Acufloor, LLC v. EvenTile, Inc., Forpac, LLC, decided May 28, 2025

Case Overview:

The case concerns a patent infringement lawsuit brought by Acufloor against EvenTile and FORPAC regarding two of Acufloor's patents related to tile leveling devices. The appeal specifically addresses challenges to the district court's construction of two claim terms. The Federal Circuit modified one claim construction, rejected the other, vacated the judgment of non-infringement, and remanded the case for further proceedings.

Parties:

• Plaintiff-Appellant: Acufloor, LLC

• Defendants-Appellees: EvenTile, Inc., FORPAC, LLC
  

Patents in Suit:

• U.S. Patent No. 10,704,274 ("the ’274 patent")

• U.S. Patent No. 10,513,857 ("the ’857 patent")
  

Subject Matter of the Patents:

The patents disclose "devices used for leveling, aligning, and properly spacing tiles." The devices, which share a common specification, aim to prevent "lippage," where the edge of one tile is higher or lower than an adjoining tile. The system involves a tile clip and a wedge. The clip has a base that goes under adjacent tiles and an upright body between the tiles with an opening. The wedge is inserted into the body's opening to press down and level the tiles. The clip includes a "frangible breakaway section" allowing the body to be broken off from the base after the tiles are set.

Key Features of the Patented Device:

• Notches in the Base: The base of the tile clip features a pair of notches. These notches allow "more of the surface area of the tile to be in direct contact with the mortar that is spread over the subfloor." ('274 patent, col. 5, ll. 4–5; see id. at Fig. 11A). The common specification emphasizes the importance of these notches for tile-to-subfloor contact, whether in a four-tile embodiment ("each tile has corner-to-subfloor contact due to the notches") or a two-tile implementation ("each tile has edge-to-subfloor contact due to the notches"). ('274 patent, col. 6, ll. 15–19).

  
  
  
  

• Spacing Pads: Attached to the stems of the clip body, spacing pads (e.g., structure 152 in Figure 11A) can be used to position tiles at a predetermined distance apart. The specification notes that the spacing pad "contributes to furnishing a combination of vertical leveling and joint spacing within a single product." ('274 patent, col. 3, ll. 23–30).

  
  
  
  

• Frangible Breakaway Section: This section connects the base and body and allows the body to be separated from the base by breaking after the leveling process is complete.
  

Procedural History:

• Acufloor filed an infringement action against EvenTile and FORPAC.

• The district court issued a claim construction order.

• Following the claim construction, the parties stipulated to a judgment of non-infringement.

• Acufloor appealed two of the district court's claim constructions.
  

Disputed Claim Constructions and Federal Circuit Rulings:

The appeal centered on the construction of two specific claim terms:

"Edge" (in the phrases "edge-to-subfloor contact" and "edge-to-mortar-to-subfloor contact"):

• District Court Construction: "the line at which a surface of a tile terminates." (App. 8).

• Acufloor's Argument: The term refers to a region in the vicinity of the very edge of the tile.

• FORPAC and EvenTile's Argument: The district court's construction is correct based on the prosecution history.

• Federal Circuit Ruling: Modified the district court's construction. The court agreed that "edge" must include the "very edge of the tile or, in the district court's words, the line at which a surface of the tile terminates." However, citing the physical impossibility of "contact" occurring at a mere line (which lacks surface area), the court held that the construction must also "include some amount of the tile’s surface inward from the very edge of the tile."

• New Federal Circuit Construction: "the area around and including the very edge of the tile."

• Reasoning: The court relied heavily on the prosecution history of both patents. The applicants repeatedly distinguished their invention from prior art (Doda and Hoffman for the '857 patent, Doda and Psaila for the '274 patent) by emphasizing that the claimed invention allowed the tile's very edge to contact the subfloor or mortar, unlike the prior art where the edge rested on solid material or mortar was pushed away from the edge. Annotated diagrams and video demonstrations presented during prosecution were cited as evidence of the applicants' intent to require contact at the very edge. The court rejected Acufloor's argument based on interpreting Figure 11A as excluding contact at the very edge, stating that "arguments based on drawings not explicitly made to scale in issued patents are unavailing." (citing Nystrom v. TREX Co., 424 F.3d 1136, 1149 (Fed. Cir. 2005) and other cases). The court clarified that they were using the prosecution history to "inform us of how a person of ordinary skill in the art would understand the term ‘edge’ as used in the asserted patents," not based on a finding of disclaimer.

