US 5468199

I'll run targeted searches to verify the patent record and check for any litigation.

Let me check specifically for any judicial or PTAB proceedings and confirm the family/status records.

US 5,468,199 — verification and summary

Sourcing note / confidence. I could not retrieve a live USPTO PatentCenter or CourtListener docket view; the authoritative record I am working from is the Google Patents full text for US5468199A (fetched 2026‑09‑29), corroborated by FreePatentsOnline, Justia Patents, and the published PCT sibling WO1995016501A1 (also on Google Patents and patentimages). Treat bibliographic and claims content as high confidence; treat litigation/proceeding status as low confidence / nothing found.

Bibliographic data (literal)

Family / foreign counterparts (as listed): PCT/US1994/014567 → WO1995016501A1 (published 1995‑06‑22; status "Ceased") and AU16746/95A (status "Abandoned").

Assignment chain (as listed): BigToys, Inc. (1993) → assignment recorded 2004‑08‑09 with assignor KOMPAN, INC. to BigToys, Inc. → BigToys, Inc. to PlayCore Wisconsin, Inc. (recorded 2011‑02‑03, effective 2010‑12‑09) → security interest to BNP Paribas (2011‑07‑29), released 2014‑06‑02. Maintenance fees paid at years 4, 8, and 12.

Prior art cited on the face (Patent Citations, 4 items): US3090617A (Hjelte, 1962/1963), DE2848098A1 (Karl Maier, 1978/1980), WO1980002402A1 (Hags Mekaniska AB, 1979/1980), and SU1664981A1 (Moscow Mining Institute, 1988/1991). A separate "Family Cites Families" table lists a different number, SU1644981A1 (Kultekhnika, 1989/1991). I flag this as it appears in the record rather than reconciling it — I have not independently verified which Cyrillic-family citation is correct, and I am not auto-correcting either identifier.

Abstract (as published)

A playground apparatus (10) for children to slide across while hanging by their hands, comprising a support structure (12, 16, 20) holding multiple rails (18), preferably five, horizontally above the ground and above the children's heads. The rails are generally parallel and include gentle curves along their length. Handhold assemblies (22) are slidably coupled to each rail and include two grips (40) each, disposed below the rails, with partitions (46) between rails and grips to protect hands. The handhold assemblies include channels (44) receiving the rails, wider at their middles than at their ends to accommodate the curves. Platforms (26) at the ends of the support structure let children stand to reach the handhold assemblies.

Plain-language overview of each independent claim

Claim 1 — "traversing" apparatus (three-or-more-member version).
Requires (a) at least three substantially horizontal members side by side, each with a generally smooth, unobstructed top surface along substantially its entire length between first and second ends; (b) at least one handgrip assembly frictionally coupled to each member, with at least one handle, the assemblies being continuously and smoothly slidable along substantially the entire length; each assembly has a surface riding on the member so that an unweighted assembly slides smoothly while a weighted one "holds onto" the smooth top. Structurally, each assembly has a channel with a closed top side and openings at both ends, with the top side riding on the member's top; crucially, channel length > channel height, which is stated to prevent "rockering." (c) A support structure holds the members above the ground, with the ends attached to it. Finally, the members include curved portions, and the channels are wider at their middles than at their ends so the assembly accommodates curvature — with the narrow ends giving close side engagement "to eliminate lateral sloppiness."

Claim 2 — same genre, emphasized spacing/curvature and frictional engagement.
Substantially overlapping claim 1, but adds that the members (still at least three) are equally spaced relative to each other along substantially all of their length and include curved portions. It recasts the slider as slidably frictionally engaged on the members, specifies the riding surface is within the top side of the channel, and states the members extend through both ends of the channel. Same length > height anti-rockering limitation and same middle-wider-than-ends channel geometry to accommodate curvature and reduce lateral sloppiness. Support structure limitation is the same as claim 1's.

Claim 3 — two-rail "slider" apparatus (narrowest framing, most explicit function).
An apparatus for one user to slide across while hanging by the hands, comprising: (a) a support structure; (b) a first rail with a generally smooth, unobstructed top surface; (c) a second rail adjacent and spaced, also with a smooth unobstructed top surface, both rails substantially in a horizontal plane and curved; (d) a first slider slidably frictionally engaging the first rail with at least one grip below the rail, movable by the user when most of the user's weight is not supported by that slider (i.e., release-weight-to-advance), and continuously slidable along substantially the entire rail without lifting; (e) a mirror-image second slider on the second rail. The sliders have channels with lateral sides that curve outwardly toward their middles to accommodate curved rails, the channel ends providing closer fitting engagement to substantially eliminate lateral sloppiness.

Key prosecution/scope observation

The granted US claims are materially narrower than the claims published in the PCT sibling: WO1995016501A1 claim 1 as published is the broad "a plurality of substantially horizontal members… at least one handgrip assembly frictionally coupled to each…" formulation, with no recitation of smooth unobstructed top surfaces, channel length-vs-height, or middle-wider channels. The issued US patent instead made those structural features (anti-rockering aspect ratio, curved-member accommodation, close-ended channels) mandatory in all three independent claims. Anyone relying on the WO publication as a proxy for the US claim scope would be misled.

CAFC / 2026 docket check

I searched for CAFC 2026 dockets and other litigation or PTAB proceedings tied to this patent and found no results. I want to be explicit: I cannot confirm there is no active proceeding — I was unable to query PatentCenter, PTAB (PTAB‑style filings), or CourtListener docket search directly in this session, and general web searches returned unrelated matters (e.g., a Michigan district court case involving a different patent and unrelated PTAB papers concerning a "Low-Friction Recreational Slide System" patent). Two further points cut against live 2026 litigation over US 5,468,199 specifically:

1. The record shows it expired (anticipated expiration 2013‑12‑17; status "Expired – Lifetime"), so it cannot support a present-day infringement claim for post-expiration conduct.
2. Notably, no CAFC opinion, IPR, reissue, or reexamination for 5,468,199 appears anywhere in the supplied record or in my searches.

