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Court “Shifts” Claim Construction for Bicycle Gear Shift Patent

July 17, 2003

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Last Month at the Federal Circuit - August 2003

Judges: Bryson (author), Lourie, and Gajarsa

In Sunrace Roots Enterprise Co. v. SRAM Corp., No. 02-1524 (Fed. Cir. July 17, 2003), the Federal Circuit reversed the district court’s claim construction of the term “shift actuator,” finding the construction too limiting, and remanded the case for further proceedings.

U.S. Patent No. 4,900,291 (“the ‘291 patent”), owned by SRAM Corporation (“SRAM”), discloses and claims a gearshifting mechanism for bicycles that uses a shift actuator designed to precisely control movement of a chain derailleur. The ‘291 patent contains apparatus claims that recite a “shift actuator” with and without a “cam means.”

Based on a letter by SRAM to Sunrace Roots Enterprise Company, Ltd. (“Sunrace”) asserting that Sunrace was infringing its reexamined ‘291 patent, Sunrace filed a DJ action claiming that it did not infringe the ‘291 patent and also that the ‘291 patent was invalid and unenforceable. SRAM counterclaimed, asserting infringement of claims 16 and 20 of the ‘291 patent. The district court construed the term “shift actuator” to mean “a mechanism for controlling the changing of gears that contains a cam configured with a series of lobes and valleys that rotates so as to engage a cam follower.” In providing this construction, the parties and the district court agreed that the plain and ordinary meaning of “shift actuator” is “a mechanism that controls the changing of gears.” However, the district court adopted a more limiting construction based on the specification and the prosecution history, finding that the cam was integral to the invention disclosed and stating that the specification did not suggest that the invention might be embodied in a structure that does not use a cam. The district court also found that the prosecution history of the ‘291 patent indicated that SRAM and the Examiner considered the “shift actuator” to require the cam mechanism.

Based on the district court’s claim construction, the parties stipulated that Sunrace’s devices did not infringe claim 16, and the district court entered judgment on that basis. SRAM appealed the district court’s claim construction of claim 16, but not claim 20.

The Federal Circuit reversed the district court’s claim construction of the term “shift actuator,” finding it unduly restrictive, and adopted instead the meaning that a “shift actuator” is “a mechanism that controls the changing of gears.”

In so doing, the Federal Circuit began with the presumption that the plain and ordinary meaning applies to disputed claim language unless such presumption has been overcome. In finding that the presumption was not overcome in this case, the Federal Circuit turned first to the doctrine of claim differentiation. The Federal Circuit noted that claim 24, which depends from claim 16, specifically recites that the “shift actuator comprises a cam means rotatably mounted on the bicycle handlebar generally coaxially of the handlebar,” and that the “cam means” portion of claim 24 was the only difference between claims 16 and 24. The Federal Circuit further relied on the fact that SRAM had canceled claims 27 and 28 during reexamination after amending claim 16 to include the limitations of those claims, but did not likewise cancel claim 24, indicating that SRAM believed claim 16 was not limited to a shift actuator including a cam means.

The Federal Circuit next considered the specification to determine if SRAM had defined “shift actuator” differently from its plain and ordinary meaning. Reviewing portions of the specification that discussed various objects of the invention as including a cam structure and which the district court had relied on in combination with the absence of any disclosure of a shift actuator that did not include a cam means in order to narrow the scope of the term “shift actuator,” the Federal Circuit found that the various statements did not evidence an intent to depart from the ordinary meaning. Instead, the Federal Circuit determined that some of the statements detailed goals of the invention relating to the apparatus claims, but that other goals also were set forth in the specification that did not relate to providing a cam mechanism. The Federal Circuit found that the ‘291 patent specification does not indicate that the cam aspect is the invention itself.

Considering the final piece of intrinsic evidence, the prosecution history, the Federal Circuit found no clear evidence of disclaimer. Regarding various statements describing the ‘291 patent’s use of a cam structure that the district court had relied on as effecting a disclaimer, the Federal Circuit concluded that those statements were not specific to method claim 16 but rather appeared to relate to the apparatus claims.

In finding that any ambiguity in the plain meaning could be resolved by the intrinsic evidence, the Federal Circuit also rejected any consideration of extrinsic evidence in the form of inventor testimony that Sunrace had offered in support of the district court’s construction.