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Ground Fault Circuit Interrupters Do Not Infringe Two Patents in ITC Investigation

09-1378
August 27, 2010
Riley, P. Andrew

Decision icon Decision

Last Month at The Federal Circuit - September 2010

Judges: Newman (dissenting), Dyk (author), Prost

[Appealed from: ITC]

In General Protecht Group, Inc. v. International Trade Commission, Nos. 09-1378, -1387, -1434 (Fed. Cir. Aug. 27, 2010), the Federal Circuit reversed-in-part the ITC’s determination that the importation, sale for importation, or sale within the United States of certain ground fault circuit interrupters (“GFCIs”) manufactured by General Protecht Group, Inc. (“GPG”), Wenzhou Trimone Science and Technology Electric Co., Ltd. (“Trimone”), and Shanghai ELE Manufacturing Corp. (“ELE”) (collectively “General Protecht”), violated section 337 of the Tariff Act of 1930, as amended, 19 U.S.C. § 1337.  Specifically, the Court found that General Protecht’s products at issue did not infringe the asserted claims of U.S. Patent Nos. 7,283,340 (“the ’340 patent”) and 5,594,398 (“the ’398 patent”).  In this decision, the Federal Circuit did not discuss the ITC’s determination that General Protecht’s products infringe U.S. Patent No. 7,164,564 (“the ’564 patent”). 

GFCIs are used in electrical outlets with the “test” and “reset” buttons, typically found in bathrooms and kitchens.  When a “ground fault” occurs—that is, when the current flowing out from the GFCI does not match the current flowing in on the “neutral” connection of the socket—the GFCI cuts off the flow of electricity to prevent the possibility of electrical shock. 

Pass & Seymour, Inc. (“P&S”), the assignee of the patents at issue, filed a complaint with the ITC in September 2007 alleging a violation of section 337 by General Protecht.  The ALJ found a violation of section 337 by General Protecht in the Initial Determination.  The ITC modified the ALJ’s claim construction but affirmed the ALJ’s findings of infringement with respect to certain claims and reversed with respect to certain other claims.  The ITC issued a limited exclusion order barring entry into the United States of certain GFCIs manufactured by GPG that infringe claims 1 and 7 of the ’398 patent and claims 14 and 18 of the ’340 patent; certain GFCIs manufactured by Trimone that infringe claims 14 and 18 of the ’340 patent; and certain GFCIs manufactured by ELE and found to infringe claims 1, 7, and 8 of the ’398 patent and claims 1 and 15 of the ’564 patent.  General Protecht appealed.

On appeal, the Federal Circuit found that substantial evidence did not support the ITC’s conclusion that ELE’s 2006 GFCIs infringed claims 14, 18, and 30 of the ’340 patent.  The ITC adopted the ALJ’s construction for the term “detection circuit” found in independent claim 14 of the ’340 patent.  According to the ALJ, a “detection circuit” means “at least one detection circuit having a circuit segment connected between the line terminals and configured to generate a predetermined signal in response to detecting a proper wiring condition, which occurs when the line terminals are connected to a source of AC power.”  Slip op. at 7-8 (citation omitted).  On appeal, ELE argued that its GFCIs did not generate a “predetermined signal” as the claim requires.  Id.  The Federal Circuit agreed and found that the expert testimony relied upon by the ITC to support its infringement conclusion did not show that ELE’s GFCIs generate a signal.  Instead, the Court found ELE’s GFCIs merely turn on when the proper current flow from the hot line terminal is present and turn off when that current flow is not present.  For the same reasons, the Court found GPG’s 2003 and 2006 GFCIs did not satisfy the “detection circuit” limitation. 

The Federal Circuit also found that the ITC erred in its construction of the term “load terminals” found in claim 14 of the ’340 patent.  Claim 14 requires “four sets of interrupting contacts that are configured to provide electrical continuity between the line terminals and the load terminals in a reset state and configured to interrupt the electrical continuity in tripped state.”  On appeal, Trimone argued its GFCIs have only two sets of “interrupting contacts.”  The other two sets of contacts counted by the ITC did not satisfy the claim because they were between the line terminals and the GFCI’s receptacle outlets, or electrical sockets, and, Trimone argued, electrical sockets are not “load terminals.”  Id. at 10-11.  The Federal Circuit agreed and found that the ’340 patent “never describes receptacle outlets as load terminals.”  Id. at 12.  In addition, the Court found “the circuit diagram drawings in the ’340 patent all clearly label the load terminals separately from the receptacle outlets.”  Id.  The Federal Circuit found unpersuasive the ITC’s and P&S’s arguments that expert testimony supported the ITC’s conclusion.  The Court noted that “[n]one of the experts identified a particular meaning in the art, and an expert’s subjective understanding of a patent term is irrelevant.”  Id.  Thus, the Court concluded that the ITC erred when it included receptacle terminals within the meaning of “load terminals.”  Under this construction, the Court found Trimone’s 2006 GFCIs and ELE’s 2006 GFCIs—that contained only two sets of interrupting contacts—did not infringe the asserted claims of the ’340 patent. 

Turning to the ’398 patent, the Federal Circuit found that substantial evidence did not support the ITC’s conclusion that GPG’s 2006 GFCIs infringe claims 1 and 7 of the ’398 patent.  Claim 1 of that patent requires a “latching means,” which the ITC construed as a means-plus-function limitation under 35 U.S.C. § 112, ¶ 6.  The ALJ found that the structure for performing the claimed “latching means” function was “a pin passing through a hole in the block having a shoulder that cooperates with a hole in the latch member and a spring biasing the pin to retain the conducting member in the first position, and equivalents thereof.”  Id. at 16 (citation omitted).  In its Final Determination, the ITC modified the structure identified by the ALJ “to include the entire ‘latch member,’ and not only the hole therein.”  Id. at 17 (citation omitted).  GPG argued on appeal that its GFCIs performed the claimed function in a substantially different way because its GFCIs used a magnet rather than mechanical elements.  Citing its decision in Toro Co. v. Deere & Co., 355 F.3d 1313, 1324 (Fed. Cir. 2004), the Federal Circuit agreed—“one system that accomplishes a function mechanically and another system that accomplishes the same function using magnetic force ‘function in fundamentally different ways.’”  Slip op. at 17. 

In a dissenting opinion, Judge Newman disagreed with the majority’s construction of the term “generate” in the “detection circuit” limitation of the ’340 patent.  In Judge Newman’s view, the accused GFCIs “generated” a signal in response to correct wiring in the same manner as described in the ’340 patent, and that the parties and the ITC all agreed on the proper interpretation of the term “generated.”  Thus, Judge Newman stated that substantial evidence supports the ITC’s finding.  Similarly, Judge Newman noted that the majority’s exclusion of receptacle terminals, or “user load terminals,” from the meaning of the term “load terminals” in the ’340 patent was contrary to the evidence in the record.  According to Judge Newman, substantial evidence, including testimony from ELE’s expert, supported the ITC’s conclusion.  Finally, Judge Newman disagreed with the majority’s use of the Court’s Toro decision as “a pronouncement of law for all mechanical-magnetic substitutions.”  Newman Dissent at 14.  Judge Newman concluded that, contrary to the majority’s conclusion, substantial evidence supported the ITC’s finding of infringement of the ’398 patent.

 

Summary authored by P. Andrew Riley, Esq.