Abstract:
Articles of apparel and the method of making the same which include a sealable cuff portion and a shaped body portion that will allow water vapor due to perspiration to transpire through the article but will prevent water from external sources from reaching the wearer&#39;s extremities. The articles of apparel include a body portion that is of three-ply construction with the inside and outside plies being knit and the intermediate ply being made from an elastomeric polyurethane film. The three plies uniquely bonded together using a pliant, waterproof adhesive. The sealable cuff portion is of a two-ply construction with the outside ply being an elastic knit and the inside ply being a continuation of the elastomeric polyurethane film of the body portion. The adhesive on the continuation of the film is melted to form a smooth surface that sealably engages the user&#39;s extremity to prevent entry of water between the user&#39;s skin and the film.

Description:
This is a Continuation-In-Part application of application Ser. No. 09/384,938 filed Aug. 27, 1999, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to articles of apparel. More particularly, the invention concerns improved articles of apparel used to cover the wearer&#39;s extremities such as an improved, waterproof sock that includes a novel sealing cuff and a body portion that will permit perspiration to transpire through the sock, but will keep water from external sources away from the wearer&#39;s foot. 
     2. Discussion of the Prior Art 
     Various attempts have been made in the past to produce breathable, waterproof articles of apparel such as gloves and socks that will keep the wearer&#39;s hands and feet dry and at the same time permit perspiration to transpire through the article. Materials, which will accomplish this desired function, have been known for sometime. Among the most successful waterproof, breathable articles of apparel ever developed are those developed by the present inventor and described in 
     U.S. Pat. Nos. 5,655,226, 5,483,703, and 5,402,540. Because of these patents to a complete understanding of the present inventions, U.S. Pat. Nos. 5,655,226, 5,483,703 and 5,402,540 are incorporated by reference as though fully set forth herein. 
     The present invention constitutes an improvement in the articles described in the aforementioned patents. More particularly, the articles of apparel of the present invention include a novel sealing cuff arrangement that guards against water entering the interior of the article at a location between the cuff and the covered extremity. 
     As will be better appreciated from the discussion which follows, the present invention provides, for the first time, articles of clothing such as socks and gloves which exhibit the comfort and stretchability of traditional types of sport socks and gloves that include a waterproof body portion and a novel, sealable cuff that provides an article that is both breathable and completely waterproof. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide comfortable articles of apparel and the method of making the same which include a sealable cuff portion and a shaped body portion that will allow water vapor due to perspiration to transpire through the article but will prevent water from external sources from reaching the wearer&#39;s extremities. 
     A particular object of the invention is to provide a footwear article of the aforementioned character which includes an elastic sealing cuff that seals against the user&#39;s leg and prevents the entry of water between the cuff and the user&#39;s leg. 
     Another object of the invention is to provide articles of the aforementioned character in which water vapor from perspiration can be transmitted from the inside to outside of the body portion so that the natural evaporative cooling effect can be achieved. 
     Another object of the invention is to provide a method of making articles of the character described in the preceding paragraphs which is simple and straight forward, does not require the use of complicated equipment and can be performed by unskilled workmen with a minimum of training. 
     A particular object of the invention is to provide a sock as described in the preceding paragraphs which is of simple construction, is lightweight, is pliant and durable in use, and is easy to manufacture. 
     In its preferred form, the footwear article of the invention comprises a sock having a sealable cuff portion and an interconnected body portion. The body portion is of three-ply construction with the inside and outside plies being knit and the intermediate ply being made from an elastomeric polyurethane film. The three plies are uniquely bonded together using a pliant, waterproof adhesive. The sealable cuff portion is of a two-ply construction with the outside ply being an elastic knit and the inside ply being a continuation of the elastomeric polyurethane film of the body portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side-elevational view illustrating the method of making the footwear article of the invention and showing the components of the article in position over a foot-shaped planar mandrel. 
     FIG. 2 is an enlarged, cross-sectional view taken along lines  2 — 2  of FIG. 1 showing the two-ply cuff construction. 
     FIG. 3 is an enlarged, cross-sectional view taken along lines  3 — 3  of FIG. 1 showing the three-ply construction of the body portion. 
     FIG. 4 is an enlarged, cross-sectional view taken along lines  4 — 4  of FIG.  1 . 
