Patent bar Obviousness (35 U.S.C. 103) question: claim recites an alloy containing

Patent barObviousness (35 U.S.C. 103)

A claim recites an alloy containing 8-12% chromium. The prior art reference describes the same alloy containing 10-20% chromium for the same purpose. The applicant offers no evidence about the significance of the claimed range. How should the examiner treat the claim under 35 U.S.C. 103?

A As prima facie obvious, because the claimed range overlaps the prior art range, absent a showing of criticality
B As nonobvious, because the reference does not disclose the 8-10% portion of the claimed range
C As anticipated, so an obviousness rejection would be improper in every case
D As nonobvious, because ranges can be rejected only under 35 U.S.C. 112(b)
E As nonobvious unless a second reference teaches the exact 8-12% range

Show the answer and explanation

Answer: A. As prima facie obvious, because the claimed range overlaps the prior art range, absent a showing of criticality

Answer: As prima facie obvious, because the claimed range overlaps the prior art range, absent a showing of criticality. Where claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists (In re Wertheim; In re Peterson). The applicant may rebut it by showing the claimed range is critical, for example through unexpected results, or that the art teaches away (MPEP 2144.05). Why not the others: - Part of the range is undisclosed: overlap, not complete identity, is enough for a prima facie case. - Anticipation only: an overlapping range may anticipate in some cases, but obviousness remains a proper ground. - A second reference: the overlap within one reference supports the case. - Only under 112(b): ranges can be indefinite, but obviousness under 103 applies to ranges like any other limitation. Rule: Overlapping or encompassing ranges create a prima facie case of obviousness, rebuttable by criticality or teaching away. Source: MPEP § 2144.05 (9th ed., Rev. 01.2024); 35 U.S.C. 103; as at Oct 2026

Common mistake

Thinking any undisclosed sliver of a claimed range defeats obviousness.

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Original study material written from the MPEP; not a question from the current exam.Independent. Not affiliated with or endorsed by the USPTO. Verify figures and rules against current guidance before relying on them.