US 186722

I'll verify against live sources before summarizing, including checking for any litigation activity.

US Patent 186,722 — "Improvement in Wash-Boards"

Verified against the full patent text at https://patents.google.com/patent/[US186722](/patent/US186722)/en (fetched 2026-09-25) and supplementary searches. Where the record itself is silent or garbled, I say so instead of filling the gap.

1. Bibliographic data (as literally recorded)

2. Abstract

There is no abstract. Abstracts were not part of US patent practice in 1877, and the published document contains none. Google Patents surfaces a "Definitions" block, but that text is machine-extracted verbatim from the specification, not an abstract supplied by the Office. The operative summary language, quoted directly:

"My invention relates to the class of wash-boards in which a face of corrugated zinc is attached to a suitable wooden back or body, and my invention is an improved form of such face."

And:

"B represents the wash-board face of sheet-zinc, formed into a series of corrugations, whose ridges, while all in a common plane, have the represented undulatin g or serpentine contour toward the head and foot alternately."

(The spacing in "undulatin g" is an OCR artifact in the source text, which the operating rules require me to preserve rather than silently repair.)

3. Claims — plain language

The patent contains exactly one claim. There are no dependent claims and no additional independent claims.

Claim text, verbatim:

"A zinc wash-board whose face consists of a series of serpentine ridges in a common plane, substantially as set forth."

Plain-language reading: The claim covers a washboard whose rubbing surface is made of zinc, where the ridges across the face are not straight but wavy/serpentine, and — critically — all of the ridge tops lie in a single common plane (i.e., the ridges undulate side-to-side within the plane of the board, but do not rise and fall toward and away from the user, as in a doubly-corrugated board).

What the claim does not cover, per the specification's own narrowing language:

• Rubbing faces of materials other than zinc (the claim is material-specific).
• Surfaces having acute, salient, or receding angles — the patentee expressly distinguishes these as the objectionable feature of "other forms of doubly-corrugated wash-board," which "have proved objectionable from their liability to accumulate dirt, and to be rapidly rusted and worn out."
• The wooden body A is described as being "of any suitable form" and is not claimed; the sole claim is directed to the zinc face.

The claimed advantage is stated as being "a more eflective [effective] rubbing-surface than the common board" while remaining "equally free from acute, salient, or receding angles."

4. Litigation check — USPTO and CAFC 2026 dockets

I searched specifically for litigation activity on this number and found none, which is the expected result rather than a search failure:

• The patent expired on January 30, 1894 and has been in the public domain for roughly 132 years. It cannot support an infringement action, an IPR, or a CAFC appeal.
• A targeted search for "186722" against 2026 CAFC/Federal Circuit reporting returned no case involving this patent. The 2026 Federal Circuit materials retrieved concern unrelated patents (e.g., Magnolia v. Kurin, Wildseed Mobile v. Google, Cisco/Centripetal, Teva/Lilly).
• Caution on identifier collisions: A bare search for the string "186722" surfaces a Soviet inventors' certificate SU 186722 (electromechanical limit differentiator, filed 1965, published 1966) and an unrelated ZIP-archive entry. These are different documents under a different numbering authority and must not be conflated with US186722A. Per the operating rules, I am treating these identifiers literally as distinct.
• One tangentially relevant historical note: this patent sits in the same crowded 1870s sheet-metal washboard art litigated in Duff v. Sterling Pump Co. (107 U.S. 636, involving reissue 6673 of Todd's patent 111,585) and Pfanschmidt v. Kelly Mercantile Co. (32 F. 667, 1887, addressing the "George" patent 187,843). US186722 is not the patent at issue in either case — I mention them only as context for the art field.

5. Related documents listed by the database

Google Patents lists the following as "Similar Documents" (not as cited prior art — 1877 grants carried no prior-art citation list). Among the nearest: US185365A (1876-12-12), US179974A (1876-07-18), US170432A (1875-11-30), US193095A (1877-07-17), US201658A (1878-03-26), US190309A (1877-05-01), US202003A (1878-04-02).

6. Explicit uncertainty flags

1. Assignee is genuinely absent, not merely unidentified by me. If an assignment was recorded later at the USPTO, it is not reflected in the source document.
2. No abstract exists — anything presented as an "abstract" for this patent is a modern extraction of the specification, not Office-supplied text.
3. Two possible transcription errors in the source text that I have deliberately not corrected: the witness name "EGKERT" and the specification's "eflective" (for "effective"). I cannot confirm the correct renderings without the original printed copy.
4. The publication number is properly cited as US186722A (or "Letters Patent No. 186,722" as printed in the document itself); the family record separately shows US186722D. I have not merged these two identifiers.

I'll research litigation involving US Patent 186722. Let me run several searches.

Let me search litigation-specific databases and the specific patent identifier.

Let me check litigation-specific portals directly.

Litigation Search Report — U.S. Patent No. 186,722

Bottom line: I found no litigation of any kind involving U.S. Patent No. 186,722.

To the extent the requested information is unavailable, the table would be:

1. Why the answer is "none known" rather than "none exists"

You asked for a definitive listing. I can give you a firm negative on every modern litigation venue, with one honest caveat about 19th‑century records:

• No district court, ITC, or CAFC activity. Nothing in the searched sources ties US 186,722 to any case caption, docket number, or investigation.
• No PTAB activity. Administrative trials at the Patent Trial and Appeal Board (and its predecessor, the Board of Patent Appeals and Interferences) cannot realistically concern this patent: it issued in 1877, more than a century before the AIA's post‑grant proceedings existed, and it was long expired by the time the AIA took effect. No IPR, PGR, CBM, or interference record appears anywhere in the results.
• The patent's own records confirm a clean, uncontested life. The Google Patents record for US186722A shows a single legal‑status event chain — grant on 1877‑01‑30 and "Anticipated expiration" on 1894‑01‑30 — with no reissue, no disclaimer, no assignment litigation, and no litigation section at all. (Google Patents automatically populates a "Litigation" panel when a patent has been asserted; that panel is absent here.) The patent is listed as "Expired – Lifetime."
• Caveat I will not paper over: pre‑1900 federal equity practice generated enormous volumes of unreported or thinly reported circuit‑court patent cases. I can state with high confidence that no reported or indexed case names this patent. I cannot exclude, with certainty, the possibility of an unindexed 1877–1894 equity bill that left no trace in the databases searched.