     FIG. 5 is an enlarged, fragmentary, cross-sectional, illustrative view showing the manner in which the sealable cuff portion of the sock sealably engages the user&#39;s leg. 
     FIG. 6 is a generally perspective view of one form of the footwear article of the invention shown covering the foot and lower leg portion of the user. 
     FIG. 7 is an enlarged, cross-sectional view taken along lines  7 — 7  of FIG.  6 . 
     FIG. 8 is a generally perspective view similar to FIG. 6 but showing the cuff portion of the footwear article folded down. 
     FIG. 9 is an enlarged, cross-sectional view taken along lines  9 — 9  of FIG.  8 . 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to the drawings and particularly to FIGS. 1 through 4, one form of the article of apparel of the present invention is there shown. The article here comprises a sock construction including a thin, pliant bladder  12  constructed from a waterproof, breathable material, such as polyurethane sheet. The polyurethane sheet can be of various thicknesses as, for example, between about 1.0 mils and about 3.0 mils. Bladder  12  is of a first size and length and includes a lower body portion  14  and an upper cuff portion  16  (FIG.  4 ). Bladder  12  includes an outer surface  18  and an inner surface  20 . Bladder  12  has the unique capability of generally conforming to the contours of the human foot and leg so that it can be comfortably worn inside a boot or shoe. 
     Bonded to the inner surface  20  of the elastomeric bladder is a lightweight covering member such as a first fabric inner sock  22  of standard construction, which is preferably made from knitted natural or synthetic fibers. Sock  22  is of a second size smaller than said first size and a second length less than the first length of bladder  12  (FIG.  4 ). 
     The article of the invention also includes a second fabric outer sock  24 , the body portion  24   a  of which is bonded to the outer surface of the body portion  14  of bladder  12 . Body portion  24   a  can be constructed from filament or spun yarns as well as from natural fibers such as wool fibers, or from a variety of synthetic fibers such as polyester or nylon and combinations thereof. Outer sock  24  also includes an upper cuff portion  24   b  that embodies elastic fibers that impart elasticity to the cuff portion causing it to be continuously urged inwardly toward the covered extremity. The techniques for weaving the stretch and return cuff portion  24   b  are well understood by those skilled in the art and several elastic fibers such as a fiber sold by duPont under the name and style “LYCRA” can be used in conjunction with other fibers to form the cuff portion. It is to be observed that second, or outer sock  24  is of a third size larger than the first size of bladder  12  and has a third length greater than the second length of inner sock  20  and also greater than the first length of bladder  12 . More particularly, as best seen in FIGS. 4 and 5, the cuff portion of outer sock  24  preferably extends beyond the upper edge  12   a  of bladder  12  by a distance of about one-half inch. 
     Inner sock  22  and a portion of outer sock  24  are bonded to bladder  12  by means of a waterproof, heat activated adhesive. A hot melt adhesive in powder form sold by Bostik, Middleton, Mass., product #5116, a polyester type, has proven satisfactory for this purpose. Other adhesives can, of course, also be used, including a water-borne urethane heat activated, two-stage fluid adhesive sold by Stahl U.S.A. of Peabody, Massachusetts, under the designation UE-41742. In any event, the adhesive should be selected and applied in a manner that the breathability of the footwear is not destroyed or substantially reduced. 
     In the novel article of the present invention, the entire outer surface of the first sock  22  is securely bonded to bladder  12 . However, as best seen in FIGS. 4 and 5, the cuff, or upper portion  16  of bladder  12 , has its outer surface securely bonded to the upper elastic cuff portion  24   b  of an outer sock  24 . In a manner presently to be described, elastic cuff  24   b  uniquely functions to urge the inner surface of the bladder into sealing engagement with the user&#39;s leg. 
     The thin, pliant, thermoplastic material from which the waterproof, breathable bladder is made is of a character that will prevent penetration of liquid water while at the same time permitting free passage of moisture vapor such as perspiration. This material can be a polyurethane sometimes described as thermoplastic urethane. A suitable material of this type is sold by Fabrite Laminating Corp. of Woodridge, N.J. Other suitable materials include elastomers made from polyesters, copolyesters, polyamides, cellulose derivatives, polyacrylic acid and its holologs, natural or synthetic rubber with hydrophilic impurities, copolyozamides, polyureas, polyelectrolytes, polyphosphates, polyvinylamid, polyvinylalcohol, polyether, and copolymers thereof, polythioether, polythioether-polyether, copolyepichlorohydrin-ether, polysulphosphates, copolyester-ether and derivatives or mixtures thereof. 
