Patent Application
20090179409
The present invention relates to a cut, sewn, and laminated inflatable vehicle occupant protection device.
It is known to inflate an inflatable vehicle occupant protection device to help protect a vehicle occupant. Examples of inflatable vehicle occupant protection devices include driver and passenger frontal air bags, side air bags, and inflatable knee bolsters. One particular type of inflatable vehicle occupant protection device is an inflatable curtain.
An inflatable curtain will inflate in response to the occurrence of an event for which inflation of the inflatable curtain is desired, such as a side impact to the vehicle, a vehicle rollover, or both. The inflatable curtain inflates away from a roof of the vehicle between a side structure of the vehicle and a vehicle occupant. A known inflatable curtain is inflated by inflation fluid directed from an inflator to the inflatable curtain via a fill tube.
Inflatable curtains may have a variety of constructions. For example, an inflatable curtain may be constructed of woven panels that are interconnected by suitable means, such as stitching, ultrasonic welding, or adhesive bonding. The gas impermeability of the inflatable curtain may be improved by coating the curtain with a material, such as silicone or polyurethane via spray coating or knife spreading. Alternatively, a film sheet material, such as polyurethane or co-polyester, may be laminated to the inflatable curtain to improve gas impermeability.
The present invention relates to an inflatable vehicle occupant protection device that includes a woven panel (41) comprising first and second side panels (40 and 42) positioned overlying each other. The side panels (40 and 42) are not coated or laminated on any surface. Stitching (58) extends through and interconnects the overlying first and second panels (40 and 42). A film layer (75) is laminated onto the woven panel (41) covering an outer surface of the woven panel and the stitching (58).
The present invention also relates to an inflatable vehicle occupant protection device including first and second panels of woven material positioned overlying each other. The second panel is configured to leave exposed portions of the first panel extending about a periphery of the first panel. Stitching extends through and interconnects the overlying first and second panels. A first film layer overlies the first panel and covers the stitching. A second film layer overlies the second panel and covers the stitching. The second film layer also covers the exposed portions of the first panel.
The present invention also relates to an inflatable vehicle occupant protection device including first and second panels of woven material positioned overlying each other. Stitching extends through and interconnects the overlying first and second panels. First and second film layers overlie the first and second panels and cover the stitching. The first and second film layers include peripheral overlap portions that extend beyond the peripheries of the first and second panels. The peripheral overlap portions overlie each other and are laminated to each other to form a peripheral edge seal that helps block inflation fluid leakage from between the first and second panels.
The present invention also relates to an inflatable vehicle occupant protection device including first and second overlying panels of woven material. A gasket is disposed between the first and second panels. The gasket includes a narrow strip of film extending along at least a portion of a periphery of the panels. Stitching extends through and interconnects the first panel, the second panel, and the gasket. A first film layer overlies the first panel and the stitching. A second film layer overlies the second panel and the stitching.
The present invention also relates to a method for manufacturing an inflatable vehicle occupant protection device. The method includes the step of providing first and second panels of woven material that are free from any coating or lamination on any surface. The method also includes the steps of positioning the first and second panels overlying each other and stitching the panels together. The method also includes the step of laminating a first film layer onto the first panel. The first film layer overlies and covers-the first panel and the stitching. The method further includes the step of laminating a second film layer onto the second panel. The second film layer overlies and covers the second panel and the stitching.
The present invention also relates to a method for manufacturing an inflatable vehicle occupant protection device. The method includes the step of providing first and second panels of woven material positioned overlying each other. The method also includes the step of configuring the second panel to leave exposed portions of the first panel extending about a periphery of the first panel. The method also includes the step of stitching together the overlying first and second panels. The method also includes the step of laminating a first film layer onto the first panel and covering the stitching. The method further includes the step of laminating a second film layer onto the second panel, onto the exposed portions of the first panel, and covering the stitching.
The present invention also relates to a method for manufacturing an inflatable vehicle occupant protection device. The method includes the step of providing first and second panels of woven material positioned overlying each other. The method also includes the step of stitching together the overlying first and second panels. The method also includes the step of providing first and second film layers that are larger than the first and second panels. The method also includes the steps of laminating the first film layer onto the first panel and over the stitching, and laminating the second film layer onto the second panel and over the stitching. The method further includes the step of laminating overlying peripheral overlap portions of the first and second film layers that extend beyond the peripheries of the first and second panels to form a peripheral edge seal.
