Invalidity dossier
US 3270441
Reduced gravity simulator
Current assignee: Individual
Added 9/17/2026, 12:57:59 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 3,270,441
Title: Reduced gravity simulator
Patent number: US 3,270,441 A
Inventors: Donald E. Hewes; Amos A. Spady, Jr.
Assignee: None identified beyond "Individual" (original assignee listed as Individual; no corporate assignee appears in the supplied text)
Dates: Application filed 1963-08-26; priority 1963-08-26; patent granted and published 1966-09-06; anticipated expiration 1983-09-06. Legal status shown as "Expired – Lifetime." The source notes the legal status and priority date are assumptions, not legal conclusions.
Purpose: The patent relates to a reduced gravity simulator system for simulating reduced and zero-gravitational fields, such as those of space stations and celestial bodies. It aims to determine the effects on man's self-locomotive capabilities when subjected for a sustained period to a gravitational field less than Earth's. The text states it can now be predicted that when man arrives on the Moon he will be able to walk, run, jump vertical distances of 12 to 14 feet without injury in falls, and climb slopes, stairs, and ladders, with additional tests possible for various space suits.
Plain-language scope: The system supports individual external body members of a test subject so each can move only in the plane parallel to the body's plane of symmetry, then inclines the subject relative to the vertical gravity vector so the in-plane gravity component equals the desired simulated reduced gravity. In one embodiment, a cable suspension system connects a movable trolley on an overhead monorail track to body harness support members. The trolley follows an inclined walkway surface parallel to and angularly displaced from the vertical plane through the trolley's path. The text describes simulating lunar gravity (an angle of about 80.5 degrees from vertical) by effectively canceling five-sixths of Earth's gravitational force, and notes zero gravity would be simulated with the subject horizontal and the walkway vertical beneath the trolley.
What this excerpt does not establish: It omits the actual claims, most of the detailed description, the figures' contents, and the full reference numerals. It does not identify a corporate assignee, any prior-art references, or the complete list of advantages. Nothing about litigation, ownership transfers, or validity is addressed here, and no such matters were researched.
Generated 10/1/2026, 10:03:13 PM
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Litigation summary
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Proceedings on file (0)
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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
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.