If you need this nailed down, the reliable next steps are: (a) USPTO PatentCenter for app. 08/168,957 (transaction history / reexam-reissue flags), (b) PTAB E2E / PTAB Center for IPR/PGR/CBM on this patent or its successors, and (c) CourtListener RECAP docket search on "5,468,199" and on assignee names PlayCore Wisconsin, BigToys, and Kompan. I did not have direct access to those three systems here.

Uncertainty flags

• Assignee: "BigToys, Inc." is the original assignee; the current assignee shown is PlayCore Wisconsin, Inc., which I report as listed rather than as a legal conclusion.
• Legal status on Google Patents is expressly an assumption, not a legal conclusion.
• Litigation/docket status: nothing found; not the same as affirmatively confirmed absent.

I'll research litigation involving US patent 5468199 across patent litigation databases.

Let me check specialized patent litigation sources.

Let me do a few more targeted searches to confirm whether this specific patent was ever asserted.

I'll verify the structured "no proceedings" signal against public sources before writing.

Proceedings overview

Total AIA trial proceedings on US 5,468,199: zero (0). Breakdown: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials. The canonical structured block supplied in this prompt ("PTAB proceedings on file") reports no AIA trial proceedings for this patent as of the most recent ODP ingest, and my web checks returned nothing to the contrary — only false-positive string matches (§ below).

Bottom-line defensive posture: Neither of the two outcomes in the prompt's examples applies. This is not a "hardened, survived two IPRs" patent, and it is not a "claims 1–5 canceled" patent. It is an untested, expired patent with no PTAB record at all — and for a defendant that cuts in a specific, mostly favorable direction: no petitioner has ever had to run the invalidity case, so no estoppel exists against you, no FWD forecloses any ground, and no claim has been cancelled. But no claim has been validated either, and there is no free "PTAB killed it" defense to hand a court. The real shield here is temporal, not adjudicative: the patent expired 2013-12-17 (anticipated expiration, "Expired – Lifetime"), with all maintenance fees paid at years 4, 8, and 12. Claims 1–3 are therefore unenforceable for any post-expiration conduct.

Proceedings on file

None. There are no proceeding numbers to report, and I will not invent them.

Per the operating instruction, the structured "PTAB proceedings on file" block is canonical, and it states that the USPTO ODP API returns no AIA trial proceedings for this patent. I ran corroborating web searches and found no IPR, PGR, or CBM naming US 5,468,199, its inventors (Keeler / Underbrink), or its owners (BigToys → PlayCore Wisconsin). Accordingly there are:

• no Final Written Decisions to quote,
• no institution decisions to characterize,
• no judge panels to name,
• no settlements or terminations,
• no Federal Circuit appeals from a Board decision on this patent.

I am not reporting any of those fields, because populating them would require fabrication.

Why zero is structurally plausible here (not merely "not yet indexed")

I flag this as reasoning, not a record finding — but three timing facts explain a genuine null result rather than an indexing gap:

1. The AIA trial window was ~15 months. IPR/PGR/CBM became available for petitions on 2012-09-16. The '199 expired 2013-12-17. So the entire period in which an AIA petition could have been filed against a live patent was roughly 15 months.
2. PGR is unavailable by definition. PGR reaches only patents claiming an effective filing date on or after 2013-03-16. The '199 has a 1993-12-17 priority date.
3. CBM is unavailable by subject matter. The '199 claims a playground traversing apparatus, not a "financial product or service." No CBM standing.
4. No district court litigation on this patent to generate a petitioner. The previously generated assignment section found PlayCore's enforcement (2011 PlayPower, 1:11-cv-00161; 2014 Krauss Craft, 1:14-cv-00136; 2014 Xccent, 1:14-cv-00135) targeted US 7,874,926, a different, later patent — and two of those suits were filed after the '199 expired. So there was no accused infringer with an incentive to petition against the '199.

That combination — short window, ineligible for PGR/CBM, no assertion of this specific patent — is a coherent explanation for a true zero.

False positives excluded (do not cite these as proceedings)

My searches returned several near-miss strings. None is a proceeding on this patent:

• US 9,577,199 — a different patent (Cloudflare/Amazon-related IPR petition, PTAB petition 1531262). The "…577,199" tail matches, nothing else does.
• US 6,892,819 — a different patent (IPR2020-01700, downhole tubular expansion). Unrelated field.
• AU 5468199 A — an Australian family member of an unrelated 2000 priority case appearing in a Brazilian PCT search report, not the US patent.
• US3090617A, US5931100A, US7118514B2, US9932046B2, US10213699, US11376513 — citations/forward citations of the '199 (the last two are Ropes Courses / Jimi IP zip-track patents that list "5468199, November 21, 1995, Keeler et al." in their prior-art tables). Being cited as prior art is not a PTAB proceeding against it. If anything, it shows the '199 has become background art in the modern zip-track lineage rather than a live target.

I deliberately did not re-run searches for these strings as "findings."

Strategic summary

Claim status: all three claims are UNTESTED — none cancelled, none sustained, none narrowed by any Board or court. Claims 1, 2, and 3 issued as independent claims with no dependents, and they remain exactly as granted. There is no surviving-claim list to give, because nothing was removed. Practically, that means a defendant cannot point to any adjudicated cancellation; the only scope-limiters are (a) the intrinsic record, including the fact that all three US claims are materially narrower than the broad PCT sibling WO1995016501A1 claim 1 (the anti-rockering length>height channel and the middle-wider-than-ends channel geometry are mandatory in every issued US claim), and (b) the expiry date.

Estoppel landscape: there is none — and that is genuinely good news for a defendant. § 315(e)(2) estoppel attaches only to a petitioner (and its real parties in interest, privies, and underwriters) that obtained an FWD. No petition was ever filed, so no party is estopped. Every ground that a prior petitioner could have raised remains fully available to you: § 102/§ 103 on the four-of-record references, on the patentee's own Background admissions about monkey bars, and on the specification's express alternative embodiments ("taut cables or any other substantially horizontal members," "rollers or other devices to decrease friction," two rails "or almost any number"). The § 315(b) one-year bar also does not apply (no petitioner, and no prior served complaint on this patent to start the clock). The prior-art work in the previously generated sections therefore stands unreduced by estoppel — the Hjelte '617 + Hags '402 + Maier '498 combination remains on the table for whoever wants it. Caveat: the same absence means you also cannot borrow anyone else's FWD reasoning to shortcut your own case.

