US 2365117

I'll verify against live sources before summarizing.

Verification note

I searched for US 2365117 and for any 2026 CAFC/USPTO litigation activity. Findings:

• The patent is confirmed at https://patents.google.com/patent/US2365117/en (family ID 3434160).
• No CAFC 2026 docket activity, and no litigation of any kind, exists for this patent. It is recorded as "Expired – Lifetime" with an anticipated expiration of 1961-12-12 (17 years from grant). A patent that lapsed in 1961 cannot be the subject of a 2026 appeal; any 2026 docket hit for the string "2365117" would be an unrelated case number or a foreign document (e.g., CA 2365117 A1, an unrelated Canadian application).
• The displayed Google Patents title string is OCR-garbled ("Physical exercising ob training"); the document's own front page reads "PHYSICAL EXERCISING OR TRAINING APPARATUS." I flag this rather than silently normalizing the ID/title.
• "US2365117D" appears in the family listing alongside "US2365117A." This looks like a Google Patents data artifact, not a separate legal document.

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US 2,365,117 — Summary

Abstract: There is no formal abstract. The patent was filed in 1942, before abstracts were required on US patents; the specification opens directly into a statement of objects. The "Definitions" block that Google Patents displays is machine-generated from the specification, not an applicant-supplied abstract.

Object of the invention (from the specification): to compactly combine many different types of physical training equipment in one structure so a large number of men can train simultaneously; sized and adapted especially, though not exclusively, for army camp installation; and built from transportable, prefabricated parts that a small crew can bolt together into a rigid, braced structure.

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Independent claims in plain language

Claim 1 — Channel-and-splice joint. A pair of structural members, each made of two end-to-end sections. Each section is two channels bolted flange-to-flange (webs notched at the end margins). The joint uses a splice-member: a bar that sits in the end notches plus I-section end pieces placed inside and bolted to the channels, holding the sections together.

Claim 2 — Same joint, spaced parallel members. Same channel/splice construction, but where the splice-member's bar holds two structural members in spaced parallel relation as well as joining each member's sections end-to-end.

Claim 3 — Tower-and-top-section frame. Spaced towers joined by a top section. Each tower = spaced posts with transverse members. The top section = longitudinal tubular rails of rectangular section, secured to the towers by U-shaped braces welded to posts and bolted to rails. Rails have registering apertures through which transverse tubular bars pass and are fixed; uprights fixed to the rails carry the top section between the towers.

Claim 4 — Tubular member detail. A tubular structural member of two companion channels joined flange-to-flange by a splice whose I-sections (two channels web-to-web) fit between the section channels, with transverse bolts through the webs and splice flanges bearing flatwise on the inner faces of the section flanges.

Claim 5 — Notched-margin splice with cross bar. Two tubular members, each with two abutting sections having notches in their end margins. A splice has I-section end portions (fully inside the sections) joined by a bar. The bar runs crosswise between the two members and is received in the opposed complementary notches, so the same hardware joins the sections and spaces the members.

Claim 6 — Claim 3 frame plus bracing. Adds horizontally and diagonally extending reinforcing members fixed to the intermediate uprights.

Claim 7 — Claim 3 frame plus inclined ladder. Adds an oblique ladder under the top section and between the towers, with side rails of multiple end-joined sections having hand-gripping (tubular grab) portions, and cross rungs joining the rails.

Claim 8 — Claim 7 plus hangers. Adds cross reinforcing members on some uprights, plus hangers depending from those reinforcing members and rigidly joined to the ladder side rails — the hangers both suspend the ladder and reinforce the joints between its side-rail sections.

Claim 9 — The cat-walk combination. Laterally spaced vertical towers with transverse and lengthwise horizontal bars (stall bar / jungle gym bars) joined at their tops by a horizontal top section carrying at least three cat-walks running lengthwise: one with a flat (horizontal) top surface, one whose cross-section is V-shaped (the "gutter" walk S), and one whose cross-section is an inverted V (the "pyramid" walk R, meeting in a central peak).

Claim 10 — The overall multi-station complex. A structure with a stall bar tower at one end and a jungle tower at the other, a top section joining them, and beneath/between them: an inclined hand-walk ladder, a crawl-tunnel, a climb-up rope depending from the top section, a climb-ramp spanning the towers, and a climbing pole hanging from the top section. This is the broad system claim covering the whole combined training course.

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Practitioner notes

• Claim strategy observation: All ten claims are independent, which is unusual by modern standards. Claims 3 and 6–8 form a self-contained "frame" family (tower + rail + U-brace + transverse-bar architecture), while claims 1, 2, 4, and 5 protect the channel-and-splice joint hardware that makes the whole thing field-assemblable. Claim 9 and claim 10 are the commercially meaningful "combination" claims — the multi-station physical training course.
• Forward citations are dominated by modern challenge course / ropes course art, e.g., Liggett (US 7,175,534, US 8,016,686), Ropes Courses Inc. (US 10,105,564, US 10,213,699, US 11,376,513 / 12,296,277), Afo S.r.l. / Amer Sports Italia (US 9,452,309, WO 2012/140622), Cooper (US 7,789,811), and Madigan (US 7,070,541). Closest listed "similar document" is US 1,779,903 (Daragon, 1930), Demountable Gymnastic Apparatus — worth reading if you are building a validity picture for this family.
• Uncertainty flags: The specification text is OCR-degraded (e.g., reference numerals render inconsistently as "I6"/"16", "Fig. 12" vs "Figure 12"), so a citation-grade reading should be checked against the PDF at https://patentimages.storage.googleapis.com/... (linked from the Google Patents page). The specifications mention Figures 7–10 in the drawing list that are not reproduced in the OCR I retrieved; I cannot characterize them. I found no recorded assignment history beyond the "by mesne assignments" statement on the front page, and no foreign priority claim is indicated.

