Patent Application
20130113192
The present invention relates to an inflatable curtain airbag assembly with an aid to verify proper installation in a vehicle.
Inflatable safety restraint devices, or airbags, are well accepted for use in motor vehicles and have been credited with preventing numerous deaths and injuries. Inflatable airbags are now mandatory on most new vehicles. Airbags are typically installed as part of a system with an airbag module in the steering wheel on the driver's side of a car and in the instrument panel on the passenger side of a car. In the event of an accident, a sensor within the vehicle measures abnormal deceleration and triggers the ignition of an explosive charge contained within an inflator. Expanding gases from the charge travel through conduits and fill the airbags, which immediately inflate in front of the driver and passenger to protect them from harmful impact with the interior of the car.
Side impact airbag systems have also been developed in response to the need for similar protection from lateral impacts between a passenger and the side of a vehicle's interior. This might occur when another vehicle collides with the side of the car, or in a rollover situation where the side of the car is repeatedly impacting the ground. One form of these airbags, provided for the protection of the head and upper torso of an occupant and commonly referred to as “inflatable curtains,” may be mounted on or near the roof rail, or a portion of a vehicle frame that extends along a length of the vehicle between the side windows and the roof.
An inflatable curtain airbag is typically compacted by folding, rolling, or a combination of both rolling and folding, to create a tube-shaped bundle for stowing the cushion behind a headliner covering the interior of the roof of the vehicle. The curtain airbag is typically designed to unroll or unfold downward from the roof of the vehicle during inflation and becomes positioned on the outboard side of the occupant. Generally, the inflatable curtain airbag is sized to descend below the window sill. Consequently, when not inflated, the curtain airbag includes a significant amount of material. This material is then rolled, folded, or otherwise gathered to form a tight, tubular bundle, which must be packed into a small packaging space. A wrapper may be added to ensure that the curtain airbag is kept rolled or folded.
The compacted curtain airbag is then mounted either on or close to a roof rail of the vehicle. A metal gas guide that extends from the inflator is then connected to an inlet port of the inflatable curtain.
Once the curtain airbag has been rolled or folded into the bundle, it is important that the curtain airbag is installed properly. The soft, pliable material of the airbag makes it possible that it is installed in an improper, twisted manner that may remain unnoticed. Installing the curtain airbag in a twisted configuration, however, may be detrimental to the proper function the curtain airbag.
In an attempt to reduce the likelihood that the inflatable curtain will be installed in a twisted manner, it has been proposed to provide alignment lines or other similar markings that give a visual guide to a person installing, inspecting, or servicing the airbag, thus helping to avoid or retroactively detect a twisted installation of a curtain airbag. Manually detecting a twisted or entangled installation of the airbag, however, requires additional time and labor and thus adds to the costs of installing curtain airbags.
It has also been suggested to provide a stiffening member built into the curtain airbag along its length that prevents twisting and retains the shape of the curtain airbag bundle. Such a stiffening member, however, adds to the bulk and weight of the airbag module. Also, the stiffening member complicates the installation of the curtain airbag because the thus reinforced bundle has a significant length that cannot be reduced by folding it due to its stiffness.
Accordingly, a need exists for an inflatable curtain airbag assembly that provides an easy and low-cost solution to ensure a proper installation and detection of a twisted installation, particularly during installation or automated quality control. It is particularly desirable to reduce labor costs while consistently ensuring proper installation.
The present invention meets this need by providing an inflatable curtain assembly that includes a luminescent visual marking that may be fluorescent or phosphorescent and that indicates a proper installation. Luminescent materials, when exposed to electromagnetic radiation of one frequency range, emit electromagnetic radiation in a defined frequency range, either at the same time (fluorescence) or for a duration extending beyond the time at which the electromagnetic energy is absorbed (phosphorescence). The emitted radiation can be automatically detected by an optical detection device. Such detection devices use sensors that are inexpensive and reliable. The emitted radiation of the marking may be in the visible light spectrum to make it detectable to the human eye and to an automatic optical detector alike. The luminescent material may absorb electromagnetic radiation in the UV spectrum, for instance so-called black light.
