US 182671

I'll run targeted searches for this specific patent number before summarizing.

US Patent 182,671 — Summary

Bottom line: US 182,671 is a very early (1876) patent, not a modern one. It has no abstract, no recorded assignee, and no conceivable Court of Appeals for the Federal Circuit (CAFC) docket — the CAFC did not exist until the Federal Courts Improvement Act of 1982, and this patent's term expired in 1893. I found no 2026 litigation or CAFC docket activity for this number, and none should be expected.

Bibliographic data

Note on "abstract": There is none. Abstracts were not part of US patent specifications in 1876. The summary below is my synthesis of the specification's own statement of invention, not a verbatim abstract.

What the invention is

A railroad car seat usable as either a day chair or a reclining chair. Its distinguishing features, in the patentee's own framing, are:

• A head-rest (I) on angular arms (H) pivoted to both the back and the tops of arm-standards, so the head-rest lies in the plane of the back when upright and automatically swings out to serve as a pillow when the back reclines.
• Knuckle-jointed arm-standards (G) tied to a bow- or crank-shaped pivot (F) beneath the seat, with a pawl (J) and rack (K) to lock the back at any angle, retractable by lever M, plus a spring (L) that keeps the knuckle joints closed and counterbalances the back.
• A cast-iron foot (A) socketing a swiveling spider, with a falling stop (Q) that drops into notches in the base to lock the chair facing forward or rearward; the stop is linked by a rod or chain (R) to the back so that tipping the back forward releases it.
• A slotted spider stem receiving a toothed arm for a folding leg-rest (N), elevated by lever P so the rest can be lowered.
• The stated utility: a high-back chair that can be reversed within the area of its own seat, allowing high-back car seats to be placed close together.

Independent claims in plain language

All seven claims are independent (1876 practice used no dependent claims; no claim refers to another by number). Each ends with "substantially as set forth" or "in the manner and for the purpose set forth."

1. Claim 1 — Head-rest assembly. The angular arms (H) and head-rest (I), rigidly connected together as one piece and hinged to the back (E).
2. Claim 2 — Reclining/locking linkage. The bow-shaped crank-lever (F) in combination with the uprights (G), back (E), arms (H), supporting pawl (J), and rack (K).
3. Claim 3 — Forward-tipping provision. The knuckle-jointed uprights (G) combined with the hinged back (E) and arms (H), to allow the back to be set forward.
4. Claim 4 — Swivel release. The back (E), arms (H), jointed uprights (G), and a supporting frame with the stop (Q), arranged so that tipping the back forward retracts the stop and frees the chair to swivel.
5. Claim 5 — Pawl release. The combination of the hinged back (E), arms (H), uprights (G), crank-lever (F), supporting pawl (J), and lever (M) for retracting the pawl.
6. Claim 6 — Spider frame. The spider having arms attaching it to the seat frame and bearings for the shaft that forms the pivot of the uprights (G).
7. Claim 7 — Leg-rest. The leg-rest (N) with the hinged supporting arm (O) working in a slot in the spider stem, and lever (P) for elevating that arm when the leg-rest is to be lowered.

Confidence and caveats

• High confidence in title, inventor, dates, claims, and claim scope — these come from the full patent text supplied as the authoritative source.
• Assignee: stated as none. I found no assignment record, but I could not directly query USPTO Assignment/PatentCenter or the CAFC docket system; my searches were web searches only. Treat "no assignee" as the absence of evidence, not a certified negative.
• OCR garbling — do not rely on reference letters in the full text. The letter for the spider is rendered inconsistently as U, 0, G, "C," and "(J" in the transcribed description (e.g., "spider, U," "spider 0," "spider G," "spider (J"). Likewise the seat frame/seat bottom is rendered "D" for both, and "bolts 0 tea cast-iron ring or frame, D" is clearly corrupt. Similarly, "fitted to rigidly secured at its ends tostandards G" is a corrupted sentence. The claim language is cleaner but still shows the same OCR noise ("hinged hack E," "spider (J," "slotin the stem").
• No CAFC or 2026 litigation exists for this patent number, and none is legally possible: the patent expired September 26, 1893, roughly 89 years before the CAFC was created. A 2026 search for "182671" in that context returns only unrelated hits (e.g., application 18/267,142, a software case — a different identifier that merely contains the same digits).
• Unrelated modern art caveat: the number 182671 is also a substring of many modern application and patent numbers. Per your instruction, I have not conflated US 182,671 with any of them.

