Elongated foot-engaging element for footwear and article of footwear
The introduction of recesses in the elongated foot-engaging elements of flip-flops addresses the inflexibility issue, allowing for multi-dimensional flexion and enhanced comfort and fit by conforming to the user's foot shape.
Patent Information
- Application Number
- JP2024600213U
- Authority / Receiving Office
- JP · JP
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2023-06-30
- Publication Date
- 2025-10-06
- Estimated Expiration
- 2033-06-30
AI Technical Summary
Conventional elongated foot-engaging elements in flip-flops lack flexibility in the plane of their major surface, leading to issues such as discomfort, poor fit, wear, and increased inventory needs due to inflexibility and rigidity.
Incorporation of recesses along the edges of the elongated portions of the foot-engaging element, allowing for flexion in both the plane of the major surface and perpendicular to it, enhancing adaptability and comfort by conforming to the user's foot shape.
The recessed design enables the foot-engaging element to flex in multiple planes, providing improved fit, comfort, and reduced wear, accommodating various foot sizes and shapes without buckling.
Smart Images
Figure 0003253092000001_ABST
Abstract
Description
[Technical Field]
[0001] FIELD OF THE INVENTION The present invention relates to elongated foot-engaging elements for footwear and articles of footwear having such elongated foot-engaging elements. [Background technology]
[0002] Articles of footwear have engaging members for securing the article of footwear to the foot of a user of such article of footwear.
[0003] In the case of substantially closed footwear, the foot-engaging element is typically what is known in the art as an "upper" that typically at least partially encases the user's foot. These uppers often extend around the sole of the footwear article and are attached to the user's foot by fastening elements, such as laces, straps, electricity, hook-and-loop fasteners, or other elements, to secure the footwear article to the user's foot.
[0004] For other types of footwear, such as sandals, strap-type devices are provided as engagement elements that effectively connect the sole member of the footwear to the user's foot, and such elements may include adjustable elements to provide fit for different foot sizes and may be easily removed and attached to the foot.
[0005] Such "flip-flop" type footwear, otherwise known as "thongs" or "jandals" or "zori" in relation to other footwear products, comprises a flexible sole member typically formed from a rubber type material or expanded polymer foam, and an engagement element typically provided as a strap formed from a rubber type material that extends from the sole between the user's toes, and typically includes bifurcated arm portions that extend over the user's foot and engage with the sole member.
[0006] Such engagement elements are elongated rectangular, flat in cross section, and generally flexible, allowing for flexion of the foot and a large amount of flexion of the sole member while maintaining the article of footwear attached to the user's foot. Summary of the Invention [Problem to be solved by the invention]
[0007] It is an object of the present invention to provide an elongated foot-engaging element for an article of footwear and an article of footwear embodying such an elongated foot-engaging element that overcomes or ameliorates at least some of the deficiencies associated with the prior art. [Means for solving the problem]
[0008] In a first aspect, the present invention provides an elongated foot-engaging element for an article of footwear, the foot-engaging element comprising two elongated portions each having a longitudinal axis and first and second opposite planar surfaces, the elongated portions having a first longitudinal edge region and an opposite second longitudinal edge, a plurality of recesses extending along at least a portion of at least one edge of at least one of the elongated portions of the foot-engaging element, the plurality of recesses in the elongated portions providing for flexion of the elongated portions in the plane of the first and second planar surfaces, the elongated portions being dimensioned and arranged with the plurality of recesses such that the foot-engaging element is substantially flexible and resilient to allow substantial flexion in use.
[0009] The recesses may be provided on both edges of the elongated portion of the foot engaging element.
[0010] Recesses may be provided on both edges of both elongate portions of the foot engaging element.
[0011] The recess on one edge of the elongated portion of the foot engaging element may be aligned with the recess on the edge on the opposite side of the elongated portion, or the recess on one edge of the elongated portion of the foot engaging element may be offset from the recess on the edge on the opposite side of the elongated portion in a direction along the longitudinal axis of the elongated portion.
[0012] The elongated foot engaging element may further include an extension portion extending from a first end of the elongated portion and having an engagement portion thereon for engaging with a sole member of the article of footwear, and a second end of the elongated portion having an engagement portion thereon for engaging with a sole member of the article of footwear.
[0013] The extension portion may be dimensioned to pass between the user's big toe and second toe, and the elongated portion may be dimensioned to extend from its first end across the top surface of the user's foot in a direction toward the rear of the user's foot, with the first and second elongated portions extending toward the lateral and medial sides of the user's foot, respectively.
[0014] The elongate foot-engaging element may be a shaped element formed from a flowable and hardenable polymeric material that, when hardened, forms the shape of the foot-engaging element and has the elastic properties.
[0015] The foot engaging element is a molded element, which may be an injection molded element, a compression molded element, a cast molded element, or a transfer molded element.
[0016] The foot-engaging element may be a layered forming element, a three-dimensional (3D) printed element, a fused filament fabricated element, a continuous liquid interface production (CLIP) element, or a digital light synthesized (DLS) element.
[0017] The foot engaging element is preferably formed from a resilient material including rubber or rubber compounds, elastomers, elastomeric polymers, polymeric resins, and the like.
[0018] In a second aspect, the present invention provides an article of footwear comprising the elongate foot-engaging element of the first aspect and a sole member.
[0019] The sole member is preferably a flip-flop sole member.
[0020] The sole member may include an upper surface, a lower surface, an upper layer for direct contact and interaction with at least a portion of the underside of a person's foot and formed from a first polymeric material having a first density, and a lower layer having sidewalls and forming substantially the entire lower surface and for direct contact and interaction with the surface and formed from a second polymeric material having a second density, wherein the first polymeric material is provided in a gel form and the second polymeric material is provided in a foam form, whereby the first density is greater than the second density.
