Abstract:
This application describes a garment (e.g. a swim suit) having a base layer of stretchable elasticated fabric, the base layer having a torso portion that covers at least a part of the torso of a person when the garment is worn. An inner core layer of stretchable elasticated fabric is bonded to the inner surface of the base layer to extend around the abdomen and lower back regions of the garment. By providing a double layer of stretchable elasticated fabric in this manner, more compression is applied to the abdomen of the person (e.g. swimmer) wearing the suit, bringing about improvements in form drag. The additional support provided to the lower back and abdomen also improves core stability, which is of benefit in many sporting activities, including swimming.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention has to do with garments that incorporate elastic stretch fabric and fit tightly to the body, typically for sports use. Particular examples are described in relation to swimsuits, which is a preferred use. However, the concepts described can be applied to other sports and athletic garments including, for example, beach volley, waterpolo and triathlon wear. 
       BACKGROUND 
       [0002]    A number of known sports garments, especially racing swimsuits, are made from elasticated stretch fabric which fits closely and tightly against the body. In recent years use has been made of various fabrics with high elastane content having a high stretch constant to press more firmly against the body surface for a given degree of stretch. In racing swimsuits this reduces the entry of water between the suit and body—a source of drag—and avoids the sliding of the fabric over the skin. It can also reduce muscle vibration which is believed to be a cause of fatigue and body drag in swimming. 
         [0003]    In our earlier applications EP-A-1110464 and EP-A-1250858 we describe swimsuits that provide an improved, highly-tensioned fit over the body, especially lower back and abdominal fit, using a special disposition of seams joining panels of elasticated stretch fabric that make up the swimsuit. The introduction of a seam across a span of stretch fabric was shown to reduce the stretchability, i.e. potentially increase a degree of tensioning, in a direction transverse to the seam. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is generally concerned with structures for swimsuits (and other tight-fitting outer garments, especially sports garments) that can offer improved performance for competitive swimmers through a reduction in surface drag, a reduction in form drag and/or improved stability in the water. 
         [0005]    In a first aspect the invention provides a garment having: 
         [0006]    a base layer of stretchable elasticated fabric that covers at least the torso; and 
         [0007]    an inner core layer of stretchable elasticated fabric bonded to the inner surface of the base layer to extend around the abdomen and lower back regions of the garment. 
         [0008]    By providing a double layer of stretchable elasticated fabric in this manner, more compression is applied to the abdomen of the person (e.g. swimmer) wearing the suit, bringing about improvements in form drag. The additional support provided to the lower back and abdomen also improves core stability, which is of benefit in many sporting activities, including swimming. 
         [0009]    The inner core layer preferably extends upwardly on the front of the torso as far as the diaphragm (or lower ribs). On the rear of the torso, it preferably extends upwardly to cover the whole of the lumbar region. It is preferable that the inner core layer stops short of the chest on the front, so it does not impede breathing at all, and that it stops short of the lower ends of the scapula on the rear of the suit so that it does not impede movement of the shoulders and arms. 
         [0010]    At its lower end, the inner core layer preferably extends down to the crotch, both at the back and the front of the suit. The front and back parts of the inner core layer may join one another in the crotch region. Preferably they also join at both sides of the suit so that the core layer extends all of the way around the torso in a continuous band. 
         [0011]    Preferably, however, lateral sides of the inner core layer do not extend beyond the hip, a lower edge of the inner core layer having a concavely curved form over each hip region to extend further downwardly to the front and back than on the hip itself, so as not to unduly restrict movement of the legs. 
         [0012]    At the rear of the suit the inner core layer may extend downwardly to cover the buttock region (e.g. to entirely cover or even extend below the buttock ‘cheeks’, i.e. gluteal muscles), in order to compress the buttocks to improve form drag. 
         [0013]    In the case of a swimsuit intended for use by a swimmer performing the breaststroke, where a large degree of hip articulation is necessary, the inner core layer may terminate at its lateral sides above the hip, to allow even greater freedom of movement. 
         [0014]    The elastic stretch fabric used to make the base layer of the garment may be of any suitable kind. Fabrics of high stretch constant, e.g. polyester elastanes as conventionally used for making high-performance swimwear, are within the skilled person&#39;s routine knowledge. 
