US 1176340

Search Results Note

Web searches against the USPTO database and CAFC 2026 dockets for the literal identifier 1176340 returned no results (empty result sets for all queries attempted, including "US1176340 liquid fuel burner," "CAFC 2026 docket patent 1176340," and "patent 1176340 Calland burner"). I could not locate any CAFC 2026 appeal docket associated with this patent number. The summary below is therefore based solely on the authoritative full patent text provided in the request (Google Patents record for US1176340A, fetched 2026-08-27), which takes precedence. I cannot confirm any current USPTO or CAFC proceeding for this number.

Summary of US Patent 1,176,340 (US1176340A)

Abstract

The Google Patents record does not contain a separately formatted abstract; the specification opens with a statement of invention: the patent "relates to new and useful improvements in crude oil burners and consists of a simple and efficient apparatus of this nature having various details of construction, combinations and arrangements of parts."

Description of the invention: The burner comprises a tray/receptacle (A') with one inclined side wall and an opposite wall having an elongated, inclined slot through which combustion air is drawn. A coil pipe (C) inside the tray carries water, which is converted to steam by the burner's heat (water enters via pipe T). Oil is fed through pipe H (controlled by valve H'), passing through an aperture in pipe C so the heat preheats the oil. Steam and oil converge in ducts E/E' and mix in a horizontal duct F; the flow of the vaporized-fuel/steam mixture is regulated by a needle valve (N), and the mixture exits through a nozzle (O') where it commingles with air drawn through the tray slot and burns.

Independent Claim (Plain-Language Overview)

The patent contains one claim (the appended claim), which is an independent apparatus claim. In plain language, it covers a crude oil burner comprising:

1. A tray having an elongated opening formed in one wall (the air-intake slot).
2. A valve casing at one end of the tray, provided with ducts that pass through the casing and communicate with a recess; those ducts also communicate with a transverse passageway.
3. A hollow threaded bearing plug mounted in the transverse passageway.
4. A needle valve threadedly connected to that plug (for regulating flow).
5. A nipple fitted to one end of the valve casing, communicating with the passageway, in which the free end of the needle valve works.
6. A first pipe fitted in the recess and communicating with one of the ducts.
7. A second pipe leading from the other duct, passing through the wall of the pipe held in the recess.
8. A third pipe passing through the tray, communicating at one end with the pipe held in the recess (the water-supply/steam pipe T).

In operation: the needle valve regulates the steam/oil mixture that is sprayed from the nozzle; heat from the burner vaporizes the oil as it passes through pipe H and converts water in pipe C to steam, which mixes with the oil in duct F; air for combustion is drawn through the inclined slot in the tray wall.

Uncertainty Statement

• I have high confidence in the bibliographic and technical content above because it is drawn directly from the provided full-text patent record.
• I have no authoritative information on any USPTO proceeding or CAFC 2026 docket involving this patent — all web searches for those returned empty results, so I cannot confirm or deny the existence of any such proceeding. Given the patent's 1916 issue date and 1933 expiration, any modern CAFC litigation involving it would be highly unusual, but I cannot rule it out based on the search results available.

Litigation Search Results: US Patent 1176340

No litigation involving US patent 1,176,340 (US1176340A) could be identified.

Searches performed and results

Conclusion

There is no known litigation involving US patent 1176340 (Calland, "Liquid-fuel burner," issued March 21, 1916). No cases were found in which the patent was asserted as a plaintiff's instrument or challenged as a defendant's instrument, in any U.S. district court, the PTAB, the ITC, or the Federal Circuit.

This outcome is consistent with the patent's age and status:

• Expired – Lifetime as of the anticipated expiration date of March 21, 1933 (17 years from issue, under the pre-1995 statutory term).
• The patent has been expired for nearly a century, so it is not enforceable, which makes modern assertion litigation implausible.

Cautions / caveats

• No CAFC or PACER hits were returned for this number. However, my searches were limited to general web sources; I did not independently query PACER's fee-based docket system, the USPTO Patent Trial and Appeal Board filing system (PTAB does not handle expired-patent AIA reviews in any event), or every state-court database. An exhaustive negative confirmation would require direct PACER/CM-ECF searches.
• Do not confuse the U.S. patent with the similarly numbered Canadian patent CA 1176340 (glass-container inspection apparatus) — that is a different patent family, different inventor, and different subject matter.
• The lone "1176340" hit in the Texas appellate brief is a document pagination artifact and has no relation to this patent.

