FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)
TITLE OF THE INVENTION
Mechanism to control dummy kinematics in vehicles with supplementary
restraint system airbags
INVENTOR
Mr. Sanjay Apte
Mr. Musaib Momin
Mr. D S Venu
Mr. Atul Ronghe
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
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in
which it is to be performed.

TITLE OF INVENTION:
Mechanism to control dummy kinematics in vehicles with supplementary restraint system airbags
FIELD OF INVENTION:
The present invention generally relates to provide a mechanism for restricting unfavorable dummy kinematics during offset deformable barrier crash, when the driver and co-driver seats have a tendency to bend towards outboard side of the vehicle. More particularly to a floating connection between chassis frame and the vehicle body to improve the performance of supplementary restraint system (SRS) airbags in vehicles.
BACKGROUND OF THE INVENTION:
An unfavorable dummy movement occurs towards vehicle front doors during offset impact. The driver and co-driver seats have a tendency to bend towards outboard side of the vehicle during offset frontal crash. This kind of the dummy kinematics is unfavorable for the performance of the supplementary restraint system (SRS) airbags. To restrict this dummy movement, a support is required from the nearest stiff member.
In conventional motor vehicles the seat generally includes four mountings which are mounted on the four brackets. The two mountings are front inboard and front outboard. Another two mountings are towards the rear side of the seat called as rear inboard and rear outboard. All the mountings are on these brackets which are in turn welded on the vehicle floor. These welded brackets occupy the shoe space of the subsequent row passenger and hence creates inconvenience and hence reduces the leg room for the subsequent row passenger. Also the rear inboard mounting is required to take high dummy inertia loads of the seat belt. Usually seat belt stalk is mounted on the rear inboard side of the seat to sustain higher load. As a result, it is designed by using high strength material with higher thickness which leads to higher weight. Hence there is a need to overcome both the above mentioned drawbacks. Hence there is a need to

eliminate the additional seat mounting bracket welded on top of the vehicle floor and hence to increase the leg room space for the passengers.
OBJECT OF THE INVENTION
The primary object of the present invention is to obviate the above mentioned drawbacks.
Another object of the present invention is to provide a mechanism to control dummy kinematics and to improve the performance of the supplementary restraint system (SRS) airbags in vehicles.
Yet another object of the present invention is to provide a floating connection between a chassis frame and the vehicle body at inboard driver and co-driver seat mountings to overcome unfavorable dummy kinematics during offset deformable barrier crash and to avoid the probable injury to the vehicle occupants.
Another object of the present invention is to avoid the driver and co-driver seats from bending towards outboard side of the vehicle during the offset deformable barrier crash.
SUMMARY OF THE INVENTION
The various embodiments of the present invention provide a mechanism to control the dummy kinematics and to improve the performance of the supplementary restraint system (SRS) airbags in vehicles. The mechanism comprises of a floating connection between a chassis frame and a vehicle body. The floating connection is provided at the inboard driver and co-driver seat mountings to overcome unfavorable dummy kinematics during offset deformable barrier crash and to avoid the probable injury to the vehicle occupants. It avoids the driver and co-driver seats from bending towards outboard side of the vehicle during the offset deformable barrier crash. For concept generation, CAE (Computer Added Engineering) analysis was done using Finite Element solver, to evaluate the offset deformable barrier crash performance by assessment of floor deformation and subsequent

seat pitching & lateral outboard movement. Ensuing to the implementation of the generated concept, there was an improvement in the dummy kinematics and mitigation of potential injury to upper body of vehicle occupants.
According to one embodiment, a support is provided to control the dummy kinematics from a nearest stiff member which is a chassis. The mechanism comprises of a support bracket welded to a vehicle floor of the body along with a 'U' support bracket. An L support bracket is welded on the chassis. An eye bolt along with sleeve, rubber bush, nut and bolt is used to provide a floating connection between the body and the Chassis.
According to one embodiment, the mechanism comprises of a 'U' bracket with a weld nut welded to it. The 'U' bracket and the weld nut is welded to the 'L' Support bracket of the vehicle floor, this is referred to as s vehicle body. The eye bolt is inserted in to the chassis 'L' support bracket along with a Nylon bush, sleeve, rubber bush and a washer. A nut is hand tightened against the eye bolt. Now this whole combination of parts summarized above is referred as the chassis. When the body is assembled on the chassis, the eye bolt from chassis is lifted in such a way that a hole in the 'U' bracket and a hole in the eye bolt lies in collinear with each other. Thereafter bolt along with washer is placed in such a way that the bolt will pass through the holes of 'U' bracket and hole in the eye bolt, therein torque is applied to tighten the bolt. To make floating connection between vehicle body and the chassis the nut is tightened in such that to have small gap between surfaces of the chassis 'L' support bracket and the rubber bush. According to present invention, during vehicle offset deformable crash, after certain free movement of the seat, no further dummy movement takes place as the eye bolt locks with the chassis 'L! support bracket and further movement of the dummy \% restricted.
A subsystem CAE model for offset deformable barrier impact load case was built and validated by correlation of its results with that of Full vehicle offset deformable barrier crash CAE. This sub system model was further used successfully for concept generation and detailed design analysis to cut down the computational time. A detailed design CAD according to one embodiment of the present invention, consisting of floating connection