[0021] The first and second polymeric materials are preferably selected and the upper and lower layers are sized and arranged so that the sole is substantially flexible and resilient to permit substantial longitudinal flexion and return of the sole in use and during a person's walking, said upper layer extending to at least an upper surface of the sole member, and the first and second polymeric materials are selected and the upper and lower layers are sized and arranged so that the upper layer provides attenuation of loads imparted to the person's foot upon contact with a surface.
[0022] Preferably, the article of footwear is a flip-flop article of footwear.
[0023] So that the foregoing invention may be more fully understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the accompanying drawings.
[0024] The drawings presented herein may not be drawn to scale, and any references to dimensions in the drawings or the following description are specific to the disclosed embodiments.
[0025] Any variation in these dimensions that enables the invention to function for its intended purposes is within the scope of the invention. Accordingly, the present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, with the understanding that these drawings depict only typical embodiments of the invention and therefore should not be considered limiting in scope. [Brief explanation of the drawings]
[0026] [Figure 1a] 1 shows a prior art flip-flop-type footwear article. [Figure 1b(i)] 1 is a photographic representation of a prior art elongated foot-engaging element for a flip-flop-type article of footwear. [Figure 1b(ii)] This is a diagram of Figure 1b(i). [Figure 1c(i)] 1b(i) is a photographic representation of a portion of the prior art elongate foot engaging element of FIG. 1b(i) in a bent state, bent in a plane perpendicular to the major plane of the elongate foot engaging element; [Figure 1c(ii)] This is a diagram of Figure 1c(i). [Figure 1d(i)] 1b(i) and 1c(i) are photographic representations of a portion of the prior art elongated foot engaging element of FIG. 1b(i) in a buckled position, buckling in a direction perpendicular to a plane perpendicular to the major plane of the elongated foot engaging element. [Figure 1d(ii)] This is a diagram of Figure 1(i). [Figure 1d(iii)] 1 shows a reference diagram for defining planes for elongated portions of a flip-flop's foot engaging element for purposes of the prior art and the present invention. [Figure 1e] 1A-1C are photographic representations of a top view of a first exemplary embodiment of a foot engaging element according to the present invention in a flat configuration and a non-upright configuration. [Figure 1f] 1c is a photographic bottom view of the embodiment of the foot engaging element of FIG. 1e in a flat and non-upright configuration. [Figure 1g] This is a diagram of Figure 1e. [Figure 2a]FIG. 1a(i) and FIG. 1b(ii) are top perspective views of one embodiment of a footwear product according to the present invention including a foot engagement element. [Figure 2b] FIG. 2a is a top view of an embodiment of the footwear product. [Figure 3a] FIG. 6 is a top view of the foot engagement elements of FIGS. 1a, 1b(i) and 1b(ii) deformed in the lateral location of the foot engagement elements. [Figure 3b] FIG. 9 is a top view of the foot engagement elements of FIGS. 1a, 1b(i) and 1b(ii) further deformed in the lateral plane of the foot engagement elements. [Figure 4a] FIG. 12 is a top perspective view of a second embodiment of a footwear product according to the present invention including a foot engagement element. [Figure 4b] FIG. 4a is a bottom view of an embodiment of the footwear product. [Figure 5a] FIG. 18 is a schematic view of a top view of the foot engagement element of the present invention. [Figure 5b] FIG. 21 is a schematic view of a top view of the foot engagement element of the present invention of FIG. 5a deformed in the lateral plane. [Figure 6a] FIG. 24 is an enlarged schematic view of a top view of the foot engagement element of the present invention. [Figure 8b] FIG. 8b shows a top view of the foot engaging element of FIG. 8a. [Figure 9a] 1 is a diagrammatic view of a portion of an elongated portion of a prior art foot engaging element. [Figure 9b] 1 is a diagrammatic view of a portion of an elongated portion of one embodiment of a foot engaging element according to the present invention. [Figure 10a] 9b is a graphical representation of the deflection of the strip of FIG. 9a. [Figure 10b] FIG. 10a is a graphical representation of the deflection of the strip of FIG. 9b. [Figure 11(i). 11(ii). 11(iii)] 11(i), (ii), and (iii) are a diagram of one embodiment of a strip, experimental damage of an embodiment of a strip, and a comparison of a numerical analysis of an embodiment of a strip, respectively. [Figure 12a] 1 is a photographic representation of an elongated foot engaging element in accordance with the present invention. [Figure 12b] 12b is an enlarged view "B" of a portion of the elongated portion of the foot engaging element of FIG. 12a. [Figure 12c] FIG. 12b is a cross-sectional view of an enlarged portion taken along line AA of FIG. DETAILED DESCRIPTION OF THE INVENTION
[0027] Detailed Description of the Preferred Embodiments FIELD OF THE INVENTION The present invention relates to elongated foot-engaging elements and articles of footwear embodying such elongated foot-engaging elements.
[0028] Still more particularly, the present invention, in preferred embodiments, relates to flip-flop type footwear, and in particular to elongated foot-engaging elements and sole members of such footwear.
[0029] Such footwear articles are referred to by different names in various parts of the world, including terms such as "flip-flops," "thongs," "jandals," and "zori" under the Globally Harmonized Tariff System. As will be appreciated by those skilled in the art, flip-flop-type footwear articles are highly flexible to allow for continuous flexion while a person is walking or walking, and the above terms may be used interchangeably.
[0030] The soles of such footwear are distinct from the soles of conventional footwear in that a relatively small amount of flex is permitted, typically part of the sole, as compared to the flex provided by flip-flop-type footwear, if desired.
[0031] Furthermore, in addition to the requirement that the sole member of a flip-flop footwear article be flexurally elastic, it is essential that the foot-engaging element allow for such large flexions while retaining the sole, and therefore the footwear article, on the user's foot during use; otherwise, the integrity of the foot-engaging element may be compromised.
