Patent Publication Number: US-2010126042-A1

Title: Shoe

Description:
The invention relates to a shoe and in particular but not exclusively a dance or performing arts shoe, especially, which provides a wearer with enhanced levels of comfort, durability, stability and shock absorption, and to methods for constructing said shoe. 
     It is convenient to refer to the field of ballet dancing to set the background for the invention but aspects of the background discussion apply equally to other fields, such as shoes and sports shoes in general. 
     During training and performances, ballet dancers are often required to dance upon their toes which is a technique known as “going en pointe” (or “sur les pointes”). Pointe ballet shoes (or toe shoes) have a blocked toe which is generally constructed by hand using layers of fabrics, cardboard, paper or leather saturated with glue as a laminant to form a reinforced toe box joined to a leather or cardboard shank. A reinforced stiffener is generally also included in the shank and the outer sole is constructed from leather. An outer layer of fabric or “upper” is sewn to the sole and usually gathered in pleats under the toe. This design and manner of construction is labour intensive and expensive to produce. Although some improvements to the construction have been proposed, such as those described in U.S. Pat. No. 4,453,996 (Ballet Makers Inc), the design of pointe ballet shoes has generally been unchanged since conception. 
     Traditional ballet shoes require extensive breaking-in before they are comfortable for use, which typically requires manual flexing, application of force, steaming or soaking in water or alcohol. Once the shoe has been broken-in, it will have a short lifespan and a ballet dancer may use 2-3 pairs of ballet shoes each week. This short lifespan is due to the deterioration of the toe box and or shank caused by the rapid breakdown of the glue used to form the laminates of the toe box. The breakdown can be accelerated by perspiration during energetic dancing. Once the shank and/or toe box have deteriorated, the shoe is useless because there will be no support for the ballet dancer. 
     Conventional ballet shoes have a number of drawbacks, for example, the toe box compresses the side of the feet and may exacerbate injuries associated with the hopping and leaping en palate required by ballet choreography. In addition, ballet shoes are noisy which results from the sound caused by the toe box striking the floor which can often detract from the illusion of effortless grace which a ballet dancer strives. A ballet dancer will often attempt to compensate for the noise by softening the impact on the floor which may detract from the performance or cause injury. 
     Thus, according to a first aspect of the invention there is provided a shoe comprising a shank portion which is engageable with a separate toe box portion and wherein, in use, the shank portion and toe box portion form a unitary part. 
     It will be appreciated that references herein to shoe include all shoes but particularly those which are used for dance or performing arts. In one embodiment the shoe is a ballet shoe. 
     According to a second aspect of the invention there is provided a shank portion configured to be engageable with a corresponding separate toe box portion. 
     According to a third aspect of the invention, there is provided a toe box portion configured to be engageable with a corresponding separate shank portion. 
     The advantage of providing separate toe box and shank portions is that a ballet dancer may select from a number of separate toe boxes with differing widths and supports which may correspondingly be engaged with one of a number of shanks providing differing levels of support. Such an arrangement provides the advantage that a ballet dancer is able to customise any given shoe for either foot. For example, in the event that the left foot differs in size or shape from the right foot, differing toe box and shank portions may be selected to account for such differences. 
     It will be appreciated that ‘engageable’ refers to any means of connection between the shank and toe box portions. 
     In one embodiment, the shank portion may be detachably engageable with a separate toe box portion. It will be appreciated that ‘detachably engageable’ refers to any means of releasable connection between the shank and toe box portions, which enables both a strong connection when the shoe is in use and a simple disconnection when the shoe is being dismantled. 
     In one embodiment, the releasable connection means may comprise co-operable components on the shank and toe box portions (e.g. co-operable male and female components). For example, the toe box portion may comprise a cavity (female component) on its base adapted to receive a protruded section (male component) on the end distal from the heel of the shank portion. Other embodiments may provide the cavity on the shank portion and the protruded section on the toe box portion. Indeed, some embodiments may provide both a cavity and a protruded section on both shank and toe box portions. In a further embodiment, releasable connection means may comprise a snap-fit locking arrangement. 
     Additionally, or alternatively, engagement may be provided by an adhesive (e.g. glue, paste, mastic or the like) or a weld joint (e.g. an ultrasonic weld joint) between the shank portion and the toe box portion once a user has selected an appropriate toe box and shank portion. This enables a stronger association between the toe box and the shank portion. 
