US 177139

I'll run searches against patent databases and court docket sources before summarizing.

Let me try more targeted queries for the patent page itself and for any litigation/docket references.

One more round to check for any litigation/assignment history and inventor corroboration.

US Pat. No. 177,139 — Verified Summary

Source of record (authoritative): the full text supplied from https://patents.google.com/patent/[US177139](/patent/US177139)/en. My web searches did not independently surface this patent page, and no CAFC/PTAB docket material for the number "177139" was returned — see caveats below.

Bibliographic data

Plain-language overview of the sole claim

The claim reads: "An improved stop device for ratchets of all kinds, consisting of the combination of the ratchet-wheel with sliding and turning pinions and locking-recesses of a retaining band or ring, substantially as specified, for the purpose set forth."

Stated plainly, the claim covers the combination of three cooperating elements:

1. a ratchet wheel;
2. one or more small pinions that both slide and rotate; and
3. a retaining band/ring encircling the ratchet that contains locking recesses,

arranged so the pinions permit rotation in one direction and positively lock the ratchet against rotation in the other direction.

Because the claim is drafted in classic 1876 "combination, substantially as specified" style with no separate structural limitations, its scope is tied to the described embodiment rather than to any sub-combination.

How the described embodiment works (context for the claim)

• Ratchet A is surrounded by a circular band/frame C ("0" in the OCR) formed with recesses a.
• Preferably three pinions B, spaced equidistantly, gear with the ratchet and rotate jointly with it, sliding within the recesses.
• Each recess is concentric with (i.e., of full pinion width at) one end and tapers toward the other end to a width less than the pinion diameter; the narrow ends are toothed to mesh with the pinion cogs.
• Free direction: the pinions roll into the wide ends and turn with the ratchet.
• Locked direction: the pinions are "instantly carried" into the narrow toothed ends, wedging between the ratchet teeth and the recess teeth — a positive lock with the load taken from different sides, claimed to reduce wear/strain.
• Optional cap-piece over ratchet and pinions, fastened by screws.
• Stated purpose: replace breakage- and wear-prone spring-pawls/clicks used where strong springs must be held at a single tooth.

Corroboration of the inventor

A later patent, US 485,645 (Electric Clock, patented Nov. 8, 1892), names James D. McAnlis and Harvey E. Fleming, of Beaver Falls, Pennsylvania — consistent with the inventor's identity and residence recited in US 177,139. That document does not establish any assignment of US 177,139.

Caveats and uncertainties (stated explicitly)

• Assignee: I have no authoritative record of an assignee or of any assignment for US 177,139. The specification as published contains no assignment recital, so I report "none stated" rather than inferring one.
• CAFC 2026 dockets: my search for "177139" in Federal Circuit 2026 docket sources returned no results. I therefore have no evidence of any 2026 litigation or appeal involving this patent. Given an 1893 expiration date, such litigation is implausible, but I am flagging the absence of confirmation rather than asserting a negative I cannot fully prove.
• No abstract exists for this patent; any abstract offered elsewhere for US 177,139 would be third-party text, not the patentee's.
• Do not confuse this with application Ser. No. 177,139, which issued as US 3,139,883 (J. M. Collins, surgical traction device for stretchers) — a different number type entirely. Similarly, the "similar documents" list on the Google Patents page (e.g., US 178,371 for watch-spring barrels; US 971,500, Groff ratchet mechanism) refers to other patents.
• The transcribed text contains OCR corruptions (e.g., "0" for reference character C, "860." for "&c.", "MoANLIS" for McAnlis). I have not auto-corrected identifiers; the readings above reflect a literal reading of the supplied text.

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

The first searches returned no matching case records. Let me run more targeted queries, including the litigation portals you named.

Let me run a few final confirmatory checks.

Result: No litigation found involving US Patent 177,139

I searched for litigation specifically tied to US Patent 177,139 (the numeral you gave — not 177,139A's family members, not similarly numbered patents) and found no district court, Federal Circuit, or PTAB proceedings. Every litigation-portal query returned zero case records for this patent number.

Important caveat on a false-positive hit

The only result in any query that contained the string "177139" was SG‑177139‑A1, a Singapore patent titled "Mobile Communication Method, Mobile Station, and Radio Base Station" (applicant NTT Docomo, priority 2008‑05‑28, grant date 2012‑01‑29), surfaced via the Unified Patents portal. That is not your patent. It is a different jurisdiction, a different technology, and a different numbering authority. Per your instruction to interpret identifiers literally, I am explicitly flagging it as excluded rather than treating it as a match. No litigation was found for it either, for what it's worth — I mention it only so you know what the search engine was actually returning.

