US 612094

I'll search for this patent number as requested.

Let me dig deeper with targeted searches, including the CAFC docket angle.

Search results and scope note

I ran targeted queries against Google Patents (the authoritative full text supplied), general web indexes, and searches aimed at Federal Circuit 2026 activity. Important caveat up front: I could not directly query USPTO PatentCenter/Patent Public Search or the CAFC docket system from these tools — my findings rest on the Google Patents record and general web results. I found no CAFC 2026 docket, appeal, or litigation involving patent 612094, and no other "612094" patent record that differs from the one below. Given the patent expired in 1915 (see below), any 2026 appellate activity would be anomalous; I treat the absence of results as expected rather than as proof of nonexistence.

Also flagged: the Google Patents page renders the title field as "flatau" rather than the actual title. That is a metadata artifact of the record, not the invention's title. I have interpreted the number literally as US 612,094 and have not substituted any similar numbers.

US Patent 612,094 — Bibliographic summary

Metadata quirks worth noting (not auto-corrected):

• The Google Patents record labels the prior-art date as 1898-10-11, which is the grant date, not the 1897-12-11 filing date.
• The application-filing line in the OCR'd header reads "D00. 11, 1897," a garbled rendering of December.
• Claim language in the record reads "theacid-bottle" (an OCR run-together).

Abstract

There is no abstract in the original 1898 document — abstracts were not required of US patents at that time. The Google Patents landing page carries only a machine-assembled snippet, not an applicant-supplied abstract. The closest authoritative substitute is the stated object of the invention:

"…to provide an improved acid-receptacle and holder so constructed and arranged that when the extinguisher is in an upright position or even tilted the acid will not escape from the acid-receptacle and mix with the alkaline solution; but when the extinguisher or device is to be used it is turned upside down, and the acid will escape from its receptacle and come in contact with the alkaline solution."

The specification also describes the apparatus class: "portable chemical fire-extinguishers … which comprise a receptacle for containing an alkaline solution and an acid-receptacle so constructed and arranged that when the contents of said receptacle are brought in contact a reaction will take place, releasing a gas which presses upon the surface of the fluid and ejects it at the nozzle."

The invention in plain language (numbered parts per the specification)

• 1 — tank/receptacle holding an alkaline solution (a salt that evolves carbonic-acid gas on contact with acid).
• 2 — screw-threaded cap on the tank's top boss; 3 — handle on the cap.
• 4 — escape passage in the cap, connected to 5 — a hose.
• 6 — rubber (or other elastic) packing ring/gasket for a tight joint.
• 7 — a cylinder/holder secured to the underside of the cap, extending downward.
• 8 — fluting at the lower ("inner") end of the holder, forming a number of passages.
• 9 — the acid-receptacle, e.g. an ordinary glass bottle, held in the holder by frictional contact.

Operation: Filled with acid and friction-fit in the holder, the bottle keeps its acid segregated while the extinguisher is upright or merely tilted. Inverting the device lets the acid flow out through the fluted passages and mix with the alkaline solution, generating CO₂ that pressurizes the tank and drives the charge out through the hose. The spec expressly contemplates square or other angular holder/bottle shapes, so long as frictional retention is preserved and there is space between bottle and holder wall.

Independent claims — plain-language overview

The patent has two claims, both independent combination claims (there are no dependent claims). Both are "substantially as described" claims typical of the era.

Claim 1 — Tank + cap + fluted holder + acid bottle.
In a portable chemical fire-extinguisher, the combination of: (a) the tank/receptacle for the alkaline solution; (b) the cap; (c) a downwardly-extending holder that is fluted at its inner end so as to form passages; and (d) the acid-bottle inserted in that holder. Broadly, this covers the core assembly of alkaline tank + cap + perforated/fluted acid-bottle holder.

Claim 2 — Claim 1's assembly plus the delivery-side details.
In a portable fire-extinguisher, the combination of: (a) the tank/receptacle; (b) a screw-cap fitted with a handle and formed with an escape-passage; (c) a hose connected to that passage; and (d) the downwardly-extending holder fluted at the inner end forming passages, with the acid-bottle inserted in the holder. This is the narrower claim, adding the screw-threaded handled cap, escape passage, and hose to the claim-1 elements.

Practical read: Claim 1 is directed to the acid-bottle retention/discharge subassembly in the tank; Claim 2 covers the substantially complete commercial extinguisher including the hose-and-cap discharge path. Because Claim 2 adds elements to Claim 1's combination, Claim 2 is the narrower of the two.

Adjudication / legal-status findings

• No CAFC 2026 docket found. Queries aimed at Federal Circuit 2026 activity produced no hits (empty result sets). I could not reach the CAFC docket system or CourtListener docket search directly, so I cannot state affirmatively that no such docket exists — only that my searches surfaced none. Practically, the patent's term expired 1915-10-11, so a 2026 appeal concerning US 612,094 would be highly unusual.
• Google Patents records legal status as "Expired – Lifetime"; family ID 2680706, single family member (US612094D / US612094A).

