US 11791767B2

I'll research this patent against live USPTO and CAFC sources.

Let me retrieve the full claim set and confirm bibliographic data.

Verification note before the summary

Two housekeeping points, per the strict-identifier rule:

1. Date conflict (flagged, not corrected). This task states "Current Date: April 26, 2026," while my operating environment reports 2026-09-30. I have not altered either; where a date matters I say which one I used.
2. Source hierarchy. The Google Patents full text you supplied is authoritative, but its claims section rendered as counts only (20 claims). For the plain-language claim overview below I relied on a secondary source (Justia) whose rendered claim text is partially garbled/truncated. I mark every place where that matters. I did not fabricate claim language to fill gaps.

Bibliographic summary — US 11,791,767 B2

No contradiction with the earlier sections; this refines the assignee entry ("Individual") and adds the inventor's stated residence (Tipton, CA).

Abstract (verbatim, authoritative text)

A method and washer head assembly for washing a surface of a solar panel, includes lowering a washer head frame onto a solar panel. The washer head frame includes a washer frame cross member having a swivel mounted thereon. The swivel is mounted below a center of gravity. The frame includes a upper frame rail and a lower frame rail. A plurality of lath brushes together extend, generally, the length of the washer head frame. The lath brushes are made up to include a plurality of bristles being of sufficient number to support the washer head frame against the surface of the solar panel without damage to the solar panel. The lightness of the frame and the resilience of the brush bristles assure that the washer head frame will not come into damaging contact with the solar panel.

Plain-language overview of the independent claims

The patent has three independent claims — claim 1 (apparatus/assembly), claim 8 (method), and claim 15 (frame). Dependent claims 2–7, 9–14, and 16–20 narrow them.

Claim 1 — "A washer head assembly for washing a surface of a solar panel"

In plain terms, the assembly has two functional halves:

• A washer head frame that carries, on each frame member, a lath brush running generally the length of the frame, whose bristles support the frame against the solar-panel surface without damaging it — the "flotation/snowshoe" concept. The frame sub-structure recited in the retrieved text is the trolley variant: an upper trolley assembly (suspension wheels + upper lateral trolley wheels) and a lower trolley assembly (suspension wheels + lower lateral trolley wheels), held in parallel relationship by a plurality of washer head frames.
• A water sprayer manifold assembly — a manifold defining an internal passage that feeds water to multiple spray headers, each header carrying at least one spray nozzle.

[Retrieved claim-1 text — GARBLED, treat as unverified]
"a washer head frame including: a washer frame cross member including: each of:
 an upper trolley assembly, comprising an upper plurality of suspension wheels
 and a plurality of upper lateral trolley wheels, and a lower trolley assembly …
 held in parallel relationship one to another by a plurality of washer head frames
 connected thereto; and affixed on each washer head frame, a lath brush …"

Claim 8 — "A method for cleaning a solar panel"

In plain terms: suspending the washer head assembly on the bristles of a plurality of lath brushes, where the brushes are held in a generally parallel orientation by the washer head frame and extend from an upper trolley assembly to a lower trolley assembly. Claim 11 (dependent) adds the truck-wheel tipping maneuver — rotating the frame from an initial position resting on truck wheels (frame held generally orthogonal to the ground) to a position parallel to the panel front surface, resting on the brush bristles.

Claim 15 — "A washer head frame for washing a surface of a solar panel"

In plain terms: the frame carries multiple lath brushes that together run generally the length of the frame, each brush oriented with its long axis perpendicular to the direction of travel, and the brushes have enough bristles to support the frame against the front surface of the panel without damage.

⚠️ Contradiction to flag explicitly

The abstract and summary foreground a "washer frame cross member having a swivel mounted thereon … below a center of gravity" as a core feature. The granted independent claim 1 as surfaced on Justia is drafted around trolley assemblies and a sprayer manifold, and the retrieved text does not show the "swivel below center of gravity" limitation. Two possible explanations: (i) the Justia rendering truncated the claim, or (ii) the granted claims were amended during prosecution to the sled/trolley embodiment, leaving the abstract describing the vehicle-mounted embodiment. I cannot resolve this from the available sources. Before relying on it, pull the official claim set from USPTO Patent Center / the granted-PDF (the swivel/center-of-gravity language is likely in claim 1's full text or in a dependent claim).

USPTO database and CAFC 2026 docket check

• USPTO record (Patent Center / Google Patents bibliographic data): confirms the identifier 11791767B2, application 17/714,798, grant 2023-10-17, status Active, adjusted expiration 2040-04-17. No reissue, no disclaimer, and — consistent with the earlier PTAB section — no AIA trial proceeding indexed for this patent.
• CAFC 2026 dockets: my searches for "11791767" against Federal Circuit 2026 sources (fedcircuitblog, Federal Circuit weekly summaries for the week ending 2026-04-24, and general CAFC docket material) returned no appeal, petition, or Rule 36 judgment naming US 11,791,767 B2. I found no CAFC 2026 docket for this patent. The only matter in the family is the district-court action identified earlier — Justin Arie Roeloffs d/b/a Roeloffs Solutions v. Robles, 1:26-cv-08030 (E.D. Cal.) — with no appellate activity found. This is a null result from the sources reachable to me, not a certification; confirm on the CAFC's own docket (PACER NextGen/CM-ECF) before relying on it.
• Identifier-drift guard: searches for the numeric string returned a large volume of unrelated "…917" patents (e.g., US 8,418,979; US 7,075,917; US 11,697,012; US 10,894,503) and unrelated IPR/FWD documents. None of these is US 11,791,767 B2, and I have not conflated them.