     In one embodiment of the invention, the shank and/or toe box portions are moulded from a thermoplastic polymeric material. In a further embodiment, the thermoplastic material has a softening point of between roughly 49° C. (120° F.) and 104° C. (220° F.). Further, the polymer may be selected from the following: an Monomer resin, an ethylene-vinyl acetate copolymer, a styrene-ethylene-butylene-styrene (SEBS) block copolymer, acrylonitrile butadiene styrene (ABS), polycarbonate (PC) and a polyurethane (e.g. thermoplastic polyurethane; TPU). In a further embodiment, the shank and/or toe box portions may be constructed from a nylon material (e.g. nylon-6, -11 or -12). The advantage of providing the shank and/or toe box portions from these materials is the life of the portions should be increased, perhaps greatly, when compared to traditional fabrication techniques. 
     It will be appreciated by the skilled person that the properties of the shank and/or toe box portions may be modified by varying the composition of the shank and/or toe box portions. For example, the composition of the shank portion may be varied in order to create a range of shank portions, wherein each portion comprises a different rigidity. This provides the advantage of allowing the user to customise the support of the shoe according to their personal preference. 
     In one embodiment, the rigidity of the shank may vary along its length. In another embodiment, the rigidity of the shank decreases along its length towards the heel. This provides the advantage of support where required whilst en pointe (mid-foot) and also allows correct anatomical positioning whilst en pointe and a better pointe when non-weight bearing. 
     In one embodiment, the shank may be constructed from a combination of more than one thermoplastic polymeric materials to provide a variation in rigidity. In a further embodiment, the more than one thermoplastic polymeric materials may be selected from thermoplastic polyurethane (TPU). In a yet further embodiment, the shank may be constructed from thermoplastic polyurethane (TPU) varying in grades from 60D to 90A towards the heel. 
     In a further embodiment of the invention, the too box portion comprises a toe housing portion. The toe-housing portion may comprise a first shock absorbing portion attached or moulded to the exterior surface of the toe housing portion and/or a toe moulding portion attached or moulded to the interior surface of the toe housing portion. It is advantageous to provide the first shock absorbing portion and/or the toe moulding portion in order to increase the comfort of the shoe. 
     In one embodiment, the toe housing portion is moulded from a thermoplastic polymeric material having greater rigidity than the shank portion, for example, having a higher softening point. In a further embodiment, the toe housing portion is moulded from a nylon material (e.g. nylon-11 or 12 having a hardness of approximately 55D) and overlaid with a styrene-ethylene-butylene-styrene (SEW) block copolymer (e.g. SEBS 35 C). 
     In one embodiment, the first shock absorbing portion is constructed from an open celled polyurethane foam or gel like substance. The first shock absorbing portion has the advantage of providing quiet contact between the shoe and the floor so that a ballet dancer can achieve graceful movement. 
     In a further embodiment of the invention, the toe moulding portion is constructed from a heat responsive polymer, for example, the viscosity of the polymer increases with application of heat. In a yet further embodiment, the toe moulding portion is constructed from a styrene-ethylene-butylene-styrene (SEBS) block copolymer (e.g. SEBS 25 C). This embodiment has the advantage of allowing the toe moulding portion to be easily moulded to the ballet dancer&#39;s foot. For example, moulding may occur by simple application of heat from a hair dryer or hot water. 
     In a further embodiment of the invention, the shank has a second shock absorbing portion attached or moulded to the heel region thereof. In a yet further embodiment, the second shock absorbing portion is constructed from a foam comprising an ethylene vinyl acetate (EVA) copolymer, a neoprene rubber or an open celled polyurethane foam or gel like substance. In a yet further embodiment, the second shock absorbing portion is constructed from an open celled polyurethane foam. The second shock absorbing portion may be provided above or below the heel region. 
     In a further embodiment of the invention, all surfaces of the shoe which are in contact with the users foot are lined with a soft, resilient coating selected from a foam comprising a polyurethane, a cross-linked polyethylene, a polyvinylchloride and nitrile rubber blend or an ethylene vinyl acetate (EVA) copolymer. In a yet further embodiment, the surface of the shank portion in contact with the user&#39;s foot is lined with a soft, resilient coating. In a yet further embodiment, the soft, resilient coating is an ethylene vinyl acetate (EVA) copolymer. 
     In a yet further embodiment, the soft resilient coating additionally comprises odour controlling means. In this embodiment, the odour controlling means may be incorporated within the outer covering (e.g. by application of odour controlling agents) or the odour controlling means may be separately applied to the surface of the shank portion in contact with the user&#39;s foot (e.g. by the presence of a detachable insole) by any of the attachment means mentioned herein. In one embodiment, the odour controlling means comprise a separate insole separately attached to the surface of the shank portion in contact with the user&#39;s foot by way of a releasable or permanent attachment, e.g. Velcro™, an adhesive (either permanent or temporary) or any other means of attachment. 
     According to a fourth aspect of the invention there is provided a shoe comprising a toe box portion and a shank portion, each of said toe box portion and said shank portion being either integrally moulded or engageable, wherein at least a portion of the shank portion comprises flexing means which, in use, is configured to: 
     (a) allow the shank portion to bend from a substantially extended state to a substantially curved state during an upward movement;
 
