US 131947

I'll run searches across the sources you specified.

Summary — US Patent 131,947 ("Improvement in ditching-machines")

Searches run: Google Patents record for US131947A; general web searches for "USPTO 131947," "US131947A," and "CAFC 2026 docket 131947." I did not find any CAFC 2026 docket entry, ITC filing, or district-court record referencing patent 131,947. Below I distinguish what is documented from what is genuinely absent.

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Bibliographic data (as recorded)

Source: https://patents.google.com/patent/[US131947](/patent/US131947)/en (fetched 2026-09-26).

Abstract

There is no abstract. US patents were not required to include abstracts until the 1952 Patent Act, 79 years after this grant. The Google Patents record has no abstract field for this document. Any "abstract" for 131,947 would be a modern editorial paraphrase, not patent text.

CAFC / litigation check

No results. Two independent reasons: (1) the Court of Appeals for the Federal Circuit was not created until October 1, 1982 (Federal Courts Improvement Act of 1982), so a "CAFC 2026 docket" for an 1872 patent would be anomalous; and (2) this patent's term expired 1889-10-08, well before any modern appellate forum existed. I found no 2026 CAFC, ITC, or district-court activity tied to this number. I cannot rule out an unrelated 2026 docket that happens to use "131947" as a docket number rather than a patent number — but I found none.

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Claims — important limitation on this answer

I cannot give you the literal claim language, and I will not reconstruct it. In the authoritative full text, the claim section is corrupted/truncated at exactly the claim. It reads, in full:

"We claimscribed.
ORSON FOSTER. OSCAR S. FOSTER."

The claims themselves did not survive OCR. Any numbered "independent claim" text for this patent that I produced would be fabricated. The Google Patents "Definitions" summary also gives no claim language — only the specification's "consists in" statements.

What I can give you, clearly labeled as specification subject matter (not claim language), are the four things the specification says the invention "consists in," in the order stated. These are the best available proxy for the claim scope, since 1870s claim practice drafted claims to mirror these "consists in" passages:

1. The combination as a whole — a ditching spade/excavator, a dirt-remover (scraper) that clears dirt off the spade, devices for feeding the machine forward, and the mechanism operating all of these together.
2. The spade-operating linkage — a construction/arrangement giving the spade free working action and "greater elasticity in yielding to large stones or other obstructions." Mechanically: spade A hangs by pivot c from horizontal beam B; beam B is pivoted to the frame at G and carries an anti-friction roller b that rides on the top of the driving/connecting beam D. Because end 11 of beam B is "always free to rise," an obstruction the spade cannot cut lifts the spade rather than stalling or breaking the machine. The beam also holds the spade down on the forward stroke via its weight, and holds it more elevated on the backward stroke.
3. The movable colter — tooth/colter H slides in the spade standard, projected from the spade point on each digging stroke and withdrawn on the return. It has a slotted head h, engaged by a projection I on beam D; as the angle between beam D and spade A changes through the stroke, the colter is automatically extended or retracted. Purpose: loosen stone and hard earth. The specification notes it could be forked into two teeth but prefers a single tooth because forking weakens the spade.
4. Spring-actuated scraper discharge — scraper J (Fig. 2) on cross-beam j, sliding in guide K and carried on swinging rod k. Return arms M on main shaft E reset it; on the discharge stroke it is thrown by spring L (strap l) for a sudden, rapid discharge, being held by a pawl released by pin 1 on the spade standard.

Drive train context: sweep S → gear wheels c, F; vertical gear F makes two revolutions per sweep revolution and carries crank f, connected to the spade by connecting-rod/beam D. Feed: windlass G, operated by adjustable crank O via lever W. Mounted on four wheels V with height set by crank-axles T T. Arms M M and crank O are both adjustable in length to regulate speed. Stated performance: digs 30 inches deep, removes stone up to the width of the ditch.

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Caveats and identifier notes

• No USPTO PatentCenter prosecution record exists in the modern sense for an 1872 grant; there is no file wrapper, examiner, or attorney-of-record data accessible. The Google Patents record is the authoritative source available here.
• Do not confuse this number with adjacent identifiers. The same digits appear in unrelated contexts: WO 2007/131947 A1 (a PCT application on pulse-width-modulated current control for inductive loads in motor vehicles) and US13194793A, an application-number fragment appearing in unrelated Google Patents family data. These are different documents, and per your instruction I have not treated any of them as equivalent to US131947A.
• Date discrepancy observed: the authoritative text was fetched 2026-09-26, while your prompt states the current date as April 26, 2026. This does not affect the 1872/1889 core facts above.
• Uncertainty declarations: (a) filing date — not available; (b) claim language — not recoverable from the source; (c) assignee — none recorded, and I found no evidence one ever existed; (d) any 2026 litigation — none found.

I'll search for litigation records involving US patent 131947.

Let me check the specific litigation databases the user mentioned.

Answer: No litigation involving US Patent 131,947 is known.

I searched litigation-focused and general sources for the exact patent number 131947 and found no federal court, ITC, PTAB, or other adversarial proceedings asserting or challenging it. Because the identifier is an 1872 patent, I want to be explicit about the reasoning and the limits of the search rather than just returning a null.

What the search covered

The only hits for the string "131947" were unrelated documents that must not be conflated with US 131,947:

• WO 2007/131947 A1 (PCT/EP2007/054552) — a Bosch PWM current-control circuit for inductive loads. Different document, different numbering system.
• JP 2008-131947 A — a Japanese published application (Sefar/KeyGene DNA fingerprinting, filed as a divisional). Different jurisdiction and series.
• EP131947 (NL register) — Air Products and Chemicals' natural-gas liquefaction patent, granted 1988, lapsed 1995. Different document.
• US land patents — BLM accession 131947 (Minnesota homestead, 1910) and CACAAA 131947 (Posey Lode mineral patent, Kern County, California, 1906). These are land grants, not patents for inventions.
• Assorted non-patent items (a Québec film classification file, a Journal of Cleaner Production article, a Bauru, Brazil municipal protocol).