I'll search for litigation records involving US patent 2365117.

Let me search additional litigation-specific sources.

Let me try a few more targeted litigation-database searches.

Litigation Search Report — U.S. Patent No. 2,365,117

Bottom line: No litigation involving U.S. Patent No. 2,365,117 was found in any of the sources searched. I could not identify a single case—district court, ITC, or Federal Circuit—naming this patent as an asserted patent.

Patent identification (verified, not auto-corrected)

What I searched

• General web / litigation-indexed searches for "2365117," "2,365,117," and the patent title combined with litigation terms.
• Party-based searches on the patent owner of record (Potomac Engineering Corporation).
• I attempted to reach Unified Patents' litigation case list and PACER-style sources; the session reached its tool-call limit before those two final queries returned, so I cannot claim a complete pass over those two specific portals.

Methodology caveat you should weigh

1. The patent expired on or about Dec. 12, 1961 (17-year term from the 1944 grant, before the GATT/URAA term change). Any infringement suit would necessarily have been filed during roughly 1944–1961.
2. Digital litigation databases (Unified Patents, PACER/CM-ECF, CourtListener/RECAP, Darts-IP, Lex Machina) have essentially no systematic coverage of U.S. patent cases filed before the 1960s–1980s. Federal court filings were paper records; PACER's electronic docket coverage is largely 1990s-forward. Consequently, a pre-1961 suit could exist in the National Archives or in print reporters (e.g., F. Supp., USPQ) and still be invisible to every tool I have.
3. The Google Patents record for this patent shows normal bibliographic data — prior-art date, cited-by references (16 modern challenge-course/playground patents), and "Similar Documents" — but no litigation, ITC, or PTAB/reexamination events. The cited-by and similar-document lists are patentability citations, not litigation, and should not be mistaken for case activity.
4. Given the patent was a WWII-era Army-camp training structure assigned to a corporation, any enforcement would likely have been a government-supply / Government-contracts dispute during the war years. I found nothing on that either, but absence of digital evidence is weak evidence of absence for this era.

Recommendation for a definitive answer

If a conclusive negative is needed (e.g., for a clearance or validity opinion), the era-appropriate searches would be:

• Print digests: Federal Reporter / Federal Supplement volumes 1944–1962 and United States Patents Quarterly (USPQ) volumes covering 1944–1962, searched under "Potomac Engineering" and "Stafford."
• NARA records: RG 21 (District Courts) docket books for the Northern District of Illinois (the assignee's home district) and the Eastern District of Missouri (Albach's residence), 1944–1961.
• Government contract claims: Court of Claims / Armed Services Board of Contract Appeals records, given the Army-camp application described in the specification.

I do not know of any litigation involving U.S. Patent 2,365,117 with high confidence to the contrary — the honest statement is that no such litigation appears in any searchable source, and the patent's 1961 expiration places it largely outside the coverage of modern litigation databases. I will not fabricate a case name, number, or forum to fill that gap.

I'll verify the structured-data finding with targeted searches before concluding.

Proceedings overview

Zero AIA trial proceedings on file. The USPTO Open Data Portal structured block returns no IPR, PGR, or CBM for US 2,365,117, and independent searching (Google Patents' "Cited By"/proceedings metadata, PTAB E2E/PTAB Center targets, CourtListener, Federal Circuit opinions) surfaced no petition, no institution decision, no Final Written Decision, and no appeal for this patent number. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied — and the defensive posture is more favorable than any IPR outcome could produce: the patent is expired and has been since 1961-12-12, roughly sixteen years before the Federal Circuit existed and fifty-one years before AIA trials were created. There is nothing for a defendant to defend and nothing for a petitioner to gain.

No proceedings to report

There is no IPR########-#####, PGR########-#####, or CBM########-##### number to list. I will not manufacture one. For completeness, the relevant negative findings:

• Structured data (canonical): PTAB proceedings on file = none as of the most recent ODP ingest. Google Patents' machine-readable record for US2365117A likewise shows no AIA-trial field populated, only the "Expired – Lifetime" legal status with an "Anticipated expiration" of 1961-12-12. Source: https://patents.google.com/patent/US2365117/en
• Web search: no petition, decision, or docket matched this patent number. Searches for "2,365,117" and "2365117" returned only (a) the patent's own Google Patents page, (b) unrelated foreign/number-collision documents (EP 2365117, DE2365117A1, CA2365117C — different subject matter entirely), and (c) an unrelated bibliographic citation of "2365117 | December 1944 | Stafford et al." in the prior-art list of a modern design patent, US D865896 ("Element for a challenge course," Ropes Courses, Inc.). Google Patents' "Cited By" list for this patent contains only post-2011 challenge-course and exercise-equipment art that cites it as background — no adversarial citation.
• False-positive warning. Almost every search hit containing a "'117 patent" is a different patent: Polaris PowerLED Technologies' US 8,223,117 / US 9,198,117 family (IPR2023-00778, the Polaris v. LG/Hisense petitions, etc.). Those proceedings have nothing to do with US 2,365,117. If any docket-tracking vendor feeds you "'117 patent IPRs," verify the number before relying on it.

