Abstract:
Self-contained disposable single-use heat generating apparatuses and methods for providing heat are disclosed. One exemplary apparatus includes a heat generating pack having a first bag layer defined by a first surface area bonded to a second bag layer defined by a second surface area and creating multiple pouches therebetween. A heat generating agent is disposed within the pouches and adapted to consume air at a predetermined consumption rate in an exothermic reaction. At least a portion of one of the first surface area and the second surface area comprises an air permeable surface area having a predetermined airflow rate such that the heat generating agent remains substantially evenly distributed within the pouches.

Description:
CLAIM OF PRIORITY  
       [0001]     This is a continuation-in-part of application Ser. No. 10/405,668, filed Apr. 1, 2003, entitled “Self-Contained Personal Warming Apparatus and Method of Warming,” to which this application claims priority. This application is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention is generally related to warming devices and, more particularly, is related to a self-contained personal warming apparatus and method of warming.  
       BACKGROUND  
       [0003]     Heat generating pouches of various configurations and shapes are designed and used for various purposes, such as hand warming, feet warming, and the like, by placing the heat generating pouch in a glove, mitten, shoe, etc. Heat generating pouches typically comprise a heat generating compound disposed between at least two layers of material, such as fabric, or the like, assembled to form a pouch. The heat generating compound emits heat during an exothermic chemical reaction resulting from exposure of the compound to air. Known heat generating compounds typically comprises a loose granular substance that is freely movable within the pouch. With a freely movable compound, when the pouch is placed flat, or horizontally, the compound is somewhat evenly distributed throughout the pouch. However, when the pouch is placed vertically, moved around, or jostled, the compound is drawn by gravity, shifts and settles toward one end of the pouch. This shifting and settling of the compound is sometimes referred to as a “tea-bag” effect. The tea-bag effect results in an uneven temperature profile along the surface area of the pouch. An uneven temperature profile can result in some areas not receiving heat, as desired, or an over concentration of heat in other areas.  
         [0004]     The problem of the compound tending to shift and settle within the pouch has been addressed by other configurations of heat generating pouches. In one embodiment, the heat generating compound is contained within pucks or pellets that are disposed between at least two layers of material. The pucks or pellets comprise a heat generating compound capable of reacting with air in an exothermic reaction. The compound is compressed into concentrated, substantially rigid, pellets. In this configuration, however, the heat emission is concentrated at the pucks, resulting in an uneven heat distribution across the surface area of the pouch. Furthermore, because the pucks are rigid, the pucks do not conform to various contours of the human body against which the heat generating pouch may be placed.  
         [0005]     The undesirable effect of a shifting compound has also been addressed by introducing air to the heat generating compound through only one of the two layers of material forming the pouch, while the other of the two layers of material comprises a self-adhesive. However, these adhesive pouches can not be easily inserted into pockets formed in socks, gloves, mittens, specially designed belts, or the like for use. Indeed, such adhesive pouches are typically fixed to an interior surface of a user&#39;s clothing. In this configuration of use, the pouch moves away from the user&#39;s skin as the clothing moves away from the user&#39;s skin. Furthermore, fixing the pouch to a user&#39;s clothing typically results in minimal or no pressure being applied to the pouch as the pouch is applied to the user&#39;s skin, thereby rendering the pouch less effective.  
         [0006]     Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.  
       SUMMARY  
       [0007]     One embodiment of the present invention provide a self-contained disposable single-use heat generating apparatus and methods of providing therapeutic heat. Briefly described, in architecture, one embodiment of the apparatus can be implemented as follows. A self-contained disposable single-use heat generating apparatus includes a heat generating pack having a first bag layer bonded to a second bag layer creating a plurality of pouches therebetween. A heat generating agent is disposed in the pouch. At least a portion of one of the first bag layer and the second bag layer has an air permeable surface area with a predetermined airflow rate. The airflow rate through the air permeable surface area is predetermined such that the heat generating agent remains substantially evenly distributed within the pouches.  
         [0008]     Other embodiments of the present invention can also be viewed as a method for providing therapeutic heat, including forming and/or using the heat generating apparatus. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: containing a heat generating composition in a plurality of pouches in a self-contained heat generating pack and introducing air to the heat generating composition, such that the heat generating composition remains substantially evenly distributed within the heat generating pack.  
         [0009]     Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0011]      FIG. 1  is a cutaway perspective view of an embodiment of the self-contained personal warming apparatus of the present invention.  
         [0012]      FIG. 1A  is a perspective view of an embodiment of a self-contained personal warming apparatus illustrated in  FIG. 1 .  
         [0013]      FIG. 2  is a plan view of an embodiment of a bag layer of the apparatus illustrated in  FIG. 1 .  
         [0014]      FIG. 3  is a plan view of an embodiment of a bag layer of the apparatus illustrated in  FIG. 1 .  
