Patent Publication Number: US-2005142334-A1

Title: Orthotic apparatus and sheet with laminated structure

Description:
TECHNICAL FIELD  
      The present invention relates to sheets such as, for example, bathroom rugs, mats for persons suffering from incontinence, and bed sheets for prevention of pressure sore, and braces to be worn on a user&#39;s body.  
     BACKGROUND ART  
      Typically, in braces to be worn on a user&#39;s body, e.g., supports, elastic chloroprene rubber has been used for the base material. However, such a base material of chloroprene rubber is poor in water permeability as well as being not breathable, thereby tending to cause the contact surface between the brace and the body of a wearer to be sweaty. In order to solve the problem, some braces have been proposed that have a base material of closed cell neoprene rubber provided with a plurality of through holes so as to provide breathability and that have a moisture-absorbing and quick-drying fabric placed over each of the inner and outer sides of the base material so as to prevent the body surface in contact with the brace from getting sweaty (see, for example, Japanese patent laid-open publication Nos. 2000-37407, 2000-37408, and 2000-37409). Another brace is also known that uses open cell latex sponge with breathability as the base material so as to prevent the body surface in contact with the brace from getting sweaty (see, for example, Japanese patent laid-open publication No. HEI 9-266927).  
      Further, there are known sheets such as bathroom rugs or the like that are made of a fabric or the like and thus have moisture absorbing property in some degree.  
      However, in such a brace as disclosed in the Japanese patent laid-open publication No. 2000-37407, which is designed to provide breathability by forming the plurality of through holes in the base material of closed cell neoprene rubber, it is almost impossible to release perspiration, which is wicked away from the body by the fabric, to the exterior of the brace because moisture within the base material can pass only through the through holes provided for ventilation. Therefore, the brace fails to sufficiently inhibit the body surface in contact therewith from getting sweaty. Such a brace as disclosed in the Japanese patent laid-open publication No. HEI 9-266927, which uses open cell latex sponge as the base material, can hardly absorb perspiration produced on the body surface in contact with the brace because the inner and outer sides of the base material are covered with a nylon fabric poor in moisture absorbing property. Therefore, the brace also fails to sufficiently inhibit the contact surface from getting sweaty.  
      Although the conventional fabric sheets which is used as bathroom rugs or the like can absorb moisture in some degree, they fail to quickly release the absorbed moisture to the exterior. Thus, it is time consuming to dry such a sheet.  
      The present invention has been made to solve the above mentioned problems, and an object of the present invention is to provide a laminated brace that can quickly absorb perspiration produced on the body surface in contact with the brace for release to the exterior of the brace so as to sufficiently prevent the contact surface from getting sweaty. Another object of the present invention is to provide a laminated sheet that can quickly release absorbed moisture to the exterior of the sheet so as to be dried in a short time.  
     DISCLOSURE OF THE INVENTION  
      In order to attain the above mentioned objectives, a laminated sheet according to an aspect of the present invention comprises: a base material which is either an open cell foam or a material formed by compression molding of the open cell foam; and a fabric placed over each of inner and outer sides of the base material, wherein the fabric is made of fibers between which spaces are narrower than spaces between fibers of a common polyester fabric.  
      In the above configuration, since the fabric placed over each of the inner and outer sides of the base material is made of fibers between which spaces are narrower than those between fibers of a common polyester fabric, it can wick moisture from the surface of the sheet by the capillary phenomenon. Further, the base material, which is an open cell foam or a material formed by compression molding of the open cell foam, has therein a great number of channels formed from open cells, so that the moisture absorbed by the fabric can be released through the channels to the exterior of the sheet. Especially in the case where the material formed by compression molding of the open cell foam is used as the base material, the channels to pass moisture are narrow as compared to the case where the standard open cell foam is used, so that the base material itself can wick moisture by the capillary phenomenon. As a result, the sheet can effectively absorb moisture on the surface thereof and quickly release the absorbed moisture to the exterior thereof so as to be dried in as short time.  
      According to another aspect of the present invention, a laminated sheet comprises: a base material which is either an open cell foam or a material formed by compression molding of the open cell foam; and a fabric placed over each of inner and outer sides of the base material, wherein the fabric is made of fibers configured to have grooves in cross section.  
      In such a configuration, since the fabric placed over each of the inner and outer sides of the base material is made of fibers configured to have grooves in cross section, it can wick moisture from the surface of the sheet through the narrow groove by the capillary phenomenon.  
