DCT
0:25-cv-61038
Yantai Mingde E Commerce Co Ltd v. Shenzhen Xiang Yun Duan Network Technology Co Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Xiang Yun Duan Network Technology Co., Ltd. et al. (People's Republic of China)
- Defendant: Dynamic Manufacturing Group LLC (Florida)
- Plaintiff’s Counsel: Gunther Legal, PLLC
- Case Identification: 25-cv-61038, S.D. Fla., 05/23/2025
- Venue Allegations: Venue is alleged to be proper based on Defendant being a Florida limited liability company with its principal place of business within the Southern District of Florida.
- Core Dispute: Plaintiffs seek a declaratory judgment that their trailer lock products do not infringe Defendant's patent and that the patent is invalid, filed in response to Defendant's patent infringement complaints submitted to Amazon's intellectual property enforcement system.
- Technical Context: The technology concerns mechanical lock assemblies designed to secure trailer couplers and their associated safety chains to prevent trailer theft.
- Key Procedural History: The litigation was precipitated by Defendant lodging an intellectual property complaint on Amazon.com against at least one of the Plaintiffs, which resulted in the delisting of Plaintiffs' products. The complaint for declaratory judgment asserts that this infringement allegation is baseless and further contends that Defendant's patent is invalid in view of multiple prior art references that were allegedly on sale more than one year prior to the patent's filing date.
Case Timeline
| Date | Event |
|---|---|
| 2016-07-20 | "Proven E Reference" prior art product allegedly available on Amazon |
| 2016-08-01 | "Proven C Reference" prior art product allegedly available for sale |
| 2017-06-05 | "Rough Riders Reference" prior art video allegedly available on YouTube |
| 2019-06-28 | U.S. Patent No. 11,427,044 Priority Date |
| 2022-08-30 | U.S. Patent No. 11,427,044 Issue Date |
| 2025-05-05 | Defendant allegedly lodged Amazon Infringement Complaint |
| 2025-05-23 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,427,044 - TRAILER COUPLER LOCK ASSEMBLY
- Patent Identification: U.S. Patent No. 11,427,044, issued August 30, 2022.
The Invention Explained
- Problem Addressed: The patent's background section describes conventional trailer locks as "extremely bulky, heavy, and very cumbersome to operate" and notes they were not typically designed to also secure a trailer's safety chain assembly (’044 Patent, col. 1:32-35). This created a need for a "small, compact, and sturdy trailer coupler lock assembly that would securely lock both the trailer coupler and safety chain assembly" (’044 Patent, col. 1:38-41).
- The Patented Solution: The invention is a multi-component lock system. It consists of a main "rigid protective case" that fits over the trailer coupler and a separate "interlock adapter" that first engages the coupler mechanism and is then secured within the protective case (’044 Patent, col. 1:57-59). A key feature is that the rigid protective case has an integrated "compartment dedicated for securing a safety chain assembly," solving the problem of securing both components with a single device (’044 Patent, col. 1:60-62).
- Technical Importance: This design aims to provide a more integrated and less unwieldy solution for trailer security by combining the functions of a coupler lock and a safety chain lock into a single, compact system (’044 Patent, col. 1:42-51).
Key Claims at a Glance
- The complaint’s non-infringement and invalidity arguments focus on independent claim 1 (Compl. ¶7, ¶13).
- The essential elements of independent claim 1 are:
- A trailer coupler lock assembly, comprising:
- a rigid protective case; and
- an interlock adapter for interlocking a trailer coupler within the rigid protective case,
- the interlock adapter being detachably associated with the rigid protective case,
- the interlock adapter including the hasp;
- the rigid protective case having a compartment for securing a safety chain assembly.
- The complaint seeks a judicial declaration that the Accused Products do not infringe "any claims of the Patent" (Compl. ¶12).
III. The Accused Instrumentality
- Product Identification: The "Accused Products" are "various trailer lock products" sold by the Plaintiffs on the Amazon marketplace, identified by a list of over a dozen unique Amazon Standard Identification Numbers (ASINs) (Compl. ¶12-13).
- Functionality and Market Context: The products are trailer locks sold through e-commerce channels, which constitute Plaintiffs' "primary sales channel into the United States" (Compl. ¶14). The complaint alleges that all Accused Products are structurally identical, being manufactured by the same factory (Compl. ¶23). For the purposes of non-infringement, the complaint alleges that the Accused Products' interlocking mechanism utilizes a "loop" rather than the "hasp" required by the patent's claims (Compl. ¶15).
