On the Edge of Claim Construction: Federal Circuit Splits Over What Counts as a Tile’s ‘Edge’

by Dennis Crouch

Acufloor, LLC v. EvenTile, Inc., No. 2023-1887 (Fed. Cir. May 28, 2025)

Although new, this case offers a classic claim construction debate with three-way divide between the majority, dissent, and district court over what counts as the "edge" of a tile. The patents here cover a tile leveling device used during install to avoid "lippage"—where one tile's edge is higher than an adjoining tile's edge. The key dispute centered on what constitutes the "edge" of a tile when the claims require "edge-to-mortar-to-subfloor contact."  U.S. Patent Nos. 10,704,274 and 10,513,857.

• Video of Operation: Presenting the Eventile Leveling System

The accused devices operate near the edge of the tile, but do not allow direct tile-to-mortar-to-subfloor contact at the very edge of the tile.  By arguing for a narrow construction of "edge"—limited specifically to the precise boundary line of the tile's surface—the defendants position themselves outside the patent claims.  The district court agreed and narrowly construed edge to "the line at which a surface of a tile terminates."  On appeal, both the the majority (Judge Bryson, joined by Judge Lourie) and the dissent (Judge Stark) agreed that the district court's construction was too narrow—concluding that "edge" of a tile in this patent is wider than the Euclidian edge definition.  However, the majority and dissent disagreed on whether the claimed "edge" contact necessarily include the very edge of the tile.

The majority construes "edge" to include the very boundary line of the tile, but also extends slightly inward to include some portion of the tile's surface adjacent to that line. In contrast, the dissent argues for a broader construction where the claimed "edge" is defined more expansively as a region or area around the tile’s boundary, and thus does not require mortar to reach precisely to the boundary line.