      Preferably, in the above, a surface of the sheet is provided with projections and depressions. This can provide increased surface area of the sheet as compared to the case where the surface of the sheet is flat. Thus, the time required for moisture released to the exterior of the sheet to evaporate can be reduced.  
      According to another aspect of the present invention, a laminated brace to be worn on a user&#39;s body, comprises: a base material which is either an open cell foam or a material formed by compression molding of the open cell foam; and a fabric placed over each of inner and outer sides of the base material, wherein the fabric is made of fibers between which spaces are narrower than spaces between fibers of a common polyester fabric.  
      In such a configuration, since the fabric placed over each of the inner and outer sides of the base material is made of fibers between which spaces are narrower than those between fibers of a common polyester fabric, it can wick perspiration away from the body surface in contact with the brace by the capillary phenomenon. Further, the base material, which is an open cell foam or a material formed by compression molding of the open cell foam, has therein a great number of channels formed from open cells, so that the perspiration absorbed by the fabric can be released through the channels to the exterior of the brace. Especially in the case where the material formed by compression molding of the open cell foam is used as the base material, the channels to pass moisture are narrow as compared to the case where the standard open cell foam is used, so that the base material itself can wick perspiration. As a result, the brace can prevent the body surface in contact therewith from getting sweaty.  
      According to another aspect of the present invention, a laminated brace to be worn on a user&#39;s body, comprises: a base material which is either an open cell foam or a material formed by compression molding of the open cell foam; and a fabric placed over each of inner and outer sides of the base material, wherein the fabric is made of fibers configured to have grooves in cross section.  
      In such a configuration, since the fabric placed over each of the inner and outer sides of the base material is made of fibers configured to have grooves in cross section, it can wick perspiration away from the body surface in contact with the brace through the narrow groove.  
      Preferably, in the above, a side of the brace that is opposite to a side to be in contact with the body is provided with projections and depressions. In such a configuration, the side of the brace that is opposite to the side to be in contact with the body can increase in area as compared to the case where it is flat. Thus, the time required for perspiration released to the exterior of the brace to evaporate can be reduced.  
      In the above, a side of the brace that is to be in contact with the body may be provided with projections and depressions. For example, the projections and depressions can be configured to conform to the muscle of a human body so as to protect the muscle of a human body.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a plan view of a laminated brace according to a first embodiment of the present invention.  
       FIG. 2  shows the brace during use on the arm of a user.  
       FIG. 3  is a cross sectional view of the brace taken along line A-A of  FIG. 1 .  
       FIG. 4   a  is cross sectional views of a urethane foam, from which an inner material for the brace is formed, and the inner material formed by compression molding of the urethane foam, and  FIG. 4   b  is cross sectional views of a urethane foam, from which an inner material for the brace is formed, and the inner material formed by compression molding of the urethane foam.  
       FIG. 5  is a cross sectional view of an inner material for a conventional brace.  
       FIG. 6  shows the respective inner materials for the conventional brace and the brace according to this embodiment, which are being tested for comparing their moisture absorbing properties.  
       FIG. 7  shows the details and results of the test.  
       FIG. 8   a  shows moisture within the inner material for the conventional brace and moisture on a cotton fabric when drops of water on the inner material is rubbed with a finger, and  FIG. 8   b  shows moisture within the inner material for the conventional brace and moisture on a cotton fabric when drops of water on the inner material is rubbed with a finger.  
       FIG. 9   a  shows moisture within the inner material for the brace according to the embodiment when moisture on the inner material is rubbed with a finger, and  FIG. 9   b  shows moisture on the cotton fabric when moisture on the inner material for the brace according to the embodiment is rubbed with a finger.  
       FIG. 10  is a cross sectional view of fibers included in a liner material for the brace according to the first embodiment of the present invention.  
       FIG. 11  is a cross sectional view of fibers included in a liner material for the conventional brace.  
       FIG. 12  shows the brace absorbing perspiration produced on the body surface in contact with the brace and releasing the perspiration to the exterior of the brace.  
       FIG. 13  is a perspective view of a bathroom rug according to a second embodiment of the present invention. 
