Aiming Tang v. Chongqing Qinglu Network Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Aiming Tang (Jinhua, China)
  • Defendant: Chongqing Qinglu Network Technology Co., Ltd (China)
  • Plaintiff’s Counsel: Glacier Law LLP
• Case Identification: 1:25-cv-07190, N.D. Ill., 06/26/2025
• Venue Allegations: Venue is alleged to be proper in the Northern District of Illinois because the Defendant, a Chinese company, operates interactive e-commerce stores targeting U.S. consumers, including those in Illinois, offers shipping to Illinois, accepts payment in U.S. dollars, and has allegedly sold infringing products to residents of Illinois, causing substantial injury in the state.
• Core Dispute: Plaintiff alleges that Defendant’s towing device products, sold online, infringe a patent related to a towing hitch with an integrated damping function.
• Technical Context: The technology relates to the field of vehicle towing hitches, specifically mechanical designs intended to reduce swaying, noise, and instability by eliminating gaps in the connection between the hitch and the vehicle.
• 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	’973 Patent Priority Date
2022-09-20	’973 Patent Issue Date
2025-06-26	Complaint Filing Date

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, titled “TOWING DEVICE WITH DAMPING FUNCTION,” issued on September 20, 2022. (Compl. ¶11).

The Invention Explained

• Problem Addressed: The patent describes a problem in prior art towing devices where an unavoidable gap between a connecting pin and its corresponding hole causes the device to sway during use, resulting in continuous collisions, noise, and abrasion of the device and vehicle body. (’973 Patent, col. 1:22-29).
• The Patented Solution: The invention addresses this problem by introducing a "cushion" that is sleeved onto the main horizontal bar (the "towing cantilever") of the hitch. A separate "tightening bolt" is then used to push this cushion forward, causing it to press firmly against the vehicle's fixed mounting point ("fixed seat"). This action fills any gaps, restrains axial movement of the cantilever, and provides a damping effect to absorb shock. (’973 Patent, col. 1:47-54; col. 4:4-17).
• Technical Importance: This design provides a mechanical solution to improve towing safety and reduce noise by actively eliminating unwanted movement at the point of connection between the vehicle and the towing hitch. (’973 Patent, col. 1:32-36).

Key Claims at a Glance

• The complaint asserts independent Claim 1. (Compl. ¶¶13, 26).
• The essential elements of Claim 1 are:
  • A towing device comprising a towing main body and a towing assembly.
  • The main body includes a towing cantilever and a vertical adjustment arm.
  • The cantilever is fixed to a "fixed seat" on a towing vehicle using fixing pins through fixing holes.
  • A "cushion" is sleeved on the cantilever, located between the fixing holes and the vertical adjustment arm.
  • The cushion has a "tightening bolt" on the side near the vertical adjustment arm.
  • The tightening bolt can be rotated to "push the cushion" so that an end surface of the cushion is "abutted against the fixed seat."
• The complaint alleges infringement of at least one claim and reserves the right to modify its infringement theory as the case proceeds. (Compl. ¶¶26-27).

III. The Accused Instrumentality

Product Identification

• The accused instrumentalities are "Towing Device Products" ("Infringing Products") that Defendant sells through e-commerce stores, including an Amazon.com storefront operating under the name "maXpeedingrods-us." (Compl. ¶¶1, 7, 16).

Functionality and Market Context

• The complaint alleges these products are towing devices that incorporate the patented "integrated damping function designed to reduce axial movement and enhance towing stability." (Compl. ¶14). The complaint includes screenshot printouts as Exhibit 2, which allegedly show Defendant's active e-commerce store and listings for the accused products. (Compl. ¶16). These screenshots are alleged to depict towing hitch assemblies offered for sale to consumers in the United States. (Compl. ¶17, Ex. 2). The complaint alleges that Defendant targets U.S. consumers through its online presence. (Compl. ¶4).

IV. Analysis of Infringement Allegations

The complaint alleges that the Infringing Products sold by Defendant infringe at least Claim 1 of the ’973 Patent. (Compl. ¶26). The complaint states that a claim chart is attached as Exhibit 3 to illustrate this infringement; however, that exhibit was not included with the filed complaint. (Compl. ¶26).

