 Skechers is suing L.L. Bean for patent infringement, accusing the Freeport-based retailer of copying a heel design in one of its slip-on shoes. The footwear company, Skechers, filed a lawsuit Monday in federal court in New York, claiming that L.L. Bean only began using the, quote, graceful sweeping design after Skechers established that it had broad consumer appeal. The company is asking the court to bar L.L. Bean from selling shoes with the design, along with unspecified damages.