OBJECT OF THE INVENTION 
       [0001]    The present invention relates to a part of an item of lingerie, and more specifically to an underwire for a brassiere, as well as to the brassiere comprising this underwire. 
       TECHNOLOGICAL BACKGROUND 
       [0002]    Lingerie articles are well known, such as brassieres which provide women with an undisputable ease of movement which contributed to their liberation. The latter may essentially be classified in two families. On the one hand, brassieres without any underwire, which are rather intended for women having small breasts, and on the other hand brassieres with underwires, which are more specifically intended for holding average or large breasts. 
         [0003]    In the case of brassieres without any underwire, this is a simple textile, either cut out and sewn, or molded for making cups, which themselves are attached to straps and to a support band, often itself in fabric. Diverse and varied attachment means may of course by contemplated for such supports. 
         [0004]    The other great family is formed by brassieres comprising a structure with underwires also called stays and which are intended to provide improved support of the breasts. 
         [0005]    Brassieres with underwires usually comprise sewn or molded cups to which are attached elements used as underwires such as stays. Conventionally, these stays are formed in a relatively rigid material such as a metal rod or optionally a rigid element in a synthetic material. Said stays are then sewn inside a fabric structure in order to protect them, notably during washing operations, and to protect the person wearing this type of brassiere. 
         [0006]    In practice, the main drawback of the use of such underwire elements formed by the stays lies in the fact that there always exists a risk of injury because of poor positioning of said stays. Further, these stays although they are often confined between two fabric layers in the brassiere may be extracted from said brassiere for example during washing in a washing machine, and consequently cause damage to said washing machine. Finally, generally, the discomfort brought by the presence of stays is larger than in the case of a brassiere without any stays. 
         [0007]    In recent years, cups which have a molded shape, were usually proposed to women. These cups are made in most cases with foam, for example a flexible polyurethane foam, subject to forming. It is also possible to directly contemplate the use of fabrics having a significant percentage of synthetic fibers, more particularly elastomeric fibers, which may be thermoformed directly in a mold and which will appear as cups without any seams. The main advantage of the use of elastomeric fibers is that the cup continues to have flexibility and therefore intrinsic deformability. 
         [0008]    The present invention is directed to proposing a novel type of brassiere, and more specifically a novel type of underwires which would provide a breast-holding capacity, which is reinforced as compared with brassieres without any underwire or stay and which does not have the drawbacks of the family of brassieres belonging to the family of brassieres with rigid underwires, and notably which is sufficiently flexible for adapting to the shape of the breast and to the movements of the latter. 
         [0009]    Further, the present invention is directed to propose a novel type of brassiere, and more particularly a novel type of underwires, which would provide not only increased comfort and hold but would also avoid any risk of losing underwire elements in particular during cleaning in a washing machine. 
         [0010]    The present invention also aims at proposing a type of brassiere, and more specifically of underwire, which will be adapted to the aesthetics desired by the creator of the lingerie. 
         [0011]    Finally, the present invention gives the possibility of adapting to any type of cup, in particular intended for small breasts, medium breasts or large breasts. 
       SUMMARY OF THE INVENTION 
       [0012]    The present invention relates to an underwire for brassiere, in the form of a profile with two limbs, characterized in that the section of each of the limbs of the profile is a polyhedron and preferably a curvilinear triangle and in that the central axis of each of the two limbs is not positioned in a single and same plane. 
         [0013]    Advantageously, the tilt angle of (between) both limbs is comprised between 5 and 40 degrees. 
         [0014]    Preferably, the underwire comprises an internal face capable, under conditions of use of coming into contact with the body of the user, an external face opposite to the internal face and turned, under conditions of use, outwards from the body of the user, the curvilinear polyhedron being defined by at least one face forming the internal face, an external face, and at least one third face protruding on the internal face and intended to support the breast of the user under conditions of use. 
