US 727414

I'll search for this specific patent number across USPTO and litigation sources.

Let me run more targeted searches on litigation databases and the patent record.

Let me do one final targeted check for any docket or reexamination record under this exact number.

Summary of US Patent 727,414

Important scoping note first: I searched for this exact number. I found no CAFC 2026 docket entry, no district-court case, and no PTAB proceeding (IPR/PGR/CBM) involving US 727,414. This is expected, not a gap in the search: the patent expired over a century ago (status "Expired – Lifetime," anticipated expiration May 5, 1920), and IPR/PGR did not exist before 2012. Two search hits with similar strings are different documents and should not be conflated with this patent:

• US 11,740,727 ("the '727 Patent") — asserted in Smith Interface Technologies LLC v. [Apple Inc.](/litigations/by-plaintiff/Apple%20Inc.), S.D. Cal. (Apple IPR filed Aug. 1, 2024). A different, modern patent.
• BE727414A — a 1969 Belgian patent (textile yarn creel guide). Different authority.
• A Google Patents page for US3014409A lists "US727414A / US72741458A" — these are serial numbers, not patents.

I was unable to retrieve live USPTO PatentCenter/Assignment records for this number; the information below is grounded in the authoritative full text of the patent itself.

Bibliographic data

Assignee caution: Google Patents' assignee fields are machine-derived. The specification itself only states that McDermott assigned by mesne assignments to the American Crude Oil Burner Company. There is no "current" owner in any live sense — the patent has been expired since 1920.

Abstract

There is no abstract in this patent. Abstracts were not required in US patent specifications until the 1940s. What Google Patents displays under "Definitions" is not an abstract but truncated excerpts of the description. A derived summary: the invention is a burner that treats fuel oil twice with steam — first by admitting regulated steam into a contracted space around the oil-pipe discharge to saturate, agitate and partly separate the oil, and second by admitting a separate regulated volume of steam into the burner chamber itself — producing a fan-shaped jet that burns completely, with no smoke and no residuum, even with heavy asphaltic California crude oils.

How the disclosed apparatus works (context for the claims)

• Oil from pump C travels via pipe D; for heavy crude it first enters chamber E with warming coil F (preferably fed by the pump's exhaust pipe G).
• The oil-pipe H passes completely through a steam-tight drum L mounted in the furnace front plate K, which is fed steam through pipe M.
• Inside the drum is an open valve-chamber N with externally operable valve n (stem O), communicating with a hollow sleeve P surrounding the oil-pipe and tapped through the drum head.
• A contracted pipe R couples sleeve P to burner J. Here the first steam treatment occurs: steam rushing into the contracted space saturates, agitates and partially separates the oil.
• The mixture then enters burner J — preferably two concavo-convex plates joined at flanges j, fan-shaped in plan view (Fig. 3), substantially elliptical in cross-section (Fig. 4), with a wide curved nozzle j throwing a fan-shaped sheet, and an internal fan-shaped horizontal diaphragm/deflector j².
• A second steam-pipe S enters the top of the burner through open valve-chamber T with valve t (stem T). This is the second steam treatment, which breaks up the watery-vapor globules and yields a highly combustible mixture. The patent expressly notes there is no blowpipe action (no steam jet behind the oil to force it through a passage).

Plain-language overview of each independent claim

Claim 1 — Dual steam injection from a single steam drum, combined with the through-passing oil pipe.
In combination with the steam-drum and the oil-pipe that passes through it: open valve-chambers inside the drum, each with a valve; a steam-pipe leading from each valve-chamber; and a burner that receives (a) the oil-pipe and one steam-pipe jointly, so that oil already mingled with steam is delivered to the burner, and (b) the other steam-pipe at a different point, to supply steam to that oil-and-steam mixture. In short: two separately valved steam feeds into the burner, the first mixing steam into the oil upstream, the second treating the mixture inside the burner.

Claim 2 — Concentric steam-pipe arrangement with a contracted coupling, framed as apparatus (not as a system).
In combination with a steam-chamber: an oil-pipe entering, passing through, and extending beyond the chamber; a steam-pipe surrounding that oil-pipe and projecting from the chamber, with valved communication to the chamber interior; a pipe attached to that surrounding steam-pipe outside the chamber and contracted relative to it; and a burner secured to the contracted pipe — the contracted pipe being the point where oil and steam are jointly received. This is the structural expression of the sleeve P / contracted coupling R / burner J assembly.

Claim 3 — The concentric arrangement without requiring the full steam-chamber/drum environment.
An oil-pipe; a member spaced from it to define a surrounding steam-space, and contracted adjacent to and beyond the open discharge end of the oil-pipe; a burner secured to that contracted portion; and a steam-pipe entering the burner independently of the oil-pipe and steam-space. This claim captures the "two-injection" concept in its broadest structural form, with the second steam feed defined independently.

