WO2000004802A1 - Improved slip resistant shoe sole - Google Patents

Abstract

An improved slip resistant shoe sole (10). A regular, tiling array of hexagonal shaped projections (32) is provided. The projections (32) are arranged with opposite sides facing generally fore-aft and are spaced from one another to provide for liquid conducting channels (38) therebetween, the liquid conducting channels (38) being substantially unobstructed over most of the sole.

Description

IMPROVED SLIP RESISTANT SHOE SOLE

TECHNICAL FIELD The present invention relates to an improved slip resistant shoe sole, particularly a shoe sole having an improved pattern of relief.

BACKGROUND OF THE INVENTION Slip and fall accidents are important concerns both in the workplace and in the home. It is often desirable to maximize slip resistance. Accordingly, there have been many attempts to provide high traction soles in footwear, particularly in athletic shoes. In many circumstances, however, cleats or other hard projections adapted for penetrating slippery surfaces to gain a purchase thereon are undesirable or impractical. Recognizing this, the prior art has attempted to provide patterns of relief in relatively compliant shoe soles that function analogously to harder projections such as cleats. Such prior art patterns have not been entirely effective, however. Accordingly, there is a need for an improved slip resistant shoe sole that increases slip resistance over that available from prior art shoe soles.

SUMMARY OF THE INVENTION The improved slip resistant shoe sole of the present invention solves the aforementioned problem and meets the aforementioned need by providing a regular array of hexagonal shaped projections at the bottom surface of the sole. The projections are arranged with respect to each other so as to form an interlocking pattern that "tiles" the bottom surface of the sole. Opposite sides of the projections generally face in the directions of a fore-aft axis extending between heel and forefoot portions of the sole. The projections terminate in projected surfaces for making actual contact with a slippery surface. The projected surfaces are substantially flat and parallel to the bottom surface to maximize the area of contact with the slippery surface.

The projections are spaced apart from one another to define channels therebetween for conducting liquid. The channels are substantially unobstructed along at least most of the perimeter of the sole and the forefoot and heel portions thereof, to conduct liquid away from the projected surfaces and the slippery surface. Therefore, it is a principal object of the present invention to provide a novel and improved slip resistant shoe sole.

It is another object of the present invention to provide such a shoe sole that optimizes the relative proportions of area provided for liquid conducting channels and for surfaces of the sole adapted for making contact with slippery surfaces. The foregoing and other objects, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a slip resistant shoe sole according to the present invention.

Figure 2 is a sectional view of the sole of Figure 1, taken along a line 2-2 thereof.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to Figures 1 and 2, a slip resistant shoe sole 10 is shown, the sole having a pattern 12 in relief. The pattern 12 may be employed in articles other than a shoe sole in which slip resistance is desired; for example, in floor coverings and bath mats.

The sole 10 includes a bottom surface 14 and is defined by a perimeter 16 which includes a toe end 18, two sides 20 and 22, and a heel end 24. The toe end corresponds to the toe end of a shoe to which the sole is attached (not shown), the heel end corresponds to the heel end of the shoe, and the sides correspond to the sides of the shoe.

The bottom surface is generally flat, though this is not essential for practice of the invention. The perimeter encloses a forefoot portion 26 of the sole, a heel portion 28 and an arch portion 30 therebetween. The forefoot, heel and arch portions of the sole correspond to similarly identifiable portions of the shoe.

The sole can be described as generally extending along a fore-aft axis "L" which runs between the toe end and the heel end. More precisely, the heel portion generally extends along a first fore-aft axis "LI" and the forefoot portion generally extends along a second fore-aft axis "L2" that makes a small angle with respect to the axis "LI," in accord with the anatomy of the human foot.

The pattern 12 provides a regular array of projections 32 extending from the bottom surface 14 and being hexagonal shaped in cross-section along their lengths. The projections 32 extend toward a contact surface 34 on which it is desired to travel on foot, for making contact with the surface. Slip tends to be induced whenever liquids, such as water and oil, are present either on the sole 10 or on the surface 34. It has been found that the hexagonal form of the projections is optimum for general, omni-directional resistance to slip. Preferably, the size of the projections 32 are such that sides "s" of the projections have equal widths "dl" of about 4.5 mm. The projections 32 terminate with projected hexagonally shaped surfaces 36 that make actual contact with the surface 34. The projected surfaces 36 are substantially flat and parallel to the bottom surface 14, to maximize the area of the contact.