None of these is US 131,947, and none is a litigation record.

Why the absence is well-founded

The authoritative Google Patents record for US131947A states:

• Title: Improvement in ditching-machines
• Inventors/patentees: Orson Foster and Oscar S. Foster, of Durhamville, Oneida County, New York
• Grant date: October 8, 1872
• Legal status: "Expired – Lifetime," with an anticipated expiration of 1889-10-08
• Assignment/USPTO assignment links: no assignment history shown; the "Family" consists solely of US131947D (the same document)

Several independent reasons support a "no litigation" finding:

1. The patent has been expired since 1889. Under the law then in force, the term was 17 years from grant. There is no live patent right to assert, and any infringement action would have had to be brought in the 1872–1889 window.
2. Federal question jurisdiction for patent suits (Act of 1870/1873 revisions) did exist in that window, so suits were legally possible — but no such case appears in the searchable record.
3. Historical digests are outside the indexed databases. Unified Patents, Docket Alarm, PACER, and CourtListener coverage of the 1870s–1880s federal dockets is sparse to nonexistent. PACER's electronic case records generally begin in the late 1980s to 2000s depending on district; a pre-1900 patent case would not appear in PACER at all. So "not found" here reflects both the near-certain legal reality and the practical coverage limits of the databases named in your request.
4. The patent even reports commercial success in the specification — "digging to a depth of thirty inches, is in practical operation and works well" — but commercial success is not litigation, and I found no evidence of either enforcement or defense.

Bottom line table

Caveat on confidence: I cannot state with absolute certainty that no 19th-century suit ever existed, because the databases you named do not comprehensively index pre-1900 federal dockets, and no full-text search of 1870s–1880s court records was available to me. What I can state is that (a) no litigation is recorded in any source I could search, and (b) the patent expired on October 8, 1889, so no litigation concerning it is legally possible today.

If you want to push further on the historical question, the productive offline sources would be the Federal Reporter volumes covering 1872–1889, Commissioner of Patents annual reports, and the subject-matter digests (Decisions of the Commissioner of Patents, and Robinson on Patents case tables) — none of which surfaced in these searches.

I'll verify the structured data against any public traces before writing.

PTAB Proceedings — US Patent 131,947

Bottom line up front: there are no AIA trial proceedings on this patent, and as a matter of law there cannot be. US131947 ("Improvement in Ditching-Machines," Orson Foster and Oscar S. Foster, Durhamville, NY) issued 1872-10-08 and reached its anticipated expiration on 1889-10-08, with legal status Expired - Lifetime. The AIA trial regimes (IPR under 35 U.S.C. § 311 et seq., PGR under § 321 et seq., CBM under § 18 of the AIA) did not exist before 2012-09-16. Every claim has been in the public domain for roughly 137 years.

Proceedings overview

Total AIA trial proceedings on file: 0 (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied). The structured PTAB block from the USPTO Open Data Portal returns no proceedings, and my web searches surfaced no IPR, PGR, CBM, or Federal Circuit appeal touching this patent. Defensive posture: there is no proceeding to analyze because assertion of this patent today is not legally possible — it is a public-domain 1872 artifact, not a live patent right. Any demand letter invoking "US 131,947" would be sanction-bait on its face, and the more likely reading is that a letter mis-cites some other patent (see caution below).

Proceeding entries

None. There is no {PROCEEDING_NUMBER}, no petitioner, no panel, no institution decision, no FWD, no settlement, and no appeal to report for US131947. Per the operating constraints against fabrication, I am not constructing placeholder entries.

For completeness on the structured data, the ODP metadata block contains only:

• Publication number US131947A, application/grants record US131947D
• Prior art date 1872-10-08; publication 1872-10-08; anticipated expiration 1889-10-08
• Legal status: Expired - Lifetime (verbatim)
• Classification trail: E02F3/00 → E02F3/04 → E02F3/28 → E02F3/36 → E02F3/40 → E02F3/413
• Family ID 2201364 (one application, US)
• Prior-art keywords: spade, ditching, machines, crank, improvement

Those "0.000 description" / "238000010276 construction" rows in the ODP dump are landscape/CPC concept-weight counters, not proceedings. Do not misread them as docket entries.

Strategic summary

Claim status. The patent has one independent claim in the modern sense — the specification's "We claim" clause is presented as a single claim covering the combination (the ditching spade with the pivoted suspension beam B and anti-friction roller b on driving beam D; the sliding movable colter/tooth H with slotted head h actuated by projection I; and the spring-thrown scraper J returned by arms M and held by a pawl on lever N). There are no canceled claims, no sustained claims, and no untested claims in any IPR sense — but all claims expired 1889-10-08 and are unenforceable as a matter of law. U.S. patent term in 1872 ran 17 years from grant (the 1861 Act term), which is exactly the 1889-10-08 date the ODP reports; even under the most generous reading there is no surviving term.

Estoppel landscape. 35 U.S.C. § 315(e)(2) estoppel is irrelevant here. Estoppel attaches to grounds a petitioner "raised or reasonably could have raised" in an instituted IPR — with zero proceedings, there are no petitioners, no privies, and no estoppel. Conversely, the on-sale / public-use and printed-publication prior art from 1872 is essentially unbounded, and the 1872 specification itself is printed publication art as of 1872-10-08 against any later patent. If your dispute actually involves a different '947 patent, that analysis must be redone against that patent number.

Pattern signals. None, and none are possible: no repeat petitioner campaigns, no patent-owner appeal practice, no defensive aggregator (Unified Patents, RPX, AST) involvement. Defensive aggregators do not challenge 137-year-expired patents, and the PTAB has no jurisdiction to try one.

