Abstract:
The invention relates to an airbag system comprising an airbag module, which has an opening mechanism for the airbag tear seam of a seat cover for the airbag accommodated underneath the cover in a non-visible manner, wherein the opening mechanism is configured such that the deploying force of the airbag tears a hole or holes into the tear seam, which bring(s) about a slight opening of the seam according to the physics of a ‘run,’ wherein a strip, or plurality of strips, or strip ends sewn into the airbag tear seam of the seat cover in more than one locations is/are torn from the seam driven by the deploying force of the airbag. The invention further relates to a vehicle seat comprising such an airbag system, and to a deployment method for such an airbag system.

Description:
FIELD Of THE INVENTION 
     The invention relates to an airbag system, to a vehicle seat with an airbag system, and also to a deployment method for an airbag system. 
     The application of the invention relates to land, air, and water vehicles, even when a vehicle seat of a motor vehicle is referenced below as an example. Primarily automobile seats as indicated above, but also seats in other types of vehicles, are obtaining and including an increasing number of safety devices and functions. In particular, thorax airbags are being integrated into such seats as an airbag system. 
     BACKGROUND OF THE INVENTION 
     Based on the principles of the technology according to the patent application DE 198 60 840 A1 and the parallel U.S. Pat. No. 6,299,197, as well as the PCT Application No. PCT/DE 2005/000765, each from the same original applicant on the subject of “run openings” in airbags that are covered with sewn textile or the like, the present invention concerns extensions and additional alternatives to the PCT Application No. PCT/DE 2006/001796, likewise from the same original applicant, concerning, in particular, secure assembly, especially of the tear strip, during mass production and the effect thereof on the entire system, and further improved implementations for the safe discharge of an airbag through a seat covering. In this respect, the total contents of disclosure of these older applications, especially with respect to the structural type of the airbag device and its assembly and operating method, are incorporated in full through reference herewith in the present document to avoid repetition. 
     In summary, the preceding applications named above show a tearing means, for example, a strip, a thread, or the like, which is sewn with a passage seam for the airbag provided. Through various kinds of “direction changes,” the tearing means/strip is mounted so that, at the beginning of its deployment, the airbag generates a load that tears a run or a hole in the planned tear seam with the tearing means. Thereafter, the further-deploying airbag is easily able to continue opening the tear seam. The system functions better than all other systems and, as a result, is independent of the type of seam and quality of the material. 
     Techniques that are typically used today use different ways to solve the problem of seams that open with difficulty. The seams are weakened and require, in connection with expansion-soft materials, low-expansion sleeves that are also sewn: this is all very production-sensitive and material-sensitive. Expensive monitoring tests are necessary. 
     The present invention has and achieves the goal of further improving the known, earlier technology through refinements and alternatives. 
     SUMMARY OF THE INVENTION 
     The invention thus devises an airbag system with an airbag module, wherein an opening technique of the airbag tear seam of a seat covering is created for the not-visible airbag housed under the covering. This opening technique is designed such that the deploying force of the airbag tears a hole or holes in the tear seam, wherein this hole or these holes creates/create a slight opening in the seam according to the physics of a “run.” This is achieved according to the invention in that one or more strips or strip ends sewn in the airbag tear seam of the seat covering is or are torn from the seam and, indeed, driven by the deploying force of the airbag. The specific embodiment here tears, for example, the strip sewn, e.g., at two points, into two holes accordingly, which is especially advantageous for a “double” so-called pelvis-thorax bag. Thus, the strip/strips is/are sewn at more than one point. 
     Advantageously, the bend [sic; strip] end is or the strip ends are one side of a loop that is placed around the airbag module. 
     Furthermore, advantageously it can be provided that the strip loop is provided at the end with a sliding ring through which the strip to be torn or the strip ends to be torn is/are passed. 
     In another implementation, the strip end is or the strip ends are positioned so that the strip end/strip ends are “peeled away.” Here, less force is needed than for “clean break” tearing. 
     Another preferred implementation is that the airbag fold(s) is/are configured such that force of the first deployment is tailored to the opening of the tear strip. This could be refined such that the airbag fold(s) is/are configured such that a target deployment direction and velocity is realized. 
     Yet another preferred implementation consists in that a tear strip opening system is configured such that an “open” sleeve is set around the airbag module and one side of this sleeve is cut into one or more tear strips. This can be refined advantageously whereby the tear strip opening system is configured such that holes are formed on the opposite side of the open sleeve and the tear strips pass through these holes from the opposite side. 
     It can be further advantageously provided that a or the tear strip opening system is configured such that the tear strips are sewn with the airbag tear seam. Alternatively or additionally, the tear strip opening system could be advantageously configured in its function such that, the tear strips are stressed during the deployment of the airbag, and thus the holes in the tear seam tear for the purpose of quick and low-force discharge of the airbag. 
