Modular occupant restraint system

A modular occupant restraint system includes a container for the folded cushion and a cover for the container. The container has lines of perforations which subdivide the walls thereof into two sets of flaps. One set of flaps permits deployment of the folded cushion along alternate paths laterally of the system and generally parallel to the driver's torso. The other set of flaps permits deployment of the cushion along the intended path toward the driver's torso. The cover has weakened lines which subdivide the cover into flaps generally coextensive with those of the container. The folded cushion has fan folded chordal portions which are located opposite the first set of flaps of the container to forcibly open such flaps.

This invention relates generally to modular occupant restraint systems for 
vehicle drivers and more particularly to an improved modular occupant 
restraint system which permits initial deployment of the cushion along 
alternate paths laterally of the module and generally parallel to the 
driver should the cushion be unable to deploy along a normal path 
forwardly of the module and toward the driver. 
Modular occupant restraint systems for vehicle drivers are known. U.S. Pat. 
Nos. 3,819,205, Dunford et al, Modular Occupant Restraint System, and 
4,25,568 Clark et al, Modular Occupant Restraint System, both show such a 
system which generally includes an inflator, an inflatable cushion, a 
box-like rectangular shaped container for the cushion, a cover for the 
container, and a support plate for mounting the inflator, cushion, 
container and cover to provide the module. The module is mounted on the 
vehicle steering wheel and has the longer sides thereof, generally called 
the 6 and 12 o'clock sides, positioned transversely of the driver's torso 
and the shorter sides thereof, generally called the 3 and 9 o'clock sides, 
positioned longitudinally of the driver's torso. 
The system of this invention is of the modular type but includes an 
improved container and cover and an improved cushion fold which permit 
initial deployment of the cushion along alternate paths should the cushion 
be prevented from deployment along its normal intended path. 
In the preferred embodiments of the invention, the container for the folded 
cushion has its side walls and its base wall provided with perforated 
lines to provide two sets of flaps. One set of flaps permits deployment of 
the cushion along a normal or intended path toward the driver's torso 
through the base wall of the container. The other set of flaps permits 
initial deployment of the cushion along alternate paths laterally of the 
module and generally parallel to the driver's torso through the longer or 
6 and 12 o'clock sides of the container should the cushion be unable to 
deploy along its normal or intended path. The lines of perforations differ 
from each other to provide the different embodiments of the invention. The 
cover is provided with weakened or score lines which overlie and generally 
match the perforated lines of the container so that the cover will 
subdivide into flaps which are generally coextensive with the container 
flaps when the cushion is deployed. 
The cushion is comprised of juxtaposed forward and rearward circular 
members which are secured to each other along their circular edge 
portions. The forward cushion member provides an impact surface for the 
driver when the cushion is deployed. When the cushion is folded, the 
forward and rearward cushion members have overlying planar diametrical 
portions. The chordal portions of the cushion members to each side of the 
diametrical portions are fan folded and located within the diametrical 
portions. The end portions of the diametrical portions and fan folded 
chordal portions are pleated to provide a folded cushion of minimum size 
which fits within the container, with the fan folded chordal portions 
being located opposite the longer or 6 and 12 o'clock side walls of the 
container, and the pleat folded end portions of the cushion being located 
opposite the shorter or 3 and 9 o'clock side walls of the container. The 
rearward cushion member has an inlet for the inflator. 
The primary feature of this invention is that it provides an improved 
modular occupant restraint system which permits initial deployment of the 
cushion along alternate paths laterally of the module and generally 
parallel to the torso of the driver should the cushion be unable to deploy 
along its intended path, forwardly of the module toward the driver's 
torso. Another feature is that the container for the folded cushion and 
the cover for the container can be subdivided into two sets of flaps, one 
set of flaps permitting the lateral and parallel deployment of the 
cushion, and the other set of flaps permitting normal deployment of the 
cushion toward the driver's torso. A further feature is that the container 
has lines of perforations which divide the container into the two sets of 
flaps, and the cover has lines of weakness which divide the cover into 
flaps which are generally coextensive with those of the container. Yet 
another feature is that the container is of generally rectangularly shaped 
box like shape, with the one set of flaps being generally located in the 
longer or 6 and 12 o'clock side walls of the container. Yet a further 
feature is that the cushion is comprised of overlying or juxtaposed 
cushion members which are folded to provide fan folded chordal portions 
located inwardly of and opposite the longer or 6 and 12 o'clock side walls 
of the container. Still another feature is that the cushion members have 
overlying or juxtaposed generally planar diametrical portions and that the 
fan folded chordal portions are located within the diametrical portions 
when the cushion is folded.

