US Patent 11297895 Footwear sole assembly with insert plate and nonlinear bending stiffness

A sole assembly for an article of footwear comprises a sole plate with a foot-facing surface with a recess disposed in the foot-facing surface. An insert plate is disposed in the recess. A length of the insert plate between anterior and posterior ends of the insert plate is less than a length of the recess. The insert plate flexes free of compressive loading by the sole plate when a forefoot portion of the sole assembly is dorsiflexed in a first portion of a flexion range, and operatively engages with the sole plate when the forefoot portion is dorsiflexed in a second portion of the flexion range that includes flex angles greater than in the first portion of the flexion range. The sole assembly is dorsiflexed, for example, when the forefoot portion is flexed in accordance with toes bending toward the top of the foot.