EP0123550A1

EP0123550A1 - Cleated athletic shoe with one-way flex outsole

Info

Publication number: EP0123550A1
Application number: EP84302736A
Authority: EP
Inventors: Bruce J. Kilgore
Original assignee: Nike International Ltd
Current assignee: Nike International Ltd
Priority date: 1983-04-22
Filing date: 1984-04-24
Publication date: 1984-10-31
Also published as: KR840008266A; JPS6034401A

Abstract

A cleated athletic shoe (10) is disclosed, A plurality of abutting elements (34, 36, 38) extend downward from an outsole layer (22) to prevent downward flexing of the ball and toe area (32,26) of the outsole layer below its normal unstressed position, while at the same time permitting further upward flexing in order to alleviate physical ailments known as turf toe in a soccer player.

Description

TECHNICAL FIELD

The present invention relates to athletic shoes, and in particular, to a cleated athletic shoe wherein the outsole includes a structure which prevents downward flexing of the ball area of the outsole.

BACKGROUND OF THE INVENTION

The modern athletic shoe is a combination of many elements which have specific functions, all of which must work together for the support and protection of the foot during an athletic event. The design of an athletic shoe has become a highly refined science. No longer do athletes and participants in sports events use a pair of "sneakers" for all sports. Athletic shoes today are as varied in design and purpose as are the rules for the sports in which the shoes are worn. Tennis shoes, raequetball shoes, basketball shoes, running shoes, baseball shoes, football shoes, soccer shoes, weight lifting shoes, etc., are all designed to be used in very specific, and very different, ways. They are also designed to provide a unique and specific combination of traction, support, and protection to enhance athletic performance. Not only are shoes designed for specific sports, they are also designed to meet the specific characteristics of the user. For example, athletic shoes are designed differently for heavier persons than for lighter persons. Some shoes are designed to correct physical problems, such as over-pronation, while others include devices, such as ankle supports, to prevent physical problems from developing.
One type of athletic shoe is a cleated athletic shoe having a plurality of relatively large cleats located in the toe, ball and heel areas of the outsole. The cleats are used to increase traction in field sports wherein direction is changed frequently or large amounts of power must rapidly be passed from the foot and leg to the remainder of the body, such as in football and soccer. The cleats may be removable from the base of the outsole or may be formed integral with it. The cleats typically have an outer surface formed of a hard rubber or thermoplastic material. Examples of prior art cleated athletic shoes are found in U.S. Patent No. 2,258,734 issued to Brady on October 14, 1941 and U.S. Patent No. 2,330,458 issued to Tubbs on September 28, 1943. In the Brady patent, the cleats are removably attached to thin metal or plastic plates within the outsole. The shank area of the outsole has a plurality of slits rendering it highly flexible in one direction of bending, without noticeably affecting its flexibility in the other direction. The Tubbs patent also discloses removable cleats attached to metal plates embedded in the outsole. The cleats in the heel area of the shoe disclosed in the Tubbs patent are arranged so that the cleat on the lateral side of the outsole is forward of the cleat on the medial side of the outsole.
Current cleated athletic shoes, which are specifically designed for soccer, typically have an outsole formed of a thermoplastic material such as nylon or polyurethane wherein cleats are either integrally or removably attached to reinforced areas of the outsole. An upper of leather or a synthetic material such as nylon or vinyl is attached to the thermoplastic outsole. The outsole typically has a built in toe spring, i.e., an upward bend of the outsole in the ball and toe area of the foot, which aids the athlete's locomotion.
One commonly occurring physical problem in field sports where feet are placed under high and sudden stresses is turf toe. Turf toe is used as a generic term to refer to numerous types of injuries to an athlete's toes. Turf toe can manifest itself in a number of ways such as inflamation or pain in the toes, stress fractures in the bones of the toe or tendonitus in the ligaments of the toes. Just as turf toe can manifest itself in numerous types of injuries, turf toe also can result from numerous causes. For example, in football, it is believed that turf toe is caused by the high stress which football linemen place on their feet, particularly their toes, as they rapidly move upward from a down lineman's stance. In soccer, it is believe that turf toe is caused by the hyperextension or backward flexing of the toes when the foot hits the ground, a ball or soccer player during kicking motions by the player. It is believed that athletic shoes to date have not been specifically designed to alleviate turf toe, particularly in soccer shoes. The present invention was particularly designed to alleviate turf toe problems in soccer shoes.