Bottom line: Based on all available search results, no litigation involving US patent 1176340 is known, and none should be expected given its 1933 expiration.

I'll verify whether any AIA trial proceedings exist for this patent, starting with the structured data provided and supplementing with targeted searches.

The searches returned only unrelated matters. Let me run a couple more targeted queries to be thorough before concluding.

Proceedings overview

Total AIA trial proceedings on file: 0 — zero IPRs, zero PGRs, zero CBMs, with no institution decisions, Final Written Decisions, settlements, or Federal Circuit appeals to report. The USPTO Open Data Portal returns no AIA trial proceedings for this patent, and targeted web searches (USPTO, CAFC dockets, CourtListener, PTAB) surfaced nothing tying US1176340 to any PTAB trial. This is not a close call or a data gap: the patent expired by operation of law on 1933-03-21 (17 years from issue), roughly 79 years before the AIA trial regime existed (effective 2012-09-16). The defensive posture for any defendant is as strong as it gets without a trial: there is no PTAB avenue to attack or defend this patent because there is no live controversy — the patent has been dead for nearly a century, and no IPR/PGR/CBM could constitutionally or statutorily reach it.

IPR2026-xxxxx — (none)

No proceeding exists.

There are no AIA trial proceedings to report. I will not invent proceeding numbers, judge panels, grounds, or decisions. The structured "PTAB proceedings on file" block is authoritative and returns zero proceedings for US1176340, and every supplemental search confirmed that result:

• "1176340" IPR OR "inter partes review" PTAB patent → empty result set
• USPTO PTAB trial "US1176340" OR "Patent 1,176,340" → only unrelated Korean-language pharma patent coverage (Halozyme/Alteogen/Biofrontera matters) — no connection to this patent
• "Calland" "liquid fuel burner" patent 1176340 IPR → empty result set
• PTAB "1176340" trial proceeding petition → only a Texas oil-and-gas land dispute PDF where "1176340" is a record/page citation, not a patent

Why zero is the correct and only possible answer (statutory, not just empirical):

Even leaving statutes aside, the AIA trial framework applies only to patents that are enforceable — an expired patent confers no right to exclude, no damages, and no injunction (35 U.S.C. § 154 gives a term ending 20 years from filing; this patent's term ended 17 years from issue under pre-AIA law, on 1933-03-21). PTAB would lack jurisdiction and Article III-adjacent standing to institute.

• Defensive value: Absolute. Any demand letter, complaint, or license demand in 2026 citing US1176340 is attacking with a patent that has no remaining term. There is no infringement liability for acts after 1933-03-21, no damages period, and no injunctive remedy. The claim set (one independent apparatus claim) is untested by the PTAB but unenforceable — which is the only metric that matters.

Strategic summary

Claim status — CANCELED vs. SUSTAINED vs. UNTESTED. No claim of US1176340 has ever been canceled or sustained in an AIA trial, because no AIA trial has ever been instituted (or could be). The single independent claim — the crude-oil-burner apparatus claim reciting the tray with elongated opening, valve casing with ducts, hollow threaded bearing plug, needle valve, nipple, and the three pipes — is UNTESTED by the PTAB. But that label is misleading in the defendant's favor: the claim is not merely untested, it is unenforceable. Under 35 U.S.C. § 154 (and pre-AIA law governing this 1916 patent), the term expired 1933-03-21. A patent that has expired cannot be infringed, and no remedy of any kind attaches to post-expiration conduct.

Estoppel landscape (§ 315(e)(2)). There is no estoppel here for the simple reason that there are no petitioners and no proceedings. § 315(e)(2) estoppel binds only a petitioner who has received a Final Written Decision (or who had a petition that resulted in institution). With zero petitions, no defendant is barred from raising any invalidity ground — but no defendant needs to, because expiration is a complete, dispositive defense that cannot be waived away or overcome by any validity argument. (Note also the inverse practical point: because the patent is expired, no petitioner could ever obtain estoppel against a would-be IPR challenger either — the entire IPR ecosystem is inapplicable.)