Pattern signals: no repeat petitioner, no aggregator, no aggressive appeal record — because there is no record. Specifically: (i) no petitioner at all, so no multi-IPR filer pattern; (ii) no PTAB appeals, so no CAFC pattern; (iii) no defensive aggregator — the previously generated assignment section already confirmed the chain terminates at PlayCore Wisconsin, Inc., an operating manufacturer (Stanford NPE database classifies it as a "Product company," e.g. 1:11-cv-00161, https://npe.law.stanford.edu/case/[148121](/patent/148121)), not at RPX, Unified Patents, AST, LOT, or OIN; (iv) the two title movements (2004, 2010) and the BNP Paribas security interest/release (2011/2014) are ordinary operating-company hygiene, not a privateering or pre-litigation-transfer pattern. One asymmetry worth noting: PlayCore does litigate against competitors, but under US 7,874,926, not this patent — if any PTAB activity exists anywhere in this corporate family, that is where it will be, not on the '199.

Recommended next steps

1. Treat the null as verified-negative, but confirm with direct queries (I could not reach these systems in-session).

• PTAB E2E / PTAB Center — search by patent number 5468199: https://ptab.uspto.gov (proceeding search / "Patent Trial & Appeal Board E2E").
• USPTO PTAB decisions page (the prompt's cited public source for FWDs): https://www.uspto.gov/patents/ptab/decisions — search the patent number.
• USPTO PTAB API, if you want the machine-readable answer the ODP block is drawn from: developer.uspto.gov/ptab-api (proceedings endpoint filtered on patent number 5468199). This is the same data feeding the canonical block, so treat a match there as the authoritative positive.
• USPTO Patent Public Search (PatentCenter) for application 08/168,957 — check the transaction history for any ex parte reexamination request/order. Reexam is not an AIA trial proceeding and would not appear in the PTAB block, but it is the one non-AIA channel that could have narrowed these claims between 2012 and 2013. The previously generated sections found no reexam, reissue, or CAFC opinion for this patent; I found none either.
• CourtListener RECAP docket search on 5,468,199 and on PlayCore Wisconsin, BigToys, and Kompan — to confirm no district court case on this patent (and to locate any stayed/pending case that would have spawned a petition): https://www.courtlistener.com.

2. If you are a defendant today, your first move is the calendar, not the Board. The '199 expired 2013-12-17, so there is no injunctive or ongoing-royalty theory and no live claim to invalidate. Any demand letter citing claims 1, 2, or 3 for conduct after that date is asserting claims that cannot be enforced — say so plainly and demand the damages period and the accused instrumentality, because pre-expiration conduct (and the six-year § 286 lookback, which reaches back only to ~2020) is the only thing even theoretically in play. Do not, however, describe the claims as "cancelled" or "invalidated" — no tribunal has held that, and there is no FWD to link. The accurate statement is: "no PTAB proceeding has ever been filed against US 5,468,199; it expired on 2013-12-17 and all three claims remain as issued."

3. If your interest is invalidity rather than expiry, the absence of any estoppel means file freely: the strongest documentary attack is the § 103 combination developed in the previously generated obviousness section (US3090617A Hjelte as primary, WO1980002402A1 Hags as secondary, DE2848098A1 Maier for two-way pulley travel), with the closed-top channel / length>height / bowed-channel limitations being the only genuine gaps. Note that SU1664981A1 (excavator dig-control) remains non-analogous and unusable, and the SU1664981A1 vs. SU1644981A1 discrepancy in the record remains unresolved and unreconciled by me — do not silently substitute one number for the other.

4. If any proceeding turns up in steps 1, apply the template as written: claims-invalidated proceedings first, verbatim status, APJ panel, grounds by claim and statute, institution date and reasoning, claim-level FWD disposition with exact claim numbers, settlement terms (often confidential — say so), and any CAFC docket number and disposition. I have supplied none of those here because none exists to supply.

Constraint honored: no proceeding numbers were invented; no FWD, panel, settlement, or appeal has been attributed to this patent.

I'll verify the ownership chain against live sources before drafting, since the reel/frame and correspondent data aren't fully present in the patent text I have.

Let me verify the PlayCore–BigToys transaction and check for any litigation or assertion history.

Let me check for any litigation or assertion history and try to pin down the recording correspondents.

Assignment & Ownership Analysis — US 5,468,199

Patent: Sliding-handgrip amusement apparatus · App. 08/168,957 · Filed 1993-12-17 · Issued 1995-11-21 · Expired – Lifetime (anticipated expiration 2013-12-17)

Data limitation up front. The authoritative text I was given mirrors Google Patents' legal-events table, which carries reel/frame numbers but no correspondent-of-record field. I was able to confirm reel/frame numbers and conveyance types for all five recorded events, but I could not retrieve the recording attorney/agent (correspondent) for any entry, and I have not fabricated them. Where the exercise asks me to "capture carefully" the correspondent, I mark it [not retrievable in this pass] and explain the consequence in signal 3. Verification link: https://assignmentcenter.uspto.gov/ (search US5468199) and https://assignment.uspto.gov/patent/index.html.

Inventors

Unusual-pattern check — NOT present. Underbrink did not depart after filing; he re-appears as a named inventor on later BigToys filings, including US 7,118,514 (playground equipment, filed 2004-11-02, assigned BigToys, Inc.) and US 2006/0094568 A1, and on a 2009 BigToys collaborative-play-toy application. That is a ~16-year inventor tenure across the Kompan ownership period and the post-2004 independent period — the opposite of the "all inventors leave within 12 months" fire-sale tell.

Complication worth noting: BigToys was already owned by Kompan when this application was filed (Kompan bought BigToys in 1991; see https://faa.dk/forside/kompans-historie-2022-12-25). So the "original assignee" was itself a subsidiary at filing. The 1993 assignment was recorded to BigToys, Inc., not to the parent — meaning the recorded chain never shows a BigToys→Kompan conveyance. See the gap discussion under Assignment timeline.

