Dongguan Hongchuang Technology Co Ltd v. Dbest Products Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Dongguan Hongchuang Technology Co Ltd. (People's Republic of of China)
  • Defendant: Dbest products, Inc. (California)
  • Plaintiff’s Counsel: Glacier Law LLP
• Case Identification: 2:26-cv-00365, W.D. Wash., 01/31/2026
• Venue Allegations: Plaintiff alleges venue is proper because Defendant directed patent enforcement activities into the district by submitting an infringement complaint to Amazon, whose personnel in Seattle then removed Plaintiff's product listing from the marketplace.
• Core Dispute: Plaintiff seeks a declaratory judgment that its collapsible cart product does not infringe Defendant's patents related to collapsible cart structures, and further alleges that the patents-in-suit are invalid.
• Technical Context: The technology concerns the mechanical design of wheeled, collapsible utility carts, focusing on the construction of foldable sidewalls and locking mechanisms intended to provide both compact storage and structural rigidity.
• Key Procedural History: The action was initiated after Defendant submitted patent infringement complaints to Amazon, which resulted in the delisting of Plaintiff’s product. In its complaint for declaratory judgment, Plaintiff identifies five separate prior art references that it alleges anticipate or render obvious the claims of the patents-in-suit.

Case Timeline

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

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

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" '446 Patent, col. 1:12-16
• The Patented Solution: The patent describes a collapsible cart with reinforced, multi-panel sidewalls that can be locked together to improve rigidity. The solution involves a sidewall constructed from a "first right panel rotatably coupled to a second right panel" and a "first lock assembly" to secure them '446 Patent, Abstract The detailed description clarifies this lock assembly can be a "first slideable member" that moves along a "first track" spanning both panels to hold them in an open, rigid position '446 Patent, col. 5:11-34 Fig. 2
• Technical Importance: This design attempts to resolve the inherent conflict between a cart’s collapsibility for storage and the structural strength required for carrying significant weight '446 Patent, col. 1:12-18

Key Claims at a Glance

• The complaint asserts non-infringement of independent claims 1, 10, 16, and 22 Compl. ¶25
• Independent Claim 1 includes the following essential elements:
  • A collapsible cart with a rigid frame forming a compartment.
  • A right sidewall comprising a "first right panel rotatably coupled to a second right panel."
  • A "first track" formed along and extending between the first and second right panels.
  • A "first slideable member" that is movable along the track to selectively lock the two panels together.
• The complaint notes that because the independent claims are not infringed, the dependent claims are also not infringed Compl. ¶30

U.S. Patent No. 12,304,546 - "COLLAPSIBLE CARTS"

The Invention Explained

• Problem Addressed: The patent background states that "the need for improvements to collapsible carts still remains" because prior art sidewalls may not be sufficiently sturdy for heavy objects '546 Patent, col. 1:25-28
• The Patented Solution: This patent discloses a specific geometry for a collapsible cart where at least three of five walls "rotatably fold inwardly" '546 Patent, col. 13:24-27 A key feature is an opposing wall made of a "first panel and a second panel" that are rotatably coupled. These panels are held in a common plane by a "first latch part" and a "second latch part" disposed on the edges of the respective panels '546 Patent, col. 13:31-48
• Technical Importance: The invention focuses on a particular mechanical arrangement of folding walls and discrete latching components to create a stable, load-bearing structure that can also be collapsed.

Key Claims at a Glance

• The complaint asserts non-infringement of independent claims 1, 9, and 17 Compl. ¶52
• Independent Claim 1 includes the following essential elements:
  • A frame with at least five walls, where at least three are configured to "rotatably fold inwardly."
  • One of the opposing walls "consists of a first panel and a second panel," with the second panel rotatably coupled to the first.
  • A "first latch part" on the edge of the first panel.
  • A "second latch part" on the edge of the second panel.
  • The latch parts are configured to "mate with one another and hold the first and second panels in a common plane."
• The complaint states that dependent claims are not infringed because the independent claims are not met Compl. ¶57

III. The Accused Instrumentality

Product Identification

• The "Accused Product" is a collapsible cart designed, sourced, and sold by Plaintiff Dongguan Hongchuang Technology Co Ltd. on Amazon.com Compl. ¶¶ 9, 22

