Exterior seat back mounted side impact airbag module assembly

A side impact airbag module assembly adapted to mount on the exterior of the side of a seat back of an automobile seat back having an access opening and receiving means within a internal structural member. The side impact airbag module assembly includes an airbag module frame having a mounting flange adapted to extend through the access opening in the seat cover and having thereon self fasteners that secure the flange in the receiving means of the internal structural member of the seat. An airbag cushion and inflator assembly is secured to the frame, and an airbag module cover is also secured to the airbag module frame to conceal and protect the airbag cushion and inflator assembly and the airbag module frame. The airbag module is provided in one variation with depth limiters that prevent the mounting flange from being inserted too far into the receiving means, and clamp supports which further secure the mounting flange to the internal structural member. In another variation, the airbag module has two spaced apart mounting flanges.

FIELD OF THE INVENTION 
The present invention relates to an airbag module assembly and, more 
particularly, to an exterior seat mounted side impact airbag module 
assembly. 
BACKGROUND OF THE INVENTION 
Providing a side impact airbag module assembly that can be securely and 
easily mounted on the exterior of an automobile driver or passenger seat 
back with minimal changes to the design and manufacture of the seat would 
be useful. 
An airbag module assembly is part of an inflatable restraint system that is 
employed in an automobile for protecting an occupant against injury by 
physically restraining the occupant's body when the automobile encounters 
a collision. The airbag module assembly normally includes an airbag 
cushion and an inflator that, once triggered by a remote collision sensor, 
provides the inflation gas for inflating the airbag cushion. As its name 
implies, a side impact airbag module assembly protects an occupant against 
an impact to the side of the automobile and is normally positioned 
somewhere between the occupant and the side of the automobile closest to 
the occupant. One of the options for a side impact airbag location which 
has proven advantageous is on the side of a seat back of a seat adjacent 
the center pillar of the auto. This location is advantageous because the 
airbag is kept in the optimum firing position, adjacent the driver's upper 
body, as the seat back is adjusted. 
Currently, most seat mounted airbag module assemblies are designed to be 
installed internally within the seat behind the padding and the upholstery 
of the seat cover. These internal installations require substantial 
changes to the design of the seat and also require the seat assembler to 
handle the airbag module. Internal installations, therefore, increase the 
chances of module damage during assembly to the seat as well as provide 
difficulties in accessing the module thereafter for servicing purposes. 
Due to the inaccessibility for servicing purposes of an airbag module 
contained within the seat itself (behind the seat cover upholstery and any 
foam or other padding) and due to other possible seat structure design 
concerns, it would be desirable to have a side impact airbag module 
assembly that attaches to the seat exterior. It would be best, therefore, 
for the airbag module to fasten to the exterior of the seat during 
assembly of the automobile and not during assembly of the seat. It would 
also be desirable if the airbag module does not adversely affect the outer 
contour of the seat, if possible. 
Some side impact airbag module assemblies that are intended to attach 
externally to the seat require an external attachment means provided by 
the seat manufacturer or a change in the outer contour of the seat in 
order to receive the airbag module. These types of airbag module 
assemblies, accordingly, also require substantial changes to the seat and 
complicate the design and manufacture of the seat. 
In summary, providing a seat mounted side impact airbag module assembly 
that can be securely and easily mounted to an exterior of the side of a 
seat back of a seat and does not require substantial changes to the outer 
contour of the seat or an external attachment means provided by the seat 
manufacturer would be useful and highly desirable. 
SUMMARY OF THE INVENTION 
An object, therefore, of the present invention is to provide a side impact 
airbag module assembly. 
Another object of the present invention is to provide an external seat back 
mounted side impact airbag module assembly. 
An additional object of the present invention is to provide an external 
seat back mounted side impact airbag module assembly that does not require 
substantial changes to the outer contour of the seat or an external 
attachment means provided by the seat manufacturer. 
In carrying out this invention, there is provided a side impact airbag 
module assembly mountable on an automobile seat having an access opening 
and receiving means within an internal structural member of the seat. 
