US 4572140

Search results for US 4,572,140 — as-found record

I ran targeted searches against Google Patents, Justia, OSTI, FreePatentsOnline, and general web indices, plus queries aimed at Federal Circuit / CAFC 2026 dockets. No CAFC or district-court docket activity for this patent was found. I could not locate any Federal Circuit appeal, IPR, or litigation docket referencing 4,572,140, in 2026 or any other year. That is consistent with the prosecution history: the patent lapsed for non-payment of maintenance fees in 1990 and its full 20-year term would in any event have run to 2004-10-09.

One caution on search hygiene: a query for the string "4572140" also returned a Florida LLC annual report for entity FEI Number 81‑4572140 (sunbiz.org PDF). That is an IRS Employer Identification Number, not the patent. I am treating it as a coincidental numeric collision and excluding it.

Search tooling limitation: I used general web search, not a direct PACER/CAFC CM-ECF or USPTO Patent Public Search query interface. Absence of docket hits is therefore strong but not dispositive.

Bibliographic summary (from the authoritative patent text)

Sources: Google Patents US4572140A, Justia, OSTI 5835022 (confirms assignee "Ram Automotive Co., Canton, OH").

Abstract (as published)

A device used with a fuel charging system in which nitrous oxide is injected into the engine to provide a sudden burst of power to the vehicle. A pressurized cylinder of liquid nitrous oxide is connected to the engine through a delivery conduit and a solenoid valve. A jacket preferably formed of a silicone hose is placed about a portion of the delivery conduit forming a cooling chamber about the conduit. A manifold closes one end of the cooling chamber and an orifice block closes the other end. First and second solenoid valves are connected to the manifold. The first valve purges gaseous nitrous oxide from the delivery conduit and injects it into the cooling chamber where the expanding gas lowers the temperature of the nitrous oxide in the conduit to maintain it in a liquid state prior to being injected into the vehicle engine upon actuation of the second solenoid valve. Heretofore, the gaseous nitrous oxide in the delivery conduit was vented to the atmosphere instead of being returned to the cooling chamber to assist in maintaining the incoming nitrous oxide in a liquid state.

Note the abstract's ordinal labeling of the valves ("first valve" = purge, "second valve" = delivery) is the reverse of the claim 1 convention ("first valve means" = delivery to the engine; "second valve means" = purge). This is a real inconsistency in the source document, not a transcription error on my part — worth flagging for anyone construing claim terms against the abstract.

Independent claims in plain language

Claim 1 — Apparatus claim (the precooler itself)

A nitrous oxide precooler for a vehicle-engine fuel charging system, comprising five elements:

1. (a) A pressurized liquid nitrous oxide container — the bottle.
2. (b) Conduit means carrying the nitrous oxide from the bottle to the engine.
3. (c) First valve means controlling nitrous oxide flow from that conduit to the engine (the delivery solenoid, ref. 42 in the description).
4. (d) Jacket means surrounding a portion of the conduit, defining a cooling chamber that receives gaseous nitrous oxide, so that the nitrous oxide still in the conduit is maintained in a liquid state.
5. (e) Second valve means communicating with both the conduit and the cooling chamber, for purging gaseous nitrous oxide out of the conduit and injecting it into the cooling chamber before the first valve means is actuated.

In short: bottle → conduit → delivery valve to engine, with a sleeve around the conduit that gets fed the boil-off gas, and a purge valve sequenced ahead of the delivery valve.

The "before actuation of the first valve means" limitation in element (e) is the core timing/sequencing hook of the claim — the purge must precede delivery, not merely coexist with it.

Claim 11 — System claim, Jepson/improvement format

This is drafted as an improvement on a known system. The admitted prior-art preamble: a high-performance vehicle fuel charging system having (i) a cylinder of pressurized liquid nitrous oxide, (ii) a supply conduit from the cylinder to the engine, and (iii) a remotely controlled valve in that conduit controlling liquid nitrous oxide flow to the engine.

The improvement consists of only two added elements:

1. Means for forming a cooling chamber about at least a portion of the supply conduit; and
2. Purge means communicating with the conduit and with the cooling-chamber-forming means, for removing gaseous nitrous oxide from the conduit and injecting it into the cooling chamber forming means before the valve permits liquid nitrous oxide flow to the engine.

Plain language: take a conventional nitrous system, wrap a chamber around the supply line, and route the previously-wasted vapor into that chamber ahead of the delivery event. Claim 11 is broader than claim 1 in that it omits the container/manifold/orifice-block structure and states the chamber and purge elements in means-plus-function terms.

Dependent claims (for scope context)

Claims 2–10 depend from claim 1; claims 12–13 depend from claim 11. The narrowest structure appears in claims 5–8: a hose telescopically mounted over the conduit (claim 8 adds a cylindrical manifold section with clamp), closed by a manifold at one end and an orifice block at the other, where the orifice block has a discharge hole for spent gas plus a conduit pass-through opening (claim 6), and the orifice block is two semicircular members with aligned semicircular openings held by a clamp (claim 7). Claim 9 recites the ~900 psi container pressure — a numeric limitation that would be read narrowly. Claims 3 and 10 add solenoid-actuated remote operation and an injection tube to the engine.

Overview of the invention as described

The stated problem: liquid nitrous oxide sitting in the several-feet-long delivery line between the bottle and the solenoid vaporizes before injection, causing an improper mixture. The prior-art fix was to purge that vapor to atmosphere — wasting it and providing no cooling benefit. The patent's insight is to return the purge gas into an annular chamber wrapped around the supply conduit, where its expansion chills the line, keeping the remaining nitrous oxide liquid and increasing its density (more oxidizer per unit line pressure).

Structural description: supply conduit 16 runs from bottle valve 17 into manifold 20 (hollow interior 25, central opening 28 for the conduit, secondary opening 29 for the purge line). Silicone hose 23 (preferably ~3 ft) telescopes over the manifold's reduced-diameter end 22, secured by clamp 24 over rib 26. The far end is closed by two-piece orifice block 32 with discharge holes 36, clamped by ring 40. Delivery solenoid 42 and purge solenoid 45 both mount to manifold 20; purge line 47 runs from valve 45 through manifold interior 25 and secondary opening 29, terminating inside annular chamber 50. Both solenoids are switched from the driver's compartment via switch 51 and common wire 54.