between chassis frame and the vehicle body near driver and co-driver seat inboard rear mountings, to rectify unfavorable dummy kinematics during offset deformable barrier crash for averting high potential injury to the upper body of vehicle occupants, was analyzed with sub system CAE.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of the mechanism to control the dummy kinematics in
vehicles with supplementary restraint system airbags, according to. one embodiment of
the present invention.
FIG. 2 shows an isometric view of the mechanism to control the dummy kinematics in
vehicles, according to one embodiment of the present invention.
FIG. 3 shows a plan view of the mechanism of FIG. 2, according to one embodiment of
the present invention.
FIG. 4 shows an exploded view of the mechanism of FIG. 2, according to one
embodiment of the present invention.
FIG. 5 shows a time history plot from CAE analysis, for comparison of floor
displacement according one embodiment of the present invention vs. that without
embodiment of the present invention, at the front seat rear inboard anchorage mounting
location.
STATEMENT OF INVENTION
Accordingly the present invention discloses a mechanism to control dummy kinematics
in vehicles with supplementary restraint system airbags comprising
an assembly constituting of at least one 'U' bracket (2) with a weld nut (3) is fastened to
the support bracket (1) fastened on vehicle floor 16;
at least one bracket (4) fastened to the chassis frame (17) is configured with at least one
eye bolt assembly for connecting said bracket (4) to said support bracket (1);

at least one bolt (12) and washer (11) configured for inserted through the holes of 'U' bracket (2) and hole in the eye bolt (5) for establishing floating connection between support bracket (1) and the chassis (17);
at least one driver and/or co-driver seats having seat mounting bracket (15) connected to vehicle floor (16).
DETAILED DESCRIPTION
Due to limitations as described above there is a need to provide a mechanism to control the dummy kinematics and to improve the performance of the supplementary restraint system (SRS) airbags in vehicles.
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 various embodiments of the present invention relate to provide a floating connection between the chassis frame and the vehicle body at inboard driver and co-driver seat mountings to overcome unfavorable dummy kinematics during offset deformable barrier crash and to avoid the probable injury to the vehicle occupants. It avoids the driver and co-driver seats from bending towards outboard side of the vehicle during the offset deformable barrier crash.
FIG. 1 shows a perspective view of the mechanism to control the dummy kinematics in vehicles with SRS airbags, according to one embodiment of the present invention. With respect to FIG. 1, the seat comprises seat back rest 13, seat cushion 14 and inboard seat mounting bracket 15. An inboard seat mounting bracket 15 is connected to the vehicle floor 16. Therein a weld nut 3 is welded to the 'U' bracket 2 having holes and this assembly is welded to the support bracket 1. The 'U' bracket 2 and the support bracket 1 are constructed from high strength metal. This assembly is then welded to the vehicle floor 16. The whole arrangement summarized above is referred as a vehicle body. The

chassis frame consists of 'L' support bracket 4 which is welded to the chassis 17. The 'L' support bracket 4 is made out of high strength metal.
FIG. 2 shows an isometric view of the mechanism to control the dummy kinematics in vehicles, according to one embodiment of the present invention. The mechanism comprises of a *U' bracket 2 with a weld nut 3 welded to it and this assembly is welded to the support bracket 1 of vehicle floor 16. This assembly is referred to as a vehicle body. The L support bracket 4 is welded to the chassis frame 17. The eye bolt 5 is inserted in to the chassis 'L' support bracket 4 along with a Nylon bush 6, sleeve 7, rubber bush 8 and washer 9. The nut 10 is tightened against the eye bolt 5. Now this whole combination of parts summarized above is referred as a chassis 17. The Nylon bush 6 is inserted into the hole of the eye bolt 5 and then this assembly is to be inserted in to the chassis 'L' support bracket 4 through the sleeve 7, rubber bush 8 and washer 9.
When body is assembled on to the chassis 17, the eye bolt 5 from chassis 17 is lifted in such a way that the holes in the 'IP bracket 2 and the hole in the eye bolt 5 should lies collinear. Thereafter bolt 12 along with washer 11 is placed in such a way that the bolt 12 will pass through the holes of 'LP bracket 2 and hole in the eye bolt 5, therein torque is applied to tighten the bolt 12. To make floating connection between vehicle body and the chassis 17, the nut 10 is tightened in such that to have small gap between surface 4a of the chassis 'L' support bracket 4 and the rubber bush 8. A washer 9 is provided between the nut 10 and the rubber bush 8. Unfavorable dummy kinematics occurs when the driver and co-driver seats have a tendency to bend towards outboard side of the vehicle during offset deformable barrier crash. This kind of the dummy movement is unfavorable for the performance of the SRS airbags. According to present invention after certain free movement, no further dummy movement takes place as the eye bolt 5 locks with the chassis 'L' support bracket 4 and further movement of the dummy is restricted. FIG. 3 shows a plan view of the mechanism of FIG. 2, according to one embodiment of the present invention. FIG. 4 shows an exploded view of the mechanism of FIG. 2, according to one embodiment of the present invention. FIG. 5 shows the displacement time history plot for the floor at the front seat inboard rear mounting location. It presents as to what

