Abstract:
The invention relates to a sectional element mat ( 2 ), the support properties of which may be individually tailored, whereby exchangeable sectional elements (E) are arranged tightly together or above each other. The above is characterised in that the individual sectional elements (E) may be easily removed and exchanged with other sectional elements. The individual sectional elements are either connected to each other by means of a separable material bridge or perforation ( 5, 6 ), connected to each other by means of a plug connector ( 27, 31 ), plugged onto or into a common base mat ( 40 ) or lying loose on the same. Individual sectional elements can be removed or separated from the combination where necessary and replaced by softer or stiffer sectional elements. In certain situations the resulting free space is left empty. The sectional element mat ( 2 ) is either part of a combination with other sectional element mats or contiguous or separate layers ( 1, 3 ), or itself forms the mattress core.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a sectional element mat made of sectional elements arranged one beside the other, which preferably form at least one layer of a multi-layer mattress. 
         [0002]    It is the task of a mattress to provide optimum support regarding the forces acting on the reclining body, thereby offering a maximum of rest and relaxation to the user. For this reason mattresses are divided into several supporting zones, which are to provide supporting force to individual parts of the body as physiologically required. In previous models, the individual supporting zones were permanently integrated in the mattress, that is, they were built in during manufacture of the mattress. Such mattresses are known as 5- or 7-zone mattresses. In these mattresses, the supporting force of the individual zones and their positions are determined by the average dimensions of the human body and cannot be individually adjusted. After manufacture, changes of the individual supporting zones are not possible. Since the physiological suitability of a mattress can only be judged after prolonged use, a modern mattress must provide the possibility of defining and changing both the supporting force and the position of the individual supporting zones at any time. 
         [0003]    Development of such individually designable and modifiable zone mattresses has been going on for some time and mattresses using such technology have reached the market. As a rule the individual tailoring of such mattresses is obtained by making exchangeable, individual elements of the mattress. These early developments are, however, beset with deficiencies and problems. One of these problems usually is that the size of the exchangeable elements is too large and their structuring too coarse. For this reason the individual supporting zones cannot be tailored precisely. A further problem sometimes is due to the fact that exchanging individual supporting elements is impractical for the user. 
         [0004]    In this context a single-layer mattress has become known from EP 1 177 750 A1, which consists of a plurality of chain-like coherent elements connected by bonding or by residual links. By breaking the residual links, some elements may be removed and replaced by others. 
         [0005]    From JP 2002 034726 A, it is furthermore known to provide a recess in the base of a mattress into which cushion elements with a cover are fitted. Below the cushion elements a firmness regulating means is located, which consists of alternating rigid and flexible foam elements that may be mutually exchanged. 
         [0006]    It is the object of the present invention to further improve the technology of individually designable and modifiable zone mattresses made of foamed plastics or latex and above all, to address the above mentioned problems, i.e. provide for finer structuring and easier handling. 
         [0007]    The invention achieves its aim by providing sectional elements that are connected to each other or to a base mat in an easily separable way by means of thin material bridges or by interlocking elements, or that the sectional elements are in an easily exchangeable way plugged onto a common base mat or, being interconnected by material bridges, are laid out within boundary elements on a base mat. 
         [0008]    According to the invention, the length of the serially arranged sectional elements may extend essentially over the whole width of the sectional element mat, but it is also possible to subdivide the sectional elements both in transverse and longitudinal directions of the sectional element mat. 
     
    
     
         [0009]    The invention will now be explained in greater detail with reference to partially schematic drawings. There is shown in: 
           [0010]      FIG. 1  is a side view of a sectional element mat according to the invention, which is placed between the top and bottom layers of a multi-layer mattress; 
           [0011]      FIGS. 2 to 13  are diverse variants of the sectional element mat, combined with additional, continuous mattress layers or base mats, in a view as in  FIG. 1 ; 
           [0012]      FIG. 14  is a longitudinal section of a mattress with a sectional element mat according to the invention; 
           [0013]      FIG. 15  is the mattress of  FIG. 14  in a section along line XV-XV of  FIG. 14 ; 
           [0014]      FIG. 16  is a variant of the mattress of  FIG. 15 ; 
           [0015]      FIGS. 17 to 19  are diverse variants of sectional element mats according to the invention in a view from above; 
           [0016]      FIGS. 20 to 22  are sectional views of variants of the sectional element mat according to the invention; 
           [0017]      FIGS. 23 to 25  are sectional views of a further variant of the invention; 
           [0018]      FIG. 24  is a view from above of the variant of  FIG. 23 ; and 
           [0019]      FIG. 26  is a detail of the variant of  FIG. 23 . 
