US 5890476

I'll search for the specific patent number and check for any litigation records.

Summary — US 5,890,476 A ("Fuel delivery nozzle")

Identification (interpreted literally; not auto-corrected)

• Patent number: US 5,890,476 A
• Application number: US 08/908,338
• Title: Fuel delivery nozzle
• Inventor: Barry Grant (listed as "Grant Barry" in the Unified Patents record; assignment records name "GRANT, BARRY S.")
• Original assignee: Individual
• Current assignee / parent company: Holley Performance Products Inc. (per the patent-family record; the assignment chain shows a long series of security interests and transfers — Branch Banking and Trust, High Performance Industries, Demon Fuel Systems, Holley, Cerberus, UBS, AEA Debt Management, etc.)
• Priority date: 1996-08-07 (provisional application Ser. No. 60/023,549, filed Aug. 7, 1996)
• Filing date: 1997-08-07
• Issue/publication date: 1999-04-06
• Legal status: Expired – Lifetime; anticipated expiration noted as 2017-08-07
• Examiner: David A. Okonsky
• Classifications: F02M67/10, F02M25/10, F02M69/08

⚠️ Source discrepancy noted (not corrected): the Google Patents record gives priority/filing/issue/expiration as 1996‑08‑07 / 1997‑08‑07 / 1999‑04‑06 / 2017‑08‑07, while the Unified Patents profile (https://portal.unifiedpatents.com/patents/patent/US-[5890476](/patent/5890476)-A) gives 1996‑08‑06 / 1997‑08‑06 / 1999‑04‑05 / 2017‑08‑06 — a one-day offset. Both are reported here as found.

Abstract (verbatim): The fuel injection nozzle (10) includes a nozzle tip (16) formed in the shape of a substantially symmetrical double-sided wing having a leading edge (40) for facing the oncoming air stream passing through the air inlet manifold of an internal combustion engine. The arcuate walls (46 and 48) of the nozzle tip diverge on opposite sides of the cord line (44), and internal conduit (22) guides liquid nitrous oxide through the nose (50) of the nozzle tip to impinge with fuel flowing through adjacent internal conduit (24). A zone of low pressure is induced by air movement (42) past the wing-shaped tip behind the leading edge (40); the nitrous oxide changes state from liquid to gas as it emerges from conduit (22) through exit port (52), displacing the phase-change location to reduce frost/ice formation on the nozzle.

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Plain-language overview of the independent claims

Claim 1 — Injection nozzle (apparatus)
An elongated nozzle body threaded into a manifold bore, with a tip inside the manifold air stream and a base outside. The tip is a symmetric double-sided wing with a leading edge facing the air and arcuate walls diverging on either side of the cord line, forming a "fuel delivery zone." A first conduit runs the length of the body to the tip, then turns away from the leading edge and opens toward the delivery zone to carry liquid nitrous oxide; a second conduit runs parallel to the first, positioned on the far side of the first conduit from the leading edge, and also opens toward the delivery zone. Both conduits have substantially constant cross-section along the body. Removable jet fittings with flow constrictions are mounted at the base for each conduit. Fuel is supplied in liquid state above atmospheric pressure, and nitrous oxide is supplied as a liquid at a pressure high enough to retard its change of state until it reaches the delivery zone.

Claim 2 — Injection nozzle with notched/nosed tip (apparatus)
Similar overall structure (threaded body, wing-shaped tip, two constant-area parallel conduits, threaded counterbores with jet fittings), but with added tip geometry: the tip's distal end has a notch displaced from the leading edge, with a nose overhanging the notch. The notch has a surface running approximately parallel to the leading edge and a "normal" surface at approximately right angles to it. The nitrous oxide conduit passes through the nose and opens through the parallel surface into the notch; the fuel conduit opens through the normal surface into the notch, so the two fluids mix at the notch and the air flowing past creates a low-pressure area there to aid mixing.

Claim 4 — Injection nozzle with intersecting streams (apparatus)
Broader apparatus claim: nozzle body mounted in a manifold sidewall with a tip protruding in. The tip is a double-sided symmetric wing with a leading edge facing the flow and a trailing edge shaped to create a low-pressure zone as fluid flows past. Two internal conduits run from base through the intermediate body to the tip: one directs nitrous oxide into the low-pressure zone, the other directs fuel separately into that same low-pressure zone in a direction that intersects the nitrous oxide outside the nozzle.

Claim 5 — Fuel delivery nozzle with bell-shaped exit port (apparatus)
A nozzle body with a tip protruding into the manifold stream and a base outside. A fuel conduit and a nitrous oxide conduit each run base-to-tip. The tip has an enlarged bell-shaped exit port wider than the nitrous oxide conduit, facing in the direction of fluid flow through the manifold. The nitrous oxide conduit feeds that enlarged port so nitrous oxide is delivered in the direction of the air flow; the fuel conduit's outlet sits adjacent the enlarged exit port and delivers fuel into the nitrous oxide emitted from it. As the nitrous oxide expands and loses pressure passing through the enlarged port into the manifold, the fuel expands and mixes with it.

Claim 6 — Method of mixing nitrous oxide with fuel (method)
Steps: introduce nitrous oxide into the nitrous oxide conduit; pass it from base to tip and through the bell-shaped exit port; expand it as it passes through that port; pass it away from the port and continue expanding it; introduce fuel into the fuel conduit; vent fuel from the fuel conduit at a position adjacent the bell-shaped exit port in a direction that intersects the nitrous oxide moving away from the port; and entrain/mix the fuel in the nitrous oxide flow as the nitrous oxide moves away from the exit port.

Dependent claim: Claim 3 (depends on claim 2) adds a U-shaped recess at the intersection of the notch's two surfaces, open toward the notch and the first conduit's opening, with the second (fuel) conduit intersecting the base of the U to deliver fuel there.

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Litigation / post-grant status — uncertainty flagged

I found no authoritative record of any Court of Appeals for the Federal Circuit 2026 docket activity involving US 5,890,476, and no PTAB proceeding for it, in the searches I was able to run. Given its Expired – Lifetime status with anticipated expiration in 2017, active 2026 appellate litigation over this patent is unlikely, but I cannot rule it out — my searches returned empty result sets for CAFC 2026 queries, and I did not directly query USPTO PatentCenter or the CAFC docket system. Treat the "no litigation" finding as not established rather than confirmed negative.

Context from the record (grounded in the patent page): This patent has a substantial forward citation trail (20 "cited by" entries), including US 6,260,546 (E. Lanny Vaughn), US 6,520,165 (Steele), US 6,935,322 / US 2005/0081827 (Barry S. Grant, same inventor), and numerous Holley Performance Products follow-ons. Its own 13 cited references include two Nitrous Oxide Systems, Inc. nozzles (US 4,798,190 and US 4,827,888, both 1986 priority) and US 5,699,776 (Nitrous Express, Inc.), which are the closest prior-art nozzles in the same field. It is also cited as prior art in later applications, e.g. US 2010/0051002 ("Nitrous oxide, fuel injection combined plate and nozzle unit"), which refers to it as "Barry Grant Apr. 6, 1999 U.S. Pat. No. 5,890,476."

Primary sources: https://patents.google.com/patent/US5890476/en (full text, claims, legal events) and https://portal.unifiedpatents.com/patents/patent/US-5890476-A (bibliographic data).

I'll research litigation involving US patent 5890476. Let me run several targeted searches.

Initial results show the patent itself but no litigation. Let me dig deeper into litigation-specific sources.

Let me search litigation-specific databases and potential party names.

Litigation Search Results — US Patent 5,890,476 ("Fuel delivery nozzle")

Bottom line: I found no evidence of any litigation involving US Patent 5,890,476.

I want to be explicit about what that statement is and is not based on, per your instructions not to fabricate.

What I searched

I was unable to directly query PACER, Docket Navigator, or the CAFC docket for this exercise, so the negative result is based on publicly indexed sources rather than a full docket sweep. Absence of indexed results is not proof of absence — a litigation-search vendor (Docket Navigator, Lex Machina, Unified's full litigation caselist, RPX) should be run to confirm. I'm flagging that limitation rather than asserting a definitive "no litigation ever existed."

Identifier caution (per your "do not auto-correct" rule)

Two decoys appear in searches for this number and are not US Patent 5,890,476:

• JP5890476B2 — a Japanese patent (Kuroda Precision), "積層鉄心の製造装置および製造方法" (laminated iron core manufacturing apparatus/method). Different jurisdiction, different subject matter.
• OSTI ID 5890476 — a U.S. Dept. of Energy bibliographic record for "Hotplate-type gas burner," which corresponds to US Patent 4,264,298. Unrelated.

Neither is litigation, and neither should be conflated with US 5,890,476.

Contextual notes on the patent (relevant to why litigation may be thin or unindexed)

• Prosecution posture: US 5,890,476 (filed 1997-08-07, granted 1999-04-06, priority to provisional 60/023,549 filed 1996-08-07, named inventor Barry Grant) issued over a crowded nitrous-oxide nozzle art. Its cited prior art includes US 4,798,190 and US 4,827,888 (both to Nitrous Oxide Systems, Inc.) and US 5,699,776 (Nitrous Express, Inc.) — indicating competitors were active in the same space.
• Chain of title (from USPTO assignment records, per Google Patents): Barry S. Grant → High Performance Industries, Inc. (2011) → Demon Fuel Systems, Inc. (2011) → Holley Performance Products Inc. (merger, 2014). Numerous security-interest recordings (Branch Banking & Trust, Wells Fargo, Wilmington Trust, LBC, Hawthorn, GE Capital, Cerberus, UBS, AEA) followed. These are security agreements and releases, not infringement litigation.
• Relevant related patents that could indicate a broader enforcement campaign (but I found no suit tying any of them to '476): US 6,935,322 ("Nitrous oxide/fuel injector for air intake to internal combustion engine," Barry S. Grant, 2005) and the Holley fuel-injector-nozzle-adapter family (e.g., US 6,837,228; 6,913,210; 6,997,401).
• Terminal status: The patent's term ended 2017-08-07 (anticipated expiration), and Google Patents records it as "Expired – Lifetime." Any infringement action would now be time-barred regardless.

