Patent Application
20160044971
The present application relates to bras that are to be worn while engaged in athletic activities.
Many sports bras are designed to limit or prevent movement of a wearer's breasts while she is engaged in athletic activity. During high impact activities, a woman's breasts do not move up and down together, but rather separately, in what can be called a “butterfly” motion. This movement of the breasts is very painful and possibly damaging to the supportive breast tissue. Currently, the common ways of supporting the breasts during athletic activity and controlling this butterfly motion are by high compression fabric, components, and construction; rigid fabric and components; and/or encapsulation of the breasts via separate breast cups, usually requiring a molded pad with or without an underwire, and usually requiring two individual cups that surround each breast, keeping, them separate.
Constructing a garment using the above-mentioned material and methods results in a tight and uncomfortable fit for the wearer; however, women who require a supportive garment to reduce breast movement during high impact exercise have no choice but to wear a similarly-constructed garment or multiple support garments to meet their breast support needs. For more information regarding breast discomfort during physical activity, and the detrimental effects thereof, please see An Abstract of the Thesis “Breast Support for the Active Woman: Relationship to 3D Kinematics of Running,” by Ann L. C. Boschma, submitted to Oregon State University on Sep. 23, 1994. Boschma summarizes her study of running kinematics with the following observation: while exercising, women of all breast sizes experience increases in breast discomfort as breast support decreases. This indicates that full support bras are more comfortable for a wearer engaged in vigorous athletic activities, no matter what her breast size.
This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In one example of the present disclosure, a front panel for a sports bra includes an interior liner layer having a back face contacting a wearer's skin, and having a size and shape configured to substantially cover a wearer's breasts. An exterior shell layer having a back face facing a front face of the interior liner layer, and also having a size and shape configured to substantially cover the wearer's breasts, is coupled to the interior liner layer. A film layer is located between the front face of the interior liner layer and the back face of the exterior shell layer. When the front panel is worn as part of the sports bra, the film layer is configured to stiffen as a frequency of movement of the wearer's breasts increases, thereby absorbing forces caused by the movement of the wearer's breasts.
In another example, a method for constructing a front panel for a sports bra that stiffens upon movement of a wearer's breasts is disclosed. The method includes providing an exterior shell layer having a size and shape configured to substantially cover the wearer's breasts, and providing an interior liner layer having a back face for contacting a wearer's skin and also having a size and shape configured to substantially cover the wearer's breasts. A film layer is provided and placed between a back face of the exterior shell layer and a front face of the interior liner layer. The film layer, the external shell, layer, and the interior liner layer are then coupled together. The film layer comprises a thermally-induced shape memory polymer that exhibits viscoelastic properties when at body temperature and stiffens to absorb between about 0.015 N and about 0.03 N of force at frequencies of breast movement of between about 6 Hz and about 15 Hz.
Examples of articles of manufacture and methods for manufacturing bras and materials that can be used to construct bras are described with reference to the following figures. These same numbers are used throughout the figures to reference like features and like components.
Straps 14a, 14b are attached to an upper portion of the back of the bra 9 via rings 26a, 26b, which also allow for adjustment of the lengths of the straps. Straps 14a, 14b are connected by rings 26a, 26b respectively to wings 28, 30. Wings 28, 30 may be connected to one another at location 31 by a hook and eye closure, or by any other closure known to those having ordinary skill in the art, such as by snaps, Velcro, magnetic closures, etc. When the bra 9 is fully assembled, wing 28 extends from left side 20 of the exterior shell layer 12 and wing 30 extends from right side 22 of the exterior shell layer 12 (see
Turning to
In one example, an underwire 34 may be coupled to the internal fabric layer 32. For example, the underwire 34 may be a plastic underwire that is surrounded by an underwire runnel casing The underwire tunnel casing may be sewn along its edges to the internal fabric layer 32. The tunnel casing may additionally or alternatively be glued, bonded, or taped to the internal fabric layer 32, or the underwire 34 itself maybe glued or taped to the internal fabric layer 32. The underwire 34 may comprise a continuous, undulating W shape, or may comprise two separate U-shaped underwires, although these are not shown herein. Each of the weight, thickness, and shape of the underwire 34 may be customized by cup size to provide the required support level. The underwire 34 may be sewn to the front face 15a of the internal fabric layer 32 such that the springiness of the spacer fabric between the underwire 34 and the wearer's skin protects the wearer from the relative rigidity of the underwire 34.