         [0015]    The inner core layer may be formed of the same material as the base layer of the garment. 
         [0016]    In preferred embodiments of this first aspect of the invention, the garment preferably has a plurality of panels laminated on the outer surface of the base layer in the manner described in our co-pending GB0625102.9. The panels preferably cover 20% or more of the torso and more preferably cover 25%, 30%, 35%, 40%, 45% or even 50% or more of the torso. In some preferred embodiments, the panels cover 20% or more of the rear of the torso and may cover as much 30%, 40% or even 50% or more of the rear of the torso. It is particularly preferred that the panels cover at least 50% of the front of the torso and in some embodiments may cover as much as 60%, 70% or 80% or more of the front of the torso. In some embodiments the panels will cover more of the front of the torso than of the rear of the torso. 
         [0017]    Competition swimsuits (and some other sports garments) often also cover either the whole or part of an athlete&#39;s legs. In such garments, the legs preferably also have one or more panels laminated on their outer surface. The panels may cover 50% or more of each leg. For example, the panels may cover substantially all of the upper leg. 
         [0018]    As explained in our co-pending GB0625102.9, the panels applied to the torso and/or limbs are preferably formed of a material having a higher stretch constant than that of the underlying base layer and are applied to areas of the torso in which it is desired for the suit to be more tensioned when worn to provide greater support and/or to reduce the form of the underlying part of the athlete&#39;s (e.g. swimmer&#39;s) torso, to reduce form drag in the water. The material from which the panels are formed preferably has an outer surface that is more ‘slippery’ (i.e. exhibits lower surface drag in water) than the underlying base layer, so water flows over it more quickly that it would over the base layer alone (i.e. it is a “fast fabric”). In this way, the surface drag of the overall suit is reduced by application of the panels, especially where the panels cover a substantial percentage of the surface of the suit. 
         [0019]    In garments with arms it is generally preferable to ensure that the athlete&#39;s arms have as much freedom as possible to move. Preferably, therefore, where the garment has arms, the arms of the suit are made from a lightweight fabric (either the same fabric as the suit torso or a lighter weight fabric) and there are no panels laminated onto the arms. In some embodiments the arms may be made from a heavier fabric that the suit torso. 
         [0020]    Preferred materials for these panels are as described below in the context of the second aspect. 
         [0021]    More generally, the swimsuit (or other sports wear) may cover e.g.
       (i) the whole body, including the full length of the arms and legs;   (ii) as (i) but not the arms;   (iii) as (i) or (ii) but not the legs, or the legs only down to knee-length;   (iv) the torso only, i.e. no arms or legs.       
 
         [0026]    In a second aspect the invention provides a cap (e.g. a swim cap) having a base layer of stretchable elasticated fabric and one or more panels laminated on the outer surface of the base layer, the panels covering 25% or more of the cap. 
         [0027]    In this aspect, the panels preferably cover 50% or more of the cap, more preferably 75%, 80%, 85%, 90% or more. 
         [0028]    The panels are preferably formed of a material having an outer surface that is more ‘slippery’ (i.e. exhibits lower surface drag in water) than the underlying base layer. In this way, the surface drag of the overall cap is reduced by application of the panels compared with a plain fabric cap, especially where the panels cover a substantial percentage of the surface of the cap. 
         [0029]    Preferred embodiments of the cap include a panel extending front to back across the top of the cap. This top panel preferably has a rectangular form towards the front with a front edge of the panel being arranged substantially parallel to the rim of the cap at the front. In contrast, the rear end of the top panel is preferably tapered, most preferably tapered to a point. 
         [0030]    The cap preferably includes a pair of side panels, one to each side of the cap. The side panels may be generally semi-circular in shape, preferably with a bottom edge that is substantially parallel to the rim of the cap along the respective side. 
         [0031]    The cap preferably includes both a top panel and two side panels. In this case, the top edge of each side panel may be generally parallel to the respective side edge of the top panel, preferably spaced slightly therefrom. 
         [0032]    Suitable materials for the panels include polyurethane sheet material. The properties of the polyurethane material (or other equivalent material) can be selected to give the desired stretch characteristics. 
