IP Law Daily Patent claims for innovative bicycle chainring not invalid as obvious
Monday, May 18, 2020

Patent claims for innovative bicycle chainring not invalid as obvious

By Thomas Long, J.D.

Cited prior art was missing a key feature of the patented invention, and that feature was what drove the chainring’s success in the market.

Substantial evidence supported a Patent Trial and Appeal Board decision that 26 challenged claims of a patent relating to an innovation in bicycle chainrings were not unpatentable as obvious, the U.S. Court of Appeals for the Federal Circuit has held. Prior art did not disclose a key limitation of the patent—that the claimed chainring’s teeth should fill a specific amount of a chain link space at the midpoint of the tooth. In addition, evidence that skilled artisans were surprised by the patent’s innovation, and that the claim limitation at issue was the primary driver of the chainring’s commercial success, supported the Board’s findings that the claims were not obvious (Fox Factory, Inc. v. SRAM, LLC, May 18, 2020, Lourie, A.).

The patent owner, SRAM, LLC, and the party challenging the patent, Fox Factory, Inc., were competitors in the bicycle market. SRAM had developed several improvements in bicycle design that enabled it to sell bicycles with a solitary chainring (the "X-Sync chainring"), which allowed the roller chain to be more snugly fit to the gears of the chainring, improving retention of the chain even under trying conditions. SRAM’s U.S. Patent 9,291,250 ("the ’250 patent") disclosed that the standard bicycle chain had alternating inner and outer links, and the outer links had a much wider space in the center. Conventional chainrings had teeth that were the same size, so the teeth fit too loosely into the outer link spaces. The ’250 patent proposed a single chainring with alternating teeth, one conventional set that fit the inner chain links and a widened set that fit the outer chain links. Claim 1 of the ’250 disclosed that the widened set should fill at least 80 percent of the width of the outer chain links.

SRAM filed suit against Fox Factory and its subsidiary, Race Face Performance Products, in an Illinois federal court, asserting infringement of the ’250 patent, along with its parent patent, U.S. Patent 9,182,027 ("the ’027 patent"). The ’027 patent also claimed a bicycle chainring where every other tooth is widened, but the claims did not specify the degree to which these teeth are widened, and they required the teeth to be offset.

Fox Factory petitioned the Board for inter partes review (IPR) of the ’250 and ’027 patents on the ground of obviousness. With respect to the ’250 patent, Fox Factory cited a Japanese patent publication, JP S56-42489 ("Shimano"), and U.S. Patent 3,375,022 ("Hattan"). Shimano taught a bicycle chainring with widened teeth to fit into the outer chain links of a conventional roller chain. Hattan described an elliptical chainring and disclosed that the chainring’s teeth should fill between 74.6 percent and 96 percent of the inner chain link space.

The Board held that the ’027 patent claims were not unpatentable as obvious. On appeal, the Federal Circuit vacated the Board’s decision because it applied the wrong legal standard for evaluating the relevance of secondary considerations to obviousness. In the court’s view, SRAM argued, in the ’027 and ’250 patent IPRs, for the nonobviousness of each patent based upon the same secondary considerations evidence. However, the court explained, the same evidence of secondary considerations cannot be presumed to be attributable to two different combinations of features.

In the ’250 patent IPR, the Board decided that the claims were nonobvious, finding that the claimed invention’s "axial fill limitation"—that the widened teeth fill at least 80 percent of the width of the outer link spaces at the midpoint of the tooth—unmet by the cited prior art. The Board found that Hattan only taught filling between 74.6 percent and 96 percent of the width at the bottom of the tooth. The Board then found that SRAM’s evidence of secondary considerations rebutted Fox Factory’s argument that a skilled artisan nevertheless would have found it obvious to modify the chainring’s teeth to meet the axial fill limitation. Fox Factory appealed to the Federal Circuit.

Fox Factory argued that the Board’s conclusion of nonobviousness was in error because the only difference between the prior art and the claimed invention was the degree to which the widened teeth should fill the outer chain link spaces, measured halfway up the tooth. It also contended that the Board erroneously presumed that there was a nexus between the claimed invention and evidence of success of the X-Sync chainring (which bolstered the nonobviousness finding). Fox factory argued that other features drove the product’s commercial success, not the axial fill limitation.

According to SRAM, Fox Factory failed to provide any prior art that rendered the axial fill limitation obvious to a skilled artisan. SRAM also asserted that the Board correctly credited its evidence of secondary considerations of nonobviousness because the X-Sync chainring’s widened teeth—the product’s novel feature—were responsible for the product’s success.

The court agreed with SRAM. "The Board found that found that SRAM’s optimization of the X-Sync chainring’s teeth, as claimed in the ’250 patent, displayed significant invention," the court said. "It based its conclusion on secondary considerations that strongly indicated that the X-Sync chainring’s success surprised skilled artisans." It was not error for the Board to conclude that this evidence defeated SRAM’s contention of "routine optimization" that did not meet the innovation requirements of 35 U.S.C. §103. The Federal Circuit said that its previous decision on the ’027 patent did not require vacatur here because critical facts differed. In particular, the ’250 patent’s recitation of the greater than 80 percent axial fill limitation.

The court concluded that substantial evidence supported the Board’s determination of nexus, based on its finding that the X-Sync chainring’s success is largely due to its teeth profile, which was essentially the claimed invention. "On this record, it makes no difference that the patent owner chose to claim those innovations in terms of how much of the outer chain link space is filled by the widened teeth," the court said. "In view of the Board’s findings on secondary considerations, we agree with its conclusion that the ’250 patent claims would not have been obvious."

This case is No. 19-1544.

Attorneys: Erik R. Puknys (Finnegan, Henderson, Farabow, Garrett & Dunner LLP) for Fox Factory, Inc. Richard Bennett Walsh, Jr. (Lewis Rice LLC) for SRAM, LLC.

Companies: Fox Factory, Inc.; SRAM, LLC

MainStory: TopStory Patent GCNNews FedCirNews

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