(b) allow the shank portion to unbend from a substantially curved state to a substantially extended state during a downward movement; and
 
(c) limit downward movement of the shank portion from a substantially extended state.
 
     It will be appreciated that the ‘downward movement’ of the shank portion corresponds to the bending of the shank portion in the direction away from the roof of the toe box. The ‘upward movement’ is a bending movement of the shank portion in an opposite direction to the downward movement, i.e. towards the roof of the toe box. 
     It will also be appreciated that references to shank portion in the ‘extended state’ refer to the shank portion when it is substantially flat. 
     The flexing means of this aspect of the invention provide the advantage of substantial strength, rigidity and therefore support to the user&#39;s foot in a downward direction while simultaneously allowing flexibility in the upward (i.e. opposed) direction for comfort, for example when “going en pointe”. The flexing means also prevent a ballet dancer from having to spend significant time “breaking-in” the shoe. 
     In one embodiment the flexing means comprise a first part, which comprises a plurality of interconnected first elements, and a second part, which comprises a plurality of interconnected second elements. It will be appreciated for the second part that a first side surface of a second element and a second side surface of an adjacent second element form an interspace. Said first part is connected or connectable to said second part when the first elements are received in the interspaces formed between the side surfaces of the second elements. 
     In one embodiment, one or more second elements comprise at least one (e.g. 2) stopping surface. In one embodiment, the stopping surface is a side surface of a second element and is angled or curved towards an adjacent second element. In one embodiment, both the opposing side surfaces of the interspace are stopping surfaces, i.e. the first side surface of a second element and the second side surface of an adjacent second element are angled or curved towards each other. 
     Thus, the at least one stopping surface forms a trapezoid shaped interspace between adjacent second elements, such that the interspace comprises a narrow end and a wide end. In one embodiment, the stopping surfaces at the narrow end of the interspace are arranged to contact or partly contact the first element received in the interspace, when the shank portion is in the extended state. 
     The stopping surfaces may be arranged on the second part such that, in use, downward movement of the shank portion from the extended state causes the narrow end of the interspace to contract. This leads to the at least one stopping surface colliding with the first element and prevents further contraction. Thus the arrangement of the at least one stopping surface offers resistance to downward movement from the extended state. 
     The stopping surfaces may also be arranged on the second part such that, in use, upward movement of the shank portion from the extended state to the curved state causes the wide end of the interspace to contract. However, unlike the narrow end of the interspace, the stopping surfaces at the wide end of the interspace do not collide with the first element. Thus, the arrangement allows upward movement of the shank portion without resistance. 
     It will be apparent to the skilled person that the width of the narrow end and wide end of the interspace may be modified to vary the rigidity and support in the downward direction and the flexibility in the upward direction. 
     In a further embodiment, the flexing means are present at the position where the shank portion engages with the toe box portion. For example, the first part, comprising the plurality of first elements, may be present on the shank portion and interconnect with the second part, comprising the plurality of second elements, present on the toe box portion. In one embodiment, the first part may be present on the end distal from the heel of the shank portion and the second part may be present on the base of the toe box portion. 
     In a further embodiment, the first and second elements may have differing numbers, size and shape. This will provide the advantage of creating a variety of shoes that may comprise differing levels of rigidity and support in the downward direction and/or differing levels of flexibility in the upward direction. It will be appreciated, however, that the number, size and shape of the first elements will correspond to the number, size and shape of the second elements, such that the first part may be connected to the second part. 
     For example, a greater number of first elements, such as 4 to 8 (e.g. 4, 5 or 6) may increase the strength, rigidity and therefore support to the user&#39;s foot in the downward direction while simultaneously allowing increased flexibility in the upward direction. Conversely a smaller number of elements, such as 1 to 4 (e.g. 3) may be used to decrease the strength, rigidity and therefore support to the user&#39;s foot in the downward direction while simultaneously allowing decreased flexibility in the upward direction. 
