Patent Publication Number: US-2017367438-A1

Title: Sole For Footwear

Description:
FIELD OF THE INVENTION 
     The present invention relates to a sole for footwear. 
     BACKGROUND OF THE INVENTION 
     A sole including those features is, for example, known from U.S. Pat. No. 2,162,912. That document sets out a sole having anti-slip features, particularly suitable for wet surfaces. That sole is constructed from rubber and has a plurality of openings which are formed in the tread surface transversely to a longitudinal toe-to-heel direction. Those openings have a small width and limited depth except for in the case of soles for heavy boots (for example, hunting boots), in which case there is provision for them to be able to reach at a maximum the middle of the thickness of the sole itself. 
     That sole is substantially suitable for constructing technical footwear in which the above-mentioned features are of main interest. 
     Another sole having anti-slip characteristics is described in US 2007/0033837. That document describes a sole for footwear comprising a plurality of channels which extend through a contact surface therewith. The channels have opposite ends which open at opposite lateral walls of the sole. The channels further open at the contact surface of the sole through openings which have a width less than the maximum width of the opening. 
     It is also known to construct soles through which a plurality of holes extend and in which the opposite surface to the tread surface is at least partially covered with a semi-permeable textile barrier. An example of that solution is described in US 2002/0189131. 
     Those soles are used to improve the transpiration of the foot because the holes allow ventilation of the foot inside the footwear while the barrier allows vapour to pass but prevents the passage of water. Those soles are, however, subjected to a potential blockage, including only temporary or partial blockage, of the holes which reduces the desired effect of transpiration as far as eliminating it. 
     SUMMARY OF THE INVENTION 
     The problem addressed by this invention is to provide a sole for footwear which allows an improvement in the flexibility of the sole, at the same time promoting the transpirability thereof and prevention of the blockage of the ventilation holes. Another object of the invention is to promote the lightness of the footwear without compromising the stability and the aesthetic appearance. 
     This problem is solved and this object is achieved by the invention by means of a sole in accordance with the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the invention will be better appreciated from the following detailed description of a preferred but non-exclusive embodiment thereof which is illustrated by way of non-limiting example with reference to the appended drawings, in which: 
         FIG. 1  is a top, rear and right side perspective view of a sole for footwear according to the invention; 
         FIGS. 2A and 2B  are partial top views of the sole according to the invention in two operating configurations; 
         FIG. 3A  is a top plan view of a sole for footwear according to the invention; 
         FIGS. 3B and 3C  are cross-sections of the sole of  FIG. 3A  along lines A-A and B-B, respectively; 
         FIG. 4  is a detail view of the perspective view of  FIG. 1 ; 
         FIGS. 5A and 5B  are top plan schematic views of two different embodiments of a sole according to the invention; and 
         FIGS. 6A-6C  are top, rear and right side perspective views of different embodiments of a sole according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the Figures, there is generally designated  1  a sole for footwear comprising a resilient structural member in which there are identified a respective forefoot zone  2 , midfoot zone  3  and backfoot zone  4  which are contiguous in a toe-to-heel direction designated X. 
     The forefoot zone  2 , midfoot zone  3  and backfoot zone  4  in the examples illustrated are substantially coplanar and generally define a tread surface  5  which has a perimeter defined by side  7 . The tread surface is the one which normally supports the sole during walking. 
     The toe-to-heel direction X defines at the side  7  of the sole  1  an internal side  7 A and an external side  7 B opposite it. Though there are set out by way of example solutions in which the three zones of the sole are coplanar, the case is further considered that they may be located in different planes, generally with the backfoot zone  4  in relief with respect to the remaining zones. 
     According to a preferred embodiment, the tread surface  5  has incisions  8  extending transversely to the toe-to-heel direction X. Preferably, the incisions  8  are open until they extend through the corresponding side  7  of the sole  1 , extending between the opposing sides  7 A and  7 B. In other words, the incisions  8  pass completely through the sole  1  from the internal side  7 A of the side  7  to the external side  7 B. 
     With reference now to  FIG. 4 , according to a preferred embodiment in the midfoot zone  3  the incisions  8  comprise a first portion  9  of laminar formation extending to a first depth  10  into the sole from the tread surface  5 , and a second portion  11  extending to another depth  12  into the sole from a lower outlet  16  of the first portion  9 . 
     Within the context of the present invention, the term “laminar formation” is intended to be understood to indicate that incisions  8  are almost completely closed in the first portion  9  at least in the region of the sides  7 A,  7 B with the sole flat, as illustrated in  FIG. 2A , and also open in a book-like configuration in the region of the sides  7 A,  7 B of the side  7  with the sole flexed, as indicated in  FIG. 2B . By way of example, the first portion  9  of an incision  8  having a laminar formation can be obtained with a laser cutter, thereby ensuring the precision required for the portion  9  so that it can effectively have the features described above. 
     Furthermore, according to a preferred embodiment, the first portion  9  has a depth  10  having an extent which is at least equal to half of the depth  12  of the second portion  11 . Even more preferably, the first portion and second portion have substantially the same depth. 
     With reference now to  FIGS. 3A-C , according to a preferred embodiment, the incisions  8  involve only the midfoot zone  3 . 
