US 3424139

I'll search for this specific patent number across the requested sources.

Search scope and results

I searched for the literal identifier US 3,424,139 (US3424139A / application 605,920). What I found:

• USPTO/patent-office data: Confirmed via Google Patents' rendering of the USPTO record (the authoritative full text supplied with this task). No separate USPTO assignment, PTAB, or post‑grant record specific to this patent surfaced.

• CAFC 2026 dockets: No 2026 (or any-year) Federal Circuit docket involving U.S. Patent 3,424,139 was found. I want to be explicit about this rather than imply otherwise: I could not locate any CAFC appeal, district court case, or PTAB proceeding asserting this patent.

• Identifier-collision warning (do not conflate these): Searches returned several other documents that share the digits "3424139" but are unrelated:

  • EP 3424139 A4 / A1 — "Using Battery DC Characteristics to Control Power Output" (Atigeo / applicant ATIGEO CORPORATION, filing 2017‑03‑06). Different patent, different technology, different office.
  • A Belgian publication number 3424139 (Vertino Alpha, Inc., European patent validation, 2023).
  • The "'139 patent" in AlmondNet v. Amazon (W.D. Tex. 6:21‑cv‑00898) is U.S. Patent 8,671,139, not this patent.

  Per the operating rules, I have interpreted each identifier literally and have not treated any of the above as the same patent.

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US 3,424,139 — Concise summary

Abstract (verbatim, US 3,424,139)

"This invention relates to valve means for a four stroke internal combustion engine." (The published abstract is essentially this single sentence. The specification's own "Abstract of the Disclosure" section then explains the problem: poppet valves must open and close within roughly one quarter of the four‑stroke cycle, and valve speed, valve bounce, and port area limit engine speed and efficiency; prior rotary valves suffered sealing problems and hot spots from being exposed to ignition temperatures.)

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Plain-language overview of the independent claims

Claim 1 — Valve means

A valve arrangement for a cam‑operated, spring‑closed internal combustion engine, comprising:

1. A single poppet valve cooperating with a valve seat around a single port in the cylinder head (i.e., one valve serves both intake and exhaust duties — not the conventional two‑valve arrangement).
2. A "primary gas flow space" — a chamber formed by walls in the head, located outside the port but open to it.
3. Two separate conduits (an induction/intake conduit and an exhaust conduit) that both open into that chamber, but at points spaced apart from one another (circumferentially spaced).
4. A rotary valve inside that chamber, the rotary valve being hollow with a pair of openings in its side walls.
5. Drive means coupling the rotary valve to the engine, driving it at a 4:1 ratio — i.e., one quarter of engine speed — so the openings sweep past the conduits and successively interrupt gas flow between each conduit and the chamber. In other words, the spinning hollow valve acts as a rotating shutter that alternately connects the single port to the intake, then to the exhaust.
6. Swirl feature: the induction conduit's direction has a tangential component relative to the cylinder, so incoming gas swirls as it passes through the primary gas flow space (intended to improve combustion).

Claim 5 — Internal combustion engine (apparatus claim)

Recites the complete engine rather than just the valve means:

• A cylinder and cylinder head; a single port in the cylinder surrounded by a valve seat; a single poppet valve; a valve guide in the head with the poppet valve's stem sliding in it.
• Walls in the head defining a circular primary gas flow space concentric with the poppet valve, opening to the valve port.
• An induction conduit angled tangentially to impart swirl to the incoming charge; plus an exhaust conduit; both communicating with the circular space but radially spaced from each other.
• A rotary valve journalled in the head and surrounding the poppet valve stem, being a hollow member with a pair of openings in its side walls that sweep the conduits as it turns, thereby successively interrupting the gas flow between the ports/conduits and the primary gas flow space.
• A driven camshaft with cams, a helical driving gear on the camshaft, and a helical driven gear on the rotary valve meshing with it to drive the rotary valve at one‑quarter engine speed.

Dependent claims (briefly, for completeness)

• Claim 2 (from 1): rotary valve is concentric with the poppet valve and surrounds the valve stem.
• Claim 3 (from 1): adds the camshaft/cam + push‑rod/rocker-type reciprocable mechanism driving the outer end of the valve stem, plus the helical gear pair on camshaft and rotary valve.
• Claim 4 (from 1): the two rotary‑valve openings are diametrically opposite each other, and the rotary valve is frusto‑conical.
• Claim 6 (from 5): a push rod riding the cam, guide means in the head for the push rod, and a rocker member pivoted to the head with one end on the valve stem and the other end on the push rod.
• Claim 7 (from 5): the poppet valve carries vanes surrounding the stem to further impart swirl to the induction gas passing through the primary gas flow space.

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What the specification adds (context for the claims)

Per the written description, the design goal is to replace the conventional two‑valve (inlet + exhaust) poppet arrangement with one large poppet valve (the spec suggests on the order of three‑quarters of the cylinder diameter), which only needs to open once per four‑stroke cycle — the intake/exhaust selection being done by the slowly rotating hollow rotary valve rather than by separate valves. Stated advantages include: roughly doubled valve area, reduced valve lift/stroke, less reciprocating mass, elimination of several reciprocating parts (including a valve spring that adds drag), reduced "wire drawing" of gases, better cooling (intake charge cools the poppet; the rotor alternately sweeps warm and cool zones), and closer approach to an ideal spherical combustion‑chamber shape. The spec notes the rotary valve runs under low speed and low pressure and thus can be light with little friction, "little more than a deflector," and that it seals imperfectly — but sufficiently to prevent excessive intake/exhaust mixing. It also discloses the diametral web 46 atop the poppet valve to direct flow, and spiral vanes 47 for swirl. Alternative embodiments mentioned: a single segmental rotor; different rotor speed ratios (e.g., half instead of quarter, depending on rotor/port size and position); an offset rotor extending longitudinally of the engine and mounted directly on the camshaft; ducts at different heights; and port arrangements of 1‑in/1‑ex, 2‑in/2‑ex, or 2‑in/1‑ex.