The side impact airbag module assembly includes at least one mounting 
projection adapted to extend through the access opening in the seat and 
into the receiving means of the internal structural member. The airbag 
module assembly has at least one self fastener located on the mounting 
projection for securing the projection within the receiving means. The 
airbag module also includes an airbag cushion and inflator assembly 
secured to the mounting projection. The airbag cushion and inflator 
assembly has an airbag cushion and an inflator connected together so that 
inflation gas from the inflator will inflate the airbag cushion upon 
actuation of the inflator. 
According to one aspect of the present invention, the side impact airbag 
module includes an airbag module cover secured to the mounting projection 
and covering the airbag cushion and inflator assembly and a portion of the 
mounting projection. 
According to another aspect of the present invention, the side impact 
airbag module includes at least one depth limiter to prevent the mounting 
projection from being inserted into the receiving means of the structural 
member past a predetermined point. 
According to yet another aspect of the present invention, the airbag module 
assembly further has at least one clamping support located on the mounting 
projection for clamping the structural member against the self fastener to 
further secure the mounting projection to the structural member. 
According to a further aspect of the present invention, the mounting 
projection comprises a single, elongated, flat mounting flange receivable 
in receiving means in the internal structural member that comprises a 
slot. 
According to still another aspect of the present invention, the mounting 
projection has a plurality of spaced-apart self fasteners, each self 
fastener comprising a resilient snap fitting having a distal end that 
extends generally transversely to and outwardly from the mounting 
projection. The snap fittings are bendable and bend towards the mounting 
projection to fit through the receiving means in the structural member as 
the mounting projection is inserted therein. Once through the receiving 
means, the snap fittings spring back away from the mounting projection so 
that the distal ends extend outwardly beyond the receiving means to 
prevent the mounting projection from being pulled out. 
According to a still further aspect of the present invention, the airbag 
module has a plurality of spaced-apart depth limiters located on the 
mounting projection. Each depth limiter comprises a tab extending 
generally transversely to and outwardly from the mounting projection. Each 
tab has a distal end adapted to extend generally transversely to and 
outwardly beyond the receiving means to prevent the mounting projection 
from being inserted into the receiving means past the tab. 
According to a yet further aspect of the present invention, the tabs are 
resilient and are positioned with respect to the snap fittings so that the 
tabs also comprise the clamping supports and are adapted to abut the 
structural member to clamp the structural member against the snap 
fittings. 
According to an additional aspect of the present invention, the side impact 
airbag module assembly has two mounting projections. The mounting 
projections comprise two flat mounting flanges that are receivable in 
receiving means in the internal structural member that comprises two 
slots. 
In summary, the present invention provides a side impact airbag module 
assembly that securely and easily mounts to the exterior of a seat back 
and does not require substantial changes to the outer contour of the seat 
or an external attachment means provided by the seat manufacturer.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1 through 3, the present invention is directed to a side 
impact airbag module assembly 10 adapted to mount on the exterior of an 
automobile seat 90 having an access opening 94 in a seat cover 92 and 
receiving means 98 within an internal structural member 96 thereof. 
The side impact airbag module assembly 10 includes a module frame 12, an 
airbag cushion and inflator assembly 14 and a module cover 16. The module 
frame 12 has an inflator receiving wall 18, a cover receiving bracket 20 
and at least one mounting projection 22 adapted to extend through the 
access opening 94 in the seat cover 92 and into the receiving means 98 of 
the internal structural member 96 of the seat 90. The airbag module 
assembly 10 has at least one self fastener 24 located on the mounting 
projection 22 for securing the mounting projection 22 within the receiving 
means 98. 
The airbag module 10 also includes at least one depth limiter 26 adapted to 
prevent the mounting projection 22 from being inserted into the receiving 
means 98 of the structural member 96 past a predetermined point. The 
airbag module assembly 10 further has at least one clamping support 26, 
which could be the same element that comprises the depth limiter 26, 
located on the mounting projection 22 for clamping the structural member 
96 against the self fastener 24 to further secure the mounting projection 
22 to the structural member 96. 
