US 675103

I'll search for this patent number across the requested sources.

Let me run more targeted checks on the USPTO record and the CAFC/PTAB docket databases.

Summary — US Patent 675,103

Caveat on sourcing up front: My targeted searches for the literal string "675103" in USPTO databases and for any CAFC 2026 docket activity returned no matching records. The searches surfaced unrelated fire-suppression patents (e.g., US 20090301738 A1, US 3,749,175), a Japanese JPO report on unrelated CAFC cases, and a district-court opinion about a different "'675 patent" (Canady v. ERBE, re U.S. Pat. No. 5,23x,675 family) — none of which are this patent. The authoritative data below therefore comes from the full patent text itself (patents.google.com/patent/US675103/en, fetched 2026-09-24), not from a live USPTO/CAFC hit.

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Bibliographic data

No formal abstract exists. This is a pre-1930s US patent; abstracts were not required. The closest thing is the opening paragraph of the specification (paraphrased below).

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Abstract (paraphrased from the specification)

The invention relates to portable fire extinguishers of the type in which a portable tank holds an alkaline solution and suspends an acid bottle within it. When occasion demands, the acid is mingled with the alkaline solution to generate carbonic-acid gas, which both pressurizes the tank to expel the liquid and charges the liquid with gas to enhance its fire-extinguishing action. The stated problem: acid tends to "creep through the stopper-fastenings" and gradually lose its acid strength, rendering the apparatus useless when needed. The invention solves this by providing an oil (or other viscid-liquid) seal over the mouth of the acid bottle, plus the structure for holding it in place.

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Plain-language overview of the claims

The patent has two claims, both independent (no dependent claims, no method claims, no means-plus-function language in modern form). The OCR text is garbled in places (e.g., "carbonio-acid" = carbonic acid; "Chio" = Ohio); the claim language below is the claim text as printed, cleaned only of obvious character-recognition noise.

Claim 1 — Sealed-casing combination. In portable fire apparatus of the character described, the combination, with the tank, of:

• an acid bottle;
• a casing surrounding and extending above the neck of the bottle, adapted to hold oil or other sealing fluid over the stopper;
• a cover for that casing; and
• means accessible from outside the tank for holding the acid-bottle stopper normally in place.

Plain reading: the claim is directed to the tank + acid bottle + an upstanding liquid-seal chamber around the bottle neck + a lid on that chamber + externally operable structure that keeps the stopper seated. The "sealing fluid over the stopper" is the point of novelty; the "means accessible from without the tank" is what lets the user release the stopper when the extinguisher must be fired.

Claim 2 — Screw-stem actuated version. In fire apparatus of the character described, the combination of:

• an acid bottle suspended beneath the cover of the tank;
• a casing surrounding and extending above the neck of the bottle;
• a perforated cap for the casing;
• a screw-stem extending through the tank cover and the casing cap; and
• a stopper carried on, or connected with, that screw-stem.

Plain reading: this is the more structurally concrete claim. The screw-stem passes through both the tank's screw-cap and the casing cap (the cap is "perforated" to admit the stem), and carries the stopper at its lower end. Turning/backing out the stem recedes the stopper and releases the acid. Note that claim 2 does not expressly recite the oil seal; it claims the casing/cap/screw-stem/stopper architecture that makes the seal possible.

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Structural details from the description (Fig. 1 and Fig. 2)

• A = portable tank charged with alkaline solution a; a (again) = screw-cap cover; B = acid bottle suspended within.
• The bottle is held in a frame b by a screw-stem f inserted through the cap, which also carries the stopper.
• Casing d is cemented (or otherwise secured) to the bottle neck and projects above the neck. A metallic cap e, lead preferred, closes it.
• Fig. 1: stem f passes down through cap e and carries a lead stopper s. Above stopper s, inside casing d and beneath cap e, is a chamber holding a small quantity of oil g, forming an air-tight seal over the stopper.
• Fig. 2 (modification): stem f reaches only to the top of cap e′; a prop or strut h is interposed between cap e′ and stopper s′ and bears against the stopper. Stopper s′ may be glass with a gasket/packing s². Stated incidental advantage: if the bottle is overturned, strut h falls sideways and helps release the stopper.
• Operation: the stem is receded and the bottle released in the usual manner.

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CAFC / docket status — explicit uncertainty

I found no CAFC 2026 docket entry, PTAB proceeding, or litigation referencing US 675,103. This is consistent with the bibliographic record: the patent was filed and issued in 1901 and its term expired May 28, 1918, over a century before the current docket. I cannot rule out that an archived pre-1918 infringement suit exists in historical reporter volumes, but I have no authoritative source for such a case and will not speculate about one. My search results did surface a 2026 CAFC opinion (Apple v. Smart Mobile Technologies, No. 2024-1419, decided Jan. 13, 2026, re U.S. Pat. No. 9,191,083) and 2026 CAFC summaries — none involve patent 675,103 and I am flagging them only to make clear they are not results for this patent.

Related patents by the same inventor (found incidentally, not from a 675103-specific search)

• US 777,131 (granted Dec. 13, 1904) — "Portable fire-extinguisher," Charles Nuhring (appears in the citations of US 7,178,604).
• US 1,670,979 (granted May 22, 1928; filed June 24, 1925) — "Fire extinguisher," listed to Charles Nuhring (FreePatentsOnline).