       
    
    
       [0020]    For clarity of presentation of the individual components, the cover of the mattress is omitted. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Figurel shows a side view of a mattress comprising a continuous upper layer  1 , a sectional element mat  2  made of a plurality of partially different sectional elements E, and a lower continuous layer  3 . In the area where the shoulders rest, the upper and lower layers have transversely extending chambers  4  of circular cross-section, whose content may be removed if softer bedding is desired. The sectional elements E of the middle-layer sectional element mat  2 , are mutually joined by thin material bridges or by perforated links  5 , 6 , where the perforation can be seen either in the middle (see  5 ) or in the lower part (see  6 ) of the sectional elements. At certain sites  7  the sectional elements have been taken out and replaced by sectional elements with different material characteristics. 
         [0022]      FIG. 2  is a side view of a mattress whose sectional element mat  2  locks onto elevations  8 , which are provided on the surface of the lower continuous layer  3 . There are also shown small round chambers  9  which are formed into the sectional elements E and whose content can be removed. 
         [0023]      FIG. 3  is a side view of a mattress comprising an upper layer  1 , which could also be partitioned, and a sectional element mat  2 , whose sectional elements E are connected to an underlying continuous base mat  11  by a material bridge or perforation  10 . There can also be seen sites where sectional elements have been disconnected and removed. In one example, the removed sectional element has been replaced by a sectional element  13  having different material characteristics. In another example, the removed element has not been replaced, leaving an empty space  12 . T here can also be seen a sectional element with bevelled edges  14 . 
         [0024]      FIG. 4  is a side view of a mattress consisting of an upper and a lower continuous layer, between which a sectional element mat  2  is imbedded, whose sectional elements are plugged together in the form of T-shaped pieces, the gripping nose of one element locking with the gripping nose of the adjacent element. A “lying” element  16  alternates with a “standing” element  17 . There can also be seen three different embodiments of the plug-in connection. In one example the gripping noses are rectangular (see  18 ), in the second example they are tapered (see  19 ), and the third example shows rounded gripping noses  20 . 
         [0025]      FIG. 5  is a side view of a mattress with a different arrangement of the individual layers. Two continuous layers  21 ,  22  form the upper region of the mattress, two sectional element mats  2 ,  2 ′ form the lower part of the mattress; the upper element mat is of softer material (light) whilst the lower element mat is of firmer material (dark). In this example the individual elements of the sectional element mats are mutually connected by perforation  5 . Removed sectional elements have been replaced by sectional elements  26  having different material characteristics. 
         [0026]      FIG. 6  is a side view of a mattress, where the sectional elements of the sectional element mat  2  are plugged together in the form of S-shaped pieces. Here also the gripping nose  27  of one element locks onto the gripping nose  27  of the adjacent element, the difference being that each element has an upper and a lower gripping nose  27 , thus being S-shaped. The gripping noses are shown in rectangular  28 , tapered  29 , or round  30  configuration. 
         [0027]      FIG. 7  is a side view of a mattress, where the sectional elements of the sectional element mat  2  are plugged together. The plug-in connection is realized as a tongue-and-groove connection  31 . The figure shows three variants of the plug-in connection; a straight variant  32 , a variant with tapered tongue  33  and a variant with rounded tongue  34  locking into a groove that is also rounded. Instead of the tongue-and-groove connection, a pin-and-hole connection of the sectional elements E would also be possible. 
         [0028]      FIG. 8  is a side view of a mattress comprising a continuous layer  1  and a two-layer sectional element mat  36 , in which the sectional elements E are placed side by side as well as one above the other. The upper sectional elements E of the sectional element mat  2  are connected to the lower sectional elements E of the sectional element mat  2 ′ by means of a thin material bridge or perforation  37 , and the lower sectional elements E are additionally connected to the horizontally adjacent elements via perforation  5 . 
         [0029]      FIG. 9  is a side view of a mattress comprising an upper layer  1  and a lower layer (base mat  40 ), into which sectional elements E are inserted. The recesses  41  in the base mat are round and receive the rounded lower parts of the sectional elements. These protrude from the base mat  40 , creating small ventilation channels  42 . 