2. What the searches actually returned (and why none of it counts)

The literal string "186722" is heavily overloaded. Each hit below is a different instrument, not US Patent 186,722:

• Allahabad High Court (India) writ petition "2025:AHC:186722‑DB" — a criminal bail matter.
• A Kosovo Basic Court decision cited as "Numri i lëndës: 2020:186722" — a damage‑compensation case.
• NLRB/Fifth Circuit matter "16‑CA‑186722" — United States Postal Service labor case.
• City of San Antonio ordinance "RFCA #22‑186722" — a fire‑department procurement.
• Ukrainian payment reference no. 186722; a Luxembourg commercial register entry no. 186722; a Russian children's art diploma no. 186722.
• Soviet inventor's certificate SU 186,722 (1966) and East German patent DD 186722 (1975) — different offices, different decades, different subject matter.
• PCT publication WO 2017/186722 — cited in US 10,858,877 as a PCT number, i.e., a third party's application number, not this patent.

None of these are assertions of US 186,722. Per your instruction not to auto‑correct identifiers, I am flagging them precisely because they are not the same identifier — they merely share digits.

3. Relevant historical context (adjacent, but not this patent)

Washboard patents of this era were actively litigated, which is worth knowing when assessing why this one may have gone unchallenged. Reported cases include:

• Duff v. Sterling Pump Co., 107 U.S. 636 (1883) — Todd reissue No. 6,673 (washboard), held not infringed by the Hull board; limited to projections bounded by crossing horizontal and vertical grooves.
• Duff v. St. Louis Wooden‑Ware Works, 22 F. 340 (C.C.E.D. Mo. 1884) — same reissue, not infringed by the Everts board (No. 201,658).
• Lapham Dodge Co. v. Severin, 40 F. 762 (C.C.D. Ind. 1889) — Heath patent No. 168,252 and George patent No. 187,842 (the latter held void for want of invention).

These cases tell a consistent story: the 1870s–80s novelty battleground in washboard art was the doubly‑corrugated / cross‑grooved face. Gould's claim — "a series of serpentine ridges in a common plane" — was deliberately drafted to sit outside that fight, and the specification says so expressly, contrasting itself with "doubly‑corrugated" boards whose "acute, salient, or receding angles" caused dirt accumulation and rust. A claim drawn to a narrow ornamental ridge geometry, in a field with a crowded prior‑art record, is a plausible candidate for a patent that was simply designed around rather than litigated over.

4. Sources and method

• Primary: the full text and bibliographic record of US186722A on Google Patents — relied on for the grant date (1877‑01‑30), expiry (1894‑01‑30), inventor (Samuel A. Gould, Osgood, Ripley County, Indiana), filing date (July 27, 1876), single claim, and the absence of any litigation or assignment‑dispute entry.
• Secondary searches against litigation‑oriented query patterns (patent number plus "litigation," "infringement," "case," and the Unified Patents litigation portal domain) returned zero results for this patent.
• A direct domain‑restricted search of portal.unifiedpatents.com for "186722" returned zero results.

5. Recommendation before you rely on this

If this search is for a clear‑opinion, freedom‑to‑operate note, or diligence file, certify the negative on the modern dockets through the primary sources themselves (PACER/CM‑ECF for the district courts, the ITC EDIS docket, the CAFC docket, and the Unified Patents litigation caselist) rather than relying on a web search. For the 1877–1894 window, the Federal Reporter volumes and the Official Gazette are the only practical indexes, and I have not exhaustively page‑searched those. Any such effort is academic for the patent itself, which has been expired since January 30, 1894 and cannot support an infringement claim — but it could matter if you are tracing the commercial history of the Gould board or its manufacturer.

Proceedings overview

Total AIA trial proceedings on file for US 186,722: zero (0). The USPTO Open Data Portal returns no IPR, PGR, or CBM proceeding naming this patent — no institution decisions, no Final Written Decisions, no settlements, no Federal Circuit appeals. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials, and the defensive posture this produces for a defendant is not "hardened patent" but rather "the asserted patent has been in the public domain for more than 130 years and cannot be infringed." There is no IPR to point to because no IPR is needed — or legally meaningful.

No proceeding entries to report

Per the operating rule to interpret identifiers literally and not manufacture numbers: I found no proceeding number to list, and I will not invent one. A targeted search (PTAB/docket-alert sources, PTAB E2E-adjacent documents, and CourtListener) surfaced only unrelated matters, including:

• O2 Micro's U.S. Patent 6,xxx,xxx "the '722 patent" litigation (Fed. Cir. No. 2008-1128/1136, O2 Micro Int'l v. Monolithic Power Systems) — a different patent that is colloquially called "the '722 patent." Do not let an opposing brief conflate the two. (Fed. Cir. opinion PDF)
• Modern PTAB petitions referring to unrelated patents numbered in the 8,xxx,xxx / 10,xxx,xxx series.
• Non-US documents bearing the number 186722 (a Hungarian patent register entry, a Soviet inventor's certificate SU 186722, an EPO priority claim to "US 186722" in EP 0 666 225, and an Allahabad High Court matter numbered 2025:AHC:186722-DB). None of these is a PTAB proceeding on US 186,722.

None of this is PTAB activity on US 186,722, and none of it should be cited as such.

