DCT
2:25-cv-02278
Westlake Royal Stone LLC v. Stone Creek Products LLC
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Westlake Royal Stone, LLC (Delaware)
- Defendant: Stone Creek Products, LLC d/b/a Affinity Stone (Illinois)
- Plaintiff’s Counsel: Stinson LLP
- Case Identification: 2:25-cv-02278, C.D. Ill., 10/16/2025
- Venue Allegations: Venue is based on allegations that the Defendant has committed acts of infringement and maintains a regular and established place of business within the Central District of Illinois.
- Core Dispute: Plaintiff alleges that Defendant’s mortarless stone veneer wall panels infringe three patents related to prefabricated panel construction, specifically focusing on integrated mounting and water drainage features.
- Technical Context: The dispute is in the field of construction materials, where panelized siding systems that mimic traditional stone masonry seek to offer easier installation and improved performance, particularly in moisture management.
- Key Procedural History: The complaint alleges that Defendant cited all three patents-in-suit on Information Disclosure Statements (IDS) filed with the U.S. Patent and Trademark Office during the prosecution of its own patents, beginning in May 2020. This alleged pre-suit knowledge forms the basis of the willfulness allegations.
Case Timeline
| Date | Event |
|---|---|
| 2008-02-06 | Earliest Priority Date for U.S. Patent Nos. 9,903,124; 10,557,273; 10,329,775 |
| 2018-02-27 | U.S. Patent No. 9,903,124 Issued |
| 2019-06-25 | U.S. Patent No. 10,329,775 Issued |
| 2020-02-11 | U.S. Patent No. 10,557,273 Issued |
| 2020-05-29 | Alleged first date Defendant cited Asserted Patents in an IDS filing |
| 2021-01-15 | Alleged second date Defendant cited Asserted Patents in an IDS filing |
| 2025-10-16 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,903,124, “Prefabricated Wall Panel with Tongue and Groove Construction,” issued February 27, 2018 (’124 Patent)
The Invention Explained
- Problem Addressed: The patent describes the challenges of traditional stone siding, which requires labor-intensive lath and mortar installation (Compl. ¶10). It notes that earlier mortarless panel systems were often difficult to secure, appeared artificial, and, critically, risked trapping moisture against a wall, which could lead to rot and mold (Compl. ¶10).
- The Patented Solution: The invention is a prefabricated wall panel that combines a cast concrete body, for an authentic stone appearance, with an integrated mounting element (Compl. ¶11). This mounting element has a first segment embedded within the concrete and a second segment projecting from it, which simplifies installation with nails or screws (’124 Patent, col. 4:41-52). The geometry creates a groove for interlocking with other panels and, crucially, incorporates weep holes to allow any trapped water to drain out, solving the moisture management problem (Compl. ¶12; ’124 Patent, col. 6:23-26).
- Technical Importance: The claimed invention aimed to provide a durable, mortarless stone veneer solution that was both simple for installers and effective at preventing water intrusion (Compl. ¶12).
Key Claims at a Glance
- The complaint asserts independent Claim 1 (Compl. ¶36).
- Essential elements of Claim 1 include:
- A wall panel with a body comprising at least one design element.
- A mounting element with a first segment embedded in the body and a second segment projecting from the body.
- A groove formed between a portion of the body and the projecting second segment.
- The groove is inset relative to a first edge of the body.
- The mounting element includes weep holes configured to drain water from the groove.
- The complaint does not explicitly reserve the right to assert other claims.
U.S. Patent No. 10,557,273, “Prefabricated Wall Panel with Tongue and Groove Construction,” issued February 11, 2020 (’273 Patent)
The Invention Explained
- Problem Addressed: The technology addresses the same problems as the ’124 Patent: the difficulty and moisture risks associated with prior art stone siding solutions (Compl. ¶10).
- The Patented Solution: The ’273 Patent also describes a prefabricated wall panel with a concrete body and a projecting mounting element (’273 Patent, Abstract). The claims focus on the spatial relationship between the mounting element, the rear surface of the concrete body, and a groove positioned between them. Like the ’124 Patent, the solution provides for water drainage via at least one hole in the mounting element, allowing moisture to escape from the groove (’273 Patent, col. 5:45-49, col. 6:23-26).
