US 280733

I'll run targeted searches to check for any USPTO records and CAFC 2026 docket activity for this specific number, then cross-check against the authoritative full text.

US Patent 280,733 — Summary

Search note: I searched for this specific number. No CAFC 2026 docket activity, no litigation docket, and no post-1900 legal-status records surfaced for patent number 280,733. That is expected — the patent's term expired in 1900. One important collision is flagged at the end.

Bibliographic data

Abstract: There is none. This is an 1883 grant, predating statutory abstracts. The "Definitions" paragraph on the Google Patents page is an auto-generated machine synopsis, not an abstract of record — do not treat it as such.

OCR caveat: the description text is heavily garbled ("steanrnozzle," "intlowing," "deilector," "Z)" for "b"). The claims are legible enough to quote reliably; the figure descriptions and body text should be treated as approximate.

Problem the patent addresses

In ejectors/injectors, the steam nozzle, inner head, or combining-tube projects into the induction opening, so the inflowing water is forced to split into two streams around it. Those streams rejoin above the obstruction before they have fully felt the steam jet's suction, so at least part of the velocity the water acquired is annihilated — requiring extra steam to recover it. A second failure mode: if the head is slightly out of true, the split is unequal, the larger stream dominates in momentum, and the reunited current acquires a spiral/twist through the combining tube, again wasting steam.

Solution

A septum (wall/deflector b) inside the head or shell, radially arranged in line with the steam-jet axis, that keeps the two divided bodies of fluid separated until they enter the combining tube. Reported benefits: quicker siphon start, no twisting of the delivery column, and greater siphoned volume for a given steam supply and pressure. Stated to apply to injectors as well as ejectors, and to single-, double-, or triple-acting forms. The septum "may be formed in casting the shell, or it may be inserted afterward."

Figures: Fig. 1/2 — longitudinal & transverse section of the base form (head A, induction opening B, steam branch C, combining tube G, per Pat. 231,789). Figs. 3–5 — double-acting siphon, septum b in the upper head H between H and inner head I, running on to combining tube J. Figs. 6–7 — a second double-acting form, septum similarly arranged. Fig. 8 — modification with a partial, gradually curving septum b' so the streams meet without colliding. Fig. 9 — an old-style siphon retrofitted with the septum.

Claims (all five are independent; no dependent claims)

Claim 1 — Generic septum preventing collision.
For an ejector/injector in which the inflowing current is divided by the steam nozzle or jet, inner head, or other device: a septum or wall b located in the head or shell so as to prevent the direct collision of the two currents in the head or shell.
Plain language: if your device splits the incoming water in two, put a wall in the head that stops the two halves from crashing into each other.

Claim 2 — Septum at the induction-opening.
A septum or deflector b projecting inwardly from the head or shell at a point about opposite the induction-opening.
Plain language: the wall sticks in from the housing, positioned opposite the water-inlet.

Claim 3 — Radial septum in line with the steam-jet axis.
An internal septum or deflector radially arranged in the head, in line with the steam-jet axis and between that axis and the shell.
Plain language: defines the wall's orientation — radial, on the steam-jet centerline, standing between the jet and the outer shell.

Claim 4 — Septum attached to the shell, projecting toward the jet axis (result-oriented).
A septum or deflector on or attached to the shell, radially projecting toward the steam-jet axis and in line with it, whereby the two bodies of water in the sides of the shell are prevented from direct collision.
Plain language: same wall, claimed by its attachment point (the shell) plus the functional result — no direct collision of the two water bodies.

Claim 5 — Narrowest / most specific: septum spanning the projecting inner head or combining tube.
In an ejector/injector having an inner head or combining-tube projecting into the shell or outer head, the combination therewith of an internal septum or deflector projecting from the shell toward (and to or nearly to) that inner head or combining-tube, in line with its axis, and extending lengthwise over the entire inwardly-projecting portion of the inner head or combining-tube.
Plain language: for the double-head/combining-tube architecture, the dividing wall must run the full length of the part that pokes into the shell — not just cover the mouth.

Claim-scope note: all five are single-element or combination claims of broad scope with only "substantially as described" as the qualifier, typical of 1883 practice. Claim 1 is the broadest; claim 5 is the most structurally constrained. No claim was narrowed by prosecution amendment visible in the printed text.

Conflicts / uncertainty

• Assignee — uncertain. No assignee appears on the face of the patent or in the Google Patents record. I cannot confirm any corporate owner. I did not find an assignment record.
• "Prior art date 1883-07-03" on the Google Patents page is simply the publication date reused; the actual filing date is October 31, 1882. Do not read it as a separate prior-art date.
• No CAFC 2026 docket entry exists for this patent to my knowledge, and none was found. Given the 1900 expiration, a 2026 appeal involving Patent No. 280,733 would be anomalous. I cannot rule out a docket reference that pairs this number with an unrelated modern patent; I found none.
• Identifier collision — flagged, not corrected. The string "280,733" also appears as a filing serial number for later, unrelated applications. Example surfaced in search: Frank W. Hall's laminated-glass application, filed June 23, 1939, "Serial No. 280,733" (issued as US 2,278,369, assigned to Pittsburgh Plate Glass Company). Google Patents also displays "US280733A" as an application identifier in the priority table of US 2,684,884 ("Cabinet shelving"). These are application serial numbers, not Patent No. 280,733, and must not be conflated with the Fulton ejector patent. If a search result for "280733" returns laminated glass, cabinet shelving, or a 1939/1952 filing date, it is this serial-number collision, not the patent requested.

Sources: authoritative full text from https://patents.google.com/patent/[US280733](/patent/US280733)/en (fetched 2026-09-29); litigation/assignee checks via web search returned no hits for this patent number.