    
    
     BEST MODES FOR EMBODYING THE INVENTION  
      Referring now to the accompanying drawings, an elbow brace (support) and a bathroom rug each embodying the present invention will be described. In the first embodiment, the present invention is applied to an elbow support.  FIG. 1  shows the inner side (the side to be in contact with a user&#39;s body) of the elbow support according to the first embodiment. The elbow support  1  includes a support portion  2  for protecting the elbow of a user and straps  3  and  4  which are members for holding the elbow support  1  on the user&#39;s arm. The support portion  2  has first and second buttresses  5  and  6  for elbow protection in the center region thereof. Each of the straps  3  and  4  has velcro fastening portions  7  and  8 , which are provided at the inner side and the outer side (the side opposite to the inner side), respectively. The support portion  2  and each of the straps  3  and  4  are stitched together with a thread  9 .  
       FIG. 2  shows the elbow support  1  during use. When the elbow support  1  is worn on a user&#39;s arm  11 , the long and short straps  3  and  4  are mounted around the upper arm  13  and the forearm  12 , respectively, with the second buttress  6  of the support portion  2  pressed against the center region of the elbow  14 . Then, the velcro fastening portions  7  and  8  provided on each of the two straps  3  and  4  are joined so as to hold the support portion  2  in the position.  
      Referring to  FIG. 3 , a description will be made as to the inner structure of the support portion  2  and the straps  3  and  4 .  FIG. 3  is a cross sectional view of the elbow support  1  taken along the line A-A of  FIG. 1 . The support portion  2  and the straps  3  and  4  each include an inner material  22  (base material in claims) formed by compression molding of an open cell urethane foam and a liner material  21  (fabric in claims) placed over each of the inner and outer sides of the inner material  22 . A portion of the inner material  22  that is located at the first and second buttresses  5  and  6  in the center region of the support portion  2  includes a large volume of cells as compared to the rest of the inner material  22  within the support portion  2 , thus being higher than the rest as shown in  FIG. 3 . The inner material  22  is higher at the second buttress  6  than at the first buttress  5 . That is because the portion of the inner material  22  that is located at the second buttress  6  to be in contact with the center region of the elbow  14  includes a larger volume of cells than the portion of the inner material  22  that is located at the first buttress  5  to be in contact with the peripheral region of the elbow  14  in order to protect the center region of the elbow  14  surely. The liner material  21  is a fabric made mainly of Technofine™ which is polyester fiber with moisture-absorbing and quick-drying properties. The Technofine™ contains 85% polyester and 15% polyurethane.  
      The support portion  2  and the straps  3  and  4  are formed by covering each of the inner and outer sides of the inner material  22  with the liner material  21  and by heating and pressing the covered inner material  22  for compression molding. In the heating and pressing step, pressure applied to the first and second buttresses  5  and  6  in the center region of the support portion  2  is lower than pressure applied to the rest of the support portion  2 . Further, pressure applied to the second buttress  6  is lower than that applied to the first buttress  5 . As a result, the inner material  22  includes a larger volume of cells at the second buttress  6  than at the first buttress  5 , where the inner material  22  includes a larger volume of cells than at the portion around the first buttress  5 .  
      Referring now to  FIGS. 4   a ,  4   b , and  5 , the inner material  22  will be described in detail.  FIGS. 4   a  and  4   b  show a urethane foam  31  from which the inner material  22  is formed and the inner material  22  formed by compression molding of the urethane foam  31 , respectively.  FIG. 5  shows a neoprene foam that is one of inner materials for conventional elbow supports. As shown in  FIG. 5 , the neoprene foam  41 , which is one of conventional inner materials, is a closed cell foam, so that cells  43  within a neoprene layer  42  are not linked with each other. Therefore, the conventional inner material of the neoprene foam  41  is provided with through holes  44  so as to be breathable. However, in the neoprene foam  41 , moisture can pass only through the through holes  44 , which are small in number. Thus, the neoprene foam can hardly release perspiration to the exterior of the elbow support  1 . On the other hand, as shown in  FIGS. 4   a  and  4   b , the urethane foam  31  that is an open cell foam and the inner material  22  formed by compression molding of the urethane foam  31  have a great number of channels for passage of moisture that are formed from cells  33  linked with each other. Thus, perspiration can be released through the channels to the exterior of the elbow support  1 .  
