US 6332448

I'll search for authoritative information on US patent 6332448, including any litigation or CAFC docket activity.

Let me search specifically for litigation and CAFC docket activity involving this patent.

Let me do a final targeted check for any litigation/PTAB/CAFC activity.

US Patent 6,332,448 — Analyst Summary

Search scope and caveat on litigation

I searched for this specific number across patent databases and for any court/CAFC activity. I found no litigation, PTAB proceeding, or CAFC 2026 docket involving US 6,332,448. The only "6332448" hits in court-related sources are citations of this patent as prior art in other parties' proceedings (e.g., an exhibit in Ford v. MIT, IPR2021‑00339/00340), not litigation against the '448 patent itself. This is consistent with the patent having expired around 2020, which makes active 2026 enforcement litigation improbable. I cannot rule out a docket I did not surface, but I have no authoritative evidence of one.

Bibliographic data

Literal-identifier notes (no auto-correction): The authoritative patent text renders the first inventor's surname as "Ilyama"; the USPTO assignment record in the same document renders it "IIYAMA". I report both as found. Some databases (e.g., Unified Patents) list the priority/filing dates as 1999‑05‑31 / 2000‑05‑31 and the grant as 2001‑12‑24, one day earlier than the patent front page — a common time‑zone/database artifact. The authoritative front‑page values are the ones in the table.

Abstract (verbatim substance)

In a fuel supply device supplying fuel from a main tank (8) to a vehicle engine (20), a fractional distiller (9) fractionates the fuel into a high octane and a low octane component, stored in subtanks (10, 11). The high‑octane component is supplied by a high‑pressure intermittent pump (16) and the low‑octane component by a variable‑pressure pump (15) to a fuel injector (17). A controller (1) identifies a running region from engine speed and load, determines the proportion of the components accordingly, and controls the variable‑pressure pump discharge pressure to achieve that proportion. When one subtank's storage falls below a minimum, the proportion supplied from the other tank is increased.

Plain-language overview of the claims

Only Claim 1 is truly independent. Claims 2–12 depend (directly or indirectly) on claim 1; claims 13–16 reference claim 1/15 and add limitations. Overview:

Claim 1 (the sole independent claim)

A fuel‑supply apparatus for an internal combustion engine that combines four elements:

1. A separating device that splits the tank fuel into plural fuel components (realized here as high‑ and low‑octane fractions);
2. A sensor detecting an engine running condition (here, load and rotation‑speed sensors);
3. A supply mechanism that feeds those components to the engine in different proportions depending on running condition — specifically a microprocessor that determines the proportion and a fuel injector that injects accordingly; and
4. A control algorithm for a compression self‑ignition engine that increases the high‑octane share in a first (high) load region and increases the low‑octane share in a second, lower load region.

Key dependent claims worth noting

• Claim 2 — adds first/second subtanks with storage‑amount sensors, and the microprocessor varies the proportion based on those storage amounts.
• Claim 3 — supply only low‑octane fuel when the high‑octane (first) subtank is at/below a first threshold while the low‑octane (second) tank is above a second threshold.
• Claim 4 — as in claim 3, plus shifting the automatic transmission's speed‑change schedule to compensate for torque loss from using low‑octane fuel.
• Claim 5 — the mirror case: supply only high‑octane fuel when the low‑octane tank is low and the high‑octane tank is sufficient.
• Claim 6 — at intermediate loads (between the first and second load regions), compare the two tanks and increase the share of whichever component has the larger stored amount.
• Claim 7 — same "use the larger stored share" logic, but applied during spark‑ignition operation.
• Claim 8 — in the first (high‑) load region, if the high‑octane tank is low, increase the low‑octane share and run it in compression self‑ignition.
• Claim 9 — builds on claim 8: if the high‑octane tank hasn't recovered after increasing the low‑octane share, further increase low‑octane and use the spark plug for auxiliary sparking to promote free‑radical formation.
• Claim 10 — in a predetermined load region with the low‑octane tank low, increase the high‑octane share and use a "device for modifying" the high‑octane fuel (e.g., a spark plug performing auxiliary sparking, per claim 11).
• Claim 12 — analogous to claim 9 but for the low‑octane‑shortage side, using auxiliary sparking as the modifying action.
• Claim 13 — the supply mechanism includes one subtank per fuel component (equal number).
• Claim 14 — the separating device is a boiling‑point‑difference separator plus a cooler that liquefies the separated component.
• Claim 15 — the separating device uses plural silica‑gel adsorbers with heaters that vaporize the adsorbed high‑octane component to regenerate the filter.
• Claim 16 — adds valves routing the remaining (low‑octane) fuel to a subtank and the desorbed high‑octane vapor to the first subtank via a cooler.

Bottom line

US 6,332,448 is a single‑independent‑claim Nissan patent (claim 1) covering an on‑board fuel‑separation, dual‑octane fuel‑supply strategy for a compression‑self‑ignition/spark‑ignition engine, with extensive dependent coverage of storage‑balance management, auxiliary sparking, and silica‑gel separation. Its practical term has lapsed (expired ~2020), and I found no CAFC 2026 docket or litigation concerning it. Where databases disagree on exact dates, I have flagged the discrepancy and deferred to the authoritative patent front page.

I'll search for litigation involving US patent 6332448 across patent litigation databases.

Let me run additional targeted searches to confirm whether any litigation exists.

Let me check a few more dedicated litigation sources to be thorough.

Litigation Search Results — U.S. Patent No. 6,332,448

Bottom line: I found no known litigation involving U.S. Patent No. 6,332,448.

The patent at issue

Sources checked and what they showed

1. Unified Patents litigation/patent portal — The dedicated patent page for US-6332448-B1 (https://portal.unifiedpatents.com/patents/patent/US-6332448-B1) lists bibliographic data, classification, patent art, and "Referenced By" and "Patent Art" sections. It surfaced no litigation records or case list for this patent.

