WO2001010685A1

WO2001010685A1 - Side impact air bag

Info

Publication number: WO2001010685A1
Application number: PCT/US2000/021933
Authority: WO
Inventors: Jennifer L. Bohlen; Nicole C. Wiggins
Original assignee: Milliken & Co.
Priority date: 1999-08-11
Filing date: 2000-08-11
Publication date: 2001-02-15
Also published as: AU6631900A

Abstract

A gas inflatable side impact air bag made from a sheet of gas impermeable material folded over on itself with a fastened periphery further comprises shape-defining vertical, non-inflating, forward and rear internal tethers, each circumscribed by a continuous fastening, e.g., stitching, of the folded sheet portions and surrounded by an inflatable area, as well as an optional central non-inflating dead space area.

Description

SIDE IMPACT AIR BAG

Field of the Invention

The present invention relates generally to inflatable side impact air cushions for vehicle occupant restraint and methods for making same.

Background

An inflatable restraint cushion, or air bag, disposed within a supporting structure such as an instrument panel, steering wheel, roof rail, door frame or other fixed portion of a car body in opposing or side relationship to a seat in the vehicle plays an important role in protecting the occupants of a vehicle from injury due to striking the car body. Typically, the air bag is inflated rapidly by gas released from an inflator during a collision. This gas release typically takes place when a gas generating agent in the inflator is ignited in response to a collision signal from a collision detecting sensor when the deceleration of the vehicle exceeds a certain level. The gas released from the inflator is then conveyed to the air bag, which expands outwardly as it fills with gas to create a protective barrier between the vehicle occupant and the steering wheel, side window glass, door frame, or other portion of the vehicle body against which the occupant might otherwise be thrown.

Roof mounted or upper doorframe mounted side impact air bags provide a side curtain upon activation to help protect against defenestration of the vehicle occupant during an accident. Given the requirements for specific placement of the activated side air bag relative to interior vehicle surfaces and occupant to be effective, side air bags require different considerations regarding their inflated shape than frontal impact air bags.

Methods for effecting specific shapes upon inflation are known in the art. For example, U.S. Patent No. 5,788,270 to HAIand discloses a side impact inflatable element comprising a plurality of substantially parallel elongated cells, which may be vented to each other, having an upper edge fastened to the upper portion of a door frame, and a lower edge which is tensionable upon inflation. U.S. Patent No. 5,899,491 to Tschaeschke discloses an air bag curtain for a vehicle window comprising several tube-shaped chambers arranged side-by-side. The chambers are crossed by a tension line connecting the two fastening points with one another and have a bulge in the area of the chamber where the tension line crosses, providing a higher tension force between the fastening points without impairing the desirable circular cross-sectional shape of the adjoining chamber areas. U.S. Patent No. 5,884,937 to Yamada discloses a curtain-shaped air bag body mounted at the roof side rail and at least one of a front pillar and a rear pillar. The air bag body is mounted and accommodated by being folded from bottom to top and thereafter being bent to run along the roof side rail and the front pillar and/or rear pillar. U.S. Patent No. 5,588,672 to Karlow et al. discloses a side impact head restraint with inflatable deployment in which an inflatable member is mounted at two fixed points of the upper side rail and third movable point of the "B" pillar. The inflatable member can be configured to comprise several parallel cylindrical cells which can be vented at both ends to one another, or several inflated tubular sections or "fingers" projecting from a common comer which deploy for head protection in side impact collisions, allowing for inflation from a single point source. However, such finger bags lack a continuous inflated portion along the bottom edge of the deployed bag which results In less than complete protection for the occupant, and also require an movable anchor point on the B-pillar. EP 0832795 A1 to Neidert discloses a side impact air bag which extends from the A-pillar to the C-pillar and which can be inflated from gas generators located in both the A-pillar and C-pillar regions. This bag lacks a continuous inflated portion along the bottom edge. U.S. Patent No. 5,865,462 to Robins et al. discloses a variety of inflatable curtains which use tensioned deployment members for side impact protection including several which can be anchored at the vehicle A-pillar and C-pillar and which extend fully along the vehicle interior side.

