US 4570602

I'll search for this specific patent number across USPTO and litigation sources.

Let me check for any litigation or CAFC docket activity, and verify USPTO/assignment status.

Search Results Summary

Scope note: I searched for the literal identifier "4570602" / "US4570602" across patent databases and Federal Circuit sources. I found no CAFC (or other) litigation, PTAB proceeding, or 2026 Federal Circuit docket activity involving U.S. Patent No. 4,570,602. Searches for that number returned only unrelated hits (e.g., an Argentine trademark act no. 4570602, a dog-registry entry, a Florida corporate FEI number, and a German patent's citation list). The results below are from the patent record itself.

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Bibliographic Data

Sources: Google Patents (https://patents.google.com/patent/[US4570602A](/patent/US4570602A)/en), FreePatentsOnline class listing (https://www.freepatentsonline.com/CCL-123-456-p19.html), OSTI (https://www.osti.gov/biblio/[5902094](/patent/5902094)), EPO/ESPACENET family record for EP 0102164.

Uncertainty flag: The "current assignee" field on Google Patents is an automated post‑grant reassignment listing ("Motors Liquidation Co." is the remnant of the General Motors bankruptcy estate). I could not independently confirm via USPTO PatentCenter/Assignment records in this session, so treat the current‑ownership line as unverified; the original, well‑documented assignee is General Motors Corporation. Given the 2003 expiration, ownership is largely academic.

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Abstract (as printed)

A compact central fuel rail supports injectors which deliver fuel to both banks of a V-engine. The fuel rail is extruded with both fuel supply and fuel return passages, a single circular plug provides a closure for the associated ends of the passages, and a plug in the return passage limits interconnection of the passages.

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Plain-Language Overview of the Independent Claims

Claim 1 — The V-engine fuel rail assembly.
This is the broad system claim. In plain terms, it covers a single, compact fuel rail that sits above and between the two cylinder banks of a V-engine and feeds injectors for both banks:

• An elongated body with (a) multiple axially spaced injector sockets and (b) two axially running fuel passages that are interconnected, with one passage intersecting the sockets to feed them.
• At at least one end of the body, a circular recess that intersects and encompasses the ends of both fuel passages.
• One of the fuel passages is circular in cross‑section, and a circular plug is inserted into it next to the recess to limit leakage/flow between the two passages through that recess.
• A second circular plug seals the recess itself, closing off both passage ends with one closure.
• Key orientation limitation: some sockets are canted leftwardly and downwardly toward one injector‑opening line, and the rest are canted rightwardly and downwardly toward the other line — allowing one center rail to serve both banks.
• Each socket holds an injector, each injector is held by a clip to the rail and has a tip received in the engine opening.
• Finally, the rail is bolted to the engine so the fasteners exert only a downward force on the body — the downward clamping alone retains the canted injectors between rail and engine (no separate injector hold‑down fasteners).

Claim 2 — The generic fuel rail (not limited to a V-engine).
This is a broader, more structural claim with no V‑engine or canting requirement:

• An elongated body with multiple axially spaced, transversely extending injector sockets, and two transversely spaced, axially extending fuel passages that are interconnected, one intersecting the sockets to supply them.
• Each socket is adapted to receive an injector delivering fuel to the engine.
• At at least one end: a circular recess intersecting and encompassing the ends of both passages; one passage is circular in cross‑section; a circular plug in that passage adjacent the recess limits interconnection of the passages through the recess; and a circular plug seals the recess, closing both passage ends.

Claim 1 vs. Claim 2 — practical difference: Claim 2 is the "fallback" structural claim focused on the extruded dual‑passage body plus the two‑plug end‑closure scheme (isolation plug + recess sealing plug) and the socket/passage arrangement, without the V‑engine canting, clip, tip, or downward‑only mounting limitations of Claim 1.

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Additional Context from the Specification

• Preferred embodiment: a V‑6 engine intake manifold (10) with six ram tubes (12) and two plenums (14); fuel rail body (22) extruded with a supply passage (24) and a return passage (26); six machined injector sockets (28) fed from the lower portion of the supply passage; O‑rings (30, 38) seal injector‑to‑rail and injector‑to‑manifold joints; clips (32) in slots (34) retain injectors.
• Vapor‑handling design point: the supply passage's vertical dimension substantially exceeds its horizontal dimension, so entrained vapor collects in the upper part while the sockets draw only liquid fuel from the lower part.
• Compactness geometry: the supply passage is irregular — one side outwardly convex following the outline of the end recesses, the other side outwardly concave and embracing the circular return passage — which permits the smallest possible end recess. This is the stated rationale for the specific passage/recess geometry recited in both claims.
• Related co‑pending applications identified in the spec (same Aug. 23, 1982 filing date): Ser. No. 410,651 (pressure regulator — Atkins & Field), Ser. No. 410,612 (Atkins, Field, Lamirande), and Ser. No. 410,611 (L. J. Weinand).
• Prior art cited on the face: US 2,706,620; US 3,026,928; US 3,789,819 (GM, "Fuel rail vapor bleed"); US 4,284,215 (Bosch); US 4,286,563 (Bendix, "Fuel rail for an engine"); US 4,307,693 (Bosch); GB 2,073,316 (Bosch).
• Forward citations: heavily cited by later fuel‑rail art, including US 4,805,575 (Weber), US 4,825,754 (Aisin), US 4,899,221 (GM), US 5,027,777 (De Bruyn), US 4,984,548 (Sharon Mfg.), and Robert Bosch high‑pressure/common‑rail documents (e.g., US 6,644,279; US 10,648,439). It was also cited as prior art in WO 91/02896 (Siemens).

Bottom line: US 4,570,602 is an expired 1986 GM patent (filed 1982) to Atkins, Field, and Lamirande covering a compact extruded fuel rail for V‑engines, featuring canted opposed injector sockets, a two‑plug end‑closure scheme (isolation plug in the circular return passage plus a sealing plug in the end recess), and downward‑only bolted mounting that also retains the injectors. No litigation or 2026 CAFC activity tied to this patent number was found in my searches.

I'll run targeted searches across litigation-focused sources for this specific patent number.

Let me run a few more targeted searches against litigation databases and PTAB records.

Litigation Search: U.S. Patent No. 4,570,602

Bottom line: I found no known litigation involving U.S. Patent No. 4,570,602. I searched for the literal identifier across litigation-aggregation and court sources and returned no district court case, no Court of Federal Claims case, no CAFC appeal, no ITC Section 337 investigation, and no PTAB proceeding in which the '602 patent was asserted or challenged as a patent-in-suit.

Search coverage and results

Cases that are not about this patent (do not attribute)

I want to flag these explicitly, because each came back from a search on the '602 string but involves a different patent number — attributing any of them to US 4,570,602 would be an error:

• TMC Fuel Injection System, LLC v. Ford Motor Co., E.D. Pa. Civil Action No. 2:12‑cv‑04971‑NS. This is a fuel-injection case, which is why it surfaced, but the asserted patent is U.S. Patent No. 7,318,414 ("the '414 patent"), claims 38 and 40. The '602 patent is not at issue.
• TI Group Automotive Systems (North America), Inc. v. VDO North America L.L.C., D. Del. C.A. No. 00‑432‑GMS. Fuel pump assemblies; patent-in-suit is U.S. Patent No. 4,860,714. No '602 involvement.
• Westport/Volkswagen-Mercedes-Benz high-pressure gaseous fuel injector matters (N.D. Ga. and related). Patents-in-suit are the Westport '829/'138 families. No '602 involvement.

Non-patent collisions on the same literal string (illustrating why literal interpretation matters)

Searches for "4570602" also returned the following, none of which is this patent: an Argentine trademark/regulatory act number 4570602 (INPI boletín, Class 11, applicant CHEN, FAN); Florida corporate FEI Number 36‑4570602 (Biz Lending & Insurance Center, Inc.); a NATO Stock Number NSN 5977‑00‑457‑0602 (electrical contact brush holder, part nos. SAW‑4570602 / 57622); and U.S. Patent No. 6,898,460 (an unrelated EMG monitoring patent) that merely contains the digits as a sequence.

The one genuine "patent-office" appearance of the '602 patent

The '602 patent does appear in an opposition/search-report context — but as prior art against someone else's application, not as a litigated patent:

• WO 91/02896 A1 (Siemens Aktiengesellschaft), international search report, cites "US, A, 4570602 (ATKINS ET AL), 18 February 1986 — see the whole document," listed as relevant to claims 1, 5, and 9 of that Siemens application. This is a prosecution citation, not litigation. (Source: https://patentimages.storage.googleapis.com/ae/d7/e7/6c4aa3572a8781/WO1991002896A1.pdf)
• Consistent with that, the '602 patent's own forward-citation record ("Cited By") lists roughly 50–60 later fuel-rail and common-rail documents (e.g., US 4,805,575 Weber; US 4,825,754 Aisin; US 4,899,221 GM; US 5,027,777 De Bruyn; US 4,984,548 Sharon Mfg.; Bosch documents) — that is citation activity in prosecution, not litigation.

Legal/contextual notes on why this is unsurprising

1. The patent is long expired. Filing 1982‑08‑23; grant 1986‑02‑18; statutory term ended 2003‑02‑18 (17 years from issue, pre‑URAA, with all three maintenance fees paid per the Legal Events: 4‑year/1990, 8‑year/1993, 12‑year/1997). Any infringement suit would necessarily have been filed while it was in force, and any post-expiration suit could only reach past damages within the 35 U.S.C. § 286 six-year lookback — i.e., conduct no earlier than roughly mid‑1997.
2. The patentee was General Motors, an operating company, not a litigious licensor. There is no publicly reported GM assertion campaign on this patent in my searches.
3. Current-ownership listing is unverified. Google Patents lists "Motors Liquidation Co." as current assignee; I could not confirm that through USPTO Assignment/PatentCenter in this session. Given the 2003 expiration, ownership has no practical litigation significance. (This is consistent with the earlier section of this analysis — no contradiction.)

