FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
An Improved passenger airbag System 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
Shailesh Kudale
Pratyush Khare
Ajit Gokhale
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:
The present invention is related to airbag system in an automobile and more particularly it relates to an improved passenger airbag (PAB) system in an automobile to improve the safety of occupant in the event of frontal crash.
Background of invention:
Generally protection of occupant is one of the major criterions for designing modern vehicles. The vehicles have been provided with restraint system to absorb the kinetic energy of occupant in a controlled manner and there by reducing the undesirable effects of the vehicle impact in a crash accident. The restraint systems primarily consist of safety belts and the same has been supplemented by airbags. Frontal airbags are provided for energy dissipation in frontal impact and side airbags are provided for mitigating the side impact accidents. The frontal airbag provided for passenger is known as "Passenger Air Bag (PAB)".
Typically the passenger airbag (PAB) is housed within the dashboard of vehicle. In the event of accident the said passenger airbag (PAB) is deployed in controlled manner to reduce the injuries to the occupants. The inflation of said passenger airbag (PAB) is guided by the vehicle windscreen to reach towards the occupant in case of top mount passenger airbag position. The top mount position of airbag comprises the opening of airbag towards the windscreen. In the event of deployment of passenger airbag, the said passenger airbag is guided by the vehicle windscreen in the initial phase of inflation. During the initial phase of PAB inflation, airbag exerts forces on windscreen. Depending on impact force of said passenger airbag (PAB) and the strength of vehicle windscreen, the damage or breakage of vehicle windscreen are observed at some instances. Such breakage of vehicle windscreen is not desirable since it would be detrimental to the integrity of the fabric of airbag. The glass particles of broken

windscreen could damage the fabric of airbag thereby leading to risk of leakage of airbag gases thereby reducing the airbag effectiveness.
Objects of invention:
The main object of the present invention is to provide an improved passenger airbag system.
Another object of the present invention is to provide an improved passenger airbag system which is having tether straps in airbags for guided deployment of said airbag to avoid the windscreen breakage.
Another object of the present invention is to provide an improved passenger airbag system which is simple in construction and cost effective.
Statement of invention:
An improved passenger airbag system comprises; a passenger airbag (01), a passenger airbag container (02) for housing said aii-bag; an inflator means (03) disposed in the dashboard (04) of vehicle; said passenger airbag (01) having at least two tether members (05, 06) for guiding the inflating airbag (01) towards occupant in the event of crash of vehicle in such a manner that said tether members (05, 06) guide and support the deployment of said passenger airbag (01) to prevent the damage of windscreen (07) of vehicle.
The airbag system, in accordance with this invention, wherein said tether members (05, 06) are provided inside stitched to the said passenger airbag (01) near to the passenger airbag container (02) such that the gas coming from the said inflator means (03) is guided away from said windscreen and towards the occupants thereby preventing the damage of said windscreen.

The airbag system , in accordance with this invention, wherein said tether members (05, 06) are flexible and configured in such a way that said tether members (05,06) guide and support the airbag (01) cushion so that the shape and size of said passenger airbag (01) can be controlled in the early phase of the passenger airbag deployment.
The airbag system, in accordance with this invention, wherein the stiffness of said tether members (05, 06) are same or greater than that of the airbag cushion and are provided in such a way that the tether members are not in the path of the airbag gas flow and the said tether members are provided away from the vent holes of airbag to improve the effectiveness of airbag deployment.
An improved passenger airbag system comprises; a passenger airbag (01), a passenger airbag container (02) for housing said airbag; an inflator means (03) disposed in the dashboard (04) of vehicle; said passenger airbag (01) having a tether member (05a) provided in the flow path of airbag gas for diverting the said gas sideways instead of allowing it towards the windscreen (07) thereby preventing the damage of windscreen of vehicle.
The airbag system, in accordance with this invention, wherein said tether member (05a) is provided inside stitched to the said passenger airbag (01) near to the passenger airbag container (02) such that the gas coming from the said inflator means (03) is diverted sideways away from said windscreen during the deployment of said passenger airbag (01) to prevent the damage of windscreen of vehicle.
The airbag system, in accordance with this invention, wherein said tether member (05a) is flexible and configured in such a way that said tether member (05a) diverts the gas sideways so that the shape and size of said passenger