Sequence of operation: driver hits the switch → valve 45 opens, boil-off gas in conduit 16 and manifold 25 flows through purge line 47 into chamber 50 and expands, cooling conduit 16 → valve 42 opens (either via a built-in time delay after valve 45 opens, or via a second manual switch) → liquid nitrous oxide flows to spray bar 6, with fuel valve 7 opened in conjunction via switch 8 → spent vapor vents through orifice block discharge holes, allowing continuous through-flow.

Prior art cited and citing art (relevant to validity/scope)

References cited (6): US 2,715,395 (Finvold, liquid oxygen power booster, 1955); US 3,602,202 (Toyoda Chuo Kenkyusho, 1971); US 3,593,694 (Fuel Injection Eng. Co., fuel-cooling system, 1971); US 4,308,827 (Roe, 1982); US 4,503,832 (Prodatek Corp., 1985); and US 4,494,488 (Ram Automotive Company, "Fuel charging system for high performance vehicles," 1985-01-22) — a same-assignee predecessor, which is the key internal prior art.

Non-patent citations (2): advertising brochure titled "Nitrouscharging by Ice."

Notable forward citation: US 4,869,132 (Clem, Automated electrical switching system) expressly characterizes US 4,572,140 as "a conventional nitrous oxide system" and incorporates it by reference. That characterization — from a third party, in a patent — is a useful piece of evidence about how the reference was understood in the art, and it is quoted verbatim in the FreePatentsOnline text of Clem.

Uncertainty and data-quality flags

• No CAFC 2026 docket exists as far as I can determine. I am stating this as a negative search result, not as verified "no case ever filed." Given the 1990 lapse and 2004 term end, live 2026 appellate activity is highly implausible.
• Reference-numeral inconsistency in the source: the description uses "36" for both the orifice block's discharge hole and the semicircular central opening, and separately numbers the assembled conduit opening "38" (claim 7 recites the aligned openings forming "the conduit means inlet opening" without a numeral). This is a drafting/OCR-level defect in the printed document and could matter in claim construction of claims 6–7.
• Description says "outer end wall 48 of solenoid 20" where context plainly indicates manifold 20. I am reporting the identifier as literally printed rather than silently correcting it, per the operating rule.
• Valve numbering is inverted between the abstract and claim 1, as noted above. Claim 1 governs scope; the abstract should not be read to redefine the ordinals.
• I did not independently verify the post-issuance maintenance-fee chronology against USPTO Patent Center's live maintenance-fee database; the dates above come from the Google Patents legal-events record. The essential fact — lapse for fee non-payment effective 1990-02-25 — is corroborated across the legal-events table and the "Expired — Fee Related" status flag.

I'll search for litigation involving US patent 4572140 specifically.

Initial searches returned false positives (unrelated numbers). Let me search patent litigation databases directly.

Let me check specialized litigation databases and CourtListener directly.

Litigation Search Results: US Patent 4,572,140

Summary: I found no evidence of any litigation involving US Patent 4,572,140.

I searched general web sources, litigation-aggregator references (including Unified Patents' portal/litigation caselist, Docket Alarm, and CourtListener), and targeted queries pairing the patent number "4572140" / "4,572,140" with the patent's subject matter ("nitrous oxide precooler") and assignee (Ram Automotive Company). No district court, CAFC, ITC, or PTAB proceeding asserting or challenging this specific patent surfaced.

No case entries to report — I will not fabricate plaintiff/defendant/jurisdiction/case-number/filing-date/outcome fields, because I have no source confirming any such case.

Important caveats and context

1. False-positive hits were discarded. Searches for "4572140" returned numerous unrelated documents (a Florida LLC's FEI number, a UK probate notice, a Czech public-contracts registry entry, a bankruptcy creditor line, a Brazilian corporate filing). None relate to the patent. I did not treat these as litigation.
2. Why litigation is unlikely. According to the patent's own legal-status records, the patent expired on 1990-02-25 for failure to pay maintenance fees (lapse recorded 1990-02-25; maintenance-fee reminder mailed 1989-09-26). The enforceable term was therefore only about four years (granted 1986-02-25). This short window, combined with the narrow field (nitrous-oxide power-boost systems for racing/high-performance vehicles), makes a substantial enforcement campaign improbable.
3. Related family activity exists, but is not litigation. The records show a related patent, US 4,494,488 ("Fuel charging system for high performance vehicles," also Ram Automotive Company, issued 1985-01-22), cited as prior art against the '140 patent. There are also later Ram Automotive filings (e.g., US 4,683,843, "Nitrous oxide fuel injection safety system") and many third-party later patents citing '140 — these are citations and continuations in the same technology space, not lawsuits.
4. Prosecution citations (not litigation). The examiner cited six references during prosecution (US 2,715,395; US 3,602,202; US 3,593,694; US 4,308,827; US 4,503,832; US 4,494,488) plus two non-patent citations (an "Nitrouscharging by Ice" advertising brochure). These are prior art, not adversarial proceedings.
5. Search limitations. Unified Patents' public portal, CourtListener, and PACER coverage are strongest for federal cases from roughly the mid-1990s onward; pre-1990s district court dockets are not uniformly digitized or free-searchable. It is therefore possible (though I found no indication) that an unrecorded 1980s–1990 lawsuit exists in a paper or non-digitized docket.

Bottom line

Based on the sources I could access, there is no known litigation involving US Patent 4,572,140. If you need a definitive negative, I'd recommend a paid PACER/docket search across all federal districts for 1986–1990 (the patent's enforceable life) and a check of Westlaw/Lexis Litigation for the same period.

PTAB Proceedings — US 4,572,140 ("Nitrous oxide precooler")

Patent: US 4,572,140 A · App. No. 06/658,667 · Filed 1984-10-09 · Granted 1986-02-25 · Inventor: William M. Wheatley · Assignee: Ram Automotive Company (Canton, OH) · Pre-AIA · Claims 1–13
Source of record: USPTO Open Data Portal structured block (canonical list); supplemented by web search of PTAB/CAFC materials.

Proceedings overview

Zero (0) AIA trial proceedings are on file for US 4,572,140 — no IPRs, no PGRs, no CBMs — leaving the patent in a posture where the PTAB question is moot because the patent itself lapsed into the public domain on 1990-02-25 for nonpayment of maintenance fees, roughly 22 years before the first IPR was ever filed on 2012-09-16. The breakdown of proceeding statuses is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. The bottom line for a defendant: this is a dead, unenforceable-by-passage-of-time patent, and a demand letter citing claims 1–13 is citing claims that no one has owned or been able to enforce since well before the AIA existed.

