US 5469623

I'll search for docket/litigation information on this patent, then summarize.

The searches returned no relevant results for this patent. Let me try one more targeted query.

Search results — litigation / docket inquiry

No results found. I searched for US5469623 in connection with CAFC 2026 dockets, infringement suits, and PTAB proceedings, and returned nothing relevant. Specifically:

• No Federal Circuit appeal, district court action, ITC investigation, or PTAB (IPR/PGR) proceeding naming US5469623 surfaced in any search.
• The only third-party database hit was a commercial patent-analytics page (patentleaderboard.com) listing the patent among Shawn P. Crosby's patents — not a litigation record.
• Several searches returned unrelated patents/tools sharing the number "5469623" (e.g., a daneshyari.com article ID, EP1232839A1, various 3M cutting-tool cases). Per your instruction, I am not treating those as this patent.

Caveat: absence of search hits is not affirmative proof that no proceeding exists. USPTO Patent Public Search / PatentCenter, PACER, and the CAFC docket are the authoritative sources; I could not query those databases directly here. If you need certainty, a PACER docket search and a CAFC case-docket search on "5,469,623" should be run directly.

I also note the patent's own prosecution/ownership record shows no litigation-related reassignment or license events — only the original 1994-04-29 assignment to Minnesota Mining and Manufacturing Company, a 1999 maintenance-fee payment (4-year), and lapse for non-payment effective 1993-11-28 (recorded as 2003-11-28), with anticipated expiration 2014-04-29.

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US 5,469,623 A — Concise summary

Abstract (as issued)

A cutting tool adapted to be reciprocated by a manually manipulated air hammer or similar device while being used to separate laminated materials. The cutting tool comprises a blade of thin resiliently flexible metal having a sharpened edge and an opposite driven edge, and an adapter comprising a blade holder portion which may include polymeric material permanently molded around a portion of the blade adjacent its driven edge, and a shank portion shaped for engagement by the air hammer attached to the blade holder that has an end shaped for engagement by the air hammer or similar device. The majority of or all of the adapter can be formed of the polymeric material to provide a low mass for the cutting tool and an average specific gravity for the adapter that is significantly less than the specific gravity of metal.

Plain-language overview of the independent claims

There are three independent claims — two apparatus (1 and 10) and one method (19).

Claim 1 — Cutting tool defined by low adapter specific gravity.
A hand-guided cutting tool driven by an air hammer to separate laminated materials (e.g., moldings/emblems from vehicle panels). It has two parts:

1. A blade of thin, resiliently flexible metal with two major faces, a sharpened edge, a driven edge opposite it, side edges between them, and an imaginary centerline midway between the side edges and running from the sharpened edge to the driven edge.

2. An adapter made up of:

   • a blade holder portion containing polymeric material wrapped around the blade near its driven edge, with a rear part abutting that driven edge and front parts extending forward along the blade's faces toward the sharpened edge;
   • means for retaining the blade portion in the holder; and
   • an elongate shank aligned so its axis lies generally in the same plane as the blade's imaginary centerline, extending rearward (away from the sharpened edge), with a rear end shaped to fit the air hammer.

   The point of novelty/scope: the polymeric material gives the adapter an average specific gravity below about 1.84 (i.e., less than magnesium), making the tool light and inexpensive while still durable and effective.

Claim 10 — Cutting tool defined by low mass per inch of blade.
Same structural elements as claim 1 (blade, blade holder portion with rear part and front parts, retaining means, shank in the same plane as the blade centerline, air-hammer-engageable rear end), but the claim is closed by a weight limitation rather than a specific-gravity limitation: the whole cutting tool must have a mass no greater than about 4.86 ounces per inch of length of the driven edge of the blade. Claim 10 does not itself require the blade holder to contain polymeric material — the weight cap is the operative limitation. (Dependent claims 11–13 tighten this to ~1.62, ~1 oz, and ~0.74 oz per inch respectively.)

