US 9335272

I'll search for authoritative information on this patent and any 2026 CAFC litigation involving it.

Let me check specifically for any litigation or 2026 court activity involving this patent.

US 9,335,272 B2 — Analyst Summary

Bottom line on the database/docket search: I searched for US 9,335,272 and found no CAFC 2026 docket, no IPR/PGR, and no district-court litigation involving this patent. This is consistent with the patent's status — it expired for failure to pay maintenance fees in 2020, so there is no live enforcement activity to litigate. I was not able to query PACER/CourtListener directly, so I cannot rule out an unindexed filing with absolute certainty; treat "no 2026 CAFC activity" as a high-confidence but not audit-grade conclusion. All bibliographic and claim data below comes from the authoritative full text provided.

Bibliographic Data (authoritative)

Abstract (as issued)

A method and composition for testing wear on mechanical hardware. A metal oxidant is applied to the hardware being tested; it deposits onto the metal and can be visually detected. A key property is that the metal oxidant is a substantially non-flowing/non-dripping medium that can be applied in situ with reduced risk to surrounding hardware.

Plain-Language Overview of the Independent Claims

There are two independent claims: claim 1 and claim 20 (claims 2–19 depend from claim 1).

Claim 1 — In-situ visual wear test using a copper gel/paste

1. Access the mechanical hardware — specifically a helicopter drive shaft or helicopter gear — while it is still essentially in its in-use/operative position (i.e., without dismantling it out of the aircraft). The hardware must have an iron-containing inner portion (e.g., a high-tensile steel core) and a silver-containing outer portion that is substantially free of that iron.
2. Apply a metal oxidant while the hardware stays in place. The oxidant must contain an ionic copper salt complex. It is applied at least where the inner portion is exposed through the outer portion (i.e., where the silver plating has worn away). The copper oxidizes the exposed iron and deposits onto it, without oxidizing the silver outer portion. Critically, the oxidant is non-flowing — it holds its shape on non-horizontal surfaces (inclined, upright, and downward-facing) so that it can be kept from running onto and contacting other hardware not under test.
3. Detect wear of the outer portion by detecting the deposited metal oxidant on the exposed inner portion (colour contrast between deposited copper and silver plating).

Claim 20 — Fuller independent method, adds pre-clean, pre-inspection, acid, timed reaction, and wash steps

1. Access a helicopter drive shaft or helicopter gear while substantially in its in-use/operative position; inner portion has iron, outer silver coating is free of iron and protects the inner core from oxidation.
2. Pre-clean to remove grease/oil.
3. Visually inspect to form a preliminary assessment of where the outer coating has been removed.
4. Apply metal oxidant while hardware remains in place; oxidant includes an ionic copper salt complex plus an acid (sulphuric and/or nitric acid); applied where the inner portion is exposed; non-flowing so it retains shape on inclined/upright/downward-facing surfaces and can be prevented from flowing onto untested hardware.
5. Allow reaction for a stipulated time so copper deposits on the exposed inner portion where the outer coating is absent, without oxidizing the outer portion.
6. Wash the oxidant off after the stipulated period.
7. Detect wear of the outer coating by detecting deposited oxidant on the inner portion, in comparison to the outer coating.

Notable dependent limitations: metal oxidant includes copper/nickel/tin (claim 2); lower oxidation potential than iron (claim 3); outer portion free of the oxidant metal, no orange/red "cupreous" look (claims 4–5); up to 50 g/l copper sulphate (claim 6); detection by naked eye (claim 7); application up to 60 min (claim 8); before/after digital image comparison (claim 9); pH 1–6 (claim 10); sulphuric acid 98% at 0.01–5.0 ml/l (claim 11); paste (claim 12) or gel (claim 17) medium; pre-cleaning (claims 13–14); ~5-minute application and water rinse (claims 15–16); gelling agents incl. gelatin/agar/silica/resins/polymers (claim 18); up to 150 g/l agar (claim 19).

Drafting Anomalies Worth Noting (literal reading)

• Claim 8 recites "step a) includes the metal oxidant being applied… for a period of up to 60 minutes," but in claim 1 step a) is the accessing step and step b) is the applying step. Read literally, this dependency does not map cleanly onto claim 1 — likely carried over from earlier claim text.
• Claim 9 refers to removing "the viscous composition," a term not used in claim 1 (which calls it "metal oxidant"). Another inherited inconsistency.
• The specification's "metal oxidant" is sometimes described interchangeably as an "oxidant," and there is a separate embodiment using a non-metallic/organic oxidant — but the issued independent claims are limited to ionic copper salt complexes and to helicopter drive shafts/gears.

Prior Art / Citations of Record

Patent citations include US 2007285 (Schauffele), US 2643205, US 3549993, US 3652224, US 6054038 (Dacco Sci, in-situ electrochemical corrosion sensor), US 2003/0188813, WO2006028941, and US 2009/0220689; family cites include US 2003/0068824 (Frankel, corrosion-sensing composition) and JPH07320535. A non-patent citation is ASTM F1089-02 (corrosion of surgical instruments). The specification also asserts the composition does not cause hydrogen embrittlement to high-strength steels under ASTM F519 slow-strain-rate testing.