Note on the "Anticipated expiration" field: Google Patents shows an anticipated term ending 2004-10-09 (20 years from the 1984-10-09 filing date). That is a term calculation, not actual survival. The prosecution record in the same source shows the operative events: maintenance-fee reminder mailed 1989-09-26, lapse for failure to pay 1990-02-25, "Information on status: patent discontinuation" 1990-02-25, and "Lapsed due to failure to pay maintenance fee" effective 1990-02-25. The patent's enforceable life ended in 1990.

Per-proceeding detail

There are no proceedings to detail. No ### {PROCEEDING_NUMBER} entries are presented because none exist, and the constraints for this task forbid inventing proceeding numbers. For completeness, the reason each AIA vehicle is unavailable or (in the one theoretical case) unused:

Search coverage / confidence: The ODP structured block reports no AIA trials. Web searches for the patent number combined with "IPR," "PTAB," "AIA trial," and the patent owner ("Ram Automotive") returned no petition, institution decision, Final Written Decision, or Federal Circuit appeal touching this patent. I found no PTAB E2E or CourtListener docket to link. I cannot prove the negative with absolute certainty — PTAB dockets are not exhaustively web-indexed — but the absence is expected and unsurprising here, and nothing in the search results contradicts the ODP's "no proceedings" answer.

Strategic summary

Claim status: claims 1–13 are neither CANCELED nor SUSTAINED — they are UNTESTED and, more importantly, UNENFORCEABLE. No PTAB panel has ever construed, invalidated, or affirmed a single claim of this patent. The claims expired intact but toothless. The four independent claims — claim 1 (nitrous oxide precooler apparatus), claim 11 (improved fuel charging system), and the manifold/orifice-block structural claims 2–10 and 12–13 depending from them — never saw an Article III or PTAB validity ruling. When this ar

I'll start by cross-checking the live record sources before assembling the ownership chain.

Ownership Record — US 4,572,140 "Nitrous oxide precooler"

Scope note on sources: The authoritative record available to me is the Google Patents legal-events export for US 4,572,140 (filed 1984‑10‑09 as application 06/658,667; granted 1986‑02‑25; 13 claims). That export shows one assignment event and no post‑issuance transfer of any kind. I attempted to pull the corresponding Assignment Center reel/frame page for the correspondent field; the search tooling returned no usable hit before my step budget was exhausted. Where a data point is not in the retrieved record, I say so rather than infer it.

Inventors

Corroborating inventor pattern (evidence he did not depart at filing): Wheatley continues to appear as a Ram Automotive co‑inventor after this case:

• US 4,683,843 "Nitrous oxide fuel injection safety system," Ram Automotive Company, filed 1986‑08‑13, granted 1987‑08‑04 — inventors John A. Norcia, William M. Wheatley, Michael D. Norcia.
• Ram Automotive bottle‑filling patent (nitrous oxide transfer system), filed 1985‑09‑27, granted 1987‑02‑03 — inventors John A. Norcia, Ray Bickar, William M. Wheatley (per the Justia assignee listing for Ram Automotive Company).

Unusual-pattern check: Not present. The classic fire‑sale precursor — all inventors leaving the original assignee within 12 months of filing — does not occur here; Wheatley is still co‑inventing on Ram Automotive filings in 1985 and 1986. The only mild oddity is timing: the assignment was executed 1984‑09‑17, i.e. 22 days before the 1984‑10‑09 filing date, consistent with a routine pre‑filing employee invention assignment rather than an arm's‑length transfer.

Original assignee

RAM Automotive Company, an Ohio corporation, 4525 Cleveland Ave., Canton, Ohio (the address of record on the assignment; the assignee is recited as "RAM AUTOMOTIVE COMPANY, AN OH CORP.").

• Business: Aftermarket high‑performance driveline and nitrous‑oxide equipment. Ram Automotive is the entity behind the RAM Clutches brand, founded by John Norcia in Canton, Ohio in 1971 and relocated to Columbia, South Carolina in 1983. The same corporate family produced the nitrous‑oxide charging hardware claimed in this patent and in sibling case US 4,494,488 (filed 1984‑05‑23, granted 1985‑01‑22, also Ram Automotive Company).
• Did it ship a product embodying the claims? Yes — the evidence is strong, though indirect: (i) a contemporaneous non‑patent citation of record, the advertising brochure "Nitrouscharging by Ice" (cited twice by the examiner and listed under Non‑Patent Citations); and (ii) a dense, self‑referential Ram Automotive patent family on nitrous charging (US 4,494,488; US 4,683,843; the 1985 bottle‑filling case), which is the signature of an operating manufacturer building a product line, not a licensing vehicle.
• Current status: The RAM Clutches brand is still trading out of Columbia, SC, family‑owned and operated by Mike and Pat Norcia. I could not confirm the current corporate status of the legal entity "Ram Automotive Company" (operating / renamed / dissolved) from the sources retrieved. Notably, this patent itself was allowed to lapse 1990‑02‑25 for non‑payment of maintenance fees, so the patent never became a licensing asset in any successor's hands.
• No public‑company dimension: no SEC 10‑K/8‑K or bankruptcy docket referencing this patent or this assignee surfaced.

Assignment timeline

Records found: one (1). There is no post‑issuance assignment chain for this patent. The Assignment Center record set for US 4,572,140 consists solely of the original inventor‑to‑company assignment. That is itself the finding: the original operating assignee was the sole owner from grant until the patent lapsed.

• 1984‑09‑17 (executed) / recorded 1984‑10‑09 — Reel 004324/0809

  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
  • Assignor: WHEATLEY, WILLIAM M. (sole inventor)
  • Assignee: RAM AUTOMOTIVE COMPANY, an Ohio corporation, 4525 Cleveland Ave., Canton, Ohio
  • Correspondent: Not retrievable from the sources available to me. The Google Patents legal‑events export reproduces the reel/frame and the free‑format text ("ASSIGNMENT OF ASSIGNORS INTEREST.; ASSIGNOR:WHEATLEY, WILLIAM M.; REEL/FRAME:004324/0809") but does not include the correspondent‑of‑record field. The Assignment Center page for reel 004324/0809 does carry a correspondent, but I could not open it. I am explicitly not naming a correspondent, because doing so would be fabrication. To complete this field, open https://assignment.uspto.gov/patent/index.html and search 4572140 to view the correspondent on reel 004324/0809.
  • Context: Ordinary pre‑filing employee/inventor assignment to the operating company — not an acquisition, fire‑sale, reorg, or securitization.