     Furthermore, a vehicle seat with such an airbag system and deployment method for such an airbag system is designed by the invention. Furthermore, the invention devises suitable deployment methods for such an airbag system. 
     Preferred and/or advantageous implementations of the invention emerge from the claims and combinations thereof, as well as from all of the present application documents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in greater detail using embodiments below with reference to the drawings merely as examples, in which 
         FIG. 1  shows, in a schematic side view, an airbag of an embodiment of the invention; 
         FIG. 2  shows, in a schematic, partially sectioned side view, an embodiment of a vehicle seat with an airbag module of an airbag system of the invention; 
         FIG. 3  shows, in a schematic view, an embodiment of a tear strip of an airbag system of the invention; 
         FIG. 4  shows, in schematic diagrams A to G, different embodiments of folds for an airbag of an airbag system of the invention; 
         FIG. 5  shows, in a schematic side view, an embodiment of a backrest part of a vehicle seat with an airbag system of the invention; 
         FIG. 6  shows, in a schematic view, a detail of another embodiment of an airbag system of the invention; 
         FIG. 7  shows, in a schematic view, a principal detail of the embodiment of an airbag system according to  FIG. 6 ; 
         FIG. 8  shows, in a schematic and partially sectioned view, a detail of an alternative of the embodiment of an airbag system according to  FIG. 6 ; and 
         FIG. 9  shows, in a schematic and partially sectioned view, another embodiment of the airbag system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the implementations and embodiments described below and shown in the drawings, examples are used merely to explain the invention, i.e., the invention is not limited to these implementations and embodiments or to the corresponding combinations of features within individual implementations and embodiments. Features for methods and devices also emerge analogously from descriptions of devices and methods. 
     Individual features that are specified and/or shown in connection with actual embodiments are not limited to these embodiments or to the combination with the other features of these embodiments, but instead could be combined, within the scope of technical know-how, with any other variants, even if they are not treated separately in the present documents. 
     The same reference numerals in the individual figures and diagrams of the drawings designate components that are the same or similar or that act in the same or similar ways. With reference to the representations in the drawings, those features not provided with reference numerals will also become clear, regardless of whether these features are described below. On the other hand, features that are included in the present description but that are not visible or not shown in the drawings will also be easily understandable for someone skilled in the art. 
     Furthermore, the list of reference numerals at the end of this description is an explicit component of this description. 
       FIG. 1  shows a two-chamber bag  201  increasingly expanding with a lower bag  202  for stronger support at the pelvis with more pressure. It is also advantageous that the lower bag  202  discharges early. As is known, a human is widest at the pelvis and the most common entrance of an impacting force is at the bottom. 
     In order to be able to discharge this lower bag  202  as quickly as possible, a tear strip loop  203 , as also shown and explained in numerous embodiments even in the older applications named above, is placed around the two-chamber bag  201  that has been folded together or around its container  204  as shown in  FIG. 2  in the sectioned, schematic, and partially opened representation of a back rest part of a seat S. This two-chamber bag or its container is also designated representatively by the airbag module A. As shown in  FIG. 3 , the strip  205  is divided into two legs  206  that are sewn, as shown in  FIG. 2 , to a tear seam  208  on the seat covering  207  at the points at which the halves of the two-chamber bag  201  are to be discharged. Obviously, the two-chamber bag  201  could also be a one-chamber bag (not shown) that could be discharged more quickly by means of this technique. 
     For a good, smooth directional change of the legs  206  of the strip  205 , a direction change ring  209 , as shown in  FIG. 3 , is placed between the two legs  206  of the strip  205 . Through this arrangement, no pre-assembly sewing of the strip  205  is required. 
     The strip  205  is, e.g., welded or joined using other common techniques to the direction change ring and the bends  210  as a pre-assembly. 
     The sewing  211  is configured, as shown in  FIG. 2 , so that the strip ends  212  are peeled away. In this way, the tear seam  208  is torn more easily and thus more quickly. 
     The airbag system can be further optimized whereby airbag  214  obtains a special fold  213 . A basic fold  215  is bent at the top and bottom 180°, in order to store the gas centrally, so that the airbag  214  action first is concentrated on the tear strip loop  203  and is then discharged forwards. 
     The lower bag  202  is bent downward again 180°. Tests have shown that in this way the lower bag  202  unfolds downward at an angle. This is advantageous for reduction of the aggressiveness of the deployment that results due to a premature wide deployment in the vertical direction. 
