Patent Publication Number: US-2019184263-A1

Title: Tibia and/or foot protection article comprising at least one shock absorbing pad

Description:
TECHNICAL FIELD OF THE INVENTION 
     This invention relates to an article for protection of the tibia and/or foot comprising at least one shock-absorbing pad. More particularly, the invention relates to a knitted sock comprising at least one internal pouch placed in front of the tibial crest and into which a removable absorbent pad, composed of a silicone layer with at least one and preferably both faces covered with a layer of fabric, can be fitted. 
     BACKGROUND ART 
     In the field of sports equipment, it is well known that textile devices comprising an elastic or non-elastic knitted structure, for example such as socks, to which a flexible pad is fixed designed to absorb shocks, can be used to protect some parts of the foot of the sock wearer. 
     Such socks are particularly described in documents FR 2 897 756, FR 2 912 879 and US 2011/0000006. 
     Documents FR 2 897 756 and US 2011/0000006 describe a foot protection article comprising a sock provided with a buffering part and at least one pouch to contain said buffering part made from a viscoelastic material, for example such as silicone. Said pouch is fixed to the sock, outside the sock, or between two layers of stretchable textile forming the sock and extends in front of the Achilles heel and the posterior part of the Achilles heel. 
     Although this type of protection does efficiently protect the Achilles heel, it has the disadvantage that it does not give good long-term stability in that the buffering part progressively becomes delaminated over time due to friction to which the buffering part is subjected, when on the one hand the sock is worn and due to successive washings of the sock. 
     Document FR 2 912 879 describes a body protection device comprising a knitted elastic structure in the form of a sock, comprising several stitches formed by at least one thread and a pad made of an elastic material such as silicone, said pad being assembled with the knitted structure and a portion of the pad being located outside the knitted structure. Said pad that extends along one of the faces of the knitted structure is assembled by means of some stitches of said knitted structure that pass inside said pad and are trapped by the elastic material of the pad thus forming a composite assembly. 
     Apart from the fact that it is expensive to manufacture because it requires a step in which the pads are moulded onto an inverted sock, this type of device has the disadvantage that it deteriorates over time. Indeed, frictions between the skin and the pads as well as successive cleaning operations of the socks cause delamination of the pad such that said socks quickly lose their shock protection properties. 
     Therefore, there is a need for socks comprising one or several inexpensive, long-lasting shock protection pads with a simple design, in addition to being comfortable to wear. 
     SUMMARY OF THE INVENTION 
     Therefore, one of the purposes of this invention is to overcome these disadvantages by disclosing. 
     To achieve this, the invention discloses an article for protection of the tibia and/or the foot composed of a sock comprising at least one pouch and at least one pad removably positioned in said pouch; said article is remarkable in that the pouch is fixed to the inside of the sock and in that the pad is composed of a flexible and flat part comprising a layer obtained from a viscoelastic material and at least one layer made of fabric fixed to at least one of the faces of the layer of viscoelastic material. 
     It will be understood that the fabric layer of the pad that enables the pad to slide inside the pouch can limit stresses on the layer made from a silicone viscoelastic material. Furthermore, said fabric layer provides better long-term cohesion of the layer made from a silicone viscoelastic material, thus preventing its untimely delamination. 
     Preferably, the pad is made from a flexible and flat part comprising a layer made from a viscoelastic material and two layers made of fabric fixed to corresponding faces of the layer of viscoelastic material. 
     Furthermore, the fabric layer of the pad has a coefficient of static friction between 0.1 and 0.5 and the Shore hardness of the viscoelastic material is between 20 and 80. 
     According to one preferred embodiment, the viscoelastic material consists of a thermoplastic elastomer. 
     Said thermoplastic elastomer consists of a non-vulcanised olefinic thermoplastic elastomer (TPO), a vulcanised olefinic thermoplastic elastomer (TPV), a polyurethane thermoplastic elastomer (TPU), a styrenic thermoplastic elastomer (TPS), a thermoplastic copolyester (ether-ester block copolymer or COPE) (TPE or TPEE), a thermoplastic copolyamide (ether-amide block copolymer or PEBA) (TPA), or a combination of these thermoplastic elastomers. 
     Preferably, said thermoplastic elastomer consists of a styrene thermoplastic elastomer (TPS) comprising polystyrene-b-polybutadiene-b-polystyrene (SBS), polystyrene-b-polyisoprene-b-polystyrene (SIS), polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS), polystyrene-b-poly(ethylene-propylene)-b-polystyrene (SEPS), polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene (SEEPS) or a composite thereof. 
     Furthermore, the pouch is fixed to the inside wall of the sock by stitching. 
     Moreover, the pouch extends in front of the tibial crest. 
     Said pouch is substantially rectangular in shape and its upper part is open, and the pad is substantially parallelepiped in shape. 
     Preferably, the width of said pad is substantially equal to the width of the pouch and its length is longer than the length of the pouch such that said pad projects outside said pouch. 
    
