Patent law is rife with rules and doctrines that can seem contradictory, especially in the realm of obviousness under 35 U.S.C. 103. One example issue arises from two conflicting principles:
There is generally no motivation to add features from a secondary reference when the motivation is merely to solve a problem that the primary prior art reference has already solved.
A skilled artisan may still have motivation to combine references and make modifications, even if the prior art performs adequately, to seek further improvement.
These doctrines appear to pull in opposite directions, leaving patent practitioners to navigate a fine line when prosecuting applications. Yet, understanding how to dissect obviousness rejections along these lines can help in framing arguments to help practitioners fall into the first category above, rather than the second. This post explores how some options to reconcile these rules in some situations so practitioners can help clients overcome obviousness rejections.
The first rule reflects a safeguard against improper motivation to combine or modify references. Examiners frequently identify a problem in the primary reference that can be addressed by a secondary reference, using this as the basis for combining the references to reach the claimed invention. However, if the primary reference has already solved the problem, there may be no valid motivation to combine them, even if the Examiner argues that the secondary reference offers a potential "further improvement." This is one reason to carefully evaluate problem-solution motivation to determine whether the supposed problem is illusory or non-existent, or already addressed by the primary reference itself.
On the flip side, the second rule acknowledges that even if prior art adequately addresses a problem, innovation does not stagnate. A skilled artisan may still be motivated to improve on existing solutions by combining references, especially if doing so offers a specific technical advantage or an improvement in functionality.
One potential approach to reconcile these rules lies in examining the reasoning provided by the examiner and strategically crafting arguments based on the strength of that reasoning.
as noted above, when forming an obviousness rejection based on a combination of prior art references, the examiner articulates a motivation for why a skilled artisan would have combined the references. It is in this explanation that patent practitioners can often find opportunities to push back.
If the motivation is simply to solve the same problem already addressed by the primary reference, there may be grounds to argue that there is no meaningful reason to combine the secondary reference. This argument could be framed as an improper attempt to reconstruct the invention using hindsight. In such cases, it may be effective to emphasize that the motivation cited by the examiner adds no value or innovation beyond what the primary reference already provides. For an example case, see a previous post here.
If the examiner’s motivation points to a furtherance of an already recognized advantage or some other technical improvement brought about by the combination, practitioners should focus on analyzing the strength of that motivation. Even if the prior art already performs the task adequately, the examiner may successfully argue that the combination yields additional benefits (e.g., improved efficiency, cost savings, or enhanced performance). In such cases, arguing that the prior art already solves the problem might be ineffective unless there is clear evidence that the combination provides no added value or lacks a reasonable expectation of success, for example.
An example of the latter case is illustrated in a recent PTAB decision - Appeal 2024-003213, Application 18/020,699. The invention by 3M relates to a fall-protection safety harness. Claim 1 is reproduced below:
1. A fall-protection safety harness configured so that when the harness is worn by a user, a first ventral strap of the harness extends from the right shoulder of the user to the right hip of the user and a second ventral strap of the harness extends from the left shoulder of the user to the left hip of the user, wherein a single first buckle portion is mounted on the first ventral strap and a single second buckle portion is mounted on the second ventral strap, the first and second buckle portions being detachably attached to each other to form a single ventral buckle; and, wherein the first and second ventral straps and the first and second buckle portions are configured so that the single ventral buckle is at least generally aligned with a sagittal plane of the user and so that a section of the first ventral strap that extends through the first buckle portion is in overlapping relation with a section of the second ventral strap that extends through the second buckle portion.
The examiner rejected the claim based on a primary reference that was missing disclosure of the alignment with the sagittal plane of the user and the overlapping relation of the recited ventral straps, and so the Examiner relied on a secondary reference. The Examiner’s reasoning for the combination was that the chest strap and buckle of the primary reference could be replaced with a buckle arrangement configured to overlap the first and second ventral straps as taught
by the secondary reference to help shift the straps away from the user’s armpits, avoiding uncomfortable pinching and allowing for greater flexibility of the of the upper while body while working.
3M argued that the primary reference did not disclose the straps as being too close to the user’s armpits to cause discomfort or restrict flexibility. Specifically, 3M pointed out that there was no justification for replacing the ventral straps and buckle of the primary reference with that of the secondary reference on the grounds that it would enhance the user's upper-body flexibility beyond that already allowed by the primary reference.
The PTAB disagreed (internal citations omitted).
As for Appellant’s assertion that [the primary reference’s] straps are not disclosed as being too close to the user’s armpits to cause discomfort or restrict flexibility, we understand the Examiner’s proposed modification to be based on an improvement to Neustater’s harness, not the disclosure of any existing deficiency in it. The fact that the prior art may already perform adequately (such as by providing sufficient flexibility and comfort) does not preclude a skilled artisan from seeking to improve upon it.
Thus, by characterizing the issue in this way, the PTAB dismisses 3M’s attack on the rejection and the case falls into the second option discussed above.
Recognizing how to reconcile the apparent contradiction illustrated in this post can be a powerful tool during patent prosecution - recognizing when the rejection is open to a strong attack versus when further amendments may be prudent. By focusing on the quality and nature of the examiner’s articulated reasoning, practitioners can craft arguments that align with the strengths or weaknesses of the examiner's rejection. If the reasoning is flawed and rests on solving a problem already addressed by the primary reference, there is a clear opportunity to push back. Conversely, if the examiner points to a legitimate improvement, the attack must focus elsewhere. Recognizing when and how to employ these strategies can be helpful to efficiently advancing prosecution.