2. Google Patents (https://patents.google.com/patent/US6332448/en) — The record shows the citation family (18 cited references, 66/159 citing publications) and the EP/DE family members (EP1057988B1, DE60025412T2), but no "Litigation" section or asserted-in-suit entries.

3. General web searches for "6332448 litigation," "6332448 patent lawsuit," "6332448 District Court complaint," and Nissan-related queries — Returned no infringement suits, declaratory judgment actions, IPR/PGR proceedings, or ITC investigations naming this patent.

Important caution about false positives

Several results in a naive "244"/"448" search are unrelated patents and should not be attributed to US 6,332,448:

• References to "'244 patent" in the Strategt v. Intel litigation and InterDigital v. ZTE proceedings concern different patents that happen to end in "244" (e.g., a 7,xxx,xxx patent), not US 6,332,448.
• The Align/3Shape, MOSAID/Powerchip, and Bilfinger (Hendrick) complaints involve patents such as US 6,980,448, US 8,297,448, etc. — not 6,332,448.
• A Docket Alarm hit for "6332448" was a prior-art citation list in an IPR exhibit (Ilyama et al., 2001-12-25), not a litigation docket.
• The "Glycine from China, India, Japan, and Thailand" ITC notice referring to "'448" patents relates to Align's orthodontic patents, unrelated to Nissan.

Conclusion

Based on the sources available (Unified Patents portal, Google Patents, and general litigation-focused web searches), there is no record of known litigation involving US Patent No. 6,332,448. This is consistent with the patent's status: it expired on 2020-06-01, and it appears never to have been asserted.

Caveat / confidence note: Public free databases (Unified Patents, Google Patents) do not index every historical district court docket, and RPX/DPI "Insight" products are partly paywalled. My conclusion is that no litigation is known, but I cannot rule out an unindexed, sealed, or very old docket entry with absolute certainty. To be fully certain, a paid Docket Navigator or LexisNexis PatentAdvisor search, or a direct PACER/CAFC query, would be the definitive check — and I was unable to complete those final queries within this session. If you have access to Docket Navigator or PACER, searching the patent number "6,332,448" (and application "09/584,403") there is the recommended next step.

I'll verify the PTAB record against public sources before drafting.

The first search returned an EDTX/IPR snippet referencing a "'448 patent" — I need to determine whether that is this patent (which expired 2020-06-01) or a different one.

The ACT/Google "'448" is US 9,042,448 — a different patent. Let me do a final confirmation sweep for any AIA trial or litigation touching US 6,332,448 specifically.

Proceedings overview

Total AIA trial proceedings on file for US 6,332,448: 0. The USPTO Open Data Portal structured block returns no IPR, PGR, or CBM proceedings, and my independent web sweep (PTAB petition documents on ptacts.uspto.gov, PTAB/docket aggregators, and CourtListener) surfaced no petition, institution decision, final written decision, appeal, or settlement naming US 6,332,448 as the challenged patent. Breakdown by status: active 0 / claims invalidated 0 / claims sustained 0 / settled 0 / institution denied 0.

The bottom line for a defendant is not "the patent is hardened by surviving IPRs" — it is stronger than that and simpler: the patent is expired and, as of 2026-06-01, its § 286 damages lookback window has closed. Per Google Patents' bibliographic data, the anticipated expiration was 2020-06-01 (20 years from the 2000-06-01 filing date), with legal status "Expired – Lifetime." All 16 claims are therefore UNTESTED (never adjudicated anywhere) and UNENFORCEABLE going forward, and any new assertion of this patent is a demand-letter problem rather than a litigation problem. There is no IPR-based defense to run, because there is no live case in which to run one.

⚠️ Do not confuse this patent with US 9,042,448. Web searching for "'448 patent" + PTAB returns a busy, live campaign — Google LLC v. Advanced Coding Technologies LLC, IPR2025-01278 (filed 2025-07-11) and IPR2025-01070, on US 9,042,448, litigated in Advanced Coding Technologies LLC v. Google LLC, No. 2:24-cv-00353-JRG (E.D. Tex.) and ACT v. Apple Inc., No. 2:24-cv-00572-JRG (E.D. Tex.). That is a 2015-family video-coding patent owned by a holding company (ACT). It shares only the last three digits with the Nissan patent at issue here. Any due-diligence memo that mixes these up will be badly wrong in both directions — I flag it explicitly because the search results are dense with it.

Nearest-miss records (for completeness — none is a proceeding on this patent)

There is no proceeding to profile, so the format's per-proceeding blocks are vacuous. Instead, here are the three near-misses I ran down and eliminated, so no one re-runs this search:

US 9,042,448 / IPR2025-01278 (Google v. Advanced Coding Technologies) — Not this patent. Different patent number, different owner, different technology (AV1 video coding), different expiration. Grounds in that petition are §§ 102/103 over Phek in view of Martins and He (Ground 1) and Sakazume in view of Martins and He (Ground 2), with a substantial Advanced Bionics / General Plastic / Fintiv discretionary-denial fight. See RPX Insight docket.

IPR2021-00340 (Inter Partes Review of U.S. Pat. No. 10,781,760) — Not this patent. US 6,332,448 appears there only as prior art cited in the file history of the challenged patent (Exhibit 1019, listing "6332448 / 2001-12-25 / Ilyama et al." among references). A patent appearing in another party's IDS list is not a proceeding against it.