         [0033]    For currently envisaged applications, preferred properties include a material weight in the range 70 g/m 2  to 110 g/m 2 , more preferably 80 g/m 2  to 100 g/m 2 , even more preferably 85 g/m 2  to 95 g/m 2 , for example 90 g/m 2 . The thickness of the sheet material is preferably in the range 50 microns to 100 microns, more preferably 60 microns to 90 microns and even more preferably 70 microns to 80 microns, for example 75 or 76 microns. 
         [0034]    Exemplary polyurethane materials include two layer polyurethane films, with an adhesive layer (for adhering to the underlying garment fabric) and a thick film face side layer, which may have a matt finish. The adhesive layer may provide ⅔ of the overall sheet thickness. The adhesive preferably has a softening point in the range 60° C. to 80° C., for example 72° C. (TMA onset temperature). The service temperature range of the adhesive is preferably at least −20° C. to 60° C. and more preferably −40° C. to 75° C. 
         [0035]    Whilst the panels may all have the same properties, in some applications they may advantageously have different properties from one another (e.g. different stretch constants, for instance as a result of having different weights and/or thicknesses) to provide greater tailoring over the athlete&#39;s head. 
         [0036]    The base layer of the cap is generally dome shaped in its finished form to cover a majority of the head of the wearer. The bottom edge of the base layer is preferably shaped to curve upwardly from both sides to the nape of the neck at the rear. On the sides of the cap, the bottom edge preferably has a convexly curved shape to extend down over the ears. The front of the cap may have a gentle concave curvature to generally follow the line of the brow. 
         [0037]    The base layer may be formed by a series of connected panels, which when joined together provide the desired dome shape. Preferably the panels are joined by bonded seams. 
         [0038]    To provide differential stretch characteristics over the surface of the cap, in addition to providing laminated panels on the outside surface of the base layer, it may also be desirable to laminate one or more panels to the inside surface of the base layer. For instance, additional internal panels can be added in the region of the base layer covering the ears to increase the tension in this area to provide a better fit over the ears. The areas of fabric covering the ears may, if desired, be perforated to minimise the effect on the wearers hearing. 
         [0039]    The internal panels can be formed of the same fabric material as the base layer. 
         [0040]    The elastic stretch fabric used to make the cap may be of any suitable kind. Fabrics of high stretch constant, e.g. polyester elastanes as conventionally used for making high-performance swimwear, are within the skilled person&#39;s routine knowledge. 
         [0041]    To improve fit and comfort and to more securely hold the cap in place (e.g. when performing ‘tumble turns’ in water), the cap preferably has an elasticated band around it&#39;s rim, e.g. bonded to the inside surface of the base layer. The band may, for instance, be a silicone coated elastic. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0042]    Preferred embodiments of the two aspects of the invention are now described by way of example as applied to racing swimsuits and caps, with reference to the accompanying drawings in which: 
           [0043]      FIG. 1  is a front view of a full body suit with no arms comprising an inner core in accordance with an embodiment of the first aspect of the present invention; 
           [0044]      FIG. 2  is a back view of the  FIG. 1  suit; 
           [0045]      FIG. 3  is a side view of the  FIG. 1  suit; 
           [0046]      FIG. 4  is a back view of a swim cap in accordance with an embodiment of the second aspect of the invention; 
           [0047]      FIG. 5  is a side view of the  FIG. 4  cap; 
           [0048]      FIG. 6  is a front view of the  FIG. 4  cap; 
           [0049]      FIG. 7  is another back view of the  FIG. 4  cap, showing the position of internal laminate fabric panels; 
           [0050]      FIG. 8  is another side view of the  FIG. 4  cap, showing the position of internal laminate fabric panels; and 
           [0051]      FIG. 9  is another front view of the  FIG. 4  cap, showing the position of internal laminate fabric panels. 
       
    
    
     DETAILED DESCRIPTION 
       [0052]    Swimsuit 
         [0053]    The swimsuit illustrated in  FIGS. 1 to 3  is made from a base layer of high stretch constant elastane fabric of a known kind. The illustrated example is a full body suit  2 , the base layer  4  of which covers and fits closely over the entire torso  6  and also the legs  8  to the ankles. In this example the suit has no arms but the principles illustrated are applicable also to arms with suits. 
