By Eric Schweibenz
On August 27, 2010, the Federal Circuit issued its opinion in General Protecht Group, Inc. v. Int’l Trade Comm’n, 2009-1378, -1387, -1434.  This is one of two opinions relating to appeals from the ITC’s March 9, 2009, final determination in Certain Ground Fault Circuit Interrupters and Products Containing Same (Inv. No. 337-TA-615).   The Federal Circuit affirmed the ITC’s determination in all respects except for reversing and remanding infringement determinations regarding two of the three patents that the ITC found infringed.

By way of background, Pass & Seymour (“P&S”) initiated the investigation against a number of respondents in connection with the importation and sales of products containing Ground Fault Circuit Interrupters (GFCI) that allegedly infringed U.S. Patent Nos. 7,212,386, 5,594,398 (the ‘398 patent), 7,283,340 (the ‘340 patent), and 7,165,564.  Only three of the original respondents are involved in the appeals:  General Protecht Group, Inc. (“GPG”), Shanghai ELE Manufacturing Corporation (“ELE”), and Wenzhou Trimone Science & Technology Electric Co. Ltd. (“Trimone”) (collectively, the “Appellants”).  The ITC found that GFCI devices manufactured by Appellants infringe one or more claims in the ‘398 patent, the ‘564 patent, and the ‘340 patent, and that none of these patents is invalid or unenforceable.  See our June 4, 2010 post for more details.

‘340 Patent

The ITC found that the GFCI devices from each Appellant infringed the ’340 patent.  Specifically, GPG’s 2003 and 2006 GFCIs infringed claims 14 and 18; Trimone’s 2006 GFCIs infringed claims 14 and 18; and ELE’s 2006 GFCIs infringed claims 14, 18, and 30.

The opinion describes the ’340 patent as directed to a GFCI receptacle that detects the wiring state of the device and inhibits operation if the device is miswired.  To effect the miswiring protection, the ’340 patent requires a “detection circuit” to detect whether the GFCI device is properly wired to an electrical circuit, and “four sets of interrupting contacts” configured to make or break an electrical circuit between the line terminals and the load terminals.

The Appellants and the ITC did not challenge the ALJ’s interpretation of “detection circuit,” as meaning “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.”  The Federal Circuit held that the ITC erred because the construed claims require the “detection circuit” to “generate a predetermined signal in response to detecting a proper wiring condition,” while the “predetermined signal” relied upon by the ITC was merely the “current flow” originating from the hot line terminal.  In other words, the identified circuit does not generate this current; it is the current that comes from the AC power connection.  So according to the opinion, instead of detecting a proper wiring condition and generating a signal in response, as the properly construed claim requires, the accused GFCIs simply have power to operate, or not.  For this reason, the Federal Circuit reversed the ITC’s determination that ELE’s 2006 GFCIs infringe claims 14, 18, and 30 of the ’340 patent and GPG’s 2003 and 2006 GFCIs infringe claims 14 and 18 of the ’340 patent.

The Federal Circuit further held that the ITC erred by counting receptacle outlets as two of the “four sets of interrupting contacts” required by the ‘340 patent.  The issue turned on whether receptacle outlets could be considered “load terminals.”  The opinion held that the ‘340 patent, “never describes receptacle outlets as load terminals,” and that, “the circuit diagram drawings in the ’340 patent all clearly label the load terminals separately from the receptacle outlets.”  Additionally, the opinion stated, “experts here never suggested that receptacle outlets, which they also called ‘user load terminals’ or ‘user accessible load terminals,’ could be referred to as simply load terminals.”  Instead, “they were fastidious in referring to them as separate elements.”  For this reason, the Federal Circuit held that Trimone’s 2006 GFCIs and ELE’s 2006 GFCIs do not infringe the asserted claims of the ’340 patent.

The ‘398 Patent

According to the opinion, the ’398 patent discloses a new mechanical architecture for a GFCI receptacle, describing an improved contact system that can move between a circuit-making position and a circuit-breaking position.  The ‘398 patent uses means-plus-function language to define several elements, including the limitation in dispute, which calls for a “latching means releasably retaining said conducting member.”   The ITC held that the latching means of the ‘398 patent, described a mechanical structure, which included a pin passing through a hole in a block having a shoulder that cooperates with a hole in a latch member, and a spring biasing the pin to retain the conducting member.  The Federal Circuit held that the ITC erred in determining that this mechanical arrangement was structurally equivalent to a magnetic latching system.  It relied on Toro Co. v. Deere & Co., 355 F.3d 1313 (Fed. Cir. 2004), which held that “one system that accomplishes a function mechanically and another system that accomplishes the same function using magnetic force ‘function in fundamentally different ways.’”

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For all of the above reasons, the Federal Circuit reversed the ITC’s findings that GPG’s 2003 GFCIs infringe claims 14 and 18 of the ’340 patent; that GPG’s 2006 GFCIs infringe claims 1 and 7 of the ’398 patent and claims 14 and 18 of the ’340 patent; that Trimone’s 2006 GFCIs infringe claims 14 and 18 of the ’340 patent; and that ELE’s 2006 GFCIs infringe claims 14, 18, and 30 of the ’340 patent.  The Federal Circuit additionally remanded to the Commission to modify its limited exclusion order.

Judge Newman filed a dissenting opinion, arguing that substantial evidence supported the ITC’s determination that Appellants’ devices contained a “detection circuit” as per the ‘340 patent.  Similarly, Judge Newman found substantial evidence supporting the position that receptacle outlets should be considered “load terminals.”  She further found that a magnetic latch was known to be interchangeable with a mechanical latch and that her colleagues incorrectly overstated Toro as holding that there can never be equivalence between a mechanical latch and a magnetic latch.