Patent Description:
Protective footwear including protective devices for shielding the toe and forefoot region of the foot from injury are widely used in various sectors of the footwear industry. These protection devices may be referred to as toe caps, safety toes, safety toe caps, toe protectors, or steel toes and may be employed as independent devices or may be integrated into the shoe or other article of footwear. Common scenarios in which such protective devices may be necessary are in construction applications, in mining, or in other like fields where the foot may be susceptible to injury due to impact with extraneous objects (e.g., falling rocks, lumber, puncture via nails, etc.). Examples of toe caps are disclosed in <CIT>.

In order for the footwear to be designated as "protective footwear", certain types of safety footwear must satisfy particular requirements. For instance, the American Society for Testing and Materials (ASTM) sets standards for protecting consumer's toes and metatarsal areas in "protective footwear" (e.g., as set forth in ASTM F2413-<NUM>). If a safety toe cap is used, it must meet certain impact resistance and compression resistance tests, indicating the toe cap can sufficiently protect a user's foot from injury.

In some cases, while the aforementioned protective devices may provide adequate protection from injury and satisfy ASTM standards, the amount and thickness of material necessary to do so may cause the protective device and footwear to be unduly heavy, bulky, and awkward for a user. A bulky device having a large profile may also be difficult to integrate into an article of footwear without significant alteration to the shape, structure, and aesthetic aspects of the footwear. In addition, a heavy protective device may be expensive to manufacture due to the high amount of metal or other protective material needed to manufacture a thick, heavy device. Other deficiencies not noted here also exist.

According to the present invention, there are provided a protective toe cap, an article of footwear and a method of manufacturing a protective toe cap as defined in the appended claims. A safety toe cap according to the present technology is adapted to provide adequate protection to a user's toe and forefoot region, while maintaining a lightweight, thin, and streamlined profile, so as to be comfortable for a user and easy to incorporate into an article of
protective footwear. The safety toe cap of the present technology includes one or more strain hardened regions which provide increased strength with decreased mass, thickness, and material usage.

In particular, in some aspects, the present technology provides a protective toe cap for an article of footwear, comprising a hemi-dome shaped body adapted to cover a user's toes once incorporated into an article a footwear, and having opposing inner and outer surfaces, a forefoot side, a midfoot side, a medial side, and a lateral side, and further including at least one strain hardened portion and at least one non-strain hardened portion.

In an embodiment, in the protective toe cap according to the present technology, the at least one non-strain hardened portion has a yield strength of about <NUM> MPa to about <NUM> MPa. Further, the at least one non-strain hardened portion may have a yield strength of about <NUM> MPa to about <NUM> MPa. In some embodiments, the at least one strain hardened portion may have a yield strength which is increased by about <NUM>% to about <NUM>% with respect to a yield strength of the at least one non-strain hardened portion. In addition, the at least one strain hardened portion may have a hardness which is increased by about <NUM>% to out <NUM>% with respect to a hardness of the at least one non-strain hardened portion.

In some embodiments, the protective toe cap may have a thickness of no more than about <NUM>, while in alternative embodiments, the protective toe cap may have a thickness of no more than about <NUM>. Additionally, a thickness of the at least one strain hardened portion may be smaller than a thickness of the non-strain hardened portion by <NUM> to <NUM>.

In some aspects, the protective toe cap may be formed of a material comprising one or more of aluminum, steel, magnesium, titanium, or an alloy thereof. In one embodiment, the protective toe cap is formed of an aluminum alloy.

In some embodiments, the at least one strain hardened portion may be formed as a continuous channel in at least one of the inner and outer surface of the hemi-dome shaped body running from the medial side to the lateral side.

In some aspect, the at least one strain hardened portion comprises two to four strain hardened portions. In an embodiment, the at least one strain hardened portion is disposed nearer the midfoot side than the forefoot side. Further, the at least one strain hardened portion may be formed as a depression in at least one of the inner surface and the outer surface without a corresponding protrusion present on the opposing surface.