It would be advantageous to provide a side impact air bag which can extend from the A- pillar to the C-pillar without requiring anchoring at the B-pillar and which provides continuous inflated coverage along its lower edge, in order to provide a vehicle occupant protection from direct contact with the side window or side window ledge. It would also be advantageous to limit the amount of gas volume necessary to inflate a large side impact air bag extending from a vehicle's A-pillar to C-pillar, in order to provide more rapid inflation and/or reduced gas generation requirements without significantly reducing the effectiveness of the side impact air bag. It would further be advantageous to provide a side impact air bag which upon activation prevents any part of a vehicle occupant from leaving the vehicle interior, as well as protecting the upper body of an occupant from interior elements. Finally, it would be advantageous to impart a desired inflated shape for a side impact air bag comprising two overlaid fabric sheets without substantial modification of said sheets, by fastening certain areas of said overlaid sheets together to provide non-inflating zones.

Summary of the Invention

In one aspect, the present invention relates to a gas inflatable side impact air bag which comprises: a single sheet folded on itself to provide a front sheet overlapping, and in substantial registration with, a back sheet, said front and back sheets having a common bottom edge defined by the resulting fold and being fastened together around their perimeters, at least one generally vertical non-inflating internal forward tether positioned in the anterior third of said air bag, said forward tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, at least one generally vertical non-inflating internal rear tether positioned in the posterior third of said air bag, said rear tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, a plurality of anchoring points along or near an upper edge of said air bag located opposite said lower edge, and an inlet for introducing gas to inflate said bag. In another aspect, the present invention relates to a gas inflatable side impact air bag which comprises: a single sheet folded on itself to provide a front sheet overlapping, and in substantial registration with, a back sheet, said front and back sheets having a common bottom edge defined by the resulting fold and being fastened together around their perimeters, a generally central non-inflating dead space area circumscribed by a substantially continuous fastening of said sheets, said dead space area being spaced apart from and above said bottom fold and apart from and below an upper edge of said sheets in order to provide a passageway for said gas below and above said dead space area, at least one generally vertical non-inflating internal tether positioned anteriorly of said dead space area and circumscribed by a substantially continuous fastening of said sheets, at least one generally vertical non-inflating internal tether positioned posteriorly of said dead space area and circumscribed by a substantially continuous fastening of said sheets, a plurality of anchoring points along or near said upper edge, and an inlet for introducing gas to inflate said bag.

In still another aspect, the present invention relates to a method for making a gas inflatable side impact air bag which comprises: a) providing a substantially gas impermeable single ply sheet which is generally symmetrical along its horizontal midline, having an initial upper edge and an initial lower edge; b) folding said sheet along said horizontal midline so that said initial lower edge meets said initial upper edge, providing a structure having opposed sheets, a folded lower edge and an unfastened, at least two-ply upper edge; c) fastening said sheets together along the at least two-ply upper edge to provide a fastened upper edge and a flattened cylindrical structure having exposed fastenings; d) optionally inverting said cylindrical structure and flattening the resulting structure; e) fastening said sheets along at least any remaining unclosed periphery to provide an inflatable bag; f) providing at least one generally vertical non-inflating internal forward tether positioned in the anterior third of said air bag, said forward tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, and at least one generally vertical non-inflating internal rear tether positioned in the posterior third of said air bag, said rear tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area; g) providing a plurality of anchoring points along or near said fastened upper edge; and h) providing a gas inlet for introducing gas to inflate said bag.

In yet another aspect, the present invention relates to a method for making a gas inflatable side impact air bag which comprises: i) providing a substantially gas impermeable single ply sheet which is generally symmetrical along its horizontal midline, having an initial upper edge and an initial lower edge; ii) folding said sheet along said horizontal midline so that said initial lower edge meets said initial upper edge, providing a structure having opposed sheets, a folded lower edge and an unfastened, at least two-ply upper edge; iii) fastening said sheets together along the at least two-ply upper edge to provide a fastened upper edge and a flattened cylindrical structure; iv) optionally inverting said cylindrical structure and flattening the resulting structure; v) fastening said sheets along at least any remaining unclosed periphery to provide an inflatable bag; vi) providing a generally central non-inflating dead space area which is circumscribed by a generally continuous fastening of said sheets, which dead space area is spaced apart from and above said folded lower edge and apart from and below said fastened upper edge of said sheets, with a gas passageway beneath and above said dead space area; vii) providing at least one generally vertical non-inflating internal tether positioned anteriorly of said dead space area and circumscribed by a generally continuous fastening of said sheets, and at least one generally vertical non-inflating internal tether positioned posteriorly of said dead space area and circumscribed by a generally continuous fastening of said sheets; viii) providing a plurality of anchoring points along or near said fastened upper edge; and ix) providing a gas inlet for introducing gas to inflate said bag.

