DCT

3:25-cv-01596

A Stucki Co v. Transquip USA Inc

Log In
Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:25-cv-01596, M.D. Fla., 01/08/2026
  • Venue Allegations: Venue is alleged based on Defendant being a Florida corporation with its principal place of business in Jacksonville, within the Middle District of Florida, and having sold the accused products in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s manway nozzle gaskets for railroad cars infringe a patent related to gaskets featuring concentric sealing rings or "chevrons."
  • Technical Context: The technology concerns resilient gaskets used to create a fluid-tight seal for manway openings on railroad tank cars, a critical component for the safe transport of materials.
  • Key Procedural History: The complaint details pre-suit correspondence in late 2025, where Plaintiff notified Defendant of the patent. Defendant allegedly replied, denying infringement based on "Differentiating Dimensions," a response Plaintiff deemed "deficient and untethered to the law of patent infringement."

Case Timeline

Date Event
2009-11-11 ’840 Patent Priority Date
2014-02-25 ’840 Patent Issue Date
2025-10-02 Plaintiff sends initial notice letter to Defendant
2025-10-31 Plaintiff sends follow-up letter to Defendant
2025-11-10 Defendant replies, denying infringement
2025-11-17 Plaintiff sends further letter asserting infringement
2026-01-08 Complaint Filing Date

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

U.S. Patent No. 8,656,840 - *"Manway Gasket"*

The Invention Explained

  • Problem Addressed: The patent’s background section describes the difficulty in achieving an adequate seal for manway covers on railroad tank cars due to the rough treatment of sealing surfaces and the unequal distribution of clamping force from the securing bolts, which is maximized at the bolts and minimized between them (’840 Patent, col. 1:30-49).
  • The Patented Solution: The invention is a resilient gasket featuring concentric, upstanding annular ribs, referred to as "chevrons," on both its upper and lower sealing surfaces (’840 Patent, col. 2:60-66). These chevrons are designed to deform under pressure, creating multiple sealing points that can accommodate irregularities on the metal surfaces of the manway nozzle and cover, thereby ensuring a fluid-tight seal (’840 Patent, col. 6:10-13). Figure 4 illustrates the triangular cross-section of these chevrons.
  • Technical Importance: The design aims to improve the reliability and integrity of seals on containment vessels, which is critical for safety and preventing leaks during the transport of materials by rail.

Key Claims at a Glance

The complaint focuses on infringement of independent claim 1.

  • A gasket for sealing a manway nozzle, comprising:
    • An annular ring member with a generally planar body, defining upper and lower sealing surfaces.
    • The upper sealing surface includes at least one "annular upstanding chevron" to engage the manway cover.
    • The lower sealing surface includes at least one "annular lower chevron" extending in the opposite direction to engage the manway nozzle.

III. The Accused Instrumentality

Product Identification

  • Defendant’s "manway nozzle gasket product" (Compl. ¶13).

Functionality and Market Context

  • The accused products are gaskets designed for sealing manway openings on railroad cars (Compl. ¶17). The complaint alleges they are marketed and sold for this purpose through Defendant's website and advertising brochures (Compl. ¶¶16-17).
  • The complaint alleges that Defendant is a direct competitor to Plaintiff in the market for railroad car components, and that the accused gaskets are marketed in direct competition with Plaintiff's own patented gaskets (Compl. ¶¶12-13).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

  • Claim Chart Summary: The complaint’s infringement theory for Claim 1 is summarized below. The allegations rely on evidence purportedly contained in an appendix to pre-suit correspondence, which is attached as an exhibit to the complaint but not provided in the filed document.

’840 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A gasket for sealing between the manway nozzle of a containment vessel and an associated cover... The accused product is a gasket for sealing between a manway nozzle of a containment vessel and an associated cover. ¶25 col. 7:34-39
an annular ring member having a generally planar annular body portion defining an upper annular cover sealing surface and a lower annular nozzle body sealing surface, The accused gasket allegedly includes an annular ring member with a planar body that defines upper and lower sealing surfaces. ¶26 col. 7:40-43
said upper annular cover sealing surface including at least one annular upstanding chevron extending therefrom..., and said lower annular nozzle body sealing surface including at least one annular lower chevron extending therefrom... The accused gasket's upper surface allegedly includes at least one upstanding chevron to engage the cover, and its lower surface allegedly includes at least one lower chevron to engage the nozzle. ¶27 col. 7:43-50
  • Identified Points of Contention:
    • Scope Questions: A central question will be the proper construction of "chevron." Defendant’s pre-suit denial of infringement based on "Differentiating Dimensions" (Compl. ¶21) suggests a dispute over whether the physical structures on the accused gasket fall within the scope of this term as used in the patent.
    • Technical Questions: What evidence does the complaint provide that the sealing structures on the accused gasket are, in fact, "chevrons" that function as claimed? The analysis will depend on the actual geometry, material properties, and performance of the accused gaskets compared to the patent's teachings.

V. Key Claim Terms for Construction

  • The Term: "chevron"
  • Context and Importance: This term defines the core structural innovation of the patent—the resilient, annular sealing ribs. The definition of "chevron" will be dispositive, as Defendant's "Differentiating Dimensions" defense (Compl. ¶21) appears calculated to argue that its product's sealing rings do not meet the definition of this term. Practitioners may focus on this term because its construction will likely determine the outcome of the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification suggests the term is not limited to a single shape, stating that the cross-sectional shape "may be other than triangular. For example, the cross-sectional shape could be semi-circular, or other suitable shape" (’840 Patent, col. 5:1-3). This language could support a construction that covers any raised, annular sealing rib.
    • Evidence for a Narrower Interpretation: The primary embodiment illustrated and described features chevrons with a "generally triangular cross section" formed by walls at an "included angle α of eighty degrees (80°)" (’840 Patent, Fig. 4; col. 4:51-58). A defendant may argue that the term should be limited to structures with a distinct, pointed peak, consistent with these specific disclosures.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement based on Defendant’s marketing of the accused gaskets and instructions provided to users that allegedly direct them to use the products in an infringing manner (Compl. ¶¶45-46). It also alleges contributory infringement, asserting the gaskets are especially made for an infringing use and are not a staple article of commerce suitable for substantial noninfringing use (Compl. ¶47).
  • Willful Infringement: Willfulness is alleged based on Defendant’s purported knowledge of the ’840 Patent since at least its receipt of Plaintiff's October 2, 2025 notice letter (Compl. ¶36). The complaint alleges that Defendant continued to infringe despite an objectively high likelihood that its actions constituted infringement of a valid patent (Compl. ¶39).

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

  • A core issue will be one of definitional scope: can the term "chevron," which is described in embodiments as a triangular structure, be construed broadly enough to read on the specific "Differentiating Dimensions" of the accused gaskets? The case may turn on whether the term implies a specific geometry or encompasses a wider range of functional sealing ribs.
  • A key evidentiary question will be one of factual comparison: assuming a claim construction is adopted, what will discovery reveal about the actual physical structure of the accused gaskets? The dispute will center on a direct comparison of the accused product's dimensions and design features against the limitations of the patent's claims.