EP0512894B1 - Asymmetrical dance shoe and a pair of such shoes - Google Patents

Abstract

Dance shoe (2) comprising a sole to which is fastened a stiffened flexible upper, at a front part as far as a substantially flat toe (7), via a vamp covered by this upper and intended to enclose the front of the foot of a dancer, characterised in that this front part has, on its top, a ridge line 10, formed by the maxima of the transverse sections of this front part, which is offset to a given side of a longitudinal plane (P) of the shoe, moving away from this plane the further it is from the toe (7) of the shoe, this front part connecting up, transversely towards the other side of the said longitudinal plane, via a zone forming a flat part (13) which is wider the further it is from this toe, by virtue of which this shoe is specifically intended for one or other of the feet of a dancer, the ridge line being intended to run along the top of the big toe of the foot in question. <IMAGE>

Description

The invention relates to a dance shoe suitable for performing steps on points of the type having the characteristics mentioned in the preamble of claim 1.

As is known, a dance shoe mainly comprises a sole to which is connected a flexible headdress or "rod", most often made of cotton or satin, which covers the front of the foot and extends from side to side. across the instep until around the heel from behind. The front of the upper is made rigid by a box or "vamp" adapted to grip the front of the foot; this upper is in practice formed from superimposed layers glued, for example cotton, jute and felt, which are then put into the desired shape, in the front bottom of the rod, thanks to a shoe tree or "shape" d '' sizing: the stiffness of the vamp depends on the quantity and the sizing glue. In practice, the sole has an outer sole, for example of leather, and an inner sole, extending to the bottom of the upper, formed of a sole plate called the first, for example of leather or cardboard and covered a cotton fabric, and an underlying stiffening plate or "shank", for example of cardboard.

Such a ballet shoe allowed generations of dancers to perform the graceful ballet steps required by their art, but at the cost of painful compressions on the front of the foot leading in particular with the famous "onion of the dancer" and sometimes capable of leading to osteo-ligamentary or musculo-tendinous pathologies.

It should be remembered in this regard that the dance steps on pointes involve a recovery of all the efforts to support the ground by the front of the foot (especially the toes) which must not tilt either forward or towards the 'rear, nor laterally. These efforts can be very significant since tests have revealed that under certain conditions, jumps on points, on concrete for example, could generate in the forefoot accelerations of the order of -10g. This explains the requirement for a very firm support of the forefoot by the vamp on pain of serious accidents.

In practice, a dance shoe, from its new state of maximum rigidity, inevitably deforms during use while its rigidity degrades until it requires replacement; in this way, during most of its life, a slipper painfully compresses the front of the foot of the dancer who uses it and a reduction in this painful period (for example by the use of a lesser amount of glue) implies a shortening of the life of the liner.

The object of the invention is to shorten this painful period or at least reduce the discomfort of the dancer during the life of use of the slipper, without reducing the latter. In other words, it aims for a bootie which, for the same duration of use as in the past, leads to less discomfort without compromising either the quality of the support of the forefoot or the safety of the dancer, and this for a bearable additional cost without deviating too much from the traditions or the aesthetics of the dance.

To this end, the invention proposes a dance shoe comprising a sole to which a flexible rod is fixed, stiffened in a front part to an end. substantially flat, by an upper covered by this rod and intended to grip the front of the foot of a dancer, characterized in that this front part has on its top a crest line, formed by maxima in height of successive transverse cuts of this front part, which is offset on a given side from a longitudinal plane of the liner by deviating from this plane all the more as one moves away from the end of the liner, this front part connecting, transversely towards the on the other side of said longitudinal plane, by a zone forming a flat that is all the wider as one moves away from this end, thanks to which this boot is specifically intended for one or the other of the feet of a dancer, the ridge line being intended to extend from above the big toe of the foot considered.

It will be appreciated that there is introduced, within the framework of the invention, a differentiation, although limited, between right and left slippers, which in itself constitutes a revolution in the field of dance.