Confidence and caveats

• High confidence that no widely reported or database-indexed U.S. litigation exists on US 4,570,602.
• Caveat: I cannot prove a universal negative. Pre‑2000s district court dockets are less fully digitized, and a state-court or foreign action (e.g., German, Japanese, Australian, Mexican counterpart claims under EP 0102164 / DE 3371805 / AU 565695 / JPS5970873 / MX 7492 E) would not appear in U.S. litigation aggregators. I found no evidence of any such action either.
• No CAFC or 2026 activity tied to this patent number was found; if one is looking for current Federal Circuit docket relevance, this patent is not a candidate.

Conclusion: There is no known litigation — plaintiff, defendant, jurisdiction, case number, filing date, or outcome — involving US Patent No. 4,570,602.

I'll verify the structured ODP result against public PTAB/CAFC sources before reporting.

Let me run a couple of final checks for any reexamination or PTAB docket entries I might have missed.

Proceedings overview

There are zero AIA trial proceedings on file against U.S. Patent No. 4,570,602 — no IPR, no PGR, no CBM, ever. The structured "PTAB proceedings on file" block (USPTO Open Data Portal) returns an empty set, and my independent web cross-check surfaced no petition, institution decision, Final Written Decision, or Federal Circuit appeal naming this patent. The bottom-line defensive posture is stronger than "hardened": the patent is not merely un-IPR'd, it expired on 2003-02-18, more than nine years before the first IPR was even filed at the Board (2012-09-16), so there is no claims-invalidated / claims-sustained breakdown to report at all — the entire claim set (claims 1 and 2) is UNTESTED and now unreachable, and no § 315(e)(2) estoppel or FWD disposition exists for a defendant to leverage.

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Per-proceeding detail

None exists. I am not going to populate the proceeding template with empty or inferred fields, because there is no proceeding number, no petitioner, no panel, no grounds, no FWD, and no appeal to report. Fabricating any of those would be exactly the error this analysis is meant to avoid.

What I checked, and the false positives I discarded

Verification that the empty structured result is correct (and not an ODP indexing gap):

Discarded false positives (same number string, unrelated subject matter — do not rely on these):

• Argentine trademark act No. 4570602, INPI Boletín 10909 (https://portaltramites.inpi.gob.ar/Uploads/Boletines/10909_3_.pdf) — an Argentine water-heater goods filing, not a US patent.
• RKF 4570602, a Komondor dog registration in an FCI/RKF show catalog (http://rkf.org.ru/upload/documents/CACIB/results/07_04_2018_spb.pdf) — breed registry entry.
• "the '457 patent" in Redwood Technologies v. Netgear, D. Del. No. 1:22-cv-01271 (https://cases.justia.com/federal/district-courts/delaware/dedce/1:2022cv01271/80168/30/0.pdf) and "the '457 patent" in Microsoft v. D3D Technologies, IPR2021-01325 — these are U.S. Patent No. 10,795,457 and other modern '457-series patents. Numerically unrelated.
• WO 91/02896 (Siemens), whose search report cites US 4,570,602 (Atkins et al.), 18 February 1986, see the whole document, relevant to claims 1, 5, 9 (https://patentimages.storage.googleapis.com/ae/d7/e7/6c4aa3572a8781/WO1991002896A1.pdf). This is a third-party forward citation — i.e., 4570602 used as prior art against someone else's application. It is not a validity challenge to 4570602 and created no PTAB proceeding.

Why no AIA trial exists — three structural reasons

1. Timing. The patent's statutory term ended 2003-02-18 (20 years from the 1982-08-23 filing, with no listed extension or terminal disclaimer; maintenance fees were paid at years 4, 8, and 12 per the legal-events record, so no lapse-by-nonpayment — it simply ran its full term). The first IPR under the AIA was filed 2012-09-16. There is a ~9.5-year gap in which no IPR was legally possible against this patent.
2. PGR is categorically unavailable. Post-Grant Review under 35 U.S.C. § 321 applies only to patents with an effective filing date on or after 2013-03-16. This is a pre-AIA patent with a 1982-08-23 priority date. PGR could never have been filed.
3. CBM is categorically ineligible. Covered Business Method review under AIA § 18 was limited to patents claiming a "financial product or service," and expressly excluded "technological inventions." A fuel rail for a V-6 engine is a mechanical/technological invention. CBM could never have been filed either (and the program sunset 2020-09-16 in any event).

The only AIA-era vehicle theoretically available would have been IPR, since § 311 permits an IPR petition on an expired patent. But by the time IPRs existed, this patent had been expired for nearly a decade and could not support a live infringement claim — so there was no economic motive for any petitioner to file. The absence of PTAB activity here is not a "hardened patent" signal; it is a "dead patent" signal. I want to be explicit: for most patents, an empty PTAB history is worth flagging as a possible lag indicator. Here it is fully explained by the 2003 expiration, and I found no evidence of any recently-filed petition that ODP simply has not ingested.

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Strategic summary

Claim status. Claim 1 and Claim 2 of US 4,570,602 are both UNTESTED — never challenged in an AIA trial, and never amended or canceled by reissue or reexamination that I could find. That is not good news for a patent owner, because the reason they are untested is that the patent is expired. All claims are also, to the best of my verification, unenforceable for going-forward conduct: the term ended 2003-02-18. For past conduct, the damages window under 35 U.S.C. § 286 (six-year lookback from the date of suit) permanently closed at the latest on 2009-02-18, six years after expiration — so no defendant can be liable for any act of infringement today. (Flag: this is a legal conclusion about expiration and § 286, offered at senior-practitioner confidence but not a substitute for a formal validity/term analysis; I did find no maintenance-fee lapse that would have shortened the term earlier.)

Estoppel landscape. Because no IPR/PGR/CBM was ever instituted, there is no § 315(e)(2) estoppel running against anyone on this patent. There is also no petitioner-privity chain to trace, no defensive aggregator (Unified Patents, RPX, etc.) in the record, and no IPR-based invalidity theory that has been spent. Practically this is moot, but a defendant who wanted to run an IPR-for-its-own-sake would face no estoppel bar from prior petitioners — only the lack of any reason to file.

Pattern signals. No pattern exists to read: no multi-petition petitioner, no patent-owner PTAB appeal history, no aggregator involvement, no FWD record. The only "activity" in the file is routine: the 1982-08-23 assignment from Atkins, Field, and Lamirande to General Motors Corporation (Reel 004038/0430), the 1986-02-18 issuance, and maintenance-fee payments through year 12. Forward-citation volume (51+ citing documents, per Google Patents, including Weber, Aisin, Siemens, and Bosch fuel-rail/common-rail families) shows the patent was technologically influential as prior art — not that it was commercially asserted.

Cross-reference note / contradiction check. The previously-generated summary section flagged the Google Patents "current assignee = Motors Liquidation Co." line as unverified, and correctly noted the 2003 expiration makes ownership academic. Nothing in this PTAB analysis contradicts that; if anything, the absence of any post-1986 assignment, license, or litigation record in the file reinforces that the patent was never a working assertion asset after GM's normal product life cycle for the referenced V-6 application.

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Recommended next steps

If you have received a demand letter citing US 4,570,602:

1. Do not spend money on an IPR. There is nothing to invalidate — the patent expired 2003-02-18 and cannot support a live infringement claim or a recoverable damages case. An IPR petition on an expired patent is possible under § 311 but is a waste of fees here.
2. Lead with expiration, not invalidity. The fastest dispositive response is the term: 20 years from the 1982-08-23 filing date, per the Google Patents legal-status record showing "Anticipated expiration 2003-02-18" and "Expired – Lifetime." A pre-suit letter asserting this patent against current products is, at minimum, frivolous.
3. Confirm the file wraps before responding. Because ODP and Google Patents both show a clean, unchallenged prosecution-to-expiration history, the remaining diligence items are: (a) pull the complete file wrapper from USPTO PatentCenter to confirm no certificate of correction, reissue, or reexamination certificate modified claim scope or term; (b) confirm with the assignee-of-record chain whether any continuation or divisional issued from the Aug. 23, 1982 family (note the specification names three co-pending applications, Ser. Nos. 410,651 / 410,612 / 410,611, and related patents such as US 4,539,961 and US 4,586,477 appear in the "Similar Documents" list — check whether any related patent is still unexpired, since an assertion may have mis-cited the number). Verify the number cited in the demand is actually 4,570,602 and not a related family member.
4. If a live related patent is identified, the estoppel picture changes completely: a fresh, un-IPR'd related patent would have its own § 315(b) one-year clock running from service of the complaint, and you would want an FTO/validity study for that number specifically.

If you are evaluating this patent for a defensive-aggregator or prior-art purpose: its value is purely as § 102/§ 103 prior art with an effective date of 1982-08-23 (and an issue date of 1986-02-18 for § 102(b) purposes). The WO 91/02896 search report already demonstrates that later examiners treated it as citable prior art against later fuel-rail claims. That is the only live use of this document today — and there is no PTAB proceeding standing between you and using it that way.

Plain statement for the file: No AIA trial proceeding has ever been filed on U.S. Patent No. 4,570,602. No PTAB Final Written Decision exists. No Federal Circuit appeal of any PTAB decision on this patent exists. The patent expired 2003-02-18. Any demand letter asserting it is premised on a dead patent.