I'll search for litigation involving US patent 280733.

Initial results referenced unrelated patents (e.g., the "733 patent" shorthand for U.S. 6,655,733 and U.S. 10,807,811 — not U.S. 280,733). Let me search more specifically.

Let me try more targeted searches for historical litigation and court records.

Litigation Search Report — U.S. Patent No. 280,733

Patent: U.S. 280,733 — "Ejector and Injector," Louis B. Fulton, Pittsburg, Pennsylvania
Filed: October 31, 1882 (Model) · Granted/Published: July 3, 1883
Status per Google Patents: "Expired – Lifetime"; anticipated expiration July 3, 1900 (17-year term).

Bottom line

No litigation involving U.S. Patent No. 280,733 was found — no district court action, no CAFC appeal, no PTAB/IPR proceeding, and no ITC Section 337 investigation. Because no case exists in the sources searched, I cannot provide plaintiff(s), defendant(s), jurisdiction, case number, filing date, or outcome/status — supplying any of those would require fabricating them.

What the searches actually returned (and why each is a false positive)

Because "280733" (with or without separators) is a very short, ambiguous numeric string, essentially every search hit resolved to a different patent. I want to flag these explicitly so this report is not misread as confirming litigation:

Corroborating "no litigation" indicators

• Google Patents litigation field: The "Cited By" section lists a single forward citation — US 2,659,375 A (Pipe preconditioner, Harlow B. Grow, filed 1949-03-15, published 1953-11-17) — and contains no "Litigation" / "Cited By (litigation)" entries, no "Cases" table, and no "Also published as" family actions. For patents with known litigation, Google Patents ordinarily surfaces a "Litigations" or "Cases" panel; none appears here.
• Family size 1, single country (US): Google Patents reports "Family Applications (1)" and "Country Status (1) — US." There are no foreign counterparts, which correlates with the absence of any recorded litigation activity.
• Expiration 1900: Any infringement suit on this patent would have had to be filed roughly between 1883 and 1900. Pre-1900 federal equity/law dockets are only partially digitized, so this is a coverage limitation, not proof that none was ever filed.

Important caveats (please read before relying on this)

1. Sources searched were general web/patent-text searches, not a complete run of the litigation databases you named. I did not successfully query the Unified Patents litigation caselist (portal.unifiedpatents.com/litigation/caselist), PACER, or a full CourtListener/RECAP docket sweep for the literal number "280733." Those are the databases where a negative result would be most meaningful.
2. CourtListener/Docket Alarm hits in my results were false positives keyed to "733"-shorthand patents (e.g., 6,655,733). A proper query must use the exact string "280,733" or "280733" and manually verify the patent number cited inside each document.
3. Historical (1883–1900) litigation is the plausible risk area. If a suit exists, it would most likely appear in:
   • Federal Reporter / Federal Cases volumes of that era,
   • the old equity dockets of the Circuit Court for the Western District of Pennsylvania (Pittsburgh) and potentially the E.D. Pennsylvania,
   • Official Gazette / trade-press noting of suits (e.g., the complainant likely being Louis B. Fulton personally or an assignee/manufacturing entity such as a Fulton siphon/ejector works).
4. No proposition is asserted as confirmed. Every negative statement above reflects "not found in the sources searched," not a verified nil return from PACER/CAFC.

Recommended next steps to close the gap

1. Query PACER's Case Locator and CourtListener/RECAP with the exact strings "280,733", "280733", "2 8 0 7 3 3".
2. Search the Unified Patents litigation caselist and PTAB caselist filtered by patent number 280733 (no separator) — a 1-family, pre-1900 patent will almost certainly return nothing, but that would be a documented negative.
3. For the 1883–1900 window: run Google Books / HathiTrust / JSTOR full-text searches on Federal Reporter and Official Gazette for "280,733" combined with Fulton and ejector.
4. Cross-check US 2,659,375 (Harlow B. Grow) and the similar-document list in Google Patents — those cite/cite-adjacent documents are the only known downstream references, and none reflect litigation.

If you want, I can run the exact-string PACER/CourtListener/Unified-Patents queries in a follow-up pass — that is the step most likely to convert "not found" into a defensible, documented negative.

Summary answer: Based on the searches performed, no litigation is known involving U.S. Patent No. 280,733. The apparent "hits" all involve different patents (notably 6,655,733, 10,807,811, 92,718, and the '210/'706 eductor patents) and must not be reported as litigation on this patent.

Proceedings overview

Total AIA trial proceedings on US 280,733: zero (0). The USPTO Open Data Portal returns no IPR, PGR, or CBM filings; I ran independent web searches against PTAB dockets, PTAB E2E-hosted documents, and CourtListener and found no AIA trial, no PTAB decision, and no Federal Circuit appeal touching this patent. There is therefore no "claims invalidated / claims sustained / settled / institution denied" breakdown to report — the category counts are all zero, and the correct defensive reading is not "the patent is hardened by surviving two IPRs," but rather "there is no PTAB record at all, because there could not be one."

The structural reason is dispositive, and any defendant should lead with it:

• US 280,733 issued 1883-07-03 ("EJECTOR AND INJECTOR," Louis B. Fulton, of Pittsburg, Pennsylvania; application filed 1882-10-31; Google Patents lists anticipated expiration 1900-07-03, legal status Expired – Lifetime).
• The AIA, which created IPR/PGR/CBM, was enacted 2011-09-16 and applies to petitions filed on or after 2012-09-16 — roughly 112 years after this patent expired.
• PGR is legally unavailable: 35 U.S.C. § 321(c) limits PGR to patents with an effective filing date on or after 2013-03-16.
• CBM is legally unavailable: the transitional program covered only patents claiming a "financial product or service" and sunset for new petitions on 2020-09-16 — and in any event this is an 1883 steam-jet pump.
• An IPR on an expired patent is conceptually possible under § 311 (the Board can review an expired patent and issue a FWD, with the patent owner unable to amend), but no one has ever filed one here, and there is no economic motive: the patent is public domain and unenforceable.

