DCT
2:25-cv-04617
Dbest Products Inc v. Wuhan LANZHI Network Technology Co Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: dbest products, inc. (California)
- Defendant: Wuhan Lanzhi Network Technology Company. LTD (China)
- Plaintiff’s Counsel: Orbit IP, LLP
- Case Identification: 2:25-cv-04617, 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 and sells the accused products.
- Core Dispute: Plaintiff alleges that Defendant’s portable carts infringe patents related to collapsible cart structures and locking mechanisms.
- Technical Context: The technology concerns collapsible, wheeled utility carts, a mature product category in the consumer goods market where improvements often focus on durability, load capacity, and ease of use.
- Key Procedural History: Plaintiff alleges a policy of marking its products with patent numbers to provide public notice of its patent rights. The complaint does not mention any prior litigation or administrative proceedings involving the patents-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2020-01-06 | Priority Date for '446 and '546 Patents |
| 2025-04-15 | U.S. Patent No. 12,275,446 Issued |
| 2025-05-20 | U.S. Patent No. 12,304,546 Issued |
| 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 problem in prior art collapsible carts where the collapsible nature of the design results in sidewalls that are not "sufficiently sturdy to allow for transporting heavy objects" (’446 Patent, col. 1:13-16).
- The Patented Solution: The invention discloses a collapsible cart with a specialized sidewall construction to improve rigidity. A sidewall is composed of two separate panels that are rotatably connected by a hinge (’446 Patent, col. 4:48-51). To lock these panels into a sturdy, flat configuration, a "slideable member" moves along a "track" that spans both panels, securing them together (’446 Patent, col. 5:19-29). This locking mechanism is designed to provide the strength of a rigid cart while retaining the ability to collapse for storage.
- Technical Importance: This design aims to overcome a primary trade-off in portable cart design by enabling a high load capacity in a product that remains conveniently collapsible.
Key Claims at a Glance
- The complaint asserts at least one claim of the ’446 patent, referring to a claim chart in an exhibit not included with the complaint (Compl. ¶15). The analysis here focuses on independent claim 1.
- Essential elements of independent claim 1 include:
- A collapsible cart with a rigid frame forming a compartment.
- 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 (allowing the panels to fold) and a closed position to selectively lock the first and second right panels together.
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 insufficient sturdiness of prior art collapsible carts for transporting heavy objects (’546 Patent, col. 1:24-26).
- The Patented Solution: This invention also describes a collapsible cart with multi-panel walls that fold inwardly. However, it claims a different mechanism for securing the panels. The patent claims a system where a "first latch part" on the edge of one panel is configured to "mate" with a "second latch part" on the edge of the adjacent panel (’546 Patent, col. 13:33-40). When mated, these latch parts hold the two panels in a "common plane," creating a rigid wall structure (’546 Patent, col. 14:1-4).
- Technical Importance: This approach provides an alternative method for achieving a rigid, load-bearing structure in a collapsible cart, focusing on a direct latching engagement between panel edges.
Key Claims at a Glance
- The complaint asserts at least one claim of the ’546 patent, referring to a claim chart in an exhibit not included with the complaint (Compl. ¶20). The analysis here focuses on independent claim 1.
- Essential elements of independent claim 1 include:
- A collapsible cart with a frame of at least five walls, where at least three walls are configured to rotatably fold inwardly.
- One of the opposing walls consists of a first panel and a second panel, which is rotatably coupled to the first.
- 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 first and second latch parts are configured to mate to hold the panels in a common plane.
III. The Accused Instrumentality
Product Identification
- The complaint identifies the accused instrumentalities as "numerous products" sold by Defendant on Amazon.com, referring to them generally as the "Accused Products" (Compl. ¶13).