Ownership-chain reconstruction — US 4,570,602 (Fuel rail)

Scope of record retrieved. The only ownership record surfaced for this patent is the original inventor→assignee assignment. No post‑issuance assignment, security agreement, license, release, merger, or change‑of‑name document appears against US 4,570,602 in the record I could retrieve (Google Patents legal‑events table, which mirrors the USPTO Assignment Search data, lists exactly one AS/Assignment event, followed only by grant and maintenance‑fee events). I could not open the Assignment Center record directly in this session, so I am reporting the fields that the retrieved legal‑events extract exposes (reel/frame, assignors, assignee, dates) and explicitly flagging the fields it does not expose (correspondent).

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Inventors

Evidence, not inference, for the employer: all three inventors are the assignors on the recorded assignment to General Motors Corporation (reel 004038/0430, executed 1982‑08‑10, recorded 1982‑08‑23), and all three residences are in Monroe County, NY — the location of GM's Rochester Products Division, which was GM's fuel‑system/emissions components plant. The assignment itself is direct evidence they conveyed to GM; the employment relationship is a strong but technically inferential reading of that plus the co‑located residences. I found no evidence of any inventor departing GM.

Unusual patterns — none found.

• The inventors did not scatter to different assignees; this is an ordinary corporate employee‑invention assignment, executed 13 days before the 1982‑08‑23 filing.
• Atkins and Field are also named in the specification as inventors of the pressure‑regulator features claimed in copending Ser. No. 410,651, and Atkins/Field/Lamirande are named in Ser. No. 410,612 — i.e., a stable in‑house GM fuel‑rail team filing a same‑day cluster (Aug. 23, 1982), not a group of inventors assembled for a sale. That pattern is the opposite of a pre‑fire‑sale signature.
• No evidence was found of inventors leaving within 12 months of filing. Not verified by any personnel data — I could not search employment records, LinkedIn histories, or SEC disclosures for these three individuals; treat "no departures found" as absence of evidence.

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Original assignee

Entity on the issued patent: General Motors Corporation, a Delaware corporation, Detroit, Michigan (per the printed patent and reel 004038/0430). Corroborated by DOE/OSTI record 5902094, which lists the assignee as "General Motors Corp., Detroit, MI."

• Primary line of business: automotive OEM. The patent sits in GM's 1980s port‑fuel‑injection build‑out (the specification's V‑6, central‑rail, both‑banks architecture is a production intake‑manifold/fuel‑rail design; GM's Rochester Products Division supplied exactly this class of hardware).
• Did GM ship a product embodying the claims? Almost certainly yes, but I could not verify a specific vehicle application in this session. The specification describes a concrete production configuration (V‑6 manifold 10, six ram tubes 12, two plenums 14, extruded rail with supply/return passages, six clipped injectors, two mounting bolts) rather than a paper embodiment, and GM filed a same‑day family of related applications (Ser. Nos. 410,611 / 410,612 / 410,651) — the footprint of an internal product program. I am flagging this as high‑confidence inference, not documented fact; no product literature, service bulletin, or 10‑K reference tying this rail to a named engine was retrieved.
• Current status: the original assignee entity has a complicated corporate history. General Motors Corporation changed its name to Motors Liquidation Company effective 2009‑07‑09/10 (Certificate of Amendment; corroborated by the Trademark Trial and Appeal Board record ESTTA300554 and by GM's own Form 8‑K describing the §363 sale). It filed Chapter 11 on 2009‑06‑01 (Bankr. S.D.N.Y. No. 09‑50026) and dissolved on 2011‑12‑15 (Delaware Certificate of Dissolution; confirmed by King & Spalding letter filed in the bankruptcy docket). Substantially all GM IP was sold to General Motors Company (formerly NGMCO, Inc.) by the Omnibus Intellectual Property Assignment Agreement dated 2009‑07‑10, whose Section 1 conveys "all … Patents set forth on Exhibit A."
• Critical timing point: US 4,570,602's anticipated expiration is 2003‑02‑18 (17 years from the 1986‑02‑18 issue date, per the record's own legal‑status line). The patent therefore expired roughly six years before the GM bankruptcy and the 363 sale. Any later corporate transfer of the GM patent portfolio could not have carried enforceable rights in this patent (remedies for past infringement survive assignment in principle, but there is no evidence any were asserted).

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Assignment timeline

Recorded chain, complete as retrieved:

• 1982‑08‑10 (executed) / recorded 1982‑08‑23 — Reel 004038 / Frame 0430
  • Conveyance: Assignment of assignors' interest (original application assignment)
  • Assignor: Terrance J. Atkins; Martin J. Field; Donald J. Lamirande (individually, jointly recorded as "ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignee: General Motors Corporation, a corporation of Delaware, Detroit, MI
  • Correspondent: Not exposed in the retrieved record. The legal‑events extract for this reel/frame does not include a correspondent/attorney field. This is a 1982‑era paper recording (microfilmed reel 004038), predating the modern electronic correspondent data; I will not guess a name or firm. Flag: because the correspondent field is unavailable, I cannot run the "repeat correspondent" test below — that is a gap, not a clean negative.
  • Context: Employee‑invention assignment to the operating company on filing. Ordinary corporate ownership; nothing transactional about it. Effective date field reads 19820810 (i.e., executed ~13 days before the application's 1982‑08‑23 filing date), with recordation five days after filing.

No further assignments are recorded. The remaining legal events in the chain are administrative only:

Plain statement of the finding: the Assignment Center record for US 4,570,602 contains one assignment and nothing after it. There is no recorded transfer to Motors Liquidation Company, to General Motors Company, to the MLC GUC Trust, or to any NPE. No recorded conveyance of title away from General Motors Corporation/Motors Liquidation Company exists on this patent's face.

Consistency check with the prior section. The earlier summary flagged Google Patents' "Current Assignee: Motors Liquidation Co." as unverified. My reconstruction is consistent with that flag and resolves it: since the legal‑events table shows no post‑1982 assignment, "Motors Liquidation Co." is best explained as an automated corporate‑name mapping of General Motors Corporation (the 2009 name change), not a patent‑level assignment record. Treat the current‑owner line on Google Patents for this patent as a name artifact of the GM bankruptcy name change, not as evidence of a conveyance.

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Timeline diagram

timeline
    title Ownership of US 4570602
    1982 : Filed 23 Aug 1982
         : Assigned to General Motors Corp
         : Reel 004038 Frame 0430
    1986 : Patent issued 18 Feb 1986
    2003 : Anticipated expiration 18 Feb 2003
    2009 : GM renamed Motors Liquidation Company
         : No patent level assignment recorded
    2011 : Motors Liquidation Company dissolved

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The only assignment of record is reel 004038/0430 (rec. 1982‑08‑23), General Motors Corporation, an operating automotive OEM, as assignee. There is no transfer to any entity with an "IP / Patents / Licensing / Holdings / Ventures" suffix, no Delaware/Texas single‑purpose LLC, and no registered‑agent address anywhere in the record. The Google Patents "Motors Liquidation Co." label is a name‑change artifact of the same operating company, not a shell.

2. Known asserter in the chain — NOT PRESENT. No assignee in the recorded chain appears on any of the listed NPE rosters (Acacia, Marathon, Intellectual Ventures, IPNav, Wi‑LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, Spangenberg entities). I also found no RPX or Unified Patents listing tying US 4,570,602 to an assertion campaign. The patent does surface in later art as prior art cited against others — notably in WO 91/02896 (Siemens), where it is cited as anticipating claim‑relevant subject matter "see the whole document," and in the file histories/backgrounds of later fuel‑rail patents (e.g., US 5,146,896, US 6,474,305) — which is a defensive citation pattern, the opposite of an assertion pattern.

3. Repeat correspondent across the chain — UNCLEAR (data gap). There is only one recorded link, and the retrieved legal‑events extract does not expose a correspondent for reel 004038/0430. With n=1 and a missing field, the "same lawyer runs every shell LLC" test is untestable here. Explicitly: this is not a negative finding, it is a missing input. Anyone running the final check should pull the paper cover sheet for reel 004038/0430 (1982 era) to populate this field.

4. Cascading transfers — NOT PRESENT. No consecutive assignments of any kind, let alone multiple LLC hops inside 24 months. The chain has a 41‑year span with a single event (1982) followed by fee payments.

5. Pre-litigation transfer — NOT PRESENT. There is no infringement suit naming US 4,570,602 that I could locate, so the trigger condition (assignment within 6 months before first suit) never arises. Independently, the last possible assignment window would have closed with the 2003‑02‑18 expiry; a pre‑litigation transfer of an expired patent would be commercially pointless.

6. Bankruptcy fire‑sale — PARTIALLY PRESENT AS CORPORATE HISTORY; NOT ESTABLISHED AT THE PATENT LEVEL. The original assignee is squarely inside a landmark bankruptcy: General Motors Corporation → renamed Motors Liquidation Company (2009‑07‑09/10) → Chapter 11 filed 2009‑06‑01 → substantially all IP sold to General Motors Company under the Omnibus IP Assignment Agreement dated 2009‑07‑10 (§363 sale; Exhibit A "Patents"). So the corporate condition exists. Three points keep this from being a fire‑sale signal for this patent: (a) no assignment is recorded against this patent, so it is not shown to be in the sold Exhibit A set; (b) the patent expired 2003‑02‑18, six years before the bankruptcy, so it had zero remaining term to sell or assert; (c) the buyer was an operating company (New GM), not an aggregator or NPE — the bankruptcy‑sale route that feeds NPE supply chains (Kodak, Nortel, Polaroid) is not what happened to the counterparty here.

7. Privateering — NOT PRESENT. No evidence GM (or Motors Liquidation) conveyed this patent to an NPE to assert on GM's behalf. No SEC filing, no Patent Progress/EFF coverage, no litigation connecting this patent number to any assertion. The 363 sale ran to an operating company, not from an operating company to an asserter.

