Patent Publication Number: US-9427061-B2

Title: Flexible artificial nails and method of forming same

Description:
RELATED APPLICATIONS 
     This application is a divisional application of U.S. application Ser. No. 13/056,554, filed Apr. 22, 2011, which is a national stage application (under 35 U.S.C. §371) of PCT/US2009/052463, filed Jul. 31, 2009, which claims the benefit of U.S. Provisional Application No. 61/085,635, filed on Aug. 1, 2008. 
    
    
     FIELD OF THE INVENTION 
     This invention pertains generally to human fingernail decorations, and more particularly to artificial nails that are intended to be adhered to a human&#39;s natural fingernail. 
     BACKGROUND OF THE INVENTION 
     For various aesthetic reasons, many individuals wish to possess elongated fingernails or fingernails having a more finished or polished appearance. However, some are unable or unwilling to grow their own natural fingernails out to the desired length. Alternately, they may not have the time, skill, or financial wherewithal to maintain or obtain a more finished appearance that may result from well manicured and/or polished nails. As a result, entire industries have developed around the artificial supplementation and enhancement of natural nails. Such enhancements may range from manicuring and polishing of natural fingernails to individually building artificial nails on the natural nail and nail form from an acrylic powder and liquid which chemically bond to the nail surface as the artificial nail is built. Between these two extremes, are preformed, artificial nails that are glued or otherwise bonded to a person&#39;s own naturally occurring fingernails. Such nails are readily available to a wide range of users through drug and department stores. Such preformed artificial nails may be clear or opaque, and/or prepolished and/or decorated to provide the desired appearance. 
     Artificial nails are commonly made from molded thermoplastic and are available in a wide range of lengths and styles. One broad category of an artificial nail style is the full nail form. As its name implies, the full nail form simulates the entire human fingernail and includes a proximal edge intended to overlay substantially the entire nail bed and a distal free edge which is intended to extend beyond the fingertip of the wearer. The proximal edge is shaped to be disposed substantially adjacent or abut against the cuticle of the finger. The distal free edge may have any of various lengths and shapes, such as oval, square, or flared, depending upon the desired look. Additionally, to further simulate a natural fingernail, the artificial nail is typically formed with a curvature between a first side edge and a second side and a curvature between the proximal and distal edges. Preferably, the artificial nail is sufficiently durable and rigid to withstand the hazards inherent in its use. 
     Manufacturers typically provide users with a range of nail sizes, e.g., identified by size numbers 0-9, to accommodate most nail sizes. Generally, artificial nails are packaged together in sets including a range of different sizes so that the purchaser receives differently artificial nails for their different fingers. In addition to the set of different sized artificial nails, the package may also include liquid adhesive and/or peel-off adhesive pads for bonding the artificial nails to the purchaser&#39;s natural fingernails. 
     It is well known, however, that the contour of natural fingernails varies greatly between individuals and even between different fingers on the same individual. Variations between the curvatures of the preformed artificial nail and the natural nail, however, may affect the integrity of the attachment to the nail, the comfort to the wearer, and the aesthetic appeal of the nail when secured to the natural nail. For example, some individuals have one or more relatively flat nail beds. When attaching an artificial nail that is more curved than the natural nail bed, there will be a gap between the artificial and natural nail bed. In order to adequately bond the artificial nail to the nail bed, a proportionally greater amount of adhesive must be applied. The best bond, however, is obtained from a thin layer of glue between adjacently disposed artificial and natural nail surfaces. A greater amount of glue may result in the formation of air pockets within the volume of glue, weakening the bond. Consequently, the use of a greater amount of glue may actually result in a less durable bond between the artificial and natural nails, and shorten wear time. Moreover, when the user presses the more arched artificial nail downward against the flatter natural nail bed of the user, and the bond is established, the artificial nail will seek to return to its natural, more arched free position. As a result, this pulling on the natural nail bed can cause the user significant pain and discomfort. 
     It has been difficult, if not impossible, to produce artificial nails having degrees of curvature between the first and second side edges and proximal and distal edges that accommodate all natural fingernails. While manufacturers may produce a large number of artificial nails with a variety of curves, this solution is undesirable and impractical because of the associated increase in manufacturing costs. As a result, manufactures typically produce a set of preformed artificial nails have varying widths and including set degrees of curvature. 
     The assignee of the present disclosure has proposed the manufacture and use of an artificial nail that tapers from the distal edge or free edge portion to the proximal edge. In this way, the thinner structure of the nail bed portion of the artificial nail, which is adapted to be disposed along the user&#39;s natural nail bed, is relatively flexible, as compared to the free edge portion of the artificial nail, wherein the thicker structure provides greater strength to the artificial nail. The design is disclosed in greater detail in U.S. Publication 2007-0051384A1, which was filed Aug. 16, 2005, and is based upon provisional application 60/601895, filed Aug. 16, 2004. 
