WO2000021797A1

WO2000021797A1 - Centralized inflation system for safety restraints

Info

Publication number: WO2000021797A1
Application number: PCT/US1999/016161
Authority: WO
Inventors: John Miller, Iii; Gerald Keller; Edward W. Clancy, Iii; Timothy W. Hill
Original assignee: Breed Automotive Technology, Inc.
Priority date: 1998-10-13
Filing date: 1999-07-16
Publication date: 2000-04-20

Abstract

A centralized, multi-function airbag system is installed within a vehicle seat (20). The system has a single source of inflation gas and a multi-function airbag (50) with a plurality of interconnected chambers that are generally simultaneously inflated.

Description

CENTRALIZED INFLATION SYSTEM FOR SAFETY

RESTRAINTS

The invention generally relates to airbags for motor vehicles and more particularly to a multifunction, centrally inflated airbag that is located within a vehicle seat.

A variety of airbag and related safety restraint systems have been proposed to protect various portions of the anatomy of the vehicle occupant during a severe crash. As an example, US 3 953 049 describes an inflatable head impact system. US 4 946 191 illustrates a side impact airbag system to protect the head and shoulder of a vehicle occupant. US 5 782 529 provides for rear impact protection by including an inflatable cushion in the seat back to reduce injuries to the spinal vertebrae and ligaments during a rear impact collision. Most of the proposed airbag systems define an airbag, which protects one particular portion of the human anatomy. The above-mentioned

US 5 782 529 illustrates a multi-purpose airbag which protects the rear of the head, the spine and includes a rearward extending cushion, the function of which is to provide a knee bolster for a vehicle occupant seated behind the primary vehicle occupant in the front vehicle seat.

Future automotive airbag systems must offer greater functionality for the same cost as current systems in production. The present invention utilizing a centralized airbag inflation methodology will allow a multi-function airbag to be inflated utilizing a single gas generator. More particularly the invention comprises a seat-mounted airbag having a plurality of inflatable chambers. These inflatable chambers will include for example, a head and thorax side impact airbag, a thigh and hip side impact airbag, a rear seat inflatable knee bolster, a rear impact protection airbag, an anti-submarining airbag and/or a center position side impact airbag.

It is an object of the present invention to provide a multi-function airbag. This object is met by the airbag system described in the appended claim 1.

Brief Description of the Drawings

FIG. 1 is a rear isometric view of a typical prior art automotive vehicle seat.

FIG. 2 is a plan view of a multi-function airbag.

FIG. 3a illustrates a partial cross-sectional view through section A-A of FIG. 2.

FIG. 3b is a partial cross-sectional view through section B-B of FIG. 2.

FIG. 4 diagrammatically illustrates the airbag 50 in an inflated condition.

FIG. 5 is a front orthogonal view of a typical vehicle seat incorporating the present invention.

FIG. 6a and 6b respectively show an isometric cross-sectional and plan cross-sectional view through the seat of FIG. 5.

FIG. 7 diagrammatically shows an automotive seat with a multi-function airbag in its inflated condition.

Detailed Description of the Invention

FIG. 1 illustrates the typical construction of an automotive vehicle seat generally 20. The seat includes a seat cushion 22 and seat back 24. Both the seat cushion and seat back are constructed using an underlying support frame covered by a foam 32 and an outer layer of protective or decorative material 34 such as woven cloth or leather. With regard to the seat back, a support frame 26 is shown having a plurality of vertical posts 28a, 28b. Connecting the posts 28a, b are a plurality of horizontal supports or springs which provide support for the foam 32 and covering material 34. The covering material typically comprises a number of panels that are sewn together at discrete seams across the surface of the seat. The seat back and seat cushion may be of integral construction, or hinged relative one to the other, as is typically the case with two-door vehicles. The foam 32 for each of the back and cushion is supported on a resilient platform, which is considered to be part of the seat frame structure. The typical automotive seat further includes a headrest 40, which is appropriately secured to a frame part. The headrest may be movable relative to the back 24 or an integral part thereof .

FIG. 2 is a plan view of a multi-function airbag 50. The airbag is made of front and rear panels 52a, 52b. The panels may comprise a continuous length of an appropriate material, or discrete pieces of an appropriate material. It should be appreciated that the panels 52a, 52b are laid flat in FIG. 2. These panels may comprise fabric such as woven nylon (for example 640 denier) which may be coated with silicone or uncoated. Alternatively, the panels can be made of polyethylene film. Each of the panels is joined at their common periphery shown by dotted line 54. This joining may be accomplished by sewing or heat sealing or other technique as is known in the art which will also depend on the particular material used for the airbag 50. The airbag has a central inflatable portion, or chamber, 56 that provides support for the vehicle occupant's spine. The upper portion 56a of the chamber 56, as described below, provides protection for the vehicle occupant's head and when inflated is positioned in front of the headrest. Extending outwardly from the center chamber is a right wing chamber 60 and a left wing chamber 62. As shown the chambers are of differing size but they can be the same size. Each of these chambers communicates with the center chamber through flow passages 60a, 60b. The seams, or sealing, 54 is also used to define the flow passages. When the larger chamber 62 is inflated it is positioned between the vehicle occupant and the vehicle structure to provide protection for the head and thorax of the vehicle occupant. This airbag acts as a side impact airbag. When the right-hand chamber 60 is inflated it extends forward from the seat 20 into the center of the vehicle and prevents the vehicle occupant from moving inwardly especially in reaction to a side impact. The lower portion 66 of the chamber 56 communicates with a manifold 80 and a rear knee bolster 68 which is also shown in FIG. 3a. The manifold, or distribution section, 80 is also made of the airbag material. An inflator 70 is inserted within the manifold as shown in FIG. 3b. The manifold 80 includes a plurality of gas flow channels or passages 72 which permit inflation gas to enter the center chamber 56 and flow into the other chambers 60, 62. A manifold section 80 may comprise non-airbag fabric such as tubes, bladders, or rigid manifolds as a means of routing gas or fluid flow from the inflator 70 to adjacent portions of the airbag 50. As with the other sections of the airbag, the manifold, in the preferred embodiment, is formed of front and rear panels 52a, 52b of a suitable material. The manifold section 80 is prevented from inflating by securing the front and rear panels together by a plurality of seams, or joints, 82 which may be accomplished by a series of sewn seams or heat stakes, depending upon the material used for the airbag. The seams define the plurality of channels, or passages, 72 to transmit inflation gas from the inflator to a lower bag 90 that, as shown below, provides an anti-submarining function. Some of the channels 72 may include openings 72a to further distribute the inflation gas generated by the inflator. Some of the channels 72 communicate with a plurality of smaller airbag chambers 92, 94 that provide protection for the vehicle occupant's thigh and/or hip. The rear panel 52b is constructed with an appendage 93, or flap, which, when inflated, breaks through a rear cover of the seat and forms a knee bolster airbag 68 for the occupant of a seat rearwardly positioned to seat.