You should know that, as has been implicitly explained above, the pairs of dance shoes known to date consisted of undifferentiated shoes, that is to say symmetrical with respect to the abovementioned longitudinal plane, developed in '' using pieces of glue shape (shoe trees) identical, and matched so as to present in practice the same shades of rod color and comparable rigidities (it should be remembered that, the manufacture of these slippers being an eminently artisanal operation , there are inevitably slight fluctuations from one liner to another).

As surprising as it may seem, it has never been proposed, to the knowledge of the inventors, to introduce in new condition any differentiation of the shoes of a pair of dance shoes.

Thus for the star dancers, the concern to minimize their discomfort was limited to the development for each of them in a specific but symmetrical form. Furthermore, attempts have been made to reduce the pathologies of the feet of dancers, for example by document WO-A-90/04338 recommending the use of new materials, but without introducing differentiation.

There are various reasons for this state of affairs.

First of all, it was very generally accepted in the world of dance that the compression of the front of the foot of a dancer by her slippers was a guarantee of good maintenance of this front of the foot during the execution of steps ballet dance: in other words, the painful nature of this compression was a necessary evil. Differentiation was made in use, but it seemed essential that it be done specifically by the very feet of the dancer who would, exclusively, keep them until complete wear.

In addition, a differentiation in the manner of right and left shoes from everyday life seemed unnecessary or even dangerous.

It should be noted in this regard that dance slippers, reserved for a limited clientele for the exercise of their art, have completely different functions from those of city or leisure shoes or the indoor slippers used by the whole of the population in everyday life: the dance slippers targeted by the invention are intended mainly, as explained above, for the execution of spikes while the shoes or slippers of the everyday life are mainly intended to support the foot flat on the ground (walking, running or even jumping ...).

This is how the dissymmetry which appears at the instep and heel of everyday shoes and slippers, is in no way imposed in the field of dance since the symmetrical upper of the dance shoes naturally conforms thanks to its flexibility to the sole of the foot and that the sole, whose role is to contribute to maintaining the arch of the foot by skirting the latter over only part of its width and its length, ensures this role much more by its ridiculousness than by its form.

Besides, the invention does not impose any differentiation of the upper or the sole (without excluding it).

As for the asymmetry which appears at the front of everyday shoes and slippers, which results in a more or less marked point, offset opposite the big toe, and by an external lateral edge more inclined in view from above than the internal lateral edge relative to the axis of the foot, it goes against the concern in the field of dance to provide, with the arched foot provided with a dance shoe, a support area on the surface ground maximum and especially centered on the axis of the foot or even the leg, which, by reasoning at first approach, required that the vamp be symmetrical.

It was also impossible to dispute that the symmetry of dance shoes contributes significantly to their aesthetics, an essential characteristic in any art, and therefore in the field of dance.

Finally, an economic approach to the production of ballet shoes dissuaded, unless there were excellent reasons, from introducing a differentiation between the shoes of the same pair, given the complications that this introduced, but such excellent reasons did not appear to exist.

In addition, the tradition in the field of dance has a great weight to the point of making a priori suspicious the innovations concerning the geometry and the nature of the materials (requirement of natural materials) chosen for the various components of the slippers.

In fact, the invention has been able to recognize the critical location of a dance shoe where a differentiation between right foot and left foot is important from the comfort point of view of the dancer while respecting the good distribution of the forces in the foot which However, at first glance pleaded in favor of respecting symmetry, this differentiation could be discreet enough to respect the general aesthetics of the slipper and the traditions of dance.

To do this, the invention has been able to abstract from the habit of a person skilled in the art of reasoning from above or from below and reasoning from the end.

• la ligne de crête s'écarte du plan longitudinal à partir du bout avec une inclinaison en vue de dessus de 5 à 15°,
• cette inclinaison en vue de dessus est comprise entre 5° et 10°,
• cette ligne de crête est au moins approximativement rectiligne en vue de côté,
• cette ligne de crête fait en vue de côté un angle d'environ 20 à 25° par rapport à la base de l'empeigne.

