US 343168

I'll verify this patent against live sources before summarizing.

Let me run more targeted queries on the patent number and on any 2026 litigation activity.

Verification note

I ran targeted searches for the exact identifier 343168 on Google Patents, the USPTO/PTAB document repositories, and Federal Circuit materials. Two identically-numbered items appear in the results and must not be conflated:

• US343168A — "Cultivator," the subject of your request (issued 1886-06-08).
• Serial No. 343,168 — the application serial number of a completely different patent, US1,333,797 ("Automobile-fender," Antonio Di Lorenzo, filed 1919-12-08, issued 1920-03-16). This is a serial number, not a patent number. See https://patents.google.com/patent/[US1333797A](/patent/US1333797A)/en

Do not use the Di Lorenzo fender as the answer. "US343168D" shown in the Google Patents family table is Google's internal application-node label for the same Gardner disclosure, not a separate document.

Bibliographic data — US 343,168 A

Abstract

There is no abstract. This patent issued in 1886, long before abstracts were used on US patents. Google Patents displays no abstract field; the "Definitions" text on that page is an auto-extracted description fragment ("WITNESSES 40 at or near the front end thereof…"), not an abstract. Any abstract you see for this patent elsewhere would be a third-party summary, not authoritative text.

Uncertainty on the filing date

The OCR of the printed specification renders the filing date as "October 531, 1885" and the Google Patents structured field shows only the issue-date-derived "prior art date" of 1886-06-08. The literal printed string is not a valid calendar date and is almost certainly OCR damage; the conventional reading would be October 31, 1885, consistent with serial no. 180,538 and a June 8, 1886 issue. I am flagging this rather than silently correcting it — I do not have an authoritative USPTO record image in hand confirming "31."

2026 litigation / CAFC docket check

No litigation or Federal Circuit activity involving patent 343,168 was found. My searches surfaced only:

• National Steel Car Ltd. v. FreightCar America, Inc., No. 1:24-cv-00594-JLH-CJB (D. Del.), stay order dated 2026-03-17 — unrelated patents (the "515" and "892" patents).
• Yechezkal Evan Spero v. Mercedes-Benz USA, LLC, No. 2025-1470 (Fed. Cir.), combined petition filed 2026-06-15 re U.S. Patent 10,894,503 — unrelated.

Two independent reasons this is expected: (1) the patent expired 1903-06-08, so it is not assertable in 2026; and (2) the Federal Circuit's docket is not publicly searchable by patent number in the manner your prompt implies. Any 2026 hit on the bare string "343168" is likely a coincidental case/docket number or the Di Lorenzo serial number above. Treat as unverified any claim of 2026 litigation over this patent.

Plain-language overview of the claims

Structural note: This is a pre-1952 Act patent. All 13 claims are drafted as standalone combination claims; none of claims 2–13 refers back to or incorporates an earlier claim. So there are effectively 13 independent claims, arranged in an escalating ladder from broadest (claim 1) to most specific (claims 12–13). Every claim ends in "substantially as described," the era's customary boilerplate.

The machine in one sentence: a horse-drawn, walk-behind frame carrying cultivator shovels, a two-compartment seed/fertilizer hopper, a ground-driven reciprocating rake, a following press roller, and a rotary marker — all driven off the rear axle through bevel gearing and a crank-shaft that periodically trips spring-returned linkages.

Practical takeaway on claim structure

Claims 1, 9, 10, 11 and 12 are the substantive ones: 1 is the broad combination, 9/10 are the gear-disconnect sub-combination, and 11/12 are the fullest machine combinations. Claims 2, 3, 4 and 5 are narrower combinations directed to the roller and marker sub-features; 6, 7 and 8 are sub-combinations for the rake drive and the intermittent seed-slide trip. Claim 13 is the only claim not directed to the drive train at all — it is a wheel/axle-adjustment claim.

Bottom line / confidence

• High confidence on title, inventor name and residence, issue date (June 8, 1886), serial no. 180,538, claim count, one-half assignment to James B. Martin, and all claim subject matter — all taken directly from the full specification text supplied in the patent record.
• High confidence that no abstract exists and that there is no corporate assignee.
• Moderate confidence on the filing date reading of October 31, 1885 (OCR-damaged as "October 531, 1885").
• High confidence that there is no 2026 litigation or CAFC docket activity for this patent; I found none, and the patent expired in 1903.
• Watch out for the Di Lorenzo application serial no. 343,168 (US 1,333,797) and for unrelated patents in the same numeric neighborhood (e.g., US 343,286, US 339,203), which appeared in my searches and are not this document.

I'll search for litigation involving US patent 343,168.

Those results are unrelated (they concern a different patent, 7,594,168, and a vaccine adverse-event ID). Let me run more targeted searches.

Let me check a few more specialized litigation sources.

Bottom line

No litigation involving U.S. Patent No. 343,168 is known.

I checked the litigation-oriented sources you named (Unified Patents portal/caselist coverage, the CAFC opinions-and-orders repository, and general open-web indexes of federal court dockets) and found zero cases — district court, CAFC, or PTAB — naming U.S. Patent 343,168 as an asserted or challenged patent. I could not produce the requested fields (plaintiff, defendant, jurisdiction, case number, filing date, status) because there is no case to populate them with. I am stating that as a null result, not as a claim that no 19th-century infringement suit ever existed.

Why the null result is expected here

The record for this patent (as reflected in the authoritative full text) makes litigation essentially implausible:

A patent that expired in 1903 cannot be asserted today, and its enforcement window closed more than 120 years ago, before modern docketing systems existed. Unified Patents' litigation caselist, PACER/CM-ECF, and the CAFC opinions database are all post-dating constructs as far as this patent is concerned; their coverage is not designed to reach suits from the 1886–1903 window, and no digitized docket would exist for any such case even if one had been filed.

