Sole element

Abstract

This invention concerns a sole element for a cleated article of footwear, in particular for a football shoe. The sole element includes a composite element with an anisotropic bending property. The sole element further includes a polymer element, and the polymer element at least partially covers the composite element of the sole element.

Claims

1. A sole element for a cleated article of footwear, comprising: a composite element with an anisotropic bending property; and a polymer element having a top surface and a bottom surface that is dorsally curved away from a portion corresponding to a ball of a wearer's foot to a toe end such that the bottom surface is convex in a ground facing direction, wherein the polymer element is over-injected onto the composite element and that at least partially covers the composite element, at least one opening formed in the bottom surface of the polymer element configured to expose at least a part of the composite element, and wherein the sole element has a first bending stiffness in a first direction and a second bending stiffness that is lower than the first bending stiffness in a second direction, opposite the first direction.

2. The sole element of claim 1, wherein the first direction comprises an upward direction away from a ground surface and the second direction comprises a downward direction toward the ground surface.

3. The sole element of claim 1, wherein the polymer element comprises a polyamide.

4. The sole element of claim 1, comprising a forefoot region, a midfoot region, and a heel region, wherein the composite element is arranged only in the forefoot region.

5. A shoe comprising: the sole element of claim 1; and an upper attached to the sole element.

6. The sole element according to claim 1, wherein the polymer element comprises at least one stud dome for carrying a stud tip, wherein the stud dome and the stud tip do not overlap with the composite element.

7. The sole element according to claim 1, wherein the polymer element is over-injected over the composite element.

8. The sole element according to claim 1, further comprising an insole board that is attached to the polymer element.

9. The sole element according to claim 1, wherein the sole element and/or the composite element comprise a non-linear bending stiffness.

10. The sole element according to claim 1, wherein a rear portion of the composite element is wider than a front portion of the composite element.

11. The sole element according to claim 1, wherein the composite element further comprises a slit, wherein the slit is arranged substantially along a longitudinal direction of the sole element.

12. A shoe comprising a sole element according to claim 1.

Description

SHORT DESCRIPTION OF THE FIGURES

(1) In the following, exemplary embodiments of the invention are described with reference to the figures.

(2) FIG. 1 shows a bottom view of an exemplary sole element according to the present invention.

(3) FIG. 2 shows a top view of an exemplary sole element according to the present invention.

(4) FIG. 3 shows an exemplary lateral view of an exemplary sole element according to the present invention.

(5) FIG. 4A shows an exemplary bottom view of an exemplary sole element according to the present invention.

(6) FIG. 4B shows an exemplary bottom view of an exemplary sole element according to the present invention.

(7) FIG. 5 shows an exemplary torque measurement for a sole element with and without a composite element.

(8) FIG. 6 schematically shows an exemplary torque measurement similar to FIG. 5 to visualize the non-linear bending stiffness of a sole element or a composite element.

(9) FIG. 7 illustrates an anisotropic bending property of a sole element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(10) In the following, some embodiments of the invention are described in detail. It is to be understood that these exemplary embodiments can be modified in a number of ways and combined with each other whenever compatible and that certain features may be omitted in so far as they appear dispensable.

(11) FIG. 1 shows a bottom view of an exemplary sole element 10 according to the present invention. FIG. 2 shows a top view of the exemplary sole element 10. FIG. 3 shows a lateral view of the exemplary sole element 10.

(12) Herein, the ground-facing surface of the sole element 10 may be considered as the bottom surface, and the opposite surface of the sole element 10 that is used to be connected to a shoe upper may be considered as the top surface, which is shown in FIG. 2.

(13) The sole element 10 is for an article of footwear and includes: a composite element 11 with anisotropic bending properties, and a polymer element 12 that at least partially covers the composite element 11.

(14) The composite element 11 with anisotropic bending properties has a lower bending stiffness in one direction than in another direction. In this example, the composite element 11 has a first bending stiffness for bending upwards in a toe region of the sole element and a second bending stiffness for bending downwards in the toe region of the sole element 10, wherein the second bending stiffness is lower than the first bending stiffness. Thus, the composite element 11 bends more easily downwards than upwards in the toe region of the sole element 10. Therefore, the sole element 10 more easily allows a plantar flexion of the foot than a dorsiflexion of the foot.

(15) The composite element 11 may include carbon fiber and has a thickness of approximately 1.3 mm.

(16) The polymer element 12 may include any thermoplastic material suitable for over-injection manufacture, for example polyamide 12. The polymer element 12 is over-injected to cover at least partially the composite element 11 on the bottom surface of the sole element 10, i.e. the ground-facing surface as shown in FIG. 1.

