Sanven Technology Ltd v. Dbest Products Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Sanven Technology Ltd. (California) and Shanghai Sishun Tech Ltd. (China)
  • Defendant: Dbest Products Inc. (California)
  • Plaintiff's Counsel: Cross-Border Counselor, LLP
• Case Identification: 5:26-cv-03249, C.D. Cal., 06/11/2026
• Venue Allegations: Venue is alleged to be proper as Defendant resides in the district, maintains a regular and established place of business in the district, and a substantial part of the events giving rise to the claims occurred in or were directed from the district.
• Core Dispute: Plaintiffs seek a declaratory judgment that their VEVOR-branded rolling carts, shopping carts, and pet carriers do not infringe four of the Defendant's patents and that those patents are invalid, following Defendant's infringement complaints to Amazon.com that resulted in the removal of Plaintiffs' product listings.
• Technical Context: The technology at issue involves designs for consumer-grade collapsible wheeled carts, shopping carts, and pet carriers, a mature field focused on improvements in portability, load capacity, and user convenience features.
• Key Procedural History: The action was precipitated by Defendant's patent complaints submitted to Amazon, which led to the removal of Plaintiffs' VEVOR-branded product listings. On December 17, 2025, Plaintiffs' counsel sent a letter to Defendant demanding withdrawal of the complaints, which Defendant allegedly refused. The complaint also notes that U.S. Patent No. 11,912,326 is the subject of an ex parte reexamination (Control No. 90/015,470), for which the USPTO has granted a request after finding a substantial new question of patentability exists for all claims.

Case Timeline

Date	Event
2013-10-20	'766 Patent Priority Date
2014-10-26	'700 Patent Priority Date
2016-01-12	'700 Patent Issue Date
2016-07-19	'766 Patent Issue Date
2020-01-06	'835 Patent Priority Date
2021-12-31	'326 Patent Priority Date
2022-05-24	'835 Patent Issue Date
2024-02-27	'326 Patent Issue Date
November 2025	Defendant submits patent complaints to Amazon
2025-12-17	Plaintiffs' counsel demands withdrawal of Amazon complaints
2026-06-11	Complaint Filing Date

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

U.S. Patent No. 11,338,835: High Load Capacity Collapsible Carts

• Patent Identification: U.S. Patent No. 11,338,835 (the "'835 patent"), "High Load Capacity Collapsible Carts," issued May 24, 2022 Compl. ¶13
• The Invention Explained:
  • Problem Addressed: The patent's background section notes that prior art collapsible carts may not be "sufficiently sturdy to allow for transporting heavy objects" '835 Patent, col. 2:10-12
  • The Patented Solution: The patent discloses a collapsible cart with a rigid frame where the side walls are formed by two panels hinged along a vertical axis '835 Patent, col. 4:15-21 To enhance rigidity when open, the invention uses one or more "slideable members" that engage with "tracks" extending across the hinged panels, locking them into a secure, open position '835 Patent, abstract '835 Patent, col. 4:43-67 This mechanism allows the cart to support heavy loads while still being able to fold inward for storage.
  • Technical Importance: The invention aims to resolve the common trade-off between the portability of collapsible carts and the sturdiness of rigid carts, offering a design that provides both convenient storage and high load capacity '835 Patent, col. 2:8-14
• Key Claims at a Glance:
  • The complaint seeks a declaratory judgment of non-infringement of the '835 patent without specifying claims, but the non-infringement summary points to limitations found in independent claim 1 Compl. ¶25 Compl. ¶32
  • Independent Claim 1 of the '835 patent includes, among others, the following essential elements:
    • A rigid frame with sidewalls, where each sidewall comprises a first panel and a second panel coupled along a vertical axis.
    • A rotatable base panel coupled to the bottom wall.
    • A first track formed along the first and second right panels, extending across the first vertical axis.
    • A first slideable member engaged with the first track, movable between an open position (allowing the sidewall to fold) and a closed position to "selectively lock" the panels together.