Uncertainty Statement

• No CAFC 2026 or other litigation found — I cannot confirm a negative with absolute certainty absent direct PACER/CourtListener access, but extensive searching surfaced nothing, and the patent's 2020 fee lapse strongly corroborates that no active dispute exists.
• Inventor is listed as Darren Gerrard only; no joint inventors appear in the authoritative record.
• All claim and bibliographic content is taken from the provided authoritative full text and is not dependent on secondary sources.

I'll search for litigation involving US patent 9335272 across the sources you mentioned.

Initial searches returned nothing relevant. Let me check the specific litigation-tracking sources you named.

Let me try a few more targeted searches to confirm whether any case exists.

Summary of Findings

No litigation involving U.S. Patent No. 9,335,272 is known or was found.

I searched for the specific number 9335272 across general web sources and the litigation-oriented sources you named (Unified Patents litigation portal, Federal Circuit, and general district-court complaint indexes). Every query returned either (a) the patent's own Google Patents page, or (b) unrelated cases involving different patent numbers (e.g., Telebrands' U.S. 9,581,272; Netlist's patents; Ziptronix/TSMC patents). Per your strict rule, I did not treat those lookalike numbers or unrelated hits as results for 9335272.

What I could positively confirm about the patent itself (from the authoritative full text, not litigation databases):

No case details can be provided (plaintiff, defendant, jurisdiction, case number, filing date, outcome/status) because no such case was located. Because the patent lapsed for non-payment of maintenance fees in mid-2020, it has been unenforceable-by-expiration for several years, which is consistent with — though not by itself proof of — the absence of any recorded assertion.

Important caveats on this negative finding:

• My searches hit a step/rate limit and returned no direct "no results" confirmation from the Unified Patents litigation case list, Docket Alarm, PACER, or CourtListener for this exact number; the conclusion rests on the searches that did complete plus the patent's expired status.
• The absence of results is a negative finding, not a certification. Doctrine of equivalents aside, a patent that was never asserted could also be litigated in a sealed or unreported proceeding, but no evidence of that surfaced.
• To obtain a definitive answer, an authoritative query would be run against: PACER (all district courts, via Docket Alarm / RPX Insight / UniCourt searching "9,335,272"), the Unified Patents litigation case list, and Westlaw/Lexis docket search for the exact number — none of which I could fully query here.

If you want, I can attempt to re-run targeted docket-database queries once the tool limit resets, focusing strictly on the exact string "9,335,272."

I'll start by verifying the structured "no proceedings" signal against public sources.

No IPR hits yet. Let me run more targeted checks against PTAB docket aggregators and litigation records.

Let me run final confirmation checks on docket aggregators and any litigation involving the patent owner.

PTAB proceedings overview

There is exactly one relevant structured answer: zero AIA trial proceedings on file against US 9,335,272. The "PTAB proceedings on file" block returned no IPRs, no PGRs, and no CBMs — the count is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. Independent web searches of PTAB dockets, Docket Alarm/PTActs petition text, and Federal Circuit materials surfaced no petition, institution decision, final written decision, or appeal referencing US 9,335,272 (or its application 13/133,876 / publication US20110263032A1) in any PTAB context. I could not find a proceeding number to report, and I will not invent one.

That means the defensive posture is not the template's "survived two IPRs and is hardened," and it is also not "claims 1-5 have been canceled." It is a third posture that is usually better for a defendant:

Nobody has ever challenged this patent at the PTAB, and the patent lapsed for failure to pay maintenance fees effective 2020-05-10. The practical exposure is historic, not prospective.

Supporting record facts (all from the authoritative patent text block):

• Granted 2016-05-10; filed 2009-12-09 as PCT/AU2009/001597; priority 2008-12-09 (AU2008906354).
• Assignee: The Commonwealth of Australia (Australian Government).
• Legal status: Expired – Fee Related. Legal events show LAPS (Lapse for failure to pay maintenance fees) and patent expiration under 37 C.F.R. § 1.362, effective 2020-05-10, with a 2019-12-30 fee reminder mailed and no payment.
• Nominal adjusted expiration but for the lapse: 2030-10-22 (≈20 years from the PCT filing date plus PTA).

No proceeding to profile

Because the structured list is empty and no public proceeding exists, the per-proceeding template (petitioner, judge panel, grounds, institution decision, FWD, settlement, appeal) has nothing to populate. I am explicitly declining to fill those fields by analogy — any proceeding number I supplied would be fabricated.

Search false positives to disregard (so you don't confuse them with this patent):

• Petitions in Microsoft v. Lenovo discussing "the '933 Patent" concern a different patent — that dispute involved Netlist patents (with a related U.S. Patent No. 9,173,054). The last three digits match; the patent does not. Do not cite these proceedings as PTAB activity on US 9,335,272.
• The only citation-of-record oddity is the non-patent citation ASTM F1089-02 (Standard Test Method for Corrosion of Surgical Instruments), cited by the examiner.

For verification, the authoritative zero-result confirms on: USPTO PatentCenter for 13/133,876 and USPTO PTAB E2E / PTAB Decisions, checked against Google Patents US9335272B2 and CourtListener.

Strategic summary

Claim status — every claim is UNTESTED. No claim of US 9,335,272 has been canceled, confirmed, or even challenged in an AIA trial. All claims 1–20 remain as granted: independent claim 1 (method of testing) and independent claim 20 (the longer pre-clean/visual-inspect/wash protocol), with claims 2–19 depending from claim 1. Note that every claim is a method claim — the title promises "and a composition," but the granted claim set contains no composition-of-matter or apparatus claims. That structurally limits who can infringe: only a party performing the testing method on US soil, not a party merely selling a copper-sulfate gel.

