DCT
2:24-cv-10842
Taizhou Luqiao Shengqiang Housewares Factory v. Dbest Products Inc
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Taizhou Luqiao Shengqiang Housewares Factory (China)
- Defendant: dbest products, Inc. (California)
- Plaintiff’s Counsel: SHM Law Firm
- Case Identification: 2:24-cv-10842, C.D. Cal., 01/24/2025
- Venue Allegations: Venue is asserted based on Defendant dbest products, Inc. being a California corporation with its principal place of business within the Central District of California, making it a resident of the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that its "Non-Infringing Shoe Boxes" do not infringe Defendant's patent related to stackable collapsible carts, and further alleges the patent is invalid and unenforceable.
- Technical Context: The technology concerns the mechanical design of collapsible storage carts, a consumer product category where features enhancing portability, durability, and stackability are sources of competitive differentiation.
- Key Procedural History: The action was precipitated by Defendant's patent infringement complaints to Amazon, which resulted in the removal of Plaintiff’s product listings. Plaintiff alleges that Defendant misrepresented its patent as a continuation (rather than a continuation-in-part) to the USPTO to claim an earlier priority date, and also failed to disclose material prior art during prosecution, forming the basis for its unenforceability and unfair competition claims.
Case Timeline
| Date | Event |
|---|---|
| 2020-01-06 | Earliest Priority Date Claimed by ’576 Patent ('956 Provisional) |
| 2021-12-03 | Chinese '334 Patent (alleged prior art) published |
| 2022-07-29 | HAIXIN product (alleged prior art) first made publicly available (on or before) |
| 2023-01-30 | Parent Application (No. 18/161,677) filed |
| 2023-03-28 | Provisional Application ('068) filed |
| 2023-12-15 | Application for '576 Patent filed |
| 2024-10-01 | U.S. Patent No. 12,103,576 Issued |
| 2024-12-05 | Plaintiff received Amazon delisting notice for '576 Patent infringement |
| 2024-12-17 | Plaintiff submitted non-infringement appeal to Amazon |
| 2025-01-24 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,103,576 - "Stackable Collapsible Carts," Issued 10/01/2024
The Invention Explained
- Problem Addressed: The patent's background section notes that due to the "collapsible nature of the prior art cart design, the sidewalls may not be sufficiently sturdy to allow for transporting heavy objects" ('576 Patent, col. 1:21-23).
- The Patented Solution: The invention is a collapsible cart with a rigid frame that transitions between a folded state for storage and an open state for use. The design aims to enhance sturdiness through specific sidewall constructions, such as a "right sidewall includ[ing] a first right panel rotatably coupled to a second right panel" and a lock assembly to secure the panels when open ('576 Patent, col. 1:37-43, Abstract). This configuration, detailed in figures like FIG. 1 and FIG. 2, provides structural integrity when the cart is expanded.
- Technical Importance: The claimed features seek to resolve the common trade-off in consumer goods between the convenience of collapsibility and the structural integrity required for carrying heavy loads.
Key Claims at a Glance
- The complaint identifies independent claims 1, 11, and 15 as being at issue (Compl. ¶18).
- Independent Claim 1: A collapsible cart comprising:
- a rigid frame with various walls, where the sidewalls fold inwardly;
- a right sidewall with a first right panel rotatably coupled to a second right panel;
- the second right panel proportioned to fit within an opening in the first right panel;
- a "first track" formed along both the first and second right panels; and
- a "first slideable member" that moves along the track between an open and closed position to lock the panels together.
- Independent Claim 11: A cart comprising:
- a rigid frame with foldable sidewalls;
- a right sidewall with a first, second, and third right panel, where the second and third panels "conform in shape to collectively cover the opening in the first right panel";
- the second right panel comprising a "ribbed wall with a plurality of ribs"; and
- a "first lock assembly integrated with the first right panel and the second right panel" for locking and unlocking them.
- Independent Claim 15: A stackable collapsible cart comprising:
- a rigid frame with rotatably coupled panels and an integrated lock assembly;
- a wheel assembly coupled to the bottom wall; and
- a rigid top cover with an "indentation pattern" that is substantially aligned with the wheel assembly's vertical axis and is "configured to receive a wheel assembly from another identical collapsible cart when stacked vertically."
- The complaint seeks a declaration of non-infringement for "any valid and enforceable claim," suggesting dependent claims may also be contested (Compl. ¶39).
III. The Accused Instrumentality
Product Identification
The products are Plaintiff's "Non-Infringing Shoe Boxes," sold on Amazon.com under the storefront name "SeespringDirect" (Compl. ¶¶ 9, 16). The complaint identifies over a dozen specific Amazon Standard Identification Numbers (ASINs) for these products (Compl. ¶9).
Functionality and Market Context
The complaint does not describe the technical functionality of the shoe boxes in detail. Instead, it defines them by what they allegedly lack in relation to the '576 Patent's claims (Compl. ¶¶ 40-42). The complaint alleges that the Amazon marketplace is Plaintiff's "primary sales channel into the United States" and that Defendant's infringement complaints to Amazon caused "immediate and substantial harm" by preventing Plaintiff from accessing its largest channel of trade (Compl. ¶¶ 14, 4-5).
IV. Analysis of Infringement Allegations
This is a declaratory judgment action for non-infringement. The following table summarizes the Plaintiff's allegations regarding which key claim elements are absent from its products.
