Abstract:
A support element for upholstering on a vehicle seat, in particular for the backrest upholstery, with a base region of large area, for supporting the upholstery and an edge surrounding the base region. At least two separate adjacent support regions are provided along the edge of the base region, projecting from the edge.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a National Phase Patent Application of International Application Number PCT/DE02/03411, filed on Sep. 9, 2002, which claims priority of German Patent Application Number 101 45 206.3, filed on Sep. 7, 2001. 
    
    
     BACKGROUND 
     The invention relates to a support element for upholstering on a vehicle seat. 
     A support element of this kind comprises a large surface area base region which is designed and provided for fitting on the back of the upholstery and which is set up to take up and distribute the compressive forces which occur when a vehicle occupant leans on the front side of the upholstery. A support element of this kind is provided in particular for fitting between the backrest upholstery of a vehicle seat and a curved element which extends along the back of the backrest upholstery and whose position and/or curvature can be adjusted by means of an adjusting device in order to be able to adapt the curvature of the backrest upholstery to the needs of the various different vehicle occupants. 
     A backrest for vehicle seats is known from DE 36 19 188 C1 where the upholstery padding can be adjusted by means of a curved element in the form of two leaf springs wherein a pressure distributing plate is mounted between the leaf springs and the padding. 
     By fitting a support element e.g. in the form of a pressure distributor plate between the curved element and the backrest padding, the curved element does not act on the upholstery direct but rather through the support element which is designed so that—even with a more marked curvature of the curved element—it ensures a large surface ergonomic support of the back region of the vehicle occupant. More particularly it is achieved through the large surface area support element that during each adjustment of the curved element the support for the back of the relevant vehicle occupant adapts to the contour of the relevant back region, i.e.,—the curvature of a sufficiently flexible (elastically arching) support element is determined not only by the adjustment of the curved element but also at the same time by the contour of the back part of the relevant vehicle occupant and is thereby adapted ergonomically in optimum manner. 
     SUMMARY 
     The object of the invention is to improve a support element for upholstering on a vehicle seat, more particularly the sitting comfort for a vehicle occupant. 
     According to this a number of separate support regions protrude next to each other from the edge of the large surface base region of the support element. It has been seen that by arranging additional support regions (support contour fingers) in this way along the edge of the large surface base region of the support element (preferably moulded on the base region) a particularly uniform support of the back region of an occupant can be achieved with a particularly good adaption to his/her back part, independently of the relevant setting of the curved element. 
     By adjacent arrangement of at least two support regions along the edge is thereby to mean that the two support regions are arranged adjacent along one spatial direction along which the edge extends between the two said support regions. The two support regions can in particular be mounted adjacent one edge section which runs along the said spatial direction. 
     Particularly preferred are at least three support regions which are arranged in succession along one edge section and are thereby arranged in pairs side by side. 
     The support regions can simply be formed by projections moulded in one piece on the edge of the base region. Through the arrangement according to the invention of several support regions along the edge of the base region which each project from the base region, the support element has a particular elasticity (raised compared with the central base region) in the region of its edge so that the possibility of adapting the support element to the back part of an occupant is improved. The support element overall is preferably formed so that it can arch. 
     In particular the support regions are spaced out from each other along the edge of the base region of the support element so that they are each only connected to the base region but not additionally however to each other. 
     Alternatively it can be proposed that individual more particularly adjacent support regions are connected together through (loose) material regions which do not (significantly) restrict the mobility of the individual support regions relative to each other, thus do not impair the elasticity of the support regions. 
     Furthermore adjacent support regions can overlap one another. The overlapping support regions are then however preferably each connected to the base region through connecting regions which are spaced from-each other along the edge of the base region. 
     The connection of the support regions to the base region is through a connecting region which tapers from the support region to the base region at least in sections, e.g. is formed in sections as a web. With a connecting region which protrudes from the base region along a first direction, e.g. substantially perpendicular to the edge of the base region, this means that the width of the connecting region, i.e. its extension perpendicular to the first direction is smaller than the maximum width of the support region on that side of the connecting region. A special elasticity of the support regions is hereby ensured and thus a particularly good adaptability to the relevant vehicle occupant. 
