If “the body of the claim fully and intrinsically sets forth the complete invention, including all of its limitations, and the preamble offers no distinct definition of any of the claimed invention’s limitations, but rather merely states, for example, the purpose or intended use of the invention, then the preamble is of no significance to claim construction because it cannot be said to constitute or explain a claim limitation.” Further, contrary to popular belief about loss of equivalency protection under Festo, the court here plainly dismissed the notion that DOE equivalency is automatically lost for every added or amended feature introduced during prosecution. Eurocopter asserted that the amendment of the claim language necessarily meant that Textron intended to limit the claim to “replacement” assemblies, but the CAFC found that the prosecution history did not support that inference. There must be a clear disclaimer – even ambiguous statements made during prosecution that “do not disavow or even clearly describe the structure … cannot fairly limit the characteristics of the claim term.”
Background / Facts: The patent here covers helicopter landing gear assemblies and is directed to way of attaching a skid-type landing gear assembly to the fuselage of a helicopter by using brackets and other components. Rather than having a single “strap” that mates with the bracket, the accused design is an OEM component that has a rubber gasket on which the bracket rests and stop pieces that mount to either side of the bracket.
Issue(s): Whether the term “replacement” added to the preamble during prosecution is limiting and confines the claimed invention to devices used to replace original equipment.
Holding(s): No. When a patentee “uses the claim preamble to recite structural limitations of his claimed invention, the PTO and courts give effect to that usage.” However, when a patentee “defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention, the preamble is not a claim limitation.” The term “replacement” does not impose any structural limitations on landing gear assemblies used as replacement parts that differ from the structure of original equipment landing gear assemblies that satisfy the limitations in the body of the claim. “Those portions of the preamble plainly contain words of context, not limitation.” Further, the prosecution history, including the amendment adding the term “replacement,” appeared to be aimed at avoiding a particular prior art reference having rivet holes at the top of the strap and crosstube, and does not contain any express statement in the amendment or elsewhere that the term “replacement” was added to overcome the rejection by limiting the invention to replacement parts only.