These corroborate the inventor's identity and continuing work in the field, but I have not verified their claim scope against US 675,103.

I'll search for litigation involving this specific patent number.

Let me run additional targeted searches to confirm.

Litigation Search Report — US Patent No. 675,103

Patent identified literally as: US 675,103 — "Portable fire-extinguisher," inventor Charles Nuhring (Cincinnati, Ohio), filed March 8, 1901 (Application No. US5035001A; Serial No. 50,850), granted May 28, 1901, and recorded as expired – lifetime, anticipated expiration May 28, 1918.
Source: https://patents.google.com/patent/[US675103](/patent/US675103)/en

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Result: No litigation is known or discoverable for US 675,103

I found no district court actions, no CAFC appeals, no PTAB proceedings, and no ITC investigations involving US Patent No. 675,103.

Because the strict instruction is to report by exact identifier, I am not substituting results for look-alike numbers. The searches surfaced only false positives, which I flag explicitly below so they are not mistaken for hits:

I also checked the sources you named — the Unified Patents litigation caselist (https://portal.unifiedpatents.com/litigation/caselist), PTAB/USPTO petition exhibits, and general CAFC/PACER-indexed docket material as reflected in search results — with no return for US 675,103.

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Attorney's analysis of why no litigation exists

1. Term. Under the law in force at grant, the patent term was 17 years from issuance. Google Patents records the anticipated expiration as May 28, 1918. The patent has therefore been in the public domain for over a century and cannot be asserted.
2. Enforceability. No pending or unreviewed claims exist to litigate; the "Expired – Lifetime" status is dispositive.
3. Art status. US 675,103 remains relevant only as prior art / historical reference. Its own Google Patents record classifies it under A62C13/00 and A62C13/003 (portable extinguishers; spraying by pressurized gas) and one of its own claims (claim 2) recites the screw-stem, casing and cap combination. Contemporary analogues cited on its face include US 315,610; US 719,403 ("Acid-holder for fire-extinguishers," 1903); and US 777,131 ("Portable fire-extinguisher," 1904) — all similarly long expired.
4. Any 19th/20th-century infringement suit (if one ever existed) would predate modern electronic docketing; it is not indexed on Unified Patents, Docket Alarm, CourtListener, or free CAFC/PACER search layers, and I cannot confirm one from the sources searched.

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Limitations on this conclusion

• I could not query PACER's paid docket system directly, nor Westlaw/LexisNexis/Docket Navigator's full historical coverage. Pre-1940 federal equity cases are only partially digitized, so an obscure 1901–1918 infringement bill in a circuit court could exist in paper/print archives and be invisible to these searches.
• The search tools returned no case with case number, plaintiff, defendant, jurisdiction or filing date tied to 675103. I will not fabricate such fields; every returned "match" was a mis-scan of a different patent number.

Bottom line: To the best of my knowledge based on the sources searched, there is no litigation — current or historical-of-record — involving US Patent No. 675,103 (Charles Nuhring, 1901). If you need negative-confirmation suitable for a due-diligence memo, the next step would be a paid full-text search of Docket Navigator / LexisNexis with the exact string "675,103" and its historical variants, plus a manual review of Federal Reporter volumes covering 1901–1918 for the Southern District of Ohio and Sixth Circuit.

PTAB / AIA-Trial Analysis — US 675,103 ("Portable fire-extinguisher," Charles Nuhring)

Proceedings overview

Zero AIA trial proceedings exist on US 675,103 — the USPTO Open Data Portal returns no IPR, PGR, or CBM for this patent, and I found no PTAB or Federal Circuit activity for it in web sources; the breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials, and the defensive posture is not "hardened patent" but "dead patent": US 675,103 issued 1901-05-28, expired at the end of its 17-year term on 1918-05-28, and has been outside the patent grant for more than 107 years — any demand letter citing it is either a clerical error pointing at a similarly-numbered live patent or an outright bad-faith demand.

This is the rarest of PTAB answers, and it is worth stating why the empty set is structural rather than accidental:

• Timing. The PTAB did not exist until § 6 of the Leahy-Smith America Invents Act (Pub. L. 112-29, 2011), and AIA trials (IPR/PGR/CBM) became available only on 2012-09-16. By then this patent had been expired for 94 years.
• No petitioner incentive. The Board does accept IPRs on expired patents as a matter of jurisdiction (see the panel discussion in Apple Inc. v. Gesture Tech. Partners, LLC, IPR2023-00590, Paper on the Board's authority over expired patents, and Ex parte Papst-Motoren on reexam of expired patents) — but a petitioner must first be served with a complaint of infringement or file a DJ action to satisfy 35 U.S.C. § 315(a)(1)/(b)(1). A patent that expired in 1918 cannot generate that predicate.
• PGR is unavailable by definition. Post-grant review reaches only patents with an effective filing date on or after 2013-03-16. CBM review reaches only covered financial-services patents. Neither category applies.

Bottom line for a defendant: there are no claim-level outcomes to report because no claim of this patent has ever been construed, challenged, or cancelled in an AIA trial — not because the claims survived, but because claims 1 and 2 lapsed with the patent's term in 1918. The patent that does exist is the specification, and its current legal value is as prior art, not as an enforceable right.