     The support regions can extend substantially in the same plane in which the associated edge region of the base region of the support element lies or, particularly preferred, can run at an obtuse angle to that plane so that at least one part of the support regions is angled towards the upholstering. The support action of the support element is hereby further improved, particularly with regard to a uniform absorption and distribution of the compressive forces. 
     With a substantially rectangular large surface base region of the support element the base region has four edge sections which are each opposite one another in pairs whereby a number of spaced support regions is provided on at least one of the edge sections. In relation to the installation position of the support element in a vehicle seat having an upright backrest the support regions can for example be provided on the upper and/or lower edge section as well as on one or preferably both side edge sections. 
     According to a further development of the invention the support element has reinforcement regions, more particularly in the form of swages or ribs, as well as where necessary weakened areas, more particularly in the form of openings or slits in order to achieve a defined pressure path which is evened out over the entire surface of the support element. The reinforcement regions can thereby extend into the base regions provided at the edge of the support element, namely preferably so that the rigidity of the corresponding support region decreases towards its free end (remote from the edge of the base region). 
     In the case of support regions which protrude from the lower edge section of the base region of a support element for backrest upholstery it can be advantageous to dispense with reinforcement regions if a particularly flexible formation of the support element is to prevent too much pressure on the spine of the occupant. 
     Furthermore in a preferred embodiment the support regions can be formed rotatable spring elastically about an axis which is defined through an elongated reinforcement region, e.g. in the form of a rib. 
     According to an advantageous development of the invention support regions of different size are arranged alternately along the edge of the base region, e.g. support regions of a first size and of a second size different herefrom are arranged alternately (in relation to their surface area in the plane of the support element) and are thereby boxed in each other. A large supporting surface area with advantageous elastic properties is hereby to be provided for example in the shoulder blade region of the occupant. Correspondingly an arrangement of this kind is to be provided particularly in the region of the upper edge section of a support element for a backrest upholstering. 
     The external contour i.e. the edge of the support regions which are mounted on the base region and which for example are formed integral therewith is preferably curved, i.e. free of sharp corners whereby particularly advantageous supporting properties are achieved. 
     According to a further development of the invention support regions are provided in the corner sections of the base region of the support element and have in relation to a rotational axis which can be formed for example by a reinforcement region, an asymmetrical division of the surface area, whereby the smaller surface points outwards, i.e. away from the support element and the larger surface points towards further support regions of the support element. The corresponding support region is hereby turned when under stress so that the outward facing outer surface region is moved forwards and the lateral hold of an occupant is hereby improved. The asymmetrical surface division required for this can be achieved for example in that an additional inwardly directed support finger is provided on the corresponding support region or that the inwardly directed surface section is enlarged in some other way relative to the outwardly directed surface section so that the inwardly directed lever arm of the support surface is greater than the outwardly directed lever arm. 
     For further levelling out the compressive forces the support element can have pressure distributing regions, more particularly in the form of through openings. 
     In a preferred embodiment the backrest has a curved element which extends along the back of the backrest upholstery, as well as an adjusting device with which the position and/or curvature of the curved element can be adjusted in order to adjust the curvature of the backrest upholstery. The support element hereby extends between the curved element and the backrest upholstery so that it is in active connection with the curved element on one side and bears against the backrest upholstery at least in sections on the other side. 
     In order to adjust the curvature of the backrest upholstery the adjusting device associated with the curved element has at least one adjusting element, e.g. in the form of an eccentric which can be brought into active connection with the curved element and hereby acts on the support element of the backrest upholstery through the curved element. 
     Both the curved element and the support element can each be fixed at selected points, more particularly in the region of their upper and lower edges on the backrest frame. The associated adjusting device can depending on the setting generate a defined curvature of the curved element or support element between the fixing points. Decisive for an ergonomic support of the back of an occupant therefore is in particular the curving properties of the support element. The curved element thereby serves to couple the support element to the associated adjusting device. This can happen both through a curvature and through a displacement of the curved element when actuating the adjusting device whereby the displacement takes place across the plane of the backrest frame. 