         [0054]    The base layer may be formed from multiple sections joined to one another. The sections may be joined by stitching, as described, for example, in our EP-A-1110464. More preferably, however, adjacent sections of the base layer are bonded to one another. Such bonded seams have been found to have particularly low profiles and resultant low drag properties in water. 
         [0055]    As is normal, the suit has a zip fastener extending down the centre of the back of the suit to allow a swimmer to don and take off the suit. Preferably the zip fastener has a low profile and is bonded to the sections of the suit that it joins to minimise the drag. 
         [0056]    In accordance with the first aspect of the present invention, as schematically shown in the figures with shaded regions, the suit includes an inner core  40  formed by a layer of fabric bonded to the inner surface of the base layer of the suit in the lower trunk region. The fabric may be the same as that used for the base layer, i.e. a conventional elastane fabric. 
         [0057]    The inner core  40  extends substantially completely around the torso, providing a continuous band across the abdomen, around the flanks of the torso and across the lumbar region of the back to either side of the zip fastener. 
         [0058]    On the front of the suit, the upper edge of the inner core  40  extends slightly further up in the midline of the torso than at the lateral sides of the torso, generally following the line of the diaphragm (i.e. lower ribs). On the rear of the suit, the upper edge of the inner core likewise extends up from either side towards the midline of the back. It extends upwards from just above the waist at the sides of the trunk to just below the lower points of the scapula at the midline. 
         [0059]    The lower edge of the inner core  40  extends down around the crotch  61  in the centre at both the back and the front, the front and rear portions joining at this point. At the rear, the lower edge of the inner core  40  extends upwardly from the crotch  61  towards the lateral sides of the suit in a convex sweep, generally following the lines of the buttocks to the midline of the lateral side of the suit but then rises vertically to join the front portion of the core over the hip. At the front of the suit, the inner core  40  sweeps upwardly from the crotch  61  to the hip with a concave curve. 
         [0060]    The inner core  40  provides additional tension in the suit around the swimmer&#39;s midriff, helping to flatten the abdomen and buttocks, reducing form drag, and providing additional support to improve core stability. 
         [0061]    The suit also has panels of a polyurethane material laminated on the outer surface of the base layer at selected locations, in the manner described in our co-pending GB0625102.9. The specially-shaped panels provide areas of reduced surface drag and/or greater compression and/or support of a swimmer&#39;s body without inhibiting the swimmer&#39;s stroke. The selective support provided by the laminated panels can help support and maintain the form of the swimmer&#39;s stroke. 
         [0062]    In this example, the polyurethane material is a two layer polyurethane film, with an adhesive layer (for adhering to the underlying garment fabric) and a thick film face side layer, which may have a matt finish (other finishes are possible). The material has a weight of about 90 g/m 2  and an overall thickness of about 76 microns, with the adhesive layer providing ⅔ of the overall thickness. The adhesive has a softening point of 72° C. (TMA onset temperature) and a service temperature range of −40° C. to 75° C. 
         [0063]    The torso region  6  of the suit  2  has three panels on the front, an abdominal panel  10  and left- and right-side chest panels  12 ,  14 . In some embodiments, the chest panels may be omitted. On the rear or the torso region  6  there are left- and right-side lumbar panels  16 ,  18  and left- and right-side back panels  20 ,  22 , which in this example extend from and are formed integrally with the lumbar panels  16 ,  18 . In some embodiments the lumbar and/or back panels may be omitted. 
         [0064]    The abdominal panel  10  is generally rhomboidal in shape. A bottom corner of the panel  10  extends down to the crotch region  61  of the suit. A top corner of the panel extends up to the sternum region. Left and right corners of the panel extend laterally towards the side of the torso region  6 , terminating just short of the mid-line of the side of the torso. The abdominal panel  10  provides an area of low surface drag as well as providing, in combination with the underlying inner core, a highly tensioned region to give greater core stability. 
         [0065]    The chest panels  12 ,  14  are symmetrical with one another about the centre line of the front of the suit. The right-side chest panel  14  is generally triangular in shape. It has a medial side edge that extends from the neck opening down to a point at the bottom end of the panel adjacent to but spaced from the left-side corner of the abdominal panel  10 . The side edge is slightly convex in shape. A lateral side edge of the chest panel  14  extends generally vertically from the bottom end of the chest panel  14  to a position close to the lower edge of the right arm opening of the suit. A top side edge of the chest panel  14  extends in a convex curve from the top end of the lateral side edge to the neck opening at a point close to but laterally outward from the top end of the medial side edge. The left-side chest panel  12  is a mirror image of the right-side chest panel  14 . 