Strategic summary

Claim status. All ten claims of US 2,365,117 are formally intact — none canceled, none held unpatentable, none disclaimed. But "intact" here means nothing, because the claims are expired and unenforceable. The patent was filed 1942-01-10, granted 1944-12-12, and carried a pre-1995 statutory term of 17 years from grant, expiring 1961-12-12 (matching the ODP "anticipated expiration" entry). An expired patent cannot be infringed prospectively; the only residual remedy for expired claims is back damages for past infringement within the 35 U.S.C. § 286 six-year lookback, which closed in 1967-12-12. Claims 1–2 and 4–5 (the channel-and-splice structural claims), claims 3, 6–8 (the tower/top-section apparatus claims), claim 9 (the three-cat-walk claim), and claim 10 (the stall-bar-tower/jungle-tower combination claim) are all UNTESTED — not because they survived anything, but because no challenge was ever worth filing, and none can now produce a commercially meaningful result.

Estoppel landscape. § 315(e)(2) is inapplicable in both directions: no IPR was instituted, no Final Written Decision issued, so no petitioner is estopped, and no patent owner secured a validity win that would make a later challenge harder. There is no estoppel to navigate — the art is wide open for whatever purpose a defendant needs it for (e.g., to show the patent is background art, to support an Alice/§ 101 or obviousness-type double-patenting argument against a modern patent, or to establish prior invention under § 102(g) principles for pre-AIA art).

Pattern signals. None. No repeat petitioner, no defensive aggregator (no Unified Patents petition, no Ropes Courses-style industry challenge), no Federal Circuit appeal, no ex parte or inter partes reexamination. That absence is explained by the economics rather than by patent strength: an apparatus whose commercial window closed in 1961 attracts no challengers because there is no licensing revenue to attack. Note the asymmetry with the prompt's framing — "well-asserted patents eventually attract IPRs" is true for live patents; for a WWII-era Army-camp training structure, the absence of PTAB activity is a signal of commercial irrelevance, not of hardened validity.

Recommended next steps

• Do not treat this patent as an assertion risk. If a demand letter cites US 2,365,117, the patent has been expired since 1961-12-12 and any damages theory runs into the § 286 bar. The correct response is a short letter noting expiration and demanding withdrawal — not an IPR. (An IPR is also procedurally pointless: it cannot revive expired claims, and no petitioner could obtain meaningful relief.)
• Redirect the diligence. Check whether the same demand letter bundles other, live patents — particularly in the modern challenge-course / functional-training space, where US D865895/D865896 (Ropes Courses, Inc.), US 7,789,811 (Cooper, "mobile training device for simultaneous use by multiple users"), and the Liggett challenge-course family (US 7,175,534 / US 8,016,686) sit. Those are the patents that actually generate PTAB activity; US 2,365,117 is the ancestor they cite, not the target. Verify each cited number individually — the "'117" collision described above is a live trap.
• If you need the prior-art value of this reference: cite it as printed art with its 1944-12-12 publication date, and link https://patents.google.com/patent/US2365117/en. Do not attribute any prior-art date other than the actual publication date (1944-12-12); note the Google Patents header's "Prior art date 1944-12-12" field is that same publication date, not an asserted priority date.
• No PTAB milestones to track. There is no institution deadline, no oral hearing date, and no 35 U.S.C. § 316(a)(11) one-year FWD clock running, because no trial exists.

Bottom line: no PTAB activity exists on US 2,365,117, and none ever will in any meaningful sense — the patent expired 1961-12-12 and no AIA trial docket, reexamination, or litigation involving it could be located.

I'll start by probing for any recorded assignment data and corporate history before writing up.

Data-availability note (read first)

I could not retrieve any Assignment Center record for this patent. The searches I ran returned no USPTO assignment data, and assignmentcenter.uspto.gov / assignment.uspto.gov are JavaScript single-page apps whose records do not surface in the indexed results I could reach. This is a failure to retrieve records, not a verified finding that no records exist. Everything below is sourced from the printed patent front page and Google Patents legal events, not from reel/frame data.

Two record-quality flags on the source itself:

• Google Patents renders the title as "Physical exercising ob training" (OCR artifact). The printed patent title is "Physical Exercising or Training Apparatus."
• Google Patents also emits US2365117D as a separate "Family Application" entry. This is an internal duplication of the same case, not a distinct document and not a legal event. Treat it literally as an artifact, not as a chain link.

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Inventors

• Filed 1942-01-10, Application Serial No. 426,290, issued 1944-12-12, 10 claims. Classification A63B17/00 (apparatus combining ladders, rods, beams, slides), later tagged A63B2225/10 (multi-station exercising machines).
• Unusual patterns: none observable — and none observable by construction, because there are no retrievable assignment records to test the "inventors departed within 12 months" hypothesis against. Note that in 1942–44, assignment of rights at filing was the norm for war-production work; the inventors assigned rather than retained, so a departure analysis would be uninformative even with full records.
• Technical read-through: the disclosure is a large, bolted-together outdoor obstacle/exercise rig (stall-bar tower section B, jungle tower section C, top section D with four cat-walks Q/R/S, crawl tunnels H, inclined ladder J, climbing poles M, swinging and inclined ropes N/P, side ramps U, jumping platform W). The objectives recite "army camp installation" and simultaneous use by "a relatively large number of men" — i.e., a WWII physical-conditioning structure, not a consumer product.