Unified Patents portal profile for US-6332448-B1 (portal.unifiedpatents.com) — Not a proceeding. This is Unified's descriptive patent database page. Unified Patents is a defensive aggregator, and it has not filed any AIA challenge against this patent; there is no "Unified Patents, LLC v. Nissan Motor Co., Ltd." record anywhere in the PTAB corpus. Note also that this page lists expiration as 2020-05-31 (vs. Google Patents' 2020-06-01) — a one-day discrepancy from priority/filing-date convention, immaterial to the analysis, and "Lifetime Renewal Fees: $0," which I cannot verify as a maintenance-fee lapse and do not rely on. The controlling fact either way is that the patent term has run.

Strategic summary

Claim status of all 16 claims: UNTESTED. Not one claim of US 6,332,448 has ever been construed, instituted against, or adjudicated by the PTAB, the Federal Circuit, or (so far as public records show) any district court. Claim 1 is the sole independent apparatus claim; claims 2–12 depend from it, claim 13 depends from claim 1, claim 14 depends from claim 1, claim 15 depends from claim 2, and claim 16 depends from claim 15. Because there is no FWD, there is no narrowing, no certificate of cancellation, and no surviving-claims list — the full original claim set is what it has always been: expired, unadjudicated, and presumptively valid on paper. That distinguishes it from a typical "IPR-hardened" or "IPR-killed" posture. The patent was never tested because there was no economic reason to test it: it was a 1999-priority Nissan engine-control filing that expired in 2020 without ever being asserted.

Estoppel landscape: none exists, and none needed. No IPR reached final written decision, so § 315(e)(2) estoppel has never attached to anyone — there is no petitioner, no RPI, and no privy carrying a "raised or reasonably could have raised" bar. The entire prior-art universe is technically unencumbered. But this is academic: the invalidity art is no longer the interesting defense. The dispositive defenses are expiration and the § 286 six-year damages bar. Since the patent's last possible infringing act was on or about the 2020-06-01 expiration date, a complaint filed on or after 2026-06-01 cannot reach any compensable act of infringement — the lookback window had already closed before today's date (2026-10-01). An accused infringer today should be thinking about Rule 11 / § 285 exposure on the plaintiff's side, not about IPR strategy. (I am applying the statute as written; a plaintiff may argue equitable tolling or some other theory, so treat this as a strong practical position rather than a legal opinion.)

Pattern signals: absent rather than adverse. The same-petitioner-multiple-IPR pattern does not exist here (no petitioner at all). The patent owner, Nissan Motor Co., Ltd., has not pursued PTAB appeals on this patent — there is nothing to appeal. No defensive aggregator has touched it. Foreign family members exist (EP1057988B1, DE60025412T2) but no AIA-relevant U.S. continuation activity. The one pattern worth noting is citation pattern, not challenge pattern: US 6,332,448 is heavily cited as prior art in later multi-fuel/octane-on-demand work (Ford Global Technologies, ExxonMobil, Saudi Aramco, and the Chinese counterpart CN101169080B all cite it), which is consistent with it being a foundational reference in the field rather than a commercially asserted asset.

Recommended next steps

• If you have received a demand letter citing US 6,332,448, do not file an IPR. It would be a waste of $150k–$450k. The patent expired 2020-06-01 (Google Patents bibliographic record) and the six-year damages lookback under 35 U.S.C. § 286 closed on 2026-06-01 — before today. Respond with the expiration date, the expired status, and the § 286 bar. There are no live claims to invalidate.
• Do not cite an FWD here. There is no Final Written Decision to link to or quote, because no trial was ever instituted. If a colleague or an outside counsel memo hands you a PTAB citation for "the '448 patent," check the digit count first — it is almost certainly US 9,042,448 / IPR2025-01278 (Google v. Advanced Coding Technologies), which is an entirely different, unexpired, actively-litigated patent.
• If you are evaluating this patent for acquisition, licensing, or as blocking art: the acquisition/licensing value is nil (expired), but the prior-art value is real and documented — it is cited by a broad family of later octane-on-demand and on-board fuel-separation patents and appears in third-party IDS lists (e.g., the IPR2021-00340 Exhibit 1019 file-history listing). Use it as § 102/§ 103 art against live patents in that space; a printed publication's date, not its claim set, is what matters.
• On the "absence is a signal" point: normally, zero PTAB activity on an asserted patent is a yellow flag suggesting the defendant should look harder at parallel litigation, ownership changes, or an ITC action. Here the absence has an innocent and fully documented explanation — the patent expired before the assertion wave in this technology space began. There is no hidden campaign to find. I verified this against PTAB petition filings (ptacts.uspto.gov), PTAB docket aggregators, and CourtListener; if a defendant's counsel nonetheless turns up a proceeding number I did not see, it would not change the outcome, since expiration and the § 286 bar dispose of the patent regardless of claim validity.

I'll research this patent's assignment history and any assertion activity before writing up.

Let me check for any post-issuance transfers or litigation involving this patent.

Ownership Analysis — US 6,332,448 B1

Patent: Fuel supply apparatus of internal combustion engine
App.: 09/584,403 · filed 2000-06-01 · issued 2001-12-25
Priority: JP 11-154089, filed 1999-06-01 (Tokugan Hei 11-154089, incorporated by reference)
Status: Expired – Lifetime (anticipated expiration 2020-06-01)

Source-access note (read first): I could not open a live USPTO Assignment Center session from this environment. The assignment facts below are reconstructed from the Google Patents legal-events register (which mirrors USPTO assignment data) and cross-checked against Unified Patents' patent portal and Espacenet. Google Patents' legal-events list for this patent contains exactly one assignment entry and zero post-issuance transfer entries. Reel/frame numbers are not exposed by that mirror — verify by patent number at https://assignmentcenter.uspto.gov/ before relying on this for standing or chain-of-title opinions.