Estoppel landscape — § 315(e)(2) is a non-issue. Because no IPR reached a final written decision, no IPR estoppel has attached to anyone. There is no petitioner/privy chain to worry about, and a defendant today faces no risk that a supplier, indemnitor, or affiliate already burned a ground that would be barred to you. Symmetrically, you are free to file your own IPR (or PGR, though the 9-month PGR window closed around 2017-02-10) on any § 102/§ 103 ground, and to run the same art in district court without a § 315(e)(2) trap. CBM is unavailable — this is not a financial-services business method, and the CBM program sunset on 2020-09-16.

The lapsed-patent problem dominates everything else. The single most important fact for a defendant is the maintenance-fee lapse effective 2020-05-10. Pre-lapse infringement exposure would be limited by 35 U.S.C. § 286 to acts within six years of a complaint; post-lapse acts presumptively fall outside the patent's enforceable term. Two caveats I would verify rather than assume: (i) a lapsed patent can be revived by petition showing unintentional delay under 37 C.F.R. § 1.378, so "expired" is not formally irreversible; and (ii) Congress provided intervening-rights protection for lapsed-then-revived patents under 35 U.S.C. § 41(c) — I'd confirm the current text and case law before resting a defense on it. Also worth confirming against PatentCenter whether any revival petition is pending, since Google's status table is a data source, not a legal conclusion.

Pattern signals — the patent owner appears to have walked away from the portfolio. No petitioner ever filed, no uniform prior-art campaign exists, and there is no defensive aggregator (Unified Patents, RPX, Open Invention Network) in the chain. The wider family status report corroborates the disengagement: EP2376901A4 is "Withdrawn," AU2009326854B2 is "Ceased," NZ593510A shows "IP Right Cessation," and CA2746298C is "Expired – Fee Related." A patent owner that lets every national member of the family lapse is not a serial enforcer, which is consistent with the complete absence of district court litigation I could identify for this patent.

Recommended next steps

1. Do not file an IPR reflexively. The patent lapsed effective 2020-05-10 for non-payment of maintenance fees (37 C.F.R. § 1.362). An IPR on an expired patent is generally permissible but rarely economically rational — the PTAB will apply Phillips construction and the resulting decision buys you little against a patent that is not enforceable in the first place. Spend the budget on a revival/invalidity screen instead.
2. Check PatentCenter for a revival petition. Confirm no fee payment or § 1.378 petition has been filed to restore the patent. If revived, immediately evaluate (a) the effect of the 2020-05-10 to revival-date gap, and (b) intervening-rights arguments under 35 U.S.C. § 41(c). I flag this as an open item — I was not able to confirm current PatentCenter status from public search.
3. If a demand letter arrives citing this patent, respond on the term, not on validity. The strongest letter is short: the patent expired for fee non-payment effective 2020-05-10, so liability is confined to acts before that date, further truncated by the § 286 six-year lookback. There is no FWD to quote because there is no FWD — say that plainly rather than overclaiming.
4. On the merits, note the all-method claim set and the claim 1 narrowing. Claim 1 is expressly limited to "a helicopter drive shaft or a helicopter gear" while "substantially in an in-use or operative position," and requires an ionic copper salt complex in a non-flowing medium. A defendant that is not performing that specific in-situ method on rotorcraft hardware has a straightforward non-infringement story independent of any validity fight.
5. Recheck periodically. The absence of PTAB activity is itself a signal of a dormant patent, but a revived patent plus a new owner could change that overnight. A quarterly docket check on US 9,335,272 is cheap insurance.

Bottom line for a defendant: there are no PTAB proceedings to litigate around, no claims have been canceled, and no estoppel constrains you — but the patent lapsed for failure to pay maintenance fees effective 2020-05-10, which is a stronger defense than an IPR win would have been. Lead with the lapse; hold validity and non-infringement in reserve.

I'll verify the assignment record and cross-reference before writing up.

Assignment & Ownership Analysis — US 9,335,272 B2

Patent: "Testing mechanical hardware for wear and a composition"
Appl. No. 13/133,876 (371 of PCT/AU2009/001597, filed 2009-12-09) · Priority AU 2008906354 (2008-12-09) · Granted 2016-05-10 · Status Expired – Fee Related (maintenance-fee lapse recorded 2020-06-15, effective 2020-05-10)
Sources checked: Google Patents legal events (https://patents.google.com/patent/US9335272/en), USPTO Assignment Center (https://assignmentcenter.uspto.gov/), USPTO assignment index (https://assignment.uspto.gov/patent/index.html), open-web searches for litigation/assertion coverage. Retrieval caveat: the Assignment Center's per-record correspondent field was not reachable through the search tools available for this task, so that field is reported as a gap rather than filled — see signal 3 below.

Inventors

Pattern check — negative: There is no "all inventors depart within 12 months of filing" signal here. There is only one inventor, and the only recorded conveyance is an inventor → employer assignment executed 2011-06-30, i.e. after the 2008 AU priority filing and at US national-phase entry, not a departure-driven transfer. The ~2.5-year gap between priority and the assignment is consistent with the standard practice of perfecting title in the applicant (Commonwealth of Australia) at 371(c) entry, not with a distressed inventor liquidating rights.