         [0015]      FIG. 4  is a plan view of an embodiment of a bag layer of the apparatus illustrated in  FIG. 1 .  
         [0016]      FIG. 5  is a plan view of an embodiment of the disclosed self-contained personal warming apparatus.  
         [0017]      FIG. 6  is a plan view of an embodiment of the disclosed self-contained personal warming apparatus.  
         [0018]      FIG. 7  is a plan view of an embodiment of the disclosed self-contained personal warming apparatus. 
     
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 1  illustrates one preferred embodiment of a self-contained disposable single-use heat generating apparatus  10  of the present invention. A heat generating pack  111  comprises a first bag layer  12 , a second bag layer  14  and a heat generating agent  16  disposed therebetween. The first bag layer  12  is defined by a first set of dimensions and has a first surface area. The second bag layer  14  is defined by a second set of dimensions and has a second surface area. It should be noted that although the dimensions of the first bag layer  12  and the second bag layer  14  are illustrated as being substantially rectangular in shape, the dimensions can form any suitable shape. The first surface area can substantially correspond to the second surface area.  
         [0020]     The first bag layer  12  and the second bag layer  14  are aligned, one on top of the other, and are fixed together by at least one seam  18 . The seam  18  can either extend around the perimeter of the heat generating pack  111  where the first bag layer  12  and second bag layer  14  meet, or run along one or a plurality of edges thereof. As illustrated in  FIG. 1 , the seam  18  runs along two opposing edges. The seam  18  is created in any suitable manner, for example by melting, bonding, or sewing.  
         [0021]     At least one enclosed space, or pouch  20 , is created between the first bag layer  12  and the second bag layer  14 . Although only one enclosed space  20  is shown in  FIG. 1 , as discussed later, multiple pouches  20  can be formed in the heat generating pack  11 . At least a portion of one of the first surface area and/or the second surface area is/are preferably air permeable as discussed in greater detail below. The first bag layer  12  and the second bag layer  14  preferably comprise a flexible fabric, material, or the like.  
         [0022]     A heat generating agent  16  is disposed within the pouch  20  and contained therein. The heat generating agent  16  comprises a main ingredient of iron powder and incorporates therein water, a water retaining material (charcoal, vermiculite, or the like), an oxidation promoter, such as activated carbon, and salt. More particularly, and as an example, the agent  16  may comprise approximately 35-50% by weight of iron powder, 25-45% by weight of water, approximately 10-14% by weight of water retaining agent, and approximately 4.5-6% by weight of salt. Upon exposure to air, oxidation of the iron begins in an exothermic reaction. The heat generated by the exothermic reaction of the agent  16  passes through the first bag layer  12  and the second bag layer  14  and radiates from the apparatus  10 . It is preferable that the heat radiating from the apparatus  10  ranges from 39-45° C. in order to provide a level of heat suitable for therapeutic heating without danger of burn to human skin.  
         [0023]     During the exothermic reaction, the heat generating agent  16  consumes air at a predetermined air consumption rate. Controlling the rate of introduction of air to the heat generating agent  16  effects both the temperature radiated from the pack  11  as well as the shifting of the agent  16  within the pouch  20 . Generally, the more air introduced to the heat generating agent  16 , the hotter the pack  11  will become. Also, where the heat generating agent  16  consumes air faster than air is introduced to thereto, a vacuum will be created.  
         [0024]     More specifically, and with reference to  FIG. 1A , an embodiment of the self-contained disposable single-use heat generating apparatus  10  is illustrated. In this embodiment, the heat generating pack  11  is disposed inside a protective package  22 . The protective package  22  can be hermetically sealed with the heat generating pack  11  inside such that no air or minimal air is introduced to the heat generating pack  11 . In this embodiment, the protective package  22  effectively eliminates the introduction of air to the agent  16  thereby substantially preventing the heat generating exothermic reaction. The heat generating pack  11  is disposed within the protective package  22  preferably at, or closely after, the time of manufacture, and the heat generating apparatus  10  can be marketed, sold and stored in this configuration.  
         [0025]     Referring next to  FIGS. 2-4 , various embodiments of bag layers  13 ,  15  and  17  are illustrated. The bag layers  13 ,  15  and  17  can comprise the first bag layer  12 , the second bag layer  14  or any suitable combination thereof in order to form a heat generating pack  11 . For example, a heat generating pack  11  can comprise a first bag layer  12  arranged in the configuration of bag layer  13  ( FIG. 2 ) and a second bag layer  14  arranged in the configuration of bag layer  17  ( FIG. 4 ).  