Inventors

Both inventors appear as assignors on the sole recorded assignment, conveying to Nissan Motor Co., Ltd. There is no evidence in any accessible register of either inventor departing Nissan within 12 months of filing, and no evidence of any subsequent inventor-side instruments (no confirmatory assignments, no nunc pro tunc corrections, no release/quitclaim filings). The two-inventor, single-employer profile is the ordinary corporate R&D pattern — this is a works-made-for-hire portfolio patent, not an inventor-owned patent later acquired by a third party.

Original assignee

Nissan Motor Co., Ltd. (2, Takara-cho, Kanagawa-ku, Yokohama, Japan) — named on the face of the issued patent, and confirmed as both original and current assignee by Unified Patents' portal ("Parent Company: Nissan Motor Co Ltd") and by Google Patents' current-assignee field.

• Primary line of business: mass-market automobile manufacturing (Nissan and Infiniti brands), including engines and powertrain control systems — the direct field of the claimed subject matter.
• Did they ship a product embodying the claims? Unclear / likely no product embodiment. The claims are drawn to a vehicle fuel system that fractionally distills or adsorbs tank gasoline on-board into high-octane and low-octane streams, stores them in separate subtanks, and meters them through a single injector to support compression self-ignition (HCCI) combustion. This is a research/feasibility architecture; no commercially sold Nissan vehicle is publicly documented as shipping an on-board gasoline fractional distillation system. The specification itself reads as a laboratory-and-simulation study (yield figures of 45%/55% RON108/RON94 at an 80 °C cut, engine-coolant-heated radiator, battery-powered electric heater). Nissan did continue prosecuting the general self-ignition/HCCI family (e.g., JP 4470951, "Combustion control device for internal combustion engine", 2007), which suggests continuing R&D interest rather than a product line.
• Current status: Operating. Nissan Motor Co., Ltd. remains an active, publicly traded global automaker. It is not in bankruptcy and has not been dissolved or acquired. Note: Nissan's alliance restructuring (Renault–Nissan–Mitsubishi) is a corporate-governance matter and is not a patent-title event — no assignment to any alliance holding entity for this patent is recorded.

Assignment timeline

Only one assignment is recorded. There is no post-issuance assignment chain for this patent.

• 2000-06-01 (executed, presumed concurrent with filing) / recorded 2000-08-24 — Reel/Frame not exposed by the accessible source (Google Patents legal events lists the event without reel/frame; obtain it from USPTO Assignment Center)
  • Conveyance: Assignment of assignors' interest (original employment/invention assignment)
  • Assignor: Akihiro Iiyama; Hiroshi Miyakubo (individually)
  • Assignee: Nissan Motor Co., Ltd.
  • Correspondent of record: Not stated in the accessible mirror. Separately, the prosecution attorney/agent of record on the issued patent's front page is Foley & Lardner (Primary Examiner: Erick Solis). This is prosecution counsel, not evidence of an assignment-recording correspondent, and cannot be used as a repeat-player tell.
  • Context: Ordinary corporate acquisition of employee inventions at filing — not a fire-sale, reorg, securitization, or transfer-to-asserter.

No other events. Specifically, there are no:

• Change of name (Nissan Motor Co., Ltd. has been the same legal entity throughout),
• Security agreements / collateral assignments / releases (nothing filed by any lender or collateral agent),
• Merger or entity-conversion conveyances,
• Assignments to any "IP / Patents / Licensing / Holdings / Ventures" entity,
• Corrective assignments.

The patent expired 2020-06-01 while still titled to Nissan. There is no terminal disclaimer, abandonment, or reissue in the record that would have altered ownership.

Absence-of-records finding: because the single recorded assignment is the original inventor→employer instrument and nothing follows it, the record affirmatively indicates Nissan Motor Co., Ltd. remained the sole owner from filing through expiration. A clean single-link chain with no downstream transfers is itself the central finding here.

Timeline diagram

timeline
    title Ownership of US 6332448
    1999 : Priority application filed in Japan
    2000 : US application filed by two Nissan inventors
         : Inventors assign rights to Nissan Motor
    2001 : Patent issued to Nissan Motor
    2020 : Patent expires still owned by Nissan
         : No assignments ever recorded

NPE / troll-pattern signals

Verdict

Insufficient data — and specifically, insufficient data because the record shows only the original assignment.

Justification: The USPTO-mirrored legal-events register contains exactly one recorded conveyance — the 2000-06-01 inventor-to-employer assignment from Akihiro Iiyama and Hiroshi Miyakubo to Nissan Motor Co., Ltd., recorded 2000-08-24 — with no post-issuance assignments, no security interests, no change-of-name filings, and no transfers to any licensing entity. The patent issued 2001-12-25 to Nissan and expired 2020-06-01 still titled to Nissan, so the ownership question is answered negatively rather than ambiguously. Not one of the eight NPE signals is present, and the only signal that could conceivably be scored (a shell transfer) is affirmatively absent.

Verification links:

• USPTO Assignment Center (search by patent 6332448): https://assignmentcenter.uspto.gov/
• Google Patents legal events: https://patents.google.com/patent/US6332448/en
• Unified Patents portal record: https://portal.unifiedpatents.com/patents/patent/US-6332448-B1
• Espacenet family: https://worldwide.espacenet.com/patent/search?q=US6332448

Caveat on completeness: I was unable to retrieve the reel/frame for the single recorded assignment, so I cannot rule out a defect that only appears in the recorded instrument image (e.g., a second patent number on the same cover sheet, or a companion application-level assignment). Anyone relying on this for a standing/chain-of-title opinion should pull the reel/frame directly from Assignment Center and confirm that no instrument recorded after 2000-08-24 lists US 6,332,448 among its properties.

I'll search for the patent and its cited prior art references.

I have the citation data. Let me verify the two most structurally similar references.

Prior-Art Analysis — US 6,332,448 B1

1. Patent identification (verified)

Sources: Google Patents US6332448, USPTO full-text PDF, Unified Patents, Justia.

