Oxygenator Water Technologies, Inc. V. Tennant Company

Case Background

On January 27, 2020, Oxygenator Water Technologies, Inc. (OWT) filed a patent infringement lawsuit against Tennant Company (“Tennant”). The case was filed in the United States District Court for the District of Minnesota (D. Minn.). The case was assigned to Judge Katherine M. Menendez and referred to Magistrate Judge David T. Schultz. [Case Number: 0:20cv358]

Cause

Oxygenator Water Technologies, Inc. (OWT), a Minnesota company, accused Tennant, another Minnesota company, of using its patented technology without permission. OWT claimed Tennant’s ec-H2OTM electrolysis modules, found in its floor scrubbers, relied on OWT’s patented method for producing micro and nanobubbles of oxygen in water.

According to OWT, Tennant had known about its technology and patents since at least 2007. Despite being approached, Tennant refused to license the technology. OWT’s complaint outlined how Tennant’s products matched the patented technology’s key features. It also accused Tennant of both direct and indirect infringement.

Damages

OWT pursued damages, additional compensation for willful infringement, legal costs, and attorney fees. It also sought a permanent injunction to stop Tennant from further using its technology.

Key Arguments and Proceedings

Legal Representation

  • Plaintiff(s): Oxygenator Water Technologies, Inc.
    • Counsel for Plaintiff(s): Aaron W. Pederson | Hannah Mosby O’Brien | J Derek Vandenburgh | Nathan Louwagie | Philip P Caspers | Richard Willets Ely
  • Defendant(s): Tennant Company
    • Counsel for Defendant(s): Bob Oakes | Douglas E. McCann | Jon Bell | Joseph B. Warden | Madison Murhammer Colon | Martina (Tyreus) Hufnal | Nitika Gupta | Taylor Reeves |

Claims

Claim 1: Patent Infringement of U.S. Patent No. RE45,415 – Cylindrical Electrode Products

OWT claimed that Tennant infringed U.S. Patent No. RE45,415, which covers cylindrical electrode technology. OWT alleged that Tennant used the patented technology in its electrolysis modules and floor scrubbers. The complaint stated that Tennant’s products matched the patent’s technical specifications, including water flow rates and electrode configurations. OWT further alleged that Tennant knew about the patents since at least 2007 but refused to license the technology. OWT sought damages and an injunction to prevent further infringement.

Claim 2: Patent Infringement of U.S. Patent No. RE45,415 – Plate Electrode Products

The Plaintiff claimed that Tennant’s plate electrode products, including electrolysis modules and floor scrubbers, infringed U.S. Patent No. RE45,415. OWT identified specific models, such as part no. 1208164 (plate electrode) and part no. 9011810 (plate electrolysis module), as representative examples. Tennant’s floor scrubbers generate an oxygenated solution using ec-H2O NanoClean® technology. OWT alleged that Tennant directly and indirectly infringed the patent, even after receiving formal notice in 2019. The Plaintiff sought damages and an injunction to prevent further violations.

Claim 3: Patent Infringement of U.S. Patent No. RE47,092 – Cylindrical Electrolysis Products

OWT asserted that Tennant infringed U.S. Patent No. RE47,092, which relates to cylindrical electrolysis modules and floor scrubbers. OWT argued that Tennant’s products met the technical limitations of the patent, including the use of a flow-through oxygenator system with two electrodes. Tennant marketed these products as “ec-H2O” and used them in demonstrations. OWT claimed Tennant continued selling the products despite receiving notice of the infringement. The Plaintiff sought damages and an injunction to prevent further infringement.

Claim 4: Patent Infringement of U.S. Patent No. RE47,665 – Cylindrical Electrolysis Products

OWT claimed that Tennant’s products, including cylindrical electrodes and electrolysis modules, infringed U.S. Patent No. RE47,665. The Plaintiff argued that Tennant’s technology, which produced oxygen bubbles through electrolysis, matched the patent’s claims. OWT cited Tennant’s promotion of the technology as ec-H2O. Despite formal notice of the infringement, OWT alleged that Tennant continued selling and promoting the infringing products. The Plaintiff sought damages and an injunction to prevent further infringement.

Claim 5: Willful Infringement

OWT argued that Tennant’s infringement was willful. The Plaintiff claimed Tennant was aware of OWT’s patents since at least 2007 but took no action to avoid infringement. Tennant did not modify its product design or seek a license from OWT. The Plaintiff contended that Tennant’s failure to address the infringement was deliberate and egregious. OWT sought enhanced damages due to the willful nature of the infringement.

Defense

In August 2020, Tennant responded to the lawsuit by denying any infringement and raising defenses, including claims that the patents were invalid. It also filed counterclaims, arguing the patents failed to meet patentability requirements and had been anticipated by prior inventions. Tennant sought court rulings to declare the patents invalid.

Jury Verdict

The case went to trial after Oxygenator had secured rulings that Tennant’s products infringed two patents. The jury deliberated on the infringement of the third patent. On November 25, 2024, before Judge Katherine M. Menendez, the jury delivered a verdict. Tennant was ordered to pay $9,815,595 for selling 18,558 infringing scrubbers. The jury also found Tennant’s infringement to be “willful.”

Court Documents:

Documents are available for purchase upon request at jurimatic@exlitem.com