US 169997

I'll search for the specific patent number and related docket information.

Let me run a few more targeted searches to check for any docket or USPTO records under this exact number.

Let me do two final checks for any litigation/docket record tied to this number.

Search scope and reliability caveat

I searched for the literal identifier 169997 against Google Patents' full-text record (fetched 2026‑09‑24), general web indexes, USPTO/PatentCenter-facing results, and CAFC 2026 docket material surfaced through those searches.

Two things must be stated up front:

1. "169997" is not a unique identifier. The same six digits appear in unrelated records, none of which are the patent at issue: WO 2022/169997 A1 (Genentech, "Lactams as Cbl‑B inhibitors," PCT/US2022/015152), Canadian application 169997 cited as foreign priority in US D878,427 S (Canadian Tire, blower nozzle), and Japanese application numbers in unrelated search reports. Per your instruction, I did not treat any of these as the same document. Note also that U.S. Patent No. 10,169,987 (Rideshare Displays v. Lyft, No. 25‑1132) is a different number and is not a match.
2. No CAFC 2026 docket record was found for patent 169997. I found no Federal Circuit appeal, IPR, or district-court docket naming this patent. I cannot verify a negative with certainty, but I have no authoritative basis to report any litigation activity. The patent is a U.S. patent from 1875 and its term expired in the 19th century; there is no plausible enforcement docket.

Bibliographic data (authoritative source: patent record)

One discrepancy worth flagging: the reference list of later patent US 2,883,248 (Hoppe, high‑low extension table) cites this patent as "169,997 Jones Nov. 18, 1875," whereas the patent's own front matter gives November 16, 1875. I am reporting the later citation literally rather than correcting it; the November 16 date is the one on the document itself.

Abstract

There is no abstract. U.S. patents of this era were not required to include one, and none appears in the record. Google Patents supplies a machine-extracted "Definitions" key in place of an abstract:

A represents the bars or links of the lazytongs frame; B, legs to the same; C, end pieces of the table-top, connected to ends of frame at D; E, removable parts of the table; F, slotted bar, and G, clamp-screw, forming an adjustable clamp for fastening the frame at any degree of extension.

(The OCR renders "B" as "13" in places; I am reading the letter designated in the specification literally as B, with that OCR uncertainty noted.)

Independent claims — plain-language overview

The patent contains exactly one claim, so that single claim is the sole independent claim. There are no dependent claims.

Claim 1 (verbatim): "The combination, with lazy‑tongs A A, pivoted to ends C C, of the centrally‑placed clamp G and slotted bar F, as and for the purpose specified."

Plain language: The claim is a combination claim. It covers a table whose top is carried on a pantograph ("lazy‑tongs") frame — the lettered bars A A — that is pivoted to the table's end pieces C C, in combination with a centrally located locking clamp made up of a slotted bar F and a clamp screw G. The clamp is what holds the frame fixed at any chosen degree of extension, so the table can be spread open and locked at a selected width.

Two practical observations about this claim:

• Breadth is narrow by construction. It is a two‑element combination: (i) the lazy‑tongs frame pivoted to the tabletop end pieces and (ii) the central slotted‑bar/clamp‑screw locking mechanism. A table lacking either element — e.g., a pantograph table with no central clamp — would not fall within the claim.
• It closes with functional language ("as and for the purpose specified"), which ties the claimed structure to the specification's described purpose of holding the frame at any degree of extension. This is characteristic of 1875-era claim drafting and it limits the claim's clarity by modern § 112 standards, though it was conventional at the time.

The specification's stated commercial advantage — that the frame "can be constructed in this form much cheaper than in the ordinary tongued and grooved sliding sections, and it is easier to adjust" — is a specification statement, not a claim limitation.

Forward citations (documents citing this patent)

• US 2,883,248 A — Hoppe, High-low extension table construction (1959)
• US 2,965,425 A — Grinsell, Portable chiropractic table (1960)

Both were listed as third‑party citations rather than examiner citations.

Explicit uncertainties

• Assignee: I found no assignee. I cannot confirm an assignment or chain of title, only that none is recorded on the face of the document.
• Abstract: None exists in the source; anything presented elsewhere as an "abstract" for this patent is synthesized, not original.
• CAFC 2026 dockets: No record found. This is a reported absence of evidence, not proof that no filing exists; CAFC docket-search coverage for pre‑20th‑century expired patents would in any event be expected to be nil.
• OCR artifacts: The specification extract is partially garbled by OCR (e.g., "aim." for the drawing section reference, "13" for the letter B, "anv" for "any"). Where the OCR obscures a character, I have flagged it rather than silently normalizing it.

I'll search for litigation involving US patent 169997.

Let me run additional targeted searches to confirm.

Answer: No litigation involving US Patent 169,997 is known.

I searched for litigation specifically on US Patent 169,997 ("Improvement in extension-tables," granted November 16, 1875, to Ansel D. Jones and Samuel L. Jones, of Kirksville, Kentucky; application filed October 8, 1875). I found no federal district court case, CAFC appeal, ITC investigation, or PTAB proceeding in which US 169,997 was asserted or challenged.

Litigation summary table

Search methodology and what I actually found

Queries run: US patent 169997 litigation; "169997" patent lawsuit plaintiff defendant; "169,997" extension table Jones patent infringement suit; Ansel D. Jones Samuel L. Jones extension table patent 169997 lawsuit court; site:portal.unifiedpatents.com "169997"; courtlistener "169997" patent case.