In still another aspect, the present invention relates to a gas inflatable side impact air bag made from a sheet of generally gas impermeable material folded over on itself. The folded over sheet comprises a fastened periphery and vertical, non-inflating, forward and rear internal tethers, each circumscribed by a continuous fastening, e.g., stitching, of the folded sheet portions and surrounded by an inflatable area. The internal tethers as well as an optional central dead space contribute to the shape of the air bag when inflated.

The present invention relates to a side impact air bag which is easy to manufacture and which can provide side impact protection coverage from a vehicle A-pillar to C-pillar, with anchor points thereat. The air bag can be mounted for deployment as a continuous curtain along the interior side of the vehicle from the rear of the A-pillar to the rear of the C-pillar, and can further comprise a non-inflatable portion which upon inflation of the air bag extends from the rear of the B-pillar back to the middle of the rear window, or the front of the C-pillar. The air bag can also comprise a continuously inflated region along its lower edge to provide a continuous cushioned lower edge surface.

The air bag of the present invention can be produced from a single piece of material which can be formed from a small number of folding and sewing steps to provide a continuous, single-chambered bag of minimal volume, given its length, and which can be easily and rapidly filled with gas from a single inlet.

Brief Description of the Drawings The above, as well as other, features of the invention will become more apparent from the following detailed description of the preferred embodiments of the invention, when taken along with the accompanying drawings, in which:

FIG. 1 shows a first embodiment of a side impact air bag of the present invention prior to folding and fastening which contains anchor point mounting slots and optional internal tether reinforcing patches.

FIG. 2 depicts a side impact air bag of FIG. 1 after folding and fastening, which contains reinforced internal tethers, a single central non-inflatable dead space area adjoining the bottom fold, and a line tether anchored in a forward lower corner area of the air bag.

FIG. 3 shows a second embodiment of a side impact air bag of the present invention prior to folding and fastening, which comprises a C-pillar conforming posterior side edge and a posterior gas inlet means.

FIG. 4 shows the side impact air bag of FIG. 3 after folding and fastening, which has figure eight-shaped internal tethers, anchor slots within non-inflatable areas and two separate central dead space areas one atop the other and a line tether anchored in the forward lower corner.

FIG. 5 shows a third embodiment of a side impact air bag of the present invention prior to folding and fastening, having foldable reinforcing tabs for anchor points and reinforcing patches for the internal tethers. FIG. 6 shows the side impact air bag of FIG. 5 having reinforced figure eight-shaped internal tethers, reinforced anchor points, two separate central dead space areas one atop the other, and a line tether anchored in the forward lower corner.

FIG. 7 shows a fourth embodiment of a side impact air bag of the present invention having a front extension, prior to folding and fastening.

FIG. 8 shows a side impact air bag of FIG.7 containing a front extension.

FIG. 9 shows a view of the side impact air bag of the present invention anchored in the vehicle roof side rail beneath the headliner and deployed.

FIG. 10 shows a view of the side impact air bag of the present invention in inflated deployment, the air bag having a front extension.

While the invention is described in connection with a preferred embodiment, it will be understood that it is no way intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the true spirit and scope of the invention as limited only by the appended claims.

Detailed Description

Reference will now be made in detail to the preferred embodiment of the present invention as illustrated in the accompanying drawings. Wherever possible, like elements have been denoted by like reference numerals in the various views.