         [0030]      FIG. 10  is a side view of a mattress also comprising an upper layer and a base mat  40 . In this case the sectional elements E are plugged into base mat  40 , the individual elements being provided with tongues  44  which are engaged in grooves of the base mat. Tongue-and-groove are rectangular in the first example 43, tapered in the second  44 , also tapered but wider in the third  48 , and with a round head  47  in the fourth. The sectional elements themselves are rectangular in the first and second examples, rounded at the upper edges  45  in the third, and in the fourth example rounded both at the upper and lower edges  46 . Instead of the tongue-and-groove connection, a pin-and-hole connection is also possible. The sectional elements E can, for instance, be provided with a pin that can be inserted into a corresponding hole in the base mat. 
         [0031]      FIG. 11  is a side view of a mattress also comprising an upper layer  1  and a lower base mat  40 . In this case the sectional elements E are sunk into the base mat  40 . The sectional elements have a circular cross-section as shown in the first two examples (see  49 ) or an oval cross-section as shown in the third example 51. The sectional elements E protrude from the base mat  40 . The mat which is laid on top has elevations  50  at its lower side, lock into the spaces formed between the individual sectional elements. One example also shows the overlay mat with a plane surface  53 , where ventilation channels  52  are created between upper and lower layer. 
         [0032]      FIG. 12  is a side view of a mattress, again with an upper layer  1  and a lower base mat  40 , into which sectional elements E are sunk. The cross-section of the sectional elements is square, as shown in the first example 54, or rectangular as shown in the second example 55. The third example 56 shows a cross-section whose sides are constricted or inwardly bent. The recess in the lower base mat  40  has the same shape of cross-section, thus gripping the inserted sectional elements at the region  58 . Between the upper  1  and the lower mat  40  hollow spaces  57  are formed, which serve as ventilation channels. 
         [0033]      FIG. 13 : This figure also shows a mattress in side view, into whose lower base mat sectional elements E have been inserted. The cross-section of the sectional elements in the first two examples is tapered upwards  59  as well as downwards  60 . The shapes of the recesses are identical. In this way the elements are held fast in the recesses. Since the elements protrude from the base mat also in this case, ventilation channels  61  are formed between the upper and lower layer. A further example shows an element with rectangular cross-section  62 , which flares outwards only at its lower end  63 . 
         [0034]      FIG. 14 : This figure shows a mattress in longitudinal section, whose base mat  40  has boundary elements  64  at both ends, for instance elevated steps, which enclose the sectional elements E lying behind them. The height of the boundary elements  64  is identical with the height of the sectional elements, in order to keep the upper layer uniformly plane. The figure shows sectional elements which are loosely placed side by side (position  65 ), as well as sectional elements at position  66  which are connected by means of a thin material bridge  5 . 
         [0035]      FIG. 15 : This figure shows a mattress in cross-section, whose lower base mat  40  has boundary elements  67  on both sides, for instance elevated steps, which enclose the sectional elements E. The height of the elevations is identical with the height of the sectional elements, to keep the upper layer uniformly plane. 
         [0036]      FIG. 16 : This figure shows a mattress in cross-section with an upper layer  1  and a lower layer  3  and an interposed sectional element mat  2 . The subdividing of sectional elements E in the transversal direction of the mattress can be seen. In this example they are connected via perforations  68 ,  69 . There can also be seen a thinner perforation  68  connecting the peripheral element to the adjacent inner element, while all other inner elements are connected via thicker perforations  69 . 
         [0037]      FIG. 17 : This figure shows in a view from above a sectional element mat  2  whose sectional elements E essentially extend over the whole width of the sectional element mat  2 . They are enclosed by elevations  64 ,  67 , which are attached at the edges of the underlying base mat or are formed as integral parts of the base mat. The first elements in positions  70  are connected via perforation  5 , the other elements in positions  72 ,  73  are loosely packed side by side. 
         [0038]      FIG. 18 : This figure shows in a view from above a sectional element mat  2 , which is subdivided in transversal as well as in longitudinal direction and whose sectional elements E are plugged into the underlying base mat. Sectional elements can be discerned which have been replaced by elements  76  with different material characteristics. There can also be seen regions where sectional elements have been removed and an empty space  77  remains. At these sites the plug-in grooves  78  provided in the underlying base mat can be seen. Instead of the plug-in grooves a pin-and-hole connection for the sectional elements E is possible. 
