The present invention relates to an apparatus for helping to protect a vehicle occupant in a vehicle collision.
Many vehicles have an air bag that inflates to help protect a vehicle occupant when the vehicle is involved in a collision. The air bag is inflated by inflation fluid provided by an air bag inflator. Certain air bag inflators produce inflation fluid by combustion of a pyrotechnic material. Combustion products in the inflation fluid may be hot, and might cause damage to the material of the air bag.
Known retainers, which retain the air bag to an air bag module, have deflectors to help direct hot inflation gas away from the air bag. As an alternative, U.S. Pat. No. 6,336,659 shows an air bag module with a shield for protecting an air bag from hot inflation fluid.
The present invention relates to an apparatus for helping to protect a vehicle occupant in a collision. The apparatus includes an inflatable vehicle occupant protection device and an inflator for providing inflation fluid to inflate the inflatable vehicle occupant protection device. The inflation fluid flow from the inflator is transverse to a central axis of the inflator. The apparatus further includes a shield. The shield includes a piece of material folded about the inflator and having a wall portion, which is interposed between the inflator and the inflatable vehicle occupant protection device and against which gas initially exiting from the inflator impinges. The wall portion has a plurality of tear seams that rupture due to inflation fluid pressure acting on the shield to enable the wall portion to form a plurality of flaps within the inflatable vehicle occupant protection device. Each flap pivots away from the central axis of the inflator about a pivot axis which extends in a direction transverse to the central axis of the inflator to block inflation fluid contact with portions of the inflatable vehicle occupant protection device.
The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, in which:
The present invention relates to an apparatus which includes an inflatable vehicle occupant protection device, such as an air bag. Other inflatable vehicle occupant protection devices that can be used in accordance with the invention include, for example, inflatable seat belts, inflatable knee bolsters, inflatable head liners, inflatable side curtains, and knee bolsters operated by inflatable air bags.
An apparatus 10 in accordance with a first embodiment of the present invention is shown in
The inflator 14 has a central axis 16 and includes cylindrical housing 15. The housing 15 includes a circular upper end wall 24 and an axially extending cylindrical side wall 27. The upper end wall 24 of the housing 15 is domed, that is, has a curved configuration projecting upward (as viewed in the drawings) and inward from the side wall 27. A circumferentially spaced plurality of outlet openings 26 are formed in the side wall 27 of the housing 15 for directing inflation gas out of the inflator 14 in directions extending transverse to the central axis 16.
A mounting flange 30 projects radially outward from a lower end (as viewed in
The air bag 12 is made from a fabric material, such as woven nylon. The air bag 12 includes a mouth portion 40, which includes a central opening 42 through which the housing 15 of the inflator 14 extends. Four circumferentially spaced openings 44 are provided in the mouth portion 40 of the air bag 12 and are aligned with the fastener openings 32 of the mounting flange 30. Parts of the main body portion 46 of the air bag 12 are omitted for clarity in
The apparatus 10 also includes a cover 50, which covers the folded air bag 12 and the inflator 14. The cover 50 has a rupturable tear seam 52, which is preferably not visible in the vehicle when the apparatus 10 is mounted in the vehicle. The cover 50 also has a mounting portion 54, which extends radially inward toward the axis 16 at a location between the air bag mouth portion 40 and the inflator mounting flange 30. The mounting portion 54 includes four circumferentially spaced fastener apertures 56.
The apparatus 10 further includes a bag retaining ring 60, which has a circular ring shaped inner portion 63 and a square shaped outer flange portion 61 (
The apparatus 10 further includes a heat shield 70. As best seen in
A first tear seam 76a begins from a location near the edge 78 of the fabric piece 72 and extends away from the opening 74 in a direction towards a rear left corner 120 of the fabric piece 70 as viewed in
The first and fourth tear seams 76a, 76d are located on a diagonal line extending between the rear left corner 120 and front right corner 126 of the fabric piece 72. The second and third seams 76b, 76c are located on a diagonal line extending between the rear right corner 122 and front left corner 124 of the fabric piece 72. Triangular inner flaps 80a-d of the fabric piece 72 are formed between adjacent tear seams 76a-d. All of the tear seams 76a-d are of equal length. When the tear seams rupture, the inner flaps 80a, 80b, 80c, 80d are allowed to pivot along their respective axes 210, 212, 214, 216. In particular, inner flap 80a is located between tear seams 76a and 76b and can pivot about axis 210. Inner flap 80b is located between tear seams 76b and 76d and can pivot about axis 212. Inner flap 80c is located between tear seams 76c and 76d and can pivot about axis 214. Inner flap 80d is located between tear seams 76a and 76c and can pivot about axis 216. Each of the axes 210, 212, 214, 216 extend in a direction transverse to the central axis 16 of the inflator 14.