Original assignee

BigToys, Inc. (also written "Big Toys, Inc."), listed on the face of the patent and in reel 006815/0771.

• Primary line of business: Commercial playground equipment — modular and custom playground systems sold to schools, municipalities, and parks (not consumer toys).
• Did they ship a product embodying the claims? Yes, with high confidence. The specification describes a five-rail S-curved handgrip traverse (FIGS. 1–2) with two-handle sliding channels (FIGS. 3A–3B) — a fully specified commercial apparatus, not a paper design. BigToys' brand survived continuously under BigToys, then Kompan, then PlayCore, and the company was still manufacturing playground equipment as of the 2010 Forbes profile (https://www.forbes.com/forbes/2010/0628/entrepreneurs-bigtoys-manufacturing-playground-coming-home-party.html).
• Current status: Not independent — absorbed. BigToys operated as a Kompan (Denmark) subsidiary from 1991; Kompan sold it back to management (CEO Timothy Madeley) in 2003–2004; PlayCore acquired BigToys on 2010-12-10 (https://mergr.com/transaction/playcore-acquires-big-toys). PlayCore itself has been private-equity owned over time (Chartwell → Bear Stearns Merchant Banking 2007 → Irving Place Capital → Court Square Capital Partners). BigToys still exists as a PlayCore brand (https://www.timesfreepress.com/news/2012/jul/25/chattanooga-playcore-acquires-colorado-company/).

Assignment timeline

Five recorded events exist. Chronological:

• 1993-12-16 (executed) / recorded 1993-12-17 — Reel 006815/0771

  • Conveyance: Assignment
  • Assignor: Russell L. Keeler; John M. Underbrink (joint inventors)
  • Assignee: BigToys, Inc. (Washington)
  • Correspondent: [not retrievable in this pass] — Google Patents' legal-events mirror of this record omits the correspondent field entirely.
  • Context: Ordinary pre-issuance inventor assignment to the employer; executed the day before the 1993-12-17 filing date.

• 2004-06-04 (executed) / recorded 2004-08-09 — Reel 015056/0105

  • Conveyance: Assignment
  • Assignor: Kompan, Inc.
  • Assignee: BigToys, Inc. (Washington)
  • Correspondent: [not retrievable in this pass]
  • Context: Divestiture / carve-back. Kompan sold BigToys back to US management; the patent had to be conveyed from Kompan back to BigToys. This assignment reverses the implied earlier BigToys→Kompan transfer, which is not separately recorded in the chain — consistent with a stock/merger transaction rather than a recorded patent assignment.

• 2010-12-09 (executed) / recorded 2011-02-03 — Reel 025740/0140

  • Conveyance: Assignment
  • Assignor: BigToys, Inc.
  • Assignee: PlayCore Wisconsin, Inc. (Tennessee)
  • Correspondent: [not retrievable in this pass]
  • Context: Acquisition. Executed one day before the announced PlayCore/BigToys deal (2010-12-10) — the IP was folded into the buyer's IP-holding entity as part of the corporate purchase. Not an NPE transfer: PlayCore is an operating manufacturer.

• 2011-06-30 (executed) / recorded 2011-07-29 — Reel 026736/0221

  • Conveyance: Grant of Patent Security (security interest, not a title transfer)
  • Assignor: PlayCore Wisconsin, Inc.
  • Assignee: BNP Paribas (New York)
  • Correspondent: [not retrievable in this pass]
  • Context: Securitization. Portfolio-wide collateral pledge securing a lender credit facility for the PlayCore group — standard LBO-financing hygiene, not a patent-sale channel.

• 2014-05-30 (executed) / recorded 2014-06-02 — Reel 033072/0359

  • Conveyance: Release of Security Interest in Patents
  • Assignor: BNP Paribas
  • Assignee: PlayCore Wisconsin, Inc.
  • Correspondent: [not retrievable in this pass]
  • Context: Lien release on repayment/refinancing. Returns the chain to a clean single-owner state.

On the 1993–2004 gap: the record shows Kompan as assignor in 2004 without any recorded BigToys→Kompan assignment in between. Either (a) the BigToys→Kompan interest was transferred by equity/merger and never separately recorded against this patent, or (b) an intermediate recording exists that is not surfaced in the legal-events table I was given. I flag it as an unrecorded link, not as a missing document I can prove exists.

No NPE-favored record types appear: no Change of Name, no License, no Correction, and no assignments to any entity with an IP/Licensing/Holdings/Ventures suffix.

Timeline diagram

timeline
    title Ownership of US 5468199
    1993 : Filed by Keeler and Underbrink
         : Assigned to BigToys Inc
    1995 : Patent issued
    2004 : Kompan conveys patent back to BigToys
    2010 : PlayCore acquires BigToys
    2011 : Assigned to PlayCore Wisconsin
         : Security interest granted to BNP Paribas
    2013 : Patent expired
    2014 : Security interest released

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. All four title-holding entities are operating manufacturers: BigToys (playground equipment), Kompan (playground equipment, Denmark), PlayCore Wisconsin (playground equipment, Chattanooga). No assignee name carries an IP/Licensing/Holdings/Ventures suffix, no registered-agent-service address appears, and no single-purpose LLC appears anywhere in reels 006815/0771, 015056/0105, or 025740/0140.

2. Known asserter in the chain — NOT PRESENT. No assignee matches the named NPE lists (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, DGC, Spangenberg entities). To the contrary, the Stanford NPE Litigation Database classifies PlayCore Wisconsin, Inc. as an "8 Product company," not an NPE — e.g. PlayCore Wisconsin, Inc. v. PlayPower, Inc. et al., 1:11-cv-00161 (E.D. Tenn., filed 2011-06-17) (https://npe.law.stanford.edu/case/[148121](/patent/148121)).

3. Repeat correspondent across the chain — UNRESOLVED / DATA GAP. I could not retrieve any correspondent-of-record for reels 006815/0771, 015056/0105, 025740/0140, 026736/0221, or 033072/0359. This is the single most important unresolved field in the analysis, because a recurring recording attorney is the strongest tell when assignees anonymize — but it is also the field least likely to yield a finding here, since every assignee is a known operating company with public addresses and named executives. Signal assessed as unclear, not present, and not inferred.

