Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to inflatable vehicular airbags. Specifically, the present invention relates to a deployment guide for use with inflatable vehicular airbags such as inflatable curtains.  
           [0003]    2. Description of Related Art  
           [0004]    In low-speed automobile collisions, occupants wearing safety belts are generally prevented from impact with objects located inside the vehicle such as the windshield, instrument panel, door, side windows, or steering wheel. In more severe collisions, however, even belted occupants may strike the interior of the car because their momentum is so great that they contact these objects before the seatbelts can fully decelerate them.  
           [0005]    Conventional airbag systems were developed to supplement safety belts by deploying between an occupant and the interior surfaces of the vehicle. This reduces the chances of occupant contact with the vehicle&#39;s interior. A conventional airbag system typically consists of several parts, including: an airbag cushion, a sensor, and an inflator. The airbag is typically made of a thin nylon fabric, which is folded to fit into a steering wheel, dashboard, roof rail, interior panel, dashboard, or other space in a vehicle. The airbag system is tuned to use sensors in the vehicle to detect the sudden deceleration characteristic of an impact of a predetermined intensity. When the system detects an impact of sufficient severity it sends an electrical signal to the inflator. The inflator then produces an inflation gas for filling the airbag cushion. The inflation gas is then channeled into the airbag, inflating it. When an occupant of the vehicle contacts the airbag, the airbag absorbs the force of the occupant&#39;s impact. The inflation gas is then vented from openings in the airbag, eventually deflating it.  
           [0006]    Airbags were first used in the front of a vehicle for an occupant&#39;s safety. More recently, vehicle manufacturers and suppliers developed side-impact airbag systems to better protect vehicle occupants during side-impact collisions. These airbag systems, which are commonly referred to as “inflatable curtains,” are designed to inflate during an accident to cover the windows, doors, and lateral surfaces of the vehicle.  
           [0007]    Inflatable curtain systems are often mounted within a housing located in the vehicle over the doors. Typically, this involves mounting the curtain along the edge of the roof of the vehicle behind interior trim such as a headliner, the A/B/C/D pillar trim, ATL&#39;s, sun visors, grab handles, coat hangers, and even weather seals. Care must be taken when designing such mounting schemes to assure that when an airbag is inflated it is able to properly displace the headliner and deploy around the interior trim of the vehicle and deploy within the vehicle to be positioned to protect vehicle occupants.  
           [0008]    During the deployment of the airbag, the inflating cushion expands by first moving into areas that provide the least resistance with the interior vehicle trim. When the internal pressure of the inflating airbag becomes sufficient to displace the interior trim, the airbag rapidly moves into the cabin of the vehicle and becomes fully inflated.  
           [0009]    Several difficulties have been encountered in assuring that inflatable curtain airbags are properly deployed during a collision. First, in many vehicles there is a void space located behind the trim near the installed airbag. Such voids are often present at the top of the structural pillars or trim of the vehicle. Of specific note are the void spaces located at the tops of pillars such as the B, C, and D pillars. During airbag deployment, the expanding airbag sometimes fills these void spaces. When this happens, as the headliner gives way, those regions of the airbag cushion that have penetrated into the void spaces may be delayed in their deployment into the cabin. Indeed, the airbag as a whole or in part may become caught in the trim and thus be prevented from properly deploying. Lastly, the caught or misdirected airbag may continue to expand and eventually detach the trim from the vehicle, possibly sending it into the passenger compartment.  
           [0010]    Additionally, in many vehicles, the pillar areas have a diverging flange to blend the shape of the pillar into the headliner surface to provide a more visually-pleasing appearance. An overlap space of at least 10 mm of the pillar over the headliner is often provided to assure that no gap will appear between them as a result of normal build variances. This overlap provides a further obstacle to the proper deployment of the airbag cushion.  
           [0011]    These deployment problems have been addressed by adding deployment “ramps” or “guides” to direct a deploying airbag over void spaces and toward the headliner. Such deployment ramps are generally made of a solid material. The ramps are often up to 1-1½ inches thick to provide sufficient resistance to direct the airbag to properly deploy through the headliner. Because of their size and shape, these ramps may complicate the airbag installation process. Additionally, the ramps add expense to the cost of airbag systems in vehicles and take up space behind the trim.  