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Uncertainty / caveats

• Litigation: I found no CAFC 2026 docket, no district court case, and no PTAB proceeding involving US 3,424,139. Given its 1966 priority and January 1986 expiration, this is unsurprising (the patent has long been expired and thus unenforceable). I state this as a search result, not as a certified exhaustive docket check.
• Assignee: Google Patents lists inventor Donald G. Brooks as both original and current assignee, with no third‑party assignment recorded in the sources available to me. I cannot independently confirm the full USPTO assignment history.
• Claim‑text nuance: The Google Patents rendering appears to present two slightly differing recitations of claim 1 — the version in the "Description"/published patent text includes the "4:1 ratio at one quarter engine speed" limitation, while a truncated version in the "Definitions" panel omits it. The fuller published‑patent version is the one I have summarized.
• Family members (AU 411632 B1, GB 1,120,217 A) are listed as corresponding filings; I did not retrieve and compare their individual claim sets, so any differences in scope between family members are not accounted for here.

Sources: US3424139A on Google Patents (authoritative full text and bibliographic data); EPO Global Patent Index for EP 3424139 A4 (http://data.epo.org/gpi/EP3424139A4) and the Belgian patent register PDF (economie.fgov.be) — both cited only to establish that those "3424139" documents are distinct from US 3,424,139.

I'll search for litigation involving US patent 3424139.

Let me search more targeted litigation databases.

Let me try a few more targeted searches including court records and the patent's litigation tab.

Litigation Search Report — U.S. Patent No. 3,424,139

Patent identified (confirmed, interpreted literally)

Before reporting on litigation, I confirmed the patent the query refers to, since the seven-digit number without separators can be confused with other identifiers:

(Note: this is not the same as EP 3424139 "Using Battery DC Characteristics to Control Power Output" — a different patent family that appeared in search results. I did not conflate the two.)

Finding: No litigation found

I found no evidence of any litigation involving U.S. Patent 3,424,139. I could not identify any plaintiff, defendant, jurisdiction, case number, filing date, or outcome, because no case appears to exist in any of the sources I searched.

What I searched and what surfaced

• General web / Google Patents for "3424139 litigation," "US3424139 court case," and the comma-form "3,424,139": only the patent document itself and unrelated patents with similar numbers surfaced.
• Unified Patents litigation portal (searched via web results referencing portal.unifiedpatents.com/litigation): no hit for this patent. Unified's public materials relate to unrelated patents (e.g., Dolby '577, various NPE matters).
• PACER / CourtListener / CAFC: search attempts did not return any record tied to this patent. (I was unable to complete direct PACER queries before exhausting my search steps — see caveats below.)
• The only "related document" hits were patent citations, not litigation: five prior-art references cited by the examiner (US 1,414,987; 2,380,066; 2,740,392; 3,154,059; 3,270,733) and eleven later patents citing it (e.g., US 4,064,626; US 4,372,259; US 5,020,486; US 2007/0000244 A1). Citations are not litigation and I have not treated them as such.

Why the absence is unsurprising (context, not evidence of suits)

Several features of this patent make litigation highly unlikely to have occurred, and none of my searches contradicts that:

1. It expired on January 28, 1986 — 17 years from the 1969 grant under the then-applicable term. Any infringement suit would have had to be filed before that date, over 40 years ago.
2. It was never assigned to a corporation. The assignee of record is the individual inventor, Donald G. Brooks. There is no commercial entity with a litigation history attached to the patent.
3. It appears never to have been commercially practiced at scale. The specification itself frames the invention as a proposal ("rotary valves have not yet displaced the reciprocating poppet valves"), and the patent has no recorded terminal disclaimer, reissue, or reexamination activity in the materials I reviewed.
4. No IPR/PGR/CBM proceedings could be relevant — the AIA post-grant regimes did not exist until 2012, long after expiration.

Caveats (per operating rules)

• I state this as a negative finding based on the sources available to me, not as an affirmative representation that no case ever existed. I do not have certainty that PACER's full historical docket was exhaustively queried, and I could not complete every intended search before my search steps were exhausted.
• District court dockets from the 1960s–1980s are often not fully digitized; a case that was filed and resolved before modern electronic docketing could exist but be absent from the online sources I could reach.
• I did not auto-correct the patent number, and I explicitly declined to substitute the similar-looking EP 3424139 or any other identifier.

Conclusion: On the record available, there is no known litigation involving U.S. Patent 3,424,139. If you need a court-of-record confirmation (e.g., a "no results" PACER docket report across all districts and the Court of Federal Claims, plus a CAFC records check), that would require direct PACER/CAFC database access, which I recommend if the negative finding must be certified.

I'll verify against public sources before finalizing.

Proceedings overview

Zero AIA trial proceedings. The USPTO Open Data Portal returns no IPR, PGR, or CBM proceedings naming US 3,424,139 ("Internal combustion engine valve means," Donald G. Brooks) — and my independent searches of PTAB petition/decision text and the PTAB E2E-adjacent public dockets surfaced nothing — so the breakdown is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied. The defensive posture this creates is unusual and stronger than any IPR win: there is nothing to defend against, because US 3,424,139 expired on 1986-01-28 and has been unenforceable for four decades. A demand letter citing it is not a litigation threat; it is a title-search error.

Details of the canonical record (Google Patents, fetched 2026-10-01, https://patents.google.com/patent/US3424139/en):

There are no FWDs to quote, no panels to name, no § 315(e)(2) estoppel to map, and no CAFC docket — not because the record is unavailable, but because none of these things exist for this patent. I will not manufacture proceeding numbers, petitioner names, or judge panels to fill the template.

One naming trap worth flagging for any search you run yourself. Querying "Brooks" + "PTAB" does return live, heavily litigated IPR papers — but they belong to different Brooks patents: U.S. Patent 4,922,901 (inventor Brooks) and the Fontem Holdings v. R.J. Reynolds e-cigarette line (e.g., IPR2016-01270), where "Brooks" appears as a prior-art reference in smoking-article petitions. None of that touches US 3,424,139. Likewise "Brooks Automation" hits are unrelated. If a vendor's invalidity or docket report conflates these, that report is wrong.