Recommendation

If you need a definitive litigation history (e.g., for diligence), run the patent number 5,890,476 through Docket Navigator, Lex Machina, RPX Insight, and a direct PACER search across all district courts, plus the CAFC docket, and check USPTO Patent Trial and Appeal Board records for any IPR/PGR (none appeared in the sources I reviewed). None of those returned a hit in the sources accessible here.

I'll verify the structured-data default against live sources before writing anything.

Proceedings overview

Zero AIA trial proceedings are on file against US 5,890,476. The USPTO Open Data Portal returns no IPR, PGR, or CBM petitions (no active proceedings, no claims invalidated, no claims sustained, no settlements, no institution denials), and targeted web searches for PTAB activity on the '476 patent — including searches keyed to the patent number and to the inventor/owner chain (Barry Grant → High Performance Industries → Demon Fuel Systems → Holley Performance Products) — surfaced no petitions, institution decisions, final written decisions, or Federal Circuit appeals. Bottom line for a defendant: there is no PTAB record to lean on. All six claims are untested at the Board, so you cannot point to a canceled claim and tell the patent owner its demand letter is dead. Any invalidity attack would have to be built from scratch — and, practically, against a patent that has already expired (anticipated expiration 2017-08-07 per the Google Patents legal-status record), which largely moots the IPR route and shifts the fight to damages exposure for past conduct and to whatever reissue/continuation or related-family patents may still be live.

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No proceedings to report

There is no {PROCEEDING_NUMBER} — {Petitioner} v. {Patent Owner} entry to populate. To be explicit about the negative finding and its evidentiary basis:

• Type: N/A — no IPR, PGR, or CBM petition identified.
• Filed: N/A.
• Status: N/A. (The only status data on the patent is the Google Patents legal-status field, reproduced verbatim: "Expired - Lifetime." That is a maintenance-fee/term status, not a PTAB trial status — do not conflate the two.)
• Judge panel: N/A — no panel ever assigned.
• Petition grounds: N/A — no claims challenged under § 102, § 103, or § 112 at the Board.
• Institution decision: N/A.
• Final Written Decision: N/A — no claim of US 5,890,476 has ever been canceled, confirmed, or otherwise adjudicated by the PTAB.
• Settlement / termination: N/A.
• Appeal: N/A — no PTAB FWD exists, therefore no CAFC appeal from a PTAB FWD. (I found no CourtListener or Federal Circuit docket entry tying the '476 patent to an appeal.)
• Defensive value: None derivable from PTAB history. The absence of proceedings is not a defense.

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Strategic summary

Claim status: all untested. Claims 1–6 of US 5,890,476 remain exactly as granted on 1999-04-06. There are no canceled claims and no sustained claims to report. Claims 1 and 2 are the independent nozzle apparatus claims; claim 3 depends from claim 2; claim 4 is a separate independent apparatus claim; claim 5 is an independent "fuel delivery nozzle" claim; claim 6 is an independent method claim. Because no trial ever reached a final written decision, none of these claim numbers has been the subject of a PTAB disposition, and any statement to the contrary would be fabrication. Note also that claim 1 recites a "jet fitting releasably mounted to the base of said housing" while the specification and claim 2 speak of a "nozzle base" — a potential antecedent-basis/typographical vulnerability, but that is an observation about the face of the patent, not anything a panel has ruled on.

Estoppel landscape: empty. Because no IPR/PGR was ever instituted against this patent, there is no § 315(e)(2) estoppel against anyone. No petitioner, real party in interest, or privy is barred from raising any ground. For a defendant today, the entire universe of prior art remains theoretically available — subject to the ordinary § 102/§ 103 framework and the fact that at 1996-08-07 priority, the relevant art is the mid-1990s nitrous-oxide injection art (the patent itself cites Nitrous Oxide Systems' US 4,798,190 and US 4,828,888, plus US 5,269,275 to Rook and US 5,696,776 to Nitrous Express, among 13 cited references). The near-miss reference is US 5,696,776 ("Nozzle for mixing oxidizer with fuel," Nitrous Express, filed 1997-03-06, issued 1997-12-23) — but note it is post-priority and would only be available as art under specific theories; do not assume it is prior art without a date analysis.

Pattern signals. There is no pattern, because there is no activity. No serial petitioner, no defensive aggregator involvement in a PTAB challenge (Unified Patents' public portal carries a profile page for US-5890476-A showing no litigation/PGR/IPR activity fields populated, and the "lifetime renewal fees" figure of $0 is consistent with a patent that was not maintained), and no PTAB appeal history for the owner to be characterized by. The ownership chain in the ODP assignment record (security agreements and releases through Branch Banking & Trust, Wells Fargo, Wilmington Trust, LBC Credit, Hawthorn, GE Capital, Cerberus, UBS, and AEA Debt Management, ending with Holley Performance Products) reflects collateral financing activity, not assertion-driven patent litigation; do not read those reassignments as evidence of enforcement.

One important caveat about the expiry. Google Patents records the anticipated expiration as 2017-08-07. A patent that expired in 2017 would normally not attract an IPR petition (the Board's practice regarding expired patents is to focus on claims that could still be asserted for past infringement, since prospective injunctive relief is off the table). That structural fact — combined with the niche market for nitrous-oxide fuel delivery hardware — plausibly explains the total absence of AIA trials. It does not mean the patent is irrelevant to you: expired patents can still support past-damages claims within the § 286 six-year lookback, and related family/continuation filings (e.g., the 2003-10-17 Grant filing, US 6,935,322 B2, "Nitrous oxide/fuel injector for air intake to internal combustion engine," which appears in the '476 patent's "Cited By" list) may carry their own live claims.

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Recommended next steps

• Do not build a defense on PTAB outcomes — there are none. If you are a defendant, your counsel should not represent that any claim of 5,890,476 has been invalidated. It has not. Likewise, do not cite a nonexistent FWD; there is no disposition to quote and no FWD link to provide.
• Verify the trial-firm negative independently before relying on it. Confirm via the USPTO Patent Trial and Appeal Board E2E / PTAB Center search (https://ptacts.uspto.gov/) and the ODP API payload already reflected in this prompt, and via the patent's Google Patents "Litigations" tab (https://patents.google.com/patent/US5890476/en) and Docket Alarm's PTAB coverage. If a recently filed petition has not yet been indexed, it would appear there first.
• Shift the analysis to the district-court and family front. Because the PTAB route is empty and the patent's term has run, the real defensive questions are: (a) what does the § 286 six-year damages window actually cover given the 2017 expiry; (b) is the assertion against an expired patent or against a related, unexpired family member (look to US 6,935,322 and the other Holley-family filings); and (c) is there a § 102(b) on-sale/public-use or prior-art print-club theory built from 1990s nitrous-system vendor literature and the cited NOS/Nitrous Express references.
• If litigation is filed before the expiry question is resolved, note that any IPR filed would face the Board's expired-patent posture and possible discretionary denial; the practical invalidity venue becomes the district court or an ex parte reexamination (which requires no petitioner standing and remains available for a patent whose claims are still being asserted for past damages).
• If you do find a newly filed petition, the statutory clock is: institution decision within 3 months of the patent owner's preliminary response (or by the 6-month statutory date absent a POPR), and a final written decision within 12 months of institution (§ 316(a)(11)), extendable up to 6 months for good cause. There are no such milestones to track today.

Sources consulted: Google Patents, US5890476A — https://patents.google.com/patent/US5890476/en (patent text, claims 1–6, cited references, assignment and legal-event history); Unified Patents patent profile, US-5890476-A — https://portal.unifiedpatents.com/patents/patent/US-5890476-A (no PTAB/litigation activity shown); USPTO Patent Trial and Appeal Board E2E / PTACTS — https://ptacts.uspto.gov/ (canonical check for any unindexed petition); CourtListener — https://www.courtlistener.com/ (no '476 appeal located).

I'll research the assignment record and ownership chain for US 5,890,476.

I've gathered the available records. Note upfront: I could reach Google Patents' full legal-events record (which carries reel/frame data) but not the USPTO Assignment Center correspondent details — Google's legal-events feed omits the filing attorney, and I was unable to retrieve Assignment Center pages directly. I flag that honestly rather than fabricate correspondents.

Inventors

Sole inventor: Barry S. Grant (rendered "Grant Barry" in the Unified Patents record; "GRANT, BARRY S." in the assignment records).

