Schmeisser GmbH v. AC-Unity d.o.o.

Schmeisser GmbH v. AC-Unity d.o.o. The Federal Circuit held that the district court erred by finding the distance-related claim terms indefinite; the terms were facially clear, supported by the specification and prosecution history, and measurable with conventional tools. The district court improperly conflated definiteness with enablement by focusing on whether a skilled artisan could use the patent to build an operable magazine. The decision reinforces that § 112(b) asks whether claim scope can be determined with reasonable certainty, not whether the specification teaches how to make a commercially or operationally successful embodiment. Reversed the indefiniteness-related portions of the claim-construction and partial summary-judgment orders, vacated the order dissolving the preliminary injunction, and remanded. The asserted patent claims a firearm magazine housing with distance-related limitations: first distance (A), second distance (B), third distance (C), and offset (V). The Federal Circuit found those terms definite because the claims, figures, specification, and prosecution history identified what the distances represent and allowed measurement after the device is made. The district court’s focus on whether a skilled artisan could determine specific design values to avoid jamming applied enablement-type reasoning, not the Nautilus definiteness standard. Because the invalidity and noninfringement summary judgment rested on the erroneous indefiniteness construction, that ruling was reversed. The preliminary-injunction dissolution was vacated because it depended on the same Markman and summary-judgment rulings. § 112(b) claim construction infringement injunction / stay standing / jurisdiction remand non-precedential § 112(a) § 112(b) claim construction injunction / stay standing / jurisdiction remand non-precedential § 112(a) infringement § 112(b) claim construction injunction / stay remand § 112(a)