US 10718643

I'll search for this specific patent number, including any litigation or CAFC docket activity.

Let me check specifically for litigation, PTAB, or CAFC activity involving this patent.

Search Results — US Patent No. 10,718,643

Search scope note: I searched for the exact identifier 10718643 and "10,718,643". I found no CAFC (Federal Circuit) 2026 docket activity and no litigation, PTAB/IPR, or appeal record tied to this patent number. The only matches to the bare string 10718643 outside patent databases were unrelated foreign filings (a Brazilian commercial-registry entry and an Irish patent-register application number 10718643.9 for an Owen Mumford pen-needle patent) — these are not the same right and should not be conflated. I have no authoritative evidence of any court or PTAB proceeding involving US 10,718,643, so I state that as a gap rather than a negative finding.

Bibliographic Summary

Minor date discrepancy to flag: Google Patents (the authoritative full text provided) lists priority 2015-07-17, filing 2016-07-12, and publication 2020-07-21. A third-party aggregator (Unified Patents) lists priority 2015-07-16, application date 2016-07-11, and grant date 2020-07-20. Per the operating rule, I treat the Google Patents full text as authoritative and flag the aggregator figures as unverified/likely time-zone or EP-vs-US bookkeeping differences.

Abstract (as issued)

"A suction module for a hand-held power tool includes a motor-driven fan wheel, an intake channel for sucking in dust-laden air, and a collecting container for dust. A flow sensor has a sensor surface, which is formed of plastic and is arranged in the intake channel, an electric field meter facing the sensor surface for determining the electrostatic field strength on the sensor surface, and an evaluating unit for determining a flow rate of dust-laden air on the basis of the determined electrostatic field strength."

Plain-Language Overview of the Independent Claims

The patent has 4 claims total, of which two are independent:

Claim 1 — Suction module (apparatus).
A suction module for a hand-held power tool comprising three elements:

1. a motor-driven fan wheel;
2. an intake channel through which dust-laden air is drawn by the fan wheel; and
3. a flow sensor made up of (a) a plastic sensor surface located inside the intake channel, (b) an electric field meter facing that sensor surface that determines the electrostatic field strength at the surface, and (c) an evaluation unit that computes the flow rate of dust-laden air from the measured field strength.

In plain terms: you don't measure airflow with a conventional flowmeter. Instead, dust rubbing against a plastic surface builds up a static charge (triboelectric effect), and an electric field meter reads that charge to infer how much dust is moving through the duct.

Claim 4 — Control method (process).
A method performed by such a suction module, comprising:

1. determining the electrostatic field strength at the sensor surface using the electric field meter;
2. calculating the flow rate of dust-laden air from that field strength using the evaluation unit; and
3. emitting a warning signal on a display when the flow rate decreases faster than a specified rate of change.

In plain terms: sense the electrostatic charge on the plastic, convert it to a dust flow rate, and trigger a display warning if dust flow drops off too abruptly (the specification ties a fast drop to a clogged hollow drill bit, while a still-faster drop is attributed to withdrawing the bit from the hole).

Dependent claims (for completeness, not independent): Claim 2 adds a warning device that emits a warning when the flow-rate decrease exceeds a specified rate of change; Claim 3 adds a display showing the flow rate.

Caveats and Uncertainty

• I could not confirm any CAFC 2026 docket, district-court case, or PTAB proceeding involving this patent. Any statement that none exists would be an inference from absence of results, not a verified fact.
• Several prior-art citations in the record (e.g., EP2599584A1, US20130136549A1, EP1245330A2) are Hilti's own earlier suction/collection disclosures; I have not independently verified their content beyond what the patent's "Citations" section lists.
• The Unified Patents record lists additional ratings/examiner fields ("Macchiarolo, Peter J," "Royston, John M") that I did not verify against the face of the issued patent.

I'll search for litigation involving US patent 10718643 across the sources you mentioned.

Let me dig deeper into the Unified Patents litigation portal and other litigation databases.

Let me check specific litigation databases and search for the patent owner's assertion activity.

Litigation Search Results: US Patent 10,718,643

Bottom line: I found no litigation involving US 10,718,643. After searching the sources you identified (the Unified Patents litigation/patent portal, Federal Circuit material, PTAB filings, and general docket-indexed web results), no district court case, CAFC appeal, or PTAB proceeding naming this patent as an asserted patent surfaced.

What I verified about the patent

Litigation table

Important caveats (per your strict-interpretation instruction)

1. I did not auto-correct anything. The two sources disagree on the priority date (2015-07-16 vs. 2015-07-17). I have reported both exactly as they appear rather than reconciling them. Note also that search hits containing the bare string "10718643" from unrelated registries (e.g., a Brazilian commercial-registry PDF, "FATE PNEUS DO BRASIL S/A") are not the patent and are excluded.
2. Absence of evidence is not proof of absence. My searches did not surface a case-specific record, but I could not fully load a live, filtered court/PTAB docket search directly, and results were constrained by available search steps. A negative result from these queries is strong but not dispositive.
3. Contextual reasons this is plausible: the patent is held by Hilti AG, an operating company (not a PAE/NPE), and covers a niche suction-module/flow-sensor feature for hand-held power tools. The "Families Citing this family" entries on Google Patents (e.g., Milwaukee Electric Tool, Makita) are forward citations, not litigation, and should not be misread as suits.

Recommended next steps to confirm definitively

• Unified Patents Litigation Caselist — https://portal.unifiedpatents.com/litigation/caselist (filter by patent).
• PACER — search "10,718,643" and the application/inventor names across district courts.
• PTAB / USPTO Patent Center — confirm no IPR/PGR; check the patent's "Proceedings" tab.
• CAFC docket and Lex Machina / Docket Navigator / RPX for any appeal.

If you want, I can run additional targeted queries against these specific databases on the exact patent number and any Hilti-related enforcement campaign.

I'll verify the structured data against live sources before drafting.

Let me run a few more targeted checks to be thorough.

PTAB / AIA Trial Proceedings — US 10,718,643 B2 ("Hand-held power tool")

Patent under review: US 10,718,643 B2 (Hilti Aktiengesellschaft) — app. 15/745,391, filed 2016-07-12, granted 2020-07-21, priority 2015-07-17. Four claims total (1–3 apparatus; 4 method).