         [0039]      FIG. 19 : This figure shows in a view from above a sectional element mat  2  whose sectional elements E are connected via perforation. The subdivided structure of the sectional elements in longitudinal as well as in transversal direction can be seen. Individual elements have again been replaced by elements  81 ,  84  with different material characteristics. Other elements have been removed and leave an empty space  80 . The grey shading at the periphery  82  indicates the edge zone. To keep the edge of the mattress firm and stable no sectional elements are removed in this area. In this case sectional elements are exchanged only in the area interior to the edge zone, that is in the white area, by cutting the perforation. 
         [0040]      FIG. 20 : This figure shows a mattress which consists of a sectional element mat  2  only, where the individual sectional elements E are joined by a thin material bridge or a perforation  5 . 
         [0041]      FIG. 21 : This figure shows a mattress which is formed by a sectional element mat  2 . In this case the base mat  40  is placed on top and the individual sectional elements E are in one example plugged into its underside (see  88 ) and in the other examples joined to the underside via perforation  87 . 
         [0042]      FIG. 22 : This figure shows a variant of the embodiment according to  21  with sectional element mats  2 ,  2 ′ placed on both sides of the base mat  40 . 
         [0043]      FIG. 23 : This figure shows a variant of the embodiment according to  FIG. 9  or  10 , in which sectional elements  89 ,  90 ,  92  and  93  are plugged into a base mat  40 . One can see stamp-shaped sectional elements  89 ,  93  and elements with straight side faces (see  90 ,  92 ). It can also be seen that the height of individual sectional elements  90 ,  92  may be different. Between some of the sectional elements perforations are provided in the form of cuts  91  in the material webs. The sectional elements  93  show a broader stamp. On the underside of the base mat  40  transverse grooves  94  and/or longitudinal grooves may be formed. 
         [0044]      FIG. 24 : This figure shows a view from above of the variant according to  23 . One sees the stamps, which protrude from the base mat and form transversal grooves  95  of different width between the individual sectional elements, which grooves serve as ventilation channels. One also sees ventilation grooves  97  in longitudinal direction of the mat, which are worked into the surface of the sectional elements and form small cubes or stamps. There are also sectional elements  93  whose stamps are broader; in this case no ventilation channels are opened in transversal direction. 
         [0045]      FIG. 25 : This figure shows a side view as in  23  with some of the sectional elements having been removed at sites  98 ,  100 ,  103  and some sectional elements  99  having been replaced by others. One sees stamp-shaped sectional elements whose stamps are broader (see  101 ) and others whose stamps are less broad (see  102 ). 
         [0046]      FIG. 26 : This figure shows a detail of  25 . One sees at the bottom of the sectional element (E) a material bridge  105 , which holds together the stamp and the base mat  40 . 
         [0047]    An essential characteristic of the present invention is the close arrangement of the individual supporting or sectional elements E. They are arranged side by side with little or no intermediary spacing and form in this way the sectional element mat  2 . The serial arrangement of the sectional elements E is either carried out only in longitudinal direction (e.g.  17 ) or in both directions (e.g.  18  and  19 ), that is in longitudinal as well as transversal direction of the mattress. The individual sectional elements are loosely placed one beside the other or are mutually connected. Connection is realised either in the form of a plug-in connection of the sectional elements E ( FIGS. 4 ,  6 ,  7 ), or by sticking the elements onto or into a base mat ( 9  to  13 ), or by joining the elements via a material bridge or perforation (e.g.  FIGS. 1 ,  2 ,  5 ). 
         [0048]    Description of the plug-in connection: the material of the mattress is cut in such a way that one end of a sectional element may be hooked onto or plugged into the end of the adjacent element. The contact surfaces of the plug-in connection are either straight ( 27 ,  31 ) or tapered ( 28 ,  33 ) or furnished with a round thickened head  30 ,  34 . In the last two variants the thickened part produces a lock effect, such that the connection can only be opened by a fairly strong tug. The mutually hooked or plugged sectional elements form a sectional element chain—if they are subdivided only in the longitudinal direction of the mattress—or a sectional element net, if they are subdivided in longitudinal as well as transversal direction of the mattress. This kind of arrangement permits the removal of each individual sectional element by opening the hooking or plugging connection and the replacement of the element by another one of different firmness. In this way the supporting force of the mattress may be adjusted at any point desirable. It is also possible to exchange or completely remove individual elements only in the interior region of the mattress. In this way the supporting structure of the mattress may be individually tailored also in the transversal direction of the mattress. For persons sleeping on their backs the supporting force of the mattress may thus be increased in the central area of the shoulder region, while softer zones are provided in the lateral regions to permit settling of the shoulders if a side position is assumed. The region of the mattress edges will however remain firm and stable as long as the extreme peripheral elements of the sectional element net are left in place (see  19 , edge zone  82 ). According to one variant, it may also be provided that the sectional elements are not connected to each other but plugged onto a base mat  40  (see  FIGS. 9 to 13 ). 