False positives I ruled out (do not confuse these with 343,168)

My searches returned several hits that superficially resemble the number but are unrelated. Per your literal-interpretation rule, I am flagging them rather than treating them as matches:

1. U.S. Patent 7,594,168 B2 — the subject of IdeaHub Inc. v. Unified Patents, LLC, No. 2024-1684 (Fed. Cir. Apr. 10, 2026) (Rule 36 affirmance of PGR2022-00044) and IPR2021-01226. This is the "('168 patent)" appearing throughout PTAB briefing. It is a 7,594,168 — a completely different patent (web-page authoring tools), not 343,168.
2. VAERS ID 343,168-1 — a 2009 Gardasil adverse-event report (VAERS line list). Not a patent.
3. BORME-A-2023-144-35 (343168) — a Spanish commercial-registry filing reference. Not a patent.
4. EP 2530157 A2, SEQ ID NO 343168 — a sequence-listing identifier. Not a patent number.

I also noted P. P. Mast & Co. v. Rude Bros. Manufacturing Co., Bray v. Gardner (UK, 1888), and Willoughby v. F. Gardner & Co.-type equity cases surfaced during searching. These involve other cultivator/planter patents (e.g., Nos. 354,717; 237,740; 2253 of 1877) and similarly named parties, but none involves patent 343,168. I did not find any case tying 343,168 to a specific defendant.

Caveats on my search

• I was unable to complete an exhaustive docket-by-docket sweep; the final PACER-oriented query was cut off. However, the three prior targeted queries (Unified Patents caselist, CAFC, and general "343168 + litigation/lawsuit" searches) each returned only the unrelated items above.
• I do not have high confidence that a comprehensive pre-1903 case-law search has been performed. Nineteenth-century federal circuit court patent suits are only partially digitized (CourtListener/HeinOnline/Fed. Cas. coverage is incomplete), and a suit on this patent, if filed, would most likely appear only as a printed reporter decision or not at all. A negative result from the tools I used cannot exclude that.
• If you need a definitive answer on this point, the appropriate next step would be a manual search of Federal Reporter/Federal Cases volumes and the Circuit Court for the Western District of Pennsylvania (the venue covering Bradford, McKean County) for the 1886–1903 period, plus a check of the patent's USPTO assignment record (reel/frame) for any recorded judgment or license assignment.

Conclusion: As of today's date, no known litigation asserts or challenges US 343,168.

I'll verify against live sources before finalizing.

PTAB Proceedings on US 343,168 — Gardner, "Cultivator"

Proceedings overview

Total AIA trial proceedings on file: 0. The canonical structured block supplied in this prompt ("The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest") is correct, and I could not surface any IPR, PGR, or CBM naming US 343,168 in web search either — searches for the patent number in combination with PTAB/IPR/petition terms returned only unrelated documents (a PCT search report, a VAERS adverse-event table, and an unrelated patent hit), none of which concern this patent. There is therefore no breakdown by status (active / invalidated / sustained / settled / denied) to report: all 13 claims are untested at the PTAB — and have been untestable for the entire life of the AIA, because the patent expired on 1903-06-08, roughly 109 years before the PTAB's first trial under the AIA (the AIA trial provisions took effect 2012-09-16).

Bottom-line defensive posture: this is not the "hardened patent" scenario, and it is emphatically not the "claims canceled" scenario either. It is the third scenario: the patent has been in the public domain since 1903. Any demand letter asserting US 343,168 against a modern product is not a patent-enforcement risk — it is a signal that the sender either has the wrong patent number or is engaged in a bad-faith demand campaign. The defensive posture is: preserve the letter, identify the sender, and treat the assertion itself as the claim (fraudulent/injurious assertion) rather than the patent.

Individual proceedings

None. There are no proceeding numbers, petitioner names, panels, institution decisions, final written decisions, settlements, or appeals to report, and I will not manufacture placeholder ones.

Why the list is empty (structural, not evidentiary)

• Grant / term dates from the structured record: publication date 1886-06-08; prior art date 1886-06-08; application filed 1885-10-31 (specification: "Application filed October [3]1, 1885. Serial No. 180,538. (No model.)" — the OCR renders "31" as "531"); anticipated expiration 1903-06-08, consistent with a 17-year term measured from grant under the law then in force.
• Legal status verbatim from the structured record: Expired - Lifetime.
• PTAB jurisdiction: the Board's AIA trial jurisdiction (IPR under § 311, PGR under § 321, CBM under § 18 of the AIA) begins at the earliest with petitions filed on or after 2012-09-16. There is no mechanism by which a 1886 grant could have generated an AIA trial in the 1886–1903 window.
• Even a hypothetical modern petition would fail for want of a remedy: with expiration in 1903, there is no pre-expiration commercial activity within 35 U.S.C. § 286's six-year lookback, and no live infringement theory. (For completeness: the Board and the Federal Circuit have addressed IPRs on recently expired patents where pre-expiration damages remained collectible — e.g., Sony Corp. v. Iancu, 924 F.3d 1235 (Fed. Cir. 2019) — but that line of authority presupposes a term that ended within living commercial memory. It has no application here.)

Confusion risk — do not conflate these

• A CourtListener-hosted opinion referring repeatedly to "the '168 patent" (concerning an "RZI 700" soil-lifting implement and a literal-infringement summary-judgment holding) is not US 343,168. I could not verify its patent number from the snippet and I am not asserting what it is; I flag it only so it is not mis-cited as a decision on this patent. CourtListener PDF
• If a demand letter's patent number is being read off a faded or OCR'ed document, verify the digit count. A seven-digit modern number, a reissue, or a reexam certificate number can be confused with "343,168." That verification should be step one, before any substantive response.

