JPH0694269B2 - Airbag gas generator mounting device - Google Patents

Description

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to an assembly useful in an inflatable restraint (airbag) system, and more particularly to a retainer that supports a gas generator that retains an airbag and shields the airbag from heated gases produced by the gas generator.

Inflatable restraint systems are becoming standard equipment for occupant protection. The basic system consists of a crash sensor mounted to the vehicle frame and an airbag assembly located within the passenger compartment. While different types of assemblies are used for driver-side and passenger-side restraint systems, the present invention is particularly suited to passenger-side airbag restraint systems. These assemblies often include an external reaction canister that receives the gas generator. This canister is a structurally strong member that absorbs and retransmits the airbag deployment force to the vehicle. The canister also supports the weight of the gas inflator and airbag. The airbag is typically located within the canister adjacent to the gas generator, and a cover over the canister maintains the bag in its undeployed or stored position. Reaction canisters are typically mounted on or near the vehicle's dashboard or instrument panel. Because the reaction canister directly supports the weight of the gas generator and airbag and transmits the deployment force, it is heavy and contributes to the overall vehicle weight.

The object of the present invention is to provide an integrated airbag/gas inflator/
It is an object of the present invention to provide a heat shielding member. A further object of the present invention is to form a single housing that defines the retainer and the heat shield, which is then formed into a cylindrical shape. Another object of the present invention is to provide a means for securing the gas generator within the housing. Another object of the present invention is to provide a device that transfers deployment recoil forces directly to the vehicle rather than to the recoil can. A further object is to use the retainer to secure the airbag, and if the airbag includes a tether, to secure the tether to the retainer.

The present invention therefore includes a retainer for use in an airbag restraint system of the type employing an airbag and a gas generator, the retainer comprising a planar metal sheet having at least one pair of opposed generally U-shaped slots therein, such that when the sheet is formed into an open-ended cylinder, the portions of the sheet initially within the slots extend away from the surface of the formed cylinder to form a plurality of first openings in the surface of the metal sheet and heat shielding means, such as vane-like projections, for insulating an airbag secured thereto from hot gases generated by a gas generator secured therein.
A securing means is included for interacting with the rear sidewall portion of the formed cylinder to press the gas generator against the front sidewall of the cylinder, thereby securing the gas generator in place. The securing means includes a plurality of bolts and a retaining member that threadably receives and guides the bolts to engage the deformable wall of the gas generator. As a result of compressively engaging the bolts with the wall,
Resilient deformation of the wall in cooperation with each bolt forms a respective recess which helps to radially and axially secure the gas generator therein.

Many other aims and objectives of the present invention will become apparent from the following detailed description of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS: FIG. 1 is a plan view of a sheet of the present invention prior to forming into a cylindrical shape.

FIG. 2 is a front plan view of the formed cage.

FIG. 3 is an end plan view of the device shown in FIG.

FIG. 4 is a cross-sectional view of the section 4-4 of FIG.

FIG. 5 is a front cross-sectional view of the device shown in FIG. 2, showing the placement of the gas generator therein.

FIG. 6 is a cross-sectional view of the section 6-6 of FIG.

FIG. 7 is a plan view of another embodiment of the present invention.

FIG. 8 is a front plan view of the cage obtained in this alternative embodiment.

FIG. 9 is a cross-sectional view of the present invention in a fully assembled configuration.

FIG. 10 is an enlarged view of a part of FIG.

FIG. 11 shows another embodiment of some of the elements of FIG.

FIG. 12 is a perspective view of the outer can.

FIG. 13 is a diagrammatic representation of an airbag that can be used in the present invention.

FIG. 14 shows a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS: Referring to the drawings, and in particular to FIG. 1, an integrated airbag/inflator/heat shield 20 (hereinafter referred to as the retainer) is shown in an early stage of assembly.
The cage 20 mainly has two internal
The metal sheet 21 comprises two opposing U-shaped slots 22a, 22b formed therein. The slots may be sharp as shown or curved. Above the slot 22a are a plurality of holes 24a, and below the slot 22b are another plurality of holes 24a.
The holes 24a and 24b are located on the sides 26a and 26b of the sheet 21.
The holes 24a, 24b are aligned so that when the planar sheet 2 is rolled up and positioned with its edges overlapping and engaging as shown in Figures 2-4, the holes 24a and 24b overlap one another. A bolt, shown diagrammatically in Figures 3 and 4, passes through the overlapping holes 24.