In addition, the present technology provides an article of footwear comprising an upper defining a cavity adapted to receive the foot of a user, wherein the upper is attached to an outsole, and a protective toe cap positioned adjacent a toe region of the footwear, the protective toe cap comprising a hemi-dome shaped body adapted to cover the user's toes, and having opposing inner and outer surfaces, a forefoot side, a midfoot side, a medial side, a lateral side, and a lower lip extending along a perimeter of the body configured to attach the protective toe cap to a sole portion of the article of footwear, the body further including at least one strain-hardened portion and at least one non-strain hardened portion.

The present technology further includes a method of manufacturing a protective toe cap, comprising: (i)providing a sheet of metal; (ii) providing a mold having first and second pressing surfaces, wherein at least one of the first and second pressing surfaces includes a protrusion; (iii) pressing the sheet of metal between the first and second pressing surfaces to produce a hemi-dome shaped body including at least one strain hardened portion formed by the protrusion; (iv)hardening the hemi-dome shaped body by heating to a first temperature within a range of about <NUM> to about <NUM> and maintaining the hemi-dome shaped body at the first temperature for a first period of <NUM> to <NUM> minutes to produce a hardened hemi-dome shaped body; and (v) tempering the hardened hemi-dome shaped body by heating to a second temperature within a range of about <NUM> to about <NUM> and maintaining the hardened hemi-dome shaped body at the second temperature for a second period of <NUM> to <NUM> hours to produce the protective toe cap.

In some embodiments, the sheet of metal comprises one or more of aluminum, steel, magnesium, or titanium, or an alloy thereof. Further, the pressing may be conducted at a temperature of no more than about room temperature.

In describing aspects of the present technology, specific terminology will be used for the sake of clarity. However, the technology is not intended to be limited to any specific terms used herein.

As used in the present application, "length" means the longest dimension of any object or shape. As used in the present application, "width" means the shortest dimension of any object or shape existing in the same plane or surface as the length. "Thickness" means the remaining dimension of a three-dimensional object which is not the length or the width.

As used in the present application, "medial" means at, towards, near, or relating to the midline of the human body, i.e. as applied to a shoe as it would be oriented when it is situated on the foot of a wearer. As used in the present application, "lateral" means at, towards, near, or relating to the edge of an object, particularly an edge or end which is away from or opposite the midline (medial region) of the human body. When the terms "medial" and "lateral" are applied to a shoe or other wearable object, they describe portions of the object as they would be oriented when worn by a wearer.

As used in the present application, "strain hardened" means a material or portion of material which has been subjected to a mechanical process in which the material or portion of material has been worked beyond its elastic limit to cause plastic deformation, resulting in increased mechanical strength. Accordingly, the material or portion of material which is "strain hardened" has a higher yield strength and hardness than adjacent areas of the same material which are not "strain hardened".

The technology disclosed herein includes, in general, protective devices such as safety toe caps, various types of protective footwear including such protective devices, and methods of making the same. The safety toe caps of the present technology include one or more strain hardened portions to increase strength and impact resistance, while simultaneously minimizing weight and material usage. These safety toe caps may be utilized as separate protective devices or may be incorporated into an article of footwear.

For example, as shown in <FIG>, <FIG>, protective footwear <NUM> may be provided with safety toe cap <NUM>, which is shaped to fully cover a user's toes and provide protection therefor. Thus, safety toe cap <NUM> is shaped as a hemi-dome in some embodiments. Safety toe cap <NUM> includes an open underside <NUM> delimited by inner surface <NUM> and shaped and sized to accommodate a user's toes. Safety toe cap <NUM> also includes an opposing upper side <NUM> defined by an outer surface <NUM> which in some aspects is shaped to conform to and fit against the upper <NUM> of an article of protective footwear <NUM>. In some embodiments, safety toe cap <NUM> also includes a lower lip <NUM> that extends around the perimeter of underside <NUM>. Lip <NUM> may be positioned in an article of footwear <NUM> under a user's foot and be utilized for attaching safety toe cap <NUM> to such footwear.