Strategic summary

Claim status: CANCELED — none. SUSTAINED — none (no tribunal has ever passed on them). UNTESTED — all 13, by the PTAB; and unenforceable in practice, by expiration. The granted claims (1–13, as set out in the specification) cover a frame/handle combination, a vertically reciprocating rake frame, a dual-compartment seed-and-fertilizer hopper with reciprocating slide and bell-crank, a marker arm, a press roller on an independent frame, a crank-shaft-driven actuating train with bevel gearing (§ 11, § 12), and the angled bracket with pivoted latch for vertically adjusting the driving-shaft and bearing wheels (claim 13). None of these has been the subject of an institution decision, an FWD, or a Federal Circuit appeal. There is no narrowing history to analyze, because there is no history.

Estoppel landscape: § 315(e)(2) estoppel is irrelevant here, and that cuts in the defendant's favor. Estoppel is a constraint on a petitioner who lost or settled; with no petition ever filed, there is no estoppel bar and, more to the point, nothing for estoppel to attach to. The governing defense against this patent is not prior art at all — it is expiration plus the absence of any enforceable right. A defendant need not build an invalidity case: the patent's own front page establishes termination of rights on 1903-06-08. If the asserting party points to some other patent and mis-cites 343,168 as support, the correct response is a demand for the actual patent number and an explanation, not an invalidity analysis.

Pattern signals: there is no pattern to read. No repeat petitioner, no serial filer, no patent-owner appellate practice, and no defensive aggregator (Unified Patents or similar) in the chain — those signals all require at least one filed proceeding. Note the asymmetry the prompt anticipates: for a live, well-asserted patent, an empty PTAB docket is a mild negative signal about defensive options. Here it is the opposite — the emptiness is fully explained by a 122-year-old expiration and carries no adverse inference about the patent's strength, because there was never an opportunity to test it.

Recommended next steps

1. If you hold a demand letter citing US 343,168: treat the assertion as the actionable item. The patent's status is Expired - Lifetime with anticipated expiration 1903-06-08 (Google Patents US343168A). Quote that page's legal-status line back to the sender and request the actual patent number relied on.
2. Do not budget for an IPR. There is no claim to challenge, no § 315(b) one-year clock running, and no trial-stage milestones (institution deadline, oral hearing, 12-month FWD due date) to calendar. Spending on a petition would be the error here.
3. Escalate the sender, not the patent. If the demand is one of many mass-mailed letters, the productive referrals are the FTC and the relevant state Attorney General's consumer-protection bureau, plus a § 285 fee/exceptional-case argument if the sender has already sued. Preserve the letter and its envelope/metadata.
4. Verify the number before conceding anything. If the sender clarifies that they meant a different patent, restart this analysis on that number — a live patent, even a related one, can absolutely have PTAB history, and the ODP block in this prompt would not describe it.
5. If you need the specification text for a museum, historical, or prior-art-dating purpose: the file is complete and public — filed 1885-10-31, Serial No. 180,538, granted 1886-06-08 — and is usable as a § 102(a)(1)/(a)(2) printed publication or "otherwise available to the public" reference against modern applications, which is the one genuinely useful direction this document runs.

Confidence note: I am highly confident there is no PTAB activity — it is structurally impossible on these dates, and the structured ODP block and independent web searches agree. I cannot, however, rule out a mis-numbered reference to this patent in some filing; if you have a specific document that cites "343,168" in a PTAB context, share it and I will trace it, because a citation that looks like this patent is more likely a different patent or a typo than a genuine filing.

I'll verify this patent's identity and check whether any assignable records exist before building the chain.

Now let me check for any litigation history and confirm the assignment database's coverage window relative to this patent.

US 343,168 — Ownership Reconstruction

Patent: US 343,168 — "Cultivator, Corn-Planter, Rake, and Roller"
Filed: 1885-10-31 (Serial No. 180,538, "No model") · Issued: 1886-06-08
Term expired (17-yr): 1903-06-08 (per Google Patents legal events: "Anticipated expiration 1903-06-08 / Expired – Lifetime")
Source of record: https://patents.google.com/patent/[US343168](/patent/US343168)/en

Methodological caveat, stated up front: I could not drive the Assignment Center query UI from my tools. My conclusion rests on (a) the patent's own front-page and specification text, (b) Google Patents' legal-events tab, which shows only the 1903 expiration event and no reassignment entries, and (c) the USPTO's own published statement of the database's temporal coverage.

Inventors

Pattern notes:

• Only one inventor is named. Martin is an assignee, so this is not a two-inventor filing.
• No corporate employer appears anywhere in the document. There is no "assignor to [Company]" recital in the specification body; the only recited transfer is Gardner → Martin, one-half.
• Local, same-county counterparty. Bradford and Kendall Creek are both in McKean County, PA. This is the signature of a local partnership or financing arrangement, not a corporate portfolio transfer.
• No inventor-departure pattern is observable. The "all inventors left within 12 months" signal presupposes a company that employed them; none is present.
• Witnesses on the instrument are Moses Sullivan and A. P. Huey. These are witnesses to the specification, not attorneys or correspondents of record. Do not treat them as chain-of-title correspondents.

Original assignee

• Assignee of record: none. The patent issued to Patrick P. Gardner, who is jointly the patentee and the assignor of one-half.
• Co-owner: James B. Martin, Kendall Creek, PA — holder of a one-half undivided interest (1/2), per the printed heading: "PATRICK P. GARDNER, OF BRADFORD, ASSIGNOR OF ONE-HALF TO JAMES B. MARTIN, OF KENDALL CREEK, PENNSYLVANIA."
• Products shipped: The patent is a combination implement — cultivator, corn-planter, fertilizer distributor, rake, and roller on one frame (12 claims). Whether a commercial product embodying claims 1–13 was ever manufactured by Gardner and/or Martin is not evidenced in any source I can verify. I found no contemporary catalog, no trade-press mention, and no litigation naming this patent. I will not assert production either way.
• Line of business: Hand- and horse-drawn agricultural implement design/manufacture, consistent with the McKean County, PA location and the 1880s Pennsylvania cultivator trade. This is an inference from the subject matter, not a documented entity.
• Current status: There is no legal entity to report. The patent expired 1903-06-08; any 19th-century partnership between Gardner and Martin left no registered corporate successor that I can identify from the record. Status: dissolved/untraceable — as an entity, not as a bankruptcy.

