Method for manufacturing pressure relief insoles for shoes

Abstract

Method for manufacturing an insole includes providing a base having a shape for insertion onto a sole of or in a shoe. The base includes a lower surface, an opposite upper surface, and at least one cavity extending inward from the lower surface over only a part of the lower surface. Over a remaining part of the lower surface, the lower surface is a lowermost surface of the insole. Each cavity is defined in part by a downward-facing surface recessed inward of the base's lower surface. A mesh is attached to the base's upper surface and forms the insole's uppermost surface. A respective air cushion is arranged at least partly in each cavity to be peripherally surrounded by the base. Each respective air cushion includes a sealing structure and foam pieces held in the cavity by the sealing structure, is part of a lowermost surface of the insole.

1 . A method for manufacturing an insole, comprising:
 providing a base having a shape for insertion onto a sole of or in a shoe, the base including a lower surface, an upper surface opposite the lower surface, and at least one cavity extending inward from the lower surface over only a part of the lower surface such that over a remaining part of the lower surface, the lower surface is a lowermost surface of the insole, the at least one cavity being defined in part by a downward-facing surface recessed inward of the lower surface of the base;   attaching a mesh to the upper surface of the base and which forms an uppermost surface of the insole; and   arranging a respective air cushion at least partly in each of the at least one cavity to be peripherally surrounded by the base, each respective air cushion including a sealing structure and lightweight foam pieces held in the at least one cavity by the sealing structure such that when in each of the at least one cavity, the respective air cushion is part of a lowermost surface of the insole.   
     
     
         2 . The method of  claim 1 , wherein the step of attaching the mesh to the upper surface of the base comprises gluing the mesh and the base together and then heat-pressing the mesh and base against one another. 
     
     
         3 . The method of  claim 1 , wherein the step of arranging a respective air cushion in each of the at least one cavity comprises placing foam pieces into the respective cavity and then sealing a membrane to the base around the respective cavity to form the sealing structure. 
     
     
         4 . The method of  claim 3 , wherein the membrane is sealed to surfaces of the base around the respective cavity by glue. 
     
     
         5 . The method of  claim 3 , wherein the membrane is sealed to surfaces of the base around the respective cavity by heat or pressure. 
     
     
         6 . The method of  claim 1 , wherein the step of arranging a respective air cushion in each of the at least one cavity comprises forming the respective air cushion with the foam pieces enclosed within the sealing structure and then inserting the sealing structure into the cavity. 
     
     
         7 . The method of  claim 1 , wherein the at least one cavity consists of a single cavity. 
     
     
         8 . The method of  claim 1 , wherein each of at least one cavity is formed to extend inward from the lower surface of the base and be defined in part by the downward-facing surface recessed inward of the lower surface of the base and a side surface at an angle to and extending around a periphery of the respective one of the downward-facing surfaces. 
     
     
         9 . The method of  claim 1 , wherein the at least one cavity consists of first, second and third separate cavities. 
     
     
         10 . The method of  claim 9 , wherein the first cavity is formed in a heel area of the insole and has an oblong shape, the second cavity is formed forward of the first cavity and has an oblong shape with a flared area that tapers outward toward a front of the insole, and the third cavity is in an area configured to accommodate a sole or ball of the foot of the user closer to the front of the insole than the second cavity. 
     
     
         11 . The method of  claim 9 , wherein each of the first, second and third cavities is formed to extend inward from the lower surface of the base and be defined in part by the downward-facing surface recessed inward of the lower surface of the base and a side surface at an angle to and extending around a periphery of the respective one of the downward-facing surfaces, the respective air cushion comprises first, second and third air cushions each situated at least partly in a respective one of the first, second and third cavities, each of the first, second and third air cushions being peripherally surrounded by the side surface of the respective one of the first, second and third cavities. 
     
     
         12 . The method of  claim 1 , wherein the sealing structure comprises a membrane under the foam pieces, the method further comprising attaching the membrane to the base around a periphery of the respective one of at least one cavity such that the lowermost surface of the insole is provided by a combination of the membrane and the lower surface of the base. 
     
     
         13 . The method of  claim 1 , wherein each of the respective air cushions comprises a membrane surrounding the foam pieces to thereby provide the sealing structure, the membrane being glued into the respective one of at least one cavity and thus attached to the base. 
     
     
         14 . The method of  claim 1 , wherein the foam pieces are placed in the respective air cushion to enable them to be freely movable in or within the sealing structure. 
     
     
         15 . The method of  claim 1 , wherein the mesh has a peripheral shape that is the same as the peripheral shape of the base such that the mesh is attached to the upper surface of the base over its entire periphery.