SUMMARY OF THE INVENTION

The present invention is directed to an outsole for use in an athletic shoe, and to an athletic shoe per se. The outsole includes an outsole layer formed of a material which extends along the bottom of the shoe and has a lower side which faces the ground and an upper side which is attached to the upper. The layer of material is flexible about its major surface. A means is connected to the outsole layer for preventing the downward flexing motion of the front end of the outsole layer while permitting the upward flexing thereof.
In a preferred embodiment, the present invention is directed to a cleated athletic shoe wherein a sole is attached to an upper. The sole includes an outsole layer which has a heel area, an arch area, a ball area and a toe area, corresponding to the general areas of the foot; and is formed of a thermoplastic material flexible about its major surface. The ball and toe areas of the outsole layer are bent upward with respect to the arch and heel areas in the normal unstressed condition of the shoe, i.e., have a built in spring.
A plurality of abutting elements extend downward from the outsole layer and function as a means for preventing the downward bending of the ball and toe area of the outsole layer below the upward bent, unstressed position, while permitting further upward bending motion. The abutting elements include a forwardmost element, a rearwardmost element and plurality of intermediate elements located between the forwardmost and rearwardmost elements. A transverse slot extends between adjacent abutting elements to separate the adjacent elements from one another and to form a contact surface on each abutting element which extends upward from the lower surface of each element. Facing contact surfaces of adjacent abutting elements are in contact with one another in the normal unstressed position of the outsole, and the abutting elements have a thickness and hardness sufficient to prevent the downward bending motion of the outsole layer from its normal unstressed position.
A plurality of cleats extend downward from the outsole layer. The cleats include a first pair of cleats connected to the forwardmost element, a second pair of cleats connected to the rearwardmost element and a third pair of cleats in the heel area.
A reinforcement element extends downward from and transversely across the heel area of the outsole layer. The heel reinforcement element extends at an angle backward from the lateral side of the outsole to its medial side. The pair of cleats in the heel area are connected to the heel reinforcement element.
Hyperextension of the toes of a soccer athletic during ball kicking motions is prevented because the abutting elements extending downward from the outsole layer do not permit the ball and toe area of outsole layer to flex downward from its upward bent toe spring position. While hyperextension is prevented, normal upward bending motion of the ball and toe of the foot is premitted because of the transverse slits between adjacent toe abutting elements. The use of the angled heel reinforcement enhances the stability of the soccer athlete, particularly during changes of direction foot motions. In change of direction of foot motions, an athlete tipically abducts, i.e., points the toes of the foot outward. In the abducted position the angled heel reinforcement element aligns parallel with the forward position of the body, thereby enhancing the stability of the athlete's foot plant.
Various advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and objects obtained by its use, reference should be had to the drawings which form a further part hereof, and to the accompanying descriptive matter in which there is illustrated and describe a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side elevational view of a cleated athletic shoe in accordance with the present invention;
Figure 2 is a bottom plan view of the outsole of the shoe of Figure 1;
Figure, 3 is a sectional view taken generally along line 3-3 of Figure 2;
Figure 3a is a sectional view similar to Figure 3 illustrating the ball area of the outsole in an upwardly flexed condition;
Figure 4 is a sectional view taken generally along line 4-4 of Figure 2;
Figure 5 is a sectional view taken generally along line 5-5 of Figure 2; and
Figure 6 is a sectional view taken generally along line 6-6 of Figure 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring the drawings, wherein like numerals indicate like elements, there is shown a cleated athletic shoe in accordance with the present invention, designated generally as 10. Shoe 10 includes a shoe upper 12 to which an outsole 14 is attached. Upper 12 can be made of any suitable material such as nylon, vinyl or leather. In one preferred form, upper 12 is made of a fine-grade leather lined with a synthetic material. Upper 12 includes a conventional counter 16 and a reinforced throat 18 provided with laceholes 20.
Outsole 14 includes an outsole layer 22 formed of a flexible thermoplastic material. In a preferred form, the thermoplastic material of outsole layer 22 is nylon having a hardness of approximately 80-85 durometer on the Shore A scale and a thickness between approximately 100 and 275 thousandths of an ineh. Outsole layer 22 is flexible about its major surface extending along the base of sole ₁4 so as to permit normal bending motion of the foot during walking and running. Outsole layer 22 has a bottom side which faces the ground and a top side which is attached to an insole and the upper by any suitable means such as gluing. For additional sturdiness, outsole layer 22 can also be riveted to the insole and upper by rivets 24 in the toe and heel area. Outsole layer 22 extends along the entire bottom of shoe 10 and, for reference purposes, can be divided into a heel area rearward of line L_l, an arch area between lines L₁ and L₂, a ball area between lines L₂ and L₃, and a toe area forward of line L₃. Lines L₁, L₂ and L₃ illustrate approximate division lines of the heel area 26, arch area 28, ball area 30 and toe area 32 which refer to the heel, arch, ball and toe portions of a wearer's foot. As best seen in Figure 1, outsole layer 22 has a built-in toe spring, i.e., an upward bend of the ball and toe area 30, 32 of outsole 22, illustrated as a distance T, above the ground G. The amount of toe spring can be varied, and is incorporated into outsole 22 to assist the athlete in attaining a ready position on the ball of the foot.