⚠️ Do not conflate the assignee with similarly-named firms. My searches surfaced 19th-century cultivator litigation involving "F. Gardner & Co." (a defendant in an 1880s PA suit concerning the James D. Willoughby seed-planter extension) and the manufacturer P. P. Mast & Co. (assignee of the Gardiner & Downey patent, No. 237,740). Neither is shown to be connected to Patrick P. Gardner. These are name collisions only; I found no evidence of affiliation and do not assert one.

Assignment timeline

The USPTO Assignment Center / Assignments-on-the-Web database contains no records for US 343,168.

This is not a data gap that further searching will close. The USPTO states the searchable assignment database "contains all recorded Patent Assignment information back to August 1980" (USPTO, What are Assignments?, https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf; echoed by Finnegan, https://www.finnegan.com/en/insights/blogs/prosecution-first/who-owns-what-finding-patent-assignment-information.html). US 343,168 issued in 1886 and its term expired in 1903 — 77 years before the electronic recordation window opens. There is no reel/frame to cite, no conveyance type, no assignor/assignee of record, and no correspondent of record. Google Patents' legal-events tab corroborates this: the only event listed is the 1903 expiration.

The single ownership fact of record is the on-face one-half assignment from Gardner to Martin, recited in the patent heading itself. That is a printed recital, not a recorded post-issuance assignment, and it carries no reel/frame.

Per the search protocol, a no-records result is itself the finding: any residual interest traces to the original patentee(s) or their 19th-century successors, and there has been no recorded transfer of this patent in the modern era. Because the instruction to stop after this section and the request for an NPE verdict are in tension, I have continued below but marked every signal as unevidenced rather than inferring from it.

Timeline diagram

timeline
    title Ownership of US 343168
    1885 : Application filed 31 Oct by P P Gardner
    1886 : Patent issued 8 Jun
         : Half interest to James B Martin
    1903 : Patent term expires
    1980 : USPTO online assignment records begin
         : No recorded transfers found

NPE / troll-pattern signals

Every signal below is assessed against the same baseline: the patent's enforceable term ended in 1903, and no assignment has been recorded since the searchable window opened in 1980. No signal can be "present" without a reel/frame, and there are none.

1. Shell-entity transfer — Not present. No assignee LLC of any kind appears. The only transfer in the record is Gardner → Martin, one-half, a same-county individual-to-individual conveyance recited on the face of an 1886 patent. A registered-agent address, single-purpose LLC, or "IP/Holdings/Ventures" suffix would require a recordation; there is none.

2. Known asserter in the chain — Not present. No assignee matches any entity on the supplied list (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities) or any RPX/Unified high-frequency-plaintiff directory. Note the category is anachronistic here: none of these entities existed during the patent's 1886–1903 enforceability window, and none has ever recorded an interest.

3. Repeat correspondent across the chain — Not present. There is no correspondent of record at all — no attorney or agent filed any recording, because no recording exists. The two names on the instrument, Moses Sullivan and A. P. Huey, are specification witnesses, not recording correspondents, and each appears exactly once. There is no recurrence to flag. I also checked whether either name surfaces on a Unified Patents / RPX / Patent Progress NPE assertion list; I found no such appearance, and I would not expect one for 1886 witnesses.

4. Cascading transfers — Not present. Zero recorded transfers, therefore no chained LLC sequence and no shared-correspondent address pattern.

5. Pre-litigation transfer — Not present. I found no infringement litigation naming US 343,168 in any source. (My searches did surface 19th-century cultivator and seed-planter suits — Eagle Mfg. Co. v. Bradley, Bray v. Gardner, and Federal Reporter cultivator cases involving patents 237,740 and Wright's 1881 spring patent — but none of those pleadings identifies US 343,168.) With no suit, there is no transfer dated within six months before one.

6. Bankruptcy fire-sale — Not present. The patentee is an individual inventor residing in McKean County, PA. No corporate assignee, no bankruptcy estate, no §363 sale. The expired-term event (1903) is a statutory lapse, not an insolvency.

7. Privateering — Not present. Privateering requires an operating-company assignor transferring to an NPE for assertion against competitors, typically evidenced in SEC filings or by EFF/Patent Progress coverage. No corporate assignor, no SEC registrant, no assertion campaign.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at statutory expiration in 1903.

Verdict

Insufficient data — in its narrowest form: only the original on-face assignment exists, and no post-issuance assignment has ever been recorded.

Justification: There are zero entries in the USPTO Assignment Center for US 343,168, and there cannot be any in the ordinary course, because the searchable database begins in August 1980 (https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf) while this patent's term expired 1903-06-08. The sole ownership fact of record is the printed one-half recital to James B. Martin in the 1886 patent heading — a recital, not a reel/frame. No NPE finding is available or even theoretically applicable: the enforceability window (1886–1903) closed roughly nine decades before the modern NPE phenomenon existed, so every one of the eight signals above is unevidenced rather than merely undetected. I am explicitly declining to name an owner-of-record or a correspondent, because doing so would require fabricating a reel/frame.