Recommended next steps

1. Do not treat this as a live-threat patent. Verify what was actually asserted. "131947" is a five-digit number that collides with tempting look-alikes:
   • US 6,411,947 ("the '947 patent") — the Bright Response / Brightware patent litigated in the Eastern District of Texas against Google (see the JMOL motion on §§ 102/103 invalidity, No. 2:07-cv-00371, E.D. Tex.) and against Polaris IP, LLC. This is the real-world '947 that generates IPR and litigation activity.
   • A separate family of PTAB and reexamination filings cite "37 CFR 1.947" — that is the rule number for third-party requester comments in inter partes reexamination, not a patent number. Any search hit containing "1.947" is a red herring.
   • Foreign 131947 records exist (JP 2008-131947 A; WO 2019/131947 A1; WO 2007/131947 A1). Unrelated.
2. If the number is confirmed as US 131,947 — the 1872 Foster ditching machine — your response to any demand is that the patent expired 1889-10-08 and is public domain; the USPTO record is at https://patents.google.com/patent/US131947/en with status Expired - Lifetime. There is no FWD to link to, because there is no proceeding: https://www.uspto.gov/ptab (PTAB E2E) and https://developer.uspto.gov/api-catalog (ODP) both return nothing for this number.
3. If instead you are looking for a live-'947 IPR analysis, re-run this exercise against the specific 8-digit or 7-digit number (e.g., 6,411,947 or 8,xxx,947) — the proceeding list, panels, FWDs, and § 315(e)(2) estoppel picture will be entirely different, and I will not infer those results from the number "947" alone.

Caveats and confidence

• High confidence that no AIA trial proceeding exists for US131947A: the statutory regimes postdate the patent by ~140 years, and both the ODP block and my searches are empty.
• Not verified by me: whether any '947 patent is currently the subject of an expressed demand, and the full docket posture of the Bright Response '947 litigation beyond the E.D. Tex. JMOL document surfaced above. I did not locate a PTAB docket number or CAFC docket number for any '947 patent in this search, so I am not supplying one — proceeding numbers must not be guessed.
• If a web source later surfaces a proceeding number for this patent, flag it: given the 1889 expiration it would almost certainly be a mis-indexed reference to a different '947 patent or to 37 C.F.R. § 1.947.

I'll verify the assignment-record situation for this patent, starting with the coverage limits of USPTO's assignment database for 19th-century grants and any trace of a recording for this number.

Confirmed the key coverage limit (assignment database = August 1980 forward). Now checking whether the inventors ever assigned, and whether any corporate successor exists.

Assignment / ownership chain analysis — US 131,947

Scope and method note (read first): I could not directly query the live USPTO Assignment Center application (https://assignmentcenter.uspto.gov/) in this session — it is a JavaScript application with no interface available to my search tool — and neither could I query RPX's or Unified Patents' member-only asserter directories. What follows rests on (a) the authoritative patent record fetched from Google Patents, (b) USPTO/Finnegan/Data.gov documentation of the assignment database's actual coverage window, and (c) contemporaneous biographical sources on the Foster family. Where a field is unknowable, I say so rather than fill it.

Inventors

Notes on inventor patterns (and what is not present):

• Family co-inventorship, not a team of employees. Orson Foster was the father of Oscar S. Foster, Theodore Foster, and William S. Foster of Durhamville, Oneida County (per the Fitch biography entries and the Universalist Memory Garden obituaries for Theodore and William S. Foster). The "all inventors departing the original assignee within 12 months" pattern is not applicable and cannot occur here, because there was no original assignee — see below. Both named inventors share a surname and a single address, which is itself the likely explanation for the absence of any corporate assignment.
• Serial independent inventor. Oscar S. Foster was granted US 72,277 on 1867-12-17 for an "Improvement in jack for pulling hop-poles," recorded as "O. S. Foster, of Durhamville, New York." He thus had a documented habit of patenting his own mechanical improvements personally, rather than through a company.
• No assignee named on the face of the patent. The front matter reads "ORSON FOSTER AND OSCAR S. FOSTER, OF DURHAMVILLE, NEW YORK," with no "assignors to" language. For 1872 practice, that means no pre-issuance assignment had been recorded at grant.
• Claim text is not recoverable from the fetched copy. The OCR of the specification garbles the claim clause ("We claimscribed."), so I cannot quote claim 1 exactly. This is an OCR defect in the fetched page, not a change to the patent. It does not affect the ownership analysis, but it does prevent me from comparing claim scope against any product.

Original assignee

There is no original assignee. US 131,947 issued to the two inventors as individuals.

• Entity named on the issued patent: none. The patentee of record is Orson Foster and Oscar S. Foster, individually, of Durhamville, Oneida County, New York.
• Product embodying the claims: The specification asserts the machine "digging to a depth of thirty inches, is in practical operation and works well, taking out stone as large as the width of the ditch will permit, and leaving the ditch in a well-finished state" — i.e. the inventors claimed a working machine, and the machine is expressly aimed at "ditching for drain-tile," the Foster family's own trade. But no entity's commercial product line is identified in the document, and no manufacturing company is named on the patent.
• Related but separate corporate entity. Oscar S. Foster's business was conducted as O. S. Foster & Brother in Utica, New York, and was incorporated in April 1893 as the Foster Brothers' Manufacturing Company (Fitch biography; William S. Foster obituary). That incorporation occurred more than three years after US 131,947 expired, so the company never could have held this patent as a live right. Current status of the company: not determinable from the sources searched (no SEC filings exist — the SEC was not created until 1934).

Assignment timeline

The USPTO Assignment database has no records for US 131,947. I state that plainly, as instructed.

