Traction Studs And Outsoles

Abstract

A traction stud comprises: a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post. The carrier may be metal and/or the tip is ceramic. The multi-pronged flange may comprise two or more prongs, each prong having a first face, a second face, a thickness, and one or more holes extending from the first face to the second face, wherein the first and second faces are substantially perpendicular to the post. Outsoles comprise the traction studs and boots and/or overshoes comprise the outsoles. The traction studs are securely retained by polymeric material of the outsoles. The studs penetrate and/or grip slippery surfaces such as ice and packed snow.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62/394,913, filed Sep. 15, 2016, the entire disclosure of which is hereby incorporated by reference herein.

TECHNICAL FIELD

[0002] The present disclosure generally relates to traction studs and to footwear having outsoles including the studs suitable for traction under slippery and/or icy conditions. In particular, traction studs comprise a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post.

BACKGROUND

[0003] Icy conditions can present risks of slip and fall injuries to persons who work and recreate on them. To enhance traction on ice and packed snow, outsoles of boots or overshoes are often provided with traction studs. Studs are desirably heavy duty to penetrate and grip slippery surfaces. Even so, over time and with use, studs are subject to breakage, separation from the outsole, and material degradation.

[0004] There is an ongoing need to provide traction outsoles that are heavy duty and remain effective to penetrate and/or grip slippery surfaces such as ice and packed snow for the effective life of footwear such as boots and overshoes.

SUMMARY

[0005] Provided are traction studs that are securely retained by polymeric material of footwear outsoles. The studs penetrate and/or grip slippery surfaces such as ice and packed snow.

[0006] An aspect is a traction stud for boots and overshoes comprising: a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post. The carrier may be metal, the tip may be ceramic, or both. In one or more embodiments, the carrier comprises a steel material and the tip comprises tungsten carbide.

[0007] The multi-pronged flange may comprise two or more prongs, each prong having a first face, a second face, a thickness, and one or more holes extending from the first face to the second face, wherein the first and second faces are substantially perpendicular to the post. The post and the tip may be coaxial. The carrier may be a unitary construction.

[0008] The tip may comprise a ceramic material selected from the group consisting of: an oxide of aluminum, zircon, silicon, titanium, tungsten; a metal carbide or nitride of aluminum, silicon, titanium, tungsten, zircon; or mixtures thereof, or a metal alloy selected from the group consisting of: bronze, brass, copper-nickel alloy, copper-aluminum alloy, or copper-beryllium alloy.

[0009] Another aspect is an outsole of a boot for traction in slippery conditions comprising: an outsole body comprising a first polymeric material and having an external surface; and a plurality of traction studs according to any embodiment disclosed herein embedded in the first polymeric material and protruding from the external surface. The first polymeric material may comprise a thermoplastic polyurethane (TPU). The external surface may comprise one or more integrally-formed features selected from the group consisting of: a toe, a heel, a heel strike, cleats, and bobs. A first plurality of studs may be located in a plurality of cleats, a second plurality of studs may be located in a plurality of bobs, or both.

[0010] A further aspect is a boot or overshoe comprising an upper and any outsole disclosed herein affixed to the upper. The boot or overshoe may further comprise a midsole comprising a second polymeric material located between the outsole body and the upper. The second polymeric material may comprise polyurethane. The midsole may comprise a midsole edge, a midsole lip, a toe cap, and a heel counter.

[0011] Another aspect is a boot or overshoe for traction in slippery conditions comprising: an upper comprising a waterproof material; an outsole comprising an outsole body comprising a first polymeric material and having an external surface and a plurality of traction studs embedded in the first polymeric material and protruding from the external surface, each stud comprising a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post; and a midsole comprising a second polymeric material, the midsole direct-attaching the upper and the outsole. The waterproof material may comprise a polyurethane-coated nylon, the first polymeric material may be a TPU, the second polymeric material may be a polyurethane, the carrier may comprise a steel, and the tip may comprise tungsten carbide. The boot or overshoe may further comprise one or both of a heel counter and a toe cap integral to the midsole.

[0012] In another aspect, provided is a method of making a boot or overshoe for traction in slippery conditions, the method comprising: obtaining a plurality of traction studs, each stud comprising a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post; forming an outsole by injection molding a first polymeric material into a first mold cavity retaining the plurality of studs; and affixing an upper to the outsole. The carrier may be metal, the tip may be ceramic, or both. Affixing the upper to the outsole may comprise direct injecting a second polymeric material into a second mold cavity retaining the outsole and the upper thereby forming a midsole that direct-attaches the upper and the outsole.

