Invalidity dossier
US 4406266
Fuel metering and discharging apparatus for a combustion engine
Current assignee: Colt Industries Operating Corp
Added 9/20/2026, 5:21:14 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 — US 4406266 A
Title: Fuel metering and discharging apparatus for a combustion engine
Patent number / application: US 4406266 A; application US06/297,164
Inventor: Norbert W. Kiesling
Assignee: Colt Industries Operating Corp (original assignee and current assignee as listed); an assignment to Colt Industries Operating Corp. (a Delaware corporation) was recorded 1983-07-20, assigning Kiesling's interest.
Key dates: Priority/filing date 1981-08-28; application granted and published 1983-09-27; anticipated expiration 2001-08-28. Legal status listed as "Expired – Fee Related" (the listing notes legal status is an assumption, not a legal conclusion).
Purpose (per the supplied text): The invention "relates generally to fuel injection systems and more particularly to fuel injection systems and apparatus for metering fuel flow to an associated combustion engine."
Plain-language scope (per the supplied text): The description discusses prior-art efforts to meet NOx emissions standards, including exhaust gas recirculation to lower combustion temperature; overly rich fuel-air metering; ignition-timing retard; lower compression ratios; and a dual-bed catalyst approach (reducing catalyst near the engine, oxidizing catalyst downstream, with extra air supplied between the beds). It notes objections to such systems: high cost, added conduitry, air pump means, an extra catalyst bed, and a tendency to form ammonia that may or may not be reconverted to NOx in the oxidizing bed. The text also discusses fuel injection replacing carbureting apparatus, injecting fuel under superatmospheric pressure through individual nozzles directly into cylinders, and states that such systems are costly and have not proven generally successful because metered fuel flow must be provided over a very wide range — systems accurate at one end of the range being relatively inaccurate at the other.
Source: https://patents.google.com/patent/US4406266/en (fetched 2026-09-20T05:21:14.152Z)
What the excerpt does not establish: It does not provide the claims' text or the full description, the abstract, the figures/drawings, or the detailed structure of the disclosed apparatus. It therefore does not establish the precise metered elements, the injection/discharge configuration, or the claimed scope. Because the text is marked as excerpted with omitted portions, this overview is limited to the material supplied and does not assess prior art, validity, or ownership beyond the recorded assignment noted above.
Generated 10/1/2026, 10:02:46 PM
Cases on file (0)
Specific litigation cases in our database that name US patent 4406266. 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.