- Technical Importance: This technology provided an integrated system for both simplified mechanical fastening and sophisticated moisture drainage in a single panelized product (Compl. ¶12).
Key Claims at a Glance
- The complaint asserts independent Claim 1 (Compl. ¶47).
- Essential elements of Claim 1 include:
- A wall panel with a concrete body comprising a design element and a rear surface.
- A mounting element projecting from the concrete body.
- A groove positioned between the mounting element and the rear surface of the concrete body.
- At least one hole that allows water to drain from the groove.
- The complaint does not explicitly reserve the right to assert other claims.
U.S. Patent No. 10,329,775, “Method of Forming a Wall Panel,” issued June 25, 2019 (’775 Patent)
Technology Synopsis
This patent claims the method of manufacturing the wall panels described in the ’124 and ’273 patents. The method involves positioning a mounting element within a mold, adding casting material (e.g., concrete) to embed a portion of it, and forming a groove between the casting material and a second, projecting portion of the mounting element (Compl. ¶58). The method results in a finished panel with the integrated mounting and drainage features central to the other asserted patents (Compl. ¶¶21, 58).
Asserted Claims
Independent Claim 1 (Compl. ¶58).
Accused Features
The complaint alleges on information and belief that the Defendant's method for manufacturing its Accused Products necessarily includes the steps recited in Claim 1 of the ’775 Patent (Compl. ¶¶59, 66).
III. The Accused Instrumentality
Product Identification
The accused products are Defendant Affinity Stone’s mortarless stone veneer panels, specifically the Ridge Cut Series and the Cliff Ledge Series (Compl. ¶24).
Functionality and Market Context
- The Accused Products are alleged to imitate the appearance and texture of real stone and feature an interlocking tongue-and-groove system for installation (Compl. ¶¶25-26).
- The complaint cites Defendant’s marketing materials, which describe the products as having a "precision-engineered tongue and groove system" and an "integrated air gap behind the panels [which] helps prevent moisture from getting trapped in the wall space" (Compl. ¶27). Annotated photographs in the complaint show a representative panel with a concrete body and a projecting mounting strip containing drainage holes (Compl. p. 7). The complaint alleges these products directly compete with Plaintiff’s Versetta Stone® products (Compl. ¶23).
IV. Analysis of Infringement Allegations
’124 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a wall panel comprising: a body comprising a[t] least one design element; | The Accused Products are wall panels with a concrete body that has a design element imitating the appearance of stone. | ¶37 | col. 4:53-54 |
| a mounting element comprising a first segment embedded within an interior portion of the body and a second segment projecting to an exterior of the body; | The Accused Products include a mounting element, where one part is embedded within the concrete body and a second part projects externally for fastening. This is shown in an annotated photograph with a cutaway view. (Compl. p. 8). | ¶38 | col. 4:41-43 |
| and a groove formed between a portion of the body and the second segment of the mounting element, the groove being inset relative to a first edge of the body... | A groove is present between the concrete body and the projecting part of the mounting element. An annotated cross-section photograph highlights this feature. (Compl. p. 9). | ¶39 | col. 5:45-49 |
| ...and the mounting element comprises weep holes configured to allow water to drain from the groove. | The mounting element of the Accused Products includes weep holes. An annotated close-up photograph shows these holes and alleges they are designed to drain water. (Compl. p. 10). | ¶40 | col. 6:23-26 |
Identified Points of Contention
- Scope Questions: The analysis may focus on whether the specific geometry of the Accused Products meets the claim limitation that the "groove" is "inset relative to a first edge of the body." This raises a factual question of how that spatial relationship is measured on the accused panel.
- Technical Questions: A potential dispute could arise over whether the "weep holes" in the Accused Products are "configured to allow water to drain from the groove" in the specific manner envisioned by the patent, or if they serve a different or additional purpose.