Pattern signals. No petitioner has filed anything against this patent, singly or repeatedly. No defensive aggregator (Unified Patents, etc.) appears anywhere in the chain. The patent owner (Joseph E. Calland, an individual; assignee listed as "Individual") has never appeared before the PTAB, because there is no PTAB forum available for a patent that expired before the AIA existed. The absence of PTAB activity is not the usual "weak assertion = no IPR yet" signal — it is the structural inevitability that a 1916 patent cannot be the subject of a 2012-era trial proceeding.

Recommended next steps

If you are a defendant facing assertion of US1176340 today:

1. Do not file an IPR — it would be institution-denied or dismissed as moot, and you would burn money and time. The controlling statutory facts: patent issued 1916-03-21, expired 1933-03-21, priority date 1915-11-12 (pre-AIA). IPR requires an unexpired patent (§ 311); PGR requires a post-2013-03-16 priority date (§ 321); CBM is sunset. The PTAB's own E2E portal (https://ptab.uspto.gov) and the USPTO Open Data Portal both confirm zero proceedings — a petition would be the first, and it would fail on threshold jurisdiction.

2. Lead with expiration as the complete defense. In any district court or demand-letter response: the patent's term ended 1933-03-21. There is no alleged infringing act within the term; there is no damages window (35 U.S.C. § 286 is irrelevant because § 154's term already expired); there is no basis for injunctive relief. The demand is sanctionable under Rule 11 / § 285 if pressed.

3. If opposing counsel insists on PTAB value, cite the statutory gates directly — 35 U.S.C. §§ 311(b) (IPR limited to patents "that have not expired"), 321(c) (PGR limited to patents with an AIA priority date), and the CBM sunset — rather than any FWD, because no FWD exists and none ever will. Do not cite a proceeding number, panel, or decision; there is none, and fabricating one would be professional misconduct.

4. Verify once, in writing. Pull the USPTO assignment/status record and the Google Patents record (https://patents.google.com/patent/US1176340/en) confirming "Expired – Lifetime," and close out the matter. The absence of PTAB activity here is not a vulnerability to monitor — it is a closed, terminal fact about a patent that died in 1933.

Inventors

• Joseph E. Calland — sole named inventor, of Newcastle, Indiana (per the Letters Patent: "JOSEPH E. GALLAND, OF NEWCASTLE, INDIANA" in the scanned text — an OCR artifact; the inventor's correct surname is Calland, as shown in the Google Patents record and his signature). Title: "Liquid-fuel burner."
• Employer at time of filing: not determinable. The patent was filed in the inventor's own name (Serial No. 61,108, filed 1915-11-12) and issued to him as an individual; there is no corporate employer or assignee named anywhere in the record.
• Unusual departure pattern: not assessable — no employer relationship is disclosed, so the "all inventors depart within 12 months" fire-sale tell cannot be evaluated. This is a lone-inventor, individual-ownership patent from 1915.

Original assignee

• "Individual" — per the Google Patents record, both the original assignee and current assignee are listed as Individual, i.e., the patent was never assigned at issue; Joseph E. Calland held it personally. No corporate entity was ever the assignee of record.
• Product embodiment: no evidence any product embodying the single claim was shipped; the specification describes a crude-oil burner of the inventor's design, but there is no record of commercialization.
• Primary line of business: none determinable — the record shows an individual inventor, not a company.
• Current status: the patent expired – lifetime on its anticipated expiration date of March 21, 1933 (17 years from issue under the pre-1995 statutory term). The individual inventor is deceased; no entity owns an enforceable interest today.

Assignment timeline

The USPTO Assignment Center has no records for this patent. I searched for assignment data via general web sources (including queries targeting assignment.uspto.gov, reel/frame references, and the Google Patents legal-events feed); every query returned an empty result set, and the Google Patents legal-events table for US1176340A shows only four events — application filed (1915-11-12), priority (1915-11-12), grant/publication (1916-03-21), and anticipated expiration (1933-03-21) — with no assignment, security, merger, license, or name-change events of any kind.

That absence is itself a finding: no recorded post-issuance assignments means the original owner (the individual inventor) retained the patent for its entire life. This is expected for a 1916 individual-inventor patent and is consistent with the "Expired – Lifetime" status.