Case table

Why the negative result is credible here (and its limits)

1. The patent's own record shows no enforcement activity. The Google Patents bibliographic record for US177139A lists only family ID 2246546, one family application, one country status (US), and a single legal event: "Anticipated expiration, 1893‑05‑09." There is no reissue, reexamination, assignment-litigation record, or third-party citation of the kind that typically accompanies an asserted patent.

2. The term had already run by the time modern reporting systems existed. Granted 1876‑05‑09 on an application filed 1876‑04‑10, the patent expired 17 years later. PACER's electronic coverage does not extend to 1870s–1890s federal filings, the Federal Circuit did not exist before 1982, and the PTAB did not exist before 2012. Unified Patents' and similar portals track post‑AIA proceedings and modern NPE campaigns; their coverage windows make a 19th‑century suit invisible to them by design. So my "no litigation" finding means no litigation appears in the sources I can reach, not that a suit provably never occurred.

3. What I cannot rule out. An 1870s–1880s infringement action, if one existed, would have been brought in a U.S. circuit court and would be documented only in (a) manuscript/National Archives docket books, (b) Federal Reporter volumes, (c) The Federal Cases digest, or (d) contemporaneous periodicals such as The Patent Record or Scientific American. I did not find any such reference, but those archives are not indexed by the tools available to me — this is a genuine evidentiary gap, not a confirmed absence.

Recommended next steps if you need a defensible negative

• National Archives (NARA) regional holdings for the Circuit Court for the Western District of Pennsylvania (Beaver Falls is in Beaver County, W.D. Pa.) — the natural venue for the patentee, James D. McAnlis.
• The Federal Cases (West, 30 vols.) and Federal Reporter vols. 1–60, searched under "McAnlis" and under the patent title keywords ratchet, pawl, click.
• USPTO Assignment records for the 1876–1893 window (recorded assignments often precede or accompany suits), and the Commissioner of Patents' annual Decisions.
• 19th‑century watch-industry trade press (e.g., Jewelers' Circular, The American Jeweler) for reports of infringement suits by or against watchmakers.

If your actual target is the Singapore patent SG‑177139‑A1 or a different similarly numbered US patent, tell me and I'll search that identifier specifically rather than assuming.

I'll verify the structured ODP data against any web-indexed PTAB activity before writing the analysis.

PTAB / AIA Trial Analysis — US 177,139 A

"Improvement in ratchet-stops for watches and other machinery"
Inventor: James D. McAnlis (Beaver Falls, Beaver County, Pennsylvania)
Application filed: 1876-04-10 · Granted: 1876-05-09 · Anticipated expiration: 1893-05-09
Source: https://patents.google.com/patent/[US177139](/patent/US177139)/en

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Proceedings overview

There are zero AIA trial proceedings on file against US 177,139 — no IPRs, no PGRs, no CBM reviews, and no Federal Circuit appeals arising from any PTAB decision. This is not a data gap to be filled by searching harder; it is the structurally correct answer for a patent that was granted in 1876 and whose term expired on 1893-05-09, roughly 119 years before the PTAB heard its first AIA petition. The defensive posture this gives a defendant is the strongest one that exists in patent law: the patent cannot be infringed by anyone, because it has been expired for over 130 years. If a demand letter cites US 177,139, the sender is not asserting an enforceable patent — and any litigation premised on it would be exposed to a § 285 fee motion and Rule 11 exposure on the face of the pleading.

The structured ODP block you supplied is canonical and returns an empty proceedings list; my independent web searches returned no PTAB, CAFC, or district-court activity tied to this patent number (search results matched only unrelated proceedings, e.g., IPR2016-00802 on US 9,044,056, which is a different patent entirely). No PTAB activity on file.

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Proceedings on file

None. There are no proceeding numbers to report, so the per-proceeding template has no entries. I am not listing placeholder or speculative proceeding numbers, and I will not infer one from the "Similar Documents" list on the Google Patents page (EP3914837B1, US20080307915A1, DE952879C, etc.) — those are classification-neighbor citations to other patents, not challenges to this one.

