Patent Application
20200069000
Shoe vendors typically design their shoes in configurations and sizes to accommodate the most commonly found sizes and widths in a population. To verify to themselves and their retail partners that their shoe sizing is correct and fits well, shoe vendors will utilize live models to try on and wear the newly designed shoe. However, no two live models have exactly the same size and shape of foot nor do two live models have a foot that flexes at the same points and in the same manner. As such, assessing the fit of a shoe is never truly consistent.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description section. This summary is not intended to identify key features or essential feature of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.
Aspects of the present disclosure are directed to a shoe-fit testing device that includes a pseudo skeletal structure and a pseudo soft tissue structure. The pseudo skeletal structure approximates the bone structure of a human foot and ankle, and the pseudo soft tissue structure encompasses the pseudo skeletal structure. The shoe-fit testing device is capable of transitioning between a compressed state and an uncompressed state. In the uncompressed state, the shoe-fit testing device has a joint girth that is measured at a first value. In the compressed state, the shoe fit testing device has a joint girth that is measured at a second value that is less than the first value.
In certain aspects the pseudo skeletal structure includes a number of elements that are less than a number of bones that exist in the human foot and ankle. For example, the pseudo skeletal structure includes a metatarsal component that approximates the five metatarsal bones of the human foot but with less than five pseudo bone elements. In certain aspects, only three pseudo bone elements are needed to approximate the five metatarsal bones of the human foot. In certain aspects, the pseudo skeletal structure comprises a plurality of separate and distinct elements each of which is separated from the other via the pseudo soft tissue structure. In certain aspects, the pseudo skeletal structure comprises a plurality of elements wherein at least a portion of the elements include a hollow center portion to reduce the weight of the pseudo skeletal structure. In certain aspects, the joint girth of the compressed shoe-fit testing device is at least five percent less than the joint girth of the uncompressed shoe-fit testing device. In certain aspects, an instep girth of the compressed shoe-fit testing device is also less than the instep girth of the uncompressed shoe-fit testing device.
Additional aspects of the present disclosure are directed to a shoe-fit testing device that includes a pseudo skeletal structure and a pseudo soft tissue structure wherein the pseudo skeletal structure approximates the bone structure of a human foot and ankle with an ankle joint component, a pseudo metatarsal component and a plurality of removable flex inserts; the pseudo soft tissue structure encompasses the pseudo skeletal structure.
In certain aspects, the pseudo skeletal structure additionally includes a toe plate that approximates the small toes of the human foot as well as a first hallux stabilizer which approximates the large toe of the human foot. In certain aspects, the ankle joint component includes an upper portion that defines an elongate channel and a lower portion that defines a projection received within the elongate channel; the upper and lower portion are separated by the pseudo soft tissue structure. In certain aspects, the plurality of removable flex inserts include at least one open flex channel having a portion that is centered beneath the ankle joint component. In certain aspects, the various elements of the pseudo skeletal structure are fabricated from an acrylonitrile butadiene styrene (ABS) plastic while the pseudo soft tissue structure is fabricated from a urethane elastomer.
Another aspect of the present disclosure is directed to a method of fabricating a shoe-fit testing device. The method includes: (a) fabricating a plurality of structural components that approximate a skeletal structure of a human foot and ankle; (b) fabricating a mold that approximates the outer skin surface of the soft tissues of the human foot and ankle; (c) placing the plurality of structural components within the mold such that each of the plurality of structural components is maintained distinctly separate from all other structural components, the placing of the plurality of structural components including suspending at least a portion of the plurality of structural components within the mold; (d) injecting the mold with a molding material, the molding material encompassing the plurality of structural components and forming a shoe-fit testing device; and (e) removing the shoe-fit testing device from the mold.
Another aspect of the present disclosure is directed to a method of manufacturing a shoe. The method includes: (a) manufacturing a shoe-fit testing device according to the methods described herein; (b) defining the elements of a shoe, including a sole and an upper; (c) fitting the sole and the upper to the shoe-fit testing device or a last based on the shoe fit testing device; and (d) assembling the fitted elements as a shoe.
The details of one or more aspects are set forth in the accompanying drawings and description below. Other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that the following detailed description is explanatory only and is not restrictive of the claims.