Proceedings overview

There are zero AIA trial proceedings on file against US 10,718,643. The structured "PTAB proceedings on file" block supplied with this task — the canonical USPTO Open Data Portal list — returns no IPR, PGR, or CBM proceeding for this patent, and my independent web checks surfaced nothing to the contrary. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. Defensive posture: the patent has never been tested at the PTAB, so it is neither "hardened" nor "weakened" — all four claims stand exactly as issued, and nothing constrains a defendant from filing a first-challenge petition. That is a neutral-to-favorable position for a defendant: no § 315(e)(2) estoppel exists against anyone, and the prior art well is entirely untapped.

Verification performed (all searches run 2026-09-29)

Caveats I must flag honestly. (a) I could not retrieve a PTAB E2E / Patent Trial docket listing directly in this session; my confidence rests on the ODP block plus negative web-search results. (b) The Hilti-related PTAB hits that do appear in search are for entirely different patents and must not be confused with this one: Hilti, Inc. v. Milwaukee Electric Tool Corp., IPR2015-01164 / IPR2016-00343 (U.S. 7,554,290), and Hilti Aktiengesellschaft v. Specified Technologies Inc. (U.S. 10,143,868). Neither involves US 10,718,643. (c) A petition filed in the last few weeks may not yet be indexed anywhere; treat the "zero" as accurate as of today's ingest, not as a permanent fact.

Per-proceeding detail

None — no proceeding numbers exist to report, and I will not invent any. The requested template (Type / Filed / Status / Judge panel / Grounds / Institution / FWD / Settlement / Appeal / Defensive value) is inapplicable here.

Strategic summary

Claim status. All of claims 1, 2, 3, and 4 are UNTESTED at the PTAB and remain in force. There are no CANCELED claims and no SUSTAINED-by-the-Board claims. Claim 1 covers the suction module itself: motor-driven fan wheel + intake channel + flow sensor having (i) a plastic sensor surface in the intake channel, (ii) an electric field meter facing that surface, and (iii) an evaluation unit determining flow rate from measured electrostatic field strength. Claim 2 adds a warning device triggered by an excessive rate of flow-rate decrease; claim 3 adds a display; claim 4 is a control method reciting the same structure plus the steps of determining field strength, calculating flow rate, and emitting a warning when the flow rate drops faster than a specified rate of change. Note the patent's adjusted expiration of 2037-02-15 — a long runway, and the statutory 4th-year maintenance fee was paid on 2024-01-11, so the asset is being actively maintained.

Estoppel landscape. Because no IPR/PGR was ever instituted, § 315(e)(2) estoppel is a non-issue: no petitioner, real party in interest, or privy is barred from anything. A current defendant can raise before the Board every ground it could raise in district court — § 102, § 103, and, for a PGR-eligible window that has long since closed, § 112/§ 101 as well (PGR was only available within 9 months of grant; the patent issued 2020-07-21, so only IPR is still available, and only on § 102/§ 103 grounds). The real practical constraint is not estoppel but § 315(b): if the defendant has been served with a complaint alleging infringement more than one year ago, the IPR door is shut. That should be checked first against the docket.

The § 325(d) trap — the single most important planning point. The § 102/§ 103 art most obviously useful against this patent is already on the face of the patent, which invites discretionary denial under § 325(d) / Becton Dickinson: EP 2 599 584 A1 (Hilti's own earlier suction device), US 4,594,901 and GB 2 166 874 (Kimberly-Clark "Electrostatic flow meter"), FR 2 851 819 ("Electrostatic flowmeter," Railway Technical Research Institute), JP S60-14153 (electrostatic-capacity measuring device), and US 2013/0136549 (Hilti suction device). A credible petition must therefore either (i) lean on art not of record, or (ii) affirmatively explain under Becton Dickinson factors (d)–(f) how the Examiner erred in evaluating this art. The cited references are also the strongest evidence that the core concept — measuring a flow by electrostatic means — is old; the likely battleground is the combination of an electrostatic field meter with a plastic triboelectric sensor surface inside a power-tool suction intake channel, and whether the cited flow-meter art renders that obvious under § 103.

Pattern signals. There is no serial-petitioner pattern, no defensive aggregator in the chain, and no PTAB-appeal history for this patent — nothing to analyze. What the record does show is that the patent owner, Hilti Aktiengesellschaft, is a large operating company (not an NPE) and is itself an active and sophisticated PTAB petitioner in the power-tool space (see its assertions against Specified Technologies). That cuts both ways: Hilti knows the Board well and will defend capably, but it also has no track record of monetizing this particular patent through assertion campaigns, which is consistent with the absence of any IPR. The absence of PTAB activity is a real signal here: patents that are broadly asserted against many defendants reliably attract IPRs, and this one has not.

One data discrepancy worth noting for diligence: Google Patents lists the priority date as 2015-07-17 (EU app. EP15177210.0), while the Unified Patents portal lists 2015-07-16 with an application date of 2016-07-11. The authoritative priority document (EP15177210.0, filed 2015-07-17) and the PCT (PCT/EP2016/066508, filed 2016-07-12) control; do not rely on the portal's dates for a § 102(b) prior-art cut-off calculation.

Recommended next steps

1. State it plainly in any opinion letter or IPR-decision memo: there is no PTAB activity on US 10,718,643. Do not characterize the patent as "survived IPR" or "narrowed by the Board" — neither is true. Any statement to the contrary is unsupported.
2. Verify independently before relying on this. Pull the PTAB E2E docket (https://ptacts.uspto.gov) and the Patent Trial case list filtered on patent number 10718643, plus a PACER/Docket Navigator litigation check on Hilti as plaintiff. My negative result is based on the ODP block plus web search; a fresh E2E check is the definitive step.
3. If you are a defendant being newly asserted against, calendar the § 315(b) bar immediately. One year from service of the first complaint alleging infringement. If that clock has run, the only remaining invalidity route is district court (or an ex parte reexamination / a § 282 defense), and the persuasion burden there is clear-and-convincing rather than preponderance.
4. If the one-year clock is open, a first IPR is available on § 102/§ 103 grounds for claims 1–4. Build the petition around art outside the face-of-patent citations listed above, or be prepared to brief the Becton Dickinson factors head-on to survive § 325(d). Note the Board's own FY24 statistics: roughly a 60% institution rate and, of instituted cases reaching FWD, ~78% of claims found unpatentable — so a well-built first petition against an untested, never-litigated patent is a genuinely viable path.
5. No appeal track to monitor. With no FWD, there is nothing at the Federal Circuit and no CourtListener docket to watch for this patent. Re-check the CAFC docket only if a proceeding is later instituted.

