Frank’s Casing Crew v. Weatherford Intl. (Fed. Cir. 2004).
Frank’s Casing owns a patent on a device for remotely controlling an oil-well casing. (U.S. Patent No. 5,049,020). Because sections of casing can be up to 36 inches in diameter and weigh 300 pounds per foot, manual alignment is difficult and poses a significant risk of injury. Frank’s Casing brought suit against Weatherford, charging patent infringement.
The district court (W.D. Oklahoma) granted summary judgment of noninfringement after interpreting the means-plus-function claim language of Frank’s patent.
On appeal, Frank’s Casing argued that the district court improperly imported structure into the term "means for selectively pivoting" that was unnecessary to perform the function of pivoting a boom about a horizontal axis.
The Federal Circuit affirmed, finding that the district court’s interpretation is necessary and "to conclude otherwise would render the patent internally inconsistent and the invention inoperable."