DCT
1:10-cv-00204
Sloan Valve Co v. Zurn Industries Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Sloan Valve Company (Delaware)
- Defendant: Zurn Industries, Inc. (Delaware) and Zurn Industries, LLC (Delaware)
- Plaintiff’s Counsel: Foley & Lardner LLP
- Case Identification: 1:10-cv-00204, N.D. Ill., 11/29/2011
- Venue Allegations: Plaintiff alleges venue is proper because Defendants transact business in the judicial district, are registered to do business in Illinois, and have committed acts of infringement in the district.
- Core Dispute: Plaintiff alleges that Defendant’s dual-mode commercial flush valve handles and assemblies infringe a patent related to a mechanical dual-axis plunger system for providing full- and reduced-flush options.
- Technical Context: The technology addresses water conservation in commercial plumbing by providing a simple, mechanical handle assembly that can convert standard single-flush toilets into dual-flush systems.
- Key Procedural History: The complaint alleges that after the patent-in-suit issued, Defendant Zurn initiated an ex parte reexamination at the U.S. Patent and Trademark Office (USPTO). The USPTO subsequently confirmed the validity of the challenged claims. The complaint further alleges that Zurn's reexamination request was based on a "deceptively" modified prior art drawing and that Zurn continued to sell the accused products even after the USPTO rejected its invalidity arguments.
Case Timeline
| Date | Event |
|---|---|
| 2001 | ASME issues American National Standard for dual flushing devices |
| 2004 | Sloan engineer John Wilson conceives the invention |
| 2005-03 | Sloan begins testing experimental handle assemblies |
| 2005-05-31 | Sloan exhibits dual mode handle assemblies at a conference |
| 2005-08-01 | Sloan announces commercial introduction of its dual mode product |
| 2005-08-04 | Zurn announces introduction of its dual mode flush valve |
| 2005-08-25 | '635 Patent Priority Date (Application Filing) |
| 2005-12-14 | Zurn adds accused product to its website |
| 2006-01 | Sloan locates Zurn's accused product in the marketplace |
| 2006-07-13 | '635 Patent application is published |
| 2006-10-24 | Zurn's counsel allegedly finds the published patent application |
| 2009-10-27 | U.S. Patent No. 7,607,635 Issues |
| 2010-09-17 | Zurn requests reexamination of the '635 Patent |
| 2011-01-10 | USPTO confirms patentability of several '635 Patent claims in reexamination |
| 2011-11-29 | Amended and Supplemental Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,607,635 - "Flush Valve Handle Assembly Providing Dual Mode Operation"
- Issued: October 27, 2009.
The Invention Explained
- Problem Addressed: The patent identifies a need for a simple, reliable, and inexpensive manual dual-mode flush valve for commercial toilets to conserve water, noting that as of 2004, such a product was not available on the market (Compl. ¶¶10-11; ’635 Patent, col. 1:7-19). Prior art attempts were described as either failing to produce significant differences in flush volumes or being unpredictable. (’635 Patent, col. 1:42-57).
- The Patented Solution: The invention is a handle assembly containing a bushing with a specially designed internal passage. This passage is defined by two partially overlapping bores, creating two distinct travel paths for a plunger. (’635 Patent, col. 2:10-26). Actuating the handle in one direction (e.g., horizontally) sends the plunger along a "horizontal axis" for a standard full flush. Actuating it in another direction (e.g., tilting the handle upwards) forces the plunger to travel along an "angled axis," causing the relief valve to close sooner and delivering a reduced-volume flush for liquid waste. (’635 Patent, col. 5:6-44, Figs. 5-6).
- Technical Importance: The invention provided a mechanical method to enable dual-flush functionality that could be retrofitted onto existing single-flush valves, offering significant water savings in commercial applications. (Compl. ¶16).
Key Claims at a Glance
- The complaint asserts independent claim 1, along with several dependent claims. (Compl. ¶78).
- The essential elements of independent claim 1 include:
- A handle assembly with an actuatable handle, a bushing, and a plunger that is "slidably and tiltably mounted" in the bushing's passage.
- The bushing passage defining "both a first axis of plunger travel and a second axis of plunger travel which is angled with respect to the first axis."
- Wherein tilting the handle in a first direction moves the plunger along the first axis, and tilting it in a second direction moves the plunger along the second, angled axis.
- The complaint asserts claims 1, 4-6, 10-12, 14, 19, 29-31, and 33-34, thereby including dependent claims in the suit. (Compl. ¶78).
III. The Accused Instrumentality
Product Identification
- The complaint names several Zurn products, including the "P6000-M-ADA-DF AquaVantage Dual Flush Handle," the "Z6000-AV-DF AquaVantage AV Exposed Flush Valve with Top Spud Connection for Water Closets with Dual-Flush Handle," and the "Exposed Z6003 AV-DF Dual Flush Model." (Compl. ¶78).
Functionality and Market Context
- The complaint alleges these are dual-mode handle assemblies and flush valves that provide users with different flush volumes. (Compl. ¶32). The infringement theory is predicated on the allegation that these products are "strikingly similar" to Sloan's patented product and were copied from it. (Compl. ¶¶30, 34). The complaint does not contain detailed technical diagrams or reverse engineering of the accused products but alleges they incorporate the features of the patented invention. (Compl. ¶32). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint does not provide a claim chart exhibit. The following summary is based on the narrative allegations.