Turning now to the drawings, FIG. 1 shows a first embodiment of a side impact air bag of the present invention prior to folding and fastening (i.e., fastening along the bag perimeter). The air bag of the present invention may be formed from a single sheet 10 which may be formed from a number of substances including by way of example only and not limitation, woven fabrics, knitted fabrics, nonwovens, films, and combinations thereof. Woven fabrics may be preferred with woven fabrics formed of tightly woven constructions such as plain or panama weave constructions being particularly preferred. Such woven fabrics may be formed of yarns of polyester, nylon, e.g., nylon 6 or nylon 6,6, or other suitable natural or polymeric materials as may be known to those of skill in the art. Multifilament yarns of nylon 6,6 having a relatively low denier per filament rating of about 6 denier per filament or less may be preferred. Denier per filament ratings of about 4 denier per filament or less may be preferred for bags requiring particularly good flexibility, but such bags may require reinforcement at stressed locations. In application, yams with deniers of about 650 denier or less are believed to be particularly useful in the side impact air bag of the present invention. The sheet may be coated on a single side or both sides, using a suitable coating material, including by way of example, neoprene, silicone, urethane, and combinations thereof, with silicone being preferred. If coated on a single side, the sheet is preferably coated on the side which forms the interior of the bag. Ideally, the sheet is generally gas impermeable to an extent sufficient to permit the bag to rapidly inflate and remain inflated for a time necessary to protect the vehicle occupants during an accident. The sheet can have an air permeability of about 1 CFM or less, preferably 0.3 CFM, when measured at a differential pressure of 0.5 inches of water across the fabric. Total fabric weight of the sheet can be less than 390 grams per square meter. It is, of course, to be understood that aside from the use of coatings, differing characteristics in the sheets may also be achieved through the use of fabrics incorporating differing weave densities and/or finishing treatments as may be known to those of skill in the art.

The sheet 10 is cut using methods known by those skilled in the art, to provide a substantially rectangular shape which can have bilateral symmetry along a horizontal fold line 11. Upper and lower anchor slots 12 and 13 can be inserted slightly inboard of the upper and lower edge of the sheet, e.g., by precision cutting with a laser, so as to register or meet upon folding. These slots can be provided at the anterior third of the air bag and at the posterior third of the air bag and optionally can be located within the intermediate third or three-fifths of the air bag, with the terms "anterior" or "forward" being relative to the front of the vehicle in which the air bag is mounted and "posterior" or "rear" being relative to the rear thereof. Upper and lower registration marks 14 and 15 can be added by precision cutting with a laser and can serve to guide assembly of the bag by aligning or registering with each other upon proper folding. At least one of the anchor points, internal tethers, and/or corners of the air bag can be reinforced by laying over at least one additional sheet on the area to be reinforced. Upper and lower reinforcing patches 16 and 17 can be fastened to the sheet by any suitable fastening method to form substantially concentric fastenings 18 and 19. In general, it is preferred to fasten reinforcements to a coated side of the air bag, where a coated side will form the interior of the air bag. Suitable fastening methods for fastening together sheets, which may include one or more reinforcing sheets, include stitching, fastening with adhesives, melt bonding, and ultrasonic bonding. Suitable stitching techniques include the use of single needle or double needle stitching where fastening two or more sheet layers together using 6 to 12 stitches per inch, say, 8 to 10 stitches per inch. Fastening thicker layers or four or more layers together, e.g., where reinforcing the bag, can be effected preferably by double needle stitching. If sufficiently heavy sheet is used, reinforcing patches are not necessary.

FIG. 2 depicts a folded and fastened air bag 20 formed by folding the lower portion of the sheet 10 of FIG. 1 as bisected by fold line 11 congruently over the upper portion to provide overlapping sheet portions. A fastening 21, such as a line of stitches, is provided slightly inboard of the upper edge to provide a tube structure which can be inverted to avoid exposing any selvage adjoining the fastening, preferably before further fastening is carried out. The side edges of the bag are then fastened with fastenings 22 and 23. Side fastening 23 stops short of upper edge fastening 21 to provide a gas inlet 24 which is further defined by discontinuous upper edge fastening 25 which is parallel to and further inboard of the upper edge fastening 21. The discontinuities in the fastening 25 provide discontinuous openings which may be of varying size, to assist in the dispersal of gas from the gas inlet. Preferably, the gas inlet is located at the upper rear corner of said air bag where it is proximal to a C-pillar mounted gas generator. The aligned anchor slots 12 are circumscribed by stitching to minimize or avoid gas loss and stress associated with bag inflation, as well as to increase durability. Generally vertical internal tethers, i.e., those having their longest dimension in a direction less than plus or minus 45 degrees of the vertical, preferably less than plus or minus 30 degrees of the vertical, are made by providing a continuous sewn loop fastening together the overlapping sheets as well as any reinforcing patches associated therewith. Reinforced forward internal tethers 28 and 28a, as well as reinforced rear internal tether 28b, are depicted. The reinforcing patches are especially useful in conjunction with overlapping sheets having reduced thickness. At least one non-inflatable dead space area or zone 29 is substantially centrally positioned, between a forward internal tether and a rear internal tether, by stitching the overlapping sheets along fastening 29a. The dead space area can be located to provide a substantially non-inflated bag area along that portion of the bag deployed along the anterior half of a rear side window in a sedan. More than 50%, 60%, or even 75% of the total area of the air bag (measured when uninflated) mounted between the B-pillar and the midline of the rear side window can be dead space area inasmuch as a rear seated occupant would be less likely to contact the anterior half of a rear side window during a side impact collision. A line tether 26 of a suitable material such as rope, cord, wire, or cable can be fastened to the air bag in the lower anterior region. The end of the line tether is mountable to the lower part of a vehicle A-pillar. The line tether 26 can alternatively be made of the same material as the air bag 20.