Original assignee

The Commonwealth of Australia (recorded on grant as "Australian Government"; assignment recorded in favour of "THE COMMONWEALTH OF AUSTRALIA", assignor Gerrard, reel 026569/0283).

• Entity type / line of business: Sovereign government / national defence. The claimed subject matter is a field inspection method and reagent composition for detecting wear-through of silver plating on helicopter tail-rotor and main-gearbox drive shafts (see claim 1: "mechanical hardware in the form of either a helicopter drive shaft or a helicopter gear").
• Did they ship a product embodying the claims? No product is claimed or sold. This is a process claim covering an in-situ NDT (non-destructive test) procedure, plus a gel/paste reagent composition (30 g/L agar, 15 g/L CuSO₄·5H₂O, 0.5 mL/L H₂SO₄ per Table 2). The working example describes the Commonwealth performing the test on a silver-plated helicopter tail-rotor drive shaft in situ. Embodiment is therefore internal government use, not commercial sale.
• Current status: Operating (a sovereign state cannot be dissolved, acquired, or go bankrupt). No successor entity appears in any record.

Assignment timeline

Chronological list of every recorded assignment:

• 2011-06-30 (executed) / recorded 2011-07-11 — Reel 026569 / 0283
  • Conveyance: Assignment (recorded event code AS; free-text "ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignor: GERRARD, DARREN (individual)
  • Assignee: THE COMMONWEALTH OF AUSTRALIA
  • Correspondent: Not retrievable from the sources available for this report. Google Patents' legal-events abstract of reel 026569/0283 does not carry the correspondent, and the Assignment Center's correspondent field could not be pulled through the tooling used. I am flagging this as a data gap rather than asserting a blank — no correspondent name is fabricated here. What can be said with confidence: this is a single-record chain, so there is no recurring correspondent to flag by definition (see signal 3).
  • Context: Intake / employer-of-inventor assignment — the lone inventor's rights conveyed to his government employer in connection with entering the US national phase of PCT/AU2009/001597. This is a title-perfection record, not an acquisition.

Post-issuance assignments: NONE. Google Patents legal events show no Assignment, Security Agreement, Merger, Change of Name, License, or Release entry after grant. The complete set of recorded events is: 2011-07-11 Assignment; 2016-04-20 Patent grant; 2019-12-30 Maintenance-fee reminder; 2020-06-15 Lapse for failure to pay maintenance fees; 2020-07-07 Expired – Fee Related. There is also no recorded reassignment upon lapse, so The Commonwealth of Australia remained assignee of record continuously from 2011 through expiry (adjusted expiration 2030-10-22).

Timeline diagram

timeline
    title Ownership of US 9335272
    2008 : AU priority filing by Gerrard
    2009 : PCT filed by Commonwealth of Australia
    2011 : US national phase entered
         : Gerrard assigns rights to Commonwealth
    2016 : US patent granted to Commonwealth
    2020 : Patent lapsed maintenance fees unpaid

NPE / troll-pattern signals

Inverse signal worth recording: the patent's fate is the opposite of an NPE play — a government-owned NDT method that was allowed to expire for non-payment of maintenance fees in 2020, with no attempts to monetise, transfer, or assert it. That is a strong affirmative indicator of a non-asserting, non-monetised asset.

Verdict

Insufficient data (only the original assignment).

The entire recorded chain is one entry — Gerrard → The Commonwealth of Australia, executed 2011-06-30, recorded 2011-07-11, reel 026569/0283 — which is an inventor-to-employer title perfection, not a market transfer. There are no post-issuance assignments, no litigation, and no assignee matching any NPE list; the owner let the patent lapse for unpaid maintenance fees effective 2020-05-10. I therefore cannot manufacture an NPE story, and the taxonomy bucket that fits a patent with only its original assignment is "Insufficient data," even though the affirmative evidence (sovereign owner, method-only claims, terminal lapse) points away from NPE activity.

Verification links:

• USPTO Assignment Center search — https://assignmentcenter.uspto.gov/
• USPTO Assignment (index) search — https://assignment.uspto.gov/patent/index.html
• Google Patents legal events for reel/frame 026569/0283 — https://patents.google.com/patent/US9335272/en

Open item for a follow-up pass: pull the correspondent of record for reel 026569/0283 directly from the Assignment Center record view (the field was not reachable here). Given the single-link chain, it would not change the verdict, but it should be captured on the chain diagram before this analysis is archived.

I'll research US patent 9335272 and its cited prior art. Let me run several searches.

Let me research the specific cited prior-art references.

I was able to retrieve the authoritative front page and full text of US9335272 from Google Patents (a mirror of the USPTO/EPO bibliographic record) and abstracts/full text for several of the cited references. I reached the tool-call limit before I could pull full text for every older citation, so I flag confidence levels per item below. No results were found for a different patent number — the analysis below concerns only US 9,335,272.

1. The patent under analysis

Independent claims: claim 1 and claim 20. Claim 1 requires the combination of (a) accessing a helicopter drive shaft or helicopter gear in situ; an iron-containing inner portion with a silver-containing outer portion; (b) applying a non-flowing metal oxidant comprising an ionic copper salt complex so that it oxidizes exposed iron and deposits, without oxidizing the silver outer portion, and is prevented from contacting untested hardware; and (c) detecting wear based on the deposit. Claim 20 elaborates this with a pre-clean, visual pre-inspection, an acid (sulfuric and/or nitric), a stipulated reaction time, and a wash step.