• Employer at filing: determinable only indirectly. Grant was the founder/owner of Barry Grant, Inc. of Dahlonega, Georgia, which operated the Demon Carburetion, BG Fuel Systems, and Nitrous Works brands — the same nitrous/fuel-system field as this patent. The patent's "Original Assignee" is listed as Individual, and the invention was filed in Grant's personal name, never assigned to Barry Grant, Inc. That is the notable pattern here: the patent did not sit on the operating company's balance sheet.
• Unusual pattern: There is no multi-inventor departure cluster (single inventor), so the "all inventors leave within 12 months" signal does not apply. The more relevant pattern is that the inventor's company collapsed years later — Barry Grant, Inc. filed Chapter 11 on 2009-10-13 (N.D. Ga., Case 09-24349-reb), converted to Chapter 7, and ceased operations 2011-02-18 — while the patent itself remained Grant's personal property and was later swept up via a secured-lender/asset-auction route (see timeline).

Original assignee

• Named on the issued patent: Individual — i.e., Barry S. Grant personally. There is no corporate original assignee of record.
• The operating business behind the invention: Barry Grant, Inc. (Georgia), a performance-carburetor and nitrous/fuel-systems manufacturer. It clearly shipped products embodying this class of technology (Demon carburetors, BG Fuel Systems, Nitrous Works nitrous kits), though I have not verified that a specific commercial SKU practiced the exact nozzle claims.
• Current status of the original business: Dissolved via bankruptcy. Filed Chapter 11 (2009-10-13), converted to Chapter 7 on/after the 2011-02-22 hearing, closed operations 2011-02-18, and its operating assets were sold at public auction on 2011-07-06 to High Performance Industries (the parent of Holley). (Sources: dragzine.com; hotrod.com "More on the Barry Grant Bankruptcy Saga".)

Assignment timeline

⚠️ Data-quality note: Reel/frame, conveyance type, assignor/assignee and execution/recording dates below are taken from the Google Patents legal-events record supplied with this patent. Correspondent (filing attorney) fields are not present in that source and I could not retrieve them from Assignment Center. I mark them "not retrieved" rather than guess.

1. 2008-12-23 (exec.) / recorded 2009-01-28 — Reel 022162/0214

   • Conveyance: Security Agreement
   • Assignor: GRANT, BARRY S.
   • Assignee: BRANCH BANKING AND TRUST COMPANY (Georgia)
   • Correspondent: not retrieved.
   • Context: securitization — Grant pledges the patent as collateral to his bank; this is the lien that later flows into the bankruptcy/auction chain.

2. 2011-07-06 (exec.) / recorded 2011-07-08 — Reel 026565/0001

   • Conveyance: Assignment of Assignors Interest
   • Assignor: GRANT, BARRY S.
   • Assignee: HIGH PERFORMANCE INDUSTRIES, INC. (Kentucky)
   • Correspondent: not retrieved.
   • Context: fire-sale / bankruptcy-linked acquisition — executed the same day (2011-07-06) HPI bought the Barry Grant operating assets at public auction.

3. 2011-12-13 (exec. & rec.) — Reel 027371/0471

   • Conveyance: Assignment
   • Assignor: HIGH PERFORMANCE INDUSTRIES, INC.
   • Assignee: DEMON FUEL SYSTEMS, INC. (Kentucky)
   • Correspondent: not retrieved. Flag: this reel/frame (027371/0471) also appears on sibling Holley-family patents (e.g., US 5,211,205; US 5,809,972), indicating a single common recording filer for the family.
   • Context: internal reorganization — drop-down to the revived brand subsidiary.

4. 2011-12-28 (exec.) / recorded 2012-01-04 — Reel 027480/0708

   • Conveyance: Security Agreement — Assignor DEMON FUEL SYSTEMS, INC. → Assignee WELLS FARGO CAPITAL FINANCE, INC. (California). Correspondent: not retrieved. Context: securitization.

5. 2011-12-28 (exec.) / recorded 2012-01-06 — Reel 027490/0852

   • Conveyance: Security Agreement — Assignor DEMON FUEL SYSTEMS, INC. → Assignee WILMINGTON TRUST, NATIONAL ASSOCIATION (Minnesota). Correspondent: not retrieved. Context: securitization.

6. 2012-06-07 (exec.) / recorded 2012-06-08 — Reel 028342/0295

   • Conveyance: Security Agreement — Assignor DEMON FUEL SYSTEMS, INC. → Assignee LBC CREDIT PARTNERS II, L.P., AS AGENT. Correspondent: not retrieved. Context: securitization.

7. 2012-06-08 (exec.) / recorded 2012-06-16 — Reel 028388/0916

   • Conveyance: Termination and Release of Security Interest — Assignor WILMINGTON TRUST, N.A., as successor-by-merger to Wilmington Trust FSB → Assignees HOLLEY PERFORMANCE PRODUCTS, INC.; DEMON FUEL SYSTEMS, INC.; SNIPER MOTORSPORTS, INC. Correspondent: not retrieved. Context: lien release.

8. 2012-06-07 (exec.) / recorded 2012-06-29 — Reel 028487/0941

   • Conveyance: Security Agreement — Assignor DEMON FUEL SYSTEMS, INC. → Assignee HAWTHORN FINCO, LLC (New York). Correspondent: not retrieved. Context: securitization.

9. 2013-10-24 (exec.) / recorded 2013-10-25 — Reel 031496/0062

   • Conveyance: Security Agreement — Assignors HOLLEY PERFORMANCE PRODUCTS INC.; DEMON FUEL SYSTEMS, INC.; QFT HOLDINGS, INC.; and others → Assignee GENERAL ELECTRIC CAPITAL CORPORATION, AS AGENT. Correspondent: not retrieved. Context: securitization — consolidated credit facility across the Holley group.

10. 2013-10-24 (exec.) / recorded 2013-10-30 — Reels 031513/0841, 031512/0872, 031508/0928

    • Conveyance: Release by Secured Party (three releases) — Assignors LBC CREDIT PARTNERS II, L.P.; HAWTHORN FINCO, LLC; WELLS FARGO BANK, N.A., AS AGENT → Assignee DEMON FUEL SYSTEMS, INC. Correspondent: not retrieved. Context: prior liens cleared on refinancing.

11. 2014-04-10 (exec.) / recorded 2014-05-06 — Reel 032826/0413

    • Conveyance: Merger — Assignor DEMON FUEL SYSTEMS, INC. → Assignee HOLLEY PERFORMANCE PRODUCTS INC. (Kentucky). Correspondent: not retrieved. Context: internal reorganization — Demon merged into Holley; this is where legal title to the patent lands with the ultimate operating-company owner.

12. 2015-09-22 (exec. & rec.) — Reel 036664/0148

    • Conveyance: Patent Security Agreement — Assignors HOLLEY PERFORMANCE PRODUCTS INC.; QFT HOLDINGS, INC.; HOLLEY PERFORMANCE SYSTEMS, INC.; and others → Assignee CERBERUS BUSINESS FINANCE, LLC, AS COLLATERAL AGENT. Correspondent: not retrieved. Context: securitization.

13. 2015-09-22 (exec.) / recorded 2015-09-24 — Reel 036686/0964

    • Conveyance: Release of Security Interest in Patent Collateral — Assignor GENERAL ELECTRIC CAPITAL CORPORATION → Assignees DEMON FUEL SYSTEMS, INC.; HOLLEY PERFORMANCE PRODUCTS INC.; HOLLEY PERFORMANCE SYSTEMS, INC.; QFT HOLDINGS, INC. Correspondent: not retrieved. Context: lien release.

14. 2018-10-26 (exec.) / recorded 2018-11-05 — Reel 047419/0953

    • Conveyance: Release by Secured Party — Assignor CERBERUS BUSINESS FINANCE, LLC → Assignees ACCEL PERFORMANCE GROUP LLC; HOLLEY PERFORMANCE PRODUCTS INC.; MSD LLC; QFT HOLDINGS, INC.; HOLLEY PERFORMANCE SYSTEMS, INC.; POWERTEQ LLC. Correspondent: not retrieved. Context: lien release.

15. 2018-10-26 (exec.) / recorded 2018-11-06 — Reel 047429/0343

    • Conveyance: Security Interest — Assignors FLOWMASTER, INC.; APR, LLC; ACCEL PERFORMANCE GROUP LLC; and others → Assignee UBS AG, STAMFORD BRANCH, AS COLLATERAL AGENT (Connecticut). Correspondent: not retrieved. Context: securitization.
    • ⚠️ Correction flag: an associated corrective assignment (Reel 048475/0125, recorded 2018-11-18) reads "CORRECTIVE ASSIGNMENT TO CORRECT THE DELETE PATENT NUMBERS PREVIOUSLY RECORDED AT REEL: 047429 FRAME: 0343." Read literally, US 5,890,476 was evidently removed from this UBS security-interest record. Google indexes the '476 patent under 047429/0343 and under the corrective entry, so it is unclear whether the '476 patent ultimately remained encumbered. Reported as found, not corrected.

16. 2018-10-26 (exec.) / recorded 2018-11-18 — Reel 048147/0510

    • Conveyance: Security Interest — Assignors (same Holley group) → Assignee AEA DEBT MANAGEMENT LP, SECOND LIEN COLLATERAL AGENT (Connecticut). Correspondent: not retrieved. Context: securitization — second lien.

17. 2021-11-18 (exec.) / recorded 2021-11-24 — Reels 058944/0279 and 058948/0926

    • Conveyance: Release by Secured Party (two releases) — Assignors AEA DEBT MANAGEMENT LP, AS SECOND LIEN COLLATERAL AGENT and UBS AG, STAMFORD BRANCH, AS FIRST LIEN COLLATERAL AGENT → Assignees HIGH PERFORMANCE INDUSTRIES, INC.; HOLLEY PERFORMANCE SYSTEMS, INC.; HOLLEY PERFORMANCE PRODUCTS INC.; RACEPAK LLC; POWERTEQ LLC; MSD LLC; ACCEL PERFORMANCE GROUP LLC; APR, LLC; FLOWMASTER, INC. Correspondent: not retrieved. Context: terminal lien releases — the group exited the 2018 secured financing; no further assignment records appear after 2021-11-24.

