## Facts

- Lockheed Martin Corp. owned U.S. Patent No. 4,084,772 covering an apparatus and method for directing satellite movements using a momentum/reaction wheel for attitude control.
- Claim 1 included a means-plus-function limitation requiring a “means for rotating [the] wheel” that “varies sinusoidally over the orbit at the orbital frequency of the satellite,” followed by a “whereby” clause describing the effect on attitude.
- The district court construed the “varies sinusoidally” requirement to mean wheel rotation “moving in one direction, slowing to zero, stopping, and then reversing direction twice during orbit.”
- Both parties accepted the construction, and Lockheed admitted the accused Space Systems/Loral satellites did not slow to zero, stop, and reverse direction twice per orbit.
- The district court granted Space Systems/Loral summary judgment of noninfringement (no literal infringement and no viable doctrine-of-equivalents theory).
- An earlier Federal Circuit affirmance based solely on prosecution-history estoppel was vacated and remanded after the Supreme Court’s decision in *Festo*; on remand, the Federal Circuit affirmed on alternative, non-*Festo* grounds.

## Issues

1. Whether summary judgment of no literal infringement was proper given the accepted construction of the “varies sinusoidally” means-plus-function limitation and Lockheed’s admission that the accused satellites did not meet it.
2. Whether Lockheed could prove infringement under the doctrine of equivalents for the means-plus-function limitation without impermissibly eliminating the claimed sinusoidal behavior under the all-elements rule and related claim-scope limits.

## Decision

- The Federal Circuit affirmed summary judgment of noninfringement.
- There was no literal infringement because, under the accepted claim construction, the accused satellites lacked the required sinusoidal rotation pattern, and Lockheed admitted that absence.
- Lockheed’s doctrine-of-equivalents theory failed because any equivalence finding broad enough to cover the accused satellites would effectively negate the specifically claimed sinusoidal stop-and-reversal behavior.
- The court affirmed on grounds not dependent on prosecution-history estoppel and thus not implicating *Festo*.

## Legal Principles

- Literal infringement requires that every claim limitation, as properly construed, be present in the accused product; an undisputed absence of a limitation supports summary judgment of noninfringement.
- A means-plus-function limitation under 35 U.S.C. § 112 ¶ 6 (now § 112(f)) covers the corresponding structure disclosed in the specification and its equivalents; claim language that specifies a particular mode of operation can constrain the scope of that structure.
- The doctrine of equivalents is limited by the all-elements rule and cannot be applied in a manner that eliminates or vitiates a claim limitation or rewrites specific operational restrictions chosen by the patentee.
- An appellate court may affirm a noninfringement judgment on alternative grounds supported by the record, including claim-scope limits independent of prosecution-history estoppel.

## Conclusion

The Federal Circuit upheld summary judgment for the accused satellite manufacturer because the accepted construction required a specific sinusoidal wheel-rotation pattern that the accused satellites admittedly did not perform, and any doctrine-of-equivalents theory broad enough to reach the accused systems would improperly erase that claim limitation.


Lockheed Martin Corp. v. Space Sys./Loral, Inc., 324 F.3d 1308 (Fed. Cir. 2003)