Inflatable side curtain

[0002] The present invention relates to an inflatable vehicle safety apparatus for helping to protect a vehicle occupant in the event of a side impact to a vehicle and/or a vehicle rollover.

[0003] It is known to inflate a vehicle occupant protection device to help protect a vehicle occupant in the event of a vehicle collision. One particular type of inflatable vehicle occupant protection device is an inflatable curtain that inflates from the roof of the vehicle downward inside the passenger compartment between a vehicle occupant and the side structure of the vehicle in the event of a side impact or rollover. Such an inflatable curtain is inflated from a deflated condition by inflation fluid directed from an inflator to the inflatable curtain through a fill tube.

[0004] The present invention relates to an apparatus for helping to protect an occupant of a vehicle that has a side structure and a roof. The apparatus includes an inflatable vehicle occupant protection device that is inflatable away from the vehicle roof into a position between the side structure of the vehicle and a vehicle occupant. An inflation fluid source provides inflation fluid for inflating the vehicle occupant protection device. The vehicle occupant protection device comprises first and second gas impermeable panels. Stitching extends into the first and second panels and secures portions of the panels together. A first gas impermeable piece is secured to the first panel in a position overlying the stitching in the first panel.

[0005] 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:

[0006] FIG. 1 is a schematic view of an inflatable vehicle safety apparatus illustrating the safety apparatus in a deflated condition;

[0007] FIG. 2 is a schematic view of the vehicle safety apparatus of FIG. 1 in an inflated condition;

[0008] FIG. 3 is an elevational view of a side curtain portion of the vehicle safety apparatus, with certain parts omitted;

[0009] FIG. 4 is an enlarged sectional view of the vehicle safety apparatus taken generally along line 4—4 in FIG. 2;

[0010] FIG. 5 is an enlarged sectional view of the vehicle safety apparatus taken generally along line 5—5 in FIG. 2;

[0011] FIG. 6 is an enlarged sectional view of the vehicle safety apparatus taken generally along line 6—6 in FIG. 2;

[0012] FIG. 7 is an enlarged sectional view of the vehicle safety apparatus taken generally along line 7—7 in FIG. 2; and

[0013] FIG. 8 is a sectional view of the vehicle safety apparatus taken generally along line 8—8 in FIG. 7.

[0014] As representative of the present invention, a vehicle safety apparatus 10 helps to protect an occupant of a vehicle 12. As shown in FIGS. 1 and 2, the safety apparatus 10 includes a vehicle occupant protection device in the form of an inflatable curtain 14, which is mounted adjacent to the side structure 16 of the vehicle 12 and the vehicle roof 18. The side structure 16 of the vehicle 12 includes side windows 22. An inflator 24 is connected in fluid communication with the inflatable curtain 14 through a fill tube 26. Securing hardware 20, such as clamps or brackets, secures the inflatable curtain 14 and the fill tube 26 to the side structure 16 of the vehicle 12.

[0015] The fill tube 26 has a first end portion 30 (FIG. 2) for receiving fluid from the inflator 24. The fill tube 26 has a second end portion 32 that is disposed in the inflatable curtain 14 along a top edge 36 of the curtain. The second end portion 32 of the fill tube 26 has a plurality of openings (not shown) that provide fluid communication between the fill tube 26 and the inflatable curtain 14.

[0016] The inflator 24 contains a stored quantity of pressurized inflation fluid (not shown) in the form of a gas to inflate the inflatable curtain 14. The inflator 24 alternatively could contain a combination of pressurized inflation fluid and ignitable material for heating the inflation fluid, or could be a pyrotechnic inflator that uses the combustion of gas-generating material to generate inflation fluid.

[0017] The safety apparatus 10 includes a housing 28 (FIG. 1) that stores the inflatable curtain 14 in a deflated condition. The fill tube 26, the deflated inflatable curtain 14, and housing 28 have an elongated configuration and extend along the vehicle roof 18 and along the side structure 16 of the vehicle 12 above the side windows 22.

[0018] As best illustrated in FIGS. 4-6, the inflatable curtain 14 comprises first and second panels 40 and 42 that are arranged in an overlying manner. Overlapping portions of the first and second panels 40 and 42 are secured together by stitching 44 (FIG. 3), which forms a seam 46 that extends along a portion of the periphery 48 of the panels. In the illustrated embodiment, the inflatable curtain 14 is formed from a sheet of material that is folded over along a bottom edge 50 of the curtain, opposite the top edge 36, to form the overlying first and second panels 40 and 42 (FIG. 4). It will be recognized by those skilled in the art, however, that the inflatable curtain 14 may have alternate constructions. For example, the first and second panels 40 and 42 could be formed from separate sheets of material arranged in an overlying manner and secured together by stitching 44 along the entire periphery 48 of the panels to form the inflatable curtain 14.