         [0015]    Advantageously, one of the limbs of the underwire, defined as the first limb, is able to be in contact, under conditions of use, with the portion of the breast of the user in proximity to the sternum and the other limb, defined as the second limb, is able to be in contact, under conditions of use, with the portion of the breast of the user located opposite relatively to the sternum, both individually considered limbs being located in a same plane. 
         [0016]    Preferably, one of the limbs of the underwire, defined as the first limb, is able to be in contact, under conditions of use, with the portion of the breast of the user in proximity to the sternum and the other limb, defined as the second limb is capable of being in contact under conditions of use with the portion of the breast of the user located opposite to the sternum, at least one of both limbs, considered individually being located in at least two different planes. Advantageously, the central axis of the second limb is located on a curved surface. Preferably, the second limb is curved (tilted) towards the inside of the underwire. 
         [0017]    In certain embodiments of the invention, both limbs of the underwire are identical. 
         [0018]    Preferably, both limbs of the underwire are dissymmetrical, the first limb being shorter than the second limb. 
         [0019]    According to a preferred embodiment of the underwire, its external face has at least one notch. 
         [0020]    Advantageously, the underwire of the invention has several notches, the density of which varies along the underwire, the density of the notches preferably being greater on the second limb than on the first limb. 
         [0021]    Preferably, the dimensions of the notches vary in at least one space direction. 
         [0022]    Advantageously, the underwire of the invention comprises (or consists of) one or several polymeric materials having a flexure modulus of more than 350 MPa, preferably comprised between 500 and 3,000 MPa, and more preferably between 800 and 2,000 MPa. The polymeric material is preferably selected from the group formed by polyethylenes, poly(vinyl chloride)s, poly(ethylene terephthalate), polypropylenes, polystyrenes, polyamides and mixtures thereof. 
         [0023]    Another aspect of the invention relates to a double underwire comprising a set of two underwires according to the invention. 
         [0024]    The present invention also relates to a brassiere comprising an underwire or a double underwire according to the invention. 
     
    
     
       SHORT DESCRIPTION OF THE FIGURES 
         [0025]      FIG. 1  shows an overview of a first preferred embodiment of a simple underwire according to the present invention. 
           [0026]      FIG. 2  shows an overall view of a second preferred embodiment of a simple underwire according to the present invention. 
           [0027]      FIG. 3  shows in a simplified way the diagram of a double underwire according to the present invention. 
           [0028]      FIGS. 4A-4B  show lateral projection views of the underwire according to the second preferred embodiment of the present invention, corresponding to the photographs of  FIGS. 5A and 5B . 
           [0029]      FIGS. 5A-5B  correspond to photographs in a side view of the underwire of  FIGS. 4A and 4B . 
           [0030]      FIG. 6  (which is equivalent to  FIG. 8A ) similarly to  FIG. 5A  illustrates a side projection view of the underwire, but according to the first preferred embodiment of the present invention. 
           [0031]      FIG. 7A  corresponds to a 3D view of a portion of the underwire according to the invention in the middle plane, while  FIGS. 7B-7C  show a view with more details. 
           [0032]      FIG. 8A  is equivalent to  FIG. 6 . 
           [0033]      FIGS. 8B and 8C  show in 3 dimensions the structure of the notches in the first preferred embodiment oft the underwire according to the invention. 
           [0034]      FIGS. 9A and 9B  show in 3 dimensions a general view of the underwire according to the second preferred embodiment of the invention, on the internal face side for  FIG. 9A , and on the external face side for  FIG. 9B . 
           [0035]      FIG. 10  illustrates the main principle for positioning the underwire according to the invention on the breast of a user. 
           [0036]      FIG. 11  shows an overall profile of a notch of the underwire according to the invention. 
           [0037]      FIG. 12  shows how two successive notches along the underwire of the invention form a tooth. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]    The originality of the brassiere according to the invention is based on a quite particular underwire, a three-dimensional underwire. More specifically, this underwire advantageously has a profile which is a geometrical configuration in three dimensions. Further, more advantageously, the structure is itself three-dimensional. 