         [0026]     Selection of the configuration of first bag layer  12  and second bag layer  14  is driven by a desired airflow rate for introduction of air to the heat generating agent  16 . An air consumption rate of the heat generating agent  16  being at least slightly greater than an airflow introduction rate to the agent  16  generates at least a slight vacuum inside the pouch  20 . The vacuum created inside the pouch  20  reduces shifting and settling of the heat generating agent  16 , or “tea-bagging,” within the pouch  20 .  
         [0027]     The substantially stationary disposition of the heat generating agent  16  inside the pouch  20  results in a heat generating pack  11  that maintains a substantially constant thickness. A substantially even heat profile is emitted across the surface area of the first bag layer  12  and the second bag layer  14 . The airflow rate through the combined first surface area and second surface area of the first bag layer  12  and second bag layer  14  preferably is less than the predetermined air consumption rate of the heat generating agent  16  during exothermic reaction. For example, a heat generating pack  11  having porosity allowing an airflow rate of 20,000 sec./100 cc of air preferably contains a heat generating agent  16  having an air consumption rate greater than 20,000 sec./100 cc of air during the exothermic reaction.  
         [0028]     Referring more specifically to  FIG. 2 , one bag layer  13  configuration comprises an air permeable surface area  24 . The air permeable surface area  24  preferably comprises a microporous fabric. A preferred microporous fabric can comprise a nonwoven fabric formed from individual fibers that are pressed together forming an interlocking web of fibers. The fibers can be fixed to each other either mechanically (for example, by tangling the fibers together) or chemically (for example, by gluing, bonding, or melting the fibers together). The present invention can comprise a microporous fabric known to one having ordinary skill in the art.  
         [0029]      FIG. 3  illustrates a bag layer  15  configuration having a portion of the surface area thereof comprising an air permeable surface area  24  and a portion of the surface area comprising an air impermeable surface area  26 . The air permeable surface area  24  preferably comprises a microporous fabric. A preferred microporous fabric for this configuration can comprise a nonwoven fabric formed from individual fibers that are pressed together forming an interlocking web of fibers. The fibers can be fixed to each other either mechanically (for example, by tangling the fibers together) or chemically (for example, by gluing, bonding, or melting the fibers together). This configuration can comprise a microporous fabric known to one having ordinary skill in the art. The air impermeable surface area  26  of the bag layer  15  can comprise polyethelene, polypropylene, or any suitable material. It is preferable that the air impermeable surface area  26  exhibits a low coefficient of friction, such as to allow the heat generating pack  11  to easily slide into a pocket (not shown) formed in a glove, sock, belt for holding heat generating packs in position, or the like. The preferred combination of air permeable surface area  24  and air impermeable surface area  26  of the bag layer  15  of  FIG. 3  is determined by the desired air flow introduction rate to the heat generating agent  16  inside a pouch  11  this bag layer  15  configuration may be used to form.  
         [0030]      FIG. 4  illustrates another bag layer  17  configuration. The bag layer  17  comprises an air impermeable surface area  26 , such as polyethelene, or any suitable material. It is preferable that the air impermeable surface area  26  exhibits a low coefficient of friction, such as to allow the heat generating pack  11  to easily slide into a pocket (not shown) formed in a glove, sock, belt for holding heat generating packs in position, or the like.  
         [0031]     Applying the above disclosed bag layer configurations  13 ,  15  and  17 , heat generating packs  11  of various configurations can be formed. One configuration of a heat generating pack  11  comprises a first bag layer  12  comprising bag layer  13  configuration having an air permeable surface area  24  (illustrated in  FIG. 2 ) and a second bag layer  14  comprising bag layer  17  having an air impermeable surface area  26  (illustrated in  FIG. 4 ). In this configuration the rate at which air is introduced to the heat generating agent  16  is controlled by allowing a pre-determined flow rate through the first bag layer  12  and allowing substantially no air flow through the second bag layer  14 .  
         [0032]     Another configuration of a heat generating pack  11  comprises a first bag layer  12  comprising bag layer  13  having an air permeable surface area  24  (illustrated in  FIG. 2 ) and a second bag layer  14  also comprising bag layer  13  also having an air permeable surface area  24  (illustrated in  FIG. 2 ). In this configuration the rate at which air is introduced to the heat generating agent  16  is controlled by allowing a pre-determined flow rate through both the first bag layer  12  and the second bag layer  14 .  
         [0033]     A heat generating pack  11  of the present invention can also comprise a first bag layer  12  comprising bag layer  13  having an air permeable surface area  24  (illustrated in  FIG. 2 ) and a second bag layer  14  comprising bag layer  15  having a portion of the surface area being air permeable  24  and a portion of the surface area being air impermeable  26  (illustrated in  FIG. 3 ). In this configuration the rate at which air is introduced to the heat generating agent  16  is controlled by the total air permeable surface area  24  of the first bag layer  12  and the second bag layer  14  combined. It is preferable that the airflow rate through the total air permeable surface area  24  of the first bag layer  12  and the second bag layer  14  combined is less than the air consumption rate of the heat generating agent  16  during exothermic reaction.  