Functionality and Market Context
- The complaint alleges the Accused Products are "portable carts" sold to consumers in the United States via Amazon.com (Compl. ¶7, ¶11). The complaint does not describe the specific features or technical operation of the Accused Products, instead referring to external exhibits not provided in the filing. No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’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 the Accused Products are collapsible carts with a rigid frame forming a compartment. | ¶15 | col. 4:45-48 |
| the right sidewall comprising a first right panel rotatably coupled to a second right panel; | The complaint alleges the Accused Products have a sidewall constructed from two rotatably coupled panels. | ¶15 | col. 4:48-51 |
| a first track formed along the first right panel and the second right panel... | The complaint alleges the Accused Products possess a track that extends along the two panels of the sidewall. | ¶15 | col. 5:9-12 |
| 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 movable, sliding member on the track to lock the two sidewall panels together. | ¶15 | col. 5:19-29 |
’546 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A collapsible cart... comprising: a frame defining a compartment, wherein... the frame comprises at least five walls, with at least three... configured to rotatably fold inwardly... | The complaint alleges the Accused Products are collapsible carts with a five-wall frame where at least three walls fold inward. | ¶20 | col. 1:40-42 |
| 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 feature a sidewall composed of two rotatably coupled panels. | ¶20 | col. 6:35-40 |
| 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 complaint alleges the Accused Products have corresponding latch parts on the edges of the sidewall panels. | ¶20 | col. 14:17-23 |
| 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... | The complaint alleges the latch parts on the Accused Products mate to hold the panels in a flat, common plane. | ¶20 | col. 14:23-26 |
Identified Points of Contention:
- Factual Questions: Given the lack of technical detail in the complaint, a central point of contention will be factual: do the Accused Products actually contain the specific structures recited in the claims? The dispute will likely focus on the mechanism used to secure the foldable wall panels.
- Scope Questions: The case raises the question of how to distinguish the "slideable member" and "track" mechanism of the ’446 Patent from the "latch part" system of the ’546 Patent. The defense may argue that the Accused Product’s mechanism, if any, does not meet the specific limitations of either claimed invention.
V. Key Claim Terms for Construction
For the ’446 Patent:
- The Term: "first slideable member cooperatively engaged to the first track"
- Context and Importance: This phrase describes the core locking mechanism of the ’446 patent. The interpretation of this term will be dispositive for infringement, as it defines the specific structural solution to the problem of sidewall instability.
- Intrinsic Evidence for a Broader Interpretation: A party might argue that the term should not be limited to the exact slide depicted in the figures, but should cover any member that slides along a guide or track to bridge and lock two panels.
- Intrinsic Evidence for a Narrower Interpretation: The specification repeatedly depicts and describes a specific embodiment of the "slideable member" (58) and "track" (46) (’446 Patent, Fig. 2; col. 5:19-29). A party could argue that the term must be limited to this disclosed structure, which moves between distinct open and closed positions to "selectively lock" the panels.
For the ’546 Patent:
- The Term: "latch part"
- Context and Importance: This term is central to independent claim 1 of the ’546 patent but is not explicitly defined in the specification. Its construction will determine what type of panel-fastening mechanism falls within the scope of the claims. Practitioners may focus on this term because its potential ambiguity creates a clear battleground for claim construction.
- Intrinsic Evidence for a Broader Interpretation: A party could argue "latch part" should be given its plain and ordinary meaning, covering any pair of corresponding components that mate or interlock to fasten the panels.
- Intrinsic Evidence for a Narrower Interpretation: A party could argue the term must be read in the context of the overall patent family, which includes the ’446 patent with its distinct "slideable member" on a "track." This suggests the patentee viewed a "latch part" as a different invention. Further, other claims in the ’546 patent use the more specific term "fastener member" (’546 Patent, col. 14:17), which could be used to argue that "latch part" implies a specific type of connection not covered by other terms.
VI. Other Allegations
Indirect Infringement
- The complaint does not allege indirect infringement. The claims for relief are based on direct infringement under 35 U.S.C. § 271 (Compl. ¶1, ¶15, ¶20).
Willful Infringement
- The complaint does not explicitly allege willful infringement or plead facts showing egregious conduct. It does allege that Plaintiff marks its products with patent numbers, which, if proven effective, could establish notice and serve as a basis for enhanced damages for any post-notice infringement (Compl. ¶10).
VII. Analyst’s Conclusion: Key Questions for the Case
- A key evidentiary question will be one of structural correspondence: Do the Accused Products, in fact, possess the specific panel-locking mechanisms recited in the asserted claims—namely, the "slideable member on a track" of the ’446 patent or the mating "latch parts" of the ’546 patent? The complaint’s lack of technical specifics places the entire burden of demonstrating this correspondence on the evidence to be produced during discovery.
- A core issue will be one of claim differentiation: Can the asserted claims from the two related patents be construed as patentably distinct? The defense may seek to exploit any perceived overlap or ambiguity between the ’446 patent’s "track" system and the ’546 patent’s "latch" system to argue that the accused design falls outside the scope of both.
- A secondary, but important, factual question will be the effectiveness of notice: The Plaintiff has pleaded patent marking. The timing, consistency, and visibility of this marking practice will be scrutinized to determine the date from which damages may begin to accrue if infringement is found.