Why the absence of AIA trials is structural, not merely incidental

This is not a "well-asserted patent that just hasn't attracted an IPR yet." The AIA trial regime cannot meaningfully reach US 186,722:

1. The term is over. US 186,722 was granted 1877-01-30 on an application filed 1876-07-27 by Samuel A. Gould of Osgood, Ripley County, Indiana, and the structured Google Patents record shows legal status "Expired – Lifetime" with an anticipated expiration date of 1894-01-30 (a 17-year term, pre-URAA). (US186722A) Any § 286 damages window (six years back from suit) closed in or about 1900. An IPR petitioner would have to justify a $40,000+ proceeding to invalidate a claim that entitles no one to a dollar — the Board's institution decisions routinely turn on whether the petitioner has identified a concrete controversy.
2. PGR is unavailable by statute. Post-grant review under 35 U.S.C. § 321(c) reaches only patents with a claim having an effective filing date on or after 2013-03-16. A 1876 filing is 137 years too early.
3. CBM is unavailable on two independent grounds. Covered business method review was limited to patents claiming a method or apparatus for performing data processing or other operations used in the practice, administration, or management of a financial product or service (AIA § 18(d)(1)), and the program sunset on 2018-09-16 for petitions filed after that date. A hand laundry rubbing board is neither a financial product nor a post-sunset-eligible target.
4. The claim itself is a single, narrow, expired apparatus claim. The entire specification ends with: "I claim as new and of my invention — A zinc wash-board whose face consists of a series of serpentine ridges in a common plane, substantially as set forth." (Claim 1, the sole claim.) Its subject matter has been freely practiced since the 1890s, and the classification is D06F 3/02 (rubbing boards).

Strategic summary

Claim status. Because no AIA trial was ever filed, no claim of US 186,722 has been canceled by the PTAB. But that is a hollow "sustain." The single claim (an unnumbered claim 1: a zinc wash-board face of serpentine ridges in a common plane) expired on 1894-01-30 and is untested in IPR only because it is unenforceable in substance — an expired patent supports neither injunctive relief nor prospective damages, and any past-damages tail closed over a century ago. There are no dependent claims; the patent text contains one claim only. Treat the claim as legally dead by expiry, not as adjudicated valid by the Board. Google's "Similar Documents" list for this patent is dense with contemporaneous washboard patents (e.g., US170432 (1875-11-30), US179974 (1876-07-18), US185365 (1876-12-12), US185786 (1876-12-26), US190309 (1877-05-01), US193095 (1877-07-17), US201658 (1878-03-26), US202003 (1878-04-02)) — evidence of a crowded art field, which is relevant only if someone tries to revive this number for a marking or a historical novelty theory, not for any live validity fight.

Estoppel landscape. Section 315(e)(2) estoppel attaches only to a petitioner, real party in interest, or privy who has been a party to an IPR that resulted in a final written decision under § 318(a), and it bars grounds that were raised or reasonably could have been raised. With zero AIA trials, there is no statutory estoppel in either direction on this patent. Practically, this makes the estoppel question moot: without an unexpired claim, there is no district-court invalidity ground to preserve and no petitioner to be estopped. If a defendant is nonetheless staring at an assertion of US 186,722, the winning motions are not § 102/§ 103 at the PTAB but (a) failure to state a claim / no enforceable right (expired patent), and (b) if the accuser is marking goods or demand letters with "patented," a referral under 35 U.S.C. § 292 — noting that post-AIA § 292(a) permits only the United States to sue for the statutory penalty, while § 292(b) allows a competitive-injury private action.

Pattern signals. None of the usual IPR-cluster signals are present. There is no repeat petitioner, no patent-owner appeal activity (Gould's patent predates the Federal Circuit by a century and predates the modern PTAB by 135 years), and no defensive aggregator involvement (Unified Patents' statutory-category challenges are limited to qualifying technology areas and to unexpired patents of commercial interest). The absence here is not the "well-asserted patent hasn't been tested yet" signal — it is the "there is nothing left to test" signal.

Recommended next steps

• No PTAB activity exists on US 186,722 — state that plainly, on the record. The canonical source is the ODP "PTAB proceedings on file" block supplied in this engagement, corroborated by search. Link the patent record itself: https://patents.google.com/patent/US186722/en. The "Expired – Lifetime" status and the 1894-01-30 anticipated-expiration entry are the dispositive facts.
• Do not file an IPR, PGR, or CBM on this patent. PGR and CBM are statutorily barred (see above); an IPR on a claim that expired in 1894 buys nothing, risks a discretionary denial for lack of a concrete controversy, and gives the other side a § 315(b)/§ 325(d) narrative it does not deserve. Spend the budget on a declaratory posture instead.
• If you are being asserted against, reframe the demand letter as the issue. An assertion of US 186,722 today implies either (i) a numeric confusion with a different, live "722" patent — verify the exact patent number and issue date on the face of the demand, because "the '722 patent" in the case law almost always means someone else's patent (cf. the O2 Micro '722 patent above); or (ii) an expired-patent shakedown. In case (ii), preserve the demand letter, the envelope, and any "patent pending"/"patented" markings, and evaluate § 292 and state-law unfair/deceptive-practices theories. Note that any live patent number in the demand is likely a typo or an intentional substitution; insist on a claim chart that quotes the specific claim language — here, "a series of serpentine ridges in a common plane" — and demand the issue date.
• Milestone tracking is not applicable. With no instituted trial, there is no § 316(a)(11) one-year FWD deadline, no institution-decision deadline, no oral hearing, and no PTAB E2E docket to monitor. For a defendant, the monitoring target is the accuser's conduct, not the Board's docket.

Confidence note. I am highly confident there are no AIA trial proceedings on US 186,722; the statutory analysis above rests on the patent's 1876 filing date and 1894-01-30 expiration, both as recorded in the source document. I did not locate any ex parte reexamination file for this patent either, but I did not have direct access to the reexamination file wrapper, so I state that as "not found," not as "confirmed absent."

I'll verify the assignment record status against live sources before reconstructing anything.

Now let me check the assignment database coverage rules and look for any historical assignment record for Gould.

Inventors

The specification header reads: "Be it known that I, SAMUEL A. GOULD, of Osgood, Ripley county, Indiana, have invented a new and useful Wash-Board." No corporate affiliation, no co-inventor, no "assignor to" recital appears anywhere in the grant.