Every hit was a false positive from a different identifier — none involved US Patent 169,997:

Why absence of litigation is the expected result — and the honest caveats

• The patent is long expired. Google Patents records an "anticipated expiration" of 1892‑11‑16, and its legal status as "Expired – Lifetime." A patent that expired in 1892 cannot be asserted in any modern case. Any litigation would have had to occur roughly 1875–1892.
• Pre-1900 litigation is not in the databases you named. The Unified Patents litigation portal, PACER, and the CAFC docket cover modern electronic records (PACER in practice begins in the late 1980s–1990s; the Federal Circuit was created in 1982). Nineteenth-century circuit court and Supreme Court patent cases are generally available only through sources such as Federal Cases, Offizin/Cases Decided in the U.S. Courts of Appeals, or archival collections — not through these tools. So my conclusion is "no litigation found in the sources searched," not a positive assertion that no suit was ever filed between 1875 and 1892.
• I could not verify via full-text historical corpora. I did not have direct access to a full-text search of 19th-century federal reporter volumes, so I cannot rule out an unreported or unrecovered 1870s–1880s action.
• Two of my tool calls returned empty or were truncated (site:portal.unifiedpatents.com "169997" returned nothing; courtlistener "169997" patent case hit the step limit), so the Unified Patents portal and CourtListener were not exhaustively queried.

Recommendation for a definitive answer

If you need a conclusive historical check, I'd suggest running the number through: (1) the Unified Patents litigation caselist (https://portal.unifiedpatents.com/litigation/caselist) with an exact-party or exact-patent filter rather than a bare numeric string; (2) CourtListener's RECAP and its Federal Cases / early-reporter collection; (3) HeinOnline or LLMC Digital full-text searches of 19th-century federal reporters for "169,997" or for the inventors' names, Jones and the "extension-table" art; and (4) Google Books / HathiTrust for contemporary legal gazettes. Note that a bare numeric search will keep returning the unrelated 8,251,997 / JP 2005‑169997 / WO 2022/169997 hits, so the query must be anchored to "U.S. Patent No. 169,997" or the patentees' names.

Bottom line: Based on the sources searched, there is no known litigation involving US Patent 169,997. The only '997-patent litigation that surfaces in these databases is the modern Warsaw Orthopedic/NuVasive dispute over a different patent, US 8,251,997, which should not be confused with it.

I'll verify the structured PTAB data against public sources before writing up.

Proceedings overview

Total AIA trial proceedings on US Patent 169,997: ZERO. The structured PTAB block is the canonical source (USPTO Open Data Portal), and it returns no AIA trial proceedings — no IPRs, no PGRs, no CBMs — for this patent. Breakdown by status is therefore: active 0 / claims invalidated 0 / claims sustained 0 / settled 0 / institution denied 0. For a defendant, the defensive posture is neither "hardened by surviving IPRs" nor "claims canceled by the Board" — it is "the Board has never touched this patent, and the Board legally cannot touch it." US 169,997 issued 1875-11-16 with a 17-year term and carried an anticipated expiration of 1892-11-16; the AIA trial regime authorizes IPR only for petitions filed on or after 2012-09-16, roughly 120 years after this patent died. There is no claim-level PTAB outcome to analyze because no AIA proceeding has ever been or could ever be instituted.

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No per-proceeding entries follow — and here is the honest reason

I will not manufacture proceeding numbers to fill out the requested per-proceeding template. The structured block supplies none, and no search of public PTAB/CAFC sources surfaced any. Because the required template presupposes proceedings that do not exist, I am substituting the two things that are actually useful to defense counsel: (a) the legal bar that makes a PTAB challenge here impossible, and (b) an explicit trap table of look-alike proceedings that will appear if anyone runs a naive numeric search — precisely the confusion that already surfaced in the litigation section of this analysis.

Why zero is the only possible number

Near-miss "proceedings" that are NOT US 169,997 — do not cite these as its PTAB history

This table matters because the same '997 collision that produced false-positive litigation hits will produce false-positive PTAB hits:

Flagged contradiction to avoid: the previously generated litigation section correctly identified US 8,251,997 / Warsaw Orthopedic v. NuVasive as a false positive. The PTAB search reproduces that same false positive almost verbatim. If any downstream section of this analysis cites "IPR2013‑00206 on the '997 patent" in connection with this patent, that is an error and should be corrected — the FWD's own caption reads "Patent 8,251,997 B2."

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Strategic summary

Claim status: the patent has exactly one claim, and it has never been tested by the Board. The specification's claim is short: "[t]he combination, with lazy-tongs A A, pivoted to ends C C, of the centrally-placed clamp G and slotted bar F as and for the purpose specified." It is a single, unaudited, unamended, un-canceled claim. There are no canceled claims to point to in a demand-letter response, no surviving claims to design around, and no PTAB claim-construction record to borrow. The only claim-level event in this patent's forensic history is its own 1892-11-16 expiration, which terminated all enforceable rights.

Estoppel landscape: § 315(e)(2) estoppel is a non-issue. Because no IPR was ever instituted, no petitioner and no privy is estopped from anything — but that cuts both ways and is worthless to a defendant, because there is also no claim to defend against. Conversely, there is no IPR-based invalidity shield to borrow from another party's prior challenge: a defendant cannot piggyback on a favorable FWD, and does not need to. Any modern "infringement theory" on US 169,997 fails at the threshold question of an unexpired term, not at the patentability question. The prior-art cupboard is, for the record, wide open — no ground has been raised, adjudicated, or estopped — but it is not the defense to lead with.

Pattern signals: none, and none are possible. No serial petitioner, because there were no petitions. No patent-owner appeal to the Federal Circuit, because the Federal Circuit was created in 1982, ninety years after expiration. No defensive aggregator (Unified Patents, RPX, etc.) in the chain, because defensive aggregators defend against asserted patents, and a patent that expired in 1892 is not asserted. If a client reports receiving a demand letter citing "US 169,997," the correct inference is not "troll" but number confusion — with US 8,251,997, a reissue/continuation numbering variant, or a foreign/PCT document such as WO 2022/169997 A1.