Two opposing U-shaped slots 22a, 22b define central member 40 and end portions 42a, b within sheet 21 therebetween.
The distance between a and b is selected so that the diameter of the sheet 21 in the rolled state is slightly larger than the diameter of the associated gas generator 50 (see Figures 5 and 6). The bolts shown in Figure 6 are shown diagrammatically.

2 shows the formed cage 20, i.e., cylinder 28, with overlapping sides 26a,b. The ends 42a,b extending forward and rearward from the central member 40 that defines the axially extending partial side 54 of the cylinder 28 form cylindrical end bands 52a,b.
a and b form the other side wall, rear side wall 56, of cylinder 28.

During the winding or forming of the planar sheet 21 into the cylindrical shape shown in FIG. 2, the sheet members 60a, b, i.e., the portions of the sheet 21 surrounded by the slots 22, are held in place by the retainer 60a, b.
Extends exactly tangentially outward on the 20 main cylinder.
The relative positions of members 60a,b to end bands 52a,b are more clearly shown in Figures 3 and 4. In this configuration, members 60a,b
The members 60a and 60b form wing-like projections extending from the generally cylindrical retainer 20. By orienting these members 60a and 60b upward, a plurality of openings 62a and 62b are formed between the end band and the side wall.

7 and 8, which illustrate an alternative embodiment of the present invention. While the cage 20' is shown in the figures, the cage 20'
Also therein are a plurality of pairs of opposing U-shaped slots 22a-c.
The metal sheet is formed from a planar metal sheet.
As mentioned above, the sides 26a,b have a plurality of aligned holes 24a,b.
The planar sheet similarly defines end portions 42 and a central member 40. Sets of slots 44a and 44b are spaced apart along the axis.

When the planar sheet 21' is wound, a substantially cylindrical retainer
The members 60a-f of the planar sheet 21' form a plurality of blade-like structures extending from the generally cylindrical retainer 20'. In this configuration, the members 60a-f form the retainer 20'.
A plurality of openings 70a-f are formed in the periphery of the spacer 0'.
As will be seen below, the space 44 (i.e., the band 52) forms the intermediate bands 52c and 52d.
It may be desirable to arrange it in line with the other two (c, d).

In the normal mode of operation, the retainer 20 or 20' provides a housing for the gas generator 50. Figure 9 shows a fully assembled cross-sectional view showing the gas generator 50 disposed within a retainer such as retainer 20. Figure 5 also shows a cross-sectional view of the embodiment of Figures 7 and 8.

In assembled form, bolts 80, having external threads 82 as fastening means, are received in the overlapping holes 24a, b and press the gas generator 50 forward against the band 52 and central member 40, i.e., the inner wall of the side wall 54. The bolts 80 can be secured to the retainer by nuts 84, shown in detail in FIG. 11. In this embodiment, one nut 84 for each hole, such as 24a, b, is secured to the inner wall of the side 26a. When the bolt 80 is inserted into the threads of the nuts 84, its end 85 is secured to the gas generator.
50, thereby compressing the gas generator against the band 52 and side wall 54 of the retainer 20. Because the gas generator 50 is most likely made of a soft metal such as aluminum, the forward compressive movement of each bolt 82 creates a respective indentation 88, shown to an exaggerated scale, in the wall 86 of the gas generator, thereby compressing the gas generator against the band 52 and side wall 54 of the retainer 20.
As you can see here, the gas generator
The extensions of the bolts 80 extending into the gas generator 50 secure the gas generator in a generally radially compressive manner.
and their respective recesses 88 cooperate to prevent lateral movement of the gas generator 50 within the retainer 20. Each bolt 80 may include a slot or recess to facilitate rotation of the bolt.

As can be seen, when the gas generator is secured in place, a portion of its wall 86 mates with the band 52 and a portion of the side wall 54;
As a result, the gas generator hole 90 (see FIG. 9)
is positioned in direct communication with opening 62 (or 70) to allow unimpeded gas transfer and facilitate efficient inflation of airbag 100. The propellant within gas generator 50 is not shown.

As can be seen above, the various bands 52 are connected to the gas generator 50
The front sidewall 54 of the cylinder 28 (retainer 20;2) provides a primary mode of securing the cylinder 28 within the formed retainer 20 and a secondary mode of securing the front-facing sidewall 54.
7. It is within the scope of the present invention that the forward sidewall 54 may be eliminated, since once the gas generator 50 is in place there is no particular need for a rigid sidewall 54. In this situation, the sidewall 54 may be replaced with any number of bands 52 (2, 3, 4, etc.) forming a corresponding number of vanes (projections) 62. For example, in FIG. 7, the various slots
22 extends midway through the sheet 21', but various projections 62
7. Once the retainer is formed, it will include a rear sidewall 56, a plurality of bands 52, and projections extending therefrom. Removal of the "sidewall" material between the bands 52 exposes a larger frontal area of the gas generator 50, providing greater options for locating its apertures 90.