Unusual-pattern check — no signal. The prompt's example (all inventors departing the assignee within 12 months of filing) cannot be evaluated here because there was never an assignee to depart from. Note two related but distinct names in the record, which I am flagging to prevent conflation:

• E. W. Gould — attesting witness. Shares the inventor's surname; likely a relative or the local notary/agent. This is a signature witness, not an inventor and not an assignee. No evidence of any ownership interest.
• John EGKERT — second attesting witness (spelling as printed/OCR'd; not corrected).

Separately, the search space surfaced a Gould Manufacturing Company of Seneca Falls (donor of a bell to a Presbyterian chapel, January 1, 1878). That is a New York entity on the opposite side of the country from Osgood, Indiana, and I found no documentary link to Samuel A. Gould or to this patent. I am explicitly not treating them as related.

Original assignee

There is no original assignee. US186722A issued to Samuel A. Gould individually on January 30, 1877, with no assignment, transfer, or corporate owner named on the face of the patent, in the specification, or in the Google Patents "Family" record.

• Entity named on the issued patent: none — the grant runs to the inventor personally.
• Product embodying the claims: Undetermined. The specification claims the face constitutes "a more eflective rubbing-surface than the common board," which is a commercial-use assertion, not evidence of manufacture. I found no advertisement, catalog, trade-press notice, or city-directory listing tying Samuel A. Gould of Osgood, Indiana to a washboard manufactory. This is a gap in the record, not a negative finding.
• Primary line of business / current status: Not determinable. An 1876 Indiana individual inventor grant predates the corporate-patent-holding era; there is no corporate predecessor or successor to trace. The patent itself expired January 30, 1894.

Assignment timeline

The USPTO Assignment Center / Patent Assignment Search has no records retrievable for this patent, and it structurally cannot. Two independent reasons:

1. Database coverage boundary. The USPTO's online assignment index (formerly Assignments on the Web / Patent Assignment Search, now Assignment Search via Assignment Center at https://assignmentcenter.uspto.gov/) "contains all recorded Patent Assignment information back to August 1980" (USPTO Assignment Database webinar materials, https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf). The corresponding bulk dataset is likewise titled "Patent Assignment XML (1980 – Present)" (https://data.commerce.gov/patent-assignment-xml-1980-present). MPEP 301.01 confirms: "The historical database of assignments is maintained separate and apart from the database of assignments affecting title recorded since 1980." A patent that issued in 1877 and expired in 1894 has no presence in that index.

2. No legal-event trail. The Google Patents record for US186722A (https://patents.google.com/patent/[US186722](/patent/US186722)/en, fetched 2026-09-25) lists exactly four legal events — Application granted (1877-01-30), Publication of US186722A (1877-01-30), Anticipated expiration (1894-01-30), and current status Expired – Lifetime. There is no assignment event. Google Patents draws its assignment events from the same post-1980 USPTO record set, and there are none to draw.

Therefore there is no assignment chain to reconstruct: no reel/frame, no conveyance type, no assignor, no assignee, and no correspondent of record. I did not fabricate any of these, and I did not assign placeholder reel numbers.

Two caveats I owe you, stated plainly:

• I could not execute the Assignment Center query interactively (my retrieval returns indexed page text, not live form submissions). My conclusion rests on the documented coverage boundary and the absence of assignment events in the Google Patents record, not on a direct read of a "no results" page. Given the 1980 coverage boundary, a positive result is not plausible, but I am labeling the method honestly rather than implying I saw a null result screen.
• Pre-1980 records do exist on paper/microfilm at the USPTO Assignment Recordation Branch and are physically available at the Public Search Facility in Alexandria, VA (patent assignment records, microfilmed deeds, and indexes). An 1877-era assignment, if one was ever recorded, would live there — not online. I am not asserting that no assignment was ever executed; I am asserting that none is retrievable and none is evidenced in any online or printed record I could reach. The practical retrieval routes would be (a) a manual search of the Assignment Recordation Branch's pre-1980 microfilm deed indexes, and (b) the Annual Report of the Commissioner of Patents for 1876–1877, whose alphabetical list of patentees annotates assignments. I was unable to retrieve the 1876 or 1877 volume to check entry 186,722 directly, and I am not going to guess at what it says.

Per the task instruction: having stated plainly that there are no Assignment Center records, the timeline below is rendered formulaically rather than as a real transfer chain. I continue into the signal and verdict sections because the required output format calls for a verdict, and because "no chain" is itself the answer.

Timeline diagram

timeline
    title Ownership of US 186722
    1876 : Application filed July 27
         : Sole inventor Samuel A Gould
         : No assignee named
    1877 : Patent issued January 30
         : No assignment on the face
    1894 : Patent term expired January 30
         : No recorded transfers in any index
    2026 : No assignment data retrievable

NPE / troll-pattern signals

Every signal below is assessed against concrete record evidence; where the answer is driven by the absence of a record rather than its content, I say so.

1. Shell-entity transfer — not present. No assignee of any kind exists. There is no transfer to an "IP / Patents / Licensing / Holdings / Ventures" entity because there is no transfer at all, and no such entity ever appears in the Google Patents family record (Family ID 2256129) or in any legal event.

2. Known asserter in the chain — not present. The named party is Samuel A. Gould, an individual inventor residing in Osgood, Indiana. He matches no entry in the public NPE rosters named in the prompt (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities) — none of which existed in 1877. Not applicable by more than a century.

3. Repeat correspondent across the chain — not present. No correspondent of record exists, because there is no recorded assignment. The attorney-correspondent tell — the single most useful signal per your framing — requires at least one recorded conveyance and there are zero. I have no name, no firm, and no reel/frame to cite, and I will not invent one.

4. Cascading transfers — not present. No consecutive assignments, no chained LLCs, no shared correspondent addresses. Zero links in <24 months, or in 24 decades.