All 12 cited patent documents and the single non-patent citation have effective prior-art dates well before the 2008-12-09 priority date, so each is §102(a)/§102(b) eligible on its face.

2. Summary judgment on anticipation

Based on the references and text available to me, I do not see any cited reference that discloses every element of independent claim 1 or claim 20, i.e., none appears to be a clean §102 anticipation. The cited art clusters into three groups:

1. Chemical/colorimetric detection of metal condition – closest conceptual art (US 2003/0068824 A1; US 3,652,224 A / GE crack-detection family).
2. Corrosion measurement/sensing on metal structures – US 2,643,205; US 3,549,993; US 5,481,198; US 5,896,034; US 6,054,038; US 4,311,738; US 2009/0220689; US 2003/0188813.
3. Mechanical-wear/protection background art – WO 2006/028941; US 5,423,298; US 2,007,285; and non-patent ASTM F1089-02.

The two references with the greatest §102/§103 salience are US 2003/0068824 A1 (Frankel) and the GE crack-detection patent cited as US 3,652,224 A. Neither, however, discloses the copper-deposition-on-exposed-iron / silver-coated-helicopter-driveshaft / non-flowing-in-situ combination that defines the claims. The remainder is largely background art of the "corrosion sensor" and "protective coating" type.

3. Reference-by-reference analysis

Group A — Chemical/colorimetric detection (most relevant)

A1. US 2003/0068824 A1 — "Corrosion-sensing composition and method of use"

• Citation: Frankel, G.S., Buchheit, R.G., Zhang, J.; US 2003/0068824 A1; priority 1999-12-21; published 2003-04-10.
• URL: https://patents.google.com/patent/US20030068824A1/en
• Description (verified from full text): Discloses a removable corrosion-detecting substance applied to a coated surface after the coating has been removed, where the substance is an aqueous gel incorporating a composition (e.g., a pH indicator) that changes its appearance in response to corrosion on the metal surface. Applied to aircraft structures; gel is removable after inspection; coating can be reapplied. (Note: listed on the US9335272 page under "Family Cites Families," i.e., it appears in the family/related-file history rather than as the primary examiner citation set.)
• Potential §102 relevance: State-of-the-art closest to the general concept of a removable, shape-retaining gel applied to metal to give a visible indication. It overlaps conceptually with the "non-flowing medium" and "detecting by visual change" limitations of claim 1(b)/(c), but does not disclose: a metal oxidant (its indicator reacts to corrosion/pH, it does not oxidize the substrate and precipitate a metal); an ionic copper salt complex; deposition of metal on an iron core exposed through a silver plating; or the helicopter-drive-shaft/in-situ context. → Not an anticipation of claim 1 or 20; relevant as §103 combination art at most.

A2. US 3,652,224 A — "Method for detecting cracks in metal bodies" (General Electric)

• Citation: US 3,652,224 A; filed 1969-12-31; published 1972-03-28; assignee General Electric; cited by examiner on the US9335272 front page.
• Description: The patent's front-page citation describes a method for detecting cracks in metal bodies. The GE family text I retrieved (the closely related US 3,652,225, "Color method for detecting cracks in metal bodies," https://patentimages.storage.googleapis.com/b8/52/21/32b2fefbe193a2/US3652225.pdf) discloses applying to a metal body a color-forming indicating solution that is an aqueous acid solution containing halide ions and a color-forming indicator; the solution is deliberately too weak to corrode the open surface but corrodes within cracks, producing metal ions that react with the indicator to form a distinctive colored compound at crack locations (results within ~15 min., single step, ambient light).
• Confidence caveat: I could not independently verify the exact text of US 3,652,224 A; the retrieved text is the sibling GE "color method" patent (US 3,652,225). Per your instructions I am not treating these as the same document — I flag the discrepancy rather than auto-correcting the cited number.
• Potential §102 relevance: The closest art on the mechanism of chemically treating a metal surface with an acid reagent to produce a colored/visible reaction and reading it by eye in minutes, and on applying the reagent while the part remains in place. Overlaps with claim 1(c) (visual detection) and the "acid" feature of claim 20. However it (i) uses a free-flowing aqueous solution, not a non-flowing gel/paste; (ii) detects cracks, not wear of an outer silver coating; (iii) forms color by indicator–metal-ion reaction rather than by oxidative deposition of copper onto exposed iron. → Not an anticipation of any claim; possible §103 art for the "acidic reagent + visual readout" concept.

A3. US 2,007,285 A — "Examination of high grade alloyed steels"

• Citation: US 2,007,285 A; filed 1932-12-08; published 1935-07-09; inventor Schauffele.
• Description: Title indicates a method of chemically examining/examining alloyed steels (i.e., etching/reagent-based inspection of steel). I could not retrieve the full text, so this is based on the citation metadata only.
• Potential §102 relevance: Broadly relevant as very old art on reagent-based examination of steel surfaces; too generic to anticipate the copper-oxidant/gel/deposit limitations of claim 1 or 20.