Original assignee

Potomac Engineering Corporation, Chicago, Illinois — a corporation of Delaware, per the patent front page. The record states the inventors are "assignors, by mesne assignments, to Potomac Engineering Corporation."

• "By mesne assignments" is the single most substantive ownership fact in the record: it recites that title reached Potomac Engineering through at least one intermediate assignment, not directly from the inventors. The chain therefore has at least one pre-issue link that I could not retrieve, and any Assignment Center query for this patent should be expected to show more than the original inventor→assignee conveyance.
• Product embodying the claims: unclear. The structure is a site-built, bolted installation ("built up of structural parts and members readily transported and co-operatively fabricated... by a relatively small installation crew"), which is consistent with an engineering/fabrication contractor selling installed training rigs to camps rather than shipping a mass-market product.
• Primary line of business: not determinable from any source I could reach (name suggests a general engineering/fabrication firm; that is inference, not evidence).
• Current status: not determinable. A Delaware corporation operating out of Chicago in 1944 would be ~80+ years old; I have no record of dissolution, merger, acquisition, or bankruptcy. I am not going to assert one. The patent itself expired 1961-12-12 (17 years from issue), so the entity's fate is commercially irrelevant to any modern assertion.

Assignment timeline

No recorded assignment is retrievable from the USPTO Assignment Center for US 2,365,117. Google Patents' legal-events table for this patent lists only:

• 1944-12-12 — Application granted; publication of US2365117A
• 1961-12-12 — Anticipated expiration; status: Expired – Lifetime

There is no reel/frame entry, no recorded conveyance of any type (Assignment, Security Agreement, Merger, Change of Name, License, Release, Correction), no recorded correspondent, and no post-1961 legal event in any source I could reach. The only ownership datum in the entire record is the front-page "by mesne assignments, to Potomac Engineering Corporation" statement, which is a recital on the face of the patent, not a recorded assignment.

Per your instruction, I stop the substantive timeline analysis here: with no records and no assignee other than the 1944 original, the chain presumptively terminates at the original assignee. I include the remaining mandated sections below, flagged as non-findings, only so the requested output shape is complete and the verdict is stated.

Timeline diagram

timeline
    title Ownership of US 2365117
    1941 : Inventors execute assignment to Potomac Engineering
    1942 : Application filed 10 January Serial 426290
    1944 : Patent issued 12 December
    1961 : Patent expired 12 December
    2026 : No assignment records retrievable

Note: the 1941 entry is inferred from the "by mesne assignments" recital plus normal pre-filing practice and is not an evidenced date; every other event above is documented.

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No post-issue assignee of any kind is retrievable. The one known assignee, Potomac Engineering Corporation, is a 1944 operating engineering corporation in Chicago, not a licensing LLC.
2. Known asserter in the chain — not present. No assignee in any retrievable record matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. (Caveat: absence of a retrievable record is not proof of absence.)
3. Repeat correspondent across the chain — not present / no data. No correspondent of record is retrievable at all, so recurrence cannot be tested. Zero correspondent data points means no finding — I decline to infer one from the Google Patents rendering.
4. Cascading transfers — not present. No transfers retrievable, chained or otherwise.
5. Pre-litigation transfer — not present. No assignment dated near any suit, and no litigation naming this patent appears in Google Patents' event data. Caveat: Google Patents' litigation coverage is thin-to-absent for pre-1990s US district court cases, so this is weak evidence of no litigation.
6. Bankruptcy fire-sale — not present. No bankruptcy, receivership, or §363 sale record involving Potomac Engineering Corporation was found.
7. Privateering — not present. No operating-company→NPE transfer, and no SEC-filed or press-reported assertion activity, is associable with this patent.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN; it terminates at expiration in 1961.

Additional negative evidence: the "Cited By" set (24 documents) is dominated by modern challenge-course and ropes-course art — Ropes Courses, Inc. (US10105564B2, US10213699B2, USD865895S1, USD865896S1, US11376513B2, US12296277B2), James A. Liggett (US7175534B2, US8016686B2), Stephen J. Madigan (US7070541B2), Cooper (US7789811B2), and AFO S.R.L. / Amer Sports Italia (US9452309B2). These are later art citing the patent as background, not licensees or plaintiffs. No reverse-payment, FRAND, or assertion trail connects them to US 2,365,117.

Verdict

Insufficient data (no records beyond the original 1944 assignment).

Justification: the only ownership fact obtainable is the printed recital that the inventors assigned "by mesne assignments" to Potomac Engineering Corporation of Chicago, a Delaware corporation, with the patent issuing 1944-12-12 and expiring 1961-12-12; no Assignment Center reel/frame, conveyance, assignee, or correspondent is retrievable from any source I could reach, so there is no post-issue chain to assess. The "verdict" is therefore driven by record absence, not by evidence of clean title — and on the evidence that does exist, zero NPE signals are present: no shell LLC, no known asserter, no cascading transfers, no pre-litigation transfer, no fire-sale, no defensive aggregator. A modern NPE pattern is implausible on its face for a patent that has been expired since 1961, but I am labeling this insufficient data rather than defensive/non-asserting because I could not verify the record rather than verifying that it is empty.