As best seen in FIGS. 2 and 3, the receiving means 98 in the internal 
structural member 96 of the seat 90 comprises a slot 98, and the mounting 
projection 22 comprises a single, elongated mounting flange 22. The airbag 
module 10 has a plurality of self fasteners 24 comprising two pairs of 
resilient snap fittings 24 having distal ends 33 that extend outwardly 
from opposite sides of the mounting flange 22. The distal ends 33 face 
away from the structural member 96 as the flange 22 is inserted into the 
slot 98 and the snap fittings 24 are bendable and bend towards the 
mounting flange 22 to fit through the slot 98 as the mounting flange 22 is 
inserted therein. Once through the slot 98, the snap fittings 24 spring 
back away from the mounting flange 22 so that the distal ends 33 extend 
transversely to and outwardly beyond the width of the slot 98 to prevent 
the mounting flange 22 from being pulled out, thereby securing the 
mounting flange 22 to the structural member 96. 
The depth limiter 26 comprises a tab 26 extending generally transversely to 
and outwardly from the mounting flange 22 opposite each snap fitting 24. 
Each tab 26 has a distal end 35 that faces towards the structural member 
96 as the flange 22 is inserted into the slot 98 and extends transversely 
to and outwardly beyond the width of the slot 98. The tabs 26, 
accordingly, prevent the mounting flange 22 from being inserted into the 
slot 98 past the tabs 26. 
The tabs 26 are resilient and are positioned on the mounting flange 22 with 
respect to the snap fittings 24 so that the tabs 26 also comprise the 
clamping supports 26. The tabs 26, and preferably the distal ends 35 of 
the tabs 26, are adapted to abut the structural member 96 adjacent the 
slot 98 to clamp the structural member 96 against the snap fittings 24 and 
further secure the mounting flange 22 to the structural member 96. 
The airbag cushion and inflator assembly 14 has an airbag cushion 38 and an 
inflator 40 assembled together so that inflation gas from the inflator 40 
will inflate the airbag cushion 38. The airbag cushion and inflator 
assembly 14 is described generally as it relates to the instant invention. 
How an inflator 40 produces inflation gas and is actuated are both known 
in the art and, accordingly, are not described in detail as they do not in 
themselves constitute features of the present system. The airbag cushion 
38 and inflator 40 are held together by a wrapper 42 having a joint 43 
that breaks apart during inflation of the airbag cushion 38. At least two 
studs 44,45 extend from the airbag cushion and inflator assembly 14 
through two respective stud receiving holes 46 (the other stud receiving 
hole is hidden and therefore not visible, but is positioned similar to 
hole 46 but in line with stud 45) in the inflator receiving wall 18 of the 
airbag module frame 12 and are secured thereto by nuts 48,49 or the like. 
The airbag module cover 16 is formed from a thermoplastic or other suitable 
material and has at least one tear seam 50 that the airbag cushion 38 can 
break through during inflation. The cover 16 also has at least two 
integral airbag module fasteners 52,53 that extend through two respective 
fastener receiving holes 54,55 in the cover receiving bracket 20 of the 
airbag module frame 12. The fasteners 52,53 have burrs or a "christmas 
tree" configuration, well known in the art, to engage the receiving holes 
54,55 and secure the cover 16 to the airbag module frame 12 without the 
use of separate nuts or the like. The module cover 16 covers the airbag 
cushion and inflator assembly 10 and a portion of the frame 12. The airbag 
module cover 16 is adapted to conceal and protect the airbag cushion and 
inflator assembly 14 and the frame 12, and be flush with the seat cover 92 
once the airbag module is mounted to the seat 90. Since the airbag module 
assembly 10 is adapted to be mounted on the exterior of the seat 90, it is 
important that the module cover 16 be aesthetically pleasing and blend in 
with the seat 90 as much as possible. 
The airbag module frame 12 is made of a light weight metal or other 
suitable material, and the snap fittings 24 and tabs 26 are simply punched 
out of the mounting flange 22. The present invention, therefore, provides 
a side impact airbag module 10 having a simple and easily manufactured 
airbag module frame 12 with a mounting flange 22 that securely mounts to 
an internal structural member 96 of an automobile seat 90. 