Outsole 22 also includes a plurality of corrugations 34 in ball area 30 to increase the flexibility of outsole layer 22 in this area. Outsole layer 22 is shown in Figure 1 in its normal rest position wherein outsole layer is unstressed and an athlete would be merely standing at rest.
A structure is provided for preventing the outsole layer 22 from bending further downward from its unstressed position, which in the preferred embodiment is an upwardly toe spring curved position, such as illustrated in Figure 1. This structure includes a plurality of abutting elements extending downward from the outsole layer 22 in ball area 30.
The abutting elements include a forwardmost element 34, a rearwardmost element 36 and a plurality of intermediate elements 38. The elements 34, 36 and 38 are separated from one another by slots 40. Slots 40 extend upward from the lower surface of elements 34, 36 and 38 to define contact surfaces 42 on the respective elements. Slots 40 are angled forward from the lateral side to the medial side of outer layer 22. In the normal unstressed position of outsole layer 22, contact surfaces 42 are in complete contact with one another as shown in Figures 2, 3 and 4. As the ball and toe area of outsole layer 22 are bent further upward, as during normal running and walking motions, the contact surfaces 42 move away from one another, as shown in Figure 3a. However, further downward bending of motion of the ball and toe areas 30, 32 is prevented by elements 34, 36 and 38. The prevention of the downward flexing motion is from the normal unstressed position of outsole layer 22, and is assured, since the contact surfaces 42 are in full contact with one another in this position, and the elements 34, 36 and 38 are of sufficient thickness and hardness to assure that the bending motion does not occur. Preferably, elements 34, 36 and 38 are made of a harder material than outsole layer 22. In fact, it is preferred that forwardmost and rearwardmost elements 34, 36 be harder than the intermediate elements 38. For example, forwardmost and rearwardmost elements 34, 36 can be formed of a densely packed fiberglass reinforced nylon having a Shore A durometer hardness of about 95, while intermediate elements 38 are formed of a less densely packed fiberglass reinforced nylon having a Shore A durometer of approximately 90. With element 34, 36 and 38 formed of the specified hardness, a thickness of aproximately 80 thousandths of an inch for the element 34, 36 and 38 has been found sufficient. Of course, other materials, as well as thicknesses and hardnesses of material can be used, as long as the function of preventing the downward flexing of the ball and toe area of the outsole is preserved.
The forwardmost and rearwardmost elements 34, 36 extend transversely across substantially the entire width of outsole layer 22, while intermediate elements 38 are formed in transversely aligned pairs along the medial and lateral sides of outsole layer 22. Corrugations 35 are located within the area bounded by the inside edges of intermediate elements 38 and the forwardmost and rearwardmost elements 34, 36. The area of corrugations 35 function as shock attenuation area allowing a limited degree of downward flexing motion to cushion the foot. By having forwardmost and rearwardmost elements 34, 36 extend across substantially the entire width of outsole layer 22, elements 34, 36 enhance the lateral stability of shoe 10 in the ball area of the foot.
Additional elements or bars 44 extend downward from outsole layer 22 in the rear portion of ball area 30 to further enhance the transverse rigidity and stability of outsole layer 22. Similarly, additional elements or ridges 46 extend downward and across at least a portion of the transverse width of outsole layer 22 along the lateral side of arch area 28 to provide further rigidity to outsole layer 22 without unduly restricting its flexibility. Elements 44, 46 are also preferably formed of a harder material than outsole layer 22, preferably of intermediate hardness such as an intermediate elements 38.
A heel reinforcement element 48 extends downward from outsole layer 22 and across substantially its entire width in the heel area 26. A medial arch support element 50 also extends downwardly from outsole layer 22, and extends forward from heel reinforcement element 48 along the medial side of outsole layer 22 and arch area 28. Both heel reinforcement element 48 and medial arch support 50 are preferably formed of a hard material, such as the material of elements 34, 36. Outsole layer 22 can also be formed thicker in an area substantially coextensive with elements 48, 50, as seen in Figure 6, for example, to a thickness in its upper range of thickness, 275 thousandths of an inch.
Heel reinforcement element 48 extends at a rearwardly sloped angle from the lateral side to the medial side of the outsole layer 22. This disposition of heel reinforcement element 48 places it in parallel alignment with the body of an athlete during typical change of direction of motion when the feet of the athlete are normally in an abducted position. Lateral stability during motion changes is thus enhanced. Medial arch support element tapers in width from its maximum width of approximately one-half the width of outsole layer at its rearward section, where it joins with heel reinforcement element 48, to its forwardmost end adjacent the forward end of arch area 28 and, thus, follows the general shape of the arch of a foot.
While elements 34, 36, 38, 44, 46, 48 and 50 are preferably formed of three different materials of different hardnesses, it is preferable to form these elements integral with outsole layer 22. In some cases, it may be desirable to form all the elements and the outsole layer of a single material, however, the function of the elements should be preserved.
A first pair of cleats 52 are connected to forwardmost element 34 in a conventional manner, such as by threading engagement or integral molding. Similarly, a second pair of cleats 54 are attached to the rearwardmost abutting element 36; and a third pair of cleats 56 are connected to the heel reinforcement element 48.
Numerous characteristics and advantages of the invention have been set forth in the forgoing description, together with details of the structure and function of the invention, and the novel features thereof are pointed out in the appended claims. The disclosure, however, is illustrative only, and changes may be made in detail especially in matters of shape, size and arrangement of parts, within the principle of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims

