Esco Corporation sued the Tru-Rol Company for infringement of U.S. Patent No. 2,919,506 covering a type of excavating teeth used on heavy machinery. The district court found that claims 1, 3, 8, 15, 20, 21 and 28 of the patent were valid and infringed. The court granted an injunction prohibiting Tru-Rol from further infringement and awarded actual damages, costs, and reasonable attorney’s fees to Esco. The court, however, denied treble damages and certain additional costs, and Esco appeals from that part of the judgment. Tru-Rol, in turn, appeals from the award of attorney’s fees. Finding no error, we affirm for reasons adequately stated by the district court.