As shown in <FIG>, safety toe cap <NUM> is shaped as a hemi-dome in some aspects. Safety toe cap <NUM> a forefoot side <NUM>, a midfoot side <NUM>, a medial side <NUM> and a lateral side <NUM>. In some aspects, safety toe cap <NUM> is asymmetrical along longitudinal line A-A extending from forefoot side <NUM> to midfoot side <NUM>. In particular, safety toe cap <NUM> may be slightly larger or longer on a medial side of line A-A than on a lateral side, so as to provide additional space for the big toe compared to the little toe. In alternative embodiments, safety toe cap <NUM> may be substantially symmetrical along a longitudinal line A-A running from forefoot side <NUM> to midfoot side <NUM>, so that regions adjacent the medial and lateral sides are generally mirror images of one another. The safety toe cap <NUM> of the present technology includes one or more strain hardened portions <NUM> (<FIG>), as described in more detail below.

Safety toe cap <NUM> is composed of a metal or metal alloy material or any other material of sufficient strength to satisfy safety standards for protective footwear, such as ASTM F2413-<NUM> or ASTM F2413-<NUM>. In particular, an appropriate material for safety toe cap <NUM>, may have a yield strength of about <NUM> MPa to about <NUM> MPa, preferably about <NUM> MPa to about <NUM> MPa, and most preferably about <NUM> MPa to about <NUM> MPa, prior to strain hardening. In addition, an appropriate material for safety toe cap <NUM>, may have a hardness of about <NUM> HRB to about <NUM> HRB, preferably about <NUM> HRB to about <NUM> HRB, and most preferably about <NUM> HRB to about <NUM> HRB, prior to strain hardening. Further, the material for safety toe cap <NUM>, may have a density of about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, more preferably from about <NUM>/cm<NUM> to about <NUM>/cm<NUM>, and most preferably from about <NUM>/cm<NUM> to about <NUM>/cm<NUM>. When the toe cap material has properties within these ranges, it is capable of sufficiently resisting deformation and damage from impact so as to protect a user's toes, as well as having the advantage of providing a lighter weight toe cap which is more comfortable from the perspective of a user.

For example, safety toe cap <NUM> may be preferably formed of a material comprising one or more of aluminum, steel, magnesium, or titanium, or an alloy thereof. The material of safety toe cap <NUM> may further comprise additional alloying elements, such as carbon, zinc, magnesium, copper, silicon, iron, manganese, chromium, or any combination therein. In a preferred embodiment, safety toe cap <NUM> is formed of <NUM> aluminum alloy (AA7075).

The safety toe cap <NUM> may have a thickness <NUM> (<FIG>) of no more than <NUM>, preferably no more than <NUM>, and most preferably no more than about <NUM>. In some embodiments, the safety toe cap <NUM> may satisfy the safety standards according to ASTM F2413-<NUM> or ASTM F2413-<NUM> even while having a relatively small thickness <NUM> such as less than <NUM>, less than <NUM>, or less than <NUM>. The safety toe cap <NUM> may be capable of maintaining adequate safety and resistance to impact due to the incorporation of one or more strain hardened portions <NUM>. In contrast, safety toe caps of the prior art which lack strain hardened portions according to the present technology may require a greater thickness, such as at least <NUM>, in order to achieve the same safety standards, resulting in heavier and bulkier toe caps which require higher material use.

As shown in <FIG>, safety toe cap <NUM> includes one or more strain hardened portions <NUM>. Each strain hardened portion <NUM> may be formed by compression in a mold or punch designed to subject certain portions to greater compression than the surrounding areas, in order to strain harden these portions. The resulting strain hardened portion <NUM> has a greater yield strength and hardness than adjacent regions <NUM> which are not strain hardened and may provide reinforcement to the structure of safety toe cap <NUM>, allowing for sufficient resistance to deformation under impact and protection of a user's toes with a significant reduction in thickness and weight of the safety toe cap <NUM>.