[0032] Prior Art - Observations The following prior art observations have been made by the inventor with respect to the present invention: Figures 1a-1d(ii) show a flip-flop and elongated foot-engaging elements typically utilized in prior art flip-flops.
[0033] It should be noted that such engaging elements are elongated, generally rectangular, flat in cross section, and generally flexible, allowing them to bend to a certain extent, allowing for flexion of the foot and a large amount of flexion of the sole member while maintaining the footwear article attached to the user's foot.
[0034] However, the inventor has noted that while such engagement elements are generally flexible and allow flexion of the foot, they are only flexible perpendicular to the flat surface of their generally rectangular cross section, and not in the plane of the flat surface.
[0035] Figure 1d(iii) shows a reference diagram for defining a plane for the elongated portion of the foot engaging element of a flip-flop, for purposes of the prior art and the present invention. With reference to Figure 1(d)(iii), for purposes of the present invention and with reference to the description of the present invention, this flat plane is the major plane of the elongated portion of the flip-flop, also called the "lateral plane", or the plane of the main surface of the elongated portion.
[0036] Accordingly, references to a "lateral plane" are planes parallel to the lateral major axis of the elongated portion of the foot-engaging element and are shown in FIG. 1(d)(iii), and such references are used consistently with respect to the prior art as well as the present invention provided by the inventors.
[0037] The inventors have identified deficiencies in such engagement elements of the prior art, which are further described below.
[0038] For purposes of illustrating the deficiencies of the prior art, reference is made to Figures 1a, 1b(i), 1b(ii), 1c(i), 1c(ii), 1d(i) and 1d(ii), all of which are prior art.
[0039] 1a, there is shown a typical prior art flip-flop-type footwear article 1000. Such article 1000 includes an elongated sole 1010 and an elongated foot-engaging element 1020.
[0040] As known to those skilled in the art, foot engaging element 1020 is retained on sole 1010 by plug elements 1027, 1028, 1029 which extend through openings in the sole and act as plugs to prevent the mating element from being removed from the sole, as shown in FIG. 1b, and such engagement is well known to those skilled in the art.
[0041] Referring now to Figures 1b(i) and 1b(ii), an elongated foot-engaging element 1020 as used in the footwear article 1000 of Figure 1a is shown, and Figures 1c(i), 1c(ii), 1d(i) and 1d(ii) show a portion of the elongated foot-engaging element 1020 of Figures 1b(i) and 1b(ii).
[0042] The illustrated foot engaging element 1020 includes a first elongated portion 1022 and a second elongated portion 1024. The first elongated portion 1022 and the second elongated portion 1024 have first surfaces 103 and 105, respectively, for engaging at least the top surface of a user's foot.
[0043] The two elongated portions 1022 and 1024 converge at a first end of the foot engaging element 1020, and the elongated portions 1022 and 1024 diverge from each other at the other end 1.
[0044] Extension portion 1026 extends from first ends of elongated portions 1022 and 1024 and has an engagement portion 1029 for engaging with a sole member of the footwear of FIG. 1a, and in this embodiment such engagement portion 1029 is provided as a plug element such as used in foot engaging element 1024 so as to be applicable for use in a flip-flip type footwear article such as FIG. 1a.
[0045] The second ends of elongated portions 1022 and 1024 also include engagement portions 1027 and 1028, respectively, which in this embodiment are also provided as plug elements such as those used in typical flip-flop style footwear.
[0046] As will be understood by those skilled in the art, extension portion 1026 is sized to pass between a user's big toe and second toe, and elongated portions 1022 and 1024 are sized to extend from their first ends in a direction across the top surface of the user's foot toward the rear of the user's foot, such that foot engaging element 1020 is a bifurcated engaging element for use in securing a flip-flop footwear article to a user's foot.
[0047] As will be described below and as will be understood by those skilled in the art, such elongated foot-engaging elements are typically formed from a rubberized or stretchable material and are substantially flat.
[0048] 1c(i) and 1c(ii), as shown, one of the substantially flat elongated portions 1024 is capable of bending and flexing, as described above and as is typical of prior art foot-engaging elements utilized with flip-flop-type footwear. As is known, such elongated portion 1024 of an elongated foot-engaging element is capable of substantially bending within a major plane, as shown in FIGS. 1c(i) and 1(c)(ii).
[0049] However, as identified by the inventors and shown in Figures 1d(i) and 1d(ii), elongated portions such as elongated portion 1024 are unable to bend, or are barely able to bend, within the plane of the major surface of the elongated portion. As will be appreciated, the plane of the major surface is the lateral plane defined and described with reference to Figure 1d(iii).
[0050] The inventors have identified this shortcoming, as shown in Figures 1d(i) and 1d(ii), whereby elongated portion 1024 is unable to bend in a lateral plane, and again, unable to bend in a plane parallel to the flat or major surface of elongated portion 1024, and have identified a consequence and shortcoming of such foot-engaging elements of the prior art, as further described and explained below.
[0051] Furthermore, the inventors have provided a novel solution to this problem as identified by the inventors, and thus have provided a foot-engaging element that does not have the drawbacks as identified by the inventors and that is unique and distinguishable from the prior art, such as that described above.
[0052] Thus, the inventor has identified shortcomings in newly identified features and has also identified shortcomings in such engagement elements that have not been identified by others.
[0053] Issues with conventional technology The inventors have determined that such inherent rigidity and inflexibility of the prior art engaging elements as shown in Figures 1a to 1d(ii) presents the following defects and drawbacks: (i) Lack of adaptability to feet of different sizes and shapes (ii) discomfort due to an ill-fitting fit on the user's foot (iii) discomfort due to pressure points caused by a poor fit with the user's foot; (iv) Wear and tear on the skin due to an ill-fitting fit on the user's foot (v) Increased inventory sizes required to accommodate different sizes and shapes of feet for different users
[0054] However, the present inventors have identified shortcomings of elongated foot engaging elements for flip-flops and have provided a unique and novel foot engaging element that addresses these shortcomings and deficiencies of prior art foot engaging elements.