• No further assignment events. Post‑grant events in the record are administrative only: maintenance‑fee reminder mailed 1989‑09‑26; lapse for failure to pay maintenance fees and patent discontinuation 1990‑02‑25 (37 CFR 1.362); "lapsed due to failure to pay maintenance fee" docketed 1990‑05‑08. The patent is expired for failure to pay maintenance fees and has been in the public domain since 1990 (its 20‑year term would in any event have run to 2004‑10‑09).

If the Assignment Center search unexpectedly surfaces links beyond reel 004324/0809 (e.g., a later Ram Automotive‑family transfer), this section should be updated — but nothing in the retrieved record supports any such link.

Timeline diagram

timeline
    title Ownership of US 4572140
    1984 : Inventor assignment executed
         : Recorded reel 004324 0809
         : Application filed by Ram Automotive
    1986 : Patent granted February 25
    1990 : Lapsed for unpaid maintenance fees
         : Rights enter public domain

NPE / troll-pattern signals

1. Shell-entity transfer — not present. There is no recorded transfer at all after reel 004324/0809 (executed 1984‑09‑17 / recorded 1984‑10‑09). The only assignee in the entire history is RAM Automotive Company, an Ohio operating corporation at a street address in Canton, Ohio — not a registered‑agent service address, and not an "IP / Holdings / Ventures" style single‑purpose vehicle.

2. Known asserter in the chain — not present. The sole assignee, RAM Automotive Company, matches none of the listed asserters (Acacia, Marathon, Intellectual Ventures, IPNav, Wi‑LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). Its patent citations‑by list reads as a who's‑who of operating fuel‑system manufacturers — Nitrous Oxide Systems, Inc., Echlin Inc., Holley Performance Products — not a litigation dossier.

3. Repeat correspondent across the chain — unclear. A chain requires two or more links to display recurrence, and this chain has one link. Independently, the correspondent field on reel 004324/0809 was not retrievable from the sources I could reach, so I cannot compare it against any Unified Patents / RPX / Patent Progress assertion list. This is a documentation gap, not a finding — it should be resolved by opening the reel entry directly before any NPE conclusion is drawn.

4. Cascading transfers — not present. Zero consecutive assignments, let alone multiple chained LLCs inside 24 months.

5. Pre-litigation transfer — not present. No assignment within 6 months preceding any suit, because no suit and no post‑grant assignment exist. I found no infringement action naming US 4,572,140 in the sources checked.

6. Bankruptcy fire‑sale — not present. No bankruptcy record, 363 sale, or asset‑sale docket tied to Ram Automotive Company surfaced. The terminal event is instead a voluntary lapse for non‑payment of maintenance fees on 1990‑02‑25 — an operating company walking away from a patent it had used commercially, the opposite of monetization.

7. Privateering — not present. No operating‑company‑to‑NPE transfer, no SEC disclosure, no Patent Progress / EFF coverage linking this patent to a proxy asserter.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. The de facto neutralization here comes from expiry/lapse (1990) plus the passage of the 20‑year term (2004‑10‑09), not from a defensive purchase.

Verdict

Insufficient data — the Assignment Center record for US 4,572,140 contains only the original assignment: executed 1984‑09‑17, recorded 1984‑10‑09, Reel 004324/0809, from sole inventor William M. Wheatley to RAM Automotive Company, an Ohio corp. There is no post‑issuance transfer, no chained LLC, and no litigation, so no NPE signal can be grounded in a reel/frame citation; the one open item is the unretrieved correspondent field on reel 004324/0809, which is a records gap rather than evidence. The affirmative counter‑evidence to an NPE read is the terminal event: the patent lapsed 1990‑02‑25 for failure to pay maintenance fees while still held by the original operating manufacturer.

Verify at: https://assignment.uspto.gov/patent/index.html (search 4572140, then open reel 004324/0809 to capture the correspondent) · https://assignmentcenter.uspto.gov/ · patent text: https://patents.google.com/patent/US4572140/en

I'll research each cited prior-art reference for US 4,572,140, verifying the record against live sources before analyzing § 102 anticipation.

Now let me research the remaining cited references individually.

Let me research the remaining three references.

I've gathered what I need on four of the six references. Note: I hit the tool-step limit before I could pull full text for US 4,308,827 (Roe) and US 4,503,832 (Prodatek) — I flag those explicitly below as lower-confidence and do not fabricate their disclosures.

Prior-Art Analysis for US 4,572,140 — "Nitrous oxide precooler"

Scope and legal framework

US 4,572,140 is a pre-AIA patent (filed 1984-10-09), so pre-AIA 35 U.S.C. § 102(a)/(b)/(e) and § 103 govern. The § 102(b) one-year critical date was 1983-10-09. Every reference the examiner cited except the two 1985-issued ones was already public more than a year before filing, i.e., straight § 102(b) art. (Sources: Google Patents US4572140A; bibliographic and citation tables therein.)

Before the per-reference breakdown, one framing point that controls the whole analysis:

The independent claims require a specific feedback loop, not just "cooling." Claim 1 element (e) requires a second valve that (i) communicates with both the conduit and the cooling chamber, (ii) purges gaseous nitrous oxide from the conduit, and (iii) injects it into the cooling chamber before the first (delivery) valve is actuated. Claim 11 recites the same idea in means-plus-function form ("purge means... injecting it into the cooling chamber forming means before the valve permits the flow"). A reference that merely cools a fuel/nitrous line — or merely vents vapor to atmosphere — does not anticipate; it must return the purge gas into the jacket as the coolant, sequenced ahead of delivery.

Applying that filter, none of the six cited references anticipates any of claims 1–13. Several are strong § 103 references. I detail each below.

1. US 2,715,395 A — Finvold

Description. A power booster that adds pure oxygen to the carbureted air/fuel mixture. It has an insulated bottle 10 holding liquid oxygen, an outlet pipe 42, a vaporizer 14 formed as a "closed cylinder... fitted around the exhaust pipe 24... thus forming an annular jacket," a delivery manifold 16 to the carburetor, and a controllable outlet/metering valve 30 tied to the throttle. Vaporization is by engine exhaust heat — the jacket is a heater, not a cooler.

§ 102 anticipation analysis.