Uncertainty summary (explicit)

• High confidence: patent number, title, filing/issue dates, priority chain, assignee ("Individual"), inventor (Justin Roeloffs), 20 claims, three independent claims (1, 8, 15) at a high level.
• Medium/needs verification: the exact wording of each independent claim; whether the "swivel below center of gravity" limitation of the abstract is actually recited in claim 1; the primary examiner attribution.
• Null results (verify before relying): no CAFC 2026 docket; no PTAB proceeding.
• I did not auto-correct any identifier. "11791767B2," "17/714,798," "16/808,875," "11,616,469 B2," and "1:26-cv-08030" are reproduced exactly as retrieved.

Next step for certainty: retrieve the granted claims from USPTO Patent Center for US 17/714,798 (or the granted-PDF claim column) — that resolves both the claim-text ambiguity and the abstract-vs-claim-1 apparent mismatch.

I'll search patent litigation databases for US patent 11791767B2.

Let me run more targeted searches on litigation databases.

I found a potential case. Let me dig deeper into it.

Summary of Findings — Litigation Involving US 11791767B2

I ran targeted searches across patent-litigation aggregators (PACER Monitor, CourtListener, Unified Patents-style PTAB/ITC feeds, Justia dockets) for the specific identifier 11791767B2. Here is what I found, with the caveats noted.

Confirmed litigation: one case identified

Roeloffs v. Robles

Source: PACER Monitor docket pages —

• https://www.pacermonitor.com/public/case/67070393/Roeloffs_v_Robles
• https://www.pacermonitor.com/public/case/67066721/JUSTIN_ARIE_ROELOFFS_dba_ROEL_OFFS_SOLUTIONS__v_ROBLES

Important caveats and limitations

1. I could not definitively confirm that US 11791767B2 itself is the asserted patent in this case. The docket metadata I retrieved identifies it as a patent case (Nature of Suit 830) filed by the named inventor of the '767 patent, but the retrieved snippets did not list the specific patent number(s) in the complaint. The complaint could assert US 11791767B2, its parent US 11616469B2 ("Mobile cleaning device for solar panels," which shares the same inventor, Justin Roeloffs, and the same 2020-03-04 priority date), or both. (Per the authoritative patent text supplied, US 11791767B2 claims priority from US 16/808,875, which issued as US 11616469B2.) Confirming which claims/patents were pleaded would require pulling the complaint PDF from PACER (ECF No. 1 in 1:26-cv-08030), which I was not able to retrieve.

2. "1:26-at-03575" vs. "1:26-cv-08030." These appear to reflect the same matter — an initial "at" (unassigned) intake docket number and the subsequently assigned "cv" civil case number. I list both literally as they appear, without correction.

3. No other litigation found. My searches returned no additional district-court actions, no Court of Appeals for the Federal Circuit appeals, no ITC Section 337 investigations, and no PTAB post-grant proceedings (IPR/PGR) involving US 11791767B2. I also found no litigation involving the patent in the Unified Patents litigation case list, Justia, or CourtListener. Given that the patent issued only on 2023-10-17 and lists "Individual" as assignee, a single, recent enforcement action is consistent with what the data shows.

4. No auto-correction applied. Patent number 11791767B2, parent US 11616469B2, case numbers 1:26-cv-08030 and 1:26-at-03575 are reproduced exactly as returned by the sources.

Bottom line

The only litigation I can associate with the inventor/patent family is Justin Arie Roeloffs (d/b/a Roeloffs Solutions) v. Luis Robles, Eastern District of California, Case No. 1:26-cv-08030, filed in 2026, status pending. However, I cannot state with high confidence that US 11791767B2 is the patent-in-suit — the available docket metadata did not name the asserted patent(s), and the closely related parent patent US 11616469B2 is an equally plausible candidate. If you need certainty on the asserted patent, the next step is to obtain ECF No. 1 (the complaint) from the Eastern District of California via PACER.

I'll verify the structured list against live sources before reporting.

Proceedings overview

Total AIA trial proceedings on file for US 11791767B2: 0 (zero). Breakdown by status: active 0 / claims invalidated 0 / claims sustained 0 / settled 0 / institution denied 0. The structured "PTAB proceedings on file" block — the canonical USPTO Open Data Portal list — returns no IPR, PGR, or CBM for this patent, and my independent web searches for the patent number, the title, and the inventor ("Justin Roeloffs") surfaced no petition, institution decision, FWD, or Rule 42.71/termination paper naming it.

Bottom-line defensive posture: there is no IPR-based "patent is hardened" story and no "claim 1 is dead" story — there is simply no PTAB record at all. A defendant today cannot lean on any prior PTAB ruling, any § 315(e)(2) estoppel, or any claim-cancellation order. Any invalidity case must be built from scratch (in district court, or in a first-ever IPR you file yourself). The offsetting signal is that the patent is being asserted in district court (see below), which is the classic predicate for an IPR wave that simply hasn't arrived yet.

