Shoe sole construction

Abstract

A shoe sole construction which features an outer sole (18) having at least one opening (26) through which a protrusion (30) of a less dense midsole (16) extends. The cutout area (26) of the more dense outsole (18) decreases the overall weight of the sole (12), while the less dense protrusion (30) aids in cushioning the foot to provide greater comfort and support. Other protrusions (32 and 68) may also be provided through other openings in the outsole to further lessen weight and increase the cushioning effect on the foot. Additionally, grooves (42) may be provided on the upper surface (40) of the midsole (16) to increase flexibility of the sole (12) and further aid in cushioning the foot and providing peripheral support where needed. The invention may be applied to athletic shoes (FIGS. 1-9), a woman's high-heeled shoe (FIGS. 10-14), or other footwear.

I claim as my invention: 
     
       1. A shoe, which comprises: an upper;   an outsole made of a material having a first density and including at least one generally oval cutout portion formed therethrough under the metatarsal arch portion of the foot of a wearer; .[.and.].   .Iadd.means for cushioning the foot of a wearer, said cushioning means comprising .Iaddend.a midsole made of a material having a second density less than said first density and positioned between said upper and said outsole, said midsole including a lower surface having a protruding portion that extends through said cutout portion of said outsole, said protruding portion forming a continuous, generally oval expanse that is positioned in the forepart of said midsole under the approximate area of the metatarsal arch of a wearer.[.. .]. .Iadd.;   wherein a portion of a lower surface of said outsole extends below said lower surface of said protruding portion.Iaddend..   
     
     
       2. A shoe as set forth in claim 1, wherein said outsole includes a bottom surface and wherein said protruding portion extends below a portion of said bottom surface. 
     
     
       3. A shoe as set forth in claim 1, wherein said protruding portion includes a longitudinally formed concavity on its lower surface. 
     
     
       4. A shoe as set forth in claims 1 or 3, wherein said protruding portion includes a transversely formed concavity on its lower surface. 
     
     
       5. A shoe as set forth in claim 2, wherein said protruding portion is adapted to contact the ground prior to said portion of said bottom surface upon foot-initiated ground impact. 
     
     
       6. A shoe as set forth in claim 5, wherein said portion of said bottom surface surrounds said protruding portion of said midsole and comprises the forefoot portion of said outsole. 
     
     
       7. A shoe as set forth in claim 1, wherein said outsole further includes a second cutout portion formed therethrough and said midsole further includes a second protruding portion that extends through said second cutout portion of said outsole. 
     
     
       8. A shoe as set forth in claim 7, wherein the first protruding portion is formed in the forepart of said midsole in the approximate area of the metatarsal arch, while said second protruding portion is formed in the rear part of said midsole in the approximate area of the heel. 
     
     
       9. A shoe as set forth in claim 8, wherein the bottom surface of said second protruding portion of said mid-sole is approximately flush with the bottom surface of said outsole. 
     
     
       10. A shoe as set forth in claim 7, wherein the first protruding portion is formed in the forepart of said midsole in the approximate area of the metatarsal arch, while said second protruding portion is formed along the instep area of said midsole in the approximate area of the inner longitudinal arch. 
     
     
       11. A shoe as set forth in claim 1, wherein said midsole further includes an upper surface a portion of which is adapted to be compressed by the foot of a wearer upon foot-initiated ground impact, said portion of said upper surface including means for making said portion more compressible than the rest of said midsole. 
     
     
       12. A shoe as set forth in claim 11, wherein said means comprises cut out areas formed in said upper surface. 
     
     
       13. A shoe as set forth in claim 12, wherein said cut out areas comprise a plurality of substantially parallel grooves formed substantially transversely across said portion of said upper surface. 
     
     
       14. A shoe as set forth in claim 13, wherein said grooves are substantially parallel to the lines of flexing of the metatarsal bones of the foot. 
     
     
       15. A shoe as set forth in claim 13, wherein said grooves are formed on said portion of said upper surface at an angle to the centerline of said midsole which angle substantially corresponds to the lines of flexing of the metatarsal bones of the foot. .[.16. A shoe sole, which comprises: an outsole having a bottom portion adapted to contact the ground and an open area formed in the forepart of the outsole generally under the metatarsal arch; and   a midsole secured to said outsole and including a protruding portion extending through said open area of said outsole for contacting the ground during ground impact for cushioning the foot of the wearer, said protruding portion forming a continuous, generally oval expanse that is positioned in the forepart of said midsole under the approximate area of the metatarsal arch of a wearer..]. .[.17. A shoe as set forth in claim 16, wherein said midsole is made of a less dense material than said outsole..]. .[.18. A shoe sole as set forth in claim 16, wherein said outsole includes a plurality of open areas and further comprising a plurality of integral portions of said midsole which respectively protrude   
     
