Endothermic footwear insert

Abstract

A personal cooling device that provides cooling to a user, e.g., a wearer's feet, assuring even temperature distribution across contoured surfaces irrespective of the orientation of the personal cooling device and regardless of the pull of gravity. The personal cooling device includes a flexible non-porous upper component, a flexible non-porous lower component, a porous absorbent carrier component, at least one dry chemical reactant and at least one containment including at least one liquid reactant. The carrier component includes at least one dry chemical reactant distributed on the surface area thereof. When the at least one dry chemical reactant is combined with the at least one liquid chemical reactant and is absorbed by the carrier component, an endothermic reaction is produced. The carrier component absorbs the resulting cool substance evenly distributed thereover and, thereby assures equal distribution of this actual cooling throughout the entire device. The at least one containment is adapted to rupture under applied pressure. The upper and lower components are inseparably sealed to each other at their respective perimeters, the attachment forming a volume adapted to encapsulate the carrier component, the at least one dry chemical reactant and the at least one containment.

1 - 20 . (canceled) 
     
     
         21 . A footwear insert for cooling a user's foot, comprising:
 flexible, non-porous upper substrate and lower substrate sealed at their peripheries to each other to form a laterally elongated interior volume and shaped to conform to a contour of an insole of the footwear;   an elongated absorbent carrier and at least one frangible liquid containment, both inside said interior volume and both extending in area along and across the interior volume except for peripheral margins within said interior volume;   at least one chemical reactant that also is inside the interior volume and is distributed relative to the area of the carrier and the at least one containment;   said at least one chemical reactant comprising both (i) individual first particles and (ii) individual second particles that are larger than the first particles; and   said upper and lower substrates being configured to hold the carrier, at least one containment, and at least one reactant in place between the substrates and maintain the at least one reactant distributed relative to the carrier;   wherein:
 when in contact with each other, the at least one reactant and a liquid from the at least one containment produce an endothermic reaction to thereby cause cooling; 
 the at least one containment is configured to rupture in response to selected pressure, thereby releasing liquid therefrom to contact the at least one reactant and cause even cooling over the area of the carrier; 
 the carrier is flexible following contact with the liquid after the at least one containment is ruptured, thereby facilitating conformance of the insert to the footwear, the insole, or an orthotic in the footwear; 
 the individual first particles and the individual second particles in the at least one reactant provide both initial and extended cooling, wherein the larger second individual particles extend the cooling beyond the period provided by the first particles alone; 
 said margins are configured to provide room in said interior volume for any excess air remaining in the interior volume after said sealing or excess liquid after the at least one containment is ruptured and the cooling reaction starts; and 
 the absorbent carrier is configured to absorb cooling liquid resulting from the endothermic reaction and, upon pressure exerted by a user's foot to facilitate migration of some of the cooling liquid from higher pressure portions to lower pressure portions of the insert. 
   
     
     
         22 . The footwear insert of  claim 21 , wherein said margins comprise a margin at a toe portion of the insert and a margin at one or both lateral portions of the insert that are between the toe portion and a heel portion, and the margin at the toe portion is longer than the width of the margin at said one or more lateral portions of the insert. 
     
     
         23 . The footwear insert of  claim 22 , wherein said margins include a margin at a heel area of the insert. 
     
     
         24 . The footwear insert of  claim 21 , wherein said margins include a margin at a heel area of the insert. 
     
     
         25 . The footwear insert of  claim 21 , wherein said at least one containment comprises at least two individual frangible liquid containments. 
     
     
         26 . The footwear insert of  claim 21 , wherein the at least one frangible liquid containment comprises one or more weakened portions configured to rupture under pressure and thereby release liquid in the insert. 
     
     
         27 . The footwear insert of  claim 21 , wherein the reactant comprises at least one dry reactant comprising said individual first particles and said individual second particles. 
     
     
         28 . The footwear insert of  claim 21 , in which said carrier comprises pores or openings and at least some of said individual first particles of the at least one reactant enter into such pores or openings. 
     
     
         29 . The footwear insert of  claim 21 , in which said carrier comprises one or more porous materials. 
     
     
         30 . The footwear insert of  claim 21 , in which said at least one liquid containment encapsulates liquid within a material that has at least one weakened portion that facilitates rupture under pressure. 
     