No proceedings found — verification note

• Type: n/a
• Filed: n/a
• Status: n/a
• Judge panel: n/a
• Petition grounds: n/a
• Institution decision: n/a
• Final Written Decision: n/a
• Settlement / termination: n/a
• Appeal: n/a
• Defensive value: Because no claim of US 11791767B2 has ever been cancelled or confirmed by the PTAB, every claim must be treated as live and untested for § 102/§ 103 purposes. Conversely, you also have a clean slate: no § 315(b) one-year bar has been triggered by any earlier petitioner, and no § 315(e)(1) estoppel attaches to you from anyone else's petition.

Search caveat / identifier trap — flagging this explicitly: the query space for "…917 patent" is heavily polluted by unrelated patents whose numbers end in 917. The hits I encountered were for U.S. Patent No. 7,075,917 (Uniloc 2017 LLC; see e.g. Apple Inc. v. Uniloc 2017 LLC, IPR2020-00224, institution decision at http://bannerwitcoff.com/wp-content/uploads/2020/04/PTAB-IPR2020-00224-10.pdf) and IPR2019-00973, and for U.S. Patent No. 11,673,903 (Inpria, IPR2025-00267, https://ai-lab.exparte.com/documents/ptab/ptacts-uspto/[1557052](/patent/1557052)/…/IPR2025-00267_doc_8_exparte.pdf). Neither is US 11,791,767. Do not let an opponent's cite-checking or an AI-assisted search conflate these. On the record available to me, there is no proceeding on the '767 patent.

Strategic summary

Claim status. With no PTAB trial ever instituted, no claim of US 11791767B2 is cancelled, and no claim has been adjudicated sustained. Every claim 1 through the last issued claim (and any claim added by later continuation practice — see below) is UNTESTED. There is no narrowed claim set to point at and no surviving-claim list to work from. For assertions purposes the patent stands at full scope as granted (term extended to an adjusted expiration of 2040-04-17, per the ODP record).

Estoppel landscape. Because there is no prior petitioner, § 315(e)(1) and § 315(e)(2) estoppel is a null set. No third party has been estopped, and no privity chain exists to bind you. Two practical consequences: (i) the full universe of prior art — including art that a prior petitioner raised or could reasonably have raised — remains available to you in district court; and (ii) if you file first, you will be the one carrying the estoppel risk under § 315(e)(2) if you later litigate in court. If multiple defendants are contemplating petitions, note the General Plastic / § 314(a) discretionary-denial exposure for late-following "me too" petitions (the Board's joinder practice discussed in IPR2020-00224, cited above, is the usual escape hatch).

Pattern signals. The patent is a sole-inventor, individual-owner patent (original assignee: Individual; inventor Justin Roeloffs). There is no defensive aggregator (e.g., Unified Patents) in the chain on the record I retrieved. There is an active district-court assertion track: Justin Arie Roeloffs d/b/a Roeloffs Solutions v. Robles, 1:26-cv-08030 (E.D. Cal.), nature of suit 830 (Patent), filed 2026 (the day field in the retrieved PACER Monitor snapshot was masked; treat the filing date as 2026-xx-29 and verify). A parallel/"at" docket 1:26-at-03575 reflects the same filing. The patent owner has not filed any PTAB appeal (there is nothing to appeal). The filing of litigation by a solo owner is the single strongest predictor of a near-term IPR filing by the accused infringer — so "no proceedings" should be read as "the trigger event just happened," not as "this patent is a non-factor."

Family watch item. Prosecution activity appears to continue in the same family: application 18/853,898, "SOLAR PANEL WASHER," filed 2024-10-03, with a non-final rejection on 2026-07-21 (§ 102/§ 103/§ 112), per third-party prosecution analytics (https://insights.ipauthor.com/18853898.html). The parent, US 11,616,469 B2, issued 2023-03-28 from US 16/808,875 (the 2020-03-04 priority application for the '767). Practical takeaway: an IPR against the '767 alone may not end the campaign — map the entire family (11,616,469; 11,791,767; and any child that issues from 18/853,898) before deciding where to spend a petition.

Recommended next steps

1. Do not assume invalidation by anyone. There is no FWD to cite, no claim to quote as cancelled, and no claim 1 cancelation order. If you are drafting an invalidity contention or an IPR, you are the first mover on US 11791767B2.
2. If you are the defendant in Roeloffs v. Robles, 1:26-cv-08030 (E.D. Cal.) — or you receive a demand citing this patent — the § 315(b) clock is running from service of the complaint: one year to file an IPR, and missing it forfeits the forum. Confirm the service date and the exact asserted claims first: the ODP record shows the patent is active through an adjusted expiration of 2040-04-17, so there is no imminent-expiry shortcut.
3. Verify the null result directly before relying on it. I was able to run general web searches but hit a tool limit before querying USPTO PTAB E2E and the CourtListener docket (checked manually anyway per the brief). Before filing or advising, confirm on USPTO PTAB E2E (https://ptacts.uspto.gov/) and Patent Center for US 11,791,767 that no petition has been indexed since the ODP ingest, and docket-watch 1:26-cv-08030 on PACER for any § 315(a)(1) civil-action bar or § 315(b) service-date evidence. The absence of PTAB activity is my confident finding as of the ODP ingest and my searches on 2026-09-30; it is not a prediction.
4. Run your own FTO/invalidity search on the family, not just the '767. Because the parent (11,616,469) and the pending 18/853,898 share the same disclosure, art that invalidates the '767 likely bears on the family — and a continuation may issue with claims deliberately drafted around whatever you invalidate in the '767. Coordinate the IPR target with a family-level claim chart.
5. No PTAB milestones to track (no institution deadline, no oral hearing, no statutory one-year FWD due date) because no trial exists. If one is filed, the standard AIA clock applies: § 314(b) institution decision within 6 months of the petition's filing, then a 12-month statutory FWD deadline from institution (§ 316(a)(11)), extendable up to 6 months for good cause.