Corroborating context (secondary source)

The Mid-Continent Railway Historical Society's Horton's Reclining Chairs page (midcontinent.org) identifies the inventor as Numon Norris Horton, M.D. (1838–1892), a Kansas City surgeon, and states he "in September, 1876, received the patent for the chair," crediting the Chicago & Alton with introducing chair cars featuring Horton's chairs in 1877. That secondary source lists a later Horton patent, US 208,907 (Oct 15, 1878), also titled Reclining Chair — consistent with, but not proof of, a continuation of the same line of work. This is hobbyist historical material, not a legal record.

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

Let me run more targeted searches across litigation databases.

Litigation Search Results: US Patent 182,671

Bottom line: No litigation is known, and none is legally possible today. No case — historical or modern — involving U.S. Patent No. 182,671 could be identified in any of the sources searched.

The patent itself (threshold issue)

Because this patent expired in 1893, its term ran out roughly 133 years ago. A U.S. patent can only be asserted during its enforceable term (plus the six-year damages lookback under 35 U.S.C. § 286). Accordingly:

• No pending or recent litigation can exist — there is no patent right to assert.
• No PTAB proceedings can exist — inter partes review, PGR, and covered-business-method review all require a patent that has not expired (see, e.g., 35 U.S.C. §§ 311, 321). Also, the AIA post-grant regime did not exist until 2012.
• Any litigation would have to be a 19th-century infringement action (1876–1893), which would not appear in the databases you directed me to (Unified Patents litigation caselist, PACER, CAFC). PACER's coverage is generally 1988-forward; the Court of Appeals for the Federal Circuit was created in 1982. Pre-1900 federal circuit court decisions are only partially digitized (e.g., Federal Reporter volumes, on law.resource.org / case.law).

What I searched, and what came back

I searched for the exact patent number "182671" / "182,671" combined with litigation terms, plus the Unified Patents caselist domain and CourtListener. Every hit was a non-match on a different identifier, which I did not treat as this patent:

Historical (non-litigation) context found

While no suit was located, a non-legal source confirms the patent was commercialized: the Mid-Continent Railway Historical Society's Horton's Reclining Chairs page records that the Chicago & Alton Railroad introduced chair cars featuring Dr. Horton's chairs in 1877, and that the Horton Reclining Chair Works was listed in the 1880 Kansas City city directory. Commercial success of that kind is often the predicate for infringement suits, but I found no record of any such suit for this patent.
Source: https://midcontinent.org/rollingstock/dictionary/hortonseats.htm

Caveats (per your instructions)

1. I did not auto-correct the number. I limited my analysis to 182671 and rejected all near-miss identifiers (e.g., the '671 application, WO 182671, other '671 patents).
2. My conclusion is absence of evidence, not proof of absence. Comprehensive pre-1900 federal case coverage is incomplete in the sources you named; a definitive check would require the Federal Cases reporter series, the Federal Reporter volumes 1876–1893, the Offensive/Decisions of the Commissioner of Patents (which published patent interferences and appeals), and N.N. Horton's probate/business records. I could not verify those archives exhaustively here.
3. I did not obtain a direct response from the Unified Patents portal query for this number; no matching entry surfaced in search results, consistent with the patent's 1893 expiry.

If you need a definitive negative: the correct next step is a manual review of Federal Reporter vols. 1–60 (1876–1893) and the Commissioner of Patents' Decisions volumes for that period, searching for "Horton" as patentee. I can pursue that if you authorize additional lookups.

Proceedings overview

Zero AIA trial proceedings on file. The USPTO Open Data Portal returns no IPR, PGR, or CBM petitions against US 182,671; my independent web searches for PTAB activity, Federal Circuit appeals, and litigation involving this patent ("182671" + IPR / "reclining chair" / Horton / Federal Circuit) returned nothing beyond an unrelated WO 2013/182671 biomass-enzyme publication that shares only the digits. The breakdown is therefore: 0 active, 0 invalidated, 0 sustained, 0 settled, 0 institution-denied. The defensive posture this gives a defendant is not "hardened patent" and not "claims are dead" — it is "no PTAB track record at all, and none is realistically obtainable," because this is an 1876 patent that expired in 1893 (Google Patents lists "Anticipated expiration 1893-09-26"). Absence of PTAB activity here is not the usual signal that "the patent is weak or under-asserted"; it is a chronological artifact.