• Claims 1(a)–(c): discloses a pressurized liquid gas container, a conduit to the engine, and valve means controlling flow — but the gas is oxygen, not nitrous oxide, and the valve is a mechanical throttle-linked metering valve, not a "first valve means" coordinated with a purge valve. The container element (a) is arguably met on a broad reading of "container holding a supply of pressurized liquid [gas]."
• Claim 1(d): discloses an annular jacket around a conduit — this is the single most structurally analogous feature in the reference — but its stated function is to vaporize the fluid using exhaust heat, the opposite of the claimed "cooling chamber... for maintaining the nitrous oxide... in a liquid state."
• Claim 1(e): absent. There is no second valve communicating with the conduit and the jacket to purge vapor into the jacket. The reference has no purge feature at all.
• Claim 10 (injection tube to engine): generically met by manifold 16.

Verdict: Anticipates no claim. Relevant as § 103 background for the idea of an annular jacket about the supply conduit (claim 1(d), claim 11 "cooling chamber forming means"), but it teaches away from the claimed purpose.

2. US 3,593,694 A — Fuel Injection Engineering Co.

Description. A fuel-cooling system for a fuel-injection engine. It expressly aims to "minimize the formation of... vapors" by cooling the fuel. Key elements: an intake tube/ram tube 15, main and auxiliary injection nozzles 19/21, a fuel-cooling jacket 23, a cooling medium (heat-exchanger bank), and "means for separating such vapors from the liquid fuel... after the fuel-cooling operation has at least begun." Excess fuel is bypassed back through a secondary tank.

§ 102 anticipation analysis. This is the closest structural analogue to the '140 patent's concept — a jacket that chills a fuel line to keep fluid liquid and suppress vapor — and it also discloses separating vapor from the line. But:

• Claims 1(a)–(c): the fluid is gasoline, the system is fuel injection, and the "valve means" is not a remotely operated delivery solenoid coordinated with a purge valve.
• Claim 1(d): discloses a cooling jacket about the conduit — potentially reads on "jacket means surrounding a portion of the conduit means" if one ignored the gas-content limitation ("to receive gaseous nitrous oxide").
• Claim 1(e) / claim 11 purge element: absent. The separated vapor is routed away (bypass/secondary tank); it is not injected into the cooling jacket, and there is no purge-before-delivery sequencing.
• Claims 5–8 (hose over conduit, manifold one end, orifice block the other): the reference has a jacket over a tube but not the two-piece orifice block + manifold + discharge-hole structure.

Verdict: Anticipates no claim (the purge-into-chamber feedback and the orifice-block structure are missing). Most relevant § 103 reference on the "cool the supply line to prevent vaporization" concept underlying claims 1(d) and 11.

3. US 3,602,202 A — Toyoda Chuo Kenkyusho K.K. (Kobayashi)

Description. Adds oxygen or nitrogen from storage cylinders to the carburetor air/fuel mixture, selectively, according to throttle position. Includes oxygen cylinder 7 and nitrogen cylinder 8, supply conduits 71/81, solenoid-operated valves 72/82, a spool valve 102 mechanically interlocked with the throttle, and a control circuit (FIG. 5) energizing the solenoid coils 721/821.

§ 102 anticipation analysis.

• Claims 1(a)–(c): discloses pressurized gas cylinders, supply conduits, and electrically (solenoid) operated valves — a decent read against the generic container/conduit/valve elements, but the gas is oxygen/nitrogen, and there is no second purge valve.
• Claim 3 (first and second valve means are solenoid-actuated, remotely operated): the reference discloses multiple solenoids on gas-supply lines, but not a delivery solenoid plus a purge solenoid on a shared manifold.
• Claim 1(d)/(e) and claim 11 improvement: completely absent — no cooling chamber, no jacket, no purge.

Verdict: Anticipates no claim. Relevant only as § 103 background for solenoid-controlled gas injection (claim 3, claim 10), and it is the weakest of the six as to the '140 point of novelty.

4. US 4,308,827 A — Roe

Description — confidence caveat. I was cut off by my tool-step limit before retrieving full text, so I will not invent its disclosure. From the title and the examiner's use, it is a fuel-injection system reference — most plausibly cited for general fuel-delivery/injection architecture in the same class, not for anything resembling a nitrous-oxide cooling jacket. Treat the description as provisional, not verified.

§ 102 anticipation analysis (provisional). On the face of its title, it neither discloses a nitrous-oxide supply system, a cooling chamber about the conduit, nor a purge valve injecting vapor into a chamber. It cannot anticipate claim 1's elements (d)/(e) or claim 11's improvement, and it lacks the claim 5–8 orifice-block/manifold structure.

Verdict: Anticipates no claim on available information. To complete this entry, pull the full text at https://patents.google.com/patent/US4308827A/en (esp. the claims and cited art).

5. US 4,503,832 A — Prodatek Corporation

Description — confidence caveat. Same limitation as above: full text not retrieved within my step budget. The title ("Liquid fuel system method and apparatus") and assignee (Prodatek) suggest a liquid-fuel delivery/handling system, plausibly with a cooling or vapor-management aspect — which would explain the examiner's interest given the '140 cooling concept. I am not asserting details I did not retrieve.

§ 102 anticipation analysis (provisional). Nothing on the face of the record connects it to a purge-vapor-to-jacket feedback or to an annular chamber closed by a manifold/orifice block. It does not appear to anticipate claims 1 or 11.

Verdict: Anticipates no claim on available information; flagged as an unverified entry. Pull full text at https://patents.google.com/patent/US4503832A/en.

6. US 4,494,488 A — Ram Automotive Company (same-assignee predecessor) — the key internal reference

Description. The closest thing in the record to the environment of the '140 patent. It discloses a nitrous-oxide charging system with: nitrous-oxide cylinder 2; a nitrogen cylinder 3; a pressure regulator 6; an adapter 10 on the nitrous bottle neck; a nitrous pickup tube 48; a nitrous supply line 39 to a spray bar 43 on base plate 41; a solenoid control valve 42 in the nitrous line; and a fuel line 44 with a second solenoid valve 45 feeding fuel spray bar 46. The invention there is a nitrogen gas blanket that maintains constant discharge pressure (~900 psi) on the nitrous oxide. Notably, it recites the same environmental pressures and the same 42/45 solenoid numbering that the '140 patent reuses.

§ 102 anticipation analysis — this is where the same-assignee relationship matters.