5. Pre-litigation transfer — not present. No assignment dated within six months before any suit, because (a) there is no assignment, and (b) the prior section of this analysis established there is no litigation involving this patent — not in 2026 CAFC/Federal Circuit reporting, and not in the 19th-century washboard cases. I re-checked and confirm: the era's actual sheet-metal washboard litigation — Duff v. Sterling Pump Co., 107 U.S. 636 (1883) — involved reissue 6,673 from original patent 111,585 (Westly Todd, Feb. 7, 1871), and Pfanschmidt v. Kelly Mercantile Co. addressed the George patent 187,843. US186722 is not at issue in either. The Duff opinion does, however, confirm the crowdedness of this exact art (Galusha & Safford 1857; Crihfield 1870; Hull 171,568) — context only, and note that Hull's US171,568 (Dec. 28, 1875) is not the same document as the US170432 (Nov. 30, 1875) listed among this patent's "Similar Documents." Do not merge them.

6. Bankruptcy fire-sale — not present. No corporate assignee ever existed to enter Chapter 7 or 11. Nothing to sell in a §363 sale.

7. Privateering — not present. No operating company in the chain, hence no operating company able to transfer to an NPE to assert on its behalf. No SEC 10-K/8-K disclosure could exist for an 1877 individual grant.

8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. This is the right outcome for the wrong reason: the patent was never acquired by anyone, so it was never neutralized. It simply expired into the public domain in 1894 — the oldest and most complete form of neutralization.

Verdict

Insufficient data — no records, or only the original assignment.

Justification: the record contains only the original grant (US186722A, issued 1877-01-30 to Samuel A. Gould individually, no assignee named, no assignment printed on the face), and zero recorded assignments — the USPTO's online Assignment Center cannot contain any, because its coverage begins August 1980 and MPEP 301.01 places pre-1980 deeds in a separate non-online historical database. There is no reel/frame, no conveyance, and no correspondent to analyze, so no NPE signal can be scored as "present" on evidence. I want to be direct about the distinction the rubric forces: this is not a case where the original assignee plausibly still owns the patent, and it is not a case where the chain was arranged for assertion — the useful, non-misleading framing is that the question is moot, since the patent expired January 30, 1894 and has been in the public domain for roughly 132 years. Calling it "NPE — moderate" or "operating-company assertion" would require me to fabricate a chain, and I will not. The genuine open item is narrow and archival: whether a pre-issuance or post-issuance assignment was ever recorded on microfilm at the USPTO Assignment Recordation Branch, which only an in-person or fee-based manual search of the pre-1980 deed indexes (or the 1876–1877 Annual Report of the Commissioner of Patents) could settle. I could not reach either, and I am flagging that as unresolved rather than resolved in the negative.

Verification link: https://assignmentcenter.uspto.gov/ — search by patent number 186722. Expect no results; per the coverage rules above, a null return on this number is a documentation artifact, not evidence of a hidden transfer. The legacy portal at https://assignment.uspto.gov/patent/index.html surfaced the same underlying post-1980 record set and, per USPTO's August 2025 announcement, was scheduled for retirement on September 27, 2025 in favor of the Assignment Center interface.

I'll verify the record directly at USPTO and Google Patents before analyzing, since the citation question turns on what is actually printed on this grant.

Let me verify whether any citation list (front-page references or examiner citations) exists for this grant, and pull the original printed text.

Let me check the original printed grant for any examiner-cited references and verify the near-date washboard art.

Prior-Art Analysis — U.S. Patent No. 186,722 ("Improvement in Wash-Boards")

Two flags before the substance:

1. Date discrepancy. This task states the current date as April 26, 2026. My session context and the Google Patents fetch timestamp both read 2026-09-25. I am not reconciling these silently — per the operating rules I flag it. It has no bearing on the analysis (the patent expired 1894-01-30), but the two dates cannot both be "today."
2. Tooling scope. I do not have a direct terminal into USPTO Patent Public Search / PatentCenter. I reached the record through web search against Google Patents (which mirrors USPTO data), USPTO-hosted petition documents, and the Federal Reporter / U.S. Reports full texts. Where I could not retrieve the actual bibliographic record of a reference, I say so rather than inferring it. I did not obtain the 1876–77 file wrapper, which is the one place a citation could theoretically hide (see §6).

Per instruction, I excluded bare-string "186722" collisions (Soviet SU 186722, DD 186722, WO 2017/186722, and unrelated docket/zip references) from the results below.

1. Headline finding: U.S. Patent 186,722 has zero patent citations

There is no citation list on this patent — not a short one, an empty one. Every entry in the following table is blank for the same reason:

Why this is the expected result and not a search failure:

U.S. patent practice in 1877 did not print cited references on granted patents. The front-page "(56) References Cited" block that modern practitioners expect did not exist. The Act of July 8, 1870, § 24 governed examination at the time, and while examiners did make rejections on "references" — the Lapham Dodge opinion records exactly that, noting that Heath's original claim "was rejected by the patent-office on two references, — the Saunders Hubbell patent of 1870; and the rejected application of William Swineburn" — those references lived in the file wrapper, not on the printed patent. Nothing in the printed US186722A records them.

Google Patents reproduces this faithfully: the US186722A page carries a "Definitions" block (machine-extracted text, as noted in the earlier section), a "Similar Documents" block, and legal-status events — but no citation section at all. Google Patents auto-populates that section whenever citations exist.

Critical distinction: the 20 documents listed under "Similar Documents" on the Google Patents page are not citations for US186722A. They are a modern classifier's text-similarity output over the D06F3/02 corpus. Treating them as "each patent citation for 186722" would be a fabrication of the record. I use them only as a ranked starting point for the reconstructed art universe in §3.

2. Legal frame — a necessary caveat before any § 102 table

35 U.S.C. § 102 did not exist in 1877. The statute in force when Gould filed (July 27, 1876) and when this patent granted (January 30, 1877) was the Act of July 8, 1870, § 24, whose prior-art conditions were framed as "not known or used by others before his invention," "not patented or described in any printed publication" in this or a foreign country before his invention or more than one year prior to his application, and "not in public use or on sale" for more than one year prior to application.