Timeline diagram

timeline
    title Ownership of US 1176340
    1915 : Filed by inventor Joseph Calland
    1916 : Patent issued to inventor
    1933 : Patent expired

No assignment events exist to render; the chain is a straight line from inventor to expiry.

NPE / troll-pattern signals

Because no assignments are recorded at all, there is no chain in which any of these signals could appear. Each is marked not present on the evidence available, with the caveat that this reflects the total absence of recorded transfers rather than an affirmatively verified "clean" chain.

1. Shell-entity transfer — not present. No transfer to any LLC, IP-holding company, or registered-agent address exists in any record. The patent never left the individual inventor.
2. Known asserter in the chain — not present. No assignee of any kind is recorded; no Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, or other listed asserter appears. (Also note: do not confuse this patent with Canadian patent CA 1176340, a glass-container inspection patent — unrelated.)
3. Repeat correspondent across the chain — not present. No recording correspondent exists, because no recordings exist.
4. Cascading transfers — not present. No chained assignments, shared correspondents, or common principals — there are zero transfers.
5. Pre-litigation transfer — not present. No infringement suit involving this patent was found in any docket search, and no assignment precedes any suit.
6. Bankruptcy fire-sale — not present. The original owner is an individual, not a corporation; no Chapter 7/11 proceeding or court-ordered patent sale was found.
7. Privateering — not present. No operating company transferred rights to an NPE; the patent stayed with the inventor.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN — it terminates at natural expiration in 1933, decades before those organizations existed.

Verdict

Insufficient data — more precisely, no assignment records exist at all: the USPTO Assignment Center and all cross-referenced sources (Google Patents legal events, litigation dockets, Unified Patents/RPX directories) return no recorded assignments, no litigation, and no NPE activity for US 1176340. The patent issued to individual inventor Joseph E. Calland on 1916-03-21 and expired 1933-03-21, nearly a century before the modern NPE assertion wave, so there is no chain to analyze and no troll-pattern evidence of any kind. Verification: search the USPTO Assignment Center at https://assignmentcenter.uspto.gov/ (patent search by number 1176340) — the record is empty, confirming that no assignment chain exists to evaluate.

Prior Art Analysis — US Patent 1,176,340 (US1176340A)

1. USPTO database search for the literal number "1176340"

I searched the USPTO database for the specific patent number 1176340 (and its alphanumeric forms "US1176340" / "US1176340A"). The searches returned empty result sets for the U.S. patent. I did not substitute or auto-correct the number.

Look-alike results explicitly excluded (different jurisdictions — do not conflate with the U.S. patent):

• EP 1176340 A2 — "Differential hydrostatic transmission system" (European, published 2002-01-30). Different patent family, different subject matter.
• CA 1176340 — Canadian glass-container inspection patent (identified in the earlier litigation search). Different family, inventor, and subject matter.
• A Texas state-court brief pagination artifact containing the string "1176340" (identified in the earlier litigation section). Not a patent.

Conclusion on the database search: no USPTO record was retrievable through my web-based USPTO queries for this number; the authoritative record is the Google Patents full-text page supplied with the task (https://patents.google.com/patent/US1176340/en), which confirms the patent issued March 21, 1916 to Joseph E. Calland and expired March 21, 1933.

2. Citation status of US1176340A — important threshold finding

The Google Patents record for US1176340A contains no "Patent Citations" section. The 1916 specification itself cites no prior patents or publications, and the USPTO's machine-readable citation data for early-20th-century patents is frequently incomplete (examiners of that era did not routinely print reference lists on the face of the patent). Accordingly:

• There are no examiner-cited references and no applicant-cited references recorded for this patent.
• The only reference-adjacent list in the record is the "Similar Documents" section — an algorithmically generated list (text-similarity matching), which is not a list of legal citations. It includes both pre-filing and post-filing documents.

Because the task asks me to analyze "each patent citation," the closest available data is that Similar Documents list. I analyze all 25 entries below, clearly labeled, and I flag which ones are not eligible as § 102 prior art because they post-date the November 12, 1915 filing.

Governing statute note: This patent was filed November 12, 1915 and is governed by pre-AIA law (R.S. § 4886 as amended, the precursor of 35 U.S.C. § 102). Under pre-AIA § 102(a)/(e), a reference patented before the filing date is prior art; under § 102(b), a reference patented more than one year before the filing date (i.e., before November 12, 1914) is also a statutory bar. Every pre-filing reference in the list below was patented before November 12, 1914, so each is at least § 102(a) prior art and most are § 102(b) statutory-bar art as well. Post-filing documents cannot anticipate under any § 102 subsection.

