Abstract:
An inlay sole for shoes is made up of sole pieces of varying Shore hardness which engage with each other on abutting edges, the width of which corresponds to the thickness of the sole pieces, with matching sinuous projections and matching recesses. The projections form extensions which engage in backcuts in the recesses, the inlay sole being made of several layers of sole pieces assembled as above. The abutting edges are offset with relation to each other from layer to layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119 to German Patent Application No. 202005018902.2, filed Dec. 2, 2005, and International Application PCT/FP2006/011369 filed Nov. 27, 2006. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an inlay sole for shoes, consisting of sole parts of different Shore hardness, wherein, at abutting edges, the width of which edges corresponds to the thickness of the sole parts, said sole parts are interlocked with each other in sinuously conjoining manner by means of projections and matching recesses, such that the projections form extensions that engage undercuts in the recesses, the inlay sole consisting of a plurality of layers of thus assembled sole parts. 
     2. Description of Background Art 
     Such inlay soles are often used to provide a pleasant contact between the shoe and the wearer&#39;s foot, for which purpose an especially elastic material is employed for the inlay sole. Such elasticity is referred to in known manner as Shore hardness. Inlay soles are additionally used for therapeutic purposes, more particularly in order to provide especially soft cushioning at certain points, for which purpose an especially soft material is then inserted into the inlay sole at the relevant point. 
     In a heel bed confined to the heel according to DE-GBM 298 06 187.2, the material of the heel bed is provided in the region of an existing heel spur with a sunk-in cushion which does not project out of the heel bed, i.e. which forms virtually an even surface with the heel bed. Said cushion has greater elasticity than the material of the heel bed, with the result that a heel spur is cushioned by a suitably soft region of the heel bed without a particularly high pressure being exerted on the heel spur. The cushion, which is sunk into the material of the heel bed, transitions via a serrated edge into the material of the heel bed, thereby providing a transitional zone between the cushion and the material of the heel bed in which, owing to said interlocking, the elasticity is perceived by the wearer as a transition of elasticity. 
     An inlay sole having the initially indicated design features is presented in FIGS. 9 and 10 of EP 1 593 360 A2, it being mentioned in the description that individual soles can be laid one on the other. The abutting sole parts have different mechanical characteristics, this allowing them to be adapted to particular needs of the person wearing shoes with such inlay soles. Where identical soles of identical inner design are laid one on the other, this results, in comparison with just one sole, at the superposed abutting edges of the sole parts in a correspondingly abrupt transition of hardness which is especially perceptible for the wearer. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     The object of the invention is to even out the transition of Shore hardness from sole part to sole part, this providing particular comfort to the user of such an inlay sole. The object of the invention is achieved in that the respective abutting edges are offset with respect to each other from layer to layer. 
     The fact that the sole parts are offset from layer to layer provides a wide scope for varying the abruptness of transition of the sole hardness along the entire inlay sole, wherein the existing distance between the respective abutting edges from layer to layer makes it possible to achieve a more or less gentle transition of the Shore hardness from sole part to sole part. 
     For inlay soles of especially great thickness, it is sufficient for them to be held together by their abutting edges with the respectively overlapping projections, without there being any additional need for special gluing of the abutting edges. However, it is also possible for the connection between the individual sole parts by means of the abutting edges to be particularly further enhanced by providing the abutting edges with an adhesive, said adhesive additionally resulting in a lasting connection between adjacent sole parts. Preferably entering into consideration for this purpose is an adhesive that remains elastic upon setting. Furthermore, the connection between the individual sole parts can be accomplished by an overlay, said overlay extending over the sole parts. Such an overlay is advantageously glued onto the assembled sole parts. The overlay may also be in the form of a sole support with a supporting effect, said sole support lending special support in particular to the metatarsus. 