This is a database-coverage finding, not a finding that no assignment ever existed:

• The USPTO's own training material states the searchable assignment database "contains all recorded Patent Assignment information back to August 1980" (USPTO, What are Assignments? webinar deck, slide 2). Finnegan's Prosecution Pointer 119 says the same: "all recorded Patent Assignment information from August 1980 to the present" (Finnegan).
• The bulk data product is likewise bounded: "Patent Assignment XML (1980 – Present) … backfile – August 1980 – December 31, 2024" (Data.gov).
• A patent granted 1872-10-08 and expired 1889-10-08 (Google Patents "Anticipated expiration") therefore falls entirely outside the searchable window. Any 19th-century assignment would exist only as a paper/microfilm record in the Assignment Recordation Branch, indexed by reel/frame but not full-text searchable by patent number.
• The Google Patents legal-events record for US131947A shows only: application filed / granted / publication on 1872-10-08, and anticipated expiration 1889-10-08. No assignment event is listed, consistent with a patent issued directly to its inventors.

Because no assignment records exist to list, there are no reel/frame numbers, execution dates, recordation dates, assignors, assignees, conveyance types, or correspondents of record for this patent. The only names on the document in a non-inventor capacity are the witnesses — "Elish N. Kelsey" and "Kelsey O. Skaden" (OCR: "ELIsH N. KELsEY," "KELsEY O. SKADEN") — who are witnesses, not assignment correspondents, and who are not evidence of any ownership transaction.

Per the template's stop rule, the remaining sections are rendered in skeletal form rather than stopped, because the verdict taxonomy explicitly provides for a "no records" outcome and the NPE-screen fields need an explicit per-signal answer.

Timeline diagram

timeline
    title Ownership of US 131947
    1872 : Issued to Orson and Oscar S Foster
         : No assignee named on the patent
    1889 : Patent expires 8 October 1889
    1980 : USPTO assignment database begins
    2026 : No recorded assignments found

NPE / troll-pattern signals

Verdict

Insufficient data — with the strong caveat that the reason is historical rather than evidentiary. US 131,947 issued on 1872-10-08 to Orson Foster and Oscar S. Foster as individuals with no assignee on the face of the patent, and it expired 1889-10-08; the USPTO's searchable assignment database only reaches back to August 1980, so the absence of reel/frame entries is exactly what the coverage window predicts and cannot be read either as proof of no assignment or as evidence of a clean chain.

There is consequently no NPE or troll pattern to report: no shell LLC, no known asserter, no repeat recording attorney, no cascading transfers, no pre-suit transfer, no bankruptcy sale, no privateering, and no defensive-aggregator termination. A pre-1900 recordation, if one exists, would have to be verified offline against the Assignment Recordation Branch microfilm and the 1872–1889 Index of Patents assignee listings — none of which are accessible through Assignment Center.

Verify the empty result yourself at the USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search Patent Number 131947); the patent record itself is at https://patents.google.com/patent/[US131947](/patent/US131947)/en.

I'll verify the citation record for US 131,947 directly rather than infer it.

Let me verify the citation record specifically and identify pre-1872 ditching-machine art.

Now let me verify the citation record directly and check the pre-1872 ditching art.

Prior Art Analysis — US Patent 131,947

1. Headline finding: this patent has zero citations of record

The task asks me to "look at each patent citation for 131947." I have to flag, up front, that there is no citation set to look at. The Google Patents rendering of the USPTO record (fetched 2026-09-26, https://patents.google.com/patent/[US131947](/patent/US131947)/en) contains:

• no "Patent Citations" block, and
• no "Cited By" block,

because US 131,947 issued 1872-10-08, and the practice of printing an examiner's reference list on the face of a U.S. patent did not yet exist. Contrast the two control cases that surfaced in the same search: US 2629023 (1953) prints a full "REFERENCES CITED / The following references are of record in the file of this patent" table, and US 601,106 (1898, Ditching-Machine, Scott) prints none. The face-citation convention sits between those poles — it is a 20th-century artifact.

Consequence for this task: any answer that supplied a tidy list of "cited references" for US 131,947 with element-by-element § 102 anticipation would be fabricated. Under the operating rule against auto-correction and fabrication, I am not constructing one. What follows is (a) the actual citation-record status, (b) what the record does contain and why it must not be mistaken for citations, and (c) genuinely independent pre-1872-10-08 prior art that I located, mapped to the claim with confidence levels.

(Note: my operating date is 2026-09-27; the task header says April 26, 2026. Treating the fetch date of the patent record — 2026-09-26 — as authoritative for citation purposes.)

2. What the record actually contains — and what it is not

The ODP/USPTO-derived fields in the record are:

Two traps here:

1. "Prior art keywords" are not prior art. They are machine-extracted concepts from the patent's own text. They describe US 131,947, they do not cite anything.
2. The "Similar Documents" list is not a citation list. Google Patents generates it by CPC/text similarity. It appears on the record below the fold and includes 25 documents, most of them post-dating US 131,947 by decades.

2a. The "Similar Documents" list, filtered by the only date that matters

For a pre-AIA patent granted 1872-10-08, art must predate the invention (≤ Oct. 1872). Of the 25 listed documents, only four predate the grant date:

Indexing-artifact warning: "peters" and "Petebs" are not inventors' names. They are OCR residue of the lithographer's imprint ("Peters, Photo-Lithographer, Washington, D.C.") that appears on 1860s–70s patent faces and that Google Patents has mis-parsed into the title/assignee field. US 82,846 A and US 109,480 A must be pulled and read before either is relied on.

3. Independently located pre-1872-10-08 art (the best available § 102 candidates)

These come from three sources: (i) the 25-item similarity list above; (ii) the prior-art table in Bowers v. San Francisco Bridge Co., 91 F. 381 (C.C.S.D.N.Y.), at https://law.resource.org/pub/us/case/reporter/F/0091/0091.f1.0381.pdf; and (iii) the OCR text of Allen's Digest of Patents (Volume 1) at https://dn760003.eu.archive.org/0/items/allensdigestofpl01alle/allensdigestofpl01alle.pdf, which abstracts pre-1872 "Ditching Machines / Ditching Plows."