           [0012]    Accordingly, it would be an advancement in the art to provide an inflatable airbag deployment guide that is integrated into the inflatable curtain module. Additionally, it would be beneficial to provide a guide that is placed for use only when it is needed, such as during the deployment of the airbag. Further, it would be an advancement in the art to provide a deployment guide that takes up little space during storage, and adds little weight and expense to the inflatable curtain system. Such an airbag deployment guide is disclosed herein.  
         SUMMARY OF THE INVENTION  
         [0013]    The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available airbag deployment guides.  
           [0014]    The invention provides a self-contained, compact, and inexpensive guide for the deployment of inflatable curtain airbag cushions. Specifically, the invention includes an inflatable guide for directing an airbag cushion over obstacles such as void spaces to assure proper deployment of the airbag. The inflatable deployment guide may be incorporated into airbags and airbag modules. The invention also includes methods of deploying an airbag cushion using such an inflatable guide.  
           [0015]    The inflatable airbag deployment guide of the invention has an inflatable bladder that is typically attached to the outside (or vehicular window side) of an airbag cushion by an inflation inlet. The inflation inlet may be connected to an early-filling portion of the cushion. The bladder and inlet may be integrated into the weave design of the cushion, or they may each be cut and assembled separately. The inflatable bladder may also be included in an airbag module. As such, the inflatable bladder may be attached to the airbag, or may be attached directly to the inflator or to the inflator housing of the module instead of to the airbag.  
           [0016]    As briefly noted, the airbag deployment guide also includes an inflation inlet. The inflation inlet allows inflation gas to pass from the airbag cushion or filling tube attached to the inflation device into the bladder of the inflatable airbag deployment guide. To do this, the inflation inlet may be coupled on a first end to an airbag cushion and on a second end to the inflatable bladder.  
           [0017]    Generally, the uninflated bladder of the inflatable guide occupies little space, and can thus be housed inside the cover system of an existing airbag module. The guide may be configured such that when the airbag module is properly installed in a vehicle, it is positioned near the void space in the trim. This places the guide in position for proper deployment during a collision event.  
           [0018]    Upon deployment of the inflatable curtain, a portion of the gas moving into the airbag cushion is channeled into the inflatable bladder. This may be accomplished either by making the inflation inlet of the inflatable bladder continuous with the interior of the airbag cushion or by directly attaching the inflation inlet to an opening of the inflator or inflator housing. In either case, the bladder is rapidly filled by the gas from the inflator.  
           [0019]    The bladder prevents entry of the airbag cushion into voids in the trim. To do this the bladder may be sized to take up all of the available space in the void area in the trim. The bladder would thus prevent penetration of the airbag cushion into the void space by occupying the space and providing resistance to the expanding cushion. Alternatively, the bladder may be sized to inflate sufficiently to merely cover over the void space. In this way, the bladder blocks the airbag cushion from accessing the void space during the deployment of the airbag. In still other alternatives, the inflatable bladder is sized to inflate and simply bridge over at least a portion of the void space.  
           [0020]    In use, the inflatable bladder deploys into or across the void space while the airbag cushion continues to fill. As the airbag cushion begins to inflate and push down out of its stored location, the filled inflatable bladder resists the force exerted upon it by the inflating airbag cushion. This prevents the airbag cushion from “seeing” any void in the trim void space as a path of least resistance. The airbag cushion thus inflates until it escapes through the headliner over the trim edge and out into the vehicle cabin.  
           [0021]    The bladder is configured to inflate either before the airbag cushion or very early in the inflation of the airbag cushion. Due to the shape and size of the bladder, as well as its proximity to an inflator, the inflatable bladder inflates rapidly. The inflatable bladder is configured to inflate, hold pressure to assure proper deployment of the airbag, and then remain inflated for the same time period as the rest of the cushion. The inflatable bladder then deflates with the rest of the module.  