Note on dates: The USPTO/Google record gives priority 1999-06-01, filing 2000-06-01, grant 2001-12-25. The Unified Patents record shows slightly shifted dates (priority 1999-05-31, application 2000-05-31, grant 2001-12-24) — a one-day offset, likely time-zone/JPO-convention artifacts. I did not auto-reconcile these; treat the Google/USPTO values as the primary record.

2. The invention in one line (claims at issue)

Claim 1 requires the combination of: (a) an on-board separating device that separates fuel in the fuel tank into plural components; (b) a running-condition sensor; and (c) a supply mechanism comprising a microprocessor + a single fuel injector that injects the plural components in a proportion determined from the running condition; with the components being high-octane and low-octane, the sensors being load and engine speed, the engine being a compression self-ignition (HCCI-type) engine, and the proportion being shifted toward high-octane at a first (higher) load region and toward low-octane at a second (lower) load region.

This is a combination claim. That matters: most cited art discloses only 1–2 of the three legs (on-board separation; octane-based fuel routing; load/speed proportioning), so most citations are § 103 material, not clean § 102 anticipators.

3. Most relevant prior art (ranked)

A. GB 2 330 176 A — Ford Global Technologies (the closest reference)

• Full citation: GB 2330176 A, "Fractional distillation of fuel and variable supply of fuel fractions for an internal combustion engine," Ford Global Technologies Inc., published 1999-04-14, priority 1997-10-09. Family: EP 1021650 B1 (granted 2002-04-24); US 6,311,649 B1.
• Descriptions: An i.c. petrol engine with a fuel tank and a distillation unit (boiler 30, compressor 50, condenser/reservoir 52) producing at least two fuel flows of different volatility; an engine management system separately meters the streams and adjusts the relative usage rates of each stream based on the rates at which they are produced; a level sensor 62 and a pressure/temperature sensor feed the EMS, which holds stored quantities constant.
• § 102 exposure: This is the only citation that discloses the core of claim 1 — on-board separation into plural components plus microprocessor-controlled proportioning of separately metered streams to the engine, with storage/reservoir sensors closing the loop.
  • Claim 1: potentially anticipatory as to elements (a), (b), (c), the "microprocessor determines a proportion," and the "separately metered streams" concept. Claim 1's octane framing, the load + rotation-speed sensors, the compression self-ignition engine, and the load-region rules are not disclosed — so claim 1 survives on those limits.
  • Claim 2: strong § 102 candidate — the reference expressly senses accumulated quantities of each fraction and varies relative usage rates accordingly.
  • Claim 14: strong § 102 candidate — separation "according to a difference of boiling points" plus a cooler/condenser that liquefies the separated vapor is squarely described.
  • Claim 13: arguably anticipated (multiple fuel fractions stored/held in reservoirs).
• Source: EPO PISE record for EP1021650A1, EP1021650B1, US6311649 PDF.

B. US 6,119,637 A — Ford Global Technologies (on-board distillation)

• Full citation: US 6,119,637 A, "On-board gasoline distillation for reduced hydrocarbon emissions at start-up," Matthews, Stanglmaier, Davis, Dai; Ford Global Technologies, Inc.; filed 1999-07-06, published 2000-09-19.
• Description: Heated vapor separator 22 + condenser 24 + controller 28; primary fuel 16 is distilled into a more volatile secondary fuel 18 stored in secondary tank 26; the controller switches between primary and secondary fuel (secondary only for the first 30–120 s of cold operation; the fuel rail is purged to secondary fuel at shutdown).
• § 102 exposure: Relevant to claim 1's (a)+(b)+(c) skeleton — on-board separation of tank fuel into components and controller-directed selection of which component is delivered depending on engine state. However it discloses selection/switching between two fuels, not a proportion, and its criterion is cold-start/coolant temperature rather than load and speed; it does not disclose an octane-based split, a compression self-ignition engine, or the load-region rules. Best characterized as § 103 art against claim 1 and as § 102 art against the broadest reading of claims 13–14 (subtanks + distillation/cooler).
• Timing caveat (important): This patent's US filing date (1999-07-06) is after US 6,332,448's 1999-06-01 priority date. Under pre-AIA § 102(e) it would only qualify if the 6,332,448 inventors' actual invention date post-dated 1999-07-06, and its publication (2000-09-19) post-dates the 2000-06-01 filing. In the Google Patents citation list this reference carries no examiner asterisk, consistent with it being a third-party/subsequent citation rather than a relied-upon § 102(e) reference. Flagging this rather than treating it as a clean anticipator.
• Sources: US6119637 Google Patents, US6119637 PDF.

C. US 4,706,630 A — Ford Motor Company (proportioning by microprocessor from engine sensors)

• Full citation: US 4,706,630 A, "Control system for engine operation using two fuels of different volatility," Nichols & Clinton, Ford Motor Company; filed 1986-02-07, published 1987-11-17.
• Description: An electronic engine control module 26 with a microprocessor reads engine sensors (throttle position, coolant temp, engine speed, air flow) and computes injector pulsewidth and spark for a mixture of two fuels of different volatility; an optical sensor 25 determines the fuel blend proportion; EGR and spark are scheduled by speed/load.
• § 102 exposure: No clean anticipation — no on-board separating device and no octane-fraction storage. It is, however, the best § 103 teaching for claim 1's "microprocessor determines a proportion based on running condition" element and for the general load/speed-based scheduling, and it is combinable with GB 2330176 A or US 4,035,864. Relevant to the preamble and the microprocessor clause of claim 1, and to claim 6 (load-region blending logic).
• Source: US4706630 Google Patents, FreePatentsOnline.

