the opening flap should not hit the passenger face, hence the flap should not clear the out of position requirement (OOP). Second requirement is opening flap should not hit the windscreen. If the opening flap hit the windscreen, the windscreen breaks which subsequently tears the airbag. Through the tear area, the air bag gas will leak out leading to reduction of intended pressure required for full passenger air bag deployment. Consequences are airbag will not work properly.
Depending on the styling and packing the conventional tear seam structures adopt U, H etc type structures for air bags. The U type tear seam has a single sided opening. During deployment, the tearing of flaps happens in U pattern and Lid open to single side, towards wind screen. The H type tear seam has a double sided opening. During deployment,

tearing of flap happens in H pattern and the flaps split into two halves and one half opens towards windscreen and other half opens towards the occupant side. In U and H type tear seam air bags the flap that is opening towards the windscreen is hitting the windscreen. But in some cases due to styling and packaging constrain the existing tear seam will not satisfy the passenger air bag (PAB) opening requirements. Hence there exists a need to develop a novel tear seam structure for airbags in vehicle.
OBJECT OF THE INVENTION
The primary object of the present invention is to provide a releasable cover assembly for inflatable air bag in vehicle
Another object of the present invention is to provide a releasable cover assembly with a tear seam structure to avoid the flaps from hitting windscreen and passenger during accident.
Another object of the present invention is to provide a releasable cover assembly which
opens at three sides to satisfy the out of position requirement (OOP) and occupant
requirement.
Another object of the present invention is to provide a releasable cover assembly for
inflatable air bag in vehicle which is simple in construction and cost effective.
STATEMENT OF INVENTION
A releasable cover assembly for inflatable air bag in vehicle, said cover assembly comprises; a first releaseable flap; a second releasable flap ; a third releasable flap; said first ,second and third flaps are hinged around the perimeter of an opening provided on instrument panel of vehicle; said first and second releasable flap having a cut-out portions; said third flap is having a matching profile to the shape constituted by cut-out portions of said first and second flaps to define a tear seam of releasable cover assembly; said flaps rotate about the hinge and said tear seam of said flaps arranged to tear open upwardly to give a way to passenger air bag during the air bag deployment.
The releasable cover assembly, in accordance with this invention, wherein said cut-out portion of said first and second flaps are L-shaped provided on front side towards windscreen to prevent hitting the windscreen during air bag deployment.

The releasable cover assembly, in accordance with this invention, wherein said first, second and third flaps are hinged on perimeter of said opening preferably rectangular, said flaps having tear edge defining tear seam to facilitate opening away from each other.
The releasable cover assembly, in accordance with this invention, wherein said first and second flaps are disposed and arranged opposite to each other along the longitudinal direction of said instrument panel,
The releasable cover assembly, in accordance with this invention, wherein said first and second flaps are mirror image to each other.
The releasable cover assembly, in accordance with this invention, wherein the dimension of said third flap is configured to avoid hitting the windscreen during passenger air bag
deployment,
The releasable cover assembly, in accordance with this invention, wherein said third flap is having a rectangular shape.
The releasable cover assembly, in accordance with this invention, wherein the ratio of the split of doors can be changed for packaging the air bag.
The releasable cover assembly, in accordance with this invention, wherein said tear seam is flexible to split open upwardly to provide a way to the passenger air bag during air bag deployment in the event of accidents or impact or collision.
BRIEF DESCRIPTION OF INVENTION
The embodiments herein provide a releasable cover assembly for inflatable air bag of vehicle. The cover assembly comprises a first releasable flap, a second releasable flap and a third releasable flap. The first, second and third flaps are hinged around the perimeter of a rectangular opening provided on an instrument panel of the vehicle. The first and second releasable flap includes a cut-out portions and the third flap is having a matching profile to the shape constituted by cut-out portions of said first and second flaps to define a tear seam of releasable cover assembly. The flaps rotate about the hinge and the tear seam of said flaps are arranged to tear open upwardly to give a way to air bag during the air bag deployment. The tear seam structure is flexible and by changing the ratio of split of flaps,