• Claim 11 (Jepson claim). The preamble of claim 11 — "a cylinder of pressurized liquid nitrous oxide, a supply conduit... to the vehicle engine, and a remotely controlled valve mounted in the conduit" — is disclosed by US 4,494,488 (and is, in any event, admitted prior art in the '140 specification). But a Jepson preamble is not the invention; anticipation requires disclosure of the improvement, i.e., (i) means forming a cooling chamber about the conduit and (ii) purge means injecting gaseous nitrous oxide into that chamber before delivery. Neither is disclosed in '488. Its nitrogen blanket does not cool the nitrous line and does not purge vapor into a jacket.
• Claim 1(a)–(c): '488 discloses the container, conduit, and delivery-valve elements, but claim 1 as a whole is not anticipated because (d) and (e) are missing.
• Claim 3 (solenoid-actuated valves 42/45): '488 literally discloses two solenoids, but they are nitrous-delivery + fuel-delivery, not delivery + purge — so even claim 3's narrower feature does not anticipate as arranged.

Verdict: Anticipates no claim, but it is the most relevant single reference for the claimed environment and the strongest evidence that the "generic nitrous charging system" elements of claim 11's preamble were known in the art. Important procedural note: because '488 and '140 were commonly owned by Ram Automotive, '488 is disqualified as § 103 prior art under pre-AIA § 103(c) — it can only be used for § 102, and it fails § 102. See the previously-generated assignment section (sole assignee Ram Automotive from grant to lapse).

Non-patent citations

Both NPL entries are the same advertising brochure, "Nitrouscharging by Ice," cited twice by the examiner. This brochure is the likely source of the admitted prior art recited in the '140 specification's Background—the system in which "a purge valve... will vent the gaseous nitrous oxide in the delivery conduit into the atmosphere." That admitted purge-to-atmosphere configuration is the closest prior art to the actual point of novelty (element (e)), because claim 1's advance is precisely redirecting that purge flow into a cooling jacket rather than overboard. A brochure, however, is unlikely to be an enabling § 102 anticipation print; its real role is as an admission against interest narrowing the scope the applicant could claim (the "purge valve" and "solenoid delivery valve" combination is conceded old).

Ranking and bottom line

Bottom line. On the cited record, no reference anticipates any of claims 1–13 under § 102. The examiner's citations collectively cover the old environment — pressurized liquid gas, a supply conduit, solenoid delivery valves (Finvold, Toyoda, Ram '488) — and the general idea of a jacket around a fuel line for thermal control (Finvold's heater jacket; Fuel Injection Engineering's cooler jacket). Not one of them discloses the two limitations that define the patent: (1) a second valve communicating with both the conduit and the cooling chamber, and (2) returning the purged gaseous nitrous oxide into the chamber as the coolant, sequenced before the delivery valve opens. The closest conceptual § 103 combination would be US 3,593,694 (cool the line / separate vapor) in view of US 2,715,395 (annular jacket about the conduit) and the admitted purge-to-atmosphere system — but the reinjection of purge gas into the jacket is the missing teaching, which is exactly why the claims issued.

Verification and confidence notes

• Dates and titles for all six references are taken from the authoritative citation table in the patent text (Google Patents US4572140A) and corroborated where searched. One discrepancy worth recording: the '140 citation table lists US 3,602,202's priority as 1968-11-30, while Espacenet separately shows a US filing of 1969-11-25 (JP priority 1968-11-30). Both are reported, not harmonized.
• Unverified entries: descriptions of US 4,308,827 and US 4,503,832 are provisional — I did not retrieve their full text. Do not rely on those two characterizations without pulling the documents.
• § 102(e) vs § 102(b): US 4,494,488 and US 4,503,832 are § 102(e) art (filed before, issued after, the '140 filing date). The remaining four are § 102(b) art.
• Common-ownership disqualification: US 4,494,488 cannot be used in a § 103 combination against the '140 claims because both were owned by Ram Automotive (pre-AIA § 103(c)).
• I did not locate any uncited art that anticipates the claims; this analysis is confined to the six patent citations and two NPL citations of record, as the task requested.

I'll ground the obviousness analysis by pulling the actual content of the cited references before assembling combinations.

Obviousness Analysis — US 4,572,140 ("Nitrous oxide precooler") under 35 U.S.C. § 103

Patent: US 4,572,140 A · App. 06/658,667 · Filed 1984-10-09 · Granted 1986-02-25 · Pre‑AIA · Inventor Wheatley · Assignee Ram Automotive Co. · Expired (lapse 1990-02-25; term would have ended 2004-10-09)
Governing law: pre‑AIA § 103(a); Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l v. Teleflex, 550 U.S. 398 (2007)
Prior art considered: the six examiner‑cited references plus the two non‑patent citations of record (per the Prior Art section of this page).

1. Threshold: level of ordinary skill and which references are available

Level of ordinary skill. A POSITA here is a mechanical engineer or automotive-performance systems designer with roughly 2–4 years' experience in engine fuel/oxidizer delivery, or equivalent hands-on racing-industry experience. The '140 specification is written at that level — the "invention" is described entirely in terms of off‑the‑shelf solenoid valves, hose, hose clamps, and a machined manifold. Nothing in the claims requires specialized knowledge beyond routine plumbing and simple thermodynamics.

Availability of the art (pre‑AIA dates):

Two points worth stating precisely. First, § 102(e) references are available in § 103 combinations under pre‑AIA law, so Prodatek '832 and Ram '488 are usable. Second, the 1999 common-ownership carve-out (§ 103(c)) does not help the '140 patentee, because it applies only to applications filed on or after 1999‑11‑29; the same-assignee Ram '488 remains available as art against '140. That is presumably why the examiner cited it (§ 102(e)) rather than raising only double patenting — and note that '488 issued before '140, so '140's claims also had to be patentably distinct from '488's claims to issue.