[0019] The first and second panels 40 and 42 (FIG. 5) are constructed of a material, such as a fabric, that is coated on at least one side with a gas impermeable coating 52, such as a urethane coating. The first and second panels 40 and 42 are arranged such that the coating 52 defines an outer surface 56 of the inflatable curtain 14.

[0020] As illustrated in FIG. 3, overlying parts of the first and second panels 40 and 42 may be secured together, by stitching 44, at desired locations within the periphery of the inflatable curtain 14. The stitching 44 forms non-inflatable portions 66 and secured together segments 68 of the inflatable curtain 14. It will be recognized by those skilled in the art that the non-inflatable portions 66 and segments 68 of the inflatable curtain 14 may be arranged in various configurations. For example, the number of portions 66 and segments 68 could be increased or decreased and the shape, size and location of the portions and segments could be changed.

[0021] As illustrated in FIG. 2, gas impermeable pieces 70 overlie the stitching 44, illustrated in FIG. 3, that forms the seam 46, the non-inflatable portions 66 and the segments 68 of the inflatable curtain 14. The gas impermeable pieces 70 (FIGS. 5 and 6) consist of a material, such as a fabric, that is coated on at least one side with a gas impermeable coating 72, such as a urethane. The materials used to construct the gas impermeable pieces 70 may be identical or similar to the materials used to construct the first and second panels 40 and 42 of the inflatable curtain 14.

[0022] As illustrated in FIG. 5, the gas impermeable pieces 70 overlie the stitching 44 that forms a linked segment 68. It will be recognized by those skilled in the art that an identical configuration may also be used to overlie the stitching 44 that forms the non-inflatable portions 66 (FIG. 3) of the inflatable curtain 14. A first gas impermeable piece 80 (FIG. 5) overlies the stitching 44 on the first panel 40, and a second gas impermeable piece 82 overlies the stitching 44 on the second panel 42. The first and second gas impermeable pieces 80 and 82 are arranged such that the gas impermeable coatings 72 of the pieces are positioned adjacent to the gas impermeable coatings 52 of the first and second panels 40 and 42, respectively.

[0023] The first and second gas impermeable pieces 80 and 82 are connected to the first and second panels 40 and 42, respectively, by a radio frequency weld 84. The radio frequency weld 84 bonds the gas impermeable coating 52 on the first panel 40 to the coating 72 on the first piece 80, and bonds the coating 52 on the second panel 42 to the coating 72 on the second piece 82. The radio frequency weld 84 surrounds the stitching 44 on the outer surface 56 of the inflatable curtain 14 and forms an airtight seal around the stitching.

[0024] The radio frequency welding process melts at least a portion of the coatings 52 and 72 and combines or fuses the coatings to form the radio frequency weld 84. For clarity, in the figures, the radio frequency weld 84 is shown schematically as a layer between the coatings 52 and 72. The radio frequency weld 84, however, is actually a blend or mixture of at least a portion of the coatings 52 and 72.

[0025] As illustrated in FIG. 6, a gas impermeable piece 70 overlies adjacent portions of the first and second panels 40 and 42 that are secured by stitching 44 along the periphery 48 of the inflatable curtain 14. The gas impermeable piece 70 has a length that extends along the top edge 36 (FIG. 2), a front edge 86 and a rear edge 88 of the inflatable curtain 14.

[0026] The gas impermeable piece 70 (FIG. 6) has a width, measured transverse to the length, that wraps around the first and second panels 40 and 42 along the top edge 36 (FIG. 2), front edge 86 and rear edge 88 of the inflatable curtain 14. The gas impermeable piece 70 is arranged such that the gas impermeable coating 72 of the piece is positioned adjacent to the gas impermeable coating 52 of the first and second panels 40 and 42.

[0027] The gas impermeable piece 70 is connected to the first and second panels 40 and 42 by a radio frequency weld 84. The radio frequency weld 84 bonds the gas impermeable coating 52 on the first and second panels 40 and 42 to the gas impermeable coating 72 on the gas impermeable piece 70. The radio frequency weld 84 surrounds the stitching 44 on the outer surface 56 of the inflatable curtain 14 and forms an airtight seal around the stitching.

