Invalidity dossier
US 2892197
Flush valve
Current assignee: Individual
Added 9/23/2026, 5:07:44 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 2,892,197 ("Flush valve")
Bibliographic data (as supplied). Title: "Flush valve." Patent number: US 2,892,197 (US2892197A). Application number: US589315A. Inventor: Emil W Flieder. Original assignee and current assignee: Individual (Google notes assignees "may be inaccurate" and that it performed no analysis). Priority/filing date: 1956-06-04. Publication (grant) date: 1959-06-30. Anticipated expiration: 1976-06-30. Legal status: Expired – Lifetime. Classification: E03D 1/30 and E03D 1/304, 1/306, 1/308 (cistern flush valves; with own buoyancy; articulated valves).
Purpose. The invention "relates to flow control valves and more particularly relates to toilet tank flush valves." The stated problem: after a period of use, mineral or other accumulation deposits on the valve element so that it will not tightly seat when closed, causing continuous leakage from the tank. Stated objects are to provide a simple, inexpensive flow control valve; a toilet tank flush valve whose element "will positively seat in water-sealing relation" despite normal mineral accumulation; and a valve element mounted both for movement toward and away from the valve seat and for movement transversely of the seat for accurate seating.
Plain-language scope (from the excerpt). A buoyant, smoothly rounded, spherically shaped valve element is mounted on a swingable mounting member that substantially encircles an annular valve seat. A shaft through the element's axis is journalled in bearings in the mounting member, so the element can rotate about that axis and can slide axially. The mounting member pivots on a shaft riding in elongated slots in frame arms, allowing movement transversely of the swing axis. An operating chain connected to the flush handle lifts the mounting member; buoyancy holds it up while water flows, and turbulent flow rotates the ball. Because the element seats in a different rotational orientation each time, mineral deposits are not concentrated in one area, so it seats tightly in water-sealing relation.
Source. https://patents.google.com/patent/US2892197/en
What the excerpt does not establish. It does not provide the full specification or complete claims (the claim text shown appears truncated), a complete drawing description, a numbered prior-art reference list, or any examiner citations. It does not establish inventorship beyond the listed inventor, ownership beyond the listed "Individual" assignee, validity, or the scope of unshown claims. No litigation or assignment history is addressed here, per instructions.
Generated 10/1/2026, 9:43:49 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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