[0055] Thus, the inventors have provided an elongated foot-engaging element for flip-flop type footwear, which is applicable to other types of footwear and to footwear embodying such an elongated foot-engaging element, which overcomes deficiencies identified by the inventors and not yet identified in the prior art, and which further provides advantages not suggested or proposed in prior art foot-engaging elements such as those utilized in flip-flop footwear and other similar types of footwear.
[0056] The present invention Referring now to Figures 1e, 1f, 1g, 2a and 2b, there is shown a first exemplary embodiment of a foot engaging element 100 according to the present invention.
[0057] In this embodiment, the foot engaging element 100 shown and described is a foot engaging element 100 suitable for engagement for use in a "flip-flop" footwear article 200, which includes a sole member 210 in conjunction with the foot engaging element 100.
[0058] It can be seen that the foot engaging element of the present invention as shown in Figures 1e-8b includes a plurality of recesses along at least a portion of the length of at least one edge of at least one of the elongated portions 110a, 110b of the foot engaging element 100.
[0059] The recesses may be on either side of a major surface of the elongated portion of the foot-engaging element, or may be on both major surfaces of the elongated portion.
[0060] As described with reference to further embodiments, the recesses in the elongated portion on a first side of the foot-engaging element may be aligned, out of phase, offset, or of a different shape than the recesses on the other, opposing side of the elongated portion of the foot-engaging element. For example, the recesses may be 180 degrees out of phase, 90 degrees out of phase, or some other amount out of phase.
[0061] Additionally, the recesses may be of different sizes and different pitches on either side of the foot-engaging portion and on the elongated portion.
[0062] As described below, when bending in a lateral plane, i.e., the major planar plane of the elongated portion, the presence of a plurality of recesses on at least the compression side of the elongated portion of the foot-engaging element allows bending in this plane by the elongated portion providing strain relief, with the asperities between the recesses being biased toward adjacent asperities during such bending, as described below.
[0063] In embodiments with multiple recesses on both sides of the elongated portion, those on the tension side are pulled apart during in-plane bending.
[0064] Referring now to Figure 2a, a top perspective view of one embodiment of a footwear article 200 according to the present invention including the foot-engaging element 220 of Figures 1a(i) and 1b(ii) is shown, and Figure 2b shows a top view of the embodiment of footwear article 200 of Figure 2a.
[0065] Article of footwear 200 includes a sole member or portion 210 having an engagement surface 210 for engaging the ground in use and an upper surface 214 for engaging the underside of a user's foot.
[0066] 3a and 3b, there is shown a portion 300 of the elongated portion of the foot engaging element 100 of FIGS. 1e, 1f and 1g.
[0067] As shown, a first side 320 (left side in this view) of the elongated portion 310 has a first plurality of recesses 324 and ridges 322 on the first side 320, and a plurality of recesses 334 on an opposing side 330 (right side in this view) having ridges 332 between the recesses 334.
[0068] As can be seen, when a load is applied to bend elongated portion 310 in the transverse plane, as defined above, which is shown parallel to the page and is the plane of the major surface of elongated portion 310, there is compression on first side 320 and tension on second side 330.
[0069] The recesses 324 on the first side 320 and the recesses 334 on the second side 330 allow flexing within the plane of the paper (the transverse plane) and provide stress and strain relief, so that the peaks 322 on the first side 320 bias toward each other and the peaks 332 on the second side 330 purge against each other.
[0070] As can be seen and demonstrated in Figure 3a, a smaller amount of load and bending allows for a first amount of deformation, but as shown in Figure 3b, the relief structure provided by the recesses 324 on the first side 320 allows for compression along the edge of the strip portion 300 on the first side 320 and biasing of the peaks 322 toward each other. Additionally, the recesses 334 on the second side 330 also allow for strain and deformation in the plane of the paper, i.e., the lateral plane.
[0071] As can be clearly seen, deformation along central axis 310 of portion 300 allows portion 300 to bend in the lateral plane, i.e., within the plane of the paper, in contrast to that of the prior art as observed by the inventors, while also, as can be seen, does not result in buckling of portion 330 out of the plane of the paper.
[0072] The inventors have found that providing such recesses in foot-engaging elements for footwear, particularly flip-flops, allows the foot-engaging element to flex in the plane lateral to its planar axis as well as in a plane perpendicular to the plane of the planar axis, i.e., the lateral plane. (i) Without buckling, (ii) bending deformation at least in the flat plane of the paper; (iii) further flex in three dimensions to conform to this shape of the user's foot, regardless of changes in the anatomical characteristics of the user's foot; (iv) The engaging elements conform to the user's foot, providing increased comfort.
[0073] Providing at least a plurality of recesses along at least one edge of the elongated portion of the engaging element, as provided by the present invention, provides the above-mentioned features and advantages, as pointed out by the inventors.
[0074] Referring now to Figure 4a, a top perspective view of a second embodiment of a footwear article 400 according to the present invention is shown, including a foot-engaging element 420 according to the present invention, and Figure 4b shows a bottom view of the embodiment of footwear article 400 of Figure 4a.
[0075] Footwear article 400 is provided in the form of a flip-flop including an elongated sole 410, an upper surface 414 for engaging the underside of a user's foot, and a foot-engaging surface 412 for engaging the ground when the footwear article is in use.
[0076] A foot-engaging element 420 according to the present invention is attached to the sole member 410 by a rear plug element 422 and a front plug element 424 that extend through openings in the sole 410 .
[0077] FIG. 5a shows a schematic diagram of a top view of a portion 500 of a foot engaging element of the present invention in an undeformed state, and FIG. 5b shows a schematic diagram of a top view of the portion 500 of the present invention of FIG. 5a deformed in the lateral plane of the foot engaging element.