improvement in floor displacement occurs according to one embodiment of present invention in comparison with that without the embodiment of present invention. The improvement in the floor displacement at front seat inboard rear mounting location subsequently improves the seat pitching and lateral outboard movement, required to control dummy kinematics in a vehicle with supplementary restraint system airbags, in order to mitigate the risk of high injury potential to upper body of vehicle occupants.
ADVANTAGES
• To provide a mechanism to control dummy kinematics and to improve the performance of the supplementary restraint system (SRS) airbags in vehicles.
• To increase the leg room space of the subsequent row passenger in the vehicle.
• To provide a floating connection between a chassis frame and the vehicle body at inboard driver and co-driver seat mountings to overcome unfavorable dummy kinematics during offset deformable barrier crash and to avoid the probable injury to the vehicle occupants.
• To avoid the driver and co-driver seats from bending towards outboard side of the vehicle during the offset deformable barrier crash.
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 mechanism to control dummy kinematics in vehicles with supplementary restraint
system airbags comprising
an assembly constituting of at least one !U' bracket (2) with a weld nut (3) is fastened to the support bracket (1) fastened on vehicle floor 16;
at least one bracket (4) fastened to the chassis frame (17) is configured with at least one eye bolt assembly for connecting said bracket (4) to said support bracket (1);
at least one bolt (12) and washer (11) configured for inserted through the holes of 'IP bracket (2) and hole in the eye bolt (5) for establishing floating connection between support bracket (1) and the chassis (17);
at least one driver and/or co-driver seats having seat mounting bracket (15) connected to vehicle floor (16).
2. The mechanism as claimed in claim 1 wherein said an assembly of at least one 'U' bracket (2) with a weld nut (3) fastened to it is further fastened to the support bracket (1) of vehicle floor 16 is referred to as a vehicle body.
3. The mechanism as claimed in claim 1 wherein said bracket (4) is 'L! shaped and said eye bolt assembly comprises of one eye bolt (5), a Nylon bush 6, sleeve 7, rubber bush 8 and washer 9.
4. The mechanism as claimed in claim 1 wherein said eye bolt assembly formed by inserting Nylon bush (6) into the hole of the eye bolt (5) is mounted on 'L' bracket (4) through the sleeve (7), rubber bush (8) and washer (9) and said eye bolt (5) is tightened by nut (10).
5. The mechanism as claimed in claim 1 wherein said 'U' bracket (2), 'L' bracket (4) and the support bracket (1) are manufactured from a high strength metal.
6. The mechanism as claimed in claim 1 wherein said nut (10) is tightened to provide small gap between surface (4a) of the chassis 'L' bracket (4) and the rubber bush (8)

configured for limiting free movement of the assembly to predetermined value, to restrict further dummy movement as the eye bolt (5) locks with the chassis 'L' bracket (4).
7. The mechanism as claimed in claim I wherein said mechanism is provided to control dummy kinematics and to improve the performance of the supplementary restraint system (SRS) airbags in vehicles.
8. The mechanism as claimed in claim 1 wherein said mechanism provides a floating connection between a chassis frame and the vehicle body at inboard driver and co-driver seat mountings to overcome unfavorable dummy kinematics during offset deformable barrier crash and to avoid the probable injury to the vehicle occupants.
9. The mechanism as claimed in claim 1 wherein said mechanism provides extra leg room space of the subsequent row passenger in the vehicle and avoids the driver and co-driver seats from bending towards outboard side of the vehicle during the offset deformable barrier crash.
10. The mechanism to control dummy kinematics in vehicles with supplementary restraint system airbags as substantially as herein described with reference to accompanying drawings.