DCT

3:25-cv-00306

Delkor Systems Inc v. Pratt Industries Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:25-cv-00306, W.D. Wis., 10/30/2025
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants have a regular and established physical place of business in Beloit, Wisconsin, and have allegedly committed infringing acts within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s corrugated cardboard packaging, which is designed to convert from a shipping container to a retail display tray, infringes patents related to convertible package assemblies and the flat blanks used to create them.
  • Technical Context: The technology addresses the market for "retail ready" packaging, which aims to reduce stocking labor and improve product presentation by allowing a single container to be used for both shipping and in-store display.
  • Key Procedural History: The filing is a Second Amended Complaint. The complaint also alleges that Plaintiff provided Defendant with actual notice of the patents-in-suit via correspondence beginning on May 29, 2024, approximately seventeen months prior to the filing of this complaint.

Case Timeline

Date Event
2013-08-23 Priority Date for ’919 and ’580 Patents
2017-01-31 U.S. Patent No. 9,555,919 Issues
2019-09-24 U.S. Patent No. 10,421,580 Issues
2024 (unspecified) Accused Product Introduced to Marketplace
2024-05-29 Plaintiff Alleges Sending Notice Letter to Defendant
2025-10-30 Second Amended Complaint Filed

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

U.S. Patent No. 9,555,919 - "Convertible Package Assembly and Display System"

Issued: January 31, 2017 (’919 Patent)

The Invention Explained

  • Problem Addressed: The patent describes a need for improved "shelf ready" packaging that is cost-effective, environmentally friendly, and easy to manufacture and use. Traditional designs often required extra material, complex assembly steps like pre-gluing, and resulted in displays with poor aesthetics due to ragged, perforated tear-lines. (’919 Patent, col. 2:2-9, 44-53).
  • The Patented Solution: The invention is a package assembly formed from a single, flat "blank" of material. It uses a specific arrangement of folded panels and a "single tear line" that allows a top shipping portion of the box to be removed cleanly. This leaves behind a sturdy bottom tray with a machine-cut front edge, improving the product's appearance on a retail shelf. (’919 Patent, col. 2:25-53; Abstract).
  • Technical Importance: This approach aims to combine the structural integrity needed for shipping with the aesthetic and functional requirements of a retail display in a single, efficiently produced package. (Compl. ¶23).

Key Claims at a Glance

  • The complaint asserts independent claim 1. (Compl. ¶44).
  • Essential elements of Claim 1 include:
    • A package assembly comprising a case formed from a single piece of packaging material with a single tear line.
    • The case has a shipping configuration and a display configuration.
    • The single piece of packaging material comprises fifteen polygonal sections folded to form the case.
    • Three of the fifteen polygonal sections are divided by the single tear line into six partial sections.
    • In the display configuration, a bottom portion for displaying products includes a front panel portion.
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 10,421,580 - "Convertible Package Assembly and Display System"

Issued: September 24, 2019 (’580 Patent)

The Invention Explained

  • Problem Addressed: As a continuation of the same patent family, the ’580 Patent addresses the same technical problems as the ’919 Patent, namely the cost, complexity, and aesthetic limitations of prior art convertible packaging. (’580 Patent, col. 2:7-14).
  • The Patented Solution: The ’580 Patent claims the precursor to the assembled box: the un-folded, flat "blank" itself. The claims define the blank by its specific geometric layout, including the number and arrangement of its "polygonal sections" and the placement of a "single tear line" designed to facilitate the conversion from shipping to display mode. (’580 Patent, Abstract; col. 9:11-14).
  • Technical Importance: By patenting the blank, the patent holder can assert rights against manufacturers of the flat, unassembled packaging material, in addition to those who assemble and sell the final box. (Compl. ¶59).

Key Claims at a Glance

  • The complaint asserts independent claim 5 and dependent claim 7. (Compl. ¶45).
  • Essential elements of Independent Claim 5 include:
    • A blank for a case convertible from a shipping to a display configuration.
    • The blank comprises fifteen polygonal sections defining a first end, a second end, a first side, and a second side.
    • The first and second ends are each defined by three polygonal sections.
    • A middle polygonal section of the first end is smaller in size than a middle polygonal section of the second end.
    • A single tear line extends from the first side to the second side of the blank.
  • The complaint does not explicitly reserve the right to assert other claims.

III. The Accused Instrumentality

Product Identification

The "Accused Product" is identified as a convertible "retail ready" package, and the case blank from which it is assembled, used for Great Value brand pizza. (Compl. ¶36).

Functionality and Market Context

  • The complaint alleges the Accused Product is manufactured by Defendant Pratt at a facility in Beloit, Wisconsin. (Compl. ¶39, ¶40). A photograph of the deconstructed Accused Product purports to show its form as a single, pre-assembled "case blank" (Compl. p. 13, ¶38). The product is designed to be assembled into a shipping container and, once at a retail location, converted into a display tray by tearing off a portion of the container. (Compl. ¶36).
  • The complaint alleges that the Accused Product is sold to customers, including Palermo's Pizza, who manufactures and boxes pizzas for Walmart's Great Value brand. (Compl. ¶41). The packaging includes a label identifying "Pratt Industries (USA)" and "Beloit, WI" as the source. (Compl. p. 12, ¶39).