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Recommended next steps

1. If you are a defendant: the patent has no PTAB history and cannot acquire one. Confirm the asserted number in writing before doing anything else, because there are no PTAB proceedings whose FWD you could link to and quote. The absence of Board activity here is not the usual "well-asserted patents eventually attract IPRs" signal — it is a chronological impossibility, and that chronological impossibility is itself the cleanest possible defense.
2. Verify the number first, then re-run the analysis on the real target. The instant — and near-certain — failure mode is the '997 collision. If the demand letter's real target is US 8,251,997, the PTAB picture is completely different and must be sourced fresh: IPR2013‑00206 (instituted 2013-09-23, claims 17–23 held unpatentable, claims 9–16 and 24–30 sustained) plus the related petition in the IPR2013‑00208 family, with CAFC appeal activity in the Warsaw/NuVasive dispute. Run the corrected number through the USPTO PTAB E2E / Public Information proceeding search (https://ptacts.uspto.gov/ptacts/) and cross-check on CourtListener (https://www.courtlistener.com/) using the patent number, not a bare 169997 string.
3. Communicate the negative finding as a finding, not a gap. State it as: "Searched the USPTO ODP structured PTAB data and public PTAB/CAFC sources on 2026-09-30; zero AIA trial proceedings exist for US 169,997; the patent expired 1892-11-16 and is categorically ineligible for IPR/PGR/CBM." A "no results" answer here is conclusive in a way that an ordinary empty litigation search is not.
4. If the goal is historical scholarship rather than defense: AIA trials are the wrong instrument entirely. The 1875–1892 window would be documented in Federal Cases, early U.S. circuit reporters, and the Commissioner of Patents' annual reports, searchable via HeinOnline, LLMC Digital, HathiTrust, or Google Books — with queries anchored to "U.S. Patent No. 169,997" or the patentees' names (Ansel D. Jones, Samuel L. Jones, Kirksville, Kentucky), never to the bare number.

Bottom line: There are no AIA trial proceedings to report, and I have deliberately reported none rather than backfilling the rubric with unrelated matters. US Patent 169,997 has zero PTAB history; its single claim was never challenged and never adjudicated because the patent expired on 1892-11-16, long before the PTAB existed. Any document that appears to show "the '997 patent" in an IPR almost certainly concerns US 8,251,997 — verify the full number before relying on it.

I'll verify the assignment record for this patent before reconstructing the chain.

Scope note before the findings

I attempted to query the USPTO Assignment Center directly. Both the Assignment Center (https://assignmentcenter.uspto.gov/) and the legacy Assignment Search (https://assignment.uspto.gov/patent/index.html) are interactive query applications; I could not execute a live patent-number query against them with the tools available, and no indexed web copy of an assignment record for this patent surfaced in search. What I can state authoritatively comes from the patent record itself, which I re-checked: the Google Patents legal-events feed for US169997A contains exactly three events — application granted (1875‑11‑16), publication of US169997A (1875‑11‑16), and anticipated expiration (1892‑11‑16). No assignment event of any kind appears. See https://patents.google.com/patent/[US169997](/patent/US169997)/en.

Result: the Assignment Center has no records for this patent. Per your instruction I am saying that plainly. I have nonetheless completed the remaining sections of the required template as null-result renderings, because a bare "no records" line would leave the mandated "pick exactly one" verdict unanswered. Every section below is explicitly marked for evidentiary basis.

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Inventors

Both named inventors are private individuals in a small Kentucky community. No corporate employer is determinable for either — there is no evidence of any institutional affiliation, and the 1875 application was plainly a personal filing.

Patterns worth flagging (inverted from your checklist):

• No "inventors departing the assignee" pattern — there was no assignee to depart from. The classic pre-fire-sale tell (all inventors leaving the original assignee within 12 months) is categorically inapplicable: the patent issued directly to the inventors, unassigned.
• Inventor death shortly after issuance — a real ownership-relevant event, not an NPE tell. Ansel D. Jones died April 14, 1879, roughly 3.5 years after the November 1875 grant (Find a Grave memorial 47803770). Whatever interest he held would have passed to his heirs by will or intestacy — an extra-record transfer that would never appear in any USPTO assignment database. This is the single most likely reason any later ownership change on this patent is invisible today.
• A second corroborating detail not in the earlier sections: one of the two witnesses attesting the 1875 specification is recorded as "HUMPHREY T. JONES." Family records list Humphrey Tunstall Jones (never married) as another son of Ansel D. Jones. If that identification is correct, both the co-inventor and one witness came from the same immediate household — reinforcing that this was a self-financed, family-scale filing, not a company project. (Caveat: the identification rests on secondary genealogy sources, not on the patent document itself; the patent records only the name.)
• The other witness was Joseph W. Mullen, of no determinable affiliation.

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Original assignee

There is no original assignee. None. The patent issued to Ansel D. Jones and Samuel L. Jones as individuals, with no assignee named in the front matter, the specification, or the legal-events feed. There is no "Assignee" field value to report.

Because your template asks for it, here is what can be said about the (nonexistent) entity:

• Entity named on the issued patent: None — unassigned issuance to two natural persons.
• Product embodying the claims: No evidence of any. The patent's one claim (lazy-tongs frame pivoted to end pieces C C plus central slotted bar F / clamp screw G) is a table mechanism, and the specification markets it on cost grounds — the frame "can be constructed in this form much cheaper than in the ordinary tongued and grooved sliding sections, and it is easier to adjust." That is an invitation to a manufacturer, not evidence of one. I found no table maker, licensee, or manufacturer connected to the patent.
• Primary line of business: Not applicable — individuals. (Ansel D. Jones's own line of business, per genealogy sources, was gunsmithing/tanning and later Kirksville-area land development; saddlery and land are not table manufacturing.)
• Current status: Not applicable. Both inventors are long deceased (Ansel D. Jones in 1879; Samuel L. Jones's date of death was not determinable from the sources searched). There is no corporate successor to search for.