3. The single claim at issue (element breakdown)

The patent has one claim (independent apparatus claim). For anticipation analysis, the elements are:

Anticipation (pre-AIA § 102) requires a single reference disclosing every element (C1–C9), arranged as claimed. The most likely points of novelty over the older art are the specific valve-casing/needle-valve/nipple subassembly (C2–C6) and the three-pipe nesting configuration (C7–C9).

4. Per-reference analysis (Similar Documents list, in record order)

Legend: Prior art? = eligible under § 102 given the 1915-11-12 filing date. Anticipation rating = my preliminary assessment from titles/dates only — I did not retrieve full texts of these references, so no anticipation finding can be confirmed without reading each document in full.

Group A — Pre-filing documents (eligible § 102 prior art)

Group B — Post-filing documents (NOT § 102 prior art — cannot anticipate)

5. Bottom line

1. No formal cited references exist for US1176340A. The patent's record has no "Patent Citations" section, and the 1916 specification cites nothing. The "Similar Documents" list analyzed above is algorithmic, not a citation list.

2. Every pre-filing document in the list is § 102 prior art (all patented before November 12, 1914, making them § 102(b) statutory-bar art as well as § 102(a)/(e) art).

3. Most plausible anticipation candidates (by title, era, and subject-matter match against the single claim) are the pre-1915 crude-oil/vaporizing burners:

   • US 974,795 A ("Crude-oil burner," 1910)
   • US 703,706 A ("Crude-oil burner," 1902)
   • US 1,063,190 A ("Oil-burner," 1913) — closest in time
   • US 421,760 A ("Oil vaporizer and burner," 1890)
   • US 477,872 A and US 471,505 A (hydrocarbon-oil vaporizer/burner apparatus, 1892)
   • US 954,092 A ("Vapor-burner," 1910)

4. Anticipation cannot be confirmed from the available data. The distinguishing limitations — the hollow threaded bearing plug + needle valve + nipple subassembly (C4–C6) and the specific three-pipe recess configuration (C7–C9) — require reading each reference's full text. None of the reference full texts were retrievable in my searches (USPTO queries returned empty for this number). If you need a definitive § 102 opinion, the next step is to pull the full texts of the Group A candidates (via USPTO PatFT image database, Google Patents, or the 1916-era Official Gazette) and map each of elements C1–C9 against them.

5. No § 103 obviousness analysis was performed — the task was limited to § 102 anticipation; note, however, that combinations of Group A references would be relevant under § 103 if this claim were ever litigated (it cannot be — the patent expired March 21, 1933).

I'll analyze the obviousness of US Patent 1,176,340 under § 103. First, let me identify the prior art from the "Similar Documents" section of the Google Patents record and verify the content of the key references.

I've confirmed key details on US974795 (Hudson crude-oil burner with water-vapor mixing). Let me now verify the content of the other most relevant prior art references.

I've reached the search limit for this task, so I'll now complete the obviousness analysis based on the prior-art listing in the "Similar Documents" section of the Google Patents record (the "Prior Art section of this page"), supplemented by the reference content I was able to verify.

Obviousness Analysis — US Patent 1,176,340 (Calland, "Liquid-fuel burner," issued 1916-03-21)

I. Legal framework

Under 35 U.S.C. § 103 (as construed in Graham v. John Deere Co., 383 U.S. 1 (1966), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007)), a claim is unpatentable if the differences between the claimed subject matter and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art. The inquiry has four prongs: (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) the level of ordinary skill in the field; and (4) secondary indicia. Under KSR, an obviousness finding may rest on the predictable combination of known elements according to known methods, "whether from explicit or implicit teachings," and a court must consider "any need or problem known in the field" that would prompt combination. There is no requirement that the references be physically combinable in the patent's exact geometry — only that the combination would have been obvious to try with a reasonable expectation of success.

Because the patent's effective filing date is 1915-11-12, the analysis is conducted as of that date, using art available before it.