The practical bottom line for a defendant: if you receive a demand letter citing US 280,733, the letter is itself the red flag. An 1883 ejector patent that expired in 1900 cannot support a live infringement claim, cannot be asserted by anyone holding enforceable rights, and cannot be the subject of a valid AIA-trial analysis. The absence of PTAB activity here is not a hardening signal — it is the absence of a live patent.

No proceedings to report

There are no proceeding numbers to list. Per the operating instructions, I will not invent IPR/PGR/CBM numbers to fill the template. For completeness, here is what I affirmatively checked and did not find:

• PTAB proceedings on file (structued ODP block): empty — zero AIA trials.
• Web search for PTAB/IPR activity on "280,733" / Fulton: no PTAB petition, institution decision, FWD, or appeal. Search results returned only 19th-century federal court litigation about other inventors' injectors (e.g., Hancock Inspirator Co. v. Regester, 35 F. 61 (C.C.D. Md. 1888), on Hancock patent 185,861; and Nat'l Pump Cylinder Co. v. Gunnison, C.C.W.D. Pa. 1883) — none of which involve US 280,733 or Fulton. These are pre-AIA district court cases, not PTAB proceedings, and should not be conflated with either.
• Appeals: no CAFC docket or CourtListener opinion referencing US 280,733. (Note: the "In re Fulton, 391 F.3d 1195 (Fed. Cir. 2004)" hit is a different Fulton matter and is not related.)

⚠️ False-positive warning for anyone running the same searches: the string "the '280 patent" appears constantly in PTAB filings about US 6,635,280 (Purdue/Shell gastric-retentive dosage forms, e.g., IPR2014-00377). That is a different patent — a 2003 pharmaceutical formulation patent — and has nothing to do with US 280,733. Do not pull those FWDs, panels, or invalidity outcomes into an analysis of this patent. I excluded them.

Related-adjudication context (non-PTAB), for completeness

Because the PTAB record is empty, the only historical validity/adjudication material bearing on this family is pre-AIA and concerns Fulton's earlier patent, which US 280,733 explicitly builds on:

• The specification of US 280,733 states: "A designates the head or shell, B the induction-opening, C the steam branch, and G the combining-tube, all as shown in Letters Patent No. 231,789, granted to me August 31, 1880." So 280,733 is a narrow improvement on Fulton's own 1880 patent, and any prior-art analysis would start there.
• The only forward citation on the Google Patents record is US 2,659,375 A ("Pipe preconditioner," Harlow B. Grow, priority 1949-03-15, published 1953-11-17) — a citation record, not a challenge.

I have no evidence of an ex parte reexamination, interference, or district court validity holding on US 280,733 specifically, and I will not assert one exists. (Pre-AIA reexamination practice has existed since 1980-12-12, so a reexam would have been technically possible during the patent's life, before 1900. None is on record in the materials I reviewed, and USPTO ODP's AIA-trial API would not surface one anyway.)

Strategic summary

Claim status: no claim has been canceled, sustained, or tested in any PTAB forum, because no PTAB forum has ever had jurisdiction over this patent in practice. All five claims as issued remain as printed: claim 1 (the genus claim to a septum/wall in the head or shell preventing direct collision of the two divided currents); claim 2 (septum or deflector projecting inwardly from the head "at a point about opposite the induction-opening"); claim 3 (septum radially arranged in the head in line with the steam-jet axis); claim 4 (septum on or attached to the shell projecting radially toward the steam-jet axis); and claim 5 (inner-head/combining-tube form with a septum projecting from the shell toward the inner head and "extending lengthwise over the entire inwardly-projecting portion" thereof). These claims were not narrowed by IPR — they simply expired on or about 1900-07-03. Distinguish "never challenged" from "survived a challenge"; here it is emphatically the former.

Estoppel landscape: there is no § 315(e)(2) estoppel to map, and none is needed. No petitioner has ever appeared, so no petitioner or privy is estopped from anything. Conversely — and this is the point a defendant should exploit — a patent owner asserting 280,733 has no PTAB-tested claim construction, no FWD findings, and no Federal Circuit affirmance to lean on. There is no § 315(e)(1) or (e)(2) bar, no § 325(e) bar, and no IPR estoppel exposure for a defendant, because the patent's invalidity posture has never been adjudicated in a post-issuance forum. The entire prior-art universe remains "unraised" and "could have raised" is inapposite.

Pattern signals: none. No repeat petitioner (there are zero petitioners). No patent-owner PTAB appeal practice (no PTAB proceeding to appeal from). No defensive aggregator — Unified Patents, RPX, or otherwise — has ever been in the chain, which is expected: defensive aggregators target asserted, live patents. The absence of any of these signals is corroborative that US 280,733 is not a patent anyone is litigating or licensing.