Claim 19 — Method of making the cutting tool.
A manufacturing method: provide a thin resiliently flexible metal blade as described (major faces, sharpened edge, driven edge, side edges, centerline), then mold polymeric material to form the adapter — the blade holder portion (rear part abutting the driven edge, front parts extending along the blade faces) and the elongate shank portion (rear end shaped for air-hammer engagement, front end attached to the holder with its axis generally in the same plane as the blade centerline, extending away from the sharpened edge). The molding must be done so that at least the majority of the adapter is polymeric material, giving the adapter an average specific gravity below about 1.84.

Notes on dependent-claim structure

• Claims 2–9 depend from claim 1: all-polymeric adapter (2); coaxially molded metal rod in the shank abutting the driven edge with a polymeric layer around it (3); radial polymer thickness exceeding rod radius (4); adapter specific gravity ≤ about 1.44 (5); holder geometry — rectangular cross-section ≥ about 0.4 in thick, equal front-part thicknesses, rear part width ≥ about 0.3 in (6); shank axis parallel to blade faces (7); 4-inch blue tempered clock spring steel blade about 0.012 in thick (8); retention via permanently molded polymer plus through-openings in the blade (9).
• Claims 11–18 depend from claim 10: progressively lower mass limits (11–13); all-polymeric adapter (14); metal rod in shank with polymer layer (15); polymer radial thickness > rod radius (16); adapter specific gravity < about 1.84 (17); ≤ about 1.44 (18).
• Claims 20–24 depend from claim 19: all-polymeric adapter (20); molding step including the coaxial rod positioning with driving end abutting the driven edge (21); polymer radial thickness > rod radius (22); blade notch centrally along the driven edge receiving the rod (23).

Disclosure highlights supporting the claims

• Blade example: 4 in × 4 in, 0.012 in thick blue tempered clock spring steel (alternatives: full hard stainless shim stock, beryllium copper).
• Adapter variants: (a) all-polymeric (FIGS. 1–4 / FIG. 5) with adapter specific gravity ≈ 1.03; (b) polymer plus a ~3/16 in diameter, 5.15 in long steel rod (solid or tubular) coaxial in the shank, driving end abutting the blade's driven edge, driven end exposed at the shank rear — adapter specific gravity ≈ 1.44; (c) a metal-only alternative (FIG. 7) using welded hollow tubes 88/92 in a T with a spool-like air-hammer-engageable portion 95 — stated as not yet built.
• Stated tool masses: about 1.62 oz (1 in blade), about 2.54 oz / 0.85 oz per in (3 in), about 3 oz / 0.74 oz per in (4 in) for the rod-reinforced version; about 1 oz (1 in), 1.9 oz / 0.64 oz per in (3 in), 2.3 oz / 0.57 oz per in (4 in) for the all-polymeric version.
• Mold method (FIG. 6): rod located by mold pins 49 and collar 52 (leaving openings 49a and annular groove 52a), plus two sets of three opposed pins 54 to keep the blade flat (leaving openings 54a).
• Commercial context: useful with 3M "Overspray Masking Liquid"; the tool is stated to mark vehicle paint less than the tool of US 5,219,378.

Literal-reading flag (no auto-correction applied)

Claim 24 reads "A cutting tool according to claim 19..." even though claim 19 is a method claim. I am reporting this exactly as written in the authoritative text rather than correcting it; it is a claim-drafting inconsistency on the face of the patent (possibly intended to depend from claim 10 or to be a method claim), which could bear on validity/clarity analysis.

Confidence

• Bibliographic data, abstract, claim text, and disclosure: high confidence — taken directly from the authoritative Google Patents full text you supplied.
• Litigation/CAFC docket status: no authoritative information obtained; my searches returned no hits, and I could not query PACER or the CAFC docket directly. Treat "no known litigation" as unverified.

I'll search litigation databases for this specific patent number.

Let me run additional targeted queries on litigation-specific databases.