IV. Analysis of Infringement Allegations
- Claim Chart Summary: The complaint pleads for a declaratory judgment of non-infringement. The following table summarizes Plaintiffs' core argument that their products do not meet all limitations of claim 1.
'044 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Plaintiffs' Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a rigid protective case | The Accused Products include a cylindrical protective shell. | ¶15 | col. 1:57 |
| an interlock adapter for interlocking a trailer coupler within the rigid protective case | The Accused Products include an interlocking component that is distinct from the protective shell. | ¶15 | col. 1:58-59 |
| the interlock adapter being detachably associated with the rigid protective case | The complaint does not contest this element but implies it through its description of a two-part system. | ¶13, ¶15 | col. 2:1-2 |
| the interlock adapter including the hasp | The Accused Products "only have a loop but do not have a hasp." The complaint argues a hasp requires a separate "fastener or plate that is slotted over the loop," which the Accused Products allegedly lack. | ¶15 | col. 2:22-23 |
| the rigid protective case having a compartment for securing a safety chain assembly | The complaint does not provide sufficient detail for analysis of this element. | - | col. 1:60-62 |
Visual Evidence: The complaint provides a side-by-side visual comparison of a figure from the '044 Patent depicting the claimed interlock adapter with its hasp, alongside a photograph of the accused product's allegedly distinct loop-based interlocking component (Compl. p. 9). Additionally, the complaint includes images of a prior art device, the "Proven E Reference," allegedly showing a "rigid protective case" and "an interlock adapter including a hasp" to support its invalidity contentions (Compl. p. 8, ¶8, Ex. E).
Identified Points of Contention:
- Scope Questions: The dispute raises a critical question of claim scope: does the term "hasp," as claimed in the ’044 Patent, read on the "loop" structure of the Accused Products? Plaintiffs' argument hinges on a narrow definition of "hasp" that requires a multi-part locking formation (Compl. ¶15).
- Technical Questions: A key factual question will be whether the structure and operation of the Accused Products' "loop" is technically distinct from the claimed "hasp." The evidence presented, particularly the side-by-side visual comparison, is intended to establish such a distinction (Compl. p. 9).
V. Key Claim Terms for Construction
- The Term: "hasp"
- Context and Importance: The definition of "hasp" is the lynchpin of Plaintiffs' non-infringement argument. The entire dispute over claim 1 turns on whether the accused "loop" falls within the scope of this term. Practitioners may focus on this term because Plaintiffs have explicitly founded their non-infringement theory on its narrow interpretation (Compl. ¶15).
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent does not provide an explicit definition of "hasp" in the specification. A party could argue that the term should be given its plain and ordinary meaning, which might be construed broadly to include any loop-like structure designed to receive a lock shackle for fastening.
- Evidence for a Narrower Interpretation: The patent consistently refers to the "hasp" in the context of specific, interacting components: "hasp 152 of rigid protective case 116" and "hasp 154 of interlock adapter 118" combine to "form the hasp assembly" (’044 Patent, col. 8:14-21). The figures, such as Figure 2H, depict the hasp (154) as a specific flat tab with an aperture, designed to pass through the protective case to be locked. This repeated reference to a multi-part "hasp assembly" and the specific structures shown in the embodiments may support the narrower construction advanced by Plaintiffs.
VI. Other Allegations
- Indirect Infringement: Plaintiffs seek a declaratory judgment that they have not infringed "either directly or indirectly" (Compl. ¶12). However, the complaint's factual allegations focus exclusively on a theory of direct non-infringement based on the absence of a required claim element and do not provide a specific basis for why indirect infringement has not occurred.
- Willful Infringement: Willful infringement is not at issue in this complaint. Instead, Plaintiffs allege that Defendant lodged its Amazon complaint in "bad faith" and with "knowledge that the '044 Patent was not infringed," which forms the basis for a related state law claim for tortious interference (Compl. ¶19).
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this declaratory judgment action appears to hinge on two central questions for the court:
A core issue will be one of claim construction: Can the term "hasp," as used in the context of the '044 Patent's detailed embodiments showing a multi-part locking mechanism, be construed broadly enough to read on the single-piece "loop" structure of the Accused Products, or is it limited to the more complex assembly depicted in the patent?
A dispositive parallel issue will be one of patent validity: Have Plaintiffs presented clear and convincing evidence that the asserted claims are anticipated or rendered obvious by the prior art references, particularly the "Proven" products that were allegedly on sale more than one year before the patent's effective filing date?