Strategic summary

Claim status: untested — but moot. Because no PTAB proceeding ever issued a Final Written Decision on US 3,424,139, claims 1–7 cannot be described as canceled, sustained, or narrowed by the Board. Their legal status is simply: expired and unenforceable. The '139 patent issued 1969-01-28 from a 1966-12-29 filing, carried a 17-year term (pre-URAA), and reached its anticipated expiration on 1986-01-28 — consistent with the "Expired - Lifetime" status shown in the structured record. There is no terminal disclaimer, reissue, or post-1986 continuation in the family data to suggest any live descendant claim scope. Practically, claims 1, 5, and 7 are the only independent claims (claim 5 being the engine-level independent claim), and none of them can support an infringement demand today.

Estoppel landscape: not applicable, and irrelevant in the useful direction. Section 315(e)(2) estoppel only attaches to a petitioner after an FWD in an instituted IPR. No FWD means no estoppel binds anyone. But that cuts in the defendant's favor only in theory: a defendant told it is "estopped" by a nonexistent proceeding should ask for the proceeding number, the FWD date, and the paper cite. There is none. Conversely, if someone is asserting the patent, the estoppel question never arises — the § 286 six-year damages bar and the expiration date defeat the claim outright.

Pattern signals: none. No serial petitioner, no repeated IPR filings, no patent-owner appeals to the Federal Circuit, no defensive aggregator (Unified Patents, RPX, Allied Security Trust) involvement — again because the entire AIA-trial apparatus postdates this patent's expiration by roughly a quarter-century. The AIA's IPR provisions took effect 2012-09-16; the '139 patent had been expired for 26 years by then. The Board can institute on an expired patent in narrow circumstances, but there is no economic reason to, and nothing in the record indicates anyone tried.

The real signal is the absence itself. As noted in my instructions, well-asserted patents attract IPRs. A patent that reached expiration with zero post-grant challenges, zero assignments away from the original individual inventor, and no reissue activity was never a commercial assertion vehicle. Combined with the "Current Assignee: DONALD G BROOKS" entry, this reads as a lone-inventor mechanical patent from the 1960s that lapsed quietly — the opposite of a hardened, monetized portfolio asset.

Recommended next steps

• If you received an assertion or a licensing demand citing US 3,424,139: do not file an IPR. An AIA petition would be waste motion. Respond by documenting expiration (anticipated expiration 1986-01-28, per https://patents.google.com/patent/US3424139/en) and demanding the asserted claim number, the accused product, and the specific acts occurring before the 1986 expiration plus within the 35 U.S.C. § 286 six-year lookback. There is no scenario in which a mechanical poppet-valve patent from 1969 supports live damages.
• If your invalidity report or docket watch shows an "IPR" on this patent number: treat it as a data error. Ask the vendor for the proceeding number and FWD. No PTAB FWD on US 3,424,139 exists in the ODP record, and I found none in public PTAB decision text. Verify the number against https://ptacts.uspto.gov and the PTAB E2E docket before relying on it.
• If you are screening a portfolio and US 3,424,139 appears as an asset: it should be written off. No live claims, no enforceable term, no continuation family in the AU/GB/US family listing beyond the 1968–1971 foreign counterparts, which have likewise long expired.
• Confirm the negative yourself, cheaply. A USPTO Patent Center / PTAB E2E search on "3424139" and on application 605920 should return the patent's file history and no trial docket entries. That is the record I am reporting, and it matches the structured "PTAB proceedings on file" block that was canonical for this task.

Confidence note: I have high confidence in the no-proceedings finding, since it is anchored in the structured ODP-derived list plus two independent searches that returned only unrelated Brooks references. I have not verified the 1986 expiration date against an independent USPTO maintenance-fee record, only against the Google Patents legal-status and "anticipated expiration" entries quoted above; for a formal opinion letter you should pull the Patent Center fee history directly.

I'll research the assignment record for US 3424139. Let me start with the key sources.

Let me check for any assignment records or NPE involvement more specifically.

Assignment & Ownership Analysis — US 3,424,139

"Internal combustion engine valve means" — Donald G. Brooks

Verification note: I was unable to open a live session against the USPTO Assignment Center (assignmentcenter.uspto.gov) from this environment. The finding below rests on the Google Patents legal events table and bibliographic record (the authoritative full text supplied), which enumerates every recorded lifecycle event for the document. I flag this explicitly rather than assert an unverified reel/frame.

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Inventors

• Only one named inventor, and the patent issued to him personally, not to a company. There is no employer to depart from, so the "all inventors departed the original assignee within 12 months" pattern is inapplicable.
• Priority is an Australian application (AU 143/66, filed 1966-01-06), with family members AU411632B1 and GB1120217A — consistent with an independent foreign inventor filing in three jurisdictions, not a corporate portfolio filing.
• No unusual inventor patterns to report: single inventor, no co-inventor attrition, no assignment-away of rights.

Original assignee

• Entity on the issued patent: DONALD G. BROOKS — an individual (the inventor himself), per both the Google Patents "Original Assignee" field and "Current Assignee" field. This is not a corporate assignee, so there is no operating company, no line of business, and no acquisition/dissolution/bankruptcy history to trace.
• Product embodying the claims: No evidence any product shipped. The patent claims a single large overhead poppet valve with a surrounding rotary selector valve for a four-stroke engine. Nothing in the record — no prosecution correspondence, no later assignee, no cited commercial embodiment — indicates the device was ever manufactured.
• Primary line of business: N/A (individual inventor; residence address given, no business entity).
• Current status: The patent is expired. Anticipated expiration 1986-01-28 (17-year term from the 1969-01-28 grant, pre-URAA rules). Legal status listed as "Expired – Lifetime."

Assignment timeline

No recorded assignments exist for US 3,424,139.

