Zhang v. =

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Weihua Zhang (People's Republic of China)
  • Defendant: Felisbieti and individuals and entities operating Felisbieti (Non-U.S. resident)
  • Plaintiff's Counsel: Law Office of Yifeng Hao
• Case Identification: 1:26-cv-06734, N.D. Ill., 06/16/2026
• Venue Allegations: Venue is asserted on the basis that Defendants do not reside in the United States and are therefore subject to venue in any judicial district, and on the allegation that Defendants conduct business and make sales to consumers in Illinois.
• Core Dispute: Plaintiff alleges that Defendant's fuel tank caps, sold through online e-commerce platforms, infringe a U.S. design patent for a fuel tank cap.
• Technical Context: The dispute is in the field of ornamental designs for automotive articles of manufacture, where visual appearance, rather than utility, is the subject of intellectual property protection.
• Key Procedural History: The current filing is an Amended Complaint. The complaint does not mention any prior litigation, inter partes review proceedings, or licensing history related to the asserted patent.

Case Timeline

Date	Event
2019-XX-XX	Plaintiff's design team launched the product corresponding to the patented design
2022-10-20	'506 Patent Priority Date
2024-03-26	'506 Patent Issue Date
2026-06-16	Amended Complaint Filing Date

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

U.S. Design Patent No. D1,019,506 S - "FUEL TANK CAP"

• Issued: March 26, 2024

The Invention Explained

• Problem Addressed: As a design patent, the '506 Patent does not address a functional problem. Instead, it protects the novel, non-functional, ornamental appearance of an article of manufacture-in this case, a fuel tank cap.
• The Patented Solution: The patent claims the specific ornamental design for a fuel tank cap as depicted in its figures '506 Patent, claim The design consists of the overall visual impression created by a combination of features, including a generally cylindrical body with a prominent, raised outer ring and a recessed, cylindrical central portion '506 Patent, FIG. 1 '506 Patent, FIG. 4 The claim protects the specific aesthetic appearance created by the proportions and arrangement of these visual elements.
• Technical Importance: The complaint alleges that the product embodying this design was the "main product of the firm" and was developed by its R&D and design team with "significant cost," suggesting the design's commercial importance to the Plaintiff Compl. ¶9

Key Claims at a Glance

• The complaint asserts the single claim of the '506 Patent Compl. ¶1 Compl. ¶¶17-25
• The claim is for: "The ornamental design for a fuel tank cap, as shown and described" '506 Patent, claim The essential elements are the collective visual features depicted in the patent's drawings, including:
  • The overall configuration and shape of the cap.
  • A raised, circular outer flange.
  • A recessed central portion set within the outer flange.
  • The specific proportions and visual relationship between the flange and the recessed center as shown in the patent's figures '506 Patent, FIGS. 1-8

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are "Infringing Products" described as fuel tank caps sold by Defendants through online commerce platforms, including an Amazon storefront operating under the name "Felisbieti" Compl. ¶1 Compl. ¶6

Functionality and Market Context

The complaint alleges that the accused products "copied the design of the Asserted Patent" and are "substantially identical" to the patented design Compl. ¶1 Compl. ¶13 It further alleges that these products are sold in direct competition with the Plaintiff's product, causing price erosion and economic harm Compl. ¶1 Compl. ¶14 The complaint does not provide specific technical details about the accused products beyond the allegation that their ornamental design is the same as that protected by the '506 Patent.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges infringement of a design patent, for which the legal test is whether an "ordinary observer, giving such attention as a purchaser usually gives, . . . would be deceived into purchasing an article which he did not intend to purchase." The complaint alleges that Defendants' products meet this standard by being "substantially identical" to the design claimed in the '506 Patent Compl. ¶13

The complaint's allegations are holistic and directed to the overall appearance of the accused products, rather than identifying infringement on a feature-by-feature basis. Due to the high-level nature of these allegations, a detailed claim chart mapping specific product features to claim elements is not feasible based on the complaint alone. The core of the infringement allegation is that the accused products create the same overall visual impression as the patented design Compl. ¶1 Compl. ¶13

• Identified Points of Contention:
  • Visual Similarity: The central dispute will be a direct visual comparison between the accused products and the figures of the '506 Patent. The outcome will depend on whether the designs are "substantially the same" from the perspective of an ordinary observer. Any differences, even if minor, may become focal points of the litigation.
  • Scope of Protection: A potential issue is the scope of the claimed design in light of prior art. The novelty of the patented design's individual features and overall appearance, when compared to earlier fuel tank cap designs, will inform the breadth of protection afforded to the '506 Patent.

V. Key Claim Terms for Construction

In design patent litigation, the "claim" is understood to be the design itself as depicted in the patent's drawings, rather than any specific textual language '506 Patent, claim Consequently, traditional claim construction of textual terms is generally not a central issue. The primary interpretive question for the court will not be the definition of a word, but the overall visual scope of the intellectual property right granted by the drawings in the '506 Patent. An analysis of intrinsic evidence to support broader or narrower interpretations of specific terms is not applicable in this context.

VI. Other Allegations

• Indirect Infringement: The complaint includes a conclusory allegation of indirect infringement Compl. ¶12 The prayer for relief also requests an injunction against "aiding, abetting, contributing to, or otherwise assisting anyone in infringing" Prayer ¶1(b) However, the complaint does not plead specific facts to support a claim for either induced or contributory infringement, such as knowledge of the patent combined with actions encouraging infringement by others.
• Willful Infringement: The complaint alleges that Defendants are "acting knowingly and intentionally or at least with reckless disregard or willful blindness" to the Plaintiff's patent rights Compl. ¶16 Compl. ¶20 The factual basis for this allegation appears to be the alleged act of copying the design and the notice provided by the filing of the lawsuit itself, as no pre-suit knowledge is explicitly alleged Compl. ¶1

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

The resolution of this dispute will likely depend on the court's findings regarding three central questions:

1. A Question of Visual Identity: Is the ornamental design of the accused "Felisbieti" fuel tank caps "substantially the same" as the design claimed in the '506 Patent from the perspective of an ordinary purchaser? The case hinges on this direct visual comparison.
2. A Question of Scope: How does the prior art in the field of fuel tank cap design limit the scope of protection for the '506 Patent? The ultimate determination of infringement will depend not just on similarity, but on similarity to the novel aspects of the patented design.
3. An Evidentiary Question: What evidence will be produced in discovery to establish the precise designs of the products sold by the Defendants? The currently general allegations of the complaint will need to be substantiated with specific accused product exemplars.