According to an aspect of the disclosure, <FIG> illustrates a flow chart for a method <NUM> to manufacture a protective toe cap. Method <NUM> includes a step <NUM> of providing a sheet of metal and a step <NUM> of providing a mold having first and second pressing surfaces, wherein at least one of the first and second pressing surfaces includes a protrusion. Method <NUM> further includes a step <NUM> of pressing the sheet of metal between the first and second pressing surfaces to produce a hemi-dome shaped body including at least one strain hardened portion formed by the protrusion and a step <NUM> of hardening the hemi-dome shaped body by heating to a first temperature within a range of about <NUM> to about <NUM> and maintaining the hemi-dome shaped body at the first temperature for a first period of <NUM> to <NUM> minutes to produce a hardened hemi-dome shaped body. Method <NUM> may further optionally include a step <NUM> of tempering the hardened hemi-dome shaped body by heating to a second temperature within a range of about <NUM> to about <NUM> and maintaining the hardened hemi-dome shaped body at the second temperature for a second period of <NUM> to <NUM> hours to produce the protective toe cap. These steps are described in further detail below.

In particular, as depicted in <FIG>, safety toe cap <NUM> may be formed by pressing a sheet (not shown) of a suitable material, such as an aluminum alloy, in a mold or punch <NUM>, illustrated schematically. In an exemplary embodiment, the punch <NUM> may have two opposing pressing surfaces <NUM>, <NUM>. The first pressing surface <NUM> may be configured to press one of the inner surface <NUM> and the outer surface <NUM> of safety toe cap <NUM> and the second, opposing pressing surface <NUM> may be configured to press the other of the inner surface <NUM> and outer surface <NUM>. The first and/or the second pressing surfaces501, <NUM> of the mold may have protrusions, ridges, or projections <NUM>, in areas which correspond to the areas of safety toe cap <NUM> which are desired to be strain hardened. Accordingly, when the sheet of material is pressed in the mold <NUM> in order to shape it into safety toe cap <NUM>, the protrusions <NUM> of the mold <NUM> will apply a greater level of compression to portions of the safety toe cap <NUM>, thereby forming strain hardened portions <NUM>. In some aspects, the pressing is conducted at about room temperature or below.

In some embodiments, as represented in <FIG>, after pressing in the mold, safety toe cap <NUM> may be subjected to further processing, including a hardening process followed by a tempering process. In particular, safety toe cap <NUM> may be hardened by heating to within the range of about <NUM> to about <NUM>, more preferably about <NUM> to about <NUM>, and maintaining that temperature for a period of <NUM> to <NUM> minutes, more preferably <NUM> to <NUM> minutes, before cooling to about room temperature or below. Subsequently, safety toe cap <NUM> may be tempered by heating to within the range of about <NUM> to about <NUM>, more preferably about <NUM> to about <NUM>, and maintaining that temperature for a period of <NUM> to <NUM> hours, more preferably <NUM> to <NUM> hours.

Hardening and tempering according to these process relieves stresses created in the material of safety toe cap <NUM> during pressing. In particular, since the material of safety toe cap <NUM> is shaped from a flat sheet into a hemi-dome shape, the required bending creates a high amount of latent stress in the material. If hardening and tempering are not performed according to the presently disclosed processes in order to relieve this stress, the toe cap <NUM> will lack the strength and material properties needed to satisfy safety standards.

Strain hardened portions <NUM> of the present technology may have a thickness <NUM> which is smaller than the thickness <NUM> of adjacent areas <NUM> which are not strain hardened. For example, a strain hardened portion <NUM> may have a thickness <NUM> which is smaller than the thickness <NUM> of the rest of toe cap <NUM> by <NUM> to <NUM>, or preferably <NUM> to <NUM>. The strain hardened portion <NUM> of the present technology may form a depression in one of either the inner <NUM> or outer <NUM> surfaces of safety toe cap <NUM>, as shown in <FIG>. However, the strain hardened portion <NUM> of the present technology does not form a corresponding protrusion on the opposing surface of toe cap <NUM>, as shown in <FIG>. For example, when a strain hardened portion <NUM> is formed as a depression in the inner surface <NUM> of toe cap <NUM>, as shown in <FIG>, the outer surface <NUM> may remain substantially flat and smooth, as shown in <FIG>. In contrast, as shown in <FIG>, toe caps <NUM> of the prior art may include depressions <NUM> in one surface which have corresponding ridges or protrusions <NUM> in the opposing surface. Such structures may be formed by a bending process, in contrast to the compression process of the present technology. Unlike the prior art structure, the structure of the present technology may provide a toe cap <NUM> with a more uniform, flat outer or inner surface which may lie flat against an upper and/or inner lining of an article of footwear. In addition, the structure of the present technology provides strain hardened portions of material having improved material properties such as increased yield strength, hardness, and density. In contrast, the prior art structure produced by bending does not provide any areas of increased material properties.