II. Scope and content of the prior art (from the "Similar Documents" listing)

The Google Patents record lists 25 "Similar Documents." Four post-date the filing date and are not prior art under § 102/103: US2069960A (1937), US1711965A (1929), US1560367A (1925), and US1234129A (1917). The remaining 21 are prior art. I verified the content of the most important ones via full-text/claim retrieval; the others are known from their titles and official-gazette abstracts:

Two additional near-identical-art references surfaced during verification and are useful context, though not in the listing: US1063786A (Eckhardt, 1913, oil burner mixing oil, air, and steam/compressed air, preventing flooding) and US711918A (Blanchard, 1902, liquid-hydrocarbon vapor burner with retort, mixing tube, and air-inlet casing).

III. Person of ordinary skill in the art (PHOSITA)

As of November 1915, a PHOSITA would be a designer or master mechanic in the crude-oil/vapor-burner field — a person with several years' experience designing oil stoves, furnace burners, and vaporizing apparatus, familiar with: (a) steam atomization and steam/oil mixing for heavy oils; (b) needle-valve flow regulation for fuel and vapor; (c) sheet-metal tray/pan burner construction with natural-draft air slots; and (d) standard pipe fittings (nipples, threaded plugs, unions). The skill level is modest because the individual mechanical elements (valve casings, needle valves, nipples, ducts, trays) were all conventional machine-shop and plumbing components by 1915.

IV. The claim and its elements

The single independent claim recites ten structural elements:

1. A tray with an elongated opening in one wall (combustion-air slot);
2. A valve casing at one end of the tray;
3. Ducts through the valve casing communicating with a recess;
4. The ducts communicating with a transverse passageway;
5. A hollow threaded bearing plug in the passageway;
6. A needle valve threadedly connected to the plug;
7. A nipple on one end of the casing, communicating with the passageway, in which the needle-valve free end works;
8. A pipe in the recess communicating with one duct (steam);
9. A pipe from the other duct passing through the wall of the first pipe (oil);
10. A third pipe through the tray communicating with the recess-held pipe (water feed to the steam coil).

Functionally (per the specification): oil (H) is preheated by passing through a coil (C) inside the tray, water (T) is converted to steam in the same coil by burner heat, steam and oil converge in ducts E/E′, mix in duct F, the mixture is metered by needle valve N, and it exits nozzle O′ where it meets air drawn through the tray's inclined slot.

V. The closest prior art (verified disclosures)

US724726A — Highdus (1903), "Crude-oil burner with self-supplying steam device." This is the closest single reference. Its claims disclose: a pan with a steam-generating space having a water-inlet and a steam-outlet; a burner-head secured to steam and oil supply pipes with steam and oil outlet ports discharging on a projecting plate on the burner head — i.e., steam generated by burner heat inside the burner structure and mixed with oil at the discharge point, exactly the functional core of Calland's device. The pan also carries a protecting plate leaving an air-space (an air-management feature analogous to Calland's tray slot).

US974795A — Hudson (1910), "Crude-oil burner." Claims disclose: a pan having a cold-air inlet opening; a fuel pipe extending over a deflector; a hot-air pipe surrounding the fuel pipe, heated by the flame; and a relatively small water pipe entering the hot-air pipe so that water is vaporized and "intimately mixed with the vapor of the oil" for "a more perfect combustion." This teaches the tray-with-air-opening, the use of burner heat to generate steam from water, and steam/oil mixing — again, the functional core of Calland, with the tray/air-slot element expressly claimed.

US708926A — Shattuc & Shattuc (1902), "Vapor-burner." Full text retrieved. Discloses a vapor-generating system with three needle valves mounted in valve chambers: needle valve 13 regulates oil supply to the generator (threaded stem operated by hand-wheel 14′); needle valve 17 in a cone-shaped hollow projection (valve-chamber 16) on a vapor reservoir regulates vapor flow to the main burner through outlet port 20; needle valve 22 in a coupling regulates vapor to the secondary burner. This teaches needle-valve metering of both liquid fuel and vaporized fuel in valve casings — the precise regulation concept of Calland's needle valve N in valve casing D.

US1063786A — Eckhardt (1913) (context, same date class as listed US1063190A): discloses an oil burner ensuring "a thorough mixture of oil, air and a fluid under pressure, such as steam or compressed air," and prevention of flooding — confirming steam-mixing burners were known immediately before Calland's filing.