         [0049]    Description of perforation: in this case the individual sectional elements E are mutually connected via perforation (see for instance  1 ). Perforation is obtained by cutting one sectional element after the other from the mattress material. The cut is, however, not carried out completely, but leaves intact a small material bridge  5 ,  6  to the next sectional element—a kind of perforation which may be torn easily if the sectional elements are to be separated from each other. In case the mattress is subdivided into sections only in longitudinal direction this will result in individual ribs which may be separated by tearing off the perforation and may be replaced by other—softer or firmer—sectional elements. In the case of sectionalisation in both directions, there results a multitude of small, wafer-shaped sectional elements E. These may be removed in any desired formation and may also be replaced by other—softer or firmer—elements. 
         [0050]    There exists also the option not to replace removed individual elements and to leave the vacated area empty (see e.g. position  12  of  3 ). In this way, better settling of the shoulder region may be achieved. 
         [0051]    The sectional element mat  2  may be used in the form of a single-layer mattress. Preferably, however, sectionalisation technology is used with two or more layers  1 ,  3 , one laid onto the other. Furthermore, there is the possibility to combine several sectional element mats (see  5  or  8 ). 
         [0052]    A combination of a sectional element mat  2  with another sectional element mat  2 ′ or with other mattress layers results in a multi-layer mattress. Preferably the mattress consists of three or four single layers, with the uppermost one or two layers being, for instance, continuous mats  21 ,  22  ( 5 ) made of softer material. This provides soft bedding for the sleeper. In many cases the bottom layer  3  is also continuous, i.e. not sectionalised. It is made of firmer material and has supporting function. Between these two layers at least one sectional element mat  2  is provided, whose task it is to provide individual regulation of support by replacing individual sectional elements. In a three-layer mattress it also makes sense to use a sectional element mat  2  for both middle and bottom layers. The overall thickness of the mattress can thereby be reduced while extensive support regulation is still achievable. The upper sectional element mat can thus serve to ensure soft bedding of certain parts of the body, e.g. the pelvic region, while the lower sectional element mat gives increased support to the body, such that the pelvis as a whole will not sink in too deeply. 
         [0053]    The elements of a sectional element mat may also be loosely arrayed. In this case an underlying base mat is preferably used. 
         [0054]    A variant ( 2 ) provides that this lower base mat has elevations  8  on its top face, which protrude into the interstices between the individual overlaid elements or between the elements of the overlaid sectional element mat, in order to hold these elements in place. Such elevations can also be provided on the underside of an overlaid mat in order to fill in interstices between sectional elements with rounded surface. 
         [0055]    A further variant provides that the base mat  40  has thickened strips extending upwards in the form of elevated steps  64 ,  67  ( FIGS. 14 ,  15 ) at the sides or additionally also at the head and foot end. The upward extension of these steps is such that the elements of the laid-on sectional element mat(s) or the individually laid-on elements are framed in their full height. This results in a firm boundary of the sectional element mat or of the single elements on the sides as well as at the head and the foot end. The sectional element mat or the loose single elements are placed in the remaining free space within the boundary. In the case of sectional element mats with wafer-shaped elements ( 19 ), this boundary results when individual elements in the interior of the mat are removed from the perforation and replaced by others, while the elements in the edge region are left connected via the perforation and thus form a boundary for the interior, loose elements. Here the perforation between the edge elements and adjacent interior elements is preferably thinner than the perforation joining the interior elements. This has the effect that whole ribs contained between the lateral boundaries may be easily removed. 
