Woodway USA, Inc. v. Lifecore Fitness, LLC — Federal Circuit Affirms PTAB Invalidity of Curved Treadmill Belt Patent

Background

Woodway USA makes premium manual (non-motorized) treadmills and holds U.S. Patent No. 10,561,884, directed to manually powered treadmills featuring a curved running belt — the signature curved-deck design that distinguishes Woodway machines from conventional flat-belt treadmills. Lifecore Fitness, which sells treadmills under the Assault Fitness brand, filed a petition for inter partes review (IPR) at the Patent Trial and Appeal Board (PTAB), challenging claims 30–34, 37–54, 57, and 59 as obvious over a combination of prior art references.

The Board agreed with Lifecore, finding the challenged claims unpatentable as obvious over three prior art references: U.S. Patent 3,637,206 (Chickering), which discloses a single-belt manual treadmill with rollers arranged in upward- and downward-sloping planes creating a curved central portion; U.S. Patent 5,538,489 (Magid), which teaches a unidirectional safety device to prevent forward belt rotation; and a mechanical-devices textbook (Sclater) disclosing a sprag-type one-way bearing. Woodway appealed to the Federal Circuit, contesting the Board’s interpretation of the “curved running surface” limitation and its rejection of commercial success evidence.

The Court’s Holding

The Federal Circuit (Lourie, Hughes, Stoll) affirmed the Board’s obviousness determination in full. On claim construction, Woodway argued that “curved running surface” must be limited to portions of the belt where a runner’s feet actually land during normal use — a construction that would have excluded Chickering’s curved roller-transition zone. The court rejected this on two grounds. First, neither party asked the Board to expressly construe the term, so there was no implicit claim construction to attack — the Board merely made factual findings about what Chickering disclosed. Second, even if the Board’s analysis implied a construction, the plain claim language and the ‘884 patent specification support the broader reading: the patent consistently describes the “running surface” as a continuous belt surface encompassing front, central, and rear regions with varying geometric configurations, none of which are limited to foot-contact zones.

On motivation to combine, the court upheld the Board’s finding that a skilled artisan would have modified Chickering’s treadmill with Magid’s ratchet-and-pawl safety device to prevent injurious forward rotation, then substituted Sclater’s one-way sprag bearing for reduced noise and improved durability — both supported by the references themselves and by expert testimony. The court likewise upheld the Board’s rejection of Woodway’s secondary considerations. The Board found no nexus between the commercial success of Woodway’s curved treadmills and the specific patented safety features: the same Woodway witness who cited safety as a commercial driver also conceded that the company’s broader brand reputation could explain commercial success, severing the required causal link.

Key Takeaways

• Claim terms cannot be limited by expert testimony that conflicts with the specification. Woodway’s expert defined “running surface” as foot-contact zones only, but the Federal Circuit refused to import that limitation where the patent itself used broader, multi-region language.
• Secondary considerations require a tight nexus to the claimed features. Commercial success of the overall product does not save a patent from obviousness unless the patentee proves that success flows specifically from the patented invention rather than brand, quality, or other unclaimed advantages.
• Prior art scope is a factual question reviewed deferentially. The Federal Circuit declined de novo review because Woodway failed to establish an actual claim construction dispute — disputes about what a prior art reference discloses are factual findings reviewed only for substantial evidence.

Why It Matters

The curved-deck manual treadmill market has grown substantially with the rise of high-intensity interval training (HIIT), and Woodway’s machines command premium prices partly on the strength of their distinctive curved-belt design. This ruling clears Lifecore’s Assault Fitness curved treadmills of Woodway’s patent claims, affirming that combining modular older references — a 1970s manual treadmill patent (Chickering) and a 1990s safety-device patent (Magid) — can anticipate modern claims over the same functional concept.

The opinion is nonprecedential and does not set binding Federal Circuit precedent, but it reinforces the court’s consistent approach to secondary considerations: without a tight causal link between the patented feature and marketplace performance, commercial success rarely defeats a well-built obviousness case. Companies relying on secondary considerations in IPR proceedings should invest early in establishing that nexus through quantitative evidence directly tied to the claimed features.