DCT
2:25-cv-00582
Zodiac Pool Systems LLC v. Wybotics Co Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Zodiac Pool Systems LLC (Delaware) and Zodiac Pool Care Europe (France)
- Defendant: Wybotics, Co. Ltd. (China)
- Plaintiff’s Counsel: Kilpatrick Townsend & Stockton LLP; Gillam & Smith, LLP
- Case Identification: 2:25-cv-00582, E.D. Tex., 05/23/2025
- Venue Allegations: Venue is asserted based on the defendant being a foreign company, which may be sued in any judicial district. The complaint also alleges specific contacts with Texas, including product importation, advertising in a local Texas newspaper, and sales activity directed at the state.
- Core Dispute: Plaintiff alleges that Defendant’s robotic pool cleaners infringe two patents related to a removable two-shell filtration system and a wheel-driven brush mechanism.
- Technical Context: The technology concerns the mechanical design of autonomous robotic cleaners for swimming pools, a market segment focused on user convenience, cleaning efficiency, and reliability.
- Key Procedural History: The complaint alleges that this lawsuit follows prior litigation between the parties, including an ITC Investigation (Inv. No. 337-TA-1326) and a parallel district court action in the Central District of California. Plaintiff asserts that it terminated the prior actions based on Defendant’s representations that it would cease manufacturing and selling the then-accused products. The current complaint alleges that the Defendant has resumed infringement with new, but not materially different, products, which may be a central issue for the willfulness allegations.
Case Timeline
| Date | Event |
|---|---|
| 2007-12-21 | Priority Date for ’031 and ’029 Patents |
| 2013-03-12 | Issue Date for ’031 and ’029 Patents |
| 2016-02-12 | Date of letter allegedly providing notice of the ’029 Patent |
| 2022-07-29 | Plaintiff files ITC Investigation and CDCA Action against Defendant |
| 2023-02-21 | ITC issues Initial Determination to terminate investigation |
| 2023-03-29 | Plaintiff voluntarily dismisses CDCA Action without prejudice |
| 2024-11-12 | Date of Texas trade show where Defendant was an alleged vendor |
| 2025-05-23 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,393,031 - "Apparatus For Cleaning A Submerged Surface With Removable Filtration Device," issued March 12, 2013
The Invention Explained
- Problem Addressed: The patent describes prior art robotic pool cleaners as having filtration systems that are inconvenient for users to access, empty, and clean. Some designs required inverting the entire heavy device, while others used complex hydraulic paths that reduced suction efficiency (Compl. ¶12; ’031 Patent, col. 1:37-52).
- The Patented Solution: The invention is a removable filtering device constructed from two primary components: a "first shell" that acts as a "pocket for recovering debris" and a "second shell" that functions as a "liquid inlet conduit." These two shells are designed to fit together to form a single, integral filtering casing that can be easily removed from the top of the cleaner. Once removed, the shells can be separated from each other, allowing for straightforward emptying and cleaning of the collected debris (’031 Patent, Abstract; col. 2:20-53).
- Technical Importance: This modular, two-shell design sought to improve the user experience by simplifying the process of filter maintenance while maintaining hydraulic performance (’031 Patent, col. 1:53-65).
Key Claims at a Glance
- The complaint asserts one or more claims, "including but not limited to claim 1" (Compl. ¶31).
- Independent Claim 1 requires, in essence:
- A body with an inlet, outlet, and filtration chamber.
- A filtering device with a "first shell" that defines a "debris recovery space" and a "second shell" fitted to the first to act as a water inlet.
- The two shells fit together to form a single, "integral filtering casing" that is "removable in one piece" from the cleaner's body.
- After removal, the two shells can be moved relative to each other to empty the retained debris.
U.S. Patent No. 8,393,029 - "Apparatus For Cleaning A Submerged Surface Including A Brushing Device Driven By Members For Driving The Apparatus On The Submerged Surface," issued March 12, 2013
The Invention Explained
- Problem Addressed: The patent identifies shortcomings in how prior art pool cleaners power their scrubbing brushes. Some systems used complex mechanisms separate from the drive wheels, making the device heavy and expensive. Other systems linked the brush directly to the wheel, but this could limit brushing effectiveness and complicate maintenance (’029 Patent, col. 1:46-col. 2:9).