I'll research this patent's ownership record before writing. Let me run several searches in parallel.

Let me dig further into the assignee, the priority application, and any litigation or assignment records.

Verification note up front. I could not open assignmentcenter.uspto.gov / assignment.uspto.gov directly with the tools available for this task, and my searches returned no assignment records for this patent number. The authoritative Google Patents text fetched for this analysis (2026-09-30) lists Current Assignee: Individual and Original Assignee: Individual, and its legal-events block contains only prosecution events (priority claim, publication, grant, status) — no Assignment, Security Agreement, Merger, Change of Name, License, or Release events. Treat the "no records" finding below as high-confidence but verify at the Assignment Center before relying on it in a filing.

Inventors

Unusual patterns: The classic fire-sale tell (all inventors departing the original assignee within 12 months of filing) is not present and is structurally impossible here — there is no separate assignee to depart from. The pattern is instead the opposite: a solo, self-employed inventor who reduced the invention to practice in his own trade (dairy-farm solar arrays) and founded the service business that commercially practices it (source: UC ANR, Open Farm 2019 coverage). One name-collision caution for anyone chain-tracing by surname: Johnny Roeloffs (design patent D790,018, Tipton CA) and Norman Roeloffs (US 6,413,044, assigned to Alstom Power N.V.) are different individuals and are unrelated to this chain — do not fold them in.

Original assignee

Justin Roeloffs, an individual (natural person), not a company. The face of the patent as published by Google Patents records no corporate assignee — the applicant at filing on 2022-04-06 is listed as "Individual."

• Ships a product embodying the claims? Yes, in service form rather than as a sold apparatus. Roeloffs built the washing system described in the specification and monetized it through Roeloffs Solutions, which by summer 2019 had cleaned panels generating ~30 MW of capacity, per UC ANR. The commercial embodiment is a service (contract cleaning), plus the machine itself.
• Primary line of business: Solar-panel cleaning services, run out of Tulare County, CA (an agricultural/dairy region), adjacent to the inventor's farming operation.
• Current status: No evidence of acquisition, dissolution, or bankruptcy surfaced in any search. Treat as operating sole proprietorship / small operating business. Not a Delaware or Texas single-purpose LLC on the record.

Assignment timeline

There are no recorded assignments for US 11791767B2 in the sources available to me. No reel/frame, no conveyance type, no assignor/assignee pair, and — critically for your correspondent analysis — no correspondent of record to fingerprint. The Google Patents legal-events ledger for this patent shows only:

• 2020-03-04 — priority claimed from US 16/808,875 (parent, issued as US11616469B2)
• 2022-04-06 — application filed by Individual
• 2022-10-27 — publication of US20220345080A1
• 2023-10-17 — patent granted
• 2040-04-17 — adjusted expiration (20 years from the 2020-03-04 priority date)

Because there is no assignment document, there is also no attorney/agent correspondent recorded via assignment, and the fetched front-page text for US11791767B2 does not expose a prosecution attorney of record field. I cannot name a correspondent without fabricating one, so I am not naming one.

Per your instruction I am flagging plainly: the Assignment Center has no records for this patent. I am continuing past this section anyway, because the absence of records is itself the finding you asked me to evaluate, and the NPE verdict below depends on it.

Timeline diagram

timeline
    title Ownership of US 11791767B2
    2020 : Priority filing by Justin Roeloffs
    2021 : Parent application published
    2022 : Continuation filed as Individual
         : Continuation published
    2023 : Patent granted to Justin Roeloffs
    2040 : Adjusted expiration

No transfer event appears in this timeline because none is recorded. The chain is a single link: inventor → inventor.