[0078] As shown, a first side 520 of the portion 500 has a first plurality of recesses 524 and ridges 522 on the first side 520 and a plurality of recesses 534 on an opposing side 530 having ridges 532 between the recesses 534.
[0079] As can be seen, when a load is applied to bend elongated portion 500 in a transverse plane as shown parallel to the page as shown in FIG. 5b, first side 520 is in compression and second side 530 is in tension.
[0080] The recesses 524 on the first side 320 and the recesses 534 on the second side 530 allow flexing within the plane of the paper (the transverse plane) and provide stress and strain relief, so that the peaks 522 on the first side 520 bias towards each other and the peaks 532 on the second side 530 purge against each other.
[0081] Such recesses also allow the elongated portion to flex in the lateral plane without buckling, thus providing greater conformance of the foot-engaging element with the outer surface of the user's foot. As discussed above, buckling of such elements not only results in the foot-engaging element not providing such improved conformance with the various geometries and shapes and anatomical variations of human feet, but such buckling can also result in discomfort.
[0082] Again, as can be clearly seen, deformation along the central axis 510 of the part 500 allows the part 500 to bend in the plane of the paper (the transverse plane), while also being seen not to result in buckling of the part 530, in contrast to the prior art.
[0083] Referring now to Figure 6a, there is shown an enlarged schematic diagram of a top view of a portion 600 of an elongated portion of a foot engaging element of the present invention, Figure 6b shows a schematic diagram of a top view of portion 600 of the foot engaging element of the present invention of Figure 6a deformed in the lateral plane of the foot engaging element, Figure 6c is a magnified portion of circle 640 of Figure 6a, and Figure 6d is a magnified portion of circle 650 of Figure 6b.
[0084] As can be clearly seen and illustrated, when load B″ is applied, the peaks 622 provided by the left recess are displaced away from each other in direction 660, while the peaks 632 on the right side are urged towards each other in direction 670.
[0085] As clearly demonstrated with reference to the accompanying drawings, the multiple recesses along the edge of the elongated foot engaging element according to the present invention allow for deformation of the foot engaging element in the lateral direction, allowing for compression on a first side of the foot engaging element while allowing tension relief on the opposite side of the foot engaging element.
[0086] Thus, as clearly demonstrated, the present invention allows for damage in the lateral plane of the foot engaging element, in contrast to the prior art, which has a flat strip with no recesses along its edges, providing advantages as identified by the inventors.
[0087] As explained, this provides many advantages including allowing for an improved fit with the user's foot, allowing for anatomical variations between different feet of different users, which also provides added comfort to the user.
[0088] As will be appreciated by those skilled in the art, the foot engaging elements of the present invention can, of course, deform in a plane perpendicular to the lateral plane (i.e., the transverse plane), and thus the present invention provides a foot engaging element that can be sufficiently deformed in three dimensions to provide improved contouring and compatibility between the elongated portion of the elongated foot engaging member and the user's foot.
[0089] 7a-7d show examples of embodiments of the present invention, showing different profiles or variations of portions of the foot engaging elements thereof.
[0090] 7a shows a top view of a portion of one embodiment of a portion 700a of an elongate foot engaging member in accordance with the present invention, in which the peaks on a first side are 180 degrees out of phase, as shown at 730a, compared to the peaks on the opposite side of the foot engaging element.
[0091] FIG. 7b shows a top view of a portion of a further embodiment of a portion 700b of an elongate foot engaging member according to the present invention, whereby the peaks on a first side of the foot engaging element are 90 degrees out of phase as shown at 730b compared to the peaks on the opposite side of the foot engaging element.
[0092] FIG. 7c shows a top view of a portion of another embodiment of a portion 720c of an elongate foot engaging member in accordance with the present invention, where ridges 710c are present only on a first side and the second side of the foot engaging element is straight.
[0093] FIG. 7d shows a top view of a portion of an alternative embodiment of a portion 700d of an elongate foot engaging member according to the present invention, whereby the peaks 710 on a first side have a different pitch than the peaks 720b on an opposite second side away from the foot engaging element.
[0094] Referring to Figure 8a, there is shown a diagrammatic view of a foot engaging element 800 according to the present invention from a side view in a deformed state. Figure 8b shows the foot engaging element 800 of Figure 8a from above.
[0095] As can be seen and understood, the multiple recesses 820 and ridges 830 on the sides of the elongated portion of the elongated foot engaging element 800 allow the foot engaging element to form in the plane of the portion of the foot engaging element, i.e., in the lateral plane, without buckling, which provides the advantage of conforming to the user's foot, as commented above.
[0096] Also, as is clearly apparent, such foot engaging elements 800 may, of course, be formed in a plane perpendicular to the lateral plane, and thus the foot engaging elements as referred to by the President allow for conformance and fit of the footwear product embodying such foot engaging elements to the foot of the user without buckling, and the walls provide comfort through their conformance and efficiency in maintaining the foot engaging element, and therefore the footwear product, on the user's foot.
[0097] Demonstration and Verification of the Invention 9a, 9b, 10a and 10b, numerical analysis is shown that demonstrates the ineffectiveness of the manner in which the elongated portions of the foot engaging elements of the present invention flex in a lateral plane, the lateral plane, as defined, being the plane in which the first and second opposing surfaces of the foot engaging element lie, i.e., the plane of the paper with respect to the illustrated drawings and figures.
[0098] FIG. 9a shows a diagram of a portion 900a of an elongated portion of a prior art foot engaging element, which is typical of the prior art and has dimensions of 18 mm height and 3 mm depth in the plane of the page.
[0099] FIG. 9b shows a diagram corresponding to a portion of the elongated portion of FIG. 9a, but with portion 900b of FIG. 9b embodying a feature of the present invention, namely, a plurality of recesses 910b extending along an edge 920b of portion 900b of the elongated portion, as shown.
[0100] The embodiment shown corresponds to that depicted in previous photographic and line drawings of the invention, such as Figures 1e-4b.