Practical consequence: with no assignee and no recorded transfers, the patent is best characterized as unassigned throughout its life, with any post-1879 ownership fragmenting among Ansel D. Jones's heirs (he had twelve children, ten surviving infancy per the family record) and never being papered through the Patent Office.

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Assignment timeline

The USPTO Assignment Center has no records for US Patent 169,997. There is no assignment timeline to reconstruct.

Two distinct reasons, and they should be kept separate:

1. Substantive: the patent was issued directly to the two inventors and no assignee has ever been identified on the face of the document or in any indexed source. The legal-events feed at https://patents.google.com/patent/US169997/en shows only grant, publication, and the 1892‑11‑16 anticipated expiration.
2. Coverage: the electronic Assignment Center database does not reach this era. USPTO's own training material for the Assignment database states that the searchable database "contains all recorded Patent Assignment information back to August 1980" (USPTO, Assignment Database Webinar, 2015‑01‑20, https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf). An 1875–1892 conveyance — recorded in the old liber/reel books, if recorded at all — would not be retrievable through the tool the task specifies. So Assignment Center's silence here is a coverage gap as much as a substantive finding, and I am not treating it as proof that no assignment was ever recorded in the 19th century.

No reel/frame entries, no conveyance types, no correspondents, no execution or recording dates can be reported. In particular, the "correspondent of record" field you flagged as the key NPE tell cannot exist for this patent: there is no recording event, and the modern correspondent field is an artefact of the 20th/21st‑century recording practice, not of 1875 practice.

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Timeline diagram

Null-result rendering. There are no assignment events to depict; every node below is a documented life-of-patent event, not an ownership transfer. The final two lines are annotations, not records.

timeline
    title Ownership of US 169997
    1875 : Filed 8 October by A D Jones and S L Jones
         : Issued 16 November to inventors
    1879 : Inventor A D Jones dies
    1892 : Patent term expires 16 November
         : No assignment recorded in USPTO databases

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NPE / troll-pattern signals

Because no assignment links exist in the chain, signals 1, 3, 4, 5, 6 and 7 have no reel/frame evidence on which to turn. I am marking them not present on the ground that there is no transfer to evaluate — not because I affirmatively verified the absence of a 19th‑century transaction.

Meta-observation: the entire NPE/patent-assertion framework presupposes an enforceable patent term. This patent's enforceable life ended 1892‑11‑16, and its granting pre-dates the corporate form of patent aggregation by about a century. High-frequency assertion on this document is not merely unevidenced — it is chronologically impossible within any of the databases and directories named in the task.

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Verdict

Insufficient data (no records, or only the original assignment — here, not even an original assignment exists).

Justification: The patent record shows no assignee on the face of the document and the Google Patents legal-events feed for US169997A (https://patents.google.com/patent/US169997/en) contains no assignment event — only grant and publication on 1875‑11‑16 and anticipated expiration on 1892‑11‑16. Because USPTO's electronic assignment database reaches back only to August 1980 (USPTO Assignment Database Webinar, 2015‑01‑20, https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf), the absence of reel/frame entries cannot distinguish "never assigned" from "assigned but recorded only in 19th‑century liber books." With no reel/frame, no correspondent, no lien, and no transfer of any kind to evaluate, no NPE signal can be scored, and none of the eight is present.

Verification links: Assignment Center search page — https://assignmentcenter.uspto.gov/ ; legacy Assignment Search — https://assignment.uspto.gov/patent/index.html (search patent number 169997). If a definitive historical answer is needed, the Assignment Center result will not supply it; a 19th‑century ownership trail for this patent would have to come from the Commissioner of Patents' annual reports (which list assignors alongside patentees), Madison County, Kentucky probate records for Ansel D. Jones's estate (d. 1879‑04‑14), or Federal Cases — none of which are assignment-record sources indexed by the tools specified.

One flag against the earlier sections: nothing here contradicts them. The previously generated "Assignee: None of record" and "no litigation found" findings are consistent with this null result; this section adds the 1879 death of inventor Ansel D. Jones and the probable father‑son relationship with co‑inventor Samuel L. Jones as the two facts that best explain why ownership on this patent, if it moved at all, never reached the USPTO.

I'll research the prior art record for US 169,997. Let me start with the specific citations and the pre-1875 extension-table art.

Let me check the Google Patents citation record directly and investigate the pre-1875 extension-table art that Google Patents lists as similar documents.

The US 2,883,248 record gives me a concrete list of early extension-table patents. Let me verify those and check what (if anything) Google Patents lists as cited art in US 169,997 itself.

Prior-art analysis — US Patent 169,997 ("Improvement in extension-tables")

Cross-reference note: This section builds on the earlier-generated summary and litigation sections rather than repeating them. Two of their findings drive everything below: (1) the patent has exactly one claim, a two-element combination claim (lazy-tongs frame A A pivoted to table-top end pieces C C, plus the centrally placed clamp G / slotted bar F); and (2) Google Patents' record for US169997A contains no "Citations" (backward-reference) section — only "Cited By (2)" forward citations and a "Similar Documents" list.

One correction to prior sections, stated explicitly: the earlier sections treated the forward citations (US 2,883,248 and US 2,965,425) as the patent's citation record. Those are documents citing 169,997 (1959–1960). They cannot be § 102 prior art against a patent filed October 8, 1875; they post-date it by 80+ years. Any analysis that maps them to § 102 would be an error, so I do not do so here.

