PTAB

IPR2019-00990

MCP IP, LLC v. Craig Yehle

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1. Case Identification

2. Patent Overview

  • Title: Cable-Synchronized Dual-Cam Archery Bow
  • Brief Description: The ’979 patent describes a cable-synchronized, dual-cam compound archery bow. The invention focuses on specific arrangements of cam assemblies, including power cable take-up and let-out mechanisms, designed to avoid a 100% "let-off" of draw force, which can cause the bow to "cock" and become inoperable or unsafe.

3. Grounds for Unpatentability

Ground 1: Claims 1-22 are obvious over Darlington in view of Wing and Kam-Act.

  • Prior Art Relied Upon: Darlington (Patent 6,990,970), Wing (a 1976 article in BOW & ARROW magazine), and Kam-Act (a 1974 article in BOW & ARROW magazine).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that the combination of references taught all limitations of the challenged claims. Darlington was argued to disclose the fundamental structure of a synchronized dual-cam bow, including a handle, limbs, and first and second cam assemblies with draw cable journals, power cable take-up mechanisms, and power cable let-out mechanisms, as recited in independent claims 1 and 12. Darlington also taught rotation stops (relevant to claims 6 and 17) and embodiments with posts instead of pulleys (relevant to claim 5). The Wing reference, an evaluation of the "Impact II" bow, was argued to supply the specific teachings on lever arm ratios that the patentee relied on to overcome prior art during prosecution. Petitioner contended that calculations based on photographs in Wing demonstrated the specific lever arm ratios recited in claims 8-10 and 19-21, and critically, disclosed a cam arrangement that inherently avoids 100% let-off by providing 46-50% relaxation at full draw. The Kam-Act reference was cited for its disclosure of selectively repositionable draw stops, which Petitioner argued rendered it obvious to make Darlington's draw stops adjustable, as recited in claims 7 and 18.
    • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would have been motivated to combine the references. Both Darlington and Wing disclose dual-cam archery bows and address the same fundamental operational principles. A POSITA seeking to design a safe and effective bow like Darlington's would have looked to contemporary designs like the Wing "Impact II" for proven, safe let-off characteristics and lever arm ratios to prevent the known danger of 100% let-off. The motivation to incorporate Kam-Act's teachings was to add adjustability to the draw stops of a bow like Darlington's, a well-known method for improving versatility and accommodating different archer preferences.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success. Combining the cam geometry and lever arm ratios from Wing with the bow structure of Darlington would predictably result in a safe, functional bow that avoids 100% let-off, as both systems operate on the same mechanical principles. Adding adjustable stops from Kam-Act was a simple mechanical modification with predictable results.

4. Key Claim Construction Positions

  • “Lever arm of the power cable take-up mechanism” and “lever arm of the power cable let-out mechanism” (Claims 8-10, 19-21): Petitioner asserted these terms mean “the perpendicular distance between the force vector of the corresponding power cable and the reference location (axis of rotation).” This construction was critical to applying the lever arm ratios calculated from the Wing reference to the claims. Petitioner argued this is the standard definition used in torque calculations and is consistent with the patent's specification.
  • “A cam assembly ‘arranged so as to avoid 100% let-off of the draw force or so as to prevent cocking of the bow’” (Claims 1, 12, 13): Petitioner proposed this phrase means “shaped or positioned to provide a reduction in the holding force when the bow is fully drawn relative to the peak force it initially took to get the bow drawn all the way back.” This construction framed the concept not as a novel feature, but as an inherent result of any cam design with a lever ratio that does not reach a 100% let-off condition, a characteristic Petitioner argued was explicitly taught by Wing.
  • “Journal” (Claims 1, 3, 4, 9-15, 20-22): Petitioner asserted that "journal" is synonymous with "groove," a feature necessary to receive a cable and prevent it from slipping off a cam assembly.

5. Relief Requested

  • Petitioner requested that an inter partes review be instituted and that claims 1-22 of the ’979 patent be cancelled as unpatentable.