1. An outsole for use in an athletic shoe comprising:

an outsole layer (22) formed of material extending along the bottom of the shoe and having a lower side adapted to face the ground and an upper side adapted to be attached to an upper (12) of the shoe, said layer of material being flexible about its major surface;

means connected to said outsole layer for preventing the downward flexing of the front end of said outsole layer while permitting the upward flexing thereof.

2. An outsole in accordance with claim 1 wherein said preventing means includes a plurality of abutting elements (34, 36, 38) extending downward from the lower surface of said outer sole layer (22) and having transverse slots (40) extending between longitudinally adjacent abutting elements to form transverse surfaces (42) on said abutting elements.

3. An outsole in accordance with claim 2, wherein facing transverse surfaces (42) of longitudinally adjacent abutting elements (34, 36, 38) contact one another in the normal stationary foot stance to prevent further downward bending of the forward end of the outer sole.

4. An outsole in accordance with any preceding claim, including a plurality of traction cleats (52, 54, 56) extending downward from said outsole layer (22).

5. An outsole in accordance with claim 4, wherein at least four of said cleats (52, 54) are located in a toe and ball area (30) of the outsole layer (22) and at least two of said cleats (56) are located in a heel area (26) of the outsole layer.

6. An outsole in accordance with claim 4 or 5, wherein said cleats (52, 54, 56) are removably attached to said outsole layer (22).

7. An outsole in accordance with any preceding claim, wherein said material of said outsole layer (22) is a thermoplastic.

8. An outsole in accordance with any preceding claim, wherein said preventing means is formed integral with said outsole layer (22).

9. An athletic shoe comprising:

an-upper (12);

a sole (14) attached to said upper and including an outsole layer (22) formed of a thermoplastic material flexible about its major surface;

said outsole layer having a plurality of elements (34, 36, 38) extending downward from the lower side of said outsole layer in the area of the ball of the foot for preventing downward flexing of the forward end of said outsole layer while permitting the upward flexing thereof.

10. An athletic shoe in accordance with claim 9, including means for increasing the flexibility of said outsole layer (22) in the area of the ball of the foot.

11. An athletic shoe in accordance with claim 10, wherein said flexibility increasing means includes a plurality of corrugations (34) in said outsolelayer (22) in the area of the ball of the foot.

12. An athletic shoe in accordance with any one of claims 9 to 11, wherein said plurality of elements include longitudinally spaced, abutting elements (34, 36, 38), transverse slots (40) extending between longitudinally adjacent abutting elements to define transverse surfaces (42) on the elements, facing transverse surfaces of longitudinally adjacent abutting elements being in contact with one another in the normal at rest position of said shoe.