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1. Threshold finding: the patent cites no prior-art documents of its own

Consequence: There is no "each patent citation for 169997" in the anticipatory sense — the patent's own face is citation-free. To answer the question I therefore reconstructed the prior art from three legitimate sources: (a) the specification's own admitted prior art, (b) the pre-1875 patents listed in the "References Cited" block of the later Hoppe patent US 2,883,248 (which itself cites 169,997), and (c) Google Patents' pre-1875 "Similar Documents."

Applicable § 102 regime: This patent pre-dates the 1952 Act, so I apply the modern statutory categories as a mapping convention only: references published before Oct 8, 1874 (one year pre-filing) fall under § 102(b); references published between Oct 8, 1874 and Oct 8, 1875 fall under § 102(a) only. Anticipation under § 102 requires a single reference disclosing every element of the one combination claim.

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2. The specification's own admitted prior art (element (ii))

The specification states the frame "can be constructed in this form much cheaper than in the ordinary tongued and grooved sliding sections, and it is easier to adjust."

• Citation: No document identified; this is a generic admission in the specification (the inventor's own characterization of the art).
• Date: Undated admission, made as of the October 8, 1875 filing.
• Description: Conventional extension tables using tongued-and-grooved bars that slide past one another to lengthen the top — the standard extension-table mechanism of the era.
• § 102 relevance: This is an admission against interest usable as prior art, but it is not a "reference" and is not dated to a specific publication. It is relevant only as background establishing that sliding-bar extension tables were old; it does not disclose the claimed lazy-tongs frame, so it cannot anticipate.

Corroborating contemporaneous evidence surfaced in search: a 19th-century U.S. circuit opinion (Harvard/CourtListener PDF, case caption truncated as "CARTER," source: https://storage.courtlistener.com/harvard_pdf/[8649561](/patent/8649561).pdf) addressed an extension-table reissue claiming a "metallic connecting slide, D, ... to be inserted in the grooves, E, E, of the wooden bars, A, B, C," and held the "double T slide" form old. That case confirms the tongued/grooved-slide art was, by the 1860s–70s, crowded and litigated. (I could not confirm the full case name, court, or year from the retrieved excerpt — treat as unverified.)

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3. Candidate § 102 prior art (pre-November 16, 1875 only)

3A. Pre-1875 patents listed in the "References Cited" block of US 2,883,248 (Hoppe)

These are the earliest extension-table patents of record. The block is quoted from the Hoppe record at https://patents.google.com/patent/US2883248 (and it is this same block that lists "169,997 Jones Nov. 18, 1875" — the date discrepancy already flagged in the summary section).

Source for US 46,240: https://patents.google.com/patent/US46240A/en (verified verbatim in this analysis).

3B. Pre-1875 "Similar Documents" from the US 169,997 record

Google Patents lists these as algorithmically similar; I have not verified their contents.

Post-dating documents I excluded as § 102 art (all publish after Nov. 16, 1875): US 186,171 (1877), US 223,615 (1880), US 227,346 (1880), US 246,217 (1881), US 271,688 (1883), US 283,582 (1883), US 291,525 (1884), US 309,252 (1884), US 316,472 (1885), US 340,641 (1886), US 349,627 (1886), US 390,687 (1888), US 433,712 (1890), US 915,061 (1909). Also excluded as different art: US 134,904 (sewing-machine tables, 1873), US 139,043 (blind-slat machine, 1873), US 145,305 (bedsteads, 1873).

3C. Non-patent prior art (element (i))

• The lazy-tongs / pantograph mechanism itself. The lazy-tongs ("pantograph") linkage is a pre-industrial mechanical movement; pantographs for copying drawings are documented from the early 17th century. Date: well before 1875.
• § 102 relevance: This bears on element (i) — but a bare lazy-tongs linkage is not a table. It does not anticipate the combination claim. It is the natural § 103 starting point (using a known lazy-tongs frame to carry a table top), and the specification's silence about the frame's novelty is consistent with the frame being old.
• Verification status: the general antiquity of the lazystongs/pantograph is well-established; I did not locate a specific pre-1875 printed publication applying lazy-tongs to an extension table, so I flag that gap explicitly rather than assert one.

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4. Claim-by-claim § 102 conclusion

Claim 1 (the sole claim) = lazy-tongs A A pivoted to end pieces C C + centrally placed clamp G and slotted bar F.

Bottom line on novelty: On the record available, no single reference anticipates claim 1 under § 102. The claim is a true combination, and the closest art (Iske US 46,240) supplies only the slotted-bar/locking half; the closest field art (US 122,946 / 123,372 / 145,049 extended tables) supplies the extension-table setting but I could not verify that any of them uses a lazy-tongs frame. Realistically, this patent's validity would have turned on § 103-type obviousness (known lazy-tongs + known slotted-bar extension-table clamp), not on § 102 anticipation — and the examiner of 1875 had no citation apparatus at all.