Applying today's § 102 to a claim drafted in 1876 is therefore anachronistic. I run it both ways below:

• § 102(a)(1) analogue — reference "patented, described in a printed publication, or in public use" before the effective filing date. Gould's effective filing date is July 27, 1876. The pre-AIA analogue is § 102(a)/(b), with the one-year critical date of July 27, 1875 for statutory bars.
• § 102(a)(2) analogue — U.S. patents whose applications were "effectively filed" before that date. This category did not exist in 1870s practice (there was no pre-AIA § 102(e) until 1952). A patent granted after Gould's filing date was not prior art to him in 1877, regardless of its own filing date. I note this because several candidates below fall into that gap.

Claim scope, restated for the infringement-of-novelty analysis. US186722A has exactly one claim (confirmed in the earlier section, and I re-verified it against the fetched text). Every reference below is therefore tested against claim 1, and there is no dependent-claim fallback:

"A zinc wash-board whose face consists of a series of serpentine ridges in a common plane, substantially as set forth."

I read claim 1 as requiring three things: (a) a zinc washboard; (b) a face whose ridges are serpentine (waved/undulating, undulating longitudinally of the board and parallel with its plane); and (c) those ridge tops in a single common plane. A reference that shows broad "corrugation," "ribbing," "diamond projections," or "grooves" does not meet this claim. This is a narrow claim, and the specification says so deliberately — it contrasts itself with "other forms of doubly-corrugated wash-board" having "acute, salient, or receding angles."

3. The most relevant prior art actually available (reconstructed universe)

Since no citation list exists, the honest answer to "identify the most relevant prior art" is to reconstruct the art universe from (i) the art the courts actually adjudicated against 1870s sheet-metal washboards, and (ii) the near-date patents the classifier surfaced. Tiers below reflect relevance to claim 1, not citation status.

Tier 1 — Strongest § 102 candidates (granted well before Gould's filing date)

Tier 2 — Same-field art granted before the filing date, content unverified

Tier 3 — Post-filing documents: not prior art to US186722 at all

These appear on the Google Patents "Similar Documents" list and are easily mistaken for citations. They are not, and by date they cannot be prior art to a July 27, 1876 filing.

4. § 102 verdict, consolidated

One further § 102 note specific to this patent: because claim 1 recites zinc ("A zinc wash-board"), a reference showing a corrugated sheet-metal face is not itself anticipatory unless it discloses or inherently teaches zinc. The Todd reissue and the Duff opinions describe the rubbing surface as "sheet zinc or other suitable sheet metal" — so zinc is disclosed there. A reference limited to, e.g., glass (US 22,053, Nov. 16, 1858, "rubber B composed of glass") or to wood would not meet element (a).

5. Sources actually relied on

• US186722A — Google Patents — used for grant/filing dates, single claim, and the absence of any Citations/Cited By panel.
• Duff v. Sterling Pump Co., 107 U.S. 636 (1883) — U.S. Reports PDF, Library of Congress and Justia — used for Todd 111,585 / Re. 6,673, Hull 171,568, and the Galusha & Safford and Crihfield references.
• Duff v. St. Louis Wooden-Ware Works, 22 F. 340 (C.C.E.D. Mo. 1884) — used for Everts 201,658.
• Pfanschmidt v. Kelly Mercantile Co., 32 F. 667 (C.C.D. Minn. 1887) — Federal Reporter PDF — used for Heath 168,252 and George 187,843.
• Lapham Dodge Co. v. Severin, 40 F. 762 (C.C.D. Ind. 1889) — CourtListener — used for the examiner-reference discussion (Saunders Hubbell 1870; Swineburn rejected application, filed Aug. 5, 1875) and for the George 187,842/187,843 discrepancy.
• Annual Report of the Commissioner of Patents, 1858, vol. 2 — used for Miner & Merrick 22,037 (Nov. 16, 1858), Keech 20,644, Barrett/Lee/Waters 20,473, and Adams 22,053.
• Smithsonian NMAH collection records — used for patent models 185,553 and 222,536.

6. Gaps and explicit uncertainty — do not treat this as exhaustive

1. The file wrapper was not examined. The Lapham Dodge opinion proves that 1875-era examiners did cite references in rejections. If Gould's application drew a rejection, the references would be in the file wrapper and nowhere in the printed patent. Without the wrapper, I cannot state that no reference was ever cited against this application — only that none appears on the grant.
2. I could not retrieve the identifiers or facsimiles for the Galusha & Safford (Dec. 1857) and Crihfield (Oct. 1870) patents. They are named in a Supreme Court opinion but their patent numbers are not stated there, and I will not guess them. These are my two strongest candidates and simultaneously my two largest evidentiary holes.
3. US 179,974 (July 18, 1876) is unexamined, and it is the reference most likely to matter by date. Same for US 170,432 (Nov. 30, 1875) and US 185,365 (Dec. 12, 1876) — the last of which additionally has an unverified filing date.
4. "Similar Documents" ≠ "citations." Any downstream document that presents the 20-document classifier list as US186722A's cited prior art is misdescribing the record.
5. Two unresolved identifier discrepancies preserved as found: Re. 6,673 / 6873, and George 187,842 / 187,843, plus the Oct. 5 / Oct. 6, 1875 reissue date. I have flagged rather than corrected all of them.
6. Practical effect. None of this is actionable. The patent expired January 30, 1894. Prior-art analysis of claim 1 has no legal consequence today; its value is historical — reconstructing why a narrow, deliberately-drawn claim in a crowded art went, so far as the record shows, unasserted.

I'll research the prior-art references identified in the record before analyzing obviousness.

Let me examine the remaining "Similar Documents" and the key prior-art patents named in the contemporaneous litigation.

Obviousness Analysis — US 186,722 under 35 U.S.C. § 103

Scope and provenance note. The task directs me to use the prior art of this record. The Google Patents page for US186722 has no cited prior-art list (1877 grants carried none) — its only "prior art" content is (a) indexer-assigned keywords and (b) the "Similar Documents" block. I verified the text of the two most date-critical items in that block and pulled in the references that the Supreme Court itself identified as the state of this art in Duff v. Sterling Pump Co., 107 U.S. 636 (1883). I flag below which reference came from where.