Known litigation involving U.S. Patent 5,469,623

No litigation is known. After searching litigation-focused sources for the specific number 5,469,623, I found zero district court actions, ITC investigations, PTAB proceedings, or CAFC appeals naming this patent.

I will not populate the requested case table with plaintiff/defendant/jurisdiction/case-number/filing-date/outcome fields, because doing so would require fabrication — no case exists in the results to fill them.

What I searched and what came back

Corroborating evidence from the patent's own record

The authoritative Google Patents full text you supplied (https://patents.google.com/patent/US5469623/en) is consistent with no litigation:

• Legal events show only: the 1994-04-29 assignment to Minnesota Mining and Manufacturing Company, a 1999 four-year maintenance-fee payment, a 2002 payor-number/entity-status event, a 2003 maintenance-fee reminder, lapse for non-payment effective 2003-11-28, and ultimate expiration for non-payment (37 CFR 1.362). There are no litigation-related reassignments, license/security-interest records, or adverse-party events.
• Cited By / Citing family lists are purely patent-document citations, not litigation citations. The nearest automotive-tool art (e.g., US 5,930,899, Snap-On Tools, "Molding and emblem removal tool"; US 8,826,544, "Sealant removal tool") are patent citations, not suits against the '623 patent.
• The patent expired for failure to pay maintenance fees effective 2003-11-28 (anticipated expiration 2014-04-29). A patent lapsed in 2003, about 28 years ago, would be an unlikely infringement-assertion vehicle.

Caveats — please read before relying on this

1. Absence of hits ≠ proof of absence. My searches surface indexed web content; they do not query authoritative litigation systems directly.
2. I could not run the searches you specifically requested against the authoritative sources. I have no direct access to PACER, the CAFC docket (cafc.uscourts.gov case search), USPTO Patent Public Search / PatentCenter, or the Unified Patents litigation portal (portal.unifiedpatents.com/litigation/caselist), and my live queries did not retrieve a case list from any of them for this patent. Three of my planned queries were cut off by a search-step limit.
3. To obtain certainty, run these directly on "5,469,623" (and on the family member US 5,640,772 / US 08/235,167):
   • PACER Case Locator (all district courts + appellate) — search "5,469,623" and "5469623".
   • CAFC case docket search on "5,469,623".
   • Unified Patents litigation/PTAB caselist portal, filtered by patent number.
   • USPTO PatentCenter "Legal Events" / assignment and PTAB proceeding search.

One consistency note for the record

Your previously generated summary states the anticipated expiration as 2014-04-29, which is correct for a patent filed/issued on these dates (20-year term from the 1994-04-29 filing). That same summary contained an internal typo — "lapse for non-payment effective 1993-11-28 (recorded as 2003-11-28)" — where the Google Patents legal-events table reads the lapse effective date as 2003-11-28. Both my analysis and the table above use 2003-11-28; the "1993" string is a typo, not a second event.

Bottom line: On the evidence available to me, no litigation involving U.S. Patent 5,469,623 is known, and its prosecution/ownership record shows none. Treat this as unverified pending a direct PACER/CAFC/PTAB check, which I was unable to complete.

PTAB / AIA trial proceedings on US 5,469,623

Bottom line up front: there are no AIA trial proceedings on file for this patent — none. The structured "PTAB proceedings on file" block supplied with this prompt (the USPTO Open Data Portal canonical list) is empty, and my independent web searches surfaced no IPR, PGR, or CBM proceeding naming US 5,469,623 or its CIP sibling US 5,640,772. Details, the reason the emptiness is unsurprising, and what it means defensively are below.

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Proceedings overview

Total AIA trial proceedings on US 5,469,623: 0 (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied). There is no PTAB outcome to cite, no FWD, no appeal, and therefore no claim of this patent has ever been canceled or confirmed in an AIA trial. Defensively, this is not a "hardened patent that survived IPRs" story — it is a dead-patent story: the patent is not merely unasserted but fee-lapsed, and no AIA trial ever existed because by the time the PTAB's IPR regime went live the patent had already been abandoned for years. A defendant's posture today is not "build an IPR defense" but "confirm the file history and maintenance-fee status, because there is no live patent to assert."

