Footwear sole plate with non-parallel waves of varying thickness

1. A sole structure for an article of footwear comprising:

a sole plate including a midfoot region and at least one of a forefoot region or a heel region;

wherein the sole plate has a foot-facing surface with ridges extending longitudinally in the midfoot region and in the at least one of a forefoot region or a heel region;

wherein the sole plate has a ground-facing surface with grooves extending longitudinally in correspondence with the ridges;

a foam midsole overlying and secured to the foot-facing surface and underlying and secured to the ground-facing surface; and

wherein the ridges and the grooves are configured such that a thickness of the sole plate from the foot-facing surface to the ground-facing surface varies at a first transverse cross-section of the sole plate through the ridges in the midfoot region, or varies along a length of at least one of the ridges, or varies at both the first transverse cross-section and along the length of the at least one of the ridges.

2. The sole structure of claim 1 , wherein the sole plate has an undulating profile at any transverse cross-section of the sole plate through the ridges.

3. The sole structure of claim 1 , wherein:

an undulating profile of the sole plate at the first transverse cross-section includes a first set of multiple waves having crests at the ridges and having troughs between respective adjacent ones of the ridges;

an undulating profile of the sole plate at a second transverse cross-section in the forefoot region includes a second set of multiple waves having crests at the ridges and having troughs between respective adjacent ones of the ridges;

waves of the first set each have a first wavelength; and

waves of the second set each have a second wavelength greater than the first wavelength.

4. The sole structure of claim 1 , wherein the foam midsole includes a first foam layer secured to the foot-facing surface and a second foam layer secured to the ground-facing surface.

5. The sole structure of claim 4 , wherein the first foam layer and the second foam layer are portions of an upper portion and a lower portion of a single, unitary, one-piece foam midsole.

6. The sole structure of claim 4 , wherein the first foam layer and the second foam layer have one or more of different compressive stiffnesses, different material compositions, or different densities.

7. The sole structure of claim 1 , wherein the sole plate includes both of a forefoot region and a heel region.

8. The sole structure of claim 7 , wherein the ridges and the grooves extend only in the midfoot region and the forefoot region.

9. The sole structure of claim 1 , wherein:

the ridges have crests at least some of which extend non-parallel with one another in a longitudinal direction of the sole plate; and

the grooves have crests at least some of which extend non-parallel with one another in the longitudinal direction.

10. The sole structure of claim 9 , wherein at least some of the crests vary in amplitude in a longitudinal direction of the sole plate such that the amplitude is greater in a zone of the sole plate configured for relatively high compressive loads than in a zone of the sole plate configured for relatively low compressive loads.

11. The sole structure of claim 9 , wherein:

the sole plate includes a forefoot region; and

at least some of the crests have an amplitude that is greater in a rearward portion of the forefoot region than in a forward portion of the forefoot region, and greater in the rearward portion of the forefoot region than in the midfoot region.

12. The sole structure of claim 9 , wherein the sole plate is a resilient material such that the crests of the ridges decrease in elevation from a steady state elevation to a loaded elevation under a dynamic compressive load and return to the steady state elevation upon removal of the dynamic compressive load.

13. The sole structure of claim 12 , wherein the sole plate is one of a fiber strand-lain composite, a carbon-fiber composite, a thermoplastic elastomer, a glass-reinforced nylon, wood, or steel.

14. The sole structure of claim 1 , wherein:

the sole plate includes a forefoot region;

the foot-facing surface is concave in a longitudinal direction of the sole plate in the forefoot region; and

the ground-facing surface is convex in the longitudinal direction of the sole plate in the forefoot region.

15. The sole structure of claim 1 , wherein:

the sole plate includes both of a forefoot region and a heel region; and

the sole plate slopes in the longitudinal direction in the midfoot region from the heel region to the forefoot region.

16. The sole structure of claim 1 , wherein:

the foot-facing surface has an undulating profile at the first transverse cross-section that includes multiple waves having crests at the ridges and having troughs between respective adjacent ones of the ridges; and

the crests at the ridges are aligned with crests of the grooves.

17. The sole structure of claim 16 , wherein the thickness of the sole plate at the first transverse cross-section is less at the crests of the ridges than between the crests of the ridges and the troughs.

18. The sole structure of claim 1 , wherein:

a lateral-most one of the ridges curves in the longitudinal direction to follow a curved lateral edge of the sole plate; and

a medial-most one of the ridges curves in the longitudinal direction to follow a curved medial edge of the sole plate.

19. The sole structure of claim 1 , wherein the ground-facing surface is flat between the grooves at the first transverse cross-section.

20. The sole structure of claim 1 , wherein the sole plate is a unitary, one-piece component.