      As can be seen from  FIGS. 4   a  and  4   b , the compression molded inner material  22  has a smaller volume of cells  33  and thus have less spaces between parts of urethane resin  32  than the original urethane foam  31 . Thus the channels to pass moisture in the inner material  22  are narrower than those in the original urethane foam  31 . As a result, the inner material  22  has enhanced ability to wick moisture by the capillary phenomenon as compared to the original urethane foam  31 , thus allowing perspiration absorbed by the liner material  21  that is in contact with the body of a wearer to be smoothly released to the exterior of the elbow support  1 . Moreover, by compression molding the original urethane foam  31  to increase the density of the urethane resin  32  in the urethane foam  31  as described above, the resultant inner material  22  of the urethane resin  32  can have contractility and flexibility as favorable as a neoprene rubber which is used as an inner material in conventional elbow supports.  
      Referring now to  FIGS. 6 and 7 , the moisture absorbing property of the inner material  22  will be described in comparison with the neoprene foam  41  that is one of conventional inner materials. As shown in  FIG. 6 , a test of water absorbing property has been conducted on the neoprene foam  41  and the inner material  22  by placing the two on a cotton fabric  46  and dropping predetermined amount of water  48  with a dropper  47 . The result is shown in  FIG. 7 . When 1-5 cc of water  48  is successively dropped onto the conventional closed cell neoprene foam  41  with the dropper  47 , the moisture  51  remains round on the neoprene foam  41  without being absorbed into the neoprene foam  41  due to lack of channels to pass moisture. On the other hand, the inner material  22  formed by compression molding of the open cell urethane foam  31  has a great number of channels to pass moisture. Thus, when 1-5 cc of water  48  is successively dropped onto the inner material  22 , the moisture  51  on the inner material  22  is absorbed into the inner material  22  as shown in  FIG. 7 . After about ten minutes since more than 3 cc of water is dropped, the moisture  51  appears on the side (back side) opposite to the side where the water  48  has been dropped.  
      When 5 cc of water  48  is dropped onto the neoprene foam  41  with the dropper  47  and drops of the water  48  is rubbed on the neoprene foam  41  with a finger, the moisture  51  on the neoprene foam  41  is spread on the surface of the neoprene foam  41  with very little absorption into the neoprene foam  41  as shown in  FIG. 8   a . Only the slight moisture  51  which passed through the through holes  44  appears on the cotton fabric  46  as shown in  FIG. 8   b . On the other hand, when 5 cc of water  48  is dropped onto the inner material  22  with the dropper  47  and the moisture  51  remaining on the inner material  22  is rubbed with a finger, the moisture  51  on the inner material  22  is almost entirely absorbed into the inner material  22  to pass through the channels formed from the open cells  33  as shown in  FIG. 9   a , and thus appears on the cotton fabric  46  as shown in  FIG. 9   b.    
      As can be seen from the test result shown in FIGS.  7  to  9 , the conventional closed cell neoprene foam  41  absorbs water very poorly due to few channels to pass moisture while the inner material  22  made of the open cell foam can absorb water powerfully and quickly owing to the great number of channels to pass moisture.  
      Referring to  FIGS. 10 and 11 , a description will be made as to moisture-absorbing and quick-drying properties of the liner material  21  shown in  FIG. 3 . As shown in  FIG. 10 , the liner material  21  is made of Technofine™ fibers  61 . The Technofine™ fiber  61  is configured to have W-shaped grooves in cross section. Thus, the liner material  21  can smoothly pass moisture via the W-shaped grooves. The void space of the W-shaped groove is minute, so that a passage of moisture in the liner material  21  is narrower than that in a material  62  made of conventional regular polyester fibers  63  shown in  FIG. 11 . Accordingly, the liner material  21  at the inner side (the side to be in contact with the body of a wearer) can quickly wick perspiration away from the surface that is in contact with the liner material  21  by the capillary phenomenon. The liner material  21  at the outer side allows the perspiration wicked from the inside liner material  21  by the inner material  22  to pass quickly for release to the exterior of the elbow support  1 . Thus, the elbow support  1  can evaporate in a short time perspiration produced on the contact surface between the support and the body of a wearer so as to sufficiently prevent the contact surface from getting sweaty as well as cooling the contact surface using the heat of evaporation.  
