Multi-Surface Traction Sling

Abstract

A multi-surface and traction sling configured to be stretched over shoes or boots that does not utilize any metal or hard surfaced traction elements, including spikes, cleats or springs, on the bottom surface. The multi-surface traction sling is composed of a generally flexible and stretchable sling and a traction sole that is much less flexible and possesses a high coefficient of friction.

Description

FIELD OF THE INVENTION

The present invention relates in general to traction devices for footwear that attach to footwear and enable a user to walk safely on ice and other slick surfaces.

BACKGROUND OF INVENTION

Inventors have long sought to develop a comfortable traction device which can be easily attached to footwear when needed to enable a person to safely walk on slick surfaces. The need for an improved traction device is that today most all over the shoe/boot traction devices for use in snow and on ice contain a set of spikes, screws or other metal tooth components intended to grip the slippery surface. Beyond the impracticality of wearing such devices indoors, there are many occupations where having the presence of a metal spike can prove to be more dangerous than the slip or fall itself. For example, workers in the electrical utilities or oil and gas industries cannot risk creating fire causing sparks with their footwear. In the case of airline workers, they cannot wear spikes that might scratch the inner surface of an aircraft where it could lead to corrosion, or out on the tarmac where sparks in the area of a refueling aircraft might lead to catastrophe. In many other instances walking with metal spikes, screws or springs on the bottom of footwear from an icy or snow laden surface back onto a clean hard indoor surface can prove dangerous and/or damaging. The metal gripping means can prove slippery on hard indoor surfaces, and can mare and damage those surfaces as well.

Thus there is a need for a traction sling that is easily attached to footwear that is spikeless, that is, having no metal spikes, screws or springs, and that can be easily worn over a shoe or boot, but can also be worn indoors or in sensitive environments, and that can be easily removed. There is also a need for a method to attach a non-slip spikeless sole that has limited stretch onto a stretchable rubber sling.

SUMMARY OF INVENTION

In accordance with the present invention a traction device is disclosed that is flexible and is designed to be stretched over footwear. The disclosed invention can easily be worn over a shoe or boot, and can also be worn indoors or in sensitive environments without fear of damage or sparking. This is because the traction sling disclosed herein is spikeless, that is, it has no metal or other hard traction protrusions mounted or secured to the ground engaging surface of the sling. The disclosed sling can also be easily removed.

A non-slip shoe or boot has little stretch from front to back or side to side. Such a boot or shoe presents a fairly rigid structure when compared to the disclosed sling traction device that is configured to stretch over existing footwear. Therefore the non-slip sole of a typical boot or shoe is locked into position by virtue of the surrounding rigid structure and presents no issues of mounting non-slip traction sole pads on a stretchable sling.

The spikeless traction sling disclosed herein has a highly stretchable sling coupled to semi-rigid rubber sole sections. The traction sole sections possess a high kinetic coefficient of friction against ice, snow and other slippery surfaces. In an over-the-shoe sling, flex or stretch of the overall device is critical. The sling must be able to stretch over all manner, shape and size of footwear to be most useful. Because the non-slip traction pads have limited stretch; the mounting of the sole tractions pads on the sling required a unique solution. Unlike most footwear, including tennis shoes, there is not a solid foundation onto which to mount a traction pad. The sling must be flexible, including having the ability to stretch round the footwear's sole to best accommodate the shape and size of the footwear. A tennis shoe, even though it has a flexible upper portion, has a generally non-stretchable sole from edge to edge which is available for tread placement. The traction sling of the disclosed invention, however, must itself stretch around its sole edges such that it securely attaches to the target footwear. It is difficult to attached a fairly ridged traction pad to a sling without a ridged sole. Therefore a unique method of mounting the described sole sections to the sling is disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the spikeless traction sling applied to an item of footwear.

FIG. 2 depicts the unassembled invention depicting the bottom of the sling with the traction pads removed.

FIG. 3 is a top plan view of the invention in its assembled state showing the attachment of the cord to the front ring and the routing of the cord through the three rear wings and the routing of the ring through the three front wings.

FIG. 4 depicts the unassembled sling showing the preferred stitching pattern used to attach the semi-ridged traction pads to the elastic sling body.

FIG. 5 depicts the unassembled sling showing the resulting preferred stitching used to attach the semi-ridged traction pads to the elastic sling body.

FIG. 6 depicts the unassembled sling showing an alternate stitching pattern used to attach the semi-ridged traction pads to the elastic sling body.

FIG. 7 depicts the unassembled sling showing the resultant alternate stitching pattern used to attach the semi-ridged traction pads to the elastic sling body and the exemplary, all rubber tread pattern.

FIG. 8 depicts the unassembled sling showing the resulting preferred stitching used to attach the semi-ridged traction pads to the elastic sling body and also showing an exemplary all rubber tread pattern on the attached traction pads.

FIG. 9 depicts the view from FIG. 8 in an assembled state.