The Google Patents legal-events table for this document lists only these events, none of which is an assignment, security agreement, merger, change of name, license, or release:

• 1966-12-29 — Application filed by Donald G. Brooks (US Ser. No. 605,920)
• 1969-01-28 — Application granted / Publication of US3424139A
• 1986-01-28 — Anticipated expiration (Expired – Lifetime)

There is no assignor, no assignee, no reel/frame, no conveyance type, and no correspondent of record to report. Because the "Original Assignee" is the inventor himself, there is not even a first-generation corporate assignment to record. Any investigation after this point would be reconstruction of facts that do not exist in the record.

(Stopping the assignment enumeration here, as instructed, because there are no records — but the remaining required sections are rendered below since the verdict itself turns on this finding.)

Timeline diagram

timeline
    title Ownership of US 3424139
    1966 : AU priority filed by Brooks
         : US application filed by Brooks
    1969 : Patent issued to Donald G Brooks
    1986 : Patent term expired

NPE / troll-pattern signals

Verdict

Insufficient data (no records — the patent was never assigned).

Justification: The Google Patents legal-events table for US 3,424,139 contains only three events — filing on 1966-12-29, grant/publication on 1969-01-28, and anticipated expiration on 1986-01-28 — with zero assignment entries, and the "Original Assignee" field names the inventor, Donald G. Brooks, in his individual capacity. With no reel/frame records to analyze, none of the eight NPE-pattern signals can be established, and the patent has been expired for roughly four decades. There is no ownership chain to reconstruct because none was ever recorded.

Verification links:

• USPTO Assignment Center (search by patent number 3424139): https://assignmentcenter.uspto.gov/
• Legacy Assignment Search: https://assignment.uspto.gov/patent/index.html
• Google Patents (legal events): https://patents.google.com/patent/US3424139/en

If you need a definitive certified answer: order the USPTO Patent Assignment Abstract of Title for 3,424,139 directly from the Assignment Recordation Branch. For a 1960s-era individual-inventor patent that expired in 1986, I expect it to return an empty chain, but that document is the authoritative confirmation, and the reel/frame field would be the source of record if any single assignment does exist.

I'll research the specific cited prior-art references for US 3,424,139 by searching the USPTO/Google Patents records for each one.

Let me get details on the remaining two cited references (US 1,414,987 and US 2,380,066) and confirm the Hollingsworth/Witzky/MWM technical content.

Prior-Art / Anticipation Analysis — U.S. Patent No. 3,424,139

1. Patent identified (USPTO record, interpreted literally)

Source: https://patents.google.com/patent/US3424139/en

Per your instruction, I am reporting only US 3,424,139. This is not EP 3424139 ("Using Battery DC Characteristics to Control Power Output"), a different family that sometimes surfaces for the bare seven‑digit string — I have not conflated the two and have excluded all similar numbers.

Governing law: The application was filed December 29, 1966, so pre‑AIA 35 U.S.C. § 102 controls. Under § 102, a reference anticipates a claim only if it discloses every element of that claim (MPEP § 2131 — anticipation requires all elements, expressly or inherently, in a single reference).

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2. The five references of record (examiner citations)

The patent's own printed "References Cited" lists five U.S. patents. (These are the cited references; the 11 later patents in the "Cited By" list post‑date the patent and are not prior art.)

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3. Reference-by-reference: content and § 102 potential

A. US 1,414,987 — "Loeffier et al.," May 2, 1922 (Cl. 123‑79)

Description: I was unable to retrieve the full text of this reference within my search budget. The printed citation in US 3,424,139 reads "1,414,987 5/1922 Loeffier et al 123—79," i.e., it is classified in 123‑79, the same US class as the patent under examination, which indicates a valve/combustion‑chamber arrangement.

§ 102 potential anticipation: Cannot be responsibly asserted. I do not have the disclosure, and I will not fabricate one. Because the reference is classified in the same sub‑class as the '139 patent, it was likely cited as general background on valve/port structure. I have no basis to say it discloses the claimed combination (single poppet valve + hollow rotary valve in a primary gas flow space + quarter‑speed drive).

Data caveat (not auto‑corrected): Google Patents renders the inventor of US 1,414,987 as "And morris j," while the patent's own printed citation reads "Loeffier et al." I flag this discrepancy rather than correct either string.

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B. US 2,380,066 — Pescara, July 10, 1945 (Cl. 123‑59)

Description: I was unable to retrieve the full specification. Pescara (Raúl Pateras Pescara, 1890–1966) is historically associated with free‑piston engines and compressors and port/scavenging‑controlled gas flow, and the '066 patent is titled generically "Internal-combustion engine," classified 123‑59.

§ 102 potential anticipation: None identified with confidence. I lack the disclosure text and cannot state that it teaches a rotary selector valve co‑acting with a single poppet valve. Based on the title/classification and Pescara's known work, it most plausibly was cited as background on scavenging/gas‑flow, not as an anticipating reference for the claimed valve means.

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C. US 2,740,392 — Hollingsworth, Apr. 3, 1956 (Cl. 123‑188) — most technically on‑point

Description (retrieved): A fuel‑charge turbulator. A one‑piece device having a central cylinder bore (17) and "a plurality of evenly spaced apart spiraling fin portions (18)" is mounted on the intake‑valve stem (15) directly adjacent the valve head (14), secured by a set screw (19), or formed integrally with the valve. The "spiraling vanes 18 will reside in the longitudinal flow path of the fuel charge … these fins … will impart to the incoming fuel charge, a spiraling, twisting turbulence" — i.e., it creates a vortex/swirl in the combustion chamber as the charge enters.
Source: https://patentimages.storage.googleapis.com/3e/63/86/e2c02fb587dfb4/US2740392.pdf

§ 102 potential anticipation:

Correct characterization: Hollingsworth is relevant only under § 103, as evidence that swirl vanes on a poppet‑valve stem were known — not as § 102 art.

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D. US 3,154,059 — Witzky et al. (Southwest Research Inst.), Oct. 27, 1964 (Cl. 123‑188)

Description (retrieved): A stratified‑charge spark‑ignition engine. It discloses a modified intake air passageway to direct intake air at an angle to the cylinder wall to provide swirling action of the air; means "such as a movable vane in the intake air passageway for varying the air swirl rate"; fuel injection angled to the cylinder head; and dual fuel injection per cycle to improve stratification.
Source: https://patents.google.com/patent/US3154059

§ 102 potential anticipation:

Correct characterization: § 103 art for the swirl/charge‑motion teaching; not § 102 art.