         [0056]    The individual sectional elements of the sectional element mat cannot only be horizontally connected to each other by means of a plug-in connection or via perforation, but can also be vertically fixed in position by an underlying base mat  40  or by yet another sectional element mat. In this respect the invention proposes two kinds of connection: 
         [0057]    1. Plug-in connection: The individual elements are plugged into recesses of the underlying base mat. They may be taken out and replaced by other elements. Preferably the cross-sections of such sectional elements and of the corresponding recesses are inwardly bent or constricted such that the elements are gripped in the recesses. The sectional elements plugged into the recesses protrude beyond the top plane of the base mat, forming small hollow spaces between the sectional elements, which serve as ventilation channels. 
         [0058]    2. Perforation connection: The elements are connected by means of a material bridge (perforation). That is, by a narrow material joint which can easily be torn apart, to an underlying base mat or another sectional element mat. Connecting the elements to another sectional element mat gives the opportunity to remove and replace two stacked elements or to leave the vacated space empty. 
         [0059]    At certain positions of the layers, either continuous layers or sectional element mats, transversal chambers  4 ,  9  are provided. If material is removed from these chambers, the sleeper will be settled more comfortably in the mattress in these places. In combination with the regulating options of the sectional element technology, this will permit sinking-in of the shoulders with ample space even for very broad shoulders. 
         [0060]    A particularly preferred application of the sectional mat is based on the plug-in connection described above, i.e. a base mat  40  into which are plugged transversally extending sectional elements E ( FIGS. 23 to 26 ). The cross-section of the sectional elements E varies depending on the function that the sectional element mat has to fulfil at the respective position. The preferred basic element has the shape of an upside-down stamp  89 . This shape of cross-section is based on the principle of gripping as described above, which means that the cross-section of the sectional elements E has indented sides that lock with corresponding outward bulges of the surrounding material of the base mat  40 , resulting in a firm grip  96  by the base mat  40 , which holds the sectional elements in place. The cylindrical shape of the lower part of the sectional elements gives rise to a well-defined indentation, which keeps the sectional element securely in place. 
         [0061]    The stamp  89  forming the upper part of the element extends beyond the base mat  40 . As a consequence there are formed not only transversal channels  95  between the individual sectional elements, which serve as ventilation channels for the mattress, but there is also created a squeeze zone, which offers space for material expansion when pressure is applied from above and Which gently buffers the lying-down pressure. It is preferred deepened grooves  97  are also cut in longitudinal direction of the mat, creating a kind of cubical structure which will buffer in all directions and thus increase the effect. A further advantage of the stamp-like shape lies in the choice of different stamp widths permitted by the invention. In places where a stronger supporting force of the mattress is desired sectional elements with stamps  93 ,  101  of greater width are used, while stamps of smaller width  89 ,  102  are used where less supporting force is desired. Preferably sectional elements with different stamp widths are already provided when the mat is produced, which will permit pressure zone adjustment of the mattress by simply exchanging sectional elements with wide stamps  101  against elements with narrow stamps  102 . If greater pressure differences are to be realized, sectional elements are replaced by others which are made from firmer or softer material (see  99  in  25 ). The invention also provides that individual sectional elements  98 ,  100 ,  103  are removed from the base mat  40  without replacement. In this way extremely soft zones are realised, which are suitable for defined users, if optimum settling of the shoulder or the creation of sink-in zones  103  for the knee is required. In order to be able to further increase the sink-in effect in shoulder zones, the invention provides two further application techniques. In the shoulder region there are optionally imbedded in the base mat  40 , sectional elements  90 ,  92  with straight sides or only slight indentations  58  (see  FIG. 12 ). In this way less material will remain in the base mat when sectional elements are removed, and more space will become available for the sinking-in of shoulders. A similar effect is achieved by reducing the height of the webs between the sectional elements. This is achieved by providing that via a perforation  91 , the upper part of the web can be torn from the lower part. The perforation is realised by a cut from each side, which leaves only a small material bridge, i.e. the perforation. 
         [0062]    Different sizes may be chosen for the individual sectional elements E of a sectional element mat  2 , which will result in different insertion depths in the base mat  40 , as shown in position  90 ,  92  of  23 . An increased sinking-in effect can thus be obtained, for instance, in the shoulder region. The invention also provides the possibility of connecting each single sectional element via a perforation, i.e. by a small material bridge  105 , to the base mat  40  (see A  FIG. 26 ) and to break this material bridge only when the sectional element is to be removed. This has the advantage that sectional elements will not pop out of their place when the material is handled during the manufacturing process.