Caution on near-miss records (do not conflate)

My searches surfaced a different Flatau patent in the Portal to Texas History / DPLA (local-cont-no 552427, dated December 31, 1895/1896, describing an acid-bottle of two concentric cylinders forming a compressed-air seal). That is a separate, earlier Flatau patent and is not US 612,094 — the 612,094 bottle is a single friction-held bottle in a fluted holder, with no concentric-cylinder seal. Sources: https://texashistory.unt.edu/ark:/67531/metapth174174/ ; https://digital2.library.unt.edu (UNT Digital Collections).

A contemporaneous newspaper item independently corroborates the grant: "Louis S. FLATAU of Dallas for chemical fire extinguisher" among patents issued to Texas residents (October 1898) — https://www.txgenwebcounties.com/burleson/news/tidbit189810.htm

Authoritative full-text source: https://patents.google.com/patent/[US612094](/patent/US612094)/en

Explicit uncertainties

1. No abstract exists in the original document; anything presented as an abstract for this patent is third-party-generated.
2. CAFC 2026 activity: not verified directly against the court's docket; my tools found none.
3. The Google Patents title field showing "flatau" is a record artifact — the specification's title is "Chemical Fire-Extinguisher."
4. I did not retrieve the original drawing sheet (the figure is described as a longitudinal sectional elevation) beyond the description's content.

I'll search for litigation records involving US patent 612094.

Initial results are false positives (other patents ending in "094"). Let me refine.

Let me check the Unified Patents litigation portal and a few more targeted sources.

Litigation Search Results — US Patent 612,094

No litigation is known for US Patent 612,094. I searched litigation-focused sources (including Unified Patents' litigation/PTAB portals, which the queries pointed to, and general web/court-document searches) and found no case — past or present — in which US 612,094 was asserted, challenged, or otherwise at issue.

Why this result is expected

US 612,094 is a historical patent, not a modern one. The authoritative patent text you provided establishes the following literal facts:

Because the patent's term expired on October 11, 1915, it has been incapable of supporting an infringement action under 35 U.S.C. § 271 for more than a century. No modern district court or CAFC action is possible, and no PTAB proceeding (IPR/PGR) can be instituted against it, as those proceedings apply only to unexpired or recently issued patents.

Search artifacts — identified and excluded

To be transparent, several search hits appeared relevant but are false positives for different patents. Per your strict rule, I did not auto-correct them; I simply note they are not US 612,094:

• Neste Oil Oyj v. Dynamic Fuels LLC — concerns U.S. Patent No. 8,212,094 ("the '094 patent"), a hydrodeoxygenation/isomerization process patent. Different patent.
• U.S. Ethernet Innovations, LLC (USEI) v. Dell, Apple, et al. (N.D. Cal., Case No. 5:09-cv-04775, filed Oct. 9, 2009) — the "'094 Patent" there is a different patent asserted alongside the '459, '872, and '313 patents. Different patent.
• Marvin Lifestyle India Private Limited — "612094" — a credit-report reference number, not a patent.
• Polish KRS register "RDF/612094/24/..." — an administrative docket number, not a patent.

None of these involve US 612,094.

Historical context

I also searched for any century-old litigation involving Flatau or his 1898 fire-extinguisher patent. I found only archival/primary records of the patent itself (e.g., the Portal to Texas History / UNT Digital Library holdings and the Google Patents record at https://patents.google.com/patent/[US612094](/patent/US612094)/en), not any reported court case. Historical patent infringement suits from that era are rarely digitized, so I cannot affirmatively rule out that an unreported 1898–1915 suit existed, but I have no evidence of one, and I will not speculate.

Bottom line

• Known litigation involving US Patent 612,094: none.
• Cases and case numbers: N/A (no plaintiff, defendant, jurisdiction, filing date, or outcome can be provided because no case exists in the record).
• The patent expired October 11, 1915, which forecloses any present or future enforcement.

If you intended a different patent (for example, U.S. Patent No. 8,212,094 or the "’094 patent" from the USEI litigation), let me know the exact number and I can search that specific patent's litigation history.

I'll verify the structured data against live sources before reporting.

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal block reports no AIA trial proceedings for US 612,094 as of the most recent ingest, and my independent checks — targeted web searches against PTAB decisions coverage, PTAB E2E-style queries, and CourtListener/Federal Circuit materials for "612094" and "Flatau" — surfaced nothing. No IPRs, no PGRs, no CBM reviews; therefore no claims invalidated, none sustained on the merits, nothing settled, no institution denials to report. The bottom line for a defendant is not the usual PTAB posture question at all: there is no live patent here to defend against. US 612,094 issued 1898-10-11 (filed 1897-12-11, Serial No. 661,537, "Chemical Fire-Extinguisher," Louis S. Flatau of Dallas, Texas, assignor of one-half to William M. Robinson) and its term expired 1915-10-11 — the ODP record itself lists that as the "anticipated expiration" date. A 128-year-old, long-expired patent cannot be asserted, so the relevant defensive move is not an IPR strategy but a demand-letter triage.

No proceedings to enumerate

Because the structured data is the canonical source and it is empty, I am not going to manufacture proceeding numbers, petitioners, panels, or dispositions to fill the template. If you need to confirm independently before relying on this, the two primary sources are the USPTO PTAB End-to-End (E2E) system and the ODP API endpoint the block was drawn from; a Freedom of Information Act request would be pointless here given the patent's age.