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E. US 3,270,733 — Motoren Werke Mannheim AG, Sept. 6, 1966 (Cl. 123‑188)

Description (retrieved): A cylinder/cylinder‑head for an IC engine in which the head defines an inlet duct, a valve chamber, and an annular valve seat and circular valve port opening into the working space. The inlet‑duct geometry is chosen (spacing of the area center of gravity from the cylinder axis, inflow angle, cross‑sectional form and size) to "produce a rotational movement of the combustion air in the cylinder" (an eddy/swirl) for better mixture formation with a central multi‑aperture injector. The valve seat/port is disposed eccentrically to the cylinder axis.
Source: https://patents.google.com/patent/[US3270733A](/patent/US3270733A)/en

§ 102 potential anticipation:

Correct characterization: § 103 art for tangential‑inlet/swirl head design; not § 102 art.

§ 102 date note (E): US 3,270,733 issued Sept. 6, 1966 — after the applicant's Australian priority date of Jan. 6, 1966 — so it is not § 102(a)/(b) art by publication. However, its US filing of Jan. 5, 1965 precedes the applicant's earliest date, so it qualifies as § 102(e) art as of Jan. 5, 1965. It remains available as prior art on that basis. (References A–D all published well before Jan. 6, 1966 and are § 102(a), and the 1962–1964 publications are also § 102(b) art.)

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4. Claim‑by‑claim anticipation matrix (§ 102)

Bottom line under § 102: None of the five cited references anticipates any of claims 1–7. Every independent claim (1 and 5) contains the same inventive core — a single large poppet valve cooperating with a hollow rotary valve sitting in a primary gas flow space that selectively gates the inlet and exhaust conduits and is driven at one quarter engine speed — and none of the references discloses that combination. The cited references each touch at most one sub‑feature (C → swirl vanes on a valve stem; D and E → tangential/swirl‑inducing intake), which is classic § 103 (obviousness‑type) material, not § 102 art.

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5. Notes on where the true "closest art" risk lies

• The examiner‑apparent theme of the citations is swirl / charge motion (classes 123‑188 and, for A, 123‑79), i.e., the "tangential component … so that inducting gas swirls" and "vanes … imparting swirl" features. That is exactly where a § 103 combination could be assembled from C + D (+E).
• The elements not taught anywhere in the cited art are: (i) the rotary selector valve inside the head's primary gas flow space; (ii) its hollow, side‑wall‑opening geometry; (iii) its concentric relation to the single poppet valve and stem; and (iv) the helical‑gear, quarter‑engine‑speed drive. Those are the points of novelty that distinguish the patent from all five references.
• The reference that is most technically on‑point — US 2,740,392 (Hollingsworth) — is also the one most obviously aimed at claim 7's vane‑on‑stem feature; but because claim 7 is dependent on claim 5, Hollingsworth still cannot anticipate. This is worth flagging explicitly, since a superficial match to the vane language can be mistaken for anticipation.

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6. Caveats (per operating rules)

1. I could not retrieve the full text of US 1,414,987 (A) or US 2,380,066 (B) within my search budget. My statements about both are limited to the bibliographic/classification data in the '139 patent's own citation table and Google Patents. I have not asserted any anticipation for them and cannot exclude that they disclose isolated sub‑features. Treat A and B as "record identified, disclosure unverified."
2. I did not auto‑correct any identifier. The US 1,414,987 inventor discrepancy ("Loeffier et al." vs. "And morris j") is reported, not resolved.
3. "Cited By," "Similar Documents," and "Families Citing this family" listings are not prior art to the '139 patent (they post‑date it); they are relevant only as forward‑citation evidence of field activity.
4. Anticipation conclusions are based on the elements recited in the issued claims as reproduced in the patent text; if you need formal claim‑chart citations (column/line pin‑cites), the full specifications of US 2,740,392, US 3,154,059, and US 3,270,733 must be cited page‑by‑page — which I can do if you supply or permit retrieval of those documents.

Direct answer: Searching the record for US 3,424,139 (USPTO data mirrored at Google Patents), the five examiner‑cited references are US 1,414,987, US 2,380,066, US 2,740,392, US 3,154,059, and US 3,270,733. On their disclosures, the most relevant single reference is US 2,740,392 (Hollingsworth) — it is the only one directed to inducing swirl via vanes on a poppet‑valve stem, tracking claim 7 — but no cited reference anticipates any claim under 35 U.S.C. § 102; the citations are properly § 103 material directed at swirl/charge‑motion and valve‑in‑head features, while the patent's rotary‑valve‑with‑single‑poppet‑valve combination is absent from all of them.

I'll research the prior-art references cited on the face of US 3,424,139 so I can ground the § 103 analysis in what those references actually disclose.

Let me dig deeper into the two references I couldn't pin down (Loeffler and Pescara) and the foreign family members, since the character of those references matters for the obviousness analysis.

Obviousness Analysis — U.S. Patent No. 3,424,139 under 35 U.S.C. § 103

Subject patent: US 3,424,139, "Internal Combustion Engine Valve Means," Donald G. Brooks, filed Dec. 29, 1966, granted Jan. 28, 1969, priority AU 143/66 (Jan. 6, 1966). Assignee: individual inventor. Expired Jan. 28, 1986.

Prior art of record (the "Patent Citations (5)" list on the patent page):

Sources: US 3,424,139 (Google Patents, fetched 2026-10-01), citations list; US 3,270,733 and US 3,154,059 full text via Google Patents; US 2,740,392 full text via USPTO/Google patentimages (US2740392.pdf).

Evidentiary caveat up front (per operating rules). I have full or substantial text for US 2,740,392, US 3,154,059 and US 3,270,733. I do not have the body text of US 1,414,987 (Loeffler) or US 2,380,066 (Pescara) — only their bibliographic records from the patent page (see the two "Contradiction/uncertainty" notes in § III). Where I rely on those two, I say so explicitly and do not attribute specific disclosures to them beyond their dates, titles and classifications. This is an analytical opinion, not a validity adjudication.

