Where plaintiff’s trade dress was functional, it was therefore invalid and district court did not err in invalidating trademark and granting summary judgment to defendant.The 7th U.S. Circuit Court of Appeals affirmed a decision by Judge Ruben Castillo, Northern District of Illinois. Flexible Steel Lacing Company (Flexco) and Conveyor Accessories, Inc. (CAI) are competitors in the belt conveyer industry. These machines are used in a wide variety of material handling operations and typically consist of an endless flexible …