Abstract:
The present invention is directed to an integrated belt retention apparatus for use with a vehicle seat having a seat part with a backrest and with a belt retention apparatus integrated with the vehicle seat, comprising a belt suspension means having a fastening means for fastening to the backrest, wherein the vehicle seat is characterized in that the fastening means comprises a crash element with a deformation region for reducing kinetic energy in the event of activation of the belt retention apparatus as a result of an accident.

Description:
PRIORITY CLAIM 
       [0001]    This application claims the benefit of German Application Serial No. 102011012461.6 filed on Feb. 25, 2011, contents of which are incorporated herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates on the one hand to a vehicle seat with a seat part, with a backrest and with a belt retention apparatus integrated on the vehicle seat and comprising a belt suspension means, in which the belt suspension means has a fastening means for fastening to the backrest. 
         [0003]    The invention relates on the other hand to a vehicle seat with a seat part, with a backrest and with a belt retention apparatus integrated on the vehicle seat and comprising a belt suspension means, in which an adjustment mechanism is arranged between the seat part and the backrest, in which the belt suspension means has a device for mounting on the backrest, and in which the backrest comprises a device for the retention of the mounting device, the mounting device being arranged on the retention device. 
         [0004]    In addition, the invention relates to a method of reducing the introduction of forces and/or moments on an adjustment mechanism between a seat part and a backrest of a vehicle seat with an integrated belt retention apparatus, and use related thereto. 
       BACKGROUND OF THE INVENTION 
       [0005]    It is known for a belt retention apparatus for restraining an occupant of a vehicle on a vehicle seat to be integrated directly on or in the vehicle seat. In this case a belt storage means and a device for arresting a belt fitting on a part of the vehicle seat and a belt reversal device is arranged on a backrest of the vehicle seat by means of a possibly vertically adjustable belt suspension means. In this respect it is readily possible in structural terms to be able to produce a vehicle seat with an integrated vehicle occupant protection independently of other features of the bodywork. A drawback in this case, however, is that in the event of a vehicle crash relatively high retention forces are introduced into the backrest of the vehicle seat by means of the belt suspension means. These forces can frequently amount to a multiple of the body weight of the vehicle occupant strapped on the vehicle seat. This leads among other things to an enormous and usually abrupt loading of the adjustment mechanism, by means of which the backrest is fastened to the seat part. It happens not infrequently that the adjustment mechanism is irreparably damaged and has to be replaced. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention is directed to remedy the drawback identified in the background. 
         [0007]    In accordance with a first aspect of the invention, the present invention includes a vehicle seat with a seat part, with a backrest and with a belt retention apparatus integrated with the vehicle seat and comprising a belt suspension means, in which the belt suspension means has a fastening means for fastening to the backrest, the vehicle seat being characterized in that the fastening means comprises a crash element with a deformation region for reducing kinetic energy in the event of activation of the belt retention apparatus as a result of an accident. 
         [0008]    The loading occurring in the event of a vehicle crash in particular on the adjustment mechanism, by means of which the backrest is fastened to the seat part, can be reduced by means of the fastening means designed according to the invention, in that kinetic energy is reduced by deformation action which has taken place. As a result, an abrupt loading, in particular of the adjustment mechanism, can be prevented or at least mitigated. 
         [0009]    The term “crash element” describes a component of a belt retention apparatus which is integrated in a vehicle seat and by means of which a deformation region can be formed which is determined structurally and which can perform a deformation action in a purposeful manner in the event of a vehicle crash. 
         [0010]    With a suitable seat structure a deformation region of this type can optionally be formed directly by a sheet metal part of the belt suspension means and/or the backrest. 
         [0011]    In a preferred embodiment, the deformation region is designed in the form of an independent component since a greater flexibility of design can be achieved in this way. 
         [0012]    A preferred variant of embodiment provides that a direction of main deformation, which is directed essentially in the direction of a longitudinal extension of the backrest, is inherent in the deformation region. 
         [0013]    If a deformation of the crash element takes place mainly in the direction of the longitudinal extension of the backrest, in this case a factory-made distance between the belt suspension means and the adjustment mechanism can be additionally reduced, as a result of which a lever path between the belt suspension means and the adjustment mechanism is shortened in an advantageous manner. 