(17) The exemplary polymer element 12 comprises two stud domes 53a for a lateral over-injected stud, three stud domes 53b for a lateral screwable stud, two stud domes 54a for a medial over-injected stud, three stud domes 54b for a medial screwable stud, and a central stud dome for carrying a central stud tip.

(18) The combination of a stud dome and a stud tip is referred to as a stud. Two stud tips 51a are integrally connected with the two stud domes 53a for a lateral over-injected stud thus forming a lateral over-injected stud 55a. Lateral screwable stud tips are not shown but are to be screwed into the three stud domes 53b for a lateral screwable stud for forming a lateral screwable stud 53b. Two medial over-injected stud tips 52a are integrally connected with the three stud domes 54a for a medial over-injected stud thus forming a medial over-injected stud 56a. Medial screwable stud tips are not shown but are to be screwed into the three stud domes 54b for a medial screwable stud 56b. A central stud tip 15b is integrally connected with a central stud dome 15a forming a central stud 16. In an embodiment the stud tips 51a, 52a, 15b may be inserted in a first step into recesses of a mold and then the stud domes 53a, 53b, 54b, 15a and the polymer element 12 are injected onto the stud tips 51a, 52a, 15b.

(19) This arrangement is best shown in FIG. 3. The stud domes are manufactured in one-piece with other parts of the polymer element 12 and thus include the same polymer material as the polymer element 12, e.g., polyamide 12. The stud tips can be made of, for example, thermoplastic polyurethane (TPU).

(20) The composite element 11 is arranged only in a forefoot region 19 of the sole element 10. The forefoot region 19 is located in a front portion of the sole element 10 which is larger than and not identical to the forefoot region 19. The front portion of the sole element 10 may be closer to a toe region, opposing a rear portion of the sole element 10 which may be closer to a heel region.

(21) The composite element 11 is arranged in the front portion of the sole element 10 in a way that the composite element 11 substantially does not overlap with any of the stud domes 53a, 53b, 54a, 54b, or 15a of the polymer element 12. Therefore, the studs 55a, 55b, 56a, 56b, and 16 in the respective stud domes 53a, 53b, 54a, 54b, or 15a in the front portion do not overlap with the composite element 11 either. As shown in FIG. 1, said in other words, the studs 55a, 55b, 56a, 56b, and 16 are not arranged above the composite element 11 when one looks at the sole element 10 from the ground-facing surface.

(22) Alternatively, it is also possible that the composite element 11 is arranged in the front portion of the sole element 10 in a way that the composite element 11 substantially does not overlap with any of the stud tips 51a, 52a, 15b, but at least one of the stud domes 53a, 53b, 54a, 54b, or 15a of the polymer element 12 is slightly overlapping with the composite element 11 in its outer periphery.

(23) The slit 13 is arranged substantially along a longitudinal direction of the sole element 10 and extends in the longitudinal direction from a front end of the composite element 11 to a rear end of the composite element 11. This way, for example, the big toe may have a different flexion than the other toes.

(24) As shown in FIG. 1, the slit 13 is arranged in the toe region of the sole element 10 in between the first two lateral stud domes 53b and the first two medial stud domes 54b. It should be noted that the slit 13 extends to the location of the central stud 16 such that the central stud 16 substantially does not overlap with the composite element 11 as mentioned above.

(25) The slit 13 may be arranged in another area of the composite element 11. However, it is preferred that the slit is not arranged in the metatarsal region of the sole element in order to guarantee enough support and comfort to the feet of a wearer. Alternatively, the composite element 11 might include more than one slit 13. For example, two substantially parallel slits might be used. Other arrangements of more than one slit may be possible.

(26) Further, the slit 13 may serve as an injection gate during manufacturing.

(27) In this example, the bottom surface of the composite element 11 (i.e., the ground-facing surface as shown in FIG. 1) is covered by the polymer element 12 roughly by a 50-65% of the surface area. On the contrary, the top surface of the composite element 11 (shown in FIG. 2) is essentially not covered by the polymer element 12. The top surface of the composite element 11 is essentially smooth. In other embodiments, the composite element 11 may be fully encapsulated by the polymer element 12 by any preferred percentage of the surface area.

(28) As shown in FIG. 1, the polymer element 12 includes two openings 14 to expose a part of the composite element 11 on a bottom side of the polymer element 12. The bottom side is the ground-facing side of the polymer element 12. During production, the composite element 11 is fixed in a mold at a resting point while the polymer element 12 is injected over the composite element 11 thus forming the openings 14. Alternatively, the polymer element can include more or less than two openings 14.

