Shoe bottom construction

Abstract

A sole assembly includes an upper midsole layer, a lower midsole layer, and an outsole layer. The upper midsole layer defines a cavity in an aft region. The cavity extends substantially transversely relative to a longitudinal axis. The lower midsole layer connects to the upper midsole layer. The lower midsole layer transversely covers the cavity. The outsole layer connects to the lower midsole layer.

What is claimed is: 
     
         1 . A sole assembly comprising:
 an upper midsole layer defining a cavity in an aft region, the cavity extending substantially transversely relative to a longitudinal axis;   a lower midsole layer connected to the upper midsole layer, the lower midsole layer transversely covering the cavity; and   an outsole layer connected to the lower midsole layer.   
     
     
         2 . The sole assembly of  claim 1 , wherein
 the cavity is a first cavity, and   the upper midsole layer defines a second cavity in the aft region extending substantially transversely relative to the longitudinal axis.   
     
     
         3 . The sole assembly of  claim 2 , wherein the first cavity is aligned with the second cavity. 
     
     
         4 . The sole assembly of  claim 2 , wherein the first cavity is in communication with the second cavity. 
     
     
         5 . The sole assembly of  claim 1 , wherein the outsole layer is grooved. 
     
     
         6 . The sole assembly of  claim 1 , wherein the lower midsole layer and the outsole layer form one or more pods. 
     
     
         7 . The sole assembly of  claim 1 , wherein the upper midsole layer defines at least one of a medial longitudinal concavity and a lateral longitudinal concavity. 
     
     
         8 . The sole assembly of  claim 1 , wherein the lower midsole layer is exposed through at least one of a window and a cut-out defined in the outsole layer. 
     
     
         9 . The sole assembly of  claim 8 , wherein
 the cut-out is a first cut-out,   the upper midsole layer is exposed through the first cut-out, and   the upper midsole layer is exposed through a second cut-out defined in the lower midsole layer.   
     
     
         10 . The sole assembly of  claim 1 , wherein a side of the upper midsole layer defines a plurality of grooves. 
     
     
         11 . The sole assembly of  claim 1 , wherein the outsole layer is connected to the upper midsole layer at a toe end and forms a toe wrap. 
     
     
         12 . The sole assembly of  claim 1 , wherein the lower midsole layer includes a forward portion and a rear portion. 
     
     
         13 . The sole assembly of  claim 1 , wherein the outsole layer includes a forward portion and a rear portion. 
     
     
         14 . The sole assembly of  claim 1 , wherein the upper midsole layer is exposed along a midfoot region. 
     
     
         15 . The sole assembly of  claim 1 , wherein the upper midsole layer includes a rear arch along the aft region. 
     
     
         16 . A sole assembly comprising:
 an outsole layer;   a lower midsole layer connected to the outsole layer;   an upper midsole layer connected to the lower midsole layer, the upper midsole layer defining a well, a first cavity, a second cavity, and a transverse passageway, the lower midsole layer transversely covering the first cavity and the second cavity, the transverse passageway being in communication with the first cavity and the second cavity; and   a drop-in layer nested in the well.   
     
     
         17 . The sole assembly of  claim 16 , wherein the drop-in layer extends beyond a footbed of the upper midsole layer. 
     
     
         18 . The sole assembly of  claim 16 , wherein the drop-in layer defines a plurality of cuts along a forward region. 
     
     
         19 . A sole assembly comprising:
 an upper midsole layer having a post located along a medial centerline, defining a valley connected to the post, and defining a transverse cavity in an aft region;   a lower midsole layer connected to the upper midsole layer, the lower midsole layer transversely covering the transverse cavity; and   an outsole layer connected to the lower midsole layer.   
     
     
         20 . The sole assembly of  claim 19 , wherein the valley is defined along the medial centerline.