According to preferred arrangements, possibly combined:

• the ridge line deviates from the longitudinal plane from the end with an inclination in top view of 5 to 15 °,
• this inclination in top view is between 5 ° and 10 °,
• this ridge line is at least approximately rectilinear in side view,
• this ridge line makes a side view of an angle of about 20 to 25 ° relative to the base of the upper.

The invention further provides a pair of dance shoes of the aforementioned type, the crest lines of which are offset in opposite directions with respect to the respective longitudinal planes of these shoes.

• la figure 1 est une vue de profil d'un pied en position de pointe muni d'un chausson droit,
• la figure 2 est une vue de face de ce chausson avec, représenté en pointillés, l'encombrement correspondant d'un chausson classique,
• la figure 3 en est une vue en bout selon la flèche III de la figure 2, et
• la figure 4 en est une vue en coupe selon la ligne IV-IV de la figure 2, avec représenté en pointillés, l'encombrement correspondant en coupe d'un chausson classique.

Other objects, characteristics and advantages emerge from the description which follows, given by way of nonlimiting example, with reference to the appended drawings in which:

• FIG. 1 is a side view of a foot in the toe position provided with a straight liner,
• FIG. 2 is a front view of this liner with, represented in dotted lines, the corresponding dimensions of a conventional liner,
• FIG. 3 is an end view thereof according to arrow III in FIG. 2, and
• Figure 4 is a sectional view along the line IV-IV of Figure 2, with shown in dotted lines, the corresponding size in section of a conventional liner.

Figure 1 shows the right foot 1 of a dancer peaking; this foot is fitted in a dance shoe 2 shown in FIGS. 1 to 4 and comprising, in a known manner, an outer sole 3 to which is attached a flexible rod 4 covering the toes and more generally the front of the dancer's foot, s' extending on either side of the instep and around the heel. Inside the upper is disposed a vamp 5 shown in dotted lines in FIG. 1, the rigidity of which is intended to firmly hold the front of the dancer's foot. Inside the rod, is fixed a part called first 6 which extends to the bottom of the vamp; an intermediate piece or shank 6A (see FIG. 4) intended for the longitudinal stiffening of the liner is sandwiched between the outer sole 3 and the first 6. The front part 7 of the liner, called the tip, is flattened with very low convexity .

Conventionally, the upper 4 is made of satin, the outer sole 3 is of leather, the first 6 and the shank are made of strong cardboard, and the upper is formed by a stack of a burlap, a piece of felt, burlap and cotton cloth, linked together and held in shape by a mass of dried impregnating glue. It should be clearly understood that the abovementioned details, conventional in themselves, are given only by way of nonlimiting example.

The dance shoe 2 has an asymmetry with respect to the longitudinal plane P of FIG. 2. This asymmetry appears mainly in FIGS. 3 and 4, in the conformation of the vamp, therefore of the boot on the top of the foot.

Unlike conventional slippers, the shape of the top of the forefoot of which is shown in dotted lines in FIG. 4, the slipper 2 has a maximum height M which is offset laterally with respect to the longitudinal plane P, d 'a side intended to follow the big toe. As can be seen from FIGS. 2 and 3, all of the points M in successive cross sections of the vamp form a crest line marked 10. This line appears to be, with respect to the plane P, offset on average from a distance of barely a few millimeters, ranging from approximately 5 mm near the point 7 of the liner (this line is hardly marked there) to approximately 12 mm near the edge 8 of the upper. Thus, starting from the point, this crest line deviates from the plane P with an inclination of about 7 to 8 degrees when viewed from above (preferably between 5 ° to 15 ° or better, between 5 ° and 10 ° depending on the size of the bootie and its width).

The offset of the ridge line in a cutting plane appears to be approximately 0.5 to 0.15 times (here approximately 0.10 times on average) of the width of the liner in this cutting plane.

This crest line, seen from the side (see FIG. 1) is practically rectilinear by making an angle α approximately constant here about 20 to 25 ° relative to the underside (or base) of the vamp.

Of course, this crest line is weakly marked, the entire half 11 of the top of the liner having to cover the big toe and part of the corresponding metatarsus (internal half) having a slowly varying curvature.