2. What each reference actually teaches (grounded)

US 4,503,832 — Prodatek (the linchpin). This reference frames the exact problem the '140 patent claims to solve. It states that liquid delivery of a vapor-type fuel "requires one of two approaches to maintaining the fuel in liquid phase: (1) increased external pressure or, (2) external cooling," and it discloses subcooling the liquid fuel in the main fuel line by vaporizing a fraction of that same fuel in a pilot line running concentrically within the main line, with the vaporizing fuel absorbing heat "all along the run of both lines" so as to "prevent vaporization." It further explains that heat transfer from the main line to the pilot line "subcools the main fuel." (Google Patents; FreePatentsOnline mirror — actual FPO page: https://www.freepatentsonline.com/[4503832](/patent/4503832).html)

US 3,593,694 — Fuel Injection Engineering (fuel-cooling system). Discloses a fuel‑cooling jacket (23) associated with the fuel line/intake structure and states the invention "minimizes the formation of these vapors through the provision of a highly efficient fuel‑cooling system." It also provides "means for separating such vapors from the liquid fuel," preferably after cooling has begun, and notes the advantages of vapor separation can be accomplished "by merely venting" the vapor. (Google Patents)

US 4,308,827 — Roe. Discloses a fuel line that is wrapped about (i.e., coiled around) the fuel injection chamber and insulated together with it, so that "the heat absorbed from the evaporation of the fuel is taken primarily from the incoming air and from the fuel in the fuel line," producing a super‑cooled charge. (Google Patents)

US 2,715,395 — Finvold (liquid oxygen power booster). Discloses an engine power booster in which oxygen is stored in liquid form in an insulated bottle (36/38) and fed through a conduit (42/46) to an annular jacket 14 (there, a vaporizer around the exhaust pipe) and then to a delivery manifold and carburetor. Critically, it also discloses sequencing of two valves: the fuel metering needle is linked by a rod (80) with a slotted portion (82) "so that the movement of the metering needle is delayed until the outlet valve 30 has started to open." (Google Patents)

US 3,602,202 — Kobayashi. Discloses an oxygen supply source → oxygen feed conduit → carburetor air‑fuel mixture, with a valve mechanism interlocked with the throttle valve to control feed from the oxygen cylinder. (Google Patents)

US 4,494,488 — Ram Automotive (the "base" system). Not retrievable in full text within my step budget. I therefore rely on (i) the '140 specification's own Background Art admission of a conventional nitrous system (cylinder at ~900 psi → conduit → solenoid delivery valve → carburetor, purge valve venting to atmosphere), and (ii) the citation record. I flag that I did not read '488's disclosure directly.

"Nitrouscharging by Ice" brochure. Content not verified — this is the wildcard. If it discloses a nitrous precooler, it is potentially a § 102(b)/§ 103 knockout. I will not assume its contents. (Google Patents record)

3. Claim 1 — element-by-element mapping and combination

Claim 1 requires (a) a pressurized liquid‑N₂O container, (b) conduit means to the engine, (c) first valve means controlling flow to the engine, (d) jacket means surrounding a portion of the conduit forming a cooling chamber to receive gaseous N₂O so the conduit contents stay liquid, and (e) second valve means communicating with both the conduit and chamber to purge gas from the conduit into the chamber before the first valve means is actuated.

The primary combination (strongest): Ram base nitrous system + Prodatek '832 + the admitted purge practice.

Motivation to combine, articulated the KSR way:

1. The problem was known and the solution set was closed. Prodatek expressly identifies a binary choice: raise pressure or externally cool. The '140 patent chose one of the two identified solutions. KSR holds that where "a finite number of identified, predictable solutions" exist, following one is "obvious to try."
2. The refrigerant already exists on the vehicle, for free. The '140 Background Art admits that a purge valve already fires before the delivery solenoid and dumps vapor overboard. A POSITA seeking external cooling has an obvious, zero‑added‑mass source of cold: the very boil‑off the system is already producing and discarding. The '140 patent's own stated advantage — "eliminating the use of any additional nitrous oxide or other chemicals, and without materially increasing the weight … which is critical in a racing vehicle" — is precisely the reason a POSITA would make the substitution, not evidence of nonobviousness.
3. The physical mechanism is Prodatek's, transposed. Prodatek subcools a liquid fuel line with a vaporizing fraction of that same fluid. The '140 device subcools a liquid nitrous line with a vaporizing fraction of that same fluid. The only change is that the vaporizing fraction arrives via the existing purge valve instead of a throttling orifice — a change in plumbing, not in principle.
4. Use of a waste stream is a recognized design incentive. Diverting a vented by‑product back into the process rather than dumping it is the classic "obvious improvement" — a predictable benefit from an established technique used in the same way.
5. The '694 and '827 references independently confirm that cooling a fuel line to keep the fuel liquid and suppress vapor was known and desirable, giving a second, redundant motivation.

Sequencing (the "before actuation" limitation) is independently supplied by Finvold's slotted linkage that delays fuel flow until the oxygen valve has opened, plus the '140 specification's own admission that the purge‑then‑deliver order was prior practice, plus the well‑known expedient of a time‑delay solenoid. Sequencing alone carries no patentable weight.

Alternative combination (secondary, if '832 were disqualified): Ram base system + '694 (fuel‑cooling jacket + vapor separation/venting) + '827 (evaporative cooling of a fuel line to keep fuel liquid) + Finvold (jacket geometry and sequenced valves). Motivation: same — vapor suppression for metering accuracy and density.

4. Claims 2–10 (dependent) — obviousness is stronger, not weaker

• Claim 2 (manifold at one end; conduit to manifold; both valves on the manifold). One inlet, two outlets on a common body is the ordinary way to split and re‑route lines at a junction. Inherent design choice; no new function. Finvold's delivery manifold 16 performs the collection/distribution function.
• Claim 3 (solenoid‑actuated remote valves). Admitted in the '140 Background Art (the base system uses a solenoid delivery valve operated by a dash switch).
• Claim 4 (purge line through the manifold interior and through a secondary opening). Pure routing/packaging choice — consolidating the purge line inside the existing manifold body minimizes parts and protects the line. No unexpected result.
• Claim 5 (hose telescoped over the conduit, manifold at one end, orifice block at the other). A sleeve closed at both ends by fittings is the most direct way to build the chamber of '832/'694. Telescoping over the existing line has an obvious commercial motivation: retrofit — the sleeve installs over an existing nitrous line without disturbing the end fittings, which is exactly what an aftermarket vendor (Ram) would want.
• Claim 6 (orifice block with discharge hole + conduit opening). A vent is required to permit the continuous through‑flow of expanding gas the specification relies on. Sizing the discharge orifice is routine optimization (and the patent gives no critical dimension).
• Claim 7 (two semicircular members with aligned semicircular openings, held by a clamp). A two‑piece split block is the textbook solution for assembling a fitting around a continuous tube that already has terminations at both ends — a one‑piece block could not be slid into place. KSR: "the predictable use of prior art elements according to their established functions." Strongest obviousness showing of the dependent set.
• Claim 8 (hose on a cylindrical manifold section, clamped). A hose clamp on a cylindrical fitting — the specification itself calls this out as incidental ("clamping band 24," "raised annular rib 26").
• Claim 9 (~900 psi). A numeric limitation, not a criticality. ~900 psi is essentially the vapor pressure of N₂O at ambient temperature — a result‑effective variable inherent in keeping N₂O liquid, not an independently selected value. No unexpected result is claimed.
• Claim 10 (injection tube from the first valve to the engine). The base system's supply line to the spray bar.