Sources consulted:

• USPTO Open Data Portal structured PTAB proceedings block (canonical, supplied in task): zero AIA trial proceedings
• https://portal.unifiedpatents.com/patents/patent/US-10718643-B2 — patent bibliographic data; no PTAB challenge listed
• https://patents.google.com/patent/US10718643/en — full text, claims 1–4, cited art, family and legal-status events
• https://ptacts.uspto.gov — PTAB E2E (recommended verification; Hilti-related hits retrieved were for U.S. 7,554,290 and U.S. 10,143,868, not this patent)
• https://www.uspto.gov/web/offices/com/sol/og/2024/week48/2024PPACAnnualReport.pdf — FY24 PTAB outcome statistics cited above

I'll research the assignment record for this patent, starting with the USPTO assignment data and cross-referencing.

Assignment & Ownership Analysis — US 10,718,643 B2

Sourcing note (important): The USPTO Assignment Center (assignmentcenter.uspto.gov) and the legacy Assignment Search (assignment.uspto.gov/patent/index.html) are JavaScript applications that are not crawlable by external search; my queries returned no indexed assignment records for this patent number or for the bare reel/frame strings. The reel/frame cited below is therefore taken from the Google Patents "Legal Events" table in the authoritative full text you supplied (which mirrors USPTO assignment data), not from a direct Assignment Center query. I could not independently verify the correspondent-of-record field, which the Assignment Center exposes but Google Patents does not mirror — that field is treated as a gap below, not as a finding. If a live Assignment Center query is run, the only expected hit is reel 044631/0923; if additional post-issuance records exist, they are not reflected in any source I could reach.

Inventors

Pattern assessment: No unusual inventor-departure pattern is visible. Both inventors assigned to the employer rather than to a third party, and both signed within the same two-week window, which is the signature of an employment/obligation assignment, not an exit or fire-sale event. The relevant oddity is timing, not identity: the assignment was executed ~29–31 months after the 2015-07-17 priority filing and recorded 2018-01-16, which is the same date the application entered the US national stage (US 15/745,391 is a §371 national-stage filing). In other words, the assignment was papered as part of the national-stage entry package, not as a later transfer. The ~40-person Hilti inventor list (per third-party assignee profiles) shows both names recurring in Hilti's construction-tool patenting, consistent with career employees rather than itinerant inventors.

(Confirmative gap: I could not verify Koenigbauer's or Appel's employment contracts or their subsequent tenure; "employee inventor" is inferred from the assignment obligation and is not independently documented.)

Original assignee

Hilti Aktiengesellschaft — Feldkircherstrasse 100, 9494 Schaan, Liechtenstein.

• Entity on the issued patent: Hilti AG / HALTI AKTIENGESELLSCHAFT is listed as Original Assignee and Current Assignee on the face of the patent and in the Google Patents record. The patent's own specification describes a hammer drill (item 1) and a hollow drill bit (TE-YD-type) with a suction module — i.e., Hilti's own commercial product architecture, not a hypothetical.
• Does it ship a product embodying the claims? Yes — with an evidentiary caveat. Hilti's public product line includes hollow drill bits (TE-YD / TE-YDA) sold together with dust-removal modules (TE DRS‑D / DRS‑D‑A family) that aspirate drill cuttings through the hollow shaft into a collecting container — the exact claim-1 architecture. The specification's own FIG. 1 and the "collecting container for dust" + "motor-driven fan wheel" + "intake channel" combination describe that product. I have not confirmed that a specific current SKU implements the plastic-sensor-surface/electric-field-meter flow sensor of claim 1 (that sensing scheme may be a forward-looking refinement over the shipped mechanical suction modules), so "ships a product falling within the claims" is stated as likely but unverified as to the sensor.
• Primary line of business: construction and building-maintenance tools — drilling/demolition, fastening (direct fastening), diamond coring/sawing, anchoring, firestop and software/measurement (Jobsite). ~30,000 employees, >120 countries.
• Current status: Operating, privately held. Name shares have been held by the Hilti Family Trust since 1980; the public listing of participation certificates ended in 2003. No insolvency, bankruptcy, or wind-down is known, so the "bankruptcy fire-sale" pathway is inapplicable.
• Note on corporate status: the assignment record uses "HILTI AKTIENGESELLSCHAFT, LIECHTENSTEIN," matching the Schaan domicile.

Assignment timeline

One recorded conveyance only. Chronological:

• 2017-12-21 → 2018-01-03 (executed) / recorded 2018-01-16 — Reel 044631/0923
  • Conveyance: Assignment of interest (inventors → employer). Recorded description: "ASSIGNMENT OF INTEREST (SEE DOCUMENT FOR DETAILS)".
  • Assignor: Egon Koenigbauer and Hans Appel (jointly, individually signing).
  • Assignee: HILTI AKTIENGESELLSCHAFT (Schaan, Liechtenstein).
  • Correspondent: Not verifiable from the sources I could reach. The Assignment Center's correspondent field was not retrievable (no crawlable index). Contextual evidence, not a citation: Hilti's US patent prosecution and trademark correspondents of record are predominantly Crowell & Moring LLP, P.O. Box 14300, Washington, DC 20044‑4300 (e.g., Hilti design patents USD 740636 and USD 752662 list "Attorney, Agent, or Firm – Crowell & Moring LLP"; Hilti's 2023 trademark filings name Crowell & Moring as correspondent). I flag this as an expected but unconfirmed correspondent — do not treat it as the recorded attorney. No recurrence signal can be scored without the field.
  • Context: Standard employer-obligation assignment for a national-stage filing — not a sale, not a fire-sale, not an internal reorg, not a securitization, not a transfer to an asserter.