Again, continuing inwardly from the internal fabric layer 32 towards the wearer's breasts, as shown in
Thus, the apertures 42a, 42b allow the volume of the user's breasts to fit within the front panel 10 despite the non-stretchy film layer 36. Generally, the apertures 42a, 42b may be sized to allow a substantial portion of the wearer's breast tissue to project there through, and in one example about 50% of a wearer's breast tissue projects through the apertures 42a, 42b, if these apertures 42a, 42b were not provided, some sort of puckering, folding, or gathering of the material of the film layer 36 could instead be provided in order to fit the volume of the wearer's breasts within the first and second breast cups 40a, 40b In the example shown, the film layer 36 comprises a single sheet having two apertures 42a, 42b; however, the film layer 36 could comprise multiple sheets sewn or otherwise connected together. As shown herein, film layer 36 is sewn or otherwise connected along seams 23 to exterior shell, layer 12, which are the same seams along which internal fabric layer 32 is sewn to exterior shell layer 12. Note that where these seams 23 are provided is also roughly where the film layer's lateral edges are located.
The film layer 36 may be molded such that the first and second breast cups 40a, 40b have a concave shape that approximates a shape of the wearer's breasts and that is predetermined based on breast size. The convex exterior of the bra shown in
Now turning to
The interior liner layer 44 may also be molded such that it has first and second breast cups 45a, 45b that have a concave shape and that fit the size of a wearer's breasts. These cups 45a, 45b, when a wearer's breasts are not in them, appear as somewhat wrinkled or looser areas in the fabric, of the interior liner layer 44, which then stretch to encapsulate the wearer's breasts when the bra 9 is worn. It should be understood that when the wearer's breasts are described as at least partially extending through the apertures 42a, 42b in the film layer 36, the wearer's breasts are in fact resting in the breast cups 45a, 45b of the interior liner layer 44, and both the wearer's breasts and the fabric of the breast cups 45a, 45b project through the apertures 42a, 42b, respectively. The interior liner layer 44 thus provides a smooth surface for contacting the wearer's skin, as well as a barrier between the wearer's breasts and the film layer 36, such that the wearer does not notice that her breasts are projecting through the apertures 42a, 42b.
Now turning to
In any of the examples of FIGS, 6, 8, and 9, the film layer 36 may be included in several different ways. The film layer 36 may be a separate layer of material that is formed as a mesh a layer of fabric with holes in it). Alternatively, the film layer 36 may be a resin layer printed On or otherwise molded or adhered to another layer of fabric made of natural, synthetic, or a blend of natural and synthetic fibers (i.e., the film layer 36 may be a resin layer covering part of the surface of at least one side of the other fabric). In yet another example, the film layer 36 may be a resin layer printed onto the back face 13b of the exterior shell layer 12, the back face 15b of the internal fabric layer 32, or the front face 19a of the interior liner layer 44.
According to the present disclosure, the material of which the film layer 36 is made becomes stiffer as a frequency of movement of a wearer's breasts increases, and thereby absorbs forces caused by the movement of the wearer's breasts. This is important because, as the frequency of a wearer's breasts increases (from moderate to strenuous exercise) the force caused by acceleration of the breasts also increases. This increasing force can be absorbed by the film layer 36 of the present disclosure, which is made of a shape-memory polymer (SMP). According to the present disclosure, the film layer 36 may comprise a thermally-induced SMP that exhibits viscoelastic properties when at or near the temperature of the human body. In other words, the SMP's glass transition temperature is at or near body temperature. The SMP stiffens to absorb energy at frequencies of breast movement between about 1 Hz and about 100 Hz and is capable of effectively absorbing forces up to and above 0.03 N, as will be described further herein below. At or near body temperature, the SMPs described herein are able to provide damping to the movement of the wearer's breasts, as they also exhibit a high energy dissipation factor (tanδ) at higher frequencies, yet maintain a good skin feel at lower frequencies, where the tanδ is also lower. Additionally, given a constant frequency, tanδ is at a maximum in the range of the temperature of the human body, and thus the SMPs described herein are particularly suited for applications in clothing.