the passenger air bag can be packaged irrespective of styling scheme. It satisfies the out of position requirement (OOP) and occupant requirement.
According to present invention, the releasable flaps are provided to avoid the flaps from hitting windscreen and passenger during accident. The said first and second flaps comprises a L-shaped cut-out portion provided on front side towards windscreen to prevent hitting the windscreen during air bag deployment. The first and second flaps are disposed and arranged opposite to each other along the longitudinal direction of said instrument panel. The dimension of the third flap is configured to avoid hitting the windscreen during PAB deployment.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure-01 which show a typical vehicle with a position for a driver airbag, passenger
airbag and a side airbag for coping with a side impact in an automobile.
Figure-02 which shows a schematic view of the tear seam defined by tear edge of said
flaps hinged on the instrument panel, according to present invention.
Figure-03 which shows the said flaps split opened at tear seam, according to present
invention.
DETAILED DESCRIPTION OF THE 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.
The embodiments herein relate to provide a releasable cover assembly for inflatable air bag of vehicle. The cover assembly comprises a first releasable flap 5, a second releasable flap 6 and a third releasable flap 7. The first flap 5, second flap 6 and third flap 7 are attached through the hinge at 8, 9 & 10 respectively around the perimeter of a rectangular opening 12 provided on an instrument panel 11 of the vehicle.
The first flap 5 and second flap 6 includes a cut-out portion 13 and the third flap 7 is having a matching profile to the shape constituted by said cut-out portions 13 of said first flap 5 and second flap 6 to define a tear seam 4 of releasable cover assembly.

The cut-out portion 13 on the first flap 5 and second flap 6 is L-shaped and is provided on front side towards windscreen to prevent hitting the windscreen during air bag deployment.
The third flap 7 is rectangular in shape which is matching with the profile created by the L-shaped cut-out portion 13 of said first flap 5 and second flap 6.
The said first flap 5, second flap 6 and third flap 7 are having tear edge opposite to the hinged edge of said flaps. The said tear edge of said flaps defining a tear seam structure 4.
The said first flap 5, second flap 6 and third flap 7 rotate about the hinge 8, 9, 10 respectively due to the force exerted by the air bag which is activated during the impact of accicents. The tear seam structure 4 are flexible and are arranged in such a way that it split open upwardly to give a way to air bag during the air bag deployment.
The first flap 5 and second flap 6 is disposed and arranged opposite to each other along the longitudinal direction of said instrument panel. The dimension of the third flap 7 is configured to avoid hitting the windscreen during PAB deployment.
The said first flap 5 and second flap 6 are mirror image to each other.
The said first flap 5, second flap 6 and third flap 7 split open upwardly to blow open the
passenger air bag during accidents or frontal impact collision.
The tear seam structure 4 is flexible and by changing the ratio of split, the passenger air bag (PAB) can be packaged irrespective of styling scheme. It satisfies the out of position requirement (OOP) and occupant requirement.
The ratio of the split of said flaps can be changed based on the requirement for packaging the air bag.
ADVANTAGES
• The present invention provides releasable flaps with tear seam notch to avoid the flaps from hitting windscreen and passenger during accident.

• The tear seam structure is flexible and by changing the ratio of split, the passenger air bag (PAB) can be packaged irrespective of styling scheme. It satisfies the out of position requirement (OOP) and occupant requirement.
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.

We Claim:
1. A releasable cover assembly for inflatable air bag in vehicle, said cover assembly comprises; a first releaseable flap; a second releasable flap ; a third releasable flap; said first ,second and third flaps are hinged around the perimeter of an opening provided on instrument panel of vehicle; said first and second releasable flap having a cut-out portions; said third flap is having a matching profile to the shape constituted by cut-out portions of said first and second flaps to define a tear seam of releasable cover assembly; said flaps rotate about the hinge and said tear seam of said flaps arranged to tear open upwardly to give a way to passenger air bag during the air bag deployment.
2. The releasable cover assembly as claimed in claim 1, wherein said cut-out portion of said first and second flaps are L-shaped provided on front side towards windscreen to prevent hitting the windscreen during air bag deployment.
3. The releasable cover assembly as claimed in claim 1, wherein said first , second and third flaps are hinged on perimeter of said opening preferably rectangular, said flaps having tear edge defining tear seam to facilitate opening away from each other.
4. The releasable cover assembly as claimed in claim 1, wherein said first and second flaps are disposed and arranged opposite to each other along the longitudinal direction of said instrument panel.
5. The releasable cover assembly as claimed in claim 1, wherein said first and second flaps are mirror image to each other.
6. The releasable cover assembly as claimed in claim 1, wherein the dimension of said third flap is configured to avoid hitting the windscreen during passenger air
bag deployment.
7. The releasable cover assembly as claimed in claim 1, wherein said third flap is
having a rectangular shape.

8. The releasable cover assembly as claimed in claim 1, wherein the ratio of the split of doors can be changed for packaging the air bag.
9. The releasable cover assembly as claimed in claim 1, wherein said tear seam is flexible to split open upwardly to provide a way to the passenger air bag during air bag deployment in the event of accidents or impact or collision.
10. A releasable cover assembly for inflatable air bag in vehicle as herein described with reference to accompanying drawings.