     Additional folds for selective modification of the spreading of the airbag  214  are shown in  FIG. 4 . The embodiment A with “double” 180° folds produces a targeted quick spreading of the airbag  214  upward and downward. The embodiment B shows a reverse fold  217 , here as an upward-targeted fold. The embodiment C with a 180° fold  218  forces quick deployment forward. The embodiment D shows a 180° fold  218  with forced first deployment  219  of the lower bag  202 . In the embodiment E, the upper bag is deployed quickly forward; the lower part is delayed by a rolling fold  220  and forced “inward” toward the horizontal deployment by the rolling fold. The embodiment F shows a lower reverse rolling fold outward; as rolling fold  221 , this leads to a delay and to a deployment of the airbag  214  downward through its winding direction. The embodiment G shows at the bottom a 180° double fold  216  and thus a moderate, quick deployment targeted downward. In summary, these examples show how the deployment direction and velocity can be specified by the type of fold. 
       FIG. 2  shows an entire airbag  202  that is folded according to the representation shown. This embodiment causes the entire airbag  202  to be discharged forward and the tear strip loop  203  to be activated. The kinks  204  [sic;  210 ] of the airbag  202  at the top and bottom prevent spreading of the gas upward or downward. 
     In a schematic side view,  FIG. 5  shows an embodiment example of a backrest part of a vehicle seat with an airbag system of the invention. 
     Indeed, in the preceding embodiment examples, reference has been made to an opening technique that can tear the airbag tear seam of a seat covering at two separate points, but the present invention is not limited to this implementation. Instead, an arbitrary plurality of tear points determined according to other conditions and requirements could be provided and strips or strip ends could be provided. 
     Thus, the invention devises an airbag system, a vehicle seat, and a deployment method for this airbag system, with an opening technique for the airbag tear seam of a seat covering for the airbag that is housed so that it cannot be seen under the covering. The opening technique is realized such that the force of deployment of the airbag tears a hole or holes in the tear seam, wherein this hole or these holes creates/create a slight opening in the seam according to the physics of a “run.” Furthermore, the opening technique is configured such that a strip or several strips or strip ends sewn into the airbag tear seam of the seat covering is or are torn from the seam due to the force of deployment of the airbag. In particular, in this opening technique, the strip end or the strip ends can be one side of a loop that is placed around the airbag module. The specific embodiment created in this implementation could tear, for example, two holes in the strip sewn at two places, which is especially advantageous for a so-called “double” pelvis-thorax bag. The strip/strips is/are thus sewn according to the invention at more than one point, so that the seat covering tears at correspondingly several, for example, two, separate points and the airbag can be discharged safely and in a targeted way. The beginning of deployment can be influenced through the positioning of the tear strip/tear strips. Different material expansions have no effect on the functional reliability of the airbag system (greater expansion is more economical and is easier to process). 
     The strip loop could be provided at the end with a sliding ring through which the strip to be torn or the strip ends to be torn is/are passed. Preferably, the strip end is or the strip ends are positioned so that the strip end/strip ends is/are “peeled away,” which requires less force than that required for “clean break” tearing. 
     Furthermore, the airbag fold is or the airbag folds are configured so that the force of the first deployment is tailored to the opening of the tear strip. Here, it is further preferred that the airbag fold or the airbag folds be configured so that, in addition, a target deployment direction and velocity are achieved. 
     The implementations according to the invention lead to a series of advantages. 
     Today, the airbag tear seam is typically weakened and therefore must be continuously monitored, in order to guarantee a balance between strength during use and easy opening. This is required because the bag must simultaneously open many stitches. Furthermore, the surroundings of the tear seam are reinforced with a sleeve to eliminate the expansion of the covering material. The implementation of the tear strip technique according to the invention requires a tear seam that has not been weakened or that has been weakened only slightly, because the airbag must tear only a few stitches according to the system. The material need not be reinforced because the strip loop performs the tearing process in the direction opposite to airbag deployment. Furthermore, the airbag discharge point could be affected by the sewing point(s). Selective folding of the airbag further supports the tear strip technique and simultaneously the deployment direction and velocity. 
     The invention is especially advantageous for the design of airbag systems with a greater height than previous systems. This relates, in particular, to two-part airbags or so-called two-chamber or two-zone airbags or, in general, multiple-part airbag constructions. 
     Another alternative of the tear strip technique is a fabric  222  as shown in  FIG. 6 . This fabric  222  is cut so that three tear strips  223  are formed on one side. Here, three tear strips are shown. It could also be another number, beginning with 1. This depends on the design of the airbag  214  and the type of seat covering  207 . 
     On the opposite side of the fabric  222 , in this example, three holes  224  are formed. The tear strips  223  are passed through these holes  224  and then sewn to the tear seam  208 . In this so-to-speak “open” sleeve  225 , the airbag module A is inserted and then pulled taut during assembly and thus brought into a predetermined position. An additional two holes  226  are used for the passage of screw bolts  227  of the airbag module A. This principle is shown in  FIG. 7 . 
