DCT
1:22-cv-06425
Zurn Industries LLC v. MiFab Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Zurn Industries, LLC (Delaware)
- Defendant: MiFab, Inc. (Delaware)
- Plaintiff’s Counsel: Quarles & Brady LLP
- Case Identification: 1:22-cv-06425, N.D. Ill., 11/16/2022
- Venue Allegations: Venue is based on Defendant's principal place of business being located in Chicago, Illinois, within the district, along with allegations that Defendant regularly conducts business and has committed acts of patent infringement in the district.
- Core Dispute: Plaintiff alleges that Defendant’s roof drain assemblies infringe patents related to a combined drain support plate and under-deck clamp designed to enable top-side-only installation.
- Technical Context: The technology concerns commercial roof drainage systems, where simplifying the installation process to eliminate work beneath the roof deck can reduce labor costs, time, and safety hazards.
- Key Procedural History: The complaint states that the ’449 Patent is a continuation of the ’242 Patent. Plaintiff alleges it provided Defendant with formal written notice of the asserted patents and its infringement allegations via a letter in August 2021, more than a year before filing the complaint. This pre-suit notice is central to the allegations of willful infringement.
Case Timeline
| Date | Event |
|---|---|
| 2002-01-15 | Priority Date for ’242 and ’449 Patents |
| 2010-08-31 | ’242 Patent Issued |
| 2011-08-30 | ’449 Patent Issued |
| 2013-02-28 | Date of MiFab Product Training YouTube Video |
| 2021-08-XX | Zurn sends notice letter to MiFab |
| 2022-11-16 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,784,242 - “Drain Support Plate/Under-Deck Clamp,” issued Aug. 31, 2010
The Invention Explained
- Problem Addressed: The patent describes the installation of traditional roof drains as a multi-step process requiring an installer to first place the drain from the top of a roof deck and then enter the building to fasten it from below using an "under-deck clamp" (Compl. ¶11; ’242 Patent, col. 2:4-14). This method is described as increasing installation time and expense and potentially posing a safety hazard (’242 Patent, col. 2:30-38).
- The Patented Solution: The invention is a "drain support plate" that combines the functions of a topside support and an under-deck clamp into a single component ('242 Patent, Abstract). This plate is designed to be attached to the drain's receptacle body first, creating a pre-assembled unit that can then be installed and secured entirely from the top surface of the roof deck, eliminating the need for a separate installation step from underneath (’242 Patent, col. 6:17-34).
- Technical Importance: The design's stated purpose is to reduce drain installation time and expense while permitting a safer, top-side-only installation process (’242 Patent, col. 2:38-41).
Key Claims at a Glance
- The complaint asserts at least independent method claim 18 (Compl. ¶28).
- The essential steps of claim 18 include:
- Forming an opening in a deck.
- Providing a drain receptacle body with an annular flange.
- Providing a drain support plate with a "recess portion" adapted to receive the annular flange.
- Attaching the receptacle body to the support plate via a member to form an assembly, with the flange received in the recess.
- Installing the entire assembly onto the upper surface of the deck.
U.S. Patent No. 8,006,449 - “Drain Support Plate/Under-Deck Clamp,” issued Aug. 30, 2011
The Invention Explained
- Problem Addressed: As a continuation of the ’242 Patent, this patent addresses the same problems of time, cost, and safety associated with traditional two-part roof drain installations (’449 Patent, col. 1:22-41).
- The Patented Solution: The patent claims the physical apparatus of the drain assembly itself, rather than the method of installation (’449 Patent, Abstract). It describes a "drain support plate assembly" comprising a drain receptacle body (with an annular flange and at least one protrusion) pre-attached to a drain support plate, which has a corresponding "recess portion" to receive the flange (’449 Patent, col. 6:45-66). This integrated assembly is structured to be installed from the top of a roof deck.
