Invalidity dossier
US 5449120
Added 9/21/2026, 10:30:42 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US5449120A
Title: Fuel feed apparatus of internal combustion engine
Patent number: US5449120A (application US08/165,310)
Inventors: Yasuhide Tani, Kiyoshi Nagata, Yoshihiko Ito
Original assignee: NipponDenso Co Ltd; current assignee listed as Denso Corp
Key dates: Priority date 1991-06-11; filing date 1993-12-13; publication/grant date 1995-09-12; anticipated expiration 2012-09-12. Legal status: Expired – Fee Related (as stated in the source; the source itself notes legal status is an assumption, not a legal conclusion).
Purpose and scope (plain language): The source text identifies this as a fuel feed apparatus for an internal combustion engine. The listed prior-art keywords—fuel, assist air, cover member, nozzle body, nozzle—indicate the disclosure concerns a fuel injector nozzle assembly in which "assist air" is used, with a cover member and nozzle body as structural elements. Classifications place it in low-pressure fuel-injection apparatus, injectors with air chambers/openings for aerating nozzles (F02M69/047), injectors injecting into the intake conduit downstream of an air throttle valve (F02M69/044), injection nozzles and valve-seat details (F02M61/18), and controlling fuel injection where fuel is injected by compressed air (F02D7/02).
What the excerpt does not establish: The supplied text contains no abstract, no claims, and no written description or drawings. It therefore does not establish the specific claimed structure, the exact arrangement or operation of the assist-air, cover-member, or nozzle-body features, the number or wording of claims, or any measured performance. It also does not establish litigation, ownership transfers beyond the recorded assignment entry, validity, or the content of any prior art. Citation counts and detailed description are omitted from this excerpt. No statement here should be treated as a legal conclusion.
Source: https://patents.google.com/patent/[US5449120](/patent/US5449120)/en
Generated 10/1/2026, 10:01:34 PM
Cases on file (0)
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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.