     Considering next the method of the invention, the thin, pliant bladder membrane is first coated with a light coating  27  of the hot melt adhesive to form a precursor, coated membrane. Next, the precursor, coated membrane is heated to a temperature slightly above the softening point of the adhesive, thereby causing the discrete particles of the adhesive which have been randomly deposited onto the bladder to fuse to the surface of the bladder material to form a coated membrane. Reference should be made to incorporated by reference U.S. Pat. No. 5,862,588 for a more detailed description of this adhesive deposition process. 
     The next step in one form of the method of the invention is the construction of the waterproof, breathable bladder. This is accomplished by overlaying two sheets of the previously described coated membrane and then to define on the membrane a line circumscribing the boundary of the bladder. This done, the sheets of coated membrane are heated along the boundary line to a temperature sufficient to sealably bond the membranes together along the boundary line. This heating-fusion step can be accomplished in several ways well known to those skilled in the art, including the techniques described in the incorporated by reference U.S. Pat. Nos. 5,655,226, 5,483,703 and 4,942,214. The heating-fusion step produces a bladder having a perimeter of a first size and length. As indicated in FIGS. 1 and 5, the bladder  12  has an extremity-receiving portion that is in the general shape of the wearer&#39;s extremity. 
     As illustrated in FIGS. 1 and 4 of the drawings, the next step in the method of the invention is to place the first covering member, or inner sock  22  over a generally foot-shaped, approximately ⅛th inch thick, generally planar mandrel  30  having smooth outer surfaces. Sock  22 , which has inner and outer surfaces  22   a  and  22   b  (FIG. 3) is placed over the mandrel so that inner surface  22   a  thereof is disposed in engagement with the faces  30   a  of mandrel  30 . As previously discussed, sock  22  can be constructed from a variety of materials and has a perimeter of a second size smaller than the size of the bladder and a second length less than the length of the bladder  12 . For cold weather comfort, the inner sock can be made utilizing THERMAX® material made by E. I duPont de Nemours and Co. of Wilmington, Del. For warm weather comfort the inner sock can be made utilizing a COOLMAX® material made by duPont. 
     After sock  22  has been placed over mandrel  30  and smoothed out so that its inner surface  22   a  is in close engagement with the faces of the mandrel  30 , a light coating  32  of adhesive is applied to the exposed surface  22   b  of sock  22  (FIG.  3 ). The adhesive can be applied to sock  22  by spraying, rolling, painting or in any other customary way. This done, a first assemblage is formed by carefully placing bladder  12  over the assemblage of sock  22  and mandrel  30  and is smoothed so that the inner surface of the bladder is in close engagement with the adhesive coated sock  22 . This first assemblage has a third size and shape as illustrated in the drawings. 
     Either before or after emplacement of the bladder onto the mandrel, a second covering member or sock  24  is emplaced over another mandrel and appropriately smoothed out. Second sock  24  has a perimeter of a fourth size larger than the size of the first assemblage and a third length greater than the second length of first sock  22 . The exposed, or second surface of sock  24 , is then coated with a layer  34  of adhesive and the adhesive is allowed to dry. The second sock is then removed from the mandrel, turned inside out and placed over bladder  12  which is mounted on the first mandrel  30  over first sock  22 . With this arrangement, the adhesive coated, second side of sock  24  is in engagement with the exposed surface  18  of bladder  12  and the second, or precursor, assemblage thus formed has the configuration shown in FIG.  4 . As can be seen in FIG. 4, the lower body portion of the precursor assemblage is three-ply while the upper cuff portion  24   b  is only two ply with bladder  12  extending a substantial distance above the upper margin  34  of inner sock  22 . 
     The precursor assembly comprising the bonded together first adhesive coated sock  22 , the bladder  12  and the second adhesive coated sock  24  is then heated and compressed in the manner described in the incorporated by reference U.S. Pat. Nos. 5,655,226; 5,483,703 and 4,942,214 to form the finished article. Briefly, this step is accomplished by placing the mandrel, upon which the precursor assembly is mounted, between two platens that can be controllably heated and urged together. During this temperature-pressure step, the polymer of the adhesive is cross linked making a permanent, waterproof bond of inner sock  22  to outside of the bladder and the outer sock  24  to the other side of the bladder. 