           [0022]    The invention also includes methods of guiding the deployment of any airbag cushion by placing an inflatable structure in the path of the airbag cushion. Such methods may include the steps of inflating an inflatable bladder in a void located near an airbag cushion and inflating the airbag cushion. When inflated, the airbag deployment guide promotes proper inflation of the airbag cushion. In these methods, the bladder and the airbag cushion may be inflated at substantially the same time, or the bladder may be inflated before the airbag cushion.  
           [0023]    These and other features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
         [0025]    [0025]FIG. 1A is a cross-sectional view of an airbag of the invention having an inflatable deployment guide positioned at the B-pillar;  
         [0026]    [0026]FIG. 1B is a cross-sectional view of an airbag showing the deployment guide of FIG. 1A folded into position and stitched for deployment;  
         [0027]    [0027]FIG. 1C is a cross-sectional view of an airbag having multiple deployment guides according to the invention;  
         [0028]    [0028]FIG. 1D is a cross-sectional view of an airbag showing the deployment guides in their deployed positions;  
         [0029]    [0029]FIG. 1E is a cross-sectional view of an airbag having multiple deployment guides;  
         [0030]    [0030]FIG. 1F is a cross-sectional view of an airbag showing the inflatable deployment guides in their deployed positions;  
         [0031]    [0031]FIG. 2 is a cross-sectional view of an airbag including the inflatable deployment guide of the invention installed in a vehicle, the airbag being shown in its stowed configuration;  
         [0032]    [0032]FIG. 3 is a cross-sectional view of an airbag including the inflatable deployment guide of the invention installed in a vehicle, the airbag being shown partially deployed;  
         [0033]    [0033]FIG. 4 is a perspective view of the inside of a vehicle including the partially-deployed airbag of FIG. 3; and  
         [0034]    [0034]FIG. 5 is a perspective view of the inside of a vehicle including a fully-inflated, inflatable curtain airbag incorporating the airbag of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]    The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, systems, and methods of the present invention, as represented in FIGS. 1A through 5 is not intended to limit the scope of the invention as claimed, but is merely representative of presently preferred embodiments of the invention.  
         [0036]    Referring to the drawings, FIGS.  1 A- 1 F show cross-sectional views of various embodiments of the inflatable airbag guide of the invention. FIG. 1A shows a first embodiment of the inflatable airbag deployment guide  10  incorporated into an inflatable curtain airbag cushion  40 . The inflatable airbag deployment guide  10  has an inflatable bladder  20  attached to the cushion  40  by an inflation inlet  30 . The inflation inlet  30  joins the bladder  20  to the airbag cushion  40  along an upper region of the cushion. This upper region of the cushion is designated the fill chamber  49 . The guide  10  is placed to deploy into the region above the B-pillar  50  of a vehicle, which may include void space between the top of the trim and the metal pillar. The curtain cushion  40  is shown to include a number of compartments  44 , separated by dividers  47 . The cushion  40  may also include an uninflated zone  45 . The illustrated airbag configuration is simply illustrative and other configurations may, of course, be used in connection with the present invention.  
         [0037]    Attachment of the inflatable bladder  20  to the fill chamber  49  of the curtain  40  allows the bladder  20  to be inflated in conjunction with (at the same time as) the fill chamber  49  prior to the inflation of the airbag  40 . This helps to assure that the inflatable bladder  20  deploys properly before the airbag  40  has expanded significantly into void spaces. Early-inflating regions of the airbag cushion  40  suitable for bladder  20  attachment include areas close to airbag inflation inlets  38 , the fill chamber  49 , and regions in the primary flow path of the gas emitted by the inflator. This early deployment, made possible by proper placement and by the relatively small size of the inflatable bladder  20 , places the inflatable bladder  20  in position prior to the deployment of the airbag cushion  40 . This helps to assure that the airbag cushion  40  is properly guided away from void spaces. The cushion  40  may be attached to a vehicle using attachment points  42 .  