Referring now to FIGS. 1 through 3 of the drawings, a modular occupant 
restraint system 20 is shown mounted in a conventional manner to the hub 
portion 22 of a vehicle steering wheel 24. The hub portion includes a 
splined bushing 26 which receives the upper splined end of the vehicle 
steering shaft 28 and is bolted thereto at 30 to secure the steering wheel 
to the vehicle steering system. 
A generally rectangularly shaped support or plate 32 has a central circular 
opening 34. The flange 36 of a conventional inflator 38 seats against the 
lower side of the plate 32 and is secured thereto in a conventional 
manner. The upper outlet portion 40 of the inflator projects through the 
plate 32 and into the interior of a folded inflatable driver restraint 
cushion 42 of conventional construction. The cushion 42 includes upper and 
lower or forward and rearward circular members 44 and 46 which are secured 
together at their circular edge portions. The upper or forward cushion 
member 44 provides the impact surface of the cushion for the driver when 
the cushion is inflated, and the lower or rearward cushion member 46 has a 
central opening 48 which receives the upper outlet portion 40 of the gas 
generator therethrough. A ring 50 is fastened at 52 to the plate 32 around 
the opening 34 therein to clamp the cushion member 46 to the plate 32 
around the opening 48 therethrough. The manner of folding the cushion 42 
will be further described. 
The inflator 38 is a gas generator which is electrically actuated from a 
conventional electrical power source when acceleration or velocity or 
other type sensors sense the impact of the vehicle with an obstacle or the 
possibility or probability of such an impact. Such sensors and the 
circuits connecting the sensors to a power source are well known in the 
art. Likewise, inflators of the gas generating type are also well known in 
the art. 
A container 54 for the cushion 42 is formed of generally rigid plastic 
material and has a generally box-like rectangular shape. The container 54 
houses the folded cushion 42 and has a flange 56 which underlies the plate 
32 and has lateral flange segments 58 therealong, FIGS. 2 and 3. An outer 
decorative cover 60 of flexible plastic material is of the same general 
shape as the container 54. The cover 60 has a flange 62 which overlies the 
flange 56 of the container. A retainer 64 overlies the flange 62 and is 
fastened at 66 to the support plate 32 to secure the container and cover 
to the support plate. The flange 62 of the cover has lateral nubs or 
projections 68 which are received in openings 70 of the retainer 64. The 
plate 32 thus mounts the inflator 38, the cushion 42, the container 54, 
and the cover 60 to provide the modular restraint system 20. 
Referring now to FIGS. 4 through 6, one embodiment of the invention will be 
described. The container 54 has a generally planar forward or base wall 72 
which is integral with a pair of longer side walls 74 and a pair of 
shorter side walls 76, with the pairs of side walls being integrally 
joined to each other at corners 78. As can be seen, the side walls 74 and 
76 and the corners 78 are slightly angular to the base wall 72. It will be 
understood that the system 20 is mounted to the steering wheel 24 with the 
base wall 72 facing the driver's torso, the side walls 74 located 
transversely of the driver's torso, and the side walls 76 located 
longitudinally of the driver's torso. Thus, the side walls 74 are 
alternately referred to as the 6 and 12 o'clock side walls and the side 
walls 76 are alternately referred to as the 3 and 9 o'clock side walls. 
