Safety sole for sport shoe

[57] ABSTRACT

A safety sole for a football shoe is described which substantially reduces injuries to a player’s ankle or knee without detracting from the shoe’s ability to provide the player with firm footing. Rather than the ground engaging cleats of the shoe being rigidly secured to the remainder of the shoe, they are secured thereto through a flat, zig-zag spring having a resistance to deformation chosen to prevent movement of the shoe with respect to the cleats under normal playing conditions, but enable limited, resisted movement of such shoe with respect to the cleats upon the shoe being subjected to lateral forces exceeding a predetermined value.

Claims, 3 Drawing Figures

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3.782,011

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3,782,011

SAFETY SOLE FOR SPORT SHOE

BACKGROUND OF THE INVENTION

This invention relates to sport shoes and, more particularly, to a safety sole for such a shoe which reduces 5 the possibility of lateral forces injuring the lower limb of the wearer without interfering with the shoe’s ability to provide non-slip engagement with a playing surface.

In most fast moving sports, it is necessary that the participant’s foot be in non-slip engagement with a 10 playing surface. For example, firm footing is a necessity for the fast changes of body motion required in games such as tennis, basketball and football. Special shoes have therefore been developed to provide the desired, non-slip ground engagement. Such shoes are in general 15 quite effective for this purpose. In fact, they are almost too effective. That is, it is not Unusual for a participant’s knee or ankle to be injured because the foot is so firmly held in position laterally with respect to the ground that it cannot give way under impact, or in re- 20 sponse to an excessively forceful movement of the participant. This problem is particularly acute in body contact sports, such as football and the like in which many severe impacts can be expected. In this connection, it should be noted that the cleats on football shoes 25 prevent substantially all lateral slippage of the foot with respect to the playing surface so that the full force of lateral impacts must be absorbed by the ankle and knee.

SUMMARY OF THE INVENTION

The present invention provides a sole for a sport shoe which substantially reduces the possibility of injury to a player’s ankle or knee because of lateral forces on his leg while at the same time not interfering with the firm ³⁵footing required to effectively participate in a sport. In its broader aspects, the safety sole of the invention includes, as is usual, a non-slip ground engaging means, such as a plurality of cleats for anchoring the foot of the player against lateral movement with respect to the ⁴⁰playing surface. However, rather than such ground engaging means being directly and rigidly secured to the remainder of the sport shoe, a resilient coupling is provided between the ground engaging means and the shoe to enable limited movement of the shoe with respect to ⁴³the ground engaging means upon the shoe being subjected to a lateral force exceeding a predetermined value. The value of the force which must be exceeded prior to the limited movement being permitted, is chosen so that the ground engaging means is generally ⁵⁰rigid with respect to the foot of the player to permit normal play. It is only exceeded upon a lateral force being transferred to the shoe by the leg of the player which is in excess of that which it is expected the player can withstand without laterally moving his foot to avoid ⁵⁵injury. The particular value of the force will depend upon the sport being played and the weight and strength of the player.

Most desirably, the resilient coupling is resistive to ₆θ the limited movement and imparts a position restoring force to the shoe which increases directly with the limited movement. This will provide gradual absorption of the force by the knee and ankle of the player as the coupling permits such movement. Since it is often a ₆₅sharp impact to a leg or foot which causes injury, this gradual absorption increases the probability that the sole of the invention will prevent injury.

The invention includes other features and advantages which will become more apparent from the following more detailed description of a preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWING

With reference to the accompanying single sheet of drawing:

FIG. 1 is an elevation view illustrating a preferred embodiment of a safety sole of the invention on a sport shoe;

FIG. 2 is an enlarged, sectional view taken on a plane indicated by the lines 2—2 in FIG. 1, illustrating details of the construction of the safety sole; and

FIG. 3 is an enlarged, partial view of the sport shoe of FIG. 1 illustrating parts of the safety sole exploded therefrom.

Detailed description of a preferred EMBODIMENT

With reference to the drawing, a football shoe 11 is illustrated with a preferred embodiment of a safety sole of the invention, generally referred to by the reference numeral 12. The shoe 11 includes, as is usual, an upper portion 13 for enclosing the foot of a wearer, an inner sole (not shown), and an intermediate sole 14 to which the safety sole of the invention is secured. The safety sole includes conventional non-slip ground engaging means in the form of a toe cleat 16 and spaced apart pairs of heel and ball cleats 17. As is illustrated, one pair of the cleats 17 is provided for the heel of the wearer’s foot, whereas two pairs of such cleats are provided on the sole for the ball of the wearer’s foot.