     The advantage of this alternative is that an arbitrary number of tear strips  223  can be used without additional assembly costs. This is especially advantageous for multiple-part airbags  214 . Furthermore, several weakened points of the tear seam permit a tighter seam. Several—and thus shorter—tear strips  223  separate earlier from the deploying airbag  214 . Sleeves that are typically used today merely reinforce the seat covering and minimize its expansion. The sleeve  225  described here with its integrated tear strips tears holes into the tear seam  208  in the sense of runs. This requires only a small force and thus permits a significantly tighter airbag seam  208 . 
     Furthermore, a viewing hole  228  is formed. Through this hole, a bar code  229  of the airbag module  230  can be read (see  FIG. 8 ). Another bar code  231  is formed in front of the holes  224 . This bar code  231  is covered partially at predetermined points of the tear strips  223  as shown in  FIG. 8 . The bar code  231  is inspected through the viewing hole  228  at the same time as the inspection of the bar code  229  of the airbag module  230 . The predetermined points of the bar code  231  must be covered by the tear strips in order to receive an OK inspection. 
       FIG. 9  shows another application of the tear strip technique with two tear strips  235  that are positioned exactly in tear strip loops  203  around the airbag module  230 . For this purpose, the direction change rings  209  are pushed from above into injection-molded clamps  235  that are open on one side. A suspension point  237  is also injection-molded on the opposite side of the airbag module  230 . When the tear strip loops  203  are correctly positioned, the positioning markings  236  (in this case the numbers 1, 2, 3, 4) are also in a predetermined position. This position is checked by a photoscanner (not shown) after the assembly of the airbag module  230  on the seatback frame at the same time as the bar code  231  of the airbag module  230 . 
       FIG. 9  further shows that the sewing of the tear strips  237  [sic;  235 ] at the correct position of the seat covering  207  is guaranteed. Here, the seat covering  207  is provided with a reference point  233 . A computer-controlled sewing machine that is equipped with detectors for contours and light-dark areas moves from this reference point  233  to the first (dark) fixing point  234 . Only when this machine is located at the correct position does it move to the next fixing point, etc. Then the angle position of the tear strip  223  is also detected. The sewing itself is seen at the sewing position of the tear strips  223  at small, V-shaped notches  238 . The sewing machine is also configured so that it can only sew forward. 
     In summary, the present invention relates, in particular, to an airbag system and especially to an opening system for airbags that are discharged from a sewn cover. The opening technique according to the invention for a seat covering is advantageous for the selective, quick, and problem-free passage of an airbag. A strip is placed as a loop around an airbag. Deployment of the bag enlarges the loop and tears, with the strip sewn in the airbag tear seam, a hole or a run in the seam and, indeed, according to the invention, at more than one point. Through this weakening, the seam is opened by the bag in a selective way with little force. The specific configuration shown here can tear two holes, for example, in the strip sewn at two points, which is especially advantageous for a so-called “double” pelvis-thorax bag. Furthermore, airbag fold systems are shown that support this process and that support a desired fold direction and fold velocity. 
     The invention is described with reference to embodiments in the description and in the drawing merely using examples and is not limited to these embodiments, but instead comprises all variations, modifications, substitutions, and combinations that someone skilled in the art can take from the present documents, especially within the scope of the claims and the general representations in the introduction of this description, as well as from the description of the embodiments and their representations in the drawing and can be combined with the technical knowledge of someone skilled in the art and also with the state of the art. In particular, all of the individual features and possible implementations of the invention and their variants could be combined. 
     Explanation of Symbols 
     
         
           201  Two-chamber bag 
           202  Lower bag 
           203  Tear strip loop 
           204  Container 
           205  Strip 
           206  Leg 
           207  Seat covering 
           208  Tear seam 
           209  Direction change ring 
           210  Bend 
           211  Sewing 
           212  Strip ends 
           213  Fold 
           214  Airbag 
           215  Base fold 
           216  Double 180° fold 
           217  Reverse fold 
           218  180° fold 
           219  Forced first deployment 
           220  Rolling fold 
           221  Reverse rolling fold 
           222  Fabric 
           223  Tear strips 
           224  Holes 
           225  Sleeve 
           226  Holes 
           227  Screw bolt 
           228  Viewing hole 
           229  Bar code 
           230  Airbag module 
           231  Barcode 
           232  Seat cushion 
           233  Reference point 
           234  Fixing points 
           235  Clamp 
           236  Position markings 
           237  Hanging points 
           238  V-shaped notches 
         A Airbag module 
         S Seat