The base wall 72 is provided with a line of perforations 80 extending 
transversely thereof between the side walls 74, and lines of perforations 
82 which cross the line 80 in H shaped fashion and are located adjacent 
the longer side edge portions of wall 72 and the juncture edge portions of 
walls 74. Lines of perforations 82 terminate short of the shorter side 
edge portions of wall 72 and the juncture edge portions of walls 76. Lines 
of perforations 84 extend transversely to the ends of lines 82 partially 
transversely of the side walls 74, terminating short of the lower or 
rearward side edge portions thereof. The lines of perforations 82 and 84 
define a first pair of downwardly opening integrally hinged flaps 86, the 
major portions of which are located in the side walls 74. The hinge line 
or hinge axis of each flap 86 extends between the free ends of a 
respective pair of lines of perforations 84. The lines of perforations 80 
and 82 define a second pair of oppositely outwardly opening integrally 
hinged flaps 88, the hinge line or hinge axis of each flap extending 
between the free ends of a respective pair of lines of perforations 82. 
The perforations of the lines 80, 82, and 84 are molded in when the 
container 54 is molded of semi-rigid plastic material. 
As can be seen from FIG. 1, the cover 60 has molded in lines 90 and 92 in 
its forward or base wall 94, and molded in lines 96 in its longer or 6 and 
12 o'clock side walls 98 which overlie and are generally coextensive with 
walls 74 of container 54. The molded in lines 90, 92, and 96 are 
respectively aligned with the lines of perforations 80, 82, and 84 of 
container 54. The lines 92 and 96 define a first pair of integrally hinged 
flaps 100 in wall 98, these flaps being respective to and generally 
coextensive with the underlying flaps 86 of container 54. The lines 90 and 
92 define a second pair of integrally hinged flaps 102 in wall 94, these 
flaps being respective to and generally coextensive with the underlying 
flaps 88 of the container 54. The hinge lines or hinge axes of flaps 100 
and 102 are generally aligned with those of their respective flaps 86 and 
88 of container 54. The cover 60 is not shown in FIGS. 4 through 6 for 
clarity of illustration. 
Referring now to FIGS. 13 through 15D, the cushion 42 will be described. 
The cushion 42 is of conventional construction and includes the circular 
cushion members 44 and 46 which are secured together along their circular 
edge portions 104, FIG. 13 and FIGS. 15A through 15D. One method of 
folding the cushion is shown in FIGS. 15A through 15D. The cushion members 
44 and 46 are located in a planar position or laid flat with respect to 
each other, as shown schematically in FIG. 15A. Then, as shown 
schematically in FIG. 15B, diametrically opposite chordal portions 106 of 
the cushion members 44 and 46 are fan folded to provide the initial fan 
fold 108. As shown schematically in FIG. 15C, the next succeeding 
diametrically opposite chordal portions 110, those immediately adjacent to 
the fan fold 108, of the cushion members 44 and 46 are then fan folded to 
provide the pair of fan folds 112, each located on a respective side of 
the fan fold 108. Then, as shown in FIG. 15D, the next succeeding 
diametrically opposite chordal portions 114, those immediately adjacent to 
the fan folds 112, are fan folded to provide the pair of fan folds 116. 
The fan folds 108, 112, and 116 are located within the remaining 
diametrical portions 118 and 120 of the cushion members 44 and 46 as shown 
in FIG. 13. The end portions 121 of the fan folds 108, 112, and 116 and of 
the diametrical portions 118 and 120 are then pleat folded at 123, FIG. 
14, to provide a fully folded cushion 42. This folded cushion is housed 
within the container 54 with the fan folds 108, 112, and 116 of the 
cushion being located opposite the side walls 74 of the container and the 
pleat folded end portions of the cushion being located opposite the side 
walls 76 of the container, as shown in FIG. 2. 
When the inflator 38 receives an appropriate electrical signal, the 
inflator generates gas which exits from the outlet portion 40 of the 
inflator, FIG. 2, into the folded cushion 42 through the opening 48 in the 
cushion member 46 to initiate inflation or deployment of the cushion. 
During normal deployment, the diametrical portion 118 of the inflating 
cushion 42 forcefully engages the base wall 72 of the container as the 
cushion 42 is initially inflated. This separates wall 72 along the lines 
of perforations 80 and 82 into the oppositely outwardly opening integrally 
hinged flaps 88, as shown in FIG. 6, and simultaneously separates the wall 
94 into the generally coextensive integrally hinged oppositely outwardly 
opening flaps 102 so that the cushion 42 can deploy forwardly along its 
normal or intended path toward the driver's torso as the fan folds 108, 
112 and 116 unfold into continuations of the cushion members 44 and 46. 