     The curvature of the support element is thereby however not only determined by the setting of the adjusting device but in particular also by the contour of the back region and by the weight of the occupant seated on the seat. 
     The curved element has in the areas in which it can be brought into contact with an adjusting element of the adjusting device, a greater rigidity than in the region which bears against the backrest. On the one hand it is hereby ensured that the curved element can take up the adjusting forces of the associated adjusting device and direct them to the support element and on the other hand a sufficiently flexible contact bearing of the curved element against the support element is achieved. 
     According to another embodiment the curved element has two elongated side regions of increased rigidity which are connected together through a central region of the curved element. The central region can be formed for example as a transverse bar or stay and is connected to the support element. To separate the regions of increased stiffness from the at least one region of lesser stiffness weakened areas in the form of slits can be provided. Reinforcement ribs or reinforcement swages are suitable for example to provide regions of increased rigidity in the curved element. 
     The support element is preferably formed with a larger surface area in its extension plane than the curved element. 
     Any elements can serve as adjusting elements which act on the curved element provided they allow the desired adjustment of the curved element, e.g. eccentric discs, or draw means in the form of cables or wires. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will now be explained in further detail with reference to the embodiment illustrated in the drawings. 
       They show: 
         FIGS. 1   a  to  1   d  four different views of a backrest frame with a curved element fixed thereon which can be adjusted by means of a drive and with a large surface support element mounted in front of the curved element; 
         FIGS. 2   a  to  2   d  four different views of the support element of  FIGS. 1   a  to  1   d;    
         FIGS. 3   a  to  3   d  four different views of the curved element of  FIGS. 1   a  to  1   d;    
         FIGS. 4   a  to  4   c  three different views of the curved element and support element of  FIGS. 1   a  to  2   d  wherein these are connected together; 
         FIGS. 5   a  to  5   c  a diagrammatic view of the arrangement of  FIGS. 1   a  to  1   d  in three different settings of the adjusting device for the curved element; 
         FIG. 6  shows a modification of the embodiment of  FIGS. 1   a  to  2   d  in respect of the adjusting device. 
     
    
    
     DETAILED DESCRIPTION 
     In the overall view according to  FIGS. 1   a  to  1   d  and the individual illustrations according to  FIGS. 2   a  to  2   d ,  3   a  to  3   d  and  4   a  to  4   c , the back rest is shown for a vehicle seat having a backrest frame  1  on which a curved element  3  is mounted for producing an adjustable lordosis support, with the curvature adjustable by means of an adjusting device  2 . Of the backrest frame only a wire grid is shown which is hung from the backrest frame and on which the adjusting device  2  is fixed. 
     The curved element  3  consists of two side sections  31 ,  32  extended in the backrest longitudinal direction L and a cross bar  30  connecting these sections  31 ,  32  together and extending across the backrest longitudinal direction L. The two side sections  31 ,  32  of the curved element  3  each have a reinforcement swage  34  and are thereby stiffer than the flexible cross bar  30 . 
     To uncouple the two side sections  31 ,  32  of the curved element  3  from the central cross bar  30 , two longitudinal slits  36  are provided which extend on the side of the relevant side section  31 ,  32  of the curved element  3  facing the cross bar  30 . These slits  36  are each formed circular at their ends  37 . 
     An additional reinforcement of the side sections  31 ,  32  of the curved element  3  is thereby reached in that the side sections  31 ,  32  are angled substantially L-shaped at their outer edges  31   a ,  32   a . This deformation of the edge areas  31   a ,  32   a  increases the stability of the reinforcement regions  31 ,  32  in a similar manner to the reinforcement swages  34 . 
     For adjusting the position and/or curvature of the curved element  3  there is an electric adjusting device  2  with two eccentric discs  21 ,  22  driven by a common drive  20  and connected together through a shaft  23 . By turning the eccentric discs  21 ,  22  it is possible to adjust the distance of the curved element  3  from the backrest frame across the extension plane of the curved element  3 , see  FIGS. 5   a  to  5   c . Adjusting the distance is thereby carried out by turning the eccentric discs  21 ,  22  by means of the electric drive  20  via the shaft  23  driven by the drive.  20  and on which the two eccentric discs  21 ,  22  are mounted rotationally secured. 