Why the list is necessarily empty

Derived-field caution for anyone reading the Google Patents page

Several machine-generated fields on the source page are artifacts, not substance, and should not be relied on in a filing:

• "Prior art date 1876-05-09" is the grant date being mapped to a prior-art field. The actual filing date is 1876-04-10. Neither is a prior-art date in the pre-AIA sense; 1876-05-09 is the § 102(a)/(b) publication date of the patent itself.
• Cooperative classification B23Q16/02–16/04 (indexing equipment; pawls for locking indexed positions) and USPC Y10T74/1558 are the mechanically sensible placements — the disclosure is a ratchet-stop/indexing mechanism. These are accurate.
• Landscape tag "241000499489 Castor canadensis" (beaver) is OCR/entity-extraction noise from the inventor's location, Beaver Falls, Pennsylvania. It has no bearing on claim scope, field of use, or prior art. Do not let it into any claim-construction or classification argument.
• Claim text and specification OCR is degraded ("MoANLIS" for McAnlis, "frame, 0" for frame "C", "Thesliding"). The Google Patents OCR renders the reference numeral for the retaining band as "0" (zero) where the drawing and context require the letter "C". If you need the claim language for a brief, pull the USPTO Patent Public Search / PatentCenter "official" full-page image (PDF) rather than the HTML-derived text.

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Strategic summary

Claim status: one claim, UNTESTED — because it can never be tested. The patent contains a single, unnumbered combination claim: "An improved stop device for ratchets of all kinds, consisting of the combination of the ratchet-wheel with sliding and turning pinions and locking-recesses of a retaining band or ring, substantially as specified, for the purpose set forth." There is no IPR certificate canceling it, no FWD sustaining it, and no district-court judgment on it. The distinction that matters for a defendant is that UNTESTED here does not mean "untested and therefore dangerous." It means there has been no adjudication because there has been no live dispute to adjudicate: the § 154 term ran out on 1893-05-09 (17 years from the 1876 grant, the then-applicable term), and the pre-1980 statute imposed no maintenance fees that could have lapsed or been revived. No claim of this patent is presently enforceable by anyone, and none has been enforceable since the 19th century.

Estoppel landscape: no estoppel exists in either direction — and that cuts only one way. Because no AIA trial has ever been instituted or carried to a Final Written Decision, no petitioner has triggered the § 315(e)(1)/(e)(2) estoppel bar, and no patent owner is protected by an earlier PTAB win. In an ordinary case that would be bad news for a defendant, who would face a full slate of unused grounds. Here it is irrelevant: every prior-art ground remains available to a defendant, but there is nothing left to invalidate for practical purposes. Even the standard six-year damages lookback under 35 U.S.C. § 286 reaches back only to 2020, which is 127 years after expiry. A defendant's real cause of action is not invalidity — it is the demand letter itself.

Pattern signals: none, and none possible. There is no repeat petitioner, no serial-IPR campaign, no defensive aggregator (Unified Patents, RPX, Unified's "IPR engine," or similar) in the chain, and no patent-owner appeal practice at the Federal Circuit. A defensive aggregator's economics require a live assertion campaign against operating companies; an 1893-expired patent cannot generate one. The absence of PTAB activity here is therefore not the usual soft signal ("well-asserted patents eventually attract IPRs"). It is a categorical signal: no entity can infringe, so no entity has standing or incentive to challenge.

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Recommended next steps

If a demand letter or pleading cites US 177,139:

• Lead with expiry, not invalidity. The patent's own front page records the expiration as 1893-05-09 ("Anticipated expiration," legal status "Expired - Lifetime" — https://patents.google.com/patent/US177139/en). Because there is no FWD to link to, your citation should be to 35 U.S.C. §§ 154, 271, and 286: a patent confers the right to exclude only during its term, and damages are unavailable for any period more than six years before suit — here, no period within the lookback can contain an act of infringement.
• Characterize the assertion correctly. A demand resting on this patent is not a close validity question; it is a non-infringement question answerable on the face of the patent. Preserve the letter and envelope, and if the matter reaches a filed complaint, consider a motion to dismiss for failure to state a claim, a Rule 11 safe-harbor letter, and a § 285 exceptional-case request. Depending on the facts and jurisdiction, state-law unfair-competition or deceptive-trade-practice theories may also be available.
• Verify the negative yourself, cheaply. (1) PTAB E2E / PTAB Center (https://ptab.uspto.gov) and the PTAB Decisions archive (https://www.uspto.gov/patents/ptab/decisions) — search the literal strings "177139" and "177,139". (2) USPTO Patent Public Search (https://ppubs.uspto.gov) for the patent's own file wrapper, to confirm no post-issuance certificate (reexam, reissue, disclaimer) was ever recorded; note that a disclaimer under 35 U.S.C. § 253 is the only realistic post-1893 event that could appear in a file wrapper. (3) CourtListener / RECAP (https://www.courtlistener.com) and Docket Alarm for any docket naming the patent number — my searches found none, but a paid docket search covers districts that are poorly indexed in free sources. (4) Federal Circuit docket search for any appeal keyed to the patent number.
• Do not cite the Google Patents "Similar Documents" or landscape tags as if they were citations of record. They are algorithmic neighbors and, in the case of the "Castor canadensis" tag, a geographic artifact of Beaver Falls. Also flag the OCR numeral error ("frame, 0" for the retaining band) if the claim text ever has to be quoted — quote from the official PDF, not the HTML.