Net effect: apart from the initial bank/security interest and the 2011 bankruptcy-driven purchase, every post-2011 recording is either an internal reorganization within the Holley/High Performance Industries corporate family or a financing/security interest (plus its release). No transfer to a third-party licensing entity is on record.

Timeline diagram

timeline
    title Ownership of US 5890476
    1996 : Provisional application filed
    1997 : Non-provisional application filed
    1999 : Patent issued to Barry S Grant
    2008 : Security agreement to Branch Bank and Trust
    2011 : Barry Grant Inc assets sold at auction
         : Assigned to High Performance Industries
         : Transferred to Demon Fuel Systems
    2012 : Lender security agreements recorded
         : Wilmington Trust lien released
    2013 : GE Capital security agreement
         : Prior lender liens released
    2014 : Demon Fuel Systems merged into Holley
    2015 : Cerberus security agreement recorded
    2017 : Patent expired
    2018 : Cerberus lien released
         : UBS and AEA security interests
    2021 : UBS and AEA liens released

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The only operating-entity-to-affiliated-entity move is Reel 027371/0471 (High Performance Industries → Demon Fuel Systems) and the later Merger at Reel 032826/0413 (Demon → Holley). Both assignees are members of the same manufacturing group; neither is an "IP/Licensing/Holdings" vehicle, and no licensing-only LLC ever appears.

2. Known asserter in the chain — Not present. No assignee in the chain (Barry S. Grant; BB&T; High Performance Industries; Demon Fuel Systems; Holley Performance Products; Wells Fargo; Wilmington Trust; LBC Credit; Hawthorn Finco; GE Capital; Cerberus; UBS; AEA Debt Management) matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Conversant/Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, or any Spangenberg-linked entity. The financial names are secured lenders, not asserters.

3. Repeat correspondent across the chain — Unclear / not retrieved. I could not obtain correspondent (filing-attorney) fields from Assignment Center, so I cannot state whether one attorney recurs. The only indirect tell available: the Demon Fuel Systems reel/frames (027371/0471, 028342/0295, 028487/0941, 031496/0062, 032826/0413) recur verbatim on sibling Holley-family patents (US 5,211,205; US 5,809,972), which shows a single common recording filer for the whole corporate family — but that is a corporate-family filing pattern, not an NPE tell, and I have no names to cite.

4. Cascading transfers — Not present (as an NPE signal). There were multiple recordings in 2011–2014, but they are sequential steps of one corporate reorganization (HPI → Demon → merged into Holley) plus their financing liens, not transfers through unrelated chained LLCs with shared agents.

5. Pre-litigation transfer — Not present. No infringement suit naming this patent was found in the searches I ran, and the chain's last movement (2021) postdates the patent's 2017-08-07 anticipated expiration by four years, foreclosing a litigation-motivated transfer window.

6. Bankruptcy fire-sale — Present (but not an NPE indicator). Barry Grant, Inc. filed Chapter 11 2009-10-13 → converted to Chapter 7 → operations ceased 2011-02-18 → operating assets auctioned to High Performance Industries 2011-07-06. The patent's own move is reflected at Reel 026565/0001 (Grant → High Performance Industries, executed 2011-07-06, i.e. the auction date), preceded by the BB&T collateral recording at Reel 022162/0214 (2008-12-23).

7. Privateering — Not present. No evidence that Holley/High Performance Industries transferred the patent to an NPE to assert on its behalf; the asset stayed in the family and never moved to an asserter.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at Holley Performance Products Inc., an operating manufacturer.

Verdict

Operating-company assertion. The chain ends at Holley Performance Products Inc., a large operating manufacturer of performance fuel and nitrous systems, following the Merger at Reel 032826/0413 (executed 2014-04-10, recorded 2014-05-06) that absorbed Demon Fuel Systems. Every post-2011 link is either an intra-group reorganization (Reels 027371/0471, 032826/0413) or a secured financing plus its release (Reels 027480/0708, 027490/0852, 028342/0295, 028487/0941, 031496/0062, 036664/0148, 047419/0953, 047429/0343, 048147/0510, 058944/0279, 058948/0926) — zero NPE signals. Caveat: the verdict label's parenthetical requires the assignee to be suing actual competitors, and I found no recorded litigation on this patent, so read this as "operating-company ownership with non-NPE chain" rather than confirmed competitive assertion. The single genuine anomaly — the 2011 bankruptcy fire-sale (Barry Grant, Inc., Chapter 7) — is a distress-driven asset sale to an operating buyer, not a troll pattern.

Verify at: https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html — search patent number 5890476 (both surface the same underlying records). Note: the USPTO Assignment Center and CAFC docket were not directly queried in this pass; the correspondent fields and the "no litigation" finding should be confirmed there before reliance.

I'll search for the patent and its cited references to verify and enrich the prior-art analysis.

Now let me research the remaining cited references to complete the prior-art analysis.

I've completed the searches I was able to run before hitting the tool-call limit. Here is the prior-art analysis. Where I could not retrieve a reference's full text, I say so explicitly rather than inferring content.

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Prior-art analysis — US 5,890,476 A ("Fuel delivery nozzle")

1. Target patent — confirmed record (not a similar number)

Source: https://patents.google.com/patent/US5890476/en ; https://portal.unifiedpatents.com/patents/patent/US-[5890476](/patent/5890476)-A

Legal-status consequence for this task: because the patent expired 2017‑08‑07 and shows "Expired – Lifetime," there is no live patent to invalidate, and no post‑grant or appellate exposure. The prior-art analysis below is therefore retrospective and probative (what the art taught, and what the examiner must have relied on to allow the claims), not defensive.

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2. The §102 gate that governs everything below

§102 anticipation requires a single reference disclosing every element of the claim, arranged as in the claim. Two dates control which of the 13 cited references can even qualify:

• Invention/priority benchmark: 1996‑08‑07 (provisional 60/023,549). References whose filing date predates this can be §102(a)/(b)/(e) art.
• §102(e) additionally captures a US patent or published application by another filed before the applicant's invention, even if it issued after. So a late‑issuing reference can still anticipate if its filing predates the applicant's invention date (or, for claims without provisional support, the applicant's effective filing date).

This gate produces the single most important finding in this report (Section 6): the closest reference to the bell‑port claims, US 5,699,776, was filed 1997‑03‑06 and issued 1997‑12‑23 — both after the 1996‑08‑07 priority date.

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3. Reference-by-reference

Retrieval status legend: ✅ = full text (spec + claims) retrieved and read; ⚠️ = citation metadata only — I did not retrieve the full text, so no §102 mapping is asserted for it.

3.1 The two Nitrous Oxide Systems "Nozzle" patents — the closest same-field art ✅

R1 — US 4,798,190 A

• Full citation: US 4,798,190 A, "Nozzle," Vaznaian, Dale L.; Thermos, Michael J.; assignee Nitrous Oxide Systems, Inc. (Cypress, CA). App. 06/868,938.
• Dates: filed 1986‑05‑30; published 1989‑01‑17 — well before the '476 priority date.
• Description (verbatim-derived): A "Y shaped nozzle having a pair of input ports and a single output port." One input feeds N₂O into a hollow sleeve exiting at the output port; the second feeds fuel through a tubular fuel line that runs the length of the hollow nozzle and terminates at the output port, "such that said fuel is constrained to travel in said fuel line and is isolated from said cavity" (claim 1). N₂O at 500–1000 PSI, fuel at 3–12 PSI. "As the nitrous oxide exits past the end of the fuel line, it creates a vacuum which aides in drawing the fuel from the line." Liquid N₂O "begins to change to the gaseous state in the nozzle housing." Housing carries a threaded region 16 for mounting into a manifold port.
• §102 relevance:
  • Claims 1, 2, 4 — no anticipation. R1 has no wing-shaped tip, no leading edge/cord line, no arcuate diverging walls, no notch/nose, no parallel constant-area conduits (its conduits are concentric, per '190 claim 2 "said cavity is substantially cylindrical"), and no jet fittings with flow constrictions at the base. The tip geometry that distinguishes all of '476's independent apparatus claims is absent.
  • Claim 5 — no anticipation. R1's output port is "an angular opening in the side of member 10," not an enlarged bell-shaped exit port of a breadth greater than the breadth of the nitrous oxide conduit facing in the direction of manifold flow.
  • Claim 6 — no anticipation. No bell-shaped exit port, hence no "expanding the nitrous oxide as it passes through the bell-shaped exit port."
  • Residual value: strong §103 art on the "liquid N₂O drawn out by high-pressure N₂O flow / low-pressure-at-outlet" concept, and on the functional "nitrous oxide supply means" element of claim 1.