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Per-proceeding detail

Not applicable — no proceedings to report. I am deliberately not populating the per-proceeding template (Type / Filed / Status / panel / grounds / institution / FWD / settlement / appeal / defensive value) for any proceeding, because doing so would require fabricating an IPR, PGR, or CBM number. The instruction not to invent proceeding numbers is dispositive here: there is no number to give.

Identifier-confusion warnings (near-miss documents that search engines conflate with US 675,103)

These are not US 675,103, and none of them is a PTAB proceeding on the Nuhring patent. They surface in any keyword search for "'675" + "IPR" or "'675 patent" and should not be misread as evidence of activity:

The structural metadata in the record is consistent with a genuine 1901 grant: application filed 1901-03-08; serial no. 50,850 (the Google Patents "application number US5035001A" is a re-keyed rendering of that same filing); granted and published 1901-05-28; legal status "Expired - Lifetime"; anticipated expiration 1918-05-28; classification A62C 13/00–13/003 (portable extinguishers pressurized by gas).

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Strategic summary

Claim status — all claims UNTESTED, and all claims LAPSED. US 675,103 contains exactly two claims, both combination claims drawn to (1) a tank with an acid-bottle whose casing holds an oil seal over the stopper, and (2) the same with a screw-stem through the tank cover and casing cap. Neither claim has been cancelled, sustained, or even challenged in an AIA trial — there is no FWD, no institution decision, and no certificate of cancellation or correction on file. What has happened is simpler and more absolute: the 17-year term from the 1901-05-28 grant ran out on 1918-05-28. There is no reissue, no disclaimer, no reexamination certificate indicated in the record. For a defendant, the operative sentence is not "claims 1–2 survived" but "claims 1–2 are unenforceable because they expired before any living person was born."

Estoppel landscape — none, and none can arise. 35 U.S.C. § 315(e)(2) estoppel is petitioner-specific and attaches only after an FWD. With no petitioner and no institution, there is no estoppel bar on anyone. Conversely, there is also no useful prior-art route to attack the patent: an IPR or PGR would be a nullity because the patent grants no exclusionary right to challenge and no petitioner can satisfy the § 315(a)/(b) service requirement. The one Petitions-side channel that does legally reach expired patents is ex parte reexamination (the PTO has expressly reexamined expired patents — see the discussion of Ex parte Papst-Motoren in recent Supreme Court briefing on expired-patent review), but filing one would be academic: reexam cannot revive a lapsed term, and 37 C.F.R. § 1.530(d) bars amendments or new claims in an expired patent. If any entity were ever to assert US 675,103, the correct response is not a validity challenge — it is a motion to dismiss for failure to state a claim plus a letter to the USPTO's enforcement office.

Pattern signals. No petitioner has filed multiple IPRs on this patent (no petitioner has filed any). The patent owner has not pursued PTAB appeals (there are none to pursue). No defensive aggregator — Unified Patents, RPX, or otherwise — appears anywhere in the chain; Unified's statutory estoppel and membership model depends on the target being an economically live assertion campaign, which a 1918-expired patent cannot be. The "Family ID=2743653" record shows a single-member family with no continuations, divisionals, or foreign counterparts. There is no continuing application that could have produced live claims — the Nuhring line instead continues in a separate, unrelated patent, US 1,670,979 (1928), which is likewise long expired.

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Recommended next steps

If you are a defendant and a letter or pleading cites US 675,103:

1. Verify the number character-for-character before doing anything else. Federal Circuit and district-court records are full of "the '675 patent" shorthand (see the Canady v. Erbe opinion above, and Intel v. Qualcomm, IPR2018-01340, on US 9,608,675). Confirm the ticker/label against the actual patent document — US675103A on Google Patents and USPTO Patent Center — before responding. If the real target is a live patent such as US 9,608,675, this analysis does not apply and you need a genuine FWD review.
2. If the number is genuinely US 675,103: the patent expired 1918-05-28 and cannot support any infringement theory for any act today. There is no claim construction dispute to win, no IPR to file, and no § 315 estoppel to consider. Demand letters citing long-expired patents are a recognized hallmark of bad-faith or fraudulent assertion; preserve the letter in full (including headers and payment instructions) and consider referral to the USPTO's enforcement contact and your state's consumer-protection or UPL authority alongside a straight non-infringement/invalidity declination.
3. Do not commission an IPR search or a prior-art study. There is no proceeding to intervene in, no FWD to cite, and no statutory deadline running.

If you are a prosecutor or litigator looking at this patent as art, not as a right:

• US 675,103's practical value today is as § 102(a)(1)/(b) prior art — an 1901-05-28 printed publication (and a publicly available patent document) usable against later claims directed to sealed acid-bottle/alkaline-tank chemical extinguisher architectures, frangible or stopper-held acid vessels, and oil- or liquid-seal arrangements over a bottle mouth. Charges 1 and 2 are the disclosure to map against a target claim: casing d surrounding and extending above the bottle neck, sealing fluid such as oil g over the stopper s, cap e, and a screw-stem f operably accessible from outside the tank.
• The key disclosure sentences for an art chart: the chamber between stopper s and cap e within casing d containing "a small quantity of oil g … covering and forming an air-tight seal over the stopper s, which protects the acid against evaporation or change"; and, in the Fig. 2 modification, the prop/strut h between cap e′ and stopper s′ which "when the bottle is overturned … falls sidewise and assists in releasing the stopper."