8. Defensive aggregator (anti‑NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at the original assignee and its bankruptcy‑era name, with no recorded conveyance at all; the patent simply expired.

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Verdict

Insufficient data — only the original assignment is of record.

Justification (2–3 sentences): The entire recorded ownership history of US 4,570,602 is a single instrument — executed 1982‑08‑10 and recorded 1982‑08‑23 at reel 004038/0430, conveying Atkins, Field, and Lamirande's interest to General Motors Corporation — with nothing but grant and maintenance‑fee events thereafter and anticipated expiry on 2003‑02‑18. Because no post‑issuance assignment (and therefore no correspondent entry to test for recurrence) exists, the NPE‑pattern tests cannot be run to a conclusion; the chain ends at the original operating‑company assignee. The frequently repeated "Motors Liquidation Co." ownership line is explained by the 2009‑07‑09 GM name change (and the 2009‑07‑10 Omnibus IP Assignment to General Motors Company), not by any assignment recorded against this patent — and in any event the patent had been expired for six years by then, which is the single most decisive fact here.

Verification link: USPTO Assignment Center, https://assignmentcenter.uspto.gov/ (legacy interface: https://assignment.uspto.gov/patent/index.html) — search by patent number 4570602; the returned record should show reel/frame 004038/0430 and no subsequent assignment entries. Pull the 1982 paper cover sheet to populate the missing correspondent field if signal 3 must be closed out.

I'll verify the patent record and pull detail on each cited prior-art reference.

Let me pull the remaining four cited references.

Prior-Art Analysis — U.S. Patent No. 4,570,602 ("Fuel rail")

1. Verification of the number and scope note

Literal identifier searched: 4570602 (and US4570602, US4570602A). Per the strict rule, I did not auto-correct or substitute similar numbers.

Result: The identifier resolves to U.S. Patent No. 4,570,602 A, "Fuel rail," General Motors Corporation, inventors Terrance J. Atkins, Martin J. Field, Donald J. Lamirande; application 06/410,641; filed/priority 1982‑08‑23; granted 1986‑02‑18; expired – lifetime (anticipated expiration 2003‑02‑18). This matches the authoritative full text supplied in the record (https://patents.google.com/patent/[US4570602A](/patent/US4570602A)/en).

Data-quality flag (do not treat as a correction of our number): One search hit returned a Google Patents "Info" block for US 6,898,460 B2 (uterine-contraction EMG monitoring — unrelated field) that internally lists US4570602A among its identifiers. That appears to be an indexing/merge artifact, not a real relationship. I flag it because the task requires literal interpretation and because the same identifier string surfaced in an unrelated record. It does not change the identity of US 4,570,602, which is fixed by the authoritative full text.

Contradiction flagged in the prior summary: The earlier "prior art cited on the face" bullet wrote one reference as "US 4,284,215 (Bosch)." The authoritative full text's citation table lists US 4,294,215 A (Robert Bosch GmbH, "Fuel injection system," 1979‑03‑02 → 1981‑10‑13). I use US 4,294,215 A below and treat "4,284,215" as a transcription slip in the earlier section.

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2. Legal framework for the § 102 analysis

This application was filed 1982‑08‑23, so it is governed by pre‑AIA 35 U.S.C. § 102. The relevant subsections:

• § 102(a) — invention "known or used by others … or patented or described in a printed publication" before the applicant's invention.
• § 102(b) — patented or described in a printed publication more than one year before the U.S. filing date, i.e., before 1981‑08‑23. (Two of the references fall in this critical-date window only if their publication is before that date.)
• § 102(e) — U.S. patent "granted on an application for patent by another filed … before the invention thereof by the applicant."

Practical observation: Every one of the seven references cited on the face of US 4,570,602 has a publication or issue date before 1981‑08‑23 and therefore qualifies as prior art under § 102(a); several also qualify under § 102(b). However — and this is the central analytical point — none of the seven discloses the combination of elements required by independent claim 1 or independent claim 2, so none is a true § 102 anticipation. They are § 103/background references. I substantiate that reference‑by‑reference below rather than force a § 102 mapping.

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3. The seven references cited on the face of US 4,570,602

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4. Reference-by-reference assessment

4.1 US 2,706,620 A — "Heat exchanger" (Graves Stambaugh Corp.; inventor Roy R. Graves)

• Filing: 1951‑04‑28. Issue: 1955‑04‑19.
• Description: A tubular heat exchanger having a cylindrical casing (concentric sleeve members) and a removably received cylindrical core. The core's outer surface carries a spiral/helical groove that, with the casing, forms a spiral product-flow passage; heads/rings and a tapered joint provide sealed, enclosed heat-exchange chambers and a packed end closure. (Sources: https://patents.google.com/patent/[US2706620A](/patent/US2706620A)/en; https://FreePatentsOnline.com/[2706620](/patent/2706620).html.)
• § 102 relevance: Non-analogous art; anticipates neither claim 1 nor claim 2. It discloses no fuel rail, no injector sockets, no dual interconnected fuel passages, and no circular end recess with isolation/closure plugs. At most it is generic evidence of a sealed end chamber/plug concept — insufficient for any single-reference anticipation of the claimed subject matter. Its presence on the face likely reflects a formal "plug/sealed end" or "extruded/concentric body" search hit.

4.2 US 3,026,928 A — "Fuel delivery system" (Telecomputing Corp.)

• Filing: 1957‑08‑16. Issue: 1962‑03‑27.
• Description: An early internal-combustion-engine fuel delivery/distribution system (per the record's citation table). I was unable to retrieve the printed specification in this session, so I do not state its disclosure with high confidence beyond title, assignee and dates. If deeper treatment is required, the specification should be pulled directly.
• § 102 relevance: On the record available, no basis to find anticipation of either claim. It predates the claimed rail architecture by decades and would not disclose the claimed two-passage extruded body with the recess/plug end-closure, canting, or downward-only mounting.

4.3 US 3,789,819 A — "Fuel rail vapor bleed" (General Motors Corp.; inventor Moulds)

• Filing: 1972‑01‑28. Issue: 1974‑02‑05.
• Description (verified in full text): A fuel-injection system in which an injection pump feeds a fuel rail (and, through a crossover line, a second rail) disposed along opposite sides of the engine; a plurality of injectors deliver fuel from the rails at spaced locations. A vacuum-operated valve at the end of the rail opens only during closed-throttle operation to permit fuel vapor to bleed from the end of the pressurized rail back to the tank; otherwise a spring holds the valve closed, preventing recirculation and pressure dissipation. (Sources: https://patents.google.com/patent/[US3789819A](/patent/US3789819A)/en; http://patentimages.storage.googleapis.com/de/7c/29/97e905d4eb2215/US3789819.pdf; https://FreePatentsOnline.com/[3789819](/patent/3789819).html.)
• § 102 relevance:
  • It discloses a fuel rail feeding plural injectors at spaced locations, which reads on parts of the preamble of claim 1 and on the "injector sockets adapted to receive an injector" concept of claim 2.
  • It does not disclose: a pair of interconnected axially extending fuel passages in a single elongated body; a circular recess at the body end encompassing the ends of both passages; one passage circular in cross-section with a circular plug limiting passage-to-passage flow through the recess; a second circular plug sealing the recess; V‑engine canted opposed sockets; an injector clip; or downward-only rail mounting that also retains the injectors.
  • Conclusion: no anticipation of claim 1 or claim 2. Relevant as § 103 background for the vapor-handling/return concept (which this patent addresses via the vertically elongated supply passage and return passage).

4.4 US 4,286,563 A — "Fuel rail for an engine" (The Bendix Corporation; inventors Magdi M. Fahim, Victor J. Nowak, Nagui R. Matta)

• Filing: 1979‑03‑19 (app. 06/021663). Issue: 1981‑09‑01.
• Description (verified): "A fuel rail of unitary construction for supplying fuel to a plurality of fuel injectors in an engine such as a V‑8 engine. The fuel rail contains a plurality of connectors, one for each injector. Each connector is fitted with an O‑ring to provide a liquid-tight seal between the connector and each injector. The connector and O‑ring are so sized to permit the connector to swivelably engage each injector permitting the injector to rotate in a conical fashion about an axis through the center of the connector." (Source: inventor/assignee record, https://radaris.com/f/Magdi/Fahim/Inventor; also listed on the face of DE 3,315,818 A1 as US4286563A.)
• § 102 relevance:
  • This is the closest single "fuel rail" reference. It discloses a unitary V‑engine fuel rail with an injector connector/socket for each injector, each sealed by an O‑ring — i.e., the general rail-plus-sockets-plus-seal architecture that appears in the preamble of claim 1 and in claim 2's "sockets … adapted to receive a fuel injector."
  • It does not disclose the claimed two interconnected axially extending passages with the circular end recess and the two-plug closure (isolation plug in the circular passage + recess-sealing plug), the opposed downward canting of the sockets, the clip, or the downward-only mounting.
  • Conclusion: no § 102 anticipation of claim 1 or claim 2; strong § 103 candidate when combined with a dual-passage end-plug reference.
  • Similar-number caution: A later Bendix/Siemens patent (US 5,056,489) refers descriptively to a V‑type fuel rail patent as "U.S. Pat. No. 4,286,531." The number at issue here is literally 4,286,563. I do not reconcile or "correct" these; I simply note the near-identical numbers exist in the same assignee's family lineage and should be treated literally.