The cushion 42 is not shown in FIG. 6 for clarity of illustration. 
Should the cushion 42 be unable to deploy along its normal or intended 
path, during initial deployment, such as by wall 94 being obstructed so 
that it and wall 72 cannot be separated into the flaps 102 and 88 by the 
force of the diametrical portion 118 against wall 72, the fan folds 108, 
112, and 116 will start to unfold and exert pressure against the side 
walls 74 of the container The force of the unfolding fan folds against 
walls 74 will separate these walls along the lines of perforations 82 and 
84 into the downwardly or rearwardly opening integrally hinged flaps 86. 
The cover 60 will generally likewise separate along the lines 92 and 96 
into the downwardly or rearwardly opening flaps 102 which open generally 
simultaneously with their respective flaps 86. This permits the fan folds 
108, 112, and 116 of the cushion 42 to unfold outwardly through the 
resultant openings, along alternate paths generally laterally of the 
system 20 or parallel to the driver's torso. The force at which walls 74 
separate into flaps 86 is determined by the material of the container, the 
thickness of the walls 74, and the extent and spacing of the perforations 
of the lines 82 and 84. Likewise, the depth of lines 92 and 96 and the 
material of the cover are selected so that the flaps 100 open generally 
simultaneously with the flaps 86. 
Referring now to FIGS. 7, 8, and 9, a second embodiment of the invention 
will be described. The container 54' of this embodiment differs from that 
of the first embodiment in the location and extent of the lines of 
perforations. Therefore, like numerals are used for like parts. As shown 
in FIG. 7, a line of perforations 122 traverses the base wall 72 and the 
side walls 74 of the container 54' and terminates short of the lower or 
free edge portions of the side walls 74. A line of perforations 124 
extends longitudinally of each side wall 74 and terminates in the side 
walls 76 adjacent the corners 78. Each line of perforations 124 is joined 
to the end of a line of perforations 122. A pair of lines of perforations 
126 in each side wall 76 extends from the ends of the lines of 
perforations 124 to adjacent the upper or juncture edge portions of the 
side walls 76. 
It will be understood that the cover 60', not shown, has lines which are 
generally aligned with the lines of perforations 122, 124, and 126 in the 
same manner as the lines 90, 92 and 96 of the cover 60 are generally 
aligned with the lines of perforations 80, 82, and 84. 
The lines of perforations 124 and 126 define a first pair of flaps 128 
which correspond to the first pair of flaps 86 of the container 54'. The 
flaps 128 are integrally hinged to the container 54' about hinge axes or 
hinge lines which extend between the upper ends of the lines of 
perforations 126, as shown in FIG. 8. The first pair of flaps 128 will be 
moved from their closed position shown in FIG. 7 to their open position 
shown in FIG. 8 during initial deployment of the cushion, in the same 
manner as previously explained in conjunction with the flaps 86 of the 
first embodiment. The first pair of flaps 128 move outwardly and upwardly 
of the container 54' to open position. Although not shown, it will be 
understood that the cover 60' includes lines generally aligned with the 
lines of perforations 122, 124, and 126. The cover 60' will subdivide 
along its lines to provide flaps, corresponding to the flaps 100 of the 
cover 60, which are generally coextensive with the flaps 128 and which 
move generally simultaneously with the flaps 128 to open position to 
permit deployment of the cushion 42 through the resultant openings 
generally laterally of the module 20 or parallel to the driver's torso. 
The lines of perforations 122 and 124 define a second pair of flaps 130 
which correspond in function and operation to the second pair of flaps 88 
of the first embodiment. Flaps 130 move from their closed position shown 
in FIG. 7 to their open position shown in FIG. 9 during normal deployment 
of the cushion 42, as previously explained in conjunction with flaps 88. 
Although the cover 60' is not shown, it will be understood that the lines 
thereof provide flaps generally coextensive with the flaps 130 during 
normal deployment of the cushion 42. The hinge axes or hinge lines of 
flaps 86 are generally coplanar with pairs of lines of perforations 126, 
while the hinge lines of flaps 130 are generally coplanar with lines of 
perforations 124. 