airbag (01) can be controlled in the early phase of the passenger airbag deployment.
The airbag system, in accordance with this invention, wherein the stiffness of said tether member (05a) is same or greater than that of the airbag cushion and is provided in such a way that said tether member is in the path of the airbag gas flow.
The airbag system , in accordance with this invention, wherein the folding pattern of the said passenger airbag 01 is such that the proportion of cushion folding mass is less than or equal to 40 % towards the windscreen and equal to or greater than 60 % towards the occupants for avoiding the breakage of windscreen of vehicle.
Brief description of drawings:
Figure - 01 shows side view of an improved passenger airbag system (PAB) and windscreen in accordance with the first embodiment of present invention.
Figure - 02 shows side view of an improved passenger airbag system (PAB) and windscreen in accordance with second embodiment of the present invention.
Brief description of invention:
In accordance with the first embodiment of present invention, an improved passenger airbag (PAB) system comprises; a passenger airbag 01, a passenger airbag container 02 for housing said airbag; an inflator means 03 disposed in the dashboard 04 of vehicle; said passenger airbag 01 having a tether members 05,06 for guiding the inflating airbag 01 towards occupant in the event of crash of vehicle in such a manner that said tether members 05,06 guide and support the deployment of said passenger airbag 01 to prevent the damage of windscreen

07 of vehicle. In another embodiment, said passenger airbag 01 comprises a tether member 05a provided in the flow path of airbag gas for diverting the said gas sideways instead of allowing it towards the windscreen (07) thereby preventing the damage of windscreen of vehicle.
Detailed description of invention:
In accordance with the first embodiment of present invention, an improved passenger airbag (PAB) system comprises; a passenger airbag 01, a passenger airbag container 02 for housing said airbag; an inflator means 03 disposed in the dashboard 04 of vehicle; said passenger airbag 01 having at least two tether members 05,06 for guiding the inflating airbag 01 towards occupant in the event of crash of vehicle in such a manner that said tether members 05,06 guide and support the deployment of said passenger airbag 01 to prevent the damage of windscreen 07 of vehicle.
The said passenger airbag 01 is folded and disposed inside the said container 02. The said container 02 is housed inside the said dashboard 04 of vehicle. In the event of crash, the inflator means 03 provides gas for inflating the said passenger airbag 01.
The said passenger airbag 01 is folded inside the said container 02 in normal operation. The said container 02 is housed inside the said dashboard 04 of vehicle at appropriate location such that the deployment of passenger airbag 01 facilitate the restraint system to absorb the kinetic energy of occupant in a controlled manner and there by reducing injuries to vehicle occupants in event of frontal impact of vehicle in accident.
In the event of crash of vehicle, the said inflator means 03 which is adapted to provide the gas for inflating the said passenger airbag 01. Upon inflation, the said passenger airbag ( PAB) is pushed towards the said windscreen.

Said passenger airbag 01 comprises at least two tether members 05, 06. The said tether members 05, 06 are provided inside the said passenger airbag 01 to guide and support the airbag 01 cushion.
The said tether members 05, 06 are provided internally stitched to the said passenger airbag 01 cushion such that the shape and size of said passenger airbag 01 can be controlled in the early phase of the passenger airbag deployment.
Upon the deployment of said passenger airbag 01, the said inflator means 03 provides the gas to the said passenger airbag 01 which inflates due to filling of the said gas. The said tether members 05, 06 guides and support the deployment of said passenger airbag 01 to prevent the damage of windscreen of vehicle.
The said tether members 05, 06 are flexible and configured in such a way that said tether members 05,06 prevents the breakage of the said windscreen by guiding and supporting the deployment of said passenger airbag 01.
The said tether members 05, 06 are provided on inner side of the said passenger airbag 01 and disposed on the windscreen side such that said tether members 05,06 extends towards windscreen and act as protection to prevent the breakage or damage of the said windscreen by guiding and supporting the deployment of said passenger airbag 01.
The said tether members 05, 06 are provided on inner side of the said passenger airbag 01 and near to the passenger airbag container 02 such that the gas coming from the said inflator means 03 is guided away from said windscreen and towards the occupants thereby preventing the damage of said windscreen.

The stiffness of said tether members 05,06 is same or greater than that of the airbag cushion and are provided in such a way that the tether members are not in the path of the airbag gas flow and the said tether members are provided away from the vent holes of airbag to improve the effectiveness of airbag deployment.
The folding pattern of the said passenger airbag 01 is such that the proportion of cushion folding mass is less than or equal to 40 % towards the windscreen and equal to or greater than 60 % towards the occupants for avoiding the breakage of windscreen of vehicle.
in accordance with second embodiment, said passenger airbag 01 comprises tether member 05a in the flow path of airbag ga£ for diverting the said gas
damage of windscreen. The said tether members 05a are provided inside the said passenger airbag 01 to divert the airbag gas.
The said tether members 05a are provided internally stitched to the said passenger airbag 01 cushion such that the shape and size of said passenger airbag 01 can be controlled in the early phase of the passenger airbag deployment.
Upon the deployment of said passenger airbag 01, the said inflator means 03 provides the gas to the said passenger airbag 01 which inflates due to filling of the said gas. The said tether member 05a divert trie gas sideways during the deployment of said passenger airbag 01 to prevent the damage of windscreen of vehicle.