No further assignment, security agreement, merger, change-of-name, license, release, or correction records appear for this patent in any source I could access. Per your instruction, I state that plainly: the chain terminates at the original operating-company assignee. The corroborating downstream evidence is the 4th-year maintenance fee paid 2024-01-11 as a LARGE ENTITY (Legal Events, recorded 2024-01-11) — a fee-and-status profile consistent with continued in-house ownership by Hilti, not with a small-entity shell.

Timeline diagram

timeline
    title Ownership of US 10718643
    2015 : Priority filing EP15177210 on 17 Jul 2015
    2016 : PCT filed 12 Jul 2016 as EP2016 066508
    2017 : Inventors execute assignment to Hilti
    2018 : Assignment recorded reel 044631 frame 0923
         : US national stage entry 16 Jan 2018
    2019 : Prepgrant publication 4 Apr 2019
    2020 : US 10718643 B2 issues 21 Jul 2020
    2024 : Fourth year maintenance fee paid 11 Jan 2024

NPE / troll-pattern signals

Verdict

Insufficient data — with the caveat that the affirmative evidence points away from NPE status.

Justification: the only recorded conveyance is the mandatory inventor-to-employer assignment recorded at Reel 044631/0923 on 2018-01-16 (executed 2017-12-21 to 2018-01-03), which coincides with US national-stage entry rather than any post-grant transaction. There is no recorded post-issuance assignment, no shell LLC, no known asserter, no cascading transfers, and no bankruptcy or privateering pathway; the current owner of record is Hilti Aktiengesellschaft, an operating construction-tool manufacturer that pays large-entity maintenance fees (2024-01-11) and litigates its own patents in its own name. Under your rubric this lands in "no records beyond the original assignment," i.e. Insufficient data for an NPE determination — but the correct practical read is non-NPE, operating-company retention, because the chain never leaves the original assignee.

Two explicit gaps I will not paper over: (a) the correspondent of record for reel 044631/0923 was not retrievable, so signal #3 is unscored; (b) I found no litigation or PTAB proceeding naming US 10,718,643 itself, so I cannot classify this as an "operating-company assertion" — Hilti's IPR activity cited above concerns US 10,143,868, a different patent.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search by patent number 10718643 or application 15/745,391; expect reel 044631/0923), and the legacy interface at https://assignment.uspto.gov/patent/index.html. Cross-check status and fee events at https://patents.google.com/patent/[US10718643B2](/patent/US10718643B2)/en.

I'll research the prior-art references cited on the face of US 10,718,643. Let me search for each key citation to verify content and dates.

Let me research the remaining key citations, especially the Hilti suction-device family and the electrostatic-flowmeter references.

I hit the tool-call limit mid-research, so I'll report what I verified directly and clearly flag what I am taking only from the patent's own citation list (which is authoritative for which references were cited, even where I could not independently pull each reference's full text).

Prior-Art Analysis — US 10,718,643 B2 ("Hand-held power tool," Hilti AG)

Scope and verification note

• The authoritative compilation of references is the "Patent Citations (19)" and "Citations (13)" lists in the Google Patents full text you supplied. I treat those as the definitive set of references of record.
• I directly retrieved and read full text/claims for: US4594901A / GB2166874A (Kimberly-Clark electrostatic flow meter), EP1245330A2 / US20020141836A1 / US6851898B2 (Hilti/Ege dust removal unit), and obtained partial content for EP2599584A1 and US20130136549A1/EP2599585 (Hilti suction device family).
• For the remaining references (JPS6014153A, FR2851819A1, CN2346548Y, US20040197953A1, US20050005711A1, US20120042715A1, CN103369995A/US9585533B2, CN202271449U, CN103128337A, US20130149056A1/US9067292B2, US20160265953A1) I did not obtain full text before the step limit; descriptions below are drawn from their titles/assignees in the citation list and general knowledge, and are flagged as not independently verified.

Critical framing for §102: The two independent claims are claim 1 (suction-module apparatus: fan wheel + intake channel + flow sensor with plastic sensor surface + electric field meter + evaluation unit) and claim 4 (control method: determine field strength → calculate flow rate → emit warning when flow drops faster than a specified rate). Anticipation under §102 requires one single reference disclosing all elements as arranged. As analyzed below, I do not find a single reference that anticipates either independent claim. The art splits cleanly into (A) references that teach the electrostatic/flow-measurement physics but not the power-tool suction module, and (B) references that teach the hand-held power-tool dust-suction module but with no electrostatic flow sensor. That split is the classic §103 obviousness posture, not §102 anticipation.

Tier 1 — Most relevant: electrostatic/particulate-flow measurement art (core of claims 1 & 4)

1. US 4,594,901 A — "Electrostatic flow meter"

• Full citation: US 4,594,901 A; inventors Eugene Norman; assignee Kimberly-Clark Corp. / Kimberly-Clark Worldwide Inc.
• Dates: priority 1984-11-09; granted 1986-06-17. (Same family/priority as GB 2,166,874 A.)
• Description (verified): Discloses measuring the mass flow rate of particulates (cellulosic fibers) transported in a conduit by a gas. A plastic semi-conductive static-charge-generating element (rod, flat sheet oriented parallel to flow, or hollow cylinder) is exposed to the particle stream; static charges form on its surface, are drained via a grounded conductor, and the resulting electrostatic current is proportional to mass flow rate. Claim 1 expressly recites a "plastic semi-conductive static charge-generating element… having a surface on which static charges are generated when exposed to the flow of particulates" and "means for measuring electrostatic current."
• Claim relevance:
  • Claim 1 (apparatus): This is the closest art for the triboelectric-sensing concept — it discloses a plastic sensor surface in a flow conduit whose static charge is a function of particulate flow (i.e., elements (a) sensor surface and (c) the infer-a-flow-rate function). But it does not disclose an "electric field meter facing the sensor surface" — it uses a grounded conductor + current-measuring means (claim 1(c); claims 2–4). It also lacks the power-tool suction-module environment (fan wheel, collecting container). → Best characterized as strong §103 art, not a §102 anticipation of claim 1.
  • Claim 4 (method): Discloses determining a charge-based quantity and correlating it to mass flow, but not "field strength… determined by an electric field meter," nor the specified-rate-of-change warning. → §103 relevance; not anticipation.
• Note: GB2166874A is the UK counterpart of the same 1984-11-09 Kimberly-Clark disclosure (verified as a family member), so its disclosure is duplicative of US4594901A.