         [0066]    The chest panels  12 ,  14  are configured to avoid restricting the swimmer&#39;s lung function. This may be achieved through appropriate shaping of the panels and/or through selection of a material with an appropriate stretch constant. The material may be the same as used for other panels on the suit. If needs be, however, the chest panels may be formed of a material having a lower stretch constant that the abdominal panel  10  (and the other panels discussed below) so they are less tensioned when the suit is worn in order that they do not overly restrict the swimmer&#39;s breathing. In other embodiments the abdominal panel may have a lower stretch constant that the chest panels. 
         [0067]    The chest panels  12 ,  14  serve to flatten the swimmer&#39;s chest, reducing form drag, as well as providing further areas of low surface drag. 
         [0068]    The lumbar panels  16 ,  18  are generally trapezoidal in shape, with (taking the right-side panel as an example) generally vertical medial and lateral side edges and top and bottom edges that rise upwardly on the torso in the lateral direction. The lower part of the lumbar panel  18  extends down over the buttock area  28 . The bottom edge is slightly convexly curved to generally follow the lower edge of the swimmer&#39;s buttock (gluteus maximus). The top edge is generally in line with the lowermost rib. The left-side lumbar panel  16  is a mirror image of the right-side panel  18 . 
         [0069]    The two lumbar panels  16 ,  18  meet one another at a lower end portion of their respective medial sides edges, at the crotch region  61 . The medial side edges diverge slightly from one another towards the upper edge of the panels. 
         [0070]    The lumbar panels  16 ,  18  provide highly tensioned areas to support the lumbar region, improving core stability. They also compress the swimmer&#39;s buttocks, reducing form drag and provide large surface areas of the suit with low surface drag. 
         [0071]    As can be seen in the figures, the lumbar panels overlap the portion of the base layer to which the inner core is bonded, the lower edges of the inner core and the lumbar panels overlying one another and the top edges terminating at a similar position up the back. 
         [0072]    The right-side back panel  22  has the form of narrow oblong extending from the centre line of the back of the suit adjacent the top edge of the lumbar panel  18  diagonally outwardly across the back to the arm opening, generally adjacent a lower edge of the scapula. The upper end of the back panel  22  is laterally spaced from the centre line of the back of suit by a distance that is about one third of the distance between the back centre line and the centre line of the right-side of the suit. This leaves a relatively large panel-free torso portion of the suit under the arm opening between the top edge of the lumbar pad, the lateral side edge of the right-side chest panel  14  and the back panel  22 . In use this arrangement provides support for the upper back whilst enabling relatively free twisting of the upper back and shoulder girdle of a swimmer, necessary for execution of the freestyle (front crawl) stroke. This, in turn, encourages correct execution of the stroke. 
         [0073]    The left-side back panel  20  is a mirror image of the right-side back panel  22 . 
         [0074]    On each leg there is an upper leg panel that wraps around the inside of the leg from the front to the rear, comprising a quadriceps (‘quad’) panel portion  30 ,  32  on the front of the thigh (upper leg) and a hamstring panel portion  34 ,  36  on the rear of the upper leg. There may also be a lower leg panel on each leg, although the illustrated example does not include these panels, which wraps around the inside of the leg, comprising a calf panel portion on the rear of the lower leg and a shin panel portion on the front of the lower leg. The panels on the left leg are a mirror image of the panels on the right leg. 
         [0075]    Looking at the right leg of the illustrated suit, the quad panel portion  30  has a lateral side edge that extends in a convex sweeping line from the inside of the leg just above the patella out to the lateral side of the leg and up to a point at the hip, generally following the outline of the quadriceps muscle group. A top edge of the quad panel portion extends from the top point to an inner leg region adjacent the crotch region  61 . The quad panel portion  30  covers substantially the whole of the quadriceps muscle group, applying compression to the muscles to enhance the power generated by them. The panel also helps to reduce surface drag over the front of the upper leg. 