         [0038]    The inflation inlet  30  of the deployment guide  10  may be a connecting region of the bladder  20 , or it may be a separate component attached to the bladder  20  and the airbag cushion  40 . The inflation inlet  30  may attach the bladder  20  to the airbag  40  for an inflation gas supply. It may alternatively attach the bladder  20  directly to the inflator (not shown) or the inflator housing (not shown) for a supply of inflation gas. Finally, in some possible configurations, the bladder  20  may be equipped with an inlet  30  and an outlet (not shown) to allow flow of the inflation gas through the bladder  20 .  
         [0039]    [0039]FIG. 1B shows the relationship of the inflatable bladder  20  to the airbag cushion  40  when in its folded and deployed configuration. Specifically, when deployed, the inflatable bladder  20  becomes folded over relative to the airbag cushion  40 . The figure shows the folding that takes place when the void space to be filled by the airbag is located beneath the installed airbag  40 . Other folding may occur when the airbag  40  is positioned differently relative to a void space. In some embodiments of the inflatable airbag deployment guide  10 , such positioning of the deployed inflatable bladder  20  may be assured by folding the inflatable bladder  20  into the proper position for storage. The inflatable bladder  20  may also first be folded over and then also attached to the cushion  40  with attachments  22  to further assure proper deployment.  
         [0040]    The inflatable deployment guide  10  of the invention is constructed using methods generally known in the art of designing and constructing vehicular airbags. As a result, the bladder  20  may be attached to the airbag cushion  40  by methods including sewing, gluing, or heat-welding. In such airbags  40 , the bladder  20  and inflation inlet  30  may be constructed out of materials similar to those used in the airbag  40 , and even from pieces of material left-over from the assembly process of the airbag  40 . This could include material cut from the uninflated zone  45  of the cushion  40 .  
         [0041]    In addition, the bladder  20  may be incorporated into the weave design of the airbag  40 , thus rendering it and the inflation inlet  30  integral parts of the cushion  40 . This simplifies the construction process, thus possibly reducing cost.  
         [0042]    Following the attachment of the bladder  20  to the airbag  40  using any of the methods known in the art, the deployment guide  10  may be folded for use. The bladder  20  may be folded over against an outside (or window-facing) face of the airbag cushion  40  to make the airbag  40  useful as a driver&#39;s side or passenger&#39;s side airbag. This assures proper positioning of the deployment guide  10 . This folding may be made permanent by attaching the deployment guide  10  to the intended face of the airbag  40 . These attachments  22  maybe made using methods such as tack-stitching, heat-welding, stapling, or gluing.  
         [0043]    [0043]FIG. 1C shows an alternative airbag cushion  140 , here an inflatable curtain, incorporating two inflatable airbag deployment guides  110   a ,  110   b  of the invention. Here, the airbag cushion  140  incorporates a first inflatable bladder  120   a  and a second inflatable bladder  120   b . The first and second inflatable bladders  120   a ,  120   b  are similar to the inflatable bladder  20  of the embodiment described above, each having an inflation inlet  130   a ,  130   b . This airbag cushion  140  provides deployment guides  110   a ,  110   b  in two locations, and is thus suitable for use in a vehicle with multiple void spaces along the deployment path of the airbag cushion  140 . This embodiment shows placement of the guides  110   a ,  110   b  above a B-pillar  150  and the C-pillar  170 . Additional guides such as  110   a ,  110   b  may be placed along longer curtains used with additional void spaces to assure proper deployment. Here again the guides  110   a ,  110   b  are joined to the airbag cushion along a fill chamber  149 . The curtain, similar to that described above, includes compartments  144 , separated by dividers  147 , and having an uninflated zone  145 . FIG. 1D shows the cushion  140  of FIG. 1C with the deployment guides  110   a ,  110   b  folded over and attached to the body of the airbag cushion  140  by attachments  122  to position them properly for deployment.  
