Abstract:
A shoe outsole comprising a substantially flat body with a top face and a lower face exhibiting a distribution of tread protrusions. The protrusions include at least one peripheral protrusion extending beyond the peripheral edge and defining a top abutment surface displaced generally downward relative to the top face of the body. In a method of assembling the outsole to a shoe upper, for each peripheral protrusion, a cut is formed in the upper, developing in accordance with the profile of the area of superimposition between the peripheral protrusion and the body&#39;s lower face. The method provides for insertion of the at least one peripheral protrusion into the appropriate cut so as to enable passage of the protrusion below the upper as a superimposition reversal between the upper and the body.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of footwear and to the relevant manufacturing processes. In particular, it relates to a new outsole structure of natural or synthetic rubber and to the method of assembling it to the upper during the shoe manufacturing process. The invention relates also to the shoe obtained in this way. 
       BACKGROUND OF THE INVENTION 
       [0002]    Various types of shoes are known wherein the upper, usually made of leather, has a base intended to be combined with a natural or synthetic rubber bottom or outsole, to obtain the shoe sole. In particular, the rubber outsole exhibits a number of outwards protrusions which, inserting into openings formed to this end in the base of the upper, become exposed, thus forming the actual sole tread. In practice, the outsole body is superimposed to the base, being kept on the inside of the shoe. The base, in the area without protrusions, remains exposed and visible between the protrusions, thus attaining an appreciated aesthetic result, more valuable than that of an outward facing surface completely made of rubber. 
         [0003]    Besides the lower face of the outsole, the protrusions may also be formed along the perimeter, so as to improve the sole resistance and anti-slip properties and, in certain cases, also to obtain a pleasant aesthetic effect. However, in this case, an external reinforcing seam connecting the outsole to the upper must necessarily be distributed on the upper leather, which is unavoidably superimposed externally to the rubber, close to the relevant protrusions. This causes a loss in the very aesthetic value of the product, which is made even more serious by the leather sharp cut edge, which remains visible on the outside. The handmade assembly between outsole and upper, moreover, can be difficult due to the need of maintaining an accurate superimposition of the leather during the stitching. 
         [0004]    Due to these disadvantages, sometimes the external protrusions are obtained with separate rubber portions applied subsequently, which of course considerably increases manufacturing times and costs. The superimposition may also be avoided, using an internal support element (a so-called “midsole”); similarly, this is a manufacturing difficulty which moreover decreases the comfort of the shoe. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention is to overcome the disadvantages mentioned above by providing a new outsole structure and a new method of assembling the same to the upper which should allow obtaining shoes with side protrusions along the perimeter of the sole, substantially of the type mentioned above, with a considerably improved aesthetic result, with elementary and low cost manufacturing methods, further improving the comfort of the shoe and the durability requirements thereof. 
         [0006]    Such object is achieved by the rubber outsole for a shoe whose essential features are defined by the first of the annexed claims. A method according to the invention for the assembly between the outsole and an upper is essentially characterised by what specified in the annexed claim  4 . 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The features and advantages of the outsole structure for a shoe, of the method of assembling the outsole to an upper, and of the shoe thus obtained according to the present invention will appear more clearly from the following description of an embodiment thereof, made by way of a non-limiting example, with reference to the annexed drawings, wherein: 
           [0008]      FIG. 1  shows a schematic view of a cross section of a shoe obtained according to the invention; 
           [0009]      FIG. 2  shows a partial axonometric view of the lower side of a rubber outsole according to the invention, shown separately, that is to say before the assembly to the upper; 
           [0010]      FIG. 3  shows again the outsole of  FIG. 2 , in a top axonometric view; 
           [0011]      FIG. 4  shows a partial view of an upper, developed on a plane, intended for the assembly with the outsole portion of  FIGS. 2 and 3 ; and 
           [0012]      FIG. 5  shows a schematic side view of a variant of a shoe obtained according to the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0013]    With reference to  FIGS. 1 to 4 , an outsole for a shoe according to the invention comprises a body  1  with substantially flat development, made of natural or synthetic rubber, shaped in accordance with the outline of the entire shoe sole or of just a portion thereof (for example the tip). In this second case, the shoe sole will be provided with two (or more) outsole semi-components physically separate from one another. 
         [0014]    Body  1  therefore exhibits a top face  2 , smooth in the schematic representation of  FIG. 2  but which could actually be grooved or cut in various ways, intended for the foot&#39;s support with the interposition of an inter-sole and/or insole. Body  1  further exhibits a lower face  3  from which a distribution of protrusions projects, adapted for defining the actual sole tread. Among these protrusion, protrusions  4  can be noticed arranged in the inner zone of the lower face  3 , that is, in a substantially central position, and peripheral protrusions  5 , arranged along the face peripheral edge. In particular, among the peripheral protrusions  5 , which shall be discussed in detail hereinafter, a tip protrusion  5   a  and two side protrusions  5   b  can be seen. 
         [0015]    A leather upper  6 , shown in cross section in the assembled configuration (that is, of the finished or semi-finished shoe as shown in  FIG. 1 ) develops with a base  6   a  defined between side vertical walls  6   b . The upper  6  is intended for being assembled with the outsole, to complete the manufacture of the sole and, at the same time, integrate it in the shoe. To this end, as shown in  FIG. 4 , in the area intended for forming the base  6   a , windows  7  are formed in upper  6 . The windows  7  have a profile that matches the profile of the central tread protrusions  4 , which are intended for engagement with the same openings  7 . 
