Running Sole Of Flexible Synthetic Material For Sports Shoes

Abstract

A running sole of flexible synthetic material for sports shoes, more particularly for athletics shoes, wherein, at least in the front portion of the sole, a plurality of integrally molded crossbars extend downwardly from the running surface of the sole and taper away therefrom. In order to impart an adequate grip on various surfaces, at least in some areas, roof-shaped projections extend downwardly beyond the cross bars, the projections having sharp edges extending substantially parallel to the running surface and also to the longitudinal direction of the crossbars, with the width of the bases of the projections corresponding substantially to the width of the crossbars. In a preferred construction the crossbars intersect one another and form therebetween honeycomb-like depressed areas, each individual roof-shaped projection being disposed between adjacent points of the intersection of the crossbars.

Description

The present invention relates to a running sole of flexible synthetic material for sports shoes, more particularly for sports shoes for running and jumping competitions.

Tracks of synthetic material are used to an ever increasing extent for performing running and jumping competitions. But this presents new problems when it is a question of transferring the leg power of the runner to the track safely and without loss of power. As is known, the conventional running spikes as used on cinder tracks penetrate into modern synthetic material tracks only with difficulty and after penetration they are so closely surrounded and retained by the track that a transverse movement of the shoe relative to the track is virtually impossible and the extraction of the spike requires considerable effort. A number of difficulties with regard to the known spikes, and even danger, result for the athlete from this behaviour of the synthetic material track. Especially when running around a bend, the shoe cannot participate in the change of direction which occurs during the rolling motion of the ball of the foot, so that the ankle joint is additionally strained. Moreover, the increased effort required reduces the performance of the athlete.

There are also known running soles for sports shoes which are formed on the running surface with crossbars or the like projecting in a honeycomb pattern and between which crossbars rhomboid depressions, for example, are formed. It is true that the crossbars provide some enhanced security of grip on synthetic tracks. But as soon as the track and the sole become wet, the friction between track and sole is reduced to such an extent that the crossbars alone are no longer sufficient to provide at least the surface grip essential for the long distance runner. Moreover, these known profiled soles are unsuitable for soft or slippery surfaces, where it is necessary for gripping elements to cut into the ground in order to obtain surface grip. But there is at present an increasing tendency to equip sports shoes with such running soles, optionally after some slight modification, to permit the shoes to be used on almost any surface.

According to the present invention, there is provided a running sole of flexible synthetic material for sports shoes, especially athletic shoes, said sole comprising a sole body having a front portion with a running surface, a plurality of crossbars molded to said body, said crossbars projecting beyond and tapering away from said running surface, and a plurality of individually roof-shaped projections extending from said crossbars away from said running surface, the projections each have a blade-like sharp edge, said edges extending substantially parallel to said running surface and in the longitudinal direction of the associated crossbars.

Such soles ensure a good grip on both hard and soft, dry and wet, surfaces, i.e. which ensure both the ground grip for the sprinter and the surface grip for the long distance runner, especially on surfaces of synthetic material, and at the same time enable the running sole to be as light as possible.

In a number of applications it will be sufficient for the crossbars to be disposed transversely of the longitudinal axis of the sole and substantially parallel to one another. In some cases, however, it may alternatively be advantageous to provide the crossbars in two sets obliquely of the longitudinal axis of the sole so that substantially honeycomb-like depressions result, the individual roof-like projections each being arranged between adjacent points of intersection of the crossbars, so that the projections extend substantially in zig-zag form.