U.S. Patent No. 9,233,700: Portable Cart With Removable Shopping Bag

• Patent Identification: U.S. Patent No. 9,233,700 (the "'700 patent"), "Portable Cart With Removable Shopping Bag," issued January 12, 2016 Compl. ¶14
• The Invention Explained:
  • Problem Addressed: The background of the patent reviews numerous prior art transport carts, implicitly suggesting a need for a lightweight, foldable cart that can handle heavy loads and uneven surfaces and that integrates with a removable bag '700 Patent, col. 1-2
  • The Patented Solution: The patent describes a lightweight (four-pound) foldable cart capable of carrying up to 160 pounds '700 Patent, abstract The design features a two-part handle structure comprising a "second upper handle section" that is rotatably connected to a "first lower handle section," allowing the cart to fold for compact storage '700 Patent, col. 7:12-30 '700 Patent, col. 8:31-48 The cart also includes a strong "honeycombed toe plate" and large wheels to facilitate movement over varied terrain '700 Patent, abstract
  • Technical Importance: The invention combines high load capacity and a very low weight in a foldable design, offering significant portability and utility for tasks like grocery shopping, enhanced by a custom-fit removable bag.
• Key Claims at a Glance:
  • The complaint does not specify which claims are at issue, but the non-infringement allegations focus on the handle structure detailed in independent claim 1 Compl. ¶26 Compl. ¶40
  • Independent Claim 1 of the '700 patent includes, among others, the following essential elements:
    • A base section with elevated horizontal sections.
    • A "first lower handle section" formed as a U-shaped member.
    • A "second upper handle section" also formed as a U-shaped member.
    • A toe plate with a honeycomb pattern.
    • Left and right bumper wheels.
    • The "upper handle section is rotatably connected to the lower handle section."

U.S. Patent No. 11,912,326: Wheeled Cart With Braking System

• Patent Identification: U.S. Patent No. 11,912,326 (the "'326 patent"), "Wheeled Cart With Braking System," issued February 27, 2024 Compl. ¶15
• Technology Synopsis: The patent addresses the problem of wheeled carts rolling away when unattended on an incline '326 Patent, col. 1:30-33 The solution is a user-selectable, foot-operated braking system where a "brake lever arm" pivots to engage a "brake feature" with a "plurality of stops" on the inside face of a wheel, thereby preventing rotation '326 Patent, abstract
• Asserted Claims: The complaint does not specify claims but alleges non-infringement of the "claimed braking system" Compl. ¶27, a central feature of independent claims 1 and 19.
• Accused Features: The complaint identifies "45L stair-climbing shopping cart" and "Basket truck / dual-basket grocery utility cart" products as the accused instrumentalities Compl. ¶21, alleging they "lack the claimed braking system and related components" Compl. ¶27

U.S. Patent No. 9,392,766: Portable Pet Carrier to Transport a Pet...

• Patent Identification: U.S. Patent No. 9,392,766 (the "'766 patent"), "Portable Pet Carrier to Transport a Pet From One Location to Another and Retain the Pet in the Carrier While Traveling," issued July 19, 2016 Compl. ¶16
• Technology Synopsis: The patent seeks to solve the discomfort a pet may experience when a rolling carrier is tilted during transport '766 Patent, col. 2:45-57 The invention provides a pet carrier that removably attaches to a flat wheeled platform ("dolly") with a telescoping handle that can be rotated to an angle, allowing the carrier to be pulled while remaining in a horizontal orientation '766 Patent, abstract '766 Patent, col. 2:50-57
• Asserted Claims: The complaint does not specify claims, but its non-infringement summary details features from independent claims 1, 2, and 10, such as the specific wheel configuration and handle mechanism Compl. ¶28
• Accused Features: "Rolling pet carrier products" are accused of infringement Compl. ¶21 The complaint alleges these products lack several claimed features, including the "two spaced-apart rear heavy-duty luggage wheels that rotate in a straight direction" and the "claimed rotatable telescoping handle" Compl. ¶28

III. The Accused Instrumentality

• Product Identification: The accused instrumentalities are VEVOR-branded "rolling cart, stair-climbing cart, basket truck, and pet carrier products" sold by Plaintiffs on Amazon.com and other online platforms Compl. ¶9 Compl. ¶19 The complaint identifies specific Amazon Standard Identification Numbers (ASINs) for products accused of infringing each patent Compl. ¶21
• Functionality and Market Context:
  • The complaint alleges that the accused products, as they relate to the '835 and '326 patents, are carts that lack the specific patented locking and braking mechanisms, respectively Compl. ¶25 Compl. ¶27
  • For the cart accused of infringing the '700 patent, the complaint alleges it uses a "single, unitary handle structure" rather than the claimed two-part rotatable handle Compl. ¶26
  • For the accused pet carrier, the complaint alleges it lacks multiple claimed elements, including the specific wheel type, handle mechanism, and fastener configuration of the '766 patent Compl. ¶28
  • Plaintiffs' VEVOR brand is positioned as a "global e-commerce brand that specializes in providing an affordable selection of tools, machinery, and equipment" Compl. ¶10

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'835 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a first track formed along the first right panel and the second right panel extending across the first vertical axis from a first position on the first right panel to a second position on the second right panel	The accused products are alleged to lack this claimed track feature.	¶25	col. 4:43-50
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 allow the right sidewall to fold inwardly, to a closed position to selectively lock the first right panel to the second right panel	The accused products are alleged to lack this claimed slideable member for locking the side panels.	¶25	col. 4:51-67

• Identified Points of Contention: The primary dispute for the '835 patent appears to be factual. The complaint alleges a complete absence of the claimed track-and-slider locking mechanism Compl. ¶25 The central question will be one of elemental presence: do the accused carts contain structures that meet these limitations, either literally or under the doctrine of equivalents?