- Technical Importance: The apparatus is designed to embody the same efficiencies as the method described in the parent patent: reducing installation complexity, time, and cost (’449 Patent, col. 2:38-41).
Key Claims at a Glance
- The complaint asserts at least independent apparatus claim 16 (Compl. ¶48).
- The essential elements of claim 16 include:
- A receptacle body with an annular flange and at least one protrusion that defines a void.
- A drain support plate with a recess portion adapted to receive the annular flange.
- The support plate is attached to the receptacle body via at least one member that is received within the void defined by the protrusion, forming the complete assembly.
III. The Accused Instrumentality
Product Identification
The "MiFab Deck Plate Assemblies," specifically including the "A2-BP Roof Drain Sump Receiver" and "A2 Roof Drain" (Compl. ¶20).
Functionality and Market Context
The accused products are part of Defendant's line of commercial drainage products (Compl. ¶19). The complaint alleges that MiFab advertises these products with advantages that mirror the purpose of the patented invention, such as "easy assembly, eliminating the costly underdeck clamp, and eliminating the labor required to install in the underdeck clamp" (Compl. ¶21). The complaint provides an exploded-view diagram of the accused MiFab Deck Plate Assembly, showing its components, including a drain body, a deck plate, and fasteners (Compl. p. 5). It is alleged that MiFab, a competitor to Zurn, began selling these products after Zurn introduced its patented "Top-Set®" drains (Compl. ¶¶19-20).
IV. Analysis of Infringement Allegations
’242 Patent Infringement Allegations
| Claim Element (from Independent Claim 18) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| b) providing a receptacle body of a drain, said receptacle body having a first end and a second end, said first end of said receptacle body having an annular flange extending away from said receptacle body... | The accused MiFab A2 Roof Drain is alleged to be a receptacle body with an annular flange (Compl. ¶¶20, 35). | ¶20, ¶35 | col. 7:20-25 |
| c) providing a drain support plate having a body... said first portion and said second portion defining a recess portion adapted to receive said annular flange... | The MiFab A2-BP Roof Drain Sump Receiver is alleged to be a drain support plate with a recess that receives the flange of the A2 Roof Drain (Compl. ¶¶20, 35). | ¶20, ¶35 | col. 7:26-34 |
| d) attaching said receptacle body of said drain to said second portion of said body of said support plate via a member for attaching said receptacle body to said body when said annular flange is received within the recess portion... | The complaint alleges that installers are instructed to attach the MiFab drain body to the sump receiver using bolts, forming an assembly (Compl. ¶35). | ¶35 | col. 8:28-35 |
| e) subsequently installing said support plate with said attached receptacle body to an upper surface of said deck... | The complaint alleges the assembled MiFab unit is then installed on a roof deck, securing the drain to the deck (Compl. ¶35). | ¶35 | col. 8:36-41 |
’449 Patent Infringement Allegations
| Claim Element (from Independent Claim 16) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a receptacle body of a drain... having an annular flange... and at least one protrusion extending away from said receptacle body... | The accused MiFab A2 Roof Drain is alleged to be a receptacle body with an annular flange and protrusions on its underside (Compl. ¶¶20, 49). | ¶20, ¶49 | col. 8:23-30 |
| a drain support plate having a body... defining a recess portion adapted to receive said annular flange of said receptacle body... | The MiFab A2-BP Roof Drain Sump Receiver is alleged to be a drain support plate with a recess that receives the flange of the A2 Roof Drain (Compl. ¶¶20, 49). | ¶20, ¶49 | col. 8:31-41 |
| wherein said support plate is attached to said receptacle body via at least one member... wherein said at least one protrusion defines a void and said at least one member is received with said void... | The complaint alleges the MiFab drain body is attached to the sump receiver with bolts ("members") that engage with tapped holes ("voids") in the underside of the drain body flange ("protrusions") (Compl. ¶¶35, 55). | ¶35, ¶55 | col. 8:42-51 |
Identified Points of Contention
- Scope Questions: A central question may be whether the accused "A2-BP Roof Drain Sump Receiver" constitutes a "drain support plate" as that term is used in the patents. The patents describe the plate as a "unitary piece of metal" in one embodiment (’242 Patent, col. 4:9-10), which may raise questions about the scope of the term if the accused product is constructed differently.