FIGS. 10, 11, and 12 show a third embodiment 54" of the container. This 
embodiment differs from the first and second embodiments in its lines of 
perforations which provide the first and second pairs of flaps. The 
container 54" includes a line of perforations 132 which traverse the base 
wall 72 of the container 54" and partially traverse each of the side walls 
74 of the container. A line of perforations 134 is provided in each of the 
side walls 74 adjacent the lower or rearward edge portion thereof, with 
this line of perforation including an angular central portion, the apex 
136 of which is joined to one end of the line of perforations 132. The 
ends of each line of perforations 134 are joined to the lower or rearward 
ends of lines of perforations 138 which extend angularly opposite to the 
corners 78 and across the juncture edge portions of base wall 72 to a 
terminus.slightly within the base wall. 
It will be understood that a cover 60" is provided with the container 54" 
and that the cover 60" has lines which are generally aligned with the 
lines of perforations 132, 134, and 138 and correspond to the lines 90,92, 
and 96 of cover 60. 
The lines of perforations 134 and 138 define a first pair of flaps 142, 
FIG. 10, which correspond in function and operation to flaps 86. Flaps 142 
move outwardly and upwardly of the module 20 to their open position shown 
in FIG. 11 to permit deployment of the cushion 42 along the alternate 
paths laterally of the module 20 and parallel to the driver's torso as 
explained in conjunction with the flaps 86 of the first embodiment. The 
coextensive flaps of cover 60", not shown, open with the flaps 142. 
The lines of perforations 132, 134, and 138 define a second pair of flaps 
144 which correspond in function and operation to flaps 88. Flaps 144 move 
from their closed position shown in FIG. 10, to their open position shown 
in FIG. 12 during deployment of the cushion 42 forwardly of the module 20 
along the normal or intended path of deployment. The coextensive flaps of 
the cover 60", not shown will likewise move with the flaps 144. The hinge 
lines or hinge axes of flaps 142 and 144 extend between the ends of the 
perforations 138. The hinge lines of flaps 142 are generally parallel to 
the upper edge portions of side walls 74, while those of flaps 144 are 
generally parallel to the upper edge portions of side walls 76, both sets 
of hinge lines being parallel to the juncture edge portions of base wall 
72. 
Each apex 136 facilitates the opening of either the line of perforations 
132 or the respective lines of perforations 134 once one of such line of 
perforations is opened. It will also be noted that the lines of 
perforations 138 are at an angle greater than 90 degrees to the lines of 
perforations 134. This facilitates the opening of either the lines of 
perforations 134 or 138 once one of such lines of perforations are opened. 
From the foregoing description, it is believed apparent that each 
embodiment of this invention includes a container having lines of 
perforations which are separable to provide first and second pairs of 
flaps during deployment of the folded cushion 42. The first pair of flaps 
provides alternate paths of initial deployment of the cushion parallel to 
the driver's torso should the second pair of flaps be unable to open to 
permit deployment of the cushion along the normal or intended path toward 
the driver's torso. The cover overlying the container has lines of 
weakness which are separable generally simultaneously with the lines of 
perforations to provide cover flaps which are generally coextensive with 
those of the container. The force against the first pairs of container and 
cover flaps is provided by the unfolding engagement of the fan folded 
chordal portions 108, 112, and 116 of the cushion against the container 
walls 74. The openings resulting from movement of the first pairs of 
container and cover flaps to open position permit the fan folded chordal 
portions of the cushion to unfold along the alternate paths of deployment 
into continuations of the diametrical portions 118 and 120 of the cushion 
members 44 and 46, generally laterally of the module and generally 
parallel to the driver's torso. The second pairs of container and cover 
flaps are moved to open position by the force of the diametrical portion 
118 of the cushion member 44 against the base wall 72 of the container to 
permit the cushion 42 to unfold along the normal or intended path of 
deployment toward thee driver's torso. 
Thus, this invention provides a modular occupant restraint system which 
permits initial deployment of the cushion along alternate paths of 
deployment generally parallel to the driver's torso should the cushion be 
unable to deploy along its intended path toward the driver's torso.