     Furthermore, a greater number of first elements may be used to extend the area of support further towards the heel end. This may be important when the ball of the user&#39;s foot is positioned further from the toe box portion than normal. This arrangement provides the advantage of accommodating differing toe lengths. 
     In a further embodiment the flexing means are constructed from a nylon material (e.g. nylon-6, -11 or -12). 
     Examples of flexing means suitable for use in the shoe of this aspect of the invention will be apparent from WO 2005/065789 (Hussenoder), the flexing arrangement of which is herein incorporated by reference. 
     In one embodiment, there is provided a detachable outer covering configured to engage with and cover both the toe box and shank portions as hereinbefore defined. 
     A shoe comprising a toe box and shank portion provides the advantage of allowing the outer cover to engage and cover the shoe before the toe box and shank portions engage each other to form a unitary part, which makes it easier to attach the outer cover to the shoe. 
     It will be appreciated that the detachable outer covering may be arranged also to engage with and cover the toe box and shank portions after the toe box and shank portions have engaged with each other to form a unitary part. It will also be appreciated that in embodiments where the toe box and shank portions are detachably engageable, the outer covering may be removed before or after disconnection of the toe box and shank portions. 
     An advantage of having a separate “inner” and “outer” shoe is to allow a wearer, such as a ballet dancer, to remove the outer covering which can be washed and reattached to the shank and toe box portions. The outer covering may also be replaced when damaged without the need to discard the entire shoe. A further advantage is that differing outer coverings can be tailored to differing costumes by applying patterns or by dyeing, etc. 
     In one embodiment, the outer covering is constructed from a man-made wick like material which retains a satin like appearance (e.g. canvas). This has the advantage of drawing perspiration away from the foot. In a further embodiment, the outer covering is constructed from a microfibre material which provides the benefit of allowing the foot of a user to breathe. The microfibre material has a further advantage of providing a greater degree of flexibility or stretching in one direction when compared with a perpendicular direction. 
     In one embodiment, the outer covering comprises one or more attachment means which allow engagement of the outer covering with a toe box portion and a shank portion of a shoe. In one embodiment, the attachment means comprise an elasticized portion. This has the advantage of providing a stretch fit over the shank and toe box portions and the foot of the ballet dancer. This arrangement will allow the outer covering to hug the foot of the wearer, such as a ballet dancer, when in a pointed position and allow the foot to expand in length when weight bearing. 
     In a further embodiment, the attachment means comprise an integral pocket feature at the base of the outer covering configured to accommodate the shank portion. This feature provides the advantage of simultaneously allowing the outer covering to slide into the shank portion while fitting the front part of the outer covering to the toe box portion of the ballet shoe. 
     In a yet further embodiment, the attachment means comprise at least one portion of Velcro™ or like material. In such an embodiment, it is envisaged that a portion of Velcro™ or like material is present on the underside of the shank portion of the shoe and the flat end part of the toe box portion of the shoe which will engage with corresponding pieces of Velcro™ or like material on the inner surface of the outer covering. Velcro™ or like attachment provides the advantage of simultaneously allowing firm attachment while also facilitating simple replacement of the outer cover. 
     In one embodiment, the outer covering comprises a slip-resistant portion. This has the advantage of providing additional grip for the ballet dancer to prevent slips and falls and therefore minimise the chances of injury. 
     According to a further aspect of the invention there is provided a kit comprising at least one of a toe box portion, a shank portion and optionally, a detachable outer covering. 
     Such a kit is advantageous because it can provide a wearer with a complete shoe. 
     It may be advantageous to provide either a plurality of toe box portions and/or a plurality of shank portions such that a wearer is provided with a flexible kit such that the shoe provided thereby can be used in a variety of situations. 
     According to a further aspect of the invention, there is provided a method of manufacturing a shoe as defined herein which comprises the steps of: 
     (a) moulding a shank portion from a thermoplastic polymeric material; and
 