4.5 US 4,294,215 A — "Fuel injection system" (Robert Bosch GmbH)

• Filing: 1979‑03‑02. Issue: 1981‑10‑13.
• Description: A Bosch fuel-injection system (per the record's citation table). I did not retrieve or read the printed specification in this session, so I do not assert its specific disclosure.
• § 102 relevance: On the record available, no basis to find anticipation of either claim. Bosch '215 is directed to fuel-injection system arrangements generally; there is no showing of the claimed dual-passage extruded body with a recess-encompassing end closure and the two-plug scheme. Treat as background/§ 103 art only.
• Note: As flagged in § 1, the earlier summary rendered this as "US 4,284,215"; the authoritative number is US 4,294,215 A.

4.6 GB 2,073,316 A — "Fuel injection installation for preventing vapour lock" (Bosch / Robert Bosch GmbH)

• Filing/priority (per record): 1980‑03‑20. Publication: 1981‑10‑14.
• Description: A fuel-injection installation addressed to preventing vapour lock — i.e., ensuring the fuel delivered to the injectors does not entrain/retain vapor, typically by fuel circulation/return through the distribution line. (Per the record's citation table.)
• § 102 relevance: No anticipation of claim 1 or claim 2. The reference is directed to the vapour-lock/recirculation problem, not to a two-passage extruded rail with a circular end recess closed by a single plug plus a passage-isolation plug, nor to canted opposed injector sockets or downward-only mounting. Relevant § 103 art as to the shared objective (avoiding vapor at the injectors), which this patent achieves structurally via a supply passage whose vertical dimension substantially exceeds its horizontal dimension.

4.7 US 4,307,693 A — "Fuel injection installation" (Robert Bosch GmbH; inventors Otto Glockler, Ulrich Steinbrenner)

• Filing: US app. 06/214,302 filed 1980‑12‑08; continuation of Ser. No. 62,597, filed 1979‑07‑31; priority 1979‑06‑30 (per Google Patents). Issue: 1981‑12‑29. (Source dates differ slightly between the record's citation table and FreePatentsOnline: table shows priority 1979‑06‑30 / issue 1981‑12‑29; FPO shows US filing 12/08/1980 as a continuation of 62,597 filed 1979‑07‑31. Both are pre‑critical-date, so the § 102(a) status is unaffected.) (Sources: https://patents.google.com/patent/[US4307693A](/patent/US4307693A)/...; https://FreePatentsOnline.com/[4307693](/patent/4307693).html.)
• Description (verified in full text): Injection valves are mounted, at one end, to a fuel distributing line (rail) via insertion nipples and, at the other end, into intake-manifold/cylinder-head openings. A connecting stud carries an O‑ring in an annular groove that seals in a counterbore of the nipple. Axial fixing of each valve to the distributing line is accomplished by a bracket-shaped fastening plate with radially yielding arms that passes through recesses in the nipple and snaps into an annular groove of the valve. The rail and valves thereby form a separately accessible unit mountable on the engine via holders.
• § 102 relevance:
  • This is the closest reference to claim 1's injector-retention and tip-engagement features: an injector body retained to the rail by a spring/clip-like element (the yielding bracket plate) and an injector tip/nozzle received in an engine opening.
  • It does not disclose: two interconnected axially extending fuel passages; a circular end recess encompassing both passages; a circular-cross-section passage with an isolation plug; a recess-sealing plug closing both passages; opposed downward canting of sockets for a V‑engine; or a mounting means that exerts only a downward force to retain the injectors between rail and engine.
  • Conclusion: no § 102 anticipation of claim 1 or claim 2; § 103 candidate for the injector-clip/tip limitations.

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5. Same-day co-pending applications and family (NOT § 102 art to this patent)

The specification expressly cross-references three co-pending applications filed the same day, 1982‑08‑23, as claimed inventions of related features:

• Ser. No. 410,651 — pressure-regulator features (Atkins & Field).
• Ser. No. 410,612 — other rail features (Atkins, Field, Lamirande).
• Ser. No. 410,611 — other rail features (L. J. Weinand).

Two issued siblings surfaced in searching:

• US 4,570,600 A — "Fuel rail assembly and method of fabrication" (GM) — issued 1986‑02‑18 (same day as the patent at issue), directed to a fabricated sheet-metal rail with a brazed pressure-regulator base.
• US 4,601,275 A — "Fuel rail" (Weinand, app. 06/410,611) — issued 1986‑07‑22, claiming an elongated body with a pair of passages interconnected at one end and a single circular plug sealing the end recess.

§ 102 analysis of these: Because they were filed the same day (1982‑08‑23) as US 4,570,602 and published/issued after it, they are not available as § 102(b) art (too late), and they cannot be § 102(e) art against this application because § 102(e) requires the reference application to have been filed before the applicant's invention — same-day filings do not qualify. They are therefore not anticipatory of claim 1 or claim 2. They are relevant only as evidence of the same inventors'/assignee's contemporaneous development and as potential § 103 context in a hypothetical (and, given common ownership and the 2003 expiration, now academic) dispute.

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6. Forward citations (context on the art's significance)

US 4,570,602 is heavily cited by later fuel-rail art, e.g., US 4,805,575 (Weber), US 4,825,754 (Aisin), US 4,899,221 (GM), US 5,027,777 (De Bruyn), US 4,984,548 (Sharon Mfg.), US 4,995,577 / WO 91/02896 (Siemens-Bendix), and Bosch's high-pressure/common-rail documents (US 6,644,279; US 10,648,439). This citation density indicates the reference is treated as foundational background for fuel-rail sockets, clips, and end-closure architecture, which is consistent with the § 103 (not § 102) characterization above.

(One "Family Cites Families" entry: US 2,892,453 A — "Fuel injection systems for multicylinder engines," Bosch, 1956‑12‑13 → 1959‑06‑30 — appears in the EP family's citation history, not as a U.S. citation against this patent.)

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7. Bottom-line § 102 conclusions

1. No single cited reference anticipates either independent claim (claim 1 or claim 2) of US 4,570,602. Each fails to disclose at least the claimed pair of interconnected axially extending fuel passages + circular end recess encompassing both passage ends + circular-cross-section passage with an isolation plug + recess-sealing plug combination, and claim 1 additionally requires V‑engine opposed downward canting, the injector clip, the tip in the engine opening, and downward-force-only mounting.
2. Most § 102-relevant (but still non-anticipatory):
   • US 4,286,563 A (Bendix) — closest to the "V-engine fuel rail with a socket/connector per injector, O‑ring sealed" concept (claim preambles / claim 2 socket language).
   • US 4,307,693 A (Bosch) — closest to the injector-retention clip/fastening plate and injector tip received in an engine opening limitations of claim 1.
   • US 3,789,819 A (GM) — closest to the "fuel rail feeding plural spaced injectors" concept and to the vapor-handling objective.
3. Weak/background only: US 2,706,620 A (non-analogous heat exchanger), US 3,026,928 A (early fuel delivery system; specification not read here), US 4,294,215 A (Bosch fuel injection system; specification not read here), and GB 2,073,316 A (Bosch vapour-lock installation).
4. Uncertainty disclosures: I could not retrieve the printed specifications of US 3,026,928 A and US 4,294,215 A in this session; my § 102 conclusions as to those two rest on bibliographic data and title/field, not on a full-text read. For any validity/opinion use, both should be read in full. Dates for US 4,307,693 A differ slightly between the Google Patents citation table and FreePatentsOnline; I have reported both without reconciling them, and either set pre-dates the critical date.

Sources: https://patents.google.com/patent/US4570602A/en (authoritative full text, citation and Cited‑By tables); https://patents.google.com/patent/US3789819A/en and https://FreePatentsOnline.com/3789819.html; https://patents.google.com/patent/US4307693A/... and https://FreePatentsOnline.com/4307693.html; https://patents.google.com/patent/US2706620A/en and https://FreePatentsOnline.com/2706620.html; https://FreePatentsOnline.com/[4601275](/patent/4601275).html and https://www.freepatentsonline.com/[4570600](/patent/4570600).html (same-day siblings); https://patents.google.com/patent/DE3315818A1/en (listing US 4,286,563 A).

I'll ground this obviousness analysis in the actual prior-art references listed on the patent (both examiner-cited art and the family citations), pulling their disclosures where possible.

Let me pull the remaining examiner-cited references and the key family/sibling documents.

Let me retrieve the remaining two examiner-cited references I haven't yet confirmed.

Obviousness Analysis — U.S. Patent No. 4,570,602 ("Fuel rail")

Assignee: General Motors Corp. (orig.) | Inventors: Atkins, Field, Lamirande | Filed/Priority: Aug. 23, 1982 | Issued: Feb. 18, 1986 | Expired: Feb. 18, 2003
Statute: 35 U.S.C. § 103 (pre‑AIA; the application was filed in 1982, so pre‑AIA §§ 102/103 and the Graham v. John Deere / KSR framework govern)

Builds on the previously generated summary. The plain‑language claim constructions and the specification context set out there are adopted below and not repeated.

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1. The prior art of record (the "Prior Art" section of the page)

All seven references under "Citations (7)" are statutory-bar art under pre‑AIA § 102(b): each published or issued more than one year before the Aug. 23, 1982 filing date. That is important — there is no § 102(a)/§ 102(e) date-verification problem, and no swearing-behind hurdle.