R2 — US 4,827,888 A

• Full citation: US 4,827,888 A, "Nozzle," Vaznaian, Dale L.; Thermos, Michael J.; assignee Nitrous Oxide Systems, Inc. (Cypress, CA). App. 07/184,334.
• Dates: priority 1986‑05‑30; filed as a continuation of the '190 application on 1988‑04‑21; published 1989‑05‑09. Prior art on any measure.
• Description: Same disclosure as R1 (continuation), with IPC classes F02M25/10 and F02M67/06 — note that F02M25/10 is also one of the '476 patent's own classifications, which is why the examiner pulled it.
• §102 relevance: Identical conclusion to R1 — no anticipation of claims 1–6. Worth noting the examiner cited both members of this family, indicating reliance on the family disclosure rather than a specific claim.
• ⚠️ Source discrepancy to flag (not corrected): the Google Patents "Patent Citations" table for '476 lists US4827888A twice (a duplicate row). The unique cited set is 13, not 14. US 5,699,776's own front page describes this family as: "N₂O nozzles having concentric fuel and N₂O conduits. Each conduit … exits into a V-shaped notch cut across the width of the nozzle body." That V‑notch is the closest antecedent in the cited art to '476's notch/nose (claims 2–3) — but it is a notch across the body, not an undercut nose with an overhanging lip and a right-angled normal surface.

3.2 The bell-emitter nozzle — closest art on claims 5–6, but with a date problem ✅

R3 — US 5,699,776 A

• Full citation: US 5,699,776 A, "Nozzle for mixing oxidizer with fuel," Wood, John M.; Stewart, John T.; assignee Nitrous Express, Inc. (Wichita Falls, TX). App. 08/812,686. Primary Examiner Erick R. Solis.
• Dates: filed 1997‑03‑06; issued 1997‑12‑23.
• Description (from the patent's own text): "A nitrous oxide nozzle … has two inlet ports, each of which communicate with a conduit. A nitrous oxide conduit vents into the apex of a bell-shaped emitter, and a fuel conduit vents into a side portion of an atomizing cavity adjacent the emitter, so that high-pressure nitrous oxide gas flowing through the emitter entrains fuel flowing through the fuel conduit, then atomizes the fuel and mixes with the fuel." Conduits are "parallel to each other or substantially so" and, in one embodiment, "each conduit has a diameter of 0.073″." Emitter axis "is at 90° to the length of the nozzle body; i.e., the emitter exhausts sideways." Body has a threaded shoulder 18 mating with female threads in the manifold runner opening. N₂O at 900–1,050 psi; fuel at high-performance pressure. Representative claim 7 (method): introducing N₂O into the conduit → passing it to an apex of the bell-shaped emitter → venting through the emitter → passing through an atomizing cavity adjacent the emitter outlet → introducing fuel via a fuel conduit "having a vent communicating with a side portion of said atomizing cavity, whereby said fuel is entrained by and mixed with a flow of nitrous oxide."
• §102 relevance:
  • Claim 6 (method) — this is the only cited reference that maps element-for-element. Compare: '476 claim 6 steps (introduce N₂O; pass base→tip through the bell-shaped exit port; expand as it passes through that port; pass away and continue expanding; introduce fuel; vent fuel adjacent the port in a direction to intersect the N₂O moving away; entrain/mix). R3's claim 7 + spec supply: the conduit run, the bell emitter (expansion), the adjacent fuel vent, the intersecting/entraining direction, and continued expansion outside the port. The residual gaps are (i) "base to tip" longitudinal framing of the conduit and (ii) explicit "continuing to expand." Both are arguably inherent in the disclosed 90°-sideways bell emitter.
  • Claim 5 (bell-shaped exit port apparatus) — close. R3 has all of: body with tip/base/intermediate mounting portion, two base-to-tip conduits, an emitter whose outlet is "enlarged" relative to the N₂O conduit (the bell has a maximum interior curvature of 50°–56°, optimal 53°), oriented to discharge in the direction of runner flow, and a fuel outlet adjacent it. The residual gaps are the claim's explicit "breadth greater than the breadth of said nitrous oxide conduit" comparison and the "fuel expands" recital.
  • Claims 1, 2, 4 — no anticipation. No wing-shaped tip, no leading edge/cord line, no arcuate wings, no undercut nose/notch, no jet fittings releasably mounted at the base with flow constrictions (R3's fittings are supply-line fittings 14).
  • ⚠️ TIMELINE FLAG — the crux. R3 was filed 1997‑03‑06 and issued 1997‑12‑23, i.e., after '476's 1996‑08‑07 provisional date. On its face, R3 cannot be §102(a)/(b) art and cannot be §102(e) art either (its filing must predate the applicant's invention). Yet it appears in the '476 face citations. Two possible explanations, both of which I flag as inferences I cannot verify: (a) Google's merging of "Citations" and "Cited By" tables has mis-binned a post-dating reference; or (b) the examiner applied R3 under §102(e) on the theory that claims 5 and 6 (the bell-port claims) were not supported by the 1996‑08‑07 provisional under §112 and therefore carry an effective date of 1997‑08‑07 — in which case R3's 1997‑03‑06 filing date would precede it and R3 would be §102(e) art against claims 5–6. I did not retrieve the provisional's text, so (b) is a hypothesis, not a finding. If (b) is correct, it explains simultaneously why the bell-port claims survived the wing-less NOS art and why the closest art in the world to those claims is on the face of the patent.

3.3 The control-system references ✅/⚠️

R4 — US 5,269,275 A

• Full citation: US 5,269,275 A, "Pulse width modulated controller for nitrous oxide and fuel delivery." Google's citation table for '476 lists the inventor as "David Rook"; the patent's own front page lists [75] Inventor: David Dahlgren with [73] Assignees: David Rook and David Dahlgren. ⚠️ I flag this discrepancy literally and do not auto-correct it. App. 07/970,395; Primary Examiner E. Rollins Cross.
• Dates: filed 1992‑11‑02; issued 1993‑12‑14 (prior art).
• Description: An electronic, PWM-based controller for metering liquid N₂O and "enrichment fuel"; claims are directed to sensor/memory/multiplier/comparator/driver circuits and to a method of continuously adjusting pulse widths by engine speed and throttle position. Figure 1 shows separate N₂O solenoid 107 and fuel injector 109 spraying into an intake passage; Figs. 2a/2b show carburetor spacer plates and a spray bar.
• §102 relevance: No anticipation of any of claims 1–6. R4 discloses no nozzle body, no tip geometry, no conduits, no jet fittings. It is background art establishing that high-pressure N₂O / low-pressure enrichment-fuel delivery systems were well known by 1992 — relevant to the preamble context and to §103, not §102.

R5 — US 5,595,163 A ⚠️

• Full citation: US 5,595,163 A, "Apparatus and method for controlling the fuel supply of a gas-fueled engine," Hitachi America, Ltd.
• Dates: filed 1995‑06‑06; published 1997‑01‑21.
• Description (from citation metadata only): an electronic/control apparatus for gas-fueled engine fuel supply.
• §102 relevance: Not established. I did not retrieve the text. On its title and field it is a control reference, not a nozzle-geometry reference; no basis to assert an §102 mapping against any of claims 1–6.

3.4 Fuel-feed and atomizing-nozzle references ⚠️

R6 — US 5,449,120 A

• Full citation: US 5,449,120 A, "Fuel feed apparatus of internal combustion engine," Nippondenso Co., Ltd. (Tani et al.). Filed 1991‑06‑11; published 1995‑09‑12. Classified in the same 123/531 neighbourhood as this art (it appears on the face of US 5,699,776 as "5,449,120 9/1995 Tani et al. …… 123/531").
• §102 relevance: Not established — text not retrieved. A fuel-feed apparatus reference; no disclosed wing tip or bell port can be attributed to it on the evidence I have.

R7 — US 5,456,415 A

• Full citation: US 5,456,415 A, "Atomizing nozzle for liquids," Gardner, James J. Filed 1994‑04‑07; published 1995‑10‑10.
• §102 relevance: Not established — text not retrieved. Cited by the examiner for the general proposition of liquid atomization at a nozzle; most plausibly §103 art on the "atomization is enhanced by low pressure and turbulence" objective, not §102.

R8 — US 5,072,883 A

• Full citation: US 5,072,883 A, "Full cone spray nozzle with external air atomization," Spraying Systems Co. Filed 1990‑04‑03; published 1991‑12‑17.
• §102 relevance: Not established — text not retrieved. This is the cited art most on-point for the external (outside-the-nozzle) low-pressure atomization concept that '476 relies on, so it is the reference I would verify next if the mapping mattered; but I will not assert a claim mapping without the text.

3.5 Older combustion/liquid-feed and jet references ⚠️

These five are the "heritage" citations typical of an examiner establishing that plural-fluid injection nozzles, multiple-jet devices and combustion control long predate the field:

R9 — US 2,551,114 A — "Two-liquid feeding device for combustion chambers," Daniel and Florence Guggenheim. Filed 1948‑03‑24; published 1951‑05‑01. §102 relevance: not established (text not retrieved). Title indicates a two-fluid (fuel + oxidizer) feeding device — the earliest two-liquid antecedent in the cited set, but no wing or bell-port geometry is attributable to it on the evidence I have.

R10 — US 2,912,064 A — "Methods and apparatus for reclassifying aerosols," C A Norgren Company. Filed 1956‑01‑13; published 1959‑11‑10. §102 relevance: not established (text not retrieved). Aerosol-classification/atomization art.

R11 — US 3,416,730 A — "Apparatus for providing multiple liquid jets," Perry, Charles C. Filed 1963‑06‑05; published 1968‑12‑17. §102 relevance: not established (text not retrieved). Multi-jet liquid delivery art.

R12 — US 3,747,859 A — "Torch for thermochemical processing of work pieces," Messer Griesheim GmbH. Filed 1970‑09‑19; published 1973‑07‑24. §102 relevance: not established (text not retrieved). Fuel/oxidizer torch art.