      Referring to  FIG. 12 , how the elbow support  1  comprising the liner material  21  and the inner material  22  wicks perspiration  52  will be summed up. The elbow support  1  uses the material formed by compression molding of the open cell foam as the inner material  22 , of which the inner and outer sides are covered with the liner material  21 . The liner material  21  is made of fibers between which the spaces are narrower than those between fibers of a conventional polyester fabric. Thus, as indicated by the arrow B in  FIG. 12 , the liner material  21  can wick perspiration  52  away from the body surface in contact therewith by the capillary phenomenon, and the inner material  22  can release the perspiration  52  via the plurality of channels formed from the open cells  33  therein to the exterior of the elbow support  1 . In such a manner, the elbow support  1  can sufficiently prevent the body surface in contact therewith from getting sweaty as well as cooling the contact surface using evaporation heat.  
      Referring now to  FIG. 13 , the second embodiment will be described. In the second embodiment, the present invention is applied to a bathroom rug.  FIG. 13  shows the bathroom rug according to the second embodiment. This bathroom rug  71  comprises two sheets  72  each having laminated structure similar to the elbow support  1  according to the first embodiment, with one laid on the other. In  FIG. 13 , the sheets  72  are shown with their height (thickness) enlarged. The actual height of each of the sheets  72  is about 1 cm while the actual width of each of the sheets  72  shown in  FIG. 13  is about 50-60 cm. Although there is a gap between each of the sheets  72  in  FIG. 13 , the sheets  72  are joined and stitched together in practice. Each of the sheets  72  comprises an inner material  22  formed by compression molding of an open cell urethane foam and a liner material  21  placed over each of the inner and outer sides of the inner material  22 . Each of the sheets  72  is formed by covering each of the inner and outer sides of the inner material  22  with the liner material  21  and by heating and pressing the covered inner material  22  for compression molding. As shown in  FIG. 13 , the upper sheet  72  has a plurality of depressions  73  at the upper surface thereof. When forming the upper sheet  72  by compression molding, the pressure applied to the sheet  72  is higher at the depressions  73  than at the rest.  
      By the above described configuration, the bathroom rug  71  allows moisture on the surface thereof to wick through the liner material  21  provided at the surface by the capillary phenomenon. The liner material  21  with improved moisture absorbing property is also provided at the bottom of the bathroom rug  71  so that water spilled on a floor can be absorbed by the liner material  21  through the side face. The inner material  22  formed by compression molding of the urethane foam has a great number of channels formed from open cells therein, thus allowing moisture absorbed by the fabric to pass through the channels and be released to the exterior of the bathroom rug  71 . The plurality of depressions  73  at the top of the bathroom rug  71  are formed for increasing the surface area of the rug  71 . The increased surface area of the rug  71  can reduce the time required for moisture released to the exterior of the rug  71  to evaporate. Further, the depressions  73  allow a user to feel comfortable when using the bathroom rug  71 .  
      The present invention is not limited to the above described embodiments but can be modified in various manners. For example, the fabric used as the liner material is not limited to the liner material  21  made of the Technofine™ fibers  61  that is used in the first embodiment, but may be another fabric as long as the spaces between fibers are narrow so that moisture can be wicked by the capillary phenomenon. The liner material may be made of fibers configured to have V-shaped or U-shaped grooves in cross section instead of fibers configured to have W-shaped grooves in cross section. While the above-described first embodiment uses the inner material  22  formed by compression molding of the urethane foam  31 , a urethane foam or another open cell foam may be used as the inner material as it is. Further, the present invention is applied to the elbow support  1  in the above-described first embodiment, but this invention may be also applied to braces for use on wrists, ankles, etc. or leggings for use in doing exercise.  
      In the above-described first embodiment, the outer side (the side opposite to the side to be in contact with the body of a wearer) of the elbow support  1  is configured to be flat. Alternatively, the outer side of the elbow support may be provided with projections and depressions. Such a configuration can increase the surface area of the elbow support at the outer side, thus reducing the time required for perspiration released to the exterior of the support to evaporate as well as allowing the body surface in contact with the support to be effectively cooled.  
      In the above-described second embodiment, the bathroom rug  71  includes the two laminated sheets  72  with one laid on another. The number of sheets included in the bathroom rug is not necessarily two, but a single sheet, or three or more sheets may be included depending on the amount of water to be absorbed.  
      In the above-described second embodiment, the laminated sheet according to the present invention is applied to the bathroom rug. The laminated sheet according to the present invention may be applied to a mat for persons suffering from incontinence or a bed sheet for prevention of pressure sore.