The present invention further relates to a method for manufacturing an inflatable vehicle occupant protection device. The method includes the steps of providing first and second panels of woven material and positioning the first and second panels overlying each other. The method also includes the step of positioning a gasket between the first and second panels along at least a portion of a periphery of the panels. The method also includes the step of stitching together the first panel, second panel, and gasket. The method further includes the steps of laminating a first film sheet onto the first panel over the stitching and laminating a second film sheet onto the second panel over the stitching.
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:
An apparatus 10 helps to protect one or more occupants 28 of a vehicle 12. As shown in
The inflatable curtain 14 is mounted adjacent a side structure 16 of the vehicle 12 and a roof 18 of the vehicle. The side structure 16 of the vehicle 12 includes side windows 20, an A pillar 30, a B pillar 32, and a C pillar 34. An inflator 24 is connected in fluid communication with the inflatable curtain 14 through a fill tube 22. The inflatable curtain 14, fill tube 22, and inflator 24 are connected to the vehicle 12 by means 36, such as brackets.
In the illustrated embodiment, the inflatable curtain 14, when inflated, extends from the A pillar 30 to the C pillar 34. Those skilled in the art will appreciate that alternative configurations could be built without departing from the teachings of the present invention. For example, the inflatable curtain 14 could be configured to extend from the A pillar 30 to the B pillar 32 only or from the A pillar to a D pillar (not shown) of the vehicle 12.
The fill tube 22 has an end portion for receiving fluid from the inflator 24. The fill tube 22 may be connected directly to the inflator 24 or a manifold (not shown) may connect the fill tube to the inflator. The fill tube 22 has a portion, disposed in the inflatable curtain 14 that has openings (not shown) through which inflation fluid is directed into curtain. The fill tube 22 may be constructed of any suitable material, such as plastic, metal or fabric. As a further alternative, those skilled in the art will appreciate that the fill tube 22 may be omitted, in which case the inflator 24 may be connected directly to the inflatable curtain 14.
The inflator 24 contains a stored quantity of pressurized inflation fluid (not shown) in the form of a gas for inflating 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. As a further alternative, the inflator 24 could be of any suitable type or construction for supplying a medium for inflating the inflatable curtain 14.
The apparatus 10 includes a housing 26 (
Referring to
The connections 50 may help define inflatable chambers 62 within the inflatable volume 60. Certain connections 50, such as the interior connections 56, may also form non-inflatable portions of the inflatable curtain 14 positioned within the inflatable volume 60. In the illustrated embodiment, the connections 50 comprise stitching 58 that extends through and interconnects the first and second panels 40 and 42.
Referring to
The inflatable curtain 14 also includes a first film panel 74 disposed on the first woven panel 40 and a second film panel 76 disposed on the second woven panel 42. The first film panel 74 covers the outer surface of the first woven panel 40, including the stitching 50. The second film panel 74 covers the outer surface of the second woven panel 42, including the stitching 50. The first and second film panels 74 and 76 are laminated to the first and second woven panels 40 and 42, respectively. The gasket 70 is positioned between and laminated to the first and second woven panels 40 and 42.
The vehicle 12 includes a sensor (shown schematically at 100 in
The inflatable curtain 14 inflates under the pressure of the inflation fluid from the inflator 24. The housing 26 (
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. The inflatable curtain 14, when inflated, helps to absorb the energy of impacts with the curtain and helps to distribute the impact energy over a large area of the curtain. The gasket 70 and film panels 74 and 76 help maintain the inflation fluid pressure in the inflatable curtain 14 at a desired level and help block inflation fluid leakage through the panels and through the seams or stitching.
According to the present invention, the inflatable curtain 14 has a cut, sewn, and laminated construction that helps maintain inflation fluid pressure in the curtain and helps prevent inflation fluid leakage from the curtain. This construction includes overlying panels that are 1) cut from an uncoated and unlaminated stock woven sheet of material, 2) sewn together, and 3) laminated with a film to form an effective seal for the inflatable curtain 14. Also, the cut, sewn, and laminated construction of the inflatable curtain 14 is efficient in terms of material usage, production time, and manufacturing costs.
In describing the construction and performance of the inflatable curtain of the present invention reference is made to
The apparatus 10a of
Referring to
Also, according to the present invention, the film panel 75 and the woven panel 41 may be cut from their respective sheets simultaneously. With the woven sheet 80 and film sheet 82 overlying each other as shown in
Referring to
Referring to
Once the gasket 70a and side panels 40a and 42a are interconnected via the connections 50a, the film panel 75 is placed overlying the first and second side panels 40a and 42a, respectively. The film panel 75 and the gasket 70a are then laminated to the woven side panels 40a and 42a through the application of heat and pressure via known means, such as heated rollers or platens. Advantageously, no curing is required when laminating the materials together.