IV. Analysis of Infringement Allegations

U.S. Patent No. 9,555,919 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A package assembly comprising: a case formed from a single piece of packaging material... The Accused Product is allegedly assembled from a single corrugated case blank. A photo shows the deconstructed product as a single piece. ¶36, ¶38 col. 9:8-10
...with a single tear line... A photo of the deconstructed sample shows it torn into two halves along what is alleged to be the claimed single tear line. ¶38 col. 9:9
...the case having a shipping configuration and a display configuration... The product is alleged to be a "convertible 'retail ready' package" used for "packaging, shipping, and display." ¶36 col. 9:10-11
...the single piece of packaging material comprising fifteen polygonal sections folded to form the case... The complaint does not explicitly count the polygonal sections, but a photograph of the unfolded blank is provided as evidence of its structure. ¶38 col. 9:14-16
...in the display configuration...a front panel portion... Photographs show Delkor's own product being converted to a display tray, which provides context for the intended function of the accused infringing package. ¶23 col. 9:25-27

Identified Points of Contention

  • Scope Questions: The complaint's allegations are conclusory and lack a detailed element-by-element mapping. A central question will be whether the physical structure of the Accused Product, particularly its unfolded blank, actually contains the specific number ("fifteen") and arrangement of "polygonal sections" required by claim 1.
  • Technical Questions: What evidence does the complaint provide that the mechanism for opening the Accused Product constitutes a "single tear line" as that term is used in the patent? The analysis will depend on the physical construction of the tear mechanism on the actual product.

U.S. Patent No. 10,421,580 Infringement Allegations

Claim Element (from Independent Claim 5) Alleged Infringing Functionality Complaint Citation Patent Citation
A blank for a case convertible from a shipping configuration to a display configuration... The complaint identifies the "case blank from which it was assembled" as part of the Accused Product. A photo of the deconstructed sample shows this blank. ¶36, ¶38 col. 10:11-13
...the blank comprising: fifteen polygonal sections... The complaint provides a photograph of the unfolded blank, which is alleged to have the claimed structure. ¶38 col. 10:14-15
...a middle polygonal section of the first end of the blank being smaller in size than a middle polygon section of the second end of the blank... The complaint does not provide specific measurements or analysis of this geometric limitation, relying on the visual representation of the deconstructed blank. ¶38 col. 10:18-21
...a single tear line extends from the first side of the blank to the second side of the blank... The provided photo of the deconstructed blank shows it separated into two pieces along an alleged tear line. ¶38 col. 10:28-31

Identified Points of Contention

  • Scope Questions: Does the term "polygonal sections" read on the specific shapes and cuts of the panels in the accused blank, especially if any edges are curved or irregular?
  • Technical Questions: The infringement analysis for the '580 patent will be highly factual and may turn on a direct physical comparison and measurement of the accused blank against the specific geometric and size-ratio limitations recited in claim 5. The complaint provides a photograph but no analysis of these dimensional requirements.

V. Key Claim Terms for Construction

  • The Term: "single tear line" (’919 patent, claim 1; ’580 patent, claim 5)
  • Context and Importance: This term appears in the independent claims of both asserted patents and is central to the invention's convertibility. The dispute will likely focus on whether the accused product's separation mechanism, which may consist of perforations, scores, or other features, meets the definition of a "single tear line."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states the tear lines "can be provided by any desired mechanism, such as for example: by providing a continuous line of perforations, a tear strip, a pre-cut incision that does not extend entirely through the material of the blank 30, etc." (’919 Patent, col. 8:13-17). This language suggests the term is not limited to a single type of structure.
    • Evidence for a Narrower Interpretation: The claims consistently use the singular "a single tear line." Embodiments show the tear lines "form a single continuous tear line." (’919 Patent, col. 4:42-43). A defendant may argue that a system with multiple, non-continuous lines of weakness or a complex opening mechanism does not meet this limitation.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges contributory infringement of the ’919 patent. It asserts that Defendant supplies the corrugated case blanks to customers (e.g., Palermo's Pizza) knowing they are "especially made or adapted for use in the patented...assembly," have no substantial non-infringing uses, and provides instructions for their assembly. (Compl. ¶51).
  • Willful Infringement: The complaint alleges willfulness based on both pre- and post-filing conduct. It alleges Defendant had constructive notice of the patents since their issue dates and actual knowledge since at least May 29, 2024, from correspondence with Plaintiff. The complaint alleges that despite this notice, Defendant "continued selling the Accused Product and to this day continues to do so." (Compl. ¶47-49, ¶55-57).

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

  • A core issue will be one of structural correspondence: does the accused Pratt packaging blank, when physically examined and measured, possess the exact number ("fifteen") and specific relative dimensions of the "polygonal sections" required by the independent claims of both patents? The outcome may depend on detailed factual evidence and expert testimony comparing the accused product to the claim language.
  • A key question of claim construction will be the definitional scope of "single tear line." The court's interpretation of this term—whether it requires a simple, continuous line of weakness or can encompass more complex, multi-part opening mechanisms—will be critical in determining whether the accused product's conversion feature falls within the patent claims.