The projections are aligned so that opposite edges "e" of the surfaces 36 generally face in the directions of, or extend perpendicular to, the fore-aft axis "L." Preferably and more precisely, the edges "e" of the surfaces 36 of the forefoot portion generally face the directions of the axis "LI" whereas opposite edges of the surfaces 36 of the heel portion generally face the directions of the axis "L2." However, as the angle between the axes "LI" and "L2" is not great, the edges "e" may be aligned to generally face directions substantially aligned with any of the axes "L", "LI" or "L2" (the "longitudinal axes") without departing from the principles of the invention. This general orientation of the surfaces 36 has been found optimum for slip resistance in the sole of a shoe, in which there is a predetermined, usual or ordinary direction of travel.

The projections 32 are arranged in a regular tiling array. That is, each projection is arranged in the regular array so that it has six nearest neighbors, and the centers of the surfaces 36 lie along lines that are oriented with respect to one another in integer multiples of 60 degrees. This forms a pattern of interlocking hexagonal shapes.

The above-described projections 32 are effective for making slip resistant contact with the surface 34. In addition, the invention further provides an effective means for removing any of the aforedescribed liquid that stands in the way of that contact. The projections 32 are spaced apart from one another to form substantially continuous channels 38 between the projections for conducting the liquid. Preferably, for the preferred dimensions of the sides "s" given above, the projections are spaced from each of their nearest neighbors a distance "d2" which is about 1.5 mm to form the channels. The channels are not substantially blocked or obstructed from conducting liquid therealong or releasing the liquid at the ends thereof (hereinafter "open"), along most of the perimeter 16 of the sole, and over at least most of the forefoot and heel portions 26 and 28 where weight distribution tends to be the greatest. Preferably, however, the toe end 18 of the sole is "closed" as shown at 40 to prevent debris from being taken up by the channels when "scuffing" the feet. Moreover, as weight distribution over the arch portion 30 tends to be relatively small, which decreases its tendency to slip, the arch portion provides a best location for an embossment 42 identifying the manufacturer. Preferably, however, the embossment does not project as far as the surfaces 36, and the channels 38 remain open over the arch portion as well.

Typically, the sole 10 is molded of a natural or synthetic rubber or other elastomeric material. Typically as well, some draft is provided in the projections 36 to facilitate economical manufacturing, for example to facilitate automatic removal of the sole from the mold or to avoid the use of slip inducing mold release agents which must later be removed. However, it is preferable to minimize draft to maximize the area of the surfaces 36. Notwithstanding, larger or smaller amounts of draft than would otherwise be required for effective mold release may be employed without departing from the principles of the invention. As illustrated by the above, it can be seen that the invention provides a slip- resistant pattern in an advantageous configuration and orientation in a shoe sole, provides improved balance between an amount of surface area employed for making frictional contact with the contact surface and the size of channels employed for conducting slip inducing liquids away from the area of contact, and opens the channels so that such liquid removal is more effective. Accordingly, it is to be recognized that, while a particular slip resistant shoe sole has been shown and described as preferred, other configurations could be utilized, in addition to configurations already mentioned, without departing from these and other principles of the invention.

The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention of the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of. the invention is defined and limited only by the claims which follow.

Claims

1. An improved shoe sole for increasing the resistance to slip on a contact surface, the sole comprising a bottom surface and defining a perimeter bounding a forefoot portion corresponding to the forefoot of the shoe and a heel portion corresponding to the heel of the shoe, wherein the sole extends generally along a fore-aft axis running from said heel portion to said forefoot portion, the sole further comprising a substantially regular tiling array of projections projecting from said bottom surface, said projections terminating in hexagonal shaped projected surfaces spaced from said bottom surface in a direction for making contact with the contact surface, said projections being oriented so that opposite edges of said projected surfaces face generally in the directions of said fore- aft axis, said projected surfaces being substantially flat and parallel to the bottom surface to maximize the area of contact with the contact surface, said projections being spaced from one another to define substantially continuous channels therebetween for conducting liquid, said channels being open over at least most of said perimeter, said forefoot portion and said heel portion of the sole.

2. The shoe sole of claim 1, wherein said perimeter defines two sides and a heel end corresponding respectively to the sides and heel end of the shoe, wherein said channels are open over the substantially the entire length of said sides and said heel end.

3. The shoe sole of claim 2, wherein the perimeter of the sole includes a toe end corresponding to the toe end of the shoe, wherein said channels are substantially closed along said toe end.

4. The shoe sole of claim 1 , wherein said projections have six sides of substantially equal size, wherein each of said sides is spaced about 1.5 mm from a corresponding side of each nearest neighbor projection.

5. The shoe sole of claim 4, wherein the widths of said sides are about 4.5 mm long.