DCT
2:25-cv-02359
Shenzhen Yihong Technology Co Ltd v. Dbest Products Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen YiHong Technology Co., Ltd. (People's Republic of China)
- Defendant: Dbest products, Inc. (California)
- Plaintiff’s Counsel: Glacier Law LLP
- Case Identification: 2:25-cv-02359, W.D. Wash., 11/24/2025
- Venue Allegations: Plaintiff alleges venue is proper because Defendant purposefully directed its patent enforcement activities to Amazon personnel located in Seattle, Washington, causing the removal of Plaintiff’s product listing.
- Core Dispute: Plaintiff seeks a declaratory judgment that its collapsible cart product does not infringe U.S. Patent Nos. 12,275,446 and 12,304,546, and/or that the patents are invalid.
- Technical Context: The technology concerns mechanical structures for collapsible storage carts, a consumer product category where innovations often focus on enhancing durability, load capacity, and ease of collapse for compact storage.
- Key Procedural History: The action was precipitated by Defendant’s filing of a patent infringement complaint with Amazon, which resulted in the removal of Plaintiff's product listing from the e-commerce platform.
Case Timeline
| Date | Event |
|---|---|
| 2020-01-06 | Earliest Priority Date for '446 and '546 Patents |
| 2023-09-01 | '446 Patent Application Filed |
| 2025-01-20 | '546 Patent Application Filed |
| 2025-04-15 | '446 Patent Issued |
| 2025-05-20 | '546 Patent Issued |
| 2025-11-21 | Amazon notifies Plaintiff of Defendant's infringement complaint |
| 2025-11-24 | Complaint for Declaratory Judgment Filed |
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 background states 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 invention discloses a collapsible cart with enhanced structural integrity achieved through multi-part sidewalls. Each sidewall is comprised of at least a "first right panel rotatably coupled to a second right panel," which allows the walls to fold inwardly for storage (’446 Patent, Abstract). To provide rigidity when open, the panels are locked together by a "first slideable member" that moves along a "first track" extending across both panels (’446 Patent, col. 7:13-39). This design is intended to create a sturdy frame when erect while remaining easily collapsible.
- Technical Importance: The described approach addresses a central design trade-off in portable storage by creating a locking mechanism integrated across articulated panels to improve the load-bearing capacity of a collapsible structure (’446 Patent, col. 1:12-19).
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 configured to transition from a closed to an open condition.
- A rigid frame with walls, configured to fold inwardly.
- The right sidewall comprising a first right panel rotatably coupled to a second right panel.
- A first track formed along the first and second right panels.
- A first slideable member that moves along the track to selectively lock the first and second right panels together.
- The complaint notes that dependent claims necessarily fail if the independent claim is not infringed (Compl. ¶30).
U.S. Patent No. 12,304,546 - "Collapsible Carts"
The Invention Explained
- Problem Addressed: The patent identifies a need for improvements in collapsible carts, noting that prior art sidewalls may lack the sturdiness required for heavy objects, a problem the invention purports to address (’546 Patent, col. 2:23-26).
- The Patented Solution: This patent also describes a cart with multi-panel walls that "fold inwardly in the closed condition" (’546 Patent, Abstract). The claims recite a frame with at least five walls, where "one of the two opposing walls consists of a first panel and a second panel" that are rotatably coupled (’546 Patent, col. 13:29-34). Rigidity is achieved by mating "a first latch part" on the first panel with "a second latch part" on the second panel, which holds the two panels "in a common plane" when latched (’546 Patent, col. 13:35-45).
- Technical Importance: The invention provides another mechanical approach to reinforcing a collapsible structure, focusing on the use of mating latch components at panel edges to create a rigid, coplanar wall from articulated segments (’546 Patent, col. 2:23-29).
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 collapsible cart with a frame of at least five walls, with at least three configured to rotatably fold inwardly.
- One of the opposing walls consists of a first panel and a second panel rotatably coupled to the first.
- A first latch part disposed on an edge of the first panel.
- A second latch part disposed on an edge of the second panel.
- The latch parts are configured to mate to hold the first and second panels in a common plane.
- The complaint notes that dependent claims are not infringed if the independent claim is not met (Compl. ¶57).
III. The Accused Instrumentality
Product Identification
- A "collapsible cart" sold by Plaintiff Shenzhen YiHong Technology Co., Ltd. on Amazon.com (Compl. ¶9, ¶22).
Functionality and Market Context
- The complaint alleges that the accused cart's sidewalls are "unitary, single-piece structures, not multi-panel assemblies" (Compl. ¶27).
- The collapsing mechanism is described as the entire wall pivoting "downward by rotating around a bottom horizontal hinge," rather than folding inwardly via articulated sub-panels (Compl. ¶27, ¶54).