2. GB 2,166,874 A — "Electrostatic flow meter"

• Full citation: GB 2,166,874 A; Kimberly Clark Co.
• Dates: priority 1984-11-09; published 1986-05-14. (Family of US 4,594,901 A — verified.)
• Description/relevance: Same disclosure as US 4,594,901 A (verified as the same priority/application family). → Same §103 relevance to claims 1 and 4; not an independent anticipation reference.

3. JP S60-14153 A — "Electrostatic capacity type measuring device"

• Full citation: JP S60-14153 A (JPS6014153A); Nippon Steel Corp.
• Dates: priority 1983-07-05; published 1985-01-24.
• Description (from citation list; not independently retrieved): A capacitance/electrostatic-type measuring device. Relevant to the general principle of determining a particulate-related parameter via an electrostatic field/capacitance technique.
• Claim relevance: Tangential. It addresses field-based measurement (potentially supporting the "electric field meter" element of claim 1), but as titled it is a measuring device, not a power-tool suction module. → §102/§103 support art only; unlikely to anticipate any claim alone. Flagged: not verified.

4. FR 2,851,819 A1 — "ELECTROSTATIC FLOWMETER"

• Full citation: FR 2,851,819 A1; Railway Technical Research Institute.
• Dates: priority 2003-02-27; published 2004-09-03.
• Description (from citation list; not independently retrieved): An electrostatic flowmeter — directly on-point for the sensing principle of claims 1 and 4.
• Claim relevance: Like the Kimberly-Clark family, it targets the flow-sensing concept but, per its title, is a flowmeter — not a hand-tool suction module with fan wheel/collecting container and not necessarily an "electric field meter facing a plastic sensor surface." → §103 relevance to the flow-rate-determining elements. Flagged: not verified; treat with caution.

5. US 2012/0042715 A1 — "Advanced micro flow sensor"

• Full citation: US 2012/0042715 A1; Northwestern University.
• Dates: priority 2010-01-14; published 2012-02-23.
• Description (from citation list; not independently retrieved): A micro-scale flow sensor. Potentially relevant to the implementation of the "electric field meter" — the '643 specification describes a micromechanical spring field meter. → §103 support for the field-meter structure of claim 1; general flow-sensing art otherwise. Flagged: not verified.

Tier 2 — Hand-held power-tool dust-suction art (the claim-1 environment)

6. EP 1,245,330 A2 — "Staubabsaugung für ein Handwerkzeuggerät / Collection of dust by suction in a hand tool"

• Full citation: EP 1,245,330 A2 (granted as EP 1,245,330 B1); applicant HILTI AKTIENGESELLSCHAFT; inventors Ege, Fünfer, Moser.
• Dates: priority DE 10115116, 2001-03-27; EP application filed 2002-03-12; published 2002-10-02; B1 grant 2006-03-29.
• Description (verified): A dust-extraction accessory for a hand-held rotary power tool (drill/rotary hammer) with a suction head (3), telescopic suction tube (4), depth stop (5), an internal pleated bellows, a suction wheel (17) coupleable to the tool's drive shaft, and a removable dust container (20) with integrated filter. It discloses the entire suction-module architecture but no flow sensor of any kind.
• Claim relevance: Anticipates only the claim-1 preamble/environment (hand-tool dust module drawing dust-laden air to a collecting container). Not the electrostatic flow sensor. → §102 for none of the claims as a whole; §103 for the suction-module context.

7. US 2002/0141836 A1 / US 6,851,898 B2 — "Dust removal unit for a hand tool device"

• Full citation: US 2002/0141836 A1 (pre-grant) → US 6,851,898 B2; applicant HILTI AKTIENGESELLSCHAFT; inventor Manfred Ege et al.
• Dates: US App. 10/106,964 filed 2002-03-26; priority DE 101 15 116, 2001-03-27; A1 published 2002-10-03; B2 granted 2005-02-08.
• Description (verified): The US counterpart of EP 1,245,330. Claims 1–5 are directed to the suction-tube assembly, depth stop, spring-biased bellows, suction head brushes, and suction wheel. No flow sensor.
• Claim relevance: Same as #6 — supplies only the mechanical suction-module environment of claim 1. → §103 context; not §102 anticipation.

8. EP 2,599,584 A1 — "Suction device" (the reference expressly discussed in the '643 specification)

• Full citation: EP 2,599,584 A1; HILTI AKTIENGESELLSCHAFT.
• Dates: priority 2011-11-29 (DE 102011087361); published 2013-06-05; status not active/withdrawn.
• Description (verified from the '643 text itself + related records): A suction module with a collecting container for dust and a motor-driven fan wheel which carries dust-laden air from an intake nozzle to the collecting container. The '643 specification expressly adopts this as the known starting point and criticizes it for covering both the drill bit and hole (making it hard for the user to detect interruptions).
• Claim relevance: This is the closest "prior art" for the apparatus skeleton of claim 1 — it discloses the fan wheel + intake path + collecting container. It is silent on any electrostatic/field-based flow sensor, the point of novelty. → Not §102-anticipatory; it is the admitted prior-art baseline against which claim 1's flow sensor is the distinguishing feature.

9. US 2013/0136549 A1 / EP 2,599,585 B1 — "Suction device and control method"

• Full citation: US 2013/0136549 A1 (Hilti) / EP 2,599,585 B1; priority DE 102011087361, 2011-11-29; published 2013-05-30.
• Description (verified, partial): A suction device with a housing, locking mechanism to a hand-held power drill, a fan motor and a controller, and a sensor for detecting the operating state of the tool's electric motor; the controller activates the fan motor when the tool motor is rotating.
• Claim relevance: Relevant to the control/automation and warning logic (claims 2/4 — triggering a signal based on a monitored condition). However, it detects motor operating state, not a dust flow rate via electrostatic field, and emits no rate-of-change clog warning. → §103 as secondary art for claim 2/4 control logic; not §102.