         [0016]    On the upper  6 , in the area of transition between base  6   a  and side walls  6   b , there are provided cuts  8 ,  9 , formed in correspondence with respective peripheral protrusions  5   b ,  5   a . More precisely, cuts  8 ,  9  extend so as to be in accordance with the profile of the area of superimposition between the respective peripheral protrusions  5   b ,  5   a , and the lower face  3 , an area which, more generally speaking, is in practice defined between the inner edge of the protrusions and the peripheral edge of body  1  (shown in dotted lines in  FIG. 2 ). 
         [0017]    In fact, with reference again to the peripheral protrusions, and with particular reference to  FIGS. 1 and 3 , there can be noted that each of them extends beyond the peripheral edge of body  1 , projecting then also upwards and defining respective top abutment surfaces  10   a ,  10   b . The latter, along the junction with body  1 , are displaced downwardly relative to top face  2 . The extent of such displacement is preferably equal to, or slightly greater than, the thickness of the leather of the upper  6 . Still according to a preferred solution, the abutment surfaces  10   a ,  10   b  develop according to the imaginary continuation of the lower face  3  beyond the peripheral edge of body  1 . 
         [0018]    The outsole and the upper are assembled as follows. After having suitably distributed the suitable adhesive substances on the relevant surfaces, the outsole is superimposed to the upper  6 , inserting a peripheral protrusion  5   a  in the relevant cut  8 . The central protrusions  4  penetrate windows  7  of base  6   a  of the upper. The lower face  3  of body  2 , in the area which is free from protrusions, will abut on base  6   a , thus being coated thereby. The other peripheral protrusions  5   a ,  5   b  are finally introduced in the respective cuts  8 ,  9 . The deformability of both the leather and the rubber of which the upper and the protrusion are respectively formed, assist in allowing such operation. 
         [0019]    In this way, peripheral protrusions  5   a ,  5   b  pass below upper  6  (the term below being referred to the shoe usage position) through the cuts  8 ,  9 , as clearly shown in  FIG. 1 . This figure shows how in the practice, due to the particular configuration and position of the peripheral protrusions relative to body  1 , the leather of upper  6  and body  1  itself carry out a superimposition reversal, highlighted at reference index S, with the leather passing from the outside the body (in the area of base  6   a ) to the inside of the peripheral protrusions  5   a ,  5   b , abutting against the relevant top surfaces  10   a ,  10   b.    
         [0020]    If, as mentioned, the displacement of the top surfaces  10   a ,  10   b  is equal to about the thickness of the leather, the shift from the outsole to the side walls  6   b  of the upper will cause no discontinuity, and therefore, no inconveniences to the wearing comfort of the shoe. If the abutment surfaces  10   a ,  10   b  substantially begin as an imaginary continuation of the lower face  3 , there will be obtained the further advantageous result of minimizing the deformation required to the upper for realising the engagement. Accordingly, the forming of wrinkling, chipping or inaccuracies in general will be avoided. 
         [0021]    With reference now to  FIG. 5 , the invention, according to methods similar to those described above, may be applied also in the case of an upper  16  which, on the top side, exhibits a continuous development from the outset. In practice, the side walls  6   b  are integrally connected above the foot before the assembly to the outsole, unlike the previous case where the connection occurred thanks to a closing operation following said assembly. In this case, it is the base  6   a  which is initially discontinuous—that is, longitudinally divided into two halves—and the procedure to be followed for carrying out the assembly will be therefore slightly different; the two base halves will be the last to be arranged between the protrusions, after the superimposition reversal between the outsole and the upper has already been carried out. 
         [0022]    It will then be appreciated that, according to the invention, when at the end of the gluing step the external fastening stitching between the outsole and the upper must be carried out, the same stitching can be applied right over the peripheral protrusions, which in this case are externally superimposed to the upper. The aesthetic result is therefore considerably improved as compared to the conventional solution with stitching running over the upper. The leather cut edges remain fully covered by the relevant protrusions, and therefore invisible. The handmade assembly between the outsole and the upper is very easy, since it is the same and very reversal engagement between the outsole and the upper, along with the particular configuration of the peripheral protrusions, that keeps the superimposition steady and accurate. No additional operations of separate rubber portions to be applied subsequently, nor the use of an internal “midsole” are required, so the method is quick and inexpensive and the shoe comfort qualities are not worsened. 
         [0023]    The method, even though with a less satisfactory result, can be carried out also with an outsole wherein the peripheral protrusions have no top abutment surfaces displaced downwards, since the cuts formed in the upper, possibly with the aid of simple reference signs on the outsole rubber, is sufficient to carry out the superimposition reversal mentioned above. The reversal will clearly exhibit variable dimensional features according to the materials used. 
         [0024]    Obviously, the protrusions, both the peripheral ones  5   a ,  5   b  and the central ones  4 , can vary in number, shape and arrangement. Accordingly, windows  7  and cuts  8 ,  9  on the upper will be adapted, as it can be appreciated by a simple comparison between  FIG. 1  and  FIGS. 2 to 4 , wherein different distributions of central protrusions  4  are noticeable. Then, as confirmed by the variant proposed in  FIG. 5 , it can be seen that the peripheral protrusions can even extend also towards the outsole center, and that therefore actual independent central protrusions may not be present. In this case, the cuts formed in the upper  16  are much more extended as compared to the previous solution, and they become actually window-shaped. 
         [0025]    Even though in the present description reference was made to leather and rubber as materials used respectively for the upper and the outsole, it is clear that the invention may be applied also with different materials, whenever there raises a problem similar to that described in the introduction. In particular, the rubber outsole could also include hide inserts or portions. 
         [0026]    Other variants and/or changes may be brought to the outsole structure for a shoe, to the method of assembling the outsole to an upper, and to the shoe thus obtained, according to the present invention without thus departing from the scope of protection of the invention itself.