4. Element-by-element § 102 mapping against the sole claim

The specification's "We claim…" clause is presented as a single combination claim (the OCR truncates it to "We claimscribed," so the claim text itself is unavailable in this record — flagging that as a data gap). Decomposing from the description:

Bottom line: on the art I could actually retrieve, no single reference discloses all of E1–E7, so no reference anticipates the claim as an entirety under pre-AIA § 102(a) or (b). The realistic risk profile — were this patent live — would be § 103 combination of US 8,731 (yield-on-obstruction) + US 90,495 or US 123,262 (colters) + US 124,974 (dirt removal), with US 27,419 as the closest whole-machine reference pending retrieval.

5. Look-alike documents that must NOT be folded in

• US 86,294 / "86,947" — Allen's Digest OCR renders the Isaac Sheets ditching-plow (Troy, OH) as both "86,294" (Bowers table and one digest line, Jan. 26 1869) and "86,947" (another digest line, Feb. 16 1869). Do not auto-correct, and do not let the terminal "947" cause this 1869 patent to be conflated with US 131,947. Number and date are internally inconsistent in the source; treat as unresolved.
• US 133,974 — Lewis W. Fisher, Rockville, IN, Ditching-Machines, 1872-12-17, claiming "frame A, adjustable spade C, spreading-beams L." Ten weeks after Foster, same title, strikingly similar vocabulary. Not prior art to US 131,947 — it is post-dating evidence of the crowded state of the art.
• US 601,106 (1898) and US 708,616 (1902) — later ditching machines; prior art against others, not against US 131,947.
• US 6,411,947 and foreign "131947" documents (JP 2008-131947 A; WO 2007/131947 A1; EP131947; BLM accession 131947) — as set out in the previously generated sections, these are unrelated documents colliding on the identifier. Nothing in today's searches disturbs that finding.

6. Confidence, gaps, and what to pull next

Gaps I could not close: USPTO Patent Public Search / Patent Center are JavaScript-gated and returned nothing ingestible, so this analysis rests on the Google Patents rendering of the USPTO record (source of the authoritative text) plus secondary sources. I did not retrieve full texts for US 27,419, 28,247, 82,846, 109,480, nor the Allen's Digest claim text for 84,136 (Rickard, 1868-11-17), 87,892 (West, 1869-03-16), 97,183 (Foreman, 1869-11-23), 97,606 (Cline, 1869-12-07), or 107,393 (John H., 1869). I also could not retrieve the patent's actual filing/invention date or the "We claim" clause text — the OCR truncates both.

Highest-yield next steps, in order: (1) pull US 27,419 in full — same statutory category, same era, explicitly listed as ditching-machine prior art in a litigated Bowers record; (2) pull US 90,495 and US 123,262, the two closest colter references; (3) pull US 28,247, 82,846, and 109,480 to resolve the mis-indexed titles; (4) obtain the original printed Specification for US 131,947 (patentimages PDF via the Google Patents "Download PDF" link) to recover the truncated claim verbatim before any final infringement/validity mapping.

Legal bottom line (unchanged from the prior sections, and not disturbed by anything found today): US 131,947 expired 1889-10-08 and is public domain. Its § 102 analysis therefore has no forward-looking legal consequence — it is of interest only as printed-publication art (as of 1872-10-08) against later patents, and as a historical record of the Foster brothers' work at Durhamville, NY.

I'll ground the prior-art references from the page before analyzing.

Let me pin down the two remaining pre-1872 references and check for secondary-art analogues.

Obviousness Analysis — US Patent 131,947 under 35 U.S.C. § 103

Built on the prior sections (patent summary, litigation summary, PTAB challenges). Where those sections are contradicted by the record, I flag it rather than repeat them.

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0. Scope note: what the "Prior Art section" of this page actually supplies

This matters more than usual, because the page's prior-art apparatus is thin and partly machine-generated. Taking it at face value, the "Prior Art" content of the record is four things:

Two findings up front:

1. The record contains no patent-citation or "Cited By" block. No examiner-cited references survive in this database entry for US131947A. Any § 103 combination therefore has to be constructed from (a) the specification's own admissions, (b) the four pre-1872 members of the Similar Documents set, and (c) contemporaneous ditching-machine art. I am not permitted to invent a "References Cited" list.

2. 21 of the 25 "Similar Documents" are not prior art at all. Every entry dated on or after 1873-07-15 post-dates the 1872-10-08 grant. Under the law in force (and equally under AIA § 102(a)(1)–(2)), a document issued after the critical date is not prior art, and § 102(a)(2) does not rescue them because their effective filing dates are also after 1872-10-08. They are usable only as evidence of the later state of the art, and using them to build a § 103 combination would be textbook hindsight.

Note on the last two: "peters" and "Petebs" are OCR corruptions of the printer's imprint line ("N. PETERS, PHOTO-LITHOGRAPHER, WASHINGTON, D.C.") that appears on pre-1870s US patent front pages. I could not retrieve the actual subject matter of US82846A or US109480A — my searches for those numbers returned only unrelated modern documents (US82846A and US109480A as application serial numbers in 20th-century patents). Placing them by date only: 82,846 falls between two confirmed ditching patents in the 82,xxx–84,xxx range (US80,880, Aug. 1868; US84,136, Nov. 1868), and 109,480 falls between US109,251 (ditching machine, Nov. 15, 1870) and US109,567 (Nov. 22, 1870) in a dense ditching-machine cluster. That is inference about the art's density, not a statement about those two documents' contents.

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1. Legal framework — and the limitation it imposes

§ 103 did not exist in 1872. The Patent Act of 1952 first codified non-obviousness. At grant, the operative statute was the Act of 1870, and the non-obviousness requirement was judge-made, dating to Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851) — whether the difference from the prior art required "more ingenuity and skill … than were possessed by an ordinary mechanic acquainted with the business." I give the modern Graham v. John Deere Co., 383 U.S. 1 (1966) / KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) analysis you asked for, but note that the Hotchkiss inquiry is the historically correct frame and produces materially the same result on this record.

The critical limitation — claim scope is unrecoverable. The claim text on the page is corrupted: "We claimscribed. ORSON FOSTER. OSCAR S. FOSTER." There is no claim language to construe. Everything below is therefore conditional, and I label the four specification "consists in" statements as proxy elements, not as claims.

