DCT

4:25-cv-01173

Chen v. Pang Pang Trading

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 4:25-cv-01173, E.D. Tex., 10/24/2025
  • Venue Allegations: Venue is alleged to be proper because Defendant is a foreign entity not residing in the United States and may therefore be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s "GraceDuck" brand of magnetic building block toys infringes two U.S. patents related to the internal structure and magnetic assembly of such toys.
  • Technical Context: The technology at issue involves the internal design of toy magnetic building blocks, specifically the use of rotatable magnets housed in corner compartments to allow for more versatile, multi-angle connections between blocks.
  • Key Procedural History: The complaint alleges that U.S. Patent No. 12,151,182 is a continuation-in-part of the application that issued as U.S. Patent No. 11,766,622. Plaintiff also alleges that Defendant had knowledge of the asserted patents before the lawsuit was filed, based on patent numbers being marked on the Plaintiff's product manuals.

Case Timeline

Date Event
2022-12-28 U.S. Patent No. 11,766,622 Priority Date
2023-01-18 U.S. Patent No. 12,151,182 Priority Date
2023-09-26 U.S. Patent No. 11,766,622 Issue Date
2024-10-XX Alleged Infringement Start Date
2024-10-18 Alleged Date of Defendant's Knowledge of Patents
2024-11-26 U.S. Patent No. 12,151,182 Issue Date
2025-10-24 Complaint Filing Date

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

U.S. Patent No. 11,766,622 - "MAGNETIC SUCTION BUILDING BLOCK"

  • Patent Identification: U.S. Patent No. 11,766,622, "MAGNETIC SUCTION BUILDING BLOCK", issued September 26, 2023. (Compl. ¶22).

The Invention Explained

  • Problem Addressed: The patent's background section identifies a limitation in existing magnetic building blocks, which it describes as having "single stacking angles" that typically permit stacking only along the "same axis." This limits creative play and the ability to construct more complex or "misplaced modeling." (’622 Patent, col. 1:19-27).
  • The Patented Solution: The invention proposes a building block with internal compartments located at the "crossed corner" where adjacent side walls meet. A magnet, capable of rotating within its compartment, is placed at each corner. This rotational freedom allows the magnet's poles to automatically align for attraction with other blocks at various angles, enabling more complex and stable off-axis connections. (’622 Patent, Abstract; col. 6:1-16).
  • Technical Importance: This design purports to greatly enrich the "building mode and playing method" of magnetic toys, allowing children to build a wider variety of models beyond simple linear stacking. (’622 Patent, Abstract).

Key Claims at a Glance

  • The complaint asserts independent Claim 1 and dependent Claim 4. (Compl. ¶31).
  • The essential elements of independent Claim 1 include:
    • A square building block main body formed by six side walls.
    • Four internal wall groups that define four compartments.
    • An "installation bracket" comprising a connecting shaft, four stop columns, and four connection portions.
    • Eight compartment units defined by the stop columns and side walls.
    • Eight magnet units, each disposed in a compartment unit and "capable of rotating."
    • Each magnet unit having a N pole and a S pole.

U.S. Patent No. 12,151,182 - "MAGNETIC SUCTION BUILDING BLOCK"

  • Patent Identification: U.S. Patent No. 12,151,182, "MAGNETIC SUCTION BUILDING BLOCK", issued November 26, 2024. (Compl. ¶23).

The Invention Explained

  • Problem Addressed: Similar to its parent patent, the ’182 Patent addresses the market need for magnetic blocks with "various stacking angles" and "more connecting modes" to overcome the limitations of single-axis stacking and enhance creative play. (’182 Patent, col. 1:28-36).
  • The Patented Solution: This patent discloses a refined internal structure featuring "supporting poles" within each corner compartment. Each supporting pole holds two magnet units, one at each of its opposite ends. This configuration, distinct from the '622 Patent, provides another mechanical means to secure and orient the rotatable magnets within the block's corners. (’182 Patent, Claim 1).
  • Technical Importance: The invention claims to provide a structure that enables "misplaced connection among the magnetic suction building blocks" and facilitates the "design and building of the misplaced shapes." (’182 Patent, col. 7:27-33).

Key Claims at a Glance

  • The complaint asserts independent Claim 1 and dependent Claim 7. (Compl. ¶43).
  • The essential elements of independent Claim 1 include:
    • A square building block main body with six side walls.
    • Four internal wall groups defining four compartments.
    • Four "supporting poles," one corresponding to each compartment.
    • Four groups of magnet units, with each group comprising "two magnet units at two opposite ends of a corresponding support pole."
    • Each magnet unit is "capable of rotating" and has a N pole and a S pole.
    • The internal wall groups extend from the lower side wall to the upper side wall.

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are magnetic building block toys sold by Defendant under the brand "GraceDuck" through an Amazon storefront. (Compl. ¶¶1, 16). The complaint identifies multiple products by their Amazon Standard Identification Numbers (ASINs). (Compl. ¶16).

