Patent Application
20210093043
The present invention relates to footwear, and more particularly to safety footwear including metatarsal guards.
The human foot includes many bones that can be subject to crushing forces when impacted by falling or dropped objects. For example, the human foot includes five adjacent elongated metatarsal bones in the instep region, which extends forwardly from the front of the ankle to the base of the toes. These bones are particularly vulnerable to fracture when impacted by falling objects. In the United States, over 100,000 individuals are injured annually due to such accidents, some being severely incapacitated or maimed.
Many manufacturers produce footwear designed to prevent injuries to the metatarsals and instep region in general. Such footwear typically includes an external metatarsal guard having a durable plastic or metal shield placed over the exterior of the footwear. The shield can extend over the instep, generally covering the metatarsal bones of the user. Many times, the shield is a simple curved and featureless component that aesthetically blends in with the footwear and is easy to manufacture.
An issue with some external metatarsal guards, however, is that they can limit mobility, and can make the appearance of the footwear unsightly. Specifically, a rigid plastic or metal shield can impair the range of motion of the foot during a natural walking or hurried gait. A rigid external shield also can pinch the instep when a wearer bends or squats. To address this, some manufacturers will segment the shield into multiple plates. Where the shield includes multiple moveable plates, those plates can provide some movement and flexibility to the otherwise rigid guard and associated footwear. Typically, however, the movable plates themselves also are relatively flat and simply contoured to the curved shape of an instep. Therefore, while the plates can dissipate forceful impacts, they do not offer much in the way of impact force deflection, such that the forces associated with an impacting object or the object itself are not directed or moved away from the instep and the foot inside the footwear. Further, many times, movable plates are joined to one another and the footwear with a lacing or other connection system. Due to the constant movement of the plates, relative to one another and the footwear, the connection can wear out rather quickly, which can require maintenance and repair of the same to ensure that the guard continues to offer suitable protection to the wearer.
Accordingly, there remains room for improvement in the field of metatarsal guards that protect the metatarsal bones and instep of a wearer's foot from forceful impacts, and simultaneously deflects such forces, yet still provides flexibility and durability.
An article of footwear is provided including a metatarsal guard having a rigid central spine, multiple ridge elements that extend transversely to the spine across an instep of the footwear, and a cushion element joined to the central spine that can extend outward under the multiple ridge elements, where the ridge elements are raised to deflect impact forces imparted on the metatarsal guard and the cushion element provides enhanced cushioning to a foot of a wearer upon impact.
In one embodiment, the central spine can lay along a longitudinal axis of the footwear, generally over the center of the instep. The ridge elements can extend transversely to the central spine and the longitudinal axis. Each of the ridge elements can include a forward wall and a rearward wall joined at a transition apex. The transition apex generally is configured to first contact and deflect an object that impacts the metatarsal guard.
In another embodiment, the cushion element can include a central cushion portion and a ridge cushion portion. The central cushion portion can diminish in thickness as it extends away from the longitudinal axis. The ridge cushion portion can extend outward away from the longitudinal axis under each of the plurality of ridge elements. The ridge cushion portion also can diminish in thickness the farther from the longitudinal axis that it extends.
In still another embodiment, the multiple ridge elements can include cantilevered portions that extend laterally and medially away from the central spine. For example, each ridge element can include a lateral cantilevered portion that extends outward from the central spine to a lateral free end on a lateral side of the longitudinal axis. Each ridge can include a medial cantilevered portion that extends outward from the central spine to a medial free end on the medial side of the longitudinal axis.
In another embodiment, adjacent lateral cantilevered portions of different ridge elements are separated by corresponding lateral gaps and adjacent medial cantilevered portions of different ridge elements are separated by corresponding medial gaps.
In even another embodiment, the cantilevered portions on both sides can curve downward over respective lateral and medial upper panels, diminishing in height to respective free ends of the cantilevered portions. In some cases, the heights of the ridges also can diminish to the free ends. At the free ends, the ridges can cleanly transition and taper down to the upper panels.
In yet another embodiment, the upper can include raised upper protrusions that interfit with the cantilevered portions of the guard. The upper protrusions can fit within the gaps adjacent the cantilevered portions. With this construction, protection of the foot can continue past the metatarsal guard, and in particular, past the free ends of the cantilevered portions on the lateral and medial sides of the footwear. This can further increase the ability of the metatarsal guard and upper to deflect forces and associated objects laterally and medially, off the instep.
In a further embodiment, the footwear can include a protective toe box integrally formed with and extending forward of the metatarsal guard at a hinge such that the metatarsal guard can hinge relative to the protective toe box. This protective toe box and the metatarsal guard can include an outer layer constructed from a material having a first durometer, and an inner layer constructed from the material but having a lesser, second durometer. In some cases, the hinge can include the inner layer, having the softer durometer. Thus, the hinge can allow the elements to move and flex relative to one another more easily.
