Patent Publication Number: US-2005138839-A1

Title: Dance shoe and last for making a dance shoe

Description:
FIELD OF THE INVENTION  
      The present invention generally relates to dance shoes and more particularly relates to dance shoes that facilitate moving a foot into a point position.  
     BACKGROUND OF THE INVENTION  
      When dancing, an individual&#39;s feet are placed in many different positions, including the rest position, the flex position, the point position and the toe position. When in the point position, a foot must be arched with the toes pointing toward the ground. As is well known to those skilled in the art, an arched foot typically has a curve on the bottom of the foot and a corresponding curve at the top or instep of the foot. In the dancing arts, many refer to an arched foot as a “banana foot.” 
      Although many dancers develop extraordinary abilities, some may be precluded from advancing in their chosen field because they are unable to form an aesthetically pleasing arch when in the point position. Thus, there have been a number of advances in the dance shoe art related to presenting a foot in an aesthetically pleasing arch position. For example, U.S. Patent Application Publication No. 2003/0033729 to Farrior discloses an apparatus and method for augmenting a dancer&#39;s foot whereby a pad having a curved top surface is attached to the top of a dancer&#39;s foot. As a result, the shape of the top of the dancer&#39;s foot is more aesthetically pleasing.  
      U.S. Pat. No. 1,553,196 to Solomonoff discloses a toe dancer&#39;s shoe that enables a dancer to assume a toe position. Referring to  FIGS. 1-2 , the shoe  10  has an upper  12  made of fabric material and a drawstring  15  for adjusting and tightening the shoe. The shoe  10  includes a toe portion  16  and padding material  17 . The shoe  10  also includes a stiffened inner sole  21  that facilitates formation of an extremely arched foot position. The shoe also has an additional arcuate-shaped, stiffening sole  22  that is attached to the stiffened inner sole  21 . One drawback of the &#39;196 patent is that the sole is inflexible, which prevents a dancer&#39;s foot from moving freely between the rest, flex, point and toe positions.  
      U.S. Pat. No. 5,649,373 to Winter et al. discloses a shoe structure having an elongate flat leaf spring element provided in the sole of the shoe. The elongate leaf spring extends from the toe region of the shoe structure beyond the location of the metatarsal-phalangeal (M-P) joints of the wearer, so as to provide a mechanical power assist to the wearer at the M-P joints.  
      In spite of the advances discussed above, none of the above-identified references teach providing a dance shoe having a flexible sole that is designed to normally urge the foot to move into the point position. In addition, none of the references teach a dance shoe having a toe region with zero or negative toe spring so that the shoe upper and sole cooperate for urging the toes of an inserted foot to move downward. Moreover, none of the references teach a dance shoe having a flexible sole that facilitates forming an aesthetically pleasing arch when a foot is in a point position. Thus, there is a need for a dance shoe that satisfies these needs.  
     SUMMARY OF THE INVENTION  
      In accordance with certain preferred embodiments of the present invention, a dance shoe adapted for urging a foot into an arch shape includes a shoe upper and a sole attached to the shoe upper. The sole preferably includes a heel region, a toe region and an arch extending between the heel region and the toe region, whereby a bottom of the heel region defines a horizontally extending ground plane. The arch is desirably sufficiently curved so that at least a portion of the toe region of the dance shoe is projected downwardly below the horizontally extending ground plane. The sole may be flexible. In certain preferred embodiments, the toe region of the sole has no toe spring relative to the horizontally extending ground plane. In other preferred embodiments, the toe region of the sole has negative toe spring relative to the horizontally extending ground plane. When a dancer&#39;s foot having toes is inserted into the dance shoe of the present invention, the shoe upper and the sole cooperate for urging the dancer&#39;s toes downwardly and the foot to assume an aesthetically pleasing arch position.  
      The sole of the dance shoe is desirably made of a material selected from the group consisting of rubber, polymer and leather. In highly preferred embodiments, the sole is flexible. The upper of the shoe is desirably made of flexible materials such as fabric. In preferred embodiments, the shoe upper is made of materials including GORE®, LYCRA®, mesh fabric, stretchable fabric, leather, cotton fabric, synthetic fabric, and polymer fabric.  
      In another preferred embodiment of the present invention, a dance shoe adapted for urging a foot into a point position includes a shoe upper and a flexible sole attached to the shoe upper. The sole desirably has a heel region, a toe region and an arch extending between the heel region and the toe region. A bottom of the heel preferably defines a horizontally extending ground plane. The toe region of the sole preferably has at least zero toe spring and the arch is sufficiently curved so that the toe region is projected downwardly below the horizontally extending ground plane. In other preferred embodiments, the toe region of the sole has negative toe spring.  