If you were expecting active proceedings: there are none, and there is no statutory path by which any could be pending. The relevant milestones (institution-decision deadline, oral hearing, one-year FWD deadline) do not exist for this patent. The final word on US 177,139 is not a PTAB disposition — it is the 1893-05-09 expiry that ended the patent's life before the Patent Act of 1952, let alone the AIA, was enacted.

I'll verify the assignment record before writing anything.

Assignment & Ownership Analysis — US Patent 177,139

Patent: "Improvement in Ratchet-Stops for Watches and Other Machinery"
Granted: 1876-05-09 · Filed: 1876-04-10 · Anticipated expiration: 1893-05-09
Source of record: https://patents.google.com/patent/[US177139](/patent/US177139)/en · USPTO Assignment Center: https://assignmentcenter.uspto.gov/

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Inventors

Notes and caveats:

• The specification is signed "JAMEs 1). MoANLIS" in the OCR text; the grant header reads "JAMES 1). MoANLIS, or BEAVER'FALLS, PENNSYLVANIA." These are OCR corruptions of a single name — the reliable reading, consistent across the header, the grant line, and the claim signature, is James D. McAnlis. No second inventor is named anywhere in the document.
• No departure pattern can be assessed. The "all inventors left the assignee within 12 months" heuristic requires an assignee of record; this patent has none (see below). Beaver Falls, PA in 1876 was a mill-and-file-works town, not a watch-manufacturing center, so no corporate employer is inferable from geography. I could not confirm any employer, partnership, or workshop association for McAnlis, and I decline to guess.
• Attesting witnesses on the specification were J. A. Cline (OCR: "J. A. OLINE") and Jno. A. B. Patterson. These are witnesses to the instrument, not assignment correspondents — they must not be reported as correspondents of record.

Disambiguation warning for anyone repeating this search: the string "177139" is highly prone to collision. U.S. Patent 3,139,883 was filed under Serial No. 177,139 — a search for "177139" surfaces that unrelated 1962 traction device as its top hit. The number analysed here is the patent number 177,139, not application serial 177,139.

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Original assignee

None. The patent issued to the inventor, James D. McAnlis, in his own name, with no assignee named on the face of the grant.

• The front page, the granting line, and the claim signature all name only the inventor. There is no "assignor to" clause and no corporate entity anywhere in the document.
• Product embodying the claims: no evidence of manufacture or commercialisation. The patent describes a bench-level improvement for escapement-adjacent ratchet/stops in watches and clocks; nothing in the record indicates McAnlis built, licensed, or sold a device.
• Primary line of business: individual mechanic/inventor, occupation unrecorded.
• Current status: the underlying rights ended at the statutory term expiry on 1893-05-09; Google Patents lists the legal status as Expired – Lifetime. The inventor is long deceased (19th-century grant). Treat the asset as public domain for ~133 years.

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Assignment timeline

The USPTO Assignment Center contains no recorded assignments for US Patent 177,139. There is nothing to enumerate.

Two independent grounds support this finding rather than merely a null search result:

1. Database coverage. The USPTO's own documentation states the assignment database "contains all recorded Patent Assignment information back to August 1980" (USPTO What are Assignments? deck, https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf). Patent 177,139 issued 1876-05-09 — roughly 104 years before the searchable record begins. Any nineteenth-century conveyances, even if they existed, were never entered into the digital record and are not searchable by patent number.
2. Google Patents legal-events log. The legal events section of the Google Patents record lists exactly four entries — application granted (1876-05-09), publication (1876-05-09), anticipated expiration (1893-05-09), and current status Expired – Lifetime. There is no "Assigned to" event. Google Patents ingests recorded USPTO assignment data, so the absence there corroborates the Assignment Center result.
3. Family records. The Google Patents family (ID 2246546) contains a single application/patent — US177139A via US177139D. No family member carries a transfer record.

Consequence: no reel/frame numbers, conveyance types, assignors, assignees, or correspondents exist to report. No correspondent-of-record analysis is possible — the shell-LLC / repeat-attorney tell that is the core of this task has no data to operate on.

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Timeline diagram

Ownership never left the inventor, so the diagram records issuance and expiry only:

timeline
    title Ownership of US 177139
    1876 : Filed by James D McAnlis of Beaver Falls
         : Patent granted to inventor alone
    1893 : Statutory term expires
         : Rights enter public domain

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NPE / troll-pattern signals

Framing note: the modern NPE taxonomy presupposes a post-1980 transfer chain. This patent has no transfer chain of any kind, and its term ended in 1893 — 87 years before the USPTO began recording assignments electronically and long before any listed asserter existed. Each signal below is therefore assessed against an empty record, and the honest answer is "no evidence" rather than "clean."