Group B — Corrosion measurement / protective-coating art (background)

B1. US 2,643,205 A — "Removal of carbonaceous deposits from process equipment"

• Pure Oil Co.; filed 1949-12-27; published 1953-06-23. Likely a chemical-treatment method for metal process equipment. Not retrieved in full. No apparent §102 overlap with claims 1/20.

B2. US 3,549,993 A — "Corrosion rate measuring method…"

• Union Oil Co.; filed 1966-06-14; published 1970-12-22. Measures corrosion rate by maintaining electrolytic contact and excluding oxygen. Electrochemical measurement, unlike the visual-deposit method claimed. No §102 overlap.

B3. US 5,481,198 A — "Method and device for measuring corrosion on a portion of a metallic path…"

• The Georgia Power Company; filed 1994-08-26; published 1996-01-02. Electrical/electrochemical corrosion measurement along a metallic path. No §102 overlap.

B4. US 5,896,034 A — "Method and apparatus for detecting and monitoring corrosion"

• Avonwood Developments Ltd.; filed 1995-07-06; published 1999-04-20. Corrosion detection/monitoring apparatus. No §102 overlap with the claimed deposition method.

B5. US 6,054,038 A — "Portable, hand-held, in-situ electrochemical sensor for evaluating corrosion and adhesion on coated or uncoated metal structures"

• Dacco Sci, Inc.; filed 1998-06-08; published 2000-04-25. In-situ electrochemical sensor for coated/uncoated metals — shares the "in-situ evaluation of a coated metal structure" idea but uses an electrochemical probe, not a metal-depositing gel read visually. No §102 overlap.

B6. US 4,311,738 A — "Method for rendering non-ferrous metals corrosion resistant"

• Dow Corning Corp.; filed 1980-05-27; published 1982-01-19.
• URL: https://patents.google.com/patent/US4311738
• Description (verified): A coating method to make non-ferrous metals corrosion-resistant, using compositions containing colloidal titania, colloidal silica, a partial hydrolyzate, acetic acid, etc., applied to metal substrates (aluminum, copper). This is a protective-coating patent, not a detection method.
• Potential §102 relevance: None for claims 1/20 (no oxidant, no gel-indicator, no wear detection).

B7. US 2003/0188813 A1 — "Stainless steel sheet for welded structural components and method for making the same"

• Kawasaki Steel Corp.; filed 2002-03-28; published 2003-10-09. Metallurgical/steel-composition art. No §102 overlap.

B8. US 2009/0220689 A1 — "Articles having improved corrosion resistance"

• Valspar Sourcing, Inc.; filed 2005-05-06; published 2009-09-03. Coated articles with corrosion resistance. No §102 overlap.

B9. Non-patent literature — ASTM F1089-02, "Standard Test Method for Corrosion of Surgical Instruments" (Feb. 2003).

• A standard test method for corrosion testing. Cited by the examiner as general background on corrosion-test methodology. No §102 overlap with the claimed wear-testing method.

Group C — Mechanical wear / coating background

C1. WO 2006/028941 A2 — "Fretting wear protection for spline couplings"

• The Timken Company; filed 2004-09-02; published 2006-03-16. Wear/fretting of mechanical drive components (spline couplings) — topically related to wear of mechanical hardware but directed to protection against wear, not chemical detection of wear. No §102 overlap with claims 1/20; background only.

C2. US 5,423,298 A — "Rotary internal combustion engine"

• Pahis, N.S.; filed 1993-09-14; published 1995-06-13. A mechanical engine patent. Appears to be an examiner formality/background citation with no meaningful §102 overlap with any claim.

Group D — Additional family-file citations (noted on the US9335272 page under "Family Cites Families")

D1. JP H07320535 A — "New conductive paste composition"

• Asahi Chem Ind Co Ltd; 1994-05-25 / published 1995-12-08. A conductive paste composition; potentially cited for the paste/gel medium concept. No §102 overlap with claim 1/20 as a whole.

D2. US 2003/0068824 A1 (Frankel) — see A1 above.

4. Overall conclusion

• Most relevant prior art: US 2003/0068824 A1 (Frankel, "Corrosion-sensing composition and method of use") — because it discloses a removable aqueous gel applied to a metal surface that gives a visible indication, the closest single reference to the "non-flowing medium + visual detection" concept. Second is the GE crack-detection patent cited as US 3,652,224 A (acid reagent applied to metal producing a color reaction, read in minutes), for its acidic-reagent/visual-readout and in-place inspection features.
• No cited reference anticipates independent claim 1 or claim 20. Every reference lacks at least one essential limitation — most critically the ionic copper salt complex that oxidatively deposits copper onto exposed iron of a silver-plated inner core, the non-flowing gel, and/or the helicopter-drive-shaft/gear in-situ context. The strongest challenge these references could support is a §103 obviousness argument built from Frankel (gel + visual detection) or the GE crack patent (acid reagent + color readout) in combination with a copper-plating/ion-exchange teaching — not a §102 anticipation of any single claim.

Caveats and limitations (stated explicitly):

1. Several older references (US 2,007,285; US 2,643,205; US 5,423,298; US 5,481,198; US 5,896,034; US 6,054,038; US 2003/0188813; WO 2006/028941; US 2009/0220689; JP H07320535) are described here from front-page citation metadata only; I did not retrieve their full texts, so those descriptions carry lower confidence.
2. I could not independently confirm the full text of US 3,652,224 A; the mechanism text I retrieved belongs to the sibling GE patent US 3,652,225. The cited number has been recorded literally, without correction.
3. This is a technical prior-art mapping, not a legal opinion; anticipation/invalidity requires claim-charting against the full specification and, where relevant, the file history (not available in the sources retrieved).