FIG. 3 depicts a second embodiment of the present invention in which an unfolded, unfastened, non-reinforced, side impact air bag comprises a sheet 10 cut to provide a substantially rectangular shape which can have bilateral symmetry along its horizontal midline fold line 11. The upper and lower edges comprise anterior taper portions 3 and 32, respectively, which serve to conform the air bag to the anterior roof rail of a vehicle, and upper and lower posterior extensions 33 and 34, respectively. The posterior side edge comprises outward taper portions 35 and 36 as well as an intermediate notch 37. These side edge modifications conform the rear portion of the air bag to the vehicle's C-pillar when the air bag is inflated. Upper and lower anchor slots 12 and 13 are formed slightly inboard of the upper and lower edge of the sheet, so as to register or meet upon subsequent folding. These slots can be provided at the anterior third of the air bag and at the posterior third of the air bag and optionally can be located within the intermediate third or three-fifths of the air bag. Upper and lower registration marks 14 and 15 can be added by precision cutting with a laser. If insufficiently heavy sheet is used, reinforcing patches are necessary.

FIG. 4 shows a folded and fastened air bag 40 formed by the lower portion of the sheet of FIG. 3 congruently folded along its horizontal midline to provide overlapping portions. A fastening 41 is provided slightly inboard of the upper edge to provide a tube structure which can be inverted before further fastening is carried out. The side edges of the bag are then fastened with fastenings 42 and 43. Side fastening 43 stops short of upper edge fastening 41 to provide a tubular gas inlet 44 defined by fastenings 43 and 41. An additional inner side fastening 45 intersects fastening 43 and extends around a posterior anchor slot 46 and is furthermore continuous with fastening 43 near or at an inboard point where it defines the gas inlet 44, thereby positioning said anchor slot 46 in a non-inflatable region of the bag. Similar isolation of anchor slot 46.2 in a non-inflatable region is effected by fastening 48 which extends continuously from the forward side edge of the bag around anchor slot 46.2 and returns to the upper side edge above its starting point, paralleling the forward portion of fastening 41. The anchor slots can also be separately stitched around their circumference if necessary for bag integrity. A non-inflatable region 49 located at the lower anterior comer of the bag is defined by a portion of horizontal fold 11 and a fastening 49.1 which extends from side edge fastening 42 to 11. A line tether 47 of a suitable material such as rope, cord, wire, or cable can be fastened to the air bag at region 49. The other end of the line tether can be mountable to the lower part of a vehicle A-pillar. A lower central dead space zone 49.3 is circumscribed by a continuous fastening 49.4 which does not abut or touch the horizontal fold 11 (defining the bottom edge of the air bag) or the upper edge fastening 41. This provides upper and lower airways around the dead space zone and between the anterior and posterior regions of the air bag which facilitates rapid and more even bag inflation. An upper central dead space zone 49.5 defined by fastening 49.6 also surrounds anchor slot 46.1 which itself can be further circumscribed by fastening 49.8, either as a continuous fastening or separate. Two internal forward tethers 49.9 and 49.91 are raked back by no greater than 45 degrees (to the vertical) and are circumscribed by figure eight-shaped fastenings or seams, 49.92 and 49.93, respectively, to provide a desired shape to the anterior portion of the air bag upon inflation. Similarly, an internal rear tether 49.94, raked forward by no greater than 45 degrees (to the vertical) and circumscribed by a figure eight-shaped fastening or seam 49.95 provides a desired shape to the posterior portion of the air bag upon inflation. Alternatively, at least one of said internal tethers can be circumscribed by a generally vertical rectangle having rounded comers. As mounted to the vehicle, this air bag upon inflation can comprise a dead space area which effectively extends from behind the vehicle B-pillar midway to the rearward half of a vehicle's rear side window. Registration mark 15 serves to guide assembly of the bag by aligning or registering with each other upon proper folding and allows proper positioning of the internal tethers 49.9, 49.91, and 49.94.