    
     
       DRAWINGS 
       Other advantages and features will become clearer after reading the following description of a single manufacturing variant, given as a non-limiting example of the tibia and/or foot protection article according to the invention, with reference to the appended drawings on which: 
         FIG. 1  is a perspective view of the tibia and/or foot protection article according to the invention, 
         FIG. 2  is a sagittal sectional view of the tibia and/or foot protection article according to the invention, 
         FIG. 3  is a cross-sectional view of the pad of the tibia and/or foot protection article according to the invention, 
         FIG. 4  is a cross-sectional view of a variant embodiment of the pad of the foot and/or tibia protection article according to the invention. 
     
    
    
     DESCRIPTION 
     In the following description, an article for protection of the tibial crest of a skier will be described, the shock absorbing pad absorbing shocks and thus preventing pain on the tibial crest caused by bending the leg on the rigid shell of ski boots; however, it is obvious that the tibia and/or foot protection article could be adapted to other sports or activities by choosing a suitable position of the pouch(es) in which the pad(s) will be placed, without going outside the scope of the invention. 
     With reference to  FIGS. 1 and 2 , the tibia and/or foot protection article according to the invention is composed of a sock  1  comprising an inner pouch  2 , placed in front of the tibial crest, and a shock absorbing pad  3  providing a shock absorbing function between the tibial crest and the ski boot of the person wearing the socks. 
     It will be noted that the term “sock” is used to mean any manufactured article wrapping the feet and rising above the ankle or higher as it is the case in the example shown in  FIGS. 1 and 2  that consists of knee-length socks. Said sock may in particular comprise reinforcement zones and/or aeration zones and/or contention zones, not shown on the figures. 
     Said pouch  2  is made from a knitted or woven part, preferably a part knitted with the same thread as the remainder of the sock  1 , substantially rectangular in shape and that is sewn onto the inside face of the sock  1  in front of the tibial crest. 
     It is obvious that the pouch  2  could be any shape, such as a trapezoidal, triangular, round or oblong shape, depending on the zone(s) of the foot and/or leg to be protected. 
     Thus, the protection article according to the invention could comprise a plurality of pouches  2 , each pouch  2  holding a pad  3  with a shape adapted to said corresponding pouch  2 , for example to protect the instep, the hallux or the Achilles heel. 
     Moreover, it is obvious that the pouch  2  could be fixed to the inside face of the sock by any other appropriate means known to the person skilled in the art such as by bonding, gluing or knitting, without going outside the framework of the invention. 
     Said pouch  2  that is open at its upper end receives a pad  3  with a parallelepiped shape with a width substantially equal to the width of the pouch  2  and a longer length longer than the length of the pouch  2  such that said pad  3  projects outside said pouch. In this way, the pad  3  can be easily slid into the pouch and then removed from said pouch  2 , the part of the pad  3  projecting from the pouch  2  acting as gripping means. 
     With reference to  FIGS. 1 to 3 , the pad  3  is made of a flexible and flat part comprising a layer  3   a  made from a viscoelastic material and at least one layer made of fabric  3   b  fixed to the at least one of the faces of the layer  3   a  of viscoelastic material. In this particular example embodiment, the pad  3  comprises a single fabric layer  3   b.    
     According to one preferred embodiment, with reference to  FIG. 4 , said pad  3  advantageously comprises two fabric layers  3   b  fixed on each side of the layer  3   a  made of viscoelastic material. 
     Furthermore, in order to facilitate introduction and removal of the pad  3  in the pouch  2 , and to limit shear stresses on the layer  3   a  made of viscoelastic material when the socks are being worn, the static friction coefficient of the fabric layer of the pad is between 0.1 and 0.5. 
     Preferably, the layer  3   a  made of a viscoelastic material is obtained from a thermoplastic elastomer with a Shore hardness of between 20 and 80. In this particular example embodiment, the thickness of the layer  3   a  made of viscoelastic material is constant and is between 2 and 6 mm. 
     It is obvious that the thickness of the layer  3   a  made of viscoelastic material can be variable depending on the shock absorption level required on the different parts of the foot and/or leg. 
     Said thermoplastic elastomer consists of a non-vulcanised olefinic thermoplastic elastomer (TPO), a vulcanised olefinic thermoplastic elastomer (TPV), a polyurethane thermoplastic elastomer (TPU), a styrenic thermoplastic elastomer (TPS), a thermoplastic copolyester (ether-ester block copolymer or COPE) (TPE or TPEE), a thermoplastic copolyamide (ether-amide block copolymer or PEBA) (TPA), or a combination of these thermoplastic elastomers. 
     Preferably, said thermoplastic elastomer consists of a styrene thermoplastic elastomer (TPS) comprising polystyrene-b-polybutadiene-b-polystyrene (SBS), polystyrene-b-polyisoprene-b-polystyrene (SIS), polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS), polystyrene-b-poly(ethylene-propylene)-b-polystyrene (SEPS), polystyrene-b-poly(ethylene-ethylene/propylene)-b-polystyrene (SEEPS) or a composite thereof. 
     It is obvious that the thermoplastic elastomer could be replaced by any other natural or synthetic viscoelastic material well known to the person skilled in the art with equivalent mechanical and/or chemical properties. 
     It is also obvious that the viscoelastic material could consist in particular of any synthetic and/or natural material well known to the person skilled in the art. 
     Obviously, this invention is not in any way limited to the embodiments described above and modifications can be made to it without going outside the scope of the appended claims.