Aiming Tang v. Yiwushi Yanzhou Riyongbaihuo Shanghang

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Aiming Tang (China)
  • Defendant: Yiwushi Yanzhou Riyongbaihuo Shanghang, d/b/a TYT-4WD (China)
  • Plaintiff’s Counsel: Glacier Law LLP
• Case Identification: 1:25-cv-07165, N.D. Ill., 06/26/2025
• Venue Allegations: Venue is based on Defendant's alleged business activities targeting consumers in the United States, including Illinois, through interactive e-commerce stores on platforms like Amazon.com, which offer shipping to Illinois and accept payment in U.S. dollars.
• Core Dispute: Plaintiff alleges that Defendant’s "Towing Device Products" sold online infringe a patent related to a towing device with a damping function.
• Technical Context: The technology concerns vehicle towing hitches, specifically a mechanism designed to reduce noise, swaying, and shock by eliminating gaps in the mechanical assembly.
• Key Procedural History: The complaint does not mention any prior litigation, inter partes review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

Date	Event
2022-03-08	U.S. Patent No. 11,446,973 Priority Date
2022-09-20	U.S. Patent No. 11,446,973 Issued
2025-06-26	Complaint Filed

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

U.S. Patent No. 11,446,973 - "TOWING DEVICE WITH DAMPING FUNCTION"

• Patent Identification: U.S. Patent No. 11,446,973, "TOWING DEVICE WITH DAMPING FUNCTION", issued September 20, 2022. (Compl. ¶11).

The Invention Explained

• Problem Addressed: The patent describes a problem in prior art towing devices where the gap between a connecting pin and its corresponding hole allows for swaying during use, leading to continuous collisions, loud noise, and abrasion of the device and vehicle body. (’973 Patent, col. 1:24-30).
• The Patented Solution: The invention introduces a "cushion" that is sleeved onto the towing cantilever, positioned between the vehicle's fixed mounting seat and the hitch's fixing holes. A "tightening bolt" is used to push this cushion against the fixed seat, thereby filling the operational gaps. (’973 Patent, col. 4:5-17). This action is intended to restrain axial movement of the cantilever, making the connection "steadier and more shock-absorbent" and reducing noise. (’973 Patent, col. 3:12-15).
• Technical Importance: This mechanical solution aims to provide a safer and smoother towing experience by actively damping the connection point between the towing vehicle and the towed trailer or equipment. (’973 Patent, col. 3:18-24).

Key Claims at a Glance

• The complaint asserts independent Claim 1. (Compl. ¶26).
• Independent Claim 1: A towing device with a damping function comprising:
  • a towing main body and a towing assembly mounted on the towing main body;
  • the towing main body comprises a towing cantilever and a vertical adjustment arm;
  • one end of the towing cantilever is connected to the vertical adjustment arm, and the other end has several fixing holes;
  • the towing cantilever is fixed, via fixing pins, on a fixed seat at a rear end of a towing vehicle;
  • a cushion is sleeved on the towing cantilever;
  • the cushion is located between the fixing holes and the vertical adjustment arm;
  • one side of the cushion close to the vertical adjustment arm has a tightening bolt; and
  • the tightening bolt can be rotated to push the cushion towards the fixing holes, so an end surface of the cushion is abutted against the fixed seat.
• The complaint reserves the right to modify its infringement theory as the case proceeds, which may include the assertion of dependent claims. (Compl. ¶26).

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are "Towing Device Products" ("Infringing Products") sold by Defendant under the name TYT-4WD through online marketplaces, specifically Amazon.com. (Compl. ¶¶1, 7, 16).

Functionality and Market Context

• The complaint alleges that the accused products incorporate the patented invention, featuring an "integrated damping function designed to reduce axial movement and enhance towing stability." (Compl. ¶14). The complaint references "screenshot printouts showing Defendant's active e-commerce store and listings of Infringing Products" as evidence of the infringing sales and product features. (Compl. ¶16, Ex. 2). These products are allegedly targeted to U.S. consumers, including those in Illinois. (Compl. ¶17).