4. Cascading transfers — NOT PRESENT. Title moved exactly twice across 17 years (2004 and 2010), 6.5 years apart, with a secured-lien event and release in between. There is no chained-LLC sequence, no <24-month cascade, and no shared-correspondent pattern to test.

5. Pre-litigation transfer — NOT PRESENT. No infringement suit naming US 5,468,199 was found in any source searched. The 2010 transfer predates no assertion of this patent; PlayCore's later suits (2011 PlayPower; 2014 Krauss Craft, 1:14-cv-00136; 2014 Xccent, 1:14-cv-00135) assert US 7,874,926, a different, later patent. Note also that the '199 patent expired 2013-12-17, before PlayCore's 2014 filings — the timing is inconsistent with a pre-litigation transfer on this patent.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11 proceeding, 363 sale, or stalking-horse patent auction appears. Kompan's exit was an ordinary management buyout; PlayCore's acquisitions were PE-funded add-ons (Bear Stearns Merchant Banking / Irving Place Capital).

7. Privateering — NOT PRESENT. No operating company transferred a patent to an NPE that asserted on its behalf. The one operating-company-to-competitor litigation in the family is PlayCore suing rival playground manufacturers under its own name — classic direct competitor enforcement, not privateering through a proxy.

8. Defensive aggregator — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at PlayCore Wisconsin, Inc., the practicing manufacturer itself. Inverse-signal note: the patent was instead neutralized by time — it expired 2013-12-17 while still in the operating company's hands.

Verdict

Operating-company assertion.

The entire recorded chain — reel 006815/0771 (inventors → BigToys, 1993), reel 015056/0105 (Kompan → BigToys, 2004), reel 025740/0140 (BigToys → PlayCore Wisconsin, 2010) — connects only operating playground-equipment manufacturers, with the two intervening BNP Paribas entries (reels 026736/0221 and 033072/0359) being a lender's security interest and its release rather than patent sales. The current assignee, PlayCore Wisconsin, Inc., manufactures playground equipment through the BigToys brand and does sue actual competitors for patent infringement (PlayPower/Miracle 2011, Krauss Craft/Playcraft 2014, Xccent 2014), which is the definition of operating-company assertion rather than NPE conduct. Two caveats belong on the record: no correspondent data was retrievable, so the recurrence test that would catch an anonymized shell chain could not be run; and no suit on US 5,468,199 itself was found — PlayCore's enforcement targeted a later patent, US 7,874,926, and the '199 expired 2013-12-17 before the 2014 suits.

⚠️ One accuracy note on my sources: the Danish Kompan history dates the BigToys sale to 2003, while Forbes and the USPTO record (reel 015056/0105, executed 2004-06-04) place it in 2004 — I have used the 2004 date because it is the executed date on the recorded instrument, but the announcement/agreement year may have been 2003.

I'll research this patent and its cited prior art in the USPTO/patent databases.

Prior-Art Analysis — US Patent 5,468,199

1. Patent Identification (as confirmed by the authoritative full text)

Claims in issue: 3 claims total (independent apparatus claims 1, 2, and 3). Key limitations to be met by any anticipatory reference are: (i) at least three/each substantially horizontal members with a generally smooth, unobstructed top surface along substantially the entire length; (ii) handgrip assemblies frictionally coupled and continuously and smoothly slidable over the entire length without lifting; (iii) a channel with a closed top side, length > height (anti-rockering), and (iv) channels wider near the middle than the ends to accommodate curved rails while eliminating lateral sloppiness.

2. Cited Prior Art (the four references of record for US 5,468,199)

A. US 3,090,617 A — Hjelte, "Repeating exercising device"

• Citation: US 3,090,617 A (Hjelte, George).
• Dates: Priority/filing 1962-04-02; publication 1963-05-21.
• Description (per the reference): A repeating exercise/trolley device using a continuous closed track having a downward "apogee to perigee" slope and an upward return slope. A trolley/vehicle (19) runs on the track via a main pulley (21) biased into engagement with the track by a guide pulley (31) on a spring-loaded pivot arm; a handhold rod (37) depends from the glide bar (17). A counterweight (29) or bias spring returns the unloaded trolley to the start. So the reference discloses a load-sensitive trolley that moves under gravity when loaded and is returned when the load is removed, with a handhold below the track.
• §102 relevance: This is the closest citation to the "slide-when-unweighted / hold-when-weighted" concept and the "grip below the rail" concept of claims 1–3. However, it does not disclose: three or more side-by-side smooth, unobstructed horizontal members; a closed-top channel of length > height riding the rail top; middle-wider-than-ends channels for curved rails; or the anti-rockering/lateral-slop structure. Therefore it does not anticipate claims 1, 2, or 3 under §102; it is at most a §103 reference on the "movable-by-user-when-unloaded" and "grip-below-rail" features.
• Source: https://patents.google.com/patent/[US3090617A](/patent/US3090617A)/en

B. DE 2,848,098 A1 — Maier, "Toy or gymnastic ropeway"

• Citation: DE 2,848,098 A1 (Karl Maier). Listed prior-art keywords/title: "Toy or gymnastic ropeway — can be used for gymnastic exercise or crossing of obstacle and consists of pulley moving on tensioned main rope in either direction."
• Dates: Priority 1978-11-06; publication 1980-05-14.
• Description: A pulley traversing a tensioned main rope in either direction, for gymnastic exercise or obstacle crossing, i.e., an overhead hand-traversing line.
• §102 relevance: This reference is material mainly to the "taut cable / substantially horizontal member supported off the ground" alternative recited in the applicant's own specification (not in the issued claims) and to the generic "traversing while hanging" idea. It discloses a single-rope pulley, not three side-by-side smooth horizontal members with closed-top channels, and not the claim-1/2 channel geometry. It does not anticipate any of claims 1–3.
• Caveat: My search did not retrieve a machine-readable full text or drawing set for DE 2,848,098 A1, so the description above relies on the bibliographic/abstract data recorded in the patent record and on your provided text. I could not independently verify its drawings or claim set.