Verify directly at: https://assignmentcenter.uspto.gov/ (search patent number 2365117 or Serial No. 426,290). If the query returns a conveyance to a name other than Potomac Engineering Corporation, the "mesne assignments" recital on the front page is the explanation, and that intermediate link should be pulled first — it is the only plausible place a deviating chain could hide. Patent record: https://patents.google.com/patent/US2365117/en

Two corrections I will not make silently: the Google Patents title "Physical exercising ob training" is OCR noise, and US2365117D is a Google Patents duplication artifact rather than a separate assignment or defensive publication.

I'll search for the specific patent's citation data and prior-art references.

Prior‑Art Analysis — U.S. Patent No. 2,365,117

Note on scope: I have reached my tool‑call limit for this session. Everything below is based on the record already retrieved (the authoritative full text you supplied, the Google Patents page, the patentimages PDF, and the Justia / Google Patents citation lists that appeared in search results). Where I could not retrieve something, I say so rather than filling the gap.

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1. Target identification (verified literally, not auto‑corrected)

Critical date for §102 analysis: the application was filed January 10, 1942, so pre‑AIA 35 U.S.C. §102 governs. That gives two relevant §102(b) windows and one §102(a) window:

• §102(b) statutory bar: printed publication in the U.S. or abroad, or U.S. patent, dated before January 10, 1941 (one year before filing).
• §102(a): art dated before the applicants' actual invention date (unknown; presumptively on or just before Jan. 10, 1942).

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2. Disambiguation — numbers that are not this patent

Per the standing instruction to interpret identifiers literally and not auto‑correct, the following surfaced during searching and are excluded; they share digits with "2365117" but are unrelated to the target:

• EP 2365117 A1 (2011‑09‑14) — "Apparatus and method for formation and collection of nanofibrous non‑woven sheet."
• DE 2365117 A1 — "Spring hammer with adjustable impact intensity, especially drill hammers."
• FR 2365117 A1 (Schenck AG, 1978‑04‑14) — railway axle test rig.
• CA 2365117 — halogen‑free flame‑retardant plastisol composition.
• US11413847 references "EP 2365117 9/2011" as a cited document, unrelated to the 1944 patent.

None of these are US2365117 and none are analyzed below.

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3. What the citation record for US 2,365,117 actually contains — and a significant finding

Finding: the indexed record for US2365117 contains no "References Cited" (backward citation) section. The Google Patents page as fetched goes from the bibliographic/definition data straight to two forward‑citation tables headed "Cited By (16)" and "Cited By (24)," plus a "Similar Documents" list. There is no list of U.S. patent documents cited by the examiner or applicants on the front page.

I must be explicit: I was not able to retrieve the front‑page "References Cited" list for US2365117. Several targeted searches (including for the Justia "Referenced Cited" table for 2365117) returned only pages of later patents that list 2365117 in their references — never a reference list belonging to 2365117 itself. This is consistent with, but not proof of, the patent having no indexed U.S. patent‑document citations. I do not know with high confidence whether the 1944 printed front page contains cited references; I could not verify it, and I will not invent a citation list to fill the section.

3.1 The "cited" patents are all forward citations — not §102 art

The 16/24 references in the "Cited By" tables (e.g., US4796884A child's play set; US5823925A stretching apparatus; US7789811B2 mobile training device; US9452309B2 modular gym structure; US10105564B2 and US10213699B2 Ropes Courses, Inc.; US20060135272A1 / US7175534B2 Liggett challenge course; US20050233862A1 / US7070541B2 Madigan educational tracks; USD865895S1 / USD865896S1 challenge‑course elements; US20190337582A1 mobile obstacle courses) all post‑date December 12, 1944 by decades.

Legal conclusion: because they postdate the grant, none of them can anticipate or render obvious any claim of US2365117 under §102 or §103. Their evidentiary value runs the other direction — they show that US2365117 is treated as seminal prior art in the modern "challenge course / jungle gym / obstacle course" field (it appears in the "Referenced Cited" tables of Justia's pages for US10478737 and design patents D865895/D865896). Treat them as lineage evidence, not as §102 art.

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4. Most relevant prior art that can operate against US2365117

Because no examiner‑cited art is available, the closest art must be drawn from (a) the "Similar Documents" set that predates the Jan. 10, 1942 filing, and (b) field‑analogous structural art. The mapping to claims below is my analysis and is expressly provisional, since I could not confirm which of these, if any, the examiner actually relied upon.

The relevant claims break into two families:

• Structural‑member claims (splice / channel / notch architecture): claims 1, 2, 4, 5
• Apparatus claims (towers, top section, rails, rungs, uprights, ladders, cat‑walks, combined equipment): claims 3, 6, 7, 8, 9, 10

4.1 Pre‑1942 references capable of §102(b) treatment (published before Jan. 10, 1941)

4.2 References that can only be §102(a) art (published after Jan. 10, 1941 but before the invention date — a narrow window)

4.3 Post‑1944 references cited in other prosecution — not prior art here, but noteworthy

• US 2,512,911 A (Benice, 1950‑06‑27) — cited as an "X" reference (whole document) against claims 1, 2, 4, 7–10, 14 of a modern modular exercise‑structure application in an EPO search report (see WO 2013/004734 A3). It postdates US2365117 and therefore cannot be §102 art against it. It is, however, a strong signal that the Benice structure and US2365117 occupy the same subject‑matter space — worth reading side‑by‑side if you are mapping US2365117's disclosure against later art.
• US 4,796,884 (child's play set, 1989), US 5,823,925 (1988/1998), US 6,030,321, US 6,113,564, US 6,634,995, US 7,070,541, US 7,170,540‑family, US 7,789,811, US 9,452,309, US 10,105,564, US 10,213,699, US 10,478,737 — all §102/§103 forward art. Irrelevant to validity of US2365117.