IV. Analysis of Infringement Allegations

The complaint alleges that the Infringing Products infringe at least Claim 1 of the ’973 Patent and references an illustrative claim chart attached as Exhibit 3, which was not provided with the filed complaint. (Compl. ¶26). The narrative infringement theory is that the Defendant's "Towing Device Products" contain all the elements recited in Claim 1. (Compl. ¶¶25-26). A central piece of visual evidence referenced in the complaint is a set of "screenshot printouts showing Defendant's active e-commerce store and listings of Infringing Products," which purportedly depict the products being offered for sale. (Compl. ¶16). Without the claim chart exhibit, a detailed element-by-element analysis based on the complaint's direct allegations is not possible. The core of the infringement allegation rests on the assertion that the accused towing devices possess a damping function achieved through a mechanism that meets the limitations of Claim 1. (Compl. ¶¶14, 26).

V. Key Claim Terms for Construction

The Term: "cushion"

• Context and Importance: This term is the central element of the claimed invention's damping mechanism. The definition of "cushion"—including its material properties, structure, and interaction with the tightening bolt—will be critical for determining the scope of the claim and whether the accused products infringe.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification suggests the "cushion" can be composed of "several damping pieces" that can be "randomly added and subtracted or replaced," which may support an interpretation not limited to a single, monolithic structure. (’973 Patent, col. 5:30-36).
  • Evidence for a Narrower Interpretation: The claims require the "cushion" to be "sleeved on the towing cantilever" and positioned so it can be pushed by a "tightening bolt" until it is "abutted against the fixed seat." (’973 Patent, col. 8:1-9). This functional language may limit the term to structures capable of performing this specific mechanical action, as opposed to any generic vibration-damping material.

The Term: "abutted against"

• Context and Importance: This term defines the required state of contact between the "cushion" and the "fixed seat" to achieve the claimed damping function. The degree of force and surface contact required to satisfy this limitation will likely be a point of dispute.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The plain meaning of "abut" suggests simple contact or adjacency, which might not require a specific level of compressive force.
  • Evidence for a Narrower Interpretation: The patent’s objective is to restrain "axial movement" and create a "steadier" connection by filling a gap. (’973 Patent, col. 3:12-15). This purpose could support a construction requiring firm, force-bearing contact sufficient to eliminate movement, rather than mere touching.

VI. Other Allegations

Indirect Infringement

• The complaint alleges that Defendant infringes "directly and/or indirectly." (Compl. ¶25). The prayer for relief also seeks to enjoin Defendant from "aiding, abetting, contributing to, or otherwise assisting anyone in infringing." (Compl. Prayer ¶A.b). However, the complaint does not plead specific facts to support the knowledge and intent elements required for induced infringement or the specific requirements for contributory infringement.

Willful Infringement

• Plaintiff alleges that Defendant’s infringement has been and continues to be "knowing[] and willful[]," based on the allegation that Defendant manufactures and sells the accused products without authorization. (Compl. ¶¶22, 25, 30). The complaint does not specify whether this allegation is based on pre-suit or post-suit knowledge of the ’973 Patent.

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

1. A Core Evidentiary Question: Given the absence of a detailed claim chart in the public filing, a primary issue will be one of factual proof: what is the precise mechanical structure of the accused "Towing Device Products"? Discovery will be needed to determine if they actually contain a "cushion" and "tightening bolt" that function together to press against a fixed seat, as required by Claim 1.

2. A Key Claim Construction Question: The case may turn on a question of functional scope: how should the term "cushion" be construed? The dispute will likely focus on whether the term covers any component that reduces vibration, or if it is limited to a distinct element that is mechanically pushed by a bolt to fill a gap and actively restrain axial movement, as detailed in the patent's specification.

3. A Question of Enforceability: The complaint alleges that the Defendant is a foreign entity that operates through online marketplaces and may be difficult to locate or enforce a judgment against. (Compl. ¶¶6, 39-40). This raises a practical question of remedy: assuming Plaintiff prevails on the merits, what mechanisms, such as injunctions against marketplace platforms, will be available and effective to halt the alleged infringement and recover damages?