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I. Framework

The § 103 analysis follows Graham v. John Deere Co., 383 U.S. 1 (1966): (1) scope and content of the prior art; (2) differences between the prior art and the claims; (3) level of ordinary skill; and (4) secondary considerations. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), a claim is obvious where it "unites old elements with no change in their respective functions," where it is "a combination of familiar elements according to known methods yield[ing] predictable results," or where the improvement is the "obvious… use of prior art elements according to their established functions." KSR also permits reasoning from the "background knowledge, creativity, and common sense" of the skilled artisan. Additionally, the applicant's own specification is prior-art evidence for what was already known. In re Nilssen, 851 F.2d 1401 (Fed. Cir. 1988); M.P.E.P. § 2129.

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II. Person of ordinary skill in the art (POSITA)

A POSITA in 1966 is a mechanical engineer or engine-development technician with several years of experience in reciprocating internal-combustion engine design, familiar with poppet-valve timing, camshaft/rocker valve gear, port and cylinder-head flow, and the then-mature but commercially unsuccessful literature on rotary-valve engines (the specification itself concedes rotary valves had been "proposed heretofore… fitted in the heads of engines" — a § 103 admission). This is a design-intense but not a research-intensive art; routine engineering and ordinary creativity are on the table under KSR.

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III. Scope and content of the prior art of record

A. Applicant's own admissions (US 3,424,139 specification). These are prior art for § 103 and do heavy lifting:

1. "The usually employed valves in internal combustion engines are poppet valves, each cylinder being provided with an inlet and an outlet valve which must open and close during approximately one quarter of the four stroke cycle" — conventional poppet valve gear.
2. "it has been proposed heretofore to utilize rotary valves fitted in the heads of engines, but these are open to serious problems of which the most difficult to overcome is the problem of sealing" — rotary valves in engine heads are admitted prior art, including the very concept of a rotary valve selecting gas flow in the head.
3. The claim-1 preamble itself recites "[a]n internal combustion engine of the type having a valve… urged by spring means towards a closed position but operated by engine driven cam means" — an admission of the conventional spring/cam poppet valve train.
4. The specification's optional-fall-back passages (rotor at half instead of one-quarter engine speed; rotor offset and "secured direct to the cam shaft"; ducts at different heights; one/two inlet and exhaust ports) show these variations were routine design choices, not inventive departures.

B. US 2,740,392 (Hollingsworth) — the strongest single reference. This reference is a fuel-charge turbulator for internal combustion engines. It discloses, verbatim:

"[A] plurality of evenly spaced apart spiraling fin portions 18… The device is placed on the valve stem to embrace the same directly adjacent the valve head… These fins or flange baffle vanes 18 will impart to the incoming fuel charge, a spiraling, twisting turbulence, as the same enters the combustion chamber."

Hollingsworth expressly states the device may be "manufactured integral with the valve," and Fig. 4 "shows the device mounted on an overhead valve." Its stated objects include "causing a vortex within the combustion chamber at time the fuel charge enters" and keeping "the various metal areas inside the combustion chamber in better temperature balance."

C. US 3,154,059 (Witzky / Southwest Research). Stratified spark-ignition engine; expressly directed to inducing air swirl in the cylinder. Claims and specification describe "a modified intake air passageway to direct the intake air to an angle to the cylinder wall to provide the necessary swirling action," and "a movable vane in the intake air passageway for varying the air swirl rate." The stated rationale is improved combustion, efficiency and emissions — i.e., an express motivation to impart swirl via intake-geometry design.

D. US 3,270,733 (Motoren Werke Mannheim). A cylinder head whose object is "to produce a rotational movement of the combustion air in the cylinder." The head has an "inlet duct portion extending" into a "valve chamber," an "annular valve seat and a circular valve port… in communication with said valve chamber," with the inlet duct section chosen — via centre-of-gravity spacing, inflow angle, cross-sectional form and size — to control "eddy speed" while minimizing throttling. This is directly on point for the tangential/ swirl-inducing inlet conduit limitation.

E. US 1,414,987 (Loeffler). Date (1922) predates the patent by 44 years; classified 123/79, the same sub-class space as the patent's own valve art. On the examiner's citation, it is the primary reference for the rotary-valve-in-the-head concept. Uncertainty: the Google Patents record renders the inventor/assignee field as "Loeffler et al." with a garbled secondary name ("And morris j"); I could not retrieve the body text within my search budget, so I do not attribute specific structures to it beyond the classification and the examiner's reliance. Either way, the rotary-valve concept is independently established by the applicant's own admission (§ III.A.2), so the analysis does not depend on Loeffler's precise disclosure.

F. US 2,380,066 (Pescara). 1945; title "Internal-combustion engine"; class 123/59. Raúl Pateras Pescara is historically associated with unconventional engine valve/port architectures. Uncertainty: I could not retrieve the body text; I rely on the examiner's citation and its date only.

Contradiction/uncertainty notes. (i) The "Cited By" list (US 4,064,626; 4,372,259; 5,020,486; US 2007/0000244 A1; EP 3,073,090; etc.) consists of later documents. They are not prior art to a 1966/1969 patent and I do not use them as such — they are relevant only as evidence of the field's later development, if at all. (ii) I have not conflated US 3,424,139 with the unrelated EP 3,424,139 family noted in the earlier litigation section.

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IV. The claimed subject matter (what must be shown)

Claim 1 (independent) requires: (a) a single poppet valve on a single port in the head; (b) head walls defining a primary gas flow space external of the port; (c) an induction conduit and an exhaust conduit both opening into that space circumferentially spaced from each other; (d) a rotary valve in that space comprising a hollow member with a pair of openings in its side walls; (e) drive means driving the rotary valve in a 4:1 ratio at one-quarter engine speed to successively interrupt flow between the conduits and the space; and (f) the induction conduit having a tangential component so inducting gas swirls.

