As discussed in a previous post, device or structure claims that recited a feature as to how a component is made are not limited to devices made by that process. Such product-by-process limitations are examined in a way that often results in the process feature being ignored. Under MPEP 2113(II),

“The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature” than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974). Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an unobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 798, 802, 218 USPQ 289, 292 (Fed. Cir. 1983) (The claims were directed to a zeolite manufactured by mixing together various inorganic materials in solution and heating the resultant gel to form a crystalline metal silicate essentially free of alkali metal. The prior art described a process of making a zeolite which, after ion exchange to remove alkali metal, appeared to be “essentially free of alkali metal.” The court upheld the rejection because the applicant had not come forward with any evidence that the prior art was not “essentially free of alkali metal” and therefore a different and unobvious product.).

So, often the fight is over whether a limitation is a process limitation or whether it is a structural limitation. In the previous post, we reviewed a Rolls Royce application where Rolls was successful, using Declaration evidence, convincing the PTAB that the claimed "ultrasonically formed geometric shapes" was a structural limitation. 

Here, the issue comes up again with respect to an edible pet chew. Claim 5 on appeal is reproduced below:

The limitation in question was the last one in Claim 5: the “single sheet having co-extruded first and second areas with a different appearance or flavor from each other.” Of course, extrusion is a method of manufacture. So, while the examiner cited prior art that shows the first and second limitations, that reference did not disclose the co-extrusion to form the first and second areas. Rather, the cited art showed an extrusion that was then surface treated to form the alleged first and second areas.

The PTAB found that the Examiner had not shown that the prior art product had the same structure as in claim 5:

Thus, because the applicant was successful in establishing that the resulting single sheet structure formed by co-extruding was a different structure than that shown in the cited art, the rejection was improper. In this way, the applicant did not have to overcome the shifted burden, and the burden remained with the examiner.

Applicants should take care when issues such as those above arise as there can sometimes be a very thin line between whether the recitation in the claims is structural or merely a product by process limitation.