US Patent 10226097 Footwear sole structure with nonlinear bending stiffness

A sole structure for an article of footwear comprises a first plate and a second plate. The first plate overlies at least a portion of a forefoot region of the second plate. The first plate and the second plate are fixed to one another rearward of the forefoot region. The first plate is configured to slide longitudinally relative to the forefoot region of the second plate in a first portion of a flexion range during dorsiflexion of the sole structure, and to interfere with the second plate during a second portion of the flexion range that includes flex angles greater than in the first portion of the flexion range.