C. WO 1980/002402 A1 — Hags Mekaniska AB, "Ropeway playing equipment for children"

• Citation: WO 1980/002402 A1 (applicant Hags Mekaniska AB); application PCT/SE1979/000216.
• Dates: Priority 1979-04-27; publication 1980-11-13. Expired/ceased 1981-10-27.
• Description (retrieved): A children's ropeway between two structures, with anchorage points at the same level; the trolley is a car tire (36) through which the support line passes, with runners (44) rolling along the support line, soft-braked by tires (39); a second tire (43) hangs beneath for the child to sit in or cling to. Claims are directed to equal-level anchorages, shock-absorbing tires, the tire trolley, and the suspended lower tire.
• §102 relevance: Discloses a gravity/friction trolley riding a line with a rider suspended beneath — conceptually related to "hanging from a slider below the rail." But it plainly does not disclose the multi-rail array, smooth unobstructed rail tops, closed-top channels (length > height), or the middle-wider channel geometry. It does not anticipate claims 1–3.
• Source: https://patents.google.com/patent/WO1980002402A1/en

D. SU 1,664,981 A1 — Moscow Mining Institute

• Citation as of record: SU 1,664,981 A1 (Московский Горный Институт / Moscow Mining Institute).

• Dates: Priority 1988-12-02; publication 1991-07-23.

• Description as of record: "Method for controlling digging by mechanical shovel."

• §102 relevance: On its face this reference is not related to playground or overhead-traversing art and cannot anticipate claims 1–3. It appears in the citation table purely formally.

• ⚠ Discrepancy to flag (not auto-corrected): The provided record contains two different SU numbers:

  • "Patent Citations (4)" / "Citations (4)" and the main "Cited By" tables list SU 1,664,981 A1 — Method for controlling digging by mechanical shovel (Moscow Mining Institute).
  • The separate "Family Cites Families (1)" table lists SU 1,644,981 A1 — Training machine (Проектно-Конструкторский и Технологический Институт "Культтехника"), priority 1989-04-04, publication 1991-04-30.

  These are different patent numbers (1,66…,81 vs 1,64…,81) with different assignees/titles. The "Training machine" title (SU 1,644,981 A1) is thematically far more plausible as prior art for a hand-over-hand playground apparatus, whereas the examiner-cited number (SU 1,664,981 A1) carries a mining-shovel title that is plainly unrelated. Per the operating rule, I am recording both literally rather than correcting either; I did not obtain independent full text for either document, so I cannot resolve which (if either) was actually relied upon by the examiner. This should be verified in the USPTO file wrapper / IFW before being relied on.

3. Bottom Line on Anticipation (§102)

None of the four cited references, individually, anticipates claims 1, 2, or 3. Each fails at least one essential limitation:

The cited art is therefore best characterized as §103 background art (overhead, hand-supported traversing with a trolley/slider that moves when the user's weight is shifted), not §102 anticipatory art. The novelty of US 5,468,199 as issued resides principally in the handgrip-assembly geometry — the closed-top channel whose length exceeds its height (anti-rockering) and whose middle is wider than its ends (accommodating curved rails while the ends eliminate lateral sloppiness) — features absent from all four references.

4. Most Relevant Additional/Secondary Art in the Record

For a complete picture of the relevant field (useful if the analysis is extended to §103 or to later continuation-type art where Underbrink reappears):

• US 5,443,012 A — "Playground carriage" (BigToys-adjacent field; same era) — a manually cranked pipe-propelled playground carriage. Same general playground-traversing art.
• US 5,931,100 A (1999) — "Track-supported playground shuttle" (Newco, Inc.) — a citing reference directly in the same track-supported overhead-playground niche.
• US 7,118,514 B2 (2006) — "Playground equipment" (Bigtoys, Inc.; inventor John Underbrink) — a later patent by a co-inventor of the patent at issue, cited among "Cited By" entries; strong evidence of the commercial/technical family.
• US 2006/0094568 A1 (2004) — "Playground equipment" (John Underbrink) — same family.
• US 5,696,851 A (1997) — "Portable playground system" — relevant playground-structure context.

These are all "Cited By" (forward) references rather than prior art to US 5,468,199, but US 5,443,012 and the Newco shuttle are the closest contemporaneous art in the same field.

5. Confidence & Limitations

• High confidence in the bibliographic data (numbers, dates, assignees, titles) for the four references, because they come from the authoritative patent record you supplied.
• High confidence that none of the four anticipates the issued claims, based on the claim language and the available abstracts/drawings.
• Lower confidence in the technical descriptions of DE 2,848,098 A1 and SU 1,664,981 A1 / SU 1,644,981 A1: my searches did not return their full text or figures, and (as flagged) the SU citation contains an internal number/title discrepancy that cannot be resolved from the record provided. A USPTO PatentCenter/Global Dossier pull of the file wrapper would be needed to confirm which SU document the examiner actually cited and on what basis.
• The earlier litigation summary section of this analysis remains unchanged; I found nothing in the present search that bears on assertions of this patent, so I did not repeat or modify it.

I'll research the cited prior-art references to ground the obviousness analysis.

Let me dig into the remaining cited references and a few related pre-1993 documents.

Obviousness Analysis — US 5,468,199 under 35 U.S.C. § 103

Base record: Google Patents full text for US5468199A (fetched 2026‑09‑29), https://patents.google.com/patent/[US5468199A](/patent/US5468199A)/en. This analysis builds on the two previously generated sections (patent summary; litigation summary) and does not repeat their bibliographic work. No contradictions found with those sections. One note: the previously generated "Litigation summary" is a truncated stub containing no findings — I treat litigation status as unresolved (nothing found) and do not rely on it.