13. An athletic shoe in accordance with claim 12, wherein the forward end of said outsole layer (22) is curved upwardly with respect to the heel end of said outsole layer in the normal at rest position of the shoe and said abutting elements (34, 36, 38) being of sufficient hardness and thickness to prevent the forward end of the outsole layer from bending further downward, while the slots (40) between said abutting elements permit further upward bending of the forward end of said outsole layer.

14. An athletic shoe in accordance with claim 12 or 13, wherein said slots (40) are angled forward from the lateral side to the medial side of said outsole layer (22).

15. An athletic shoe in accordance with any one of claim 9 to 14, wherein a plurality of cleats (52, 54, 56) are attached to said outsole layer (22).

16. An athletic shoe in accordance with claim 15, wherein a first pair (52) of said cleats are attached to the forwardmost (34) of said abutting elements, a second pair (54) of said cleats are attached to the rearwardmost (36) of said abutting elements, and a plurality of intermediate abutting elements (38) are located between said forwardmost and rearwardmost abutting elements.

17. An athletic shoe in accordance with claim 16, wherein a third pair (56) of said cleats is located in the heel area (26) of said outsole layer (22).

18. An athletic shoe in accordance with claim 17, wherein said third pair of cleats (56) are attached to a heel reinforcement element (48) extending downward from and transversely of said outsole layer (22), and an arch support reinforcement element (50) extends downward from said outsole layer and along the medial side thereof.

19. An athletic shoe in accordance with claim 18, wherein said arch support reinforcement element (50) tapers in width from approximately one-half the width of said outsole layer (22) at its rearward end where it joins with said heel reinforcement (48) to its narrowest width at its forward end adjacent the forward end of the arch area (28) of the outsole layer.

20. A cleated athletic shoe comprising:

an upper (12);

a sole (14) attached to said upper and including an outsole layer (22) having a heel area (26), an arch area (28), a ball area (30) and a toe area (32), and being formed of a thermoplastic material flexible about its major surface, the ball and toe areas of said outsole layer being bent upward with respect to said arch and heel areas in the normal unstressed position of the shoe;

means in said ball area of said outsole area for preventing the downward bending of the ball and toe area of said outsole layer below said upward bent unstressed position and permitting further upward bending motion, said preventing means including a plurality of abutting elements extending downward from said outsole layer;

said abutting elements including a forwardmost element (34), a rearwardmost element (36) and a plurality of intermediate elements (38) located between said forwardmost and rearwardmost elements, a transverse slot (40) extending between adjacent abutting elements to separate the adjacent elements from one another and to form a contact surface (42) on each abutting element extending upward from the lower surface of each element, facing contact surfaces of adjacent abutting elements being in contact with one another in said normal unstressed position and said abutting elements having a thickness and hardness sufficient to prevent the downward bending of said outsole layer in said ball and heel areas from its normal unstressed position; and

a plurality of cleats (52, 54, 56) extending downward from said outsole layer in at least said ball and heel area.

21. A cleated athletic shoe in accordance with claim 20, wherein said cleats includes a first pair of cleats (52) connected to said forwardmost element (34), a second pair of cleats (54) connected to said rearward most element (36) and a third pair of cleats (56) in said heel area (28).

22. A cleated athletic shoe in accordance with claim 20 or 21, wherein said forwardmost and rearwardmost elements (34, 36) extend across substantially the entire width of said outsole layer (22) and said intermediate elements (38) are formed as laterally spaced pairs along the lateral and medial edges of said outsole layer.

23. A cleated athletic shoe in accordance with claim 21, where-in the area of said outsole layer (22) longitudinally between said forwardmost and rearwardmost elements (34, 36) and laterally between said intermediate element (38) is formed with corrugations (34) to increase the flexibility of said outsole layer in said ball area (30).

24. A cleated athletic shoe in accordance with any one of claims 20 to 23, wherein said outsole layer (22) is formed of nylon having a thickness of approximately one hundred thousandths of an inch and a hardness between approximately 80 and 85 durometer on a Shore A scale, and said abutting elements (34, 36, 38) are formed of fiberglass reinforced nylon having a thickness of approximately eighty thousandths of an inch and a hardness between approximately 90 and 95 durometer on a Shore A scale.