     
        through said plurality of open areas..]. 19. A shoe, which comprises: an upper;   an outsole having a bottom portion adapted to contact the ground and an open area formed in the forepart of the outsole generally under the metatarsal arch; and   a midsole .Iadd.comprised of a cushioning material for cushioning the foot of a wearer upon ground impact, said midsole .Iaddend.secured to said outsole and said upper, said midsole including a protruding portion extending through said open area of said outsole for contacting the ground during ground impact for cushioning the foot of the wearer, said protruding portion forming a continuous, generally oval expanse that is positioned in the forepart of said midsole under the approximate area of the metatarsal arch of a wearer.[...]. .Iadd.;   wherein a portion of a lower surface of said outsole extends below the   
     
     
        lower surface of said protruding portion.Iaddend.. 20. A shoe as set forth in claim 19, wherein said midsole is made of a less dense material than 
     
     
        said outsole. 21. A shoe as set forth in claim 19, wherein said outsole includes a plurality of open areas and further comprising a plurality of integral portions of said midsole which respectively protrude through said 
     
     
        plurality of open areas. .[.22.  A midsole, which comprises: an upper surface a portion of which is adapted to be compressed by the foot of a wearer upon foot-initiated ground impact, said portion of said upper surface including cut out groove means for making said portion more compressible than the rest of said midsole; and   a lower surface including a continuous, generally oval protrusion extending under the metatarsal arch of a wearer for contacting the ground during foot-induced impact for cushioning the metatarsal arch of the wearer..]. .[.23. A midsole as set forth in claim 22, wherein said cut out groove means comprise a plurality of substantially parallel grooves formed substantially transversely across said portion of said upper surface..]. .[.24. A midsole as set forth in claim 23, wherein said grooves are substantially parallel to the lines of flexing of the metatarsal bones of the foot..]. .[.25. A midsole as set forth in claim 23, wherein said grooves are formed on said portion of said upper surface at an angle to the centerline of said midsole which angle substantially corresponds to the lines of flexing of the metatarsal bones of the foot..]. .[.26. A shoe, which comprises:   an upper;   an outsole; and   a midsole positioned between said upper and said outsole;   said midsole including an upper surface a portion of which is adapted to be compressed by the foot of a wearer upon foot-initiated ground impact, said portion of said upper surface including cut out groove means for making said portion more compressible than the rest of said midsole; and   a lower surface including a continuous, generally oval protrusion extending under the metatarsal arch of a wearer for contacting the ground during foot-induced impact for cushioning the metatarsal arch of the wearer..]. .[.27. A shoe as set forth in claim 26, wherein said cut out groove means comprise a plurality of substantially parallel grooves formed substantially transversely across said portion of said upper surface..]. .[.28. A shoe as set forth in claim 27, wherein said grooves are substantially parallel to the lines of flexing of the metatarsal bones of the foot..]. .[.29. A shoe as set forth in claim 27, wherein said grooves are formed on said portion of said upper surface at an angle to the centerline of said midsole which angle substantially corresponds to the   
     
     
        lines of flexing of the metatarsal bones of the foot..]. .Iadd.30.  A shoe as recited in claim 19, further comprising a plurality of lugs extending from a peripheral portion of said outsole. .Iaddend. .Iadd.31. A shoe as recited in claim 19, wherein said bottom portion of said outsole extends below a lower surface of said protruding portion. .Iaddend. .Iadd.32. A shoe as recited in claim 30, wherein said protruding portion forms a 
     
     
        continuous, generally oval expanse. .Iaddend. .Iadd.33.  A shoe as recited in claim 1, further comprising a plurality of lugs extending from a 
     
     
        peripheral portion of said outsole. .Iaddend. .Iadd.34.  A shoe sole which comprises: an outsole having rear and middle portions, an upper surface, a plurality of peripheral lugs and a cutout portion, said cutout portion positioned between said peripheral lugs;   a midsole secured to said upper surface of said outsole, said midsole including a bottom surface having a protruding portion in said cutout portion of said outsole;   wherein the lowermost portion of said lug members extend below the lower   
     
     
        surface of said protruding portion. .Iaddend. .Iadd.35.  A shoe sole as recited in claim 34, wherein said cutout portion is substantially oval. 
     
     
        .Iaddend. .Iadd.36.  A shoe sole as recited in claim 35, wherein said protruding portion is tapered in width towards said middle portion. .Iaddend. .Iadd.37. A shoe sole as recited in claim 36, wherein said bottom surface of said protruding portion is flush with said lower surface 
     
     
        of said outsole. .Iaddend. .Iadd.38.  A shoe sole as recited in claim 35, wherein said protruding portion is substantially oval. .Iaddend. 
     
     
        .Iadd.     A shoe sole as recited in claim 38, wherein said bottom surface of said protruding portion is flush which said lower surface of said outsole. .Iaddend. .Iadd.40. A shoe sole as recited in claim 34, wherein said cutout portion is tapered in width towards said middle portion. 
     
