Reliance on a Single Non-Enabling Reference to Establish Obviousness

May 10, 2021 – Article

Raytheon appealed a final inter partes review decision of the Patent Trial and Appeal Board (Board) finding claims 3 and 16 of US 9,695,751 unpatentable as being obvious in view of the Knip reference. The Board found that Knip discloses the claimed power density limitation for a geared gas turbine engine. During the proceeding, Raytheon submitted evidence establishing that Knip’s disclosure of highly aggressive performance parameters for a futuristic turbine engine was based on the use of nonexistent composite materials. In response, the petitioner, General Electric Company (GE), never provided any evidence suggesting a skilled artisan could have made a turbine engine with the claimed power density. “Because the relied-upon prior art fails to enable a skilled artisan to make and use the claimed invention,” the Federal Circuit (the Court) reversed.

The Court reminded that there usually is no dispute about whether an asserted prior art reference is “self-enabling.” “This appeal, however, requires us to consider when a reference needs to have a self-enabling disclosure for supporting an obviousness case. We have explained that there is no absolute requirement for a relied-upon reference to be self-enabling in the § 103 context, so long as the overall evidence of what was known at the time of invention establishes that a skilled artisan could have made and used the claimed invention. We have also previously expounded the principle that if an obviousness case is based on a non-self-enabled reference, and no other prior art reference or evidence would have enabled a skilled artisan to make the claimed invention, then the invention cannot be said to have been obvious.”

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. The distinguishing feature of the claims is the recitation of a “power density” range that the patent describes as being “much higher than in the prior art.” In its petition, GE argued that the Knip reference disclosed performance parameters that would permit a skilled artisan to derive the power density of their respective engines from those disclosed parameters. According to GE, those power densities render obvious or anticipate the claimed power density range. Raytheon argued at the Board that Knip’s disclosure failed to enable a skilled artisan to make the claimed invention as the aggressive parameters disclosed in Knip, and, therefore, its power density relied on “revolutionary” materials unavailable as of the priority date of the ’751 patent. In response, GE argued that the issue of whether Knip enabled its advanced engine was “irrelevant” to the “question whether a [skilled artisan] reviewing Knip could make the [’]751 Patent’s engine (using any already available materials) without undue experimentation.”

The Board concluded that Knip was “enabling,” because it provided enough information to allow a skilled artisan to “determine a power density as defined in claim 1, and within the range proscribed in claim 1” and determined that GE had met its burden of proving that claims 3 and 16 were unpatentable as obvious. On appeal, the Court pointed out that “[l]ike its enablement analysis, the Board’s overall conclusion focused on the narrow question of whether Knip provided enough disclosure to enable a skilled artisan to calculate what would be the power density of Knip’s advanced engine. The Board further supported its obviousness conclusion in view of Knip by concluding that, even if Knip’s power density did not fall within the claimed power density range, power density is a result-effective variable." Raytheon appealed the decision of the Board.

On appeal, Raytheon presented one issue: “whether the Board erred in finding Knip ‘enabling’ of the claimed invention.” Raytheon argued that the Board improperly focused only on whether Knip enables a skilled artisan to calculate the power density of Knip’s contemplated, futuristic engine, rather than also considering whether Knip enables a skilled artisan to make the claimed invention. Raytheon argued that “when viewed under the proper legal standard, nothing in the record demonstrates that Knip enables a skilled artisan to make the claimed invention.” The Court agreed.

The Court noted that a prior art reference must enable a person to make and use the claimed invention based on self-enablement or on a non-enabling reference. In case a prior art reference provides enablement to arrive at the invention, there is enough evidence for obviousness. In case a prior art reference is non-enabling, it could still be considered along with other prior art or evidence to show obviousness. The Court reminded that “even though a non-enabling reference can play a role in an obviousness analysis, the evidence of record must still establish that a skilled artisan could have made the claimed invention.” “In the absence of such other supporting evidence to enable a skilled artisan to make the claimed invention, a standalone § 103 reference must enable the portions of its disclosure being relied upon. See Ashland Oil, Inc. v. Delta Resins & Refractories, Inc., 776 F.2d 281, 297 (Fed. Cir. 1985).”

The Court agreed with Raytheon that the Board legally erred in its prior art enablement analysis. The Court noted that the only prior art GE relied on to establish that one of skill in the art would have been able to make a turbofan engine with the claimed power density was the Knip reference. “But rather than determining whether Knip enabled a skilled artisan to make and use the claimed invention, the Board focused only on ‘whether [a skilled artisan] is provided with sufficient parameters in Knip to determine, without undue experimentation, a power density.’”

The Board defended its inquiry by noting that the claims at issue do not require the advanced materials recited by Knip. According to the Board, whether Knip’s advanced engine had been or could be implemented “is not the proper consideration” and rejected Raytheon’s argument that Knip’s advanced engine must be “physically achievable based on the reference’s disclosure itself.” The Board cited that “enablement does not require that Knip’s advanced engine was actually implemented.” On appeal, GE echoes the Board’s statements and goes further, claiming that “it is irrelevant whether Knip actually enables a [skilled artisan] to build the specific engine contemplated by Knip.” The Court disagreed and pointed out that “[t]hat position may have carried the day if GE had presented other evidence to establish that a skilled artisan could have made the claimed turbofan engine with the recited power density. But no such other evidence was presented. Thus, Knip’s self-enablement (or lack thereof) is not only relevant to the enablement analysis, in this case it is dispositive.”

The Court also noted that GE’s expert never suggested that a skilled artisan could have actually built such an engine. In contrast, Raytheon presented extensive, unrebutted evidence of non-enablement, e.g. a declaration from a professor of materials science, detailing the unavailability of the revolutionary composite material contemplated by Knip. Additionally, Raytheon submitted evidence that the exceptional temperature and pressure parameters cited in Knip had not been achieved through other means as of the priority date. “Raytheon’s unrebutted evidence that Knip fails to enable a skilled artisan to physically make Knip’s advanced engine is conclusive, given that this was the only evidence GE presented for why a skilled artisan could achieve the claimed power density.”

The Court concluded that GE failed to provide an evidence-based case for how the turbofan engine claimed in the ’751 patent having a particular power density is enabled by Knip’s disclosure and that “the Board’s finding that Knip is ‘enabling’ is legal error.”

This decision provides deeper insight into obviousness. A prior art reference must enable a person to make and use the claimed invention based on self-enablement or on a non-enabling reference. When relying on a non-enabling prior art reference, it could still be considered along with other prior art to show obviousness. However, supporting evidence must still establish that a skilled artisan could have made the claimed invention. In the absence of such supporting evidence to enable a skilled artisan to make the claimed invention, a standalone § 103 reference must enable the portions of its disclosure being relied upon.

Raytheon Technologies Corp. v. General Electric, No. 2020-1755 (Fed. Cir. Apr. 16, 2021),

http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/20-1755.OPINION.4-16-2021_1764430.pdf