     Where there are two adjacent layers of assembled sole parts, a sole support can advantageously be accommodated between the two layers, this resulting in an inlay sole with integral sole support, wherein the sole support can, in this case, be adapted to the particular shape of the user&#39;s foot, being more particularly of a special shape in order to support the foot with an especially desired therapeutic effect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An illustrative embodiment of the invention is presented in the drawings, in which: 
         FIG. 1  shows a top plan view of an individual inlay sole consisting of five sole parts; 
         FIG. 2  shows a section along line II-II from  FIG. 1 ; 
         FIG. 3  shows a section through a two-layer inlay sole with abutting edges offset with respect to each other; and 
         FIG. 4  shows a section through an inlay sole with a sole support enclosed by two layers. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  presents a top plan view of the inlay sole with five sole parts  1 ,  2 ,  3 ,  4  and  5 , all of which sole parts are of different Shore hardness. As an example, in the inlay sole presented in  FIG. 1 , sole part  1  is of a material of high Shore hardness; sole part  2  is of a material of medium Shore hardness; and sole parts  3 ,  4  and  5  are of a material of low Shore hardness. Of course, the sole parts can also be differently arranged with respect to each other within the inlay sole, it likewise being possible for there to be a different number of sole parts. More particularly, it is possible for the inlay sole to be composed of just sole parts  1 ,  2  and  4 , i.e. for sole parts  3  and  5  to be omitted, it also being possible, of course, for the abutting edges  6 ,  7 ,  8  and  9  to be differently positioned in order to suit the specific therapeutic purpose. As can be seen in  FIG. 1 , each of the sole parts  1 ,  2 ,  3 ,  4 ,  5  has a different surface area. In addition, each of the sole parts  1 ,  2 ,  3 ,  4 ,  5  has a curved peripheral portion Pp. 
     The abutting edges  6 ,  7 ,  8  and  9  are so formed as to, as it were, wedge into each other, i.e. the projections  10  of each sole part engage between the projections  11  and  12  of the adjacent sole part, as is the case with the two sole parts  1  and  2 . On account of the shapes of the projections along the abutting edges  6 ,  7 ,  8  and  9 , the extensions of the projections (e.g.  10 ) are matched by undercuts on the respective adjacent projections, with the consequence that the thus shaped abutting edges  6 ,  7 ,  8  and  9  result in the interlocking of adjacent sole parts, said interlocking making it virtually impossible for the individual sole parts  1 ,  2 ,  3 ,  4  and  5  to be pulled apart, the inlay sole thereby assuming the form of a single unit. In addition, of course, it is possible for an adhesive to be inserted along the abutting edges  6 ,  7 ,  8  and  9 . 
       FIG. 2  presents a section along line II-II from  FIG. 1 , where said section traverses sole parts  5  and  2 . The sectional representation in  FIG. 2  illustrates that each sole part extends over the entire thickness of sole parts  5  and  2 . Of course, the same is true of the other sole parts.  FIG. 2  further presents the overlay  13 , which covers the entire inlay sole on the upper side of sole parts  2  and  5  facing the wearer&#39;s foot. Such an overlay serves in known manner to improve the foot climate in the shoe and is preferably glued onto the sole parts. 
       FIG. 2  additionally presents a sole support  14 , which sole support  14  provides the inlay sole with a desired supporting curvature of the type employed in known inlay soles. The principal purpose of such a sole support is to provide particular support for the metatarsus. In this case, the sole support  14  is attached by permanent connection to the undersides of sole parts  2  and  5  and, of course, also to the other sole parts. 
     Where soft transitions are desired from sole part to sole part, the individual layers are so assembled as presented in  FIG. 3 . The two layers  17  and  18  comprise sole parts  2  and  5 , which are offset with respect to each other, so that the respective abutting edges  7  are at a distance from each other, this resulting in a transition of softness from sole part  2  to sole part  5  at the respective abutting edge  7  as a consequence of the other sole part. The individual sole parts can be suitably relocated from layer  17  to layer  18 , depending on the desired characteristics of said transition. As can be understood, when the assembled inlay sole is viewed in side elevation view, each of the abutting edges  6 ,  7 ,  8 ,  9 , at a periphery P of the inlay sole is seen to extend substantially orthogonally relative to upper and lower surfaces of the inlay sole, and each of the abutting edges of the upper layer  17  is offset with respect to each of the abutting edges of the lower layer  18 . 
     An inlay sole composed of two layers is also especially well suited to enclose a sole support. Such an arrangement is presented in  FIG. 4 . The two layers  19  and  20  with their sole parts  21 ,  22 ,  23  and  24  enclose the sole support  25 , the support plate  26  of said sole support  25  being shown in section. Said support plate  26  is supported at its ends  27 ,  27  in known manner in the direction of the shoe and thus carries the upper layer  19 . With such an arrangement as presented in  FIG. 4 , it is possible in especially advantageous manner to combine the effect of the two individual layers  19  and  20  with a sole support, namely the sole support  25 , this resulting in an inlay sole with a particularly supportive effect.