Much has been written on appeal practice in general, including the best strategies for briefs. See, for example, some great posts here, here, and here. To be sure, many of these points apply to ex parte appeals before the PTAB. But ex parte (and inter parte for that matter) patent appeals also have some unique aspects, and anyone thinking that the approach used in general appellate briefs directly translates in the patent prosecution realm is in for a rude awakening.

As a quick review, in ex parte patent appeals, the typical appeal procedure starts with the applicant filing a notice of appeal after a claim is finally rejected or twice rejected. The applicant then files the substantive Appeal Brief. After the examiner conducts an internal appeal conference, assuming that conference votes to maintain the rejection, the examiner writes an Answer. Finally, the Applicant also has the optional to file a Reply Brief, enabling the applicant to have the last word before the case is transferred to the Board for an optional hearing and then decision.

One area where practice can differ is that, perhaps due to the ex parte nature of proceedings, the PTAB has a tendency to view the Examiner’s rejection through a lens that can morph what seemed to be the real basis of the rejection. This, coupled with the fact that the PTAB will find waiver wherever possible to reduce issues, leads to long appeal briefs that address every single statement or point made by the examiner, even if due to nothing more than a slightly different phrasing in one part of the rejection as compared to another. Such long briefs can often feel repetitive and difficult to follow to those outside patent prosecution. Nevertheless, even missing the slightest statement by an examiner (for example 4 words in a 10 page Rejection) can lead to an easy affirmance by the PTAB.

Consider US application 15/878,886 assigned to Hamilton Sundstrand. The invention relates to methods of supplying inert gas to an aircraft fuel tank. Claim 11, reproduced below, illustrates the claimed subject matter:

11. Method of supplying inert gas to a fuel tank of an aircraft, the method comprising:
supplying a first reactant from a first reactant source, comprising a liquid fuel from a fuel tank, to a direct injection assembly;
supplying a second reactant from a second reactant source to the direct injection assembly to mix the second reactant with the liquid fuel, wherein the liquid fuel is vaporized during the mixing with the second reactant within the direct injection assembly;
directly injecting the mixed liquid fuel and second reactant into a catalytic reactor;
catalyzing the mixed liquid fuel and second reactant within the catalytic reactor to generate an inert gas; and
supplying the inert gas to the fuel tank to fill a ullage space of the fuel tank, wherein the liquid fuel is supplied to the direction injection assembly without the use of a heater.

Claim 11 was rejected by the examiner based on a combination of references. The examiner relied on modifying a primary reference (Johnson) with the teachings of a secondary reference (Lui). Specifically, the examiner’s rejection modified Johnson’s approach (of an evaporator prior to combining the fuel with air) to utilize Lui’s approach (that eliminated the separate vaporizor for the fuel and utilized air mixing with an air-assisted injector to vaporize the fuel). The examiner’s reasoning in the final rejection was as follows:

Hamilton Sunstrand took issue with this motivation to combine and pointed out, including with declaration evidence from an expert in the field, that the primary reference (Johnson) has no issue with coke formation and could not even form coke (because of the temperature and type of reactions). Thus, whether or not Lui’s approach could reduce coke was irrelevant. From there, Hamilton Sunstrand argued that without the coking issue, the examiner’s reasons for combining are flawed. Implicit in this argument was an assumption that the examiner’s reasoning was that the modification was motivated by the idea of reducing coking issue with a simplified system. While this may be a reasonable assumption given that the examiner combined these reasons into a single sentence, the USPTO is unforgiving to applicants who miss even the slightest nuance (yet the USPTO feels no remorse in modifying their own position at will and at the last possible second).

While the Examiner’s Answer again rehashed the coking issue and argued against the declaration, the examiner did throw in a “modification” of his reasons for combining at the end, noting that:

While this is arguably a different motivation than previously set forth, in ex parte appeal practice the burden is on the applicant to address it, even at this late stage, via the “optional” reply brief. Failing to do so means the entire appeal can be lost, as Hamilton Sundstrand unfortunately found. From the PTAB’s decision (which sidestepped the coking issue entirely):

Appellant, however, fails to address the Examiner’s rationale regarding simplifying Johnson’s system by addressing the cost, weight and complexity an evaporator adds to the system. See id.; Final Act. 4–5; Adv. Act. 2; Ans. 5. Nor has Appellant filed a Reply Brief addressing this specific motivation.

…

Thus, we need not and do not address whether Appellant’s arguments and Declaration testimony regarding the Examiner’s “coke formation” rationale would have been otherwise dispositive in this case. On this record, the Examiner finds an undisputed motivation to combine the reference teachings, and the Examiner has pointed to express disclosure in Lui to support that finding.

The PTAB did not seem to even consider that the final rejection appeared to co-mingle the coking issue and the complexity reduction, or that the Appellant’s arguments talked about the inability to successfully achieve the results the Office relied upon.

The PTAB (and the USPTO in general) can be unforgiving – if you miss it in your appeal brief, you waive it.  If the Examiner adds something in the Answer and you don’t address it, the PTAB can take it as undisputed fact. And under obviousness law, the examiner only needs one reason to combine, not more.

So, that is why appeal briefs need to be so thorough and complete. And that is why a Reply brief is likely needed in almost every appeal - the examiner’s Answer almost always rephrases or modifies or adds something.