Rolls-Royce Uses Declaration Evidence To Win Patent Appeal

Use of declaration evidence in patent prosecution is thought of by some attorneys as the last possible thing anyone should ever do. However, as discussed in previous posts, there can be strategic reasons to utilize declaration evidence in prosecution, and it can be quite helpful in certain situations.

Rolls-Royce recently relied on declaration evidence successfully in an appeal relating to composite gas turbine engine components (SN 12/847,608). The issue related to whether a certain limitation, as interpreted under the Broadest Reasonable Interpretation (BRI), was a product-by-process limitation or a structural limitations. As skilled prosecutors know, this distinction can be critical as product-by-process limitations are effectively useless in all but the rarest of circumstances. Claim 1 is reproduced below, and specifically requires that the cooling opening is "defined by a plurality of ultrasonically formed geometric shapes."

gas turbine.png

At issue here was whether the "ultrasonically formed geometric shapes" was a structural limitation. The Examiner maintained that this was merely defining an opening that was made be a certain process, and did not impart any structural limitations. To be sure, this is a difficult proposition for an applicant to overcome without some sort of evidence in the specification to rebut the Examiner's position. However, Rolls-Royce used a declaration to establish certain technical facts, including that ultrasonically formed openings result in a structural difference as compared to openings formed by laser or electrical discharge machining (which was in the cited prior art) because openings formed by ultrasonic machining in a composite material (such as CMG) result in a 20-25% improvement in the discharge coefficient. This evidence was critical to convincing the PTAB that the claimed element was structural, and was dispositve on appeal because the prior art formed the openings by a different process thus resulting in a different structure.

The details of Rolls Royce's argument here are of interest as the Examiner went to great lengths to maintain the rejection, including attacking the declaration as merely providing an opinion, as opposed to evidence. The declaration established the declarant's expertise in the field and then explained that an unexpected benefit of the claimed features was that the discharge coefficient improved by at least on the order or 20-20% as compared to laser machining. It was so surprising to the inventors that it required a redesign of the cooling openings to reduce the flow to avoid over-cooling. This evidence therefore confirmed that the claimed element resulted in a structural difference that was not shown by the cited art. The PTAB was not convinced that the declaration provided only an opinion, because it specifically set forth the improvement by a specified percentage. Whether or not the declaration had test data was therefore not relevant and the Examiner's obsession with requiring test data was improper.

So, the first lesson here is that sometimes limitations that seem as though they can be characterized as product-by-process limitations are actually structural, and it is possible to convince the PTAB judges of this fact. Further, do not let Examiner's ignore factual evidence by stating that only test data will qualify.

Another interesting aspect of this case is how the declaration, while establishing facts related to the proper claim interpretation, also set forth evidence that tended to show the advantageous nature of the invention. While technically not relevant to the issue, such evidence tends to set the decision-maker in the right set of mind in order to find for the inventor.  Specifically, the declaration explained how even as a skilled artisan, the idea that the claimed approach could be achieved was surprising:


Thus, the second lesson here is that sometimes evidence of surprising results or unexpected benefits can be helpful, even though the application is not necessarily trying to win by establishing secondary indicia of non-obviousness (which is very difficult to do).