'635 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a handle assembly mounted on the body and including an actuatable handle, a bushing having a passage defined therethrough and a plunger slidably and tiltably mounted in said bushing passage... | The accused Zurn dual mode handle assemblies, which are alleged to incorporate the features of the invention. | ¶¶32, 78 | col. 4:20-39 |
| the bushing passage defining both a first axis of plunger travel and a second axis of plunger travel which is angled with respect to the first axis of plunger travel... | The internal mechanism of the accused Zurn dual mode handle assemblies, which allegedly provides for two different flush volumes by infringing the patented dual-axis system. | ¶¶32, 78 | col. 4:45-54 |
| wherein tilting of the handle in a first direction moves the plunger along the first axis of plunger travel and tilting of the handle in a second direction tilts the plunger and moves the plunger along the second axis of plunger travel. | The operation of the accused Zurn dual flush handles, which allegedly function by moving a plunger along two distinct paths corresponding to different user inputs to achieve dual-flush capability. | ¶¶30, 78 | col. 5:6-44 |
- Identified Points of Contention:
- Technical Questions: The central factual dispute will be whether the accused Zurn products achieve their dual-flush capability through the specific dual-axis plunger mechanism claimed in the ’635 Patent. The litigation will likely require discovery, expert analysis, and potentially reverse engineering to compare the internal operation of the Zurn handle with the patent’s claims.
- Scope Questions: A question for the court will be how broadly to interpret the "first axis" and "second axis" limitations. The dispute may focus on whether Zurn's mechanism, even if it creates two different outcomes, does so via a structure that can be fairly described as a "bushing passage defining" two distinct, angled axes of travel for a tiltable plunger.
V. Key Claim Terms for Construction
The Term: "bushing passage defining both a first axis of plunger travel and a second axis of plunger travel which is angled with respect to the first axis"
- Context and Importance: This phrase captures the core of the invention. The outcome of the infringement analysis will depend heavily on whether the internal structure of the accused Zurn product is found to meet this geometric and functional limitation. Practitioners may focus on this term because it is the primary point of novelty that distinguishes the invention from prior art single-axis flush handles.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself does not limit the shape of the passage or the precise angle, which could support an interpretation covering any bushing structure that creates two distinct, angled paths for a plunger.
- Evidence for a Narrower Interpretation: The specification discloses a specific embodiment where the passage is formed by "first and second bores which partially overlap," creating a "somewhat oval shape" at the outer end. (’635 Patent, col. 2:12-16, Fig. 7). A party could argue that the term should be limited to a structure consistent with this described two-bore construction.
The Term: "plunger slidably and tiltably mounted in said bushing passage"
- Context and Importance: This term is critical because it requires the plunger to be capable of two distinct types of motion—sliding and tilting. Infringement requires proving the accused plunger performs both functions as constrained by the passage.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself is general, suggesting any mounting that allows for both linear movement and angular deviation could meet the limitation.
- Evidence for a Narrower Interpretation: The detailed description links the tilting motion directly to the plunger entering the angled second bore as a result of a specific user action on the handle. (’635 Patent, col. 5:20-34). An argument could be made that the "tilting" must be a rigid angling of the plunger shank into a defined angled bore, as opposed to mere flexing or wobbling.
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement.
- The inducement claim is based on allegations that Zurn sold the accused handle assemblies while "providing instructions for installing such handles" into flush valves, knowing this would cause direct infringement by the end-user. (Compl. ¶¶88-89).
- The contributory infringement claim is based on allegations that the Zurn handle assemblies are a "material part" of the patented invention, were "especially made or especially adopted" for an infringing use, and are not a staple article of commerce suitable for substantial noninfringing use. (Compl. ¶¶92-94).
- Willful Infringement: The complaint alleges willful infringement based on Zurn's alleged knowledge of the patent and its patent application. (Compl. ¶80). The willfulness claim is supported by allegations that Zurn had knowledge of the published application as early as 2006 (Compl. ¶42), was a direct competitor who allegedly copied the product (Compl. ¶34), and continued to sell the accused products after the lawsuit was filed and even after the USPTO confirmed the patent's validity in a reexamination proceeding that Zurn itself had initiated. (Compl. ¶¶46, 57).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of technical infringement: does the internal mechanism of Zurn's accused handle assembly operate using the specific dual-axis, tilting-plunger system described and claimed in the ’635 Patent, or does it achieve a dual-flush result via a distinct, non-infringing design? The plaintiff’s allegation of direct copying will be a central theme tested against the physical evidence.
- The case will also turn on claim construction: specifically, how the court defines the scope of a "bushing passage defining both a first axis...and a second axis...angled with respect to the first axis." Whether this term is construed broadly to cover functionally similar mechanisms or narrowly to the specific two-bore structure shown in the patent’s figures will likely be dispositive.
- A third key question will relate to willfulness and damages: given the detailed allegations regarding Zurn’s pre-suit knowledge and its decision to continue selling products after an unsuccessful reexamination challenge at the USPTO, a central issue for the court will be whether Zurn's conduct was objectively reckless, potentially justifying an award of enhanced damages.