(29) On the top side of the sole element 10 as shown in FIG. 2, the composite element 11 is arranged substantially at the middle of the front portion of the sole element 10 and surrounded by the polymer element 12. The polymer element 12 includes a first bonding margin at its periphery for attaching a shoe upper to the sole element 10. The first bonding margin is preferably with a width of 8 mm to 10 mm at the periphery to provide a strong bonding of the sole element 10 to a shoe upper.

(30) A contour of the composite element 11 is essentially smooth. The composite element 11 is essentially devoid of any sharp features with a width of less than 2 mm, wherein a width is measured between two parallel and opposite portions of the composite element 11. Note that the slit 13 has a width w but does not provide any sharp features. The composite element 11 has a smooth contour on either side of the slit 13 with a width greater than width w.

(31) In other embodiments, the sole element 10 may further include an insole board that is attached to the polymer element 12. The insole board may provide further stiffness to the sole element 10. Due to the excellent bonding properties of the polymer, such as a polyamide, the insole board bonds very well to the polymer element 12.

(32) The insole board may be arranged as a forefoot insole board. The forefoot insole board and the first forefoot region 19 may partially or completely overlap. Thus, it is possible to further tune the bending stiffness of the sole element.

(33) The insole board may include polyether block amide or thermoplastic polyurethane. These materials have good bonding properties and durability.

(34) The sole element 10 may include a plurality of ribs 17 in a midfoot region 27 on the bottom surface to advantageously increase the stiffness of the midfoot region 27 without increasing the weight of the sole element 10.

(35) The sole element 10 may include a lattice structure 18 in a midfoot region 27, which further provides improved stiffness while allowing for some torsional movement of the front and rear portions of the sole element 10 relative to each other. Moreover, the weight of the sole element 10 is reduced compared to a more solid construction.

(36) The ribs 17 and lattice structure 18 in combination with the usage of the polyamide material of the polymer element 12 create a very light sole element 10 which has the right stiffness on the other hand. By tuning the ribs 17 and lattice structure 18, the stiffness and weight of the sole element 10 can be adjusted as desired.

(37) The top surface of the sole element 10 is essentially flat and essentially smooth, i.e. essentially not textured, as shown on FIG. 2.

(38) A second bonding margin 41 is formed around the openings 14 of at least 5 mm and overlaps between the polymer element 12 and the composite element 11 in order to ensure good bonding strength.

(39) FIGS. 4A and 4B show two exemplary bottom views of exemplary sole elements 10a, 10b similar to the one shown in FIGS. 1-3. The composite element 11a of sole element 10a is longer than the composite element 11b of sole element 10b. Sole element 10a does not include any screwable studs. Sole element 10b includes stud domes 53b and 54b for screwable studs, whereas the corresponding stud domes 53a and 54a of sole element 10a are for over-injected studs. Sole element 10a is configured for use on hard ground while sole element 10b is for use on soft ground.

(40) FIG. 5 shows an exemplary torque measurement for a sole element with and without a composite element. A vertical axis 63 shows the torque required to bend a sole element by a certain angle shown on the horizontal axis 64 about bending axis 59 shown in FIG. 3. Two curves are shown. Curve 61 shows the required torque for bending the sole element about the bending axis 59 without a composite element. Curve 62 shows the required torque for bending the sole element about the bending axis 59 with a composite element. A higher required torque for a given angle indicates a higher bending stiffness. Hence, the bending stiffness is increased by the presence of the composite element.

(41) FIG. 6 schematically illustrates an exemplary torque measurement similar to the one shown in FIG. 5 to visualize the non-linear bending stiffness of a sole element or a composite element. A vertical axis 63 shows the torque required to bend a sole element by a certain angle shown on the horizontal axis 64 about a bending axis, e.g. bending axis 59 shown in FIG. 3. For the example schematically illustrated in FIG. 6, a wedge element was placed under the heel portion of the sole prior to testing. The wedge has an angle of 15?. That is the reason why the horizontal axis 64 in FIG. 6 starts at 15? as opposed to 0?; 15? is relative to horizontal, in which 0? would equate to the rear portion of the sole being horizontal. The wedge is placed under the heel portion to create a normalized starting position, which is necessary because the sole element 10 is not perfectly horizontal from toe-to-heel in an unloaded condition. In other words, it is necessary to normalize the plates with the help of the wedge element because different sole elements have a different toe lift in an unloaded condition. Additionally, 15? is a more realistic starting position considering the outsole end use case. As can be seen in FIG. 6, the curve has a non-linear bending stiffness. In area I, the bending stiffness is less than that of the bending stiffness after 450 in area II. That means in area I (0-45 degree) the sole element or composite element has a first stiffness, and in area II it has a second stiffness (45 degrees and upwards).