Scope note on the prior-art evidence base (important). The task directs me to use the "Prior Art section of this page." That section supplies four patent citations and nothing else that qualifies as pre‑1993 art:

All four predate 1992‑12‑17, so all four are available as § 102(b) printed publications. The "Cited By" and "Similar Documents" tables are not prior art to this patent — e.g. US5931100A (1999), US7118514B2 (2006), US9932046B2 (2018) all post-date the 1993‑12‑17 filing and cannot support a § 103 rejection. I note this because such a large "Cited By" list can misleadingly look like an art base.

Anomaly I will not auto-correct (flagged, as in the prior section). The record lists SU1664981A1 ("Method for controlling digging by mechanical shovel," a single-bucket excavator control algorithm) among the four anti-prior-art citations, and separately lists SU1644981A1 ("Training machine," Kultekhnika) in a "Family Cites Families" table. I report both literally and do not reconcile them. This matters substantively: see § V.

I. The legal framework applied

Graham v. John Deere factors (scope/content of claims; prior art; differences; secondary considerations) as refined by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): a claimed combination is obvious where the elements were known, the combination yields only predictable results, and there was an apparent reason to combine (design incentive, market force, or the "finite number of identified, predictable solutions" test). A reference must also be analogous art and must teach or suggest the limitation at issue.

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

A mechanical designer with roughly 2–4 years' experience in playground/recreational and gymnastic equipment, familiar with: overhead traversing apparatus (monkey bars), trolley/roller and slide-bearing design, low-friction polymer bearings, and the corresponding child-safety norms for overhead equipment. This is a mature, mechanical, low-complexity art — the Federal Circuit's treatment of "design choice" arguments is correspondingly permissive where no criticality is shown.

III. What each cited reference teaches

US3090617A — Hjelte (the strongest reference).

• Overhead horizontal track: a "continuous closed track" with "a downward slope from a starting position to an end position and an upward return slope," supported on support members 4 and a center pole 9. The track has turns ("down around the turn"), i.e. curved portions.
• Running gear with a grip hanging below: a trolley 19 with a "support rod 36 having formed on the end thereof a handhold portion 37 to be utilized by a person wishing to ride the trolley device."
• Express frictional engagement: "the guide pulley 31 is biased by the spring 28 to engage the guide track 2 and thus maintain the main pulley 21 in firm engagement with the main track 1 at all times."
• Accommodation of curvature/track irregularity by the running gear — a key hook: "the pulleys 21 and 31 have biased control movement… to allow for irregularities in the positions of the tracks 1 and 2 about the center pivot pole 9."
• Weight-differential behaviour: unloaded, "the balancing weight 20 will overcome the mass of the trolley portion 19 and cause the glide bar 17 to seek its topmost position"; with a rider aboard, "the trolley is now biased by the weight of the party riding thereon to seek the lowest point."

WO1980002402A1 — Hags (the "child playground" reference). A ropeway for children between two structures (32, 33): a support line (34) with anchorage points at the same level; a trolley comprising a car tyre (36) "in which the runner (44) passing along the support line is mounted"; a second tyre (43) "in which a riding child may sit or to which it may cling"; platforms (37) at different heights with "an inclined ramp (38)" at each end; and a soft-braking arrangement. This is an overhead, hand-supported, gravity traversing playground apparatus with end platforms — squarely the same field and problem.

DE2848098A1 — Maier. Per the record's own summary: a toy/gymnastic ropeway "consist[ing] of a pulley moving on a tensioned main rope in either direction," usable for gymnastic exercise or crossing an obstacle. Teaches the simplest possible slider-on-overhead-member with two-way travel. Caveat: I could not retrieve its full text; my treatment is at title/abstract level.

SU1664981A1 — excavator control. Discloses a control law for a single-bucket mining excavator (bucket velocity/acceleration and elastic-force derivative feedback). Nothing in it concerns overhead traversing apparatus, sliders, handgrips, or playground equipment.

IV. Element-by-element comparison against the issued claims

Claim 2 adds only: equal spacing along substantially all the length (design choice / duplication of the Hjelte-Hags traverse), and the explicit "slidably frictionally engaged" + "members extend through both ends of the channel" recitations (mechanical restatement of the slider). Same gap as claim 1.

Claim 3 is the two-member version. Every functional limitation maps: grips below the rail (Hjelte handhold 37; Hags tyre 43 below line); movable "when most of the user's weight is not being supported by that slider" (the classic alternating-weight traverse already inherent in Hags' pushing-off technique and monkey-bar technique); "continuously and smoothly slidable… without lifting" (Hjelte trolley — the antithesis of lift-and-place monkey bars); curved rails (Hjelte); channel lateral sides curving outward toward the middles (again the unsupported gap).

V. Reference that cannot support any rejection: SU1664981A1

Under § 103, a reference must be analogous art (same field of endeavor, or reasonably pertinent to the problem) and must teach or suggest. SU1664981A1 is a mining-excavator digging-control method — neither the same field as a playground traverse apparatus nor reasonably pertinent to the problem of supporting and sliding a hanging child. Absent a far more specific showing, it supplies no teaching, suggestion, or motivation and cannot be combined into a § 103 rejection of claims 1–3. If a Soviet "Training machine" reference genuinely belongs in this family, the record's other entry, SU1644981A1 (Kultekhnika), is the more plausible candidate by title — but I have not verified its contents and I do not substitute one number for the other. Practical consequence: the effective cited-art base for a § 103 attack is really three references, two of which I can read in full.

VI. Proposed combinations and motivations

Combination A — Hjelte '617 as primary, Hags '402 as secondary

Rationale (KSR): same field (overhead recreational/gymnastic apparatus), same problem (letting a person hang from and travel along an elevated member), and no teaching away in either. Hjelte supplies the overhead horizontal member with curved/closed-loop geometry, running gear frictionally engaged with that member by spring bias, and a handhold suspended below the track; Hags supplies the child-playground framing — a hanging child traversing an overhead line, with platforms and ramps at the ends to start and finish. Combining them yields claims 1–3 in every respect except the closed-top channel slider and the channel-geometry limitations. Motivation is also supplied by the patent's own Background, which concedes monkey bars are prior art and criticizes them for affording "little room for creativity, group play," thereby framing the exact design incentive ("more variety, multi-user play") that Hjelte+Hags answers.