[0101] In this diagram of a portion of an elongated portion of one embodiment of a foot-engaging element according to the present invention, for comparison, the dimensions match those of the prior art in Figure 9a, where the overall height of the elongated portion is 18 mm and the depth (into the plane of the page) is 3 mm. Such dimensions match those of the present invention as shown in the accompanying photographic representations and drawings.
[0102] With respect to the recesses 910b along the edge 920b of the strip portion 900b, these have a depth of 2.5mm, a pitch (on centres) of 12.5mm, and a phase offset of 180 degrees between opposite edges of the strip.
[0103] Referring now to Figure 10a, there is a graphical representation of the deflection of portion 1000a corresponding to elongated portion 900a of Figure 9a under load. This is a computer simulation model of the deflection and stress of portion 900a of the elongated portion of Figure 9a.
[0104] As can be seen, little deflection of portion 1000a is introduced by such a portion of constant rectangular cross section. Furthermore, edges 1010a, 1020a of portion 1000a remain substantially straight and parallel, with minimal and nearly straight deflection in the lateral plane.
[0105] Furthermore, tensile stresses are evident at the upper edge 1010a, and compressive stresses at the lower edge 1020a have a buckling-inducing effect and a tendency for portion 1000a to be biased out of or into the plane of the paper, consistent with deficiencies in the prior art identified by the inventors, as experimentally depicted and shown in Figures 1d(i) and (ii). The stresses as shown are Von Mises stress fields, the details of which are known to those skilled in the art.
[0106] Referring now to Figure 10b, there is shown a graphical representation of the deflection of the elongated portion of Figure 9b. This is a computer simulation model of the deflection and stress of portion 900b of the elongated portion of Figure 9b. Portion 1000b of elongated portion 900b of Figure 9b corresponds to that of the embodiment of the invention previously described and illustrated.
[0107] As can be seen, there is significant deflection of portion 1000b in the lateral plane, which is significantly greater than the deflection of portion 1000a of the prior art elongated portion as shown in FIG. 10a, allowing for greater deformation and conformance of the foot engaging element of the present invention to variations in foot geometry and anatomy by the user.
[0108] Furthermore, the deflection in the lateral plane is non-linear, and the portion 1010b in accordance with the present invention exhibits greater deflection and flexibility in the lateral plane than the prior art, as shown in Figure 10a. Such improved variation in flexibility provides greater compatibility with various shapes and geometries of users' feet and anatomical variations in which the elongated portion of the difficult-to-engage element is used.
[0109] Also, as shown in FIG. 10b, stresses are distributed by the plurality of recesses 1010b, distributed over the plurality of upper edges 1012b and over the plurality of recesses 1020b onto the lower edge 1022b of the strip portion 1000b, thus minimizing, reducing, or preventing buckling of the strip portion in and out of the plane of the page compared to the prior art shown and illustrated above.
[0110] Furthermore, as can be seen in the figure, the peaks 1030b between the recesses 1010b on the upper edge 1012b, i.e., the tension sides of the elongated portions of portion 1000b, are biased in a direction 1032b away from each other, and the peaks 1040b between the recesses 1050b on the lower edge 1014b, i.e., the compression sides of the elongated portions of portion 1000b, are biased in a direction 1042b towards each other.
[0111] Referring now to Figures 11(i), (ii) and (iii), there is shown a comparison of a line drawing of one embodiment of strip portion portion 1100a corresponding to Figure 9b, an experimental variation of an embodiment of strip portion portion 1100b corresponding to the photographic representation of Figure 3a, and a numerical analysis of an embodiment of strip portion portion 1000b of Figure 10b, respectively.
[0112] As has been demonstrated both experimentally and theoretically, the plurality of recesses 1120a, 1120b, 1120c provide and enable bending and flexing of the elongated portions 1100a, 1100b, 1100c within the plane of the first and second flat surfaces of the elongated portions 1100a, 1100b, 1100c.
[0113] Thus, the present invention has been clearly demonstrated to show that an elongated portion having multiple recesses as provided by the present invention provides for improved conformance of the foot engaging element with the anatomical shapes and various used foot deformities in varying amounts as needed due to the flexibility of the elongated portion, and thus provides for such flexion and deformation in the lateral plane providing a more comfortable and form fitting for the engaging element, as well as the other advantages and benefits listed and elucidated.
[0114] 12a, 12b and 12c, FIG. 12a shows a photographic representation of an elongated foot engaging element 1200 according to the present invention, FIG. 12b shows a view "B" of an enlarged portion of portion 1200 of elongated portion 1210 of foot engaging element 1200 of FIG. 12a, literally through elongated portion 1210 and recess 1240, and FIG. 12c shows a cross-sectional view of the enlarged portion along line AA of FIG. 12b.
[0115] As will be appreciated, the cross-sectional area of the elongated portion 1210 of the foot engaging element 1200 may have varying cross-sectional areas or geometric shapes and is not necessarily rectangular, and the analytical model described above has been simplified as a rectangular cross-section to facilitate demonstration of the inventive concepts and functionality provided by the present invention and its multiple resources.
[0116] In this embodiment, as can be readily apparent from the cross-sectional view of FIG. 12c, the elongated portion 1210 tapers laterally outward from the center of a portion 1220 of the elongated portion 1210, tapering to a smaller cross-section toward the outer edge 1230 of the portion 1220 of the elongated portion 1210.
[0117] As will be appreciated, other and alternative geometries and cross-sections are equally applicable to the present invention and will be understood by those skilled in the art to be within the scope of the present invention.
[0118] Additionally, while the elongated portions of the foot-engaging elements of the present invention are shown as being approximately the same size and shape along the length of the elongated portion, those skilled in the art will understand that the size and geometry may be modified and may vary along the length of the elongated portion, and that the edges of the elongated portion need not necessarily be parallel to one another.