     
         31 . A cooling insert for cooling a user's foot in footwear, comprising:
 flexible, non-porous upper and lower substrates attached to each other to form an interior volume;   said substrates being configured to conform to a contour of an insole for the footwear;   a carrier and at least one frangible liquid containment that are one over the other inside said interior volume, wherein the carrier extends over substantially the entire area of the insert except for peripheral margins of said interior volume;   at least one chemical reactant distributed over the carrier area inside said interior volume of the insert;   said at least one chemical reactant comprising both (i) individual first particles and (ii) individual second particles that are larger than the first particles; and   said interior volume having unwanted air evacuated therefrom to cause the upper and lower substrates to envelop and hold the carrier, the at least one containment, and the at least one chemical reactant in place in said interior volume, with the at least one chemical reactant distributed relative to the carrier;   wherein:
 the liquid and at least one chemical reactant produce an endothermic reaction when in contact to thereby cause cooling; 
 the at least one containment is configured to rupture in response to selected pressure, releasing a liquid therefrom to contact the at least one chemical reactant and cause the endothermic reaction; 
 the individual first particles and the individual second particles in the at least one chemical reactant provide both initial and extended cooling, wherein the larger individual second particles extend the cooling beyond the period provided by the first particles alone; 
 said peripheral margins are configured to provide room in said interior volume for any excess air or liquid; and 
 the carrier is configured to absorb cooling liquid resulting from the endothermic reaction and upon pressure exerted by a user's foot to facilitate migration of some of the liquid from a higher-pressure area toward a lower pressure area of the insert. 
   
     
     
         32 . The insert of  claim 31 , wherein the at least one liquid containment comprises two or more containments. 
     
     
         33 . The insert of  claim 31 , wherein said margins include a margin at a toe portion of the insert. 
     
     
         34 . The insert of  claim 33 , wherein said margins further include a margin at one or both sides of the insert, wherein the length of the margin at the toe portion of the insert is greater than the width of the margin at one or both sides of the insert. 
     
     
         35 . The footwear insert of  claim 34 , wherein said margins include a margin at a heel area of the insert. 
     
     
         36 . The footwear insert of  claim 31 , wherein said margins include a margin at a heel area of the insert. 
     
     
         37 . The insert of  claim 31 , wherein the carrier comprises absorbent material with pores into which at least some of the at least one reactant enters before the endothermic reaction starts. 
     
     
         38 . The insert of  claim 31 , wherein the at least one reactant comprises a dry reactant. 
     
     
         39 . A method of making a cooling insert for cooling a user's foot in footwear, comprising:
 providing a carrier, at least one liquid containment that contains liquid and is configured to burst under selected pressure and thereby release said liquid, and at least one chemical reactant that comprises both individual first particles and individual second particles that are larger than the first particles, wherein the liquid causes an endothermic reaction when in contact with the at least one chemical reactant but the at least one containment keeps the liquid out of the contact with the at least one chemical reactant before bursting;   sealing the carrier, the at least one containment, and the at least one chemical reactant between an upper substrate and a lower substrate that are shaped to conform to a contour of an insole of the footwear, with the at least one reactant distributed relative to the carrier;   said sealing comprising evacuating unwanted air from space between the upper and lower substrates, thereby facilitating holding the carrier, the at least one liquid containment, and the at least one chemical reactant in place relative to each other and to the substrates;   said sealing further comprising leaving margins surrounding at least a portion of the periphery of at least the carrier, which margins provide space between the substrates where any excess liquid or excess air can migrate after said liquid containment has burst and said endothermic reaction has started.   
     
     
         40 . The method of  claim 39 , wherein said leaving margins surrounding at least a portion of the periphery of at least the carrier comprises a margin at one or both sides of the insert, wherein the length of the margin at a toe portion of the insert is greater than the width of a margin at one or both sides of the insert. 
     
     
         41 . The method of  claim 39 , further comprising providing said insert with an adhesive or non-slip material configured to hold the insert only to the footwear or an insole or orthotic therein and keep the insert in place in the footwear while a user's foot is being cooled by said endothermic reaction. 
     
     
         42 . The method of  claim 39 , further comprising providing said at least one liquid containment with weakened portions configured to break under selected pressure to thereby burst the liquid containment.