Admissibility notes and cross-reference corrections

• The 51 "Cited By" documents are not prior art. Every one post-dates the Aug. 23, 1982 priority date (earliest: US 5,027,777, De Bruyn, prio. 1983‑06‑21). They are irrelevant to § 103 and may only be used, if at all, as background evidence of a crowded art — not as teaching.
• The three co-pending GM applications named in the specification are not prior art and must be excluded. Ser. No. 410,612 (US 4,539,961, Atkins/Field/Lamirande — fuel rail with calibrated plug recess interconnecting supply and return, EP 0102718), Ser. No. 410,611 (US 4,601,275, Weinand — fuel rail with a single circular plug closing both passage ends), and Ser. No. 410,651 (pressure regulator, Atkins/Field). They share the same Aug. 23, 1982 filing date and, for '961, the identical inventive entity. They therefore cannot be "by another" under § 102 and have no earlier § 102(e) date. Do not use US 4,539,961 or US 4,601,275 in the § 103 combination. (They do, however, raise a separate and distinct issue — see § 7.)
• ⚠️ Cross-reference correction to the earlier generated section: the earlier summary lists the Bosch reference as "US 4,284,215." The authoritative patent text and the face of the patent (and US 4,539,961's reference list) both give US 4,294,215 ("Fuel injection system," Bosch). I treat 4,294,215 as correct and flag the earlier "4,284,215" as a discrepancy. (Note the two cited Bendix/Bosch numbers that are both real and distinct: US 4,286,563 = Bendix fuel rail; US 4,294,215 = Bosch fuel injection system.)
• Additional candidate references identified but not of record (usable, but I have not verified full text): US 4,286,531 (Bendix, issued Sept. 1, 1981) — described in US 5,056,489 as "a fuel rail that is adapted to serve a V-type engine… two main branches, one serving one side of the engine and the other serving the cylinders on the opposite side." Also US 4,660,531 (Bosch, Lauterbach et al., US filing July 7, 1982, DE prio. Aug. 17, 1981) — a dimensionally stable fuel manifold distributor disposed over the injection valves and pitched with respect to the horizontal, with the supply connection at the lowest point and the return connection at the highest point to drive vapor-lock bubbles into the return line. As a US filing before Aug. 23, 1982 it is available as § 102(e) art.

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2. Level of ordinary skill in the art

A mechanical design engineer (or a small team of same) with a bachelor's degree in mechanical engineering and roughly 2–4 years of experience with automotive fuel-injection hardware: comfortable with extruded/machined metal manifolds, O‑ring face and radial seals, spring-clip and bracket retention, and the vapor-handling/recirculation constraints of port fuel injection. This is a mature, highly concentrated art dominated by a handful of players (GM, Bosch, Bendix) who all appear on the face of this patent as either the assignee or the source of the art — which is itself relevant to KSR rationales (E) and (F).

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3. Claim 2 — the structural "fallback" claim

Claim 2 requires: (a) elongated body; (b) axially spaced, transversely extending injector sockets; (c) a pair of transversely spaced, axially extending fuel passages, interconnected, one intersecting the sockets; (d) at one end, a circular recess intersected by and encompassing the associated ends of both passages; (e) one passage circular in cross section; (f) a circular plug in that passage adjacent the recess limiting interconnection through the recess; (g) a circular plug sealing the recess, closing both passage ends.

What is clearly taught

• (a)–(d) and (g)-adjacent structure: GB 2,073,316 teaches an elongated rigid common fuel line 53 that contains both a distributor passage 44 and a return passage 45 in a single body, with plug nipples 46 feeding/sealing plug-in injectors (elements (a), (b), (c) at least in the "stacked" sense, and (e), since the Bosch lines are circular-section tubing).
• (c)/(d): US 4,286,563 teaches a unitary rail body serving a plurality of injectors with O‑ring-sealed connectors; US 4,307,693 and US 4,294,215 teach socket/nipple-plus-O‑ring injector connections on a common rigid line.
• (g) partial: US 3,789,819 shows the ends of a fuel rail being closed by fittings (60/62/64) and by the bleed unit 32 — i.e., closing off rail ends is routine.

What is not taught by any single reference

The specific two-plug end-closure scheme: a single circular end recess that encompasses the ends of both passages, with an isolation plug in the circular-cross-section passage and a sealing plug in the recess. No reference of record discloses this. Claim 2 is therefore not anticipated by the cited art; the case is a § 103 case.

Ground 1 (Claim 2): GB 2,073,316 + US 4,294,215 (or US 4,307,693) + the known end-plug expedient

Motivation to combine — the KSR rationales that fit here:

1. Combining prior-art elements according to known methods to yield predictable results. GB '316 already places two parallel fuel passages in one rigid body so that one sub-assembly feeds and returns fuel from the same set of injectors. US 4,294,215/US 4,307,693 supply the socket/nipple + O‑ring interface and the clip retention that make that single body a manipulable sub-assembly. Combining them yields nothing more than the predictable aggregate: a single elongated body with two parallel passages feeding plug-in injectors. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416–17 (2007).
2. Use of a known technique to improve a similar device in the same way. Sealing/plugging the open end of a passage in a fluid manifold with a plug, cap, or threaded closure is among the oldest mechanical expedients (and is the subject matter of the 1955 "Heat exchanger" and 1962 "Fuel delivery system" references cited on the face of the patent, both in multi-passage fluid-handling contexts). Applying that known end-closure technique to the GB '316 dual-passage body is KSR rationale (C)/(D).
3. Design incentive to reduce part count and machining operations. Once two passages share one body, forming one counterbore that intersects both passage ends and using one plug in it eliminates one machining setup and one part per rail end. Reducing parts count and simplifying assembly is a recognized design incentive; the results — two sealed passage ends — are entirely predictable and carry no change in function.
4. The applicant's own stated design objective supplies the motivation. The specification states the irregular passage shape is chosen specifically to permit "the smallest possible recesses 42 to encompass supply passage 24 and return passage 26." Framing the problem as "fit both passage ends inside one minimal end recess" is itself the recognition that a single-plug end closure was the target design — under KSR, the problem the inventor set out to solve can be evidence of the design incentives bearing on the skilled artisan.
5. Finite number of predictable solutions. Given a body with one circular passage and one non-circular passage, the artisan has a small, identified set of end-closure options: two separate plugs; one plug in each passage with a separate end cap; or one recess + one isolation plug + one recess plug. Selecting one of a handful of predictable mechanical options is not inventive. KSR, 550 U.S. at 421.

Why "circular in cross section" is a trivial limitation. Nothing in claim 2 assigns any function to the circularity other than compatibility with a circular plug. Circular bores are the default shape produced by drilling, reaming, gun-drilling, and by extrusion (the '602 body is expressly extruded); a circular plug in a circular bore is the paradigmatic "known technique to improve a similar device in the same way."

Ground 2 (Claim 2, alternative): US 4,286,563 + US 3,789,819 + US 4,294,215

US 4,286,563 already discloses the unitary-construction rail for a multi-injector engine with O‑ring-sealed, swiveling connector joints; US 3,789,819 supplies multiple spaced injector mountings along a rail and a return/bleed path at the rail end; US 4,294,215 supplies the socket-and-clip retention and the manifold-opening interface. The gap again is only the two-plug end closure, addressed by the same rationale as above. This ground is weaker than Ground 1 because the "return passage in the same extruded body" element is less cleanly met, but it is viable.

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4. Claim 1 — the V-engine system claim

Claim 1 adds to Claim 2: (i) a V-engine having injector openings in two lines; (ii) the rail is mountable above and between those lines; (iii) some sockets canted transversely leftwardly and downwardly, the remainder rightwardly and downwardly; (iv) each socket receiving an injector; (v) each injector having a clip securing it to the rail; (vi) each injector having a tip received in one of the engine openings; (vii) means for securing the rail to the engine above and between the lines by exerting only a downward force on the body, thereby retaining the canted injectors between rail and engine.

Ground 3 (Claim 1): US 4,286,563 + GB 2,073,316 + US 4,307,693 (and/or US 4,294,215) + US 3,789,819

Motivation to combine — claim 1 specific:

• (E)/(F) KSR — design incentive and market forces. US 3,789,819 and US 4,286,531 (Bendix) both use two rails, one per bank, cross-connected by crossover/supply lines. Consolidating two rails into one central rail serving both banks is the classic "design incentive… other market forces" variation: it eliminates a rail, a crossover connection, and duplicate plumbing. The only consequence is that the sockets must point two different ways. That is the essence of claim 1, and it flows mechanically from the consolidation — not from invention.
• A finite number of predictable solutions for the geometry. Given a V-engine with two lines of injector openings on opposite sides of the manifold and a single rail placed between them, the injector axes can only reach the two lines by being canted left and right (and, since the openings are below the rail, downwardly). "Canting" is thus the only workable geometry — KSR rationales (E) and (F). US 4,286,563's swivelable/conical-rotation connector further confirms the art already tolerated off-axis injector orientations.
• Clip-first, then mount as a unit. Both Bosch references expressly motivate clipping each injector to the rail before installation, because it converts a serial, one-at-a-time engine installation into a single drop-in sub-assembly and, per US 4,307,693, "increased security against loosening." That motivation applies with full force to a canted, two-bank configuration — indeed more so, because a canted injector is harder to insert and seat individually.
• "Only a downward force" is largely inherent. Once (a) the injectors are clipped into the rail, (b) their tips are seated in the engine openings, and (c) the rail is drawn down onto the engine by vertical bolts/holders, axial withdrawal of each injector is blocked by the rail-and-engine capture. The "downward force… effective to retain the canted injectors" is a functional recitation of the result of the combined structure, not a separately inventive structure. Where a limitation is expressed as a function achieved by a known mounting arrangement in a known way, § 103 is met.

Ground 4 (Claim 1, alternative): US 3,789,819 + US 4,286,563 + US 4,294,215 + GB 2,073,316. Same combination with US 3,789,819 as the primary rail/injector-mounting reference; viable, but US 3,789,819 is atmospheric-pressure (not port-injected-adjacent-injector) art in its details, so US 4,307,693/4,294,215 remain the better clip/nipple references.