Caveat on method: the ODP block is authoritative here. Absence of search hits is not proof of absence, and I could not run a direct query against PTAB E2E / PTAB Center. What follows states searches actually run and their results, without inventing proceeding numbers.

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Per-proceeding detail

None. There is nothing to render in the required per-proceeding template.

For completeness, here is what the record does contain, and what I looked for:

Why there is no PTAB activity — and it isn't luck. Tracing the patent's own Legal Events table (from the authoritative Google Patents text):

• 1994-04-29 — application filed; assigned to Minnesota Mining and Manufacturing Company (Reel/Frame 006981/0254).
• 1999-03-29 — 4-year maintenance fee paid.
• 2003-06-18 — maintenance-fee reminder mailed.
• 2003-11-28 — "Lapse for failure to pay maintenance fees" (recorded lapse date 2003-11-28; docketed 2004-01-27 "Lapsed due to failure to pay maintenance fee," effective date 2003-11-28).
• Anticipated expiration listed as 2014-04-29.

The AIA's IPR/PGR/CBM provisions were enacted 2011-09-16 and IPR petitions became available 2012-09-16. This patent had already been abandoned for roughly eight years and ten months before the first IPR petition could even be filed. There was no commercial reason for anyone — including a defensive aggregator like Unified Patents — to spend $30,500+ in USPTO fees challenging claims that had been unenforceable since late 2003.

Contradiction flag (per your cross-reference instruction): the previously generated "Patent summary" section states the maintenance-fee lapse was "effective 1993-11-28 (recorded as 2003-11-28)." The 1993 date is wrong — it precedes the 1994-04-29 filing date and cannot be a lapse date. The authoritative Legal Events text gives 2003-11-28 only. Treat 2003-11-28 as the lapse date.

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Strategic summary

Which claims are canceled vs. sustained vs. untested. In AIA-trial terms, all 24 claims (1–9, 10–18, 19–24) are UNTESTED. No claim was canceled, no claim was confirmed, no certificate issued under §§ 318(b) or 328(b). The only narrowing this patent ever experienced was prosecution-stage: the file is a straight 1994 filing that issued 1995-11-28 as US 5,469,623 A, with a continuation-in-part that issued as US 5,640,772 on 1997-06-24 (also with no PTAB activity on the supplied ODP list). That CIP added a "rough peripheral surface" limitation on the metal rod (e.g., threaded, knurled, ringed, slotted, or perforated) and a corresponding set of method claims — notably, US 5,640,772's own claim set repeats the same drafting tic seen here, a claim reading "A cutting tool according to claim 15..." where claim 15 is a method claim.

Estoppel landscape. § 315(e)(2) estoppel is not triggered and effectively unavailable to analyze, because estoppel attaches to a petitioner who obtains an FWD — and there is no petitioner and no FWD. There is therefore no bar on any prior-art ground arising from AIA trials. Every ground a defendant might have wanted to raise remains formally unraised. This is cold comfort in the wrong direction: it means the patent's invalidity was never tested at the PTAB, so there is no ready-made "claims are dead" record to hand a judge. It also means the whole prior-art universe remains open — including the art cited on the face of the patent (US 833,869; US 2,264,374; US 2,335,872; GB 844,416; US 3,782,482) and the closest reference, US 5,219,378 (Arnold), which the specification itself characterizes as a two-part metal blade holder that is expensive to make and heavy — making the asserted point of novelty little more than "substitute high-impact ABS for the metal holder."

Pattern signals. No repeated petitioner (none exists). No patent-owner PTAB appeal history (nothing to appeal). No defensive aggregator in the chain. The only "pattern" is the inverse of the usual one: a patent that the patent owner itself stopped paying for in 2003, four years before the first Federal Circuit appeal of an IPR ever existed. Note also the family history — the EPO counterpart EP 0 757 612 A1 is recorded as withdrawn, the PCT as ceased, and the Canadian application CA 2,187,888 A1 as abandoned, with only the Japanese case JPH09512721A listed as active/pending in the listing. That is a family that was being pruned commercially, not one being litigated.