In still a further embodiment, the cushion element can be disposed directly under the central spine and ridge elements. The cushion element can include a central cushion portion that diminishes in thickness as it extends away from the longitudinal axis. It also can include a ridge cushion portion that extends outward under respective lateral cantilevered portions and medial cantilevered portions of the ridge elements. The central spine and the ridge elements can be integral with one another and constructed from a rigid first material. The cushion element can be constructed from a second material, different from the rigid first material of the central spine and ridge elements.
In yet a further embodiment, the second material can have a first durometer and a second durometer that is less than the first durometer. The central cushion portion can include the material with the first durometer, while the ridge cushion portion can include the material with the second durometer. The harder first durometer can provide greater rigidity and protection along the longitudinal axis of the footwear, over the instep, where impacts are more likely to occur with the metatarsal guard.
In even a further embodiment, the central cushion portion can include a first thinned portion on the lateral side and a second thinned portion on the medial side under multiple individual ridge elements. A first ridge cushion portion can extend over the first thinned portion on the lateral side, and a second ridge cushion can extend over the second thinned portion on the medial side under the each of the ridge elements. The first thinned portion and the second thinned portion of the central cushion portion can be constructed to include a first durometer, while the first ridge portion and the second ridge portion can be constructed to include a second durometer, less than the first durometer. The various thinned and ridge portions can be constructed from a common material having the different durometer portions that are co-molded with one another.
In another, further embodiment, the common material can be a strain rate dependent polyurethane foam that can have the different durometers.
The footwear of the current embodiments provides a metatarsal guard assembly having exceptional impact deflection and impact absorption. In turn, this can provide enhanced protection to the metatarsal bones and instep region of the wearer's foot. In addition, the metatarsal guard assembly, with its system of transverse ridge elements mounted to a common central spine element, and in some cases including cantilevered ridge portions, can be exceptionally flexible, allowing the foot to follow a more natural range of motion during a gait cycle of the wearer, with less impairment of foot mobility during a given workday.
These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and of being practiced or being carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components.
An article of footwear in accordance with the current embodiment is shown in
As illustrated in
Although the current embodiments are illustrated in the context of a working boot or safety shoe, they may be incorporated into any type or style of footwear, including performance shoes, hiking shoes, trail shoes and boots, hiking boots, all-terrain shoes, barefoot running shoes, athletic shoes, running shoes, sneakers, conventional tennis shoes, walking shoes, multisport footwear, casual shoes, dress shoes or any other type of footwear or footwear components. It also should be noted that directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. Further, the terms “medial,” “lateral” and “longitudinal” are used in the manner commonly used in connection with footwear. For example, when used in referring to a side of the shoe, the term “medial” refers to the inward side (that is, the side facing the other shoe) and “lateral” refers to the outward side. When used in referring to a direction, the term “longitudinal direction” refers to a direction generally extending along the length of the shoe between toe and heel, and the term “lateral direction” refers to a direction generally extending across the width of the shoe between the medial and lateral sides of the shoe. The use of directional terms should not be interpreted to limit the invention to any specific orientation.
Further, as used herein, the term “arch region” (or arch or midfoot) refers generally to the portion of the footwear or sole assembly corresponding to the arch or midfoot of the wearer's foot; the term “forefoot region” (or forefoot) refers generally to the portion of the footwear forward of the arch region corresponding to the forefoot (for example, including the ball and the toes) of a wearer's foot; and the term “heel region” (or heel) refers generally to that portion of the footwear rearward of the arch region corresponding to the heel of the wearer's foot. The forefoot region 12, arch region or mid-foot region 14 and heel region 16 generally are identified in
The sole assembly 30, can include an outsole 31 having a lowermost or ground contacting surface LGC and can include multiple lugs, treads, spikes, cleats and/or other features designed to enhance traction between the footwear and an underlying surface. Where present, the lugs and treads can be arranged as desired, and not necessarily in a repeating pattern. The lugs and treads can include one or more geometric shapes. The outsole tread can be constructed from one or more materials, for example, natural and/or synthetic rubber, thermoplastic polyurethane elastomers (TPU), nylon, polymer blends, wear resistant polymers, elastomers and/or other materials. Other materials, such as fiber-reinforced polymers can be used, which can include epoxy, polyethylene or thermosetting plastic reinforced with carbon, glass and/or aramid fibers for enhanced protection. The outsole material can have a durometer, optionally about 40 Shore A to about 70 Shore A, further optionally about 68 Shore A to 72 Shore A.