The said tether member 05a is flexible and configured in such a way that said tether member 05 prevents the breakage of the said windscreen by diverting the gas sideways during the deployment of said passenger airbag 01.
The said tether members 05a is provided on inner side of the said passenger airbag 01 and disposed on the path of gas flow of passenger airbag such that said tether member 05a extends and direct the gas in sideways acting as protection to prevent the breakage or damage of the said windscreen by diverting the gas sideways during the deployment of said passenger airbag 01.
The said tether members 05a is provided on inner side of the said passenger airbag 01 and near to the passenger airbag container 02 such that the gas coming from the said inflator means 03 is diverted sideways and away from said windscreen and towards the occupants thereby preventing the damage of said windscreen.
The stiffness of said tether members 05a is same or greater than that of the airbag cushion and is provided in such a way that the tether members are the path of the airbag gas flow.
The folding pattern of the said passenger airbag 01 is such that the proportion of cushion folding mass is less than or equal to 40 % towards the windscreen and equal to or greater than 60 % towards the occupants for avoiding the breakage of windscreen of vehicle.
The dimensions of the said tether members 05,06 are determined to control shape of the said passenger airbag 01 in the vicinity of the said windscreen 07

such that the impact forces generated on the said windscreen are minimized and the possible fragmentation of the said windscreen is avoided.
The said tether members are simple in construction and cost effective. The present invention is capable of reducing the possible damage of windscreen in the event of deployment of passenger airbag during the impact of vehicle in accident. The present invention ensures the effectiveness of the said passenger airbag 01 which is guided and supported by said tether members towards the occupants and away from the said windscreen and prevents the damage of said windscreen thereby improving the effectiveness of said passenger airbag 01.
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. An improved passenger airbag system comprises; a passenger airbag (01), a passenger airbag container (02) for housing said airbag; an inflator means (03) disposed in the dashboard (04) of vehicle; said passenger airbag (01) having at least two tether members (05, 06) for guiding the inflating airbag (01) towards occupant in the event of crash of vehicle in such a manner that said tether members (05, 06) guide and support the deployment of said passenger airbag (01) to prevent the damage of windscreen (07) of vehicle.
2. The airbag system as claimed in claim 1, wherein said tether members (05, 06) are provided inside stitched to the said passenger airbag (01) near to the passenger airbag container (02) such that the gas coming from the said inflator means (03) is guided away from said windscreen and towards the occupants thereby preventing the damage of said windscreen.
3. The airbag system as claimed in claim 1, wherein said tether members (05, 06) are flexible and configured in such a way that said tether members (05,06) guide and support the airbag (01) cushion so that the shape and size of said passenger airbag (01) can be controlled in the early phase of the passenger airbag deployment.
4. The airbag system as claimed in claim 1, wherein the stiffness of said tether members (05, 06) are same or greater than that of the airbag cushion and are provided in such a way that the tether members are not in the path of the airbag gas flow and the said tether members are provided away from the vent holes of airbag to improve the effectiveness of airbag deployment.
5. An improved passenger airbag system comprises; a passenger airbag (01), a passenger airbag container (02) for housing said airbag; an inflator means (03) disposed in the dashboard (04) of vehicle; said passenger airbag (01) having a tether member (05a) provided in the flow path of airbag gas for diverting the said gas sideways instead of allowing it towards the windscreen (07) thereby preventing the damage of windscreen of vehicle.

6. The airbag system as claimed in claim 5, wherein said tether member (05a) is provided inside stitched to the said passenger airbag (01) near to the passenger airbag container (02) such that the gas coming from the said inffator means (03) is diverted sideways away from said windscreen during the deployment of said passenger airbag (01) to prevent the damage of windscreen of vehicle.
7. The airbag system as claimed in claim 5, wherein said tether member (05a) is flexible and configured in such a way that said tether member (05a) diverts the gas sideways so that the shape and size of said passenger airbag (01) can be controlled in the early phase of the passenger airbag deployment.
8. The airbag system as claimed in claim 5, wherein the stiffness of said tether member (05a) is same or greater than that of the airbag cushion and is provided in such a way that said tether member is in the path of the airbag gas flow.
9. The airbag system as claimed in claim 1 and 5, wherein the folding pattern of the said passenger airbag 01 is such that the proportion of cushion folding mass is less than or equal to 40 % towards the windscreen and equal to or greater than 60 % towards the occupants for avoiding the breakage of windscreen of vehicle.
10.An improved passenger airbag system as substantially herein described with reference to accompanying drawings.