Why the absence is structural, not just incidental. The AIA trial regimes are date-bounded: IPR became available 2012-09-16, PGR applies only to patents with an effective filing date on or after 2013-03-16, and CBM review (limited to covered business method patents) sunset on 2020-09-16. US 612,094 predates all of them by more than a century, and its 17-year term under the law then in force ran out in 1915. The one theoretical hook — that the Board will sometimes institute on an expired patent where past damages remain in controversy, a point the Federal Circuit addressed in Sony Corp. v. Yissum Research Development Co. — has no application to a patent that expired before the Wright brothers' first flight.

Two record details worth not confusing with PTAB activity. First, the Google Patents page for US612094 lists a long "Similar Documents" set (US195370, US337344, US568658, US515846, US609584, US578324, US555022, US105279, US149044 and others, all 1870–1923 vintage fire-extinguishers). That is a citation/similarity graph generated by the platform, not a petition or proceeding list — automated scrapers routinely mistake it for one. Second, the ODP "Family ID=2680706" lists exactly one application, US612094. There are no continuations, divisionals, or continuations-in-part issuing from this disclosure, so there are no sibling patents to check for assertion either. The patent contains only two claims — claim 1 (tank + cap + downwardly-extending holder fluted at the inner end forming passages + acid-bottle inserted in the holder) and claim 2 (the same combination plus a screw-cap with a handle, an escape-passage, and a connected hose). Neither has ever been construed, challenged, or adjudicated in any forum I can identify.

Strategic summary

Claim status across the patent. Claims 1 and 2 are UNTESTED — there is no cancellation certificate, no reexamination certificate, no certificate of correction, no statutory disclaimer, and no adverse judgment against them, because none of those mechanisms has ever been invoked. They are not "sustained" in any meaningful sense either; the patent has simply aged out. Under the term rules applicable to a patent filed in 1897 and granted in 1898, the grant ran 17 years from issuance and terminated 1915-10-11, which the ODP record confirms. What remains is prior art and public-domain technical literature — the holder/fluted-passage acid-bottle arrangement described in the specification, and its two claims, are freely usable today and are themselves citable art against modern "upside-down reactant-mixing" extinguisher designs.

Estoppel landscape. § 315(e)(2) estoppel is inapplicable: estoppel attaches to a petitioner who obtains a final written decision, and there is no petitioner and no FWD. For a defendant being asserted against today, the practical point is stronger than "all prior-art grounds remain available" — there is no valid claim to attack in the first place. Note the corollary for the other side: because no IPR was ever filed, § 315(b)'s one-year bar from service of a complaint has been running nowhere, but that is academic.

Pattern signals. No repeat petitioner, because there is no petitioner. No PTAB appeals, because there is no Board decision to appeal. No defensive aggregator (Unified Patents or similar) in the chain, because aggregators target patents with live assertion campaigns. If a demand letter is in front of you, the number is almost certainly being cited in error, or is being cited in the seven-digit modern format ("US 6,120,094," a number in the 2000-era 6,000,000 series) rather than the six-digit 1898 grant. I could not confirm what, if anything, issues as US 6,120,094, so verify the number on the face of the letter rather than assuming — treating a live 2000-vintage patent as this expired 1898 one, or vice versa, would be a costly mix-up in either direction.

Recommended next steps

• If you received a demand letter citing US 612,094 (six digits, issued 1898-10-11): this is a nullity. Quote the ODP record's own expiration entry — "1915-10-11 Anticipated expiration" — and the grant date of 1898-10-11, and note that under the pre-1995 17-years-from-issue term the patent has been expired for over 110 years. There is no PTAB proceeding to point to because none is possible; a response letter should cite the patent's own front-page data rather than a Board decision.
• Verify the number on the letter's face. Six-digit 612,094 (1898) and seven-digit 6,120,094 are different patents in the same sequential US series. Confirm which is cited before drafting a reply; if the letter cites the seven-digit form, the analysis above does not apply to it and a fresh IPR/PTAB and prior-art check should be run against that patent.
• If you are a patent owner or portfolio manager who found this record while mapping a fire-extinguisher family: there is nothing to license or enforce here, and US 612,094's 1898 disclosure should be treated as prior art / public-domain subject matter, citable against later chemical fire-extinguisher claims.
• Documentation to keep on file: the Google Patents record at https://patents.google.com/patent/US612094/en (source of the grant data, claims, and family information used above). USPTO PTAB E2E has no entry to link, and there is no Federal Circuit opinion or CourtListener docket to cite for this patent.

Confidence and caveats. High confidence on the zero-proceeding count: the ODP block is empty, this patent's 1915 expiration predates the availability of every AIA trial vehicle by roughly a century, and multiple targeted searches produced no contrary result. Moderate confidence that no obscure pre-2012-style proceeding (e.g., an inter partes reexamination, which is a different animal from an AIA trial and would not appear in the ODP trial-proceedings field at all) touches this patent — I found no evidence of one, but I could not query the reexamination database directly, and if that distinction matters to your matter it should be checked separately. I did not find any evidence that a modern US 6,120,094 exists, and I am not representing that it does.

I'll verify the assignment record before writing this up.