A plurality of fastener apertures 82 are provided in the fabric piece 72 near the periphery of the fabric piece 72. The fabric piece 72 has front and rear edges 84, 86, and right and left side edges 88, 90. Four apertures 82a-d are located near the left side edge 90 and are each spaced the same distance from the left side edge 90. The distances between adjacent apertures 82a-d are also equal to one another. Four apertures 82e-h are located near the right side edge 88 and are each spaced the same distance from the right side edge 88. The distances between the adjacent apertures 82e-h are also equal to one another.
Two apertures 82i, 82j are located near the rear edge 86 and are each spaced the same distance from the rear edge 86. Two apertures 82k, 82l are located near the front edge 84 and are each spaced the same distance from the front edge 84.
As seen in
The folded over portions 94, 96, 98, 100 are clamped between the mouth portion 40 of the air bag 12 and the bag retaining ring 60. When in this position, fabric piece 72 forms the heat shield 70 for the air bag 12. During the assembling of the apparatus 10, the fabric piece 72 and retaining ring 60 are assembled as a unit as seen in
The studs 62a-d also extend through the openings 44 of the mouth portion 40 of the air bag 12, the respective apertures 56 in the mounting portion 54 of the cover 50, and fastener openings 32 in the mounting flange 30 of the inflator 14. Nuts 95 screwed onto the studs 62a-d clamp the mouth portion 40 of the air bag 12 between the retaining ring 60 and inflator mounting flange 30 and secure the heat shield 70, the inflator 14, and the air bag 12 in the apparatus 10.
The housing 15 of the inflator extends through the mounting portion 54 of the cover 50 and through the central opening 42 in the mouth portion of the air bag 12. The tear seams 76a-d are spaced apart around the end wall 24 of the housing 15 of the inflator 14. As seen in
Silicone material is coated on an inner surface 104 of the wall portion 102 facing the inflator 14. The wall portion 102 extends over the inflator 14 and covers the inflation outlets 26. The wall portion 102 is spaced outwardly from the inflator to define a chamber 105 between the inner surface 104 and outer side surface 22 of the housing 15 of the inflator 14 as shown in
The vehicle in which the apparatus 10 is mounted includes known electrical means (not shown) for sensing an impact to the vehicle and for actuating the inflator 14 in response to the sensing of an impact. The electrical means may, for example, include a deceleration sensor and vehicle circuitry for electrically actuating the inflator 14 in response to sensing vehicle deceleration greater than a predetermined threshold value for which inflation of the air bag 12 is desired to help protect the vehicle occupant. The electrical means is electrically connected with the inflator 14 for providing an actuation signal to the inflator 14.
In operation, when the inflator 14 is actuated, inflation gas, as indicated by the arrows in
The difference between the gas flow rate into the chamber 105 and the gas flow rate out of the chamber 105 causes the pressure in the heat shield 70 to increase. The pressure increase and the gas flow against the seams 76a-d cause the seams to rupture or tear, and the triangular flaps 80a, 80b, 80c, 80d to pivot about their respective axes 210, 212, 214, 216 away from the inflator 14 at a predetermined time, e.g., about 5 milliseconds or less, after actuation of the inflator 14.
As more inflation gas flows from the inflation fluid outlets 26, the inner flaps 80a, 80b, 80c, 80d pivot about their respective axes 110, 112, 114, 116 away from the upper end wall 24 and central axis 16 of the inflator 14 to a position shown in
In this embodiment, the apertures 82i, 82j are located at opposite ends of the cut out portion 192a of the rear edge 186. The apertures 82f, 82g are located at opposite ends of the cut out portion 192b of the right side edge 188. The apertures 82l, 82k are located at opposite ends of the cut out portion 192d of the front edge 184. The apertures 82b, 82c are located at opposite ends of the cut out portion 192c of the left side edge 190. Adjacent apertures in different edges are aligned with each other when the edges 184, 186, 188, 190 are folded over to form the folded portions 194, 196, 198, 200 as seen in
The bag retaining ring 160 includes a circular inner lip portion 163 and a barrel shaped flange portion 161. The inner lip portion 163 extends upwardly from the flange portion 161. The bag retaining ring 160 circumscribes the inflator 14. The retaining ring 160 is made of plastic or any other suitable material. The four steel mounting studs 62 are insert molded on the outer flange portion 161 of the retaining ring 160. The other elements and their operation in this second embodiment is the same as that of the first embodiment.
From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, the apparatus 10 may not include a bag retaining ring. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.