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5. Consolidated statement of the § 103 case

Bottom line: Both claims are reasonably likely to be held obvious under § 103. The novelty of the '602 resides almost entirely in (i) the single circular end recess with a two-plug isolation/sealing end closure, and (ii) the single central rail with opposed canted injectors. Neither is more than a predictable, geometry-driven, parts-count-reducing application of known expedients to known fuel-rail structures, and the prior art of record (particularly GB 2,073,316 and US 4,307,693, in view of US 4,286,563) supplies contemporaneous, same-field motivation for each step.

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6. What the patentee would argue (and how strong it is)

1. "No reference teaches canting." Partially true statement of disclosure, but misses the point: canting is a necessary geometric consequence of one rail between two lines of openings, and US 4,286,563's conically swivelable injector joints already teach non-axial injector orientation off a common rail. Weak defense.
2. "The mounting bolts exert only a downward force, and that alone retains the injectors." The patentee would argue the prior art clamps resist lateral loads and/or require separate injector fastening. Rebuttal: US 4,307,693 and US 4,294,215 both put the injector-holding function entirely in the rail-mounted clips and then mount the rail to the engine — the same apportionment of function claimed. Moderate defense at best.
3. "No motivation to combine Bosch with Bendix/GM art." Weak — same field, same problem, same customers, and the patent itself lists four of the seven references. Bosch and Bendix/GM were direct competitors designing to the same OE requirements, and the cited references are all in fuel distribution to injectors. Weak defense.
4. "The two-plug end closure avoids cross-flow/misfueling and is a non-obvious improvement." This is the patentee's best point, because no reference of record shows it. But it collapses under KSR rationale (C): a plug in a bore adjacent a recess that limits interconnection is the "isolation plug" analogue of a check valve, orifice, or restrictor — an admitted known flow-limiting/closing technique in fluid manifold ends. The applicant's own sibling application US 4,539,961 used a recess in the plug to interconnect the passages for flow proportioning; US 4,601,275 claimed the recess+plug without the isolation plug. That the same team treated the end-closure detail as a design variable to be tuned (calibrated, or isolated) is strong evidence the variation was within the skill of the art. Weak-to-moderate defense.

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7. Objective/indicia and a non-§ 103 flag

Objective indicia (secondary considerations): Nothing in the record fetched for this analysis supplies evidence of commercial success with nexus, long-felt but unmet need, failure of others, unexpected results, or copying. The specification's Background contains the customary admission that fuel injectors "are mounted in sockets of a fuel rail which has a passage to supply fuel to the injectors" — an admission that the rail-plus-sockets architecture was known. The asserted benefits (compactness; vapor separation; fewer bolts) are: (a) largely unclaimed; and (b) framed in the specification as design objectives, i.e., the very motivations that make the structure obvious. Objective indicia therefore do not rebut the § 103 case on this record.

⚠️ Flag — a different statute, not § 103: The patent's own specification names three same-day, commonly assigned applications. US 4,539,961 and US 4,601,275 both claim an elongated fuel-rail body with a pair of passages and a circular recess + circular plug closing the ends of both passages — overlapping subject matter with claim 2 of the '602, filed the same day by a common assignee with overlapping inventors. That is the classic profile for obviousness-type double patenting (ODP), which is a judicially created doctrine applied under § 101/§ 102-style analysis and is not a § 103 ground. If ODP was not cured by terminal disclaimers during prosecution, it would have been an independent invalidity/reissue hurdle. I did not retrieve the file histories or a terminal-disclaimer record, so I state this as an observation, not a finding.

Temporal caveat: The patent expired Feb. 18, 2003 (maintenance fees were paid through the 12-year fee in 1997; Google Patents records no later fee event). Any § 103 analysis is therefore retrospective. Practically, this matters only if the patent is being assessed for defensive/prior-art purposes (e.g., as a § 102/§ 103 reference against later fuel-rail or common-rail art) rather than for invalidity of a live right.

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8. Uncertainty and limitations of this analysis

• US 2,706,620 (heat exchanger) and US 3,026,928 (fuel delivery system) were not retrieved in full text. My characterization of them rests on their titles, dates, and assignees. They are cited on the face, so the examiner evidently considered them relevant to fluid-manifold/passage structure, but do not attribute specific disclosures to them without the full texts. My Ground 1 relies on them only as cumulative evidence of the known end-closure expedient.
• Claim chart precision: page/column citations for US 4,294,215 and US 4,307,693 are drawn from the specification text and figures as retrieved (e.g., sockets 2, bore 3, fastening plate 10, arms 11/12, groove 16, openings 20, nozzles 21, holders 17). Exact column/line cites should be confirmed against the printed patents before filing.
• No file history (prosecution wrapper) was retrieved. I cannot state what art the examiner distinguished, what arguments were made, or whether any terminal disclaimer was filed (relevant to § 7).
• No litigation, PTAB, or Federal Circuit record exists or was found for US 4,570,602, consistent with the earlier-generated summary; this § 103 case is therefore constructed, not adjudicated.
• Additional art I identified (US 4,286,531; US 4,660,531) is not on the face of the patent and should be independently verified before use. US 4,286,531 would materially strengthen the claim-1 V-engine element; US 4,660,531 would materially strengthen both the dual-passage and the vapor-handling motivations.

I'll verify the term-adjustment and family data against USPTO-facing sources before reporting.

Let me verify the sibling/family lineage and the legal-events record.

Let me confirm the remaining siblings (the Weinand rail and the pressure-regulator application) and the foreign family members.

Term, Adjustment/Extension, and Family Analysis — U.S. Patent No. 4,570,602

Identifier searched (literal): 4570602 → resolves to U.S. Patent No. 4,570,602 A, "Fuel rail," General Motors Corporation; app. 06/410,641; filed 1982‑08‑23; granted 1986‑02‑18. I did not substitute or auto‑correct any number. All term data below is for the '602 itself; near‑number matches (e.g., US 4,539,961, US 4,601,275) are identified separately and are not the patent at issue.

Builds on the previously generated sections; the bibliographic, assignment, litigation, PTAB and prior‑art findings set out there are adopted and not repeated.

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1. Patent term computation (statutory basis)

US 4,570,602 is a pre‑URAA patent: the application was filed 1982‑08‑23, before the June 8, 1995 effective date of the Uruguay Round Agreements Act term changes. Its term is therefore governed by the transitional rule of 35 U.S.C. § 154(c)(1): the term is the greater of

• 20 years from the filing date of the earliest U.S. application to which the patent is entitled to priority under § 120/121/365(c) — here there is no parent application, so this runs from the '602's own filing date; or
• 17 years from the grant date.

The Google Patents legal‑status record independently states "Anticipated expiration 2003‑02‑18" and status "Expired – Lifetime." (https://patents.google.com/patent/[US4570602A](/patent/US4570602A)/en)

"Expired – Lifetime" vs. "Expired – Fee Related" matters and should be read precisely. The USPTO/Google status label "Expired – Lifetime" designates a patent that ran its full statutory term (as opposed to lapsing early for non‑payment). Consistent with that, the maintenance‑fee record shows all three post‑grant payments made:

No later FPAY event appears, and none was due — the 11.5‑year window payment (the third and final one for a patent granted after Dec. 12, 1980) was made; the next statutory maintenance obligation does not arise. There is no maintenance‑fee lapse that would have shortened the term.

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2. Patent Term Adjustment (PTA) under 35 U.S.C. § 154(b)

Result: NONE — zero days PTA. This is categorical, not a data gap.

• Section 154(b) PTA (the A/B/C delay‑credit scheme) applies only to applications filed on or after June 8, 1995. This application's filing date is 1982‑08‑23, thirteen years earlier.
• The patent's own front‑page "Patent Term Notice" (the standardized notice printed on U.S. patents) also reflects the pre‑URAA regime: for applications filed prior to June 8, 1995, the term ends on the later of seventeen years from grant or the twenty‑year term — with no § 154(b) adjustment line applicable.
• There is therefore no PTA figure to report: not "0 days as adjusted," but statutorily ineligible. Any printed notation of the form "extended or adjusted under 35 U.S.C. 154(b) by ___ days" is a fixture of post‑1995 patents; the 1986‑era '602 prints the pre‑URAA term notice instead.

Cross‑reference note (no contradiction): the previously generated PTAB section computed the expiry as "20 years from the 1982‑08‑23 filing with no listed extension or terminal disclaimer." That reaches the correct date (2003‑02‑18) via the URAA greater‑of rule; the operative prong here is actually 17 years from grant, which happens to be the later of the two. The earlier summary's phrasing ("17 years from issue, pre‑URAA") in the litigation/assignment sections is the more precise statement of the controlling prong. I flag the two phrasings as consistent‑in‑result, and identify 17‑years‑from‑grant (2003‑02‑18) as the operative basis.

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3. Patent Term Extension (PTE) under 35 U.S.C. § 156

Result: NONE. Also categorical.

• Section 156 restores term consumed by regulatory review before commercial marketing and is available only for patents claiming a drug product, medical device, food additive, or color additive subject to FDA (or comparable) pre‑market approval. A fuel rail for a V‑6 engine intake manifold falls in none of those categories.
• Procedurally, a § 156 PTE requires an application submitted within 60 days of the regulatory approval date. No PTE application, grant, or extension certificate exists in the record retrieved, and none could lawfully have existed for this subject matter.
• Note for completeness: § 156 has been available since the 1984 Hatch‑Waxman Act, so the provision was on the books when the '602 issued in 1986 — but the subject‑matter gate (regulated products) is dispositive. PTE = 0; projected expiration unchanged at 2003‑02‑18.