'576 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a first track formed along the first right panel and the second right panel extending from a first position on the first right panel to a second position on the second right panel | Plaintiff alleges its products lack this "first track" feature. | ¶40 | col. 11:52-56 |
| a first slideable member cooperatively engaged to the first track, the first slideable member is movable along the first track between an open position to a closed position to selectively lock the first right panel to the second right panel... | Plaintiff alleges its products lack this "first slideable member." | ¶40 | col. 11:57-67 |
| Claim Element (from Independent Claim 11) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
| a first lock assembly integrated with the first right panel and the second right panel, the first lock assembly having a first condition for locking the first right panel to the second right panel, and a second condition for unlocking the first right panel from the second right panel | Plaintiff alleges its products lack this "first lock assembly." | ¶41 | col. 12:63-13:1 |
| Claim Element (from Independent Claim 15) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
| an indentation pattern being at least substantially aligned with the vertical axis of the wheel assembly, the indentation pattern configured to receive a wheel assembly from another identical collapsible cart when stacked vertically | Plaintiff alleges its products lack this "indentation pattern." | ¶42 | col. 14:12-16 |
- Identified Points of Contention: The dispute centers on literal non-infringement, with Plaintiff contending its products are missing entire claim limitations.
- Scope Questions: The case will raise questions about the scope of several key terms. For example: Can a simple guide or edge on the accused product be construed as the claimed "first track"? Does a simple latch or clip meet the definition of the claimed "first lock assembly"?
- Technical Questions: A primary technical question will be whether any feature of the "Non-Infringing Shoe Boxes" performs the functions recited in the claims, even if not explicitly designed for that purpose. The complaint provides a side-by-side comparison of Figure 42A from the '576 Patent and Figure 5 from a Chinese patent to argue the patented design was copied from prior art, which indirectly supports its non-infringement theory by highlighting the specificity of the claimed features it alleges are absent from its own products (Compl. p. 9). This visual shows the detailed panel and locking mechanism that Plaintiff argues is missing from its products (Compl. p. 9).
V. Key Claim Terms for Construction
The Term: "first track" (Claim 1)
- Context and Importance: Plaintiff's core non-infringement argument for Claim 1 rests on the absence of this feature (Compl. ¶40). The definition will be critical to determine if any structure on Plaintiff's shoe boxes could be considered a "track."
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term "track" is not explicitly defined, which may allow for an argument that it should be given its plain and ordinary meaning, potentially encompassing any guide or channel that directs movement.
- Evidence for a Narrower Interpretation: The specification consistently shows the track (46, 48) as a distinct, raised rail-like structure along which a slideable member moves (e.g., '576 Patent, Fig. 2; col. 6:62-67). This may support a narrower construction limited to such an explicit structure.
The Term: "first lock assembly integrated with the first right panel and the second right panel" (Claim 11)
- Context and Importance: Plaintiff's non-infringement argument for Claim 11 hinges on the absence of this "lock assembly" (Compl. ¶41). The meaning of "lock assembly" and "integrated" will determine if a simple latching mechanism could meet the limitation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent describes various locking mechanisms, including a "first slideable member" (col. 1:47), a spring-loaded peg system (col. 9:22-26), and a lock for the top cover (col. 9:57-63), which could suggest "lock assembly" is a generic term for any fastening component.
- Evidence for a Narrower Interpretation: Claim 11 requires the assembly to be "integrated with" two different panels and have distinct locking/unlocking conditions. The detailed description of the slideable member (58) in FIG. 42A and 42B locking the panels (26, 28) provides a very specific embodiment that may be used to argue for a narrower definition ('576 Patent, col. 9:22-34).
VI. Other Allegations
- Inequitable Conduct & Unenforceability: The complaint alleges the '576 Patent is unenforceable due to inequitable conduct. The specific allegations are that Defendant knew of the material prior art HAIXIN '334 Chinese Patent, which allegedly discloses the "third right panel" of Claim 11, and deliberately withheld it from the USPTO with the specific intent to deceive the office (Compl. ¶¶ 34-36). The complaint includes a visual comparison between the '576 patent drawings and the '334 patent drawings to support this allegation (Compl. p. 9).
- Improper Priority Claim: Plaintiff alleges that Defendant misrepresented the '576 Patent as a continuation when it should have been a continuation-in-part, as it allegedly contains new matter (the "third right panel") not disclosed in its parent applications. This, Plaintiff argues, means Claim 11 is not entitled to the earlier priority date (Compl. ¶¶ 27-28).
- State Law Claims: Plaintiff brings claims for unfair competition and tortious interference under California law, alleging that Defendant acted unlawfully and unfairly by submitting baseless infringement complaints to Amazon to disrupt Plaintiff's business operations (Compl. ¶¶ 45-51).
VII. Analyst’s Conclusion: Key Questions for the Case
- Validity over Prior Art: A core issue will be the patent's validity. The court must determine whether the allegedly withheld Chinese '334 patent and the publicly available HAIXIN products render claims like Claim 11 obvious or anticipated, and whether the failure to disclose the '334 patent constitutes inequitable conduct sufficient to render the entire patent unenforceable.
- Claim Construction and Factual Infringement: The case will turn on a classic infringement analysis: first, construing the scope of key terms like "track", "lock assembly", and "indentation pattern"; and second, a factual determination of whether any structures on Plaintiff's "shoe boxes" meet those construed limitations, either literally or under the doctrine of equivalents.
- Defendant's Pre-Litigation Conduct: A significant part of the dispute centers on Defendant's actions. The court will examine whether Defendant's use of Amazon's IP enforcement system was a legitimate defense of its patent rights or constituted an act of unfair competition and tortious interference, the answer to which will be closely tied to the court's findings on infringement and validity.