During gas generation by the gas generator 50, a tremendous amount of heat is generated. It is desirable to protect the airbag 100 from these heated gases to prevent it from melting or burning. The various vanes 60 of the retainer 20 and 20' embodiments extend substantially tangentially outward from the rear of the wrapped retainer 20. In this configuration, the various vanes 60 provide a heat shield for the airbag 100 and direct the hot gases, indicated by arrows 92, forward into the airbag.

Airbag 100 of Figure 9 is shown in a folded condition secured to a retainer such as 20. Airbags such as those usable in the present invention are disclosed in commonly-owned, pending U.S. patent application Ser. No. 35/029,999.
No. 0,431, which is incorporated herein by reference. The airbag comprises a nylon pillow material having an open end closed at one end and containing flaps 102a,b. The flaps have a plurality of overlapping holes 106a,b (see FIGS. 9, 13, and 14).
14), which when stacked on the retainer 20 are aligned with holes 24 positioned for the bolts 80 to pass through.

The air bag is maintained in a folded state relative to the retainer 20 by a band or other material 110 received therein.
The material is selected to have a tensile strength sufficient to maintain the airbag 100 in its pre-deployment folded state. The strength of the material is such that the deployment force during the initial deployment of the airbag 100 is strong enough to rupture it, thereby allowing the bag 100 to expand with little restriction. The material used may be a plastic film, fabric, or other suitable material depending on the application.
It may be a spun-bonded olefin material such as those manufactured under the K designation.

A further advantage of the present invention is that the airbag 100 and retainer 110 can be attached to the retainer 20 prior to insertion of the gas generator. This allows partial assembly of the retainer/airbag/retainer separate from the gas generator so that the subassembly can be stored in environments that may be hostile to the gas generator.

10 is an enlarged view of a portion of FIG. 9, showing an alternative means for securing the end 26 of the sheet 21 and supporting the bolt 80. In this embodiment, one set of holes 24a is made slightly wider than the corresponding set of holes 24b. A clinch nut or rivet 140 having internal threads 142 is inserted into the holes 24a and 24b. When formed, the clinch nut 140 has a thread 142 at the end 26.
a, b and the clinch end 144 that secures them in place
The bolt 80 is then threaded onto the clinch nut 140 to engage the gas generator 50.

The following describes a general assembly sequence for use with the present invention. The planar sheet 21 is formed into a generally cylindrical shape as shown in Figure 2. While a circular cylinder is shown, other shapes are within the scope of the present invention. The bolts 80 are threaded or otherwise fitted into corresponding nuts 82, clinch nuts 140, etc., into the slots or recesses 9 at the ends of the bolts 80.
The airbag with overlapping flaps 102 is placed in the retainer in an overlapping configuration with the associated holes 106 that fit each bolt 80. The fasteners 110 are then threaded into the retainer 2.
0, air bag 100, and bolt 80 are arranged as shown in FIG.
12. Such an assembly can be placed within a partial enclosure such as 124 or an outer can 130 such as that shown in FIG. 8. As will be apparent, the enclosure 124 or can 130 can be formed as an integral part of the vehicle's instrument panel or as a separate element. If a partial enclosure is used, the retainer 20 with the airbag or the like is placed therein with bolts 80 received in aligned holes 126. If a can such as 130 is used with the retainer 20 or airbag placed within the can, the bolts 80 extend through cooperating holes 134 in its rear wall. The gas generator can then be slid into the retainer 20 through holes 136 in the side wall 138. The bolts are then moved to engage the gas generator in its fixed configuration, and nuts 140 are placed on each bolt 80 to secure the gas generator 50, retainer, or the like within the can 130 or enclosure 124.
For proper mounting of the above-described device, the instrument panel may be mounted to a structurally sound member of the vehicle, shown diagrammatically as 138, near the instrument panel. A portion of the instrument panel or a separate cover (not shown) is positioned over the airbag.

As can be seen from the above, the retainer 20-20' secures the gas generator 50 and provides a heat shield for protecting and inflating the airbag. The retainer is attached to the vehicle structure via bolts 80 or other means, thereby forming an enclosure 124.
The canister 130 can be made of a very lightweight material, such as plastic, since the recoil force generated by ignition of the gas generator is transmitted directly to the vehicle support member 138. The enclosure 124 or canister 130 can, of course, itself be a structural member designed to absorb some of the recoil force, in which case such element, i.e., enclosure or canister, would be made of metal or the like.