Contradiction flagged (per your instruction). The earlier Patent summary section correctly stated: "I cannot give you the literal claim language, and I will not reconstruct it." The earlier PTAB challenges section then asserted: "The patent has one independent claim in the modern sense — the specification's 'We claim' clause is presented as a single claim covering the combination (…)." Those two statements are in tension. The specification's "consists in" passages are not claim language, and treating them as a single combination claim is an inference. I proceed on that inference because it is the only workable hypothesis for a § 103 exercise — but it is an assumption, and every conclusion below inherits its uncertainty.

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2. The proxy elements

(Substance is in the prior sections; reproduced only as labels to hang the rejections on.)

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3. Level of ordinary skill — October 1872

A POSITA here is not a modern engineer. The person is a practical mechanic/millwright experienced in horse-powered agricultural and earth-moving machinery: competent to design gear trains, crank-and-connecting-rod drives, pivoted beam suspensions, pawl-and-spring trips, sliding tool mounts, and gauge/height adjustment, working from printed specifications and the trade press. No formal degree; ordinary mechanical drawing literacy; the reference works are the annual Commissioner of Patents reports and commercial digests of the sort I cite below. The art was extremely crowded (see § 5, Ground D), which under KSR raises the presumption that most incremental changes were within skill.

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4. The four usable references — what they actually disclose

4.1 US8731A — Calvin Willey, Jr., "Excavating and dredging machine," 1852-02-10

patentimages PDF · Google Patents

Four stated aspects, two of which are directly on point:

• Pivoted/swinging digging frame with obstruction protection. The frame G is "attached to the shaft B, by means of collars c, so that it may be free to move or swing on said shaft … moving in the arc of a circle."
• Express problem statement matching Foster's. Willey states the invention includes "hanging the frame which carries the plows and buckets so that it may be lowered by a positive motion, instead of by its own weight, to prevent the plows from being drawn too rankly into the bank when striking against or cutting through any hard substance," and that this "prevents the plows and buckets from cutting too deep and from drawing or forcing themselves into the bank, when cutting through any hard material which would otherwise break up the machine."
• Feed-rate regulation. "The motion of this drum, which feeds up, as it were, the machine to its work may be regulated by the size of the drum, or of the cog wheel which operates it, so as to adapt the feed to the peculiar quality of the material to be excavated."
• Plows precede buckets — the cut-then-gather ordering.

4.2 US28247A — Benedict & Cummings, "Ditching-machine," 1860-05-15

patentimages PDF · Google Patents

• A colter co-acting with a ditching scraper. "Q is a broad plow scraper extending across the frame and firmly secured to it immediately under the elevators, by which the earth is plowed or loosened up for the more direct action of the buckets, on one side of the scraper and a little in advance of the same is a colter R …, for the purpose of cutting the turf or earth whereby the scraper can the more easily follow and perform its work."
• Powered dirt discharge from the excavating member. Deflecting rods O, O′ tip the loaded buckets so that they "discharge their contents," and side guides P, P right them for refilling.
• Depth/width regulation. Depth set by caster wheel C "regulated … by the lever and screw, D"; gauge wheel S "so connected with the frame … by the means of a slotted slide and set screw that it may be placed at any desired distance."
• Drive. Cogs H on driving wheels B → pinions I → shafts J → pinions K → disk rims L, carrying the excavating buckets M.

4.3 US31,376 — Doolittle & Eldridge, "Ditching-machine," 1861-02-12 (secondary reference)

patentimages PDF

Not on the page's Similar Documents list, but I use it because it supplies elements the page's list does not, and it is squarely § 102(b) art:

• A scoop suspended in a frame that rises and falls within the ditch ("an interior sliding frame (E) … suspended from a pulley (a′)"), with lifting by pawl-and-ratchet.
• Powered clearing of a sticky/stuck load by induced vibration: the spout J is arranged so that it "may be lowered in order to give a shaking motion to the spout, to facilitate the discharge of the earth."
• Roller on a band to take up slack as the scoop changes elevation ("a roller (g) which is so arranged as to raise the band, and take up the slack").

4.4 US31,551 — E. C. Martin, "Improved Ditching-Machine," 1861-02-26 (secondary reference)

patentimages PDF

"two adjustable friction-rollers, N N" in a ditching implement follower, adjusted "so as to allow the rollers to project more or less beyond the under surface."

4.5 Contemporaneous crowding evidence (docket/digest, pre-1872 only)

• Bowers v. San Francisco Bridge Co., 91 F. 381, prior-art table (US letters patent): 27,419 — J. Barcroft, "Improvement in ditching machines," Mar. 13, 1860; 24,750 (Menge, dredging, 1859); 38,544/39,194 (Atkinson, 1863); 75,003/75,004 (Duvall, 1868). PDF
• Allen's Digest of Patents (contemporaneous, listing claims verbatim) shows the 1868–1872 ditching-machine series already claiming, e.g.: US90,495 (Burtless, 1869) — "scoop G, colters I I, and adjustable mold-board K"; US97,606 (Cline, 1869) — "the broad curved scraper I, working up and down on guides b b"; US105,995 (Stephens, Aug. 2, 1870) — "the pivoted cutter L, operated by the lever M, adjustable on the perforated bar N"; US107,393 (Martin & Bradshaw, Sep. 13, 1870) — "the adjustable rotary colter D"; US108,217 (Vannatta, Oct. 11, 1870) — "beam B, standards a, hinged bars b, windlass C and d, and frame A … chains or rods i, and a plow"; US109,091 (Winter, Nov. 8, 1870) — "the device B C D … with the revolving cutters L L"; US119,209 (Whitesell, Sep. 19, 1871) — "disks C to cut the sides of the ditch, the disk L to centrally incise the sod," plus "movable axle-frame … so as to raise and lower the point of the plow." PDF, pp. 157ff

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5. Grounds of rejection

Ground D first (it frames the others) — E1: the combination as a whole

Rejection: E1 is obvious over US28247A in view of US8731A, and further in view of the crowded contemporaneous art (§ 4.5).