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Recommended next steps

1. Lead with expiration, not invalidity. If you are a defendant and a demand letter cites US 5,469,623, the dispositive response is not "IPR estoppel" or "the claims are invalid" — it is that the patent lapsed for non-payment of maintenance fees effective 2003-11-28 per the USPTO's own Legal Events record, and the asserted term has long since run. Confirm the current fee/status in USPTO Patent Center (https://patentcenter.uspto.gov) and pull the maintenance-fee transaction history before responding. Do not rely on the Google Patents "Expired - Fee Related" label alone.
2. Run the authoritative negative checks directly (I could not, and I will not represent search absence as proof):
   • PTAB E2E / PTAB Center — https://ptab.uspto.gov (search on "5,469,623" and on application 08/235,167, and on the CIP 08/423,206 / US 5,640,772).
   • USPTO Patent Public Search (https://ppubs.uspto.gov) — check for any ex parte reexamination or supplemental examination request, which the ODP AIA-trial list would not capture.
   • PACER / CourtListener — https://www.courtlistener.com — for any district-court or CAFC matter naming 5,469,623 (the earlier litigation search in this analysis returned nothing, but that too is unverified).
3. If, contrary to expectation, a live assertion exists, the practical posture changes: there is no FWD to quote and no canceled claim to point to (so you cannot say "claim 1 is dead — any theory built on it is sanction-bait"). Your strongest substantive arrows would be (a) the § 102/§ 103 overlap with Arnold US 5,219,378, which the patent itself admits discloses every structural element except the material substitution; (b) the § 112 indefiniteness / statutory-class problem in claim 24, which reads "A cutting tool according to claim 19" while claim 19 is a method claim — a defect of exactly the IPXL Holdings / Mastermine type that examiners and the Board have repeatedly held indefinite; and (c) the purely conformational "about 0.4 inch," "at least about 0.3 inch," and "less than about 1.84" boundaries in claims 5, 6, 8, 17, and 18.

Nothing in this section should be read as reporting an outcome. The accurate statement is: no AIA trial proceeding on US 5,469,623 is on file, no claim was ever tested at the PTAB, and the patent lapsed for non-payment of maintenance fees effective 2003-11-28.

I'll verify the assignment record before reconstructing the chain.

Ownership Analysis — US 5,469,623 A

Sources actually consulted in this pass: the authoritative Google Patents full text supplied in the prompt (its "Legal Events," "Application filed / Assigned to," and "Family Applications" blocks), the earlier litigation/docket search in the summary section (no relevant hits), and targeted web searches this pass for USPTO assignment records, 3M/3M Innovative Properties recordings, and any assertion history. USPTO Assignment Center was not directly queryable from this environment; the findings below rest on the assignment data surfaced in the Google Patents legal-events block plus the searches. Flagged where that limits confidence.

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Inventors

Patterns noted:

• No inventor-side assignments to any party other than 3M were recorded, and there is no separate inventor-to-employer agreement reel besides 006981/0254. That is the normal signature of employee inventors under a standing obligation to assign, not of a fragmented inventorship chain.
• Departure-based fire-sale pattern: not determinable. I have no reliable source for the employment tenure or departure dates of Roeker, Manor, or Crosby, and I will not infer a "all inventors left within 12 months" pattern from the absence of data. The one adjacent datapoint is that a continuation-in-part (US 5,640,772, filed 1995-04-17, i.e., 12 days inside the COP window closing 1995-04-29) was filed on the same subject matter, and 3M prosecuted the family (WO1995029797A1, EP0757612A1, CA2187888A1, JPH09512721A) — consistent with a live in-house program rather than an abandoned one.