Functionality and Market Context

• The complaint alleges the Accused Product's sidewalls are "unitary, single-piece structures," not multi-panel assemblies as required by the patents Compl. ¶27
• Functionally, the sidewalls are described as collapsing "downward by rotating around a bottom horizontal hinge," which is contrasted with the patents' claimed "inwardly" folding mechanism Compl. ¶¶ 27, 54
• The locking mechanism is alleged to be a "rotatable snap-on latch" that pivots to secure the top of the single-piece wall to the cart's frame, rather than a sliding member on a track or mating parts on separate panels Compl. ¶¶ 28, 55
• Plaintiff alleges that the Amazon marketplace is its "primary sales channel in the United States" and that Defendant's enforcement action has caused significant commercial harm Compl. ¶¶ 14, 21

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

'446 Patent Infringement Allegations

'546 Patent Infringement Allegations

Identified Points of Contention

• Scope Questions: A central dispute will be whether the claim phrase "a sidewall comprising a first... panel rotatably coupled to a second... panel" can be construed to cover a single, unitary wall that pivots downward from its base. Plaintiff alleges these are fundamentally different structures Compl. ¶¶ 27, 54 Similarly, the court may need to determine if "folding inwardly" can describe a wall that "collapses downward" Compl. ¶27
• Technical Questions: The case raises the question of whether the accused product's "rotatable snap-on latch" is structurally and functionally the same as the claimed "slideable member" that moves along a "track" ('446 Patent) or the "first and second latch parts" that "mate" to hold two panels coplanar ('546 Patent). Plaintiff argues the mechanisms are distinct in structure, operation, and result Compl. ¶¶ 28, 55

V. Key Claim Terms for Construction

The Term: "a...sidewall comprising a first...panel rotatably coupled to a second...panel"

• (Appears in '446 Claim 1 and '546 Claim 1)
• Context and Importance: This term is critical because Plaintiff's core non-infringement theory is that its product has "unitary, single-piece" sidewalls, not the two-part, articulated construction explicitly recited in the claims Compl. ¶¶ 27, 54 The construction of this term may be dispositive for literal infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent owner may argue that any hinge or fold line within a wall effectively creates a "first panel" and a "second panel" for claim purposes, focusing on the function of collapsing rather than the specific manufacturing method.
  • Evidence for a Narrower Interpretation: The specifications of both patents consistently describe and depict two distinct panel components joined by a vertical hinge (e.g., '446 Patent, Fig. 2, items 26, 27, 28; col. 5:48-51). This explicit disclosure of separate, coupled panels may support a narrower construction that excludes a single-piece structure.

The Term: "slideable member"

• ('446 Claim 1)
• Context and Importance: Plaintiff contends its "rotatable snap-on latch" is not a "slideable member," making the construction of this term key to both literal infringement and the doctrine of equivalents analysis Compl. ¶28 Practitioners may focus on this term because it distinguishes the linear motion implied by "slideable" from the pivoting motion of the accused latch.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent owner might argue "slideable member" should be interpreted functionally as any component that moves to lock the panels, regardless of the specific path of motion.
  • Evidence for a Narrower Interpretation: The specification describes the member as "movable along the first track between an open position to a closed position" '446 Patent, col. 7:30-33 and is shown moving linearly in figures (e.g., '446 Patent, Fig. 2, item 58 on track 46). This may support a construction requiring linear, not rotational, movement.

VI. Other Allegations

• Indirect Infringement: The complaint seeks a declaratory judgment of non-infringement both directly and indirectly, but does not provide specific facts regarding a potential theory of indirect infringement that Defendant might assert Compl. ¶48
• Willful Infringement: This allegation is not applicable in its traditional sense, as the complaint is a declaratory judgment action filed by the accused infringer. The complaint does not set forth allegations by the patentee regarding willfulness.

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

• A core issue will be one of definitional scope: Can the claim language requiring a sidewall "comprising a first panel rotatably coupled to a second panel" be construed to cover the accused product's unitary, single-piece wall that collapses downward on a bottom hinge?
• A second central question will be one of structural and functional distinction: Does the accused product’s "rotatable snap-on latch" infringe, either literally or under the doctrine of equivalents, claims requiring a "slideable member" moving on a track or two distinct "latch parts" that mate to hold panels coplanar? Plaintiff's argument that this would vitiate claim limitations suggests this will be a heavily contested issue.
• A third key question is one of patent validity: Will the patents-in-suit withstand the invalidity challenge based on the five prior art references cited in the complaint, which allegedly disclose key features such as multi-panel folding structures and various locking mechanisms?