DCT
1:24-cv-04550
Angel Water, Inc.
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Angel Water, Inc. (Illinois)
- Defendant: Adam's Water Treatment, Inc. (Illinois)
- Plaintiff’s Counsel: McDonnell Boehnen Hulbert & Berghoff LLP
- Case Identification: 1:24-cv-04550, N.D. Ill., 05/31/2024
- Venue Allegations: Venue is alleged to be proper as Defendant is an Illinois corporation that transacts business and has a regular and established place of business in the district.
- Core Dispute: Plaintiff alleges that Defendant’s water filtration systems infringe a reissued patent related to the on-demand, flow-triggered injection of chlorine for water treatment.
- Technical Context: The technology addresses the need for efficient and effective disinfection of well water in residential and small commercial settings by activating a chemical pump only when water is being used.
- Key Procedural History: The asserted patent is a reissue of an earlier patent. The complaint alleges that Plaintiff filed for reissue after Defendant, in response to an infringement notice on the original patent, provided a prior art reference. Plaintiff asserts it cited this reference during the reissue prosecution, suggesting an attempt to secure claims that are valid over that art.
Case Timeline
| Date | Event |
|---|---|
| 2013-03-14 | Earliest Priority Date for U.S. RE49,098 Patent |
| 2019-12-10 | Issue Date of original U.S. Patent No. 10,501,348 |
| 2020-04-13 | Plaintiff sends letter to Defendant re '348 Patent |
| 2020-08-10 | Plaintiff files application for reissue patent |
| 2022-06-07 | Issue Date of U.S. Reissued Patent No. RE49,098 |
| 2024-02-19 | Plaintiff sends letter to Defendant re '098 Patent |
| 2024-05-31 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Reissued Patent No. RE49,098 - "Water Flow Triggering of Chlorination Treatment"
- Patent Identification: U.S. Reissued Patent No. RE49,098, "Water Flow Triggering of Chlorination Treatment," issued June 7, 2022.
The Invention Explained
- Problem Addressed: The patent addresses the challenge of efficiently and effectively neutralizing bacteria and other harmful substances in untreated well water for residential or small commercial use (RE49,098 Patent, col. 2:15-23).
- The Patented Solution: The invention is a system that uses a flow valve to detect when water is being drawn by a user. This detection responsively triggers a pump to inject a chlorinating substance into the water supply. The treated water then enters a contact reservoir, which provides sufficient time for the chemical to mix with the water and disinfect it before it proceeds to the user (RE49,098 Patent, Abstract; Fig. 1). The system is designed so that the disinfecting chemical is used "only when needed" (RE49,098 Patent, col. 2:31-32).
- Technical Importance: This on-demand approach to chlorination aims to provide more precise dosing and effective purification compared to less responsive systems, thereby improving water quality while potentially conserving chemicals (RE49,098 Patent, col. 4:52-66).
Key Claims at a Glance
- The complaint asserts infringement of claims 1-5 and 10-11, which include independent claims 1 (a system) and 10 (a method) (’098 Patent, col. 5:41, col. 6:52).
- Independent Claim 1 (System) requires:
- A first unit of piping for untreated water.
- A pump configured to inject a chlorinating substance when "remotely triggered by a flow valve that is downstream from the pump," with the valve "electronically coupled to the pump by a triggering line."
- A "contact reservoir" downstream from the pump to receive and combine the water and a chlorinating substance.
- A "flow head" coupled to the contact reservoir.
- The "flow valve," which is in "downstream fluid communication with the contact reservoir" and is configured to sense the water flow and, in response, "generate and transmit to the pump an electronic control signal" to trigger injection.
- The complaint reserves the right to assert other claims.
III. The Accused Instrumentality
Product Identification
- The complaint identifies the accused product as Defendant’s water filtration system ("the Infringing System") and its use as "the Infringing Method" (Compl. ¶22).
Functionality and Market Context
- Based on a diagram from Defendant's website, the accused system draws raw well water and passes it through several components (Compl. ¶23, Fig. 2). Figure 2 from the complaint depicts a schematic of the accused system, showing the relative positions of its components. (Compl. ¶23). The system includes a chlorine pump that injects chlorine from a holding tank into the water line at an injection point (Compl. ¶23, Fig. 2, items C, D, F).
- The chlorinated water flows into a "Contact tank" before passing through a "flow switch" and then a "carbon filter" (Compl. ¶23, Fig. 2, items B, G, E). A photograph in the complaint shows a close-up of the accused chlorine pump (Compl. ¶25, Fig. 4). The complaint alleges these systems are advertised and sold to customers in Illinois (Compl. ¶8).
IV. Analysis of Infringement Allegations
The complaint does not contain a claim chart exhibit. The following analysis is based on the narrative allegations and figures provided in the complaint body.