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Original assignee

Minnesota Mining and Manufacturing Company (St. Paul, Minnesota) — the entity named on the face of the issued patent, and the assignee in the only recorded assignment (006981/0254, executed 1994-04-29).

• Did they ship a product embodying the claims? Yes, in substance — with a caveat. The specification itself is a commercial-goods disclosure: the cutting tool is described as used with 3M's own "Overspray Masking Liquid," is sized for standard air hammers, and the patent states the tool marks vehicle paint less than the rival tool of US 5,219,378 (Arnold). This is a 3M aftermarket body-shop accessory, not a bare laboratory disclosure. I did not find a current 3M catalog listing for the exact tool, so I state product-shipping as well-supported by the specification's commercial framing, not as independently catalog-verified.
• Primary line of business: diversified industrial/manufacturing conglomerate (abrasives, adhesives, tapes, automotive aftermarket, medical). The relevant internal unit is 3M's automotive aftermarket body-repair products business.
• Current status: operating. 3M Company (the renamed successor, see below) is a going concern and has never been in Chapter 7/11. The patent, by contrast, is expired — fee related: 4-year fee paid 1999-03-29; 8-year fee not paid, lapse recorded 2003-11-28, formal lapse registered 2004-01-27; a bulk database entry on 2018-01-26 records expiration for nonpayment under 37 CFR 1.362. Anticipated expiration was 2014-04-29. The foreign family was also dropped (CA abandoned, EP withdrawn, PCT ceased, JP the only application still listed as pending in the family table).
• Note on the "3M Co" current-assignee listing: Google Patents lists "3M Co" as current assignee and "Minnesota Mining and Manufacturing Co" as original assignee. That reflects the 2002 corporate change of name to 3M Company (and the existence of 3M Innovative Properties Company as 3M's IP-holding affiliate). No change-of-name recording, merger recording, or 3M→3M Innovative Properties transfer for this specific patent appears in the legal-events block. Treat the "current assignee" field as a database normalization, not as evidence of a recorded conveyance. Concretely: the record I can see does not show whether this patent was swept into 3M Innovative Properties Company by a bulk name-change/assignment recording.

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Assignment timeline

Only one recorded assignment exists in the chain. It is the original inventor-to-employer assignment, executed on the application filing date.

• 1994-04-29 (executed) / recorded 1994 — Reel 006981 / Frame 0254
  • Conveyance: Assignment (recorded as "ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignors: ROEKER, DAVID C.; MANOR, EDWARD L.; CROSBY, SHAWN P.
  • Assignee: MINNESOTA MINING AND MANUFACTURING COMPANY, St. Paul, Minnesota
  • Correspondent: Not retrievable from the records available to me. The Google Patents legal-events entry exposes only the reel/frame and the assignor string; it does not print the correspondent of record. I decline to name an attorney here. For context only — not as a finding for this reel — 3M recordings of that era were filed by 3M's own in-house Office of Intellectual Property Counsel, St. Paul, MN (e.g., the 1998 Dow/3M recording at reel 009596/0391, cover-sheet correspondent "H. Sanders Gwin, Esq., Office of Intellectual Property Counsel"). If you need the correspondent for 006981/0254, the cover sheet must be pulled directly from Assignment Center; it is not in the text I have.
  • Context: Original inventor-to-employer assignment filed contemporaneously with application 08/235,167. Not an acquisition, not a fire-sale, not a reorg.

No other recordings. There is:

• No security agreement or lien (no securitization signal),
• No license or release recording,
• No merger or change-of-name recording against this patent number,
• No post-issuance transfer of any kind.

Everything else in the legal-events block is maintenance-fee administration, not ownership: FPAY (1999-03-29), FEPP (2002-12-02), REMI (2003-06-18), LAPS (2003-11-28), FP (2004-01-27), STCH (2018-01-26).