     It has also been proposed to provide a two-part nail including a partial underlay of a deformable material beneath a polymeric body, as disclosed in U.S. Pat. No. 7,150,281. The underlay of deformable material that extends to the proximal edge of or beyond the proximal edge of the stiffer polymeric body to form the proximal end of the artificial nail to be disposed adjacent the user&#39;s cuticle. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a preformed artificial nail that is designed to allow the artificial nail to flex and conform to the curved shape of a nail bed of a natural fingernail along the nail bed portion, while maintaining the strength and durability of conventional nails. The preformed artificial nail is formed of first and second materials, the first material being comparatively more flexible than the second material. The artificial nail includes a nail bed portion and a free edge portion, the free edge portion being adjacent to and distal the nail bed portion. The free edge portion including an upper portion and a lower portion, the lower portion extending subjacent the upper portion. The nail bed portion has a proximal edge defining the proximal edge of the artificial nail, which is intended to abut against or be disposed substantially adjacent the user&#39;s cuticle. The free edge portion has a distal edge defining the distal edge of the artificial nail, which is generally intended to extend beyond the tip of the wearer&#39;s natural fingernail. The first material extends substantially from the proximal edge to the distal edge of the artificial nail and forms the nail bed portion and the upper portion of the free edge portion. The second material forms the lower portion of the free edge portion and extends substantially to the distal edge of the artificial nail, the second material being disposed subjacent the first material along the free edge portion. 
     The disclosure also includes a package including a plurality of such nails, and optionally including adhesive, adhesive pads, an emery board, a manicuring stick, a cleaning pad, an application tool, and/or instruction or product information. 
     The disclosure additionally includes a method of forming such an artificial nail utilizing a multipart mold wherein one of the nail bed portion and the upper portion of the free edge portion, or the lower portion of the free edge portion is molded in a first cavity formed by first and second mold portions. The second mold portion is then removed and replaced with a third mold portion, and the other of the nail bed portion and the upper portion of the free edge portion, or the lower portion of the free edge portion molded to the component already formed in the mold to create the full nail of the structure described above. 
     In use, the preformed artificial nail may more closely conforms to the natural nail than traditional single material, single shot nail designs. Accordingly, the arrangement minimizes the chances of formation of air pockets within the layer of glue between the artificial and natural nails. Thus, it may provide a stronger bond between the artificial nail and the natural fingernail, and a reduction in user discomfort. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a package of artificial nails constructed in accordance with teachings of the invention. 
         FIG. 2  is a top plan view of an artificial nail of  FIG. 1 . 
         FIG. 3  is a side, cross-sectional view taken along line  3 - 3  in  FIG. 2 . 
         FIG. 4  is a side, cross-sectional view, similar to  FIG. 3 , of an alternate embodiment an artificial nail constructed in accordance with teachings of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the drawings, wherein like reference numbers refer to like elements, there is illustrated in  FIG. 1  a nail kit  16  comprising a package  18  containing a plurality  20  of preformed artificial nail assemblies  22 , and in  FIG. 2 , an enlarged plan view of an artificial nail  22  of  FIG. 1 . Referring to  FIG. 2 , each artificial nail  22  has a proximal edge  30  and a distal edge  32 , the area between the proximal and distal edges  30 ,  32  generally defining the nail bed portion  34  and the free edge portion  36 . The artificial nails  22  further include right and left side edges  37 ,  38 . The length of the artificial nail  22  is defined between the proximal and distal edges  30 ,  32 , while the width of the nail body is defined between the left and right side edges  37 ,  38 . 
     So that the artificial nail  22  appears natural and appropriately sits upon the wearer&#39;s fingernail, the nail  22  is generally formed with a curved or an arched shape between the right and left side edges  37 ,  38 , and a generally less arched contour between the proximal and distal edges  30 ,  32 . The artificial nail  22  includes an upper surface  40  and a lower surface  42 . In use, the proximal edge  30  of the artificial nail  22  is adapted to be placed generally adjacent the user&#39;s cuticle with lower surface  42  of the nail bed portion  34  being adapted to be placed adjacent the user&#39;s natural nail bed. The free edge portion  36  is adapted to typically extend beyond the end of the user&#39;s finger with the distal edge  32  generally being disposed at or beyond the end of the user&#39;s natural nail when properly placed. 