Recommended next steps

• If you are a defendant being threatened with US 280,733: Do not build an IPR strategy. There is nothing to invalidate that is not already in the public domain. The correct response is a demand-letter analysis: identify the sender's asserted interest, note that the patent issued 1883-07-03 and expired on or about 1900-07-03 (Google Patents legal status: "Expired – Lifetime"), and treat any assertion of live rights as meritless on its face. Confirm the expiration date against the USPTO PatentCenter record for US 280,733A before responding in writing.
• If you are evaluating the patent as prior art (the realistic use of an 1883 ejector reference): the full text is available at https://patents.google.com/patent/[US280733](/patent/US280733)/en and the USPTO PatentCenter/Global Dossier records linked from that page. Treat the disclosure as a printed publication dated 1883-07-03, with claims 1–5 as the enumerated subject matter. Its § 102(a)(1)/pre-AIA § 102(b) value as a printed publication is unaffected by the absence of PTAB activity.
• If you are a practitioner who found "IPR" and "the '280 patent" in the same document: re-check the patent number. The Purdue v. Andrx/Shell line of PTAB decisions uses "'280" as shorthand for US 6,635,280 (dosage forms), not US 280,733 (ejectors). Conflating them would put fabricated panels, grounds, and dispositions into your work product.
• On the absence itself: per the task framing, no PTAB activity "is itself a signal — well-asserted patents eventually attract IPRs." Here the absence is a different and stronger signal: the patent has been dead for over a century, so it has never been assertable in the AIA era. Do not represent to any tribunal or client that US 280,733 has "survived" or "been tested by" PTAB review — it has done neither.

Verification note: I could not locate any PTAB FWD, institution decision, or CAFC opinion for US 280,733 to link, because none exists. The only URLs I can ground statements on are the Google Patents record above (which supplies the 1883-07-03 issue date, 1882-10-31 filing date, 1900-07-03 anticipated expiration, and "Expired – Lifetime" status) and the USPTO ODP structured block supplied in the prompt (zero proceedings).

I'll research the assignment record for this patent before producing the analysis.

Ownership & Assignment Record — US 280,733

Headline finding up front: I could not establish an assignment chain, because the USPTO's online assignment system does not index this era. The Patent Assignment Search (https://assignment.uspto.gov / Assignment Center) covers only recordations made from August 1980 forward; pre-1980 records sit in a separate historical database that is not exposed through the online search (MPEP 301.01: "The historical database of assignments is maintained separate and apart from the database of assignments affecting title recorded since 1980."). US 280,733 issued 1883-07-03 and expired 1900-07-03 — roughly 80 years before the online index begins. There is therefore no reel/frame to cite, and no correspondent of record to harvest. I am not going to manufacture one.

Inventors

Notes on pattern:

• The header reads "LOUIS B. FULTON, OF PITTSBURG, PENNSYLVANIA" with no assignee line. Google Patents likewise shows no assignee field for this record.
• This is an unassigned individual filing, and the specification shows Fulton operating as a serial independent inventor in one narrow field: he expressly incorporates "Letters Patent No. 231,789, granted to me August 31, 1880" and builds the entire improvement on top of that earlier, self-owned disclosure. Filing (1882-10-31, per "Application filed October 3l, 1882") sits ~26 months after the 1880 parent — consistent with a lone mechanic/engineer iterating by reissue-adjacent filings, not a corporate R&D pipeline.
• The "all inventors departed the assignee within 12 months" fire-sale pre-signal is inapplicable — there was no assignee for anyone to leave.

Original assignee

None. The patent issued to Louis B. Fulton, individually. There is no corporate original assignee, so the usual questions (product embodying the claims, line of business, current status) have no entity to attach to.

• Entity: individual inventor, not a legal entity.
• Product: the claimed subject matter is a steam ejector / injector (siphon pump and boiler-feed injector) with an internal radial septum b in the head or shell that prevents the two split water currents from colliding and losing velocity (claims 1–5). No commercial product of Fulton's is documented in the patent or the records I checked.
• Current status: the patent is expired (17-year term, anticipated expiration recorded 1900-07-03) and legally dead for over a century. Any individual owner would be long deceased.
• Forward-citation footprint: exactly one — US 2,659,375 A (Pipe preconditioner, Harlow B. Grow, 1953). That is a citation event, not an ownership event, and it carries no assignment significance.

Assignment timeline

There are no recorded assignments retrievable for this patent.

Concretely:

1. No records in the Assignment Center. Querying by patent number returns nothing, because the coverage floor is August 1980 and this patent's entire enforceable life ended in 1900.
2. No reel/frame can exist for the 1883 era. Reel/frame indexing is a 20th-century convention; an assignment recorded in the 1880s would not carry one, and USPTO's historical database is not available through the public online tool — it requires the Assignment Recordation Branch or a PTRC, and there is no online document image to pull.
3. Google Patents legal events for this record show only: Application granted (1883-07-03), Publication of US280733A (1883-07-03), Anticipated expiration (1900-07-03). No assignment events.
4. Practical conclusion: on the face of the issued patent the inventor retained ownership, and no transfer was ever surfaced. Whether some 1880s–1890s transfer exists on paper at the USPTO cannot be confirmed or excluded from the online index — but it would be moot, since the term expired in 1900.

Per your instruction, the chain ends here. I've kept the remaining sections minimal but present, because your verdict rubric explicitly provides for the "no records" case and the required output order includes them.

Timeline diagram

timeline
    title Ownership of US 280733
    1880 : Fulton secures earlier patent 231789
    1882 : Application filed by Louis B Fulton
    1883 : Patent issued with no assignee named
    1900 : Patent term expires
    1980 : USPTO online assignment index begins
         : No records exist for this patent

NPE / troll-pattern signals

Every signal is scored against an empty assignment chain. None can be "present," but note the structural blind spot: the pre-1980 paper index is not searchable online, so for signals 1–7 the honest label is not present on the available record, not a positive clearance.

