DCT

1:25-cv-00114

Apexturbo LLC v. Apex Diesel

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00114, W.D. Pa., 05/05/2025
  • Venue Allegations: Venue is alleged to be proper because Defendants maintain a regular and established place of business in the district and have allegedly committed acts of patent infringement within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s aftermarket turbochargers and compressor wheels infringe three patents related to "hub-less and nut-less" wheel designs for turbochargers.
  • Technical Context: The technology relates to high-performance turbochargers for internal combustion engines, where design modifications that improve airflow can significantly increase horsepower output.
  • Key Procedural History: The complaint alleges that Plaintiff sent a notice letter with exemplary claim charts to Defendants on June 2, 2023. Following the notice, Defendants' counsel allegedly represented that a redesign would occur to avoid infringement, but Plaintiff alleges that infringement continued and that Defendants altered product photographs on their website to obfuscate the infringing features.

Case Timeline

Date Event
2018-08-21 Earliest Priority Date for ’231, ’677, and ’294 Patents
2021-02-09 ’231 Patent Issued
2021-04-20 ’677 Patent Issued
2023-03-07 ’294 Patent Issued
2023-06-02 Plaintiff sent pre-suit notice letter to Defendants
2023-06-14 Defendants' counsel allegedly agreed to redesign products
2024-08-06 Alleged sale of an infringing product by Defendants
2025-05-05 Complaint Filed

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

U.S. Patent No. 10,914,231 - "Hub-Less and Nut-Less Turbine Wheel and Compressor Wheel Design for Turbochargers," issued February 9, 2021

The Invention Explained

  • Problem Addressed: The patent's background describes that traditional turbocharger compressor and turbine wheels feature a large central hex nut or hub, which is used during manufacturing and assembly (’231 Patent, col. 1:43-54). This central feature creates a disturbance in the airflow passing through the turbocharger, which limits its horsepower potential (’231 Patent, col. 2:36-41).
  • The Patented Solution: The invention eliminates the central nut and hub. Instead, the leading edges of the wheel's blades are extended toward the center to meet and form an "apex" that is aligned with the shaft's centerline (’231 Patent, Abstract). This "nut-less" design is intended to remove the flow obstruction, maximize fluid flow and blade length, and thereby significantly increase horsepower without enlarging the overall turbocharger frame size (’231 Patent, col. 2:50-59).
  • Technical Importance: This design allows for increased power output from a turbocharger of a given size, a significant advantage in high-performance motorsports where regulations often limit turbocharger dimensions (’231 Patent, col. 1:38-43).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 13 (Compl. ¶33).
  • Claim 1 (a turbocharger) requires:
    • A housing, a rotatable shaft, a turbine wheel, and a compressor wheel.
    • At least one of the wheels has a plurality of blades with leading edges that "converge at an apex" aligned with the centerline.
    • The leading edges extend helically from an inboard point to an outboard point.
    • The inboard points are positioned "closer to the centerline than the radius of the shaft."
  • Claim 13 (a compressor wheel) requires:
    • A body with a bore having a threaded portion to receive a shaft.
    • A plurality of compressor blades with leading edges that "converge at a compressor apex" aligned with the centerline.
    • The leading edges extend helically from an inboard point at the apex.
    • The inboard points are positioned "closer to the centerline than the radius of the threaded portion of the bore."

U.S. Patent No. 10,982,677 - "Hub-Less and Nut-Less Turbine Wheel and Compressor Wheel Design for Turbochargers," issued April 20, 2021

The Invention Explained

  • Problem Addressed: While removing the central hub improves airflow, it also eliminates the primary interface used by technicians to grip the wheel for installation or removal from the shaft (’677 Patent, col. 1:45-55). A method is needed to service the nut-less design.
  • The Patented Solution: This patent discloses a compressor wheel that also has blade edges converging at a central apex, but adds a mechanism for installation and removal. The solution is a "temporary fixation mechanism" comprising at least one "through bore" extending through the wheel at a location offset from the centerline. This bore is configured to receive a "fixation member" (such as a pin or tool), which can lock the wheel against a backing plate, allowing a technician to apply torque to the shaft for tightening or loosening the wheel without damaging the blades (’677 Patent, Abstract; col. 2:27-42).
  • Technical Importance: The invention provides a practical and non-destructive method for assembling and servicing the aerodynamically superior nut-less compressor wheels, enhancing their commercial viability.

Key Claims at a Glance

  • The complaint asserts independent claim 11 (Compl. ¶43).
  • Claim 11 (a compressor wheel) requires:
    • A body with an exducer plate and a plurality of compressor blades having leading edges that converge at an apex.
    • "at least one through bore, extending through the compressor wheel at a location that is offset from the centerline of the shaft."
    • The bore is configured to receive a "fixation member" such as a dowel pin, set screw, fastener, or tool.

U.S. Patent No. 11,598,294 - "Hub-Less and Nut-Less Turbine Wheel and Compressor Wheel Designs and Installation/Removal Tool," issued March 7, 2023 (Multi-Patent Capsule)

The Invention Explained

  • Technology Synopsis: This patent claims a forced induction device that combines the nut-less compressor wheel design with a specific tool for its installation and removal (’294 Patent, Abstract). The compressor wheel has one or more through bores offset from the centerline, and the claimed tool includes corresponding posts that engage these bores to allow a technician to rotate the compressor wheel relative to the shaft (’294 Patent, col. 2:18-29). This provides a complete system for utilizing and servicing the hub-less wheel design.

Key Claims at a Glance

  • Asserted Claims: Independent claims 1 and 10 (Compl. ¶51).
  • Accused Features: The complaint alleges that Defendants' forced induction devices infringe by including a compressor wheel with an internally threaded bore and at least one offset through bore configured to receive a tool for installation and removal, thereby embodying the claimed invention (Compl. ¶¶52-55).