- The Patented Solution: The invention proposes a specific gear mechanism where a drive wheel is fitted with an "internally toothed ring." A pinion connected to the brush assembly engages these internal teeth. A key aspect of this configuration is that the rotation of the wheel causes the brush to rotate in the same direction, providing a compact and efficient power transfer from the wheel to the brush (’029 Patent, Abstract; col. 3:20-29).
- Technical Importance: This drive mechanism aimed to provide a simple, robust, and easily maintainable method for driving a cleaning brush using the motion of the cleaner's wheels (’029 Patent, col. 3:30-44).
Key Claims at a Glance
- The complaint asserts one or more claims, "including but not limited to claim 1" (Compl. ¶41).
- Independent Claim 1 requires, in essence:
- A body with an inlet, outlet, and a pumping device.
- A wheel configured for rotation.
- The wheel has an "internally toothed ring."
- A brush assembly with a rotating brush and shaft.
- A "pinion engaging the internally toothed ring" and connected to the brush shaft, such that the wheel's rotation in a "first direction" causes the brush to rotate in the "first direction."
III. The Accused Instrumentality
Product Identification
The complaint identifies a range of robotic pool cleaners, including the Wybot C1, Wybot C1 Pro, Wybot C1 Max, Wybot S2, Wybot S2 Pro, Wybot S2 Solar, AquaClean, Winny HJ3172, Bugson, Bugson Plus, and Aquamoto Scrubo Pro (collectively, the "Accused Products") (Compl. ¶5).
Functionality and Market Context
The Accused Products are described as robotic pool cleaners manufactured and sold by the Defendant for use in the United States (Compl. ¶4). The complaint alleges that a new line of products (Wybot C1 and S2 series, AquaClean) are "non-materially different with respect to the infringing features" from an older line of products that were the subject of a prior ITC investigation (Compl. ¶26). The complaint references a "Customer Distribution Map" from the Defendant's materials showing the U.S. as a market, allegedly demonstrating intent to serve the U.S. market (Compl. ¶3).
IV. Analysis of Infringement Allegations
The complaint alleges that the Accused Products meet every limitation of at least claim 1 of each asserted patent and incorporates by reference exemplary claim charts that were not attached to the pleading (Compl. ¶¶ 32, 42). The infringement theory is summarized below.
’031 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a. a body comprising an inlet, an outlet, a filtration chamber, and a rear; | The main chassis and water-flow components of the Accused Products. | ¶32 | col. 2:10-15 |
| b. a filtering device positioned between the inlet and the outlet and comprising... (i) a first shell... to define a debris recovery space... and (ii) a second shell fitted to the first shell... | The Accused Products' filter cartridge is alleged to be a two-part assembly comprising a debris-holding portion and an inlet portion. | ¶32 | col. 2:20-35 |
| in which... the first and second shells are configured to be fitted together to form an integral filtering casing... removable in one piece... when the filtering casing is removed... one... may be movable relative to the other for emptying debris... | The Accused Products' filter cartridge is alleged to be a single unit that can be removed from the cleaner and subsequently separated into two parts for cleaning. | ¶32 | col. 2:36-53 |
’029 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a. a body comprising (i) an inlet and (ii) an outlet separate from the inlet; b. a pumping device configured... | The main chassis and pump system of the Accused Products. | ¶42 | col. 7:5-15, 26-30 |
| c. a wheel configured for rotation and having an internally toothed ring; | The drive wheels of the Accused Products are alleged to contain an internal gear ring. | ¶42 | col. 3:20-22 |
| d. a brush assembly... comprising a brush and a shaft about which the brush rotates; | The rotating cleaning brushes on the Accused Products. | ¶42 | col. 3:14-17 |
| e. a pinion engaging the internally toothed ring and connected to the shaft so that rotation of the wheel in a first direction causes rotation of the pinion and the brush in the first direction. | The gear mechanism in the Accused Products that allegedly connects the internal wheel gear to the brush, causing them to rotate in the same direction. The complaint references the "Wybot C1 Operating Manual" as evidence of these infringing uses (Compl. ¶33). | ¶¶ 33, 42, 43 | col. 3:23-29 |
Identified Points of Contention
- Scope Questions: For the ’031 patent, a central question may be whether the accused filter assembly constitutes two distinct "shells" as claimed, or if it is a different structure, such as a single integrated basket with a lid. For the ’029 patent, a dispute may arise over the definition of "internally toothed ring" and whether the accused mechanism meets that specific structural limitation.