1. Shell-entity transfer — Not present. No assignee of record exists at all; no IP/Holdings/Licensing-suffixed entity appears anywhere in the file.
2. Known asserter in the chain — Not present. No assignee to compare against Acacia, Marathon, IV, Wi-LAN/Conversant, Pendrell, Round Rock, et al. The patent expired 1900-07-03, so it cannot be in any live NPE portfolio.
3. Repeat correspondent across the chain — Not present. Zero correspondents of record. Nothing to recur.
4. Cascading transfers — Not present. No consecutive LLC-to-LLC transfers; no chain at all.
5. Pre-litigation transfer — Not present. No assignment, and no infringement suit could be identified — the patent has been expired for 126 years. There is no litigation window to time a transfer against.
6. Bankruptcy fire-sale — Not present. The owner was an individual inventor, not a Chapter 7/11 debtor entity.
7. Privateering — Not present. No operating company and no NPE counterparty exist in the record.
8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at statutory expiration.

Verdict

Insufficient data.

This is not an NPE case and cannot be scored as one: the patent issued 1883-07-03 to Louis B. Fulton individually with no assignee named on its face, carried a 17-year term that expired 1900-07-03, and has no entry in the USPTO Patent Assignment Search because that index begins August 1980 — roughly eight decades after this patent's enforceability ended. There is no reel/frame, no assignor, no assignee, and no correspondent to cite; the single forward citation (US 2,659,375 A) is a technical reference, not a title event. The only residual uncertainty is the USPTO's un-indexed pre-1980 historical record, which would have to be pulled manually from the Assignment Recordation Branch — and which, given the 1900 expiration, could have no bearing on modern assertion.

Verify: https://assignmentcenter.uspto.gov/ · https://assignment.uspto.gov/patent/index.html · https://patents.google.com/patent/[US280733](/patent/US280733)/en

Method note / caveats: I did not find, and did not invent, any assignment records. The strongest verifiable primary facts here are (a) the no-assignee face of the patent as reproduced in the full text, (b) the application filing date of 1882-10-31 the specification recites, and (c) the August 1980 coverage floor of the USPTO online assignment database, corroborated by Finnegan's and Caltech's descriptions of the AOTW database and by MPEP 301.01's statement that pre-1980 records are maintained separately. One item I flag at lower confidence: I saw a search hit suggesting a "Louis B." inventor on US 220,471, which may be another Fulton injector/ejector patent, but I could not confirm the full name or that it is the same Louis B. Fulton — treat that as unverified.

I'll research US patent 280733 and its cited references. Let me run several searches.

Let me dig into the specific cited reference (US 231,789) and the Google Patents citation data for US 280,733.

Search results summary

I ran targeted searches against the Google Patents/USPTO records for US 280,733 and for its cited reference US 231,789. Here is what I can confirm and, importantly, what I could not confirm.

Caveat on the "citation" data (read first)

The authoritative full text of US 280,733 that I was given contains no backward "Patent Citations" (prior-art) list. The only citation block present is a forward citation — "Cited By (1): US2659375A" — plus a list of algorithmically "Similar Documents," which are not legal citations. My follow-up web searches did not surface any additional backward citations for US 280,733 either. Accordingly, the only reference actually cited by US 280,733 is the one named inside its own specification: US Patent No. 231,789. I will not fabricate additional § 102 references that the record does not show.

1. Reference cited by US 280,733

Why § 102 is not triggered. All five claims of US 280,733 require the septum/deflector element:

• Claim 1 — "a septum or wall, b … in the head or shell" to prevent direct collision of the two currents;
• Claim 2 — "a septum or deflector, b, projecting inwardly from the head or shell at a point about opposite the induction-opening";
• Claim 3 — an internal septum "radially arranged in the head in line with the axis of the steam-jet";
• Claim 4 — a septum "radially projecting toward the steam-jet axis, and in line therewith";
• Claim 5 — septum "projecting from the shell toward … the said inner head or combining-tube, in line with the axis thereof, and extending lengthwise over the entire inwardly-projecting portion of said inner head or combining-tube."

US 231,789 is the reference described in US 280,733 as lacking that septum (the collision/velocity-loss problem is attributed to exactly this construction). A reference that does not disclose the claimed septum cannot anticipate any of claims 1–5 under § 102. At most it is background art relevant to §§ 102(a)/103 obviousness-type analysis — and since it is the same inventor's own earlier patent, it is the starting point the new claims build upon, not an anticipating disclosure.

2. Forward citation (NOT prior art)

3. "Similar Documents" (not citations — do not treat as prior art)

The record lists ~24 documents returned by similarity heuristics (e.g., US 277,072 "Double-headed ejector" (1883); US 246,084 "Ejector" (1881); US 249,876 "Injector" (1881); US 436,932 "Injector" (1890); US 380,907 "Ejector" (1888); US 950,598 "Spiral-jet injector" (1910), etc.). These are not § 102 citations. Several (e.g., the 1881–1883 items) are close in date and could in principle be relevant to patentability, but they are not cited references and I cannot confirm what any of them disclose from the available data.

Bottom line

• The only prior-art reference actually cited in/for US 280,733 is US Patent No. 231,789 (Fulton, August 31, 1880).
• It anticipates none of claims 1–5, because each claim requires a septum/deflector absent from that earlier structure.
• US 2,659,375 (Grow, 1953) is a forward citation only and has no § 102 effect.
• The "Similar Documents" list is not a prior-art citation list.

Limitation / honesty note: The fetched US 280,733 record shows no backward "Patent Citations" section, and my supplementary searches returned no additional references cited by US 280,733. If the USPTO's original 1883 file-wrapper or a fuller Google Patents view lists examiner-cited references not present in this snapshot, I could not retrieve them here; I have deliberately avoided inventing any such citations (including any 1820s–1870s "Coll/Giffard injector" references that appear only in unrelated litigation and Smithsonian texts, not in this patent's own citation record).

I'll build on the prior-art section, but first run targeted checks on the only candidate secondary references the record offers (the contemporaneous "Similar Documents"), since a § 103 combination requires naming a specific second reference.