10. US 2013/0149056 A1 / US 9,067,292 B2 — "Vacuum device"

• Full citation: US 2013/0149056 A1; US 9,067,292 B2; HILTI AKTIENGESELLSCHAFT.
• Dates: priority 2011-11-29; A1 published 2013-06-13; B2 granted 2015-06-30.
• Description (from record/citation list; partially verified): A vacuum/dust-extraction device for a power tool (part of the same 2011-11-29 Hilti filing cluster). Google Patents' coupling page shows US9067292B2 citing EP2599584A1 and being cited alongside the '643 patent.
• Claim relevance: Supplies the suction/vacuum environment only. → §103 context; not §102. Flagged: full text not independently retrieved.

11. CN 103128337 A — "Suction device" (Chinese counterpart of the above Hilti cluster)

• Full citation: CN 103128337 A; priority 2011-11-29; published 2013-06-05.
• Description: Chinese-language counterpart in the Hilti 2011-11-29 suction-device family. → Same §103 context as #8–#10; duplicative. Flagged: not independently verified.

12. CN 2346548 Y — "Electric hammer dust-proof device"

• Full citation: CN 2346548 Y; 海尔集团公司 (Haier Group).
• Dates: filed/priority 1998-10-21; published 1999-11-03.
• Description (from citation list): A dust-proofing device for an electric hammer. → Purely mechanical dust-guard context; not relevant to the electrostatic sensing or the warning logic. Flagged: not independently verified.

13. CN 202271449 U — "Dust absorption type hollow drill"

• Full citation: CN 202271449 U; 南通山剑石墨设备有限公司.
• Dates: priority 2011-09-23; published 2012-06-13.
• Description (from citation list): A dust-absorption (suction) hollow drill — relevant to the hollow-drill-bit workpiece context of the '643 embodiment (the hollow drill through which cuttings are aspirated). → Background/context art only. Flagged: not independently verified.

Tier 3 — Ancillary: general flow sensing, sensor packaging, and vacuum-filter art

§102 anticipation assessment, claim-by-claim

Claim 1 (apparatus — independent). Requires, in a single reference: (i) motor-driven fan wheel; (ii) intake channel for dust-laden air; (iii) plastic sensor surface in the intake channel; (iv) electric field meter facing the sensor surface; (v) evaluation unit computing flow rate from the electrostatic field strength.

• The electrostatic-flowmeter references (US4594901A/GB2166874A — verified; JPS6014153A, FR2851819A1 — unverified) supply the physics of (iii)–(v) but measure electrostatic current with a grounded conductor, not field strength with an "electric field meter," and lack the power-tool suction module of (i)–(ii).
• The Hilti suction-module references (EP2599584A1, EP1245330A2/US6851898B2/US2002/0141836A1 — verified in part) supply (i)–(ii) but contain no flow sensor at all.
• → No single reference anticipates claim 1. This is a §103 case (combining particulate-flow electrostatic sensing with a hand-tool suction module).

Claim 2 (dependent — warning device, rate-of-change threshold). No reference found that discloses emitting a warning when a flow-rate decrease exceeds a specified rate of change tied to clogging. The closest is US2013/0136549A1 (motor-state-based control), which is a different trigger. → Not anticipated; §103 combination at best.

Claim 3 (dependent — display showing flow rate). Display-of-parameter features are common; the Kimberly-Clark references describe correlating charge/current to flow, but the display element would come from routine art. → Not anticipated by any single reference alone; §103.

Claim 4 (method — independent). Requires the same sensor hardware plus the rate-of-change warning step. Same analysis as claims 1+2: the sensing-references lack the tool environment and the warning step; the tool references lack the sensor. → No §102 anticipation; §103 posture.

Bottom line

1. Most relevant references of record:
   • US 4,594,901 A (and its UK twin GB 2,166,874 A) — Kimberly-Clark, 1986 — is the single most on-point reference for the sensor concept of claims 1 and 4: plastic charge-generating surface in a particulate-laden conduit, with charge correlated to mass flow.
   • EP 2,599,584 A1 and the EP 1,245,330 A2 / US 6,851,898 B2 / US 2002/0141836 A1 Hilti-family references are the most on-point for the claim-1 suction-module environment (fan wheel, intake path, dust container).
2. No reference in the record anticipates any claim under §102 individually. Every candidate teaches only part of the claimed combination — the art divides between the electrostatic flow-sensing physics and the power-tool dust-suction module. The likely examiner posture is §103 obviousness over an electrostatic-flowmeter reference (prototypically US4594901A) combined with a Hilti-type suction module (EP2599584A1 / EP1245330A2).
3. Verified vs. unverified: US4594901A/GB2166874A, EP1245330A2, US20020141836A1, US6851898B2, EP2599584A1, and US20130136549A1 were directly retrieved and confirmed. The Chinese references (CN2346548Y, CN202271449U, CN103128337A, CN103369995A), JPS6014153A, FR2851819A1, US20040197953A1, US20050005711A1, US20120042715A1, US20160265953A1, and US9067292B2 / US20130149056A1 were not independently retrieved before the research step limit; their characterizations above rest on the citation list and should be re-verified against full text before being relied on as §102/§103 grounds.
4. Do not conflate the "Citations (13)" forward citations (e.g., Milwaukee Electric Tool US11,673,217B2; Makita JP7174660B2; EP4126448B1) — these are references that cite this patent and are not prior art to it.

If you'd like, I can pull the full text of the unverified references (JPS6014153A, FR2851819A1, US20120042715A1, US9585533B2, CN202271449U) in a fresh pass to convert those to verified assessments — that is the main remaining gap in this analysis.

I'll ground this obviousness analysis in the actual prior-art references listed on the patent page. Let me pull details on the most probative ones.

Let me pull the other electrostatic-sensing references and Hilti's own earlier dust-collection disclosure.

Let me check the remaining candidates, including the "similar documents" hit that is directly on-point.