      In still other preferred embodiments of the present invention, a dance shoe designed for normally urging a foot into a point position includes a flexible sole having a heel region, a toe region and an arch extending between the heel region and the toe region, wherein the toe region of the sole has a negative toe spring. The dance shoe also preferably includes a shoe upper attached to the sole, whereby the sole and the upper cooperate for urging a dancer&#39;s foot inserted into the dance shoe to move into the point position.  
      In yet another preferred embodiment of the present invention, a dance shoe includes a flexible sole having a heel region, a toe region remote from the heel region, an arch between the heel region and the toe region and a ball region between the arch region and the toe region. The dance shoe also preferably includes a shoe upper attached to the sole, whereby the toe region of the flexible sole has no toe spring. In other preferred embodiments, the toe region of the flexible sole has negative toe spring so that when a dancer&#39;s foot having toes is inserted into the dance shoe, the shoe upper and the sole cooperate for urging the dancer&#39;s toes downwardly.  
      These and other preferred embodiments of the present invention will be described in more detail below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1A  shows a foot of a dancer in a rest position.  
       FIG. 1B  shows a foot of a dancer in a flex position.  
       FIG. 1C  shows a foot of a dancer in a point position.  
       FIG. 1D  shows a foot of a dancer in a toe position.  
       FIG. 2  shows a foot of a dancer in a point position.  
       FIG. 3  shows a prior art dance shoe with the foot of a dancer in the point position.  
       FIG. 4  shows a prior art shoe having toe spring.  
       FIG. 5  shows a cross-sectional view of a shoe last for a dance shoe, in accordance with certain preferred embodiments of the present invention.  
       FIG. 6A  shows a side elevational view of a shoe last for a dance shoe, in accordance with certain preferred embodiments of the present invention.  
       FIG. 6B  shows a perspective view of the shoe last of  FIG. 6A .  
       FIG. 6C  shows another side view of the shoe last of  FIG. 6A .  
       FIG. 6D  shows an underside of the shoe last of  FIG. 6A .  
       FIG. 6E  shows a bottom view of the shoe last of  FIG. 6A .  
       FIG. 6F  shows a front elevational view of the shoe last of  FIG. 6A .  
       FIG. 6G  shows a top plan view of the shoe last of  FIG. 6A .  
       FIG. 7  shows a dance shoe mode using the shoe last of  FIGS. 6A-6F , in accordance with certain preferred embodiments of the present invention.  
       FIG. 8  shows a dance shoe made using the shoe last of  FIGS. 6A-6F , in accordance with still other preferred embodiments of the present invention.  
       FIG. 9  shows a dance shoe made using the shoe last of  FIGS. 6A-6F , in accordance with yet further preferred embodiments of the present invention. 
    
    
     DETAILED DESCRIPTION  
      When dancing, an individual&#39;s feet must be placed in many different positions.  FIG. 1A  shows a foot in a rest position whereby both a heel  22  and a ball region  24  of a shoe  20  are in contact with a ground plane  26 . In the rest position, the foot is relaxed and the shoe  20  generally maintains the foot in the relaxed position.  FIG. 1B  shows a foot in a flexed position with the ball  24  of shoe  20  flexed so that heel  22  may be lifted off the ground plane  26 .  FIG. 1C  shows a foot in a point position with a toe  28  of shoe  20  engaging ground plane  26  and an arch  30  formed between the heel  22  and the ball region  24 . The top of the foot, commonly referred to as the instep  31 , is also curved. In order to move a foot into a point position, the muscles of the foot must be used to curve the shoe sole from the normal position shown in  FIG. 1A  to the arched position shown in  FIG. 1C .  FIG. 1D  shows a foot in the toe position, with the toe  28  of the shoe  20  engaging the ground plane  26  and the heel  22  lifted off of the ground plane  26 . In the toe position, the protracted arch attained in the point position ( FIG. 1C ) is no longer apparent.  
       FIG. 2  shows a bare, human foot  32  having a heel  34 , a toe region  36 , a ball region  38  and an arch  40 . The foot is configured in what is commonly referred to as the point position, one of the most aesthetically pleasing positions in dance. In the point position, the arch  40  and the instep  42  are curved and the toes  36  are pointed downwardly.  
