BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the passenger compartment of a motor vehicle showing three simulated vehicle occupants of various sizes.
FIG. 2A is a plan view similar to FIG. 1 showing a 50th percentile male.
FIG. 2B is the plan view of FIG. 2A showing the initial contact of the airbags with the 50th percentile male.
FIG. 3A is a plan view similar to FIG. 1 showing the 5th percentile female.
FIG. 3B is the plan view of FIG. 3A showing the initial contact of the airbags with the 5th percentile female.
FIG. 4A is a plan view similar to FIG. 1 showing a three to six year old child.
FIG. 4B is the plan view of FIG. 4A showing the initial contact of the airbags with the three to six year old child.
FIG. 5A is a larger toddler in a forward seated child motor vehicle rear seat with the airbag of the present invention deployed.
FIG. 5B is a plan view of a passenger compartment of a motor vehicle with a small toddler in a rearward facing child seat and the airbags of the present invention deployed.
FIG. 5C is an infant in a rearward facing infant seat attached to the front passenger seat with the airbags of the present invention deployed.
FIG. 6 is a perspective view of a base plate with two inflators.
FIG. 7 is a side cross sectional view of the base plate with an inflator.
FIG. 8 is a perspective view of the two top plates.
FIG. 9 is a perspective view of an airbag module assembly.
FIG. 10 is a perspective view of a preferred embodiment module assembly having a single dual level or dual stage inflator.
FIG. 11 is a cross sectional view of the preferred module assembly of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-5 the airbags 40, 50 of the airbag module assembly 30 of the present invention are shown in various stages of deployment with vehicle occupants of different sizes. FIG. 1 is a plan view of the passenger compartment of a motor vehicle showing three simulated vehicle occupants, a three to six year old child, a 5th percentile female and a 50th percentile male all seated in a typical relationship based on their respective size. In FIG. 1 the three vehicle occupants are shown superimposed so that the relative position and size of the vehicle occupants can be easily visualized. In FIG. 1 all of the airbags of the present invention are shown being initially deployed. As shown a child 100C in the three to six year old range is shown in the most forward position. A female 100F of the 5percentile size is shown in the middle position, and the male 100M of the 50th percentile is shown in the furthest back position on the seat 82. For each seating position shown there is an indication of the location marked by a C, F or M for the various vehicle occupants. As shown the seat 82 is in the position M or furthest back and is shown near the lowest part of the seat portion 84 of the seat 82 at the indication of location mark M. The airbags 40, 50 are shown in the initial deployment stages. The lower airbag 40 deploys substantially horizontally towards the torsos of the vehicle occupants whereas the upper airbag 50 is positioned above the lower airbag 40 and between the lower airbag and the windshield 70. Both of the airbags 40, 50 are shown coming from the instrument panel 80.
With reference to FIGS. 2A and 2B the airbags 40, 50 are shown initially deployed in FIG. 2A as the airbags are projecting outwardly. It can be initially observed that the 50th percentile male 100M seated in the location M is further back than the airbag and therefore as the airbags deploy the lower airbag strikes the male around the torso approximately in the chest area driving him further back into the seat whereas the upper airbag is independently striking the head region. It is believed that this method of providing two independently operable airbags provides a system that is less traumatic to the head and neck region as the airbag is being deployed. This is true in that the airbag's primary force can be provided in the lower airbag which would drive the vehicle occupant back into the fully seated position while the upper airbag maintains the head contact and will strike in such a fashion that it does not provide an upward thrust as is commonly found in conventional front passenger airbags wherein the airbag deployment provides an aggressive upward force causing the neck to take an exaggerated movement that can in some cases cause neck injuries. This clearly is avoided in the present invention in that the airbags acting independently will strike the vehicle occupant in such a fashion that the contact avoids the driving of the head in an upward thrusting motion, and instead pushes mostly horizontally backwards towards the seat and the seat headrest. In each of the views it is shown that the vehicle occupant is restrained by the seatbelt system 62.
With reference to FIGS. 3A and 3B a female 100F of the 5th percentile is shown where the seat 82 is moved to the position F. The seat 82 as shown with the female 100F restrained by the seatbelt system 62 in such a fashion that the lower airbag 40 and upper airbag 50 similarly will strike the female vehicle occupant 100F in the torso area with the lower airbag 40 while the upper airbag 50 strikes the head of the female vehicle occupant 100F.