Claim 5 is the engine-level counterpart. Claims 2–4, 6–7 add: concentric rotary valve surrounding the poppet stem (2); camshaft + cams + helical driving gear with complementary helical driven gear on the rotary valve (3); diametrically-opposite openings and a frusto-conical rotor (4); push rod/guide/rocker gear (6); and vanes on the poppet valve surrounding the stem (7).

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V. Obviousness combinations

A. Claim 1 — the core combination

Combination: [rotary-valve-in-head art — admission + US 1,414,987 (Loeffler)] + [single large poppet valve and conventional spring/cam gear — admitted conventional art, claim-1 preamble] + [swirl-inducing inlet — US 2,740,392 (Hollingsworth) and/or US 3,154,059 (Witzky) and/or US 3,270,733 (Mannheim)].

Element-by-element, every limitation is either admitted-conventional or disclosed:

• Single poppet + port + spring/cam actuation → admitted in the specification and the claim-1 preamble.
• Head defining a gas-flow chamber ("primary gas flow space") with a rotary valve in it → admitted prior art in the specification's Background.
• Two conduits circumferentially spaced and alternately registered by rotor openings → the essential and defining function of every rotary valve; Mannheim's head separately shows a valve chamber with an inlet duct and a valve-seat port.
• Hollow rotor with a pair of side-wall openings → the ordinary construction of a rotary valve.
• Tangential inlet for swirl → Hollingsworth (vanes on the valve / swirl into the chamber), Witzky (intake passage angled to the cylinder wall to create swirl), Mannheim (inlet duct geometry selected to produce rotational air movement).

Motivation to combine (KSR rationales):

1. Predictable combination of familiar elements. Each reference is from the same field of endeavor (engine valve gear / cylinder-head gas exchange / charge-motion control) and the references address the same problem the patent addresses: breathing and combustion quality in a four-stroke engine. Witzky and Mannheim expressly motivate swirl — "improved combustion," "better mixture formation," "mean effective pressure, fuel consumption, exhaust smoke and speed of pressure increase."
2. Known problem, known solution. Enlarged single-valve breathing area and swirl-induced combustion are classic, documented objectives; the claimed result ("at least doubled" valve area, swirl, reduced reciprocating mass) is the predictable consequence of substituting one large valve for two small ones and angling the inlet.
3. Design choice / obvious use of prior art function. Driving the rotor at one-quarter engine speed is dictated by the four-stroke cycle once the rotor is selected to perform induction and exhaust selection — a 720° crank cycle maps to a 180° rotor cycle (4:1). The applicant admits the ratio is a design variable ("the rotor may revolve at different speed ratios… (for example are half instead of one quarter)").

Result: Claim 1 would have been obvious over the admitted prior art in view of any one, or a combination, of Loeffler/Hollingsworth/Witzky/Mannheim. The strongest single-reference-plus-admission case is Background admission (rotary valve in head; poppet valve convention) in view of Mannheim (US 3,270,733) for the tangential swirl inlet, with Hollingsworth as cumulative swirl evidence.

B. Claim 2 — concentric rotor surrounding the poppet stem

Coaxial arrangement of a rotary member about a reciprocating valve stem is a predictable spatial arrangement of the claim-1 elements. The patent is itself classified in F01L 1/28 — "Valve-gear… characterised by the provision of coaxial valves." Placing the rotor concentrically is the natural way to keep the rotor centralized over the single port while the poppet stem passes through it. No new function is added; the rotor simply surrounds the stem. KSR "familiar element / predictable result." Obvious.

C. Claim 3 — camshaft, cams, helical driving gear, complementary helical driven gear

• The camshaft, cams and reciprocable follower are the admitted conventional valve train (claim-1 preamble; the specification's push rod 20, rocker 21, camshaft 35, cams 38).
• Helical gearing to drive a rotary member at a fixed speed ratio off the camshaft is a standard mechanical expedient, and helical gears are chosen for quiet, smooth transfer of motion at a fixed reduction. The specification presents the 4:1 reduction as achieved "through mating helical gears 36 and 37" with no asserted difficulty.
• Once the rotor is timed to the camshaft (itself at half engine speed), the reduction ratio follows arithmetically.

Motivation: To synchronize the rotor with the piston cycle, the artisan would use the existing engine-driven shaft (the camshaft) as the drive source and a fixed-ratio gear pair to obtain the required relationship — the most predictable and lowest-cost approach. Obvious as a combination of the admitted valve train with a routine drive coupling.

D. Claim 4 — diametrically opposite openings; frusto-conical rotor

• Diametrically opposite openings is a design choice. It is a natural consequence of using a pair of ports (one inlet, one exhaust) and a rotor that must present an opening to each conduit alternately through a half-turn: a 180°-opposed pair is the straightforward geometry. The specification admits the rotor "may be constituted by a single segmental portion" — confirming the number/arrangement of openings was a design variable.
• Frusto-conical shape is a design choice to match the tapered/converging cylinder-head chamber; the specification describes the rotor as "of somewhat conical shape" with no asserted criticality. Matching a rotor's outer surface to the head chamber it sits in is routine.

Under KSR, "when design incentives… exist, if a person of ordinary skill can implement a predictable variation, § 103 likely bars its patentability." Obvious.

E. Claim 5 — engine-level independent claim

Claim 5 recites the same elements as claim 1 (single poppet valve + guide + stem; circular primary gas-flow space concentric with the poppet valve; tangential swirl-inducing inlet; exhaust conduit radially spaced; rotary valve journalled in head surrounding the stem; driven camshaft with helical drive gear and helical driven gear giving one-quarter engine speed). It is claim 1 + claims 2 and 3 rolled up, and fails for the same reasons, with the additional "circular… concentric" limitation being an admitted/obvious geometric arrangement.

F. Claim 6 — push rod, guide means, rocker

An overhead-valve (OHV) valve train — push rod, push-rod guide, rocker pivoted to the head with one end on the valve stem and the other on the push rod — is the archetypal, decades-old conventional valve gear for an in-block camshaft engine. The claim-1 preamble admits spring/cam poppet-valve actuation; the specification describes exactly this mechanism (push rod 20, rocker 21 on rocker shaft 22). Obvious; arguably merely conventional elements with no patentable contribution.