The strain hardened portions <NUM> may also have increased hardness in relation to adjacent portions <NUM> of safety toe cap <NUM>. For example, the hardness of the strain hardened portion <NUM> may be greater than that of adjacent portions <NUM> of the safety toe cap <NUM> by about <NUM>% to about <NUM>% and more preferably about <NUM>% to about <NUM>%. In addition, the strain hardened portions <NUM> may also have increased yield strength in relation to adjacent portions <NUM> of safety toe cap <NUM>. For example, the yield strength of the strain hardened portion <NUM> may be greater than that of adjacent portions <NUM> of the safety toe cap <NUM> by about <NUM>% to about <NUM>%, or more preferably about <NUM>% to about <NUM>%.

In some aspects, the strain hardened portions <NUM> may be formed as continuous lines or channels in a surface of safety toe cap <NUM>. Such channels may be substantially linear, or may form various different patterns or shapes, such as curved lines, sinusoidal or wavy lines, or zig-zag lines. In some embodiments, the strain hardened portions <NUM> may be provided in a configuration capable of strengthening a portion of the toe cap <NUM> which is structurally weaker than adjacent portions. Additionally or alternatively, the strain hardened portions <NUM> may be provided in a location which tends to be subjected to greater stresses during use or during impact from above. Accordingly, the strain hardened portions <NUM> may be provided in a configuration which reinforces these locations and dissipates stress to underutilized and understressed areas of the structure of the toe cap <NUM>.

As shown in <FIG>, in a preferred embodiment, one or more strain hardened portions <NUM> may be formed as depressions in the inner surface <NUM> of toe cap <NUM>. In such an embodiment, the outer surface of the toe cap <NUM> may remain substantially flat and smooth, as shown in <FIG>. Each of the strain hardened portions <NUM> may be substantially linear in shape and forms a channel in the inner surface <NUM> of toe cap <NUM>, running from a medial side <NUM> to a lateral side <NUM> of toe cap <NUM>. In an embodiment, two to five, more preferably two to four, or most preferably three strain hardened portions are provided, with each of the strain hardened portions being generally parallel to one another. In some embodiments, the one or more strain hardened portions <NUM> may be provided nearer a midfoot side <NUM> of toe cap <NUM> than a forefoot side <NUM>. During use, the midfoot portion of toe cap <NUM> is more likely to be subjected to significant stresses upon impact from objects dropped from above. Accordingly, providing one or more strain hardened portions <NUM> near the midfoot side may reinforce this area and allow for dissipation of stress to the forefoot region of toe cap <NUM>, which is generally subjected to less stress from downward impact.

In some embodiments, as shown in <FIG>, in addition to medial-lateral running strain hardened portions <NUM>, safety toe cap <NUM> may also include strain hardened portions <NUM> running in a direction from a midfoot side <NUM> of toe cap <NUM> to a forefoot side <NUM> of toe cap <NUM>. These midfoot-forefoot strain hardened portions <NUM> may be substantially linear in shape or may be curved, zig-zagged, etc. In some embodiments the midfoot-forefoot strain hardened portions <NUM> may be disposed nearer a forefoot side <NUM> of toe cap <NUM> than a midfoot side <NUM>. Thus, these strain hardened portions may cooperate with medial-lateral strain hardened portions <NUM> to provide further reinforcement of the forefoot region in addition to strengthening of the midfoot region.

