Invalidity dossier
US 246987
timby
Added 9/23/2026, 8:07:34 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 246,987
Title: Subterranean System of Coast Defense
Patentee: Theodore R. Timby, of Nyack, Rockland County, New York
Patent Number: US 246,987
Application Filed: August 17, 1881
Granted/Published: September 13, 1881
Anticipated Expiration: September 13, 1898
Legal Status (as listed): Expired – Lifetime
Source: https://patents.google.com/patent/[US246987](/patent/US246987)/en
Purpose
The patent describes a subterranean fortification that, when not in use, can be lowered beneath or to ground level to be out of sight and concealed, and when needed can be quickly elevated to present a fully equipped, potentially revolving fort or tower for action.
Plain-Language Scope
The fort (C) sits within a water-tight pit (B) in the ground (AA). Water supplied from tanks (D) through pipes (E) and controlled by cocks (F) provides buoyant flotation to raise the structure; a waste-pipe (H) with cock (I) discharges water to lower it. The lower stories (cc) remain permanently underground and can serve as storage or quarters. The upper part is armor-plated with a casemate (K) housing guns (L), and above that a barbette (M) with a central lookout-tower (N). The whole fort rotates on a central pillar (P) via an internal gear (Q) and pinion (R), with a shaft (S) rotated by hand-wheel (T) and bevel-gears (U). A lookout platform (O) is raised and lowered independently by a hydraulic ram (piston V, cylinder W).
Claims
- The combination of a water-tight pit, a buoyant fort centered to rotate on a vertical axis within it, a top casemate sinkable within the pit, and water-supply connections of sufficient elevation and capacity to raise the casemate for action and lower it for protection.
- The combination, with pit B and revolving tower C, of the sloped embankment A', permitting gun discharge at moderate elevation while protected from enemy fire.
Not Established by the Excerpt
No assignee is named; no litigation, ownership transfers, validity analysis, or prior-art comparison is present. Classification and legal-status entries are auto-generated assumptions, not legal conclusions. Ordinary-level (AA), suggested mechanisms for revolving towers, and patent citations to Timby's earlier work are referenced but not detailed.
Generated 10/1/2026, 9:41:35 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 246987. The free-form analysis below may also discuss cases beyond this list.
No cases on file mention this patent. Upload a CSV or add a case manually in Admin → Manage litigation cases.
Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.