'700 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a second upper handle section which is formed in one piece as an elongated U-shaped member... a first lower handle section which is formed in one piece as an elongated U-shaped member	The accused products are alleged to use a "single, unitary handle structure" instead of a two-part assembly.	¶26	col. 7:12-30
the upper handle section is rotatably connected to the lower handle section	The accused products' alleged "single, unitary handle structure" suggests it may lack the claimed rotatable connection between two distinct sections.	¶26	col. 8:31-48

• Identified Points of Contention: The dispute regarding the '700 patent raises a question of claim construction and factual comparison. The complaint alleges the accused products use a "single, unitary handle structure" Compl. ¶26 This raises the question of structural scope: can the claim terms "first lower handle section" and "second upper handle section" that are "rotatably connected" be interpreted to cover a single-piece handle with a folding point, or do they require two physically separate components?

V. Key Claim Terms for Construction

'835 Patent: "slideable member"

• The Term: "slideable member"
• Context and Importance: This term is critical because Plaintiffs allege their products lack this element entirely Compl. ¶25 The definition of what constitutes a "slideable member" that performs the claimed locking function will be central to determining infringement. Practitioners may focus on this term to determine if any component on the accused product could be argued to be its structural or functional equivalent.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim describes the member functionally as being "movable... to selectively lock the first right panel to the second right panel" '835 Patent, claim 1 This functional language could support a construction that encompasses any component that slides to perform this locking function.
  • Evidence for a Narrower Interpretation: The specification describes and depicts a specific embodiment: "The collapsible cart 10 may also include a first slideable member 58" ('835 Patent, col. 4:51-52). Figure 1 shows element 58 as a distinct piece that slides along a track. This may support an argument that the term is limited to a structure analogous to the one disclosed in the preferred embodiment.

'700 Patent: "second upper handle section... rotatably connected to the... first lower handle section"

• The Term: "second upper handle section... rotatably connected to the... first lower handle section"
• Context and Importance: The core of the non-infringement argument for this patent is that the accused product has a "single, unitary handle structure" Compl. ¶26, not the claimed two-part structure. The case will turn on whether the claim requires two separate pieces. Practitioners may focus on this term because it creates a clear potential point of distinction between the patent and the accused product's design.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term "rotatably connected" could arguably be met by any structure allowing relative rotation, such as an integrated living hinge within a unitary piece, if one were to argue the unitary piece has two "sections."
  • Evidence for a Narrower Interpretation: The claim recites "a first lower handle section" and "a second upper handle section" as distinct elements '700 Patent, claim 1 The specification consistently describes these as separate components: "the cart includes a first lower handle section 30" and "a second upper handle section 50" ('700 Patent, col. 7:12-16). The figures further depict two separate U-shaped members joined by pins (e.g., '700 Patent, Fig. 5, pins 150, 160), strongly supporting an interpretation that requires two physically distinct structural components.

VI. Other Allegations

• Indirect Infringement: As a complaint for declaratory judgment of non-infringement, it does not make affirmative allegations of indirect infringement. Rather, it seeks a declaration that Plaintiffs are not liable for infringement of any kind, which would include indirect infringement (Compl. ¶¶33; 41; 49; 58).
• Willful Infringement: This section is not applicable. The complaint does not contain a claim for willful infringement; it is a defensive action seeking a declaration of non-infringement and invalidity.

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

1. A central issue will be one of elemental presence vs. absence: For the '835 patent (collapsible cart lock) and '326 patent (brake system), the complaint alleges the complete absence of key claimed mechanisms. The case will likely turn on a factual, evidentiary question: does discovery reveal the presence of these claimed elements, either literally or, as the patentee might argue, under the doctrine of equivalents?

2. A second core issue will be one of structural definition and claim construction: For the '700 patent (two-part handle), the dispute centers on whether the accused "single, unitary handle structure" can infringe claims reciting two distinct, "rotatably connected" handle sections. The outcome will likely depend on how the court construes the claim language in light of the patent's specification and figures, which appear to show two separate components.

3. A third key question will be the viability of the asserted patents, particularly the '326 patent. The complaint not only challenges the validity of all four patents but specifically highlights that the '326 patent is already undergoing ex parte reexamination where the USPTO found a substantial new question of patentability. This procedural posture raises a significant question about whether the '326 patent's claims will survive scrutiny by both the USPTO and the court.