The film materials and gasket 70a may be any plastic or elastomeric film material suitable for manufacturing the inflatable curtain 14a in accordance with the methods described herein, and capable of displaying desired properties, such as leak prevention, adhesion, and anti-blocking performance.
The film material typically consists of an adhesive layer and a surface layer. The surface layer has a melt temperature substantially above the adhesive layer. This is typically referred to as a Duplex or Co-ex film. The gasket and adhesive layer should have similar thermal properties. The film material can also be made up of two separate films, the first an adhesive and the second a surface film. In either case, the adhesive film is positioned between the woven panel and the surface film. The gasket film is positioned in-between the woven fabric sides.
The materials used to construct the woven panels 40a and 42a are selected to provide desired performance characteristics, such as strength, abrasion resistance, puncture resistance, and gas impermeability. For example, the panel 41 may be constructed of a fabric woven in a 1×1 plain weave pattern using a conventional weaving process, such as rapier, air jet, or water jet weaving. In one example, the yarn used to construct the panel 41 may be a 470 dtex (470 grams per 10,000 meters) polyamide 66 (PA66) nylon yarn. The construction may have a relatively low weave density, such as 18 picks/cm and 18 ends/cm. In another example, the yarn used to construct the woven panel 41 may be a 350 dtex PA66 nylon yarn with a relatively low weave density, such as 21 picks/cm and 21 ends/cm.
The thread used to interconnect the side panels 40a and 42a may also be a PA66 nylon thread, such as a T135 (135 grams per 1,000 meters) PA66 nylon thread or a T90 PA66 nylon thread. In one example configuration, a T135 PA66 thread may be used in a double needle lock stitch pattern in which the needle spacing is approximately 3 mm.
Constructed in accordance with the above description, the inflatable curtain 14a is configured to exhibit exceptional performance in terms of blocking or otherwise preventing leakage. The film panel 75 helps block inflation fluid leakage through the woven panel 41 and also through the stitching 58a and the areas of the panels through which the stitching extends. The gasket 70a also helps block inflation fluid leakage through the stitching 58a and the areas of the panels adjacent the stitching and through which the stitching extends. The gasket 70a provides the additional advantage of helping to block inflation fluid from between the overlying side panels 40a and 42a.
To evaluate and illustrate the effectiveness of the curtain construction described above, a test curtain was prepared. The test curtain had the same basic cut, sewn, and laminated configuration shown in
The curtain was tested using a deployment simulation device. Helium was used to pressurize the bag to approximately 140 kPa. The time required to reach this pressure from 0 kPa is typically about 50 milliseconds (see
The pressure maintaining criteria for an inflatable curtain can vary, depending on a variety of factors, such as the architecture of the vehicle and the particular government or automaker standards against which the inflatable curtain is judged. For example, generally speaking, for a full size rollover inflatable curtain, it may be desirable to maintain 50% of peak pressure at 6 seconds after deployment.
In general, for any particular inflatable curtain construction, the volumetric flow rate of inflation fluid from the inflatable curtain is typically highest in areas of the curtain that undergo high stresses both during deployment and post-deployment. Examples of these high stress areas may be those areas adjacent or near the location where the inflator extends into and is secured to the inflatable curtain.
The volumetric flow rate of inflation fluid through these high stress areas of the inflatable curtain does not depend on the size or volume of the curtain itself. The size or volume of the inflatable curtain does, however, impact the rate of curtain depressurization resulting from the volumetric flow rate of inflation fluid through those high-stress areas of the curtain. Therefore, those skilled in the art will appreciate that, with the volumetric flow rate through the high stress areas being equal, inflation fluid pressure in the curtain will decay more rapidly in a smaller, low volume curtain than in a larger, high volume curtain.
The test configuration used to perform the tests illustrated in Table 1, i.e., the configuration illustrated in
From the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
Advantageously, the film panel 75 can be applied simultaneously, does not require curing, and requires little time to cool, which helps reduce manufacturing time. The fact that the woven panel 41 is free from any coatings further helps to reduce manufacturing time, due to the fact that coatings typically require a, significant amount of time for curing.
Also, from the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
The method 200 illustrated in
For example, referring to
As another example, referring to
A second embodiment of the present invention is illustrated in
The inflatable curtain 14b of the second embodiment has a cut, sewn, and laminated construction that helps maintain inflation fluid pressure in the curtain and helps prevent inflation fluid leakage from the curtain. This construction includes overlying panels that are 1) cut from an uncoated and unlaminated stock woven sheet of material, 2) sewn together, and 3) laminated with a film to form an effective seal for the inflatable curtain 14b. Also, the cut, sewn, and laminated construction of the inflatable curtain 14b is efficient in terms of material usage, production time, and manufacturing costs.