[0119] As will be explained below, the recesses as shown and described in the previous figures extend from the side edges of the elongated portion in an inward direction in the electrical plane of the elongated portion.
[0120] As will be further explained below, in the aforementioned drawings, the recesses are represented by wave-like structures having a curved, wave-like profile, whereby the recesses are generally curved in nature and the peaks between the recesses are represented as oppositely shaped but convex surfaces or portions.
[0121] The recess is therefore a convex recess in the transverse plane, extending at least partially in a direction along the longitudinal axis of the elongated portion inwardly from the outer longitudinal edge of the elongated portion.
[0122] As will be appreciated, while the concave and convex chevron portions are shown equally curved in the above-described embodiments, other and alternative geometries and profiles are equally applicable to and are understood to be within the scope of the present invention.
[0123] Therefore, no geometric or structural limitations should be construed or inferred from the accompanying examples, and any structural feature, shape or geometry that provides a plurality of recesses extending longitudinally of the longitudinal axis of the elongated portion along at least a portion of the side edges of the elongated portion and that provides bending and deformation in the lateral plane is understood to be within the scope of the present invention.
[0124] Foot Engaging Elements of the Present Invention The foot-engaging elements of the present invention are preferably "shape-formed" elements, which is defined as an element or product formed from a material provided in a flowable form, which upon solidification or hardening assumes the required shape of the product or element.
[0125] Thus, a "shaped" product or element is one that is formed from material provided in a flowable form, rather than being cut, machined, or fabricated from a solid material. Examples of shape-forming processes include molding processes and additive manufacturing processes.
[0126] The foot-engaging elements of the present invention are therefore preferably formed from a flowable and hardenable polymeric material which, when hardened, forms the shape of the foot-engaging element and has the above-mentioned elastic properties, and may be selected from the group including rubber or rubber compounds, elastomers, elastic polymers, and the like.
[0127] Those skilled in the art will appreciate that other elastic or polymeric materials may be utilized to form foot engaging element 100 in other and alternative embodiments of the present invention.
[0128] Such foot engaging elements of the present invention may be formed from a molding process, such as an injection molding process or other molding process including a compression molding process, a casting molding process, a transfer molding process, or the like.
[0129] Alternatively, the foot engaging elements of the present invention may be formed by additive manufacturing processes including three-dimensional (3D) printing processes, fused filament fabrication processes, continuous liquid interface manufacturing (CLIP) processes, digital light synthesis (DLS) processes, and the like.
[0130] The illustrated foot-engaging element includes a first elongated portion and a second elongated portion, each having a first surface for engaging at least the upper surface of a user's foot.
[0131] Such first surfaces are typically provided as smooth surfaces for contact and engagement with the upper surface of a user's foot. Alternatively, the first surfaces may be textured. The foot-engaging elements have second surfaces, each opposite the first surface.
[0132] In this embodiment, the foot engaging element includes two elongated portions that converge at a first end of the foot engaging element and the elongated portions diverge from each other at the other end.
[0133] The extension portion extends from a first end of the elongated portion and has an engagement portion thereon for engaging with a sole member of the footwear article, and in this embodiment, such engagement portion is provided as a plug element such as used in a foot-engaging element so as to be applicable for use in flip-flip type footwear articles.
[0134] The second ends of the elongated portions are also provided with engagement portions, which in this embodiment are each provided as a plug element such as those used in typical flip-flop style footwear articles.
[0135] As will be understood by those skilled in the art, the extension portion is sized to pass between the user's big toe and second toe, and the elongated portion is sized to extend from its first end across the top surface of the user's foot in a direction toward the rear of the user's foot, such that the foot engaging element is a bifurcated engaging element for use in securing the flip-flop footwear article to the user's foot.
[0136] Process for forming foot-engaging elements applicable to the present invention As noted above, the foot-engaging elements of the present invention are "shaped" elements, meaning that the elements are formed from a material that is provided in a flowable form, and upon solidification or hardening, assumes the required shape of the product or element.
[0137] Thus, a "shaped" product or element is one that is formed from material provided in a flowable form, rather than being cut, machined, or fabricated from a solid material. Examples of shape-forming processes include molding processes and additive manufacturing processes.
[0138] As mentioned above, the foot engaging elements of the present invention may be formed from a molding process, such as an injection molding process or other molding process including a compression molding process, a casting molding process, a transfer molding process, or the like.
[0139] Injection molding applicable to the present invention typically utilizes an injection molding machine, raw plastic material, and the necessary mold. In such a process, the necessary elastomeric material is injected into a mold cavity having the required shape for the foot engaging element in a flowable and moldable state. Examples of suitable moldable elastomeric materials include rubber or rubber compounds, elastomers, elastomeric polymers, etc. Once the elastomeric material is cured, the mold is opened and the foot engaging element is removed from the mold.
[0140] In other embodiments for forming the foot-engaging element, compression molding may be performed, whereby a moldable material is generally preheated and first placed into an open, heated mold cavity that defines the desired shape and geometry of the foot-engaging element. The mold is then closed with an upper force or plug member, and pressure is applied to force the material into contact with all mold areas within the mold cavity, maintaining the heat and pressure until the material hardens. Such methods typically use a thermosetting resin in a partially cured stage, either in the form of granules, a putty-like mass, or a preform.
[0141] As will be understood and appreciated by those skilled in the art, it is also understood that other molding processes, such as casting or transfer molding, may be implemented and are included within the scope of applicable molding processes for forming foot engaging elements in accordance with the present invention.
[0142] Alternatively, the foot engaging elements of the present invention may be formed by additive manufacturing processes including three-dimensional (3D) printing processes, fused filament fabrication processes, continuous liquid interface manufacturing (CLIP) processes, digital light synthesis (DLS) processes, and the like.
[0143] Different 3D printing processes may be utilized to form the foot-engaging elements as "shaped" elements, such as fused filament fabrication.