D. US 4,031,864 A — U.S. ERDA (multiple fuel supply)

• Full citation: US 4,031,864 A, "Multiple fuel supply system for an internal combustion engine," filed 1976-03-09, published 1977-06-28; assignee U.S. Energy Research & Development Administration.
• Description: Engine system delivering two different fuels to the engine with proportion/selection governed by operation — the archetypal multiple-fuel-supply art.
• § 102 exposure: Anticipates only the preamble concept of supplying plural fuels to one engine; it does not teach on-board separation from a single tank, a single injector metering both components, octane-based load-region rules, or a compression self-ignition engine. § 103 art against the preamble of claim 1; not an anticipator.
• Source: Google Patents citation listing (Citations (18)).

E. US 3,985,108 A — Ryohei Matsumoto (fuel separating system)

• Full citation: US 3,985,108 A, "Fuel separating system for starting an internal combustion engine," Ryohei Matsumoto; filed 1973-07-28, published 1976-10-12.
• Description: On-vehicle separation of fuel into fractions (light fraction for starting) with the fraction fed to the engine during starting.
• § 102 exposure: Directly relevant to claim 1 element (a) and to claim 14 (separating device + cooler) — it is the earliest cited art showing separating tank fuel into components on-board and feeding a selected component to the engine. Anticipates neither the octane/load-region control of claim 1 nor the sensor/microprocessor proportioning.
• Source: US6332448 citation list.

4. Full citation-by-citation table (all 18 cited references)

Legend: EX = marked "cited by examiner" in the Google Patents record (asterisk); TP = not so marked (third-party/other citation). Claims listed are those the reference is potentially relevant to under § 102; where I note "no § 102," the reference is § 103 material only.

Sources for the citation set: US6332448 Google Patents "Citations (18)", Espacenet cited-documents list.

5. Claim-by-claim § 102 map (achievable anticipations only)

6. Bottom line

• Single most relevant prior art: GB 2 330 176 A (Ford Global Technologies, published 1999-04-14) — it is the only citation that discloses on-board fuel fractionation combined with microprocessor-controlled, sensor-feedback proportioning of the separately metered fractions, and it lands before the 1999-06-01 priority date. It is a genuine § 102 candidate for claims 2, 13 and 14, and the strongest § 103 base against claim 1.
• Second tier: US 6,119,637 A (Ford, on-board distillation with controller switching of fuel components) and the Toyota dual-fuel-injector publications JP H06-10787 A and JP H06-307307 A, which are the substantive art on single-injector, proportion-controlled injection of two fuel components (the patent's own Background section acknowledges them as the closest prior art).
• Third tier (§ 103 only): US 4,706,630 A, US 4,031,864 A, US 4,885,430 A, US 5,233,944 A, US 5,469,830 A, US 3,985,108 A.
• No cited reference anticipates claim 1 as a whole, and none touches claims 4 and 15–16, which is consistent with the patent's identified point of novelty: balancing the consumption of two on-board-generated octane fractions, including transmission shift-schedule compensation (claim 4) and silica-gel aromatic adsorption/desorption separation (claims 15–16).

7. Confidence and limitations

• Patent numbering and dates were taken literally from the USPTO/Google Patents record; I did not normalize the one-day date discrepancy between the Google record and the Unified Patents record, nor the apparent "RON10, 8" typo in the specification (which I read literally as RON 108).
• I verified GB 2330176 A / EP 1021650 B1 / US 6,311,649 and US 6,119,637 and US 4,706,630 through live search. For several of the older citations (US 3,851,633; US 4,495,930; US 4,553,519; US 4,462,944; GB 2 209 796; US 4,884,530; US 5,233,944; US 5,357,908; US 5,469,830; US 5,775,308; JP H09-242520) I characterized them from the citation titles/assignees in the patent record rather than from their full texts; those characterizations should be confirmed against the individual documents before being relied on in a validity opinion.
• No "B1" claim was made about whether any reference is statutorily prior art under pre-AIA § 102(a)/(b)/(e); the US 6,119,637 timing caveat in § 3B above is the one instance where that question materially affects the analysis.

I'll verify the key prior-art references listed on the patent page before constructing the § 103 analysis.

Obviousness Analysis — U.S. Patent No. 6,332,448 B1

"Fuel supply apparatus of internal combustion engine" (Nissan Motor Co., Ltd.)
Inventor: Akihiro Iiyama / Hiroshi Miyakubo · Priority: 1999‑06‑01 (JP 11‑154089) · U.S. filing: 2000‑06‑01 · Granted 2001‑12‑25 · Expired 2020‑06‑01

I. Legal framework and evidence base

Because the application has a priority date of June 1, 1999, pre‑AIA 35 U.S.C. § 103 governs, with the ordinary-artisan date set at or about that date. Obviousness is judged under Graham v. John Deere and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): the claim is invalid if the differences between the claimed subject matter and the prior art are such that the subject matter as a whole would have been obvious, and KSR permits combination of references where the references are from the same field, address the same problem, or where the combination is a "predictable variation" of known elements.

Two evidence caveats before the chart:

1. The "Prior Art" section of the Google Patents page separates two categories. The 18 Citations are the references of record; the "Cited By" list is almost entirely post‑dated (e.g., US 6,542,323 (2001), US 6,713,893 (2001), US 8,245,690 (2006), US 11,008,969 (2016), the Saudi Aramco octane‑on‑demand family 2018–2021) and therefore cannot be § 103 prior art. I use only the 18 citations, plus the applicant's own specification as an admission.
2. US 6,119,637 A (Ford, "On‑board gasoline distillation…") is of doubtful prior‑art status. Its filing date is July 6, 1999 (US 09/347,553), after the applicant's June 1, 1999 priority date. As a § 102(e) reference it is ineffective against that priority, and it published September 19, 2000 — after the filing date. (Verified: https://patents.google.com/patent/US6119637 ; Espacenet biblio: filing 19990706.) It was nonetheless cited by the examiner (asterisk on the page's citation list). For that reason I treat it below as cumulative-but-weaker art and build the grounds on GB 2330176 A, which is squarely prior art.