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5. Claim‑by‑claim summary of the strongest candidate art

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6. Confidence, limitations, and what a definitive answer requires

1. No examiner/applicant "References Cited" list was retrievable for US2365117. I could not complete a direct USPTO Patent Public Search / Patent Center "front page" pull, and the Google Patents record as fetched contains no backward‑citation table. Section 4 is therefore my proposed prior art, not the patent's actual citation list. Do not represent it as the latter.
2. Filing dates for the pre‑1942 references are not in the retrieved data — only publication dates. For a strict §102 analysis you need the actual filing dates (relevant if the applicants swear behind a reference under §1.131) and, more importantly, the actual invention date of Stafford and Albach, which is not of record in anything I retrieved.
3. Statutory nuance: because the filing date is Jan. 10, 1942, only art published before Jan. 10, 1941 is unambiguously §102(b) art. US 2,267,638 A (Dec. 23, 1941) and US 2,512,911 A (1950) fall outside that (the latter is post‑grant entirely).
4. The strongest single anticipation candidate across the apparatus claims is US 1,779,903 A (Daragon, 1930) — a demountable gymnastic apparatus with towers/standards and transverse exercising bars — reinforced in the structural claims by US 1,969,656 A (knockdown scaffolding, 1934) and US 1,721,670 A (scaffold, 1929).
5. To close this out definitively you would need: (a) the actual printed front page of US2365117 (USPTO Patent Public Search / Patent Center full document); (b) the January 1942 file wrapper (Serial No. 426,290) for the examiner's cited art and any §1.131 affidavits; and (c) full‑text review of US 1,779,903 A, US 1,969,656 A, US 1,721,670 A, and US 2,267,638 A. I flagged those three retrieval failures rather than substituting fabricated citations.

Explicit statement of uncertainty: I do not know, with high confidence, the identity of the references the examiner actually cited against US2365117, and I have not verified the disclosure content of the references listed in §4 (I read their titles, numbers, and publication dates only). Any §102 mapping above should be re‑verified against the full text of each reference before being relied on.

I'll ground this analysis in the prior-art record on the Google Patents page for US2365117 and verify the pre-1942 references individually.

Let me verify the remaining pre-1942 "Similar Documents" and check whether the patent's own page lists any cited prior art.

Obviousness Analysis — U.S. Patent No. 2,365,117 under 35 U.S.C. § 103

0. Scope note: what the page actually supplies as "prior art"

Before mapping combinations I have to flag a framing problem with the source record, because it materially affects how this analysis can be done.

The Google Patents record for US2365117 as reproduced above contains no "(56) References Cited" section. This patent was granted in 1944 and was not printed with a front-page prior-art citation list. What the page does supply, and what I therefore treat as the "Prior Art section" for this exercise, is:

Contradiction flagged with the prior Litigation section: that section lists the patent's "Prior art date" as 1944-12-12 and "Prior art keywords" as fields of record. The 1944-12-12 date is the publication date, not a § 102 critical date. For § 103 purposes the controlling dates are:

• Filing date: January 10, 1942 (App. Ser. No. 426,290) → § 102(a) art cutoff
• § 102(b) statutory-bar date: January 10, 1941 → one year before filing

This matters, because one of the listed "Similar Documents" falls in the narrow window between those two dates:

The Cited By lists matter in a different way: they establish that the field — challenge courses, playground climbing structures, balance apparatus (Ropes Courses Inc., Liggett, Cooper, Madigan, Afo S.r.l./Amer Sports, Whincup) — remained actively developed from 1982 onward. That is evidence of a crowded, incremental art, which under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), supports a finding that combining known exercise stations on a common frame is the predictable work of a skilled artisan. It is not evidence of what was known in 1941.

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1. Level of ordinary skill in the art (PHOSITA)

A person of ordinary skill in the 1941 art would be a structural/mechanical engineer or experienced erector of knockdown steel scaffolding and gymnasium apparatus, with knowledge of: (a) bolted/knockdown structural joints for channel and tubular members; (b) standard gymnastic apparatus (Swedish bars, stall bars, inclined ladders, horizontal bars, climbing poles and ropes) as catalogued in the 1928–1941 literature; and (c) playground/camp installation practice (foundations, bracing, guard rails). This is a low-to-moderate skill level — no sophisticated technology is involved, and the reference art itself is largely 1889–1940.

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2. The threshold problem: this patent claims essentially two different things

Claims 1, 2, 4 and 5 are joint/structural-member claims whose bodies recite only a splice geometry; the exercise function appears only in the preamble ("In physical training apparatus…"). Claims 3 and 6–10 are apparatus claims to a multi-station training structure. Obviousness must be assessed separately for each group, and the two groups fail for different reasons.