FIG. 5 shows a third embodiment of the present invention, an unfolded unfastened air bag 50 similar to that of FIG.3. Air bag 50 additionally comprises foldable reinforcing forward corner tabs 51 and 52 and foldable reinforcing anchor slot tabs 53 and 54 which contain tab anchor slots 55 and 56 which are registrable with adjacent anchor slots 12 and 13 upon subsequent folding. This embodiment further comprises upper and lower reinforcing patches 16 and 17 which are positioned to conform with the intended orientation of subsequently added internal tethers. The reinforcing patches are fastened to the sheet to form substantially continuous concentric fastenings 18 and 19. FIG. 6 shows a folded and fastened air bag 60 formed by folding the lower portion of the sheet of FIG. 5 and fastened and otherwise modified in accordance with the description of FIG. 4. In addition, the foldable reinforcing forward corner tabs 51 and 52 of FIG. 5 are folded over to form a four-ply reinforced upper forward corner 61 while foldable reinforcing anchor slot tabs 53 and 54 are folded over to form four-ply reinforced anchor mounts 63.

FIG. 7 shows a fourth embodiment of the present invention in which an unfolded, unfastened airbag 70 similar to that of FIG. 3 additionally comprises an anterior extension 71 of the lower anterior side edge, obtained during the cutting of single sheet 10 or by fastening additional material to the sheet. The anterior extension has at least one anterior extension perforation 72 along the horizontal midline which is located to provide access to an anterior line tether 47 in the assembled air bag.

FIG. 8 shows a folded and fastened air bag 80 formed by folding the lower portion of the sheet of FIG. 7 and fastened and otherwise modified in accordance with the description of FIG. 4. The bag includes an anterior extension 81 projecting at the lower anterior portion of the bag, resulting from the folding and fastening of the anterior extension 71. The anterior extension 81 includes ports 82 which provide access to a non-inflating anterior lower edge area of the bag in which a line tether 47 can be placed. The air bag can be stored with the anterior extension folded back so that the storage length of the air bag is not increased over an air bag without the anterior extension. Upon inflation and deployment, the anterior extension will unfold and extend anteriorly along the line tether to cover the vehicle front quarter window.

FIG. 9 depicts a deployed and inflated air bag 90 of the present invention (from FIG. 8) mounted to vehicle 91 which is mounted in the roof side rail 92 at mounting location points 93 at air bag anchor points and by a line tether 94 connecting the air bag to the lower part of A-pillar 95.1. When undeployed, the air bag can be stored along the A-pillar, side rail and C-pillar 96.1 , and may be hidden from view by an interior headliner which has associated therewith a means for releasing the air bag into the occupant compartment upon inflation, such as a line of weakness or a hinged panel. The front line tether 94 can be stored along the A-pillar and is hidden from view during storage by a displaceable trim piece which is displaced upon inflating the air bag. The bag comprises two forward internal tethers 95, a rear interal tether 96, and upper and lower central dead space areas 97 and 98. The deployed side air bag can extend posteriorly of the C-pillar. The central dead space area extends from behind the B-pillar 99 to the middle portion of the vehicle rear side window opening. The bag is inflated during a collision which induces a signal from a collision detecting sensor causing release of gas from an inflator 99.1 mounted to the rear of the air bag.

FIG. 10 depicts a deployed and inflated air bag 100 (from FIG. 6) similar to FIG. 10 but having an anterior extension 101 which covers the front quarter side window opening.