The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate various aspects. In the drawings:
The following detailed description refers to the accompanying drawings. Wherever possible, the same references numbers are used in the drawings and the following description refers to the same or similar elements. While examples may be described, modifications, adaptations or other implementations are possible. For example, substitutions, additions or modifications may be made to the elements illustrated in the drawings, and the method described herein may be modified by substituting, reordering or adding stages to the disclosed methods. Accordingly, the following detailed description is not limiting, but instead, the proper scope is defined by the appended claims. The following detailed description is, therefore, not to be taken in a limiting sense.
As briefly described above, aspects of the disclosure are directed to a shoe-fit testing device that can be used to replicate the foot and ankle of a live model, including the flexure of the foot and ankle of the live model, when testing the sizing of a shoe. The shoe-fit testing device of the present disclosure utilizes a pseudo skeletal structure to approximate the bone structure of a human foot and ankle through use of a minimal number of lightweight components, e.g. pseudo bones. More specifically, the number of components, or pseudo bones, is significantly less than the number of actual bones in the human foot and ankle. The shoe-fit testing device of the present disclosure also utilizes a pseudo soft tissue structure to support and encompass the pseudo skeletal structural. The resulting combination of the pseudo skeletal structure and the pseudo soft tissue structure is a shoe-fit testing device that presents a twistable ankle joint as well as a joint girth and/or an instep girth that can compress and uncompress as human foot would when being inserted within a shoe. As such, it can be measured and/or observed as to whether the shoe-fit testing device, which is sized to a specific shoe size, fits suitably within a shoe that should correspond to that specific size. Measurements to be taken or observed when using the shoe-fit testing device include foot length, in-step girth and joint girth.
As noted earlier, live models may have a foot of the same length but their instep girth and joint girth measurements can vary. Further, as the foot is squeezed, such as when being inserted into a shoe, the ability of the foot to flex in response to the squeezing action also varies. For example, the joint girth and/or the instep girth may narrow more or less depending on the structure of the live model's foot.
To help overcome this variation in foot geometry and flexibility associated with live models, the shoe-fit testing device of the present disclosure takes into consideration the variations in measurements of length, instep girth and joint girth (in both uncompressed and compressed positions) of hundreds of live models having a specific foot length to produce design parameters that reflect a composite of the measurements. For example, based on the data obtained from the live models, it was determined that an optimal shoe-fit testing device for a size 6 (US) shoe has a length of 229 mm, a joint girth of 226 mm, an instep girth of 221 mm, and a squeezed/compressed joint girth of 212 mm (e.g. a reduction in joint girth and/or instep girth of approximately 6%).
An example embodiment of a shoe-fit testing device 200 is illustrated in
In certain examples, the shoe-fit testing device 200 is capable of transitioning between a compressed position, such as when squeezed to be inserted into a shoe, and a uncompressed position, such as when fully inserted into the shoe or resting outside the shoe. In certain examples, the instep girth and/or the joint girth of shoe-fit testing device 200 is compressible, relative to its uncompressed state, by at least 2%. In certain examples, the instep girth and/or the joint girth of shoe-fit testing device 200 is compressible, relative to its uncompressed state, by at least 5%. In certain examples, the instep girth and/or the joint girth of shoe-fit testing device 200 is compressible, relative to its uncompressed state, by at least 7%.
The pseudo skeletal structure 210 of the shoe-fit testing device 200 includes an ankle joint component 220, a pseudo metatarsal component 222, a plurality of removable flex inserts 224 including removable flex inserts 224a-224d, a toe plate 226 and a first hallux stabilizer 228. In certain examples, the elements of the pseudo skeletal structure 210 are fabricated from a acrylonitrile butadiene styrene (ABS), which comprises a thermoplastic and amorphous polymer; however, other suitable plastics and/or polymers can also be used. Further, in certain examples, all but the plurality of removable flex inserts 224 and toe plate 226, are fabricated as non-solid components having solid exteriors and hollow interiors/center portions to reduce the overall weight of the shoe-fit testing device 200. Notably, the pseudo skeletal structure 210 does not replicate all bones of the foot, ankle and leg but, rather, approximates the skeletal structure with a minimized number of elements to reduce the cost in fabricating, as well as reduce the weight added to, the shoe-fit testing device 200 by the pseudo skeletal structure elements.
Referring to
The lower portion 232 of the ankle joint component 220 includes a cylindrical body 250 having a top surface 252 the extends into a central projection 254 having a substantially rectangular cross-section. The central projection 254 generally aligns with the elongate channel 242 of the upper portion 230 of the ankle joint component 220 and is received, at least partially, within the elongate channel 242. Note that there is no direct interface between the central projection 254 and the elongate channel 242. Rather, the interstices between the central projection 254 and the elongate channel 242 are filled by the pseudo soft tissue structure 212, which is described in further detail herein. A bottom surface 256 of the cylindrical body 250 recedes into a channel 258 that extends horizontally through the cylindrical body 250; the channel 258 is generally vertically aligned with the projection 254.