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Verdict

Insufficient data — no recorded assignments exist for this patent.

Justification: a search of the USPTO Assignment Center (https://assignmentcenter.uspto.gov/) returns no assignment records for US 177,139, which is expected because the database only reaches back to August 1980 while this patent's entire enforceable life ran from 1876-05-09 to 1893-05-09. Google Patents' legal-events log for the same patent likewise contains only grant, publication, and expiry entries with no "Assigned to" event, and the patent document itself names James D. McAnlis of Beaver Falls, Pennsylvania as the sole owner with no assignee on the face of the grant. The correct characterisation is therefore not "clean NPE record" but "no data" — the patent expired 133 years ago and its subject matter is public domain, which also makes every NPE signal in the checklist inapplicable rather than affirmatively negated. Verification link: https://assignmentcenter.uspto.gov/ (search Patent Number 177139); canonical document at https://patents.google.com/patent/US177139/en.

I'll verify the USPTO record and hunt for any citation data before analyzing prior art.

Key disambiguation hit: a serial number 177,139 surfaced (US3139883A). Let me confirm the citation record for the actual patent and check its "Cited By" trail.

Prior-Art / Citation Analysis — US Patent No. 177,139

1. Record verification (USPTO / Google Patents mirror)

2. Patent citations of record for US 177,139 — none exist

This is the central finding, and it is a negative one by design, not by search failure:

• "Patent Citations" table: absent. The US177139A record contains no front-page "References Cited," no "Patent Citations" table, and no examiner-cited art. The only machine-generated lists present are Classifications, a "Prior art keywords" extraction (ratchet, watches, machinery, pinions, stops), and a "Similar Documents" carousel.
• "Cited By" table: absent. No later patent in the record cites US 177,139 as prior art.

Why: U.S. patents did not print front-page "References Cited" in this era. Applicant/examiner citation listings on the printed patent became standard only in the mid-20th century (the classic example is the "References Cited in the file of this patent" block on post-1940s grants). A patent granted 1876-05-09 therefore has no citation artifact to retrieve — its prosecution record is a manuscript original in the National Archives, not a searchable citation field.

Consequence for your question: I cannot build a strict "for each reference cited on 177139, which claim does it anticipate under §102" table, because the set of cited references is empty. Producing such a table would require fabricating citations. I have not done so. What follows instead is (a) the identifier-collision exclusions you need, and (b) the closest substitute prior art that is verifiable, each with an explicit §102 mapping — clearly labeled as not-of-record.

3. The claim being tested

The patent carries a single claim, at the tail of the OCR:

"An improved stop device for ratchets of all kinds, consisting of the combination of the ratchet-wheel with sliding and turning pinions and locking-recesses of a retaining band or ring, substantially as specified, for the purpose set forth."

Supporting disclosure: one or more (preferably three) pinions B gearing with ratchet A; pinions slide in recesses a of an encircling toothed band/frame C; recesses are concentric to the pinions at one end and narrow toward the other end to less than pinion diameter; the narrow end is toothed to mesh with pinion cogs. Forward rotation carries pinions into the wide ends (free turning); reverse rotation drives pinions into the narrow, toothed ends to lock positively. Optional cap-piece over ratchet and pinions.

Claim 1 is the sole unit of analysis. Every §102 mapping below is to Claim 1.

4. Identifier collisions — excluded, per literal-interpretation rule

Table A — Excluded identifiers

Both are exactly the kind of near-number artifact your instruction warns against; I am excluding them rather than treating them as prior art or as the target patent.

5. Substitute prior art (NOT of record) with §102 mapping

Because no citations exist, the only verifiable candidates come from (i) the applicant's own admissions in the specification, and (ii) the "Similar Documents" carousel — which is a machine-similarity list, not a citation list, and which is overwhelmingly later art.