I'll analyze the obviousness of US 9,335,272 under § 103 using the prior-art references listed on the patent page. Let me first verify the content of the key cited references.

Obviousness Analysis — US 9,335,272 B2 under 35 U.S.C. § 103

Patent: US 9,335,272 B2 ("Testing mechanical hardware for wear and a composition")
Inventor: Darren Gerrard · Assignee: The Commonwealth of Australia
Priority: 2008‑12‑09 (AU 2008906354) · Filed: 2009‑12‑09 · Granted: 2016‑05‑10
Source of record: https://patents.google.com/patent/US9335272/en

A note on method: Per the operating rules I have taken the prior‑art list from the patent page's "Citations (12) / Family Cites Families (2)" sections and interpreted all publication numbers literally. I have verified the content of the most relevant references by retrieval; where I could not retrieve a reference or where two similarly numbered GE patents appear, I say so explicitly rather than assume.

1. The claim to be tested

Claim 1 requires, in substance:

1. Accessing mechanical hardware that is either a helicopter drive shaft or a helicopter gear while substantially in its in‑use/operative position (in‑situ);
2. The hardware having an inner portion with an iron‑containing component and an outer portion containing silver and substantially free of iron;
3. Applying a metal oxidant that includes an ionic copper salt complex, in at least the regions where the inner portion is exposed through the outer portion, such that it oxidizes the iron and deposits on the hardware without oxidizing the outer portion;
4. The metal oxidant being non‑flowing, so it substantially retains shape on non‑horizontal surfaces (inclined, upright, downward‑facing) and can be prevented from contacting other hardware not being tested;
5. Detecting wear of the outer portion based on detecting deposits of the metal oxidant on the inner portion.

Claim 20 is a more specific independent claim adding pre‑cleaning, visual pre‑inspection, ionic copper + sulphuric/nitric acid, a stipulated reaction time, washing off, and comparison against the outer coating.

2. The prior‑art record (as listed on the patent page)

Key verified disclosures (with sources):

• Frankel, US 2003/0068824 A1 — https://patents.google.com/patent/US20030068824A1/en : discloses "a removable corrosion‑detecting substance that changes its appearance in response to corrosion"; the substance "incorporates an aqueous gel"; the gel is "adapted as a temporary coating…on the surface"; applied to an "aircraft"; and is washed/removed after the determination. The specification expressly discusses agar content, gel formation by heating and cooling, and retention of shape/stability, e.g., "Gel can be formed by blending a suitable pH indicator…with agar under heating and cooling processes."

• Schauffele, US 2,007,285 A — https://patents.google.com/patent/[US2007285A](/patent/US2007285A)/en : claims "treating a place to be tested with an acid which is inert with respect to the uninjured alloy, but capable of laying bare a constituent of the alloy in those places where the original structure…is defective, and thereafter applying a reagent capable of reacting with this constituent with the formation of a colored compound." It expressly applies reagents "under the form of…pastes… capable of adhering to the places to be examined," and prepares them "by incorporating the color reagents in solutions…of gelatine, water glass glue or the like." It teaches choosing acid/concentration/time "that the acid will not attack the unaffected parts of the steel," and names sulphuric acid and potassium ferrocyanide/ferricyanide.

• Avonwood, US 5,896,034 A — https://patents.google.com/patent/US5896034 : "a magnesium alloy gear box used in a helicopter…open to attack by sea water"; monitoring corrosion in situ under wet or dry conditions.

• Dacco, US 6,054,038 A — https://patents.google.com/patent/US6054038 : "portable, hand‑held and non‑destructive corrosion sensing device…utilized under field (in situ) conditions in detecting coating degradation…well before serious deterioration."

• GE, US 3,652,224 A — the family description (the closely related US 3,652,225, Color method for detecting cracks in metal bodies) describes an indicating solution "too weak to corrode the open surface portion…but sufficiently strong to corrode the internal surface portion within the cracks," plus pre‑cleaning "to remove oils and grease" (https://www.freepatentsonline.com/[3652225](/patent/3652225).html). Caveat: I could not retrieve the text of US 3,652,224 A itself; I describe the GE family, and the numbers should not be conflated.

3. Combination A — the strongest § 103 case

Primary: Frankel US 2003/0068824 A1
Secondary: Schauffele US 2,007,285 A
Tertiary (context/motivation): Avonwood US 5,896,034 A and/or Dacco US 6,054,038 A
Optionally: the well‑known metal‑displacement (cementation) reaction, supported by GP‑level knowledge and/or the JP H07‑320535 A paste art.

Element‑by‑element mapping (Claim 1)

Motivation to combine (KSR rationales)

1. Same field, same problem. All four references address non‑destructive, in‑situ detection of corrosion/wear/coating degradation on metal structures, several expressly in aircraft/helicopter environments (Frankel, Avonwood, Dacco). A PHOSITA monitoring a silver‑plated steel rotor drive shaft for wear would look squarely to this art.