Ownership & Assignment Analysis — US Patent 612,094

Patent: US 612,094 — "Chemical Fire-Extinguisher" (Flatau)
Filed: 1897‑12‑11 (Serial No. 661,537) · Issued: 1898‑10‑11 · Anticipated expiration: 1915‑10‑11 · Status: Expired – Lifetime
Primary source check: USPTO Patent Assignment Search (https://assignment.uspto.gov/patent/index.html) and Assignment Center (https://assignmentcenter.uspto.gov/) — searched by patent number.

Inventors

Notes and caveats:

• This is a single-inventor patent. There is therefore no "all inventors departed within 12 months" cluster to assess, and no pre‑filing corporate obligation is evidenced on the face of the document.
• The patent issued to the inventor with a one‑half undivided interest assigned to William M. Robinson, of Dallas (see the patent heading: "LOUIS S. FLATAU, OF DALLAS, TEXAS, ASSIGNOR OF ONE‑HALF TO WILLIAM M. ROBINSON, OF SAME PLACE"). That is a pre‑issuance transfer of title appearing on the printed patent — not a post‑issuance event and not an online Assignment Center record.
• Records for related Flatau fire‑extinguisher filings exist in the UNT Digital Library / Portal to Texas History (digitized patent copies dated Dec. 31, 1895 covering a concentric‑cylinder acid‑bottle extinguisher, and a further item dated Dec. 31, 1896). I could not confirm the patent numbers of those items, and their metadata dates do not match US 612,094's issue date, so I treat them as possibly related but unverified — they point to Flatau as an independent inventor working serially on chemical‑extinguisher acid‑receptacle designs rather than as an employee‑inventor.
• One UNT metadata record (https://texashistory.unt.edu/ark:/67531/metapth174174/) lists additional associated names — Robinson, William M.; Givans, E. B.; Card, J. R.; Ourand, F. L.; Louis Bagger & Co.; Andrew B. Graham Co. — but these are unattributed contributor strings in a library record and are consistent with witnesses and Washington‑D.C. patent‑printing/illustration firms appearing on the printed copies. I do not treat them as assignees or employers. Do not rely on them as ownership evidence without pulling the original documents.

Original assignee

There is no corporate original assignee. The issued patent names two individual co‑owners:

• Product embodying the claims: No evidence found that either co-owner manufactured or sold a commercial extinguisher. No company, brand, catalog, or trade listing was located in the searches run. I will not assert that a product did or did not ship — the record is silent.
• Primary line of business: Not determinable for either individual from the patent or any located record. Robinson is identified only as "of same place" (Dallas).
• Current status (as entities): Both are private individuals from the 1890s; no corporate successor, merger, acquisition, or bankruptcy proceeding is of record, and none would be expected. The patent itself expired 1915‑10‑11 and entered the public domain; any residual title in the co‑owners' estates is legally moot and commercially unverifiable.
• Belated regional re-checks: Because the USPTO's online assignment system does not reach this era, the only way to establish whether title moved between 1898 and 1915 would be to order the pre‑1980 historical assignment records from the USPTO Assignment Recordation Branch (MPEP 301.01 maintains these "separate and apart from the database of assignments affecting title recorded since 1980"; see the coverage summary at https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf and https://blueironip.com/ufaqs/how-are-historical-patent-assignment-records-maintained/). Note that even then, assignments executed before 1898 would sit in the same historical microfilm/paper series rather than in any indexed electronic file.

Assignment timeline

The USPTO Patent Assignment Center / Assignment Search returns no records for US Patent 612,094.

Per the mandated output rule, I state that plainly and stop the enumeration here: there are zero recorded assignments to list, no reel/frame numbers, no conveyances, no assignors/assignees, and no correspondent of record for this patent.

Why this is the expected result, not a search failure:

So the absence of online records is a coverage artifact of the 1980 database boundary, not evidence that the 1897–98 Flatau→Robinson transfer never occurred — that transfer is affirmatively visible on the face of the patent, but its reel/frame (a pre‑1980 microfilm citation) is not retrievable through Assignment Center or the assignment‑search API.

Timeline diagram

timeline
    title Ownership of US 612094
    1897 : Application filed Dec 11
         : Flatau half interest to Robinson
    1898 : Patent issued Oct 11
    1915 : Patent term expired Oct 11
    1980 : USPTO online assignment records begin
         : No records found for this patent

NPE / troll-pattern signals

Each signal is assessed against what is actually on the record. There are no post‑issuance reel/frame entries to cite, which constrains most calls to not present or unclear — I flag that limitation rather than inferring from the 1890s names.

Cross‑reference result: SEC filings (10‑K/8‑K) are not applicable — neither co‑owner is a public company and no multinational successor exists. The RPX and Unified Patents asserter directories contain no entry connected to US 612,094; a 1915‑expired patent cannot appear on a high‑frequency‑plaintiff list, since no cause of action under 35 U.S.C. § 271 is possible.

Verdict

Insufficient data (only the original assignment is documented).

Justification: The USPTO Assignment Center/Assignment Search returns no records for US 612,094, and that is a coverage limit rather than a finding of no transfers — the online assignment database only reaches back to August 1980, while this patent's sole documented ownership event is the pre‑issuance assignment of a one‑half undivided interest from Louis S. Flatau to William M. Robinson, both of Dallas, appearing on the printed patent issued 1898‑10‑11 with no retrievable reel/frame. Title cannot be traced past that point without ordering the pre‑1980 historical records from the USPTO Assignment Recordation Branch, and no NPE signal can attach in any event because the patent expired 1915‑10‑11 and Google Patents' legal‑events list for it contains no assignment activity whatsoever.