In one example, the polymer from which the SMP fabric is constructed may include polyurethane elastomer resin and polystyrene elastomer resin blended, for example, in a ratio of 9:1. In another example, the polymer is a blend of thermoplastic polyurethane and thermoplastic polyurethane-silicone elastomer (made by a dynamic vulcanization process), combined, for example, at a mass ratio of 90:10 to 60:40. In still other examples, parts or all of the film layer 36 are made of 100% silicone, or 100% thermoplastic polyurethane (TPU), such as DESMOPAN® Developmental Product DP 2795A-SMP provided by Bayer Material Science of Pittsburgh, PN.
In another example, described in as-yet unpublished Japanese Patent Application No. 2015-17206, filed on Jan. 30, 2015 by SMP Technologies, Inc. of Tokyo, Japan and by inventor Dr. Shunichi Hayashi, and hereby incorporated herein by reference, the SMP film layer 36 may comprise a polyurethane elastomer produced by the polymerization of a bifunctional diisocyanate, bifunctional polyol and bifunctional chain extender using the pre-polymer method or bulk method at a molar ratio of 2.00-1.10:1.00:1.00-0.10, and may have multiple apertures at an aperture ratio ranging from 10-90% (inclusive). The molecular weight of the bifunctional diisocyanate can range from 174 to 303, the molecular weight of the bifunctional polyol can range from 300 to 2500, and the bifunctional chain extender can be a diol or diamine with a molecular weight ranging from 60 to 360. The number of apertures in the film per unit area can range from 30/cm2 to 150/cm2 (inclusive). Specific examples of the bifunctional diisocyanate include 2,4-toluene diisocyanate, 4,4′-diphenyl methane diisocyanate, carbodiimide-modified 4,4′-diphenylmethane diisocyanate and hexamethylene diisocyanate. Specific examples of the bifunctional polyol include polypropylene glycol, 1,4-butane glycol adipate, polytetramethylene glycol, polyethylene glycol, and propylene oxide adducts of bisphenol-A. The bifunctional polyol can also be further modified by reacting it with a bifunctional carboxyllic acid or cyclic ether. Examples of the diols which can be used include ethylene glycol, 1,4-butane glycol, bis (2-hydroxyethyl, hydroquinone, ethylene oxide adducts of bisphenol-A and propylene oxide adducts of bisphenol-A. Examples of the dimities which can be used include ethylene diamine. The glass-transition temperature of the film should fall within a range of 0 to 40° C., with a range of 25 to 35° C. preferable.
In another example, the film layer 36 is a composite fabric including a fabric produced from natural fiber, synthetic fiber or a mixed fiber containing both natural fiber and synthetic fiber, as well as a synthetic resin layer which covers part of the surface of at least one side of the fabric. The synthetic resin layer is composed primarily of the above-mentioned polyurethane elastomer, and the coverage ratio of the synthetic resin layer relative to the surface of the fabric ranges from 10 to 90% (inclusive). For example, see
If the synthetic resin layer is a continuous film containing, apertures, the aperture ratio of the synthetic resin layer ranges from 10 to 90% (inclusive), or more specifically from 20 to 50% (inclusive). The number of apertures per unit area ranges from 30/cm2 to 150/cm2 (inclusive). The thickness of the synthetic resin layer ranges from 20 to 1,000 μm (inclusive).
For Example 1, a film was formed over a release sheet using gravure printing and the release sheet was applied to a fabric to prepare the composite fabric detailed below.
In order to demonstrate the superiority of the shape Memory polymers described herein and of fabric/SMP composites over materials generally used to construct front panels of sports bras,
Turning to
Turning to
The efficacy of the SMP film in counteracting movement of a wearer's breasts can also be studied by measuring the storage elastic modulus and loss modulus of the SMP film. The synthetic resin constituting the synthetic resin layer described in Example 1 above shows as higher storage elastic modulus E′ as well as a higher loss modulus E″ at frequencies which correspond to exercise versus frequencies which correspond to a rest state. The synthetic resin layer also shows a high mechanical dynamic loss tangent (tanδ) within the frequency range of the surface of the human body (0.1 to 100 Hz).
