Holding: A statement made during prosecution may disclaim claim scope even if it does not lead to allowance, so long as the applicant’s characterization of the invention is clear and unambiguous.
Barrette owns US Patent No. 9,151,075 and several other patents that are directed to a fencing assembly that includes pivoting, sliding connectors to connect pickets to rails. Barrette sued Fortress Iron, alleging infringement of the ‘075 Patent and its related patents. The asserted claims recite connectors with “bosses” or “projections” that are used to connect the pickets to the rails.
At the Markman hearing, Barrette argued that the terms “boss,” “nub,” and “projection” should be construed according to their plain and ordinary meaning as simply being protrusions. However, based on both the specification of the ‘075 Patent and statements made during prosecution of the ‘075 Patent, the district court found disclaimer of claim scope and ruled that these terms were limited to bosses or projections that do not include fasteners. Since the accused Fortress Iron products included fasteners, the district court found no infringement of the Barrette patents.
Barrette appealed, arguing that the district court erred in construing the bosses or projections to be integrally formed to the connectors without a fastener based on both the specification and the prosecution history of the ‘075 Patent. The Federal Circuit only partially agreed with Barrette, finding no disclaimer of claim scope in the specification, but upholding the district court’s finding of prosecution history disclaimer.
The district court’s finding of disclaimer in the specification was based on criticism of the use of bosses with fasteners. However, the specification of the ‘075 Patent discusses at least two advantages over the prior art fencing systems, quick and easy installation and improved racking ability. Although fastener-less bosses are helpful for quick and easy installation, a fastener-less boss is not required for improved racking ability. Since the specification describes multiple advantages over the prior art, and not all of these advantages depend on the use of a fastener-less boss, there is no clear disavowal of claim scope based on the criticism of bosses that include fasteners.
As for the prosecution history disclaimer, during prosecution, Barrette distinguished the claims of the ‘075 Patent from the prior art by arguing that the prior art failed to disclose an integral boss. Purported disavowals of claim scope must be interpreted in view of the prosecution as a whole. The Federal Circuit found that Barrette clearly distinguished the prior art from its own claims by stating that its claims require an integral boss. Therefore, the term “boss,” “projection,” and other related terms are limited to features that are integral and do not include fasteners.
Barrette argued that its disavowal of claim scope should not apply since the examiner did not agree with its arguments regarding the prior art, and the ‘075 Patent was allowed based on alternative arguments. However, the Federal Circuit held that just because an applicant gains allowance of a patent on an independent ground does not mean that the prior characterizations of claim scope were insufficiently clear to find prosecution history disclaimer.
In this case, the examiner did not disagree with Barrette’s characterization that its claims required an integral boss, but instead disagreed with Barrette’s argument that the prior art bosses were not integral. Since the prosecution history does not indicate that Barrette’s assessment of its own claim scope was incorrect, a reader could reasonably conclude that Barrette had limited the scope of its claims. The fact that Barrette’s statements that its claimed bosses were integral were not successful in overcoming the prior art does not make this disclaimer ineffective. Further, disclaimer applies even to the earlier issued, related patents. A statement made during prosecution of related patents may be considered to construe a claim term that is common to those patents regardless of whether that statement is made before or after the date of issuance of the related patents.
In response to Barrette’s arguments regarding disclaimer, Fortress Iron argued that Barrette waived many of its arguments denying disclaimer by relying on portions of the prosecution history that were not presented to the district court. However, the Federal Circuit held that Barrette did not forfeit these arguments. A party is allowed to cite portions of the intrinsic record on appeal to support a claim construction even if the party did not cite that evidence at the district court. The prosecution history is intrinsic evidence that may be properly considered on appeal. When a district court holds that there is prosecution history disclaimer based on a portion of the prosecution history, the patentee may, on appeal, support its original construction of the claims with citations to other portions of the prosecution history not cited by the district court.
The Federal Circuit also denied Fortress Iron’s appeal regarding the district court’s finding that claim terms stating that the rails and pickets are “slidably engaged” are not indefinite. Fortress Iron argued that these terms are functional limitations and are therefore inherently ambiguous. The asserted patents do not specifically define the amount of force that is needed for sliding to occur, but this sort of precise description not required for definiteness. The specification of the ‘075 Patent provides sufficient guidance to allow a person of ordinary skill in the art to determine what it means for two structures to be slidably engaged. A specification is sufficiently definite if the specification allows a person of ordinary skill to compare a potentially infringing product with the examples in the specification to determine the scope of the claim.
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