[0028] The securing hardware 20 (FIG. 2) extends through apertures 98 that are spaced along the top edge 36 of the inflatable curtain 14. As illustrated in FIGS. 7 and 8, an aperture reinforcing structure 100 consists of third and fourth pieces 102 and 104, which are arranged in an overlying manner with uncoated surfaces 106 of the pieces positioned adjacent to each other and the coating 72 facing outward. The aperture reinforcing structure 100 has an oval or generally elongated circular shape and includes an aperture 110 that extends through the third and fourth pieces 102 and 104. The third and fourth pieces 102 and 104 are connected to each other by stitching 112, which encircles the aperture 110.

[0029] The aperture reinforcing structure 100 is positioned between the first and second panels 40 and 42 with the aperture 110 in the seal in alignment with the aperture 98 in the inflatable curtain 14. In the illustrated embodiment, a portion of each of the first and second panels 40 and 42 is coated with a layer of gas impermeable coating 114, which surrounds the apertures 98 on inner surfaces 116 of the panels. It will be recognized by those skilled in the art that the entire inner surface 116 of the first and second panels 40 and 42 may also be coated with the gas impermeable coating 114.

[0030] The aperture reinforcing structure 100 is connected to the inflatable curtain 14 by a radio frequency weld 84. The radio frequency weld 84 bonds the gas impermeable coating 114 on the first panel 40 to the coating 72 on the third piece 102, and bonds the coating 114 on the second panel 42 to the coating 72 on the fourth piece 104. The radio frequency weld 84 surrounds the aperture 98 and forms an airtight seal around the aperture.

[0031] Those skilled in the art will recognize that the aperture reinforcing structure 100 may have alternate constructions. For example, in the illustrated embodiment, the aperture reinforcing structure 100 is connected to the first and second panels 40 and 42 by the radio frequency weld 84, alone. It may be desirable, however, to secure the aperture reinforcing structure 100 to the first and second panels 40 and 42 in a manner such that a stronger connection is provided. In this instance, the stitching 112 may extend through the third and fourth pieces 102 and 104 and through the first and second panels 40 and 42. Also, it may be desirable to provide a gas impermeable coating on both sides of the third and fourth pieces 102 and 104 such that a radio frequency weld that surrounds the stitching 112 between the pieces can be provided.

[0032] The vehicle 12 includes a sensor mechanism 120 (shown schematically in FIGS. 1 and 2) for sensing a side impact to the vehicle 12 and/or a rollover of the vehicle 12. The sensor mechanism 120 actuates the inflator 24 in response to the sensing of a side impact or a vehicle rollover.

[0033] In the event of a rollover of the vehicle or a side impact to the vehicle 12 of a magnitude greater than a predetermined threshold value, the sensor mechanism 120 provides an electrical signal over lead wires 122 to the inflator 24. The electrical signal causes the inflator 24 to be actuated in a known manner. The inflator 24 discharges fluid under pressure into the fill tube 26. The fill tube 26 directs the fluid into the inflatable curtain 14.

[0034] The inflatable curtain 14 inflates under the pressure of the inflation fluid from the inflator 24. The housing 28 (FIG. 1) opens and the inflatable curtain 14 (FIG. 2) inflates away from the roof 18, in a downward direction as shown in the drawings and with respect to the direction of forward travel of the vehicle 12, into the position illustrated in FIG. 2.

[0035] When the inflatable curtain 14 is in the inflated condition, the first panel 40 is positioned adjacent the side structure 16 (FIG. 2) of the vehicle 12. The top edge 36 of the inflatable curtain 14 is positioned adjacent to the intersection of the roof 18 and the side structure 16 of the vehicle 12. The front edge 86 of the inflatable curtain 14 is positioned adjacent to an A pillar 62 of the vehicle 12. The rear edge 88 of the inflatable curtain 14 is positioned adjacent to a C pillar 64 of the vehicle 12.

[0036] The inflatable curtain 14, when inflated, extends along the side structure 16 of the vehicle 12 and is positioned between the side structure and any occupant of the vehicle. In the inflated condition, the inflatable curtain 14 extends between the A pillar 62 and the C pillar 64 of the vehicle 12 and overlies at least a portion of the A pillar, C pillar, and a B pillar 124 of the vehicle. The inflatable curtain 14, when inflated, helps to protect a vehicle occupant in the event of a vehicle rollover or a side impact to the vehicle 12.

[0037] The gas impermeable pieces 70 help block inflation fluid from leaking through the stitching 44. The aperture seals 100 help block inflation fluid from leaking through the apertures 98. The inflatable curtain 14 thus has a substantially airtight construction. This helps to ensure that the inflatable curtain 14 will remain inflated throughout the duration of a side impact to the vehicle 12 and/or a vehicle rollover.

[0038] From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.