No proceedings to report

There is no proceeding number to place at the top of this section, and I will not invent one. For completeness, the searches that came back empty:

• USPTO ODP AIA trial proceeding list for US 182,671 (the canonical structured block provided in this task).
• US 182671 patent PTAB IPR proceeding — returned only WO 2013/182671 (Alforex/Novozymes-type biomass enzyme application), a false-positive on the digits.
• "182671" IPR inter partes review "reclining chair" — no results.
• Numon N. Horton patent 182671 litigation Federal Circuit appeal — no results.

If you want to verify independently rather than rely on the ODP ingest, the three live sources are:

• PTAB E2E / PTAB Decisions: https://developer.uspto.gov/ptab-api/swagger-ui/index.html and https://www.uspto.gov/patents/patent-trial-and-appeal-board
• Patent Trial and Appeal Board End-to-End (E2E) system: https://e2e.uspto.gov/
• CourtListener (CAFC dockets + opinions): https://www.courtlistener.com/?q=%22182%2C671%22&type=o and https://www.courtlistener.com/?q=%22182671%22&court=cafc

Strategic summary

Claim status — nothing has been tested at the PTAB, because nothing can be. US 182,671 issued 1876-09-26 to Numon N. Horton, M.D., of Kansas City, Missouri, on an "Improvement in Reclining-Chairs," with 7 claims (the angular arms + head-rest; the bowed crank-lever F with uprights G, back E, arms H, pawl J and rack K; knuckle-jointed uprights G with hinged back E and arms H; back/arms/jointed uprights with stop Q; the combination with retracting lever M; the four-armed spider with crank-pivot bearings; and the leg-rest N with slotted-stem supporting-arm O and lever P). Google Patents records the anticipated expiration as 1893-09-26 — seventeen years from grant under the law of the era. Claims 1–7 are therefore UNTESTED at the PTAB and, more to the point, long expired. Do not characterize any of them as canceled or sustained.

Jurisdictional reality for a defendant. Three structural points matter more than any docket search:

1. PGR is unavailable by statute — post-grant review reaches only patents with an effective filing date on or after 2013-03-16 (AIA § 6(c)(2)(A)). This patent predates that by 137 years.
2. CBM is unavailable on subject matter — covered business method review was limited to financial-services/business-method claims. A mechanical car-seat recline mechanism is not a CBM, and the program sunset on 2020-09-16 in any event.
3. IPR is theoretically available but practically moot. An IPR petition must be filed by a person who is not the owner and who has been served with a complaint or charged with infringement (§ 311(a), § 315(b) one-year bar), and the Board may consider whether the patent is expired. Where a patent expired decades ago, there is no live exclusionary right to review and no ongoing royalty base; any IPR would be an academic exercise about historical claims. I have not found a single instance of an AIA trial against a pre-1900 patent being instituted, and I would not advise spending petition fees on one.

Estoppel landscape — no § 315(e) estoppel attaches to anyone. Because no IPR/PGR was instituted, no petitioner (or privy, or real party in interest) carries any estoppel from § 315(e)(2). That cuts both ways and is essentially irrelevant here: the absence of estoppel does not create an available invalidity defense, because the patent itself carries no enforceable term. If someone is asserting US 182,671 today — a demand letter, a cease-and-desist, a licensing shakedown citing "US Patent 182,671" — the correct response is not an IPR. It is a § 282 / Rule 12 motion pointing to the 1893 expiration, plus a 35 U.S.C. § 292 false-marking posture if "Patent" or "Pat. 182,671" is being marked on a product, and potentially state-law/UCL exposure for the assertion itself.

Pattern signals. None to report. No petitioner has filed multiple IPRs, there is no patent-owner PTAB appeal history, and there is no defensive aggregator (Unified Patents, RPX, LOT, etc.) in the chain — aggregators target asserted patents with living claims, and this one has neither. The only third-party traffic on this patent number appears in Google Patents' "Similar Documents" list (e.g., US 141,318; US 142,039; US 242,733; US 234,041), which reflects classification co-occurrence under A47C1/02 and A47C1/036–1/037, not adversarial activity.

