elements 6 a which are disposed next to one another in the transverse direction can also be counted as only one zone conversely the coherent surface 6 b in the example of fig8 d may be considered as being formed of several zones which alternate in the longitudinal direction with first elements 6 a or with zones formed by these elements further possible configurations of layers 6 are described below in fig9 a to 9 e for the layer 6 shown in fig9 a the first elements 6 a correspond to those of fig7 the second elements 6 b are provided with a rectangular cross section for the layer shown in fig9 b the first elements 6 a are made from a solid material however they have a thickened head on a narrower neck and may thus be deformed well sideways in all directions as well as tangentially for the embodiments shown in fig9 c and 9 d the first elements 6 a are formed by dimensionally stable burls 6 aa which are connected over a type of an elastically deformable membrane 6 ab with the second elements 6 b and by this configuration can be deflected vertically as well as to about the same extent horizontally for the version shown in fig9 e two elastic strata are connected with one another at least the outer layer being continuous and relatively flat with the exception of indentations the indentations together with approximately opposite similar protrusions of the.