A sports shoe having, especially in the region of the front of the sole, a running sole designed in accordance with the invention provides a very good grip for the athlete. On conventional synthetic tracks only the bladelike edges of the roof-shaped projections which edges are substantially parallel to the running surface will become effective in normal running. Only the necessary number of these projections is present. Since they do not penetrate too deeply into the synthetic material track a relatively slight exertion of force on the part of the athlete is required both for inserting and for withdrawing the projection, so that the performance of the athlete hardly suffers. In extreme situations, for example on take-off, the projections can, however, be thrust so deeply into the synthetic material track that the honeycomb-like arranged crossbars are also urged against the surface of the track. The safety of grip is thereby additionally improved beyond the extent resulting per se from the deeper penetration. In a similar manner the crossbars will also act supportingly when a sports shoe having a running sole constructed in accordance with the invention is used on soft ground, i.e. when the individual roof-shaped projections penetrate deeply into the ground, whereby in soft ground the ground grip is also appreciably enhanced. When the crossbars intersect and include substantially diamond or honeycomb-like depressions between them, then it is even possible to count on these depressions exhibiting some suction cup effect on slippery, particularly wet, tracks. A further advantage of the running sole of the invention is to be found in that the body portion of the sole may optionally be kept comparatively thin and thus comparatively light, since the crossbars covering the sole ensure sufficient rigidity of the sole plate. Therefore a running sole according to the invention can, despite the presence of a relatively great number of roof-shaped projections, be produced at a relatively light weight. For the sake of completeness it should also be pointed out that the substantially triangular lateral faces of the roof-shaped projections of course offer satisfactory safety against slipping in the direction of the blade-like edge of the projections.

Normally the free edges of the roof-shaped projections will protrude to an equal extent above the running surface of the running sole. For special purposes, however, it may be advantageous if the roof-shaped projections are designed in stepped manner with formation of a plurality of edges projecting to varying degrees from the running surface. On the one hand there is thus obtained a further refinement of the adaptation to track surfaces of various hardnesses. Moreover, tilting of the shoe in the direction of the free edge is thereby facilitated but at the same time the original grip is increased by a further edge engaging the ground, i.e. that of the shallower step. Optionally only the roof-shaped projections provided in the marginal regions of the sole may be stepped in this manner.

It is contemplated that the roof-shaped projections be arranged in a plurality of zones spaced from one another in the longitudinal direction of the sole, preferably in a plurality of rows extending transversely of the longitudinal axis of the sole. The projections of a row may in this context be oriented in zig-zag form. As a result of the regional manner of fitting the projections the weight of the sole is, of course, kept relatively low. Moreover, the crossbars may in that case engage earlier. The rows will generally be arranged where spikes are provided in conventional sports shoes. The rows need not, of course, extend across the entire running sole. They could alternatively be disposed only in the marginal region or at other locations which may prove suitable.

At least one rib may extend around the periphery of the running sole and is surmounted by respective spacedly arranged, roof-like projections.

In order to widen the sphere of applicability of the sole according to the invention, spikes or the like can replaceably be fitted to the sole. The spikes are preferably screwed into circular support plates molded into thickened regions of the running sole. Suitably the thickened regions have an annular rim the height of which above the running surface of the running sole corresponds substantially to that of the roof-shaped projections, whereby when the spikes are absent satisfactory grip is still ensured in the region of the annular rims. The annular rim of the supporting plates may be continuous but it is advantageous for it to be severally interrupted by recesses.

The roof-shaped projections are preferably of substantially triangular cross-section. In order to ensure also a satisfactory gripping effect of the crossbars it is proposed to form these also of triangular cross-section, the roof-shaped projections and/or the crossbars most frequently having the cross-section of an isosceles triangle. But at certain positions of the running soles it may be more advantageous if some of the individual roof-shaped projections have lateral surfaces of differing inclination so as to reinforce the gripping power in certain directions in this way. This applies particularly for the roof-shaped projections at the edge of the sole where the inwardly, with respect to the sole, pointing surface of the projections will frequently include a larger angle with the running surface of the sole than that surface of the projection which faces outwardly.

The sole according to the invention may, of course, be produced of the most diverse materials. But it is of particular advantage to produce the sole of a tough nylon and as a single piece.

In order that the invention will be more fully understood, embodiments of the running sole according to the invention will be described with reference to the accompanying drawing, in which:

FIG. 1 is a schematic underneath plan of a first embodiment of foresole according to the invention;

FIG. 2 is a similar view of a different design of sole;

FIG. 3a is an enlarged perspective view of portions of two intersecting crossbars having two roof-shaped projections, approximately corresponding to the area III of FIG. 1, the body portion of the sole not being illustrated;

FIG. 3b is a similar view of a portion of a crossbar having a projection of stepped design; and

FIG. 4 is a section taken along line IV--IV of FIG. 2.