Recommended next steps

• If you are a defendant facing an assertion of US 182,671: the patent has no invalidated claims and no FWD to link to — but you do not need one. Pull the Google Patents record showing "Anticipated expiration 1893-09-26" (https://patents.google.com/patent/[US182671](/patent/US182671)/en) and pair it with the grant date of 1876-09-26. There is no live claim scope to infringe. Do not file an IPR; do not cite an FWD that does not exist.
• If you are evaluating the patent as prior art (the realistic modern use): US 182,671 is citable as a printed publication and as § 102 prior art for its 1876 disclosure date, and the classifications it sits in (A47C1/02, A47C1/031, A47C1/036, A47C1/037, B60N2/20) make it relevant to recliner/head-rest/leg-rest coupling art. Its PTAB history — or lack thereof — is irrelevant to its prior-art value.
• If you are monitoring for future activity: there is nothing to milestone. No institution-decision deadline, no 1-year trial clock, no oral hearing, no FWD due date. Any future filing would be the first of its kind, and I would flag it as extraordinary if it appeared.
• Verification: the PTAB E2E system (https://e2e.uspto.gov/) and the PTAB API (https://developer.uspto.gov/ptab-api/swagger-ui/index.html) should both return empty for this patent number. If a search engine surfaces "US182671A" as a publication number, note that this is Google Patents' normalized form of the 1876 grant — it maps to US 182,671, not to a separate document, and it is not an AIA-trial-related identifier.

Confidence note. I am highly confident there are no AIA trial proceedings on US 182,671, based on the ODP structured block plus the independent searches above. I cannot rule out a state-court or pre-AIA proceeding from the 1870s–1890s (nineteenth-century equity suits would not appear in PTAB E2E or CourtListener), and I have not attempted an archival search of that material — if that history matters to you, say so and I will treat it as a separate research task rather than assume it is empty.

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

Assignment & Ownership Analysis — US Patent 182,671

Headline finding: there is no recorded assignment chain. The USPTO Patent Assignment Search / Assignment Center shows no recorded assignment, security interest, merger, name change, license, or release for US 182,671 — and the reason is structural, not evidentiary: the Assignment Center backfile covers recordations from August 1980 forward, and this patent's term expired 1893-09-26.

Two independent confirmations:

Instruction conflict flagged: the task says to "stop after this section" when Assignment Center has no records, but the same task mandates a Verdict section with exactly one enumerated choice. I have resolved this by stating the null result plainly first, then continuing with the remaining sections marked not present / insufficient data rather than omitting the required verdict. No reel/frame numbers appear anywhere below because none exist to cite.

Inventors

• Single-inventor patent — there are no co-inventors, so the "all inventors departed the assignee within 12 months" pattern is structurally inapplicable.
• The closest thing to a corporate affiliation is his railroad-surgeon practice, which explains the field of invention (railroad car seating) but does not evidence employment by, or assignment to, any railroad. I found no evidence he assigned to the Chicago & Alton or any other carrier.
• Background per Mid-Continent Railway Historical Society: born Genesee County, Michigan; University of Michigan / College of Physicians and Surgeons (NYC), graduated 1862; Union Army assistant surgeon (6th Division, Army of Tennessee; 8th Regiment Louisiana Volunteers of African Descent; 47th U.S. Colored Infantry); practiced in Ft. Scott, Kansas ~8 years, then Kansas City from ~1873. Source: https://midcontinent.org/rollingstock/dictionary/hortonseats.htm
• He died 1892-02-10, roughly 19 months before the patent expired (1893-09-26). Any residual title would have passed through his estate/heirs; no recordation of any such transfer was found online.

Original assignee

None. US 182,671 issued to Numon N. Horton, M.D., individually. The printed specification contains no "assignor to" recital and no assignment was recorded at issue. Under the practice of the era this is unremarkable and is the default: the 1836/1870 Act framework granted to the inventor, with recordation of assignments optional (though encouraged) — and pre-1980 recordings live only on USPTO microfilm, not in the online Assignment Center.

Commercial "operating entity" (contractual, not recorded): A Horton Reclining Chair Works, with an office in the old Union Station, appears in the 1880 Kansas City, Missouri city directory. In 1877 the Chicago & Alton Railroad introduced chair cars fitted with Dr. Horton's chairs, and built six more three years later. Whether the Chair Works was a Horton-owned sole proprietorship, a licensee manufacturer, or a marketing vehicle is not determinable from the sources I reached — no corporate registration, charter, or assignment document surfaced.

Assignment timeline

No recorded assignments exist for US 182,671. Stated plainly: the USPTO Assignment Center returns nothing, and Google Patents' legal-events feed lists no assignment, license, security agreement, merger, name change, or release. There is therefore no reel/frame to report, no assignor, no assignee, and no correspondent of record — I will not manufacture any.

What can be dated is the commercial history of the invention, which is not the same as recorded title:

Caveat on completeness (important): the Assignment Center's August 1980 coverage floor means this analysis can only prove a negative for post-1980 recordations. A pre-1893 assignment — e.g. Horton to the Chicago & Alton, or a license to a car builder — could exist on USPTO microfilm reels predating August 1980 or in Jackson County, Missouri deed/probate records, and would not appear in any online search I can run. Historical assignment records for the 1870s–1890s are also absent from Google Patents' legal-events data as a rule. Treat "no assignments" as the online record is empty, not as a certified negative for the 19th century.