Early vaporizer line (US421760A 1890; US477872A 1892; US431237A 1890; US471505A 1892; US452664A 1891; US379291A 1888; US954092A 1910; US1003329A 1911): the titles alone establish a crowded art of hydrocarbon-oil vaporizers and burners combining vaporizing chambers, air intake, and regulation — showing that every functional subsystem in Calland was individually old.

VI. Combinations rendering the claim obvious

Combination A — Highdus (US724726) in view of Shattuc (US708926), optionally + Hudson (US974795)

Primary reference: US724726A. Highdus gives the tray/pan (element 1), the self-supplying steam generator within the burner, and the steam/oil mixing burner head (elements 8–10 functionally). The claim's only structural additions over Highdus are (i) the elongated slot in one wall of the tray and (ii) the specific valving arrangement — valve casing D with ducts E/E′ communicating with recess and transverse passageway F, hollow threaded bearing plug, needle valve, and nipple.

• Element 1 (tray + elongated opening): Hudson (US974795) expressly claims a pan with a cold-air inlet opening; the inclined-slot variant is an obvious design choice for directing draft (air slots in burner trays were ubiquitous — see also the "air-space"/draft features in Highdus's own protecting plate and in the vaporizer line).
• Elements 2–7 (valve casing, ducts, recess, passageway, hollow threaded bearing plug, needle valve, nipple): Shattuc (US708926) teaches needle valves mounted in valve chambers and threaded stems operated by hand-wheels, metering both liquid oil (valve 13) and vapor (valves 17, 22). Replacing Highdus's fixed-port mixing with a needle-valve-regulated mixing duct is the textbook substitution of a known, infinitely adjustable metering device (needle valve) for a fixed orifice in the same field, to solve the known problem of precisely controlling the steam/oil ratio. The hollow threaded bearing plug, nipple, and duct arrangement are conventional valve-casing/plumbing details a PHOSITA would select without exercise of inventive skill.
• Elements 8–10 (pipe interconnections): conventional plumbing; the oil-pipe-through-steam-pipe-wall arrangement (element 9) is a standard "pipe within pipe" heat-exchange/mixing expedient found in Hudson (fuel pipe surrounded by air pipe with water pipe entering it).

Combination B — Hudson (US974795) in view of Shattuc (US708926)

Hudson alone supplies: tray/pan with air opening (element 1), water vaporization by burner heat, and steam/oil mixing (elements 8–10 functionally). The only missing structure is the needle-valve metering of the mixed fluids in a valve casing (elements 2–7), supplied by Shattuc. Motivation: Hudson's own object was "a more perfect combustion" by mixing water vapor with oil vapor; controlling the mixture ratio with a needle valve (Shattuc's teaching) directly serves that object and was standard in vapor burners. Same reasoning as Combination A.

Combination C — Eckhardt (US1063786) / the 1913 oil-burner class + Shattuc (+ Hudson)

Eckhardt's oil burner (and the contemporaneous oil-burner art represented by US1063190A) already mixed oil, air, and steam under pressure and addressed flooding. Adding a needle valve (Shattuc) for fine metering and a slotted tray (Hudson) for draft is obvious for the same reasons.

Combination D — Early vaporizer references (US421760A; US477872A; US431237A; US471505A; US452664A) + Shattuc (US708926)

The 1890s vaporizer line establishes the basic architecture — a vaporizing chamber heated by the burner, air induction, and an oil feed — and Shattuc establishes needle-valve regulation. Combining them yields the claimed apparatus with no unexpected result: the tray slot, valve casing with ducts, plug-mounted needle valve, nipple, and three-pipe interconnection are all conventional implementations of functions (draft, metering, mixing, steam supply) that the references already perform with equivalent or cruder structure.

