Dbest Products Inc v. Guanghzou Nafenai Trading Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Dbest Products, Inc. (California)
  • Defendant: Guanghzou Nafenai Trading Co, Ltd. (China)
  • Plaintiff’s Counsel: Orbit IP, LLP
• Case Identification: 2:25-cv-04601, C.D. Cal., 05/21/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is subject to personal jurisdiction in the district, where it allegedly conducts substantial business.
• Core Dispute: Plaintiff alleges that Defendant’s portable collapsible carts, sold in the United States via Amazon.com, infringe two patents related to collapsible cart construction and locking mechanisms.
• Technical Context: The technology relates to mechanical improvements in consumer-grade collapsible utility carts, focusing on enhancing structural rigidity and load-bearing capacity while maintaining collapsibility.
• Key Procedural History: The complaint alleges that Plaintiff has complied with its statutory marking obligations by affixing the relevant patent numbers to its products, which may be relevant to questions of notice and damages. The patents-in-suit claim priority to a family of applications originating in early 2020.

Case Timeline

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

U.S. Patent No. 12,275,446 - "High Load Capacity Collapsible Carts"

• Issued: April 15, 2025

The Invention Explained

• Problem Addressed: The patent's background section identifies a key deficiency in prior art collapsible carts: their sidewalls "may not be sufficiently sturdy to allow for transporting heavy objects" ('446 Patent, col. 1:13-16).
• The Patented Solution: The invention addresses this problem with a novel sidewall construction. The sidewalls are composed of at least two separate panels connected by a hinge. To enhance rigidity when the cart is open, the patent discloses a "slideable member" that moves along a "track" spanning the two panels. When engaged, this sliding lock secures the panels together, creating a more stable and robust sidewall capable of supporting heavier loads ('446 Patent, Abstract; col. 5:18-35).
• Technical Importance: This approach seeks to combine the storage convenience of a collapsible design with the structural integrity typically associated with non-collapsible, rigid carts ('446 Patent, col. 1:13-18).

Key Claims at a Glance

• The complaint asserts at least one claim of the '446 Patent, but does not specify which (Compl. ¶15). Independent Claim 1 is representative and includes the following essential elements:
  • A rigid frame forming a compartment with a front wall, rear wall, right sidewall, left sidewall, and bottom wall.
  • The right sidewall comprising a first right panel rotatably coupled to a second right panel.
  • A first track formed along the first right panel and the second right panel.
  • A first slideable member cooperatively engaged to the first track, which is movable between an open position and a closed position to selectively lock the first right panel to the second right panel.

U.S. Patent No. 12,304,546 - "Collapsible Carts"

• Issued: May 20, 2025

The Invention Explained

• Problem Addressed: Like its related '446 Patent, this patent addresses the problem that prior art collapsible carts may lack the sturdiness required for "transporting heavy objects" ('546 Patent, col. 2:25-27).
• The Patented Solution: The patent describes a collapsible cart frame with at least five walls, where multiple walls are configured to fold inwardly. The invention focuses on the specific manner in which hinged wall panels are secured. It discloses a system of corresponding "latch parts" or "fastener members" disposed on the edges of the panels. When the cart is expanded, these parts are configured to mate with one another to hold the panels in a "substantially coplanar alignment," thereby forming a solid, continuous wall ('546 Patent, Abstract; col. 14:12-28).
• Technical Importance: This invention provides an integrated method for locking the walls of a collapsible cart in an open and sturdy configuration, also contemplating features like stackability with other identical carts ('546 Patent, Abstract; col. 3:45-51).

Key Claims at a Glance

• The complaint asserts at least one claim of the '546 Patent without identifying it (Compl. ¶20). Independent Claim 9 is representative and includes the following essential elements:
  • A frame with at least five walls, where at least three walls are configured to fold inwardly.
  • A third wall comprising a first panel and a second panel, with the second panel rotatably coupled to the first.
  • A fastener configured to selectively secure the first and second panels in a "substantially coplanar alignment."
  • The fastener comprises a "first fastener member integrally disposed on an edge of the first panel" and a corresponding "second fastener member integrally disposed on an edge of the second panel."
  • The fastener members are configured to "mate with one another" to hold the panels in alignment.

III. The Accused Instrumentality

Product Identification

The complaint identifies the "Accused Products" as "numerous products" sold by Defendant on Amazon.com (Compl. ¶¶ 11, 13). A specific schedule of Amazon Standard Identification Numbers (ASINs) is referenced as Exhibit C, but this exhibit was not provided with the complaint (Compl. ¶13).