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5. Explicit uncertainties (per the strict rules)

• "169997" is not a unique string. Searches returned unrelated documents bearing the same digits — chiefly US 3,109,757 A (a 1962 phosphate-coating method whose application number is US169997A, appearing in the family table of DE 1,243,945 B, https://patents.google.com/patent/DE1243945B/en). Per the operating rules I did not treat it as the same document. This is the same class of false positive flagged in the earlier summary section.
• I did not read the full texts of US 6,557, 18,636, 23,219, 122,946, 123,372, 145,049, 148,611, 157,232, or 163,122. Their descriptions above are title-level only, taken from the Hoppe "References Cited" block and the Google Patents "Similar Documents" list. Any § 102 mapping for them is therefore provisional.
• USPTO PatentCenter / the official database was not directly searchable in this session. The record used is the Google Patents mirror (https://patents.google.com/patent/[US169997](/patent/US169997)/en, fetched 2026-09-24). I cannot rule out that a pre-1875 examiner's "References Cited" notation exists on the original printed copy, though 1875 practice did not require it.
• Filing dates for the cited early patents are unknown (the 19th-century records often list only the grant date); I marked them "not stated in record reviewed."
• Date discrepancy carried forward, not re-litigated: Hoppe's reference list gives "Nov. 18, 1875" while the patent's own front matter gives November 16, 1875. Reported literally, not corrected, per the strict rule.
• The "CARTER" extension-table case (Harvard/CourtListener PDF) is cited only as contemporaneous corroboration that the tongued/grooved-slide art was litigated; the caption was truncated in retrieval, so the case name, court, and year are unverified.
• One tool call was cut off (a query on US 145,049 returned a step-limit message), so that reference's full text was not obtained.

I'll first try to verify the content of the pre-1875 documents that appear on this page (the "Similar Documents" list and the forward citations), since an obviousness analysis requires actual prior-art disclosures rather than a citation list.

Now let me verify the other pre-1875 "Similar Documents" and check the state of lazy-tongs art before 1875.

Obviousness Analysis — US Patent 169,997 under 35 U.S.C. § 103

Patent: US169997A, "Improvement in extension-tables." Ansel D. Jones and Samuel L. Jones, Kirksville, Kentucky. Application filed October 8, 1875; granted November 16, 1875. Sole claim: "The combination, with lazy-tongs A A, pivoted to ends C C, of the centrally-placed clamp G and slotted bar F, as and for the purpose specified."

This builds on the earlier claim-construction work and does not repeat it.

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I. Two threshold problems that must be stated before any § 103 analysis

1. Section 103 did not exist in 1875. The Patent Act of 1952 created 35 U.S.C. § 103. This patent was examined under the Act of 1870 (Rev. Stat. §§ 4886, 4920) and expired in 1892 per the Google Patents record. Any § 103 analysis is therefore a hypothetical application of a modern statute to a 19th-century claim. I run it two ways below: (a) the historically correct standard, and (b) the modern § 103 standard, which is the one the task asks for. They do not give the same answer, and that difference is itself the most important finding on this page.

2. The page contains no citations of record — the "Prior Art" section is machine-generated. The Google Patents page's prior-art content consists of only two things:

• "Prior art keywords": extension, improvement, tables, jones, frame — these are extracted keywords, not references.
• "Similar Documents": a similarity-ranked list, which is a computed output, not an examiner citation, and which includes documents that postdate this patent by up to 34 years (e.g., US915061A, 1909).

There is no list of references cited against this patent. The only "Cited By" entries are forward citations — US 2,883,248 A (Hoppe, 1959) and US 2,965,425 A (Grinsell, 1960) — which are legally incapable of being prior art to an 1875 patent. Consequently, every obviousness combination below had to be constructed from outside the page's four corners, using the pre-1875 entries that happen to appear in the "Similar Documents" list. I flag each reference whose content I verified versus those I only have bibliographic data for.

Also note a date-field trap: Google Patents records "Prior art date = 1875-11-16." That is the grant date. The operative date is the filing date, October 8, 1875 (absent evidence of earlier invention). Using 1875-11-16 as the cutoff would wrongly sweep in three additional months of art.

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II. The statutory-bar cutoff, and which entries on this page actually qualify

Under Rev. Stat. § 24 (Act of 1870), a patent was invalid if the invention was patented or described in a printed publication before the applicant's invention, or more than two years before the application. With a filing date of 1875-10-08, the two-year bar line falls at 1873-10-08 (before that date, publication is a bar regardless of invention date; after it, the reference can only be used if the Joneses' invention date is later than the reference's publication date). Applying that to the pre-filing entries in "Similar Documents":

This is a materially useful result: only two of the pre-1875 "Similar Documents" are both (i) unambiguously available as statutory-bar art and (ii) verified as to content. The rest of the list is either unavailable on the date or unverified by me.

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III. Verified prior-art reference profiles

Reference A — US 46,240 A, Iske, "Improved Extension-Table" (granted Feb. 7, 1865)

https://patents.google.com/patent/US46240A/en — content verified.

What it discloses (from the retrieved text): an extension table with a central support column or foot A carrying cross-pieces B C that are "slotted, as shown, d d." Cross-slats s are "centrally secured by a fixed pivot at their combined terminus, under each segment, and also by a central pivot... to the center of the cross-pieces," with "sliding pivots 2, 3, 4, and 5, in said slots, d d d d."

Claim 1 of Iske (verbatim, as retrieved): "The central column or support, A, with its cross-pieces B G and slots d, in combination with the cross-slats s and their sliding pivots 2, 3, 4, and 5, in said slots, d d d d, arranged and operating substantially in the manner and for the purpose specified."

Relevance: this is a genuinely close structural analogue. Iske is an extension table whose centrally located structure carries slots in which pivots slide to accommodate and hold the table at a selected degree of extension — the functional twin of the Jones "slotted bar F" plus "centrally-placed" clamp, minus the screw. Note the drafting parallel too: Iske's claim closes with the same "in the manner and for the purpose specified" formula, evidence that this was boilerplate of the era rather than a limiting recitation.

Reference B — US 123,372 A, Wales, "Improvement in Extension Tables" (granted Feb. 6, 1872)

https://patents.google.com/patent/[US123372](/patent/US123372) — content verified.

What it discloses: a table of "a series of narrow strips... tongued on one side and grooved on the other," one series fixed to cross-bars C C on four legs E and a second series B on cross-bar D on two legs F, sliding in the spaces between the first series, "extended and contracted after having been set... without... a removal... of the articles placed upon it." Claim: "An extension table or counter-top having a series of tongued-and-grooved strips sliding in spaces between another and similar series, substantially as set forth."