Claim 4 — The burner head itself (the fan-shaped two-plate chamber).
An oil-burner comprising: two concavo-convex plates secured together to form a chamber substantially fan-shaped in plan view with a narrow discharge slit or orifice; a pipe for mixed oil and steam at the rear of the chamber and in line with the discharge slit; a steam-pipe entering the chamber at an angle to the oil-and-steam pipe to supply additional steam for mixing; and a deflecting plate situated opposite the inlet from the steam-pipe and arranged longitudinally of the chamber. This is a pure apparatus claim to the physical burner geometry (plates at flanges j, nozzle j, deflector j²).

Notes and caveats

• All four claims are independent. There are no dependent claims in this patent.
• The OCR text contains artifacts that I have interpreted literally but should not be "corrected" into different terms: "detlector j²" / "detlecting-plate" = deflector/deflecting-plate; "serai No. 54,145" = Serial No. 54,145; "Fig. 8" appearing where Fig. 3 is meant; "the mixed oil and steam Before leaving enter the burner J" is a garbled sentence order. The claim language as printed in the patent is reproduced above as faithfully as the source allows.
• Uncertainty to flag: I could not directly confirm the grant, assignment chain, or any post-1903 maintenance/expiry events against a live USPTO PatentCenter or assignment record because no authoritative USPTO record was returned in my searches. The bibliographic fields above come from the patent document and the Google Patents record for US727414A, which agree with each other.
• The specification's stated purpose — burning heavy asphaltic California crude with no residuum and practically no smoke — is a technical assertion by the inventor ("as demonstrated by me in actual practice"), not an independently verified result.

I'll search for litigation records involving this patent number, treating the identifier literally as given.

Initial searches returned only unrelated hits (including a '414 patent from Apple v. Samsung — U.S. 7,761,414 — which is a different number and must not be conflated). Let me run more targeted checks.

Let me run two final diligence checks — one on the patent's own litigation data, one on the assignee.

Result: No litigation found

I searched for litigation involving US patent 727414 literally as an identifier, and found no known litigation — no district court case, no CAFC appeal, no PTAB proceeding, no ITC action. The result is the same whether or not the "A" kind code is attached.

What was searched and what came back

Why the null result is expected — and self-consistent

The authoritative Google Patents record establishes that this is a 1903 patent, not a modern one:

• Application number: US5414501A (ser. No. 54,145, per the specification)
• Filing date / priority date: 1901-04-03
• Publication (grant) date: 1903-05-05
• Anticipated expiration: 1920-05-05
• Legal status: Expired – Lifetime
• Inventor: John McDermott, of West Berkeley, California
• Assignee: American Crude Oil Burner Company (a California corporation), by mesne assignments
• Title: "Oil-burning apparatus" — classification F23D11/10

A patent that expired in 1920 has been in the public domain for over a century. Any infringement suit would have had to be filed roughly 1903–1920, and litigation from that era is not indexed in the modern databases the instruction points to (Unified Patents portal, PACER, and CAFC opinions all cover the modern era; PACER's earliest civil records are mid-20th century). Consequently:

• A "no results" answer from these sources does not affirmatively prove no 1903–1920 suit existed; it proves only that no litigation is retrievable from the specified modern sources.
• Any historical enforcement would need to be checked in printed Federal Reporter volumes, the Patent Office Official Gazette, or the National Archives — sources outside the scope of this search.

Important disambiguation warning (do not auto-correct)

Several near-miss identifiers appeared in the results. Per the operating rule that IDs are to be read literally, none of these is US 727414 and none should be attributed to it:

• U.S. Patent 7,761,414 — asserted in Apple Inc. v. Samsung Electronics Co., No. 5:12-cv-00630-LHK (N.D. Cal.) (Apple's '414 patent; claim term "concurrently with" construed April 10, 2013). This is seven-million 761,414 — a different patent from a different century.
• U.S. Patent 3014409 — an unrelated 1962 patent whose application serial number was 727,414 (ser. No. 727,414, filed 1958). This is a coincidental application-number match, not the same patent, and any litigation on it would attach to patent 3,014,409.
• Various '414 / '727 shorthand references (Medicines Co./Angiomax, Snap v. YouMap, Omega Patents v. Enfora, Amphenol IPRs) — unrelated.

Bottom line

No adjudicated case or PTAB proceeding involving U.S. patent 727414 is known from the sources specified. Because the patent is a 1903 artifact (expired 1920-05-05), the absence is expected rather than indicative of a hidden dispute; confirming the negative definitively would require pre-PACER archival research beyond the named databases. I did not find, and therefore cannot report, a plaintiff, defendant, jurisdiction, case number, filing date, or outcome.

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

Proceedings overview

Zero AIA trial proceedings on file. The USPTO Open Data Portal structured block returns no IPR, PGR, or CBM for US 727,414, and my independent searches (Google Patents prosecution/legal-status data, PTAB petition documents surfaced through USPTO PTACTS, and general PTAB/CAFC coverage) surfaced nothing either — no petition, no institution decision, no Final Written Decision, no appeal. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. The defensive posture for a defendant is not the usual "hardened vs. dead claims" question: US 727,414 issued 1903-05-05 and expired 1920-05-05; the patent is public domain and all four original claims have been unenforceable for over a century. Any demand letter citing "US 727,414" as a live patent is either (a) a clerical error pointing at a different modern patent, or (b) a bad-faith assertion. That is the whole of the PTAB story.

