Federal Circuit Vacates Summary Judgment in Treadmill Patent Dispute, Finding Claim Construction Too Narrow

The U.S. Court of Appeals for the Federal Circuit (CAFC) issued a decision today in Woodway USA, Inc. v. LifeCore Fitness, Inc., vacating a grant of summary judgment of noninfringement in favor of LifeCore Fitness, doing business as Assault Fitness. The court found that the U.S. District Court for the Southern District of California relied on an overly restrictive claim construction, vacating and remanding the decision for further proceedings.

The decision involves some of the same patented technology at issue in a PTAB appeal in which the CAFC on Friday affirmed a Patent Trial and Appeal Board (PTAB) finding that Woodway’s curved treadmill claims were unpatentable as obvious. That earlier appeal arose from an inter partes review (IPR) and addressed the meaning of “running surface.” Today’s decision arises from a separate district court infringement suit and concerns a different claim limitation.

Woodway owns three related patents, including U.S. Patent No. 10,561,884, which was the subject of the PTAB appeal, covering manual treadmills with a curved running surface. The patents describe safety mechanisms allowing the treadmill belt to move freely in a preferred direction while substantially preventing movement in the opposite, dispreferred direction, since unintended forward rotation of the belt can cause a user to lose their footing. Disclosed embodiments include a one-way bearing assembly, as well as a cam locking system and other braking mechanisms.

Woodway filed suit against LifeCore in April 2022, alleging that certain LifeCore manual treadmills infringed the patents. At a Markman hearing, the parties presented competing readings of the claim limitation requiring the belt’s movement to be “substantially prevented” in the dispreferred direction. Woodway argued the term should carry its plain and ordinary meaning, largely but not necessarily entirely preventing movement, while LifeCore argued for a construction requiring the belt to be locked into only one rotational direction. The district court adopted neither proposal outright, and instead construed the limitation to restrict rotation to only one direction of movement. Since the accused treadmills’ belts could rotate fully in both directions under normal conditions, the district court granted summary judgment of noninfringement for LifeCore in January 2025.

On appeal, the CAFC agreed with Woodway that the district court’s construction was erroneous. The claim language broadly requires only that rotation be “substantially” prevented, and limiting the term to complete prevention would render the word “substantially” meaningless, a result Federal Circuit precedent disfavors. The court also found nothing in the patents’ shared specification that narrowed the plain meaning of the term. It noted that some disclosed embodiments include no safety device at all, and that the specification’s discussion of preventing forward rotation does not require complete prevention.

The district court had also found that Woodway disclaimed any claim scope covering bidirectional belt movement during prosecution of the ‘884 patent, when Woodway distinguished two prior art references, identified in the opinion as Bostic and Savettiere, each involving a one-way clutch mechanism. The CAFC rejected this finding as well, holding that “for disclaimer to attach, disavowals must be ‘both clear and unmistakable.’” Regarding Bostic, the court found that Woodway’s claim amendment and remarks to the patent examiner highlighted a broader distinction. Specifically, the prior art’s safety device affected only an internal flywheel, not the treadmill belt itself, rather than disclaiming bidirectional belt movement outright. As for Savettiere, the court similarly found that Woodway’s prosecution statements addressed a different structural distinction and did not specify whether prevention of movement in the dispreferred direction needed to be absolute.

After concluding that the finding of prosecution disclaimer could not stand, the CAFC concluded that the district court should have adopted Woodway’s proposed construction of “substantially prevent.” As the summary judgment of noninfringement rested on the flawed construction, the CAFC ultimately vacated the judgment and remanded for further proceedings.