Functionality and Market Context

The complaint alleges that the Accused Products are portable carts sold to consumers in the United States and within the judicial district (Compl. ¶11). It further alleges that Plaintiff identified these products while monitoring online retail platforms for infringing goods (Compl. ¶12). The complaint does not provide specific details about the technical functionality or operation of the Accused Products.

IV. Analysis of Infringement Allegations

The complaint alleges that representative claim charts demonstrating infringement are attached as Exhibits D and E for the '446 and '546 Patents, respectively (Compl. ¶¶ 15, 20). As these exhibits were not provided, the following analysis is based on the complaint's narrative allegations and the patent language. No probative visual evidence provided in complaint.

The complaint’s infringement theory is conclusory. For both patents, it asserts that Defendant directly infringes by "offering for sale, selling, and/or otherwise distributing the Accused Products" and states that an attached, but missing, exhibit demonstrates that the products satisfy "each limitation of at least one claim" of each patent (Compl. ¶¶ 15, 20).

Identified Points of Contention

• '446 Patent Scope Questions: The central infringement question for the '446 Patent will be whether the Accused Products practice the claimed "track" and "slideable member" combination. A dispute may arise over whether the locking mechanism on the accused carts, if any, functions by sliding along a defined path as required by the claim, or if it operates via a different mechanical principle (e.g., a snap-fit, a rotating latch, or a simple clip). The scope of "slideable member" will be a focal point.
• '546 Patent Technical Questions: For the '546 Patent, the analysis will likely turn on the specific structure of the accused locking mechanism. What evidence does the complaint provide that the Accused Products possess "fastener members" that are "integrally disposed on an edge" of the folding panels, as required by Claim 9? The determination of infringement may depend on whether the locking components are molded as part of the panels themselves or are separate components attached later.

V. Key Claim Terms for Construction

'446 Patent

• The Term: "slideable member" (from Claim 1)
• Context and Importance: This term is the core active component of the locking system in Claim 1. Proving that an accused product contains a "slideable member" as construed by the court will be essential to Plaintiff's infringement case for this claim.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A party seeking a broader construction may argue that the term should encompass any component that slides relative to the wall panels to achieve a lock. The specification describes the member as being "cooperatively engage[d] to the first track" and "movable between an open position... to a closed position," without limiting its specific form ('446 Patent, col. 5:18-23).
  • Evidence for a Narrower Interpretation: A party seeking a narrower construction may point to the embodiments shown in the figures, which depict a specific C-shaped bracket (58, 60) that travels along a raised rail (46, 48) ('446 Patent, FIG. 2, FIG. 8). They may argue the term should be limited to a structure that slides along a defined, external track, rather than any component that moves linearly.

'546 Patent

• The Term: "substantially coplanar alignment" (from Claim 9)
• Context and Importance: This term defines the required final state of the wall panels when they are locked. The degree of planarity required by "substantially coplanar" will be critical, as minor deviations or angles in an accused product's locked panels could be sufficient to argue non-infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: A proponent of a broad reading could argue that the term's meaning is informed by the patent's stated goal: to create a "sturdy" wall for carrying heavy objects ('546 Patent, col. 2:25-27). This suggests the alignment needs to be functionally, not perfectly, planar, allowing for manufacturing tolerances.
  • Evidence for a Narrower Interpretation: A proponent of a narrow reading may argue that "coplanar" is a precise geometric term and "substantially" does not vitiate the requirement for the panels to lie essentially in the same plane. The claims also use terms like "selectively align" ('546 Patent, col. 8:29), suggesting an intended precision that would exclude panels that are noticeably angled or offset when locked.

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

Given the minimal factual detail in the complaint, the litigation will likely center on evidence developed during discovery and the court's interpretation of key claim terms. The central questions for the case appear to be:

1. A core issue will be one of claim construction: Can the term "slideable member" in the '446 patent be construed broadly to read on any locking component that moves linearly, or is it limited to the specific track-and-bracket embodiment shown in the patent's figures? Similarly, what degree of flatness is required by the "substantially coplanar alignment" limitation in the '546 patent?

2. A key evidentiary question will be one of technical equivalence: Assuming the claim terms are construed, does the locking mechanism on the Accused Products operate in the manner required by the claims? Specifically, does it feature a component that slides along a track to lock hinged panels, or does it achieve the lock through a fundamentally different mechanical action, such as snapping, rotating, or clipping?