Differences from a single reference: US28247A has spade-equivalent excavator (bucket disks), a scraper (Q), a colter (R), powered discharge (rods O/O′), feed/drive gearing, and depth regulation — but the digging member is a rotating bucket train, not a reciprocating spade; and US8731A has a swinging digging frame with a crank-and-drum drive and regulated feed, but a chain of plows rather than a ditch spade.

Motivation to combine, per KSR: (i) both references are in the same field (earth excavation for drainage/waterways) and address the same known problem — protecting the digging element from the hard material that "would otherwise break up the machine" (Willey); (ii) the field had by 1872 a finite, small, and well-catalogued set of known solutions for ditch digging — reciprocating spade, endless-chain plows + buckets, rotating shovels, and plow/scraper graders — as the digest and the Bowers table demonstrate; (iii) market pressure was explicit and strong: tile-drainage ditching was a volume agricultural need, and the digest titles themselves market "more effectively and expeditiously and hence much cheaper" (US28,247); (iv) a POSITA had a reasonable expectation of success because each sub-combination (spade + scraper + crank drive + windlass feed) was individually known and its function predictable.

Corroborating admission — this is the strongest single point in the analysis. The specification itself concedes the entire environment is conventional: the machine "is operated by the sweep S, and is fed forward … by a windlass, G, as ordinarily"; "The machine is mounted on four small wheels, V, as usual, and its height is regulated by crank-axles T T." An applicant's own specification is prior art against him, and these are express admissions that the drive, feed, and mounting elements are old. Likewise Google's own prior-art keyword extraction reduces the document to "spade, ditching, machines, crank, improvement" — every term but "improvement" names an old element. E1 therefore reduces to an aggregation of admitted-old parts plus three mechanisms, each separately old (§ 4), each performing its own expected function. That is the paradigm KSR case: "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results."

Expected rebuttal and its weakness: the patentee would say the combination achieves a unitary result (a well-finished ditch 30 inches deep, stone cleared). But that is the sum of the parts' separate functions, and the record contains no evidence that the combination produced a result beyond what the individual mechanisms predict. The patentee's own words — "is in practical operation and works .well" — assert operability, not synergy.

Ground A — E2: the beam-B / roller-b / free-to-rise suspension

Rejection: E2 is obvious over US8731A in view of US28247A (and either US80,880, Smith & Buckley 1868 — "hanging the ditcher in a frame … avoiding the use of a beam," or US31,376).

• US8731A teaches the genus: pivot the digging assembly so it swings in an arc, and configure the suspension so that encountering hard material does not break the machine. That is Foster's stated purpose ("greater elasticity in yielding to large stones or other obstructions") verbatim in substance.
• US28247A teaches a ditching machine whose working member (scraper/buckets) is mounted on a frame with screw/gauge height control — i.e., the ditch-digging context in which the POSITA would apply the Willey teaching.
• The specific mechanics — a pivoted beam carrying an anti-friction roller on its free end riding a reciprocating member — are routine: rollers on reciprocating/oscillating earth-working elements appear in US31,551 ("adjustable friction-rollers N N," in a ditching implement) and US31,376 (roller (g) taking up slack on a band). Using a roller instead of a sliding shoe to reduce friction on a travelling beam is a design choice with a predictable benefit.

Motivation: both references address breakage/digging-in on hard material; a POSITA seeking a machine that "can be forced up by any obstruction that it does not overcome" would naturally look to the pivoted-frame art, and gravitationally biasing the beam to hold the tool down on the cutting stroke while leaving the free end unrestrained on the return is the most obvious mechanical arrangement available.

The one genuine teaching-away argument, and why it fails: Willey says he lowers his frame "by a positive motion, instead of by its own weight, to prevent the plows from being drawn too rankly into the bank." A patentee could argue this disparages weight-actuated depth behaviour. It does not teach away from Foster. Willey's objection is to using gravity as the depth-setting mechanism, which would let the tool "be drawn too rankly into the bank." In Foster, depth is set by the crank throw and connecting beam D; beam B only supplies a downward bias within that envelope and yields upward on obstruction. Willey's concern is not implicated, so the reference is not "taught away" in the KSR/In re Gurley sense — it is simply addressed to a different failure mode.

Ground B — E3: the sliding, stroke-actuated colter

Rejection: E3 is obvious over US28247A in view of US105,995 (or US107,393 / US119,209).

• Colter-per-se in a ditcher: US28247A's colter R, positioned "a little in advance" of the scraper "for the purpose of cutting the turf or earth whereby the scraper can the more easily follow." Foster's stated purpose — loosen stone and hard earth so "the spade cuts freely" — is the same stated purpose, achieved with the same class of tool in the same location (at the leading edge of the digging member).
• Making the cutter movable so that it acts only on the working stroke: US105,995 (1870) claims "the pivoted cutter L, operated by the lever M, adjustable on the perforated bar N," establishing movable/adjustable cutters in ditchers. US107,393 (1870) claims an "adjustable rotary colter D." US119,209 (1871) claims disk cutters "to cut the sides of the ditch."
• Automatic actuation from an existing reciprocating member: converting "operated by the lever M" into actuation by the machine's own cycle is the ordinary substitution of an automatic follower for a manual lever — a predictable improvement in a machine that already reciprocates a driving beam. Slotted-head-and-pin lost-motion couplings were standard mechanical vocabulary for converting angular change into limited linear travel.

Motivation: retracting a colter on the non-cutting stroke reduces drag, plowing resistance, and wear; projecting it only during the cut concentrates the loosening force where it is needed. Foster states exactly this benefit, which is itself evidence that the benefit was foreseeable in advance — the hallmark of obviousness rather than invention.

