Hangzhouzhenshanwangluokejiyouxiangongsi v. Dynamic Mfg Group LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Hangzhouzhenshanwangluokejiyouxiangongsi (China)
  • Defendant: Dynamic Manufacturing Group, LLC (Florida)
  • Plaintiff’s Counsel: YK Law LLP
• Case Identification: 8:25-cv-00654, M.D. Fla., 03/17/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Middle District of Florida because Defendant is a Florida corporation and directed its patent enforcement activities at Plaintiff through an Amazon.com complaint, which allegedly harmed Plaintiff's business in the district.
• Core Dispute: Plaintiff seeks a declaratory judgment that its trailer coupler lock assembly does not infringe Defendant's patent related to trailer lock technology and that the patent is invalid, following an infringement complaint Defendant filed against Plaintiff via Amazon's intellectual property notice program.
• Technical Context: The technology involves mechanical assemblies designed to lock a trailer's coupler, preventing theft, with a specific focus on also securing the trailer's safety chains.
• Key Procedural History: The lawsuit was precipitated by Defendant's filing of a patent infringement complaint with Amazon.com on or about March 12, 2025, accusing Plaintiff's products. Plaintiff states that it filed this action in federal court in part because Amazon's internal dispute resolution program does not consider patent invalidity challenges.

Case Timeline

Date	Event
2019-06-28	U.S. Patent No. 11,427,044 Priority Date
2022-08-30	U.S. Patent No. 11,427,044 Issued
2025-03-12	Defendant files patent infringement complaint with Amazon
2025-03-17	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, “TRAILER COUPLER LOCK ASSEMBLY,” issued August 30, 2022. (Compl. ¶17).

The Invention Explained

• Problem Addressed: The patent’s background section notes that conventional trailer coupler locks were often "bulky, heavy, and very cumbersome to operate" and were not typically designed with the intent to also secure a trailer's safety chain assembly. ('044 Patent, col. 1:31-34). This created a need for a compact and sturdy lock that could secure both components simultaneously. ('044 Patent, col. 1:39-44).
• The Patented Solution: The invention is a trailer lock assembly comprising a "rigid protective case" and a detachable "interlock adapter." ('044 Patent, col. 2:55-59). The adapter is first placed into the trailer coupler and latched. The rigid case, which contains a "compartment dedicated for securing a safety chain assembly," is then slid over the coupled adapter and locked in place, thereby securing the coupler, its latch, and the safety chains within a single housing. ('044 Patent, col. 2:59-62; col. 4:21-30).
• Technical Importance: The patented design provides an integrated method for securing not only the trailer coupler to prevent unauthorized towing but also the safety chains, which could otherwise be used to improperly tow the trailer. ('044 Patent, col. 3:7-11).

Key Claims at a Glance

• The complaint seeks a declaratory judgment of non-infringement of "at least one claim of the '044 Patent." (Compl. ¶24). Independent claim 1 is representative.
• The essential elements of independent claim 1 are:
  • A rigid protective case; and
  • An interlock adapter for interlocking a trailer coupler within the rigid protective case;
  • The interlock adapter is detachably associated with the rigid protective case;
  • The interlock adapter includes the hasp;
  • The rigid protective case has a compartment for securing a safety chain assembly. ('044 Patent, col. 13:19-27).
• The complaint's prayer for relief seeks a judgment that all claims of the '044 Patent are invalid, indicating an intent to challenge the patent's full scope. (Compl. p. 7, Prayer for Relief ¶2).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Plaintiff’s "trailer coupler lock assembly," referred to in the filing as the "Non-Infringing Product." (Compl. ¶2). These products are sold on Amazon.com under seller aliases including "Jyoelron." (Compl. ¶14).

Functionality and Market Context

The complaint, being a declaratory judgment action, does not describe the technical functionality of the Plaintiff's product. It makes the conclusory allegation that the "Non-Infringing Products do not infringe the ‘044 Patent because none of the Non-Infringing Products possess all the elements and limitations of any claim of the ‘044 Patent." (Compl. ¶22). The complaint alleges that sales on the Amazon marketplace account for a "significant portion of Plaintiff's business." (Compl. ¶13).

IV. Analysis of Infringement Allegations

The complaint does not provide sufficient detail for analysis of infringement allegations. As a declaratory judgment action initiated by the accused infringer, it denies infringement without articulating the patent holder's specific infringement theory or providing any claim charts or technical comparisons.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

• The Term: "a compartment for securing a safety chain assembly" ('044 Patent, col. 13:26-27)

• Context and Importance: This limitation is a primary point of novelty described in the patent. The dispute will likely center on what structural features are required to meet the definition of a "compartment" and what actions constitute "securing" the chain assembly.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself is broad. The specification summary refers generally to the case "having a compartment dedicated for securing a safety chain assembly" without further structural limitation in that section. ('044 Patent, col. 2:60-62).
  • Evidence for a Narrower Interpretation: The detailed description discloses specific structures for this purpose, including "rear barriers 254 and 256 that prevent safety chain assembly 102 from sliding out of rigid protective case 116." ('044 Patent, col. 5:27-30). A defendant may argue that a "compartment for securing" requires these specific "chain retainers" or functionally equivalent structures, not merely a void where chains can be placed.

• The Term: "interlock adapter... detachably associated with the rigid protective case" ('044 Patent, col. 13:22-24)

• Context and Importance: The two-piece nature of the lock assembly is fundamental. Practitioners may focus on this term because the specific manner in which the two main components interact defines the assembly process and security.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term "detachably associated" could be argued to cover any non-permanent connection between the adapter and the case.
  • Evidence for a Narrower Interpretation: The patent discloses a specific sliding mechanism where "lateral insertion slots 138 and 140" on the protective case are configured to "receive lateral engagement flanges 142 and 144 of interlock adapter 118." ('044 Patent, col. 5:41-44). An argument could be made that "detachably associated" is limited to this specific type of sliding, interlocking engagement.

VI. Other Allegations

• Indirect Infringement: The complaint broadly denies indirect infringement by either Plaintiff or its customers but provides no specific factual basis for the denial, as is typical for a declaratory judgment action. (Compl. ¶25, ¶28).
• Willful Infringement: Willfulness is not alleged against the Plaintiff. Rather, the Plaintiff alleges that the Defendant's infringement accusations are "baseless and exceptional," potentially laying the groundwork for a motion for attorneys' fees under 35 U.S.C. § 285 by characterizing Defendant's enforcement action as improper. (Compl. ¶29).

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

• A primary issue for the court will be one of evidence: As the complaint provides no technical description or visual representation of the Plaintiff's product, the initial phase of the case will revolve around discovering the actual design and operation of the "Non-Infringing Product" to enable a comparison against the patent's claims.
• The case will likely involve a key question of definitional scope: Can the term "compartment for securing a safety chain assembly," as claimed in the '044 Patent, be construed to read on any structure that simply holds the chains, or is it limited by the specification's embodiments to a structure with specific retaining features like tabs or barriers?
• A central validity question will be one of obviousness: Plaintiff alleges the patent is invalid in view of prior art. (Compl. ¶33). The court will likely need to determine whether a person of ordinary skill in the art would have been motivated to combine prior art trailer coupler locks with features for securing safety chains to arrive at the claimed invention.