III. The Accused Instrumentality

Product Identification

  • The accused products include the "Apex Diesel 3x3.5” Ball Bearing 1.25 T4 Turbo," "Apex Diesel 2.6 Smooth Bore Boreless S400 Turbo," "Apex Diesel 3.0 Smooth Bore Boreless S400 Turbo," and similar turbochargers and compressor wheels sold by Defendants (Compl. ¶21).

Functionality and Market Context

  • The complaint alleges that the Accused Products are aftermarket turbochargers and components for internal combustion engines (Compl. ¶21). The central accused feature is that they "lack a nut at the leading end of the compressor wheel," which directly corresponds to the "nut-less" technology of the patents-in-suit (Compl. ¶21). Exhibit 9 of the complaint provides photographs of an accused compressor wheel, which show the leading edges of the blades converging toward the center of the wheel (Compl. ¶30, Ex. 9).

IV. Analysis of Infringement Allegations

The complaint references exemplary claim charts in an "Exhibit 10," which was not filed with the public complaint (Compl. ¶35, ¶45, ¶53). The narrative infringement theory is summarized below.

The complaint alleges that the Accused Products directly infringe the '231 Patent because they are turbochargers and compressor wheels that embody the claimed "nut-less" design (Compl. ¶33). Specifically, it alleges the products have blades with leading edges that converge at a central apex, eliminating the central hub found in conventional designs (Compl. ¶21, ¶34, ¶36).

For the ’677 Patent and ’294 Patent, the infringement allegation centers on the inclusion of features for installing and removing the nut-less wheel. The complaint alleges the Accused Products possess the elements of the asserted claims, which suggests they are alleged to contain at least one "through bore" offset from the centerline that is configured to receive a tool or fixation member for installation and removal (Compl. ¶44, ¶52, ¶54).

Identified Points of Contention

  • Scope Questions: An issue for the court may be whether the precise geometry of the Accused Products' wheels meets all claim limitations. For example, in claim 1 of the ’231 Patent, a dispute may arise over whether the "inboard points of the leading edges are positioned closer to the centerline than the radius of the shaft."
  • Technical Questions: A primary evidentiary question for the ’677 and ’294 Patents will be whether the Accused Products in fact contain the claimed "at least one through bore" offset from the centerline for receiving an installation tool. The complaint alleges this feature is present, but the provided photographs do not definitively confirm its existence, making this a likely focus of discovery (Compl. ¶30, Ex. 9).

V. Key Claim Terms for Construction

  • The Term: "converge at an apex" (’231 Patent, Claim 1)

    • Context and Importance: This term defines the core structural innovation of the patents—the replacement of a central nut with blade edges that meet at the wheel's center. The case may turn on whether the accused design, which lacks a nut, constitutes a convergence "at an apex" as construed by the court.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification's stated goal is to eliminate the "flow obstruction created by the hex nut" to "maximize fluid flow" (’231 Patent, col. 2:53-58). This functional language may support a construction covering any design where blade edges meet centrally to eliminate the hub, even if not forming a perfect geometric point.
      • Evidence for a Narrower Interpretation: The patent figures show the blade edges meeting at a sharp, distinct point (’231 Patent, Figs. 5, 11). The specification also describes the blades forming a "pointed shape at the compressor apex" (’231 Patent, col. 6:35-36), which could support a narrower construction requiring a geometrically sharp point.

  • The Term: "at least one through bore... configured to receive a fixation member" (’677 Patent, Claim 11)

    • Context and Importance: Infringement of the ’677 Patent hinges on the presence of this structure. The dispute will likely focus on whether any holes or features on the accused wheel meet this functional and structural definition.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The claim language is broad, covering "one of a dowel pin, set screw, fastener, or tool" as the fixation member (’677 Patent, col. 9:14-16). This suggests that any bore offset from the center that can be used with a tool to lock the wheel for installation could satisfy the limitation.
      • Evidence for a Narrower Interpretation: The specification's primary embodiment shows the through bores located in the "exducer plate" at the rear of the compressor wheel (’677 Patent, Fig. 13; col. 9:25-34). A defendant might argue that the term should be limited to bores in this specific location, intended to align with a corresponding "backing plate."

VI. Other Allegations

  • Indirect Infringement: The complaint includes general allegations of indirect infringement (Compl. ¶33, ¶43, ¶51). However, it does not plead specific facts detailing how Defendants would have induced or contributed to infringement by third parties.
  • Willful Infringement: The complaint alleges willful infringement based on Defendants' alleged knowledge of the patents-in-suit since at least June 2, 2023, the date of Plaintiff's notice letter (Compl. ¶40, ¶48, ¶58). The allegations are strengthened by claims that after receiving notice, Defendants' counsel represented a redesign would occur, but that Defendants continued to sell infringing products and allegedly altered website photos to conceal the infringing features (Compl. ¶¶25-28, ¶41, ¶49, ¶59).

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

  • A central issue will be one of geometric scope: do the accused "nut-less" compressor wheels meet the specific claimed geometry of an "apex" where blade edges converge, and are the "inboard points" of those edges located "closer to the centerline than the radius of the shaft" as required by the ’231 Patent?
  • A key evidentiary question will be one of feature presence: does discovery show that the accused products contain the "at least one through bore... offset from the centerline" required by the ’677 and ’294 patents, a feature that enables installation and removal without a central nut?
  • Finally, the litigation will likely examine culpability: given the allegations of pre-suit notice, a subsequent promise of a redesign, and alleged continued sales, did Defendants' alleged conduct constitute willful disregard of Plaintiff's patent rights sufficient to warrant enhanced damages?