The narrative infringement theory is that Defendant makes, uses, sells, and imports towing devices that possess all the elements of Claim 1. (Compl. ¶27). Specifically, the complaint alleges that Defendant’s products incorporate the key inventive features, including an "integrated damping function" that serves to "reduce axial movement and enhance towing stability." (Compl. ¶14). The complaint references visual evidence in the form of screenshot printouts of the accused product listings on Amazon.com, which are attached as Exhibit 2. (Compl. ¶16). One such screenshot in Exhibit 2, for example, allegedly shows a towing hitch assembly with components that correspond to the elements of the patented invention. (Compl. Ex. 2). The core of the infringement allegation is that these accused products operate in the manner described by Claim 1, using a cushion and tightening mechanism to stabilize the hitch connection.

Identified Points of Contention

• Scope Questions: Claim 1 recites that the towing device is fixed on a "fixed seat pre-arranged at the rear end of a towing vehicle" and that the cushion is pushed until it is "abutted against the fixed seat." This raises the question of whether the sale of the towing device alone, without the vehicle's "fixed seat," can constitute direct infringement, or if the "fixed seat" is merely part of the intended environment of use. The resolution may determine whether the plaintiff must prove direct or indirect infringement.
• Technical Questions: A central factual question will be whether the accused product’s components function as claimed. What evidence does the complaint provide that the accused product’s tightening mechanism is structured to "push the cushion" in a manner that causes an "end surface of the cushion" to be "abutted against the fixed seat"? The complaint relies on the un-filed Exhibit 3 for this detailed technical mapping.

V. Key Claim Terms for Construction

The Term: "cushion"

• Context and Importance: This term defines the central element of the claimed "damping function." The scope of this term will be critical to determining infringement, as it defines what structure satisfies this key limitation.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the function of the cushion broadly, stating it can "absorb and relieve most of the impact force," suggesting the term could cover any component that performs this function. (’973 Patent, col. 4:60-62). The patent also discloses that the cushion can comprise "several damping pieces," which may support an interpretation not limited to a single, monolithic structure. (’973 Patent, col. 5:30-31).
  • Evidence for a Narrower Interpretation: The figures, particularly the exploded view in Figure 5, depict the cushion (27) as a specific, rectangular, ribbed block. A party could argue the term should be limited to the structure shown in this preferred embodiment or a structural equivalent, rather than any generic piece of material.

The Term: "abutted against the fixed seat pre-arranged at the rear end of the towing vehicle"

• Context and Importance: This phrase appears at the end of Claim 1 and describes the functional result of the invention. Practitioners may focus on this term because its construction will likely determine whether selling the towing device alone constitutes direct infringement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim is for "A towing device... comprising..." various components. The "fixed seat" is not listed as part of the device itself but as an external object the device interacts with. This may support a construction where the claim covers a device that is merely capable of being abutted against a fixed seat when installed, thus making the sale of the device a direct infringement.
  • Evidence for a Narrower Interpretation: The language requires an "end surface of the cushion is abutted against the fixed seat" (emphasis added). This could be interpreted to mean that the "fixed seat" is a required element of the claimed invention in its final, infringing state. Under this view, selling the device alone would not be direct infringement, as the "fixed seat" is part of the customer's vehicle, potentially pushing the case toward a more difficult-to-prove theory of indirect infringement.

VI. Other Allegations

Indirect Infringement

• The complaint makes a conclusory allegation of indirect infringement, stating Defendant's product "infringes directly and/or indirectly the '973 Patent." (Compl. ¶25). The prayer for relief also seeks to enjoin Defendant from "aiding, abetting, contributing to, or otherwise assisting anyone in infringing." (Compl. Prayer for Relief ¶A.b). The complaint does not, however, plead specific facts to support the elements of knowledge and intent required for induced or contributory infringement, such as references to user manuals or advertising that instruct users to infringe.

Willful Infringement

• The complaint alleges that Defendant’s infringement "has been and continues to be willful." (Compl. ¶30). The allegations state that Defendant has "knowingly and willfully" infringed, but do not provide a factual basis for this knowledge, such as pre-suit notice via a cease-and-desist letter or prior litigation. (Compl. ¶22, 25).

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

• A core issue will be one of claim scope: can Claim 1, which recites a functional relationship where the device’s cushion "is abutted against the fixed seat" of a vehicle, be construed to cover the sale of the standalone towing device itself? The court's interpretation of this language will likely determine whether direct infringement is a viable theory or if Plaintiff must prove the elements of indirect infringement.
• A key evidentiary question will be one of technical proof: as the case proceeds, what evidence will be presented to demonstrate that the accused device’s mechanism operates in the specific manner required by the claim? Lacking a detailed claim chart, the case will hinge on future discovery and expert analysis to map the physical operation of the accused product to the claim's functional limitations.