Conventionally, the cleats on a football shoe are rigidly secured thereto. As mentioned before, although such a rigid arrangement will provide the firm engagement of a player’s foot to the playing field required for effective play of football, it will also in many cases prevent the player’s foot from giving way under the force of a severe impact, with the result that the player’s ankle or knee is injured. As a particularly salient feature of the instant invention, the safety sole includes a resilient coupling between the shoe 11 and each of the ball and heel cleats 17 which allows limited movement of the shoe with respect to the cleats, and, hence, the playing surface, upon a lateral force being applied to the shoe exceeding a predetermined value so that, in effect, the player’s foot does “give way” when subjected to a severe impact or a driving force sufficiently strong to cause injury. The coupling accomplishes this without adversely affecting the normal firm footing provided by the cleats during play. More particularly, each pair of the cleats 17 are secured via threaded posts 18, spacers 19 and nuts 21 to a bar or plate 22 which extends generally transversely with respect to the longitudinal axis of the shoe, which axis is indicated by the line 23 in FIG. 1. Each plate 22, in turn, is coupled to the intermediate sole 14 of the shoe by a flat spring 24. As is illustrated, each spring 24 is in the form of a metal rod which is bent from one side to the other, i.e., in zig-zag form, and extends generally transversely of the shoe. Such springs add a minimum of thickness to the shoe sole while at the same time providing the desired resilient coupling between the cleats and the shoe as will become more apparent hereinafter.

Each plate 22 is secured to its associated spring 24 at spaced locations on opposite sides of the longitudinal axis 23 of the shoe. To this end, a pair of spaced apart

3,782,011 pins 26 project from each plate 22 to locations in the respective end loops of the spring. The plates and spring ends are thus secured for movement together in directions transversely of the shoe.

Each of the springs is secured to the intermediate sole 14 via a stud 27 which projects from such intermediate sole from a position generally on the longitudinal axis 23 of the shoe. As best illustrated in FIG. 2, such pin extends between, and in contact with, the bent portions of the rod forming the central loop thereof. The studs and springs thus define the normal positions of the plates 22 and, hence, of the cleats 17 with respect to the remainder of the shoe.

Each of the spring and plate combinations fits within an associated cavity 28 defined by a gasket outer sole 29 of the sole. A cover plate 31 is secured over each of the cavities to enclose the same and hold the plate 22 in proper position. The cleat posts 18 of each pair of cleats 17 extend to the plate 22 to which they are secured through appropriately located slots 32 in the associated cover plate 31. As is illustrated, the slots 32 are elongated transversely of the shoe to enable transverse movement of the cleats with respect to the cover plate and the shoe.

In use, a football shoe having the sole of the invention secured thereto is worn in the conventional manner. It will be noted that the construction of the resilient coupling is such that movement of the shoe relative to the cleats 17 in a direction along the longitudinal axis of the shoe is always prevented. Thus, the rigidity of the cleats with respect to the shoe during forward driving movements, the major kind of movement in which firm footing is required are not adversely affected by the resilient coupling. Moreover, lateral movement of the shoe with respect to the cleats in a direction transversely of the shoe is also prevented to the extent the force causing such movement does not exceed the force value required to compress the spring 24. It will be appreciated that the value of such force will depend, among other things, on the material and thickness of ⁴⁰the rod from which each spring is made and the configuration into which the rod is formed, including the number of bands and the spacing between adjacent bands.

The predetermined value of force to which the spring is responsive will depend upon the weight and strength of the particular player. For example, the predetermined value chosen for a shoe designed for use by professional football players was 400 pounds. That is, the spring was constructed with the strength required for it to withstand the application through the stud 27 of 400 pounds to its center loop before allowing movement. Upon such force being exceeded, the spring will allow the limited movement, but will resist the same and impart a restoring force to the stud to again locate the cleats 17 in their normal position relative to the shoe. Because of the construction of the spring, such restoring force will increase directly with respect to the amount of such movement. Thus, the spring acts to gradually absorb any force causing the movement and thus reduce the effect of the force on the ankle and knee of the wearer.

It should be noted that because of the particular manner in which the spring is connected between the shoe and the cleats, it will permit force in either direction transversely of the shoe, i.e., from left to right or from right to left as viewed in FIG. 1, to be absorbed. That is, the spring will be compressed on any force in either of such directions exceeding the predetermined value and will apply a force tending to restore the position of the shoe with respect to the cleats which increases as 5 the amount of movement increases.

Although the invention has been described in connection with a preferred embodiment, it will be appreciated that various changes and modifications can be made without departing from its spirit. For example, 10 rather than each of the cover plates being a flat plate as illustrated, it can be made cup-shaped to define the cavity for the spring and cleat plate associated therewith so as to eliminate the need for the gasket sole. Moreover, although the invention is described in con15 nection with a football shoe, it is equally applicable to other types of shoes, including ones having non-slip ground engaging means different than cleats. It is therefore intended that the coverage afforded applicant be limited only by the claims and their equivalents.