Arcadia Products LLC v. Millwork Artisans LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Arcadia Products LLC (Colorado)
  • Defendant: Millwork Artisans LLC (South Carolina)
  • Plaintiff's Counsel: Womble Bond Dickinson (US) LLP
• Case Identification: 2:26-cv-01331, D.S.C., 03/30/2026
• Venue Allegations: Plaintiff alleges venue is proper in the District of South Carolina because Defendant has regular and established places of business in the district and has allegedly committed acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant's steel doors and windows infringe a patent related to the "sandwich" construction of thermally insulated window and door frames.
• Technical Context: The technology concerns methods for manufacturing thermally broken metal frames for windows and doors, a key feature for energy efficiency in construction.
• Key Procedural History: Plaintiff alleges that Defendant has been on notice of the patent-in-suit and its alleged infringement since receiving a letter on January 20, 2026, which may form the basis for a willfulness claim.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,572,929 - "WINDOW OR DOOR ELEMENT"

• Issued: November 5, 2013

The Invention Explained

• Problem Addressed: Traditional metal frames for windows and doors are often produced from hollow profiles that require complex manufacturing processes like cold-forming or extrusion '929 Patent, col. 1:11-25 The patent sought to create a simpler method for producing such elements '929 Patent, col. 1:26-31
• The Patented Solution: The invention proposes a "sandwich construction" where an "insulation body" (3) is placed between an outer flat metal frame (4) and an inner flat metal frame (5) '929 Patent, abstract '929 Patent, col. 1:47-50 This layered approach, using flat metal plates instead of complex profiles, is intended to simplify manufacturing while maintaining thermal insulation '929 Patent, col. 1:32-40 '929 Patent, Fig. 2
• Technical Importance: This approach allows for the production of thermally insulated window and door frames without relying on specialized extrusion or cold-forming equipment, potentially lowering manufacturing costs and complexity '929 Patent, col. 1:26-31

Key Claims at a Glance

• The complaint asserts at least independent Claim 1 Compl. ¶14
• Essential elements of Claim 1 include:
  • A window or door element with a metal frame and an insulated glass pane.
  • The frame comprises an outer flat metal frame, an inner flat metal frame, and an insulation body positioned between them using "sandwich construction."
  • The inner cutout of the outer flat metal frame is slightly smaller than the inner cutout of the inner flat metal frame.
  • This size difference forms a "circumferential contact ridge" for the insulated glass pane.
• The complaint does not explicitly reserve the right to assert dependent claims, but the prayer for relief requests a declaration of infringement of "one or more of the claims" Compl. ¶Prayer A

III. The Accused Instrumentality

Product Identification

The Accused Products are Defendant's "construction products having a metal frame," specifically identified as steel doors and windows Compl. ¶6 Compl. ¶13

Functionality and Market Context

The complaint alleges that Defendant manufactures, distributes, and sells these steel doors and windows in the United States Compl. ¶12 It notes that Defendant describes these products on its website and in brochures Compl. ¶13 The complaint alleges that Defendant is a direct competitor of the Plaintiff in the field of construction products Compl. ¶12 Compl. ¶16 No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that the Accused Products infringe at least Claim 1 of the '929 Patent Compl. ¶14 The specific factual basis for this allegation is detailed in a claim chart attached as Exhibit C to the complaint; however, this exhibit was not provided Compl. ¶14 The complaint itself does not provide a narrative description of how the Accused Products meet the limitations of the asserted claim.

Identified Points of Contention

Lacking a detailed claim chart, the analysis must anticipate likely areas of dispute based on the claim language and the general description of the accused products.

• Structural Questions: A primary question will be whether the Defendant's steel doors and windows are manufactured using a "sandwich construction" comprising distinct outer and inner flat metal frames with an insulation body positioned between them, as required by the claim. The dispute may focus on whether the components of the accused products are structurally equivalent to the claimed "flat metal frames" and "insulation body."
• Scope Questions: The infringement analysis will likely turn on whether the accused products create a "circumferential contact ridge" for the glass pane by using an outer frame with an inner cutout that is "slightly smaller" than the inner frame's cutout. The evidence presented will need to demonstrate this specific dimensional relationship and function in the accused products.

V. Key Claim Terms for Construction

The Term: "sandwich construction"

• Context and Importance: This term is central to the patent's claimed solution and appears in the preamble of independent Claim 1. Its construction will define the fundamental architecture required for infringement. Practitioners may focus on this term because the patent contrasts it with prior art methods using hollow or extruded profiles '929 Patent, col. 1:11-25
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the construction simply as an "inner insulation body 3 is positioned between an outer flat metal frame 4 and an inner flat metal frame 5" '929 Patent, col. 1:47-50 This could support a reading that covers any layered arrangement of these three components.
  • Evidence for a Narrower Interpretation: The detailed description and figures consistently depict the three components as distinct, separate elements assembled together (e.g., with adhesive strips or bolts) '929 Patent, Fig. 2 '929 Patent, Fig. 3 '929 Patent, col. 2:60-67 '929 Patent, col. 3:6-13 This may support a narrower construction requiring three physically separate and later-assembled layers, as opposed to a more integrated or co-molded structure.

The Term: "flat metal frame"

• Context and Importance: This term defines the primary structural components of the claimed invention. The nature of what constitutes a "flat metal frame" will be critical, as the accused products are "steel doors and windows," which may be constructed from materials that are not perfectly planar or that are formed rather than being cut from a plate.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term itself is general. The patent does not appear to impose strict limitations on the thickness or absolute planarity of the frame, which could support a broader definition.
  • Evidence for a Narrower Interpretation: The specification explicitly states that the frame can be "cut out from a planar metal plate or a metal strip" '929 Patent, col. 1:37-39 '929 Patent, claim 2 A defendant may argue this language limits the term to frames produced by such cutting methods, excluding frames formed by bending, stamping, or other processes.

VI. Other Allegations

Indirect Infringement

The complaint does not contain specific allegations to support claims of induced or contributory infringement. The sole count for infringement alleges direct infringement under 35 U.S.C. § 271(a) Compl. ¶19

Willful Infringement

The complaint alleges that Defendant has had knowledge of the '929 Patent and its infringing activities since at least January 20, 2026, the date of a notice letter sent by Plaintiff Compl. ¶15 Compl. ¶21 The complaint asserts that infringement from that date forward has been "willful and deliberate" Compl. ¶21

VII. Analyst's Conclusion: Key Questions for the Case

The resolution of this dispute appears to hinge on two primary questions for the court:

• A core issue will be one of structural identity: do the Defendant's accused steel doors and windows possess the specific three-layer "sandwich construction" defined in the '929 Patent, or do they utilize a different frame architecture that falls outside the claim scope?
• A key evidentiary question will be one of dimensional functionality: can the Plaintiff demonstrate that the accused products create a "circumferential contact ridge" for holding a glass pane as a direct result of the outer frame's inner cutout being "slightly smaller" than the inner frame's cutout, as explicitly required by Claim 1?