If you were expecting PTAB activity here and found none: that is the correct and complete answer for US 675,103. The absence is not a data gap — it is the consequence of a patent term that ended 94 years before the PTAB opened, and it should be reported to your client as a categorical, not a probabilistic, conclusion.

I'll verify the assignment record before drafting. Let me check the USPTO Assignment Center and related sources.

Inventors

Notes and pattern flags:

• Single-inventor, unassigned filing. The specification states "I, CHARLES NUHRING, a citizen of the United States, residing at Cincinnati… have invented." There is no "assignor to" language and no company named on the face of the patent. Google Patents' parsed fields corroborate: Original Assignee: Individual, Current Assignee: Individual.
• Employer — suggestive, not documented. Auction listings for vintage apparatus (e.g. EBTH item 8952913, EBTH item 8455465) identify a maker "C. Nuhring & Bro. Fire Appliances, Cincinnati, Ohio." The name match is strong but I found no instrument, directory entry, or corporate record tying the patentee to that firm. Treat as a lead, not a finding.
• No "inventors departing within 12 months" pattern. That tell presupposes a corporate assignee with an employee-inventor roster. Here there is no assignee, so the signal is structurally inapplicable. Nuhring instead looks like a career independent inventor-manufacturer: he filed repeatedly in the same art (e.g. US 697,006, fire-extinguishing apparatus, filed Nov. 1901; US 777,131 and US 773,971, 1904 — the latter two indexed on Google Patents as Charles Nuhring inventions; US 1,486,600, pump fire extinguisher, 1921 filing; US 1,670,979, fire extinguisher, 1925 filing).
• Not an assignment correspondent. The grant lists two witnesses — Walter A. Knight and L. M. Hosea (OCR "L. M. HosEA") — plus the inventor's signature. These are §1.68 witnessing signatures on the specification, not an attorney or agent of record for an assignment, and must not be reported as a correspondent. No attorney-of-record line appears in the OCR'd grant text.

Original assignee

• None. The patent issued to the inventor personally. US 675,103 (filed 1901-03-08, serial No. 50,850, granted 1901-05-28, No model) was granted to Charles Nuhring as an individual, with no recorded pre-issuance or at-issuance assignment. Google Patents carries the placeholder Individual for both original and current assignee, which in practice means "no corporate assignee was ever recorded," not an affirmative ownership statement.
• Product embodying the claims. The patent describes a portable Babcock-type tank of alkaline solution with a suspended acid bottle, the novel point being an oil (or other viscid-liquid) seal held over the acid-bottle stopper inside a casing d that projects above the bottle neck, under a metallic (lead-preferred) cap e, with the stopper held by a screw-stem f through the tank cover (claim 1; claim 2 recites the perforated casing cap, screw-stem and stopper combination). Whether the Nuhring-Brothers extinguishers sold in Cincinnati actually embodied the oil-seal chamber is unverified — the surviving artifacts are untested and the feature is internal.
• Primary line of business. Not determinable from the patent or from any filing I could reach; the only commercial lead is small-scale manufacture/sale of hand fire apparatus in Cincinnati.
• Current status. Not determinable as a legal entity from any source I could reach. The patent status, however, is unambiguous: legal status Expired – Lifetime, with an anticipated expiration of 1918-05-28 (17-year term from grant, consistent with pre-1995 law). The disclosure has therefore been in the public domain for over a century and is unenforceable.

Assignment timeline

The USPTO Assignment Center has no recorded assignments for US 675,103 — and none can exist in the reel/frame system. Stating this plainly, as instructed.

Why the null result is structural rather than a search failure:

1. Record-coverage cutoff. Per 37 CFR 1.12(a)(1), USPTO assignment indexes for original and reissue patents are open to public inspection for assignments recorded on or after May 1, 1957; 37 CFR 1.12(a)(2) provides that all patent assignments recorded before May 1, 1957 are held by NARA, not by the USPTO (eCFR §1.12, GovInfo 37 CFR 1.12). The parallel trademark rule in TMEP 503.08 spells out the mechanic: pre-1955 documents sit in bound volumes at "liber and page," and only since 1955 are they microfilmed at "reel and frame."
2. US 675,103's entire life predates that. Filed 1901-03-08, granted 1901-05-28, expired 1918-05-28 — i.e. the patent's enforceable life ended 39 years before the reel/frame system began. There are no reel/frame numbers to report, no assignors, no assignees, and consequently no correspondent of record to profile (the repeat-player-attorney tell is inapplicable by construction).
3. Live index coverage is even narrower. The searchable Patent Assignment database is documented as containing recorded assignment information back to August 1980, with the historical (pre-1980) assignment database maintained separately apart from the post-1980 title records (USPTO Assignment Database webinar, uspto.gov PDF; MPEP 301.01 as summarized at BlueIron). A 1901 patent with no post-1980 recording therefore returns nothing.
4. Google Patents legal events confirm the null. The only events on the record for US 675103A are three prosecution/term events — 1901-03-08 application filed / priority, 1901-05-28 application granted / publication, 1918-05-28 anticipated expiration. There are no assignment, security-agreement, merger, change-of-name, or license entries.
5. No adverse-inference finding. A chain that is empty because the patent is 125 years old and expired is not the same as a modern patent with no recorded assignments (where the inference "original assignee still owns it" would be drawn). Here the correct reading is simply that title history, if any was ever recorded, lives in NARA's liber/page volumes and is not reachable through Assignment Center.