         [0039]    According to the invention, this underwire has an adapted conformation for providing both good support of the breast and sufficient flexibility for the user, i.e. both the rigidity required for efficient mechanical support and optimum comfort of use. 
         [0040]    Advantageously, the underwire further has an adapted composition which contributes to ensuring this double role. 
         [0041]    Thus, from a conformational (therefore geometrical) point of view, the underwire or stay  1  according to present invention corresponds to a part with a profile (and preferably the central axis of said profile) which has a shape (geometrical configuration) of an arch or a circular arc such as for example a U-shape, preferably truncated, and adapted for supporting either the right breast, or the left breast of the user as shown in  FIG. 1  and in  FIG. 2 . 
         [0042]    Alternatively, the underwire (more commonly called stay)  1  according to the present invention corresponds to a single part with a double profile forming a double U or a double arch adapted for supporting both the right breast and the left breast of the user, as shown in  FIG. 3 . 
         [0043]    The dimensions of the underwire will be adapted to the various measurement standards currently used in the field of lingerie, in particular as regards the size of the cup. 
         [0044]    The profile  1  consists of two limbs  2 ,  2 ′, preferably non-symmetrical, joined to each other at an area  3  called a &lt;&lt;junction area&gt;&gt;. This junction area  3  corresponds, under conditions of use, to the area of maximum support of the breast (of the weight of the breast) by the profile  1 . 
         [0045]    Each limb  2 ,  2 ′ comprises a free distal end  4 ,  4 ′ forming one of two edges of the underwire  1 , and a proximal area  5 ,  5 ′, which by joining up with the proximal end  5 ′,  5  of the other limb  2 ′,  2  defines the junction area  3 . 
         [0046]    A central axis (not shown) is also defined for each limb  2 ,  2 ′. This may be an axis corresponding to the succession of the geometrical centers or centers of gravity of the successive perpendicular sections for a same corresponding limb. In the case of homogenous material, the centre of gravity will correspond to the geometrical centre. It is also possible to contemplate that this central axis be materialized for example by a mechanical support having some flexibility. 
         [0047]    As illustrated in these same  FIGS. 4A and 4B , as well as in  FIGS. 5A ,  5 B and  6 , the three-dimensional nature of the geometrical configuration of the underwire according to the invention first of all comes from the fact that both limbs  2 ,  2 ′, and more specifically the central axis of each of both limbs  2 ,  2 ′ are tilted, of the profile  1  (of the arch) are not located in the same plane. In other words, both limbs  2 ,  2 ′ of the profile  1  are tilted by a certain angle  6  relatively to each other. This characteristic of the underwire according to the invention contributes to optimal adaptation of the underwire to the shape of the body of the user, i.e. to her anatomy, including when the latter performs movements. 
         [0048]    Preferably, this angle  6  varies between 5 and 40°, and preferably between 15 and 35°, and still more preferably between 20 and 30°. 
         [0049]    Further, each of the two limbs  2 ,  2 ′ taken individually is positioned either in a single and same plane, or according to a curved surface not corresponding to a single and same plane but then contributing in the latter case to the three-dimensional nature of the geometrical configuration of the profile  1 , as shown for example in  FIG. 4A  or in  FIGS. 5A and 5B . 
         [0050]    Thus, in a particular advantageous way, the limb  2  i.e. the limb intended to be in contact, under conditions of use with the portion  18  of the breast  19  of the user placed against the sternum (see  FIG. 10 ) has a conformation in space such that it is curved towards the inside of the underwire, as illustrated in  FIG. 4A . The curved side is therefore placed towards the sternum. 
         [0051]    By means of this conformation, the breast of the user is better supported, as encased and held, giving a pleasant effect upon wearing the brassiere. 
         [0052]    Advantageously, the inner curvature of the underwire gives the possibility of maintaining the brassiere well adhered to the body even if the weight of the breasts tend to detach the middle of the underwire which will be set into place by means of this curvature. 