With reference to FIGS. 4A and 4B a child 100C of the three to six year age group is shown seated in the location C and the child is also shown restrained by a seatbelt system 62. As shown the lower airbag 40 strikes the child in the torso region driving him further back in the seat 82 and the upper airbag 50 strikes the child 100C in the head region. While these child vehicle occupants are substantially smaller than the 50th percentile male or the 5th percentile female, it is also true that these child vehicle occupants will normally be seated directly on the seat portion 84 as shown or could be in a booster child seat thereby moving the vehicle occupant vertically upwardly. This is true because most vehicle occupants want to see out of the windshield meaning the head is positioned above the instrument panel 80. Using this as a guideline it is possible to provide the vehicle occupant with an airbag system that provides a lower airbag 40 for striking the torso and an upper airbag 50 that will contact the head as shown.
Another advantage of the present system is shown in FIGS. 5A, 5B and 5C wherein the airbag module assembly can be used in such a fashion that a rearward seated toddler 100T, a forward seated toddler 100T of a weight of twenty to forty pounds or a rearward seated infant 100I in a rearward facing infant seat 90 fastened to the seat 82 would be protected by the airbags 40, 50 to the extent that the rearward facing infant seat 90 would be impinged only by the lower airbag 40 while the upper airbag 50 would not have a tendency to provide an upward thrust on the infant seat. The airbags as shown would be suitable for a situation where an infant is placed in such a rearward facing infant seat 90 attached to a vehicle seat 82. Similarly a small toddler 100T typically weighing twenty to forty pounds could be placed in a rearward facing child seat 92 and a larger toddler of forty pounds or greater could be placed in a forward facing child restraint seat 92 wherein the lower airbag 40 and the upper airbag 50 operate to provide an air cushion protection safely due to the independent action of the airbags 40, 50 and their generally horizontal directed deployment on contact with the vehicle occupant. While front passenger seating of toddlers and infants is not generally recommended in today's motor vehicles, it is important to note that providing an airbag system 30 of the present invention makes it feasible for such a condition to occur as many drivers would prefer to have their infant child in the forward passenger compartment so they are easily accessible. In many small two seat motor vehicles such seating is inevitable. Unfortunately, heretofore, the present airbag systems do not provide a means for doing this in a safe manner. The present invention provides the capability of allowing this to occur in that the lower airbag 40 will prevent the upper airbag 50 from ever contacting the infant 100I in the rearward facing infant seat 90 and the impact on the toddlers' upper extremities is greatly reduced by the use of two independent airbags. Each of the airbags 40, 50 is provided with vent holes 42, 52 to ensure that upon inflation the airbags 40, 50 can deflate after deployment.
A passenger side airbag module assembly 30 for restraining movement of an adult or a child is accomplished by providing an airbag module housing 34 for attaching or holding an upper airbag 50 and a lower airbag 40. The lower airbag 40 is positioned in front of the upper airbag 50 in the module housing 34. Each airbag is inflated by an inflator 2.
In the embodiment shown in FIGS. 6-9 two inflators are employed. The inflator 2 shown in FIG. 7 is single stage inflator having only a single inflator output level. A first inflator 2 is provided for inflating the upper airbag 50 and a second inflator 2 is provided for inflating the lower airbag 40. Each inflator 2 is housed within the airbag module housing 34. A means 15 for attaching to and to direct the deployment of each airbag from the airbag module is provided. The means 15 for attaching the airbag provides a means of separating the inflation gases from the first inflator 2 and the second inflator 2 such that each can act independently to inflate their respective airbags 40, 50. The airbag module assembly 30 further includes a means for activating 5 one or both inflators whereupon deployment the lower airbag 40 has an upper surface 41 that extends outwardly from the housing 34 and is substantially horizontal or lower than horizontal in direction and the upper airbag 50 extends with the lower surface 51 adjacent to the upper surface 41 of the lower airbag 40. The upper airbag 50 when deployed is adjacent to the windshield 70 of the motor vehicle and above the lower airbag 40.