Referring to
The first and second film panels 74b and 76b of the second embodiment have a configuration identical or substantially identical to the first panel 40b. To assemble the inflatable curtain 14b, the woven panels 40b and 42b are positioned overlying each other and interconnected via connections 50b, i.e., stitching 58b, that extend through the panels. As shown in
Once the panels 40b and 42b are interconnected via the connections 50b, the first and second films 74b and 76b are placed overlying the first and second panels 40b and 42b, respectively. The first and second films 74b and 76b are then laminated to the woven panels 40b and 42b through the application of heat and pressure via known means, such as heated rollers or platens. Advantageously, no curing is required when laminating the films 74b and 76b and the gasket 70b.
As shown in
The film materials used to construct the first and second films 74b and 76b may be any plastic or elastomeric film material suitable for manufacturing the inflatable curtain 14b in accordance with the methods described herein, and capable of displaying desired properties, such as leak prevention, adhesion, and anti-blocking performance.
For example, the first and second films 74b and 76b may comprise an adhesive film and a surface film. The adhesive film and surface film of the first and second films 74b and 76b may comprise separate film layers that are positioned overlying their corresponding panels 40b and 42b of the inflatable curtain 14b with the adhesive film layers being positioned adjacent the panels. Alternatively, the first and second films 74b and 76b may comprise a duplex film comprising a single sheet with an adhesive film layer and a surface film layer. In this instance, the duplex first and second surface films 74b and 76b are positioned overlying their corresponding panels 40b and 42b of the inflatable curtain 14b with the adhesive film layers positioned adjacent the panels.
The materials used to construct the woven panels 40b and 42b are selected to provide desired performance characteristics, such as strength, abrasion resistance, puncture resistance, and gas impermeability. For example, the first and second panels 40b and 42b may be constructed of a fabric woven in a 1×1 plain weave pattern using a conventional weaving process, such as rapier, air jet, or water jet weaving. In one example, the yarn used to construct the panels 40b and 42b may be a 470 dtex (470 grams per 10,000 meters) polyamide 66 (PA66) nylon yarn. The construction may have a relatively low weave density, such as 18 picks/cm and 18 ends/cm. In another example, the yarn used to construct the panels 40b and 42b may be a 350 dtex PA66 nylon yarn with a relatively low weave density, such as 23 picks/cm and 23 ends/cm.
The thread used to interconnect the panels 40b and 42b may also be a PA66 nylon thread, such as a T135 (135 grams per 1,000 meters) PA66 nylon thread or a T90 PA66 nylon thread. In one example configuration, a T135 PA66 thread may be used in a double needle lock stitch pattern in which the needle spacing is approximately 3 mm.
Also, as with the embodiment of
In this instance, the portion of the single woven panel forming the second panel 42b would be configured smaller than the portion of the single woven panel forming the first panel 40b. As a result, the peripheral overlap portion 250 is formed when the panels are folded to overlie each other. The portions of the single film sheet forming both the first and second films 74b and 76b would be configured the same as the first panel 40b. The second panel 42b would be configured smaller than the portion of the single woven panel forming the first panel 40b.
To evaluate and illustrate the effectiveness of the curtain construction of
The first curtain set included inflatable curtains in which the woven panels were cut from conventional 585 dtex PA66 fabric woven in a 1×1 plain weave with a weave density of 17 picks/cm and 17 ends/cm. The fabric was coated on one side with 25 grams/square meter of silicone. The silicone coated sides of the panels were positioned on the inside of the curtains. The panels were stitched together using T90 PA66 sewing thread with a double needle lock stitch pattern in a stitch count of 50 stitches per 100 mm. There were no films laminated to the curtains.
The second curtain set included inflatable curtains in which the woven panels were cut from conventional 585 dtex PA66 fabric woven in a 1×1 plain weave with a weave density of 17 picks/cm and 17 ends/cm. The fabric was uncoated. The woven panels had the same configuration, i.e., no peripheral overlap portion was formed. The panels were stitched together using T90 PA66 sewing thread with a double needle lock stitch pattern in a stitch count of 50 stitches per 100 mm. The inflatable curtain was then laminated on both sides with a duplex foil in which the adhesive layer was a polyurethane material and the surface layer was a copolyester.
The third curtain set included cut, sewn, and laminated inflatable curtains in accordance with the present invention, as shown in
The curtains of all three sets were inflated with shop air to 35 kPa and the leak rate for each curtain was measured. The results of these measurements are illustrated below in Table 1:
As shown in Table 1, the inflatable curtains of the third curtain set, which were cut, sewn, and laminated in accordance with the present invention to include the peripheral edge seal, displayed significantly improved performance in terms of gas holding and leakage preventing properties.