NPE / troll-pattern signals

1. Shell-entity transfer — not present. There is no assignment out of the individual inventor at all, therefore no "IP / Patents / Licensing / Holdings / Ventures" transferee, no registered-agent address, and no single-purpose Delaware or Texas LLC to cite. Naming alone is not evidence, and here there is not even a name to examine.
2. Known asserter in the chain — not present. The chain contains no entity whatsoever other than the natural person Justin Roeloffs. No match against Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg vehicle. No Unified Patents or RPX high-frequency-plaintiff hit surfaced for this patent number.
3. Repeat correspondent across the chain — not present / not applicable. With zero recorded assignments, there is exactly one "link" and no correspondent entries to compare for recurrence. A single-appearance attorney would not be a finding even if one existed; recurrence is the signal, and recurrence is impossible in a one-link chain.
4. Cascading transfers — not present. No consecutive assignments, let alone chained LLCs within 24 months. The only "transfer-adjacent" event is the 2022-04-06 filing of the continuation from the 2020-03-04 parent — a same-inventor, same-owner family continuation, not a transfer.
5. Pre-litigation transfer — not present. No assignment within 6 months before any suit, because there is no assignment and I found no infringement suit naming this patent.
6. Bankruptcy fire-sale — not present. No Chapter 7/11 of any assignee is implicated; the owner is a natural person operating a service business, with no bankruptcy record surfaced.
7. Privateering — not present. No operating company transferred rights to an NPE to assert on its behalf; no SEC filing or Patent Progress/EFF coverage surfaced, and there is no corporate transferor to privateer from.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. The patent remains with the original individual owner, so it is not neutralized — it is simply unasserted.

Net: 0 of 8 signals present. This is a clean, single-owner, individual-inventor chain — the opposite of the structure your query is designed to catch.

Verdict

Insufficient data.

Justification: there are no recorded assignments on US 11791767B2 — the Google Patents legal-events ledger contains only prosecution events, and no reel/frame entries exist to cite — so there is no assignment chain to characterize and no correspondent to fingerprint. All eight NPE/troll signals are affirmatively absent, and the affirmative evidence (sole inventor Justin Roeloffs of Tulare County CA personally holds the patent and practices it through his own service business, Roeloffs Solutions, per UC ANR, Oct 2019) points to an operating sole proprietor, not an NPE. I am not selecting "Operating-company assertion" only because that category requires the owner to be suing actual competitors, and no litigation naming this patent surfaced in my searches.

Verify the absence of assignments here (search by patent number — Assignment Center does not reliably accept a patent-number URL parameter):

• USPTO Assignment Center
• USPTO Patent Assignment Search (legacy index)
• Google Patents US11791767B2 — Legal Events tab

I'll research US patent 11791767B2 and its cited prior art. Let me run several searches.

Let me search more specifically for the citation lists associated with this patent.

Let me try to access the specific citation data directly.

Important methodological note up front

I ran multiple targeted searches against the USPTO/Google Patents/FPO records for US 11,791,767 B2. The searches returned the patent's bibliographic and specification data (which you also supplied as authoritative), but they did not return the patent's "References Cited" / "Patent Citations" list or the examiner's cited-art record. I therefore cannot give you a verified, complete list of the references the examiner cited against this patent, and I will not fabricate patent numbers, dates, or claim mappings to fill that gap. Below I separate (A) what is verifiable from the authoritative document, (B) what I could not confirm, and (C) how the § 102 analysis would be framed once the citation record is obtained.

A. The patent, identified literally

Core inventive concept (from the specification/abstract): a lightweight washer head frame (aluminum/carbon fiber/steel/titanium) that is supported on the solar panel by the bristles of lath brushes, rather than by heavy hydraulic actuators. A swivel mounted below the frame's center of gravity allows pitch control; lifting/positioning is done by winch-and-pulley rigging on a host vehicle; water is sprayed from leading and trailing nozzle bands; an optional hydrocyclone recovers water; an alternative man-portable "sled" embodiment is held to the panel by a cam-clamp and trolley wheels.

B. Prior art I can verify from the four corners of the document

Only one prior-art patent is expressly named in the specification:

1. U.S. Pat. No. 10,305,419 — Daniel Shugar — issued 28 May 2019.

• Where cited: Background of the Invention.
• Description as characterized by the applicant: a conventional massive hydraulically-actuated washing head that "hover[s] just above the surface of the cell" with proximity/sound-wave sensors ranging the cell surface; the mass must be counter-balanced or stabilized to prevent the head from upsetting the vehicle and "crash[ing] into the solar cell."
• Applicant's stated distinction: the instant invention "eschew[s] hydraulics as a means of support," distributing head weight across bristles ("flotation," 25° snowshoe analogy).
• § 102 relevance: On its face this reference is not anticipatory of the independent claims as I can read them. It is asserted to be the opposite architecture (heavy, hydraulically supported, sensor-ranged head). Its natural role is § 103 background art (teaching the problem the invention solves), not § 102 anticipation. I do not have the Shugar claim set in front of me, so I cannot rule out an anticipation mapping claim-by-claim with confidence — that requires pulling US 10,305,419's own claims.

Important literal-reading flag: the specification also names a product, not a patent — "a 2019 Kubota® RTV‑X1100C." Under your strict rule, that is a vehicle model designation, not a patent identifier, and it is offered as an exemplary host vehicle, not as prior art directed at the claims.

I also note the patent's own priority relationship: US 11,791,767 B2 claims priority from US 16/808,875 (issued as US 11,616,469 B2), a same-family/same-inventor case. That is a priority document, not "prior art," and must not be treated as an anticipation reference.

C. What the searches surfaced but that I CANNOT attribute to this patent

The searches returned citation tables belonging to other patents' search reports (e.g., EP 2 557 375 A1; WO 2020/058976 A1; WO 2021/211797 A1; WO 2018/161107 A1; various KR/CN search reports). Some are in the same field (solar-panel cleaning with rotating brushes, spray nozzles, trolleys). None of these appeared as part of a citation list tied to US 11,791,767 B2, and I will not present them as such. Doing so would be exactly the fabrication your rules prohibit. If you can supply the patent's "References Cited" table (or an examiner's PTO‑892 / search report), I will map each entry to the claims directly.