Relevance: Wales is almost certainly the art the Joneses are disparaging when they say the frame "can be constructed in this form much cheaper than in the ordinary tongued and grooved sliding sections." Wales is therefore admitted prior art by the applicants' own specification — a significant point, because an applicant's characterisation of the prior art in the specification is usable against him. Wales shows the extension-table art, the problem (extension without disturbing articles; rigidity; "cannot warp or twist"), and the absence of any positive lock.

Reference C — US 331,776 A, Doyle & Sceurman, "Extension-Step" (granted Dec. 8, 1885)

https://patentimages.storage.googleapis.com/3e/76/cc/009947189d875e/[US331776](/patent/US331776).pdf — content verified, but this reference POST-DATES the patent by ten years and is NOT prior art.

Why I still profile it: it is the only document I actually retrieved in this session that discloses a lazy-tongs frame in combination with a lock. It describes rods "B, C, D, and F" that "form lazy-tongs, by means of which the step G may be extended... or folded up," locked by a hand-lever M engaging a rack-tooth P or spring-pawl R. It is useful strictly as evidence of the level of ordinary skill and the notoriety of the lazy-tongs-plus-lock concept as of 1885 — it cannot be used in a § 103 combination against an 1875 filing, and I am not using it as such.

Reference D — US 572,172 A, Krueger, "Circular Extension-Table" (granted 1896)

Retrieved, content verified. Post-dates the patent — not prior art. Mentioned only to note that I did not rely on it.

Reference E — 19th-century extension-table validity opinion (CourtListener PDF, "CARTER (Case No ...)")

https://storage.courtlistener.com/harvard_pdf/[8649561](/patent/8649561).pdf — retrieved, citation and date incompletely captured; I cannot verify the full cite.

The retrieved text concerns a reissued patent on "a metallic connecting slide, D, for the bars of extension tables" with dovetail and T forms and a pin-and-notch lock, and reasons that "making one side of the slide thicker or larger than the other, so as to be driven firmly into the groove on one side, was not new," that "transmitting a mode of constructing wooden slides... to metallic slides, is not invention," and that the change "rises hardly to the dignity of mechanical judgment." I flag this as counsel on the contemporaneous standard, not as prior art, because I could not confirm the reporter citation.

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IV. Claim 1 element-by-element, for the obviousness mapping

This mapping is the crux of the analysis, and it is unfavourable to a clean § 103 rejection: E1 has no verified prior art, and E4 has no verified prior art.

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V. Proposed combinations and the motivation analysis

Combination 1 — Primary: a pre-1875 lazy-tongs disclosure (unverified) + Secondary: Iske (US 46,240)

Structure of the rejection. If a pre-1875 reference discloses lazy-tongs used to spread two members (an expanding rack, gate, tongs, parallel rule, or an extension table), then E1 and E2 are disclosed. Iske supplies E3 and the concept of centrally located slotted structure that fixes an extending tabletop at a selected spread. The only element left is E4 — an ordinary clamp screw.

Motivation, under the law then and now:

• Same field of endeavour. Iske and the Jones patent are both in A47B1/00–1/08 (extensible tables; with extensible frames). KSR treats common field and common problem as strong motivation.
• Same problem, expressly stated. The Jones claim's functional language is "fastening the frame at any degree of extension." Iske's slots-and-pivots exist precisely to accommodate and hold an extension, and Iske's own claim uses the same "manner and purpose specified" formula. A PHOSITA seeking to hold an extending frame at an arbitrary width would look to exactly this structure.
• The specification supplies the motivation itself. The applicants state the frame is "cheaper... than in the ordinary tongued and grooved sliding sections, and it is easier to adjust" — i.e., they are improving on Wales. Where the applicant identifies the deficiency of the known art (Wales: strips that slide but do not lock) and the improvement sought, KSR rationale (4) — "applying a known technique to a known device ready for improvement to yield predictable results" — applies directly.
• Known mechanical expedient. Locking a sliding member by a screw bearing on it is the paradigm of a "simple substitution of one known element for another" (KSR rationale 2), and the substitution of a screw clamp for Iske's pin-in-slot produces no new or unexpected function.

Weakness of the combination. Combination 1 depends on a primary reference I could not verify. Without it, this rejection is a template, not a completed case. Anyone relying on it must first produce the pre-1875 lazy-tongs reference.

Combination 2 — Primary: Iske (US 46,240) + Secondary: Wales (US 123,372), with the ordinary skill of the art supplying the screw clamp

Structure. Wales shows the extension-table context and the accepted practice of extending a tabletop by sliding sections on cross-bars supported on legs — and notably by two leg sets (F on cross-bar D), i.e., the tabletop's ends are what move. Iske shows the central slotted structure that holds an extension at a set spread. The Jones frame (lazy-tongs) is then a known equivalent mechanism for achieving the same two-members-apart result that Wales achieves with sliding strips. Under the contemporaneous "aggregation" doctrine (below) and under modern KSR rationales 1–4, replacing one known parallel-motion mechanism with another known parallel-motion mechanism, in the same art, for the same purpose, is an obvious substitution.

Motivation: Wales leaves a known problem — sliding tongued-and-grooved sections that "slide free" and provide no positive lock; Wales's own claim protects the strips, not a lock. The Joneses' spec names this art and criticises it. Iske supplies the lock concept. A PHOSITA combining them would do so to obtain a table that extends and stays put.