The searches surfaced two date-qualifying secondary references not in the record's citation list, plus confirmation of one entry on the "Similar Documents" list. Let me verify a couple of details before writing.

Obviousness Analysis — US 280,733 (Louis B. Fulton, "Ejector and Injector")

Builds on: the Prior Art section above. I do not repeat its findings; where I refine or contradict them, I flag it explicitly under §7.

1. Threshold point that must be settled before § 103 is even arguable

US 280,733 issued July 3, 1883, on an application filed October 31, 1882. It was examined under the statute then in force (R.S. § 4886), which required "invention" as construed in Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1850). 35 U.S.C. § 103 did not exist — it was enacted July 19, 1952, effective January 1, 1953. Any § 103 analysis of this patent is therefore an analogical exercise: the historic "invention"/"mechanical skill" standard is the functional equivalent of modern § 103 (Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007)).

That equivalence is not speculative here — it is documented in the contemporaneous case law on the very same art. In Hancock Inspirator Co. v. Jenks, 21 F. 911, 918–920 (C.C.S.D.N.Y. 1884) (§ upstream of Hancock Inspirator Co. v. Regester, 35 F. 61 (C.C.D. Md. 1888); Hancock Inspirator Co. v. Lally, 27 F. 88 (C.C.N.D. Ill. 1886)):

• the court treated a difference in the extent of projection of the steam-nozzle into the head as "only a question of mechanical skill" — i.e., the 1884 mechanical-skill doctrine maps onto modern § 103 reasoning as to degree/positional changes; and
• the court nonetheless sustained the patent because a new result was produced, and identified the "essence" of that patent as "the separation of the inflowing steam and water before they reach the combining tube."

URLs: https://law.resource.org/pub/us/case/reporter/F/0021/0021.f.0918.html ; https://www.courtlistener.com/opinion/[8341730](/patent/8341730)/hancock-inspirator-co-v-jenks/ ; https://storage.courtlistener.com/harvard_pdf/8341730.pdf

Consequence: the outcome of this analysis turns on whether the septum is a "new result" or a "mechanical variation" — exactly the question § 103 asks today.

2. Person having ordinary skill in the art (PHOSITA), c. October 1882

An engineer/machinist building steam injectors and ejectors, familiar with Giffard-type injectors, Jenks's injector (US 233,418, Oct. 19, 1880), Hancock's injector patent (No. 185,861, June 2, 1877), variable-area/sliding combining tubes (Robinson & Gresham, 1866 — Smithsonian Institution, https://repository.si.edu/bitstream/handle/[10088/10218](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=10088-10218)/1/USNMB_1731939_unit.pdf), and with ordinary-engineering knowledge of jets discharging into coaxial annular inflows.

3. Claim elements and where each is found

Full text: https://patents.google.com/patent/[US280733](/patent/US280733)/en

4. Direct § 103 (obviousness) attack — the viable combinations

Because US 231,789 supplies every element except the septum, the whole case reduces to: was adding a dividing wall to a known ejector head an exercise of invention or of mechanical skill? Below are the combinations that can actually be constructed from the record and from my supplementary retrieval, with motivations and weaknesses stated candidly.

Combination 1 — US 231,789 + the common knowledge of the art ("Official Notice" route) ★ strongest

Reasoning. KSR: "the combination of familiar elements according to known methods is likely to be obvious"; and where design incentives and the number of possible solutions are finite, the solution is obvious to try. Given a central obstruction on the head axis (steam nozzle and/or combining-tube mouth), the head can only be partitioned into two independent flow paths in a finite number of ways — essentially (i) a radial septum lying in the plane that contains the jet axis, or (ii) a coaxial/annular arrangement. Claim 3's placement ("radially arranged in the head in line with the axis of the steam-jet") is therefore not merely a solution; it is the geometrically forced one.

Reinforcing admissions in the patent's own text (usable against it, and analogous to KSR's "ready for patenting" / mere-addition line):

• "The septum may be formed in casting the shell, or it may be inserted afterward." → a wall is an add-on element, not a redesign.
• Claim 4 recites the septum merely "on or attached to its shell."
• The stated benefit is functional and predictable ("a total avoidance of the loss of steam caused by the destruction of the velocity … by reason of back or counter currents, eddies, twists, or whirls").

Weakness: needs evidentiary support for "common knowledge," which is where Combinations 2–4 come in; standing alone this route is vulnerable to the objection that the problem itself was previously unrecognized (see §6).

Combination 2 — US 231,789 + US 259,649 (Murdock, "Injector," granted June 13, 1882; filed Oct. 12, 1881)

Disclosure (verified): an injector steam-plug "cast with a recess, N … such recess being divided by the partitions a, cast therein," and a combining-tube seat-ring with flanges c; the patent expressly contemplates screw-plugs for both the steam-jet and combining tubes. URL: https://patentimages.storage.googleapis.com/78/2c/dc/a658d30e7a8ca3/[US259649](/patent/US259649).pdf

Motivation (same field / same device, same manufacturing technique): Murdock is an injector head; it shows that casting dividing partitions and ribs inside the injector's nozzle/throat plugs was conventional in the same art, using the same casting method the Fulton specification invokes.

Weakness (real): Murdock's partitions serve a wrench-engagement/purchase purpose (the gas-pipe tool D "engages with the partitions"), not a flow-dividing purpose. Under KSR's "predictable use of prior art elements according to their established functions," using wrench-lug partitions as a flow septum is a change of function, which weakens the motivation. This combination is best used for the manufacturing-practice point in Combination 1, not as a standalone primary-plus-secondary pairing.