       FIG. 3  shows the foot of  FIG. 2  positioned in a prior art dance shoe  44 . The shoe is primarily shaped to accommodate a foot that is in the rest position ( FIG. 1A ). This is due, in part, to the fact that shoes are generally manufactured using lasts that are modeled after a foot in a rest position.  
       FIG. 3  shows some of the problems associated with prior art dance shoes that are designed for feet in the rest position. First, when a foot is placed in the point position, wrinkles  46  develop in the fabric of the upper located near the arch region  45  of the shoe  44 . Wrinkles  48  also develop in the toe region of the shoe. Moreover, the tape  50  around the shoe opening will typically pinch the dancer&#39;s ankle at the points designated  52  and  54 . Gaps also tend to develop between the dancer&#39;s heel and the heel of the shoe, as well as between the ball of the dancer&#39;s foot and the ball region of the sole of the shoe. In addition, if laces for the shoe have been tightened, a lace region  56  of the shoe may apply pressure on the instep of the foot.  
       FIG. 4  shows a prior art shoe  43  having a sole  45  with an upwardly turned sole in the toe region  47 . An upwardly turned sole in the toe region is typically referred to as toe spring. A shoe with toe spring urges a wearer&#39;s toes upwardly and provides resistance against a dancer&#39;s efforts to move the foot into the point position. The present invention provides a shoe that eliminates many of the obstacles that stand in the way of moving a dance shoe and foot into a point position.  
       FIG. 5  shows a last for making a dance shoe, in accordance with certain preferred embodiments of the present invention. The last  58  includes an upper section  60  designed for forming an upper of a shoe. The upper section  60  includes a heel region  62 , a toe region  64  and an intermediate region  66  between the heel region and the toe region. The last  58  also includes a lower section  68  designed for forming the sole of a shoe. The lower section  68  includes a heel region  70 , a toe region  72 , a ball region  74  and an arch region  76 . In certain preferred embodiments, the last  58  is specially designed so that it has zero toe spring. As used herein, the terminology “toe spring” means a feature built into a last and shoe to compensate for lack or absence of shoe flexibility at the ball. As is well known to those skilled in the art, the “toe spring” of a shoe creates a rocker effect on the shoe sole so that the shoe forces the foot to “roll” forward like the curved bottom of a rocking chair. Soles that are relatively thicker and/or stiffer than normal require even greater toe spring due to the lack of flexibility of the shoe sole. Moreover, a shoe with toe spring typically causes the toes of the foot to be angled upwardly approximately 5-20°. As will be described in more detail below, the shoe last of the present invention does not have “toe spring” so that shoes manufactured using the shoe last do not force the toes to tilt upwardly. In some preferred embodiments, the last has “zero toe spring,” whereby the toes are not urged upwardly as is common with conventional shoe soles. In other preferred embodiments, the last has “negative toe spring” so that a shoe manufactured using the last urges the toes downwardly such as into an aesthetically pleasing point position.  
      Referring to  FIG. 5 , a shoe last  58  having negative toe spring is positioned over an imaginary, horizontally extending ground plane designated by reference numeral  78 . The bottom of heel region  70  is positioned in substantial alignment with the ground plane  78 , whereby at least a portion of the toe region  72  of the last  58  projects downwardly below the ground plane  78 . Thus, the toe region of the shoe last  58  has negative toe spring. In contrast, if the toe region  72  projected above the ground plane  78  as shown in  FIG. 4 , then the toe region would have a positive toe spring.  
       FIGS. 6A-6G  show a shoe last, in accordance with another preferred embodiment of the present invention. Referring to  FIGS. 6A and 6B , the shoe last includes an upper section  160  adapted for forming an upper of a shoe. The upper section  160  includes a heel region  162 , a toe region  164  and an intermediate region  166 . The shoe last  158  also includes a lower section  168  adapted for forming a sole of a shoe. The lower section  168  includes a heel region  170 , a toe region  172  and a ball region  174 . The lower section  168  also includes an arch  176 . The last is designed to manufacture a shoe having a negative toe spring so as to encourage a foot to move into a point position. As such, when an imaginary, horizontally extending ground plane  178  is placed in substantial alignment with a bottom of heel region  170  at an underside of the last  158 , the ground plane  178  extends through at least a portion of the toe region  172  of the sole.  