Verification links: USPTO Assignment Center · legacy Patent Assignment Search · Google Patents US675103A · for any pre-1957 record, NARA.

Per the no-records rule, I stop here. The Timeline diagram, NPE / troll-pattern signals, and Verdict sections are omitted by that rule; for the record, the only category this record could support is Insufficient data — there is no assignee chain to test for shell entities, cascading transfers, pre-litigation transfers, privateering, or defensive aggregation, and no assertion activity against a patent that expired in 1918 could be evidenced.

I'll run targeted searches against the USPTO record and the citation/neighbor data for US 675,103.

The generic searches returned mostly noise. Let me pin down the citation record and a few specific neighbor references.

Scope note: what the USPTO/Google record for 675,103 actually contains

I searched for the exact string, as instructed. Three findings must be stated up front before any prior-art table:

1. US 675,103 has no "References Cited" section. This is not a search failure — it is a property of the document. The fetched full text (https://patents.google.com/patent/[US675103](/patent/US675103)/en) contains bibliographic data, a Description, two claims, and a "Similar Documents" table. It contains no "Patent Citations," no "Cited By," no examiner citation list. Mandatory citation listing on US patent fronts did not begin until the mid-1940s; a March 1901 filing would have had none. I therefore cannot give you "each patent citation for 675103" in the strict sense, because the set is empty.

2. The "Similar Documents" list is algorithmic, not a citation list. Google's similarity model, not an examiner. This matters for your § 102 question, because most of those documents post-date US 675,103 and cannot be prior art against it.

3. ⚠️ Corrections to the previously generated sections.

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⚠️ Identifier collisions for the literal string "675103"

Two of my searches returned different inventions under adjacent identifiers. Reporting literally, not auto-correcting:

Anyone running a bare-string search for "675103" against a patent database will surface the transit-time modulator and the Canadian switch. Both must be excluded.

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Nearest available prior-art neighborhood: the "Similar Documents" table

Reproduced faithfully from the fetched record (dates as printed there; garbled entries flagged rather than guessed).

A. Pre-1901 documents — capable of being § 102 prior art

B. Post-1901 documents — cannot be § 102 prior art against US 675,103

US 675,103 was filed 1901-03-08. Every document below issued after that date, so none can anticipate it; they are downstream art, and several are probably its own forward citations.

Also located in search and likewise post-dating 675,103: US 887,392 (Harker, Cincinnati — filed 1906-04-07, granted 1908-05-12, "Fire-Extinguisher," acid-bottle cage with a lead stopper 13 held by a cross-pin 12 through an elongated slot 14 so the stopper cannot be misplaced); US 1,009,490 (Driscoll, filed 1910-12-28); US 686,056 (Hale & Wiesner, filed 1901-06-21 — three months after Nuhring, granted 1901-11-05). Harker's stopper-retention scheme is directly comparable to Nuhring's Fig. 2 strut/cap arrangement, but it is not prior art.

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C. The single most relevant reference located: Enno Sander, US 111,877 (1871)

This is the only reference for which I obtained actual claim and specification text, and it is the strongest § 102 candidate in the set.

• Full citation: E. Sander, "Improvement in Fire-Extinguishers," U.S. Patent No. 111,877, granted Feb. 14, 1871.
• Disclosure: A gas-generating tank A with a screw-capped fill opening B; an acid-chamber D of lead bolted to the tank with a ground/gasket joint; a conical discharge valve H seated in the lead bottom of the acid chamber; the valve actuated by side rods J J′ through stuffing-boxes K K, driven by an operating screw M turning in a cross-head L, with handle P lockable by staple R. Stated object: generate carbonic-acid gas to expel tank contents, with the valve-operating mechanism kept outside the acid chamber so it is not exposed to corrosion.
• § 102 mapping:
  • Claim 1 — no anticipation. Sander lacks the casing surrounding and extending above the neck of the bottle, the oil/viscid sealing fluid over the stopper, and the cover for that casing — i.e., the entire point of novelty. Sander's acid chamber has a bolted cap, not a fluid-sealed stopper chamber.
  • Claim 2 — partial only. Sander discloses "means accessible from without the tank" operating a closure for the acid chamber (screw M → cross-head L → side rods J J′ → valve H). That reads on the functional element of claim 2, but claim 2 is a combination claim expressly requiring a perforated casing cap and a screw-stem extending through the tank-cover and the casing-cap. Sander has neither a casing cap nor a component passing through the tank cover — his rods pass through stuffing-boxes in the acid chamber. On the text I have, no anticipation. Note the structural contrast is instructive: Sander routed actuation around the acid chamber; Nuhring routed a stem through it and sealed it with oil.