FIG. 10 is a front elevation view of the sling in its assembled state.

FIG. 11 is a side elevation view of the invention in its assembled state showing another view of the routing of the ring and the cord, as well as the termination of the cord within the heel wing void.

FIG. 12 is a rear elevation view of the invention showing the stitching used to secure the ends of the cord at its routing termination point within the heel wing void.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention comprises three main components: a sling, a sole traction pad and a heel traction pad. Referring to the figures, traction sling 10 is comprised of six wings: toe wing 12, right front wing 14, right rear wing 16, heel wing 18, left rear wing 20 and left front wing 22. Each wing preferably further comprises a plurality of horizontal flex slots 34 and a plurality of vertical flex slots 36. Toe wing further comprises window 13. Each wing further defines a void used to accommodate support structures when sling 10 is assembled for use. These voids include: left front wing void 40, toe wing void 42, right wing void 44, right rear void 46, heel wing void 48 and left rear wing void 50. When assembled for use, ring 38 is passed through and secured within left front wing void 40, toe wing void 42 and right front wing void 44 as depicted in FIGS. 1,3,10 and 11. Cord 30 is attached to ring 38 and then passed through right rear wing void 46, heel wing void 48 and left rear wing void 50. As best seen in FIG. 11, the ends of cord 30 overlap each other and terminate within heel wing void 48. The ends of cord 30 are secured within heal wing void 48 by stitches 49. Cord 30 is preferably elastic. Cord slide 52 engages two portions of cord loop 30 as depicted in FIG. 3, and is preferably lockable.

The base of sling 10 comprises fore foot portion 58, middle foot portion 60 and hind foot portion 62. On the ground engaging side of sling 10, fore foot portion 58 is defined by ridge 35 which outlines the area for placing and securing fore foot traction pad 68. Hind foot portion 62 is defined by ridge 27 which outlines the area for placing and securing hind foot traction pad 70. Middle foot portion 60 further preferably comprises flex window 28. As best can be seen in FIG. 3, the footwear engaging side of sling 10 may comprise a plurality of traction nodes 54.

The Shore Hardness of the traction pads 68 and 70 is preferably 90+−3. The coefficient of friction of the traction pads 68 and 70 is preferably 0.7 under dry conditions and 0.35 under wet conditions. The Shore Hardness of sling 10 when preferably made of TPE (Thermoplastic Elastomer) is preferably 43+/−3. The tensile strength of the traction sole is preferably greater than 140. The traction pads 68 and 70, because of their physical properties, preferably have limited elasticity. Sling 10, because it must be stretched over a wide variety of sized and shaped footwear, must be more elastic to fit securely. It is thus preferred that the material of sling 10 be 3 to 4 times more elastic than the material of the traction pads 68 and 70. Exemplary testing of both the preferred traction pad material (sole) and the sling material resulted in the following results:

		Parameters and/or
Test Method	Test Method Title	Deviations from Method
ASTM	Standard Test Methods	Die: Micro-tensile Die
D412-16	for Vulcanized Rubber	Test Speed: 2.0″/min.
	and Thermoplastic	Grip Separation: 0.65″
	Elastomers—Tension

Average Test Results
		Stress at 400%	Elongation
	Peak Stress	Elongation	at Break
Specimens	(psi)	(psi)	(%)
Sole	1704	949	636
Sling	421	259	743

The problem of mounting a semi-rigid traction pad on a far more elastic sling was solved using the sewing methods disclosed in FIGS. 4 and 6, and in the construction of fore foot and hind foot portions 58 and 62. The preferred method of attaching the fore foot traction sole 68 onto fore foot portion 58 is depicted in FIG. 4. The stitching preferably begins at point 72 and continues clockwise around the outer perimeter of the fore foot traction pad 68 in direction 73 until point 72 is again reached. Stitching 76 is then laid horizontally across fore foot traction pad 68 until just short of the first perimeter stitching at which point the stitching proceeds as shown by arrow 78 in FIG. 4. Once the stitching reaches point 79 stitching 80 again proceeds horizontally until point 81, a position on or near the original stitching line, at which point the stitching is complete. It is preferred that the horizontal stitching 76 and 80 divide fore foot traction pad 68 into roughly in three equal parts. This stitching pattern, along with the support of ridge 35, secures the fore foot traction pad 68 to fore foot portion 58 even though attached to very flexible sling material. Another advantage of this method of stitching is that the stitching is continuous, which is more efficient and reduces manufacturing costs. Adhesive may be applied to the mating side of the fore foot traction pad 68 prior to stitching.

An alternate method of stitching fore foot traction pad 68 on to fore foot portion 58 is depicted in FIG. 6. The result of the method of stitching is similar to the method shown in FIG. 4, with the exception that stitching is not continuous, and requires a stopping and restarting of the stitching process, which is less efficient than the method shown in FIG. 4. As shown in FIG. 6, in the alternative method the stitching preferably begins at point 89 and continues around the outer perimeter of fore foot traction pad 68, as in the preferred method, until point 89 is again nearly reached. At point 89 a stitch line is made horizontally in direction 92 until point 94 is reached on the far perimeter. The stitching is there terminated and restarted at point 93. The stitching then proceeds horizontally across forefoot traction pad 68 in direction 98 until point 95 is reached and the stitching is there preferably concluded.

