Patent Application
20140248822
The invention relates to circularly.knitted upper and lower torso garments, such as a brassiere or brief. More particularly, the present invention relates to a circularly knitted brassiere and a lower torso undergarment having an improved chest band and waist band, respectively, affixed between the overlapping plies of fabric.
Upper torso garments, such as, brassieres generally and sports bras in particular have a torso encircling band that is knitted at or attached to the lower edge of the brassiere to provide stability and additional support to the wearer. Such bands also are knitted at or attached to the upper edge of lower torse undergarments, such as briefs, to function as a waist band. One known way to form a chest band or waist band is to knit a turned welt during the process of knitting the fabric tube. An alternative method is to stitch an elastomeric band to the bottom edge of the brassiere, or the top edge of the brief, around the entire periphery; this additional step requires additional labor and increases costs. The resulting band tends to be relatively bulky and thick, and, therefore more visible and less comfortable when worn.
An aspect of the present invention is a circularly knitted garment, such as a brassiere or brief, having a thin elastomeric band affixed between overlapping plies of knitted fabric. In one exemplary embodiment, the elastomeric band comprises a thin polyamide film having a modulus (kilograms of holding power) that is greater than can be achieved by conventional elastomeric yarns, such as spandex and Lycra®. The modulus of the plies and film combined may be between about 1.0 kg and 4 kg. As used herein, the term “modulus” refers to the kilograms of recovery force available in the material at a given percentage of stretch. The greater the modulus, the stiffer the material, i.e. the more resistant the material will be to linear stretch. Depending upon the type of elastomeric material, its width and thickness, its modulus may vary widely.
Another aspect of the present invention is a method of forming a brassiere or lower torso undergarment having an elastomeric band affixed between the overlapping plies of fabric. The method comprises circularly knitting a body that is symmetrically dimensioned for forming a two-ply garment, comprising inner and outer layers when folded about a central fold line. The elastomeric band is positioned proximate the fold line and the plies are symmetrically overlapped about the fold line, thus enclosing the elastomeric band and forming the two-ply garment with a torso band that is thinner and, therefore, less visible and more comfortable when worn. In one embodiment, the elastomeric band is affixed to one or both of the inner and outer layers of knitted fabric by the application of temperature and pressure for a selected amount of time.
The present invention will be more apparent from the following detailed explanation of embodiments of the invention in connection with the accompanying drawings.
One aspect of the present invention is directed to an upper torso garment, such as, a brassiere, a sports bra or a camisole. Referring to
The brassiere body may be formed of any of the conventional materials such as polyester, nylon, etc. The body may be formed by also knitting in one or more elastomeric yarns, such as spandex, having some degree of elasticity for securing the garment about the wearer's torso. Each ply of fabric for the embodiments described herein may be between about 0.6 mm and about 2.0 mm thick.
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Turning now to
In one embodiment, the elastomeric band 170 comprises a thin film of thermoplastic elastomer (TPE). The thermoplastic elastomer may comprise a polyamide blend. One such polyamide blend is available under the trademark Pebax® from Arkema Inc. of King of Prussia, Pa. Other thin elastomeric materials, including other films, having the physical properties described below, may be suitable to form the elastomeric band 170.
By way of example and comparison, for the exemplary embodiments shown herein, a typical knitted-in torso band, e.g., a turned welt, would be approximately 2.0 mm thick. A cut and sew brassiere with a sewn in elastic band of similar weight to the turned welt would be approximately 1.8 mm thick. A band having the polyamide film would be approximately 1.5 mm thick.
The modulus of the elastomeric material depends on its type of material, width and thickness. In the exemplary embodiments described herein, an optimal modulus may be between about 1.0 and 4.0 kilograms. As shown in the several examples in Table 1 below, this range in the modulus corresponds to between about 95% and 140% in deformation (stretch) when the elastomeric band 170 is subjected to a length direction static load of 7 kilograms.
By way of comparison, the body of brassiere 100 will have a modulus of less than 1 kilogram. For example, the two overlapped plies, formed from a conventional blend of 89% weight nylon and 11% weight spandex has a modulus of about 0.132 kg at 40% elongation and about 0.35 kg at 60% elongation. As seen in Table 1 above, the elastomeric bands provide a reduced increase in modulus with increased elongation. This produces a brassiere 100 that will be comfortable over a larger range of sizes. In the torso band region at the bottom of the brassiere proximate the fold line 173, the two-ply body material alone would allow for elongation of 160% when tested under the same 7 kg load as the samples in Table 1.
Referring again to
The elastomeric band 170 is positioned proximate the center fold line 173 on what will become the inner surfaces of the two-ply brassiere body when the tube is folded. The elastomeric band 170 may be coated on one or both sides with a heat-sealable adhesive 172 for adhering the elastomeric band 170 in position once the brassiere construction is complete. One suitable heat-sealable adhesive 172 is RX 2641, available from Bixby International Corp. of Newburyport, Mass. The invention, however, is not limited to using a heat-sealable adhesive to adhere the band 170; rather, the use of other suitable materials and methods for securing the band to the garment are within the scope of the invention.
The inner 112 and outer 114 layers of the brassiere body are next symmetrically overlapped about the fold line 173, enclosing the elastomeric band 170 and forming the two-ply brassiere body as described above. Where a heat-sealable adhesive 172 is applied to one or both sides of the elastomeric band 170, the elastomeric band 170 is affixed between the two plies with an air-operated press having upper and lower heating elements. An application temperature may be between about 150 degrees Fahrenheit and 380 degrees Fahrenheit, preferable about 320 degrees Fahrenheit. The application pressure should be no less than about 10 psi and no more than about 120 psi, preferably between about 30 and about 60 psi. The preferred pressure should be applied for no less than about 5 seconds and no more than about 90 seconds, preferably between about 20 and about 30 seconds.
Once the elastomeric band 170 is adhered between the inner 112 and outer 114 layers, the brassiere body may be cut to the desired shape. Subsequently, trim 190 is applied along the free edges, shoulder straps 160 attached, and fasteners 150 are affixed to complete the brassiere 100 construction. Where shoulder strap portions 160 are formed and cut with the brassiere body, they need only to be seamed together proximate the top of the shoulder. Similarly, where the torso strap 135 is continuous, no fasteners 150 are necessary.
Another aspect of the present invention is directed to a circularly-knitted lower torso undergarment, such as a boxer, a brief, a boxer brief, panties, pantyhose or shapewear. Referring to
The briefs 200 of the present invention comprises a pair of leg openings 210, a crotch portion 230 and a waist opening 220 surrounded by a waist band 250 of the present disclosure. The embodiment illustrated includes leg portions 240 as is typical of boxer style briefs. Conventional briefs, i.e. without leg portions 240, for males or females having the waist band 250 are also within the scope of the invention.
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It should be understood that the foregoing descriptions and examples are only illustrative of the invention. Various alternatives and modifications thereof can be devised by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications, and variations.