R13 — US 4,270,508 A — "Combustion control system," U.S.A. 161 Developments Ltd. Filed 1979‑10‑12; published 1981‑06‑02. §102 relevance: not established (text not retrieved). Combustion-control art.

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4. Anticipation matrix

Legend: ✗ = no anticipation (assessed against retrieved text); ▲ = would anticipate if the reference qualifies as prior art, which turns on the priority-date question in Section 6; "not established" = full text not retrieved, no mapping asserted.

✗ for claims 1–4 across R1/R2/R3/R4 is firm, because those four texts were retrieved. The distinguishing element is consistent: no cited reference discloses the "substantially symmetrical double-sided wing" tip with a leading edge facing the air stream, a cord line, and arcuate walls diverging on opposite sides of the cord line as recited in claims 1, 2 and 4 — nor the undercut nose overhanging the notch with a right-angled "normal surface" of claims 2–3.

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5. Where the claims came from — the likely allowability picture

• Claims 1, 2, 4 (wing-tip family): allowed over the entire cited set on the wing geometry and the tip-internal conduit routing (first conduit through the nose, turned ~90° away from the leading edge; second conduit on the remote side of the first, substantially parallel, both constant cross-section, both discharging into the fuel delivery zone). Nothing in R1–R4, or in the citation-titled R9–R13, teaches a wing.
• Claims 5, 6 (bell-port family): these are the divergence point between the '476 patent and US 5,699,776. Both claim an "enlarged bell-shaped exit port/emitter" fed by the N₂O conduit with an adjacent fuel outlet entraining fuel into the N₂O stream; '776's claim 7 method is, on the record, the closest thing in the cited art to '476's claim 6 method. The only reason '476's claims 5–6 were patentable over '776 is the date relationship — which is exactly why the §102(e)/provisional-support question in Section 6 is the analytically decisive issue for this family.
• Claim 3 (U-shaped recess): no cited reference discloses it. R1/R2's V-shaped notch is the nearest neighbour but is structurally different (a lateral V-cut across a body with concentric conduits, versus a U-recess at the intersection of a longitudinal surface and a right-angle normal surface, with the fuel conduit intersecting the base of the U). Claim 3 was almost certainly allowed on that distinction.

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6. Anomalies and open questions — flagged, not resolved

1. Date anomaly (highest significance). US 5,699,776 (filed 1997‑03‑06; issued 1997‑12‑23) postdates the '476 priority date of 1996‑08‑07, yet appears among the '476 face citations. Either the citation binning is an artifact, or the examiner applied it under §102(e) — which would imply claims 5–6 were held not entitled to the 1996 provisional's benefit (effective date 1997‑08‑07). I did not retrieve provisional 60/023,549 and cannot confirm which it is. See the prior section's parallel flag on the one‑day Google/Unified date offset (1996‑08‑07 vs 1996‑08‑06), which compounds the precision problem on this exact date comparison.
2. Inventor discrepancy on US 5,269,275. Google's '476 citation table gives inventor "David Rook"; the '275 front page gives inventor David Dahlgren with Rook and Dahlgren as assignees. Reported as found; not auto-corrected.
3. Duplicate row. US 4,827,888 A is listed twice in the Google Patents "Patent Citations (13)" table. Unique count = 13; do not treat the list as 14 references.
4. Unverified references (9 of 13). I retrieved full text for only US 4,798,190, US 4,827,888, US 5,699,776 and US 5,269,275. Anticipation mappings for the other nine are not established. If any of them matters (most plausibly US 5,072,883 for external air atomization, and US 5,456,415 for liquid atomizing nozzles), their full texts should be pulled before anyone relies on a "no anticipation" statement for them.
5. Anticipation vs. obviousness. Most of what R1–R13 supply is §103 material (a low-pressure zone drawing N₂O out; liquid-to-gas phase change assisting atomization; plural-fluid nozzles; bell emitters), not §102 anticipation of any complete claim. I have labelled them accordingly rather than over-claiming.
6. No litigation/post-grant finding is asserted. Consistent with the earlier section: an expired‑lifetime patent with 2017 expiration is very unlikely to be in live 2026 CAFC/PTAB proceedings, and my searches returned nothing — but this is not established as a confirmed negative.

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7. Bottom line

• Most relevant prior art overall: (1) US 4,827,888 and (2) US 4,798,190 (Vaznaian/Thermos, Nitrous Oxide Systems) — the same-field nozzles that establish concentric conduits, high-pressure liquid N₂O with a vacuum-drawn fuel line, and a V-notch outlet; (3) US 5,699,776 (Wood/Stewart, Nitrous Express) — the closest structural and methodological match to '476's bell-shaped-exit-port claims, subject to the date gate; (4) US 5,072,883 (external air atomization) and US 5,456,415 (liquid atomizing nozzle) as secondary atomization art, both unverified here.
• No cited reference anticipates claims 1, 2, 3 or 4, on the retrieved texts. The wing-shaped tip with its leading edge, cord line and arcuate diverging walls, and the undercut nose/notch geometry, are simply not in the cited art.
• The only genuine §102 exposure in this record is to claims 5 and 6, and only through US 5,699,776 — and that exposure exists only if those claims are not entitled to the 1996‑08‑07 provisional. Resolving that single question resolves the entire anticipation picture for this patent.
• Contradictions with the earlier-generated section: none material. The prior summary's note that '476 is itself later cited as prior art (e.g. in US 2010/0051002 / US 7,966,998 B2, Wade) is consistent with the forward-citation record; the earlier flag on the Google-vs-Unified one-day date offset is directly relevant to item 1 above and should be read together with it.

I'll ground this analysis in the actual cited references before building the §103 combinations.

Now let me pull the remaining cited references to complete the element mapping.

Obviousness Analysis — US 5,890,476 ("Fuel delivery nozzle") under 35 U.S.C. § 103

Prepared 2026-04-26 (per task header) | Analyst: senior US patent analyst

Builds on, and does not repeat, the earlier "Patent summary" and "Litigation summary" sections. Where those sections made findings that bear on §103 (effective dates, citation lists, ownership), I cross-reference them rather than restating. Two new contradictions found today are flagged in §2.4 and §9.

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1. Legal framework applied

Practical consequence: because the priority date is 1996-08-07 and the filing date 1997-08-07, only art dated before those dates qualifies, except §102(e) art (a U.S. patent granted on an application filed before the applicant's invention). That exception is decisive for one reference — see §6, Ground C.

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2. Factual predicates

2.1 Critical dates (as found on the record; not auto-corrected)

• Provisional Ser. No. 60/023,549 — filed 1996-08-07
• Non-provisional 08/908,338 — filed 1997-08-07; issued 1999-04-06
• Google Patents anticipated expiration 2017-08-07, status Expired – Lifetime

2.2 Prior-art reference dates (the 13 examiner-cited references)

2.3 References retrieved in full text today (my confidence floor for the analysis)

Retrieved / verified: US 4,798,190 (claims + full description), US 4,827,888 (continuation of '190; same specification), US 5,699,776 (full text + claims), US 2,551,114 (full description), US 5,072,883 (full text + claims). Also retrieved as secondary interpretive evidence: US 6,520,165 (Steele, 2003) and US 6,116,225 (Thomas, "Laminar flow nozzle"), both of which describe the '476 and '776 from the perspective of later artisans.

NOT retrieved (title/date/assignee only — I will not invent disclosures): US 2,912,064; US 3,416,730; US 3,747,859; US 4,270,508; US 5,269,275; US 5,449,120; US 5,456,415; US 5,595,163. Where a ground depends on one of these, I say so.

2.4 New contradiction flagged (per the "do not auto-correct" rule)

US 5,269,275's inventor is given inconsistently in the record: the Google Patents page for US 5,890,476 lists it as "David Rook"; the front page of US 5,699,776 and Justia's '776 page both list the identical patent number as "Dahlgren." I report both and correct neither. This is a new discrepancy, distinct from the one-day Google/Unified date offset already flagged in the prior "Patent summary." Neither discrepancy changes any §103 conclusion below — Wood's 1997-03-06 filing is ~7 months after either candidate priority date (1996-08-06 or 1996-08-07).

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3. Level of ordinary skill in the art (PHOSITA)

Circa August 1996 in the nitrous-oxide / high-performance fuel-delivery field, a PHOSITA would have had either (a) a bachelor's degree in mechanical engineering plus 2–3 years of experience in engine induction and fluid-handling hardware, or (b) — more realistically for this art, given its lineage — several years of hands-on nitrous-system design/tuning experience with working knowledge of (i) N₂O phase behavior and the 500–1,100 psig supply range, (ii) replaceable-jet metering, (iii) two-fluid (gas-assist) atomization, and (iv) the effect of manifold obstructions on airflow.

This matters because a pragmatic-skills PHOSITA, not a PhD aerodynamicist, is the correct yardstick — and a pragmatic mechanic would know that a streamlined body in a duct creates a low-pressure wake, and would know that a jet of high-pressure gas entrains and atomizes a liquid stream.

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4. Claim construction of the terms that drive the §103 result

Drafting defects noted (not §103, but they affect claim scope and enforceability): claim 1 recites "releasably mounted to the base of said housing" while the antecedent is "nozzle body" (antecedent-basis defect); and the "bell-shaped" claim term is unsupported by the specification's vocabulary. These broaden or muddy the claims in ways that generally assist a §103 challenger.

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5. Reference capsules (grounding for the combinations)

5.1 US 4,798,190 / US 4,827,888 — Vaznaian & Thermos, Nitrous Oxide Systems ("NOS")

Fully retrieved. The closest same-field, same-problem art, and on the face of the '476.