"the combination of the first notch and the second notch providing a majority of an area of tile-to-mortar-to-subfloor contact for the leveling device within the bounds of the base" (appears in the ’274 patent claims):

• District Court Construction: "the notches in the base collectively span an area that is larger than the solid portions of the base." (App. 11). This effectively compares the area of the notches to the solid area of the base.

• Parties' Dispute: Whether the phrase refers to a majority of the area of contact between the tile and the subfloor (Acufloor's view) or a majority of the area of the base (Defendants' and district court's view).

• Federal Circuit Ruling: Disagreed with the district court.

• New Federal Circuit Construction: "the combination of the first notch and the second notch providing the majority of the area of the tile-to-mortar-to-subfloor contact that exists within the bounds of the base."

• Reasoning: The court emphasized the plain language of the limitation, which explicitly refers to "a majority of an area of tile-to-mortar-to-subfloor contact." The court found that the district court's construction improperly related the majority to the area of the base, which is not what the claim language states. While the prosecution history shows the examiner suggested focusing on the notch size relative to the base, the applicants ultimately adopted different language that directs the comparison to the area of contact. The court also noted that the applicants' arguments distinguishing their device from prior art (Doda and Psaila) were based on the area of contact permitted by the notch compared to the area of contact permitted by other openings, supporting the view that the limitation refers to the area of contact. The court acknowledged that the claims use the term "comprising," making them presumptively open to other openings, which further supports comparing the notch area to other potential open areas for contact.
  

Concurring and Dissenting Opinion (Circuit Judge Stark):

• Agreement: Judge Stark agreed with the majority that the district court erred in the construction of the "majority of an area" term and joined the majority's construction of that term. He also agreed that the judgment should be vacated and remanded.

• Disagreement: Judge Stark dissented from the majority's construction of the term "edge."

• Stark's Proposed Construction: "edge" refers to "an area or region where two surfaces of a tile meet." This construction would not require contact at the very edge, but would allow it.

• Reasoning: Judge Stark argued that the specification, particularly the depiction in Figure 11A, supports Acufloor's broader construction. He believed Figure 11A shows an embodiment within the claims' scope where the very edge of the tile rests on a portion of the base, preventing direct contact with the subfloor at that precise line. He argued that the majority improperly dismissed reliance on Figure 11A by overemphasizing the rule that drawings are not to scale, especially when the figure is explicitly stated to show a claimed feature.

• Prosecution History Interpretation: Judge Stark found the prosecution history "too ambiguous" to support the majority's conclusion that the inventor limited the claim scope to require contact at the very edge. He offered alternative plausible readings of the applicants' statements, suggesting they were distinguishing prior art based on the type of contact (edge-to-groove vs. edge-to-subfloor/mortar-to-subfloor) or the benefit of getting mortar close to the edge, rather than a strict requirement of contact at the precise edge line. He also argued that the "Bunch Device" shown in the video demonstration, which the applicants presented as an example of their invention, appears not to show contact at the very edge according to Acufloor's interpretation, and excluding this embodiment based on the majority's construction would be an "implausible result."

• Potential Invalidity: Judge Stark noted that his broader construction of "edge" "may well be" that it renders Acufloor's claims invalid for indefiniteness, but stated he would leave that issue for the district court to litigate on remand.
  

Outcome:

The Federal Circuit vacated the stipulated judgment of non-infringement and remanded the case to the district court for further proceedings consistent with the Federal Circuit's modified and rejected claim constructions. The district court will need to apply the new claim constructions to determine infringement and potentially address invalidity arguments on remand.