FIG. 14 shows the airbag 100 in an inflated state. The retainer, shown diagrammatically at 20, is positioned in a known manner within the upper portion of the vehicle dashboard (not shown) so that upon inflation, the airbag expands and abuts the windshield 150. The airbag is then deflected forward and downward toward the occupant. To help limit the trajectory the airbag takes as it inflates, and to limit its inflated shape at all, many airbags include tethers such as 152a, b. These tethers known in the prior art generally consist of sections of reinforcing material that are sewn to selected portions of the interior of the airbag 100. One example of a tether used in the prior art is:
There is a reinforced narrow band of material similar to the webbing of a seat belt. This tether is typically sewn across the surface 154 of the airbag at locations 156a-b. The tether extends toward the narrow neck portion 158 of the airbag and is typically sewn thereto at location 160. Another type of tether is formed by a trapezoidal piece of material with a wider end at location 156 of the airbag and its narrow end near the neck 158 of the airbag sewn at location 160. Sewing the tether at location 156 forward of the airbag is a relatively simple process. However, sewing the tether at location 160 is significantly more difficult. 152
When two tethers, a and b, are used, the sewing operation typically requires sewing both tethers together to the airbag at location 160. This problem is eliminated with the present invention. It is contemplated that tether 152 may be sewn to the airbag at location 156 in the conventional manner. As is known in the prior art, the tether is received loosely against the side of the airbag and extends toward the narrow neck 158 of the airbag. However, the tether of the present invention does not require a retainer.
22. This additional material 162 also includes a length of additional material shown generally as 162 that engages the rear side of bolt 8.
It includes a hole 164 so that it can receive a 0.
In this way, the mooring can be fixed to a permanent and definitive reference point, and the airbag trajectory and any mooring reaction loads carried by the retainer 22 apart from those absorbed by other parts of the airbag can be more accurately determined.

Many changes and modifications can, of course, be made to the above-described embodiments of the present invention within the scope thereof, which is therefore intended to be limited only by the appended claims.

──────────────────────────────────────────────────── Continued from the front page (72) Inventor: Fontecchio, Robert Paul 658, Timberline, Michigan, USA 48309 (72) Inventor: Good, Stanley Bey 2810, Richmond Boulevard Lane, Michigan, USA 48062 (72) Inventor: Hendricks, Troy Calvin 336, Box, Maryville, Tennessee, USA 37801 5

Claims (7)

[Claims] 1. A method for manufacturing a cylindrical member or cylinder (28) comprising forming at least one pair of first slots (22a, b) in a planar metal sheet (21, 21') and connecting said planar sheet to said cylindrical member or cylinder (28).
and a cylindrical member (28) formed therein, the flat metal sheet device (20) is formed to receive the gas generator (50) therein, and includes a fixing means (80) that interacts with the rear side wall of the cylindrical member to press the gas generator (50) against the front side wall of the cylindrical member and fix the gas generator (50) in place.
The device comprising: [Claim 2] The device of claim 1, wherein both sides (26a, b) of said sheet (21:21') overlap and engage with each other when forming a cylinder, forming a rear side wall of the cylinder substantially opposite said opening (62a, b). 3. The apparatus of claim 1, wherein the end portions (42a,b) of said sheet on either side of said slot form respective end bands (52a,b) in conjunction with the formation of a cylinder. [Claim 4] The apparatus of claim 1, wherein a central portion of the sheet (21) generally parallel to the sides 24 of the sheet forms a cylinder and also forms an axially extending forward side wall (54) circumferentially separating opposing openings (62). 5. The apparatus of claim 1, wherein the fixing means includes a first member (80) that is radially advanceable along the rear sidewall of the cylinder (28) and engages with a portion of the gas generator to press the gas generator from the rear sidewall against the front sidewall. 6. The method of claim 1, wherein at least one second set of slots (22a, 22b) is axially spaced from said first slots.
2. The apparatus of claim 1, wherein the first and second portions (60a, b, 60c, d) of the sheet formed by the respective slots are formed so that when the cylinder is formed, the first and second portions (60a, b, 60c, d) of the sheet extend in directions substantially parallel to each other away from the surface of the cylinder to form a plurality of openings (62a-d) in the surface. [Claim 7] The device of claim 1, further comprising an airbag (100) in a folded state, which encases the cylinder (28) and the extended first portion, and holds the airbag (100) through each first member so as to be separated from at least the first openings (62c, d) by the extended first portion.