Discloses: a nozzle housing with first and second input ports and an output port, mounted by a threaded region 16 "which allows the nozzle … to be easily mounted into a threaded opening in a manifold port leading to the combustion chamber" (claim 14: "threads formed thereon for threaded engagement with manifolding"); N₂O at 500–1,000 psig, fuel at 3–12 psig; N₂O "enters the nozzle housing in liquid form … pressurized at approximately 800 PSI. Upon entering the nozzle housing, there is a pressure drop to approximately 500 PSI. The liquid nitrous oxide begins to change to the gaseous state in the nozzle housing"; and "the high pressure nitrous oxide gas exits the nozzle, and thereby creates a vacuum in the fuel line 13, drawing fuel into the stream of nitrous oxide" — i.e., a low-pressure zone at the outlet that draws fuel out of its conduit. It also discloses an "angular opening in the side of member 10" as the output port (i.e., a conduit that turns to discharge laterally), and "threaded coupling members 17 and 18 … inserted in the threaded openings to form inlet ports 11 and 12" (i.e., releasable threaded base fittings). The multi-port plate embodiment (Fig. 3–5) has multiple outlets.

Crucially, US 5,699,776 characterizes this family for us: "U.S. Pat. Nos. 4,798,190 and 4,827,888 disclose N₂O nozzles having concentric fuel and N₂O conduits. Each conduit in this type of nozzle assembly exits into a V-shaped notch cut across the width of the nozzle body. Because the fuel and N₂O can spread laterally and exit the sides of the V-shaped notch as well as the wide mouth of the notch, the two components are not mixed as thoroughly as possible."

That is a notched, overhung discharge tip with two conduits opening into a common recess — the structural genus of '476 claim 2.

5.2 US 5,699,776 — Wood & Stewart, Nitrous Express ("Wood")

Fully retrieved. Filed 1997-03-06; issued 1997-12-23.

• Two "parallel to each other or substantially so" conduits, each "0.073 inch" diameter, running the length of the body — squarely the '476's "substantially parallel … substantially constant cross-sectional area" limitation.
• Bell-shaped emitter 24 with the "N₂O conduit 20 … drilled so as to communicate with and vent into an apex of the bell-shaped emitter 24."
• "The axis of symmetry of the emitter 24 is at 90° to the length of the nozzle body; i.e., the emitter exhausts sideways relative to the nozzle body" — with the nozzle installed through the manifold wall, "sideways" = along the manifold runner, i.e., in the direction of fluid flow through the manifold.
• "the exhaust end of the emitter 24 opens into an atomizing cavity 26"; "An outlet end of the fuel conduit 22 vents through the wall of atomizing cavity 26. The high-velocity flow of the N₂O from the emitter and through the atomizing cavity caused a decrease in pressure in the zone adjacent the flow; the reduced pressure pulls the liquid fuel from the end of the fuel conduit into the oxidizer stream."
• "Mixing of fuel and oxidizer occurs within the atomizing cavity 26 and continues in a zone outside of and adjacent to the atomizing cavity."
• Threaded shoulder 18 for manifold installation; N₂O at 900–1,050 psi; "Earlier versions of N₂O nozzles extended only slightly into the runner. Experiment has shown, that maximum performance occurred when the body … extended further into the runner, so that the emitter is near the centerline of the runner."

5.3 US 2,551,114 — Goddard ("Goddard")

Fully retrieved. Two-liquid (gasoline + liquid oxygen) feed for a combustion chamber: a conical/pointed member 12 with one liquid forced through it as a fine mist and the second delivered through an annular slot 18 "against the outer surface of the member 12 … forms a thin film along said outer surface and becomes intermingled with the mist or spray of gasoline." Expressly: "This film of oxygen not only mixes effectively with the gasoline but also acts as a cooling agent for the outer surface of the member 12."

Goddard is the only cited reference that expressly addresses cooling the discharge member with the co-delivered fluid — which is exactly the problem the '476 identifies in its Background (frost/ice build-up altering the flow pattern).

5.4 US 5,072,883 — Vidusek, Spraying Systems ("Vidusek")

Fully retrieved. A two-fluid external-mixing atomizer: liquid from a diverging outlet end 55 of a central orifice; a second pressurized fluid delivered through an annular slot 62 formed between the diverging outlet and a frusto-conical end cap 40, and "the discharge of air through the slot 62 is in a direction generally transverse to the direction of the liquid spray discharge," so that the gas "surrounds and impinges upon the liquid flowing from the orifice, and atomizes the liquid." Its liquid passage is fed by a slant bore 22, i.e., a conduit that turns.

5.5 US 2,912,064; 3,416,730; 3,747,859; 4,270,508; 5,269,275; 5,449,120; 5,456,415; 5,595,163

Not retrieved. Used below only for their titles/classes, and I say so explicitly. The 1956 Norgren reference — "Methods and apparatus for reclassifying aerosols" — is, on its title, a gas-stream re-atomization disclosure, which would be the most on-point teaching for "use a flowing gas stream to break up a liquid into droplets," but I have not verified its disclosure and will not build a ground on it.

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6. Grounds of rejection

GROUND A — Claims 1, 2, 3, 4: NOS ('190/'888) in view of Wood ('776), further in view of Goddard ('114)

Motivation (Ground A): both '190/'888 and Wood are in the identical field (N₂O + fuel nozzles for high-performance engines), address the identical problem (thorough mixing/atomization; avoiding puddled fuel), and Wood expressly identifies the deficiencies of the '190/'888 V-notch ("the two components are not mixed as thoroughly as possible"). That is a textbook TSM-style motivation supplied by the art itself. Goddard supplies the further, independent motivation — cool the discharge member by directing the co-delivered fluid against/around it — which is precisely the '476's stated objective.

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GROUND B — Claims 1 and 4: NOS ('190/'888) in view of Goddard ('114) and Vidusek ('883)

Independently of Wood, Vidusek supplies the "external, transverse two-fluid impingement" architecture the '476 claims:

• Two concentric fluid paths (central liquid orifice + outer annular passage) — NOS's concentric N₂O cavity/fuel line is the same architecture;
• The second fluid turns through an annular slot 62 and is discharged "in a direction generally transverse to the direction of the liquid spray discharge" — the '476's "first conduit … turned at an angle … opening toward said fuel delivery zone";
• The gas "surrounds and impinges upon the liquid flowing from the orifice … external to the liquid discharge orifice" — the '476's low-pressure, external two-stream intersection;
• A diverging outlet end 55 producing a spray cone — the '476's "enlarged/bell-shaped exit port."

Motivation (Ground B): Vidusek is analogous art (fluid atomization by gas impingement) in the same physical problem class; its express object — "atomizing jets … directed inwardly toward the centerline of the nozzle" so the gas "coact[s] with the liquid discharge at a point downstream of, and thus external to, the liquid discharge orifice" — is the same improvement a PHOSITA would seek for the NOS nozzle. KSR rationale: use of a known technique (two-fluid external-mixing atomization) to improve a similar device in the same way, with predictable results.

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GROUND C — Claims 5 and 6: Wood ('776) alone (plus NOS for the manifold-mount context)

This is the strongest single-reference ground in the file, and it should be run carefully because of the §102(e) timing issue.

Element-by-element against claim 5:

Claim 6 (method) maps to Wood step-for-step; compare Wood's own claim 7:

Wood claim 7: "introducing nitrous oxide into said nitrous oxide conduit, passing the nitrous oxide through said nitrous oxide conduit to an apex of said bell-shaped emitter, venting the nitrous oxide through said bell-shaped emitter, passing the nitrous oxide through an atomizing cavity adjacent an outlet of said emitter, and introducing fuel into said atomizing cavity via a fuel conduit having a vent communicating with a side portion of said atomizing cavity, whereby said fuel is entrained by and mixed with a flow of nitrous oxide…"

'476 claim 6: "introducing nitrous oxide into the nitrous oxide conduit, passing nitrous oxide from the base to the tip … through the bell-shaped exit port, expanding the nitrous oxide as the nitrous oxide passes through the bell-shaped exit port, passing the nitrous oxide away from the bell-shaped exit port, continuing to expand …, introducing fuel into the fuel conduit, venting fuel from the fuel conduit at a position adjacent the bell-shaped exit port in a direction to intersect the nitrous oxide passing away from the exit port, and entraining fuel in and mixing fuel with the flow of nitrous oxide as the nitrous oxide moves away from the exit port."

These are the same method with different nouns. The only arguable distinction is that Wood's fuel vents into the cavity/side wall whereas the '476 vents fuel into a U-shaped recess (that is claim 3, not claim 5/6).

⚠️ The timing problem — state it plainly. Wood issued 1997-12-23, i.e., after the '476's 1997-08-07 filing date, so it is not §102(a) or §102(b) art. It can only be §102(e) art, which requires Wood's 1997-03-06 filing date to precede the applicant's date of invention. If claims 5 and 6 are entitled to the provisional's 1996-08-07 date, Wood does not qualify. If the "bell-shaped exit port" limitation and the claim-6 method steps were not supported by provisional 60/023,549 (a real possibility given that the specification never uses the phrase "bell-shaped" and describes only an "enlarged exit port 52"), then claims 5 and 6 get the 1997-08-07 date and Wood is §102(e) art.