Functionality and Market Context

The complaint alleges that the accused products are "unauthorized imitations" that incorporate the "innovations pioneered and developed by CHEN." (Compl. ¶¶6, 10). It further alleges the products possess the "distinctive internal configuration and magnetic assembly methods claimed in the Asserted Patents." (Compl. ¶8). The products are allegedly marketed and sold to consumers throughout the United States, including within the Eastern District of Texas, via an interactive e-commerce storefront. (Compl. ¶¶11, 15). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references claim charts for both asserted patents as Exhibits 6 and 7, but these exhibits were not filed with the complaint. (Compl. ¶¶31, 43). Therefore, the infringement allegations are summarized below in narrative form.

11,766,622 Infringement Allegations

The complaint alleges that the accused GraceDuck products directly infringe, either literally or under the doctrine of equivalents, at least Claim 1 and Claim 4 of the ’622 Patent. (Compl. ¶¶26, 31). The narrative theory of infringement rests on the assertion that Defendant's products are a "blatant copying of the patented structures" and embody the specific internal magnetic assembly methods claimed in the patent. (Compl. ¶8). The complaint does not provide a public, element-by-element breakdown of how the accused products meet the limitations of the asserted claims.

12,151,182 Infringement Allegations

The complaint makes parallel allegations regarding the ’182 Patent, asserting that the accused products directly infringe at least Claim 1 and Claim 7. (Compl. ¶¶38, 43). The infringement theory is identical to that for the ’622 Patent, based on allegations that the accused products are imitations that copy the patented internal structures. (Compl. ¶¶8, 10).

Identified Points of Contention

  • Evidentiary Question: A threshold issue will be establishing the actual internal construction of the accused GraceDuck products. The complaint's infringement allegations are conclusory, and without technical diagrams or reverse engineering results, the factual basis for infringement remains unsubstantiated pending discovery.
  • Technical Question: A key technical dispute may arise over whether the accused products contain a structure corresponding to the ’622 Patent's claimed "installation bracket" or the ’182 Patent's claimed "supporting poles." The specific geometry and function of the components that house the magnets in the accused products will be central to the infringement analysis.

V. Key Claim Terms for Construction

U.S. Patent No. 11,766,622

  • The Term: "installation bracket"
  • Context and Importance: This term appears in independent Claim 1 and is defined by its constituent parts: a "connecting shaft, four stop columns... and four connection portions." The presence or absence of a structure meeting this definition in the accused product will be dispositive for infringement of this claim. Practitioners may focus on this term because its detailed structural requirements offer a clear path for a non-infringement defense if the accused product's internal structure differs.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the bracket's function as being to "stop[] the magnet... in the compartment." ('622 Patent, col. 8:49-51). A party might argue that any internal structure that performs this magnet-stopping function should be considered an "installation bracket."
    • Evidence for a Narrower Interpretation: Claim 1 itself defines the term with high structural specificity. The detailed embodiment in Figure 2, which shows all the recited sub-components, may be used to argue that the term should be construed narrowly to cover only the precise structure disclosed or its structural equivalents. (’622 Patent, Fig. 2; col. 8:51-53).

U.S. Patent No. 12,151,182

  • The Term: "supporting poles"
  • Context and Importance: Independent Claim 1 of the ’182 Patent requires "four supporting poles," each holding two magnet units at opposite ends. The definition of this term is critical to distinguishing this invention from the prior art and from the "installation bracket" of the parent '622 Patent. Practitioners may focus on this term to dispute whether the accused product's internal supports qualify as "poles."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Dependent Claim 2 adds the limitation that "each supporting pole is rod-shaped." (’182 Patent, Claim 2). Under the doctrine of claim differentiation, this suggests that the term "supporting poles" in independent Claim 1 is not limited to a rod shape and could encompass other structural forms that support the magnets.
    • Evidence for a Narrower Interpretation: The word "pole" itself suggests an elongated, slender object. A party could argue that, despite the language of the dependent claim, the specification's context and figures do not disclose any embodiment of a "supporting pole" that is not functionally rod-like, thereby limiting the term's scope.

VI. Other Allegations

Indirect Infringement

The complaint pleads inducement to infringe and contributory infringement for both patents, alleging Defendant "actively and knowingly induced and continues to actively and knowingly induce manufacturers, shippers, distributors, and retailers to directly infringe." (Compl. ¶¶28-29, 32, 40-41, 44).

Willful Infringement

Willfulness is alleged based on pre-suit knowledge. The complaint asserts that Defendant had knowledge of, or was willfully blind to, both asserted patents "since at least October 18, 2024, as CHEN marked the patent number on the product's manual." (Compl. ¶¶32, 44).

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

  • A central evidentiary question will be one of structural identity: what is the precise internal construction of the accused "GraceDuck" products, and can Plaintiff produce evidence showing that this structure contains the specific elements required by the asserted claims, such as the '622 Patent's "installation bracket" or the '182 Patent's "supporting poles"?
  • A core legal issue will be one of definitional scope: how will the court construe the key structural terms of the claims? Specifically, can the term "installation bracket" in the ’622 Patent cover structures that deviate from the specific sub-components recited in the claim, and does the term "supporting poles" in the ’182 Patent require a distinct rod-like element?
  • A key question for damages will be one of pre-suit knowledge: can Plaintiff substantiate its claim that Defendant was aware of the asserted patents prior to the litigation based on patent marking on a competitor's product manual, and does the alleged copying constitute the type of egregious conduct necessary for a finding of willful infringement?