         [0053]    Also, by means of this particular confirmation, the underwire, under conditions of use, cannot deform, it only becomes a little detached when the weight of the breast of the user is exerted towards the front, i.e. typically when the person bends forward. The underwire comes back into place and is again adhered to the body as soon as the person straightens back. 
         [0054]    The underwire or stay  1  has an internal face  7 , intended, under conditions of use, to be in contact with the thorax of the user, and an external face  8 , opposite to the internal face  7  and therefore oriented, under conditions of use as indicated by its name, towards the outside. Therefore it should be understood that the external face  8  of the underwire  1 , under conditions of use, is not in contact with the thorax of the user, as illustrated in  FIGS. 4B and 6 . 
         [0055]    The three-dimensional nature of the underwire according to the invention also comes from the fact that the profile  1  has an essentially three-dimensional structure, i.e. which has a section of the shape of a polyhedron/polygon, and preferably a section with a triangular shape, and still more preferably a section with a curvilinear triangular shape. In other words, if a section of the profile of the underwire is carried out in the middle plane, a polyhedron and preferably a curvilinear triangle are obtained, i.e. the profile draws a polygon or a triangle for which at least one of the sides is curved, as illustrated in  FIGS. 7A ,  7 B and  7 C. 
         [0056]    Preferably, this curvilinear triangle has three sides:
       the first side  10  is defined by the internal face  7  of the underwire  1  which preferably has a convex surface;   the second side  11  is defined by the plane  9  which will protrude from the internal face  7  of the underwire  1 ; this is the side on which under conditions of use, the breast of the user is supported; this second side  11  therefore ensures a function for supporting the breast;   at least one third side  12  is defined by the external face  8  of the underwire  1 ; this side  12  is curved and may be concave or convex (see  FIG. 7C ).       
 
         [0060]    The internal face  7  of the profile  1  is therefore preferably convex so as to be able, under conditions of use, to fit at best the anatomy of the user, and more specifically the shape of the thorax on which it rests and fit at best the shape of the side(s) on which it rests. 
         [0061]    However, alternatively, the internal face  7  may also have a globally planar surface rather than convex. 
         [0062]    It is also possible to contemplate that the profile of the underwire  1  has a section with a more complex shape than the curvilinear triangle. One skilled in the art may easily anticipate other shapes which may also be suitable in order that the underwire  1  may fulfill its role. 
         [0063]    Preferably, the profile  1  according to present invention is provided on its external face  8  with at least one notch  13  (see  FIGS. 8A-8C  and  9 A- 9 B). Nevertheless, alternatively, the underwire according to the invention may also not have any notch. 
         [0064]    When the profile  1  has notches  13 , the density of the latter advantageously varies along the underwire depending on the desired degree of flexibility. 
         [0065]    Preferably, the density of the notches  13  varies along the underwire  1 , this density being larger on the limb  2 ′ than on the limb  2 . In other words, as shown in  FIG. 10 , preferably according to the invention, the underwire  1  comprises more notches  13  on its portion intended to be in contact, under conditions of use, with the portion  18 ′ of the breast  19  of the user opposite to the sternum than on its portion intended to be in contact with the portion  18  of the breast of the user in proximity to the sternum. 
         [0066]    Thus, the underwire  1  once set into place in a brassiere may, under conditions of use, adapt at any instant at best to the shape of the thorax of the user, and more specifically of her rib cage, while ensuring maximum support of the breast, thereby increasing the comfort of the user, including when the latter is moving, and this regardless of the nature of these movements. 
         [0067]    Preferably, the density of the notches is such that the number of notches varies between 5 and 15, and still more preferably between 8 and 11, on the limb  2 , while the number of notches varies between 15 and 30, and still more preferably between 17 and 28, on the limb  2 ′. 
         [0068]    Also, the dimensions of the notches  13  may advantageously vary depending on the desired degree of flexibility. Thus, preferably, the depth of the notch (dimension in the plane  9 ) will be maximum at locations where it is desired that the underwire has maximum flexibility, i.e. on the portion intended to be in contact with the outside of the breast of the user. 