Weakness: neither reference teaches a pantograph carrying a tabletop. The combination requires an additional piece of reasoning (lazy-tongs = a known parallel-motion linkage = an equivalent of Wales's sliding strips) for which I have not retrieved a supporting document, though it is the kind of reasoning a PHOSITA could supply as common knowledge. I flag this as an argument that rests on judicial notice of the art rather than on a document.

Combination 3 — Prior-art "wrong result" / aggregation attack on the claim as a whole

This is a different form of attack and, in my view, the strongest one available on the present record — but it is not a § 103 reference combination.

The Jones claim is a combination of two sub-assemblies each of which performs its own, separate function: the lazy-tongs frame extends the table; the slotted-bar-and-clamp holds whatever is clamped. Nothing in the claim requires the two to interact to produce a result beyond the sum of the parts. That is the classic aggregation-versus-combination problem. The contemporaneous authority is Hailes v. Van Wormer, 87 U.S. (20 Wall.) 353 (1873) — decided two years before this grant and squarely on point for the proposition that a combination must produce a new and useful result beyond the mere addition of the separate results (I cite this with moderate confidence; it is a well-known 1873 aggregation case, but I did not re-verify the citation in this session). Reckendorfer v. Faber, 92 U.S. 347 (1876), decided the following February and therefore not available to the 1875 examiner, made the same point with the pencil-and-eraser aggregation.

Two supporting facts run the same way:

• The stated advantage is cost, not function. The only asserted benefit — "much cheaper... and... easier to adjust" — is a manufacturing and assembly economy. Cheaper construction and easier adjustment of known parts is, both then and now, weak ground for patentability; an improvement in degree or in manufacturing convenience is generally not the kind of new result the combination doctrine protected.
• The functional closing language is boilerplate. Iske's claim closes identically ("in the manner and for the purpose specified"), which shows the formula carried little distinctive weight.

Caveat on this line: an aggregation attack is a validity argument, not an obviousness rejection, and it would not be framed as § 103 today. I include it because it is the argument most likely to have defeated this claim in its own era.

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VI. The historical answer versus the modern answer — and why they diverge

Historical standard (Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1850), and the Act of 1870). Pre-1952 doctrine required an act of invention beyond the skill of the ordinary mechanic; mere mechanical skill, superior workmanship, change of material, or change of degree was insufficient. The threshold was, if anything, higher than today's KSR "predictable results" standard in the sense that it was applied as a qualitative hurdle rather than a checklist of rationales. The fact that the 1875 examiner allowed a one-claim combination of a known linkage type with a known clamping arrangement is consistent with the era's practice of allowing narrow combination claims whose novelty lay in the specific organisation of parts.

Modern standard (35 U.S.C. § 103, Graham/KSR). Applied today to this claim, the exposure is greater:

Bottom line of the two-track analysis: the claim would very likely have been upheld under the 1875 standard (it issued, and its narrowness — a two-element combination with a central-clamp limitation — gives it limited but real scope). Under modern § 103 it is vulnerable, but a properly built rejection would require three references: (i) a pre-1875 lazy-tongs disclosure (which I could not locate), (ii) Iske for the slotted central structure, and (iii) a reference or common-knowledge showing of a screw clamp for locking a sliding member — a third reference I also do not have.

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VII. Express uncertainties and limits of this analysis

1. I have no verified pre-1875 prior art for the lazy-tongs element (E1). This is the single largest gap. The only lazy-tongs disclosure I retrieved, US 331,776 (1885), post-dates the patent by a decade and is legally unusable. I searched for pre-1875 lazy-tongs art and the search terminated at the step limit before returning a result. I am not asserting that no such reference exists; I am asserting that I did not find one, and I will not supply a citation I have not seen.
2. I have no verified prior art for the central clamp screw (E4) beyond the general proposition that screw clamps for locking sliding parts were and are routine. That proposition is common sense, not a citation.
3. Iske (US 46,240) and Wales (US 123,372) are the only two references whose full text I actually read. Every other pre-1875 entry in the table is bibliographic only; I cannot state what US 122,946, US 134,904, US 139,043, US 145,049, US 145,305, US 148,611, US 157,232, or US 163,122 disclose. My search on US 145,049 returned unrelated art (US 136,193, Utley, a machine for making extension-table tops), which is a false positive and not a substitute for US 145,049 itself.
4. "Similar Documents" is not a prior-art citation list. Its presence on the page is not evidence that any listed document was considered, cited, or is material. I treated it only as a starting point for locating real references, and I discarded every post-filing entry.
5. Confidence levels, stated plainly: US 46,240 content — high. US 123,372 content — high. The Iske-as-analogue-for-slotted-bar argument — moderate (it is a pivot-in-slot, not a screw clamp, and I am reasoning by analogy of function, not identity of structure). The Hailes v. Van Wormer aggregation citation — moderate (well-known 1873 case but not re-verified here). The "CARTER" opinion citation — low; I could not capture the party names, court, or year.
6. No contradiction with the previously generated sections. The forward-citation list (US 2,883,248 and US 2,965,425), the absence of an assignee, and the absence of an abstract are all consistent with this page. The prior section's flag — that US 2,883,248 cites this patent as "Nov. 18, 1875" while the document itself shows November 16, 1875 — stands unchanged and does not affect this analysis, except that it reinforces that the October 8, 1875 filing date, not any cited date, is the correct prior-art cutoff.

One-line conclusion: On the record actually available — an unverified primary element (lazy-tongs), Iske (US 46,240) for the slotted central structure, and Wales (US 123,372) for the extension-table context the applicants themselves disparaged — a modern § 103 obviousness rejection of Claim 1 is constructible in outline but not completable, because the two references I could verify cannot between them reach the "lazy-tongs" limitation, and no verified reference discloses the central clamp screw. The claim was correctly allowed under the 1875 "invention" standard, and its narrowness is its best defence.