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D. Assessment against the claims

Applicable law caveat. US 675,103 issued 1901 and expired 1918. "35 U.S.C. § 102" did not exist at either date — the governing statute was Rev. Stat. § 4886 (novelty) and § 4920 (defenses). I am answering the § 102 question you asked, but flagging that the mapping is anachronistic and the controlling test would have been novelty/priority of invention, not the 1952 Act's subsections.

What I could not determine — stated plainly rather than guessed:

• I could not retrieve the specification or claims of US 95,840; US 143,794; US 315,610; US 337,344; US 373,919; US 489,767; US 578,434; US 598,826; US 601,435; or US 626,988. Six of these have incomplete titles in the source record. I will not characterize their disclosures.
• I could not retrieve a forward-citation ("Cited By") list for US675103A; the fetched page does not contain one. Claims in the prior sections that later patents "cite" it are therefore unverified by me, except that US 777,131 is Nuhring's own continuation of the same subject matter.
• No non-patent literature was located; 1901-era fire-extinguisher trade catalogs and the Scientific American / Iron Age product notices that often anticipate this class of art are not indexed in the sources searched.

Bottom line: US 675,103 has no citation list on its face, so the literal request has an empty answer set. The substitutable evidence is Google's "Similar Documents" table, of which 10 entries pre-date the 1901-03-08 filing and are the only § 102-capable references; the other 15 are downstream. Of the pre-1901 group, the one reference I could actually read — Sander, US 111,877 (1871) — anticipates neither claim in full and touches only the "externally operable closure" concept. The oil-seal limitation of claim 1 is the element no located reference meets. The correct next step is a full-text pull of the ten pre-1901 references from USPTO Patent Public Search (ppubs.uspto.gov) or a paid OCR archive, which I could not complete within the search budget here.

I'll ground the prior-art references from the page before running the §103 analysis.

Now let me ground the oil-seal prior art and check dates on the closest references.

Obviousness Analysis — US Patent 675,103 (35 U.S.C. § 103)

Building on the previously-generated claim construction and bibliographic/litigation sections; those are not repeated here. All identifiers are reported literally as they appear on the face of the record or in the source cited.

Two housekeeping flags before the analysis.

1. Date inconsistency: this task header states "Current Date: April 26, 2026," while the session date is 2026-09-29. The analysis below is date-insensitive, but I'm flagging the mismatch rather than silently choosing one.
2. Search capacity: three of my queries (a Nuhring 777131 check and two liquid-seal queries) returned a step-limit error, not substantive results. Where that limits the analysis, I say so explicitly. Nothing below is asserted as a verified reference unless I cite it.

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1. Framing: which law applies, and to what

US 675,103 issued May 28, 1901 and expired May 28, 1918. For a grant of that vintage, the historically applicable validity test was the pre-1952 "invention" standard — Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851) ("ordinary skill of the calling"), later Cuno Eng'g Corp. v. Automatic Devices Corp., 314 U.S. 84 (1941), and A&P Tea Co. v. Supermarket Equipment Corp., 340 U.S. 147 (1950). The modern § 103/Graham framework you've asked for is applied below as requested, but the two standards point the same direction, and the older one is stricter against the patentee, because it demanded a qualitative "flash" rather than mere predictability. A claim that fails § 103 (KSR) a fortiori fails Hotchkiss/Cuno.

I also note the art is ancient and crowded: the specification itself refers to the tank as a "portable Babcock tank" and repeatedly describes the stopper/stem arrangement as operating "in the usual manner." Those are patentee admissions that the base combination was old — powerful § 103 evidence independent of any reference.

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2. Which references on this page actually qualify as prior art

Critical threshold point: the Google Patents "Similar Documents" list mixes pre- and post-filing references. Only art publicly available before March 8, 1901 can be combined. Element mapping against post-1901 documents is legally improper (though it is probative of what the art later considered routine).

(Note: I have not read the internal disclosures of 578,434, 601,435, 373,919, 489,767, 337,344, 95,840, or 143,794. They are date-eligible and any of them could supply additional element disclosure; I make no representation about their contents.)

Additional date-eligible references I did verify from the primary documents, and which materially strengthen the rejections:

Legal support for treating distant arts as analogous: in The Fire-Extinguisher Case (Graham v. Johnston), 21 F. 40 (C.C.D. Mass. 1884) — https://law.resource.org/pub/us/case/reporter/F/0021/0021.f.0040.pdf — the court held the beverage-carbonating-fountain art ("Nichols' fountain") analogous to fire extinguishers, because both use "the prompt generation of carbonic-acid gas and the impregnation of water with it" and "the same projectile force… to expel the acidulous water." It then held the "obvious addition of so simple an element… cannot constitute the combination of a new and patentable one." That decision is directly on point for the scope of analogous art in this exact field and for the obviousness of adding a routine sealing expedient.

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3. Element mapping — Claim 2 (the structurally concrete claim)

Claim 2 recites: acid bottle suspended beneath the tank cover; casing surrounding and extending above the neck; perforated cap for the casing; screw-stem extending through the tank-cover and casing-cap; stopper carried on or connected with the stem. Notably, claim 2 does not recite the oil seal at all — it claims only the architecture.

Combination 1 → Claim 2 obvious: Thomas 598,826 in view of Gee 315,610.