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3. Group A — the splice claims (1, 2, 4, 5)

The claimed subject matter

• Companion channels bolted flange-to-flange into a rectangular tubular "section" (¶ "each rail or beam d … including co-operable or companion pairs of channel-sections 4, 4'")
• Sections joined end-to-end by a splice-member (E) = a bar embraced by notches in the end margins of the channel webs, plus I-section end members (back-to-back channels) sitting inside the sections and bolted through the webs
• Two such members held in spaced parallel relation by the splice-member's cross-bar (claim 2, claim 5)

Combination 1 → Claims 1, 2, 4

Motivation. Marlowe's stated purpose — a scaffold that knocks down for shipment and re-erection — is the identical problem to the one this patent's specification sets out: "built up of structural parts and members readily transported and co-operatively fabricated for convenient, rigid connection one with the other by a relatively small installation crew." When a reference addresses the same problem the patentee identified, that is the classic KSR "design incentive" motivation. A PHOSITA seeking a demountable joint for the very channel sections this structure uses would arrive at a notched-web/bolted-splice joint by routine mechanical design: the notch-plus-cross-bar is the obvious way to (i) index two sections for end-to-end alignment and (ii) simultaneously space two parallel rails.

Caveat on my evidence. I retrieved only the bibliographic record for US1969656A (title, inventor, filing/issue dates, assignee, IPC E04G1/34, classes 182/152, 211/192, 52/637, 52/690). I did not obtain its specification text in this session. I therefore cannot quote the specific splice structure it discloses, and I will not assert one. The combination above is grounded in Marlowe's title and classification plus the field's general knowledge; a definitive § 103 ground would require pulling the Marlowe drawings.

Combination 2 → Claims 1, 2, 5 (the parallel-member/notched-web variant)

Claim 5's "complementary notches … embraced by a bar connecting I-section end portions" is a straightforward mechanical improvement over Combination 1. The bar-embraced-in-opposed-notches geometry is the same load path as the U-bolt cross-connections used in pre-1941 pipe-frame playground structures — e.g., US1471465 (climbing structure, 1923) and US1488246 (1924, pipe playground framework joined by mutually straddled U-bolts passing through drilled pipe) — combined with Marlowe's knockdown splice. Motivation: reinforcing the butt joint between contiguous sections while rigidly spacing parallel members, which is exactly the dual function the specification attributes to the splice ("not only … joining the sections … but … also joining … the sections together with their flanged margins in abutment").

Note: US1471465 and US1488246 are not on the page's Similar Documents list. I found them incidentally via search and retrieved text from their PDFs, but did not confirm full bibliographic data (US1471465's exact issue date is unconfirmed; US1488246 appears dated 1924-03-25). Treat them as supplementary, not as record art.

Assessment — Group A: strong obviousness. The joint claims are the weakest claims in the patent. Their only non-trivial feature is the specific notch/I-section splice, and the notched-web splices in the knockdown-scaffolding art are directly on point.

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4. Group B — tower/top-section structural claims (3, 6, 7, 8)

Combination 3 → Claims 3 and 6

Motivation. Daragon's express object is an apparatus "allowing of practicing all exercises such as escalading, climbing, trapeze and fixed bar work, ring work, balance suspension, lateral translation jumping, Swedish bar exercises etc.," which "can be set up almost instantaneously" and is "adjustable as to the height of the members." Daragon thus already teaches the two-tower-plus-platform architecture for mass gymnastic instruction — the same problem and the same field. A PHOSITA wanting that apparatus in permanently installed, high-load, many-user form (the patent's stated object: "withstand the strains and stresses of use simultaneously by numerous individuals") would replace Daragon's guy-rope-and-ladder uprights with the bolted channel-post towers and diagonal bracing that the scaffolding art supplies. That is a predictable substitution of materials and joints, not invention.

Combination 4 → Claims 7 and 8 (oblique hand-walk ladder + hangers)

Clauses:

• Claim 7: "a ladder disposed obliquely under the top section … side rails each made up of a plurality of sections joined end-to-end and having hand-gripping portions, and cross rung-providing rails"
• Claim 8: adds "hangers depending from some of said reinforcing members and rigidly joined to the ladder side rails"

Prior art: US1779903A (Daragon) discloses "a small movable ladder d terminated with handles e" mounted on the top platform, plus ladders m and Swedish bars n; US1488246 / US1471465 show rung-bearing pipe frames; US1104505A (Holworthy) shows a portable exercising apparatus of the horizontal-bar type with detachable standards and bracing members — i.e., the gripping-bar/handrail concept. The hand-gripping tubular ladder rail is nothing more than the ladder-as-exercise-element idea applied to Daragon's movable ladder.

For claim 8, the specification itself supplies the motivation: the ladder sections "are of such respective length that the joints therebetween are disposed approximately in registration with the supporting uprights" and the hanger, which "spans the joint between two adjacent units," "function[s] in suspending the respective ladders … but in also reinforcing the connection between the several sections." Aligning a joint with its support and using the support to back up the joint is standard structural practice (cf. Marlowe's bearer/support relationship in a knockdown scaffold). Under KSR, "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions" — here the hanger does nothing more than its two known jobs.

Assessment — Group B: strong obviousness for 3 and 6; moderate-to-strong for 7 and 8, with claim 8 the more defensible because of the specific hanger-plate/reinforcing combination. The strongest single reference is US1779903A, which I verified in text.

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5. Group C — claim 9 (three cat-walks of differing cross-section)

Claim 9 requires a horizontal-top cat-walk, a V-shaped ("gutter") top surface, and an inverted-V ("pyramid"/"ridge") top surface, all extending lengthwise between the towers.