From the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
Advantageously, the first and second film layers 74b and 76b can be applied simultaneously, do not require curing, and require little time to cool, which helps reduce manufacturing time. The fact that the panels 40b and 42b are also free from any coatings further helps to reduce manufacturing time, due to the fact that coatings typically require a significant of time for curing.
From the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
A third embodiment of the present invention is illustrated in
The inflatable curtain 14c of the second embodiment has a cut, sewn, and laminated construction that helps maintain inflation fluid pressure in the curtain and helps prevent inflation fluid leakage from the curtain. This construction includes overlying panels that are 1) cut from an uncoated and unlaminated stock woven sheet of material, 2) sewn together, and 3) laminated with a film to form an effective seal for the inflatable curtain 14c. Also, the cut, sewn, and laminated construction of the inflatable curtain 14c is efficient in terms of material usage, production time, and manufacturing costs.
Referring to
As illustrated in
To assemble the inflatable curtain 14c, the woven panels 40c and 42c are positioned overlying each other and interconnected via connections 50b, i.e., stitching 58b, that extend through the panels. As shown in
Once the panels 40c and 42c are interconnected via the connections 50c, the first and second films 74c and 76c are placed overlying the first and second panels 40c and 42b, respectively. The first and second films 74c and 76c are then laminated to the woven panels 40c and 42c through the application of heat and pressure via known means, such as heated rollers or platens. Advantageously, no curing is required when laminating the films 74c and 76c and the gasket 70c.
As shown in
The film materials used to construct the first and second films 74c and 76c may be any plastic or elastomeric film material suitable for manufacturing the inflatable curtain 14c in accordance with the methods described herein, and capable of displaying desired properties, such as leak prevention, adhesion, and anti-blocking performance.
For example, the first and second films 74c and 76c may comprise an adhesive film and a surface film. The adhesive film and surface film of the first and second films 74c and 76c may comprise separate film layers that are positioned overlying their corresponding panels 40c and 42c of the inflatable curtain 14c with the adhesive film layers being positioned adjacent the panels. Alternatively, the first and second films 74c and 76c may comprise a duplex film comprising a single sheet with an adhesive film layer and a surface film layer. In this instance, the duplex first and second surface films 74c and 76c are positioned overlying their corresponding panels 40c and 42c of the inflatable curtain 14c with the adhesive film layers positioned adjacent the panels.
The materials used to construct the woven panels 40c and 42c are selected to provide desired performance characteristics, such as strength, abrasion resistance, puncture resistance, and gas impermeability. For example, the first and second panels 40c and 42c may be constructed of a fabric woven in a 1×1 plain weave pattern using a conventional weaving process, such as rapier, air jet, or water jet weaving. In one example, the yarn used to construct the panels 40c and 42c may be a 470 dtex (470 grams per 10,000 meters) polyamide 66 (PA66) nylon yarn. The construction may have a relatively low weave density, such as 18 picks/cm and 18 ends/cm. In another example, the yarn used to construct the panels 40c and 42c may be a 350 dtex PA66 nylon yarn with a relatively low weave density, such as 23 picks/cm and 23 ends/cm.
The thread used to interconnect the panels 40c and 42c may also be a PA66 nylon thread, such as a T135 (135 grams per 1,000 meters) PA66 nylon thread or a T90 PA66 nylon thread. In one example configuration, a T135 PA66 thread may be used in a double needle lock stitch pattern in which the needle spacing is approximately 3 mm.
Also, as with the embodiment of
In this instance, the butterfly formed first and second films 74c and 76c would be configured larger than the butterfly formed first and second panels 40c and 42c. As a result, the peripheral overlap portions 340 and 342 are formed when the panels are folded to overlie each other with the first and second panels 40c and 42c sandwiched between.
From the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
Advantageously, the first and second film layers 74c and 76c can be applied simultaneously, do not require curing, and require little time to cool, which helps reduce manufacturing time. The fact that the panels 40c and 42c are also free from any coatings further helps to reduce manufacturing time, due to the fact that coatings typically require a significant of time for curing.
From the above, those skilled in the art will appreciate that the embodiment of the present invention illustrated in
Also, from the above, those skilled in the art will appreciate that the embodiments of the present invention illustrated in
From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, the cut, sewn, and laminated construction of the present invention could be used to manufacture types of inflatable vehicle occupant protection devices other than an inflatable curtain, such as a frontal air bag, a side air bag, an inflatable knee bolster, or an inflatable seatbelt. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.