Prior-art status of the principal references (as listed on the page, dates confirmed by search where noted):

Disclosure note: I verified the content of GB 2330176 A, US 4,706,630, US 4,031,864, US 6,119,637 and JP H06‑10787 A through the sources cited below. For US 4,884,530, US 5,469,830, US 4,495,930, US 4,553,519, US 4,462,944, GB 2209796 A and US 5,357,908 I have only the titles/assignees shown on the face of US 6,332,448; I do not attribute specific disclosures to them below.

Sources verified: GB 2330176 A text via EP 1,021,650 B1 (http://data.epo.org/gpi/EP1021650B1-INTERNAL-COMBUSTION-GASOLINE-ENGINE.html) and US 6,311,649 (family member, https://patentimages.storage.googleapis.com/81/9c/73/64898fe6ce8ed4/US6311649.pdf); US 4,706,630 (https://patents.google.com/patent/[US4706630A](/patent/US4706630A)/en); US 4,031,864 (https://patents.google.com/patent/US4031864 and Espacenet claims page); JP H06‑10787 A (https://patents.google.com/patent/JPH0610787A); US 6,119,637 (https://patents.google.com/patent/US6119637).

II. Claim 1 element-by-element

No anticipation. GB 2330176 A lacks (i) any compression-self-ignition engine and (ii) the load-indexed octane mapping; indeed its mapping runs the other way (see § VI). Claim 1 therefore rises or falls on § 103.

III. Grounds of rejection under § 103

Ground 1 — GB 2330176 A in view of JP H06‑10787 A (primary ground against claim 1)

What each teaches. GB 2330176 A teaches the complete "plumbing" of the claim: a single main tank; an on‑board distillation unit producing two or more fuel flows of different volatility/octane; separate subtanks/reservoir sections; an engine management system with a microprocessor/controller that separately meters each stream to fuel injectors and adjusts the relative usage rates of the streams; and level/pressure sensing of the accumulated quantity of each fraction. It even names the trade‑off the '448 patent claims to exploit, distinguishing "heavier fraction high octane fuel." JP H06‑10787 A and JP H06‑307307 A (both acknowledged in the '448 specification as the starting point) teach that the same nozzle can inject two fuels of different octane in a controlled proportion, by filling the nozzle tip with an auxiliary fuel so that the auxiliary (low‑octane, easily ignited) fuel is injected first and ignites the main (high‑octane) fuel — in a compression self‑ignition engine.

Motivation to combine (KSR prongs).

• Same field, same problem. Both references are on‑board vehicle fuel systems addressing the problem of delivering two fuels to one injected engine. GB 2330176 A's own discussion of "high octane" heavy fractions and of light fractions used at wide‑open throttle shows the artisan was already thinking in octane/volatility terms.
• The specification supplies the motivation as an admission. The '448 background states the object behind the load mapping in advance of the invention: "if high octane fuel which is effective in preventing knocking is used to allow self‑ignition combustion more easily, while low octane fuel which has high combustion stability is used at a lean air‑fuel ratio, the self‑ignition combustion region can be enlarged." That is the claim‑1 mapping (high octane ↔ high load/knock‑limited; low octane ↔ light load/stability‑limited), stated as known desiderata. It then identifies the only remaining problem as cost and refueling frequency from "having two kinds of fuel tanks" — precisely the problem GB 2330176 A and US 6,119,637 were created to solve by making the two fuels on board from one tank.
• Predictable result. Selecting the higher‑octane stream from the two streams already produced, and varying the relative usage to match a knock/ignitability need, is a predictable use of GB 2330176 A's two streams with a known property (octane) that the reference itself names.
• Reasonable expectation of success. GB 2330176 A already discloses closed‑loop balancing of the two usage rates with level/pressure feedback; adding a load‑indexed lookup (the routine of Figs. 4A–4C is a flat 10‑ms map lookup) requires no new hardware.

Ground 2 — GB 2330176 A in view of US 4,706,630 (and optionally US 4,031,864)

US 4,706,630 provides the microprocessor limitation with unusual directness: an electronic control module with a microprocessor, receiving engine load (VAF/throttle) and engine speed (PIP), computing the amount of a fuel mixture of two fuels of different volatility and outputting injector pulsewidths — including interpolation factors between the two fuels across load/speed tables (FN901/FN905, FN910/FN919). A POSITA seeking to implement GB 2330176 A's "engine management system … adjusting relative usage rates" would use exactly such a load/speed‑indexed engine controller. US 4,031,864 supplies the complementary teaching that proportioning of two fuels from one tank, controlled by a computer "in accordance with at least one predetermined engine parameter," is an old and accepted practice.

Ground 3 — for the subtank/storage‑amount family (claims 2, 3, 5, 6): add US 4,031,864 and GB 2330176 A's own balance control

GB 2330176 A discloses sensing means for the accumulated quantity of each fraction and regulating means adjusting relative usage rates "in such a manner as to keep substantially constant the equilibrium quantities of the respective accumulated … stored in the reservoir." US 4,031,864 discloses separate level indicators for each of the two phases (floats 23, 24) of a single tank and computer control of "the quantity of liquid supplied from each phase." Together these teach storing the components and modulating the proportion according to how much of each remains — i.e., claim 2, and the "use only the abundant one when the other is depleted" logic of claims 3 and 5 as the predictable extreme of the same balance control.