[0013] Another aspect is a method of providing traction in slippery conditions, the method comprising: forming any boot or overshoe disclosed herein; and wearing the boot or overshoe for transport on the slippery surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a schematic side view of a traction stud;

[0015] FIG. 2 is a schematic front view of an outsole comprising a plurality of traction studs; and

[0016] FIG. 3 is a plan side view of an overshoe or boot comprising an outsole comprising a plurality of traction studs.

DETAILED DESCRIPTION

[0017] Traction studs disclosed herein have an advantage in that a multi-pronged flange is used to improve continuity within the structure of a polymeric/rubber outsole. That is, the use of more than one prong at the base of a post holding a tip allows for smaller and more spaced distances where the material of the outsole is interrupted. The use of one or more holes in the prongs through a thickness from face-to-face allows for the outsole material to be continuous not only above and below the faces, but therethrough. Prior art studs offer only a single flange at the base of a post, which results in a relatively large area of disrupted material and contact only above and below the flange faces (not through them). Upon wear and tear of the prior art studs and outsoles, the studs loosen and can dislodge from the outsole, which diminishes ice traction performance.

[0018] Boots and overshoes provided herein have an advantage in that their outsoles utilize traction studs having a multi-pronged flange that is securely embedded in the material of the outsole.

[0019] Reference herein to "stud" refers to a structure that provides a protrusion from a surface of an outsole. The stud is usually a different material from the outsole.

[0020] A "cleat" is a feature of an outsole, which is integral to a body of the outsole protruding from a surface of the outsole for traction purposes.

[0021] A "bob" is a specific type of cleat, having a round shape.

[0022] An array of cleats and bobs constitutes a tread pattern.

[0023] Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

[0024] Turning to the figures, FIG. 1 is a schematic side view of a traction stud 100. The stud 100 comprises a carrier 102 and a tip 104. In one or more embodiments, the carrier is metal and/or the tip is ceramic. The carrier 102 comprises a post 106 having a distal end 118 and a proximal end 110 and a flange 108. The carrier 102 may be a unitary construction, where the post 106 and flange 108 are one piece, being formed of any material that is suitable for outdoor use under wet, icy and/or slippery conditions. For example, materials that are non-corrosive and non-rusting are preferable. A preferred metal material is steel. Exemplary steel materials, include stainless steel, or a carbon steel such as carbon steel T14 which is a hardened and tempered steel, which may have an electrolytic coating to protect against corrosion and enhance durability. Suitable electrolytic coatings include but are not limited to copper (99% purity) and/or nickel (99% purity).

[0025] The post 106 has a length "B" and a hollow (not numbered) that provides an opening at its distal end 118 in which the tip 104 resides. The tip is securely bonded in the hollow. The hollow has a length that is shorter than the post's length "B". The tip 104 extends past the distal end 118 of the post 106 for a distance of "A" as shown in FIG. 1. The hollow and likewise, the tip 104 are generally coaxial with the post 106 for symmetry. The tip may comprise any suitable material for outdoor use under wet, icy and/or slippery conditions. For example, materials that are non-corrosive and non-rusting are preferable. Non-sparking materials may also be suitable. The tip may comprise a ceramic material selected from the group consisting of: an oxide of aluminum, zircon, silicon, titanium, tungsten; a metal carbide or nitride of aluminum, silicon, titanium, tungsten, zircon; or mixtures thereof. Preferably, the ceramic tip is tungsten carbide. The tip may comprise a metal that is iron-free. The tip may comprise a metal alloy such as bronze, brass, copper-nickel alloy (Monel metal), copper-aluminum alloy (aluminum bronze), or copper-beryllium alloy (beryllium bronze).

[0026] Dimensions of the carrier and tip depend on the application. Generally, the tip extends from the distal end of the post far enough to provide traction and not too far as to be prone to breakage. The post is sized to protrude from an external surface of an outsole and to provide structure to the tip. The flange is sized and the holes are designed to provide surface area for the outsole material to adhere and connect to itself. In one or more non-limiting embodiments, the post 106 has a length B in the range of 7-11 mm.+-.2%. In one or more non-limiting embodiments, the tip 104 extends past the distal end 118 for 1-1.15 mm.+-.1%. The tip 104 may have a total length in the range of 6-6.2 mm.+-.1%.