(b) moulding a separate toe box portion from a thermoplastic polymeric material;
 
such that said shank portion and toe box portion are configured to be engageable.
 
     In a further embodiment, the method comprises the additional step of: 
     (c) engaging the shank portion and toe box portion to form a unitary part. 
     In a yet further embodiment, the method may comprise the additional step of: 
     (d) bonding the shank portion to the toe box portion with an adhesive or weld joint. 
     In one embodiment, the thermoplastic material has a softening point of between 49° C. (120° F.) and 104° C. (220° F.). The material may be selected from an ionomer resin, an ethylene-vinyl acetate copolymer, a styrene-ethylene-butylene-styrene (SEBS) block copolymer and a polyurethane (e.g. thermoplastic polyurethane; TPU). 
     In one embodiment, the toe box portion is moulded from a thermoplastic polymeric material having greater rigidity than the shank portion. 
     In a further embodiment of the invention, the method additionally comprises the steps of: 
     applying a first shock absorbing portion to the exterior surface of the toe box portion or integrally moulding said first shock absorbing portion to the toe box portion, perhaps in step (b); and/or
 
applying a toe moulding portion to the interior surface of the toe box portion or integrally moulding said toe moulding portion to the toe box portion, perhaps in step (b).
 
     In one embodiment, the first shock absorbing portion is constructed from an open celled polyurethane foam or gel like substance. 
     In one embodiment, the toe moulding portion is constructed from a heat responsive polymer. 
     In a further embodiment of the invention, the method additionally comprises the step of: 
     applying a second shock absorbing portion to the heel region of the shank portion or integrally moulding said second shock absorbing portion to the shank portion, perhaps in step (a). 
     In one embodiment, the second shock absorbing portion is constructed from a foam comprising an ethylene vinyl acetate (EVA) copolymer, a neoprene rubber or an open celled polyurethane foam or gel like substance. In a further embodiment, the second shock absorbing portion is constructed from an open celled polyurethane foam. 
     In a further embodiment of the invention, the method additionally comprises the step of: 
     applying a soft, resilient coating to the surface of the shank portion in contact with the user&#39;s foot, perhaps in step (a). 
     In one embodiment, the soft, resilient coating is an ethylene vinyl acetate (EVA) copolymer. In a further embodiment, the soft resilient coating additionally comprises odour controlling means as hereinbefore defined. 
     In a further embodiment of the invention, the method additionally comprises the step of: 
     applying an outer covering to the shank and toe box portions. This may be done before or after step (c). 
     In one embodiment, the outer covering is detachable and as hereinbefore defined. 
     In a further embodiment of the invention, the method additionally comprises the step of 
     applying a slip-resistant portion to the outer covering. 
     It will be appreciated by the skilled person that the above method steps can be carried out in, any desired sequence. 
    
    
     
       The invention will now be described, by way of example only with reference to the accompanying drawings in which 
         FIG. 1  shows an exploded view of the components of a shoe of the invention; 
         FIG. 2  shows an assembled view of the embodiment shown in  FIG. 1 ; and 
         FIG. 3  show a plan view of the first part of the flexing means of the invention. 
         FIG. 4  show a plan view of the second part of the flexing means of the invention. 
         FIGS. 5 to 8  show a plan view of the flexing means of the invention. 
     