Combination 3 — US 231,789 + US 265,246 (Conord, "Ejector for Raising Liquids," Oct. 3, 1882; filed June 21, 1882)

Disclosure (verified): a shell E "formed in two halves, and clamped together… formed with a bore or tubular channel passing longitudinally through it"; a suction chamber j "into which the water from the well flows through two tubular channels or apertures, g y, cast half in each half of the shell"; a steam-nozzle F and throat G in the bore. URL: https://patentimages.storage.googleapis.com/ff/76/8b/2e9f4887b9329f/[US265246](/patent/US265246).pdf

Motivation: Conord teaches a jet pump whose shell is (a) built in two longitudinal halves and (b) supplies the suction chamber through two separate cast channels — i.e., the art already fractionated the liquid body entering the head. Extending that fractionation as an internal wall between the two halves is a short, mechanical step in the same field.

Weakness: Conord was granted only ~4 weeks before Fulton's filing, so it is § 102(a)/§ 102(e)-style art at best (see §7.2) and its two channels are inlets, not a partition downstream of the nozzle. Motivation is moderate, not compelling.

Combination 4 — US 231,789 + the head-region teachings of Hancock's patent No. 185,861 as described in Hancock Inspirator Co. v. Jenks ★ best "same-field, same-location, same-problem" pairing

Disclosure (verified via the opinion's verbatim quotations): Hancock's specification addresses conditions in the injector head before the combining-tube mouth and identifies, as the essence of the invention, "the separation of the inflowing steam and water before they reach the combining tube"; the patent substituted "a plate with an orifice" for the ordinary nozzle so that the nozzle projects into the steam chamber only minimally. The opinion also records that Giffard's own specification contemplated "divid[ing] the actuating steam-jet into two parts."

Motivation: this is the strongest available teaching in the same field (boiler injectors), at the same location (the head/suction chamber upstream of the combining tube), addressed to the same generic problem (loss of motive effectiveness caused by the geometry of the head before the combining tube). A PHOSITA reading 231,789 and Hancock would be prompted to look at the head geometry and to keep the co-flowing bodies in the head separated rather than letting them run together.

Weakness: Hancock's separation is a steam-versus-water (thermal) separation, not separation of the two halves of a split water current; and the Jenks opinion's own "mechanical skill" holding cuts both ways.

Combination 5 — US 231,789 + US 259,206 (from the record's "Similar Documents" list; now verified)

Disclosure (verified; the record's garbled assignee/title text "Goldsbuby h" in fact reads "Goldsbury H. Pond," "Reducing Wood, &c., to Fiber"): two opposed steam jets inject two streams that are "thrown forcibly against each other," the "collision serv[ing] to shatter the particles"; and the specification emphasizes confining a steam jet so it "cannot expand laterally and thus lose its force." URL: https://patents.google.com/patent/[US259206](/patent/US259206)#1

Assessment — do not use this as a § 103 reference. It is (i) non-analogous art (wood-pulping), and (ii) it teaches toward stream collision where Fulton teaches away from it. If an examiner advanced it, the proper response is a non-analogous-art and teaching-away argument.

Combination 6 — US 231,789 + US 35,575 (Millholland, 1862)

Verified disclosure: "a chamber with certain branches in combination with an internal nozzle," the nozzle "project[ing] through the chamber" into the bore with a narrow annular space between them (https://patentimages.storage.googleapis.com/da/cf/c4/b398f5588cb1f6/US35575.pdf). This is structural context for the "nozzle standing across the line of the induction-opening" geometry Fulton describes, but it adds nothing on the septum. Not a § 103 combination by itself.

Combinations I could not support

• US 2,659,375 (Grow, 1953) — forward citation only; post-dates the patent by ~70 years. Not available. (Consistent with the Prior Art section.)
• US 246,084 (Ejector, 1881) and US 249,876 (Injector, 1881) — both on the "Similar Documents" list and both comfortably pre-dating the Oct. 31, 1882 filing. My retrieval attempts returned a different document (US 241,334, Eames) rather than their texts, and my second query hit the tool-step limit. I could not verify their disclosures and will not assert them. They remain the most promising unverified candidates, precisely because both are pre-1882 jet-pump patents to a possibly related inventive line.

5. Claim-by-claim vulnerability

6. The genuine non-obviousness case (steel man)

Any § 103 rejection of this patent must overcome three real arguments:

1. Unrecognized source of the problem. The specification does not merely claim a structure; it claims a diagnosis: "I have discovered that from this fact arise two drawbacks … the two bodies of water meet, and the result is that part, at least, of its previously acquired velocity is annihilated…" and, in the out-of-true case, "the remainder rendered ineffective by the resultant spiral direction." Where the art had not appreciated the cause of an observed inefficiency, the discovery of the cause and its remedy is the classic case of invention. The best contemporaneous counter-tool for the challenger is Hancock v. Jenks's "mechanical skill" line — but Jenks also upheld the patent there on precisely the "new result" rationale, which is adverse authority to the challenger.
2. No express suggestion anywhere in the verified references to put a wall between the two halves of the split water current. Combinations 2–4 all require arguing structure/function analogy rather than finding a direct teaching. Silence in the art is not teaching away, but it does raise the evidentiary burden on the motivation-to-combine element, and a PHOSITA cannot be assumed to have known why the head was misbehaving.
3. Claim 5's extent limitation — see table above.

What the record does not supply to the patentee: no objective evidence of commercial success, no long-felt-but-unmet need, no failure of others (the record instead shows a crowded, active 1880s injector market — the Smithsonian collection lists dozens of contemporaneous injector patents and models, https://repository.si.edu/bitstream/handle/[10088/10218](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=10088-10218)/1/USNMB_1731939_unit.pdf — which is neutral-to-unhelpful), no copying, and no comparative test data. The specification's assertions of improved siphon starting, avoided twisting, and greater volume "for a given steam supply and pressure" are attorney/specification argument, not evidence, and carry no nexus showing.

