TITLE
Insert for an article of footwear
CROSS-REFERENCE TO RELATED APPLICATIONS Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE OF A "MICROFICHE APPENDIX" Not applicable.
FIELD OF THE INVENTION
The present invention relates to inserts for footwear to cushion and support a region of a foot.
BACKGROUND
The present invention is an improvement over known cushioning elements or inserts used in footwear to cushion a wearer's foot by storing and absorbing impact energy. Typical prior art inserts include bladders enclosing material that is pressurized, such as to a pressure greater than
the ambient pressure surrounding the cushioning element. Representative materials include gases, viscous liquids, and gels.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided an improved and pliable insert for an article of footwear including: a compressible core; the compressible core having a top surface, a bottom surface and a peripheral surface; and a casing for surrounding the compressible core, the casing fitting snuggly adjacent the top surface and the bottom surface and being spaced from at least a portion of the peripheral surface; the casing having a first compressibility when fitting snuggly adjacent the top and bottom surfaces and a second compressibility when spaced from the peripheral surface, the second compressibility being greater than the first compressibility. When pressed, the insert satisfies a desired "thumb test" of elasticity.
In accordance with a second aspect of the present invention, the second compressibility is approximately 10-40% greater than said first compressibility.
In accordance with a third aspect of the present invention, the second compressibility is at least 10% greater than said first compressibility.
In accordance with a fourth aspect of the present invention, the second compressibility is at least 20% greater than said first compressibility.
Additional aspects, features and advantages of exemplary embodiments of the present invention will become better understood with regard to the following description in connection with the accompanying drawing(s).
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-9 depict exemplary embodiments of the present invention in accordance with the teachings presented herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It should be apparent to those skilled in the art that the described embodiments of the present invention provided herein are illustrative only and not limiting, having been presented by way of example only. All features disclosed herein, including dimensions, materials, etc may be replaced by alternative features serving the same or similar purpose, unless expressly stated otherwise. Therefore, numerous other embodiments of the modifications thereof are contemplated as falling within the scope of the present invention as defined herein and equivalents thereto.
INTRODUCTION
The present invention is an improved insert for an article of footwear. The insert comprises: a compressible core; the compressible core having a top surface, a bottom surface and a peripheral surface; and a casing for surrounding the compressible core, the casing fitting snuggly adjacent the top surface and the bottom surface and being spaced from at least a portion of the peripheral surface; the casing having a first compressibility when fitting snuggly adjacent the top and bottom surfaces and a second compressibility when spaced from the peripheral surface, the second compressibility being greater than the first compressibility. The second
compressibility is approximately 10-40% greater than the first compressibility, with at least 10% greater or at least 20% greater than the first compressibility being preferred. So constructed, if portions of the insert having the second compressibility are exposed along the sides of the article of footwear, a customer, pressing the exposed portions will readily appreciate the insert's cushioning effect.
The internal compressible element may comprise a single unitary member having either a plurality of holes, ridges or none at all to best suit the effect on the foot of the user and to minimize weight where necessary. For decorative effect, the internal compressible element may comprise a plurality of circular/oval/ formations/patterns positioned along the outer edges. Each of the plurality of formations/patterns may still further be enhanced with color for visual impact.
The insert may comprise a variety of shapes to optimally flex with the bend lines of the foot. As shown in the drawings however, one insert is preferably of trapezoidal shape and a second insert is preferably of kidney-like shape.
The material for the casing may be selected from the following exemplary materials bearing in mind that other suitable materials are also contemplated: thermoplastic polyurethane (TPU), polyester-TPU, polyether-TPU, polyester-polyether TPU, polyvinylchloride, polyester, thermo plastic ethyl vinyl acetate, styrene butadiene styrene, TPU blends including natural and synthetic rubbers. The material for the internal compressible element may be selected from the following exemplary materials bearing in mind that other suitable materials are also contemplated: ethyl vinyl acetate co-polymer, thermo-set polyether and poly-ester urethane, ethyl vinyl vcetate co-polymer blends including isoprene rubber, poly-olefins, natural and synthetic rubbers. FIG. 9 depicts a preferred combination of materials.