Table B — Applicant-admitted prior art (admissions in the spec itself)

Table C — "Similar Documents" from the US177139A record (machine similarity, not citations)

Dates as listed; only two predate the 1876-04-10 filing and thus are even eligible as §102 art:

Table D — Adjacent contemporaneous art surfaced during searching (context only, not-of-record)

6. Methodological caveats you should carry forward

1. §102 is anachronistic here. 35 U.S.C. § 102 dates from the Patent Act of 1952. Novelty for an April 1876 filing was governed by R.S. § 4886 (as amended 1870/1874) and the defenses in R.S. § 4920. A modern §102(a)/(b) frame is a convenient translation, but for a historical validity opinion the controlling statute is the Revised Statutes provision.
2. §102(a)(2)/§102(e) has no work to do. Pre-grant publication did not exist in 1876, so no secret prior application can be §102 art against this patent.
3. No reissue, no foreign priority, no family. The record shows a single legal event — anticipated expiration 1893-05-09 — and no reissue of 177,139 (contrast the 1876 reissues in the Hartshorn/Campbell line, which are a different patent family entirely).
4. OCRed pre-1950 patents are lossy. Names ("McAnlis" → "MoANLIS"/"lVlGANLIs"), reference letters (band "0" is certainly C), and the US 100246 A title in the Similar Documents list are corrupted. I have not silently corrected anything and have marked the unreadable item as unreadable.
5. Date discrepancy in this analysis packet. The task header states "Current Date: April 26, 2026," while the fetched Google Patents record and the system date are 2026-09-28. This does not affect any of the above (all findings are historical), but I am flagging it per the contradiction rule.

7. Bottom line

• For US Patent No. 177,139 specifically: zero patent citations of record, and zero citing documents. The answer to "look at each patent citation for 177139" is that the set is empty, for documented historical reasons (pre-1947 citation practice), not because the search failed.
• No reference can be mapped to Claim 1 as an anticipation. The only pre-filing artifacts reachable are the applicant's own admissions (spring-pawls, pivot-pawls/dogs) and two Similar-Documents entries (US 100246 A, unverifiable; US 150166 A, a nut-lock, non-anticipatory).
• If you need a legally defensible prior-art set for this patent, the only route is paper: the 1876–1879 Commissioner of Patents' Decisions, NARA holdings for the Examiner's original, and The Federal Cases / Federal Reporter vols. 1–60 under "McAnlis," "ratchet," "pawl," and "click." Those sources are not indexed by the tools available to me.
• Do not substitute US 3,139,883 A or SG 177139 A1 for this patent; the first matches only on an application serial number (177,139), the second is a different jurisdiction's numbering series.

I'll ground this analysis in what the Google Patents page actually contains before reasoning about § 103. Let me verify the "Similar Documents" references and search for genuine pre-1876 one-way-drive art.

§ 103 Obviousness Analysis — US 177,139 (McAnlis, "Improvement in Ratchet-Stops for Watches and Other Machinery")

Cross-reference note: this builds on the verified summary and litigation sections already produced. One small inconsistency to flag: the litigation/summary sections were generated against a 2026-09-28 fetch date, while this task specifies "Current Date: April 26, 2026." Nothing in the analysis turns on that four-month delta, but the legal-status and docket statements should be read against the earlier date.

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1. What the "Prior Art section" of this page actually contains — and what it does not

This is the single most important threshold finding, and it constrains everything below.

The Google Patents page for US177139A does not contain a "Patent Citations" block, a "Cited By" block, or any examiner-cited reference list. The prior-art content on the page consists of exactly two things:

1. Seven machine-generated keyword tags: ratchet, watches, machinery, pinions, stops (plus, in the raw fetch, three ML concept-tag artifacts — "Castor canadensis," "Menyanthes trifoliata," "Canis lupus familiaris" — which are beaver/buckbean/dog taxonomy labels from a similarity model and are not prior art in any sense).
2. A "Similar Documents" list of 25 references, generated by a text-similarity model keyed to the page's stated "Prior art date" of 1876-05-09 (which is the issue date, not a real priority date — another artifact of the model).

Consequence: nothing on this page is prior art of record. The "Similar Documents" list is an algorithmic suggestion list, not a citation list. Any § 103 analysis must therefore (a) screen those 25 references for chronological admissibility, and (b) supplement with independently located pre-1876 art.

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2. Governing framework

• Modern hypothetical: 35 U.S.C. § 103 as construed in Graham v. John Deere Co., 383 U.S. 1 (1966), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007); the MPEP 2143 rationales (A)–(G).
• Historical reality: § 103 did not exist in 1876. Non-obviousness was then judge-made, tracing to Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1850) — whether the variation required more ingenuity "than was possessed by an ordinary mechanic acquainted with the business." The 19th-century "analogous use" line (Tucker v. Spalding, 80 U.S. 453 (1871); Smith v. Nichols, 88 U.S. 112 (1874); Roberts v. Ryer, 91 U.S. 150 (1875)) is the functional ancestor of the § 103 inquiry and is directly on point here: McAnlis took a known mechanical expedient and applied it in a new setting.
• Because the patent has been expired since 1893 (per the page's own legal-events record), any § 103 analysis today is academic/hypothetical — relevant to historical validity, claim-scope reconstruction, or use as prior art against later patents, not to live enforcement.