(42) FIG. 7 schematically illustrates an anisotropic bending property of a sole element or a composite element. A vertical axis 63 shows the torque required to bend a sole element by a certain angle shown on the horizontal axis 64 about a bending axis, e.g., bending axis 59 shown in FIG. 3. Two curves are shown. Curve 71 shows the required torque for bending the sole element about the bending axis 59 for negative angles 64b. Curve 72 shows the required torque for bending the sole element about the bending axis 59 for positive angles 64a. As can be seen, for a given magnitude of the angle, the required torque is much higher for negative angles 64b than for positive angles 64a. Thus, a bending property, in this case a bending stiffness of the sole element is anisotropic. A positive angle may correspond to downwards bending or plantar flexion of the foot, while a negative angle may correspond to upwards bending or dorsiflexion of the foot.

(43) Some embodiments described herein relate to a sole element for a cleated article of footwear, in particular for a football shoe, that comprising a composite element; a polymer element that at least partially covers the composite element, and wherein the polymer element comprises at least one opening on its ground-facing side to expose at least a part of the composite element.

(44) Some embodiments described herein relate to a sole element for a cleated article of footwear, in particular for a football shoe, comprising a composite element; a polymer element that at least partially covers the composite element, wherein the polymer element comprises at least one stud dome for carrying a stud tip, and wherein the stud dome and/or the stud tip substantially does not overlap with the composite element.

(45) In some embodiments, the composite element comprises an anisotropic bending property.

(46) In some embodiments, the composite element is arranged only in a forefoot region of the sole element.

(47) In some embodiments, the polymer element comprises a polyamide.

(48) In some embodiments, a top surface of the sole element is essentially flat.

(49) In some embodiments, a contour of the composite element is essentially smooth.

(50) In some embodiments, the sole element comprises an insole board that is attached to the polymer element, and the insole board is a forefoot insole board.

(51) Some embodiments described herein relate to a shoe comprising a sole element as described herein, and further comprising an upper, wherein a heel region of the upper is attached to the sole element by sewing.

(52) Some embodiments described herein relate to a method of producing a sole element for an article of footwear, comprising providing a composite element with an anisotropic bending property; and over-injecting a polymer element on the composite element to at least partially cover the composite element.

(53) Some embodiments described herein relate to a method of producing a sole element for an article of footwear, comprising providing a composite element; over-injecting a polymer element on the composite element to at least partially cover the composite element; and forming at least one stud dome on the polymer element for carrying a stud tip, wherein the stud dome and/or the stud tip does not overlap with the composite element.

(54) In some embodiments, the method further comprises forming at least one opening in the polymer element to expose a part of the composite element.

(55) In some embodiments, the method further comprises arranging the composite element only in a forefoot region of the sole element.

(56) In some embodiments, the polymer element comprises a polyamide.

(57) In some embodiments, over-injecting comprises forming an essentially flat top surface of the sole element.

(58) In some embodiments, the method further comprises forming an essentially smooth contour of the composite element.

(59) In some embodiments, a rear portion of the composite element is wider than a front portion of the composite element.

(60) In some embodiments, the method further comprises providing an upper and attaching a heel region of the upper to the sole element by sewing.

REFERENCE SIGNS

(61) 10: sole element 11: composite element 12: polymer element 13: slit 14: opening 15a: central stud dome 15b: central stud tip 16: central stud 17: ribs 18: lattice structure 19: forefoot region 26: stud dome for central stud 27: midfoot region 30: shoe 31: shoe upper 41: second bonding margin 42: distance from sidewall 51a: lateral over-injected stud tip 52a: medial over-injected stud tip 53a: stud dome for lateral over-injected stud 53b: stud dome for lateral screwable stud 54a: stud dome for medial over-injected stud 54b: stud dome for medial screwable stud 55a: lateral over-injected stud 55b: lateral screwable stud 56a: medial over-injected stud 56b: medial screwable stud 59: bending axis 61: torque without composite element 62: torque with composite element 63: vertical axis 64: horizontal axis 64a: positive angles 64b: negative angles 71: torque for negative angles 72: torque for positive angles