     Whether the change in the distance between the backrest frame  1  and the curved element  3  in the initial instance leads to a curvature of the curved element  3  or substantially to a displacement of the curved element  3  transversely to the longitudinal direction L of the backrest depends on the arrangement of the curved element  3  in relation to the backrest frame  1 . 
     In the diagrammatic views according to  FIGS. 5   a  to  5   c , the curved element  3  is mounted displaceable relative to the seat frame  1  transversely to the longitudinal direction L of the backrest. An adjustment of the eccentric discs  21 ,  22  leads in this case to a displacement of the curved element  3  transversely to the backrest longitudinal direction L. 
     If the curved element  3  on the other hand is fixed by its upper and lower ends directly on the backrest frame L, see here the following comments on  FIG. 6 , then an adjustment of the eccentric discs  21 ,  22  causes mainly a change in the curvature of the curved element  3 . 
     According to the present invention the curved element  3  is not provided directly for bearing against the upholstery of the backrest, but an additional support element  4  extends in front of the curved element  3  and thus between the curved element  3  and seat upholstery of the seat back so that there is no direct action of the curved element  3  on the backrest cushion. The position of the backrest upholstery P is shown diagrammatically in  FIG. 1   b.    
     The support element  4  which is to be mounted in front of the curved element  3  in the form of a backrest shell comprises an elastically curving base body  40  with a large surface area as base region which is provided with a number of openings  49 . These openings  49  in the form of through apertures form pressure distributing regions which prevent the buildup of pressure at individual points on the support element  4  and which produce the most even pressure path possible acting over the entire surface area of the base region  40 . 
     The base region  40  of the support element  4  is surrounded by an edge R 1 , R 2 , R 3 , R 4  which is formed by opposite pairs of edge sections R 1 , R 2  and R 3 , R 4 . In relation to the installation position of the support element  4  in a vehicle seat when the backrest is set up vertical, these edge sections form two side edge sections R 1  and R 2 , an upper edge section R 3  and a lower edge section R 4 . 
     Support regions  41  to  44  are moulded on the side edges R 1 , R 2  and on the upper and lower edge R 3 , R 4  of the support element  4  in the backrest longitudinal direction L and are each connected through connecting webs V in one piece with the base region  40  of the support element  4 . The connecting webs V associated with the support regions  41  to  44  thereby have transversely to their extension direction (connecting direction from the relevant support region  41 ,  42 ,  43  and  44  to the large surface base region  40 ) a smaller extension than the supporting regions  41  to  44  themselves,i.e., the width b of the webs (corresponding to the extension of the webs perpendicular to the connecting direction defined at the top) is less than the corresponding width B of the individual support regions  41 ,  42 ,  43 ,  44  in this direction. 
     These one piece moulded support regions  41  to  44  act as support contour fingers which aligned in position uniformly support the side and upper and lower back regions and which as a result of the connecting webs of reduced width b are sufficiently elastic to adapt to the contour of the back of the occupant in dependence on the sitting position of same. 
     Particularly from  FIGS. 2   b  to  2   d  and from  FIG. 4   a  it can be seen that the support regions  41 , 42 ,  43 ,  43 ′,  43 ″,  44 ,  44 ′ are each inclined at an obtuse angle to the extension plane of the base region  40  of the support element  4 . The support regions  41 ,  42 ,  43 ,  43 ′,  43 ″,  44 ,  44 ′ are thereby angled from the base region  40  so that they extends towards the backrest upholstery which is to be mounted on the front side of the support element  4 , i.e., on the side of the support element  4  away from the curved element  3 . 
     For particularly good support properties the outer contour of the individual support regions  41 ,  42 ,  43 ,  43 ′,  43 ″,  44 ,  44 ′ is each formed curved, thus in particular free of sharp edges. 