Date discrepancy, flagged not resolved. The task header says today is April 26, 2026; the previously generated sections are dated 2026-09-25. The prior sections also state the correct legal conclusion — expired 1894-01-30, unenforceable. § 103 analysis below is therefore hypothetical/retrospective, not a live validity contest.

1. The claim, decomposed

Sole claim (verbatim): "A zinc wash-board whose face consists of a series of serpentine ridges in a common plane, substantially as set forth."

Two elements are admitted prior art in the patent's own text. This matters enormously for § 103, because an applicant's specification admissions are evidence of the state of the art:

• Element C is conceded "as usual" — i.e., lateral corrugations were the norm.
• Element E is conceded: the tops "are in one common plane, as in the common zinc wash-board." Gould expressly places the common-plane geometry in the prior art.
• Element B (zinc) is never asserted as novel; the specification opens by classifying the invention as the "class of wash-boards in which a face of corrugated zinc is attached to a suitable wooden back or body."

That leaves element D — the serpentine trace — as the sole candidate point of novelty. The entire § 103 question is whether making the axis of an admitted-common-plane corrugated zinc face wavy instead of straight was obvious in July 1876.

2. Governing framing and the critical date

• Filing date of record: July 27, 1876; patent issued January 30, 1877.
• The operative prior art therefore includes everything public or patented before Gould's invention, plus US patents filed before July 27, 1876 (pre-AIA § 102(e); AIA § 102(a)(2)).
• § 103 did not exist in 1877 (the Act of 1870 required that the subject matter be "not known or used by others"); I apply modern § 103 as instructed, including KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).
• Because the art below ranges from 1857 to 1876, the combination survives even if Gould swears behind the newest references. That is the decisive structural point: the core teaching predates 1876 by up to nineteen years.

3. The prior art of record

Not evaluated (honest gap). US 185,365 (1876-12-12), US 190,309 (1877-05-01), US 193,095 (1877-07-17), US 202,003 (1878-04-02), and US 170,432 (1875-11-30) are on the page's Similar Documents list. Three of them grant after Gould's July 27, 1876 filing (relevant only if their filing dates precede it — unverified); US 170,432 (1875-11-30) is prior art by grant date, but I could not retrieve its text and will not characterize it. I also could not retrieve the Galusha & Safford or Crihfield patent numbers; I know their contents only through the Supreme Court's descriptions and decline to invent numbers for them.

4. The obviousness combinations

Combination 1 (primary): Galusha & Safford 1857 + the common-plane single-corrugated zinc face

What is combined. The admitted common zinc washboard face of element C/E (straight lateral corrugations, crests in one plane) is given the ridge geometry taught by Galusha & Safford (1857): rows of corrugations offset alternately so that the ends of elevations in one row overlap the ends of the next, with inclined ends and sides and rounded edges.

Result. Tracing the crest of a corrugation across a board whose successive rows are offset produces exactly a wave/serpentine path across the board, in the plane of the board, with crests at one height. The Gallusha & Safford structure's stated purposes are identical to Gould's: form channels for water escape downward and stiffen the plate relative to "the old form of parallel flutes extending entirely across the plate." Gould's asserted benefit — a more effective rubbing surface, "equally free from acute, salient, or receding angles" — is the inherent and expected consequence of the offset-and-rounded geometry.

Realistic weakness of this combination: G&S's disclosure, as reported, is of discrete oblong elevations, not continuous ridges. A PHOSITA must make the modest step of continuing the offset elevations into a continuous semisinusoidal ridge. That step is a predictable change in geometry and can be executed by the same roll-forming or die-stamping operations Crihfield already used — but it is an inference, not a literal disclosure. This is the reference whose full text I most need and do not have.

Combination 2 (the strongest motivation-based case): Todd US 179,974 + Latcher US 146,921

Todd's own disclaimer is an admission that zigzag-across-the-board corrugations were known in this art by June 1876. Todd then chose V-shaped corrugations meeting at an angle on the centerline. A serpentine ridge is the same genus as a zigzag ridge — the same idea with the corners rounded off rather than sharp. Latcher supplies the express reason to round those corners: angular abrupt rib terminations "injure the clothes." Rounding off the apex of a zigzag corrugation so it becomes a continuous wave, while keeping the crest in the same plane, is a simple substitution of one known ridge trace for another, both serving the same drainage and rubbing functions, and a known technique (rounding/blending rib transitions) applied to yield a predictable result.

Swearing-behind caveat: Todd 179,974 filed June 12, 1876 and granted July 18, 1876, only 9 and 45 days before Gould's filing. If Gould established an earlier invention date he could remove it as a § 102 reference. That does not defeat the ground, because Todd's disclaimer is evidence of public knowledge in the art (which cannot be sworn behind), and because Combinations 1, 3 and 4 rest on 1857–1875 art.

Combination 3: Crihfield 1870 (+ Galusha & Safford) applied to an ordinary zinc plate

Crihfield gives (i) zinc, (ii) rows of raised projections in which alternate rows are offset and unequal in count, producing oblique channels running up and down the board, and (iii) the express manufacturing route: "stamped out by die plates." Combining that offset-row geometry with an ordinary corrugated zinc face to create continuous oblique/serpentine ridges is a use of a known technique to improve a similar device in the same way, with the added advantage that the ridge pattern is produced in one stamping/rolling operation.

Combination 4: the design-around motive (documented in the litigation record)

The 1870s washboard art was in active litigation over crossing-corrugation faces — Todd's reissue 6,673 (vertical grooves crossing horizontal) against Hull's diagonal diamonds (Duff, 107 U.S. 636), and against Everts' T-shaped ridge plate, US 201,658 (Duff v. St. Louis Wooden-Ware Works, 22 F. 340 (C.C.E.D. Mo. 1884)). A PHOSITA in mid-1876, reading that art, had a concrete, documented commercial motivation to produce a face with (a) a rasping, channelling surface, but (b) no crossing grooves and no sharp angles, precisely to stay outside the Todd reissue's "longitudinal and transverse grooves" claims and to avoid the dirt-accumulation/rust/corner-wear problems the art already attributed to angular geometry. Gould's specification states this motivation almost verbatim: his board is "equally free from acute, salient, or receding angles, which, in other forms of doubly-corrugated wash-board, have proved objectionable." KSR makes an articulated design-around motivation a legitimate § 103 rationale.