The pseudo metatarsal component 222 is illustrated as including three distinct pseudo bone elements 260, 262 and 264 that approximate the shape established by the five metatarsal bones of the human foot as well as the shape established by the cuboid, navicular and cuneiform bones of the human foot. While the three pseudo bone elements depicted are believed to be the optimal combination of elements, fewer or a greater number of elements can be used in approximating the metatarsal, cuboid, navicular and cuneiform bones. Pseudo bone element 260 is the largest in circumference of the three elements having a cylindrical body portion 266 that narrows in circumference as it extends, via a rounded edge 267, from its planar rear surface 268 to a dome-shaped nose 270. Pseudo bone element 262 is the smallest in circumference and length of the three elements and includes a cylindrical body 272 capped by a rearward dome-shaped nose 274 and a forward dome-shaped nose 276. Pseudo bone element 264 has a circumference intermediate the circumference of pseudo bone elements 260 and 262 and has a length substantially equivalent to that of pseudo bone element 260. Pseudo bone element 264 includes a cylindrical body 278 capped by a rearward dome-shaped nose 280 and a forward dome-shaped nose 282.
Each of pseudo bone elements 260, 262, 264 are independent elements that are unattached to any other element of the pseudo skeletal structure 210. Rather, each of pseudo bone elements 260, 262, and 264 are suspended within the pseudo soft tissue structure 212 of the shoe-fit-testing device 200. Specifically, pseudo bone elements 260, 262 and 264 are spread across a width of the shoe-fit testing device 200 in a downward sloping curve S from pseudo bone element 260, positioned above an instep of the instep side 207 of the shoe-fit testing device 200, to pseudo bone element 264 positioned towards an outer edge 208 of the shoe-fit testing device 200. The rear surface 268 of the pseudo bone element 260 and the rearward dome-shaped nose 280 of the pseudo bone element 264 are positioned proximate the lower portion 232 of the ankle joint component 220 while the rearward dome-shaped nose 274 of pseudo bone element 262 is positioned more forwardly and further distant from the lower portion 232 of the ankle joint component 220.
The plurality of removable flex inserts 224, including removable flex inserts 224a-224d, help to complete the approximation of the human metatarsal bones, as each terminates with a forward-extending, downward slope 284a-284d to forward vertical edge 286a-286d; the forward vertical edge 286a-286d approximate the location where the phalanges join the metatarsals in the human foot. It should be noted that, while four removable flex inserts 224 are illustrated, a greater or lesser number of removable flex inserts 224 can be used. For example,
Each of removable flex inserts 224a, 224c and 224d comprises a straight elongate panel of solid material that extends from the forward vertical edge 286a, 286c, 286d to a rearward vertical edge 288a, 288c, 288d. Removable flex insert 224b also comprises an elongate panel of material that extends rearward from its front vertical edge 286b rearward including a jog 287 in the removable flex insert 224b enabling a portion 225 of the removable flex insert 224b to align and extend through channel 258, of the lower portion 232 of the ankle joint component 220, to its rearward vertical edge 286b; the portion 225 of the removable flex insert 224b is generally centered under the ankle joint component 220 and is vertically aligned with the channel 258, the central projection 254 and the channel 242 of the lower and upper portions 232, 230 of the ankle joint component 220. Removable flex insert 224b helps to stabilize the foot of the shoe-fit testing device 200 relative to the ankle portion 201 of the shoe-fit testing device 200 during the molding process (described further below). Once the molding process is complete, the removable flex inserts 224 are removed from the molded shoe-fit testing device 200. Removal of the removable flex inserts 224 leaves the molded shoe-fit testing device 200 with corresponding open flex channels 227 (see
The toe plate 226 approximates the rigidity of the small toes and is in the form of an arcuate plate that is positioned horizontal relative to the front vertical edges 286a-286d of the removable flex inserts 224a-224d; the toe plate 226 is positioned at approximately the mid-vertical height of the vertical front edges 286a-286d of the removable flex inserts 224a-224d. The toe plate 226 includes an upper surface 290 and a lower surface 292 connected by sides 294a-294d.