This method of deployment ensures that a vehicle occupant when looking out a windshield will be struck by the lower airbag 40 upon initial contact in the region of the torso while the upper airbag 50 would strike primarily the head region of the vehicle occupant. Preferably each of the inflators 2 has at least two or more inflator outputs, a low inflator output for low risk deployment requirements and a high or full inflator output for dynamic performance requirements wherein the means for activating 5 can selectively activate one or both airbags 40, 50 at the same or different output levels. With reference to FIG. 11, there is illustrated an inflator 2 that has two stages, or at least two inflator output levels. This is particularly beneficial in low impact risk wherein an aggressive deployment of the airbag would not be desirable. However, a lower output level would sufficiently protect the vehicle occupants with minimal risk. In a more severe crash a dynamic response would be needed and the inflators 2 could provide full gas inflation such that both of the airbags 40, 50 deploy rapidly and quickly to provide maximum protection. The lower cushion airbag 40 alone or in combination with the upper cushion airbag 50 when deployed at low inflator outputs will provide the low risk deployment requirement for three to six year old children. This is true in that these children generally are seated in a condition wherein they are seated in a position where they can view through the windshield and over the instrument panel. If this is the condition the lower airbag 40 will clearly strike the child 100C around the torso area and provide maximum protection for children in this location. The second inflator 2 activated at high or full output provides the low risk deployment requirement for a one year old in a rearward seated infant seat 90. This is important in that normally children are not seated in a front passenger side seat for fear that the airbag will provide a risk of injury to the infant seated in such a rear seated infant seat. The present invention permits the lower airbag 40 to provide contact initially to the rearward facing infant seat 90 and since it is moving in a primarily horizontal position independent of any upward thrust it is clear that the airbag 40 can fulfill this requirement. When both the first and second inflators 2 are activated at high or full output levels the airbag dynamic performance for a 5th and 50th percentile adult is clearly achieved. In many cases it is desirable to have the lower airbag 40 deployed preceding the upper airbag 50 by having a second inflator 2 activated prior to the first inflator 2, wherein the second inflator 2 will inflate the lower airbag 40 initially while the first inflator 2 being delayed slightly will then start to inflate the upper airbag 50.
It may be preferable to provide a means 5 for activating that is responsive to one or more sensor means for establishing the vehicle occupant's size or position and the severity of a crash and a means for controlling the output gas levels. This is commonly done in many of the airbag systems currently provided in motor vehicles. These sensors (not illustrated) can be used in combination with the airbag module assembly 30 of the present invention to provide a more sophisticated sensing for the vehicle occupants and the vehicle occupant's position enabling the airbags 40, 50 to act either independently or in cooperation with each other to complimentarily provide the best crash protection for a given vehicle occupant and crash scenario.
The upper airbag 50 and the lower airbag 40 each has a frontal surface 43, 53 that extends toward a vehicle occupant a distance substantially equal relative to the vehicle occupant when the airbags 40, 50 are fully deployed. The frontal surface 43 of the lower airbag 40 upon contact with a seated vehicle occupant will initially contact the vehicle occupant's torso well below the chin as previously mentioned when the vehicle occupant is properly positioned to look through the windshield. The frontal surface 53 of the upper airbag 50 upon contact with the seated vehicle occupant will initially contact the vehicle occupant's head above the chin when the vehicle occupant is properly positioned to look through the windshield. An out of position vehicle occupant upon initial inflation of the lower airbag 40 will be pushed rearward toward the seat 82 prior to the upper airbag 50 being deployed if the airbags 40, 50 are sequenced such that the lower airbag 40 is initially inflated prior to beginning the inflation of the upper airbag 50. This is beneficial when a vehicle occupant has a limb that is positioned on or in contact with the instrument panel. Preferably a means for sensing an out of position vehicle occupant having one or more legs resting on the instrument panel 80 can be detected such that the lower airbag 40 can be deployed at low or high inflation output without inflating the upper airbag 50, if so desired. An exemplary airbag module assembly is described in FIGS. 6 through 9.
FIG. 6 shows two inflators 2 mounted to a base plate 1. The base plate 1 serves the purposes of housing the inflators 2 and directing gas flow from the inflators. The base plate 1 has two cylindrically shaped recesses 3 defining an area for receiving tubular shaped inflators. One skilled in the art appreciates that other shaped recesses 3 can be utilized to accommodate other shaped inflators. The base plate 1 is made from stainless steel, but other suitable materials may be employed such as aluminum, plastics, etc. Around the circumference of the base plate 1 and along the dividing member, there are a plurality of holes 4 for receiving fasteners 20 for fastening the top plate 15 to the base plate 1.
The inflators 2 shown in FIG. 7 have an end cap 5 comprising a squib or igniter 11. The igniter 11 has a socket for receiving an electrical wire from an electronic control unit (not shown), which receives signals from various crash and/or vehicle occupant sensors that also are not shown. The inflators 2 in FIG. 6 represent generic inflators and may be cold gas inflators or hybrid inflators. Both of these inflators have a generally tubular shape. A cold gas inflator operates by quickly releasing inflation gas to fill an airbag. A hybrid inflator operates by releasing heated inflation gas to fill an airbag. The gas is heated by burning a heating material that is mixed with stored gas. Even though not illustrated, other types of inflators may be employed in the present invention namely a pyrotechnic inflator.