Trap to avoid — do not confuse this with US 4,540,623. A search hit surfaced a recorded assignment at reel 009596/0391 (executed 1998-05-18 by Dow / 1998-11-03 by Minnesota Mining and Manufacturing Company) covering a schedule of patents that includes 4,540,623 ("Coextruded multi-layered articles," Im/Shrum). That is a different patent — a 1985 Dow/3M joint-work assignment. It is not a link in the US 5,469,623 chain, and I am not treating it as one. Per the operating rule, I read the identifier literally.

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Timeline diagram

timeline
    title Ownership of US 5469623
    1994 : Application filed by 3M inventors
         : Assignment to Minnesota Mining and Mfg Co reel 006981 frame 0254
    1995 : Patent issued
         : Continuation in part filed as US 5640772
    2003 : Patent lapsed for unpaid maintenance fee
    2014 : Anticipated expiration date

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NPE / troll-pattern signals

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Verdict

Insufficient data — specifically, the "only the original assignment" branch of that category.

Justification: the entire recorded ownership chain for US 5,469,623 is a single inventor-to-employer assignment executed 1994-04-29 and recorded at reel 006981 / frame 0254 to Minnesota Mining and Manufacturing Company; there are no post-issuance conveyances of any type, no security interests, no change-of-name recording against this patent number, and no license/release entries. The only later events on the patent are maintenance-fee administration — the 4-year fee in 1999 and lapse for nonpayment recorded 2003-11-28 — which means the patent was out of force more than a decade before its 2014-04-29 anticipated expiration, and the foreign family was abandoned or withdrawn in parallel. No NPE signal is available to assess because no transfer to any non-operating entity was ever recorded, and none of the eight signals is present.

Verification link: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ ; legacy search interface — https://assignment.uspto.gov/patent/index.html (search 5469623 or 08/235,167). Two items are worth pulling from the original cover sheet that I could not retrieve here: (a) the correspondent of record on reel 006981/0254, and (b) whether any change-of-name / 3M→3M Innovative Properties recording exists that was not surfaced in the legal-events block for this patent number.

I'll search for the patent on USPTO and verify each cited reference.

Prior-Art Analysis — US 5,469,623 A ("Cutting tool and method for manufacture")

1. USPTO record for patent number 5469623 (literal match only)

I searched for the exact number 5469623. The only records matching that number are this patent and its own file/child:

Confirmed against the authoritative Google Patents full text, and independently corroborated by the Justia and FreePatentsOnline mirrors. I did not count other "5469623"-adjacent hits (e.g., a daneshyari.com article ID, EP1232839A1) — those are unrelated documents. Note that EP1232839A1 (2002) actually cites US5469623A/US5640772A in its search report; a later document cannot be prior art to this patent, so it is excluded.

Caveat on method: I could not query USPTO Patent Public Search / PatentCenter directly; my verification came via the authoritative full text supplied plus web mirrors. The citation list below is the "References Cited" set printed on the face of US 5,469,623 A (6 patents/printed publications).

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2. The cited prior art — § 102 analysis

All six citations are to the claim-1/10/19 subject matter as a whole. Anticipation under § 102 requires that a single reference disclose every element of a claim. Key threshold point: all three independent claims are drawn to a cutting tool (or its molding method) that is driven by a manually manipulated air hammer, or that has the low-adapter-specific-gravity / low-mass-per-inch characteristic that is the stated point of novelty. That frame drives the analysis.

Reference 1 — US 833,869, Almon F. Bowen, "Reefing-tool" (filed 1906-04-25; published 1906-10-23)

A turn-of-the-century sail-reefing hand tool. It has no reciprocating power drive, no air-hammer-engagement shank, no adapter "specific gravity" or mass-per-inch teaching.
§ 102: Anticipates no claim. It has no air-hammer-driven shank or adapter-mass/SG limitation (claims 1, 10, 19), and no dependent claim can be anticipated if the independent claim is not.

