IP Law Daily, PATENT—W.D. Wis.: Crossbow patent fight largely resolved on claim construction, (Apr 21, 2026)

By George Basharis, J.D.

Competing summary judgment motions turn on cable configurations and claim language, producing mixed results across ten asserted patents and narrowing the case to a limited set of surviving infringement issues.

A dispute over competing crossbow designs turned on the meaning of claim language describing how cables are arranged and positioned, with the resulting constructions resolving most infringement questions without trial and leaving only a narrow set of claims for further proceedings. In a detailed opinion addressing ten asserted patents, the analysis focused on whether the accused devices satisfied specific structural limitations tied to cable routing, positioning, and interaction with rotating components, leading to a split outcome that favored the accused manufacturer on several patents while allowing others to proceed or prompting additional briefing (MCP IP, LLC v. Ravin Crossbows, LLC, No. 3:22-cv-00004-jdp (W.D. Wis. Apr. 15, 2026)).

Background. MCP IP, LLC and Ravin Crossbows, LLC design and sell compound crossbows used primarily for hunting. MCP owns a portfolio of patents developed by its founder, while Ravin Crossbows entered the market several years later with its own line of products. Both companies produce high-performance crossbows that rely on compound bow technology, in which pulleys and cables create mechanical advantage and allow for increased power and accuracy. The asserted patents relate largely to the configuration of pulleys, cables, and related components that store and transfer energy when a crossbow is drawn and fired.

Modern compound crossbows use rotatable members, such as cams or pulleys, connected by a bowstring and power cables that flex the limbs and store energy during the draw cycle. The patents at issue focus on how those cables are routed and positioned relative to the shooting axis, including configurations designed to balance forces on the rotating components while maintaining a clear path for the arrow.

The accused products include Ravin’s R500 series crossbows, which incorporate a distinct cable and limb configuration, including a double-limb arrangement and multiple cable segments. The parties did not materially dispute how the accused devices operate or their underlying mechanical structure. The dispute instead centered on how the patent claims should be interpreted and whether those claims, as construed, read on the accused designs.

Summary judgment. MCP and Ravin Crossbows filed cross-motions for summary judgment, with both sides asking the court to resolve infringement and validity issues as a matter of law. The court applied the standard two-step framework for patent disputes. First, the relevant claim terms were construed in light of the patent language, specification, and prosecution history. Second, the construed claims were compared to the accused devices to determine infringement or invalidity.

Because the structure and function of the accused crossbows were largely undisputed, the infringement analysis turned almost entirely on claim construction. The court emphasized that where the material features of an accused device are not in dispute, the question of infringement may be resolved at summary judgment if it depends solely on the meaning of the claim terms.

The court addressed a series of disputed limitations across the asserted patents, including terms governing how cables “extend between” components and whether cable positioners “bias” those cables away from the shooting axis. Those constructions proved dispositive for most of the asserted claims, allowing the court to resolve most infringement issues without proceeding to trial.

Mixed outcomes. The court analyzed ten patents covering different aspects of crossbow design, producing a range of outcomes. Several patents were resolved entirely in favor of Ravin Crossbows, with findings of noninfringement across all asserted claims. Others resulted in findings of infringement as a matter of law, coupled with rejection of invalidity defenses. A subset of patents remains in dispute. For those, the court either denied summary judgment or directed further briefing on whether judgment should be entered for MCP.

The mixed outcomes turned largely on how specific claim limitations apply across related patents, a point illustrated by the court’s treatment of a common group of cable-configuration patents.

“Over-under” cable. Turning to those patents, the court considered a group that share a common specification and describe a cable arrangement in which one cable runs above the shooting axis, and another runs below it. This configuration is intended to balance forces acting on the crossbow’s rotating components while preserving a clear path for the arrow.

The patents require, among other things, that cables extend between rotating members and be positioned relative to the shooting axis in specified ways, often in conjunction with a cable positioner that offsets the cables from that axis. The dispute focused on whether Ravin’s R500 design, which uses a different cable routing and limb configuration, satisfies those requirements as properly construed.