RE49,098 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a pump... configured to inject a chlorinating substance into the first unit of piping when remotely triggered by a flow valve that is downstream from the pump, the flow valve electronically coupled to the pump by a triggering line | The accused system includes a "Chlorine pump" (D) and a "Flow switch" (G). The complaint's diagram shows the flow switch positioned downstream of both the injection point (F) and the contact tank (B), implying it triggers the pump when water flows through it. | ¶¶23, 25, Fig. 2 | col. 4:50-57 |
| a contact reservoir, in downstream fluid communication with the first unit of piping and the pump, configured to receive the untreated water and the chlorinating substance, and to combine the untreated water and a chlorinating substance to produce chlorinated water therefrom | The accused system includes a "Contact tank" (B) located downstream of the chlorine injection point (F) and configured to hold the mixture of water and chlorine. | ¶23, Fig. 2 | col. 3:5-15 |
| the flow valve, in downstream fluid communication with the contact reservoir and electronically coupled to the pump, configured to: receive a flow of water from the contact reservoir; sense the flow through the flow valve; and in response to sensing the flow, generate and transmit to the pump an electronic control signal... that remotely triggers the pump | The accused system's "Flow switch" (G) is positioned downstream of the "Contact tank" (B) and is alleged to sense water flow and, in response, activate the chlorine pump. | ¶23, Fig. 2 | col. 6:2-17 |
- Identified Points of Contention:
- Technical Questions: A primary question will be whether the accused "flow switch" performs all the functions of the claimed "flow valve," specifically whether it can be shown to "generate and transmit... an electronic control signal" that "remotely triggers the pump." Evidence of the electronic connection and the nature of the signal between the switch and the pump will be critical.
- Scope Questions: The dispute may center on the interpretation of "remotely triggers." The parties may contest whether a direct electrical wire between a switch and a pump, as is common in such systems, satisfies the "remote" limitation, or if the term implies a more technologically sophisticated or physically distant control mechanism.
V. Key Claim Terms for Construction
The Term: "flow valve"
Context and Importance: The definition of this term is central, as the infringement analysis depends on whether Defendant's "flow switch" (Compl. ¶23, Fig. 2, item G) meets its limitations. Practitioners may focus on this term because the patent uses the word "valve," which could be argued to imply flow control, whereas the accused component is called a "switch," which may only imply an on/off state detection.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification suggests a broad functional definition, stating the component is configured to "detect when water is flowing" and may "detect changes in water pressure or to detect water flow in some other way" (’098 Patent, col. 3:35-37, col. 4:47-49). This language may support an interpretation covering any device that senses flow and generates a corresponding signal.
- Evidence for a Narrower Interpretation: The term "valve" itself might be argued to require a structure capable of modulating or shutting off flow, a function not explicitly attributed to the accused "flow switch." While the claim only recites sensing and signaling functions, a party could argue that the choice of the word "valve" over "sensor" or "switch" was intentional and carries a more restrictive meaning.
The Term: "remotely triggers"
Context and Importance: This term defines the required relationship between the flow-sensing component and the pump. The infringement case rests on showing that the accused flow switch "remotely triggers" the accused pump.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the "triggering line" in broad terms, stating it "may include electrical wire, optical fiber, network cable, or some other medium that transports one or more types of signals" (’098 Patent, col. 4:57-61). This could support a broad definition where "remote" simply means not mechanically contiguous, thereby covering a standard hard-wired connection.
- Evidence for a Narrower Interpretation: A party could argue that in the context of electronics, "remotely" implies a connection that is not a direct, dedicated wire, such as a wireless signal or a networked command. However, the specification's explicit inclusion of "electrical wire" may undermine this narrower interpretation.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement by asserting that Defendant "has instructed its customers through its website to use the Infringing System in an infringing manner" (Compl. ¶40). This allegation points to public-facing documentation as evidence of the specific intent to cause infringement.
- Willful Infringement: The willfulness claim is supported by allegations of pre-suit knowledge. Plaintiff alleges it sent a notice letter regarding the asserted '098 Patent on February 19, 2024 (Compl. ¶41). Further, the complaint details a history of interaction regarding the original '348 Patent dating to April 2020, including Defendant's provision of a prior art reference that Plaintiff subsequently cited during the reissue proceeding (Compl. ¶¶30-34).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim construction: can the term "flow valve", as defined in the patent, be construed to read on the accused system's "flow switch"? The outcome will depend on whether the court finds that the term requires only the claimed functions of sensing and signaling, or if it imparts a structural or functional limitation (e.g., flow modulation) not present in the accused device.
- A second central question will concern willfulness and the parties' litigation history: how will the court view the pre-suit communications, Defendant's identification of prior art, and Plaintiff's subsequent decision to pursue a reissue patent citing that art? Plaintiff may frame this as evidence of deliberate infringement in the face of a strengthened patent, while Defendant may argue it demonstrates a good-faith belief that its system relies on designs in the public domain.