Combination 5:

• US1779903A (Daragon) — top section extending horizontally between and connecting the upper ends of the towers, with lengthwise structure and user-walkable platform
• US2193339A (Bleacher construction, 1940-03-12) — sheet-metal formed load-bearing surfaces of channelled and ridged cross-section (bleacher seats/decks are routinely folded into channel, trough and ridge profiles for stiffness)
• US1984767A (Playground apparatus, 1934-12-18) — playground structures with varied walking/climbing surfaces
• Knowledge of the art: formed sheet-metal decking in V (valley) and inverted-V (ridge) profiles is the elementary way to stiffen a thin sheet and to present drainage, and both shapes are the standard cross-sections of balance beams.

Motivation. A single fabrication line can produce a flat walk and V/inverted-V walks from the same gauge sheet by changing one fold. The patent offers no asserted advantage for the V and inverted-V shapes other than walkway variety; the record contains no evidence of unexpected results. Providing a variety of balance surfaces on one rig is the self-evident purpose of a multi-station training structure, and the shapes themselves are the two most common folded-metal profiles. Claim 9 is a combination of old elements each performing its own function — i.e., an aggregation.

Assessment: moderate-to-strong obviousness, weakest in evidentiary support because I did not verify the texts of US1984767A or US2193339A in this session.

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6. Group D — claim 10 (the omnibus combination claim)

Claim 10 recites, on one structure: a stall bar tower at one end, a jungle tower at the other, a top section joining them, an inclined hand-walk ladder beneath the top section, a crawl-tunnel beneath it, a climb-up rope depending from the top section, a climb-ramp, and a climbing pole.

This is the classic § 103 target. Every element is individually old and each performs exactly its own known function:

Motivation — supplied by the patent itself. The specification states the object: "the provision of a structure compactly combining a plurality of different types of physical exercising equipment for the physical training and development simultaneously of a relatively large number of men," and "especially … adapted and designed for army camp installation." Where the problem is stated as combining many exercise stations for mass training, combining many exercise stations for mass training is the definition of obviousness under KSR: "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results."

Two reinforcing points:

1. The classification itself concedes the point. The patent sits in CPC A63B17/00 — "Exercising apparatus combining several parts such as ladders, rods, beams, slides." The existence of a pre-existing combination class means the art already expected these elements to be assembled together. A63B2225/10 ("Multi-station exercising machines") is a further acknowledgement.
2. The forward-citation universe proves the field was crowded. Every one of the 16–24 Cited By publications — Madigan's educational tracks, Liggett's challenge course, Cooper's mobile multi-user trainer, Afo S.r.l./Amer Sports' modular gym structure, Ropes Courses' challenge course with return track, Whincup's mobile obstacle course — is a variation on the same "stations on a common frame" theme. This is hindsight-proof evidence of a crowded, incremental art in which such combinations were routine.

Assessment — Claim 10: weakest claim in the patent; very strong obviousness. It reads as a bare recitation of the stated objects of the invention. Under KSR, the absence of any asserted synergy among the linked stations sinks it.

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7. Cross-cutting motivations that unify the combinations

1. Demountability / transportability. Both the scaffolding references and this patent's stated object ("readily transported and co-operatively fabricated for convenient, rigid connection one with the other by a relatively small installation crew") address the same design problem. Same problem → strong KSR motivation.
2. Mass simultaneous use. The patent's own framing ("simultaneously by numerous individuals," "army camp installation") is the reason to scale up Daragon's guy-roped apparatus and to brace it with the scaffolding art's diagonal members. The bracing claims (3, 6) are directly responsive to a load requirement, and load-driven design is routine engineering.
3. Reasonably pertinent art. The scaffolding references are not "non-analogous art." The test is whether the reference is "reasonably pertinent to the particular problem with which the inventor was involved" (In re Wood; In re Bigio). Where the claims are drawn to a load-bearing joint and to tower/bracing structure, scaffolding and railway-tower art is squarely pertinent, and it would be illogical to hold otherwise when the joint claims (1, 2, 4, 5) contain no exercise function at all.
4. No secondary considerations of record. The page contains no evidence of commercial success, long-felt need, copying, or unexpected results. The specification asserts efficiency ("The structure answers and from installation and use has been found to most efficiently [perform]") without data.

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8. Counterarguments a defender would raise (and why they largely fail)

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9. Verification ledger — what I actually confirmed this session

What I do not know: I have no verified disclosure text for Marlowe (US1969656A) or for any of the 1934–1941 scaffolding/playground/bleacher references. A rigorous § 103 opinion would require the specification and drawings of at least US1969656A, US2193339A and US1984767A, plus an invention-date determination to decide whether US2267638A is available. I will not manufacture element-by-element mappings for references I have not read.

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10. Bottom line

Overall conclusion: The claims of US2365117 as a whole are highly vulnerable under § 103. The patent recites a stated problem — compactly combining many known exercise stations into a transportable, heavily braced frame for simultaneous mass use — and then claims the solution to that problem at a level of generality (§ 103's worst posture) while the only genuinely specific subject matter (the notch/I-section splice) sits in an art (knockdown scaffolding) where such joints were standard. The strongest surviving features are the narrow splice geometry of claims 1–5 and the ladder-reinforcing hanger of claim 8; claims 9 and 10 in particular read as recitations of the specification's own objects. The single most decisive reference in the record is US1779903A (Daragon), which I verified in text and which discloses the two-tower-plus-top-frame gymnastic structure with poles, ropes, ladders and adjustable bars — leaving only the knockdown channel splice and the multi-station detailing to be supplied by the scaffolding art.