[0144] In other and alternative embodiments, other additive manufacturing processes can be utilized to provide "shaped" foot-engaging elements, such as the Continuous Liquid Interface Manufacturing (CLIP) process, whereby a continuous process begins with providing a pool of liquid photopolymer resin. A portion of the pool's bottom is transparent to ultraviolet light and is referred to as the "window." A beam of ultraviolet light is utilized to shine through the window, illuminating a precise cross-section of the object, and the light solidifies the resin. The object is slowly raised, enough so that the resin flows underneath the object and remains in contact with the bottom of the object.
[0145] In other embodiments, the shapes may be formed using a digital light synthesis (DLS) process.
[0146] Advantages of the Invention The present invention overcomes the problems and deficiencies of the prior art as identified by the inventors by providing a bifurcated elongated foot engaging element having a plurality of recesses extending along at least a portion of one side of at least one of the elongated portions of the foot engaging element, and provides a bifurcated elongated foot engaging element, including: (i) Adaptation to feet of different sizes and shapes (ii) Comfort through compatibility (iii) mitigating or minimizing skin abrasion and damage through increased conformability; and (iv) reductions in inventory size and quantity
Claims
1. 1. An elongated foot-engaging element for an article of footwear, said foot-engaging element comprising: two elongated portions each having a longitudinal axis and first and second opposed planar surfaces, said elongated portions having a first longitudinal edge region and an opposed second longitudinal edge; a plurality of recesses extending along at least a portion of an edge of at least one of the elongated portions of at least one of the foot-engaging elements, the plurality of recesses in the elongated portion providing for flexion of the elongated portion in the plane of the first and second planar surfaces, the elongated portion being sized and positioned with the plurality of recesses such that the foot-engaging element is substantially flexible and resilient to permit substantial flexion in use; An elongated foot-engaging element for an article of footwear.
2. The elongated foot-engaging element of claim 1 , wherein the recesses are provided on both edges of the elongated portion of the foot-engaging element.
3. 3. An elongate foot engaging element according to claim 1 or 2, wherein the recesses are provided on both edges of both elongate portions of the foot engaging element.
4. 4. An elongated foot-engaging element according to claim 2 or 3, wherein the recess on one edge of the elongated portion of the foot-engaging element is aligned with the recess on an opposite edge of the elongated portion.
5. 4. An elongated foot engaging element according to claim 2 or 3, wherein the recess on one edge of the elongated portion of the foot engaging element is offset from the recess on the opposite edge of the elongated portion in a direction along the longitudinal axis of the elongated portion.
6. 6. The elongated foot-engaging element of claim 1, further comprising: an extension portion extending from the first end of the elongated portion and having an engagement portion thereon for engaging with a sole member of an article of footwear; and each of the second ends of the elongated portions having an engagement portion thereon for engaging with a sole member of an article of footwear.
7. 7. The elongated foot engaging element of claim 6, wherein the extension portion is sized to pass between a user's big toe and second toe, the elongated portion is sized to extend from the first end thereof across an upper surface of the user's foot in a direction toward the rear of the user's foot, and the first and second elongated portions extend toward the lateral and medial sides of the user's foot, respectively.
8. 8. An elongated foot engaging element according to any one of claims 1 to 7, wherein the foot engaging element is a shaped element formed from a flowable and hardenable polymeric material, which when hardened forms the shape of the foot engaging element and has the elastic properties.
9. The elongate foot engaging element according to any one of claims 1 to 7, wherein the foot engaging element is a molded element.
10. The elongated foot engaging element of claim 9 , wherein the foot engaging element is an injection molded element.
11. The elongated foot engaging element of claim 9 , wherein the foot engaging element is a compression molded element.
12. The elongated foot engaging element of claim 9 , wherein the foot engaging element is a cast element.
13. The elongated foot-engaging element of claim 9 , wherein the foot-engaging element is a transfer molded element.
14. The elongate foot engaging element according to any one of claims 1 to 7, wherein the foot engaging element is a stacking forming element.
15. The elongated foot-engaging element of claim 14 , wherein the foot-engaging element is a three-dimensional (3D) printed element.
16. The elongate foot engaging element of any one of claims 1 to 7, wherein the foot engaging element is a fused filament manufactured element.
17. 17. The elongated foot-engaging element of claim 16, wherein the foot-engaging element is a Continuous Liquid Interface Production (CLIP) element.
18. 16. The elongated foot-engaging element of claim 15, wherein the foot-engaging element is a Digital Light Synthesized (DLS) element.
19. The elongate foot engaging element of any one of claims 1 to 18, wherein the foot engaging element is formed from a resilient material including rubber or rubber compounds, elastomers, elastomeric polymers, polymeric resins, and the like.
20. An article of footwear comprising an elongate foot engaging element according to any one of claims 1 to 19 and a sole member.
21. 21. The article of footwear of claim 20, wherein the sole member is a flip-flop sole member.
22. 22. The article of footwear of claim 21, wherein the sole member includes an upper surface, a lower surface, an upper layer for direct contact and interaction with at least a portion of an underside of the person's foot and formed from a first polymeric material having a first density, and a lower layer having a sidewall and forming substantially the entire lower surface and for direct contact and interaction with a surface and formed from a second polymeric material having a second density, wherein the first polymeric material is provided in a gel form and the second polymeric material is provided in a foam form, whereby the first density is greater than the second density.
23. 23. The article of footwear of claim 22, wherein the first and second polymeric materials are selected and the upper and lower layers are sized and arranged so that the sole is substantially flexible and resilient to permit substantial longitudinal flexion and return of the sole during use and walking by the person, the upper layer extends to at least the upper surface of the sole member, and the first and second polymeric materials are selected and the upper and lower layers are sized and arranged so that the upper layer provides attenuation of loads imparted to the person's foot upon contact with the surface.
24. 24. The article of footwear of any one of claims 20 to 23, wherein the article of footwear is a flip-flop footwear.