     Preferably, the sole  1  comprises a plurality of auxiliary incisions  8 ′ which are formed in the forefoot zone  2  and backfoot zone  4 . 
     According to a preferred embodiment, the auxiliary incisions  8 ′ in the forefoot zone  2  and backfoot zone  4  are thicker and more spaced-apart than the incisions  8  in the midfoot zone  3 . That feature contributes to a distinction between the characteristics of the sole in the different zones, also taking into account the structural differences between the incisions  8  and the auxiliary incisions  8 ′, as will be better set out below. 
     In an embodiment, the auxiliary incisions  8 ′ can, unlike the incisions  8  in the midfoot zone  3 , be limited only to the laminar formation of the first portion  9 ′ over the entire depth thereof, as can be seen in  FIG. 3C . 
     Preferably, the depth of the first portion  9 ′ of the additional incisions  8 ′ is generally equal to the depth  10  of the first portion  9  of the incisions  8  of the midfoot zone  3 . However, there is provision for the depth of the auxiliary incisions  8 ′ in those zones to be able to be different from the depth of the laminar portion  9  of the corresponding incisions  8  of the midfoot zone  3 . 
     Preferably, the incisions  8  and  8 ′ have a longitudinal extent which extends transversely relative to the toe-to-heel direction X of the sole  1 , with an angle of transverse incidence which can be constant (generally 90°— FIGS. 1 and 3 ) or variable in the toe-to-heel direction X ( FIGS. 5A and 5B ). 
     With reference again to  FIG. 4 , according to a preferred embodiment, in the midfoot zone  3  the incisions  8  have a width  13 , measured transversely to the longitudinal extent of the incision  8 , which is less in the first portion  9  with respect to the corresponding width  14  of the second portion  11 . 
     Preferably, the first portion  9  has a width  13  which is constant over the entire depth  10  thereof. 
     Preferably, the variation of the width between the first portion  9  and the second portion  11  is brought about in a discontinuous manner at a transition zone between the first portion  9  and the second portion  11 . In this manner, along the first portion  9 , with a laminar extent, the incision  8  is maintained sufficiently closed. This is also promoted by the fact that, as previously illustrated, the depth  10  of the first portion  9  is at least equal to half of the depth  12  of the second portion  11 . 
     In a preferred embodiment, the incisions  8  have a cross-section which is substantially T-shaped. 
     In other words, the incisions  8  along the first portion  9  and the second portion  11  have a constant width over the extent thereof in terms of depth, respectively. 
     Conversely, according to a preferred embodiment, the additional incisions  8 ′ have a constant width. 
     According to a preferred embodiment, the second portion  11  of the incisions  8  has a multiple width  14 , which is not necessarily an integer multiple, of the width  13  of the first portion  9  while the depths  10 ,  12  of the portions  9 ,  11  is preferably but not necessarily equal or similar, that is to say, in the same order of magnitude. 
     As indicated above, the incisions  8  are not necessarily provided over the whole of the tread surface of the sole, the presence thereof being preferably limited to the midfoot zone  3 , or at the limit in the positions immediately adjacent thereto. However, it is considered by the present invention that the incisions  8  may also involve partially or completely the forefoot zone and backfoot zone. 
     With reference now to  FIGS. 3B and 3C , ventilation holes  15  may extend through the sole  1  in order to extend to the bottom of the second portion  11  of the incisions  8 . Preferably, the ventilation holes  15  extend through the sole  1  from a surface  5 A opposite the tread surface  5 , until they extend to the bottom of the second portion  11 . 
     According to a preferred embodiment, the sole  1  comprises a lightening area  20  which is formed in the tread surface  5  with an extent in the toe-to-heel direction X in the form of a groove 
     Preferably, the lightening area  20  has a variable width, having a width which is greater at the midfoot zone  3 . Preferably, that lightening area  20  has a curved extent with a flexion in the intermediate midfoot zone  3 . 
     In an embodiment, the lightening area  20  further has an increasing depth from the respective forefoot zone  2  and backfoot zone  4  towards the midfoot zone  3 . The depth of that lightening area  20  can reach the depth of the second portion  11 . 
     The lightening area  20  groove preferably has a width that tapers from a wider midfoot zone width to a narrower, reduced width at the toe and heel ends. Optionally, the groove has a depth that also tapers from a deeper midfoot zone depth to a shallower, reduced depth at the toe and heel ends. Different forms of the lightening area  20  are illustrated in  FIGS. 6A-C . As can be seen in  FIGS. 6A-C , the lightening area  20  may be generally straight, or curved, including having the heel and toe ends of the groove curved in opposite directions. 
     The form of the lightening area  20  allows promotion of the torsion movement of the sole which is derived from the natural dynamics of the foot during walking. In addition, the characteristics of the lightening area  20  allow an improvement of the ventilation in the region thereof and the central arrangement and the greater opening thereof in the midfoot zone  3  prevent the presence thereof from excessively impairing the impermeability of the sole and the aesthetic appearance thereof. 
     The invention thereby solves the problem set out, achieving a number of advantages, including the possibility of providing controlled flexion and greater resilience of the sole, ensuring balance during all the phases of walking as a result of greater support for the foot and grip with respect to the ground. Those advantages are further achieved with an implemented lightness and general comfort of the foot.