Proceedings

No proceedings to itemize. There is no {PROCEEDING_NUMBER} to report, so I am not manufacturing one. For completeness on why the ordinary per-proceeding template is inapplicable:

• IPR (35 U.S.C. §§ 311–319) — The AIA trial regime only reaches petitions filed on or after 2012-09-16, and § 311(c) bars a petition more than one year after service of an infringement complaint. US 727,414 has been expired since 1920-05-05, so there is no live controversy, no possible infringing act after expiration, and no conceivable § 315(b) timeline in which a petition could be filed. No IPR exists and none can be meaningfully filed.
• PGR (35 U.S.C. §§ 321–329) — Unavailable by statute: PGR is limited to patents issued from applications filed under the AIA first-inventor-to-file provisions. This patent was filed 1901-04-03 (Serial No. 54,145).
• CBM — Unavailable: the transitional CBM program (AIA § 18) sunset on 2020-09-16 and, in any event, applied to AIA-era patents in the financial-services arts (this is a 1903 oil burner classified F23D 11/10).
• Federal Circuit appeal — None possible; no appealable PTAB decision exists. Nothing on the CAFC docket or CourtListener tied to this patent number.

Confounding check (important — this is the likely source of any "there are IPRs on the '414 patent" claim you may hear): "the '414 patent" is a heavily overloaded shorthand in PTAB practice, and none of the well-known proceedings concern US 727,414:

So if someone hands you an IPR number and says it killed "the '414 patent," verify the full seven-digit number. US 727,414 is the 1903 McDermott oil burner; US 7,318,414 and US 7,727,414 and US 10,313,414 are unrelated modern patents.

Strategic summary

Claim status. All four claims of US 727,414 — claims 1–4 as granted — are untested by any AIA proceeding and remain exactly as issued in 1903. There is no IPR-induced narrowing, no certificate of cancellation, no reissue, and no ex parte reexamination narrowing on the public record that I can confirm. The claims on their face are: (1) the steam-drum combination with dual open valve-chambers and a burner receiving oil + steam at one point and additional steam at another; (2) the steam-chamber/through-pipe/surrounding-steam-pipe/contracted-pipe/burner subcombination; (3) the oil-pipe + spaced surrounding member + contracted discharge + independent steam-pipe entry into the burner; and (4) the fan-shaped, concavo-convex-plate burner with narrow slit, angled steam-pipe, and longitudinal deflecting plate. "Canceled vs. sustained vs. untested" resolves to: 0 canceled, 0 sustained by any tribunal, 4 untested — and all 4 expired. Whatever judicial treatment these claims received in 1900s-era infringement litigation is a separate historical question; I did not find and will not assert any such holding.

Estoppel landscape. There is none. § 315(e)(2) estoppel runs only against a petitioner, real party in interest, or privy that obtained an FWD — and no IPR was ever instituted, so no petitioner is estopped from anything. There is no IPR art record for a defendant to inherit or to be blocked by. Conversely, a defendant gains nothing from IPR practice either: there is no FWD to cite, no cancellation to point to, and the Board cannot be used as a cancellation shortcut for a patent that expired in 1920. The only "ground" that matters is the expiration date itself — no act after 1920-05-05 can infringe, and pre-1920 damages claims are barred by laches and the statute of limitations many times over.

Pattern signals. None of the usual signals apply. No serial petitioner (no petitioner at all). No PO appellate activity (no appealable decision). No defensive aggregator — Unified Patents or otherwise — has ever touched this patent, which is expected: aggregators challenge asserted, live patents, and US 727,414 is neither. The absence of PTAB activity here is not the "nobody cared enough to file" signal it would be for a modern patent; it is the structural signal of a patent that has been in the public domain for 106 years and whose classification (F23D 11/10, steam-atomized liquid-fuel burners) is a historical art field, not a litigation field.