Timeline diagram

timeline
    title Ownership of US 182671
    1876 : Filed by Numon N Horton MD
         : Patent granted to Horton alone
    1877 : Horton chairs placed in service
    1880 : Horton Reclining Chair Works listed
    1892 : Horton dies in Kansas City
    1893 : Patent term expires
    1980 : USPTO online assignment records begin
         : No recorded assignment for 182671

NPE / troll-pattern signals

Every signal is marked against the specific reel/frame and date evidence — of which there is none in this chain.

Pattern note (not a signal): the only co-occurrence data attaching to this number is Google Patents' "Similar Documents" list (US 141,318; US 142,039; US 234,041; US 242,733; US 271,512, etc.), which reflects shared classification under A47C1/02 and A47C1/036–1/037. That is classification proximity, not adversarial or transactional activity, and does not support any NPE inference.

Verdict

Insufficient data (no records, or only the original assignment).

US 182,671 was issued 1876-09-26 to Numon N. Horton, M.D., individually and with no assignee on its face; the USPTO Assignment Center — whose coverage begins August 1980 — contains no recordation of any kind for this number, and Google Patents' legal-events feed confirms this by listing only grant, publication, anticipated expiration, and "Expired – Lifetime," with zero assignment events. Because there is no reel/frame, no assignor, no assignee, and no correspondent to evaluate, every NPE indicator above is not present on an empty record rather than affirmatively negated — which is precisely the "insufficient data" case, not a "non-asserting" or "operating-company" finding. The patent expired 1893-09-26, 19 months after the inventor's death, so no modern enforcement, licensing, or aggregation outcome is legally possible.

Verification links:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search patent number 182671)
• USPTO Patent Assignment Search: https://assignment.uspto.gov/patent/index.html
• Google Patents legal events: https://patents.google.com/patent/[US182671](/patent/US182671)/en
• Corroborating non-legal history: https://midcontinent.org/rollingstock/dictionary/hortonseats.htm

Confidence: high that the online assignment record is empty; not high that no 19th-century assignment ever existed. A definitive pre-1980 answer requires the USPTO microfilm assignment reels, Jackson County, Missouri deed and probate records, and the Patent Office's own 1876–1893 assignment copies — none of which are searchable online through the sources available here. I have not fabricated a reel/frame or correspondent, and I decline to infer NPE status from the absence of evidence.

One source-consistency note for the file: the Mid-Continent table of Horton's patents omits US 327,686, "Surgeon's or Reclining Chair," granted 1885-10-06 to Numon N. Horton of Kansas City (seen in the USPTO printed copy), which sits in the same classification neighborhood and is a stronger companion reference to US 182,671 than several entries the table does list. That is a gap in the secondary source, not a conflict with the authoritative patent text.

I'll research prior art for US 182,671. Let me start with the authoritative sources.

Let me dig deeper into the citation record and contemporaneous prior art.

The direct citation record is coming up empty, which is itself significant. Let me verify what Google Patents shows and probe contemporaneous art.

Prior Art Analysis — US Patent 182,671

Threshold finding: there is no citation record for this patent

I could not find any patent citation for US 182,671 — and there almost certainly is none to find. This is not a search failure; it is a structural feature of an 1876 patent. Three independent reasons:

1. The duty of disclosure and citation practice did not yet exist. The "References Cited" / "(56)" section that appears on every modern patent is a product of 20th-century practice (the duty of candor under 37 C.F.R. § 1.56 dates to 1977; printed examiner citations became routine only after the 1940s–50s). An 1876 specification has no citation block, no references-cited list, and no antecedent-art statements. The Google Patents record supplied as the authoritative source confirms this: it has no "Citations" and no "Cited By" section at all — only a "Similar Documents" list.
2. "Similar Documents" is not citational prior art. The list on the Google Patents record (US 799128, US 242733, US 141318, US 142039, US 140868, US 234041, etc.) is a classification/embedding-similarity list (the patent sits in A47C1/02, A47C1/031, A47C1/036, A47C1/037, B60N2/20). It is not a record of what the 1876 examiner considered or what the patentee disclosed. Treating it as a citation record would be a category error.
3. Pre-AIA § 102 prior art was found by examiners without printed citation. 1870s examiners worked from the classified shoe, the Official Gazette, and foreign patents. Their rejections survive, if at all, in the abandoned-file record and the Decisions of the Commissioner of Patents — not in the printed patent.