Honesty about the gap: I have not located a pre-1872 reference disclosing the specific combination of (a) colter sliding inside the spade standard, and (b) actuation by a projection on the driving beam engaging a slotted head so that angular change between beam and spade drives the colter out. If the claim is drawn narrowly to that lost-motion linkage as a structure, Ground B is the weakest of the four and I would not predict invalidity on this record alone. If the claim is drawn to a movable colter projected on the digging stroke and withdrawn on the return (the functional statement the specification actually makes), Ground B is strong.

Ground C — E4: spring-thrown scraper discharge with trip release

Rejection: E4 is obvious over US28247A in view of US31,376, and further in view of the ordinary spring-and-pawl trip art.

• US28247A discloses powered, machine-timed discharge of the excavating member's load by fixed deflecting rods (O, O′) acting as the element passes — i.e., automatic discharge cued to the machine cycle. That is the function of Foster's arms M and pin 1.
• US31,376 discloses (i) pawl-and-ratchet control of the scoop, (ii) a scoop on a sliding frame that is raised and lowered, and (iii) deliberate agitation of a discharge member to clear stuck earth — "lowered in order to give a shaking motion to the spout, to facilitate the discharge of the earth." A POSITA seeking "a very sudden and rapid movement … for its discharge" (Foster's stated object) has a well-known answer: substitute a stored-energy spring for the gravity/agitation discharge of the prior art. Spring-loaded ejectors and spring-thrown trips were ubiquitous in contemporaneous agricultural and earth-working machinery.
• Timing the release off the main cycle (pin 1 on the spade standard tripping the pawl on lever N) is the same design pattern the reference already uses (US28247A's fixed deflecting rods keyed to machine position; US31,376's pawl/ratchet). In a single-crank machine with one reciprocating spade, indexing a trip to the spade's position is the most natural available trigger.

Motivation: two mutually consistent rationales — (1) speeding the discharge stroke to raise machine throughput (the specification itself ties throughput to an adjustable, i.e. speed-regulated, feed: crank O "adjustable in length, to regulate the speed of the machine"), and (2) overcoming the adhesion/sticking problem US31,376 already identified and solved by agitation. Replacing agitation with a spring-thrown snap is an obvious strengthening of the same solution.

Honesty about the gap: the specific lever N / pawl / pin 1 interlock is a detail-oriented limitation. I found no single pre-1872 reference disclosing a spade-standard pin releasing a scraper pawl. That element would likely survive a § 103 challenge if it were recited as a structural sub-combination in its own right — but as part of a broad combination claim to the machine as a whole, it is one more mechanism in an aggregation of old mechanisms.

Ground E — E5: the ancillary/adjustability features

Trivially obvious. Adjustable-length cranks and adjustable-length striker arms to vary machine speed are disclosed as the patentee's own stated purpose ("to regulate the speed … as desired"). Where the only difference is making an existing element adjustable to a range of known operating conditions, § 103 is met: the result (variable feed rate) is predictable, and US8731A already teaches matching feed rate to "the peculiar quality of the material to be excavated."

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6. Consolidated motivation to combine

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7. What this analysis does not establish

1. No anticipation (§ 102) is made out from the page's prior art. None of the four pre-1872 references discloses the whole of any proxy element in a single document. This is a § 103 case or nothing. I want to be explicit rather than let the four grounds drift into an anticipation claim they cannot support.
2. Claim language is unknown. Everything rests on the assumption that the claim follows the "consists in" statement — an assumption I flagged as an inference and which conflicts with the express refusal to reconstruct claims in the earlier Patent summary section.
3. US82846A and US109480A are unretrieved. Both fall inside a dense ditching-machine cluster by date, but I could not verify their subject matter, and I have not used them in any ground. If either is a ditching machine with a pivoted tool-carrying beam, a movable colter, or a spring discharge, it could strengthen (or, if it anticipates, collapse) Grounds A–C.
4. No file wrapper, no examiner's rejection, no contemporaneous validity challenge on this patent (consistent with the litigation and PTAB sections). So there is no historical record of how the Office actually treated these elements, and no inter partes record to test the combinations against.
5. The Graham secondary-considerations record is essentially empty. The only candidate is the specification's "in practical operation and works .well," which is the patentee's own uncorroborated assertion, lacks any third-party evidence of commercial success, has no established nexus to any specific proxy element, and shows no long-felt but unsolved need, no failure of others, and no copying. It does not outweigh the art.

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8. Bottom line

On the record available, the strongest § 103 position is Ground D (the combination as a whole) supported by Grounds A and C. The invention as the specification describes it is an aggregation of admitted-conventional machine elements (sweep, gears, crank, windlass feed, wheels, crank-axles) plus three mechanisms each of which has a close pre-1872 analogue in the same field: a pivoted, obstruction-yielding digging frame (US8731A), a leading colter acting with a ditch scraper (US28247A), and machine-timed powered discharge of a sticky load (US28247A; US31,376). Each mechanism performs its own expected function, and the applicant's stated benefits are the predictable consequences of those functions. Under KSR, that is obviousness.

Ground B (the stroke-actuated colter) is the fragile one. If the claim is construed to the specific spade-standard-sliding colter with a slotted head driven by a beam projection through angular change, I cannot invalidate it on the references I have, and I say so rather than stretch a reference to fit. Ground C has the same shape of weakness at the pawl/pin-1 interlock, though less severely.

Confidence: High that this is a textbook obviousness-over-old-elements case in its broad aspect; materially lower as to any narrow structural sub-combination in E3 or E4, because the claim text is unrecoverable and I am reasoning from an inferred claim. Reproduce the claim from the original printed patent (or the patentimages PDF US131947A) and this analysis must be re-run claim-by-claim; likewise retrieve US82846A and US109480A, which are the two prior-art entries on the page I could not read.

Minor record note, already flagged in the earlier section: the fetched page is timestamped 2026-09-26 while the task states the current date as 2026-04-26. Neither affects the 1872/1889 critical facts.