Recommended next steps

1. Do not build a PTAB strategy. There is nothing to institute against, no statutory vehicle (IPR barred in practice; PGR and CBM barred by statute/sunset), and no live controversy to anchor jurisdiction. Recommending an IPR petition against US 727,414 would be a waste of the client's money.
2. Confirm the number before responding to any demand. If a letter asserts "US 727,414," demand the full patent number, the issue date, and the asserted claims. Cross-check against the authoritative record at https://patents.google.com/patent/[US727414](/patent/US727414)/en — title "Oil-burning apparatus," inventor John McDermott of West Berkeley, California, filed 1901-04-03, granted 1903-05-05, assignee American Crude Oil Burner Company, legal status "Expired – Lifetime," anticipated expiration 1920-05-05. If the letter's patent has a 2000s-era issue date, you are dealing with a look-alike patent number (most likely US 7,318,414, US 7,727,414, or US 10,313,414) and the analysis restarts from scratch.
3. If the number is genuinely 727,414: respond with the expiration and public-domain point, request withdrawal of the demand, and preserve a 35 U.S.C. § 285 / Rule 11 record on the basis that the assertion could not have been made in good faith after a five-minute patent-number lookup. Note that the claim text itself (e.g., claim 1's "steam-drum," "open valve-chambers... having valves," and "burner") is directed to a coal-fired-boiler-era oil burner, which should make the assertion's absurdity obvious on its face.
4. If, contrary to the ODP data, a recently filed proceeding does exist (post-dating the most recent ODP ingest — I found none, and I am not asserting one exists), the operative milestones would be: institution decision within 6 months of the petition's filing date, and an FWD within 12 months of institution per § 316(a)(11). Monitor via PTAB E2E (https://ptacts.uspto.gov/ptacts/) rather than relying on this snapshot. I have flagged this only as a caveat, not as a factual claim: the honest statement of the record today is no PTAB activity on file.

I'll verify what assignment data actually exists before writing anything.

Assignment Record Reconstruction — US 727414 ("Oil-burning apparatus")

Bottom line up front: I found no recorded post-issuance assignment documents for this patent, and no reel/frame entries at all. This is a May 5, 1903 patent from the pre-electronic-record era, and its 17-year term expired May 5, 1920. The Assignment Center / Assignment Search database (and the Google Patents legal-events mirror of it) surfaces only filing, grant, and expiry events — no assignee changes. Per your stop rule, the NPE analysis is truncated below; the honest verdict is Insufficient data, driven by the absence of records rather than by an absence of a chain.

Inventors

• McDermott is the sole named inventor. No co-inventors are listed on the face of the patent.
• The only other names appearing on the face of the patent are the two witnesses, Zenas U. Dodge and L. W. Seely (signature block, March 26, 1901). The reproduced front matter lists no attorney or agent of record — this is "SER. NO. 54,145. (NO MODEL.)" with witnesses only, consistent with 1901 practice. These witnesses are not a recorded assignment correspondent and should not be treated as one.
• Unusual-pattern check: the "all inventors departing within 12 months" heuristic is inapplicable/undeterminable — there is one inventor, he is the patentee, and no employment records, corporate minutes, or personnel data for a 1901 California corporation are digitized. Unclear.
• Related-family note (relevant to who was asserting): McDermott held a cluster of oil-burner patents in this period. Ninth Circuit appeal records from the 1915–1922 oil-burner litigation list "Letters Patent No. 722,530, Issued to J. McDermott for Oil Burner" and "Letters Patent No. 727,415, Issued to J. McDermott for Oil Burner" as defense exhibits (govuscourtsca9briefs1231, gov.uscourts.ca9.03367.b.01.pdf). Note carefully: the exhibit list names 727,415 (a sibling), not 727,414. I did not find 727,414 named in those briefs, and I will not assert that it was litigated.

Original assignee

American Crude Oil Burner Company, a corporation of California (per the printed patent's assignee line: "JOHN MCDERMOTT, OF WEST BERKELEY, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO AMERICAN CRUDE OIL BURNER COMPANY, A CORPORATION OF CALIFORNIA").

• Line of business: manufacture/sale of oil-burning apparatus for boilers and furnaces. The specification is written from the perspective of a commercial vendor selling against coal economics in the same boiler ("very marked commercial economy as compared with former results in the same boiler when using coal"), which is consistent with an operating manufacturer rather than a holding vehicle.
• Did they ship a product embodying the claims? Unclear. The specification describes demonstrated practice ("as demonstrated by me in actual practice") and the drawing (Fig. 1) shows an installation with boiler, furnace, pump, and connections, indicating at least a working commercial installation. I found no catalog, no trade-press record, and no corporate registry entry confirming volume production.
• Current status: Defunct / dissolved. A 1901-vintage California corporation; no SEC filings exist (SEC was created in 1934), and no successor entity is named in any record I located. The patent term expired 1920-05-05 (Google Patents legal events: "1903-05-05 Application granted," "1920-05-05 Anticipated expiration," status "Expired - Lifetime").
• Do not conflate similarly named entities. Ninth Circuit records from this era repeatedly name American Standard Oil Burner Company (owner of the King patent 1,158,058, predecessor to Bunting Iron Works) and W. S. Ray Manufacturing Co. They are litigants in the same technical space but are different companies with different patents; I found no document linking either to American Crude Oil Burner Company. Treating them as predecessors would be a fabrication.

Assignment timeline

The USPTO Assignment Center / Assignment Search has no recorded assignment documents for US 727414 that I could locate. No reel/frame numbers, conveyances, assignors, assignees, or correspondents are retrievable for this patent number. Two independent checks agree: (a) the Google Patents legal-events table for this patent shows only 1901-04-03 filed by AMERICAN CRUDE OIL BURNER Co, 1901-04-03 priority to US5414501A, 1903-05-05 granted, 1903-05-05 publication, 1920-05-05 anticipated expiration — no assignment events; and (b) targeted searches of the assignment record and related litigation do not surface any reel/frame entry for 727414.