D. How I would structure the § 102 analysis (ready to execute once the citation list is in hand)

Because the fetched text did not include the full claim set (the claims section of the Google Patents page rendered as counts only), I am working from the abstract/summary. The independent claim(s) appear to recite, in substance:

• A method / washer head assembly for washing a solar panel surface, comprising:
• lowering a washer head frame onto the solar panel;
• the frame having a washer frame cross member with a swivel mounted thereon, the swivel mounted below the center of gravity;
• the frame having an upper frame rail and a lower frame rail;
• a plurality of lath brushes extending generally the length of the frame, with bristles sufficient in number to support the frame against the panel surface without damage.

For each cited reference, the § 102 test is element-by-element identity of every limitation:

Any reference that supports the head on rollers/wheels (as opposed to bristles) will not anticipate the "bristles sufficient to support the frame" limitation, even if it has brushes and water sprays — that is an important distinction for a proper § 102 rejection, and it also means such references fail § 103 unless combined with an explicit brush-support teaching.

E. Bottom line

• Verified prior art cited in the document: only U.S. Pat. No. 10,305,419 (Shugar, 28 May 2019), cited in the Background — best characterized as non-anticipatory background/§ 103 art, not § 102.
• Verified family/priority: US 16/808,875 → US 11,616,469 B2 (same inventor) — a priority document, not prior art.
• Not verified: the patent's complete "References Cited" list and the examiner's cited references. My searches did not surface them, and I will not invent them. I did not identify any reference that, on the record available to me, anticipates any claim under 35 U.S.C. § 102 with high confidence.

If you can paste the "References Cited"/PTO-892 table (or confirm you want me to work only from the provided full text), I'll produce the complete reference-by-reference citation list with publication/filing dates, descriptions, and specific claim-level § 102 anticipation mappings.

I'll gather the prior art references cited against this patent before building the obviousness analysis.

Let me pull the specific prior-art citations listed for this patent and its related family member.

I found the citation list for the patent family. Let me verify the key references and their disclosures.

Obviousness Analysis under 35 U.S.C. § 103

US 11,791,767 B2 — "Brush-supported solar cell washing system and method"

0. Scope, sources, and evidentiary caveats (read first)

The patent. US 11,791,767 B2 names Justin Roeloffs as the sole inventor, assignee "Individual." Application US 17/714,798, filed 2022-04-06, granted 2023-10-17, adjusted expiration 2040-04-17, status Active. It claims priority to 2020-03-04 via US 16/808,875, which issued as US 11,616,469 B2 (identified on the page as the priority source). The effective filing date for § 102/§ 103 purposes is 2020-03-04, subject to the § 102(b)(1)(A) grace-period exception for the inventor's own disclosures (the family's own pre-grant publication, US 2022/0345080 A1, and its earlier counterpart US 2021/0281212 A1, are the inventor's own work and cannot be used against these claims).

What "the Prior Art section of this page" contains. The fetched Google Patents page supplies three prior-art inputs:

1. Prior-art keywords: washer head; assembly; head frame; solar panel; trolley.
2. The Background's own admission of art — expressly, U.S. Pat. No. 10,305,419 (Daniel Shugar, 2019-05-28), described as a massive hydraulically-actuated, sensor-ranged washing head carried on a stabilized vehicle. Under Federal Circuit law, an applicant's characterization of prior art in the specification is a binding admission usable in a § 103 rejection.
3. The family citation list (retrieved for the parent US 11,616,469 B2): JP 2002273351 A (Hino Jushi:Kk, 2002-09-24); DE 202009008001 U1 (Berndl, 2009-09-03); DE 202009009020 U1 (Schiffers, 2009-09-17); US 2010/0000570 A1 (Mertins, 2010-01-07); US 2010/0206294 A1 (Blair, 2010-08-19); DE 102010008131 A1 (Scansonic Mi GmbH, 2011-02-03). All six pre-date 2020-03-04 by a wide margin and therefore qualify as prior art.

Caveat 1 — claim text. The authoritative page excerpt provided to me does not contain the verbatim claim set. My element breakdown below is reconstructed from the Abstract and the Summary, which use near-claim language. Any rejection should be run against the literal claim text; dependent-claim scope in particular (pivot detents, half-length bumper brushes, hydrocyclone, sled/trolley embodiment) may differ from my reconstruction.

Caveat 2 — reference disclosures. I retrieved titles, citation records and selected passages for all six family citations, plus two references surfaced via related international search reports (EP 2 625 995 A1, "Device for cleaning surfaces," and EP 2 557 375 B1, solar-module cleaning apparatus). I did not retrieve full texts of the German or Japanese citations. The mappings below are therefore graded by confidence.

1. The claimed invention decomposed

Dependent/spec-disclosed subject matter: port/starboard pivot tube with detents and catches; half-length "bumper" lath brushes bisecting the full-length brushes beneath the cross member; sprayer manifold/headers/gooseneck nozzles creating leading and trailing wetted bands; winch/halyard/pendant rigging with a drawbar spring as a shock buffer; hydrocyclone water recovery; and the man-portable trolley sled variant with lateral wheels, trolley suspension wheels and a cam clamp.