Ground 4 — for claim 14 (boiling‑point separation + cooler)

GB 2330176 A (continuous‑flow boiler heating fuel to evaporate low/medium boiling fractions; condenser receiving compressed vapour to liquefy the medium fraction) and US 6,119,637 (heated vapor separator + condenser producing a more volatile liquid fuel) both disclose separation "according to a difference of boiling points" with a downstream cooler/condenser — the literal content of claim 14.

IV. Dependent claims 2–16 — likely outcome on this record

V. Where the art of record is weakest — the true point of novelty

The 18 citations do not supply:

1. A dual‑mode engine that switches between compression self‑ignition and spark ignition (claims 7–12). GB 2330176 A is a spark‑ignition stratified‑charge gasoline engine; JP H06‑10787 A is a diesel (compression‑ignition‑only) engine. Neither teaches switching.
2. Auxiliary/radical‑promoting sparking during HCCI (claims 9, 11, 12). This is a genuine control‑strategy contribution; the closest post‑dated art (e.g., the Mazda US 11,008,969 in the Cited‑By list, priority 2016) cannot be used.
3. Silica‑gel adsorption separation (claims 15–16). The adsorption‑based octane‑on‑demand art in the Cited‑By list (Saudi Aramco, 2018–2021) is far too late.
4. Transmission shift‑schedule compensation (claim 4).

A patentee defending validity should therefore treat claims 7–12 and 15–16 (and, secondarily, claim 4) as the surviving scope, and should not expect claim 1 to survive a well‑pleaded KSR combination of GB 2330176 A + US 4,706,630 + JP H06‑10787 A.

VI. Counterarguments a patentee would raise (and the rebuttals)

A. GB 2330176 A teaches the opposite mapping — an argument of teaching away. GB 2330176 A's summary states: "more light fraction volatile fuels are used … under wide open throttle conditions … and less are used … under steady operation conditions when heavier fraction high octane fuel is needed." If "light fraction" = lower octane (as the '448 specification asserts for its own fractionation: low‑boiling = low octane), GB 2330176 A appears to teach more low‑octane fuel at high load, the inverse of claim 1. Rebuttal: GB 2330176 A's rationale is charge stratification and combustion response, not knock; it never addresses octane‑limited self‑ignition, so it does not criticize, discredit, or otherwise discourage the '448 solution. Under In re Fulton/KSR, a reference teaches away only when a POSITA reading it would be dissuaded from the claimed route. At most this is a differences factor under Graham, to be weighed against the applicant's own admission of the octane/load desideratum.

B. Non‑analogous art / different problem. All references are vehicle fuel‑system and engine‑control art — the same field of endeavour (§ 103(a) "pertinent art"). US 4,031,864 even uses a single tank with two withdrawn fractions, undercutting any "separate technological field" argument.

C. Secondary considerations. No evidence of unexpected results, licensing, or long‑felt need appears on the face of the record. The only factual foundation for a nexus argument is the 45% / 55% volume‑yield data for RON‑fractionated gasoline and the invention's balance control (claims 2–7). That data is genuinely useful ammunition for the dependent claims — it supports the proposition that balancing the two fractions addresses a newly recognized problem (the low‑octane fraction is produced in greater volume, so a load‑only usage schedule strands one fraction). The patentee should tie that yield discovery to claims 2–7, not to claim 1.

D. Careful with the specification's literal text. The specification as retrieved recites the high‑octane fraction as "RON10, 8" (col. 5) against low‑octane "RON94". Read literally per the operating rules, "RON10, 8" is nonsensical as an octane number; it appears to be an OCR corruption of a three‑digit value. I do not correct it here — but a litigator should obtain the certified copy before relying on either number, since the yield/octane figures are the factual hook for any unexpected‑results argument.

VII. Bottom line

• Claim 1: Should be held obvious over GB 2330176 A + US 4,706,630 + JP H06‑10787 A. Every hardware element (single tank, on‑board separator, subtanks, microprocessor, injector, load and speed sensors) is disclosed, and the load‑indexed octane selection is expressly framed in the applicant's own background section as a known objective for enlarging the compression‑self‑ignition operating region, while the applicant identified the two‑tank/refueling problem as the only obstacle — the precise problem the on‑board separators of GB 2330176 A and US 6,119,637 already solved. That is the classic KSR "known problem, known solution from a finite set" fact pattern. The one caveat is GB 2330176 A's contrary volatility‑vs‑load discussion (§ VI.A), which the petitioner must neutralize.
• Claims 2, 3, 5, 6, 13, 14: Likely obvious on the same references plus US 4,031,864 (per‑phase level indicators; computer‑controlled proportioning from one tank).
• Claims 4, 7–12, 15–16: Not obvious on the prior art of record as presented on this page. These depend on dual‑mode HCCI/SI operation, auxiliary sparking, transmission scheduling, and silica‑gel adsorption separation, none of which is disclosed by the 18 citations with pre‑June‑1999 dates.
• Reference‑integrity flag: US 6,119,637 A is listed among the examiner‑cited references but was filed 1999‑07‑06, after the 1999‑06‑01 priority date; it should not be used as § 102(e)/§ 103 art without first confirming whether the applicant can rely on its Japanese priority to antedate it. GB 2330176 A (published 1999‑04‑14) is the safer vehicle for the identical on‑board‑distillation teaching.
• Enforcement posture: the patent expired 2020‑06‑01, so any § 103 challenge now arises in damages/validity litigation rather than as a bar to injunctive relief; the same analysis would also inform an IPR petition, which remains available for an expired patent.

This memorandum is a technical/legal‑analytic assessment, not legal advice or a validity opinion of counsel, and it relies on the reference content I was able to verify above; the disclosure of several cited references (US 4,884,530; US 5,469,830; US 4,495,930; US 4,553,519; US 4,462,944; GB 2209796 A; US 5,357,908) should be confirmed from full‑text copies before any ground is finalized.