Why no records — two structural reasons, neither of which is evidence of a chain:

1. Era. Electronic assignment recordation with indexed reel/frame coverage effectively begins in the mid-20th century (the modern reel/frame system postdates this patent by decades). A 1901-filed patent's paper assignments, if any, sit in microfilm/paper archives that are not exposed as indexed reel/frame records in the online Assignment Search.
2. Termination. The patent expired May 5, 1920. There is no live asset to assign, and no modern assignment activity is possible.

The one documented chain-of-title fact, from the patent's own front matter: the assignee designation reads "by mesne assignments," which legally means McDermott's title reached American Crude Oil Burner Company through one or more intermediate assignees, not by a single direct assignment. That intermediate link(s) is real but is not documented in any record I can retrieve — I have no dates, no names for the intermediate assignee(s), and no reel/frame. I am flagging it as an open gap rather than filling it in.

This patent is also referenced by application serial No. 54,145 — the same serial appears as "SER. NO. 54,145" in the case-law text retrieved, confirming the application-number identity of this 727,414 filing; note the legal-events field lists "US5414501A" as the application number, consistent with that serial.

Per your stop rule: no Assignment Center records exist, so the chain analysis terminates here. For completeness and auditability I am still supplying the requested diagram, a signals matrix marked on the evidence available, and a verdict — but every entry below is grounded in the absence of records, not in fabricated reels.

Timeline diagram

timeline
    title Ownership of US 727414
    1901 : Filed by John McDermott
         : Rights reach American Crude Oil Burner Co by mesne assignments
    1903 : Patent issued May 5
    1920 : Patent term expired May 5
         : No recorded assignments in electronic records

NPE / troll-pattern signals

Analysis is not applicable in the ordinary sense (a 1903 patent that expired in 1920 cannot be asserted by anyone), but per your format, each signal is called on the evidence actually available:

Verdict

Insufficient data — no records, or only the original assignment.

Justification: The electronic assignment record contains no recorded assignment documents for US 727414 — no reel/frame, no conveyance type, no correspondent — and the Google Patents legal-events table shows only the 1901-04-03 filing by American Crude Oil Burner Co, the 1903-05-05 grant, and the 1920-05-05 expiry. The sole chain-of-title evidence is the printed patent's own designation of American Crude Oil Burner Company as assignee "by mesne assignments," which proves at least one intermediate transfer occurred but documents none of its parties, dates, or reels — so even the known link cannot be presented as a recorded entry. Any NPE characterization would be anachronistic: the patent's term ended in 1920, more than sixty years before the earliest entity on your asserter list existed.

Verification links:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search patent number 727414)
• USPTO Assignment Search mirror: https://assignment.uspto.gov/patent/index.html
• Google Patents legal events: https://patents.google.com/patent/US727414/en
• Era litigation context naming sibling McDermott patent 727,415 as a defense exhibit: http://archive.org/download/govuscourtsca9briefs1231/govuscourtsca9briefs1231/gov.uscourts.ca9.03367.b.01.pdf

Recommended next step if this matters: a pre-1955 recordation for this patent, if it exists, would be found only by pulling the paper/microfilm Assignment Division records or the original file wrapper (National Archives / USPTO Patent Files). Nothing in the digitized record can confirm or deny the intermediates implied by "mesne assignments."

I'll research this systematically. Let me start with searches on the patent itself and its citation record.

The search results are revealing something important. Let me verify the citation record and check key details.

1. Search result: scope and source of truth

I searched for the specific identifier 727414 as directed. Two distinct records match that identifier literally, and per your strict rule I am reporting both rather than silently picking one:

Your target is the first: US Patent 727,414, "Oil-burning apparatus," John McDermott, of West Berkeley, California, assignor by mesne assignments to American Crude Oil Burner Company (a California corporation). Application Serial No. 54,145 (serai No. 54,145 in the printed specification), filed April 3, 1901, no model. CPC F23D 11/10 (burners using a direct spraying action induced by a gaseous medium, e.g. water vapour). Legal status: Expired – Lifetime, anticipated expiration 1920‑05‑05.

⚠️ Identifier-collision warning (not auto-corrected, per your rule): Google's own record for US 3,014,409 renders the 1958 application number as US727414A US3014409A. Any naive search for "727414" in a modern full-text database therefore surfaces the 1961 retroreflective-sheeting patent, which is a different field (optics) and a different legal instrument (application serial vs. patent number). I have kept them separate.

2. The central finding: US 727,414 has no patent citations of record

This is the honest answer to your instruction "look at each patent citation for 727414," and it is not an artifact of a bad query.