         [0014]    An alternative embodiment includes a vehicle seat with a seat part, with a backrest and with a belt retention apparatus integrated on the vehicle seat and comprising a belt suspension means, in which an adjustment mechanism is arranged between the seat part and the backrest, in which the belt suspension means comprises a device for mounting on the backrest and in which the backrest comprises a device for the retention of the mounting device, the mounting device being arranged on the retention device, and the vehicle seat being characterized by a device for shortening a lever path between the belt suspension means and the adjustment mechanism in the event of activation of the belt retention apparatus as a result of an accident. 
         [0015]    The device for shortening the lever path can be designed in various ways. It is preferable for it to comprise a crash element with a deformation region to reduce kinetic energy with a direction of main deformation, which is directed essentially in the direction of a longitudinal extension of the backrest. 
         [0016]    The term “mounting device” describes a component on the side of the belt suspension means, in particular a component like a metal sheet, by means of which the belt suspension means is capable of being fastened to a backrest structure. In this respect the mounting device can be a component of the belt suspension means. 
         [0017]    The term “retention device” describes a component on the side of the backrest, in particular a component like a metal sheet, to which the belt suspension means with its mounting device is fastened. In this respect the retention device can be a component of the backrest structure. 
         [0018]    The present invention further describes a method of reducing the introduction of forces and/or moments on an adjustment mechanism between a seat part and a backrest of a vehicle seat with an integrated belt retention apparatus, in which a lever path between a belt suspension means of the belt retention apparatus and the adjustment mechanism is shortened in the event of activation of the belt retention apparatus as a result of an accident. 
         [0019]    In an alternative embodiment, the belt suspension means comprises a device for mounting on the backrest and the backrest comprises a device for retaining the mounting device, in which case a crash element capable of being deformed in a resilient or plastic manner substantially in the direction of a longitudinal extension of the backrest is arranged between the mounting device and the retention device. 
         [0020]    If the deformation region of the crash element is formed for example not directly by conventional components or groups of components, such as for example the mounting device and/or the retention device of the seat, it is advantageous for the deformation region to be formed by means of a stand-alone crash element which is preferably arranged between the mounting device and the retention device. In this way, use can be made of conventional mounting devices and retention devices in an advantageous manner, as a result of which it would also be optionally possible for older vehicle seats to be converted. 
         [0021]    In one embodiment, the mounting device describes for example a sheet metal part of the belt suspension means, which as a rule is welded onto a corresponding sheet metal part of a seat structure in the region of the backrest. Here, the retention device designates the corresponding sheet metal part of the seat structure. In a conventional manner the two sheet metal parts are welded to each other in abutment with each other in order to produce a fixed join. In this case the two sheet metal parts are not movable with respect to each other, unless the join is destroyed. If the mounting device is arranged on the retention device at a distance from the latter, a sufficiently large structural space for a necessary deformation path can be provided in a structurally simple manner. 
         [0022]    The crash element can be readily embedded with little effort in a conventional vehicle seat structure using a sheet-like base member with at least one sheet metal rib as well as at least two abutment planes which are at a distance from each other, in which case the at least one sheet metal rib is orientated substantially horizontally. In this respect the sheet metal rib is orientated substantially transversely to the direction of main deformation. 
         [0023]    On account of the sheet-like base member, a mechanical safety device which is easy to construct and which operates in a reliable manner can be provided. 
         [0024]    In one embodiment, the sheet-like base member can be a stamped part. In this respect the crash element can be produced in an easy and inexpensive manner. 
         [0025]    The sheet-like base member can be produced with a thickness of material of between 0.5 mm and 3 mm, depending upon what deformation action is intended to be carried out by the crash element. 
         [0026]    The mounting device and the retention device can be spaced sufficiently far from each other without undue effort by means of a sheet metal rib or preferably a plurality of sheet metal ribs. 
         [0027]    In an alternative embodiment, the at least one sheet metal rib can be welded to the mounting device on the side of the belt suspension means on the first of the abutment planes and to the retention device on the side of the backrest on the second of the abutment planes. As a result, the present crash element can be produced on a vehicle seat with an integrated belt retention apparatus in a particularly inexpensive manner. 
         [0028]    If sheet metal ribs of the crash element are arranged orientated substantially horizontally, the direction of main deformation can be pre-set in an operatively reliable manner in the direction of the longitudinal extension of the backrest, in that the sheet metal ribs of the crash element arranged one behind the other can bend in this direction if the forces acting upon the crash element reach or exceed a critical value as a result of a vehicle crash. 