[0027] The flange 108 is at the proximal end 110 of the post 106, preferably having two or more prongs 116a, 116b, 116c, 116d, i.e., being multi-pronged. The flange 108 has a thickness of "C" and a width at its widest part of "E". In one or more embodiments, the thickness C is in the range of 1-1.2.+-.1% and the width E is in the range of 9.8-10.0 mm.+-.2%. Total height of the stud 100 is "D", which equals A+B+C, and may be in the range of 9-9.35.+-.1%. Each prong has a first face 112 and a second face (not shown) opposite the first face 112 separated by the thickness C. The flange 108 is substantially perpendicular to the post in that there is a nominal 90.degree..+-.5% angle where the flange 108 meets the proximal end of the post 110, allowing for tolerance errors machining and/or molding. Each prong 116a-d comprises one or more holes 114 extending from the first face 112 to the second face. The prongs preferably have the same number of holes each for symmetry, but should a need arise, the number of holes per prong may vary. The holes may be of any diameter and cross-section shape as desired. The holes are sized and located to facilitate manufacture of the studs themselves and also for readily receiving injected polymer so that upon formation, the outsole material is above, below, and through the prongs of the stud, which acts as a locking mechanism to hold the studs in place.

[0028] FIG. 2 is a schematic front view of an outsole 200 comprising an outsole body 202 and a plurality of traction studs 100 embedded therein. The outsole body 202 has an external surface 204, which faces the ground during use. Portions of the external surface 204, primarily projecting portions, are in contact with the ground during use. The outsole body 202 comprises a polymeric material that is suitable for outdoor conditions. A preferred polymeric material for the outsole body is a thermoplastic polyurethane. The outsole 200 is formed by injection molding the polymeric material into a mold cavity of a desired tread pattern having projecting features, some of which retain the traction studs 100. The polymeric material flows around the multi-pronged flange and through the one or more holes of the prongs, which upon curing and solidifying results in embedding the studs 100 in the polymeric material. Without intending to be bound by theory, it is thought that a reinforcement of the studs to the outsole is formed by the flow of polymer through the holes of the prongs, which forms connecting polymer material to the polymer material that is on both sides of the prongs. This results in securely retaining the studs as compared to the prior art.

[0029] A mold for the outsole is prepared according to desired design features. One or more integrally-formed features of the outsole tread include but are not limited to: a toe 208, a heel 210, a heel strike 212, one or more cleats 214, and one or more bobs 216. The studs are generally retained in one or more cleats and one or more bobs, which are throughout the external surface 204 of the outsole body 202 including the heel 210. Generally, there are not studs located in the heel strike or the toe. Placement of the studs is throughout the outsole body to ensure the studs will be in contact with the ground and to provide traction during walking and striding. Preferably, the studs are in staggered positions to obtain maximum traction with the fewest studs. In one or more non-limiting embodiments, studs may be placed along the perimeter of the outsole in cleats and in the interior in bobs. Left and right outsoles are generally mirror images of each other.

[0030] FIG. 3 is a plan side view of an overshoe or boot 300 comprising an outsole 200, which has a plurality of traction studs 100, an upper 312, and a midsole 302. The outsole 200 is according to any disclosed herein. The upper 312 may be any suitable material for the application. Generally, the upper is waterproof. Materials for the upper include but are not limited to polymeric materials and textile or fabric materials that have been waterproofed. For example, the upper may be a woven nylon that is coated with polyurethane. The upper is generally stitched together and the seams are rendered waterproof. The upper may contain additional features as desired, such as reflective piping for enhanced safety; gussets to assist in donning an overshoe; a strap to secure the overshoe during use; and a gaiter to provide extended waterproof coverage on the leg.

[0031] The midsole 302 comprises a polymeric material that is generally different from the polymeric material of the outsole, but which is compatible to facilitate direct attachment of the outsole to the upper by injection molding. By this method, an internal waterproof membrane is not needed to ensure waterproofing of the boot or overshoe. The midsole may comprise a polyurethane. In one or more embodiments, to form the midsole 302, a mold cavity holds a pre-fabricated outsole 200 and a pre-fabricated upper 312. Polyurethane is injected to form the midsole 302 having a midsole edge 304, which provides a boundary with the outsole 200. In this embodiment, a midsole lip 306 is integral to toe cap 308 and heel counter 310, while providing a boundary with the upper 312 where it meets the upper 312. The midsole 302 may further have one or more features including but not limited to: a toe cap 308 and a heel counter 310, which may be designed to accommodate various applications. Generally, the toe cap 308 and the heel counter 310 are formed integrally with the midsole. In a detailed embodiment, the midsole 302 comprises: the midsole edge 304, the midsole lip 306, the toe cap 308, and the heel counter 310.