    
    
     Referring first to  FIGS. 1 and 2 , a shoe, shown generally as  1 , comprises a shank portion  2  and a toe box portion  3 . In this embodiment, the shoe is drawn as a ballet shoe, although the invention finds wider applicability in a variety of other footwear. The toe box portion  3  additionally comprises a toe housing portion  4 , a toe moulding portion  5  which fits inside the toe housing portion  4  and a first shock absorbing portion  6  which attaches to the outer surface of the toe housing portion  4 . The shank portion  2  comprises a protruding male component  7  on the end distal to the heel, which is engageable with a female cavity component  8  on the base of the toe moulding portion  5  of the toe box portion  3 . Both the shank portion  2  and the toe box portion  3  are constructed from a thermoplastic polymeric material such that the shank portion  2  has a lower softening point than the toe box portion. The outer surface of the toe moulding portion  5  is constructed from a thermoplastic polymeric material and has an inner layer of heat responsive polymer. The first shock absorbing portion  6  is constructed from an open celled polyurethane foam. The shank portion  2  has a soft, resilient coating of foam (not shown) on the upper surface which is in contact with the user&#39;s foot which additionally comprises odour control agents. 
       FIGS. 3 and 4  show one embodiment of the flexing means according to the invention.  FIG. 3  shows an embodiment in which the first part  11  comprises a plurality of interconnected first elements  11   a - 11   e . It will be appreciated that the number of first elements may vary. In this embodiment, the size of the first elements increases incrementally from  11   a  to  11   e.    
       FIG. 4  correspondingly shows an embodiment in which the second part  10  comprises a plurality of interconnected second elements  10   a - 10   f  and in which two stopping surfaces  12  are formed between each of the second elements  10   e - 10   f . It will be appreciated that the number of second elements and stopping surfaces may vary. The arrows in each of  FIGS. 3 and 4  show the intended side of interaction of the first part  11  with the second part  10 . 
       FIG. 5  shows a plurality of interconnected first elements  11   a - 11   d  present on the shank portion  2  at the point of the shank portion  2  which engages with the toe box portion  3  and a plurality of interconnected second elements  10   a - 10   e  which are present on the toe box portion  3  at the point of the toe box portion  3  which engages with the shank portion  2 . 
       FIGS. 6 to 8  show the interconnection of the plurality of first elements  11  (five first elements in  FIG. 6  and six first elements in  FIGS. 7 and 8 ) with the plurality of second elements  10  (six second elements in  FIG. 6  and seven second elements in  FIGS. 7 and 8 ) when the shank portion  2  engages with the toe box portion  3 . It will be appreciated that the subsequent use of adhesive or welding will enable a stronger association between the toe box portion and shank portion. 
     In use, a ballet dancer will connect the shank portion  2  to the toe box portion  3  which results in a constructed shoe. The resultant shoe will then be moulded to the user&#39;s foot by application of heat to the toe moulding portion  5  which simply adjusts the shoe to the contours of the user&#39;s foot to enhance comfort. During a performance, the dancer will be comfortable with the shoe because it will have easily been moulded to the contours of their feet. Furthermore, the discomfort associated with “going en pointe” will be minimised by virtue of the presence of the first shock absorbing portion  6  which not only softens the impact on the toes but also ensures that noise is minimised when the toe box portion  3  strikes the floor. 
     During a performance, comfort is further enhanced by the presence of the flexing means shown in  FIGS. 3 to 8 . For enhanced flexibility, the plurality of first elements  11  and second elements  10  are configured to allow the shank portion  2  to be flexible only in one direction (as shown by the arrow in  FIG. 7 ). For example, stopping surfaces  12  are formed between at least two of said second elements  10 . This flexibility is required most when “going en point”, but flexibility is limited to one direction so that simultaneous support is provided to the foot of the user. 
     It is intended that the shank portion  2 , toe box portion  3  and detachable outer covering will comprise separate items of commerce which may be purchased by a ballet dancer or their employer separately. Therefore, once any part of the shoe has been worn out then it may simply be replaced without the need for entire replacement of the shoe. 
     Furthermore, this interchangeability has the advantage that a dancer may retain the same toe moulding portion  5  which has been perfectly adapted to their feet and insert it into the toe housing portion  4  of a separate shoe.