• The authoritative full text supplied for US727414A contains no "References Cited," no "Patent Citations," and no "Cited By" section. The only tabular blocks present are Classifications, Definitions, Landscapes, Similar Documents, Priority Applications, Applications Claiming Priority, Publications, Family Applications, and Country Status.
• This is historically expected. The USPTO did not print examiner-cited references on the face of the patent in 1903; the front-page "References Cited" practice dates from roughly 1908 onward. A 1903 patent therefore has a citation record only in the paper prosecution file (Serial No. 54,145), not on the printed document and not in Google's OCR of it.
• I attempted to corroborate the negative via additional searches (Google Patents citation blocks, Espacenet-style citation listings). Those queries returned irrelevant modern documents and were truncated before completion, so my verification of the absence rests primarily on the authoritative full text you supplied, which is the preferred source under the stated rules. Confidence: high that no citations are printed on the document; moderate that no citation data exists anywhere in a machine-readable record.

One weak counter-signal, flagged rather than resolved: a search hit on the Google Patents page for US 75,165 returned the fragment US727414A (en) | Oil-burning apparatus. That is the exact cell format Google uses for its Similar Documents tables (it matches verbatim the row format in US727414's own "Similar Documents" block), so I read it as an algorithmic similarity link on the US75,165 page, not as US75,165 being cited by US727414. I could not confirm which section it sits in. Treat it as unverified.

3. Prior art that is affirmatively on the record: the applicant's own admissions

Because there is no citations block, the only prior art grounded in the document itself is the art acknowledged in the specification. These are usable as applicant admissions, and they matter because they narrow what claims 1–3 can cover:

The prosecution history of Serial No. 54,145 presumably contains examiner citations corresponding to that admitted art, but I have not retrieved or verified any such file-wrapper references, and I will not reconstruct them from inference.

4. Closest analogous art — Google's "Similar Documents" list (NOT citations)

The following is the complete Similar Documents table from the US727414A record. I want to be explicit: this is a machine-similarity ranking, not a citation list, and a similarity ranking is not evidence that any of these was before the examiner or is statutory prior art. Dates below are the publication/grant dates exactly as Google reports them; I was unable to verify the corresponding filing dates for most of these before my search budget was exhausted.

Note the internal inconsistency: the list includes four references granted after US727414 issued (1910–1925). That is itself proof the table is a semantic-similarity output, not a prior-art or citation set. I have labeled them accordingly rather than presenting them as §102 art.

5. §102 mapping against the actual claims of US727414

Legal framing caveat (important): US 727,414 was filed April 3, 1901, before the 1952 Act. Its novelty was governed by R.S. §4886 (as amended) — invention not "known or used by others in this country, or patented or described in a printed publication" before the applicant's invention — with the two-year publication/use bar and the R.S. §4920 defenses. A literal 35 U.S.C. §102 analysis is anachronistic for this filing date. Modern §102(a)(1)/(a)(2) with the 1901 priority date is the closest functional mapping, and I use it below only as a labeled convenience. Because the patent expired in 1920, this analysis is historical/defensive in character, not a live validity question.

For each candidate that is even arguably statutory art (pre-filing and disclosed in a printed publication before the invention date), the potential anticipatory exposure by claim is:

• Claim 4 (the structural burner claim: two concavo‑convex plates, fan‑shaped plan chamber, narrow discharge slit, mixed oil/steam inlet at the rear aligned with the slit, a steam‑pipe entering at an angle, and a fan‑shaped deflecting plate disposed opposite the steam inlet and longitudinally of the chamber): the narrowest and strongest claim. None of the similarity-listed references is reported as a fan-shaped, concavo-convex, slit-orifice burner with an opposed longitudinal deflector. §102 exposure appears low, but I have not read the disclosures of the pre-1901 references, so this is an inference from titles/classifications, not a claim-by-claim comparison.
• Claim 3 (oil-pipe + surrounding spaced steam member contracted adjacent to and beyond the oil-pipe mouth + burner + a steam-pipe entering the burner independently): the independent second steam admission is the likely point of novelty. Pre-1901 injector art (US 444,115; US 426,040; US 431,237) plausibly reads on the surrounding-steam-member sub-combination, but the separate burner-entering steam line is the element most likely to be missing. Moderate §102 exposure on the sub-combination.
• Claim 2 (steam-chamber + through-passing oil-pipe + valved surrounding steam-pipe + relatively contracted pipe + burner): parallel analysis to claim 3.
• Claim 1 (two open valve-chambers inside the drum, a steam-pipe from each, burner receiving oil+steam jointly from one line and the other steam-pipe at another point): the two-valve, two-steam-path architecture is the broadest claim in concept but the most elaborately specific in structure; on the face of the title-level data, low §102 exposure.

I am deliberately not asserting that any specific reference "anticipates" a specific claim: doing so requires the actual disclosure text of each reference, which I did not retrieve. Any statement of the form "US 639,257 anticipates claim 3" would be fabrication on the current record.

6. What I could not verify

• Whether the paper file wrapper of Serial No. 54,145 contains examiner citations (the true citation record for this patent).
• Filing dates and full disclosures for the pre-1901 references in the Similar Documents table, including the four with OCR-garbled titles (US 325,376 / 420,534 / 425,872 / 395,786).
• The section (Citations vs. Similar Documents) in which US727414A appears on the US 75,165 page.
• Whether US 703,706 or US 707,911 carry earlier filing or pre-filing publication dates that would make them statutory art notwithstanding their 1902 grant dates.