         [0044]    [0044]FIG. 1E shows yet another airbag cushion  240  having other embodiments of the inflatable airbag deployment guide  210  of the invention. This figure shows an airbag cushion  240  having multiple inflatable deployment guides  210   a ,  210   b . In this cushion  240 , the guides  210   a ,  210   b  comprise additional embodiments of the invention. Multiple guides providing an airbag cushion  240  with multiple inflatable bladders,  220   a ,  220   b  may be incorporated into an airbag cushion such as an inflatable curtain  240  with a large deployment area extending over several void spaces. In FIG. 1E, the airbag cushion  240  has a first inflatable airbag deployment guide  210   a  and a second inflatable airbag deployment guide  210   b.    
         [0045]    This airbag cushion is adapted for use in vehicles requiring large airbag cushions such as  240  which require multiple airbag inflators (not shown) for proper protection of vehicle occupants. The first inflatable airbag deployment guide  210   a  comprises an inflatable bladder  220   a  and an inflation inlet  230   a , placed in a region corresponding to the location of the B-pillar  250 , which also serves as a first airbag inlet  234   a . In this deployment guide, initiation of an inflator (not shown) attached to the inflatable bladder  220   a  by the inlet  230   a  provides inflation of the guide  210   a  immediately prior to the inflation of the airbag cushion  240 . Inflation gas produced by the inflator is channeled to the airbag cushion  240  through an airbag outlet  232   a.    
         [0046]    The cushion  240  further includes a second inflatable airbag deployment guide  210   b  which is positioned behind the first guide  210   a  in a region corresponding to the location of the C-pillar  270 . Guide  210   b  is inflated by inflation gas channeled from the airbag inlet  234   b  through the fill chamber  249  located in an upper region of the cushion  240 . This guide  210   b  includes an inflatable bladder  220   b  and an inflation inlet  230   b . The inflatable bladder  220   b  further includes a bladder outlet  232   b  through which inflation gases may pass to the airbag cushion  240 , filling compartments  244 , which are separated from each other by dividers  247 . FIG. 1F shows the cushion of FIG. 1E with the inflatable bladders  220   a ,  220   b  folded down into position for proper deployment and attached to the cushion  240  by attachments  222 . The cushion may comprise attachment points  242 .  
         [0047]    [0047]FIG. 2 is a cross-sectional view of the vehicular airbag  40  of FIGS. 1A, 1B, shown installed in a vehicle  2  in its stowed configuration. This figure shows an airbag module  8  including having a deployment guide  10  mounted to the roof rail  56  of the vehicle  2  by an airbag mount  60 . The airbag cushion  40  is shown enclosed in a module cover  48 . The airbag module is shown to be enclosed in a space defined by the roof rail  56 , a headliner  54  separating the module from the passenger compartment  58 , and the B-pillar trim  52 . In this configuration, a void space  18  is located below the airbag module  8  in the path of the inflation of the airbag cushion  40 .  
         [0048]    When in a folded, or stowed, configuration such as is shown in FIG. 2, the inflatable airbag guide  10  is generally small enough to be used with current airbag housings. Specifically, the airbag guide  10  adds little bulk to the folded airbag cushion  40 , and requires a minimal amount of inflation gas. This allows it to be added to an existing airbag design without necessitating changes to the airbag&#39;s housing, mounting, or deployment equipment. This helps to reduce the cost impact of the addition of the inflation guide. The inflatable airbag guide  10  may be folded or rolled in a variety of ways to place it in its stowed configuration.  
         [0049]    [0049]FIG. 3 shows a similar side cutaway view of the mounted vehicular airbag  40  of FIG. 3, here shown with the airbag  40  partially deployed and the deployment guide  10  fully inflated. As the airbag cushion  40  begins to inflate, it forces cover  48  open and begins to drop through the joint between the headliner  54  and the B-pillar trim  52  into position within the passenger compartment  58 . Early in this process, the deployment guide  10  deploys as the inflatable bladder  20  inflates using gas from an airbag inflator that has been channeled along an upper portion of the airbag cushion  40  which forms a fill chamber  49 . The inflatable bladder  20  is positioned so as to block void space  18  by closing off access to it, filling it at least in part, or bridging over it at least in part. Proper positioning may be aided by folding the bladder  20  along the divider  47  which separates the bladder  20  from the airbag cushion  40 . This may be additionally reinforced by attaching the bladder  20  to the airbag cushion  40  in this folded-over configuration by an attachment  22 . Such an attachment  22  may take the form of stitches, welds, staples, adhesive, or other suitable methods or materials.  