It is intended that the side impact airbag module assembly 10 will be able 
to be mounted to the seat 90 by the automobile manufacturer during 
assembly of the automobile and not be required to be mounted by the seat 
manufacturer during assembly of the seat 90. The airbag module assembly 10 
according to the present invention is mounted to the seat 90 by simply 
inserting the mounting flange 22 through the access opening 94 in the seat 
cover 92 and into the slot 98 in the structural member 96. The snap 
fittings 24 bend in as they pass through the slot 98 and the tabs 26 
prevent the flange 22 from being pushed too far into the slot 98. Once 
through the slot 98, the snap fittings 24 spring back out to prevent the 
flange 22 from being pulled out of the slot 98 and clamp the structural 
member 96 against the tabs 26, thereby securing the mounting flange 22 to 
the structural member 96. The present invention accordingly provides a 
side impact airbag module assembly that easily and securely mounts to the 
exterior of the side of a seat back of an automobile driver or passenger 
seat. 
In addition, the present invention provides an externally mounted, side 
impact airbag module assembly that does not require substantial changes to 
existing seats. The internal structural member 96 need only be a plate of 
suitable material, including a rigid plastic or metal, having a slot 98 
therein. The tabs 26 may be spaced further apart from the snap fittings 24 
to fit a thicker structural member 96. The access opening 94 in the seat 
cover 92, extending through any foam or seat padding 99 located between 
the cover 92 and the structural member 96, only has to be large enough to 
allow access of the mounting flange 22 with extending tabs 26 
therethrough. 
Referring to FIG. 4, another side impact airbag module assembly 60 
according to the present invention is shown. The airbag module 60 has a 
mounting flange 62 that has only the snap fittings 24 extending outwardly 
from opposite sides thereof, and does not include the tabs 26 of FIGS. 1 
through 3. The snap fittings 24 are resilient and have distal ends 33 that 
face away from the structural member 96 as the flange 62 is inserted into 
the slot 98. The snap fittings 24 are bendable and bend towards the 
mounting flange 62 to fit through the slot 98 as the mounting flange 62 is 
inserted therein. Once through the slot 98, the snap fittings 24 spring 
back away from the mounting flange 62 so that the distal ends 33 extend 
outwardly beyond the width of the slot 98 to prevent the mounting flange 
62 from being pulled out and thereby secure the mounting flange 62 to the 
structural member 96. 
Referring to FIG. 5, an additional side impact airbag module assembly 70 
according to the present invention is shown. The airbag module 70 has two 
mounting projections 72,73 comprising two spaced apart mounting flanges 
72,73. The mounting flanges 72,73 are receivable in a seat 90 having 
receiving means, in an internal structural member 96, comprising two slots 
76,77. Each mounting flange 72,73 has a self fastener comprising a snap 
fitting 24 extending from opposite sides thereof. Additionally, each 
mounting flange 72,73 has a tab 26 comprising both a depth limiter and a 
clamping support extending from opposite sides thereof. The snap fittings 
24 bend in as they pass through the slots 76,77 and the tabs 26 prevent 
the flange 72,73 from being pushed too far into the slot 98. Once through 
the slots 76,77 the snap fittings 24 spring back out to prevent the flange 
72,73 from being pulled out of the slot 98 and clamp the structural member 
96 against the tabs 26, thereby securing the mounting flanges 72,73 to the 
structural member 96. 
The present invention may also include other changes and modifications 
without departing from its true spirit and scope. For example, the 
mounting projection 22 could comprise one or more cylindrical projections 
adapted to extend into a receiving means 98 in an internal structural 
member 96 of a seat 90 comprising circular apertures, each projection 
having snap fittings 24 thereon. Additionally, the mounting flange 22 
could include more or fewer snap fittings 24 or tabs 26. Other variations 
are possible. 
In summary, the present invention provides a side impact airbag module 
assembly that securely and easily mounts to the exterior of a seat back 
and does not require substantial changes to the outer contour of the seat 
or an external attachment means provided by the seat manufacturer. 
Since other requirements and environments varied to fit particular 
operating requirements and environments will be apparent to those skilled 
in the art, the invention is not considered limited to the examples chosen 
for purposes of illustration, and includes all changes and modifications 
which do not constitute a departure from the true spirit and scope of this 
invention as claimed in the following claims and equivalents thereto.