The foresoles shown in FIGS. 1 and 2 consist of a flexible synthetic material, in the present case for example of tough nylon. On the sole body 2 forming the running surface crossbars 3 and 4 are provided, both in the embodiment of FIG. 1 and that of FIG. 2, which crossbars extend at about equal spacing obliquely of the longitudinal axis of the sole and project out from the running surface 1. The crossbars 3 or 4 respectively are parallel to one another so that a rhomboid pattern is formed on the running surface of the sole.

For reasons of clear representation the respective crossbars 3 and 4 are only indicated by two parallel lines in FIG. 1 and 2. In fact, however, three lines should be drawn since the crossbars 3, 4 have substantially the cross-section of an isosceles triangle, as is shown in FIGS. 3a and 3b.

As is shown in FIG. 3a especially the crossbars 3, 4 are at least in some regions raised between adjacent points of intersection 5, thus forming roof-shaped projections 6. These roof-shaped projections each have blade-like sharp free edges 7 so that the projections 6 can serve as gripping elements. In FIGS. 1 and 2 the respective projections 6 are only schematically indicated by the third line between the two lines representing the crossbars 3, 4.

Both in the foresole of FIG. 1 as in that of FIG. 2 a rim 9 substantially corresponding to the crossbars 3, 4 runs along the rim 8 of the sole, which further crossbar is also provided with further projections 10 in principle corresponding to the projections 5 of FIG. 3a. Furthermore, at least one further rim 12 provided with projections 11 is present in the toe region of the foresoles. The projections 10 and 11 in particular could be so constructed that their lateral surfaces, i.e. the actual "roof surfaces," are of different inclination relative to the running surface 1 of the sole 2, preferably such that the surfaces directed towards the centre of the sole are more steeply disposed than the outwardly facing surfaces.

FIG. 1 shows a foresole which is not provided with any special fittings or the like, or which may be not so provided. In this sole the projections 6 surmounting the crossbars 3, 4 are provided in three substantially parallel rows 13 arranged at a certain spacing from one another. Any of the adjacent projections 6 form different angles with the longitudinal shoe axis. It may in this context be preferred for the rows 13 of projections to be arranged in about that region where the spikes are provided in conventional sports shoes.

The embodiment of FIG. 2 differs from that of FIG. 1 on the one hand in that it is provided with support thickened portions 15 provided with threaded inserts or plates 14 for spikes or the like. In the region of greater thickness the threaded insert 14 is molded in with a flange 16 or the like (FIG. 4). FIG. 4 shows clearly that an annular rim 18 ending in an upper sharp edge 17 is provided around the support plate 15. The edge 17 of the annular rim 18 is at substantially the same level as the top edges 7 of the projections 6. Incisions 19 subdivide the annular rim 18 into a plurality of segments 20 having some mutual mobility. In use on suitable ground a spike of appropriate configuration, especially of appropriate dimensions, is screwed into the threaded insert 14. When the use of spikes is undesirable or disadvantageous the threaded insert 14 can be blanked off by means of a filling piece not shown in the drawing. This filling piece could optionally also be provided with a cutting edge at its upper surface, corresponding to the edges 7 or 17.

While in the foresole of FIG. 1 the projections 6 of the individual rows 13 follow one another in zig-zag formation and only single rows of such projections are provided, the projections 6 of the foresole of FIG. 2 are so arranged in areas 21 that any four projections 6 surround a honeycomb-like depression 22. Thus groups of projections of diamond shaped outline are, as it were, formed. In this way a certain suction action is sometimes exercised, in addition to the gripping action already present as a result of the projections being thrust into the track, which suction action can have a beneficial effect, especially on greasy or wet tracks. Moreover, the engagement of the track surface between the projections 6 of a diamond shaped group results in some springing which may have a beneficial effect on the athlete in the course of his run.

Of course, the projections 6 and the crossbars 3, 4 need not necessarily have the cross-sectional shape of isosceles triangles as shown in FIGS. 3a and 3b. Moreover, it is not absolutely essential for the faces 23 of the projections 6 to jut out substantially normal to the running surface 1 of the sole. The faces 23 can in particular merge in a rounded off manner into the crossbars 3, 4.