     To enable the artificial nail  22  to abut against and generally trace the cuticle, the proximal edge  30  is typically shaped as a rounded curve extending between the left and right side edges  37 ,  38 . In the embodiment illustrated in  FIGS. 1 and 2 , the distal edge  32 , in contrast to the proximal edge  30 , is generally squared-off. However, the shape of the distal edge  32  is a function of fashion and the squared-off appearance is only one example of the possible shapes that the distal edge can have. By way of example only, the shape of the distal edge  32  could alternately be rounded, relatively pointed, expanded and/or flattened at along the free edge portion  36 . 
     To bond the artificial nail to the natural fingernail, a liquid adhesive  44  (see  FIG. 1 ) or an adhesive pad (not shown) is typically placed between the lower surface  42  and the nail bed of the natural fingernail while the artificial nail  22  and natural fingernail are pressed together. Preferably, the adhesive or adhesive pad is degradable to permit easy removal of the artificial nail with an appropriate, safe solution. Although not illustrated in this embodiment, the artificial nails  22  may include structure to assist in the application of the artificial nail  22  to a user&#39;s natural nail, such as an application tab, for example, which may be similar to that illustrated in U.S. application Ser. No. 11/739,371 filed Apr. 24, 2007, which is likewise assigned to the assignee of this disclosure and incorporated herein by reference, or an alternate design. 
     The nail kit package  18  typically includes an outer covering  46 , here in the form of a box, having at least one transparent portion  48  for viewing the contents of the package  18 . The package  18  further includes an inner support housing  50  that generally retains the contents of the package  18  in position within the outer covering  46 . The inner support housing  50  is typically formed of a polymeric material, although it may be of an alternate material, such as cardboard. The inner support housing  50  generally includes a plurality of recessed areas  52 , and additional contents of the package  18  may be retained in a rear open portion of the inner support housing  50 . The package  18  may additionally contain items such as, for example, adhesive  44 , a rosewood stick, an application tool, an emery board, instruction or product information, etc. Although all such possibilities are not illustrated in the embodiment shown, it will be appreciated by those of skill in the art that the package  18  may additionally contain these and other materials. 
     Returning now to  FIG. 2  and the structure of the artificial nails  22 , in order to provide a more universal fit to user&#39;s natural nails, the nail bed portion  34  of the nail  22  is formed of an elastically deformable material  54 , while the free edge portion  36  is formed of both the elastically deformable material  54  and a relatively stiffer material  56 . The relatively stiffer material  56  is in the form of a lower portion of the free edge portion  36  or an underlayment  58 , the elastically deformable material  54  extending along an upper portion of free edge portion  36 , the underlayment  58  being disposed subjacent the upper portion along the free edge portion  36 . In this way, the elastically deformable material  54  of the nail bed portion  54  may readily conform to the upper surface of the user&#39;s natural nail, while the stiffer material  56  of the underlayment  58  provides enhanced rigidity to the free edge portion  34  of the artificial nail  22 . Accordingly, the elastically deformable material  54  provides comfort, while the stiffer material  56  provides rigidity similar to the rigidity of the free edge of a natural nail. 
     Preferably, the elastically deformable material  54  extends along substantially the entire length of the artificial nail  22 , that is, from the proximal edge  30  to the distal edge  32  of the nail  22 . It will be appreciated, however, that the deformable material  54  need not extend all of the way to the distal edge  32 , so long as it extends over at least a portion of the underlayment  58 . From an aesthetic standpoint, however, a continuous surface of the elastically deformable material  54  extending along both the nail bed portion  34  and the free edge portion  36  of the artificial nail  22  from the proximal edge  30  to the distal edge  32  provides a smooth upper surface  40 , similar to a natural nail. Further, depending upon the opacity of the elastically deformable material  54 , the delineation of the underlayment  58  in the artificial nail  22  may additionally simulate the coloring or delineation of a natural nail. 
     The underlayment  58  may have any appropriate structure. For example, the underlayment  58  may be of a wedge shape, such as it shown in the embodiment of  FIG. 3 . In the illustrated embodiment, the large end of the wedge shape is shown at the distal edge  32  of the nail  22 . In this way, the rigidity of the free edge portion  36  of the nail  22  will gradually increase as it approaches the distal edge  32 . Such a structure may further enhance the comfort of the user when the artificial nail  22  is secured to the user&#39;s natural nail. It will be appreciated, however, that the underlayment  58  may have an alternate structure. By way of further example, the underlayment  58  may have a relatively uniform cross-section, such as in the underlayment  58  shown in  FIG. 4 , although an alternate structure may be provided. 
