DCT

1:24-cv-04284

Milwaukee Electric Tool Corp v. Klein Tools Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-04284, N.D. Ill., 05/23/2024
  • Venue Allegations: Venue is alleged to be proper in the Northern District of Illinois because Defendant Klein Tools maintains its corporate headquarters and a regular and established place of business in the district, where the alleged acts of infringement are also occurring.
  • Core Dispute: Plaintiffs allege that Defendant’s MODbox™ line of modular tool storage products infringes three patents related to coupling mechanisms for detachably connecting containers.
  • Technical Context: The technology relates to interlocking modular storage systems, a market segment where customizable and transportable tool and equipment organization is critical for professional tradespeople.
  • Key Procedural History: The complaint notes that the asserted patents are part of a large family of applications stemming from priority applications filed in 2016 and 2017, suggesting a long-term and focused development effort in this technology area.

Case Timeline

Date Event
2016-05-02 Earliest Priority Date ('026, '952, '167 Patents)
2022-06-21 '026 Patent Issued
2023-10-24 '952 Patent Issued
2024-04-09 '167 Patent Issued
2024-05-23 Complaint Filed

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

U.S. Patent No. 11,365,026 - "Utility Assembly and Coupling Mechanism"

  • Patent Identification: U.S. Patent No. 11,365,026, "Utility Assembly and Coupling Mechanism", issued June 21, 2022 (’026 Patent).

The Invention Explained

  • Problem Addressed: The patent addresses the need for a "coupling mechanism facilitating detachably attaching" two or more "utility modules" (e.g., tool boxes, organizers) to one another to form a customized assembly (’026 Patent, col. 1:29-31).
  • The Patented Solution: The invention provides a coupling system where one container has a female coupler (a "depressed locking location" with a projecting "rib") and another container has a corresponding male coupler (a "projecting locking location" with a "tongue") (’026 Patent, col. 1:50-65). The containers are slid together, causing the tongue and rib to engage, and are secured by a separate locking latch that prevents sliding displacement, thereby creating a stable, interconnected assembly (’026 Patent, col. 16:29-42; Fig. 3A-3D).
  • Technical Importance: This approach provides a standardized mechanism for creating versatile and durable modular storage systems that users can reconfigure to suit specific needs (Compl. ¶8).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2-5 and 7-11 (Compl. ¶27).
  • Independent Claim 1 requires:
    • A first container with a first coupler (comprising sidewalls, a back wall, and a rib projecting from a depressed surface), a lid, and a toggle locking latch.
    • A second container with a second coupler (comprising a tongue offset from its face and engageable with the rib), a lid, and a toggle locking latch.
    • An engagement mechanism where the containers connect by sliding along a path defined by the rib and tongue.
    • A locking latch arresting location on one container.
    • A locking latch on the other container that engages the arresting location to limit sliding displacement.

U.S. Patent No. 11,794,952 - "Utility Assembly and Coupling Mechanism"

  • Patent Identification: U.S. Patent No. 11,794,952, "Utility Assembly and Coupling Mechanism", issued October 24, 2023 (’952 Patent).

The Invention Explained

  • Problem Addressed: Similar to the ’026 Patent, this patent is directed to a mechanism for detachably connecting utility modules (’952 Patent, col. 1:26-31).
  • The Patented Solution: The solution is also a slide-to-lock coupling mechanism based on a rib-and-tongue engagement with a separate locking latch (’952 Patent, Abstract). This patent's claims add specific requirements for the container's external geometry, including distinct front and side faces and protective "corner bumpers" coupled to the container at the intersection of those faces (’952 Patent, col. 1:32-41).
  • Technical Importance: The addition of claimed features like corner bumpers suggests a focus on enhancing the durability and robustness of the modular containers in demanding work environments.

Key Claims at a Glance

  • The complaint asserts claims 1-23 (Compl. ¶44).
  • Independent Claim 1 requires a container assembly with a first and second container, each with couplers, lids, and latches, similar to the ’026 Patent. It adds the requirements for the second container to comprise:
    • A front face, a first side face, and an opposing second side face.
    • A first corner bumper coupled between the front and first side faces.
    • A second corner bumper coupled between the front and second side faces.
    • Each bumper defines an outer surface that "faces away from each of the front face and the side face."

U.S. Patent No. 11,952,167 - "Utility Assembly and Coupling Mechanism" (Multi-Patent Capsule)

  • Patent Identification: U.S. Patent No. 11,952,167, "Utility Assembly and Coupling Mechanism", issued April 9, 2024 (’167 Patent).

Technology Synopsis

This patent also discloses a modular container system with a slide-to-lock coupling mechanism. The asserted claims are distinguished by limitations relating to the relative dimensions of the interlocked containers, specifically requiring an assembly where one container is approximately half the width of another, enabling side-by-side stacking of smaller units on top of a larger base unit (’167 Patent, col. 19:19-20:5).

Asserted Claims

Independent claim 1 and dependent claims 2-9, 11, and 13-16 are asserted (Compl. ¶61).

Accused Features

The complaint accuses assemblies of MODbox™ products, such as combining a half-width component box with a full-width box, of infringing this patent (Compl. ¶63).

III. The Accused Instrumentality

Product Identification

The accused products are Klein Tools’ MODbox™ modular storage system, including the Rolling Toolbox (54802MB), Medium Toolbox (54803MB), Small Toolbox (54804MB), and various full- and half-width component boxes, a tool bag, and a cooler (collectively, the "Accused Products") (Compl. ¶24).

