Two Amazon Sellers Ask a New York Court to Declare a Portable Oil Pump Patent Invalid After Their Listings Were Removed.

The parties and the patent

The case is Hangzhou Checheng Technology Co., Ltd. v. Star Smart Limited, No. 1:26-cv-08974 (S.D.N.Y.). Checheng, a Chinese company based in Hangzhou, operates the Atutos Amazon storefront, and Jianfeng, a Hong Kong company, operates the Jianfeng US storefront. The complaint describes Star Smart as a Hong Kong company that sells under the CADALU brand. U.S. Patent 12,473,848, Portable Oil Pump With Charging Function, issued November 18, 2025 from an application filed May 22, 2025.

What the patent covers

Claim 1 covers a portable oil pump with a main unit, a pumping pipe with the pump body inside it at the end away from the main unit, and an outlet pipe connected to the pumping pipe near the main unit, where the main unit holds a circuit board, a rechargeable battery, and a power interface. A charging unit, a main control unit, and a driving unit are integrated on the circuit board: the charging unit converts power from the interface to charge the battery, the main control unit switches battery power to the pump through the driving unit, and the power source connected to the interface has a voltage range of 5V to 75V.

What the complaint alleges

The complaint says Amazon notified Jianfeng on August 10, 2026 that the patent had been asserted against its listing through Amazon's patent evaluation procedure and later removed it, and that a September 2, 2026 complaint submitted under the CADALU name led Amazon to remove Checheng's listing. It says the plaintiffs' pumps do not meet claim 1, including the 5V to 75V range. It alleges that the claims are invalid under 35 U.S.C. 102, 103, and 112, including obviousness over references such as U.S. Patent 11,686,297, four Chinese publications, and charging-chip datasheets, and lack of written description and enablement under 35 U.S.C. 112(a) for the 5V to 75V range.

The tortious interference count alleges, on information and belief, that Star Smart's representations to Amazon were objectively baseless and made in bad faith, with knowledge that the claimed combination was in the prior art or in reckless disregard of it. The complaint says Checheng estimates its lost sales to date at not less than $47,308 and Jianfeng at not less than $29,592.60, and that 459 and 740 units, respectively, are stranded in Amazon fulfillment centers.

Relief requested

The plaintiffs ask for declarations of invalidity and non-infringement under the Declaratory Judgment Act, 28 U.S.C. 2201; an order requiring Star Smart to withdraw, within three business days, Amazon Complaint ID 21422850121, the patent evaluation assertion against Jianfeng's listing, and any other assertion of the patent against their listings, and to notify Amazon in writing; a preliminary and permanent injunction against asserting or threatening to assert the patent against them, their products, or their customers, including through Amazon or any other online marketplace; compensatory damages on the tortious interference count with pre-judgment and post-judgment interest; fees under 35 U.S.C. 285; and costs. The complaint does not include a jury demand.

What it means

This is one of two declaratory judgment suits filed by Amazon sellers between October 9 and October 11, 2026 after patent owners used Amazon's enforcement procedures. The complaint pleads personal jurisdiction over the Hong Kong patent owner under Federal Rule of Civil Procedure 4(k)(2), alleging that Star Smart has no presence in any state and directed its patent enforcement at the United States as a whole, and in the alternative under New York's long-arm statute, N.Y. C.P.L.R. 302(a), based on its Amazon sales into New York.

What to watch next

Watch for service on Star Smart, any motion to dismiss for lack of personal jurisdiction, and whether Amazon reinstates the listings while the case is pending.