If you want, I can run the next pass specifically on the pre-1901 set — pull each reference's filing date and claim text and produce a true element-by-element §102 chart against claims 1–4 — and, separately, attempt the USPTO PatentCenter/first-page image for US 727,414 to confirm the absence of printed references on the original document.

I'll ground this analysis in the prior-art listing on the US727414 page, and verify what I can about those references before reasoning.

Good grounding on three references. Let me pull the remaining key ones, especially any that disclose two-stage steam mixing or a fan-shaped/slotted burner chamber.

Obviousness Analysis — US727414 ("Oil-burning apparatus," J. McDermott)

Source of record: https://patents.google.com/patent/US727414/en
Filed 1901-04-03 (Serial No. 54,145); granted 1903-05-05; assignee AMERICAN CRUDE OIL BURNER Co; CPC F23D11/00 / F23D11/10; status Expired – Lifetime (anticipated expiration 1920-05-05).

0. Analytical ground rules and honest scope limits

1. The patent is expired. A §103 invalidity holding has no live effect on US727414 itself. The exercise is relevant to (a) historical validity study, (b) use of US727414 as §102/§103 art against later filings, and (c) written-description support analysis.
2. Cut-off rule. Under §103 the only usable references are those qualifying as §102 prior art. On this record that means references granted before 1901-04-03. Several entries in the page's "Similar Documents" list post-date the filing and must be excluded: US696457A (1902-04-01), US703706A (1902-07-01), US707911A (1902-08-26), US715639A (1902-12-09), US737676A (1903-09-01), US947363A (1910-01-25), US1148796A (1915-08-03), US1188381A (1916-06-27), US1533081A (1925-04-14). A pre-AIA §102(e) argument for the 1902 grants would require their filing dates, which the page does not supply.
3. Verification transparency. I obtained full text for US431237A and US426040A; I confirmed only bibliographic data (title/date/inventor) for US639257A (Luckenbach, filed 1899-07-03, granted 1899-12-19). For US444115A, US474344A, US477872A, US379291A, US452664A, US233212A, US173327A, US371784A, US158315A, US431237A and the four OCR-mangled entries (US325376A "Elbeidge baker", US395786A "Half to thomas h", US420534A "dea-ke", US425872A "fellowes") I have titles and dates only — I did not verify their disclosures, and I will not pretend otherwise. Grounds resting on those references are flagged as unverified hypotheses.
4. The "Similar Documents" table is a similarity listing, not a statement of record; the page shows no "Citations"/"Cited By" section, so there is no evidence any of these were before the examiner.

1. Claim element breakdown (from the patent text)

The patent's own characterisation of the prior art is critical: it concedes that burning oil+steam from "an open jet or nozzle" was known but produced "dense black smoke… only partial [combustion]," and that smoke is cured only by the second steam treatment in the burner.

2. Grounds of rejection

Ground 1 — Claims 2 and 3 over US426040A (Moore, "Injector oil-burner," 1890-04-22), alone or in view of US431237A (Swift, 1890-07-01)

Verified disclosure of US426040A (https://patents.google.com/patent/US426040A/en): inner oil-tube L terminating in tapered nozzle l; outer "air or steam tube K" screwed into the same casting, "inclos[ing] the oil-tube L through-out its length," the annular space communicating with both a steam-pipe G and an air-pipe M; tube K terminates in a tapered nozzle k "which loosely surrounds the nozzle l, leaving an annular steam-outlet around the point of the latter"; a longitudinally adjustable tapered valve H with a long stem threaded at h' and a handle h³ "to permit of convenient adjustment"; the supply pipes "both are provided with suitable valves for regulating"; and the steam is superheated by being routed through the combustion chamber.

Motivation: Moore's stated objects are the same objects as US727414's — "to secure perfect combustion of fuel" and "a uniform fire of any desired intensity… without requiring the services of an attendant." Same field, same problem, overlapping solution; combination is a textbook KSR rationale (use of known elements for their known function, with predictable result).

Gap and how Swift fills it: Moore mixes oil and steam at the nozzle mouth; US727414 claim 1/3 requires a second, independent steam stream entering the burner. Verified disclosure of US431237A (https://patents.google.com/patent/US431237A/en; PDF: http://patentimages.storage.googleapis.com/34/61/4b/9ac5f2d0b20308/[US431237](/patent/US431237).pdf): air-pipe E enters the chamber and terminates "substantially opposite the outlet-opening D… [and] discharges a supply of air centrally into the body of the vapor," with pipe F beyond the outlet "to hold the oxygen and oil-vapor together and to intermix them"; claim 2 adds "an additional air-supply arranged around the said chamber… whereby air may be discharged upon the outside of the vapor passing from the said outlet." Swift expressly states the problem is "the deposition of carbonaceous matter in the form of soot around the edges of the outlet D, and also along the walls of the pipe F."

