Dun LAN v. Changzhou Zite Trading Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Dun Lan (undisclosed jurisdiction)
  • Defendant: Changzhou Zite Trading Co., Ltd, D/B/A Mellbree (China)
  • Plaintiff's Counsel: Stratum Law LLC
• Case Identification: 1:26-cv-06779, N.D. Ill., 06/08/2026
• Venue Allegations: Venue is asserted on the basis that Defendant is a foreign entity that can be sued in any judicial district. The complaint further alleges personal jurisdiction in Illinois exists because Defendant targets and sells products to Illinois residents via interactive commercial websites, accepts payment in U.S. dollars, and has allegedly stored infringing products in Amazon fulfillment centers within the state.
• Core Dispute: Plaintiff alleges that Defendant's "HVAC Adaptor Cord," sold online, infringes a U.S. design patent for an ornamental cord design.
• Technical Context: The dispute concerns the ornamental appearance of an electrical adapter cord, an accessory commonly used in the heating, ventilation, and air conditioning (HVAC) industry.
• Key Procedural History: The complaint alleges that Defendant has continued its infringing activities "in spite of Plaintiff's enforcement efforts, such as take down notices," but does not provide specific details or outcomes of these prior actions.

Case Timeline

Date	Event
2022-04-14	'513 Patent Priority Date
2023-05-09	'513 Patent Issue Date
2026-06-08	Complaint Filing Date

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

U.S. Design Patent No. D985,513 - "HVAC ADAPTOR CORD"

The patent-in-suit is U.S. Design Patent No. D985,513, issued May 9, 2023 (the "'513 Patent").

The Invention Explained

• Problem Addressed: Design patents protect ornamental appearance rather than functional utility. The '513 Patent addresses the creation of a new, original, and ornamental design for an HVAC adaptor cord, distinguishing it visually from other cords on the market '513 Patent, claim
• The Patented Solution: The patent discloses a specific visual design for an adapter cord. The design features a single electrical plug at one end, a length of cable, and a trifurcated junction leading to three separate wires, each terminating in an alligator-style clip '513 Patent, Fig. 1 The claim covers the overall ornamental appearance of the article as depicted in the patent's various figures, which show the cord assembly from multiple perspectives '513 Patent, description '513 Patent, Figs. 1-15
• Technical Importance: The design provides a specific aesthetic for a component used in the HVAC field, which may serve as a source identifier for consumers familiar with the Plaintiff's products Compl. ¶5

Key Claims at a Glance

• Design patents contain a single claim. The asserted claim is: "The ornamental design for a HVAC adaptor cord, as shown and described" '513 Patent, col. 2:1-3
• The scope of the claim is defined by the solid lines in the patent's drawings '513 Patent, description The claim encompasses the overall visual impression created by the combination of the plug shape, the cord configuration, the trifurcated split, and the design of the alligator clips.

III. The Accused Instrumentality

Product Identification

The accused product is an "HVAC Adaptor Cord" sold by Defendant under the name "Mellbree" through an Amazon storefront Compl. ¶1

Functionality and Market Context

The complaint identifies the product by its name and provides images, but does not detail its specific technical functionality beyond what is implied by its name Compl. ¶1 Compl. Ex. 4 The core of the allegation is not about function but about appearance, with the complaint asserting that the accused product is "practically identical to the asserted design" Compl. ¶17 The product is allegedly marketed and sold to consumers throughout the United States via online marketplaces Compl. ¶7 Exhibit 4 of the complaint provides a side-by-side comparison of the patented design and photographs of the accused product Compl. Ex. 4, p. 2 This visual shows the accused product, featuring a plug, a black cord, and three alligator clips with colored sleeves (red, green, and black).

IV. Analysis of Infringement Allegations

The infringement test for a design patent is whether an "ordinary observer," familiar with the prior art, would be deceived into purchasing the accused product believing it to be the patented design. The complaint alleges that the accused product creates the same overall visual impression as the patented design Compl. ¶17

D985,513 Infringement Allegations

Claim Element (from the Single Claim)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
The ornamental design for a HVAC adaptor cord, as shown and described.	The complaint alleges that Defendant's "HVAC Adaptor Cord" is "practically identical" to the patented design and creates the "same overall visual impression on an ordinary observer." The provided claim chart visually compares the patent figures to photographs of the accused product to support this assertion.	¶17; Ex. 4	col. 2:1-3

Identified Points of Contention

• Visual Similarity: The central issue will be a direct visual comparison. The court will need to determine if the overall appearance of the accused cord is substantially the same as the design claimed in the '513 Patent. The complaint's visual evidence in Exhibit 4, which juxtaposes patent figures with product photos, will be a primary focus Compl. Ex. 4
• Scope Questions: A potential defense could focus on any perceived differences between the accused product and the patent drawings, such as subtle variations in the proportions or surface ornamentation of the plug housing or alligator clips. For example, the complaint's photographic evidence shows colored sleeves on the accused product's clips, whereas the patent drawings are monochrome line drawings Compl. Ex. 4, p. 2 The question for the court will be whether such differences are sufficient to create a distinct overall visual impression in the eyes of an ordinary observer.

V. Key Claim Terms for Construction

In design patent cases, formal claim construction is less common than in utility patent cases, as the drawings themselves typically define the claim's scope. However, the identification of the article of manufacture can be relevant.

• The Term: "HVAC adaptor cord"
• Context and Importance: This term identifies the article of manufacture to which the ornamental design is applied '513 Patent, claim Practitioners may focus on this term because its definition helps establish the relevant field of art. This field of art, in turn, informs the perspective of the "ordinary observer" and defines the universe of prior art designs against which the patented design's novelty and the accused product's similarity are judged.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent itself does not provide a specific definition beyond the term's use in the title and claim, suggesting the term should be given its plain and ordinary meaning within the relevant industry '513 Patent, title '513 Patent, claim
  • Evidence for a Narrower Interpretation: The scope of the article is visually defined by the drawings, which depict a specific configuration of a plug, a trifurcated cable, and three alligator clips '513 Patent, Figs. 1-15 A party could argue that the "HVAC adaptor cord" to which the design applies is limited to this general arrangement, potentially excluding other types of cords with different functional ends or numbers of connectors.

VI. Other Allegations

• Indirect Infringement: The complaint makes conclusory allegations of both direct and indirect infringement Compl. ¶9 Compl. ¶17 The prayer for relief also requests an injunction against "aiding, abetting, contributing to, or otherwise assisting" infringement Compl. p. 6, prayer 1(b) However, the complaint does not plead specific facts detailing how Defendant might be inducing or contributing to infringement by a third party.
• Willful Infringement: The complaint alleges that Defendant's infringement was willful Compl. ¶14 This allegation is based on the assertion that Defendant acted "knowingly" and continued its sales "in spite of Plaintiff's enforcement efforts, such as take down notices" Compl. ¶12 Compl. ¶13 These allegations of pre-suit knowledge, if substantiated, may support a claim for enhanced damages.

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

1. A core issue will be one of visual identity: In a side-by-side comparison, is the accused "HVAC Adaptor Cord" substantially the same as the design claimed in the '513 Patent from the perspective of an ordinary observer? The case will likely depend heavily on the visual evidence presented, such as the comparison chart in the complaint's Exhibit 4.
2. A second key question will be evidentiary support for willfulness: Can the Plaintiff prove its allegation that the Defendant had knowledge of the '513 Patent, for instance through "take down notices," and continued to sell the accused product regardless? The answer to this question will be critical for the Plaintiff's pursuit of enhanced damages or infringer's profits.