Verification links:

• Assignment Center search (patent number field): https://assignmentcenter.uspto.gov/
• Legacy Assignments-on-the-Web entry point: https://assignment.uspto.gov/patent/index.html
• Google Patents record and legal events: https://patents.google.com/patent/US343168/en
• USPTO PEDS/ODP and SEC EDGAR are not applicable — there is no pending application, no living assignee entity, and no public-company assignor to cross-reference.

I'll search for the patent record and its citation data.

Let me query patent-specific databases for the citation record.

Let me verify whether the patent record lists any cited references, and check for forward citations.

Direct answer to the task as posed

I searched for the citation record of US 343,168 and the honest result is a null set: the patent of record carries no patent citations. There is no "References Cited" section, no examiner citation list, and no applicant-submitted reference list anywhere in the authoritative text of US 343,168 A. Consequently I cannot populate a "full citation / date / description / anticipating claim" table for each citation, because there are none to enumerate. What I can do — and do below — is (a) show why the record is empty, (b) flag two identifier collisions that will contaminate any naive search for "343168," and (c) give you the closest available substitute (Google Patents' algorithmic "Similar Documents" list) clearly labeled as not prior art of record, plus the pre-1885 art I would actually evaluate under § 102 if you commission a real clearance search. I separate record facts from my own analysis throughout.

1. The record for US 343,168 A

This is consistent with the litigation section already generated for this file (no known litigation, expired June 8, 1903). Two points of internal consistency worth noting: the filing date/serial number here match what the earlier section recorded, and the "US343168D"/"US343168DA" values that appear in the Google Patents "Application number" field of this record are database artifacts, not real application numbers (see § 2 below).

Why the record is empty — and the limits of that statement. US patents from this era were not published with a front-page "References Cited" box; that is a 20th-century convention, and the applicant-side duty to disclose references in its modern form is far more recent still. So the absence of citations on the face of US 343,168 is expected and is not evidence that the examiner considered no prior art — examiners certainly did, but pre-1900 prosecution files are not part of the printed patent and the 1885–86 application papers (Serial No. 180,538) are not transcribed into the digitized record either. More precisely:

• Verified: the digitized specification text contains no citation list, and Google Patents lists no "Cited" or "Cited By" entries for US 343,168 A.
• Not verified: whether the original printed sheet (microfilm/Patent Public Search image) carries any examiner marginal notation. I did not retrieve the page images, so I will not assert that it definitively lacks one.

I also flag a date discrepancy in the task inputs: your instruction states the current date is April 26, 2026, while my operating context says September 30, 2026. I have used neither to change any substantive finding — nothing here is date-sensitive — but you should reconcile that before relying on the timestamps.

2. Identifier collisions — do not conflate these with 343,168

Per the strict literal-interpretation rule, these are the things a "343168" search actually returns, and none of them is the cultivator patent:

1. US 1,333,797 A — "Automobile-fender," Antonino Di Lorenzo (https://patents.google.com/patent/[US1333797A](/patent/US1333797A)/en). Its application is Serial No. 343,168, filed December 8, 1919. In Google Patents' family data this application is indexed under the identifier "US343168A", i.e. the same string that is the publication number of the 1886 cultivator. This is a genuine identifier collision between a serial number and a patent number, and it is almost certainly the source of the odd Application number values inside the US 343,168 A record itself. Different inventor, different field, different century.
2. US 7,594,168 B2 — the "('168 patent)" litigated in IdeaHub Inc. v. Unified Patents, LLC and IPR2021-01226, already flagged in the previously generated litigation section. Web authoring tools, not agriculture.
3. Modern litigation practice's "'168 patent" shorthand (e.g., the Toro v. John Deere soil-aerification briefing and the National Harrow/"168" line of cases that surfaced in search) refers to unrelated patents. Do not read any of them as citations to or from US 343,168.

3. The nearest thing to a citation list — and it is not one

Google Patents renders a "Similar Documents" table for US 343,168 A. This is a machine-similarity output, not a list of references cited during prosecution, and it should never be cited as prior art of record. It is, however, the only reference list attached to this patent, so here it is in full, with each entry separated into pre- and post-filing status relative to the October 31, 1885 filing date (dates are as printed in the record):

Published before the filing date — facially available as prior art (pre-AIA § 102(a)/(b) analogues; govern by R.S. § 4886 in 1885):

Published after June 8, 1886 — categorically not prior art against this patent:

US 411,470 (1889-09-24); US 418,062 (1889-12-24); US 445,557 (1891-02-03); US 447,205 (1891-02-24); US 376,243 (1888-01-10); US 392,928 (1888-11-13); US 436,649 (1890-09-16); US 550,015 (1895-11-19); US 591,937 (1897-10-19); US 669,981 (1901-03-19); US 791,465 (1905-06-06); US 987,482 (1911-03-21).

Critical caveat, stated plainly: I have only the titles and dates for the eleven pre-filing entries above. I did not retrieve or read any of their specifications or claims. A title like "Improvement in combined seeders and cultivators" (US 120,354) is a lead, not a § 102 mapping. I am therefore not asserting that any of these anticipates anything, and I am specifically declining to fabricate per-claim § 102 conclusions from titles alone.

4. Prior art I would actually evaluate (analyst-supplied, not record citations)

Because the record is empty, the useful deliverable is a candidate set drawn from contemporaneous cultivator/planter art in the same classification neighborhood (A01C5/04 and its 19th-century equivalents) that surfaced during searching. Every entry below is my own reconstruction, with the source of each lead named so you can audit it:

Two of these — US 259,656 (June 13, 1882) and US 260,447 (July 4, 1882) — are post-dating nothing and pre-dating the filing, so they are available; US 329,371 is available only if its invention date precedes Gardner's, since its grant (Oct 27, 1885) precedes the filing by four days — a point that would require the interference/priority record to resolve.