Therefore: the honest answer to "look at each patent citation for 182671" is that the set is empty. I will not manufacture citations. Below I substitute the only defensible analysis: the temporally qualifying prior art (published before the April 19, 1876 filing date) that a § 102 analysis would actually reach, plus an element-by-element anticipation screen against the seven claims.

Governing law for the analysis

US 182,671 was filed April 19, 1876 and granted September 26, 1876. The controlling statute was R.S. § 4886 (Patent Act of 1870, § 24), which barred a patent where the invention had been:

• patented or described in a printed publication in this or any foreign country before the invention thereof; or
• in public use or on sale for more than two years before the application; or
• patented or described in a printed publication more than two years before the application.

I frame the analysis in modern 35 U.S.C. § 102 terms as you requested, but note the date mapping: a pre-1876 publication is § 102(a)-type art; a publication or use more than two years before April 19, 1876 (i.e., before April 19, 1874) is § 102(b)-type art. US 182,671 received no benefit claim and is not related by continuation to anything, so its critical date is unambiguously April 19, 1876 (filing) / its 1876 invention date.

The only temporally qualifying references on the record

Of the ~25 documents in the Google Patents "Similar Documents" list, only three pre-date the April 19, 1876 filing date. These are the only listed documents that can function as § 102 prior art against US 182,671 (all others post-date it and are, at most, evidence of the art's subsequent development):

What I can and cannot say about A–C

I must be explicit about an evidence limit. I retrieved their numbers, dates, and titles from the Google Patents record, and their dates establish they are temporally eligible. I did not retrieve or read their full specifications, and I will not assert what they disclose. A defensible anticipation call under § 102 requires element-by-element identity, which I cannot certify from titles alone. What follows is a screening analysis flagged as such.

• US 141,318 A — "Improvement in reclining-chairs" (1873-07-29). Most relevant title on the list. A pre-1876 reclining-chair patent is the natural § 102 candidate against claim 2 (the bow-shaped crank-lever F with uprights G, back E, arms H, pawl J, rack K) and claim 5 (adding retracting lever M), since those are the claims that read on the recline-and-lock mechanism itself rather than on the car-seat swivel environment. Confidence that it discloses a bowed/crank pivot lever with pawl-and-rack: low-to-moderate, unverified. This is the single reference I would pull first.
• US 142,039 A — "Improvement in self-reclining chairs" (1873-08-19). "Self-reclining" implies weight-actuated recline, a different mechanism from Horton's lever-and-pawl. Relevant to the general recline mechanism (§ 102 against claims 2/5) only insofar as it discloses a back-adjustment lock. Confidence: low, unverified.
• US 140,868 A — "Improvement in invalid-chairs" (1873-07-15). Invalid chairs of this era commonly carried adjustable backs and leg rests. Potentially relevant to claim 1 (head-rest on arms hinged to the back), claim 3 (hinged back for folding), and claim 7 (leg-rest). Confidence: low, unverified. Note Horton himself conceded in the specification that "some portions of my invention are equally applicable to invalid and easy chairs for house use" — an admission that the invalid-chair art was adjacent.

No listed reference is a plausible standalone anticipation of claim 6 (the four-armed spider with crank-pivot bearings) or claim 4 (the stop Q retracted by tipping the back forward) — those elements are keyed to the railroad-car swivel problem, which these three titles do not suggest.

Non-patent prior art leads (higher-confidence as art, unverified as disclosure)

Element-by-element anticipation screen against the seven claims

Framing each claim against the only date-eligible art identified. "No candidate identified" means exactly that — I found no reference on this record that reads on the element, not that none exists.

Net: three of the seven claims (1, 3, 4, and arguably 6 — i.e., the head-rest automation, the forward-tipping provision, the stop-release interlock, and the spider) have no anticipation candidate at all on this record, consistent with the patent's own claim of novelty resting on the car-seat-reversal problem rather than on reclining per se.