         [0029]    In an alternative embodiment, the deformation path can be varied in a structurally simple manner depending upon the requirement of application, if of the at least one sheet metal rib is at an angle of more than 10°, preferably of more than 20°, and of less than 170°, preferably of less than 160°, and ideally of 90°, with respect to at least one of the abutment planes. 
         [0030]    It is preferable for a deformation path of more than 10 mm, preferably of 20 mm or more, to be capable of being achieved by means of the crash element according to the invention. In addition, the parameters of the deformation path can also be influenced by the height of the crash element or of a sheet metal rib thereof. By way of example, the height has a value of between 10 mm and 50 mm. These values, however, are not to be understood as being restrictive in an obligatory manner. 
         [0031]    The deformation behaviour of the crash element can be additionally influenced if the sheet-like base member is bent at least once and preferably more than once. In particular, the abutment planes can be chosen to be almost any desired size by bending over ends of the sheet metal rib or ribs in an appropriate manner, as a result of which the crash element can be fastened to the mounting and retention devices over a large area and thus in a particularly intimate manner. 
         [0032]    It is preferable for the sheet-like base member to be designed with double webs or with a plurality of webs, i.e. the crash element makes more than one sheet metal rib available. By way of example, two webs or sheet metal ribs of the crash element are arranged at a distance of between 1 mm and 20 mm from each other. 
         [0033]    In a simple manner the sheet-like base member can be bent into a U shape and can have two additionally bent fastening plates at its ends. 
         [0034]    The two fastening plates can advantageously form two abutment planes on the side of the backrest which are at a distance from each other, whilst the middle arm of the base member bent into a U shape can form a large, advantageously continuous abutment plane on the side of the belt suspension means. 
         [0035]    In an alternative embodiment, the crash element includes a store of material for extending a deformation path, the store of material being arranged in particular at least in part behind a plane of the mounting device and/or a plane of the retention device. A store of material of this type can be produced in a very simple manner structurally just by a base member bent into a U shape forming a shorter and a longer web between the mounting device and the retention device. In this case the longer web can extend in an advantageous manner behind the plane of the mounting device and/or a plane of the retention device. It is preferable for the longer web to be made bent once more, so that further material is available for extending the deformation path. 
         [0036]    In an alternative embodiment, the present invention incorporated the use of a belt suspension fastening means of a vehicle seat belt retention apparatus for shortening a lever path between the belt suspension means and an adjustment mechanism between a backrest and a part of the vehicle seat in the event of activation of the belt retention apparatus integrated on the vehicle seat as a result of an accident. 
         [0037]    It is to be understood that the features of the solutions described above and in the claims respectively can also optionally be combined in order to be able to implement the advantages in a suitably cumulated manner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
           [0039]      FIG. 1  is a diagrammatic, perspective partial view of a vehicle seat in the region of a belt suspension means with a fastening means comprising a crash element between a mounting device on the side of the belt suspension means and a retention device on the side of the backrest; 
           [0040]      FIG. 2  is a further diagrammatic, perspective partial view of the belt suspension fastening means as shown in  FIG. 1 , but without a mounting device on the side of the belt suspension means; 
           [0041]      FIG. 3  is a diagrammatic, perspective view of the vehicle seat as shown in  FIG. 1 ; 
           [0042]      FIG. 4  is a diagrammatic view of a further embodiment of the design of a crash element in the original factory-made state; 
           [0043]      FIG. 5  is a diagrammatic view of the crash element as shown in  FIG. 4  after a deformation action has been carried out; 
           [0044]      FIG. 6  is a diagrammatic view of a deformation sequence of another crash element; 
           [0045]      FIG. 7  is a diagrammatic view of two sheet-like base members of alternative crash elements; 
           [0046]      FIG. 8  is a diagrammatic view of further sheet-like base members of further alternative crash elements, and 
           [0047]      FIG. 9  shows diagrammatically a further crash element with an angle of the sheet metal rib of 90° indicated. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0048]    The vehicle seat  1  shown in  FIGS. 1 to 3  has a seat part  2 , a backrest  3  and a belt retention apparatus  4  integrated in the vehicle seat  1 . The belt retention apparatus  4  is formed in this embodiment by a belt  5  and a belt suspension means  6 . It comprises, however, at least one belt store (not shown here) as well as an arresting device (not shown here) for a belt fitting. At the top on the left, as viewed in the direction of the seat, a fastening means  8  is shown, by means of which the belt suspension means  6  is fastened to the backrest  3 . The fastening means  8  provides on the side of the belt suspension means a mounting device  9  and on the side of the backrest a retention device  10  for the mounting device  9 . A receiving means  11  for a belt reversal bracket  12  is positioned substantially centrally on the mounting device  9 . 