5. Claim 11 and claims 12–13

Claim 11 is a Jepson improvement whose preamble admits the entire prior‑art base: pressurized liquid N₂O cylinder, supply conduit to the engine, remotely controlled valve in that conduit. The improvement adds only (i) means forming a cooling chamber about the supply conduit and (ii) purge means communicating with the conduit and chamber to inject gas into the chamber before the valve permits liquid flow.

This is the broadest claim and the easiest § 103 kill, because the admitted preamble carries most of the structure and the two added means are stated in pure means‑plus‑function terms with no structure. Under § 112 ¶ 6 (pre‑AIA), the corresponding structure is '832's concentric heat‑exchange arrangement / '694's jacket / the '140 hose‑and‑manifold embodiment — all of which are disclosed or obvious. The single functional element distinguishing claim 11 from the admitted art is the destination of the purge gas, which is exactly the point on which Prodatek supplies both the motivation and the mechanism.

Claims 12–13 merely re‑state claims 5–6 in means language (sleeve closed by manifold and orifice block; discharge opening; purge tube), and fall with them.

6. Teaching away and objective indicia (steelmanning the patentee)

Teaching away — weak, and confined to one reference. Finvold's jacket 14 is a vaporizer wrapped around the exhaust pipe — i.e., it deliberately heats the oxidizer to gasify it before carburetion. A patentee could argue Finvold teaches away from chilling the oxidizer feed line. The argument fails for three reasons: (i) Finvold's heating function serves a different downstream goal (vapor delivery through a carburetor), not the metering‑accuracy problem in a purge‑and‑hold nitrous line; (ii) the teaching‑away inquiry looks at what the reference would have suggested to a POSITA about the claimed problem, and Prodatek, '694, '827 and the admission in '140's own Background Art all point the other way; a single contrary reference in a crowded field does not defeat a § 103 combination.

Objective indicia — essentially unavailable and largely counter‑productive. The specification asserts only the expected physics: lower temperature → greater density → more N₂O per unit line pressure. That is a statement of well‑understood thermodynamics, not an unexpected result, and it is asserted without data. Its stated benefit of "no additional weight" is a mere recognition of an advantage inherent in using an existing stream. On this record I see no teaching‑away, no unexpected results, no evidence of long‑felt need or failure of others, and no commercial‑success nexus (the patent lapsed in 1990 while still held by the original operating manufacturer, which cuts against arguments that the claims drove a valuable, protected market).

Weaknesses in the § 103 case (stated honestly). The combination is a genuine two‑reference plus admitted‑art combination, not a single‑reference anticipation. No single reference of record appears to disclose routing the system's own purge gas into a coaxial, through‑flow, vented annular jacket — Prodatek uses a separately throttled pilot line inside the main line and discharges it to an idle circuit rather than venting it to atmosphere. A patentee could point to that gap. But under KSR's "obvious to try" and "predictable use of elements according to their established functions" lines, that gap is bridgeable, and the commercial/racing incentive to do so is documented in the patent's own text. My assessment: more likely than not invalid under § 103, with claim 7 (split block) and claims 5–6 the most defensible and claims 1, 11, 9 the most vulnerable.

7. Contradictions and data‑quality flags

1. Contradiction with the previously generated PTAB section. That section's Strategic Summary refers to "the four independent claims" and then lists claim 1, claim 11, "and the manifold/orifice‑block structural claims 2–10 and 12–13." That is internally inconsistent and inaccurate: per the authoritative claim set, there are two independent claims (1 and 11) and eleven dependent claims. I use two independents throughout. (The same section also loosely calls claim 11 dependent — it is not.)
2. Valve‑ordinal inversion (carried forward). The abstract's "first valve purges / second valve delivers" is the reverse of claim 1's "first valve means" = delivery. For § 103 mapping I have used claim 1's convention, since the claims govern. Anyone construing "first valve means" against the abstract will mis‑map the reference teachings.
3. "36" is used twice in the '140 description (both the orifice‑block discharge hole and the semicircular opening), with the assembled opening separately numbered 38. This matters only to claim construction of claims 6–7, not to the § 103 mapping, which turns on function, not numerals.
4. Ram '488 (US 4,494,488) and the "Nitrouscharging by Ice" brochure remain unread. Every statement I make about '488 rests on the '140 specification's admission and the citation record, not on '488's disclosure. The Ice brochure is undated on the retrieved record and its contents are unverified — it is the single largest source of uncertainty in this analysis. If it discloses a nitrous precooler, claim 1 becomes a § 102 problem for the patentee, and if it is § 102(b) art it also collapses the "motivation to combine" debate.
5. NPL count. The retrieved record lists "Advertising Brochure entitled 'Nitrouscharging by Ice'" twice under Non‑Patent Citations — apparently one document, duplicated in the export, consistent with the earlier section's note. Not two separate publications.
6. Date discrepancy in the task framing. The system context gives today as 2026‑09‑29; the current‑task block says April 26, 2026. It does not affect the analysis (the patent lapsed in 1990 and expired in 2004 regardless), but it is an unresolved inconsistency in the inputs.
7. Confidence. High confidence on the teachings of '832, '694, '827, '715395 and '602202 (retrieved full or extensive text). Moderate confidence on the overall § 103 conclusion. Low confidence on any proposition that depends on the contents of '488 or the Ice brochure.

Practical bottom line: the § 103 analysis is legally academic in 2026 — the patent lapsed for non‑payment of maintenance fees effective 1990‑02‑25, and even the calendrical term ended 2004‑10‑09 (consistent with the earlier sections; no contradiction there). Its only remaining use is as a validity study for the surrounding Ram family (e.g., US 4,683,843) or for assessing pre‑1990 conduct. On the merits, claims 1–13 are vulnerable to a § 103 combination of Ram's own admitted base system plus US 4,503,832, with US 3,593,694, US 4,308,827 and US 2,715,395 supplying the jacket, evaporative‑cooling and sequenced‑valve teachings.