Post-dating references — expressly NOT prior art

For completeness and to prevent conflation, the following appear on the record but post-date US 182,671 and cannot be § 102 art against it. They are useful only for tracing the art's later development or for reading Horton's claims in context:

• US 208,907 (1878-10-15), "Reclining Chair" — Horton's own later patent (per the Mid-Continent Railway Historical Society source). Same inventor; cannot be prior art.
• US 234,041 (1880-11-02), "Leg-rest and reclining-chair" — the nearest later art on claim 7.
• US 242,733 (1881-06-07), "Reclining-chair"; US 236,368 (1881-01-04), "Reclining or invalid chair"; US 271512 (1883); US 320265 (1885); US 337521 (1886); US 551968 (1895); US 795535 / US 799128 (1905); US 813799 (1906); US 786308 (1905); US 1125167 (1915); US 2674303 (1954).
• US 267,748 (1882) — the revolving double car chair located in search (ratchet-bar B³, ratchet-bar lever, foot-rest lever under a rotating base-plate, head-rest mechanism per Fig. 12). Genuinely close in subject matter to claims 2, 4, 6, and 7, but issued six years after 182,671. It is a strong candidate as later art, not prior art.

Confidence and caveats

• High confidence that US 182,671 has no patent-citation record: the authoritative Google Patents text contains no Citations or Cited By block, and 1876 practice created none. This is a firm conclusion from the record supplied.
• High confidence that only US 140,868, US 141,318, and US 142,039 (all 1873) are date-eligible among the listed documents, and that everything else listed post-dates the patent.
• Low confidence on the actual disclosures of those three 1873 patents. I did not retrieve their specifications, and I have labeled every anticipation statement as potential/unverified rather than asserting it. Anyone relying on this for a validity opinion must pull the full text and drawings of at least US 141,318 and US 140,868.
• Do not treat the "Similar Documents" list as prior art. It is a similarity artifact; presenting it as a citation record would misstate the patent's prosecution history.
• The Allen tilting-seat patent is a lead only. I have the Allen v. Koechling opinion discussion (120 Mass.) but not the patent number or date, so I cannot cite it as a verified reference.
• A definitive § 102 search would require the pre-April-1876 USPTO classified shoe (Class 297 antecedents), the Official Gazette 1860–1876, the Decisions of the Commissioner of Patents for interferences, British Abridgements of Specifications (Class 52/other, "chairs and seats") through 1876, and the 1876 abandoned-file record if it survives. I could not access those archives here, and my search budget for this task is exhausted. I flag the gap rather than paper over it.

One contradiction to note with the earlier sections: the earlier litigation section correctly identified Archer v. Arnd, 31 F. 475 (E.D. Mo. 1887) as a reclining-chair case from the patentee's own district (E.D. Mo.). Its patent was Leidecker 102,688 (reissue 7,820) — not Horton's 182,671. That is consistent with, not contrary to, the finding here: even the contemporaneous St. Louis reclining-chair litigation did not involve this patent.

I'll research the prior-art references listed on this patent's page before running the § 103 analysis.

Obviousness Analysis — US Patent 182,671 (35 U.S.C. § 103)

Reference: US 182,671, Improvement in Reclining-Chairs, Numon N. Horton, M.D. (Kansas City, Mo.), filed Apr. 19, 1876, granted Sept. 26, 1876, 7 claims, expired Sept. 26, 1893.

1. Two threshold findings that must frame everything below

(a) Section 103 did not exist when this patent was granted. 35 U.S.C. § 103 was enacted by the Patent Act of 1952, 76 years after this patent issued. The non-obviousness condition in 1876 was a judicial doctrine — Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851) (patentable only if the improvement required "more ingenuity and skill … than were possessed by an ordinary mechanic acquainted with the business"). Any "§ 103 analysis" of this patent is therefore counterfactual: I apply § 103 machinery (Graham factors, motivation to combine, KSR-type reasoning) as a modern analyst's lens, but the historically correct legal test was Hotchkiss, and the Hotchkiss "ordinary mechanic" standard is slightly more forgiving to the patentee than modern § 103 in one respect and harder in another (it had no secondary-considerations apparatus until later case law developed it).

(b) The patent has no live claim scope. It expired in 1893. Nothing below produces an invalidity judgment that matters to anyone's freedom to operate. The value of this exercise is (i) assessing US 182,671's strength as § 102/§ 103 prior art in modern cases (its realistic modern use, per the earlier sections), and (ii) historical interest.

Not prior art on this page: Google's "Prior art keywords" block (seat, rest, chair, lever, reclining) is machine-generated topical indexing, not evidence of any reference. Do not cite it as prior art. I treat only the "Similar Documents" list as candidate art.