More or fewer elements of the sole assembly 30 can be included in some embodiments. The outsole 31 can be integrated into and or joined with a midsole 32, which can be a single one piece unit joined with and above the outsole. The midsole can be constructed from a molded material, such as EVA foam, PU, latex, gel or other materials, and by virtue of its compressibility, provide cushioning, and may also conform to the foot in order to provide comfort, support, and stability. The joining of the outsole and the midsole can be accomplished using adhesives, cement, injection molding, pour molding or any other technique used to join an upper and outsole. The components of the sole assembly 30 can individually and/or collectively provide the article of footwear 10 with a number of attributes, such as support, rigidity, flexibility, stability, cushioning, comfort, reduced weight and/or other attributes. Generally, regardless of which components are present, the sole assembly 30 can form the bottommost portion of the footwear 10.
As mentioned above and shown in
The upper 20 can include a lower periphery that is attached to the sole assembly 20. For example, a lower peripheral allowance or edge 24 of the upper can be stitched, cemented, or otherwise fastened to a Strobel board (not shown) of the upper 20. The lower peripheral allowance and Strobel board can be joined with the sole assembly using adhesives, cement, injection molding, pour molding or any other technique used to join an upper and sole assembly.
As illustrated in
Optionally, the metatarsal guard 40 can include an integral, rigid protective toe element 90. As described below, this element can be constructed from some of the same materials as the guard and can be of a sufficient thickness to deflect forces and/or loads from objects dropped on the toe. The protective toe element 90 can be configured to extend throughout the toe region 11 of the wearer's foot generally extending rearwardly toward the arch region 14, but located substantially within the forefoot region 12 (
The upper 20 can include an upper material 24 which can be any conventional upper material, such as mesh, fabric, plastic, rubber, leather or other materials. The upper 20 can extend to and can terminate at the protective toe element 90, with the protective toe element forming an exterior, wearing portion of the upper. In other cases, the toe element 90 can be covered by other material of the upper. A portion of the upper and an inner liner can extend within and under the toe box of the element, bounding a portion of the void 21 inside the upper.
Optionally, the upper can include raised upper protrusions 20A, 20B, 20C, 20D, 20D, 20E. The upper protrusions can be raised or can extend above surrounding upper exterior surface 21E of the upper for a preselected distance. The upper protrusions can be formed in a variety of manners. For example, they can be stamped or pressed portions of a leather or polymeric material. Alternatively, as shown, the upper protrusions can be formed from a molded mesh material having a foam backing thereunder and generally interior to the upper. The foam backing can be added to the mesh or some other fabric or material to provide additional shock protection to the wearer's foot and thus enhance impact absorption. In some cases the protrusions can be a rigid polymeric material, separately constructed from the metatarsal guard, as can be the remainder of the upper.
As further shown, the raised protrusions can be in the form of polygonal structures, such as raised pyramids for example. The raised protrusions can include backbones. For example, backbone 20BB of the protrusion 20B can extend downward, away from the metatarsal guard toward the sole assembly 30. The other protrusions can be similarly formed and aligned, and can include similar backbones. In some cases, the raised upper protrusions can include uppermost portions 20BT, optionally in the form of points for tips. These tips can be pointed, as shown or more rounded or even polygonal depending on the application. These tips can be located at the uppermost extremities of the protrusions, farthest from the sole assembly and/or closest to the metatarsal guard 40. These uppermost portions 20BT of the upper protrusions can extend into gaps defined between cantilevered portions of different rigid elements. For example, as shown in
Optionally, where the upper protrusions fit within the gaps adjacent the cantilevered portions, protection of the foot can continue past the metatarsal guard, and in particular, past the free ends of the optional cantilevered portions, or downward, below the metatarsal guard perimeter. This can increase deflection characteristics as well. Of course, in some applications, the upper protrusions can be eliminated, with the exterior of the upper adjacent the metatarsal guard 40 generally flat and/or contoured to the features of the foot.
With reference to
Portions of the central spine 50 can serve as a primary protection element across the uppermost portion of the instep 13 of the footwear. The ridge elements themselves can extend upward and above the portions 51, 52, 53, etc., of the central spine that connect adjacent ridge elements. For example, as shown in
As also shown in
With reference to
Each of the ridge elements can include lateral cantilevered portions as well as the medial cantilevered portions. As shown in
As mentioned above, the footwear 10 can include a protective toe 90, shown in
Returning to
In some cases, each of the protective toe box and the metatarsal guard can include an outer layer 61L1 constructed from a material having a first durometer and an inner layer 61L2 constructed from a material having a lesser second durometer. As an example, the ridge elements and central spine can be constructed from TPU. The toe box can be constructed from TPU as well. With reference to
Optionally, the metatarsal guard and protective toe element can be constructed from a variety of materials. These materials can be substantially rigid and generally inflexible except under significant force. For example, the plates can be constructed from a thermoplastic material, such as TPU as described above, which can include different portions of different durometers. Other examples include, but are not limited to, polypropylene, polyethylene, nylon, ABS, polycarbonate, polystyrene, polyvinylchloride, Teflon or other polymeric materials. If desired, the metatarsal guard and toe element alternatively can be constructed from metals, composites, glass or fiber reinforced materials and the like.