         [0069]    Thus, advantageously, the depth of the notches (dimension in the plane  9 ) varies between 0 and 50 mm, and preferably between 0.1 and 20 mm. 
         [0070]    The depth of the notches  13  may also be constant along the underwire in certain embodiments. 
         [0071]    Advantageously, two successive notches  13 ,  13 ′ form together a tooth  16  for which the width  17  (dimension along the curvature of the underwire) may preferably vary between 2 and 30 mm, preferably from 2 to 10 mm (see  FIGS. 6 and 12 ). 
         [0072]    The shape of the notches  13  may also vary. Advantageously, the edges  14 ,  14 ′ of the notches  13  are rounded so as to avoid catching the fabric once it is set into place in the brassiere, as shown in  FIG. 11 . 
         [0073]    As shown by  FIGS. 2 ,  4 A- 4 B,  5 A- 5 B,  6 ,  9 A- 9 B, and as already mentioned above, preferably, both limbs  2 ,  2 ′ of the underwire according to the invention are not symmetrical. 
         [0074]    In order to be able to be integrated at best into the brassiere, the underwire may advantageously be sewn on the piece of fabric forming the brassiere by means of one or several apertures  15 ,  15 ′ located on its edges as shown for example in  FIGS. 1 and 2 . 
         [0075]    As illustrated in  FIG. 10 , when the brassiere is set into place, the underwire or stay is positioned under the breast, and the brassiere may either be closed on the back or on the front, this for example by means of a fastening hook positioned on a supporting band surrounding the body, this band being essentially positioned perpendicularly with respect to the torso and allowing the brassiere to be maintained in place. 
         [0076]    As regards its composition, preferably, the underwire or stay according to present invention consists of one or several polymeric materials having a flexure modulus of more than 350 MPa, preferably comprised between 500 and 3,000 MPa, and more preferably between 800 and 2,000 MPa. 
         [0077]    Preferably, the polymeric material is selected from the group of polyethylenes (PE), polyvinyl chloride)s (PVC), polyethylene terephthalate) (PET), polypropylenes (PP), polystyrenes (PS), and polyamides (PA). 
         [0078]    Preferably, the polymeric material comprises polypropylene (PP) or high density polyethylene (HDPE). 
         [0079]    From among polypropylenes, random copolymers having a low ethylene content are preferred, indeed they have a flexion modulus comprised between 900 and 1,200 MPa, which represents a good compromise between the rigidity required for efficient mechanical support and optimum comfort of use. They further have a reduced glassy transition temperature of less than 0° C., which gives the possibility of avoiding their becoming fragile for example during transport in cold regions. Finally, these random polymers have improved transparency, which allows greater freedom in colors and in appearance selections for the brassiere designer. 
         [0080]    High density polyethylenes (having a density of more than 0.93 g/cm 3 ) have similar properties, nevertheless with a lower melting point (+/−130° C.) and a glassy transition below −50° C. As this is a material having a high crystallinity level, it is also less transparent than polypropylene. 
         [0081]    Both by its conformation and its particular composition, the underwire according to the invention allows optimum distribution of the weight of the breast, notably for large breasts, thereby avoiding any forward movement of the weight of the breast, and therefore any sensation of discomfort for its user. The underwire according to the invention avoids after a few movements of the torso, that the breast slips forward and collapses, and that the base of the brassiere does not detach from the body, as this is known with conventional metal underwires, thereby ensuring constant aesthetics in spite of the movements.
The invention relates to a part of an item of lingerie, specifically to a three-dimensional underwire ( 1) for a brassiere, the profile thereof being in the form of an arch with two limbs ( 2, 2'), characterised in that the cross-section thereof is an essentially curvilinear triangle and in that the two limbs ( 2, 2') are inclined in relation to each other at a certain angle. The invention also relates to a brassiere comprising said underwire ( 1).