In general, the deployed but uninflated air bag of the present can be mounted at points along the vehicle roof side rail through the air bag anchor points. The air bag line tether can be anchored to a lower part of the vehicle A-pillar and the upper posterior portion of the air bag can be mounted on the roof side rail behind the vehicle C-pillar through a posterior air bag anchor point. The undeployed air bag can be stored along the A-pillar, side rail and C-piilar, and is hidden from view by an interior headliner which has associated therewith a means for releasing the air bag into the occupant compartment upon inflation, such as a line of weakness or a hinged panel. The front line tether is stored along the A- pillar and is hidden from view during storage by a displaceable trim piece.

The bag is inflated during a collision by gas flowing through the air bag gas inlet from an inflator that is actuated by a signal from a collision detecting sensor causing release of gas from the inflator through the air bag gas inlet which rapidly inflates the air bag causing its release from storage into the occupant compartment of the vehicle, through the headliner. The inflation also exerts tension on the front line tether causing it to displace the trim piece. The internal tethers and a central dead space area of the bag contribute to its shape upon inflation. The inflated bag can cover the side of the occupant compartment, from the rear of the A-pillar to the rear of the C-pillar providing extensive occupant protection. The central dead space area reduces inflated gas volume of the bag and may extend from the rear edge of the B-pillar until the middle of the rear side window.

Having described the principles of the invention in the form of the foregoing exemplary embodiments, it should be understood by those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles, and that all such modifications falling within the spirit and scope of the following claims are intended to be protected hereunder.

Claims

It is claimed:

1. A gas inflatable side impact air bag which comprises: a single sheet folded on itself to provide a front sheet overlapping, and in substantial registration with, a back sheet, said front and back sheets having a common bottom edge defined by the resulting fold and being fastened together around their perimeters, at least one generally vertical non-inflating internal forward tether positioned in the anterior third of said air bag, said forward tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, at least one generally vertical non-inflating internal rear tether positioned in the posterior third of said air bag, said rear tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, a plurality of anchoring points along or near an upper edge of said air bag located opposite said lower edge, and an inlet for introducing gas to inflate said bag.

2. The air bag of claim 1 which further comprises at least one dead space zone between said internal forward tether and said internal rear tether.

3. The air bag of claim 1 wherein at least one of said anchor points, internal tethers and/or corners of said air bag is reinforced by at least one additional sheet.

4. The air bag of claim 1 wherein said sheet is a single side coated woven fabric having a total fabric weight of less than 390 grams per square meter, denier size of less than 650 denier, and an air permeability of about 1CFM or less when measured at a differential pressure of 0.5 inches of water across the fabric, said coating is selected from the group consisting of neoprene, urethane and silicone, and said fastening of sheets Is a sewn fastening.

5. The air bag of claim 1 which further comprises a line tether anchored to an anchor point at its anterior lower corner and connectable to a lower portion of a vehicle A-pillar.

6. The air bag of claim 1 wherein at least one of said internal tethers is circumscribed by a fastening selected from the group consisting of figure eight-shaped fastening and generally vertical rectangular fastening having rounded corners.

7. The air bag of claim 1 which further comprises an anterior extension projecting at a lower anterior portion of the air bag.

8. The air bag of claim 1 wherein at least one of said forward tethers is raked back no greater than 45 degrees and/or at least one of said rear tethers is raked forward no greater than 45 degrees.

9. The air bag of claim 1 wherein said gas inlet is located at the upper rear corner of said air bag.

10. The air bag of claim 1 wherein at least one of said anchor points is located within a non-inflatable dead space area.

11. A gas inflatable side impact air bag which comprises: a single sheet folded on itself to provide a front sheet overlapping, and in substantial registration with, a back sheet, said front and back sheets having a common bottom edge defined by the resulting fold and being fastened together around their perimeters, a generally central non-inflating dead space area circumscribed by a substantially continuous fastening of said sheets, said dead space area being spaced apart from and above said bottom fold and apart from and below an upper edge of said sheets in order to provide a passageway for said gas below and above said dead space area, at least one generally vertical non-inflating internal tether positioned anteriorly of said dead space area and circumscribed by a substantially continuous fastening of said sheets, at least one generally vertical, non-inflating internal tether positioned posteriorly of said dead space area and circumscribed by a substantially continuous fastening of said sheets, a plurality of anchoring points along or near said upper edge, and an inlet for introducing gas to inflate said bag.