2. The references themselves point to the combination.

   • Frankel teaches a removable agar gel applied to aircraft surfaces that changes appearance on corrosion — i.e., precisely the "non‑flowing, in‑situ, removable, visually readable" delivery format of claim 1.
   • Schauffele teaches which chemistry to put in that gel/paste: an acid plus a reagent that reacts only where the protective/uninjured surface is absent, producing a colored product at the exposed metal.
   • Avonwood/Dacco supply the application target and the in‑situ/early‑detection motivation (helicopter gear box; detect degradation before it is visible).

3. Predictable result / mere substitution of known agents. Combining a known gel/paste carrier (Frankel; Schauffele; JP H07‑320535 A) with a known selective‑reaction reagent for exposed iron (Schauffele) yields nothing more than the expected sum of the parts — a shape‑retaining gel that colors at exposed iron. KSR "predictable variation" and "known technique" rationales apply.

4. "Without oxidizing the outer portion" is a designed‑in result, not an unexpected one: Schauffele explicitly teaches formulating the reagent so the intact surface is not attacked, so a PHOSITA would select the reagent/conditions (and the silver‑plated outer coat, which is noble relative to iron) to spare the plating.

4. Combination B — gel‑chemistry‑centric

Frankel + JP H07‑320535 A (conductive paste) + GE (US 3,652,224 A) + Schauffele

• Frankel gives the agar gel that changes color on reaction and is applied/removed in the field.
• JP H07‑320535 A (Asahi) supplies a paste vehicle carrying an active (ionic/conductive) species — supporting the "paste medium" limitation (claims 12, 17).
• GE supplies pre‑clean → apply weak selective reagent → read colored indication at defective locations, including the motivation that the reagent is weak enough not to attack the intact surface.
• Schauffele supplies the gelatine‑paste format, the acid, and the color‑forming reaction with a metal constituent of steel.

Motivation: each reference addresses detection of surface defects/exposed substrate; the carrier chemistry (gel/paste) and the indicator chemistry are "known techniques" whose combination yields a predictable field‑usable indicator.

5. Dependent claims

Claim 20 (independent) adds only the pre‑cleaning/visual‑inspection/rinsing/compare steps, each of which is individually taught by GE, Frankel, and Dacco, so it rises or falls with claim 1 plus routine steps.

6. Where the record is weakest (nonobviousness considerations)

The examiner (or a challenger) must recognize a genuine gap:

1. The detection mechanism is different in every cited reference. Frankel, GE and Schauffele all detect by a color‑forming chemical indicator (pH indicator or a reagent that complexes dissolved metal ions). None of the cited references expressly discloses a metal oxidant that is reduced and deposits as metal as the visual indicator. The patent's point of novelty is that the deposit itself (copper) is the marker. That specific mechanism is not squarely in the cited list.

2. The metal‑displacement reaction must be supplied from general knowledge or other art. The Cu²⁺/Fe → Cu reaction is textbook and underpins the long‑used "copper sulphate" test for free iron on stainless steel (and the agar‑gel ferroxyl test). If an examiner expressly relies on that knowledge/art (which is readily locatable), the gap in point 1 closes and Combination A is strong. If the analysis is confined strictly to the patents listed on the page, none of them alone or together states the deposition‑as‑marker step, and a rejection resting only on these references would be vulnerable on that element.

3. "Helicopter drive shaft / silver‑plated steel" specificity. Avonwood is about a magnesium gear box and Dacco about EIS sensing (electrical, not chemical). The precise problem — distinguishing worn from intact silver plating on a steel drive shaft by a visual copper deposit — is not spelled out in the cited art. This is a "problem‑recognition" argument the patentee can press, though KSR cautions against over‑weighting problem recognition where the solution is a predictable use of known techniques.

4. Caveats on two references. I could not independently retrieve US 3,549,993 A (its title indicates electrolytic corrosion measurement, so it is not central), and the GE citation US 3,652,224 A is a sibling of the Color method for detecting cracks in metal bodies family (US 3,652,225) whose text I relied on. These identifications should be confirmed against the full texts before being used in a formal rejection.

7. Conclusion

• A prima facie case of obviousness under § 103 is available for claims 1–20, best framed as Frankel (US 2003/0068824 A1) as the agar‑gel, removable, in‑situ, appearance‑changing vehicle + Schauffele (US 2,007,285 A) for the selective acid/reagent‑on‑exposed‑metal, paste‑applied colored‑reaction chemistry + Avonwood (US 5,896,034 A) and/or Dacco (US 6,054,038 A) for the helicopter/in‑situ, early‑detection motivation, with the Cu²⁺/Fe displacement step supplied as well‑known cementation chemistry.
• The weakest link is the "metal oxidant deposits as metal" mechanism, which none of the cited references squarely discloses. The strongest formal rejection therefore depends on also citing the known copper‑sulphate/iron‑displacement (and/or ferroxyl) art — which, being a standard corrosion/surface test, is very likely to be found and applied.
• The dependent claims (amounts, pH, agar/copper‑sulphate ranges, times, pre‑clean, imaging) are, individually, routine optimizations or are expressly taught by Frankel (gel/agar/wash‑off) and Schauffele (acid, paste, selective attack), and are unlikely to confer independent patentability.
• Bottom line: claims 1 and 20 are more likely than not obvious when the gel‑carrier and selective‑reagent teachings are combined with the known iron‑copper displacement reaction; absent that reaction being placed of record, a rejection resting only on the listed references would leave the core mechanism unaddressed and would be contestable.