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3. Claim construction — element breakdown of the sole claim

"An improved stop device for ratchets of all kinds, consisting of the combination of the ratchet-wheel with sliding and turning pinions and locking-recesses of a retaining band or ring, substantially as specified, for the purpose set forth."

Two construction points matter for obviousness:

• "Substantially as specified" is a scope-limiting phrase tying the claim to the described embodiment (three equidistant pinions; tapered, toothed recess ends). A validity attack must reach the specific structure, not just the generic idea of a wedge one-way drive.
• "For ratchets of all kinds" and "for the purpose set forth" are statements of intended use and carry no patentable weight for § 103 purposes. The claim's breadth (one or more pinions) works against the patentee — the broader the genus claimed, the easier it is to find a species in the art.

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4. Level of ordinary skill in the art (PHOSITA)

A watchmaker/clockmaker or mechanician in 1876: trained in ratchet-and-click winding mechanisms, mainspring barrels, going barrels, fusees, and stop works; familiar with the routine practice of multiplying pawls to distribute load; and conversant with friction one-way drives. No formal engineering degree is required — this is a skilled-trade art, which raises the likelihood that a given substitution is "mere mechanical skill" rather than invention.

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5. The applicant's own specification admits the prior art

The specification contains an express admission that is prior art against the applicant under both 1876 practice and modern law (MPEP 2129):

"spring-pawls for ratchet-wheels in watches, clocks, and other machinery in which strong springs and other devices have to be retained at one point or tooth of the wheel, so that the tooth click or spring is liable to break and get worn…"

This is a problem admission (single-tooth pawl stops break and wear under strong-spring loads) and it is the linchpin of the motivation inquiry: the patentee himself defines the problem the claimed device must solve.

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6. Chronological admissibility screen of the "Similar Documents" list

Result: 23 of 25 "Similar Documents" are legally unavailable as prior art. They post-date the filing by 6 months to 148 years. They may be cited only as evidence of the level of ordinary skill and of the predictability of pinion/ratchet interlock — not as § 102/§ 103 references.

This is worth stating bluntly because a careless reviewer could easily build a superficially persuasive rejection out of DE 952 879 C, US 9,811,053, or EP 3,914,837 — all of which disclose substantially the same kinematic principle as McAnlis (satellite pinions locking against ratchet teeth in a coaxially retained assembly). See DE952879 and the Google Patents page itself. That would be legally improper.

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7. Combination 1 — the strongest genuine § 103 attack

References:

• Primary: US 67,659 (Langen, "Overrunning Clutch," August 1867) — a roller-ramp one-way clutch in which rollers wedge between concentric race members on tapered ramps, self-locking without springs. I located this reference only indirectly: US 9,810,272 B1 describes it as "the Langen Overrunning Clutch (U.S. Pat. No. 67,659 August 1867)… an example of a roller-ramp clutch using no biasing springs" (US9810272.pdf). I have not retrieved US 67,659 itself — flagging that as an evidentiary gap, but the 1867 date makes it admissible and squarely on point.
• Secondary: the conventional watch ratchet-wheel-and-click, as admitted in the specification and ubiquitous in pre-1876 horology (the page's own prior-art keywords classify the field as ratchet / watches / machinery / pinions / stops).
• Optional tertiary: US100246A (1870) — verified as Allen & Banta's watch regulator, which teaches replacing ordinary cog gearing with round-pin engagement and forked jaws so that "the tooth may roll between said jaws… without any lost motion" (US100246A). It is not a ratchet stop, but it is direct evidence that horological artisans of 1870 were already thinking about positive, low-play, rolling contact between a pinion-like element and a toothed member — exactly the design vocabulary of E2.

Motivation to combine (KSR rationales (A), (C), (D)):

1. The patentee's own admission establishes the problem: single-tooth pawl stops fail under strong-spring loads.
2. Langen establishes the known solution for automatic one-way locking: substitute a wedging body on a tapered surface for a spring-loaded detent, so that reverse rotation creates the lock rather than relying on a stressed spring.
3. A PHOSITA with a broken-spring-pawl problem and a known wedge-clutch expedient has an articulated reason to transfer the expedient, and a reasonable expectation of success, because both devices perform the identical function (permit rotation one way, resist it the other) in the identical environment (coaxial rotating members).
4. The friction-to-positive-lock bridge: Langen's lock is frictional and can slip under extreme torque. A watch mainspring is a high-torque energy source requiring positive retention. Toothing the wedging surfaces — i.e., substituting a toothed pinion for Langen's roller, and toothing the narrow recess ends to give a positive mesh — is a simple substitution of one known element for another to obtain predictable results (KSR rationale (B)) and applying a known technique to a known device ready for improvement (rationale (D)).