Verification link: https://assignment.uspto.gov/patent/index.html (search "612094") and https://patents.google.com/patent/US612094/en — both return no assignment events for this patent.

I'll research this literally as US Patent No. 612,094, focusing on its citation record and the pre-1898 prior art in its field.

Let me verify whether the USPTO record shows any cited references, and pin down the related Flatau filings.

I hit the tool-call limit before I could finish retrieving full texts for every candidate reference. Here is my analysis based on what I did retrieve plus the authoritative patent text. I have flagged clearly where I could not verify something rather than guessing.

Prior Art Analysis — US Patent No. 612,094 ("Chemical Fire-Extinguisher," L. S. Flatau, granted Oct. 11, 1898)

1. Source status and a transparency note

• I treated 612094 literally as US 612,094, the Louis S. Flatau chemical fire-extinguisher. No number correction was applied anywhere.
• I was not able to complete a direct query of the USPTO Patent Public Search / Patent Center database for this number before exhausting my research budget. I am therefore working from (a) the authoritative full text you supplied (Google Patents, https://patents.google.com/patent/[US612094](/patent/US612094)/en) and (b) the search results returned.
• I will not assert anticipation for any reference whose text I did not actually read. Several of the similar-document references below are flagged "content not verified."

2. Threshold finding: US 612,094 has no patent citations of record

This is the single most important finding, and it responds directly to your instruction to "look at each patent citation for 612094."

The authoritative record for US612094A contains no "Citations" / "References Cited" / "Patent Citations" section at all. It contains only:

• a "Similar Documents" list (25 entries), which is a machine-generated similarity table produced by Google Patents, not a citation record, and not a USPTO examiner citation; and
• a "Landscapes" list (CPC/technology-area groupings).

This absence is expected and not a data gap: the United States did not print "References Cited" on the face of issued patents until the late 1940s. For an 1898 patent, the front page is essentially the bibliographic data plus the drawing; examiner citations were not published. Accordingly:

There are zero patent citations of record for US 612,094. The "Similar Documents" table is not a citation list, and I have analyzed it as candidate prior art only, with that distinction stated explicitly.

(One item in the search results — a court opinion excerpt discussing a foaming-extinguisher appeal — is not about 612,094; it concerns the Laurent patent and later foam extinguishers such as Phomene and Foamite. I flag it so it is not mistaken for 612,094 material.)

3. Framework caveat (required before any § 102 mapping)

You asked for anticipation "under 35 U.S.C. § 102." Two caveats must be stated, because otherwise the analysis would be silently anachronistic:

1. § 102 did not exist in 1898. The statute was created by the Patent Act of 1952. The novelty condition governing Flatau's Dec. 11, 1897 application was Rev. Stat. § 4886, as amended March 3, 1897 (requiring that the invention was not "known or used by others in this country," and not "patented or described in any printed publication in this or any foreign country," before the applicant's invention). The mapping below is a modern § 102 labeling of a 19th-century record, which is the only way to answer the question as asked.
2. Under either regime, anticipation requires a single reference disclosing every claimed element. For claims 1–2 of 612,094 the complete element set is:
   • Claim 1: tank/receptacle for alkaline solution + cap + a downwardly-extending holder fluted at its inner (lower) end forming passages + an acid-bottle inserted in that holder.
   • Claim 2: all of claim 1 + the cap being a screw-cap + a handle + an escape-passage formed in the cap + a hose connected to that passage. (Claim 2 is thus narrower and correspondingly harder to anticipate.)

The "fluted-at-the-inner-end" holder and the frictional bottle retention are the points of novelty Flatau's own specification stresses ("the lower end of which is fluted, as shown at 8, forming a number of passages"; "held in the holder by frictional contact"). A reference that shows only a plain cup or a perforated basket does not meet the claim as worded.

4. Date-eligible candidate prior art (published before the Dec. 11, 1897 filing)

These are the only entries in the similar-documents table that can even theoretically be § 102 art against 612,094. Dates are as reported in the records I retrieved. None of these reference texts was retrieved by me; conclusions are conditional and flagged.

Bottom line for this group: I can confirm only that these are date-eligible. I cannot state that any of them anticipates claim 1 or claim 2, because I did not read their specifications or claims. Anyone completing this analysis must pull the full text/claims of at least US 578,324, US 555,022, US 515,846, and US 149,044 first — those four are the plausible § 102 candidates.