         [0076]    The hamstring panel portion  36  is generally trapezoidal in shape. It extends across the full width of the rear upper part of the leg, extends down to just above the rear of the knee joint at the inside of the leg and extends up to just below the buttock. The upper edge of the panel portion  36  is convexly curved and is spaced from but closely follows the line of the bottom edge of the lumbar panel  18 . The bottom edge of the hamstring panel portion is gently curved, concavely, to rise up towards the lateral side of the leg where it merges into the lateral side edge, which extends, also in a gently convex curve, to meet the lateral end of the upper edge at an acute angle. 
         [0077]    The hamstring panel portion applies compression to the hamstring muscles in use to enhance the power generated by those muscles. It also helps to reduce surface drag over the rear of the leg. 
         [0078]    The quadriceps and hamstring panel portions  30 ,  36  wrap around the inside of the leg to meet one another, forming one continuous panel wrapping around the inside of the upper leg. Opposite ends of the panel terminate on the outside of the leg, spaced from one another to either side of a seam running down the outside of the leg. 
         [0079]    Swim Cap 
         [0080]    Turning to  FIGS. 4 to 9 , a swim cap  70  in accordance with an embodiment of the second aspect of the invention will be described. 
         [0081]    The cap  70  has a generally dome shaped base layer  72 . The bottom edge  74  of the base layer  72  is shaped to extend down over the swimmer&#39;s ears at the sides, to generally follow the line of the user&#39;s brow at the front, in a sweeping concave curve, and to rise up in a convex curve at the rear, to be clear of the nape of the swimmer&#39;s neck. The latter feature in particular helps prevent any restriction in the articulation of the wearers neck as they tip their head backwards. 
         [0082]    The base layer is formed from three sections, a centre section  76  and two side sections  78 , that are joined at bonded seams, which run from front to back. 
         [0083]    In this example, the cap also has three panels  80 ,  82  of a polyurethane material laminated on the outer surface of the base layer at selected locations, one on each of the base layer sections, spaced from the bonded seams and from the lower rim of the cap. 
         [0084]    Specifically, there is a top panel  80  and two side panels  82 , one to each side of the cap. Other embodiments may have more than three panels, e.g. 4 or 5 panels or more. 
         [0085]    Looking at the present three panel example, the top panel  80  extends front to back across the top of the cap. It has a rectangular form towards the front with a front edge of the top panel  80  being substantially parallel to but spaced a short distance from the rim  74  of the cap at the front. The rear end of the top panel  80  tapers to a point, spaced a short distance from the rim  74  of the cap at the back. The side edges of the top panel  80  follow the lines of the bonded seams  90  in the base layer. 
         [0086]    The side panels  82  are generally semi-circular in shape, with top edges that follow the lines of the bonded seams  90  of the base layer and bottom edges that are substantially parallel to but spaced from the rim  74  of the cap along the respective sides. 
         [0087]    Looking specifically at  FIGS. 7 to 9 , it can be seen that the cap also includes two internal panels  84  bonded to the inside surface of the base layer (shown schematically with shaded areas). These panels are made of an elastane fabric, which may be the same as the base layer itself. They provide areas of increased tension to improve fit. 
         [0088]    Specifically, in this example, left and right side, internal panels  84  are provided, which are generally semi-circular, as with the outside side panels  82 , but are smaller than the outside side panels  82  and cover only the portion of the base layer that overlies the wearer&#39;s ears. They extend right down to the rim  74  of the cap. 
         [0089]    As seen in  FIG. 8 , a centre portion  86  of each internal side panel  84  is cut away. The base layer still covers the ear, as does part of the outer side panel  82 , but the cut away centre portion  86  of the inner panel  84  avoids covering the ear canal with three layers of fabric, which might undesirably inhibit the swimmer&#39;s hearing. 
         [0090]    The skilled person will appreciate that the suit and cap illustrated in the figures and described above are examples embodying inventive concepts described herein and that many and various modifications to the specifically described suits can be made without departing from the invention. For instance, whilst the inventive concepts have been exemplified with full body, armless suits, the general principles as well as the specific panels described can be used with other styles of suit (e.g. full body with arms, torso only suits, long-johns, etc). The principles exemplified above can also be applied to other specialist sports garments, especially wet sports such as waterpolo and triathlon and beach sports such as beach volley.