         [0050]    The inflatable bladder  20  is positioned and inflated between the roof rail  56 , and the trim of the B-pillar  52 . In this way, the bladder  20  “blocks” the void space  18  by covering it completely or in part. In some embodiments of the guide  10 , the bladder  20  will be configured to block the void by filling up space within the void  18  sufficient to significantly block entry of the airbag cushion  40  into the void  18 . Others will block the void  18  by using a bladder  20  configured to significantly cover over any access to the void space  18 . Yet other embodiments guide the inflating airbag cushion  40  away from the void space  18  by providing inflatable bladders  20  which act as guides over portions of the void space  18  to act as bridges guiding the airbag cushion  40  across it.  
         [0051]    [0051]FIG. 4 shows a perspective view of the guide of FIG. 1A, 1B (in phantom) deployed and positioned and an airbag cushion  40  partially inflated. This figure shows the function and positioning of the guide  10  of the invention during the deployment of the airbag  40 . This figure shows the deployment guide  10  mounted above the B-pillar  50  in use with an inflatable curtain airbag  40  to protect a vehicle occupant (not shown) situated in seat  4 . This is only one of the potential mounting locations for the guide  10 . Here, the guide  10 , shown in phantom, includes an inflatable bladder  20  and an inflation inlet  30 . This guide  10  receives inflation gas  6  indirectly from an airbag inflator (not shown) through the attachment of the inflation inlet  30  of the guide  10  to the airbag cushion  40  such that the interior of the airbag cushion  40  is continuous with the interior of the inflatable bladder  20 . This allows inflation gas to flow freely from an inflator through the airbag cushion  40  and the inflation inlet  30  into the inflatable bladder  20 . The bladder  20  is shown here to be folded and positioned to properly block a void space in the B-pillar  50 . This proper positioning is assured by attachments  22 , which may include stitches, welds, and/or glued joints.  
         [0052]    The airbag cushion  40  may be attached to the roof rail  56  of a vehicle  2  by attachment points  42  located across a top edge of the airbag cushion  40 . The cushion  40  further comprises compartments  44  which inflate, and which are partially separated from each other by dividers  47 . The airbag cushion  40  further includes a so-called “uninflated zone”  45  which is preferably placed adjacent to the headrest of the front seat  4  of the vehicle  2 . The cushion  40  is inflated by an airbag inflator (not shown) attached to an airbag inlet  34  which transmits inflation gas  6  into the cushion  40  through the fill chamber  49 . The airbag  40  may also include tethers  62 . In this airbag embodying the guide  10  of the invention, the airbag does not overlap C-pillar  70 , thus obviating the need for a guide  10  at that pillar.  
         [0053]    [0053]FIG. 5 shows a perspective view of the interior of a vehicle including the inflatable airbag deployment guide  10  of FIG. 4. In FIG. 5, the deployment guide  10  is shown mounted and deployed in a vehicle  2  with a fully-deployed airbag cushion  40 , here an inflatable curtain airbag. The deployment guide  10  is inflated behind and/or above the B-pillar trim  52 . The deployment guide  10  inflated to prevent the cushion  40  from entering void space within the B-pillar  50 . As a result, the airbag cushion  40  deployed properly into the vehicle  2  to provide protection. Proper airbag deployment is critical to assure the proper protection of vehicle occupants.  
         [0054]    Thus, the invention discloses an inflatable airbag deployment guide. The guide first comprises an inflatable bladder. This bladder blocks access to the void by filling, covering, or bridging a void space near the folded airbag cushion during deployment of the airbag cushion. This helps to prevent malfunctions of the airbag such as incomplete or improper deployment. Such malfunctions may be caused when the airbag, following the path of least resistance during deployment, enters a void space in the trim of the vehicle and becomes lodged there as the cushion inflates.  
         [0055]    The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.  
         [0056]    What is claimed and desired to be secured by United States Letters Patent is:

Technology Category: 7