[0032] Reference throughout this specification to "one embodiment," "certain embodiments," "various embodiments," "one or more embodiments" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in various embodiments," "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0033] Although the disclosure herein provided a description with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope thereof. Thus, it is intended that the present disclosure include modifications and variations that are within the scope of the appended claims and their equivalents.

Claims

1. A traction stud for boots and overshoes comprising: a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post.

2. The traction stud of claim 1, wherein the carrier is metal, the tip is ceramic, or both.

3. The traction stud of claim 1, wherein the multi-pronged flange comprises two or more prongs, each prong having a first face, a second face, a thickness, and one or more holes extending from the first face to the second face, wherein the first and second faces are substantially perpendicular to the post.

4. The traction stud of claim 1, wherein the post and the tip are coaxial.

5. The traction stud of claim 1, wherein the carrier is a unitary construction.

6. The traction stud of claim 1, wherein the tip comprises a ceramic material selected from the group consisting of: an oxide of aluminum, zircon, silicon, titanium, tungsten; a metal carbide or nitride of aluminum, silicon, titanium, tungsten, zircon, or mixtures thereof; or a metal alloy selected from the group consisting of: bronze, brass, copper-nickel alloy, copper-aluminum alloy, or copper-beryllium alloy.

7. The traction stud of claim 1, wherein the carrier comprises a steel material and the tip comprises tungsten carbide.

8. An outsole of a boot for traction in slippery conditions comprising: an outsole body comprising a first polymeric material and having an external surface; and a plurality of traction studs of claim 1 embedded in the first polymeric material and protruding from the external surface.

9. The outsole of claim 8, wherein the first polymeric material comprises a thermoplastic polyurethane (TPU).

10. The outsole of claim 8, wherein the external surface comprises one or more integrally-formed features selected from the group consisting of: a toe, a heel, a heel strike, cleats, and bobs.

11. The outsole of claim 10, wherein a first plurality of studs is located in a plurality of cleats, a second plurality of studs is located in a plurality of bobs, or both.

12. A boot or overshoe comprising an upper and the outsole of claim 8 affixed to the upper.

13. The boot or overshoe of claim 12 further comprising a midsole comprising a second polymeric material located between the outsole body and the upper.

14. The boot or overshoe of claim 13, wherein the second polymeric material comprises polyurethane.

15. The boot or overshoe of claim 13, wherein the midsole comprises a midsole edge, a midsole lip, a toe cap, and a heel counter.

16. A boot or overshoe for traction in slippery conditions comprising: an upper comprising a waterproof material; an outsole comprising an outsole body comprising a first polymeric material and having an external surface and a plurality of traction studs embedded in the first polymeric material and protruding from the external surface, each stud comprising a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post; and a midsole comprising a second polymeric material, the midsole direct-attaching the upper and the outsole.

17. The boot or overshoe of claim 16, wherein the waterproof material comprises a polyurethane-coated nylon, the first polymeric material is a TPU, the second polymeric material is a polyurethane, the carrier comprises a steel, and the tip comprises tungsten carbide.

18. The boot or overshoe of claim 16 further comprising one or both of a heel counter and a toe cap integral to the midsole.

19. A method of making a boot or overshoe for traction in slippery conditions, the method comprising: obtaining a plurality of traction studs, each stud comprising a carrier comprising a post, a hollow defined by the post that opens at a distal end of the post, and a multi-pronged flange at a proximal end of the post; and a tip bonded in the hollow and extending past the distal end of the post; forming an outsole by injection molding a first polymeric material into a first mold cavity retaining the plurality of studs; and affixing an upper to the outsole.

20. The method of claim 19, wherein the carrier is metal, the tip is ceramic, or both.

21. The method of claim 19, wherein affixing the upper to the outsole comprises direct injecting a second polymeric material into a second mold cavity retaining the outsole and the upper thereby forming a midsole that direct-attaches the upper and the outsole.

22. A method of providing traction in slippery conditions, the method comprising: forming a boot or overshoe of claim 16; and wearing the boot or overshoe for transport on the slippery surfaces.