- The locking mechanism is alleged to be a "rotatable snap-on latch" that "pivots to secure the sidewall to the front frame," which is distinct from a sliding member on a track (Compl. ¶28, ¶55).
- The product is sold on the Amazon marketplace, which the complaint identifies as the Plaintiff's "primary sales channel in the United States" and its "most significant channel of trade" (Compl. ¶14).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
'446 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| the right sidewall comprising a first right panel rotatably coupled to a second right panel | The accused product's right and left sidewalls are unitary, single-piece structures, not multi-panel assemblies. The walls collapse downward via a bottom hinge. | ¶27 | col. 4:48-51 |
| a first track formed along the first right panel and the second right panel | The accused product lacks the claimed track-and-slider locking assembly and contains no "track" as required by Claim 1. | ¶28 | col. 5:9-15 |
| a first slideable member cooperatively engaged to the first track...movable along the first track...to selectively lock the first right panel to the second right panel | The accused product employs a rotatable snap-on latch that pivots; this rotating latch is alleged not to be a "slideable member." | ¶28 | col. 5:16-24 |
'546 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| one of the two opposing walls consists of a first panel and a second panel...the second panel rotatably coupled to the first panel | The accused product's sidewalls do not comprise first and second panels coupled along a vertical axis; each sidewall is a unitary, monolithic structure. | ¶54 | col. 13:29-34 |
| a first latch part disposed on an edge of the first panel...and a second latch part disposed on an edge of the second panel...configured to mate...and hold the two panels in a common plane | The accused product uses a rotatable snap-on latch that engages the top of a single-piece wall to the frame, which is alleged to be structurally and functionally distinct from mating latch parts designed to hold two separate panels coplanar. | ¶55 | col. 13:35-45 |
- Identified Points of Contention:
- Scope Questions: The complaint raises the question of whether a unitary sidewall that collapses downward can meet the "fold inwardly" limitation, which the patents appear to associate with articulated, multi-panel walls.
- Technical Questions: A central dispute concerns whether the accused product’s "rotatable snap-on latch" is structurally and functionally equivalent to the claimed "slideable member" that moves along a "track" (’446 Patent) or the claimed mating "latch parts" designed to hold two distinct panels coplanar (’546 Patent). The complaint frames these as fundamentally different mechanisms (Compl. ¶29, ¶56).
V. Key Claim Terms for Construction
The Term: "a right sidewall comprising a first right panel rotatably coupled to a second right panel" (’446 Patent, Claim 1); "one of the two opposing walls consists of a first panel and a second panel...rotatably coupled to the first" (’546 Patent, Claim 1).
Context and Importance: This language is central to the dispute, as the Plaintiff’s core non-infringement argument is that its cart has "unitary, single-piece" sidewalls (Compl. ¶27). Practitioners may focus on whether this claim language requires two structurally separate components or could be read to cover a single piece of material with a flexible hinge or score line.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party seeking a broader construction might argue that the term "panel" is not explicitly defined as a separate piece of material and that a "rotatable coupling" could include an integrated living hinge within a monolithic structure.
- Evidence for a Narrower Interpretation: The detailed description of the '446 Patent consistently depicts two distinct components: a "first right panel 26" and a "second right panel 28" joined by a "first hinge 27" (’446 Patent, col. 4:48-51; Fig. 2). This repeated illustration of separate parts may support a narrower construction requiring physically distinct panels.
The Term: "a first slideable member" (’446 Patent, Claim 1).
Context and Importance: Plaintiff contends its product uses a "rotatable snap-on latch," not a "slideable member" (Compl. ¶28). The distinction between sliding and rotating motion is a key point of contention.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A patentee could argue that "slideable" should be interpreted functionally to mean any member that translates position to lock the panels, without being strictly limited to linear motion.
- Evidence for a Narrower Interpretation: The claim specifies the member is "movable along the first track" (’446 Patent, Claim 1). The specification further describes the member (58) as moving along a track (46), and figures like Fig. 8 show a clear linear path of engagement. This may support an interpretation requiring linear, sliding motion along a defined track.
VI. Other Allegations
The complaint does not contain allegations of indirect or willful infringement, as it is a declaratory judgment action filed by the accused infringer.
VII. Analyst’s Conclusion: Key Questions for the Case
This case appears to center on fundamental questions of claim construction and the comparison of mechanical structures. The outcome may depend on the court's resolution of two key issues:
- A core issue will be one of structural interpretation: Can the claim language requiring a wall "comprising a first...panel rotatably coupled to a second...panel" be construed to read on the accused product's alleged "unitary, single-piece" walls that collapse via a bottom hinge?
- A key evidentiary question will be one of mechanical distinction: Does the accused product's "rotatable snap-on latch" perform the same function in substantially the same way to achieve the same result as the claimed "slideable member" moving on a "track" or the mating "latch parts" holding two panels coplanar, or is there a fundamental mismatch in their structure and mode of operation?