Functionality and Market Context

The complaint alleges the MODbox™ system is advertised as a "modular System with locking components" that allows users to "easily interchange products to customize and mobilize with vertical and side locking components" (Compl. ¶22). Plaintiffs present evidence from Defendant’s website and videos allegedly showing the Accused Products being interconnected to form a "customized modular tool storage system" that can be easily reconfigured (Compl. ¶31, ¶48). An image from Klein Tools' website shows a user transporting a stack of interconnected orange and black MODbox™ units (Compl. ¶29, Ex. 7). This positions the MODbox™ system as a direct competitor to Plaintiffs' own PACKOUT™ system in the professional tool storage market.

IV. Analysis of Infringement Allegations

The complaint references, but does not attach, claim charts detailing the infringement theories (Compl. ¶32, ¶49). The narrative infringement theory is summarized below.

The complaint alleges that using the Accused Products together to form a "container assembly" infringes the asserted patents (Compl. ¶29, ¶46). The core of the infringement allegation is that the connection mechanism on the MODbox™ products meets the structural and functional limitations of the claimed couplers. Plaintiffs allege that Defendant's marketing, including a "MODbox™ Buildverse" online tool, demonstrates and encourages this infringing use (Compl. ¶34). A screenshot from this tool depicts a virtual assembly of multiple MODbox™ units with an option to "BUY NOW" (Compl. ¶34, Ex. 19). For the ’952 Patent, this infringement theory implicitly relies on the visible external structures of the Accused Products meeting the "corner bumper" limitations. For the ’167 Patent, the theory focuses on combinations of full- and half-width MODbox™ units (Compl. ¶63).

Identified Points of Contention

  • Scope Questions: A central dispute may be whether the specific structures of the MODbox™ connection mechanism fall within the scope of the patent claims. For example, does the MODbox™ system's locking feature meet the definition of a "toggle locking latch configured to latch the lid" of each container, or is its function different? Similarly, does the structure on the corners of the Accused Products meet the definition of a "corner bumper" as recited in the ’952 Patent?
  • Technical Questions: An evidentiary question will be whether the physical implementation of the MODbox™ connection mechanism corresponds to the claimed structure of a "rib" projecting from a "depressed surface" on one container and an engaging "tongue" on the other. The complaint relies on external product images and marketing statements, but the dispute may require a more detailed comparison of the products' internal coupling geometries to the claim language.

V. Key Claim Terms for Construction

Term: "a first coupler extending from a first face ... comprising two sidewalls, a back wall, and a rib" (’026 Patent, Claim 1)

Context and Importance

This term defines the "female" portion of the patented connection. The infringement case depends on whether the recessed connection points on the MODbox™ products have this specific recited structure. Practitioners may focus on this term because modular connection systems can be implemented with many different geometries, and a mismatch here could be a basis for a non-infringement defense.

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The patent describes the overall invention as a "coupling mechanism configured for readily detachably attaching any first article to any second article" (’026 Patent, col. 1:44-46), which might support a more functional interpretation focused on the ability to connect rather than the precise form.
  • Evidence for a Narrower Interpretation: The specification and Figure 1B describe a specific embodiment with a "laterally projecting locking rib 36 extending from a rear portion of the depressed locking location 32" (’026 Patent, col. 16:36-39). This detailed description of a specific structure could be used to argue that the term "coupler" is limited to this or a very similar geometry.

Term: "a first corner bumper coupled to the second container" (’952 Patent, Claim 1)

Context and Importance

This element is a key addition in the ’952 Patent. Infringement will depend on whether the corner structures of the Accused Products are properly characterized as "bumpers."

Intrinsic Evidence for Interpretation

  • Evidence for a Broader Interpretation: The patent does not provide an explicit definition of "corner bumper," which may support an argument that the term should be given its plain and ordinary meaning, covering any structure at the corner that provides protection.
  • Evidence for a Narrower Interpretation: Figure 1A of the patent family (e.g., in the ’026 Patent) shows distinct elements labeled as "fender-like protectors 90 at their corners" (’026 Patent, col. 17:50-51). A defendant may argue that a "bumper" must be a structurally distinct component intended for impact absorption, not merely the integrated molded corner of the container's main body.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement, stating that Klein Tools provides instructions and advertisements (e.g., its website and the "Buildverse" tool) that direct and encourage customers to assemble the Accused Products in an infringing manner (Compl. ¶33-34, ¶50-51, ¶67-68). It also alleges contributory infringement on the basis that the Accused Products are especially made for this infringing use and are not staple articles of commerce (Compl. ¶38, ¶55, ¶72).

Willful Infringement

Willfulness is alleged based on Defendant's knowledge of the asserted patents "at least as early as the filing of this Complaint" (Compl. ¶36, ¶53, ¶70). This frames the willfulness claim as being based on post-suit conduct.

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

This dispute will likely center on two fundamental issues for the court to resolve:

  1. A core issue will be one of structural correspondence: Does the specific geometry of the Klein Tools MODbox™ interconnection mechanism—how the parts slide and lock together—map onto the detailed structural limitations of the asserted claims, including the "rib," "tongue," and "locking latch" elements, or is it a functionally similar but structurally distinct design?
  2. A key question of definitional scope will be central to the ’952 Patent: Can the term "corner bumper" be construed to read on the integrated corners of the accused toolboxes, or does the patent's intrinsic evidence limit the term to a more distinct, fender-like protective component?