“[I]n the absence of other supporting evidence to enable the claimed invention, a standalone Section 103 reference must enable the portions of its disclosure relied upon to support an obviousness finding.”
Last week, the U.S. Court of Appeals for the Federal Circuit (CAFC) reversed an inter partes review (IPR) decision from the U.S. Patent and Trademark Office’s (USPTO’s) Patent Trial and Appeal Board (PTAB) in Raytheon Technologies Corporation (Raytheon) v. General Electric Company (GE). The PTAB found claims 3 and 16 of U.S. Patent No. 9,695,751 (the ‘751 patent) unpatentable under Section103 as obvious in view of a 1987 NASA technical memorandum (the “Knip” reference). Raytheon submitted evidence that the Knip reference relied on the use of nonexistent composite materials, and thus failed to enable one of ordinary skill in the art to make and use the claimed invention. The PTAB sided with GE, even though GE made no attempt to rebut the evidence presented by Raytheon. The CAFC disagreed.
Geared Gas Turbine Engines
The ‘751 patent is directed to gas turbine engines, more specifically geared turbofan engines, which are commonly used to power airplanes with great efficiency because of the higher rotational speed of the turbine and compressor. This higher speed allows a compressor or turbine to perform work in fewer stages, leading to reduced weight and volume of the turbine and the engine. The ‘751 patent claims a geared gas turbine engine with two turbines and a specific number of fan blades and turbine rotors and/or stages. Its key distinguishing feature in the claims is “a ‘power density’ range that the patent describes as being ‘much higher than in the prior art[,]’” with power density defined as the “‘sea-level-takeoff (SLTO) thrust’ divided by the engine turbine volume.”
PTAB Finds ‘751 Patent Obvious, Sides in Favor of GE
GE challenged claims 104, 9-10, and 15-16 of the ‘751 patent as obvious in view of the Knip reference. GE also challenged claims 1-2 and 15 as anticipated by or obvious in view of Gliebe alone and claim 23 as obvious in view of Gliebe. Raytheon disclaimed claims 1-2, 4, 9-10, 15, and 23 to effectively moot all grounds of review relying on Gliebe, leaving dependent claims 3 and 16 to be challenged solely based on the Knip reference. GE argued that Knip disclosed performance parameters that would enable or make obvious to one of ordinary skill in the art to derive power density of their respective engines from the reference. GE also argued that even if Knip did not disclose turbine volume or SLTO thrust that resulted in power density in the same range, it would have been obvious to modify the turbine volume or thrust to optimize power density.
Despite disclaiming claims 1 and 15, Raytheon relied solely on the claim limitations of the claimed power density range to rebut GE’s argument and make two arguments in favor of the patentability of claims 3 and 16. First, it argued that GE’s expert’s methodology was flawed in deriving the power density of Knip’s advanced engine from the parameters disclosed by Knip. Second, it argued that the Knip reference lacked enablement of the claimed invention, because it relied on “‘revolutionary’” materials that were unavailable as of the filing date of the ‘751 patent. GE did not rebut either of these arguments, and instead argued that enablement was irrelevant to the question of whether a person of ordinary skill in the art reviewing Knip could make the ‘751 patent’s engine without undue experimentation. The PTAB concluded that Knip was “enabling” because it provided enough information to allow one of skill in the art to “‘determine a power density as defined in claim 1, and within the range proscribed in claim 1[,]’” rendering claims 3 and 16 of the ‘751 patent obvious.
CAFC: Standalone Section 103 References Must Be Enabling
Raytheon argued on appeal that the PTAB erred in focusing only on whether the Knip reference enables a person of skill in the art to calculate the power density of Knip’s futuristic engine, rather than on whether it enables a skilled artisan to make the claimed invention. Agreeing with Raytheon, the CAFC found that the Knip reference recites the superior performance characteristics of an “imagined ‘advanced turbofan engine’ ‘incorporating all composite materials[,]’” and that the turbofan engine in the reference was, and still is, “undisputedly unattainable.” Furthermore, the reference does not explicitly disclose power density, turbine volume, or SLTO thrust. According to the court, a prior art reference asserted under Section 103 does not necessarily have to be self-enabling to be used in determining obviousness. However, the record must still establish that a person of ordinary skill in the art could have made the claimed invention. Quoting the Sixth Circuit, the CAFC explained that in the absence of other supporting evidence to enable the claimed invention, a standalone Section 103 reference must enable the portions of its disclosure relied upon to support an obviousness finding. See Minn. Mining & Mfg. Co. v. Blume, 684 F.2d 1166, 1173 n.10 (6th Cir. 1982).
The only evidence GE relied on to establish that a skilled artisan would have been able to make a turbofan engine with the ‘751 patent’s claimed power density was the Knip reference, said the court; and instead of determining if the Knip reference enabled one of skill in the art to make and use a turbofan engine with the claimed power density range, the PTAB focused on if the Knip reference enabled one of skill in the art to make and use a turbofan engine with a power density generally. GE argued on appeal that whether Knip actually enables a skilled artisan to build the specific engine contemplated by Knip is irrelevant. The CAFC disagreed, finding that this inquiry was relevant because no other evidence was presented to establish enablement. GE argued that the PTAB found that Knip’s engine could be successfully constructed and thus enabled, but the CAFC was unpersuaded. The court found that GE’s expert only constructed a computer model simulation of Knip’s engine, and never suggested that a person of skill in the art could successfully build a physically working engine. This was the only evidence submitted by GE to rebut Raytheon’s argument that the Knip reference failed to enable a person of skill to physically make Knip’s engine. Therefore, the CAFC found that GE failed to provide evidence that the turbofan engine claimed in the ‘751 patent having a specific power density is enabled by the Knip reference. Furthermore, held the CAFC, GE’s argument that it would have been obvious to modify the turbine volume or thrust of the Knip reference to optimize power density is moot because “[i]f a skilled artisan cannot make Knip’s engine, a skilled artisan necessarily cannot optimize its power density.”