Every element is present; the only structural gap in Thomas (a dedicated casing around the bottle neck with its own cap) is supplied by Gee, which teaches precisely a flanged throat cemented to the acid receptacle and clamped under the tank cap, with the operating rod passing through a packed aperture. Both are chemical fire extinguishers using suspended acid receptacles closed by a stem-operated stopper; both operate through the same sealed-cap architecture; the substitution of Gee's neck/cap for Thomas's cage is an interchange of known equivalents for the known function of enclosing and sealing the top of the acid receptacle. Under KSR, "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results," and here the result (a sealed, externally releasable acid bottle) is exactly what both references were designed to produce.

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4. Element mapping — Claim 1 (the "means accessible from without" claim)

Claim 1 adds the casing + cover combination and recites: acid bottle; casing surrounding and extending above the neck, adapted to contain oil or other sealing fluid over the stopper; cover for said casing; and means accessible from without the tank for holding the stopper normally in place.

Combination 2 → Claim 1 obvious: Thomas 598,826 + Gee 315,610 + Schaefer 616,362 (+ liquid-seal art, § 5), or Gee as primary with Thomas and Schaefer as secondaries.

Schaefer is worth emphasizing: it discloses a stopper seated in the bottle mouth, carried on a bolt that passes through a packed, screw-threaded opening in the tank cap, and raised/lowered by cams operable from outside the tank. That is functionally the "means accessible from without the tank for holding the said acid-bottle stopper normally in place."

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5. The one genuinely contestable element: the oil/viscid-liquid seal

This is where the patent's asserted novelty lives — "a seal of oil or other suitable viscid liquid as a seal over the mouth of the acid-bottle." I want to be precise about what I can and cannot support:

• What I can support. (a) The problem was squarely recognized in the pre-1901 art: Macomber's 411,552 seals "to prevent any evaporation"; Harden's 282,981 coats a cork with "sealing-wax, cement, lead, or other soft metal" expressly "to prevent the leaking of gas through the pores of said cork" and "for holding said stopple in place"; Flatau describes a "compressed-air seal"; Gee packs the cap aperture and the throat with washers. (b) The patentee himself concedes the problem was one "experienced with such constructions" — i.e., a known, pre-existing deficiency, not a newly discovered one. (c) Capping and enclosing the acid-receptacle neck was routine (Gee; Douglas).
• What I cannot support. I did not locate, and do not assert, a pre-March-1901 U.S. reference that expressly puts a body of oil (a liquid) over the acid-bottle stopper as a vapor barrier in a fire extinguisher. The closest structural analogue is Harden's solid coating over a cork stopper, and the closest functional analogue is Macomber's hermetic film cover. My confirming searches on this narrow point were truncated by a step limit.
• The obviousness argument therefore rests on two legs:
  1. General chemical-arts knowledge. Liquid (oil/water/hydraulic) seals over volatile liquids and around imperfect closures were long-standing workshop practice in acid handling, carboy transport, soda-water and gas apparatus. I flag this as requiring documentary corroboration (a good-faith § 103 report needs the actual reference, e.g., a pre-1901 carboy or aerated-water patent) rather than assuming it.
  2. KSR rationale of a known technique for a known problem. "[A] known technique that has been used to improve one device" and "the simple substitution of one known element for another" are cited-by-the-book obviousness grounds. Selecting an inert, non-reactive liquid to blanket a stopper that is already known to leak vapor is a predictable use of a known sealing technique, with no unexpected result alleged. Nuhring alleges no criticality of oil over any other seal, no unexpected degree of protection, and no measurement. Under Hotchkiss/Cuno this is even more clearly "the work of the ordinary mechanic."

A reasonable examiner could also break the seal limitation down as a product-by-function recitation: "adapted to contain oil or other sealing fluid" is a capability statement. Gee's throat C / Thomas's hub b³ already define an enclosed chamber around the stopper; whether it is filled with oil is arguably an intended use, not structure. That is a viable alternate rejection path and a viable § 112 written-description/indefiniteness attack on the "adapted to" language under pre-1952 functional-claim cases.

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6. Why a person of ordinary skill would have combined these references

The same four rationales recur across every combination above:

1. Same field, same problem, same art. All primary references are class "chemical fire-extinguisher, soda-acid type, agent expelled by self-generated gas" — the very class the patent's own first sentence identifies. Gee, Thomas, Douglas, Schaefer and 147,442 address the identical problem: keep the acid sealed and releasable from outside a closed tank.
2. Same structural approach, already refined across the art. Each reference already mounts the acid receptacle under the tank cover, closes it with a stopper, and (except Douglas) operates it through a packed stem or rod. Combining Gee's neck-and-cap with Thomas's screw-stem is not a leap; it is the assembly of two components designed to be used together — one supplies the sleeve, the other the actuator.
3. Predictable, finite solution space. The patent's problem — "liability of the acid to creep through the stopper-fastenings" — admits of a small number of known fixes: a better packing (Gee), a coating (Harden), a hermetic film (Macomber), a pressure seal (Flatau), or a liquid blanket. KSR treats such "finite number of identified, predictable solutions" as strong evidence of obviousness.
4. Design incentives and synergy with the reference's own goals. Thomas's stated goal is that "it is absolutely impossible that any chemicals should spurt out around the hand of the operator or should get at the bearings to corrode them fast" — i.e., Thomas already cares about isolating the acid from the operator and the mechanism. Adding a fluid barrier inside an already-enclosed chamber is fully consistent with Thomas's own objective; it does not change Thomas's principle of operation. There is no teaching away anywhere in the record, and none of the references disparages fluid seals.

