In a dispute between two competing firearms manufacturers involving claims of patent infringement and trade secret misappropriation, among others (only the patent claim is discussed herein), the CAFC affirmed the district court's granting of summary judgment that Claims 31-36 of plaintiff Atlantic Research Marketing Systems' ("ARMS") U.S. Reissue Patent No. 39,465 (the "'465 patent") were invalid for failing to meet the written description requirement of 35 USC § 112, ¶ 1. Atlantic Research Marketing Systems, Inc. v. Troy, Case No. 2011-1002, -1003 (Fed. Cir. October 6, 2011). As explained below, sometimes in claim construction, be careful what you wish for because you might just get it.

ARMS sued Troy for infringement of Claims 31-36 of its '465 patent, directed to a "sleeve" assembly that attaches to a firearm. Atlantic Research Marketing Systems, Inc. v. Troy, Case No. 07-CV-11576 (D. Mass.). Independent Claim 31 reads as follows:

A system for attaching modular enhancements to a firearm, said firearm having a receiver, said receiver having a top and a barrel receiving receptacle at a forward end thereof, said firearm further including a barrel received in said barrel receiving receptacle and a barrel nut received around an outer surface of said barrel receiving receptacle to retain said barrel within said barrel receiving receptacle, said system comprising: an upper handguard piece having a forward end and a rearward end, and further having a dovetail rail extending longitudinally between the forward end and the rearward end;

a U-shaped supporting yoke removably secured to said rearward end of said upper hand guard, said U-shaped supporting yoke including engagement surfaces configured to cooperatively engage an outer surface of said barrel nut and thereby support said upper handguard piece relative to said barrel nut, wherein said upper handguard piece extends from said forward end of said upper receiver forwardly above said barrel without engaging said barrel.

Claim 31 specifically required that the handguard (i.e., the protective component that prevents the user's hand from touching the barrel of the firearm) be supported solely by a "barrel nut." ARMS asserted that Troy infringed its claims because Troy's firearms have a handguard that attaches only with a barrel nut and do not have a receiver sleeve attachment point. Slip Op. at 9. This latter point being critical to the district court's holding that the claims did not satisfy § 112, ¶ 1.

During claim construction, ARMS requested and ultimately received a construction whereby the barrel nut provided complete support for the handguard. Specifically, ARMS argued that the handguard is "supported by the barrel nut with or without the receiver sleeve" and that the receiver sleeve "could provide additional support but not necessary support." Slip Op. at 11. Unfortunately for ARMS, getting the claim construction it wanted for infringement purposes ultimately led to the invalidating of its claims because they were not supported by the specification.

Indeed, the specification only taught the handguard being supported by two support points: one being the barrel nut, the other being at the receiver sleeve. Given this, the district invalidated the asserted claims. See In re Katz Interactive Call Processing Patent Litig., 639 F.3d 1303, 1319 (Fed. Cir. 2011) ("The purpose of the written description requirement is to ensure that the scope of the right to exclude, as set forth in the claims, does not overreach the scope of the inventor's contribution to the field of art as described in the patent specification.") (internal quotation marks omitted).

On appeal, ARMS argued that the district court's claim construction conflicted with the specification, which required that the handguard be supported not just by a barrel nut but an additional support point. In affirming the district court, the CAFC viewed ARMS' about-face with "extreme disfavor." Slip Op. at 15, citing N. Telecom Ltd. v. Samsung Elecs. Co., 215 F.3d 1281, 1290 (Fed. Cir. 2000) ("[W]e look with extreme disfavor on appeals that allege error in claim constructions that were advocated below by the very party now challenging them."). The CAFC further noted "[w]hile we do not address whether Atlantic Research is judicially estopped from asserting contradictory claim construction arguments on appeal, we note that these inconsistencies undermine Atlantic Research's current claim construction argument." Id.

The moral of the story: When you argue a claim construction with your sights on infringement, be careful you don't shoot yourself in the foot.