         [0034]     A heat generating pack  11  of the present invention can also comprise a first bag layer  12  comprising bag layer  17  having an air impermeable surface area  26  (illustrated in  FIG. 4 ) and a second bag layer  14  comprising bag layer  15  having a portion of the surface area being air permeable  24  and a portion of the surface area being air impermeable  26  (illustrated in  FIG. 3 ). In this configuration the rate at which air is introduced to the heat generating agent  16  is controlled by the total air permeable surface area  24  of the second bag layer  14 . It is preferable that the airflow rate through the total air permeable surface area  24  of the second bag layer  14  combined is less than the air consumption rate of the heat generating agent  16  during exothermic reaction.  
         [0035]     It should be noted that the above described heat generating packs  11  are mere examples and that any configuration combining air permeable surface area  24  with air impermeable surface area  26  is within the spirit of the present invention.  
         [0036]     In one method of use of an embodiment of a self-contained disposable single-use heat generating apparatus  10  of the present invention, a heat generating pack  11  is disposed in a protective package  22  to eliminate, or at least minimize, introduction of air to the heat generating agent  16  disposed inside the pack  11 . The heat generating pack  11  is removed from the protective package  22 . Air is introduced to a heat generating agent  16  disposed within a pouch  20  of the heat generating pack  11 . The pouch  20  is formed by a first bag layer  12  and a second bag layer  14  being peripherally bonded to each other. The heat generating pack  11  is agitated, such as by shaking or crumpling the pack  11  in order to begin or speed up an exothermic reaction of the heat generating agent  16  with air. The heat generating agent  16  consumes air in a heat generating exothermic reaction, thereby emitting heat from the heat generating pack  11 . At least one of the first bag layer  12  and the second bag layer  14 , or a combination thereof, allow air to be introduced to the heat generating agent  16 . The introduction of air is preferably at a flow rate less than the air consumption rate of the heat generating agent  16  during the exothermic reaction. The heat generating pack  11  can be positioned, as desired.  
         [0037]     In one method of use, the heat generating pack  11  can be inserted into a pocket, for example a pocket disposed in a belt for heat application near a user&#39;s skin on their back, stomach, or any desired location. The heat generating pack  11  can also be inserted into a pocket formed in a sock or glove for a user to warm toes and fingers, respectively. The exothermic reaction of the heat generating agent  16  when introduced to air produces a heat emission ranging between 39-45° C. for approximately 12 to 18 hours. Upon the conclusion of the exothermic reaction and the cooling down of the heat generating pack  11 , the heat generating pack  11  can be removed from the position at which it was placed for use and disposed.  
         [0038]     As noted above and demonstrated in  FIG. 5 , multiple pouches  20  can be formed in the heat generating pack  11 . In one exemplary configuration, the first bag layer  12  and the second bag layer  14  are fixed together or joined at multiple seams, such as seams  18 ,  19  shown in  FIG. 5 . In one such embodiment, the seams  18 ,  19  compartmentalize the heat generating pack  11  into separate heat generating pouches  20 . In the embodiment depicted, the first seam  18  extends around the perimeter of the heat generating pack  11 . The second seam  19  extends between two separate pouches  20 . The first seam  18  and  19  can be formed in the same or a different manner. For example, one seam  18  can be formed first, followed by the formation of the second seam  19 . Alternatively, both seams  18 ,  19  can be created by, for example, melting both seams at the same time. Even though one particular configuration has been shown in  FIG. 5  for the seams  18 ,  19 , one can envision other embodiments of a multi-seamed pack  11 , for example in a criss-cross shape (as illustrated in  FIG. 6 ), or multiple vertical and/or horizontal seams.  
         [0039]     Alternatively, multiple pouches  20  can be formed from the first bag layer  12  and the second bag layer  14  as shown in  FIG. 7 . The pouches  20  can be smaller in size and can be formed more as pockets in the heat generating pack  11 . In this manner, areas  30  are formed in the pack  11  whereby the first bag layer  12  and the second bag layer  14  are touching in some manner to prevent shifting of the heat generating agent from one pouch  20  to another. The pouches  20  illustrated in  FIG. 7  can be formed by discrete seams around each pouch, or by generally melting or bonding the first bag layer  12  to the second bag layer  14  to bonded areas  30 .  
         [0040]     In one embodiment of the disclosed heat generating apparatus  10 , the pouches  20  can include one or more scented compositions. As the heat generating agent  16  emits heat, the scented substances in the pouches  20  will emit a stronger fragrance with the heat. The scent can be, for example, but not limited to one or more of the following: fruits, flowers, spices, or combinations thereof.  
         [0041]     It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations, and are merely set forth for a clear understanding of the principles herein. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.