Shenzhen Doumi International Trade Co., Ltd. v. Happiier, LLC, No. 2:26-cv-04311 (W.D. Wash., Seattle), is a declaratory judgment complaint filed November 5, 2026. The complaint says Doumi is a Chinese company based in Shenzhen that sells the accused liners on Amazon.com, and alleges, on information and belief, that Happiier is a Florida limited liability company based in DeLand, Florida. The complaint says Happiier sells products under the CrockPockets brand. It pleads that the action arises under the patent laws and the Declaratory Judgment Act, 28 U.S.C. §§ 2201 and 2202, with subject matter jurisdiction under 28 U.S.C. §§ 1331 and 1338(a), and bases personal jurisdiction and venue on the forum clause of the APEX agreement, which names the courts in King County, Washington. Doumi demands a jury trial.
The patent
U.S. Patent 12,702,250, titled Adjustable Cooking Divider System for Food-Heating Appliances, issued August 11, 2026 from application 19/079,559, filed March 14, 2025. Its face names Happiier, LLC as applicant and assignee and Emilie Wren and Patricia Schmitz as inventors. The patent states that it is a continuation-in-part of application 17/574,502, filed January 12, 2022, which issued April 1, 2025 as U.S. Patent 12,262,843.
What the complaint alleges
According to the complaint, Happiier submitted Amazon complaints under the '843 patent in August 2026, Amazon removed five listings and reinstated them on September 11, 2026 after receiving a non-infringement letter, and on October 8, 2026 Happiier executed an APEX agreement asserting claim 1 of the '250 patent. On October 13, 2026, Amazon told Doumi the listings would be removed unless, within three weeks, it resolved the claim with Happiier, agreed to neutral evaluation, or filed a declaratory judgment suit of non-infringement and gave Amazon a copy of the complaint.
Doumi contends that every claim requires a food-heating appliance, which it does not sell with its liners, and containers that maintain full contact with the appliance's heating surfaces, which it says its two separate silicone containers do not. On invalidity, it argues that claims 1, 10, and 17 are entitled only to a March 14, 2025 effective filing date because the full contact and heating surface language first appeared in that application, making Happiier's own 2022 parent publication prior art, and it also cites Korean Patent Application Publication No. 10-2017-0099164, U.S. Publication No. 2009/0095169, and its own Amazon sales since at least August 10, 2023. In the alternative, it pleads that the three claims are indefinite under 35 U.S.C. § 112(b), and it alleges that prosecution history estoppel, based on amendments and arguments made to overcome the York reference, bars Happiier from relying on the doctrine of equivalents for the claim limitations it says the liners lack.
Counts and relief
Count I seeks a declaration of non-infringement of the '250 patent and Count II a declaration that claims 1, 10, and 17 are invalid. The prayer also asks for an injunction, to the extent needed to carry out the judgment, against asserting adjudicated claims against Doumi, its products, or its customers, including through Amazon complaints; a finding that the case is exceptional under 35 U.S.C. § 285 with attorneys' fees; and costs.