The Toro Company ("Toro") is the assignee of U.S. Patent No. 4,694,528 (the '528 patent) directed to a device designed for yardwork that may be converted from a vacuum to an air blower. The device has an air inlet cover fitted with a restriction ring which can be placed over the air inlet to restrict the flow of air entering the device. When used as a blower, the air inlet cover is placed over the air inlet so that the velocity of air passing through the device is increased by reducing the size of the opening. When used as a vacuum, the cover is removed to increase the size of the air inlet and to reduce the velocity of air flowing through the device.
Toro filed suit against White Consolidated Industries ("White") for infringement of the '528 patent. White's device similarly increases air velocity by reducing the size of an aperture ring. However, White's air restriction ring is a removable part that requires operator insertion while Toro's restriction ring is directly attached to the cover for operator convenience. The district court granted summary judgment to Toro for literal infringement of the '528 patent and did not reach the issue of infringement under the doctrine of equivalents. White appeals the ruling of literal infringement.
The Federal Circuit construed the claims de novo, and found that the district court did not clearly err in applying 35 U.S.C. § 112, paragraph 6 to find equivalence in the means used by the two devices to attach the air inlet ring to the cover. The Court affirmed the district court's interpretation of the "attachment means" and its finding that the two devices perform an identical function. Thus, the Court reversed the district court's finding of literal infringement.
The Court then examined the remaining disputed clause to determine if it requires that the ring be attached to the cover for literal infringement to occur. The Court found that this question did not involve the statute, but should be interpreted within the context of the patent. In examining the specification, the Court found only one embodiment described in which the cover "includes" the air inlet ring. The Court noted that all diagrams and descriptions describe the ring as directly attached to the cover; thus, there is no basis for construing "including" the ring to mean a variation in which the cover and ring are separated. Under this corrected claim construction, the Court held that White did not literally infringe the '528 patent.
The Court, however, remanded for examination of the merits of infringement under the doctrine of equivalents.
Prepared by the liibulletin-patent Editorial Board.