     The support regions  43 ,  43 ′,  43 ″ moulded on the upper edge R 3  of the base region  40  of the support element  4  have a different size, i.e., a different extension in the plane of the support element  4 . In particular two support regions  43  have a greater extension in the direction perpendicular to the upper edge section R 3  of the base region  40  than the further support regions  43 ′,  43 ″. Larger support regions  43  and smaller support regions  43 ′ are thereby arranged alternately side by side and are boxed together so that they form one large surface area elastic support region for the upper back part of a vehicle occupant. 
     From  FIGS. 1   a  to  4   c  it is further clear that the support regions  43 ′,  44 ′ provided in the corner sections of the base region  40 , i.e., at the intersection points of the side edge sections R 1 , R 2  with the upper and lower edge section R 3 , R 4  each have an additional finger  43   f  and  44   f  directed inwards (i.e., to an adjoining support region  43 ,  44 ). As a result of this additional finger  43   f ,  44   f  the inner region  43   a ,  44   a  respectively of the relevant support elements  43 ′,  44 ′ has a larger surface area than the corresponding region  43   b ,  44   b  lying on the outside whereby the relevant inner region  43   a ,  44   a  faces an adjoining support region  43 ,  44  and the outer region  43   b ,  44   b  faces outwards away from the support element  4 . Through this asymmetric division of the surface area it is reached that in the event of strain on the corresponding support region  43 ′,  44 ′ by a vehicle occupant resting against the backrest upholstery, the relevant support region  43 ′,  44 ′ is turned so that the region  43   b ,  44   b  on the outside is moved forwards, thus towards the backrest upholstery and thus the lateral hold is improved. 
     Furthermore elongated reinforcement regions in the form of reinforcement ribs  48  are provided on the support element  4  (backrest shell) and here extend in the region of the upper moulded material sections  43 , namely parallel to the relevant connecting webs V from the relevant support region  43  to the base body  40 . The stiffness of the upper integral moulded support regions  43  is hereby increased compared with the remaining sections  41 ,  42 ,  44 . It has been seen that a reinforcement of the upper support regions  43  which are associated with the upper back or shoulder region of a vehicle occupant leads to particularly advantageous support properties. The support regions  43 ,  43 , are thereby each time formed rotatable spring elastically about the axis formed by the relevant elongated reinforcement region  48 . With the lower support regions  44  which are allocated to the lower spinal column of the vehicle occupant however a comparatively softer formation is advantageous. 
     It can be seen particularly in respect of  FIG. 4   a  that the elongated reinforcement regions  48  taper toward the free end (remote from the base region  40 ) of the corresponding support regions  43 ,  43 ′. Here the stiffness of the relevant support region  43 ,  43 ′ decreases towards its free end and the elasticity of the relevant support region  43 ,  43 ′ increases towards its free end. 
     The reinforcement regions  48  also serve to divide the support regions  43 ′ provided in the upper corners of the base region  40  into an inner region  43   a  and an outer region  43   b  which are separated from each other by the reinforcement region  48 . 
     In its central region  45  the support element  4  has recesses  46  and webs  47  extending transversely to the longitudinal direction of the backrest whereby a free space is provided for the spinal column of the occupant. 
     As a result with the embodiment of the invention illustrated in  FIGS. 1   a  to  4   c  an advantageous ergonomic adaption of the arrangement supporting the back region, particularly the lordosis region, of the occupant is achieved in that the curved element  3  on which the adjusting device  2  acts, on the one hand and the support element  4  formed as the backrest shell on the other, are arranged behind each other in two different planes. The advantageous actions of this arrangement are clear particularly from the second embodiment illustrated diagrammatically in FIG.  6 . 
     According to  FIG. 6  a tensioning or tightening element  27  in the form of a wire which can be tensioned by a drive  2 ′ and is guided by means of a sleeve  26  from the drive  2 ′ to the curved element  3  serves as the adjusting element for setting the curvature of curved element  3 . The curved element  3  is fixed in the region of its upper end  3   a  on the backrest frame and is connected in the region of its lower end  3   b  to the tensioning or tightening element  27 . If the tensioning element  27  is tightened by means of the drive  2 ′ then this intensifies the curvature of the curved element  3  which changes for example into the state illustrated by  3 ′ in FIG.  6 . This leads at the same time to a change in the position and curvature of the support element  4  which is mounted in front of the curved element  3  and then changes for example into the state illustrated by  4 ′ in FIG.  6 . 
