Traction cleat for footwear

1. A traction cleat for attaching to and locking with a shoe-mounted receptacle, said cleat comprising:

a hub having to and bottom surfaces and a longitudinally extending cleat attachment axis extending substantially perpendicular to said top and bottom surfaces;

at least one ground-engaging traction element projecting generally downward from said bottom surface;

at least one stem having a proximal end at the top surface of said hub and a distal end, said stem extending axially upward from said top surface substantially concentrically about the cleat attachment axis;

an attachment flange structure configured to be received in the receptacle and having a predetermined lateral periphery configuration and including at least one flange member extending generally radially from said stem proximate the distal end of said stem;

a cleat locking structure for engaging a mating structure in the receptacle to prevent inadvertent rotation of the cleat in the receptacle from a locking angular orientation; and

at least one arcuate hub ramp segment projecting gradually in an axial direction from the hub to surface as a function of angular location about the cleat attachment axis to provide an angled interface for contacting the receptacle, the hub ramp segment having maximally and minimally raised angularly displaced ends disposed at different distances from said hub top surface;

wherein said attachment flange structure includes plural flange members extending generally radially from said stem proximate the distal end of said stem at angularly spaced positions about the cleat attachment axis.

2. A traction cleat for attaching to and locking with a shoe-mounted receptacle, said cleat comprising:

a hub having top and bottom surfaces and a longitudinally extending cleat attachment axis extending substantially perpendicular to said top and bottom surfaces;

at least one ground-engaging traction element projecting generally downward from said bottom surface;

a stem having a proximal end at the top surface of said hub and a distal end, said stem extending axially upward from said top surface substantially concentrically about the cleat attachment axis;

an attachment flange structure configured to be received in the receptacle and having a predetermined lateral periphery configuration and including first and second flange members extending generally radially from said stem proximate the distal end of said stem and angularly spaced by 180°;

a cleat locking structure for engaging a mating structure in the receptacle to prevent inadvertent rotation of the cleat in the receptacle from a locking angular orientation; and

at least one arcuate hub ramp segment projecting gradually in an axial direction from the hub top surface as a function of angular location about the cleat attachment axis to provide an angled interface for contacting the receptacle, the hub ramp segment having maximally and minimally raised angularly displaced ends disposed at different distances from said hub top surface;

wherein each flange member has an undersurface spaced from and facing said hub with a slope that increases the longitudinal thickness of the flange member as a function of angular location about the cleat attachment axis, said undersurface being configured to abut and become more closely engaged in an increasing friction fit with a surface in the receptacle as the flange member is rotated in the receptacle.

3. The cleat of claim 2 wherein the thickness of each flange member in a dimension parallel to the cleat attachment axis is 1.6 millimeters or less.

4. The cleat of claim 2 wherein the cleat locking structure extends upward from said base in radially spaced relation from said stem and includes at least two convex ridges separated by a recess facing said stem.

5. The cleat of claim 2 wherein in order for the cleat to be locked in the receptacle in a predetermined angular locking orientation, the cleat further comprising a plurality of separate cleat angular stop shoulders located at different radially spaced locations from said cleat attachment axis, each of said cleat stop shoulders being positioned to abut a corresponding receptacle stop shoulder at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

6. The cleat of claim 2 wherein the receptacle is arranged to lock the cleat in a predetermined angular locking orientation, and wherein said cleat locking structure comprises at least one angular stop shoulder spaced a first radial distance from said cleat attachment axis and positioned to abut a corresponding receptacle stop shoulder at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

7. The cleat of claim 6 wherein said cleat locking structure further comprises at least one angular stop member spaced a second radial distance from said cleat attachment axis and positioned to abut a corresponding receptacle stop member at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

8. The cleat of claim 7 wherein each flange member includes a leading edge facing in the direction of rotation of the flange for insertion into the receptacle, and wherein the leading edge of each flange is positioned to abut a respective receptacle stop wall at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

9. The cleat of claim 6 wherein each flange member includes a leading edge facing in the direction of rotation of the flange for insertion into the receptacle, and wherein the leading edge of each flange is positioned to abut a respective receptacle stop wall at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

10. The cleat of claim 2 wherein the durometer of the flange members is in the range of 55D-75D.

11. The cleat of claim 2 wherein the receptacle is arranged to lock the cleat in a predetermined angular locking orientation, and wherein said cleat locking structure comprises at least one angular stop member spaced a predetermined radial distance from said cleat attachment axis and positioned to abut a corresponding receptacle stop member at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction; and wherein each flange member includes a leading edge facing in the direction of rotation of the flange for insertion into the receptacle, and wherein the leading edge of each flange is positioned to abut a respective receptacle stop wall at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

12. The cleat of claim 2 wherein the receptacle is arranged to lock the cleat in a predetermined angular locking orientation, and wherein each flange member includes a leading edge facing in the direction of rotation of the flange for insertion into the receptacle, and wherein the leading edge of each flange is positioned to abut a respective receptacle stop wall at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

13. The cleat of claim 1 wherein the thickness of each flange member in a dimension parallel to the cleat attachment axis is 1.6 millimeters or less.

14. The cleat of claim 1 wherein the receptacle is arranged to lock the cleat in a predetermined angular locking orientation, and wherein each flange member includes a leading edge facing in the direction of rotation of the flange member for insertion into the receptacle, and wherein the leading edge of each flange member is positioned to abut a respective receptacle stop wall at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

15. The cleat of claim 14 wherein said cleat locking structure comprises at least one angular stop shoulder spaced a first radial distance from said cleat attachment axis and positioned to abut a corresponding receptacle stop shoulder at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.

16. The cleat of claim 15 wherein said cleat locking structure further comprises at least one angular stop member spaced a second radial distance from said cleat attachment axis and positioned to abut a corresponding receptacle stop member at said angular locking orientation to prevent further rotation of the cleat relative to the receptacle in the insertion direction.