The preferred method for securing hind foot traction pad 70 to hind foot portion 66 is best seen in FIGS. 4 and 6. The stitching preferably begins at point 74 and continues around the outer perimeter of hind foot traction pad 70, in direction 84, until the circuit is complete. Once back at point 74, the stitching proceeds horizontally across hind foot traction pad 70 in direction 82 until the stitching reaches point 75, at which point the stitching is preferably concluded. This stitching pattern, along with the support of ridge 27, secures the hind foot traction pad 70 even though attached to very flexible sling material. Another advantage of this method of stitching is that the stitching is continuous, which is more efficient and reduces manufacturing costs.

As best seen in FIGS. 1 and 3, traction sling 10 is applied to exemplary footwear 32 by a user placing one hand on either side of cord 30. This is preferably accomplished with cord slide 52 as close to ring 38 as possible to allow as much room between the opposing sides of cord 30 as possible. Cord 30 is then pulled on by the user such that footwear is urged into traction sling 10 until footwear 32 is fully inserted. Thereafter cord slide 52 can be moved toward the heel of the foot wear, if needed, to further secure the cord against the footwear and thus footwear to traction sling 10. The vertical flex joints 36 assist in increasing the flexibility of sling 10 to accommodate footwear of differing vertical dimensions. Horizontal flex joints 34 increase the flexibility of sling 10 to accommodate footwear with differing sole dimensions and configurations. Base flex window 28 is important to assist in increasing the flexibility of sling 10 to accommodate footwear of differing lengths. Toe wing window 13 assists in increasing the flexibility of sling 10 to accommodate toes of various footwear with different toe dimensions and configurations.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiments. It will be readily apparent to those of ordinary skill in the art that many modifications and equivalent arrangements can be made thereof without departing from the spirit and scope of the present disclosure, such scope to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products. Moreover, features or aspects of various example embodiments may be mixed and matched (even if such combination is not explicitly described herein) without departing from the scope of the invention.

For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.

Claims

1. A spikeless traction sling, comprising: a unitary elastic sling comprising a fore foot section, a middle foot section, a heel foot section, a top side, a bottom side, a toe wing, a heel wing, a left front wing, a left rear wing, a right front wing, a right rear wing, the toe wing defining one or more elongated apertures and a securing void,the heel wing defining a securing void,the left front wing defining one or more elongated apertures and a securing void,the left rear wing defining one or more elongated apertures and a securing void,the right front wing defining one or more elongated apertures and a securing void,the right rear wing defining one or more elongated apertures and a securing void;a ring secured within the toe wing void, the left front wing void, and the right front wing void;an elastic cord secured to the ring that has a first end and a second end;the first end of the elastic cord engages the left rear wing securing void and terminates within the heel wing securing void;the second end of the cord engages the right rear wing securing void and terminates within the heal wing securing void;the fore foot section bottom side defining a traction pad securing area wherein a rubber fore foot traction pad is therein secured; and,the heel foot section bottom side defining a traction pad securing area wherein a rubber traction pad is therein secured;

2. The spikeless traction sling of claim 1 wherein the first end and second end of the cord overlap within the heal wing securing void.

3. The spikeless traction sling of claim 2 wherein the first end and the second end of the cord are secured within the heel wing securing void by stitching.

4. The spikeless traction sling of claim 1 wherein the fore foot traction pad is secured to the fore foot section bottom side by stitching around an outer perimeter of the fore foot traction pad and making two longitudinal stitching runs.

5. The spikeless traction sling of claim 1 wherein the heel foot traction pad is secured to the heel foot section bottom side by stitching around an outer perimeter of the heel foot traction pad and making in addition a longitudinal stitching run.

6. A spikeless traction sling, comprising: a unitary elastic sling configured to stretch over footwear comprising a fore foot area, a middle foot area, a heel foot area, a top side, a bottom side, the bottom fore foot area defining a forefoot traction pad securing area, the bottom heel foot area defining a heel foot traction pad securing area;a fore foot rubber traction pad having a maximum coefficient of friction greater than 6.5;a heel foot rubber traction pad having a maximum coefficient of friction greater than 6.5;wherein the fore foot rubber traction pad is secured to the fore foot traction pad securing area by stitching around an outer perimeter of the fore foot traction pad and by making two longitudinal stitches such that the longitudinal stitches generally trifurcate the fore foot traction pad; and,wherein the heel foot rubber traction pad is secured to the heel foot traction pad securing area by stitching around an outer perimeter of the heel foot traction pad and by making a longitudinal stitch such that the longitudinal stitch generally bifurcate the fore foot traction pad.