A further alternative is shown in FIG. 3b where in lieu of one projection 6 two projections 6a and 6b of different height are provided, but they each have the shape of a cutting edge at their free edges 7a or 7b. Such stepped projections afford the advantage that by virtue of the reduced width of the cutting edge 7a as compared to the cutting edge 7b the rolling movement of the foot over the edge 7a toward the crossbars 3, 4 is facilitated. Moreover, an even more precise adaptation to varying hardness of surface can optionally be obtained. It is of course, not necessary to provide the design of the projections according to FIG. 3b at all locations where projections jut out above the crossbars 3, 4. It would rather alternatively be possible to fit the stepped projections 6a, 6b only in the region of the outer ball of the foot so as to facilitate the rolling movement over the outer ball of the foot.

While in the illustrated exemplary embodiments the crossbars were always arranged in two groups of mutually parallel rows extending obliquely of thee longitudinal axis of the sole so that a honeycomb design of the sole resulted, it may be convenient for some spheres of application to provide the crossbars only transversely of the longitudinal direction of the sole, i.e. substantially perpendicular of the longitudinal shoe axis. In such an event the projections are naturally also arranged in a row and spaced from one another rather than in zig zag formation as in the illustrated embodiments.

Furthermore the design of the sole according to the invention may not only be contemplated for the foresole but also in the heel region, it being additionally possible to choose the roof-shaped projections to be of differing height in the foresole and in the heel region.

Finally, it should be pointed out that the crossbars need not, of course, be of triangular cross-section as in the exemplary embodiments described. Alternatively forms of crossbars which in cross-section taper semicircularly or trapezoidally or otherwise could form the running surface of the sole.

Claims

I claim:

1. A running sole of flexible synthetic material for sports shoes, especially athletic shoes, said sole comprising, in combination:

a. a sole body having a front portion with a running surface;

b. a plurality of crossbars molded to said body, said crossbars projecting beyond and tapering away from said running surface;

c. a plurality of individually roof-shaped projections extending from said crossbars away from said running surface; and

d. a blade-like sharp edge on each of said projections, said edges extending substantially parallel to said running surface and in the longitudinal direction of the associated crossbars.

2. A running sole as claimed in claim 1, wherein the base width of said projections is substantially equal to the base width of the associated crossbars.

3. A running sole as claimed in claim 1, wherein said roof-shaped projections are arranged in groups and wherein the edges of one group are arranged at a different angle to the longitudinal axis of the sole from the edges of another group.

4. A running sole as claimed in claim 1, wherein at least some of said roof-shaped projections are of stepped design effective to define a plurality of sharp edges projecting to different extents from the running surface of the sole body.

5. A running sole as claimed in claim 1, wherein the individual shaped projections are provided in a plurality of areas spaced longitudinally of the soles.

6. A running sole as claimed in claim 1, wherein the individual roof-shaped projections are arranged in a plurality of rows extending transversely on the longitudinal axis of the sole.

7. A running sole as claimed in claim 6, wherein the individual roof-shaped projections of a row are arranged such that the sharp edges are in substantially zig zag formation.

8. A running sole as claimed in claim 1, and further comprising at least one rib extending around the periphery of said front portion, said rib being molded to said body and projecting beyond and tapering away from said running surface, further individual roof-shaped projections being provided in said rib said further projections extending beyond said rib and having a sharp edge substantially parallel to and aligned with the rib at the location of said further projections.

9. A running sole as claimed in claim 1, and further comprising thickened regions on the front portion of said sole body, supporting plates molded into said thickened regions, and spikes detachably secured to said support plates.

10. A running sole as claimed in claim 9, and further comprising an annular rib projecting outwardly from the periphery of said thickened portions and tapering away therefrom.

11. A running sole as claimed in claim 10, and further including means defining spaced apart incissions in said annular rim.

12. A running sole as claimed in claim 1, wherein the individual roof-shaped projections and/or the crossbars are of substantially triangular cross-section.

13. A running sole as claimed in claim 12, wherein said triangular cross-section is an isosceles triangular cross-section.

14. A running sole as claimed in claim 1, wherein the sole is made of a tough nylon.

15. A running sole as claimed in claim 1, wherein the crossbars are arranged substantially parallel to one another and transversely of the longitudinal axis of the sole.

16. A running sole as claimed in claim 1, wherein the crossbars are arranged in two sets, the individual crossbars of a set being parallel to one another, and the crossbars of one set being arranged to intersect the crossbars of the other set effective to form honeycombe-like depressions therebetween, and wherein said roof-shaped projections are each arranged between adjacent points of intersection of the crossbars.