The simplest marking consists of a line extending along the length of the airbag bundle. Such a line can be manufactured by weaving a luminescent thread into the airbag material. The thread has been dyed with a luminescent dye before weaving. The marking may also be applied to an assembled curtain airbag by painting or printing so that the unprocessed airbag fabric itself does not need a marking specific to an individual type of airbag. To facilitate recognition of the marking in an automated quality control, the marking may consist of a number of parallel lines, a portion of which may be broken lines, or a row of dots lined up along the length of the bundle. When the curtain airbag is compacted to a bundle, the marking may be located anywhere on the surface of the bundle in an area facing the interior of the vehicle or in an area accessible to an optical inspection after installation.
In one configuration according to this invention, the inflatable curtain airbag is rolled into a bundle. For such a bundle, the surface of the bundle is formed by portion of the curtain airbag that is proximate to fastening structures for mounting the curtain airbag on one side of the curtain airbag. The marking can be applied before compacting the curtain airbag because the surface of the bundle facing the vehicle interior is known before compacting.
In another configuration according to the invention, the inflatable curtain airbag is folded into a bundle. The surface of the folded bundle is formed by narrow stripes of airbag fabric. Variances in folding the airbag may make it harder to determine in advance which portions of the airbag fabric will be forming the surface of the bundle after compacting. In such a case, the marking may be applied with luminescent paint or ink after folding the curtain airbag to a bundle.
Further details and advantages become apparent from the following description of exemplary embodiments illustrated in the attached drawings. The drawings are included for illustrative purposes only and are not to be considered to limit the scope of the invention.
In the drawings,
In
The inflatable protection area 27 is divided into a number of chambers 5, 6, 7, 8, and 9 which are divided from one another by darts or stitchings 10, 11, 12, and 13. Chambers 5, 6, 7, 8, and 9 are arranged in such a way that a front section of the protection area is formed for the front seats of a motor vehicle by means of chambers 7, 8, and 9 and a rear section of the protection area is formed for the rear seats of a motor vehicle by chambers 5 and 6. Between the front section and the rear section a non-inflatable section 14 is formed in an area which no vehicle occupant can typically reach during the accident. This can be in the area of a vehicle B pillar, for example.
Two guide chambers 15 and 16 are provided in the upper section 2 of curtain airbag 1, which are connected in one piece with the protection area and which project over upper section 2. They are connected from the point of view of gas flow with filling channel 26 of curtain airbag 1, so that the gas which is created by gas generator 25 can enter quickly into guide chambers 15 and 16. Guide chambers 15 and 16 may be each located between two mounting links 4 whereby front guide chamber 15 is allocated to the B pillar area of the vehicle and rear guide chamber 16 is allocated to a C pillar area of the vehicle when in a mounted state.
A horizontal marking 19 extends along the entire length of the airbag 1 near the mounting tabs 4. The marking 19 consists of a luminescent material that is produced by weaving a luminescent thread into the airbag fabric. The luminescence may be due to a fluorescent or a phosphorescent property of the thread. But the marking 19 may also be painted or drawn with a stroking utensil like a paintbrush or a marker, or printed or stamped onto the fabric of the airbag 1 by contact with a utensil transferring a printing line or pattern. The material of the marking 19 emits electromagnetic radiation in a frequency that is distinguishable by an automated optical detection device 29 (as indicated in
A plurality of retaining straps 20 extending like a cover around the rolled curtain airbag 1 may be assigned to the mounting links 4, which hold the airbag in its rolled state. The retaining straps 20 may be configured to tear when the curtain airbag 1 is inflated. A perforation can be provided for this purpose, or the material thickness can be correspondingly thinner. As an alternative to straps 20, a single wrapper can be provided which corresponds to the length of curtain airbag 1. If a continuous wrapper is used, the marking 19 may be applied to the wrapper, or the wrapper may be translucent so as to allow the optical detection device 29 to detect the marking 19 through the wrapper.
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If folding the airbag 1 involves variances in locations of creases, the marking 19 may be applied to the compacted airbag 1 after folding. That way, it is ensured that the marking 19 is located on the outside of the folded airbag 1 where it is accessible for inspection. The marking 19 may be sprayed on, stamped, or applied with a marker pen or applied by any other method that is suitable for reliably transferring luminescent paint, ink, or dye onto the airbag material.
The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