5. Why a PHOSITA would have combined these — the motivation analysis

1. Same field, same problem, same parts. Every reference is a hand laundry rubbing board with a formed sheet-metal face; all pursue rasping friction, stiffening of thin sheet, and water/dirt drainage (Duff, 107 U.S. at 639: "the surface broken into protuberances formed of the body of the metal so as to make a rasping surface and to strengthen the metal by its form and to provide channels for the water to run off").
2. The claim's own element E is admitted prior art, so the combination changes nothing about the principle of operation — the crest stays in one plane; only the trace in that plane changes.
3. The design space was explicitly a "form" space, and it was crowded. The Supreme Court's holding is, for § 103 purposes, an unusually blunt statement of the art level: "In the field of wash-boards… Todd was not a pioneer. He merely devised a new form to accomplish those results." Where the field is one of selecting a form from a known menu — straight flutes, zigzag (disclaimed in US 179,974), V-bent (US 179,974), oblique/diagonal (Hull 171,568), offset ovals (G&S 1857), offset diamonds (Crihfield 1870), crossing grooves (Todd 111,585) — choosing a waved/serpentine trace is a design choice among a finite set of known geometries with predictable results, not an invention.
4. Predictable results / reasonable expectation of success. Corrugated sheet with a waving profile was known and indeed preferred in the sheet-metal art since Palmer's 1829 patent, and roll-forming/die-stamping machinery for waved corrugations had existed since 1844–46 (Warr, 1990). Producing a serpentine ridge in a zinc face required no new tooling concept — only a different forming die or roller profile. There was, accordingly, a reasonable expectation that a waved ridge would (i) drain, (ii) stiffen, (iii) scrub, and (iv) eliminate sharp corners.
5. Rounding to avoid injury was a recognized desideratum, per Latcher US 146,921 (rib ends beveled to avoid "angular abrupt terminations… which would injure the clothes") and G&S (edges "somewhat rounded").
6. No unexpected results are demonstrated. The specification asserts a benefit ("a more eflective rubbing-surface") without data, and the benefit claimed is the direct, expected consequence of the geometry.

6. Rebuttal evidence and counterarguments I would expect, and how they fare

• "No single reference shows a continuous serpentine ridge with coplanar crests in zinc." Correct, and I did not find one. The ground is a combination, not an anticipation. The strongest 102-style reference (G&S 1857) discloses offset, rounded, inclined, discontinuous elevations, not continuous ridges.
• "The result is more ornamental than functional." This cuts against the patent: if the serpentine trace produces no new function, the claim's asserted functional advantage ("more effective rubbing-surface," freedom from angles) either is absent or is inherent in the known geometry.
• "Secondary considerations — commercial success." Not in evidence before me. No evidence of the Gould board's commercial success, copying, or industry praise appears in the record; conversely, the litigation record shows the commercially significant boards of the period were the Globe, New Era, and Great Western (Duff v. St. Louis Wooden-Ware Works, 22 F. 340), which were not Gould boards.
• Historically, examiner practice in 1876 was narrower than modern § 103 and the claim was allowed. That is a fact about the Office, not about obviousness.

7. Verification gaps (stated, not papered over)

1. I could not retrieve the Galusha & Safford (1857) or Crihfield (1870) patents themselves — only the Supreme Court's description of them. I have no patent numbers for them and have not assigned any. Their full texts could either strengthen or weaken Combination 1.
2. I did not verify the filing dates of US 185,365, US 190,309, US 193,095, or US 202,003, and therefore cannot say whether any is § 102(e)-type art against July 27, 1876.
3. Identifier discrepancy in the record: Pfanschmidt v. Kelly Mercantile Co. (32 F. 667) refers to the George patent as No. 187,843, while the patent print itself and Lapham Dodge Co. v. Severin use No. 187,842. Per the operating rules I have not auto-corrected either; both appear in the sources.
4. The Palmer-1829 and sinusoidal-profile material is from a secondary, non-patent source (a 1990 conference paper reproduced in a heritage study). It is useful for the state of the sheet-metal forming art but is not a patent-of-record here.
5. All of the above is moot as a live matter: US 186,722 expired 1894-01-30 and cannot be asserted.

8. Bottom line

The sole claim is, on the patent's own admissions, an admitted common-plane corrugated zinc rubbing face with the corrugation axis made wavy instead of straight. The record supplies (i) an 1857 sheet-metal rubbing board whose corrugations are offset row-to-row with inclined, rounded, semi-cylindrical forms expressly described as an improvement over "parallel flutes extending entirely across the plate" (Galusha & Safford); (ii) an 1870 zinc board with offset rows forming oblique channels, made by die-stamping (Crihfield); (iii) a June 1876 zinc board expressly disclaiming zigzag-line corrugations as known (Todd, US 179,974); (iv) an 1874 teaching that angular rib terminations should be rounded to avoid injuring cloth (Latcher, US 146,921); and (v) a documented commercial motive to avoid the crossing-groove faces then in litigation. Combining these to arrive at a serpentine, coplanar-crested zinc ridge is a predictable variation of form within a crowded and expressly "not pioneer" art, with a reasonable expectation of the very drainage, stiffening, and non-injuring results the patent asserts.

My assessment: the claim would be invalid as obvious under § 103 on the Galusha & Safford (1857) + Crihfield (1870) + Latcher (1874) combination, with Todd US 179,974 supplying the art's own admission that zigzag ridge traces were old. My confidence is high on the legal framework and on the art-level characterization (the Supreme Court's own words establish it); my confidence on Combination 1's precise mapping is moderate pending retrieval of the actual Galusha & Safford and Crihfield texts, which I was unable to obtain and which I have declined to fabricate.