Obviousness Analysis — US 10,718,643 B2 under 35 U.S.C. § 103

Analysis date as stated in this task: April 26, 2026. Note: the system prompt for this session gives 2026-09-29. I flag the discrepancy rather than silently pick one.

Scope note. Per the instruction, I use the references appearing in the Prior Art section of the patent page (the 13/19-entry "Citations" tables plus the "Similar Documents" list), and I ground the analysis in the full text supplied. Where I could not verify a reference's content, I say so explicitly and do not rely on it for the core conclusion.

1. The §§ 102/103 landscape in one paragraph

No single reference on the page anticipates any claim. The "suction-module" art (Hilti's own EP2599584A1, US20130136549A1/US9067292B2/US20130149056A1, EP1245330A2) discloses the apparatus environment and the control/warning concept but not a triboelectric/electrostatic dust-flow sensor. The "electrostatic flow" art (US4594901A + GB2166874A; FR2851819A1; JPS6014153A) discloses the sensing principle but in industrial pneumatic-conveying ducts, not in a hand-tool suction module — and, importantly, US4594901A measures current through a grounded conductor, whereas claim 1 recites an electric field meter facing the sensor surface measuring field strength. The case is therefore a § 103 combination case, and the combination is strong. The crux disputed element is the non-contact field-strength read-out, and it is the weakest link in any non-obviousness argument.

2. Person having ordinary skill in the art (PHOSITA)

A PHOSITA here is a mechanical or electro-mechanical design engineer holding a bachelor's degree in mechanical or electrical engineering, with approximately 3–5 years of experience in the design of hand-held power tools and/or power-tool dust-extraction (suction) systems, and working familiarity with (a) the pneumatic path of a suction module for a hollow-drill-bit hammer drill, and (b) conventional techniques for measuring particulate flow in a gas stream (differential pressure, capacitive, optical, and triboelectric/electrostatic). This skill level is supported by the patent's own characterization of the field meter as a bolt-on: "Other construction methods for electric field meters are known and can also be used" (US20190101422A1 [0011]).

3. Claim 1 — element-by-element mapping

Key evidentiary point on US4594901A. That reference's own statement of problem is essentially the '643 problem statement for the sensor: "none of the prior art teaches a simple means for detecting the mass flow rate of particles in a conduit by simply measuring electrostatic current resulting from static charge formation." It further teaches that "any common resinous plastics or polymers such as acrylics, fiberglass, polycarbonates" work as the charge-generating element, and that the element may be a hollow cylinder sized to replace a segment of the conduit — i.e., directly readable on the plastic inner wall of the intake channel recited in claim 1 (the '643 spec equates the two: "Sensor surface 25 can be formed for example by interior side 20 of intake channel 21").

Where US4594901A falls short of claim 1: it drains charge to ground through an embedded conductor and measures current, not field strength, and it is not a hand-held-tool suction module. That gap is what the combination must bridge, and it is bridged by the well-known non-contact field meter (a "field mill" / micromechanical-spring field meter, exactly the implementation the '643 spec calls "an illustrative implementation").

4. Why the combination is motivated (KSR rationales A–E)

Rationale A — known elements combined by known methods, predictable result. The suction module and the electrostatic particulate flow meter were both mature, well-documented technologies in the same technical field (measuring the flow of particulate-laden gas in a duct). Placing a charge-generating plastic surface in the module's intake channel and reading it with an established field meter yields nothing more than the expected sum of the parts: a signal proportional to dust flow.

Rationale B — simple substitution of one known sensing element for another. Substituting a non-contact electric field meter for US4594901A's grounded conductor + ammeter is a substitution of one known electrostatic read-out for another, both being standard options for reading charge on a dielectric surface. The '643 patent itself concedes the field meter is a known component ("Other construction methods for electric field meters are known").

Rationale C — same problem, same way. The '643 specification supplies the motivation on its face: "An indication of hollow drill bit 5 being clogged is for example a rapid drop of dust content in the airflow." A PHOSITA seeking to detect that drop has a known instrument for measuring the dust content of an air stream — the triboelectric/electrostatic dust monitor — and would apply it in the intake channel where the dust-laden air is concentrated (the spec relies on precisely this: dust-laden air from the bit + dust-free air from the environment, with clogging changing the ratio).

Rationale D — known technique applied to a known device "ready for improvement." Hilti's own prior suction devices were already being instrumented for closed-loop control: US20130136549A1 is titled "Suction device and control method" and uses a sensor to detect the power tool's operating state and to activate/deactivate the fan motor. A device already carrying electronics and a control method is the paradigm of a device "ready for improvement."

Rationale E — a finite number of identified, predictable solutions, with a reasonable expectation of success. Options for sensing particulate flow in a duct were: differential pressure, capacitive, optical/light-scattering, and triboelectric/electrostatic. FR2851819A1 expressly acknowledges a commercial triboelectric instrument in this exact role — the "Dust Concentration Meter, Frictional Charge Type Dust Monitor PFM 92 Series" (Matsushima Machinery Laboratory, catalog CPFM-102J, Oct. 2001). A commercial, off-the-shelf device measuring dust concentration via frictional charging is strong evidence that the triboelectric route carried a reasonable expectation of success.

Additional design incentive — placing the sensor in the wall, facing across the duct. The plastic sensor surface as an inlet wall/pad (rather than a probe) obstructs nothing and cannot clog — a meaningful and predictable advantage in a duct whose entire purpose is to convey dust that is prone to clogging (the very failure the patent exists to detect). This is a "design incentive" of the kind KSR treats as evidence of obviousness.

5. Claims 2 and 3

Claim 2 (warning device; warning if the flow-rate decrease exceeds "a specified rate of change"):

• Hilti's US20130136549A1 discloses a control method for a suction device in a hand tool that monitors an input signal and switches the fan motor accordingly (including a timer for delayed deactivation) — a monitoring-and-react architecture to which a rate-of-change threshold is a routine addition.
• US9585533B2 / CN103369995A (Kärcher) discloses monitoring a vacuum cleaner and triggering filter cleaning on a monitored condition — i.e., detecting a degraded airflow path and responding.
• Comparing a derivative of a measured flow signal to a stored threshold, and storing that threshold from bench testing, is routine engineering. The '643 spec confirms the empirical, routine nature of that step: "The first rate of change is determined in tests and is stored in a memory in warning device 29." Per KSR, a value "determined in tests" and stored is a design choice, not an inventive contribution.
• GB2486805A ("Measuring and dust extraction device for a power tool," 2012-06-27) appears on the patent page's Similar Documents list and is facially on point (measurement in a power-tool dust-extraction context). I flag that I did not retrieve its disclosure, so I rely on it only as corroboration that flow/dust measurement in a power-tool extraction system was known; the claim-2 conclusion does not depend on it.

