DCT
2:25-cv-04618
Dbest Products Inc v. Guangzhou Shijun Technology Co Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Dbest Products, Inc. (California)
- Defendant: Guangzhou Shijun Technology Co., Ltd (China)
- Plaintiff’s Counsel: Orbit IP, LLP
- Case Identification: 2:25-cv-04618, C.D. Cal., 05/21/2025
- Venue Allegations: Plaintiff alleges venue is proper because Defendant is subject to personal jurisdiction in the district, based on doing substantial business and committing acts of patent infringement in the Central District of California.
- Core Dispute: Plaintiff alleges that Defendant’s portable carts sold in the U.S. via Amazon infringe two patents related to high-capacity collapsible carts.
- Technical Context: The technology involves mechanical designs for wheeled, collapsible storage carts, focusing on specific locking mechanisms that reinforce foldable sidewalls to increase load capacity while maintaining a compact, storable form.
- Key Procedural History: The complaint alleges that Plaintiff marks its patented products, providing constructive notice to the public and potential infringers. No other prior litigation or administrative proceedings are mentioned.
Case Timeline
| Date | Event |
|---|---|
| 2020-01-06 | Earliest Priority Date for '446 and '546 Patents |
| 2025-04-15 | U.S. Patent No. 12,275,446 Issues |
| 2025-05-20 | U.S. Patent No. 12,304,546 Issues |
| 2025-05-21 | Complaint Filed |
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 identifies a shortcoming in prior art collapsible carts, noting that their collapsible nature means the "sidewalls may not be sufficiently sturdy to allow for transporting heavy objects" ('446 Patent, col. 1:13-16).
- The Patented Solution: To solve this, the invention discloses a cart with sidewalls composed of two separate panels connected by a hinge (e.g., first right panel 26 and second right panel 28). A "track" (46) runs across both panels, and a "slideable member" (58) moves along this track. By sliding the member from an "open" position on one panel to a "closed" position spanning both, the two panels are locked together, creating a rigid and sturdy sidewall. ('446 Patent, col. 5:9-30, FIG. 2).
- Technical Importance: This design purports to provide the structural integrity of a rigid cart while retaining the convenient storage benefits of a collapsible one.
- Key Claims at a Glance:
- The complaint asserts at least one claim of the '446 Patent (Compl. ¶12). Independent Claim 1 is representative and includes the following essential elements:
- A collapsible cart with a rigid frame (front, rear, right, left, and bottom walls).
- The right sidewall comprises a first right panel rotatably coupled to a second right panel.
- A "first track" is formed along both the first and second right panels.
- A "first slideable member" is engaged with the track and is movable between an open position and a closed position to "selectively lock" the first right panel to the second.
- The complaint asserts at least one claim of the '446 Patent (Compl. ¶12). Independent Claim 1 is representative and includes the following essential elements:
- The Invention Explained:
U.S. Patent No. 12,304,546, Collapsible Carts, issued May 20, 2025
- The Invention Explained:
- Problem Addressed: Like the '446 Patent, this patent addresses the problem that in prior art carts, "the sidewalls may not be sufficiently sturdy to allow for transporting heavy objects" ('546 Patent, col.2:24-26).
- The Patented Solution: This patent claims a solution where a collapsible sidewall, made of a first and second rotatably coupled panel, is secured by a different mechanism. The solution described in the claims involves a "first latch part" on the edge of the first panel and a "second latch part" on the edge of the second panel. These latch parts are "configured to mate with one another" to hold the two panels together in a "common plane," thereby creating the rigid sidewall. ('546 Patent, col. 13:23-35). The detailed description illustrates an embodiment with a slideable member similar to that in the '446 patent. ('546 Patent, col. 7:4-16, FIG. 2).
- Technical Importance: This approach also aims to enhance the load-bearing capacity of a collapsible cart by providing a mechanism to securely lock its hinged sidewalls into a rigid, planar configuration.
- Key Claims at a Glance:
- The complaint asserts at least one claim of the '546 Patent (Compl. ¶20). Independent Claim 1 is representative and includes the following essential elements:
- A collapsible cart with a frame of at least five walls.
- One of the opposing walls consists of a first panel and a second panel, rotatably coupled.
- A "first latch part" is disposed on an edge of the first panel.
- A "second latch part" is disposed on an edge of the second panel.
- The latch parts are configured to "mate with one another" to hold the panels in a common plane.
- The complaint asserts at least one claim of the '546 Patent (Compl. ¶20). Independent Claim 1 is representative and includes the following essential elements:
- The Invention Explained:
III. The Accused Instrumentality
- Product Identification: The complaint identifies the "Accused Products" as numerous portable cart products sold by Defendant on Amazon.com (Compl. ¶¶11, 13). A specific list of products by Amazon Standard Identification Number (ASIN) is referenced as Exhibit C, which was not publicly filed with the complaint (Compl. ¶13, Exhibit C).
- Functionality and Market Context: The complaint alleges the Accused Products are "portable carts" that infringe the patents-in-suit (Compl. ¶¶7, 13). It asserts that these products are sold and offered for sale to consumers throughout the United States, including within the judicial district, via online retail platforms (Compl. ¶11). The complaint does not provide further technical details on the specific construction or operation of the Accused Products, instead incorporating by reference claim chart exhibits that were not filed on the public docket (Compl. ¶¶12, 20). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint alleges direct infringement of both patents but does not include the referenced claim chart exhibits. The infringement theory is summarized below based on the narrative allegations and the requirements of the representative independent claims.