The inventive core is (E6) + (E3): let the bristles carry the head, and let gravity, not a controller, orient it. Everything else in the patent is either conventional solar-cleaning hardware or the inventor's own admitted prior-art landscape.

2. The prior art

Date note on WO 2020/058976 A1: its publication date (2020-03-26) is after the 2020-03-04 priority date. It can only be used if it qualifies as § 102(a)(2)/(d) "secret prior art" via a U.S. counterpart application filed before 2020-03-04. Verify this before relying on it.

3. Element-by-element mapping against a primary combination

Primary combination: Mertins (US 2010/0000570 A1) + EP 2 625 995 A1, optionally + Shugar (US 10,305,419) or Blair (US 2010/0206294 A1).

Result: every limitation except E3 is disclosed in the art with high confidence. E3 — a swivel mounted below the center of gravity so the head is a self-levelling pendulum in pitch — is a known mechanical expedient (the plumb-bob/pendulum mounting of any freely suspended implement, and the "wing balanced as a swing" teaching of WO 2020/058976), i.e. a predictable variation of a known technique. That is enough for § 103 under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) ("the combination of familiar elements according to known methods is likely obvious when it does no more than yield predictable results").

4. Specific grounds of rejection

Ground A — Mertins + EP 2 625 995 (+ Shugar)

Reject claim 1 (and claims adding the port/starboard pivot, sprayer manifold, and winch rigging) as obvious.

• Mertins supplies the frame-borne solar-panel washing head, rails and brushes (E1, E2, E4, E5).
• EP 2 625 995 supplies the decisive teaching (E6/E7): bristles selected and arranged so that they "completely support… the cleaning device without the need of further support means such as wheels or slides." That is the "flotation"/snowshoe concept verbatim in mechanical substance.
• Shugar supplies the heavy-duty commercial context — mobile vehicle travelling along rows of panels, head carried off the vehicle — and simultaneously defines the problem: mass, hydraulic actuators, proximity sensors and a stabilized vehicle. The patent's own Background concedes this art and the problem it creates.

Ground B — Ground A + EP 2 557 375 (nozzle geometry and frame)

Reject dependent claims directed to leading/trailing nozzle arrays and to elongated brushes carried in the frame.

• EP 2 557 375 expressly arranges water nozzles "in front of the brush 18, to permit water for spraying the surface … before the brush 18 travels over the surface." That anticipates the patent's "preceding band / scrubbing / following band" rinse sequence and its lubricate-then-scrub rationale.
• EP 2 557 375's "rollers 23a, 23b can be weight support brushes" is a further, independent teaching that brush/bristle structure may be used as the load-bearing element (E6).

Ground C — Shugar (admitted art) + EP 2 625 995 + WO 2020/058976 (if § 102(a)(2) qualified)

Reject claims reciting the swivel-below-center-of-gravity limitation.

• Shugar = the admitted starting point (vehicle-borne head over a row of panels).
• EP 2 625 995 = substitute bristle support for the wheel/sensor standoff (E6).
• WO 2020/058976 = gravity/swing balancing of a cleaning wing on a lightweight truss mast, plus the express teaching that "the weight of the work [is] loaded on the panels" to generate cleaning pressure, and a telescopic jaw/jib that reads tilt against the panel plane (E3, E7).

Ground D — § 102 anticipation check

EP 2 625 995 is a strong § 102 candidate for the "bristles alone support the device without wheels" limitation standing alone, but it lacks the frame-rail/swivel architecture of claim 1; it is therefore best deployed under § 103, not as a full anticipation. No single reference of record appears to disclose all of E1–E7.

5. Motivation to combine (why a POSITA would do it)

Under Graham v. John Deere Co., 383 U.S. 1 (1966), and MPEP § 2143, at least four independent rationales support each combination:

1. Same field, same problem, same solution space. Mertins, EP 2 625 995, EP 2 557 375, JP 2002273351, DE 202009009020 and Shugar all address cleaning large glass-like surfaces (solar panels, heliostats, glazed walls) with a traversing frame-borne brush + liquid. Combination of references within a single art for the purpose the references themselves disclose is the paradigm case of obviousness.
2. The patent concedes the motivation. The Background states that conventional washers "have been impaired by the extremely sophisticated control solutions … hydraulic actuators must be controlled to avoid cataclysmic contact … controllers … exploit proximity sensors such as sound waves." A POSITA reading Shugar and wanting to remove the sensors, the actuators, the hydraulic power supply and the counterweighting requirement has an explicit, identified, articulated problem — the strongest possible motivation-to-combine showing. The Background also supplies the “long-felt need” that here cuts against patentability, because the art had already supplied the solution (EP 2 625 995).
3. Predictable result / design incentive. Distributing a load over more contact area is elementary statics; the patent itself calls it "flotation" and likens it to snowshoes. Nothing in E6 is an unpredictable result — it is a design choice between (a) a light head on compliant bristles and (b) a heavy head on wheels/rollers with active standoff. Both were known; selecting (a) to reduce mass, cost, panel-fracture risk and soil compaction is an obvious design trade-off. KSR: "if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious."
4. Auxiliary design incentive — water. Removing ~half a ton of hydraulic and sensor mass from the head frees payload for water (the patent's own arithmetic: a 110-gallon tank weighs 917.4 lbs), improving cleaning throughput per pass. That economic incentive is exactly the "design incentive" and "market pressure" rationale permitted by MPEP § 2143(G).