5. The most relevant prior art I did find: Flatau's own earlier chemical fire-extinguisher

Separately from the table, the search surfaced an earlier Louis (Spencer) Flatau chemical fire-extinguisher held by the Portal to Texas History / UNT Digital Library:

• Citation: Flatau, Louis Spencer, Chemical Fire-Extinguisher, United States Patent Office; digitized at the Portal to Texas History / DPLA — https://texashistory.unt.edu/ark:/67531/metapth174174/ and https://texas.dp.la/item/c09cab2dea15576d05243890c2a99c72
• Date as reported: December 31, 1895 (one record shows the digitized item as 1896-12-31 — I flag this discrepancy rather than resolve it)
• Description (quoted): "the acid-bottle consists of two concentric cylinders, the inner one of which is open at top and bottom, and which, when the bottle is placed in the cylinder containing the water and soda, potash, or other material, a compressed-air seal will be formed, preventing the acid and water from commingling; but when the bottle is inverted the seal will be broken, and the water and acid coming together will generate the gas."
• Relevance: Same inventor, same class of apparatus (acid-receptacle for a soda-acid chemical extinguisher), and — on the reported date — published before Flatau's Dec. 11, 1897 filing, and more than one year before it.
• Anticipation assessment: This reference does not appear to disclose the "downwardly-extending holder fluted at its inner end forming passages" with an inserted glass bottle of claims 1–2; its acid-bottle is a two-concentric-cylinder structure with a compressed-air seal. So it does not read on claims 1 or 2 on the described disclosure. Its real significance is different: because it is by the same inventor and more than a year before the 612,094 filing, it would have been a statutory-bar / double-patenting concern (pre-AIA § 102(b) is not limited to "by others"), not a clean anticipatory reference.
• Critical caveat: I could not verify this reference's patent number, and I did not read its full claim set. It must not be cited as a specific patent number until confirmed. I also could not reconcile Flatau's residence across records (612,094 says Dallas, Texas; the UNT record associates the 1895 item with Camp County, Texas) — flagged, not resolved.

6. Date-ineligible references (post-date the Dec. 11, 1897 filing — cannot be § 102 anticipation)

For completeness and to prevent miscitation, these entries in the similar-documents table were published after Flatau's filing date and therefore cannot anticipate claims 1–2 (a published-after-filing document is not "prior" art as of the filing/invention date; it could only matter on a later-proven invention date, which is not at issue here):

US 596,622 (1898-01-04) · US 609,584 (1898-08-23) · US 626,988 (1899-06-13) · US 649,160 (1900-05-08) · US 675,103 (1901-05-28) · US 713,946 (1902-11-18) · US 779,435 (1905-01-10) · US 780,898 (1905-01-24) · US 785,610 (1905-03-21) · US 893,153 (1908-07-14) · US 1,018,124 (1912-02-20) · US 1,072,351 (1913-09-02) · US 1,104,079 (1914-07-21) · US 1,237,550 (1917-08-21) · US 1,259,783 (1918-03-19) · US 1,452,657 (1923-04-24)

Note also the two source-data artifacts in this list — US 596,622 (title recorded as "Arthur c") and US 626,988 (title recorded as "douglas") — which I have not corrected, per the strict rule.

These later patents are useful only as evidence of the state of the art and of claim-drafting conventions; they are not § 102 references against 612,094.

7. Bottom line

1. US 612,094 has no patent citations of record. Its Google Patents page shows a machine-similarity "Similar Documents" table, not a citation list. Pre-1947 US patents do not carry printed examiner citations.
2. The only § 102-eligible candidates are the nine pre-December 11, 1897 references in § 4 above, of which US 578,324 (1897-03-09), US 555,022 (1896-02-18), US 515,846 (1894-03-06), and US 149,044 (1874-03-31) are the priority pulls.
3. I did not read the specifications of any of those nine references, so I explicitly decline to assert that any of them anticipates claim 1 or claim 2. On the present record, no reference can be confirmed as anticipating either claim.
4. The most relevant document in the entire record is Flatau's own earlier 1895/96 chemical fire-extinguisher (two concentric cylinders, compressed-air seal) — relevant as a same-inventor, more-than-one-year statutory-bar/double-patenting item, not as an anticipatory reference to the fluted-holder claims. Its patent number is unverified, and its reported date is internally inconsistent in the sources (Dec. 31, 1895 vs. Dec. 31, 1896).
5. Applying the label "§ 102" to an 1898 patent is anachronistic; the governing provision was Rev. Stat. § 4886 (as amended March 3, 1897).

Open items I could not close

• Direct USPTO Patent Public Search / Patent Center record for 612,094 (to confirm absence of citations from the USPTO side, not just Google's rendering).
• Full text and claims of US 578,324, US 555,022, US 515,846, US 149,044, US 195,370, US 105,279, US 568,658, US 337,344, US 534,552.
• The patent number and exact grant date of Flatau's earlier concentric-cylinder extinguisher.

If you can lift the tool-call limit or authorize another pass, the fastest route to a defensible anticipation opinion is to pull those four priority references' claims and drawings and compare them element-by-element against the "fluted inner end forming passages" + "acid-bottle inserted in said holder" limitation.

I'll analyze the obviousness question, but first I need to characterize the prior-art references listed on the page. Let me pull what details I can on the pre-1897 references (the only ones that can qualify as §103 prior art against a December 11, 1897 filing).

Obviousness Analysis — US Patent 612,094 (Flatau), 35 U.S.C. § 103

Scope note. Per the page's structure, there is no section literally labeled "Prior Art." The page supplies (a) a set of Prior art keywords — "acid, receptacle, holder, extinguisher, flatau" — and (b) a Similar Documents list of 27 U.S. patents. This analysis uses that list as the prior-art pool, as instructed. The litigation section above already established the patent expired October 11, 1915 and was never litigated; the §103 analysis below is therefore a retrospective/hypothetical validity study, not a live-controversy question.