On the other hand, the other half 12 (external half) has a flat 13 that is all the more wide and marked as one moves away from the point of the bootie until, in the example considered, becoming slightly concave (see Figure 4).

The examination of FIG. 1, where the dotted lines represent, for comparison purposes, the outline in top view of a conventional slipper, shows that the differentiation in top view of slipper 1 is very moderate and only disturbs very slightly the aesthetics of the slipper; it has in fact been exaggerated to make it visible, but it only appears to the eye on an actual bootie with very little difficulty, much less clearly than the dissymmetry of the uppers. This differentiation consists of a widening along the big toe then a narrowing on the approach of the instep and, on the other side, a narrowing along the small toes.

In fact, this differentiation between the sides of the vamp is advantageous but not essential; indeed, the improvement in the comfort of a dancer with the bootie 2 both at the end of the big toe and on the sides of the foot appeared surprisingly to come first from the asymmetry of the upper of the vamp.

• préparation d'une tige symétrique fixée à une semelle extérieure symétrique,
• préparation par empilage et encollage de couches éventuellement symétriques de jute, de feutre, de jute et de coton puis leur engagement à force au fond de la partie avant de la tige,
• fixation, après durcissement de la colle, d'une première symétrique s'étendant jusqu'au fond de l'empeigne et d'un cambrion lui aussi symétrique.

It will be appreciated that the invention introduces only a very limited number of asymmetries, therefore requires very few modifications in the process of manufacturing the slippers, the principle of which was recalled at the beginning of this description: it suffices to modify the shoe trees intended for shaping during the drying of the adhesive, all other things which can remain unchanged compared to the conventional stages of manufacture:

• preparation of a symmetrical upper attached to a symmetrical outsole,
• preparation by stacking and gluing of possibly symmetrical layers of jute, felt, jute and cotton then their engagement by force at the bottom of the front part of the rod,
• fixing, after hardening of the glue, a first symmetrical extending to the bottom of the vamp and a shank also symmetrical.

Of course, any subsequent differentiation of these elements cannot be excluded, but this would complement the improvement in comfort of the dancer without however being the main responsible.

A shoe for the left foot (not shown) has the same characteristics as shoe 2, but by reversing the halves 11 and 12 on either side of the longitudinal plane.

By matching these right and left slippers, we obtain a pair of differentiated but symmetrical slippers from each other.

It goes without saying that the above description has been offered only by way of nonlimiting example and that numerous variants can be proposed to those skilled in the art without departing from the scope of the invention as defined. by the appended claims.

Claims (6)

1. Ballet shoe (2) comprising a sole (3, 6) to which is fixed a flexible upper (4) stiffened in a front part up to a substantially flat end (7) by a vamp (5) covered by said upper and adapted to surround the front part of the foot of a dancer, characterised in that said front part of said upper has on its upper surface a peak line (10) formed by points (M) of maximum height of successive transverse cross-sections of said front part of said upper which is offset to one side of a longitudinal plane (P) of the shoe, diverging from this plane in the direction away from the end (7) of the shoe, this front part of said upper being joined transversely on the other side of said longitudinal plane to an area forming a flat (13) widening in the direction away from said end, whereby said shoe is specifically intended for a respective foot of a dancer, the peak line being adapted to run along the top of the big toe of the foot in question.
2. Ballet shoe according to claim 1 characterised in that, starting from said end of said shoe, the peak line (10) diverges from the longitudinal plane at an angle of 5 to 15° as seen from above.
3. Ballet shoe according to claim 2 characterised in that the angle of divergence as seen from above is between 5 and 10°.
4. Ballet shoe according to claim 1 or claim 2 characterised in that said peak line is at least approximately straight as seen from the side.
5. Ballet shoe according to claim 4 characterised in that said peak line is at an angle of approximately 20 to 25° to the base of the vamp (5) as seen from the side.
6. Pair of ballet shoes comprising two shoes as claimed in any one of claims 1 to 5 in which the peak lines are offset in opposite directions relative to the respective longitudinal planes of said shoes.

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