12. The air bag of claim 11 wherein at least one of said anchor points, internal tethers and/or corners of said air bag is reinforced by at least one additional sheet.

13. The air bag of claim 11 wherein said sheet is a single side coated woven fabric having a total fabric weight of less than 390 grams per square meter, denier size of less than 650 denier, and an air permeability of about 1CFM or less when measured at a differential pressure of 0.5 inches of water across the fabric, said coating is selected from the group consisting of neoprene, urethane and silicone, and said fastening of sheets Is a sewn fastening.

14. The air bag of claim 11 which further comprises a line tether anchored to an anchor point at its anterior lower corner and connectable to a lower portion of a vehicle A-pillar.

15. The air bag of claim 11 wherein at least one of said internal tethers is circumscribed by a fastening selected from the group consisting of figure eight-shaped fastening and generally vertical rectangular fastening having rounded corners.

16. The air bag of claim 11 which further comprises an anterior extension projecting at a lower anterior portion of the air bag.

17. The air bag of claim 11 wherein at least one of said forward tethers is raked back no greater than 45 degrees and/or at least one of said rear tethers is raked forward no greater than 45 degrees.

18. The air bag of claim 11 wherein said gas inlet is located at the upper rear corner of said air bag.

19. The air bag of claim 11 wherein at least one of said anchor points is located within a non-inflatable dead space area.

20. A gas inflatable side impact air bag comprising: a sheet of generally gas impermeable material folded over on itself to provide folded sheet portions having a fastened periphery; generally vertical, non-inflating, forward and rear internal tethers, each circumscribed by a continuous fastening of said folded sheet portions and surrounded by an inflatable area; and an optional non-inflating central dead space area.

21. A method for making a gas inflatable side impact air bag which comprises: a) providing a substantially gas impermeable single ply sheet which is generally symmetrical along its horizontal midline, having an initial upper edge and an initial lower edge; b) folding said sheet along said horizontal midline so that said initial lower edge meets said initial upper edge, providing a structure having opposed sheets, a folded lower edge and an unfastened, at least two-ply upper edge; c) fastening said sheets together along the at least two-ply upper edge to provide a fastened upper edge and a flattened cylindrical structure having exposed fastenings; d) optionally inverting said cylindrical structure and flattening the resulting structure; e) fastening said sheets along at least any remaining unclosed periphery to provide an inflatable bag; f) providing at least one generally vertical non-inflating internal forward tether positioned in the anterior third of said air bag, said forward tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area, and at least one generally vertical, non-inflating internal rear tether positioned in the posterior third of said air bag, said rear tether being circumscribed by a substantially continuous fastening of said sheets and surrounded by an inflatable area; g) providing a plurality of anchoring points along or near said fastened upper edge; and h) providing a gas inlet for introducing gas to inflate said bag.

22. A method for making a gas inflatable side impact air bag which comprises: i) providing a substantially gas impermeable single ply sheet which is generally symmetrical along its horizontal midline, having an initial upper edge and an initial lower edge; ii) folding said sheet along said horizontal midline so that said initial lower edge meets said initial upper edge, providing a structure having opposed sheets, a folded lower edge and an unfastened, at least two-ply upper edge; iii) fastening said sheets together along the at least two-ply upper edge to provide a fastened upper edge and a flattened cylindrical structure; iv) optionally inverting said cylindrical structure and flattening the resulting structure; v) fastening said sheets along at least any remaining unclosed periphery to provide an inflatable bag; vi) providing a generally central non-inflating dead space area which is circumscribed by a generally continuous fastening of said sheets, which dead space area is spaced apart from and above said folded lower edge and apart from and below said fastened upper edge of said sheets, with a gas passageway beneath and above said dead space area; vii) providing at least one generally vertical non-inflating internal tether positioned anterioriy of said dead space area and circumscribed by a generally continuous fastening of said sheets, and at least one generally vertical, non-inflating internal tether positioned posteriorly of said dead space area and circumscribed by a generally continuous fastening of said sheets; viii) providing a plurality of anchoring points along or near said fastened upper edge; and ix) providing a gas inlet for introducing gas to inflate said bag.