1. Governing framework

The four Graham v. John Deere inquiries apply: scope and content of the prior art, differences between the claims and the prior art, level of ordinary skill, and secondary considerations. KSR v. Teleflex supplies the motivation/ predictability overlay: an express teaching is unnecessary where the combination is of known elements to yield a predictable result.

2. The claims, elementized

Claim 1 — combination, with the alkaline-solution tank, of: (a) a cap; (b) a downwardly-extending holder fluted at the inner end forming passages; (c) an acid-bottle inserted in the holder, "substantially as described."

Claim 2 — same plus: (a) a screw-cap; (b) provided with a handle; (c) formed with an escape-passage; (d) hose connected therewith; (e) the fluted holder; (f) the acid-bottle.

Two construction points matter for the §103 analysis:

• "Substantially as described" is a 19th-century claim formula that ties scope to the specification. The structure actually disclosed is narrow: a cylindrical (or "square or of any other angular shape") holder gripping the bottle by frictional contact, with the flutes creating "a number of passages" at the lower end.
• The specification contains an admission that is highly relevant to obviousness: "I have shown in the present instance a cylinder-holder … but it may be made square or of any other angular shape to receive a correspondingly-shaped bottle without departure from the invention." The patentee thus represents that the cross-sectional geometry is a matter of design choice, and that the sole functional requirement is that the bottle be held frictionally and that "there is a space or spaces between it and the inner side of the holder."

That reduces the asserted novelty to: provide passages between an acid bottle and its holder. The rest of both claims is conventional.

3. Threshold screen: which listed references can be combined at all?

This is the most consequential finding, and it is often overlooked. 18 of the 27 "Similar Documents" post-date the December 11, 1897 filing and cannot be used as §103 prior art at all. (They are the patent's own progeny — useful only as "state of the art"/later-development context and as evidence the field was crowded.)

Potentially admissible (pre-critical-date):

Excluded as post-dating the filing (grant dates given): US 596,622 (1898-01-04), 609,584 (1898-08-23), 626,988 (1899-06-13), 649,160 (1900-05-08), 675,103 (1901-05-28), 713,946 (1902-11-18), 780,898 (1905-01-24), 785,610 (1905-03-21), 893,153 (1908-07-14), 1,012,124 (1912-02-20), 1,072,351 (1913-09-02), 1,104,079 (1914-07-21), 1,237,550 (1917-08-21), 1,252,783 (1918-03-19), 1,452,657 (1923-04-24). (US 596,622 carries a pre-AIA § 102(e) caveat — a U.S. patent granted on an application filed before the applicant's invention date is prior art as of its filing date. The page does not give filing dates, so this one must be checked.)

Flagged discrepancy / verification item. A UNT Portal to Texas History record surfaces a second Flatau patent — "Chemical Fire-Extingusiher," Flatau, Louis S., dated 1896-12-31, described as providing "an improved acid-receptacle which will obviate the objects [objections] to the ordinary acid-bottles now in use" (https://texashistory.unt.edu/ark:/67531/metapth174174/). That language does not appear in US 612,094, whose specification instead says the bottle "may consist of an ordinary glass bottle." This appears to be a different, earlier Flatau patent, and it must be verified. It would not be "by others" prior art under pre-AIA § 102(a), but it could support a statutory double-patenting rejection and is strong evidence of the state of the art.

Supplementary reference surfaced in searching (not on the page's list). Aldrich & Hall, US 514,534, "Fire-Extinguisher," granted Feb. 13, 1894, filed Aug. 19, 1893 (https://patentimages.storage.googleapis.com/49/e2/5c/963930ff17c0c0/[US514534](/patent/US514534).pdf). It discloses a reservoir whose filling opening "will be closed by a screw cap 8 having a suitable air- or gas-tight packing," with outlet pipes and "the hose pipe 9" connected to the discharge. This directly supplies the screw-cap + tight-joint + hose environment of claim 2.

4. The obviousness combinations

Ground A — Claim 1: extinguisher art + acid-receptacle-holder art

Primary reference: a portable chemical extinguisher of the same class from the admissible group — e.g., US 515,846 (Stempel, granted Mar. 6, 1894; a commercial article — the B.C. agent offered Stempel extinguishers to Vancouver City Council on Oct. 3, 1898 at $20 each, illustrated by the US 515,846 drawing: https://transcribimus.ca/wp-content/uploads/2025/05/1898-Oct-03_Minutes_Transcribed.pdf), or US 568,658 (1896), US 555,022 (1896), or US 578,324 (Mar. 9, 1897). Each is a tank-type chemical extinguisher with a cap and discharge.

Secondary reference: the acid-receptacle-in-tank art — US 195,370 (1877), US 149,044 (1874), or US 105,279 (1870) — each titled to a fire-extinguisher improvement of this very class.

The combination: mount the acid receptacle on a downwardly-extending holder secured to the cap, the holder being fluted/otherwise formed so that passages exist between the bottle and the holder wall.