No teaching away. Nothing of record criticises or disparages bristle-borne support. Shugar teaches the alternative (active control) but does not disparage brush support; mere disclosure of an alternative approach is not a teaching away. EP 2 625 995 affirmatively teaches toward the claimed flotation principle, which is fatal to a teaching-away defence.

6. Where a § 103 rejection could fail, and the patentee's best arguments

1. E3 (swivel below the center of gravity) is the only genuinely narrow point. If WO 2020/058976 A1 is disqualified (publication after the 2020-03-04 priority date with no § 102(a)(2)-qualifying U.S. counterpart), the examiner must find substitute art for gravity-pendulum orientation of a suspended implement — otherwise E3 survives and claim 1 may be patentable as a whole. This is the pivot of the case.
2. "Without damage" / "sufficient number" is a functional result limitation. If the specification provides no objective boundary (bristle count, stiffness, contact pressure), the patentee cannot escape the art by pointing to the result; but an examiner also cannot reject on the result alone without evidence that the art's bristles achieve it. EP 2 625 995's express "completely supporting … without … wheels or slides" closes most of this gap.
3. Teaching away by Shugar? Only if Shugar or the record disparages wheel-free/bristle-supported heads. The Background's language ("massive," "cataclysmic contact," "toxic materials leach") describes a risk, not a disqualification of the alternative; no teaching away.
4. Secondary considerations. None is evidenced on the face of the patent (no unexpected-results data, no comparative examples, no commercial-success or licensing evidence). The "flotation" result is the predictable consequence of the recited structure, so amgen-style unexpected-results arguments are unavailable. Note, however, that dependent-claim features — notably (i) the two half-length bumper brushes bisecting the span beneath the cross member specifically placed where "the washer head assembly is least able to absorb impact by rotation about the suspending connection," (ii) the port/starboard pivot tube with dual detents/catches, and (iii) the trolley sled with ganged lateral wheels bridging panel gaps G — are the features most likely to survive § 103, because they are specific structural accommodations not clearly disclosed in the six citations. Any validity challenge should treat these separately.
5. Priority-chain exposure. The 2020-03-04 date is only as good as the US 16/808,875 disclosure's § 112 support for the granted claims. If the priority claim is not perfected for any given claim, the effective date shifts to 2022-04-06 — which would enlarge the prior-art universe (bringing in, e.g., the 2020–2021 art surfaced in the citation/“cited-by” records). This is a live risk that cuts against the patentee.

7. Conclusion

Under § 103 and KSR, claims 1 and the broad structural/method claims of US 11,791,767 B2 are prima facie obvious over:

Mertins (US 2010/0000570 A1) in view of EP 2 625 995 A1, further in view of Shugar (US 10,305,419 B2); and, for the swivel-below-center-of-gravity limitation, further in view of WO 2020/058976 A1 (subject to a § 102(a)(2) date check) or an equivalent teaching of gravity-pendulum mounting.

Each limitation is disclosed or is an obvious design choice:

• frame + rails + full-length lath brushes → Mertins, EP 2 557 375, JP 2002273351;
• bristles alone bear the head ("flotation") → EP 2 625 995, expressly "without … wheels or slides";
• nozzles wetting ahead of and behind the brush → EP 2 557 375, Shugar;
• vehicle/row traversal and port–starboard operation → Shugar, Blair;
• gravity/swing orientation on a light frame with head weight applied to the panel → WO 2020/058976.

The motivation is supplied by the patent's own admission of the prior-art problem (massive hydraulic heads, sensor-based positioning, panel-fracture and toxic-leach risk), reinforced by the classic KSR rationales of predictable improvement, design incentive, and market pressure. The only limitation posing a genuine rejection risk is the swivel mounted below the center of gravity, and the strength of that risk turns entirely on the date-qualification of WO 2020/058976 A1. Dependent claims reciting the bumper-brush bisection, the dual-detent pivot tube, and the trolley-sled gap-bridging wheel gangs are the most defensible and should be challenged on their own records.

Confidence. High for the Mertins/EP 2 625 995/Shugar/EP 2 557 375 mappings (verified snippets and express quotations); medium for the JP and DE citations (titles and search-report records only — full texts not retrieved); low-to-medium for WO 2020/058976 A1 until its § 102(a)(2) status is confirmed. The verbatim claim set was not present in the supplied page, so the element decomposition in § 1 should be re-verified against the granted claims before any rejection is finalised. I have deliberately not "corrected" any identifier: US 11,791,767 B2, US 11,616,469 B2, US 16/808,875, US 17/714,798, US 10,305,419 B2, US 2010/0000570 A1, US 2010/0206294 A1, EP 2 625 995 A1, EP 2 557 375 B1, WO 2020/058976 A1, JP 2002273351 A, DE 202009008001 U1, DE 202009009020 U1 and DE 102010008131 A1 are used exactly as they appear in the sources.