On August 9, 2016, District Judge Ronnie Abrams (S.D.N.Y.) granted defendant Richloom Fabrics Group, Inc.’s motion to dismiss plaintiff Anchor Sales & Marketing, Inc.’s allegation of patent infringement based on the doctrine of equivalents.

Richloom Fabrics’ motion to dismiss, or alternatively for summary judgment, arose in response to Anchor Sales’ Amended Complaint alleging infringement of U.S. Patent No. 7,213,633 (the “‘633 Patent”), which is directed to “a method of forming scalloped configuration incurtains and draperies used for hanging from windows.” Anchor Sales argued that three of Richloom Fabrics’ valances infringe on claim 1 of the ‘633 Patent under the doctrine of equivalents, contending that the allegedly infringing products “are ‘made by the same method steps as in claim 1.’”

During prosecution of the ‘633 Patent, the examiner rejected all claims as unpatentable over two prior art references. In response, the patentee argued without amending the claims that the distinguishing element in his invention was the bead for raising curtains, stating that “sliding the [bead] up and down is the essence of this invention.”

Anchor Sales acknowledged that Richloom Fabrics’ allegedly infringing products do not use the bead that is recited in the claims. As the Court observed, where infringement is alleged based on the doctrine of equivalents, prosecution history estoppel can be a bar if the patentee had “narrow[ed] a claim ‘to avoid the prior art, or otherwise to address a specific concern . . . that arguably would have rendered the claimed subject matter unpatentable’” during prosecution. (citation omitted).

While the Court held that amendment-based estoppel does not apply in this case because there were no narrowing amendments, the Court did find that the arguments made during the prosecution do apply. In doing so, the Court explained that argument-based estoppel bars an argument for patent infringement under the doctrine of equivalents when the patentee “explicitly disavowed a specific feature in the prior art” by, for example, “assert[ing] the singularity or uniqueness of the claimed invention in arguing for its patentability.” (citations omitted). Here, the Court found that argument-based estoppel does apply, and, in granting Richloom Fabrics’ motion to dismiss the patent infringement claim, held that:

“the patentee here clearly and unmistakably indicated to competitors that he had surrendered methods of forming scalloped curtain designs that did not involve ‘sliding [a bead] up and down[]’ . . . [such that] [c]onsidering the ‘633 Patent’s prosecution history as a whole, . . . argument-based estoppel bars Plaintiff from now arguing infringement under the doctrine of equivalents for methods that do not involve sliding a bead up and down.”

Case: Anchor Sales & Mktg., Inc. v. Richloom Fabrics Grp., Inc., No. 15-CV-4442 (RA), 2016 BL 257084 (S.D.N.Y. Aug. 09, 2016).