The ridge elements 60 also can be constructed to be of varying heights to offer different levels of deflection and impact absorption in different regions of the footwear over the instep. For example, closer to the protective toe element, where impacts are probably more likely to occur, the lower ridge element 61 can be larger and wider than the upper ridge element 65. The lower ridge element 61 also can be taller and can extend well above the central spine 50 and the connecting portions between the spine and the respective ridges. For example, the lower ridge element 61 can extend to the transition apex 61A a height H1 above the central spine portion 52. The upper or fifth ridge element 65 can extend upward, above the central spine portion 55 a height H3. The distance H3 can be greater than the distance H1. The respective front and rear walls of the first ridge element also can be taller and/or larger in surface area than the respective front and rear walls of the upper ridge element 65. With the shorter upper ridge elements, the metatarsal guard also can allow objects to slide forwardly along the foot out and over the protective toe element in some cases. This in turn can further improve deflection.
Optionally, as further shown in
As shown in
The metatarsal guard 40 can include a cushion element 70 as shown in
The cushion element 70 can be constructed from a second material that is different from the material from which the central spine and ridge elements are constructed. Optionally, the second material can be a strain rate dependent polyurethane foam. In some cases, different parts of the cushion element can have different durometers. The second material can be bonded glued or otherwise secured to the first material of the central spine and ridge elements and/or protective toe element. Further optionally, the second material can have a density of optionally at least 9 lbs. per cubic foot, further optionally 9 lbs. per cubic foot to 25 lbs. per cubic foot, further optionally about 12 lbs. per cubic foot to about 20 lbs. per cubic foot and yet further optionally, about 15 lbs. per foot. It can have a hardness or durometer of optionally 10 Shore O, further optionally 10 Shore 0 to 32 Shore 0, further optionally 19 Shore O. Of course, other densities and durometers can be selected depending on the particular application. The material can have a tensile strength measured under ASTM D 3574 Test E of optionally 200 kPA to 1,000 kPa, further optionally 207 kPa to 965 kPa, even further optionally 310 kPa to 689 kPa, and even further optionally about 483 kPa. One type of open cell, breathable foam commercially available and suitable for the use in the current embodiments is sold under the trade name Poron® XRD™ Extreme Impact Protection foam, available from Rogers Corporation of Woodstock, Conn. Other foams, polymers, composites or materials may be substituted in this construction to provide an adequate internal metatarsal guard as desired.
As shown in
The central cushion portion 71 can extend in toward a first thinned portion 72 and a second thinned portion 73 on the respective medial M and lateral L sides of the longitudinal axis LA. The cushion element 70 also can include a first ridge portion 72R that extends over the first thinned portion 72 on the medial side M. The cushion element can include a second ridge portion 73R that extends over the first thinned portion 73 on the lateral side.
Optionally, the central cushion portion 71 can be constructed from the second material and can have a first durometer. The first ridge portion and the second ridge portion can be constructed to include a second durometer, less than the first durometer. Even with these different durometers first and second durometers, each of the first thinning portion, second thinning portion, first ridge portion and second ridge portion can be constructed from a common material such as the foam described above. However, the different durometer portions of the material can be separated into the central cushion portion and the respective first and second or lateral and medial ridge portions of that foam that extend outwardly, under the respective lateral and medial portions of the ridge elements. It is to be appreciated that although only the first or lower ridge 61 of the metatarsal guard 40 is shown in
Optionally, the respective ridge portions of the cushion element can extend from the respective thinned portions of the central cushion element to the respective lateral and/or medial free ends on the respective lateral and medial sides, under the respective ridge elements. Of course, in some cases, the central portion cushion portion 71 and the respective ridge portions 72R and 73R can be formed from the same material having a single continuous durometer. This however can make the ridge elements in some cases too rigid, which can impair flexability of the central spine. Optionally, the central cushion element 71 can be disposed within a central width portion CW shown in
Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s).
In addition, when a component, part or layer is referred to as being “joined with,” “on,” “engaged with,” “adhered to,” “secured to,” or “coupled to” another component, part or layer, it may be directly joined with, on, engaged with, adhered to, secured to, or coupled to the other component, part or layer, or any number of intervening components, parts or layers may be present. In contrast, when an element is referred to as being “directly joined with,” “directly on,” “directly engaged with,” “directly adhered to,” “directly secured to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between components, layers and parts should be interpreted in a like manner, such as “adjacent” versus “directly adjacent” and similar words. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular. Any reference to claim elements as “at least one of X, Y and Z” is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z.