- '446 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A collapsible cart configured to transition from a closed condition where it is folded up to an open condition where it is expanded for use, the collapsible cart comprising: a rigid frame forming a compartment... | The complaint alleges that the Accused Products are collapsible carts that embody the features of the '446 patent. (Compl. ¶¶13, 15). | ¶15 | col. 4:46-48 |
| the right sidewall comprising a first right panel rotatably coupled to a second right panel; | The complaint alleges the Accused Products possess sidewalls made of at least two panels that are rotatably coupled. (Compl. ¶¶12-13, 15). | ¶15 | col. 4:49-51 |
| 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; | The complaint alleges the Accused Products' sidewalls include a track that extends across the rotatably coupled panels. (Compl. ¶¶12-13, 15). | ¶15 | col. 5:9-14 |
| and 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... | The complaint alleges the Accused Products use a slideable member on the track to lock the sidewall panels together. (Compl. ¶¶12-13, 15). | ¶15 | col. 5:20-27 |
- '546 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A collapsible cart configured to transition from a closed condition... the frame comprises at least five walls... one of the two opposing walls consists of a first panel and a second panel; and the second panel rotatably coupled to the first panel; | The complaint alleges the Accused Products are collapsible carts with a frame and two-part, rotatably coupled opposing walls that meet the limitations of the '546 patent. (Compl. ¶¶13, 20). | ¶20 | col. 6:38-46 |
| a first latch part disposed on an edge of the first panel when the collapsible cart is in the closed condition and the open condition; and a second latch part disposed on an edge of the second panel when the collapsible cart is in the closed condition and the open condition... | The complaint alleges the Accused Products possess latch parts on the edges of the sidewall panels. (Compl. ¶¶13, 20, Exhibit E). | ¶20 | col. 13:23-28 |
| wherein the first latch part and the second latch part are configured to mate with one another and hold the first and second panels in a common plane when the first and second latch parts are latched together; and when... unlatched... the second panel is capable of rotating relative to the first panel. | The complaint alleges the latch parts on the Accused Products mate to lock the panels together into a plane. (Compl. ¶¶13, 20, Exhibit E). | ¶20 | col. 13:29-35 |
- Identified Points of Contention:
- Factual Dispute: The central dispute will be factual: do the Accused Products actually contain the specific mechanical structures recited in the claims? For the '446 Patent, this involves proving the existence and function of a "track" and "slideable member." For the '546 Patent, it requires proving the existence of "latch parts" on the panel edges that "mate."
- Technical Mismatch: A key question is whether the locking mechanism used in the Accused Products, if any, operates in the same way as the claimed inventions. The two patents claim distinct locking approaches ("slideable member on a track" vs. "mating latch parts"), raising the possibility of a mismatch between the accused functionality and the specific requirements of one or both sets of claims.
V. Key Claim Terms for Construction
Term from '446 Patent: "slideable member"
- Context and Importance: This term defines the specific locking component in Claim 1 of the '446 Patent. The entire infringement analysis for this patent will likely depend on whether the locking feature on the Accused Products falls within the court's construction of this term.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself is general, requiring only a "member" that is "slideable" and "cooperatively engaged to the first track" ('446 Patent, col. 7:27-28). This could support an argument that the term covers any component that slides along a guide to perform the locking function.
- Evidence for a Narrower Interpretation: The specification describes a specific embodiment, "first slideable member 58," which functions as a clip that moves along the track (46) to secure the panels ('446 Patent, col. 5:20-30, FIG. 2). A defendant may argue that the term should be limited to the characteristics of this disclosed embodiment.
Term from '546 Patent: "latch part"
- Context and Importance: This term is the central feature of the locking mechanism in Claim 1 of the '546 Patent. Its definition is critical, as infringement hinges on whether the Accused Products have components that qualify as "latch parts" that "mate."
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: "Latch part" is a common mechanical term. A plaintiff may argue it should be given its plain and ordinary meaning, covering a wide range of interlocking or fastening components disposed on the panel edges.
- Evidence for a Narrower Interpretation: The detailed description of the '546 Patent does not appear to explicitly define "latch part" or illustrate an embodiment using that terminology; instead, it describes the "slideable member" embodiment ('546 Patent, FIGS. 1-9; col. 7:4-24). Practitioners may focus on this term because a defendant could argue that the lack of a specific corresponding description in the specification renders the term indefinite or limits its scope, raising a potential question regarding the patent's written description support for the claimed invention.
VI. Other Allegations
- Indirect Infringement: The complaint does not allege indirect infringement (inducement or contributory infringement). It contains a single count of direct infringement for each patent (Compl. p. 4-5).
- Willful Infringement: The complaint does not explicitly allege willful infringement. It does, however, request attorneys' fees and costs and alleges that Plaintiff has complied with patent marking statutes since the patents issued (Compl. ¶¶10, 18, 23). These allegations may lay a foundation for a later willfulness claim or a motion for enhanced damages and attorneys' fees.
VII. Analyst’s Conclusion: Key Questions for the Case
An Evidentiary Question of "What is it?": Given the factually sparse complaint, a threshold question will be evidentiary. Can Plaintiff produce evidence to demonstrate that the Accused Products, sold by a foreign entity on a third-party platform, actually incorporate the specific locking mechanisms claimed—either the "track and slideable member" of the '446 Patent or the "mating latch parts" of the '546 Patent?
A Claim Construction Question of Scope: The case will likely turn on claim construction. A core issue for the '546 Patent will be one of definitional scope: what is a "latch part" in the context of the patent, and does the specification provide adequate written description to support the full scope of that term as claimed?
A Technical Question of Infringement: Assuming the claims are construed, a key question will be one of functional correspondence: does the locking mechanism on the accused carts perform its function in a way that aligns with the specific limitations of the claims? The court will need to determine if there is a match between the accused technology and the distinct "slideable member" or "latch part" mechanisms required by the patents.