The examiner cited Wood on the face of the '476, and the '476 nonetheless issued with claim 6 mirroring Wood's claim 7 — which supports the inference that (a) the examiner treated Wood as available prior art (likely under §102(e), implying some claims were not provisional-supported), and (b) the applicant was able to distinguish it on some basis, or relied on the provisional date for the claims that read on Wood. Reproducing this ground requires pulling the 08/908,338 prosecution history (file wrapper) to see exactly how Wood was applied and traversed. Without that, I assign Ground C a high technical strength but a contingent legal status.

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GROUND D — Claims 5 and 6, fallback: NOS ('190/'888) in view of Wood ('776) and Vidusek ('883)

If Ground C fails on the provisional-benefit question, claims 5 and 6 remain obvious over NOS + Vidusek + the knowledge in the art:

• NOS supplies manifold-threaded body, two inlet ports, two conduits, high-pressure liquid N₂O, low-pressure draw of fuel at the outlet, and a turned/angular output port;
• Vidusek supplies the two-fluid external-mixing geometry: a diverging orifice outlet and a second fluid discharged transversely, external to the orifice, to surround and atomize the first;
• The bell-shaped/enlarged character of the outlet is an obvious shape choice for a diverging discharge orifice, taught literally by Vidusek ("diverging outlet end 55") and by Wood's "bell-shaped emitter."

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GROUND E — The "jet fitting" limitations (claims 1 and 2): NOS ('190/'888) + art-recognized replaceable jets

• NOS discloses threaded coupling members 17 and 18 inserted in threaded openings in the nozzle base to form the two inlet ports — a releasable, threaded base fitting in fluid communication with each conduit.
• Replaceable metering jets with selected orifice diameters were not merely known but the ordinary metering mechanism of the field; Wood's nozzle uses supply-line fittings at a flared inlet end and its later critics (e.g., US 6,116,225: "jets 4b each have an orifice 4c … to regulate the rate of fuel or gas entry") confirm the practice. KSR: "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results."

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GROUND F — "Substantially constant cross-sectional area" (claims 1, 2)

Wood's 0.073" uniform-diameter, parallel conduits running the full length of the nozzle assembly meet this limitation outright (and Wood claims the 0.073" dimension). The '476's specification states the rationale itself ("so as to reduce the tendency of the fluids to change pressure as the fluids flow through the conduits"), which converts a §103 dispute into an admission of the function — the structure is then a predictable design choice.

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7. Why a PHOSITA would have combined these references (KSR rationales, itemized)

1. Same field, same problem, same solution type. All of NOS, Wood, and (for the later claims) Steele's field are nitrous-oxide/fuel nozzles for high-performance engines; the references share the express objects of thorough fuel/oxidizer mixing and improved atomization.
2. Express criticism in the art supplies the TSM. Wood's Background states the '190/'888 V-notch nozzle lets "the fuel and N₂O … spread laterally and exit the sides of the V-shaped notch … [so] the two components are not mixed as thoroughly as possible." That is a suggestion to modify the NOS tip — precisely the modification the '476 claims.
3. A reference that addresses the '476's stated problem directly. Goddard teaches that the second fluid, directed against the discharge member's outer surface, "acts as a cooling agent" — answering the frost/ice problem the '476 recites in its Background.
4. Simple substitution of known elements. Concentric → parallel, side-by-side conduits (Wood); angled → bell-shaped/enlarged discharge (Wood, Vidusek); single fluid orifice → annular second-fluid orifice (Vidusek). Each is a substitution of a known element for a known element with a predictable result.
5. Use of a known technique to improve a similar device in the same way. External, transverse gas-impingement atomization (Vidusek) applied to a nitrous nozzle.
6. Design incentives and market forces. The sanctioning rules of the field capped the emitter orifice diameter (US 6,116,225: NHRA 0.110", IHRA 0.116") and jet orifices were the primary metering knob — foreclosing the flow-rate variable and pushing development toward tip geometry, exactly the variable the '476 claims. Cf. KSR ("design incentives and other market forces can prompt variations").
7. Deep-insertion teaching. Wood teaches that maximum performance occurs when the nozzle body "extended further into the runner, so that the emitter is near the centerline." Placing the tip squarely in the fastest-flowing part of the runner increases the aerodynamic consequences of tip shape and gives a concrete reason to streamline it and to exploit (rather than fight) the local low-pressure region.
8. Common sense / elementary fluid mechanics. A streamlined body in a duct creates lower pressure loss and a low-pressure wake than a bluff body. Creating and using that wake to draw fluids out and away from a nozzle is a predictable use of known physics, and the '476's own Background frames it as a desideratum ("it is desirable to form a zone of low pressure about the nozzle tip … so as to tend to draw the nitrous oxide into the zone of low pressure and away from the nozzle").

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8. Best counterarguments for the patentee (and how they fare)

(A) "The NOS reference teaches away." NOS states the liquid N₂O "begins to change to the gaseous state in the nozzle housing" and that this vaporization "serves to cool the fuel line within the nozzle" — an intended internal phase change. Claim 1 requires N₂O pressure "sufficient to retard the change of state … until it approaches said fuel delivery zone." This is the patentee's strongest §103 argument for claim 1.

• Rebuttal: Wood expressly teaches N₂O expanding from the emitter apex onward (i.e., at the discharge zone), so the combined teachings supply the limitation; and the '476's own spec concedes the N₂O "begins its change of phase as the nitrous oxide passes through the enlarged exit port," so the limitation is a matter of degree, not a bright line. Also, NOS's phase change is incidental to cooling the fuel line, not a teaching that external flashing is inoperative or inferior.

(B) "The specific symmetrical airfoil/wing geometry is not disclosed." True as to exact curvature. But claims 1, 2, and 4 recite no numerical curvature, camber, or thickness ratio — they recite symmetry, a leading edge, diverging walls, an undercut nose, and a notch. Those are the generic features of a notched/streamlined discharge tip (NOS's V-notch + Wood's cavity + the ordinary choice to streamline). Claim 4 is broader still ("trailing edge shaped to form a zone of low pressure") and is essentially a functional recitation of any flow-obstructing tip.

(C) "The combination changes the principle of operation of NOS." Weak: the principle (high-pressure N₂O entrains and atomizes low-pressure fuel at the discharge) is preserved; only the conduit arrangement and tip geometry change, and Wood shows exactly that change in the same family of device.

(D) §112 defenses. Available (see §4: "cord line," claim 1's "housing"/"body" antecedent, claim 5's unsupported "bell-shaped"), but these attack validity on grounds other than §103 and don't defeat the obviousness grounds — if anything they make the claims easier to read onto the art.

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9. Claim-by-claim conclusions

Required next step to convert Ground C from "contingent" to "established": obtain the 08/908,338 file wrapper from USPTO PatentCenter (the earlier sections correctly noted PatentCenter was not directly queried) to determine (i) whether the provisional supports the "bell-shaped exit port" limitation and claim 6's steps, and (ii) how the examiner applied and how the applicant traversed US 5,699,776.

New contradiction flagged (see also §2.4): the prior "Patent summary" listed US 5,269,275's inventor as "David Rook" without noting that US 5,699,776's front page and Justia give the same patent as "Dahlgren." Neither identification affects the §103 dates. I flag it rather than reconcile it.

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10. Secondary considerations (Graham factor 4)

I found no evidence of secondary indicia — no commercial-success data with a nexus to the claims, no industry praise, no licensing attributable to the '476, no copying evidence, and no prior adjudication of validity. The record instead shows:

• Post-'476 designs around and improvements on the same problem space — e.g., US 6,520,165 (Steele) criticizes both Wood's '776 and Grant's '476 as still relying on the N₂O stream for atomization and switches to a slot-emitted fuel spray; US 6,116,225 (Thomas) rejects the "bell-shaped emitter" arrangement outright in favor of near-laminar convergence; US 7,147,173 (Competition Cams, "Nitrous fuel nozzle and method of use") is a further follow-on. That pattern suggests the '476's approach was one of several predictable options, which cuts against non-obviousness rather than for it.
• The '476's 41 forward citations show the field built on and around it, but citation volume is not a Graham secondary consideration.
• The dense security-interest/assignment record (Branch Banking & Trust → High Performance Industries → Demon Fuel Systems → Holley, plus Wells Fargo, Wilmington Trust, LBC, Hawthorn, GE Capital, Cerberus, UBS, AEA) documents collateral, not commercial success attributable to the claimed nozzle.

If the patentee needed a rebuttal, the strongest available theme would be that the art was crowded, that the '476 was the first to couple aerodynamic low-pressure generation to the phase-change location, and that the examiner allowed the claims over 13 references — but none of that substitutes for evidence of unexpected results or nexus.

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11. Explicit caveats and confidence

1. What I verified: full text of US 4,798,190 / 4,827,888, US 5,699,776, US 2,551,114, and US 5,072,883; plus US 6,520,165 and US 6,116,225 as interpretive evidence. What I did not verify: US 2,912,064, 3,416,730, 3,747,859, 4,270,508, 5,269,275, 5,449,120, 5,456,415, 5,595,163 — I have not asserted any specific disclosure for these, and no ground above depends on them.
2. The '190 drawing was not retrieved; the "V-shaped notch" description of the '190/'888 tip comes from Wood's Background section, which is a party admission about prior art but is not the primary document. A challenger should confirm against the '190/'888 figures.
3. Ground C's legal status turns entirely on the effective date of claims 5 and 6, which I could not resolve without the file wrapper. Presented as contingent, not established.
4. Statement of the standard limit: this is a technical/validity-style analysis, not a legal opinion, and nothing here is a conclusion of law on validity, enforceability, or infringement (or non-infringement) of US 5,890,476.