     It is decisive that the sharp curvature of the curved element  3  which is a result of the tightening of the tensioning element  27  is not transferred directly to the support element  4 . Depending on how the support element  4  is connected to the backrest frame a change in the curvature of the curved element  3  leads to a different sharp change in the curvature and/or displacement of the support element  4 . 
     With the embodiment illustrated in  FIG. 6  the support element  4  can for example be hung from the backrest frame in the region of its upper and lower ends each time elastically through tensile springs. The support element  4  can therefore as a whole be moved against the action of these spring elements perpendicular to the backrest longitudinal direction L when the curved element  3  is curved. Depending on the strength of the springs through which the support element  4  is hung from the backrest frame, it thereby also results in a more or less strong change in the curvature of the support element  4 . As the increase in the curvature is greater, the greater the spring force is, for the possibility of moving the support element  4  as a whole is hereby restricted. 
     It is decisive that the shape of the support element  4  (backrest shell) is determined not only through the curvature of the curved element  3 , but is also determined through the contour of the back area of a person located on the seat. An optimum ergonomic adaption to the back region of the vehicle occupant is hereby possible with simultaneous support action in the region of the lordosis (as a result of the supporting action of the curved element  3 ). 
     Overall this arrangement enables a uniform support over a large surface area and the possibility of flexible adaptation to the individual back properties of different persons, more particularly with regard to their size. 
     The concrete deformation of the curved element  3  as well as the support element  4  with an adjusting of the adjusting device  2 ′ (with the drive  20 °) is decisively determined by both the type of connection between the curved element  3  and the backrest frame as well as the support element  4  and the backrest frame. 
     The curved element  3  which is preferably made of metal can be hung for example from the backrest frame by spring elements or wire elements. Alternatively or in addition the curved element  3  can be connected to the seat base by fixing brackets. 
     The support element  4  which is preferably made of metal or plastic can be connected to the curved element  3  in the region of its cross bar  30  (preferably linearly), e.g. by adhesive or rivets. Furthermore a connection of the support element  4  with the seat upholstery is possible, e.g. through adhesive, rivets or (partly) foaming into the upholstery foam. Finally the support element can also be connected to the backrest frame (preferably through further elements, such as e.g. springs). 
     As a result the arrangement and design of the curved element  3  and the support element  4  are to be such that the curved element  3  as a result of its spatial position which is adjustable by means of the associated adjusting device  2 ′ (particularly its position perpendicular to the extension plane of the backrest frame) provides a base curvature of the support element  4  whereby its curvature as a whole is determined decisively by the interaction with the back part of a person seated on the corresponding vehicle seat. For this the support element  4  must have a sufficient elasticity (elastic deformability) which is preferably greater than that of the curved element  3 . This can be achieved through a corresponding choice of material and shaping whereby the support element  4  furthermore has a larger surface area than the curved element  3 . 
     A special elasticity, flexibility and adaptability of the support element  4  to the back part of a person located on the corresponding vehicle seat is thereby achieved in particular also through the support regions (support contour fingers) protruding from the edge of the base region of the support element and which have an increased elasticity compared with the base region of the support element. This is also due to the fact that the support regions are each connected to the base region of the support element through connecting regions in the form of webs (connecting regions provided with constrictions). 
     It can be seen in  FIG. 1   a  to  1   d  that an additional support element  5  in the form of a shell for supporting the shoulder region of the occupant is provided on the backrest frame  1  above the backrest shell (support element  4 ). This is vertically adjustable along a toothed rod  62  by means of an adjusting device  6  having an electric drive  60  and a pinion  61 . 
     A corresponding arrangement for adjusting the height can also be provided for the lower support element  4  which serves for the lordosis support. 
     The support element  5  which serves as the shoulder support can be formed in the same way as the support element  4  serving for the lordosis support, thus provided with weakened and reinforced regions as well as with material regions moulded on its edges.