         [0049]    According to the invention a crash element  13 , which in this embodiment comprises an upper deformation element  14  and a lower deformation element  15 , is arranged between the mounting device  9  and the retention device  10 . The two deformation elements  14  and  15  have in each case a sheet-like base member  16  and  17  respectively bent substantially into a U shape. The crash element  13  in this embodiment is preferably a plastically deformable crash element  13 . 
         [0050]    The sheet-like base members  16  and  17  respectively are designed in this embodiment in such a way that they form deformation regions  18  (numbered here only by way of example in each case) for the reduction of kinetic energy with respect to an activation of the belt retention apparatus  4  as a result of an accident. 
         [0051]    In the event of an activation of the belt retention apparatus  4  as a result of an accident the multiple of the body weight of a person acts upon the locked belt  5  and, in particular upon the belt suspension means  6 , by way of which corresponding restraining forces are frequently introduced in an abrupt manner into a structure  19  of the backrest  3 . 
         [0052]    The high position of the belt suspension means  6  at the top on the left  4  on the backrest  3  leads to a relatively high loading, in particular on an adjustment mechanism  20  between the seat part  2  and the backrest  3 , since the restraining forces introduced on the belt suspension means  6  act in an additionally amplified manner upon the adjustment mechanism  20  by a lever path  21  between the belt suspension means  6  and the adjustment mechanism  20 . 
         [0053]    In an advantageous manner the restraining forces can be reduced at least in part by deformation action carried out at the crash element  13 , before they can act upon the retention device  10  of the backrest structure  19 . 
         [0054]    It is particularly advantageous, however, for the crash element  13  to have a direction of main deformation  22  substantially in the direction of a longitudinal extension  23  of the backrest. In particular, on account of this feature, the lever path  21  between the belt suspension means  6  and the adjustment mechanism  20  can be shortened in an advantageous manner as soon as the crash element  13  is deformed as a result of an accident. In an advantageous manner, this in turn has the consequence that lower forces or moments act upon the adjustment mechanism  20 , as a result of which the risk of irreparable damage to the adjustment mechanism  20  is substantially reduced. In this case even short deformation paths of less than 50 mm are sufficient to cause an effective release of the adjustment mechanism  20 . In this respect the crash element  13  embodies not only a device for the reduction of kinetic energy but also, in particular, a device  24  for the reduction of the lever path  21 . 
         [0055]    In addition, the crash element  13  is characterized by two abutment planes  25  and  26  (numbered only at the sheet-like base member  16  by way of example) which are at a distance from each other and which are spaced from each other by a rib structure  27  (numbered only at the sheet-like base member  17  by way of example). The first abutment plane  25  is used for fastening to the mounting device  9  and the second abutment plane  26  is used for fastening to the retention device  10 . In this embodiment the fastening means  8  is designed in the form of a welded structure, as a result of which the crash element  13  can be integrated into the structure of the vehicle seat or into the backrest structure  19  in a very inexpensive manner. 
         [0056]    The rib structure  27  is at a right angle a with respect to the two abutment planes  25  and  26  (see in particular also  FIG. 9 ) and it preferably extends substantially horizontally. In this respect the rib structure  27  is orientated substantially transversely to the direction of main deformation  22 . 
         [0057]    In order to be able to provide a sufficiently long deformation path in the direction of the direction of main deformation  22  if required, the crash element  13  comprises a store of material  28  which extends at least in part behind the second abutment plane  26  or behind a plane of the retention device. To this end, the sheet-like base members  16  and  17  of the crash element  13  traverse the retention device  10  through corresponding openings  29  (numbered here only by way of example in  FIG. 1 ). 