- Technical Questions: For the ’449 Patent, a key issue may be whether the accused product's use of "bolts into the tappings on the underside of the A2 body flange" (Compl. ¶35) meets the specific claim limitation of a "member" being "received with said void" that is defined by a "protrusion." The analysis will turn on the precise structure of the accused product's flange and connection points compared to the patent's description.
V. Key Claim Terms for Construction
The Term: "drain support plate"
- Context and Importance: This term defines the central component of the invention. The infringement analysis for both patents depends on whether the accused MiFab "A2-BP Roof Drain Sump Receiver" falls within the proper construction of this term.
- Evidence for a Broader Interpretation: The claims define the plate functionally by its first, second, and intermediate portions and its ability to form a recess to receive the drain flange, without strictly limiting its material or overall shape (’242 Patent, cl. 18; ’449 Patent, cl. 16).
- Evidence for a Narrower Interpretation: The specification describes a preferred embodiment as being made from a "unitary piece of metal" and depicts a specific rectangular outer shape with a circular inner portion (’242 Patent, col. 4:9-10; Fig. 4). A defendant may argue these details from the embodiment limit the scope of the term.
The Term: "recess portion"
- Context and Importance: The physical and functional interaction between the "recess portion" of the support plate and the "annular flange" of the drain body is a required element in both asserted claims. Practitioners may focus on this term because the specific geometry of this connection is critical to how the patented assembly is formed and supported.
- Evidence for a Broader Interpretation: The claims require only that the recess portion be "adapted to receive said annular flange" (’242 Patent, cl. 18) or "configured for receiving said receptacle body" (’449 Patent, cl. 1), suggesting a functional rather than a strictly structural definition.
- Evidence for a Narrower Interpretation: The patent figures depict a specific cross-sectional profile where the tapered intermediate portion of the support plate creates a defined channel for the flange to sit in (’242 Patent, Fig. 8). A party could argue the term should be limited to a structure that provides this specific type of nesting support.
VI. Other Allegations
Indirect Infringement
The complaint alleges induced infringement, citing MiFab's affirmative acts of providing instructions, marketing materials, and a product training video on YouTube that allegedly encourage and direct installers to assemble and use the accused products in an infringing manner (Compl. ¶¶ 34-36, 54-56). The complaint also pleads contributory infringement, alleging the accused components are material parts of the patented invention and lack substantial non-infringing uses (Compl. ¶¶ 41-42, 61-62).
Willful Infringement
Willfulness allegations are based on MiFab's alleged actual knowledge of the patents. The complaint claims this knowledge arises from "competitive analysis" and, more specifically, from an August 2021 notice letter Zurn sent to MiFab that identified the patents and included infringement claim charts (Compl. ¶¶ 22-24, 45, 65).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "drain support plate", which is described in an embodiment as a "unitary piece of metal," be construed to read on the structure of the accused MiFab "A2-BP Roof Drain Sump Receiver"? The outcome of this claim construction will be critical for the direct infringement analysis.
- A key evidentiary question will be one of structural correspondence: does the accused assembly’s mechanism for connecting the drain body to the deck plate—allegedly bolts threaded into tappings—satisfy the specific limitation in claim 16 of the ’449 patent requiring a "member" to be "received with said void" defined by a "protrusion," or will this point require a doctrine of equivalents analysis?
- The claim for willful infringement will likely depend on the evidence surrounding the August 2021 pre-suit notice letter. The central questions for the fact-finder will be whether Defendant's conduct after receiving this notice was objectively reckless and reflected a disregard for a known risk of infringement.