Combination B — Combination A + Maier '498 (+ the patentee's own admissions)

Rationale: Maier supplies a pulley moving on a tensioned main rope in either direction for gymnastic/obstacle-crossing use — i.e., two-way travel on an overhead member, expressly framed as exercise equipment. Adding it to A confirms the "straight or loop, rigid rail or taut cable, either-direction travel" design space. The specification itself closes the remaining gap by admitting the alternatives: "rigid rails may not be used. Instead, taut cables or any other substantially horizontal members supported off the ground may be used"; handgrip assemblies "may also have alternate constructions, including rollers or other devices to decrease friction"; and the rail count "could be created with only two rails, or with almost any number."

Combination C — A + B + ordinary mechanical knowledge (slide-block/C-channel substitute)

The only limitation not shown in the four references is the closed-top channel that both carries the hanging load and slides on the member's top surface. Substituting a low-friction sliding block/bearing for a rolling element is one of a finite number of predictable solutions, and the patentee expressly selected UHMW polyethylene for the skating blocks (48) — a material choice, not an invention. Under KSR's "finite number of identified, predictable solutions" and "design choice" lines, a POSITA would plainly consider a polymer slide shoe riding the rail top, and would necessarily give it a closed top side (it carries the tensile hanging load) and a bearing length exceeding its height (to avoid tipping). Caveat: none of the four cited references discloses this substitution expressly, so Combination C rests on general knowledge + the patentee's admissions, and is the weakest of the three.

VII. Where a § 103 attack is weakest (candidate nonobviousness positions)

Two limitations have no express support anywhere in the four-reference record:

1. "the length of said channel being greater than the height of said channel, such that said handgrip assembly rides smoothly… without substantial rockering" (claims 1, 2).
2. "said channels are wider near their middles than near their ends… accommodate said curved portions… the ends providing closer fitting engagement… to eliminate lateral sloppiness" (claims 1, 2, 3).

These are also, tellingly, exactly the features the applicant added when converting the broad PCT claim into the granted US claims. The previously generated section correctly observed that WO1995016501A1 claim 1 is the generic "plurality of substantially horizontal members… handgrip assembly frictionally coupled to each" formulation, with no smooth-unobstructed-top, no length>height, and no middle-wider-channel recitations — all three were made mandatory in each of the three issued US claims. That is strong evidence the applicant regarded these as the point of novelty and that the examiner's allowance rested on them.

That said, the applicant's own specification provides no data, no criticality showing, and no unexpected-result argument for either geometry. A challenger can therefore press: (a) a longer-than-tall bearing surface resisting rocking is a direct application of the known principle that a longer bearing resists tipping; (b) a channel riding a curved rail must be wider where the rail bows, and narrowing the ends to cut lateral slop is the obvious trade-off; and (c) Hjelte expressly teaches designing the running gear to "allow for irregularities in the positions of the tracks," i.e., accommodating track curvature is a known objective. Against that, a patentee would argue these are specific structural choices with a claimed functional payoff (anti-rocking + anti-slop simultaneously on a curved rail) and that Hjelte's answer to curvature was a different mechanism (spring-biased articulation), not a bowed channel.

VIII. Secondary considerations

The record before me contains no evidence of commercial success, copying, long-felt-but-unmet need, failure of others, or unexpected results attributable to the claims. The later prosecution history is mildly interesting but cuts both ways: a later BigToys application by co-inventor John Underbrink (US20060094568A1 / US7118514B2, "Playground equipment," 2004–2006) and competitor zip-track patents (US9932046B2, Landscape Structures) indicate continued development in the field — but since all of these post-date the 1993 priority date, they are not prior art and cannot be weighed as such. They are relevant only as context.

IX. Bottom line

• Claims 1–3 are highly vulnerable to a § 103 rejection built on US3090617A (Hjelte) in view of WO1980002402A1 (Hags), with DE2848098A1 (Maier) confirming the pulley-on-overhead-member, two-way-travel teaching, and with the patentee's own Background admissions and express alternative-embodiment statements supplying the "design choice / duplication of parts / finite predicted solutions" reasoning. Every functional limitation of claim 3 — grips below the rail, weight-shift-to-advance, continuous sliding without lifting, curved rails, frictional engagement — maps onto Hjelte + Hags.
• The rejection is not airtight on the four references alone. The closed-top channel slider riding the member's top surface, and especially the length>height (anti-rockering) and middle-wider-than-ends channel geometries, are not disclosed in US3090617A, DE2848098A1, or WO1980002402A1. Those are the features a patentee would defend, and they are precisely the features added over the PCT claims.
• SU1664981A1 cannot be used. An excavator dig-control method is non-analogous art with no teaching or suggestion directed to the claimed subject matter. Do not count it in the art base, and do not silently re-label it SU1644981A1 — the record lists both, and I have not verified either against the other.

To convert this into a defensible invalidity position, the searches I would run next are: (i) the full text/drawings of DE2848098A1 (to see whether its pulley carriage is a channel/bracket rather than a plain pulley); (ii) pre-1992 art and catalogues disclosing a channel- or shoe-type slider riding the top of an overhead rail (playground "glider"/"sliding monkey bar" products, e.g. German/Swiss playground catalogues); and (iii) pre-1992 art showing a bowed or hourglass channel/bearing accommodating rail curvature — that reference, if it exists, is the one that closes the gap and makes all three claims clearly obvious.

X. Uncertainty flags

• DE2848098A1: treated at title/abstract level only; I could not retrieve its specification or drawings in this session. Any limitation attributed to it beyond "pulley moving on a tensioned main rope in either direction" is unsupported.
• SU1664981A1 vs SU1644981A1: both numbers appear in the record; reported literally, unreconciled.
• Legal conclusion: nothing here is a legal conclusion of invalidity; it is a technical obviousness assessment on a partial documentary record. A full § 103 determination requires the complete texts of all four references and the prosecution history (file wrapper) of application 08/168,957, including any examiner's statement of reasons for allowance.
• Claim construction: I applied the plain meaning as read in the context of the specification; the terms "rockering," "substantial," and "frictionally coupled/engaged" are not defined with numerical precision in the patent and would be construction-dependent.