Traction cleat and receptacle

Abstract

In traction cleat and receptacle system in a shoe outsole, unauthorized cleats are prevented from connection to a receptacle by a projection in the receptacle cavity and a recess in the cleat attachment stem for receiving the projection. A locking arrangement includes an annular array of twelve locking teeth on a boss surrounding the receptacle cavity, wherein every fourth tooth has a steeper side angle to in cooperate with mating cleat locking posts. A cylindrical shroud prevents the locking posts from damaging the outsole material during cleat rotation.

What is claimed is: 
     
         1 . An engagement system comprising:
 a receptacle having an attachment axis mounted in a shoe sole;   a replaceable traction cleat having a cleat rotation axis configured to rotationally attach in an insertion direction to said receptacle;   an engagement stem projecting from said cleat;   a cavity defined in said receptacle and configured to rotationally receive and engage said stem with said rotation axis and said attachment axis disposed coaxially;   means for preventing an unauthorized traction cleat from being rotationally attached to the receptacle, said means comprising:
 a projection member within said cavity, said projection member extending from a proximal end wall of the receptacle cavity and disposed concentrically about said attachment axis; 
 a recess defined in a distal end of said stem disposed concentrically about said rotational axis and configured to receive said projection member without interference when said cavity rotationally receives and engages said stem; 
 wherein said projection member within said cavity blocks cleats having engagement stems without a recess defined therein from being rotationally received and engaged in said cavity. 
   
     
     
         2 . The engagement system of  claim 1 , wherein said projection member is a right at least partially conical member having a longitudinal axis disposed on the cavity rotation axis. 
     
     
         3 . The engagement system of  claim 2 , wherein said recess has a configuration that is at least partially conical to receive said projection member. 
     
     
         4 . The engagement system of  claim 1 ,
 wherein said cleat further comprises a hub having a perimetric edge surrounding said rotation axis, a top surface and a bottom surface, and   wherein said stem extends from said top surface disposed concentrically about said axis.   
     
     
         5 . The engagement system of  claim 1 ,
 wherein said receptacle further comprises a hollow generally cylindrical boss surrounding and defining said cavity, and   wherein the cylindrical boss has a threaded interior cavity wall configured to receive and threadedly engage the stem.   
     
     
         6 . The engagement system of  claim 5 , wherein said receptacle has an axial length of about 4.0 millimeters. 
     
     
         7 . The engagement system of  claim 1 ,
 wherein the receptacle cavity has an axial length, and   wherein the projection member is at least one-half the axial length of the cavity.   
     
     
         8 . The engagement system of  claim 7 , wherein the projection member is a truncated cone member having a base, and
 wherein the truncated cone member tapers from its base at a convergence angle in the range of approximately 14 to 20 degrees.   
     
     
         9 . The engagement system of  claim 7 , wherein the projection member has a height above an interior surface of the proximal end wall of the receptacle cavity in the range of about 1.70 to about 1.95 millimeters. 
     
     
         10 . The engagement system of  claim 1 , wherein the recess defined in the distal end of the stem extends axially at least about 1.0 millimeter or more into the distal end of the stem. 
     
     
         11 . A replaceable cleat for use with a receptacle mounted in a shoe, the receptacle having a cavity defined therein with a projection member extending into said cavity, said cleat comprising:
 at least one traction element; and   an engagement stem having a distal end with a recess defined and extending axially in the stem to a length of at least one millimeter,   wherein the recess in said engagement stem is configured to be received in and engaged by the receptacle cavity, and   wherein said recess is further configured for receiving the cavity projection member without interference when the cavity receives and engages said stem, whereby said cavity projection member blocks cleats having engagement stems without a recess defined therein from being received and engaged in said cavity.   
     
     
         12 . The replaceable cleat of  claim 11 , wherein said recess has a frustoconical configuration. 
     
     
         13 . The replaceable cleat of  claim 11 , further comprising:
 a hub having a perimetric edge surrounding a rotation axis, a top surface and a bottom surface, wherein said stem extends from said top surface disposed concentrically about said axis; and   wherein said at least one traction element comprises:
 a plurality of angularly spaced dynamic traction elements, each being arcuately configured in a direction transverse of said axis and including a proximal section extending outward and slightly downward from a respective location substantially at said perimetric edge, and a distal section extending substantially downwardly from said proximal section, said distal section terminating in a turf-engaging end, 
 wherein each of said dynamic traction elements is sufficiently flexible relative to said hub as to be pivotally flexible in an upward direction about said perimetric edge, and 
 wherein each of said dynamic traction elements is positioned in angularly spaced pairs with angular spacing between pairs greater than angular spacing between elements within each pair. 
   
     
     
         14 . The replaceable cleat of  claim 13 , wherein said angularly spaced pairs consists of three equiangular spaced pairs of traction elements. 
     
     
         15 . The replaceable cleat of  claim 11 , further comprising:
 a hub having a perimetric edge surrounding a rotation axis, a top surface and a bottom surface, wherein said stem extends from said top surface disposed concentrically about said axis; and   wherein said at least one traction element comprises a plurality of said traction elements extending from said hub, at least some of said traction elements being sufficiently flexible relative to said hub as to be pivotable about said perimetric edge.   
     
     
         16 . A replaceable cleat for engaging a receptacle mounted in a shoe in locking relation, the receptacle having a cavity defined therein with a projection member extending into said cavity, said cleat comprising:
 a hub having a perimetric edge surrounding a rotation axis, a top surface and a bottom surface;   an engagement stem extending from said top surface configured to be received in and engaged by the receptacle;   a recess defined in a distal end of said engagement stem disposed concentrically about said rotational axis and configured to receive the projection member without interference when said cavity rotationally receives and engages said stem; and   a plurality of angularly spaced dynamic traction elements extending in a cantilevered manner from said perimetric edge;   wherein said recess has a frustoconical configuration,   wherein the recess defined in the distal end of the stem extends axially at least about 1.0 millimeter or more into the distal end of the stem, and   wherein each of said plurality of angularly spaced dynamic traction elements is pivotably flexible in an upward direction about said perimetric edge when subjected to weight of a person wearing a shoe in which the cleat is installed.   
     
     
         17 . The replaceable cleat of  claim 16 , wherein each of said plurality of angularly spaced dynamic traction elements includes a proximal section extending in an angularly arcuate orientation outward and arcuately downward from the perimetric edge of said hub. 
     
     
         18 . The replaceable cleat of  claim 17 , wherein said proximal section of each of said plurality of angularly spaced dynamic traction elements smoothly arcuately transitions both angularly and downwardly into a distal section that turns almost vertically downward while maintaining its angular outward curvature. 
     
     
         19 . The replaceable cleat of  claim 18 , wherein said proximal section of each of said plurality of angularly spaced dynamic traction elements subtends an angle in a vertical plane with the top surface of said hub of approximately 30 degrees, and the distal section of each element subtends an angle in the vertical plane of approximately 80 degrees. 
     
     
         20 . The replaceable cleat of  claim 18 ,
 wherein said distal section of each of said plurality of angularly spaced dynamic traction elements terminates in a turf-engaging edge which frictionally traverses turf to provide traction, and   wherein the arcuate configuration of each of said plurality of angularly spaced dynamic traction elements provides for longer opposed concave and convex edges extending along an entire length of said elements, thereby providing greater radial lengths along sides of the traction elements.