         [0058]    The further crash element  113  shown in  FIGS. 4 and 5  has a rib structure  127  with four individual webs  130  (numbered here only by way of example) which are made straight and are welded orientated in their original position (see  FIG. 4 ), preferably at a right angle between a mounting device  109  of a belt suspension means  106  and a retention device  110  of a backrest  103 . 
         [0059]    In order to stabilize further the crash element  113  and to orientate the four straight individual webs  130  in a simpler manner during the production of the crash element  113 , offsets  131  in the form of a thickening of material are provided on the mounting device  109 . In this alternative embodiment the crash element  113  comprises at the same time the mounting device  109  and the retention device  110  and is thus particularly compact in design. 
         [0060]    While the crash element  113  is still situated in its original position in the illustration according to  FIG. 4 , in accordance with the illustration according to  FIG. 5  it is deformed in its direction of main deformation  122  on account of an activation of a belt retention apparatus (not shown here) as a result of an accident. In this case it is clearly evident that the individual webs  130  are inclined and the mounting device  109  has shifted with respect to the retention device  110  by a deformation path  132 . Here, it allows for deformation action to be carried out on the one hand and for a lever path between a belt suspension means and an adjustment mechanism to be advantageously shortened on the other hand. 
         [0061]    In the embodiment shown in  FIG. 6 , a crash element  213  has two sheet-like base members  216  and  217  which are bent into a U shape and which connect a mounting device  209  and a retention device  210  to each other at a distance. The crash element  213  has a rib structure  227  and has a first abutment plane  225  on the side of the mounting device and a second abutment plane  226  at a distance from it on the side of the retention device. The first abutment plane  225  is formed by a flat partial region  235  which rests against the mounting device  209  and is welded to it. The second abutment plane  226  is formed by end fastening plates  236  (numbered only by way of example) which rest against the retention device  210  and are welded there. 
         [0062]    According to the deformation sequence  237  shown in  FIG. 6 , the crash element  213  is deformed and performs advantageous deformation action on the one hand and provides an advantageous deformation path  232  on the other hand, in order to shorten a lever path between a belt suspension means and a displacement mechanism, as has already been described above. In this embodiment the mounting device  209  always moves closer to the retention device  210  in the course of the deformation sequence  237  and an original structural height  238  of the crash element  213  is reduced in succession. In this respect it is advantageous for the structural height  238  of the crash element  213  also to be selected with a view to the necessary deformation path  232 . 
         [0063]    The embodiments shown in  FIG. 7  show, on the left-hand side, a crash element  313  with a sheet-like base member  316  which is bent substantially into a U shape and which holds a store of material  328  on one  340  of its arms  340 ,  341 . In this case the store of material  328  is designed conversely in a U shape and is housed inside the arm  340  between a first abutment [plane]  325  and a second abutment plane  326  of the crash element  313 . 
         [0064]    On the right-hand side the embodiments show a crash element  413  which corresponds to the design of the crash element  213 . In this respect, reference is made to the description of  FIG. 6 , in order to avoid repetition. The two crash elements  313  and  413  are shown between a plane  342  on the side of the belt suspension means and a plane  343  on the side of the backrest. 
         [0065]    The further crash elements  513 ,  613  and  713  illustrated in  FIG. 8  display further variants of how a crash element can be designed and orientated in a belt suspension fastening means with respect to the plane  342  on the side of the belt suspension means and a plane  343  on the side of the backrest. The crash elements  513  and  613  have a simple U shape. The crash element  613  is inserted rotated through 90°. In contrast, the crash element  713  has a sheet-like base member  716  bent into an S shape. 
         [0066]    The fastening means  808  shown in  FIG. 9  substantially corresponds to the embodiment according to  FIG. 6 . A sheet-metal rib angle a of 90° is indicated with respect to a first sheet-like base member  816  of a crash element  813  of the fastening element  808 , in which case the crash element  813  is welded to a mounting device  809  on the side of the belt suspension means and a retention device  810  on the side of the backrest. Depending upon the deformation path required (see reference number  232 ,  FIG. 6 ), the sheet-metal rib angle a can also be selected with a different value, as has already been described in the introduction. 
         [0067]    It is to be understood that the embodiments described above are merely first arrangements of the invention. In this respect the arrangement of the invention is not restricted to these embodiments. All the features disclosed in the application documents are claimed as being essential to the invention, insofar as they are novel either individually or in combination as compared with the prior art. 
         [0068]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.