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7. Single-reference and near-anticipation observations

• Thomas 598,826 is close enough to claim 2 that, if a court or examiner were to read Thomas's hanger/cage F (with its "hollow shell-like depending portion" and stopper seat f′), the spider f⁹ supporting the bottle-neck, and the cap hub b³ perforation b² as together constituting a "casing surrounding the neck" with a "perforated cap," claim 2 could be attacked as anticipated under § 102 rather than merely obvious. I flag this as the single most dangerous reading of the prior art against this patent; the suspension beneath the cover, screw-stem, and stopper carried on the stem limitations are, on my reading, all literally present in Thomas.
• Badger US 730,333 discloses an annular "cup of which the stopper constitutes the bottom," an adjustably screwed sleeve, and a skeleton cage — structurally the closest thing in the record to Nuhring's casing/cap-and-oil-cup idea — but it was filed November 29, 1901, after Nuhring's March 8, 1901 filing, so it is not available as prior art. Its existence is nonetheless probative of how quickly and independently the art gravitated to enclosing the bottle mouth with a cup-like structure.
• Hale & Wiesner US 686,056 (filed June 21, 1901) states the object of guarding "against the liability of the inoperativeness of the extinguisher, as is in practice found to be the case in the use of this class of fire-extinguishers generally." Post-filing, so not citable, but it independently corroborates that the reliability problem Nuhring addressed was a general, recognized industry problem as of that moment — which cuts against "long-felt but unsolved need" while also supporting "known problem."

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8. Secondary considerations (Graham factor 4)

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9. What the patentee would argue, and how strong it is

1. "No reference discloses a liquid seal over the stopper." Strongest argument, applicable only to claim 1. The response: the seal is a known technique applied to a conceded problem; independent corroborating art is needed, and Harden/Macomber/Flatau supply the problem-and-solution context even if not the exact medium.
2. "The claim requires a fluid reservoir — a new structural element, not a substitution." Moderate. Rebutted by Gee's throat C and Thomas's hub, which already define an enclosed annular chamber around the stem above the stopper; the oil merely occupies existing space. Also rebutted by the "adapted to contain" functional phrasing.
3. "Non-analogous art." Weak here. All references are in the identical field, and Graham v. Johnston already held the carbonating-fountain art analogous.
4. "Claim 2 preserves the casing/cap that no reference shows." Weak. Gee shows it (cemented flanged throat under the cap), and the assembly function is unchanged.
5. Historically: "flash of genius" / more-than-ordinary-skill. Unavailable in substance. As the pre-1952 cases themselves framed it, sealing a leaky closure is the archetype of the ordinary mechanic's work.

Net assessment: Claim 2 is highly likely obvious and arguably anticipated by US 598,826 (Thomas) in view of US 315,610 (Gee), with US 616,362 (Schaefer) as a further secondary. Claim 1 is likely obvious over the same combination plus art showing (a) external stopper actuation (147,442; Schaefer) and (b) a barrier/seal over a stopper to prevent loss (Harden 282,981; Macomber 411,552) — but claim 1 is the only claim with a plausible (not strong) defense, and that defense stands or falls on the § 5 evidentiary gap.

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10. Explicit limitations on this analysis

• I have read the primary documents for US 315,610, US 598,826, US 626,988, US 616,362, US 282,981, US 147,442, US 411,552, US 730,333, US 686,056 and the Flatau UNT records. I have not read US 578,434, US 601,435, US 373,919, US 489,767, US 337,344, US 95,840, or US 143,794, all of which are date-eligible and may independently disclose the casing/neck/cap or stopper-sealing elements. Nothing in this report should be treated as a complete prior-art search.
• No pre-1901 reference expressly disclosing an oil (or other liquid) seal over an acid-bottle stopper was located. I do not assert one exists; I assert only that the problem was known and that non-liquid sealing expedients were known. A defensible obviousness position on the "sealing fluid" limitation requires a second, corroborating documentary search — I recommend a full-text search of the 1860–1900 U.S. classifications covering acid carboys, aerated-water apparatus, and chemical extinguishers for terms such as "oil," "liquid seal," "hydraulic seal," "sealing fluid," and "viscid."
• Date qualifiers: US 719,403, US 730,333, US 686,056, US 777,131, US 754,037, US 750,416, US 778,439, US 779,435 and all post-1905 documents on this page post-date the March 8, 1901 filing and are not § 102/§ 103 art for this patent. US 626,988's printed filing date is internally inconsistent in the OCR (Oct. 20, 1899 vs. Oct. 20, 1898); I report both literally and note only that either date is before March 8, 1901, so the reference remains prior art on either reading.
• Unverified identifier: the application/serial-number discrepancy for US 675,103 itself (US5035001A vs. "Serial No. 50,850") was flagged in the earlier bibliographic section and is not re-litigated here.