DCT
2:24-cv-00916
Traxxas LP v. Foshan Zhengze Model Technology Co Ltd
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Traxxas, L.P. (Texas)
- Defendant: Foshan Zhengze Model Technology Co., Ltd. (China)
- Plaintiff’s Counsel: The Davis Firm PC
- Case Identification: 2:24-cv-00916, E.D. Tex., 11/12/2025
- Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendant, directly or through intermediaries, sells or offers to sell the accused products to consumers in the district.
- Core Dispute: Plaintiff alleges that Defendant’s radio-controlled model vehicle infringes a patent related to a simplified portal gear assembly.
- Technical Context: Portal gears are mechanical systems used in vehicles, including high-performance model vehicles, to increase ground clearance and provide torque-multiplying gear reduction at the wheel hub.
- Key Procedural History: The complaint is a First Amended Complaint, and alleges that Defendant’s knowledge for the purposes of indirect and willful infringement dates from the service of the original complaint in this litigation. Prior to the filing of the lawsuit, the patent-in-suit was the subject of a supplemental examination, which concluded with a certificate issued on June 26, 2024, finding no substantial new question of patentability.
Case Timeline
| Date | Event |
|---|---|
| 2017-01-27 | '975 Patent Priority Date |
| 2021-12-28 | '975 Patent Issue Date |
| 2024-06-26 | '975 Patent Supplemental Examination Certificate Issued |
| 2025-11-12 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,207,975 - "Portal Gear for Model Vehicles"
The Invention Explained
- Problem Addressed: The patent's background section describes conventional portal gears as being associated with "concerns for additional costs" and complexity, typically requiring a four-gear design (input, output, and two idlers) ('975 Patent, col. 1:29-32). This complexity can also increase the size of the assembly ('975 Patent, col. 2:47-49).
- The Patented Solution: The invention is a simplified portal gear for model vehicles that uses a two-gear design, eliminating the idler gears to reduce cost and size ('975 Patent, col. 2:41-47). The design transfers rotational torque from a drive shaft in an "upper location" to an axle in a "lower location" ('975 Patent, col. 1:49-54). To further save space, the design consolidates the drive shaft and the input gear into a single assembly via a universal joint ('975 Patent, col. 2:55-60).
- Technical Importance: This simplified approach aims to provide the performance benefits of a portal gear—increased ground clearance and gear reduction—while lowering manufacturing cost and creating a more compact assembly suitable for a model vehicle wheel ('975 Patent, col. 1:31-34, col. 2:47-49).
Key Claims at a Glance
- The complaint asserts independent claim 1 ('975 Patent, col. 6:3-19).
- The essential elements of claim 1 include:
- a drive shaft rotatively coupled to an input gear via a universal joint;
- a first and second input bearing rotatively supporting the input gear;
- an axle coupled to an output gear;
- a housing configured to vertically contain the input gear and the output gear;
- wherein the drive shaft transfers a rotational torque from an upper location to a lower location via the input gear rotating the output gear; and
- wherein the universal joint is within one of the first or the second input bearings.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
The accused product is the "1:24 FCX24 Smasher V2” model vehicle (Compl. ¶12). The infringement allegations are directed at the vehicle's portal gear assemblies, which the complaint calls the "Accused Components" (Compl. ¶12).
Functionality and Market Context
The complaint alleges that the accused vehicle contains portal gears that are "substantially similar" to an illustration it provides (Compl. ¶12). This exploded-view diagram shows a mechanical assembly comprising a drive shaft, a U-joint, multiple gears, bearings, an axle, and a multi-part housing (Compl. p. 3). The complaint alleges the Accused Products are sold in direct competition with Plaintiff's products (Compl. ¶14).
IV. Analysis of Infringement Allegations
The complaint alleges that the Accused Products are covered by at least claim 1 of the ’975 Patent but does not provide a detailed mapping of claim elements to specific features of the accused device (Compl. ¶18). The infringement theory appears to be based on the overall structure and function of the "Accused Components" as depicted in the complaint (Compl. ¶12).
’975 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a drive shaft rotatively coupled to an input gear via a universal joint; | The complaint alleges the Accused Components include these parts, which function together as claimed. | ¶12, ¶18 | col. 2:55-63 |
| a first and second input bearing rotatively supporting the input gear; | The complaint alleges the Accused Components include these parts, which function together as claimed. | ¶12, ¶18 | col. 5:12-15 |
| an axle coupled to an output gear; | The complaint alleges the Accused Components include these parts, which function together as claimed. | ¶12, ¶18 | col. 3:21-23 |
| a housing configured to vertically contain the input gear and the output gear; | The complaint alleges the Accused Components include these parts, which function together as claimed. | ¶12, ¶18 | col. 2:32-34 |
| wherein the drive shaft transfers a rotational torque from an upper location to a lower location via the input gear rotating the output gear; and | The complaint alleges the Accused Components perform this function. | ¶12, ¶18 | col. 1:49-54 |
| wherein the universal joint is within one of the first or the second input bearings. | The complaint alleges the Accused Components are configured with this specific spatial relationship. | ¶12, ¶18 | col. 6:17-19 |
Identified Points of Contention
- Scope Questions: The complaint's use of the phrase "substantially similar" to describe the accused components raises the question of whether the infringement theory will rely on the doctrine of equivalents rather than literal infringement (Compl. ¶12).
- Technical Questions: A key technical question will concern the final limitation of claim 1: "wherein the universal joint is within one of the first or the second input bearings." The complaint's exploded-view diagram does not provide sufficient detail to confirm this specific spatial relationship in the accused product. The factual determination of whether the accused device's U-joint is positioned "within" a bearing as claimed may be a central point of dispute.
V. Key Claim Terms for Construction
- The Term: "within one of the first or the second input bearings"
- Context and Importance: This term defines a precise geometric relationship between the universal joint and an input bearing, which appears central to the patent's claimed compact design. The outcome of the infringement analysis may depend heavily on the construction of this spatial limitation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue that "within" should be interpreted functionally to mean that the universal joint is located in the same general axial position as the bearing, or that its operational area is contained within the radial envelope projected by the bearing. The claim language does not specify that the joint must be physically inside the bearing's races.
- Evidence for a Narrower Interpretation: A party could argue that "within" requires the universal joint to be physically located, at least in part, inside the inner or outer diameter of the bearing itself. Figure 5 of the patent, which shows a cross-section of the assembly, depicts the pivot point of the universal joint (part of drive shaft 102) to be axially aligned with bearing 175, and could be used to support either interpretation depending on how the spatial boundaries are defined ('975 Patent, Fig. 5).
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement, stating Defendant provides user manuals and customer support that instruct consumers on how to use the accused products in an infringing manner (Compl. ¶20). It also alleges contributory infringement on the basis that the "Accused Components" are especially made for this infringing use and are not staple articles of commerce (Compl. ¶21).
- Willful Infringement: The complaint alleges willful infringement based on Defendant's continued infringement after having notice of the ’975 Patent "at least since the filing and service of Traxxas’ Original Complaint in this litigation" (Compl. ¶23).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of structural correspondence: does the accused portal gear assembly contain a universal joint that is physically located "within one of the first or the second input bearings," as required by the final limitation of Claim 1? The resolution of this question will likely require detailed technical evidence beyond what is provided in the complaint.
- The case may also turn on a question of claim construction: how will the court define the scope of the spatial term "within"? The construction of this single term could be dispositive of infringement, potentially determining whether Plaintiff must prove its case under the more stringent requirements of the doctrine of equivalents.