Explicit non-answers: the two "marker" and "rake-frame" features that carry several claims (claims 4, 5, 6, 8, 11, 12) have no obvious pre-1886 anticipation surfaced by my searches at all. I do not have a candidate reference for the continuously-reciprocating rake of claims 2, 3, 5, 6, 11, 12, or for the marker arm of claims 4 and 5. I am stating that as an absence in my search, not as confirmation the art does not exist.

5. Text-quality warning affecting any claim-based § 102 analysis

The digitized specification is badly OCR-garbled in the very passages that matter for claim construction — e.g. shaft "P" appears as "I", "1?", and "1"; shaft "O" appears as "0"; hopper "L" appears as "1"; table section "g" appears as "9"; spring "s" as "8"; aperture "s" as "3" or "8"; and the linkage text around the seed-slide is partly duplicated/mis-sequenced. Claim 13's text is also visibly interleaved with the testimonium clause in the OCR. Anyone mapping a reference onto claims 7, 8, 10, 12, or 13 should work from the printed page images, not this text.

6. Bottom line

• Patent citations of record for US 343,168: zero. There is no citation list on the face of this 1886 patent, no forward-citation list, and the 1885–86 prosecution papers are not in the digitized record. I will not manufacture references to fill the requested table.
• What exists instead: an algorithmic "Similar Documents" list (11 pre-filing, 12 post-filing entries), which is not prior art of record, plus Google's "Prior art keywords" tags (shaft, frame, crank, rake, seed), which are also not citations.
• Most probative candidate art if you want a real § 102 study: US 237,740 (Gardiner & Downey, 1881) against claim 13 and the frame elements, and US 329,371 (Davis, Oct. 27, 1885) against the rake-and-roller claims — both with the caveats above, and neither verified against its own full text by me.
• To close this out properly: (1) pull the printed patent images from USPTO Patent Public Search (ppubs.uspto.gov) for US 343,168 to confirm no examiner citation notation; (2) read the full texts of US 120,354, US 154,842, US 196,291, and US 210,214 (the four closest pre-filing titles) rather than relying on titles; (3) treat every "343168" hit that resolves to US 1,333,797 A (serial 343,168, 1919) or US 7,594,168 B2 as a different patent.

I'll ground the analysis in the prior-art references listed on the patent page, checking what several of them actually disclose.

Now let me examine several more of the listed prior-art references, plus look for art on the rake/roller and marker sub-combinations.

I've hit the tool-call limit, so here is the analysis grounded in what I retrieved plus the authoritative page text. Where I could not verify a reference, I say so.

Obviousness analysis — US 343,168 ("Cultivator," Gardner, June 8, 1886)

0. Three threshold caveats before the §103 analysis

(a) §103 did not exist when this patent issued. US 343,168 granted on the Patent Act of 1870. The operative test in 1886 was the "invention" requirement of Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851) — the improvement must reflect more ingenuity than that of "an ordinary mechanic acquainted with the business" — plus the aggregation/combination doctrine of Hailes v. Van Wormer, 87 U.S. 353 (1873) (bringing together old elements that each perform their own function, with no new co-operative result, is not patentable). A modern §103 analysis (the Graham/KSR framing used below) is therefore a useful heuristic here, not the historically applicable law. I flag this rather than apply §103 silently.

(b) The Google page's "Prior art date 1886-06-08" is not the critical date. The specification states the application was filed October 31, 1885 (Serial No. 180,538). The OCR renders this as "October 531, 1885," which I am reading as a scan artifact for "31" — flagging rather than silently correcting, per the literal-reading rule. The correct prior-art cut-off for US patents and printed publications is therefore on or before 1885-10-31, not the June 8, 1886 grant date Google displays.

(c) Most of the "Similar Documents" list is not prior art at all. That list is a similarity/citation-graph output, not an examiner's citation list (the OCR of the printed patent shows no "References Cited" section). Filtering by the 1885-10-31 critical date:

Note in particular that US 791,465 A — the fertilizer-distributer/planter reference — issued nineteen years after this patent. It cannot be combined against these claims under any reading. Similarly, US 411,470 A (Piland) and US 436,649 A (corn-planter + fertilizer-distributer) post-date the filing and are usable only as evidence of ordinary skill, if at all.

1. Level of ordinary skill

A millwright/mechanician in the 1880s agricultural-implement trade: fully familiar with (i) traction-wheel drive trains and right-angle bevel gearing to a seed shaft; (ii) crank-and-pitman and cam/tappet mechanisms for reciprocating a seed slide; (iii) slide plate-and-aperture seed metering with spring return; (iv) pin-and-aperture depth adjustment and latch-locked pivoting brackets; (v) clutches, pawls/ratchets and lever-shifted gear trains for engaging and disengaging a seeder from the ground wheels. This art was extraordinarily crowded — the Smithsonian patent index I retrieved alone lists dozens of 1878 "Planter, Corn," "Grain Drill," "Marker, Corn," and "Cultivator" patents.

2. Claim-by-claim mapping

Group A — traction-driven train with a single take-off operating rake and seed-drop (claims 1, 6, 9, 10, 11, 12)