“Extending between” limitation. One key issue was the meaning of the phrase “extending between” in claims describing the path of cables between rotating members. MCP argued for a broader interpretation that would include cables located within the space between components. Ravin Crossbows urged a narrower reading requiring contact with both rotating members.

The court adopted a construction requiring that the cable reach from one rotating member to the other, including at least indirect attachment to both. Applying that interpretation, the accused crossbows did not meet the limitation. The R500 design uses a double-limb configuration in which cables terminate at anchors on the limbs rather than at the opposing rotating member. As a result, the cables do not extend between the two rotating components in the manner required by the claims. That conclusion led to summary judgment of noninfringement for two of the patents in this family.

Doctrine of equivalents. MCP also invoked the doctrine of equivalents, arguing that the accused design performs substantially the same function in substantially the same way to achieve the same result. The court rejected that argument, finding the supporting expert analysis too conclusory and insufficiently tied to the claimed limitations. The expert’s opinion consisted of only a brief, generalized assertion that the accused system stored energy and drew the limbs together in a similar manner, without addressing the specific claim element at issue or explaining how the accused configuration matched the claimed structure.

The court emphasized that the relevant function of the disputed limitation was not simply to draw the limbs together, but also to balance forces on the rotatable members and maintain clearance along the shooting axis. On that point, the record showed that the accused design achieves force balancing and clearance through a different structural approach, relying on a dual-limb configuration and multiple pairs of cables rather than routing a single set of cables between opposing rotatable members.

The court also noted that the accused crossbow terminates its cables at limb-mounted anchors positioned away from the opposing rotatable member, a configuration that differs from the claimed arrangement and alters how the system distributes forces. Considering those structural differences, the court concluded that the doctrine of equivalents could not be used to capture the accused design, particularly where the proffered analysis did not address how the claimed “extending between” limitation was met in an equivalent manner.

“Biasing” and “arranged to bias.” The court separately analyzed limitations requiring a cable positioner that “biases” cables away from the shooting axis. On this point, the accused devices were found to satisfy the claim language.

Photographic and structural evidence showed that the cable positioners in the accused crossbows deflect the cables away from a direct path between their endpoints, creating a measurable offset and maintaining clearance for the arrow. The court rejected the argument that any deflection was merely incidental, explaining that the claims do not require proof of a particular design purpose, only that the structure in fact biases the cables away from the axis.

For claims requiring a component “arranged to bias” the cables, the court adopted a construction meaning “configured to” perform that function, rather than merely capable of doing so. The court declined to read in a further limitation that the cable positioner must be necessary to achieve clearance, noting that such a requirement does not appear in the claim language and was not supported by the prosecution history.

Applying that construction, the court found that the accused devices meet the limitation because their cable positioners are structured in a way that causes the cables to be displaced from the shooting axis, regardless of whether other features of the design also contribute to that positioning.

Surviving claims. Because the “extending between” limitation was not present in all patents, some claims survived summary judgment. In particular, a related patent using the term “cable segment” rather than requiring cables to extend between rotating members was not subject to the same limitation. The court refused to import the “extending between” requirement into those claims, rejecting the argument that the shared specification compelled a narrower reading. It applied the ordinary meaning of “cable segment,” which does not require attachment to both rotatable members.

That distinction proved dispositive. While the accused crossbows failed to meet the “extending between” requirement in other patents, the absence of that limitation allowed certain claims to proceed, particularly where other elements, such as cable positioning and biasing, remained in dispute. Consequently, certain infringement issues remain unresolved and may be subject to further proceedings or additional rulings, including instances in which the court directed additional briefing on whether judgment should be entered for MCP on specific claims.

The Case is No. 3:22-cv-00004-jdp.

Judge: Peterson, J.

Attorneys: Carl Bruce (Fish & Richardson) for MCP IP, LLC. Adam P. Seitz (Erise IP, P.A.) for Ravin Crossbows, LLC.

Companies: MCP IP, LLC; Ravin Crossbows, LLC

Cases: Patent WisconsinNews