      Referring to  FIGS. 6C and 6D , in one preferred embodiment of the present invention, a last  158  for a size 7M shoe has a heel length A of approximately 2.0-2.20 inches and more preferably about 2.10-2.15 inches in length, an arch length B of approximately 3.50-3.70 inches and more preferably about 3.60-3.65 inches, and an arch depth C measured from apex D to imaginary line E of approximately 0.45-0.50 inches and more preferably about 0.47 inches. The last also has a toe length F extending between the toe of the last and the forward end of the arch of approximately 3.15-3.20 inches and more preferably about 3.19 inches in length. The last  158  also has a toe height G of approximately 0.90-1.00 inches and more preferably about 0.94 inches, an instep circumference H of approximately 8.15-8.20 inches and more preferably about 8.19 inches, and an instep length I of approximately 6.45-6.55 inches and more preferably about 6.50 inches in length. The last  158  also has a quarter or heel height J of approximately 2.55-2.65 inches and more preferably about 2.60 inches.  
      Referring to  FIG. 6D , last  158  has a heel width K of approximately 2.15-2.25 inches and more preferably about 2.20 inches. Referring to  FIG. 6E , last  158  has an overall length L of approximately 8.90-9.00 inches and more preferably about 8.94 inches. At the ball region  174  of last  158 , the last has a width M of approximately 2.90-3.00 inches and more preferably about 2.95 inches.  FIG. 6F  shows a front elevational view of last  158  having a toe height G of approximately 0.90-1.00 inches and more preferably about 0.95 inches.  FIG. 6G  shows a top plan view of last  158 .  
       FIG. 7  shows a dance shoe  258 , in accordance with certain preferred embodiments of the present invention. The dance shoe  258  includes a shoe upper  260  and a flexible sole  268  having a heel region  270 , a toe region  272  and a ball region  274 . When the bottom of heel region  270  is placed in substantially parallel alignment with imaginary, horizontally extending ground plane  278 , at least a portion of the toe region  272  of the sole projects through the imaginary plane  278 . As a result, the dance shoe  258  has negative toe spring, which normally urges a wearer&#39;s foot to move downwardly into a point position. Specifically, the shoe urges a wearer&#39;s toes to move downwardly. Moreover, the shoe preferably urges the wearer&#39;s foot to move into an arch position. Moreover, since the sole  268  is designed to have a negative toe spring, the upper  260  attached to the sole will be devoid of wrinkles that typically appear in the upper material located above the arch  276 , as well as in the upper material located around the toe  272 . Although not limited by any particular theory of operation, it is believed that the dance shoe of the present invention normally urges an at rest foot to move toward the point position. As a result, the shoe does not provide the level of resistance found in prior art shoes as the dancer attempts to move the foot into the point position. In addition, the shoe has a more aesthetically pleasing appearance when in the point position because the upper of the shoe does not wrinkle and/or buckle as is found in prior art shoes.  
       FIG. 8  shows a dance shoe  358  in accordance with another preferred embodiments of the present invention. The dance shoe  358  includes a shoe upper  360  and a sole  368  having a heel region  370 , a toe region  372  and a ball region  374 . When the bottom of heel region  370  is placed in substantially parallel alignment with imaginary, horizontally extending ground plane  378 , at least a portion of the toe region  372  of the sole projects through the imaginary plane  378 . As a result, the dance shoe  358  has negative toe spring, which normally urges a wearer&#39;s foot to move downwardly into a point position.  
       FIG. 9  shows a dance shoe  458  in accordance with another preferred embodiments of the present invention. The dance shoe  458  has a shoe upper  460  and a sole  468  having a heel region  470 , a toe region  472  and a ball region  474 . When the bottom of heel region  470  is placed in substantially parallel alignment with imaginary, horizontally extending ground plane  478 , at least a portion of the toe region  472  of the sole projects through the imaginary plane  478 . As a result, the dance shoe  458  has negative toe spring, which normally urges a wearer&#39;s foot to move downwardly into a point position.  
      Although the present invention is not limited by any particular theory of operation, it is believed that providing a shoe having a negative toe spring will facilitate movement of the foot into the point position. Providing such a shoe will also prevent wrinkling of the material in the upper of the shoe when the foot is in the point position because the upper material is attached to the sole when the sole has a negative toe spring configuration. Moreover, it is believed that providing a dance shoe with negative toe spring will urge the foot to move into a point position, even when a wearer&#39;s foot is at rest. Moreover, because the shoe does not resist a wearer&#39;s efforts to move to the point position, moving the foot into the point position will be easier. In addition, the aesthetic appearance of a dancer&#39;s foot will be enhanced and the shoe will help provide the protracted arch sought by dancers.  
      Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.