2. Which "Similar Documents" are actually available as § 103 prior art

Prior art must predate the invention (here, presumed the Apr. 19, 1876 filing date). The page's Similar Documents list is dominated by post-dating documents, which are categorically unavailable:

Supplementary pre-1876 art I located independently (not on this page's list; flagged as such and usable only as secondary teaching if a court/analyst accepts them):

• US 137,069 — Goss, Improvement in Reclining-Chairs, Mar. 25, 1873 (PDF) — hinged back + rods + double rack for infinite-inclination locking.
• US 141,121 — Collins, Improved Reclining-Chair, July 22, 1873 (PDF) — back pivoted to seat, notched bars to arms, occupant-accessible handles, and a pedestal globe-joint for changing the chair's facing direction.
• Hammitt, US 9,449 (1852), cited in the Schliephacke dissent as evidence that "links and pivots … have been used by designers of reclining chairs at least since 1852" (opinion) — useful only as state-of-the-art background.

Caveat (important): searches for US 140,868 and US 141,318 returned no specification text, and I did not retrieve Clough or Yengling texts as prior art for the reasons above. I will not assert what those two references disclose.

3. Level of ordinary skill and the field

A person having ordinary skill in this art (1876) is a practicing chair and car-seat mechanic/designer — not an engineer — familiar with: hinge and rule ("knuckle") joints; rack-and-pawl and notched-bar locks for adjustable seat backs; cast-iron base plates, pedestals, and globe joints for swivel seating; spiral-spring counterbalancing; and folding/ hinged leg-rests and head-rests on invalid and barber chairs. The Schliephacke record establishes the field was crowded — "over one hundred and fifty patents in the field," recliner patents "as early as 1852" — which under KSR supports a finding that improvement here was ordinary, not inventive.

4. Claim-by-claim obviousness map

Corroboration, not prior art: Yengling US 242,733 (1881) discloses "combining with a hinged head-rest rods or tubes … for the purpose of raising the head-rest automatically as the back approaches a recumbent position" and a lever/bolt-and-segment lock — structurally very close to claims 1, 5 and 7. Clough US 228,869 (1880) discloses a sliding seat, hinged back, and spring-pressed automatic foot-rest "peculiarly well adapted for … railroad-cars." Both post-date Horton by 4–5 years and cannot be used for § 103 combination. They are relevant only to secondary considerations: they show that Horton's objectives were recognized and pursued in the field, which undercuts any argument that the art lacked a reason to make these combinations. Conversely, if the patentee wanted to argue non-obviousness, these later patents are also available as evidence that others were still working the same problem.

5. Reconstruction hazard: 19th-century claim construction

These claims close with "in the manner and for the purpose set forth" / "substantially as set forth" and are written in the pre-1952 means-plus-description register. Nineteenth-century courts construed such claims narrowly and in light of the specification (see the Allen tilting-seat construction discussed in the Massachusetts report at case.law: the patentee was "not limited to the particular form and position of the several parts" only where the claim was drafted in general terms). Claims 4, 6 and 7 in particular are tied to the exact described structure — the four-armed spider, the slotted stem, the specific back-to-stop linkage. A § 103 attack that reads these broadly will fail on claim construction before it reaches obviousness. Any serious invalidity theory must map Goss/Collins/Niderkorn onto the narrow, as-construed structure, which I cannot fully do without the US 140,868 and US 141,318 texts.

6. Conclusion

• A colorable § 103 case exists against claims 1, 2, 3 and 5, built on Goss US 137,069 + Collins US 141,121 (+ Niderkorn US 142,039). The bowed crank-lever, the occupant-reachable release lever, and the forward-tipping jointed standard are each predictable mechanical expedients or mere changes of form over what these references disclose, and the crowdedness of the 1852–1876 recliner art supplies the KSR "design incentive" and "predictable solution" rationales.
• Claims 4 (linked swivel-stop release) and 6 (spider with integral crank-pivot bearings) are the most defensible, because the record I can reach shows the components but not the specific cooperating structure. Claim 7 sits in between.
• Caveat, stated plainly: my conclusion is limited by (i) inability to retrieve US 140,868 and US 141,318 — the only two pre-1876 references the patent's own page lists; (ii) the anachronism of applying § 103 to an 1876 grant; and (iii) the fact that the patent expired in 1893, so this analysis has prior-art and historical value only, not enforceability consequences. If you want a defensible invalidity position, the next step is to pull the full specifications of US 140,868 and US 141,318 (and, for background, Hammitt US 9,449) from Google Patents/patentimages and re-run claims 1, 4, 6 and 7 against them.

Sources: US182671A · US137069 · US141121 · US142039 · US242733 · US228869 · Schliephacke appeal dissent · Allen construction, Mass. reports