• Frame + seed-dropping devices + drive from ground wheels: US 120,354 A (Webb, Oct. 24, 1871 — "improved frame on wheels, adapted to receive either a cultivating, planting, or seed-dropping device"), https://patents.google.com/patent/[US120354](/patent/US120354) ; supplemented by US 204,765 A (Sarlls & Kelman, 1878: frame, hopper over axle, clutches C on the axle so the wheels carry the axle forward only) and US 204,671 A (Kelley, 1878).
• Intermediate shaft geared between driving and crank shafts: US 42,112 A (Ross, Mar. 29, 1864 — a wheel-hub cog wheel o driving cog m on shaft a⁴, with "a lever that throws cog-wheel m in and out of gear with cog-wheel o"), https://patents.google.com/patent/US42112 . Three-shaft countershaft trains (axle → countershaft → seed/crank shaft) were routine; Gardner's claim 1 recites nothing more than a re-arrangement of that two/three-shaft chain.
• Mechanism for operating rake and seed-drop simultaneously from one crank-shaft: US 9,468 (1852 seed-planter: slides d driven by a vibratory lever f off a "crimped wheel," with a pivoted throw-out) shows a single rotating member driving a slide train; US 200,415 A shows cranks f, connecting-rods F, and a spring-returned drop-pin H. Combining a second output (an oscillating rake shaft) onto the same crank-shaft is the paradigm case of a predictable, one-output-to-two-output mechanical duplication.
• Lever for throwing driving and intermediate shafts out of engagement (claim 9): squarely old — US 42,112 A explicitly discloses the lever-shift of a cog wheel in and out of gear, twice, for both the planter and the sower trains. US 204,765 A discloses the equivalent, a slipping clutch on the axle. Claim 9's "lever" is a mechanical equivalent of Ross's lever.
• Right-angle intermediate shaft in laterally movable boxes, actuated by a pivoted lever (claim 10): this is the bevel-gear analogue of the same throw-out. US 42,112 A's cog-wheel throw-out and US 9,468's throw-out teach the function; shifting a bevel pinion on a laterally sliding journal box is a known, predictable alternative to shifting a spur gear, requiring no new principle.

Group B — rake and roller (claims 2, 3, 5)

• US 204,671 A (Kelley, 1878) discloses an "opener or marker S" in front of the discharge aperture and, in the rear, a roller-frame M with roller O journaled therein (the roller "serves to press the earth on the seed and to gage the depth of the coverers") — i.e., a roller carried on a frame at the rear of a planter.
• US 30,832 A (Naylor & Ward, Dec. 4, 1860) discloses a drill-roller-and-corn-planter in which the forward part of the frame rests on roller C and the rear on wheels B — a roller as a ground-following support.
• Motivation to make the roller "movable independently of the rake-frame" (claim 2) — the specification itself supplies it: the roller must "keep ... in contact with the ground at all times" and must not be disturbed by the rake's continuous reciprocation. Given that stated function, hanging the roller on its own loosely pivoted frame (Gardner's own frame T pivoted to arms U) is the obvious expedient, not an inventive departure.

Group C — marker simultaneous with seed-drop (claims 4, 5)

• US 204,671 A discloses a marker/opener on a planter frame. Corn-planter markers driven off the seed mechanism were a distinct, heavily patented sub-class — the Smithsonian index lists e.g. "207,031 — Marker, Corn — Harmer — 1878." Driving a rotating marker-arm from the same transverse shaft that already times the seed-drop requires only keying a bent arm to an existing shaft, as Gardner does with marker-arm O′ on shaft O.

Group D — spring-returned reciprocating seed-slide struck by a rotating crank, via a bell-crank lever (claims 7, 8)

• The "tappet/striker" mode — a rotating member on the ground-driven shaft striking a spring-loaded, normally-out-of-the-path follower once per revolution, with the follower returning the slide to a closed position — is old. US 9,468 (1852: "reciprocating motion of the two metal slides ... occasioned by ... a vibratory lever"; the lever is turned "for the purpose of throwing the pins of the slides out of gear") and US 342,103 (tapped-lever H in the path of tapped-pins b′ on the main wheel, driving seed-slide e) show the same principle; US 204,765 A's face-pins on a dropping wheel operating a chopper show the striker concept on an 1878 planter.
• A bell-crank lever to reverse the direction of a link's motion is a trivial mechanical element; substituting it for a straight lever does not change the principle or mode of operation.

Group E — pivoted two-armed axle bracket + perforated arm + latch + pawl (claim 13)

This is the one claim with a genuinely narrower structural recitation.

• Pivoted/swing-link axle mounting with aperture-and-pin depth adjustment: US 204,765 A ("Several holes are formed in the standards M O to receive the bolts and enable the said standards to be raised and lowered to cause the plows to work shallower or deeper"). US 221,684 (Olivier-Lecq, 1879) discloses "the axle E, mounted in bearings in the links D D, hung on the rod C, ... the links ... provided with curved extremities e e, the tie-rod d, and lever e" — a swinging-link axle with adjustment, as summarized in Allen's Digest of Agricultural Implements, https://dn760003.eu.archive.org/0/items/allensdigestofpl01alle/allensdigestofpl01alle.pdf . US 222,255 (De Force & McConnell, 1879) discloses pivoted arms E on the axle carrying a chopper-shaft, raised by a lever and rock-shaft.
• Pawl limiting upward adjustment: a one-way stop pawl on a swing member is standard ratchet practice and was ubiquitous on planters (clutches/pawls in US 204,765 A).
• Because the claim combines a swing bracket + perforated arm + latch + pawl, all individually old in the same art, its validity rests entirely on the pre-1952 aggregation analysis (below).

3. Motivation to combine — the governing rationales

1. Common ownership of the problem. Every reference cited above is drawn from planting/cultivating implements — the same field, addressing the same problems (depth control, seed metering, ground-following, clearing the furrow). KSR-style "analogous art" is satisfied without argument; there is no field-boundary problem in this analysis.
2. Single traction take-off. Designers of combined seeders/cultivators repeatedly sought to drive all cycling functions from one ground-wheel take-off to keep the seed spacing synchronized with travel. US 42,112 A's lever-shiftable cog train and US 9,468's crimped-wheel drive show the practice. Once one shaft is timed to ground travel, tapping it for a second output (rake oscillation, marker) adds no new timing problem — the very reason Gardner's own shaft O drives both the crank-arms and the marker-arm.
3. Converting a seeder to a cultivator. A well-known commercial desideratum, explicitly recited in US 120,354 A (frame "adapted to receive either a cultivating, planting, or seed-dropping device"), US 30,832 A (drill parts "may be removed ... whenever it is desired to use the machine as a planter merely"), and US 42,112 A (throw-out levers). That objective directly motivates claims 9 and 10 (throw the drive out of engagement) and the caster/roller adjustment of Gardner's own bearing-roller D.
4. Predictable results. Nothing in claims 1–12 produces a result beyond the sum of the expected effects of the assembled old elements: the seed slide opens on cue, the marker strikes at intervals, the rake oscillates, the roller presses. No new co-operative result (e.g., a change in the kind of motion or a new interaction between rake and metering) is recited.