The equidistant, plural-pinion feature (E2's "one or more"): multiplying pawls/engaging elements and spacing them equidistantly to balance load was routine in ratchet and gear art well before 1876. This is the weakest of the claim's features and adds essentially nothing to the obviousness inquiry — "the mere duplication of parts" and "symmetry of arrangement" were, and remain, classic indicia of obviousness.

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8. Combination 2 — the wedge-lock cluster, and its admissibility problem

The "Similar Documents" list contains a dense cluster of nut-lock references (US150166A 1874; US712905A 1902; US385442A 1888) plus related wedge/taper locking art. The 1874 member, US150166A, is chronologically admissible. The family context is illustrated by contemporaneous nut-locks such as De Forest's US 152,344, which locks a nut against reverse rotation using a key seated in a groove and bent into a notched flange so that "no jarring motion can possibly release or unlock the nuts" (US152344.pdf).

Argument: the concept of a tapered/notched seat that admits relative motion in one direction and wedges the moving body against reversal was a fully settled mechanical expedient in the 1870s fastener art.

Counterargument (and my honest assessment): fastener nut-locks are likely non-analogous art to horological ratchet stops under the field-of-endeavor prong. They can be reached only under the "reasonably pertinent to the particular problem" prong — plausible under KSR's functional approach ("prevent reverse rotation without a spring"), but contestable. I would not lead with this combination; it is a supporting rationale at best.

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9. Where the claim plausibly survives — and it is one specific place

I could not locate, in any chronologically admissible reference, the feature that the specification treats as the mechanical heart of the device:

"The narrower ends of the recesses are toothed to mesh with the cogs of the pinions… the reliable and positive locking of the ratchet by the joint action of the pinions on the teeth of the ratchet, and on the teeth of the narrower recessed parts."

This is a double toothed engagement — the pinion cog simultaneously meshes with the ratchet teeth and with the teeth of the narrowing recess — producing a purely positive (non-frictional) lock with the reaction load taken in two places. Langen's clutch is frictional; the nut-locks are non-rotational; US100246 is a regulator, not a stop. A § 103 rejection that does not supply an actual teaching of toothed recess ends would be vulnerable to the argument that the claimed coaction of elements (the joint tooth-and-tooth wedging) is not shown and is not a predictable result of merely combining the references.

If a validity challenge exists, that is the feature to hang it on.

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10. Secondary considerations

There are none of record. The specification's assertions of less wear and strain and "a superior and stronger stop device" are attorney/inventor argument in the specification itself, which is entitled to no evidentiary weight on non-obviousness in either the 1876 or modern framework. No commercial success, no licensing, no copying, no long-felt-but-unsolved-need evidence, no industry praise, and no nexus evidence appears anywhere in the record. Accordingly, there is no objective evidence to rebut a prima facie case — which cuts strongly against the patent once a prima facie case is made.

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11. Bottom line

Assessment: On the admissible record, US 177,139's sole claim is more likely than not obvious under a KSR-style analysis, principally because the patentee conceded the problem and the solution was a known mechanical expedient (wedge one-way locking) applied in a watchmaking context, with the plural-pinion feature amounting to mere duplication. If the claim has a survivor's chance, it is the specific positive double-toothed engagement in the tapered recess ends — a feature for which I found no admissible anticipating or suggestive reference. That gap is not proof of non-obviousness, but it is the honest limit of what the accessible prior art supports.

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12. Explicit uncertainties

• US 67,659 (Langen, 1867) — I identified it only through a later patent's background section (US9810272.pdf). I did not retrieve the document itself. Its date, title, and roller-ramp character should be independently confirmed before being relied on in any written opinion.
• US150166A — the Similar Documents list labels it "Improvement in nut-locks," 1874-04-28. My searches surfaced other 1874 nut-locks (US 147,305; US 152,344; US 162,167) but not US 150,166 itself. Treat its subject matter as unverified.
• US178371 — the Similar Documents entry ("Improvement in barrels for watch-springs," 1876-06-06) is listed by the Pocket Watch Database with inventor "Sherman D.," not McAnlis. It therefore does not corroborate the prior summary's McAnlis/Fleming corroboration thread, and it post-dates the patent by four weeks regardless.
• No § 103 analysis can substitute for the actual references. The foregoing is a legal-reasoning exercise on a thin evidentiary base; a real rejection would require the primary references in hand, with the toothed-recess-end feature addressed directly.