Motivation, articulated:

1. Same field, same problem, same solution family. The references are not analogous-art candidates at all; they are the same art. The patent's stated object — prevent acid escape when upright or tilted, permit escape when inverted — is the recognized design constraint of every invert-to-actuate soda-acid extinguisher.
2. A recognized deficiency in the art. The patent's own premise is that the existing arrangement (an unheld or inadequately held bottle) allowed premature escape/mixing. Where the art knows the problem, a change addressing it is obvious. KSR.
3. The asserted point of novelty is a design choice, by the patentee's own admission. The specification concedes the holder "may be made square or of any other angular shape" so long as the bottle is held frictionally and there are "spaces between it and the inner side of the holder." Fluting a cylindrical holder to create passages is the paradigm of a predictable mechanical expedient — it adds no new function, only a known way of making a passage. Fluted/grooved/ribbed holders, funnels, and grips for releasing or draining the contents of a held vessel were long-standing mechanical conventions.
4. Predictable result, no unexpected property. The patent asserts no result beyond the expected one (acid retained upright; acid released inverted).

Conclusion (conditional): Claim 1 would likely have been obvious. The only element not clearly shown is the specific fluting geometry, and the specification itself characterizes that geometry as interchangeable with any angular shape.

Ground B — Claim 1 via the aerated-liquid/soda-fountain art

US 534,552, "Siphon or vessel for aerated liquids" (Feb. 19, 1895), is on the list and is squarely in the recognized analogous art. Contemporaneous authority treats this art as combinable with fire extinguishers as a matter of law. An opinion retrieved in the search — https://storage.courtlistener.com/harvard_pdf/[9304503](/patent/9304503).pdf — held, of a soda-water fountain containing a separate acid chamber discharged into a water vessel by gas pressure:

"It is plain to my mind that it is only necessary to add a hose and nozzle to the discharging stop-cock in the Nichols fountain, to make it as effective a fire-extinguisher as the complainant's. … The obvious addition of so simple an element … cannot constitute the combination of a new and patentable one."

That passage is directly probative on (i) the analogous-art status of soda-fountain/aerated-liquid vessels and (ii) the obviousness of adding the hose and nozzle recited in claim 2.

Caveat: I could not verify US 534,552's internal disclosure. Its title places it in the aeration/siphon art where a separate acid vessel is released on inversion — the same function Flatau relies on — but the mapping is an inference, not a verification.

Ground C — Claim 2: cap + handle + escape-passage + hose

Claim 2's added elements are the least inventive part of the disclosure:

• Screw-cap with gas-tight packing: shown in US 514,534 (screw cap 8 with "air- or gas-tight packing").
• Hose connected to a portable chemical extinguisher: shown in US 514,534 (hose pipe 9) and, per the contemporaneous decisions above, treated as an obvious addition.
• Handle on the cap: a portable extinguisher's cap-handle is a convenience element with no asserted functional interaction with the fluting or the bottle.
• Hollow-journal/hose-and-reel analogy: Steiner Fire Extinguisher Co. v. City of Adrian, 59 F. 132 (https://law.resource.org/pub/us/case/reporter/F/0059/0059.f1.0132.pdf), held that applying a hose-and-reel arrangement long used in other liquid-throwing machines to a chemical fire engine "did not involve any invention," rejecting the argument that chemical engines were a different art.
• The underlying chemistry was itself old: Graham v. Johnston, 21 F. 40, and the companion "Fire-Extinguisher Case" (https://law.resource.org/pub/us/case/reporter/F/0021/0021.f.0040.pdf; https://www.uspto.gov/sites/default/files/aia_implementation/pur-2011oct25-thomas_kowalski.pdf) establish that extinguishing fire by mingled carbonic-acid gas and water driven by the gas's own elasticity dates to Graham's 1837 application and to successful use by 1853.

Conclusion (conditional): Claim 2 is obvious with high confidence — it is claim 1 plus four conventional elements, each separately old in the portable-extinguisher art.

5. Secondary considerations

No Graham secondary-consideration evidence appears anywhere in the record:

• No commercial success evidence with nexus; the only transactional fact is assignment of one-half to William M. Robinson (Dallas).
• No evidence of failure of others — the opposite: the page's Similar Documents list shows an extraordinarily crowded field, with dozens of chemical-extinguisher patents issued from 1870 through the 1920s. Rapid, incremental patenting in a predictable art cuts against nonobviousness under KSR.
• No copying, licensing, industry praise, or long-felt-but-unmet need documented.
• The application was filed and prosecuted without a model ("No Model"), consistent with a modest mechanical improvement.

6. Bottom line (with explicit confidence levels)

Critical limitation on this opinion. I obtained verified content for only a few of the references. I could not retrieve the full text of US 195,370, US 149,044, US 105,279, US 337,344, US 555,022, US 568,658, US 578,324, or US 534,552 in this session (tool limit reached). Statements mapping specific structures to claim elements for those references are inferences from titles and art context, not verified disclosures, and I am flagging them rather than presenting them as established. The obviousness conclusion should be treated as conditional pending element-by-element verification.

Verification checklist (would materially change the answer):

1. Retrieve full texts of the nine admissible references and confirm which one(s) show an acid bottle seated in a downwardly-extending holder secured to a cap, with passages at the lower end.
2. Confirm US 596,622's filing date (pre-AIA § 102(e) may pull it into the prior art).
3. Establish the identity, number, and date of the 1896 Flatau acid-receptacle patent (UNT ark/67531/metapth174174) — double-patenting and state-of-the-art implications.
4. Look for uncited 1890s art on fluted/grooved receptacle holders outside fire-fighting, which would strengthen Ground A's "known expedient" rationale.