     
        .Iaddend. .Iadd.41.  An athletic shoe which comprises: an upper;   an outsole having rear and middle portions, a peripheral portion, upper and lower surfaces, and a longitudinal cutout portion, said cutout portion disposed inwardly from said peripheral portion in said rear portion of said athletic shoe; and   means for cushioning the foot of a wearer, said means comprising a midsole secured to said upper surface of said outsole, said midsole including a bottom surface having a protruding portion in said cutout portion of said outsole of said athletic shoe;   wherein a portion of said lower surface of said outsole extends below a   
     
     
        bottom surface of said protruding portion. .Iaddend. .Iadd.42.  A shoe sole as recited in claim 41, wherein the density of said outsole is 
     
     
        greater than the density of said midsole. .Iaddend. .Iadd.43.  A shoe sole as recited in claim 41 wherein said cutout portion and said protruding 
     
     
        portion taper in width towards said middle portion. .Iaddend. .Iadd.44. An athletic shoe as recited in claim 41, wherein said cutout portion and said protruding portion extend from said rear portion to said middle portion. .Iaddend. .Iadd.45. An athletic shoe as recited in claim 44, wherein said cutout portion extends substantially along the longitudinal 
     
     
        axis of said outsole. .Iaddend. .Iadd.46.  A shoe which comprises: an upper;   an outsole made of a material having a first density and including at least one cutout portion formed therethrough; and   a midsole made of a material having a second density less than said first density and positioned between said upper and said outsole, said midsole including a lower surface having a protruding portion in said cutout portion of said outsole; wherein said outsole includes a plurality of lug members that extend from the periphery of said bottom surface, the lowermost portions of certain of said lug members extending below said protruding portion and thereby adapted to contact the ground before said protruding portion contacts the ground upon foot-initiated ground impact. .Iaddend. .Iadd.47. A shoe as set forth in claim 46, wherein said midsole   
     
     
        material is EVA. .Iaddend. .Iadd.48.  A shoe, which comprises: an upper;   an outsole made of a material having a first density and a cutout portion formed therethrough;   a midsole made of a material having a second density less than said first density and positioned between said upper and said outsole, said midsole including a lower surface having a protruding portion that extends in said cutout portion of said outsole; said protruding portion being formed along the instep area of said midsole in the approximate area of the inner   
     
     
        longitudinal arch. .Iaddend. .Iadd.49.  A shoe sole as recited in claim 48, wherein said outsole further comprises a plurality of lugs disposed along the periphery of said outsole. .Iaddend. .Iadd.50. A shoe as set forth in claim 48, wherein said midsole material is EVA. .Iaddend. .Iadd.51. A shoe sole as recited in claim 48, wherein said cutout portion in said outsole extends from said heel portion to said arch portion. 
     
     
        .Iaddend. .Iadd.52.  A shoe sole as recited in claim 51, further comprising a plurality of lugs disposed along the periphery of said 
     
     
        outsole. .Iaddend. .Iadd.53.  A shoe sole which comprises: an outsole having rear and front portions, an upper surface, a lower surface, a plurality of peripheral lugs and a cutout portion, said cutout portion disposed substantially along the longitudinal axis of said outsole;   a midsole having a lower surface, said midsole disposed above said outsole;   cushioning means located on said lower surface of said midsole, said cushioning means including a pad portion exposed by said cutout portion of said outsole;   wherein the bottom surface of said peripheral lugs extends below the bottom   
     
     
        surface of said pad portion. .Iaddend. .Iadd.54.  A shoe sole as recited in claim 53, wherein said pad portion is integral with said midsole. .Iaddend. .Iadd.55. A shoe sole as recited in claim 53, wherein the density of said outsole is greater than the density of said pad portion. 
     
     
        .Iaddend. .Iadd.56.  A shoe sole as recited in claim 53, wherein said cutout portion and said pad portion are disposed in said rear portion of said outsole. .Iaddend. .Iadd.57. A shoe sole as recited in claim 56, wherein said lower surface of said outsole extends below said bottom surface of said pad portion. .Iaddend. .Iadd.58. A shoe sole as recited in claim 53, wherein said cutout portion and said pad portion are disposed in 
     
     
        said front portion of said outsole. .Iaddend. .Iadd.59.  A shoe sole which comprises: an outsole having rear, middle and front portions, a peripheral portion, upper and lower surfaces, a cutout portion, and a plurality of lugs extending from said peripheral portion of said lower surface of said outsole; said cutout portion positioned between said lugs;   a midsole secured to said upper surface of said outsole, said cutout portion of said outsole exposing a portion of said midsole;   said lugs extending below said exposed portion of said midsole. .Iaddend. .Iadd.60. A shoe sole as set forth in claim 59, wherein said cutout portion is disposed in said rear portion of said outsole. .Iaddend. .Iadd.61. A shoe sole as set forth in claim 59, wherein said cutout portion is disposed in said front portion of said outsole. .Iaddend. .Iadd.62. A shoe sole as recited in claim 59, wherein said outsole has a density greater than the density of said midsole. .Iadd.63. A shoe sole as recited in claim 59, wherein said exposed portion of said midsole extends in said cutout portion. .Iaddend.