FIGURE 1
FIG. 1 depicts exemplary first and second inserts in accordance with the present invention for use in an article of footwear for cushioning and supporting a region of a foot. Each one of the first and second inserts comprises a casing that encapsulates an inner compressible element. Shown are several views of the casing, casing including the compressible element and the compressible element.
FIGURE 2
FIG. 2 depicts alternative first and second inserts in accordance with the present invention for use in an article of footwear for cushioning and supporting a region of a foot. Each one of the first and second inserts comprises a casing that encapsulates an inner compressible element. As shown, the compressible element includes a plurality of ridges and a plurality of circular patterns positioned along the sides of the element. Each of the plurality of patterns may still be further enhanced with color for visual impact.
FIGURE 3
FIG. 3 depicts additional alternative first and second inserts in accordance with the present invention for use in an article of footwear for cushioning and supporting a region of a foot. Each one of the first and second inserts comprises a casing that encapsulates an inner compressible element. The internal compressible element may compπse a single unitary member having a plurality of holes to best suit the effect on the foot of the user.
FIGURE 4
FIG. 3 depicts a further alternative first and second inserts in accordance with the present invention for use in an article of footwear for cushioning and supporting a region of a foot. Each one of the first and second cushions comprises a gas- or air-filled casing having at least one pinch/locator mark. The cushions may include stubs, (as shown), which can be sealed to prevent the cushion from releasing the gas and/or emitting noises each time a step is taken as the gas is sucked in and blown out through the stub. Sealing the stubs also prevents fluids/debris/other objects that may be present on a walking surface from entering the cushion
FIGURES 5 - 8
FIG. 5 depicts bottom, heel and toe views of a sole of an article of footwear including inserts constructed in accordance with the present invention. As shown, the heel portion of the sole includes first and second chambers, each housing an insert. The chambers move, such as by flexing, with respect to one another. At least a portion of the inserts may be exposed to touch e.g., along the medial and lateral sides of the article of footwear.
FIG. 6 depicts top, medial and lateral views of FIG. 5. FIG. 7 depicts sectional views along lines A-A1, B-B1 and C-C1 of FIG. 5. FIG. 8 depicts sectional views taken along lines D- D1 - L-L1 of FIG. 5. FIG. 8 also shows a reduced scale 0.5:1 of the bottom, medial and lateral views of the sole having the inserts.
MANUFACTURING OPTIONS
In addition to blow molding, various other conventional techniques, e.g., vacuum molding, extruded tube molding, injection molding, etc, may be used to form the insert of the present invention. With respect to blow molding for example, standard blow molding equipment may be used in which a tube of resin is dropped from a die and mandrel. The compressible element or foam is placed on one end of a pin. The other end of the pin is inserted into the blow nozzle of the blow molding equipment. A tube of parasin is dropped over the foam/pin. Mold plates close around foam and parasin. Air is blown up and around foam and pin, pushing the parsin into the cavities of the mold. Component is pulled from the mold. Pin is removed. Components are die cut from flashing. Blow holes in blow molded plastic are high frequency welded shut.
Regarding vacuum molding, the casing is created with two pieces. The first piece is vacuum formed into a shell. The foam is placed in the shell (centered on locator pins to ensure there is an air gap, e.g., a 1-3 mm air gap). A second piece of casing (un-molded film) is placed on top of the first piece and is welded to the first piece of molded casing using a high frequency weld. Two vacuum formed pieces can also be welded together with the insert inside.
With respect to extruded tube molding, an extruded tube is formed. The insert is placed inside the tube and the edges of the tube are high frequency welded.
Regarding injection molding, the casing is created with two pieces. The first piece is injection molded into a shell. The foam is placed in the shell (centered on locator pins to ensure there's a 1-3 mm air gap). A second piece of casing (un-molded film) is placed on top of the first piece and is welded to the first piece of molded casing using a high frequency weld. Two injection molded pieces can also be welded together with the insert inside.
With all of the above options, the insert is formed so that it is smaller than the casing (creating a gap, e.g., 1-3 mm air gap).