PTAB Designates Two Decisions Illustrating Bounds of Obviousness Rejections based upon “Design Choice”

On October 15, 2019, the PTAB designated as informative two decisions illustrating the bounds of use of “design choice” by Examiners in support of an obviousness rejection.

In Ex parte Spangler, Appeal No. 2018-003800 (Feb. 20, 2019) Ex-parte-Spangler, Appellants’ claimed invention related to a featherseal incorporating two longitudinal tabs that engage with a post on a blade outer air seal (“BOAS”), thereby preventing movement, creating a seal and eliminating the need for a hardcoating.  The underlying application is brief – thirty-two paragraphs, only two of which describe the disputed tabs.  Though the figures show that the tabs have differing lengths and are not equidistant from either end, no mention is made of the dimensions or spacing of the tabs in the Spangler specification, nor is any explanation or reasoning provided tying the particular configuration to any of the disclosed advantages.

The Examiner applied prior art alleged in combination to teach the claim recitations, and in order to avoid these references, Appellants amended the claims to recite the particular configuration of the tabs, arguing that the Figures provided support to do so.  The Examiner responded by maintaining the rejection over the same references, arguing that it would be a mere matter of design choice to modify the length and spacing of the tabs taught in the prior art to arrive at the claimed invention. Appellants argued the aforementioned benefits were evidence of the criticality of the claimed tab structure and spacing, but in the end Appellants’ own specification was used against them by the Examiner:

Further regarding the locking feature, the tabs create this locking feature by engaging the post 88 in the BOAS.  The post 88 engages the feather seal in the tab space 84 created between the first and second tabs…The Appellant has stated, see paragraph 28, lines 3-4, that “the post 88 may be of any shape.”  If the post can be of any shape, then the tab space can also be of any corresponding shape.  The size and shape of the post affects the size and spacing of the tabs.  Therefore, the Appellant’s specification appears to teach away from criticality of the tab sizes and spacing.  Examiner’s Answer, page 4, 2nd full paragraph, January 24, 2018.

PTAB was thus persuaded, and affirmed the Examiner.

In contrast, in Ex parte Maeda, Appeal No. 2010-009814 (Oct. 23, 2012) Ex-parte-Maeda, Appellants’ claimed a machine for dispensing soft-serve ice cream wherein a “Y-shaped” conduit was used to combine flows of the dessert mixture and air, and thereafter provide that mixture to a cooling chamber.  This “combined passage member” was located inside a “cold storage” cabinet.  The specification described many advantages associated with this arrangement, i.e., enhanced cleanability of the unit, simplified design of the machine, and temperature control of the mixture. In rejecting Appellants’ claims as obvious, the examiner cited pieces of prior art that disclosed all features of the appellants’ machine, but for the location of the Y-shaped conduit which the Examiner deemed an obvious design choice.  For their part, Appellants argued that modification in the manner required would change the function of the prior art.

The PTAB began their analysis with the following admonition:

We discourage examiners from relying on “design choice” because it is generally a mere conclusion, which is no substitute for obviousness reasoning based on factual evidence.  Nonetheless, “design choice” may be appropriate where the applicant fails to set forth why the difference between the claimed invention and the prior art would result in a different function or give unexpected results.

And continued:

However, in this case, Appellants have explained how moving the combined passage member to cold storage as claimed would result in a different function than that shown by Meserole.  Namely, combining the air and dessert mix inside the cold storage would prevent the entrained air from increasing the temperature of the mixture.  By contrast, because Meserole injects air directly from the compressor 25a into the cooled dessert mix at “air injection point 35”, we agree with Appellants that Meserole’s air injection increases the temperature of the mixture of dessert mix and air.  The Examiner has not set forth an explanation or technical reasoning why moving the combined passage member 35 of Meserole to cold storage would not result in a different function than that shown by Meserole, as Appellants suggest.  We therefore find that the Examiner’s proposed modification of Meserole is not an obvious design choice and reverse the Examiner’s rejection…

By designating these decisions at the same time, it would appear that PTAB was attempting to illustrate the bounds of the use of “design choice” as a rationale for obviousness determinations.  On one hand, in Spangler, the Appellant had no description of criticality of the spacing and lengths of the tabs, and the tabs disclosed in the prior art were asserted to have the same functionality whether modified as claimed.  And on the other, in Maeda, the specification described multiple advantages associated with the location of the combined passageway, and Appellants were able to argue persuasively that the softserve dispenser of the prior art would not function the same if it were modified to meet the pending claims.