     Additionally, due to the unique design of the article of apparel of the invention, during the temperature, pressure step, portion  16  of bladder  12 , that is the portion of the bladder extending above margin  34  of inner sock  22 , is urged against the smooth surfaces  36  of mandrel  30  (FIG.  4 ). As the adhesive  27 , which was previously deposited on bladder  12 , melts and is pressed against the mandrel, it will melt to form a smooth surface that exhibits exceptional sealing capabilities. 
     After completion of the heating and compression step, the precursor assembly is removed from the press and allowed to cool thoroughly prior to doffing the completed waterproof footwear article from the mandrel. When removed from the mandrel, the footwear article is generally planar in shape and in one form of the invention, the article may be stitched along the margin of the bladder and the cuff. In use, when the foot is inserted into the open cuff of the article, the foot engaging portion of the sock will neatly and smoothly conform to the shape of the wearer&#39;s foot. 
     Similarly, when the sock is in use, the elastic cuff portion  24   b  of the outer sock  24  exerts inward forces against the user&#39;s extremities as indicated by the arrows  35  in FIG.  5 . These forces cause the glaze-like surface formed on the bladder to sealably press against the skin of the user forming a substantially water tight seal. As indicated in FIG. 5, even when the user&#39;s extremity “E” is submersed in water “W”, this seal will prevent water from passing between the upper bladder portion  16  and the user&#39;s skin. 
     Turning to FIGS. 6 and 7, a slightly different sock construction of the invention is shown in position over a user&#39;s foot and lower leg. This sock construction is substantially similar to that shown in FIGS. 1 through 5 of the drawings and like numbers are used to identify like components. As before, the sock construction comprises a thin, pliant bladder  12  constructed from a waterproof, breathable material, such as polyurethane sheet (FIG.  7 ). Bladder  12  includes a lower body portion  14  and an upper cuff portion  16  and has an outer surface  18  and an inner surface  20 . As earlier pointed out, bladder  12  has the unique capability of generally conforming to the contours of the human foot and leg so that it can be comfortably worn inside a boot or shoe. 
     Bonded to the inner surface  20  of the elastomeric bladder is a lightweight covering member such as a first fabric inner sock  22  of standard construction, which is preferably made from knitted natural or synthetic fibers (FIG.  7 ). Sock  22  is of a second size smaller than said first size and a second length less than the first length of bladder  12 . 
     The article of the invention also includes a second fabric outer sock  40 , the body portion  40   a  of which is bonded to the outer surface of the body portion  14  of bladder  12  in the manner previously described. Outer sock  40  also includes an upper cuff portion  40   b  that embodies elastic fibers that impart elasticity to the cuff portion causing it to be continuously urged inwardly toward the covered extremity in the manner indicated by the arrow  42  of FIG.  7 . As in the earlier described embodiments outer sock  40  is of a third size larger than the first size of bladder  12  and has a third length greater than the second length of inner sock  20  and also greater than the first length of bladder  12 . Also shown in FIG. 1, the cuff portion of outer sock  40  uniquely comprises a first or lower section  44  that is in overlaying engagement with bladder  12  and a second upper section  46  that extends beyond the upper edge  12   a  of bladder  12 . 
     As before, the entire outer surface of the first sock  22  is securely bonded to bladder  12 . However, as best seen in FIG. 7, the cuff, or upper portion  16  of bladder  12 , has its outer surface securely bonded to the elastic cuff portion  44  of an outer sock  40 . With this construction, elastic cuff  44  uniquely functions to urge the inner surface of the bladder into sealing engagement with the user&#39;s leg “L” in the manner illustrated in FIG. 7 (see also FIGS.  1  and  5 ). 
     If desired, the portion of the elastic cuff that extends beyond upper edge  12   a  of the bladder can be folded down in the manner shown in FIGS. 8 and 9. When so folded down, additional forces are exerted on the bladder in the direction of the arrows  47  of FIG. 9 that tend to urge the bladder into sealing engagement with the user&#39;s leg “L”. When the sock is in use, these inward forces cause the glaze-like surface  49  formed on the bladder portion  44  to sealably press against the skin of the user forming a substantially watertight seal. As previously mentioned, even when the user&#39;s foot and lower leg is submersed in water, this novel seal action will prevent water from passing between bladder portion  44  and the user&#39;s skin. 
     Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.