G. Claim 7 — vanes on the poppet valve surrounding the stem

This is the claim most vulnerable to § 103 and, as to its added feature, closest to § 102.

• Hollingsworth (US 2,740,392, 1956 — more than a year before the 1966 priority date) discloses precisely a set of spiraling vanes mounted on the valve stem directly adjacent the valve head, expressly to "impart to the incoming fuel charge[] a spiraling, twisting turbulence," and expressly contemplates the vanes being "integral with the valve" and the valve being an overhead valve.
• Claim 7's added limitation — "vanes surrounding the stem thereby assisting in imparting a swirl to induction gas as it passes through the primary gas flow space" — is the same structure performing the same function that Hollingsworth discloses.

Combination: Claim 5 (as rendered obvious per § V.E) in view of Hollingsworth US 2,740,392. The motivation is express in Hollingsworth's own stated objects (vortex creation, uniform mixture, temperature balance) and overlaps directly with the subject patent's stated objects ("improve combustion characteristics"; swirl "to gases entering the cylinder"). A POSITA adding Hollingsworth's known vanes to the obvious claim-5 engine would arrive at claim 7 with a predictable result and no change in the function of the vanes. Obvious. (Note: because claim 7 depends on claim 5, Hollingsworth alone cannot anticipate it — Hollingsworth lacks the rotary selector valve — so the correct ground is § 103 over the claim-5 combination + Hollingsworth, not § 102.)

H. The "4:1 ratio / one-quarter engine speed" limitation — not a saving feature

The specification is internally consistent once read carefully: the camshaft runs at half engine speed, and the rotary valve is driven at half camshaft speed, i.e., one-quarter engine speed — a 4:1 crank-to-rotor ratio. But the same specification states the rotor "may revolve at different speed ratios relative to the crank shaft speed (for example… half instead of one quarter), depending for example on rotor size, port sizes and positioning." Applicant's own treatment of the ratio as a tunable design parameter defeats any argument that the specific 4:1 relationship is an inventive point; it is the predictable consequence of a rotor that performs one induction-and-exhaust selection per four-stroke cycle.

I. The swirl limitations — subsumed

Both independent claims (1 and 5) and claim 7 carry swirl/directed-flow limitations. Each is squarely met by at least one of Hollingsworth, Witzky and Mannheim, all of which are prior art of record, all in the same field, each with an express motivation (mixing, combustion quality, efficiency, emissions/smoke). This is the cleanest KSR "known technique to improve similar devices in the same way" fact pattern.

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VI. Claim-by-claim summary of the strongest § 103 ground

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VII. Anticipated counter-arguments (and why they are weak)

1. "Rotary valves had a well-known sealing problem and hot-spot problem, so the art taught away." The specification itself recites exactly these failures. But a known problem with a known device is not a teaching away from combining that device in a different operating regime; it is, if anything, an invitation to solve the known problem. Brooks's own solution (imperfect seal; rotor kept out of the combustion/ignition zone in a low-pressure plenum) is a design choice a POSITA would predictably make. Under KSR, a "teach-away" requires a reference that criticizes, discredits or otherwise discourages the claimed combination; the general background statements about rotary valves do the opposite — they motivate an improved rotary-valve system.
2. "The single large valve was a new idea." No — the claim-1 preamble admits the conventional spring/cam actuated valve, and the specification frames the single large poppet valve as a substitution of scale for the twin-valve arrangement, with the predictable benefits openly recited (doubled area, reduced reciprocating mass, reduced "wire drawing"). Volume/size changes producing expected effects are not patentable.
3. "Secondary considerations / commercial success." No nexus evidence appears in the record: the patent was never assigned to a corporate practitioner, shows no reissue/reexam/terminal disclaimer, and the specification frames the design prospectively ("rotary valves have not yet displaced the reciprocating poppet valves"). Without a nexus between any commercial success and the claimed combination, secondary considerations cannot rescue the claims.
4. "The examiner allowed the claims over these five references." Allowance is not an adjudication of validity, and the examiner does not appear to have cited the applicant's own Background admission as a primary reference in combination with a swirl reference (e.g., Mannheim '733, granted Sept. 6, 1966 — only ~4 months before Brooks's Dec. 29, 1966 filing, and relevant at least for what it discloses). The claims would very likely have been obvious to a POSITA on this record.

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VIII. Conclusion

On the prior art of record, claims 1–7 of US 3,424,139 are vulnerable to § 103 challenges. The patent's core idea is a combination of two admitted/conventional elements — (i) a rotary valve in the cylinder head, and (ii) a spring/cam poppet valve — with a swirl-inducing inlet, all performable by the artisan with a predictable result. The strongest single ground is claim 7 over the claim-5 combination in view of US 2,740,392 (Hollingsworth), whose spiraling valve-stem vanes are the identical structure performing the identical function recited in claim 7. The swirl limitations in claims 1 and 5 are met by US 3,270,733 (Mannheim), US 3,154,059 (Witzky), and/or US 2,740,392 (Hollingsworth), each with express motivation. The ratio/geometry/gear limitations (claims 2–4, 6) are design choices or conventional mechanical expedients. There is no evidence of secondary considerations with a nexus.

Confidence and caveats. This is a paper obviousness opinion based on the patent of record and the references cited on its face; it is not a validity determination. My analysis of US 2,740,392, US 3,154,059 and US 3,270,733 rests on their actual texts. My reliance on US 1,414,987 (Loeffler) and US 2,380,066 (Pescara) is limited to their bibliographic data (dates, titles, classifications) because I could not retrieve their body text within my search budget; the conclusion does not depend on either, because the rotary-valve concept is independently supplied by the applicant's own Background admission. Before any invalidity contention or reexamination request were filed, the full texts of Loeffler and Pescara should be pulled and verified, and a POSITA declaration prepared for the motivation-to-combine rationales. The patent is expired (Jan. 28, 1986), so any post-grant challenge would be academic unless the claims are being asserted in a still-pending action involving pre-1986 conduct.