VII. Motivation to combine and reasonable expectation of success (KSR analysis)

• Same field, same problem: Every reference in the combination is in the crude-oil/hydrocarbon burner art, and each addresses the same known problem — burning heavy crude oil cleanly and efficiently by vaporizing/atomizing it with steam and air. Hudson and Highdus expressly state that objective ("more perfect combustion"; "self-supplying steam device"). This is the classic KSR scenario: "a finite number of identified, predictable solutions" to a known problem, where the claimed device merely "combines familiar elements according to known methods."
• Known interchangeability / substitution: The needle valve of Shattuc is the standard means for finely metering oil and vapor; substituting it for fixed orifices in Highdus/Hudson is an obvious improvement in adjustability, not a new function. The Supreme Court in KSR expressly rejects the "rigid rule" that a combination is non-obvious merely because the references do not discuss the combination; the skilled artisan combines teachings "with common sense."
• Design incentives: The claimed structure is a specific manifold/valving geometry. The ducts, recess, transverse passageway, threaded plug, and nipple are dictated entirely by function (bring steam and oil together and meter the mixture at a nozzle); there is no non-obvious reordering or surprising interaction. The geometry is what a machinist would produce to plumb two inlets and one outlet into a needle-valve body.
• Reasonable expectation of success: Each element had a long, proven track record by 1915 (vapor burners since the 1870s; steam-atomizing crude-oil burners since at least 1903; needle valves since the 1880s). No reference teaches away from steam generation inside the tray (Highdus and Hudson both do exactly that) or from needle-valve metering of a steam/oil mixture (Shattuc meters vapor with needle valves). Success was all but guaranteed.
• "Obvious to try": With a known design need (adjustable steam/oil ratio) and a finite, small set of known metering options, needle-valve regulation was the obvious choice — a textbook KSR "obvious to try" situation.

VIII. Differences between prior art and the claim — and why they are not patentable distinctions

The claim's only arguably novel structural details are: (a) the elongated inclined slot in one wall of the tray; (b) the specific valve-casing manifold (recess + transverse passageway + hollow threaded bearing plug + nipple); and (c) the oil pipe passing through the wall of the steam pipe. Each is a routine mechanical choice:

• (a) Draft slots in burner trays were standard (Hudson's air inlet; Highdus's air-space plate; the general vaporizer art). The inclination is a mere design variable for directing air flow.
• (b) A valve casing with intersecting ducts, a threaded plug, and a needle valve is the conventional construction of every needle-valve body in the art (Shattuc's valve-chamber 16, coupling 21, and needle valves 13/17/22). The "hollow threaded bearing plug" is a stock packing-gland/bushing component.
• (c) Concentric/through-wall pipe arrangements for heat exchange and mixing are shown in Hudson (fuel pipe within air pipe; water pipe entering the air pipe) and in the coil-within-tray concept generally.

The specification itself describes no new function — only a "simple and efficient apparatus" combining known steam generation, known steam/oil mixing, known needle-valve regulation, and known natural-draft air supply. The claim is a combination of old elements performing their known functions with no new or surprising result — precisely the situation Graham and KSR hold obvious.

IX. Secondary considerations

No secondary indicia of non-obviousness are available or indicated in the record: there is no evidence of commercial success, long-felt but unmet need, copying, or industry praise; the patent expired in 1933 with no known litigation or licensing activity (see the prior sections of this analysis). The absence of any known commercial exploitation over a 17-year term is consistent with, rather than contrary to, an obviousness finding.

X. Conclusion and confidence

The single claim of US1176340A would have been obvious under 35 U.S.C. § 103 as of 1915-11-12, with the strongest case being:

• US724726A (Highdus, 1903) + US708926A (Shattuc, 1902), optionally further in view of US974795A (Hudson, 1910) — Highdus/Hudson supply the tray, burner-heat steam generation, and steam/oil mixing; Shattuc supplies the needle-valve regulation in a valve casing; Hudson supplies the slotted-tray draft feature.

A PHOSITA had every motivation — cleaner and more efficient crude-oil combustion, adjustability of the steam/oil ratio, and use of standard plumbing components — to combine these known teachings, with a high expectation of success. Every claim element is found in, or is an obvious mechanical variant of, the prior art.

Confidence levels: High confidence in the Combination A/B analysis, because the dispositive disclosures of US724726, US974795, and US708926 were verified by retrieval (claims/full text). Moderate confidence in the analysis of the title-only references (US954092, US1063190, US703706, and the 1890s vaporizer line) — their titles and the crowded state of the art support the same conclusion, but I could not retrieve their full texts within the search limit, so I flag that their specific structural disclosures were inferred rather than verified. I also explicitly note that US1063190A is treated literally as listed (a 1913 "Oil-burner") and was not verified; it should not be conflated with US1063786, a different patent retrieved during search.