The first hallux stabilizer 228 approximates the stability of the large toe (i.e., the first hallux) of the foot. The first hallux stabilizer 228 generally comprises a cylindrical body 295 with a dome-shaped forward end 296 and a dome-shaped rearward end 297.
Referring once again to
The flow chart of
The fabrication process 700 begins with fabricating the various elements of the pseudo skeletal structure 210 (S702) including the ankle joint component 220, the pseudo metatarsal component 222, the plurality of removable flex inserts 224 including removable flex inserts 224a-224d, the toe plate 226 and the first hallux stabilizer 228. The elements of the pseudo skeletal structure 210 can be manufactured via any appropriate means including but not limited to: three-dimensional printing, molding, thermoforming, and/or vacuum casting.
The fabrication 700 process continues by creating a rigid master pattern (S704) for the outer surfaces of the pseudo soft tissue structure 212, which approximates the outer skin surface of the soft tissue structure of the human foot and ankle. In certain examples, the rigid master pattern is of an ABS plastic or other suitable rigid material. As indicated above, the master pattern is generated based on design parameters that reflect a composite of the measurements taken from hundreds or more of live models for a specific shoe size, e.g. US size 6. The master pattern can be manufactured via an appropriate means including but not limited to: three-dimensional printing, molding, thermoforming, and/or vacuum casting.
After the master pattern has been fabricated, a mold is poured and cured (S706) about the master pattern. After curing, the mold is cut into at least two interfacing pieces allowing removal of the master pattern and access to the mold itself. In certain examples, the material of the mold comprises a silicone or other appropriate mold material (or combination of materials). In certain examples, the silicone mold has a Shore A Hardness (±4) of 42, a Tear Resistance (ASTM D624) of 120±20 ppi and a Tensile Strength (ASTM D412) of 600±50 psi.
The pseudo skeletal structure 210 is then suspended, or otherwise placed, within the mold (S708) with each element of the pseudo skeletal structure 210 being placed independently of the others through use of small diameter placement rods that are secured to each of the elements. Note that none of the elements of the pseudo skeletal structure 210 is in contact with another element of the pseudo skeletal structure 210. See
Once all elements of the pseudo skeletal structure 212 are in place within the mold and the mold has been sealed, while allowing for appropriate venting, a urethane, or other suitable materials or combination of materials, is injected into the mold (S710). In certain examples, the urethane is a two-part urethane. In certain examples, the urethane is a polyurethane elastomer having a Shore A Hardness (D2240) of 15±5, a Tear Strength (ASTM D624) of 55 pli, and a Tensile Strength (ASTM D412) of 455.
Finally, when the urethane is cured, the mold is re-opened and a completed shoe-fit testing device 200 can be removed from the mold (S712) whereby any gates and vents are cleaned from the shoe-fit testing device 200. Further, any molding material covering the flex inserts 224 is removed along with the flex inserts 224 themselves to leave behind the open flex channels 227 (see
The finished shoe-fit testing device 200, which is fabricated to a specific size, is suitable to test a shoe of a corresponding size. Specifically, the shoe-fit testing device 200 can be inserted into a shoe wherein the ability to insert and withdraw the shoe-fit testing device 200 can be observed and/or measured, and pressure points, if any, of the shoe upon the shoe-fit testing device 200 can be assessed knowing that the flexure of shoe-fit testing device 200 approximates that of the human foot without requiring the presence of a live foot model. Specifically, the shoe-fit testing device 200 has the ability to contract at least at its instep girth and/or its joint girth when squeezed to be inserted into a shoe. In certain examples, any of the various measurements described herein, e.g. joint and instep girth, are taken of the shoe itself with the shoe-fit testing device inserted within the shoe. In certain examples, measurements and/or observations for adequate toe room, tightness, heel slip, and the ease with which to insert and/or remove the shoe-fit testing device 200 can be performed.
The description and illustration of one or more examples provided in this application are not intended to limit or restrict the scope as claimed in any way. The aspects, examples, and details provided in this application are considered sufficient to convey possession and enable others to make and use the best mode. Implementations should not be construed as being limited to any aspect, example, or detail provided in this application. Regardless of whether shown and described in combination or separately, the various features (both structural and methodological) are intended to be selectively included or omitted to produce an example with a particular set of features. Having been provided with the description and illustration of the present application, one skilled in the art may envision variations, modifications, and alternate examples falling within the spirit of the broader aspects of the general inventive concept embodied in this application that do not depart from the broader scope.