With reference to
In one example of the method, the film layer 36 is formed as a mesh. The mesh may be formed by placing a melted composition of SMP in a mold sized and shaped to produce a mesh having a thickness between about 0.15 mm and about 0.30 mm, and cooling the melted composition in the mold. The formed mesh may have a hole density of 480 holes/in2. The hole to SMP ratio of the mesh may be 1:4. In one example, the mesh may have a weight of about 136.8 g/m2 and a thickness of 0.22 mm, where both figures may vary by +/−10%. Such a mesh may have the following properties:
Alternatively, the film layer 36 can be formed via intaglio printing techniques, including gravure printing. A suitable catalyst can be added and melted into the bifunctional diisocyanate, bifunctional polyol and bifunctional chain extender mixture prepared at the above mentioned ratio range of 2.00-1.10:1.00:1.00-0.10 as needed to prepare a molten synthetic resin material. Given formability considerations, the molten synthetic resin material should show a viscosity ranging from 500 to 5,000 Pa·s at the relevant molding temperature (190 to 230° C.) with a range of 1,000 to 2,000 Pa·s preferable. The type (molecular weight) and relative proportions of the bifunctional diisocyanate, bifunctional polyol and bifunctional chain extender are selected in order to satisfy the above viscosity constraints. A plate corresponding to the shape of the synthetic resin layer is set within a priming apparatus. Prepared molten synthetic resin material is fed onto the printing apparatus plate and printed onto a release sheet. In this way a film is prepared on the release sheet. The film may be peeled off and used alone, or the release sheet may be bonded to a natural, synthetic, or natural/synthetic blend fabric. When the release sheet is peeled off, the film is transferred onto the fabric to form a synthetic resin layer thereon.
Alternatively, a synthetic resin film constituting a single continuous film can be formed on the fabric, after which part of the film is removed, in order to form a synthetic resin layer on the fabric. For example, the above mentioned bifunctional diisocyanate, bifunctional polyol and bifunctional chain extender mixture starting material can be cross-linked, after which it is mixed with a suitable solvent to prepare a synthetic resin solution. The synthetic resin solution is then applied to the surface of the fabric using known methods (e.g., screen printing). Subsequently, part of the synthetic resin film is removed via mechanical puncturing or laser treatment.
After it is formed, the mesh film or mesh film/fabric composite may be formed into a first breast cup 40a and a second breast cup 40b within a second mold. Care should be taken not to heat the mold to temperatures that will damage the properties of the film. Alternatively, the first and second breast cups can be formed while the mesh is first being cooled from its molten state in the mold or on the plate that was used to mate the mesh in the first place. After the mesh film or mesh film/fabric composite has been removed from the mold, the method may further include cutting or stamping a first aperture 42a at an apex of the first breast cup 40a and a second aperture 42b at an apex of the second breast cup 40b, the first and second apertures 42a, 42b configured to allow a wearer's breast tissue to project there through when the bra is being worn. If the mesh film is created using a printing technique, the apertures 42a, 42b may be formed by leaving unprinted areas. The method may further comprise molding the first and second breast cups 40a, 40b to a concave shape that approximates a shape of the wearer's breasts that is predetermined based on breast size, i.e., the graduation of the mold is changed based on the breast size for which the breast cup is molded.
The interior liner layer 44 can also be molded to create breast cups 45a, 45b, which can then be aligned with the breast cups 40a, 40b and apertures 42a, 42b of the film layer 36 as the two layers are combined to form the front panel 10 of the bra 9.
In the above description certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different articles of manufacture and methods described herein above may be used in alone or in combination with other articles of manufacture and methods.
The present application claims the benefit of U.S. Provisional Application Ser. No. 62/036,723, filed Aug. 13, 2014, and of U.S. Provisional Application Ser. No. 62/116,081, filed Feb. 13, 2015, both of which are hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62036723 | Aug 2014 | US | |
| 62116081 | Feb 2015 | US |