- Technical Questions: A key factual question for the ’029 patent will be whether the gear train in the Accused Products actually causes the brush to rotate in the same direction as the drive wheel, as explicitly required by claim 1. For the ’031 patent, the analysis may focus on whether the accused filter can be removed "in one piece" while the cleaner is "positioned upright," and whether its components function as the distinct "debris recovery space" and "inlet conduit" described in the patent.
V. Key Claim Terms for Construction
Term ('031 Patent): "a first shell" and "a second shell"
- Context and Importance: The infringement case for the ’031 patent hinges on whether the accused filter cartridge can be characterized as being composed of two separate "shells" that are "fitted together." The definition will determine if a more integrated filter design falls within the claim scope.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the two shells being fitted together to form an "integral filtering casing," which might suggest that as long as two separable components perform the recited functions and form a single unit for removal, they meet the limitation (’031 Patent, col. 2:36-39).
- Evidence for a Narrower Interpretation: The patent abstract and figures distinguish the shells by function, with the first acting as a "pocket for recovering debris" and the second as a "liquid inlet conduit." Figure 7 depicts two clearly distinct and separate structural components (49 and 55), which could support a narrower construction requiring two physically discrete parts even before assembly (’031 Patent, Abstract, Fig. 7).
Term ('029 Patent): "internally toothed ring"
- Context and Importance: This term is central to the specific mechanical linkage claimed in the ’029 patent. Whether the accused products infringe will depend on whether their drive mechanism includes a gear that meets this description.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language does not specify the precise location or configuration of the ring, potentially covering any toothed surface on the inner circumference of the wheel.
- Evidence for a Narrower Interpretation: Figure 4 of the patent illustrates a specific embodiment where the toothed ring (5) is a peripheral component of the wheel (2), with a pinion (42) engaging it from inside the wheel's diameter. A defendant may argue this disclosure limits the term to a specific type of ring gear arrangement, excluding other gear types like face gears that might be placed on an inner surface of the wheel (’029 Patent, Fig. 4).
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement for both patents. Inducement is based on allegations that the Defendant provides operating manuals and instructions that guide end-users to operate the products in an infringing manner (Compl. ¶¶ 33, 43). Contributory infringement is based on allegations that the products are specifically made for infringing use and have no substantial non-infringing uses (Compl. ¶¶ 34, 44).
- Willful Infringement: Willfulness is a prominent allegation for both patents. The complaint grounds this claim in the Defendant's alleged knowledge of the patents from prior litigation, including an ITC investigation filed on July 29, 2022, and a pre-suit notice letter regarding the ’029 patent dated February 12, 2016 (Compl. ¶¶ 38, 43). The claim is further supported by allegations that the Defendant resumed infringement after representing to the ITC that it would stop, and then advertised on its website that it had not made any commitments to cease its activities (Compl. ¶¶ 26-27, 38).
VII. Analyst’s Conclusion: Key Questions for the Case
- A primary question will be one of procedural and equitable significance: What legal effect, if any, will Defendant’s alleged representations to the ITC that it would cease infringement have on the current case, particularly concerning the plausibility of the willful infringement allegations?
- A core issue for the ’031 patent will be one of structural definition: Can the two-part filter design of the accused products be mapped onto the claim language requiring a "first shell" and a "second shell," each with distinct structural and functional properties, or does it represent a non-infringing design alternative?
- A key evidentiary question for the ’029 patent will be one of mechanical operation: Do the accused products employ the specific gear train recited in claim 1—an internally toothed wheel ring engaging a pinion to produce same-direction rotation—or do they achieve brushing via a different, non-infringing mechanism?