On February 2, 2026, the Federal Circuit affirmed summary judgment of non-infringement in Range of Motion Products, LLC v. Armaid Company Inc., No. 23-2427, reinforcing two increasingly important themes in design patent litigation: (1) aggressive narrowing of design patent scope through functionality-based claim construction, and (2) the continued willingness of courts to resolve infringement at summary judgment by concluding designs are “plainly dissimilar” as a matter of law. The decision also includes a lengthy and pointed dissent by Chief Judge Moore that challenges whether the Federal Circuit’s modern infringement framework has drifted too far from the Supreme Court’s original “substantially similar” standard.
Background and the Design at Issue
Range of Motion Products (“RoM”) owns U.S. Design Patent No. D802,155, titled “Body Massaging Apparatus.” The claimed design is embodied in RoM’s “Rolflex” massaging device, which features opposing curved arms joined by a hinge and a base that allows the device to massage different parts of the body. Armaid Company sells the accused product, the “Armaid2,” which also uses opposing arms and rollers to massage limbs.
Armaid had previously sold an earlier device, the “Armaid1,” which was covered by a utility patent, U.S. Patent No. 5,792,081. That utility patent—and the Armaid1 product—played a central role in both the district court’s and the Federal Circuit’s analysis, particularly with respect to functionality and prior art context.
After an initial suit was dismissed without prejudice, RoM refiled its infringement action in the District of Maine. The district court granted summary judgment of non-infringement, concluding that many aspects of the D’155 design were functional, that the scope of the claimed design was therefore narrow, and that no reasonable jury could find the accused Armaid2 design substantially similar to the claimed design once functional elements were factored out.
Claim Construction and Functional Versus Ornamental Features
On appeal, RoM first challenged the district court’s claim construction, arguing that the court improperly eliminated entire structural elements—particularly the shape of the arms—from the claimed design by labeling them functional.
The Federal Circuit rejected this argument. Relying heavily on Sport Dimension, Inc. v. Coleman Co., PHG Technologies, LLC v. St. John Companies, and Ethicon Endo-Surgery, Inc. v. Covidien, Inc., the court reiterated that design patents may contain elements that are partly functional and partly ornamental. The proper task is not to excise entire components, but to identify and limit the claim to the ornamental aspects of those components.
Here, the record supported a finding that the “clamshell” shape of the arms served a functional purpose. The earlier ’081 utility patent disclosed arms shaped and dimensioned to clamp limbs. Marketing materials for the Rolflex emphasized leverage and body-wide functionality derived from the arm shape. Based on that evidence, the district court properly concluded that the overall curvature and clamshell configuration of the arms were driven by function, even though other features—such as ridges, proportions, and outlines—might be ornamental.
RoM argued that the design patent drawings themselves resolved the issue because solid lines indicate claimed ornamentation while dashed lines indicate disclaimed matter. The Federal Circuit firmly rejected that approach. Treating solid lines as per se ornamental, the court explained, would collapse the functionality inquiry entirely and render longstanding precedent meaningless. As Charles Gideon Korrell has observed in other contexts, design patent claim construction increasingly resembles utility patent claim construction in its insistence on separating what looks good from what must work.
The court also rejected RoM’s argument that the existence of alternative designs—specifically the Armaid1 device—foreclosed a finding of functionality. Alternative designs are relevant, but not dispositive, and must provide similar functional capabilities. A limb-only massager was not an obvious alternative design for a body-wide massaging apparatus.
Infringement and the “Plainly Dissimilar” Framework
Turning to infringement, the Federal Circuit affirmed summary judgment under the ordinary observer test articulated in Egyptian Goddess, Inc. v. Swisa, Inc. Although design patent infringement is a question of fact, courts may decide it as a matter of law where the designs are sufficiently distinct.
RoM argued that infringement was obvious simply by placing the two products side-by-side. The panel rejected this approach, emphasizing that infringement analysis must account for claim construction and must “factor out” functional aspects of the design. Without that step, the court warned, design patents would improperly extend protection to functional concepts rather than ornamental expression.
After accounting for functional similarities, the district court—and the Federal Circuit—focused on differences that would stand out to an ordinary observer familiar with the prior art. These included:
- The prominence and proportions of the base and hinge structure.
- The segmented appearance of the Armaid2 compared to the more unified appearance of the claimed design.
- Differences in slot sizing and visual emphasis.
- Differences in curvature and overall “stylized impression.”
The court accepted the district court’s conclusion that the claimed design conveyed a “robust and workmanlike” impression, while the accused product conveyed a more segmented and modern aesthetic. Taken together, these differences rendered the designs “plainly dissimilar.”
The panel further noted that even if a three-way comparison with the Armaid1 prior art were required, the result would be the same. Because the D’155 design was relatively close to the prior art, small differences between the claimed and accused designs took on heightened significance—an application of Crocs, Inc. v. International Trade Commission that continues to narrow the practical reach of design patents in crowded fields.
Chief Judge Moore’s Dissent: A Call to Revisit Egyptian Goddess
Chief Judge Moore dissented vigorously, arguing that the majority’s analysis—and modern design patent jurisprudence more broadly—has subtly but materially shifted the infringement inquiry away from “substantial similarity” and toward “plain dissimilarity.”
In her view, this linguistic shift matters. Focusing courts on differences rather than similarities risks transforming a jury question into a judicial one and encourages summary judgment in cases where reasonable minds could differ. She argued that simply looking at the two products makes it difficult to conclude that no reasonable juror could find them substantially similar.
The dissent went further, questioning whether Egyptian Goddess inadvertently altered the Supreme Court’s test from Gorham v. White. Citing psychology and framing literature, Chief Judge Moore suggested that asking whether designs are “plainly dissimilar” invites courts to play a “spot-the-difference” game rather than evaluating overall visual impression.
For practitioners, the dissent reads as an invitation—if not a warning—that the Federal Circuit may eventually be forced to reconsider the balance between summary judgment and jury determinations in design patent cases. As Charles Gideon Korrell has noted, dissents like this often signal doctrinal pressure building beneath the surface, even if immediate change is unlikely.
Key Takeaways
This decision reinforces several practical lessons for design patent owners and accused infringers alike:
First, design patent scope will be aggressively narrowed where functional considerations are present, even if the design is depicted entirely in solid lines. Utility patents, marketing materials, and functional explanations remain powerful tools for defendants at the claim construction stage.
Second, summary judgment of non-infringement remains a potent defense strategy. Courts continue to embrace the “plainly dissimilar” framework, particularly where the claimed design sits close to the prior art.
Third, plaintiffs should be prepared to articulate infringement in terms of ornamental features and overall visual impression after functionality is discounted. Side-by-side similarity alone is unlikely to survive summary judgment.
Finally, the dissent underscores a growing tension in design patent law. Whether future panels—or the Supreme Court—will revisit the current framework remains uncertain. For now, however, Range of Motion v. Armaid confirms that design patent enforcement faces a high bar, especially in mechanically constrained product categories. Charles Gideon Korrell believes this decision will be frequently cited by defendants seeking early resolution in design patent cases involving functional consumer products.