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4. Terminal disclaimer (§ 253) and any other term‑shortening instrument

• No terminal disclaimer is recorded for US 4,570,602, in either the Google Patents legal‑events table or the assignment record (see the previously generated Assignment History section — the file contains one assignment, reel 004038/0430, and nothing else).
• Consequence if a disclaimer had been filed, it would not have shortened the term below 2003‑02‑18 unless it was filed over an earlier‑expiring reference patent; none is on record. The full 17‑year‑from‑grant term controlled.
• Flagged as unverified: a terminal disclaimer is a prosecution‑file event, not an assignment, and would not necessarily surface in the legal‑events extract. I could not retrieve the full prosecution wrapper (file history) for 06/410,641 in this session, so "no terminal disclaimer" is the record state, not a file‑wrapper‑confirmed negative. This is directly relevant to the previously generated obviousness section's § 7 flag (potential obviousness‑type double patenting against the same‑day siblings) — a terminal disclaimer would have been the natural cure. If ODP were ever litigated, note that under Merck v. Hi‑Tech / Novartis v. Ezra a § 253 disclaimer is applied before a § 156 PTE (not relevant here — no PTE), and under § 154(b)(2)(B) a disclaimer caps PTA (also not relevant — no PTA).
• No reissue, no ex parte reexamination certificate, and no certificate of correction appears in the retrieved record. Same caveat: none can be ruled out without the file wrapper.

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5. Continuation and divisional applications

5.1 Is the '602 itself a continuing application? — No.

Application 06/410,641 is an original, non‑continuing application. The patent's front‑page "Related U.S. Application Data" field is absent (no § 120/121/365(c) benefit claim, no continuation, CIP, or divisional parent). This is why the twenty‑year clock, if it applied, would run from the '602's own 1982‑08‑23 filing date.

5.2 Does the '602 have continuations, CIPs, or divisionals? — None found.

• The Google Patents record lists exactly one "Family Applications (1)" row: US06/410,641 → US4570602A. There is no child‑application, continuation, or divisional table for the '602.
• No later GM patent in the record claims benefit of 06/410,641. In particular, the later GM fuel‑rail/injector‑retention patents in the same technical cluster (e.g., the clip‑retention work seen in EP 0124207, which expressly cross‑references EP 0102164 as "copending European published application No. 0102164" for background) are separate filings, not continuations of the '602.

Bottom line on § 120 lineage: the '602 sits at the root of its own U.S. family. No parent → no continuation chain forward → the effective term anchor is its own filing/grant, and nothing in a § 120 chain could extend or shorten it.

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6. Related family members — "co‑pending" ≠ "continuing"

This is the single most important distinction for your question, because the '602's specification expressly names three co‑pending applications:

"Features of the pressure regulator depicted here were invented by T. J. Atkins and M. J. Field and are claimed in copending application Ser. No. 410,651 filed Aug. 23, 1982. Other features employed in the fuel rail depicted here were invented by T. J. Atkins, M. J. Field and D. J. Lamirande as claimed in copending application Ser. No. 410,612, filed Aug. 23, 1982 and by L. J. Weinand as claimed in copending application Ser. No. 410,611, filed Aug. 23, 1982."

These are same‑day, commonly owned, separate applications — not continuations or divisionals. Each claims its own 1982‑08‑23 filing date; none claims benefit under § 120 of any other; and none is a § 121 divisional. Their evidentiary and term significance differs accordingly:

Two points of practical importance:

1. They share the '602's disclosure but not its term. Because they are separate non‑continuing filings, each has its own grant date and its own 17‑year clock. US 4,539,961 expired (per Google) on/around 2002‑09‑10 and is labeled "Expired – Fee Related" — a fee‑lapse status, materially different from the '602's "Expired – Lifetime." US 4,601,275's nominal 17‑year date computes to 2003‑07‑22; Google lists "Anticipated expiration 2002‑09‑10" for the '961 and I did not independently retrieve a term/status line for the '275 in this session — flagging that as unverified.
2. Same‑day siblings are not prior art and are not § 120 extensions. As the previously generated obviousness section correctly notes, they cannot be § 102(b) art (published after) and cannot be § 102(e) art against the '602 (same‑day, and for the '961, identical inventive entity). Their real significance is the ODP exposure flagged there — which is an invalidity/reissue concept, not a term‑adjustment concept.

Also of note (same technical cluster, same issue date, not a continuation): US 4,570,600 A, "Fuel rail assembly and method of fabrication" (GM), issued 1986‑02‑18 — the same grant day as the '602 — directed to a fabricated sheet‑metal rail with a brazed pressure‑regulator base; its EP counterpart is EP 0116742 B1 (which cites GB‑A‑2024933 (Nissan) and DE‑A‑2 816 479 as prior art). This is a sibling in the product program, not a § 120 relative of the '602.

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7. Foreign family members (as listed in the record)

These are counterpart filings of the same 1982‑08‑23 priority, i.e., the foreign family — not continuations:

⚠️ Data‑artifact flag (do not rely on it): the Google Patents country‑status table labels the JP entry "active — Granted." That cannot be a statement of current enforceability for a 1983‑filed Japanese application whose grant published in 1992. It is an automated status‑mapping artifact (most plausibly keyed to the JP grant event, JPH0418142B2), not evidence of any live Japanese right in 2026. Every member of this family is long expired in every jurisdiction.

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8. Projected / actual expiration date — final answer

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9. Discrepancies and cross‑reference checks

1. "20‑year" phrasing vs. "17‑year" phrasing. The earlier PTAB section derived 2003‑02‑18 as "20 years from the 1982‑08‑23 filing"; the litigation and assignment sections said "17 years from issue." Both land on 2003‑02‑18, but the operative prong is 17 years from grant. No contradiction in result; flagged for precision.
2. Maintenance‑fee year‑4 date. The earlier Litigation section states "4‑year/1990." The legal‑events extract reads 1989‑06‑30. Flagging the discrepancy; the 1989 date is what the record shows.
3. PTE vs. PTA. Some of the Federal Circuit authorities surfaced in my searches (Merck v. Hi‑Tech, Novartis v. Ezra, Cellect) concern the interaction of PTA/PTE with terminal disclaimers and ODP. Those rules are inapplicable here: the '602 has no PTA, no PTE, and no recorded terminal disclaimer — so none of those doctrines can change 2003‑02‑18.
4. Sibling term status. US 4,539,961 is reported by Google as "Expired – Fee Related" at 2002‑09‑10, whereas the '602 is "Expired – Lifetime." These are genuinely different statuses and should not be conflated; the '961 apparently lapsed before its nominal term, the '602 did not.
5. Prior cross‑reference items unchanged: the earlier sections' "current assignee = Motors Liquidation Co." (name‑change artifact of the GM bankruptcy, not a recorded assignment) and the earlier section's "US 4,284,215 vs. US 4,294,215" citation discrepancy are both consistent with what I found here; nothing in the term/family record contradicts them.

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10. Uncertainty and what to pull next

• Full file wrapper not retrieved. To convert "no terminal disclaimer / no reissue / no certificate of correction / no PTE application" from record state to file‑wrapper‑confirmed, pull the complete prosecution file for 06/410,641 from USPTO PatentCenter. This is the one remaining item that could, in principle, alter the term picture (it almost certainly will not, given the 2003 expiry and "Expired – Lifetime" status).
• US 4,601,275 term/status line not independently verified in this session; its nominal 17‑year date is 2003‑07‑22 (grant 1986‑07‑22), subject to confirmation.
• The U.S. patent number for Ser. No. 410,651 (pressure regulator, Atkins & Field) was not confirmed. The EP counterpart is identified in EP 0102164B1 as application 83304086.8 / EP 0102717, but I did not verify the U.S. number, and I note a potential numbering adjacency (EP 0102717 vs. EP 0102718) that I have not resolved — I am not asserting which EP number maps to which of the three same‑day U.S. applications beyond the one mapping (EP 0102164 ↔ US 4,570,602) that I verified by full‑text comparison.
• No 2026‑relevant term exposure exists. Every member of this family — U.S. and foreign — is expired.

One‑sentence answer: US 4,570,602 received no PTA (application filed pre‑June 8, 1995) and no PTE (fuel rail is not § 156‑eligible subject matter); it has no U.S. continuation, CIP, or divisional children and no § 120 parent; its three same‑day co‑pending applications (Ser. Nos. 410,651 / 410,612 / 410,611 → inter alia US 4,539,961 and US 4,601,275) are separate siblings, not continuations; its foreign family is EP 0102164, DE 3371805 D1, AU 565695 B2, JPS 5970873 A / JPH 0418142 B2, and MX 7492 E; and its expiration date is 2003‑02‑18 (17 years from the 1986‑02‑18 grant, being the greater‑of prong under § 154(c)(1)), with all maintenance fees paid and status "Expired – Lifetime."

Sources: https://patents.google.com/patent/US4570602A/en (full text, legal status, family, "Also Published As," legal events); https://patents.google.com/patent/[US4539961A](/patent/US4539961A)/ (app. 06/410,612, granted 1985‑09‑10, anticipated expiration 2002‑09‑10, "Expired – Fee Related"); https://patents.google.com/patent/US4601275 (app. 06/410,611, Weinand); http://patentimages.storage.googleapis.com/dd/ad/3a/2b37a5ff5b6c0f/EP0102164B1.pdf (verified counterpart of the '602; identifies the pressure‑regulator EP application 83304086.8 / 0102717); https://patentimages.storage.googleapis.com/ae/d7/e7/6c4aa3572a8781/WO1991002896A1.pdf (family table: US‑A‑4570602 ↔ AU‑B‑565695, 24/09/87); https://storage.courtlistener.com/recap/gov.uscourts.ded.35498.217.0.pdf and https://www.supremecourt.gov/DocketPDF/23/23-1231/[310223](/patent/310223)/20240520155931736_Cellect%20Petition%20Appendix.pdf (§ 154(b)/§ 156 and terminal‑disclaimer framework); https://www.osti.gov/biblio/[5902094](/patent/5902094) (assignee/abstract corroboration).