Lugus IP, LLC v. Volvo Car Corp.

When a patent claim is narrowed during prosecution, prosecution history estoppel may limit the application of the doctrine of equivalents.

Opinion (Irenas): Plaintiff Lugus IP, LLC (“Lugus”) contended that Defendants Volvo Car Corporation and Volvo Cars of North America, LLC (“Volvo”) infringed U.S. Patent No. 5,806,926 (the “'926 patent”). The ‘926 patent describes a seat with an adult/undeployed setting, and a child/deployed setting. Volvo’s allegedly infringing product is styled as an “integrated two-stage booster seat.” In the adult/stowed position, Volvo's booster seat is equipped for an adult, who may sit normally in the seat with the standard three-point seatbelt arranged to fall across their body at the shoulder and waist.

Patent infringement occurs when “whoever without authority makes, uses, offers to sell, or sells any patented invention, within the United States or imports into the United States any patented invention during the term of the patent.” Indirect liability may also be imposed for inducing another to infringe. Analysis of a patent infringement claim entails a two-step inquiry: (1) a court must first construe the patent claims, and (2) then determine whether the accused product contains each limitation of the properly construed claims, either literally or under the doctrine of equivalents. “To prove an accused product literally infringes the patent in suit, the product must contain each and every limitation of the asserted claim(s).” If even one limitation is missing in the accused product, there is no literal infringement.

Lugus’s complaint asserted two claims against Volvo: (1) direct infringement of the ‘926 patent, and (2) indirect infringement by inducing others to purchase and use Volvo’s booster seat. Volvo argued that its booster seats do not infringe on the terms of the patent. Specifically, Volvo contended that its booster seats do not automatically retract into a fully contoured adult seat, its booster seats do not automatically retract when a child is not located in the seat, and that its booster seats do not infringe under the doctrine of equivalents.

The court found that under the constructions of the claim terms, Volvo’s accused product does not “automatically” retract to form part of a fully contoured adult seat, nor does the accused product retract when a child is removed from the seat. By requiring manual interaction to reach the adult setting and become a part of the fully contoured adult seat, Volvo’s product does not contain the automatic limitation, and therefore does not literally infringe the patent’s terms.

The doctrine of equivalents “allows the patentee to claim those insubstantial alterations that were not captured in drafting the original patent claim but which could be created through trivial changes.” However, when a patent claim is narrowed during prosecution, “prosecution history estoppel may limit the application of the doctrine of equivalents.” As Volvo highlighted, a “narrowing amendment to a patent claim that adds an additional claim limitation creates a presumptive surrender of equivalents.”

To overcome this estoppel, a patentee must establish one of three possible exceptions by a preponderance of the evidence: (1) the equivalent would have been unforeseeable at the time the narrowing amendment was made; (2) the rationale underlying the narrowing amendment bore no more than a tangential relation to the equivalent at issue; or (3) there was some other reason suggesting that the patentee could not reasonably have been expected to have described the alleged equivalent.

Here, the ‘926 patent’s prosecution history demonstrated a limitation of Claim 1. The claim, initially phrased as two dependent claims, was “objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims [that were rejected because they were anticipated as prior art].” As a result, the patentee rewrote those dependent claims to include “in independent form including all of the limitations of the base claim and any intervening claims,” so as to comply with the examiner’s commentary and submit a permissible claim. This change limited the ‘926 patent to covering the automatic retraction from the seat’s child setting to its adult setting.

Lugus failed to rebut this presumptive surrender of equivalents, putting forth no evidence in the record to support one of the relevant exceptions. Instead, Lugus contended that Volvo misconstrued the prosecution history. However, given the limitation added during prosecution and found in the language of Claim 1 of the ‘926 patent—that retraction occurs automatically, when the pressure from the child was removed from the seat—the doctrine of equivalents does not offer a basis for determining that Volvo’s product infringes.

Ultimately, the court GRANTED Volvo’s motion for summary judgment, finding that Volvo’s product does not infringe the ‘926 patent.