This is a two-zone, staged gas-admission teaching — exactly the structural analogue of claim 1's "the other steam-pipe communicates at another point to supply steam to the mixture of oil and steam," and of claim 3's independently entering steam-pipe. Swift's stated carbon/soot problem is the very problem US727414 says it solves ("without leaving a residuum and practically without smoke").

Why steam-for-air substitution is a rational, not inventive, step: Moore's own reference calls K the "air or steam tube" and plumbs both a steam-pipe G and an air-pipe M into one casting — an express teaching of interchangeability. The contemporary art classification (US Naval Liquid Fuel Board Report of 1904, reproduced in a later history of liquid fuel) grouped burners as "outside mixing" vs. "inside mixing," the latter including "chamber burners, comprising a chamber in which a preliminary mixing of oil and steam takes place… resulting in a better pre-heating, lower viscosity of the oil and therefore better pulverization." (Caveat: that classification is circa 1904 and thus post-filing — useful only as evidence of the artisan's established design space, not as §102 art.)

Ground 2 — Claim 1 over US426040A + US431237A + routine skill

Claim 1's added elements over Ground 1 are (i) a steam-drum with the oil-pipe passing through it; (ii) both valves housed in chambers inside the drum; (iii) one steam-pipe feeding the pre-mix and a second treating the mixture.

• (i)/(ii): Moore already gathers oil and steam/air into a single body casting with multiple regulated inlets, and supplies steam from the steam-dome of the boiler. Consolidating two needle/plug valves into a common steam chest on the oil line is a predictable mechanical rearrangement, motivated by the art's own concern for "thoroughly satisfactory adjustment of the oil supply" and by compactness in a furnace front plate.
• (iii): supplied by Swift's staged admission (see Ground 1).
• The drum L of US727414 is merely a steam-tight jacket admitting boiler steam through pipe M — a conventional steam-jacketed oil line; nothing in the claims recites unobvious structure beyond the valving.

Confidence: moderate as to claim 1, moderate-high as to claims 2–3.

Ground 3 — Claim 4 (fan-shaped chamber, angle-entering steam, deflecting plate) — unverified hypothesis

I could not retrieve the disclosures of the listed candidates US474344A ("Apparatus for generating heat," 1892-05-03), US477872A ("Hydrocarbon-oil vaporizer and burner," 1892-06-28), US379291A ("Hydrocarbon-burner," 1888-03-13), US452664A ("Hydrocarbon-burner attachment," 1891-05-19), or US639257A (Luckenbach, 1899-12-19). Claim 4 would most plausibly be met by pairing a chamber-type burner reference from that group (for the slit/fan chamber and deflector) with US426040A + US431237A for the steam introduction. The motivation would be: (a) a fan/slot discharge matches the flat under-boiler furnace geometry — throw-away "sheet" flames are the standard way to spread heat along a boiler crown; (b) a deflector opposite an angled steam inlet is the predictable way to distribute the second steam volume over the mixture and break up globules, which is precisely the function US727414 ascribes to element j².

I am not able to state this as a supported conclusion. Claim 4 is the claim most likely to survive on this record, because (i) its geometry is specific and (ii) I cannot verify any listed reference discloses the concavo-convex-plate/fan-slit/deflector combination. Note also a lead I encountered but could not verify and which is not in the page's prior-art list: US275124, which appears to disclose a removable diaphragm and a flame-expander — treat as a lead only.

3. Rebuttal evidence the analyst should expect

1. Teaching away / scepticism: US727414 itself says prior open-jet oil+steam burning "is marked by dense black smoke… only partial" — if the art regarded two-stage steam treatment as doubtful, that supports patentability. The strongest such statement is the 1904 Navy report's "schemes for superheating the atomizing agent or for converting the oil into a gas before leaving the burner are of doubtful value" — but it is post-dating (1904) and therefore not properly usable as §102 art; it is at best context.
2. Unexpected results / secondary considerations: the specification asserts commercial economy with heavy asphaltic California crude in the same boiler, "practically no smoke at any pressure," and a flame range from a candle-flame to a jet "so intense that fire-brick… cannot withstand it." Commercial success and long-felt need for smokeless heavy-oil combustion are classic Graham v. John Deere factors and would be the main validity battleground.
3. Explicit disavowal of a prior-art mode: the patent disclaims "blowpipe action… where a jet of steam is introduced behind the current of oil" — a fixed-claim-construction point that narrows the art but does not square the relevant art is also limited to a surrounding steam space, a distinction Moore's annular tube k comes very close to meeting.

4. Bottom line

Caveats, stated plainly: (a) I could not verify disclosures for eight-plus of the listed references; the garbled titles US325376A "Elbeidge baker," US395786A "Half to thomas h," US420534A "dea-ke," US425872A "fellowes" are indeterminate as cited on the page and I have not auto-corrected or guessed at them. (b) All references granted on or after 1901-04-03 were excluded regardless of their titles. (c) Because US727414 is expired, none of this has live legal effect.