Further, in some embodiments, as shown in <FIG>, safety toe cap <NUM> may be provided with strain hardened portions <NUM> on both the inner <NUM> and outer <NUM> surfaces. In particular, safety toe cap <NUM> may comprise strain hardened portions <NUM> formed as depressions on the inner surface <NUM> of toe cap <NUM>, as well as strain hardened portions <NUM> formed as depressions on the outer surface <NUM> of toe cap <NUM>. In such an embodiment, these strain hardened portions <NUM> would be formed by a mold in which both the first and second pressing surfaces have protrusions configured to create strain hardened portions. Such an embodiment differs from toe caps <NUM> of the prior art in that each depression on the inner surface <NUM> of the toe cap <NUM> may not have a corresponding protrusion on the outer surface <NUM> of the toe cap <NUM> and vice versa. In a bent toe cap <NUM> of the prior art, such as the one shown in <FIG>, each depression on a surface of toe cap <NUM> corresponds to a protrusion on the opposing surface. In contrast, the toe cap <NUM> of <FIG> may have depressions formed independently on both the inner <NUM> and the outer <NUM> surfaces by protrusions on the corresponding pressing surface of a mold. These depressions do not necessarily have a corresponding protrusion on the opposing side of the toe cap <NUM>.

In addition, the one or more strain hardened portions <NUM> may be formed in various alternative configurations designed to reinforce safety toe cap <NUM> against impact. For example, as shown in <FIG> and <FIG>, strain hardened portions <NUM> may be formed in the inner <NUM> and/or outer <NUM> surfaces as continuous wavy or sinusoidal lines placed to strengthen both a midfoot and forefoot region of safety toe cap <NUM>. Alternatively, as exemplified in <FIG>, strain hardened portions <NUM> may be formed as linear channels extending radially from a point in the midfoot region of safety toe cap <NUM> to multiple endpoints along the forefoot side of safety toe cap <NUM>. Various other configurations and placements of strain hardened portions are also contemplated.

A safety toe cap <NUM> according to the present technology may be provided as a separate protective device or may be incorporated into an article of footwear <NUM>, as depicted in <FIG>. In the case in which the safety toe cap <NUM> is incorporated into an article of footwear or shoe <NUM>, the outer surface <NUM> of the toe cap <NUM> may be shaped and sized to fit within and lie flush with an inside surface of an upper <NUM> of the shoe.

Toe cap <NUM> can be incorporated into a variety of different types of footwear, to allow for safety and protection of the toes of a user from impacts and falling objects while also providing lightweight footwear with a slim, streamlined profile.

Referring back to <FIG>, footwear <NUM> incorporating toe cap <NUM> may include all standard aspects of normal footwear, including but not limited to an outsole <NUM>, an upper <NUM> attached to outsole <NUM>, forefoot <NUM>, arch <NUM>, and heel <NUM> regions, and a tongue <NUM> forming part of upper <NUM>. Although other common footwear components are not described in detail herein, footwear <NUM> may include such components as is apparent in the figures (e.g., laces, etc.).

Footwear <NUM> according to the present technology also includes a toe cap <NUM> embedded within its forefoot region <NUM>. Toe cap <NUM> may be incorporated into the toe region of footwear <NUM> and may be arranged with its lip <NUM> adjacent outsole <NUM>, so that its outer surface <NUM> sits flush against upper <NUM>. Inner surface <NUM> of toe cap <NUM> may be covered by a lining, mesh, or other fabric or padding disposed within upper <NUM>. Toe cap <NUM> may therefore provide protection for a user's toes against, for example, a falling object.

Claim 1:
A protective toe cap (<NUM>) for an article of footwear (<NUM>), comprising:
a hemi-dome shaped body adapted to cover a user's toes once incorporated into an article a footwear (<NUM>),
the body having opposing inner (<NUM>) and outer (<NUM>) surfaces, a forefoot side (<NUM>), a midfoot side (<NUM>), a medial side (<NUM>), and a lateral side (<NUM>),
the body further comprising at least one strain hardened portion (<NUM>; <NUM>, <NUM>) and at least one non-strain hardened portion (<NUM>),
wherein a thickness (<NUM>) of the at least one strain hardened portion (<NUM>; <NUM>, <NUM>) is smaller than a thickness (<NUM>) of the non-strain hardened portion (<NUM>), and
wherein the at least one strain hardened portion (<NUM>; <NUM>, <NUM>) is formed as a depression in at least one of the inner surface (<NUM>) and the outer surface (<NUM>) without a corresponding protrusion present on the opposing surface.