The inflators 2 are installed into the base plate 1 by first adding a first retainer 6 to the end cap 5 of the inflator. The first retainer 6 is preferably made from a nylon material. The base plate 1 has one large igniter access slot 7 on each of its side portions for receiving the end caps 5 of the inflators. Each inflator is secured to the base plate 1 by an interference fit created by the incorporation of a second retainer 9 between the bottom end 8 of the inflator and the base plate 1. The second retainer 9 is added after the inflator is dropped into the base plate 1 and slid as far as possible in the direction of the slot 7. The present invention may accommodate inflators 2 of various lengths by utilizing retainers of various thicknesses. Preferably, the inflators 2 are oriented in opposite directions so that the end cap of one inflator is facing the opposite direction as the end cap from the other inflator. The benefit of mounting the inflators in opposite directions is the avoidance of accidental actuation of an inflator by the other inflator. Even though highly improbable, the heat generated by the actuation of one inflator could ignite pyrotechnic material in the second inflator. Even though not the preferred embodiment, the inflators 2 may be positioned so that they are facing the same direction.
FIG. 7 shows a side cross sectional view of one of the inflators 2 mounted in the base plate 1. In FIG. 7 the retainer 9 abuts both the bottom end 8 of the inflator and the sidewall of the base plate 1. The retainer 9 prevents the inflator from sliding back and forth in the base plate 1.
The top plates 15 are shown in FIG. 8, and each of these plates has a long cut out section 14 for inflation gas to pass through during the inflation of the airbag. Only inflation gas from one inflator travels through one top plate 15. As shown the top plates 15 when attached to the base plate 1 provide a means for directing the gas flow and the deployment of the airbag. As shown in FIG. 9 the module housing 30 holds both of the inflators 2 and provides a forward location 31 for attaching a lower airbag 40 and a rear location 32 for attaching an upper airbag 50.
The two airbags 40, 50 contemplated in the present invention are made of a suitable airbag material. Each airbag comprises an inflation chamber that is capable of receiving inflation gas upon deployment of the vehicle occupant protection system during a motor vehicle crash. The airbag material of each airbag 40, 50 has a ventilation opening 42, 52 therein for venting inflation gas to provide a compliant airbag surface upon impact by a vehicle occupant. As used herein, the term “airbag material” is understood to mean any suitable coated or uncoated woven or knit fabric as well as nonwoven films that may be used for an airbag.
The airbags 40, 50 are attached to the base plate 1 via the top plates 15. The top plates 15 are inserted into separate airbags. The holes (not shown) of the top plates 15 are aligned with the gas inlet openings of the airbags (not shown). Fasteners 20 are inserted through the holes in the top plates 15, the holes in the airbags, and then through the holes in the base plate 1. As opposes to the fasteners being inserted through the holes in the top plate 15, the fasteners may be permanently affixed to the top plate. Nuts are utilized to engage with the fasteners to secure them in place. Alternatively, the holes in the base plate 1 may be threaded eliminating the need for nuts.
In operation, inflation gas exits the inflator 2 through the exit ports. The base plate 1 acts as a manifold in directing the inflation gas toward the airbags 40, 50. The inflation gas passes through the cut out section 14 in the top plate 15 and ultimately travels into the airbag 40, 50. Inflation gas from one of the inflators 2 provides inflation gas for the lower airbag 40, and the other inflator provides inflation gas for the upper airbag 50. The utilization of two separate top plates 15 ensures that inflation gas from one of the inflators 2 only flows into one of the airbags. As shown to facilitate the substantially horizontal deployment of the lower airbag 40 the base plate 15 is inclined slightly such that the opening 14 is tilted at least slightly in the forward direction whereas the base plate 15 of the upper airbag is horizontally oriented to direct the upper airbag along the windshield and outward toward the vehicle occupant.
With reference to FIGS. 10 and 11, a preferred embodiment is shown wherein the two inflators 2 are replaced by a single inflator 2. In this embodiment the single inflator 2 is of a type having a dual inflator output levels. The dual output level inflator 2 accordingly has a first output level for simultaneously filling both the lower airbag 40 and the upper airbag 50 at a high inflation pressure and a second output level for filling the airbags 40, 50 at a lower inflation pressure. The inflator 2 shown in FIG. 11 is similar to the inflator 2 shown in FIG. 7, but it has two end caps 5 and two a squibs or igniters 11. The inflator 2 in FIG. 11 represents generic multi-stage inflators and may be a cold gas inflator or hybrid inflator, or even an all pyrotechnic inflator. As shown the inflator2 in FIG. 11 has a generally tubular shape. In a high risk deployment both igniters 11 fire allowing for a rapid inflation at a high pressure. In the lower risk deployment one igniter is fired allowing the air bags 40, 50 to fill simultaneously, but at a lower pressure. The airbag housing is designed to allow the inflation gases to pass through both openings or long cut out sections 14 in the top plate 15 as was described earlier in the two inflator design, this preferred embodiment is simple and lower in cost while still providing the benefits earlier described. The only significant difference is the single inflator cannot sequentially fill the airbags 40, 50 but fills both simultaneously.
While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.
Patent Application
20080054602