4. Where the obviousness case is weak — and where it fails

I want to be explicit that this is not a clean "all claims invalid" story:

• No verified pre-1885 reference in the page's list discloses a vertically reciprocating rake or a "continuously-moving rake." The rake-and-roller sub-combination (claims 2, 3, 5, and the rake element of 1, 4, 6, 8, 11, 12) is the least-supported element in my search. The closest pre-1885 item I located is US 207,808 (Henigst, Sept. 10, 1878), whose claim 2 recites "the vertically-swinging arms i₁ carrying either shields or rakes" on a wheeled cultivator frame — but I have only the digest's claim summary, not the full specification or drawings, so my confidence in the disclosure level is moderate at best. A searcher would need to run this element down properly.
• US 210,214 A: the page lists it as an 1878 "combined drill and corn-planter." My search surfaced US 210,262 A (Lindsay et al., Nov. 26, 1878, "Combined Seed-Drill and Corn-Planter" — two-part seed boxes, slide a beneath the box bottom, seed cylinder on the axle) rather than 210,214. I did not verify 210,214's content and will not attribute Lindsay's disclosure to it. Per the literal-ID rule, 210,214 A and 210,262 A are different documents.
• Claim 13's pawl/latch geometry is not disclosed as a two-armed pivoted bracket with latch and pawl in any reference I verified. Its invalidity argument is an "old elements, expected function" argument, not anticipation.
• Aggregation attack (the strongest pre-1952 argument). Under Hailes v. Van Wormer (1873), claim 4 (seed-drop devices + marker actuated simultaneously + a vertically-moving rake) is vulnerable as a mere aggregation: nothing in the claim recites the rake as co-acting with the marker or the seed-drop — each simply performs its own function on the same frame. The same criticism applies to claim 2 (rake + independent roller: the claim's own point is that they are independent). Conversely, claims 1, 6, 7, 8, 9, 10 are true combinations (a common drive train co-acts), so they must be met on §103/hotchkiss grounds rather than aggregation.
• Claim-drafting limit. Every claim ends "substantially as described," which under 1886 practice confines the claim to the specific disclosed structure. That cuts against invalidation breadth-wise (narrow claims are harder to invalidate) but for the defendant's non-infringement position — which is exactly the dynamic recorded in Pattee v. Moline Plow Co., 9 F. 821 (C.C.N.D. Ill. 1881), retrieved from law.resource.org, where the court held the cultivator patents to be "mere combinations of old parts" yet found no infringement because the defendant used a different joint.

5. Secondary considerations

I found no evidence of commercial success, long-felt need, industry acquiescence, or copying for US 343,168. The full text contains no such assertion, and the page's family/status data show only the single grant, expiring as "anticipated" on 1903-06-08. One tangentially related data point: the comparable combined seeder/cultivator US 120,354 A is recorded at datamp.org as "Not known to have been produced" (https://datamp.org//patents/displayPatent.php?id=51557) — meaning the analogous prior art in this field was itself largely paper. With no objective indicia, claims 1–13 must stand or fall on the prior-art record alone.

6. Bottom line

Net: the mechanized sub-combinations — claims 7–12 and the throw-out features of 9–10 — are the parts of this patent most exposed to a §103 (or Hotchkiss) attack, and the art needed to make that attack is ordinary, same-field, and pre-dates the 1885 filing. The claims that turn on the rake itself (2, 3, 4, 5, and the rake recitations elsewhere) are not established as obvious on the record available to me, and I would not represent otherwise. A complete analysis requires full-text retrieval and image review of the twelve pre-1885 references I have flagged as unverified — US 196,291; 154,842; 110,706; 242,063; RE 6,274; 111,687; 181,294; 205,020; 108,656; 210,214; 139,340; and US 207,808 — plus a targeted classification search (A01C 5/04 and its 1880s predecessors) for vertically-reciprocating rake/cleaner mechanisms on wheeled planters.

Sources cited above: https://patents.google.com/patent/[US343168](/patent/US343168)/en (authoritative full text) · https://patents.google.com/patent/US120354 · https://patents.google.com/patent/US411470A/en · https://patents.google.com/patent/US42112 · https://patents.google.com/patent/US9468 · https://patentimages.storage.googleapis.com/a3/45/52/47138b60d5cfe3/[US210262](/patent/US210262).pdf · https://patentimages.storage.googleapis.com/00/9f/28/4b62b6ccc51970/US30832.pdf · https://patentimages.storage.googleapis.com/ba/37/2f/12b0079c4994ae/[US200415](/patent/US200415).pdf · https://patentimages.storage.googleapis.com/bc/21/6c/4c5f5573e84931/[US204765](/patent/US204765).pdf · https://patentimages.storage.googleapis.com/b9/54/82/654fc06dcf0c8e/[US204671](/patent/US204671).pdf · https://dn760003.eu.archive.org/0/items/allensdigestofpl01alle/allensdigestofpl01alle.pdf · https://dn760104.eu.archive.org/0/items/digestofagricult01alle_0/digestofagricult01alle_0.pdf · https://law.resource.org/pub/us/case/reporter/F/0009.f1.hein.pdf · https://datamp.org//patents/displayPatent.php?id=51557