It’s not unusual for examiners to reach for a prior art figure showing a device mid-assembly and assert that it meets a product claim. But when the claim is to the final product, not the work-in-progress, that kind of shortcut can run into trouble.

Rejections that rely on intermediate or unfinished products can raise subtle but important issues in patent prosecution. Whether the claim is directed to a method or a product often determines how persuasive such a rejection will be, and how the applicant reacts.

In method claims, prior art disclosures of intermediate steps may be more relevant, because what matters is whether the steps themselves are taught or suggested. For example, if the prior art discloses performing a manufacturing step that temporarily creates a structure or state, that temporary state can sometimes satisfy a claimed method step.

But for product claims, the analysis can be different, especially when the missing limitation can be characterized as result-oriented. What matters is more the final structure of the product itself—not what temporary configurations may exist during manufacture.

A recent PTAB decision, Appeal 2024-004140, illustrates this distinction clearly.

The Case: Unsealed Gaps and Unfinished Products

The claims at issue were directed to an intraluminal imaging device and required, in part:

“a flexible substrate rolled around the central longitudinal axis such that a first end and a second end of the flexible substrate are spaced from one another such that an unsealed gap is formed between the first end and the second end.”

The Examiner relied on a prior art reference that depicted a gap R during manufacture, arguing that this “unsealed gap” satisfied the claim limitation. As the Examiner explained, the gap was shown at an “intermediate step” in the manufacturing process and was “filled later in a manufacturing step” using adhesive, which fixed the ends of the layers together.

The PTAB disagreed. It found that:

“the cited prior art fails to disclose ‘an unsealed gap is formed between the first end and the second end’ as claimed wherein the gap extends between an outer surface and an inner surface of the flexible substrate.”

And further:

“the [prior art] reference only discloses this ‘unsealed gap’ in an unfinished manufacturing state and the rejection fails to provide articulated reasoning with rational underpinnings to use this ‘unfinished product’ in the combination with the other elements of the claim.”

Because the claims were directed to a device with certain structure, the prior art’s depiction of a temporary gap during manufacturing did not anticipate or render obvious the final claimed structure. The “intermediate state” was not itself a product meeting the claim limitations.

Practice Tips

• For product claims, consider focusing the argument on whether the final structure of the prior art corresponds to the claimed structure—not whether some transient state during manufacturing looks similar. If possible, amend the claims to make clear that certain structure is achieved in the product.
• Scrutinize the Examiner’s reliance on intermediate steps. If the rejection is based on a manufacturing intermediate, consider whether that intermediate is actually disclosed as a final product, or whether it is simply a temporary configuration that is later changed or eliminated. Also consider whether there are any hints in the prior art to use an intermediate product.
• Distinguish teaching from suggestion. Even if a temporary intermediate step superficially resembles the claimed structure, it may not teach or suggest that structure as a final product—especially if the reference may lack a suggestion to use the intermediate product by, for example, promptly modifying it.

Intermediate product rejections often arise in fields like medical devices, packaging, and semiconductor fabrication, where temporary structures are common. But as Appeal 2024-004140 shows, for product claims, “almost” doesn’t count—an unfinished structure during manufacturing is not the same as the claimed product itself.