The covering material 34 of the automotive seat typically comprises a plurality of different panels that are joined at a variety of seams. As an example, the seat cushion 22 includes a top outboard seam 100a and a top inboard seam 100b. The various panels forming the front of the seat back 24 and the sides of the seat back are joined at seams 102a, 102b. The top of the seat back additionally includes a top seam 104. In the present invention the airbag will break open these various seams is it inflates. In an alternative embodiment discrete deployment doors replace some of the breakable seams . Each of these doors would be affixed to the material 32 or to another portion of the seat. As a particular chamber of the airbag inflates the corresponding deployment door is opened and the inflating airbag chamber continues to inflate. As illustrated in FIGS. 1 and 5, the seat back 24 may also include an inboard and outboard wing 24a, 24b respectively .

During the construction of the seat 20, the foam or cushioning layer 32 is fixed to the various seat frame members in a known manner. The airbag 50, in its non-inflated condition, is laid upon the (partially constructed) seat such that chamber 56 is positioned to lie behind the foam forming the seat back and may be secured to the back support frame 26 which supports the back foam. The side chambers 60, 62 of the airbag are positioned upon the wings 24a, 24b or at the side of the seat back. The manifold 80 is positioned on the resilient seat support 25a below the foam 32b forming the seat cushion. As can be seen from FIGS. 6a or 6b, the inflator 70 is positioned below the lower seat frame 25. The lower chamber 90 (in relation to FIG. 2) is drawn through a slot 27 (see FIGS. 5, 6a andδb) in foam 32b and positioned on or toward the top front of the foam 32b. The smaller side cushions 92, 94 are folded and placed on a respective side of the seat cushion foam 32b. The airbag 50 may be held in place by securing selective corners or other portions of the airbag by hooks and wires to adjacent frame parts. Upon installation of the seat covering 34, the configuration of the seat 20 is that shown in FIG. 5.

The inflator 70 is in communication with a control unit, which receives input from a variety of crash sensors (not shown) in a known manner. These crash sensors may sense a frontal impact, side impact, rear impact, or a vehicle rollover. Upon sensing one or more of these events, the control unit generates an activation signal causing the inflator, of known construction, to provide or generate inflation gas to inflate the airbag 50. Upon receipt of the inflation gas, regardless of the type of accident the vehicle may be involved in, each of the various chambers of the airbag is generally simultaneously inflated to protect the vehicle occupant.

FIG. 7 illustrates the vehicle seat 20 with the multi-function airbag 50 inflated.

While the preferred embodiment of the invention describes a multi-function airbag made of two panels which are formed and joined to define a plurality of separate chambers, the scope of the invention includes using a plurality of previously sewn or joined- together airbags that are linked together to provide the multi-function airbag.

Claims

1. An airbag system for installation within a vehicle seat comprising a single source of inflation gas and a multi-function airbag (50) comprising a plurality of spaced apart interconnected chambers (56, 60, 62) which are generally simultaneously inflated.

2. The airbag system of claim 1 wherein the seat (20) comprises a seat back (24) and a seat cushion

(22) covered with a layer of covering material (34), the airbag installed beneath the covering material, the airbag (50) including a first chamber (56) laid upon an under-support (32) of the seat back which on inflation provides support to the at least the vehicle occupant's spine, the airbag further including a first (60) and a second (62) side chamber situated on respective sides of the seat back under-support which upon inflation define a side impact airbag positioned between the vehicle occupant and a side of the vehicle, and a center chamber located generally adjacent an inboard side of the seat, the airbag additionally includes a manifold means (70) integrally a part of the airbag for transporting inflation gas to remote chambers of the bag, the manifold means situated below the under-support of the seat cushion (22), one of the remote chambers being formed by an end cushion (90) in communication with the manifold, the end cushion positioned upon the top of the under-support of the seat cushion.

3. The airbag system of Claim 2 further comprising additional remote chambers formed of side chamber (62) is located on opposite sides of the manifold means which upon inflation are positioned generally adjacent the thigh and hips of the vehicle occupant .

4. The airbag system of Claim 3 wherein the airbag is of integral construction.

5. The airbag system for installation of Claim 3 wherein each of the chambers of the airbag (50) are separate chambers joined together.

6. The airbag system of Claim 2 wherein the first and second side chambers (62) have different sizes.

7. The airbag system of Claim 3 wherein the airbag comprises a system of discrete cushions connected by a series of passages (60a, 60b) .