     As will be appreciated by those of skill in the art, the artificial nail  22  may be formed in any appropriate manner. For example, it may be formed in a multi-part, typically three-part mold assembly. That is, two portions of the mold assembly form a first cavity into which one or the other of the elastically deformable material  54  or the relatively stiffer material  56  is injected, or otherwise transferred to form either the nail bed portion  34  or the free edge portion  36 , respectively. With the first formed portion  34  or  36  of the nail  22  remaining in the mold assembly, a portion of the mold assembly is then replaced to form a cavity in the mold assembly adjacent the first formed portion  34  or  36  contained therein. The second material, that is, either the stiffer material  56  or the elastically deformable material  54 , is injected or otherwise transferred to form the second portion  36 , or  34 , respectively, of the nail  22 , the two materials bonding together along the joint  54  of the structure describe herein. 
     While the relatively stiffer material  56  may be any suitable material, it is preferably a thermoplastic material. By way of example only, suitable thermoplastic materials include acrylonitrile butadiene styrene (ABS), polyethylene (PE), polyvinyl chloride (PVC), and polyethylene-terephthalate (PET) and combinations thereof. 
     The elastically deformable material  54  can be any suitable material that is comparatively more flexible and deformable relative to the relatively stiffer material  56 . The deformable material  54  may include such materials as a rubber, silicone, or silicone derivative. Examples of such materials include silicone elastomers, silicone-containing macromers, hydromacromers, TPU (thermo plastic urethane), TPR (thermo plastic rubber), TPE (thermo plastic elastomer), menoprene, and mixtures of the same. Furthermore, the composition of material in the nail body can be consistently uniform throughout or can be comprise generally discrete regions of differing materials or combinations of materials. 
     In various embodiments, the elastically deformable material  54  and the relatively stiffer material  56  of the nail bed portion  34  and the free edge portion  36  of the artificial nails  22  can be opaque, translucent, or transparent. Additionally, the artificial nails can be provided in various colors and glosses that simulate painted fingernails and may include nail tattoos or charms. Moreover, the artificial nails can be painted in different colors and patterns to simulate decorations, such as strips or flowers. In further embodiments, the artificial nails can be formed with raised protuberances that are shaped to simulate, for example, decorative flowers. 
     It will thus be appreciated by those of skill in the art that the artificial nail  22  is provided with a degree of flexibility such that the nail bed portion  34  of the preformed artificial nail may be flattened or more arched as it is applied to the user&#39;s natural nail such that the artificial nail  22  more closely conforms to the user&#39;s natural finger nail. More specifically, inasmuch as the nail bed portion  34  more flexible than the free edge portion  36 , the nail bed portion  34  may be “flattened” to conform to the natural shape of a flatter nail bed. When pressed against the nail bed of a flatter natural fingernail, the portions of the right and left side edges  37 ,  38  extending along the nail bed portion  34  contact the natural nail bed first and are deflected apart until the lower surface  42  of the nail bed portion  34  lies adjacent the natural fingernail. Conversely, when pressed against the nail bed of a more arched natural fingernail, the portions of the right and left side edges  37 ,  38  of the nail bed portion  34  may be manually arched downward to contact the user&#39;s natural nail bed until the lower surface  42  of the nail bed portion  34  conforms to the nail bed of the natural fingernail. Thus, even if the degree of curvature formed into the nail bed portion  34  during molding is greater or less than the degree of curvature of a natural fingernail, the artificial nail  22  may still be utilized in that it may be conformed to the natural nail bed in placement. 
     By conforming the nail bed portion  34  to provide substantially full contact the natural nail bed, a stronger bond between the artificial nail  22  and natural fingernail is produced. Specifically, where liquid adhesive or adhesive pads are used to bond the artificial nail  22  to the natural fingernail, the adhesive bond between the lower surface  42  and the natural fingernail will have a more uniform profile along the curvature of the natural fingernail. Additionally, because of the added flexibility of the deformable material of the nail bed portion  34 , the nail  22  will have less of a tendency to separate itself from the natural fingernail due to the resilient forces of the flexible material, and will provide the user a more comfortable fit than conventionally molded, single material artificial nails. This is especially advantageous during application when the artificial nail  22  has been pressed adjacent to the natural fingernail, but the applied adhesive or adhesive pad has yet to completely cure. Furthermore, conforming the shape of the nail bed portion  34  to the natural nail bed provides a more natural appearing and aesthetically pleasing joinder between the two. 
     Inasmuch as the free edge portion  36  of the artificial nail  22  is more rigid than the deformable nail bed portion  34 , the free edge portion  36  of the artificial nail  22  intended to extend beyond the natural finger nail free edge portion is provided with added strength. Hence, the artificial nail  22  is more resistant to deformation due to impact with external objects. Accordingly, the artificial nail  22  provides enhanced durability and comfort over traditional artificial nails. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.