7. Explicit flags on the Prior Art section, and scope corrections

7.1 — § 102(b)-type status of US 231,789 (refinement, not a contradiction). The Prior Art section says US 231,789 is "at most … background art relevant to §§102(a)/103." That understates it. US 231,789 was granted August 31, 1880, roughly 26 months before the October 31, 1882 filing of US 280,733. Under the statute then in force (R.S. § 4886) that pre-filing interval barred the reference irrespective of inventorship — i.e., Fulton's own earlier patent was available against his later claims. The modern analogue is pre-AIA 35 U.S.C. § 102(b) (a one-year grace period), which likewise applies to an inventor's own prior patent; § 103(c)-type common-ownership exclusions do not reach § 102(b) art. Confidence note: the exact historical grace period in 1882 was governed by R.S. § 4886 and was amended in the 1890s (I believe by the Act of March 3, 1897); I am not fully certain of the 1882 figure, but 26 months exceeds the bar under either the pre-1897 or the modern one-year standard, so the conclusion is robust to that uncertainty. The Prior Art section's § 102 anticipation conclusion (no claim 1–5 is anticipated) remains correct.

7.2 — The "Prior art date 1883-07-03" in the fetched record is the grant/publication date, not the filing date. Google Patents' 19th-century "Prior art date" field tracks the issue date here (hence the "Anticipated expiration 1900-07-03" = 17 years from grant). The operative critical date is October 31, 1882, per the specification ("Application filed October 31, 1882"). This materially changes the qualification of items on the "Similar Documents" list: e.g., US 277,072, "Double-headed ejector," published 1883-05-08 post-dates Fulton's filing, so it can qualify only as § 102(a)/§ 102(e)-type art (US patent granted on an application filed before Fulton's invention), not as a § 102(b)-type bar. Any obviousness combination built on it must clear that threshold. (US 277,072 appears repeatedly as a citation in later jet-device patents — e.g., https://patents.google.com/patent/[US3047208](/patent/US3047208)#5 — which tells us it is structurally relevant but not, from this record, what it discloses.)

7.3 — Update to "I cannot confirm what any of them disclose." I have now verified the disclosure of US 259,206 (Pond, "Reducing Wood, &c., to Fiber," June 6, 1882) and described it at § 4 / Combination 5. I additionally located two date-qualifying injector references not in the record's citation or similarity lists — US 259,649 (Murdock) and US 265,246 (Conord) — and the Hancock line of authority describing US 185,861. I did not verify US 246,084 or US 249,876 and assert nothing about them. No backward "Patent Citations" list exists in the fetched record (unchanged).

7.4 — Eames "diaphragm" caveat. US 241,334 (Eames, "Air-Ejector," May 10, 1881) does contain an ejector "diaphragm," but it is a pressure-responsive actuating diaphragm connected by a lever to a valve — not a flow-dividing septum. A challenger must not equate the two; a change of function argument defeats that pairing under KSR. I mention it so the distinction is not blurred.

7.5 — Date discrepancy. The task header states the current date as April 26, 2026, while my operating parameters give September 29, 2026 (the latter matches the fetch timestamp on the patent record). Immaterial to the analysis; flagged per rule.

8. Bottom line

• On the record as fetched, there is no established § 103 combination. The patent's own citation record contains exactly one backward reference (US 231,789) plus one forward citation (US 2,659,375, 1953, unavailable), and the "Similar Documents" list is not a citation list.
• The claims are nevertheless substantially exposed to a § 103-type attack, and the strongest construction of that attack is:
  Primary: US 231,789 (Fulton) — supplies head A, induction-opening B, steam branch C, combining-tube G, and expressly the split-current geometry.
  Secondary (choose one): (a) the head-region "separation before the combining tube" teaching of Hancock's US 185,861 as quoted in Hancock Inspirator Co. v. Jenks, 21 F. 911 (same field, same location, same problem) — preferred; or (b) US 259,649 (Murdock) for the routine casting of dividing partitions in injector plugs; or (c) US 265,246 (Conord) for the two-channel, two-half shell.
  Motivation: same field of endeavor (boiler feed injectors / ejectors); the head upstream of the combining tube was the recognized locus of efficiency loss; casting a wall is the same method the art already used; only one sensible axial placement exists; the specification itself admits the wall may be "inserted afterward." Expectation of success: high — a static partition is not an unpredictable element.
• Claims 1, 3 and 4 are the most vulnerable (functional result language; geometrically forced orientation; add-on element). Claim 5 is the most defensible (extent of the septum over the entire projecting portion), but only if the patentee can show criticality — the record contains no data.
• The best non-obviousness arguments are the unrecognized-problem/diagnosis argument and the absence of any express suggestion in the verified art — supported by the Jenks court's own willingness to find patentable "new results" in this exact art, but undermined by that same court's "only a question of mechanical skill" holding for positional/degree changes.
• Ancillary: because US 231,789 and US 280,733 name the same inventive entity, obviousness-type double patenting (patent-to-patent) is a theoretically available rejection ground had the claims been patentably indistinct — but the septum is a structural difference, so ODP would be unlikely to carry the day and, in any event, is a prosecution/reexamination ground, not a defense against an expired patent (both patents long expired: 231,789 in 1897; 280,733 in 1900).

Highest-value next step if further work is authorized: retrieve the full texts of US 246,084 and US 249,876 (both 1881, both on the record's Similar Documents list, both pre-dating the October 31, 1882 filing). Either could convert the "common knowledge" Combination 1 into a two-reference combination with an express structural teaching — which would be the difference between a rejectable and a non-rejectable case.