’273 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a wall panel comprising: a concrete body comprising a design element and a rear surface; | The Accused Products consist of a concrete body with a stone-like design element on the front and a rear surface. | ¶48 | col. 4:53-54 |
| a mounting element projecting from the concrete body; | The Accused Products include what Defendant's product documentation identifies as a "fastening strip" that projects from the concrete body. An annotated diagram from this documentation is provided. (Compl. p. 13). | ¶49 | col. 4:41-43 |
| a groove positioned between the mounting element and the rear surface of the concrete body; | The Accused Products have a groove located between the projecting mounting element and the rear surface of the panel's concrete body. | ¶51 | col. 5:45-49 |
| and at least one hole that allows water to drain from the groove. | The Accused Products include holes marketed as part of a "built-in drainage plane" or "rain screen" to allow water to drain. | ¶52 | col. 6:23-26 |
Identified Points of Contention
- Scope Questions: The infringement analysis may turn on the construction of "groove positioned between the mounting element and the rear surface of the concrete body." The precise definition of this spatial relationship will be critical in comparing the accused product's structure to the claim language.
- Technical Questions: The complaint's reliance on marketing materials describing a "drainage plane" (Compl. ¶52) suggests a key question will be whether the accused product's holes function to drain water specifically "from the groove" as required by the claim, or from the general rear surface of the panel.
V. Key Claim Terms for Construction
"mounting element" (’124 & ’273 Patents)
- Context and Importance: This term defines the central component that enables both mechanical installation and water drainage. Its scope is critical, as it must read on the "fastening strip" of the Accused Products.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the "mounting element 16 may be made from a material selected from a group consisting of... metal, plastic... corrosion-resistant steel, aluminum, stainless steel, zinc, copper and combinations thereof" and may be formed as a "solid sheet" or a "mesh" (’124 Patent, col. 4:6-20). This language suggests the term is not limited to a specific material or form.
- Evidence for a Narrower Interpretation: The figures consistently depict the mounting element as a single, continuous, bent strip (e.g., ’124 Patent, Fig. 2, element 16). A defendant may argue that the term should be construed as limited to a structure consistent with these embodiments.
"groove" (’124 & ’273 Patents)
- Context and Importance: The location and formation of the "groove" is a key limitation in both asserted apparatus claims. The slight linguistic variation between the patents—the ’124 patent claims a groove "formed between a portion of the body and the second segment of the mounting element," while the ’273 patent claims a groove "positioned between the mounting element and the rear surface of the concrete body"—may become a focal point of claim construction.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term could be interpreted as any channel or recess sufficient to receive the tongue of an adjacent panel and collect water for drainage.
- Evidence for a Narrower Interpretation: The specification and figures show the groove (36) is formed specifically by the precast body (12) and the front face of the projecting second end (20) of the mounting element (’124 Patent, Fig. 2; col. 5:45-49). This could support a narrower construction tied to this specific geometry.
VI. Other Allegations
Indirect Infringement
The complaint alleges that Defendant "markets and instructs customers that the Accused Products are designed to address water entrapment by providing an air gap and drainage holes" (Compl. ¶53). This allegation may be used to support a claim for induced infringement by encouraging an infringing use.
Willful Infringement
The complaint alleges willful infringement based on Defendant's alleged pre-suit knowledge of all three Asserted Patents (Compl. ¶¶45, 57, 70). The primary factual basis for this allegation is that Defendant cited the patents on Information Disclosure Statements submitted to the USPTO during the prosecution of its own patent applications, starting as early as May 29, 2020 (Compl. ¶¶28, 33-34).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim construction and scope: will the specific geometric and spatial relationships required by the claims—such as the precise location of the "groove" relative to the "body," "rear surface," and "mounting element"—be construed in a way that reads on the physical structure of the accused panels?
- A second central issue will be willfulness: the complaint’s allegation that the Defendant cited the patents-in-suit during its own patent prosecution proceedings presents a significant factual question for the court regarding pre-suit knowledge and whether any infringement was undertaken with reckless disregard for the Plaintiff's patent rights.
- For the method patent (’775 Patent), a key evidentiary question will be one of direct evidence: Plaintiff will need to establish, likely through discovery, that the Defendant’s confidential manufacturing process practices each step of the claimed method, as infringement of a method claim cannot be determined solely from the structure of the final product.