Claim 3 (display showing the flow rate): a measured quantity displayed as a number or bar graph. US4594901A's readout instrument, plus the well-known practice of displaying measured tool parameters, makes this claim obvious; it adds no technical step beyond "the display can indicate the flow rate as a representative number or symbolically using a bar display" (spec) — i.e., the claim covers any display of the value.

6. Claim 4 (independent method claim)

Claim 4 = the claim-1 structure + (a) determine field strength, (b) calculate flow rate, (c) "emitting a warning signal on a display when the flow rate decreases faster than a specified rate of change."

• Steps (a)–(b): US4594901A in view of EP2599584A1 / US20130136549A1 (plus a field meter reference), as above.
• Step (c): US20130136549A1 is directly on point on the "control method … suction device for a hand tool" aspect, and alerting/warning in response to a monitored extraction condition is known from US9585533B2 (Kärcher filter-cleaning trigger) and generally from GB2486805A. Threshold-plus-derivative detection is a routine technique (see § 5).
• Because claim 4 recites the same single "specified rate of change" as claim 2 (differing only in that it names a display), claim 4 adds nothing over the claim 1 + claim 2 combination beyond presenting the same steps as a method.

Important claims/disclosure mismatch to flag. The specification's most interesting insight — storing two rates of change, a larger one (bit withdrawn from the hole, no new cuttings) versus a smaller one (bit clogged) — is not claimed. Claims 2 and 4 recite only one "specified rate of change." Under the rule that claims be commensurate with the disclosed contribution, the arguably non-obvious discrimination logic cannot rescue these claims; the claims read on the broad genus (warn on any sufficiently fast drop), which the prior art/known techniques supply.

7. Claim-construction issue that cuts both ways

Claims 1 and 4 recite a "flow rate of dust-laden air," while the specification describes the evaluation as determining the "flow rate of dust in the airflow" / the "dust content." These are not the same quantity. This ambiguity is material:

• If construed as particulate (dust) mass flow rate, US4594901A is an excellent match — it expressly measures "mass flow rate of particles" proportional to the electrostatic signal, and the '643 title/abstract's "flow rate … of dust-laden air" is then satisfied.
• If construed as bulk volumetric/air flow rate, US4594901A maps less cleanly, and the patentee's best non-obviousness argument (the sensor measures dust, not air — see the spec's discussion of mixing dust-laden and dust-free air) becomes available.

I flag this as an unresolved construction question rather than resolving it. Analytically, the narrower reading is the patentee's best § 103 defense; under either reading, the combination (plastic surface in the duct + electrostatic read-out + flow-rate computation) is taught or suggested.

8. Best combinations, ranked

9. Explicit gaps and uncertainties

1. US20160265953A1 (Endress+Hauser) — examiner-cited, priority 2015-03-10, published 2016-09-15. Its priority/filing date precedes the '643 priority date of 2015-07-17, so it is a candidate AIA § 102(a)(2) reference (art effective as of its filing date) even though it published after the '643 filing date. I could not retrieve its disclosure (my lookup hit the step limit), so I do not rely on it. If it discloses non-contact electrostatic charge/field measurement of a flowing medium, it would strengthen the field-meter element of Combination 1 considerably. Recommended verification: read US20160265953A1's claims.
2. JPS6014153A (Nippon Steel, "Electrostatic capacity type measuring device") — listed in the page's citation table with priority 1983-07-05; I did not retrieve its text. Its title indicates capacitive field-type measurement, but I treat the specific disclosure as unverified.
3. Prosecution history — the page's Legal Events show only docketing (2019-05-14), a non-final action (2019-10-17), a response (2020-01-22), and Notice of Allowance (2020-03-27). The substance of the examiner's rejections is not on the page, so I cannot report which art the examiner applied or whether § 103 was raised and overcome. This is a gap, not a negative finding; the file wrapper (USPTO PatentCenter for 15/745,391) should be pulled.
4. GB2486805A is in the Similar Documents list, not the citation tables; I did not verify its content, and I use it only as corroboration.
5. No objective evidence of non-obviousness located. Consistent with the earlier sections of this analysis, no litigation, PTAB, or license record tied to this patent surfaced, and I found no nexus-qualifying commercial-success or unexpected-results evidence. Absence of such evidence is an inference from my searches, not a verified fact.
6. Date discrepancies already flagged earlier recur here and I do not auto-correct them: the Google Patents authoritative text gives priority 2015-07-17 / filing 2016-07-12, while the aggregator gives 2015-07-16 / 2016-07-11; and the two dates given in this session for "today" differ (2026-04-26 vs. 2026-09-29).

10. Bottom line

Claims 1–4 are, in my assessment, more likely than not invalid under § 103 over EP2599584A1 (or US20130136549A1) in view of US4594901A/GB2166874A, further in view of a conventional non-contact electrostatic field meter and, for claims 2–4, a known monitored-condition warning/control arrangement (e.g., US20130136549A1; US9585533B2). The strongest patentee counter-argument is a claim-construction argument (§ 7) plus the substitution of a non-contact field meter for US4594901A's grounded-conductor current measurement (§ 3); a secondary counter is a teaching-away argument from FR2851819A1, which criticizes the "space-charge effect" error in simple frictional-charge dust monitors — though that criticism is directed at a specific prior geometry and, notably, the '643 specification admits the same practical problem ("air humidity and leakage currents … discharge sensor surface 25") without claiming a solution to it. The unclaimed two-threshold clogging-vs-bit-withdrawal logic is the only genuinely inventive-looking content in the disclosure, and it is not in the claims.