Reference 2 — US 2,264,374, Ferdinand A. Henschell, "Flexible blade pot scraper" (filed 1939-04-19, Ser. No. 268,801; published 1941-12-02; 2 claims, class 30-169)

A thin flexible metal (preferably stainless-steel) scraping blade with a handle — relevant only as general art showing a thin flexible metal blade, an idea already old. Notably, the spec mentions "plastics" as an alternative blade material, but the reference is a manual kitchen implement.
§ 102: Anticipates no claim. It lacks the air-hammer structure, the molded polymeric adapter, and the SG/mass limitations. At most a general-technology reference; it does not disclose the claim-1 combination.

Reference 3 — US 2,335,872, Walter G. Mitchell, assignor to Sears, Roebuck & Co., "Cutlery and method of making the same" (filed 1940-07-27; published 1943-12-07)

Discloses a molded plastic (e.g., aceto-butyrate) handle bonded to a metal tang with a thermo-fluid bonding material, with interlock rivets/pits; relevant only to the general notion of molding polymeric material around a metal member and to low-density (plastic) handles.
§ 102: Anticipates no claim. It is a cutlery handle, not a reciprocating cutting tool; it discloses nothing of the air-hammer shank, the blade-holder geometry of claims 1/10, or the adapter-SG / mass-per-inch limitations.

Reference 4 — GB 844,416, Polycell Products Ltd., "Improvements in or relating to a decorator's tool" (filed 1958-01-07; published 1960-08-10)

A hand decorator's tool (scraper/putty-knife-type implement). General art for a thin flexible blade with a holder.
§ 102: Anticipates no claim. No air-hammer drive, no polymeric adapter SG/mass limitation.

Reference 5 — US 3,782,482, E. Miller, "Pistol-grip garden hoe" (filed 1972-05-24; published 1974-01-01)

A garden hoe with a pistol grip. Cited only for handle/implement configurations.
§ 102: Anticipates no claim.

Reference 6 — US 5,219,378, Robert A. Arnold, "Reciprocating cutting tool and method" (filed 1992-04-28; published 1993-06-15) — the only genuinely analogous reference

This is the prior art the patent expressly acknowledges and distinguishes. Its disclosed structure maps closely onto the structural preamble of claims 1 and 10:

• a shank (18) mountable in an air hammer / pneumatic hammer;
• a blade holder assembly comprising a base member and a retainer member with a shoulder received in a recess, clamped by screws, forming a blade receiver terminating at the shoulder;
• a blade with a fixed proximate end clamped in the receiver in abutment with the shoulder and a distal cutting edge; the patent's background describes this as a thin resiliently flexible clock-spring-steel blade with a sharpened edge and an opposite driven edge;
• a shank/shaft whose axis is aligned with the blade and extends away from the cutting edge;
• an air-hammer-engageable shank end/an annular retainer flange.

What US 5,219,378 does not disclose (the decisive gaps):

1. Claim 1: it is a two-part metal construction (base + retainer + screws), not an adapter "comprising polymeric material," and therefore cannot meet the limitation "said polymeric material in said adapter providing an average specific gravity for said adapter that is less than about 1.84." Its all-metal adapter would be far above 1.84.
2. Claim 10: nothing in the reference establishes the claimed mass of no greater than about 4.86 oz per inch of driven-edge length. (Notably, claim 10 does not require polymeric material — this is exactly why the present spec states a metal version (FIG. 7) could meet the mass limits; but the record contains no measurement of Arnold's device, so the mass element is unproven against Arnold.)
3. Claim 19 / method: no molding of polymeric material around the blade end to form the adapter; Arnold is an assembly-and-clamp method.

§ 102: US 5,219,378 anticipates none of independent claims 1, 10, or 19, and therefore none of the dependent claims that fall with them (2–9, 11–18, 20–24). It is the most relevant prior art — and almost certainly the reference against which the claims were allowed — but its relevance is as a § 103 obviousness starting point, not as § 102 anticipation. The claimed low-SG / low-mass adapter and the molding step are precisely the features absent from it.

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3. Overall § 102 conclusion

• Anticipated claims: none. No single cited reference discloses all elements of claim 1, 10, or 19.
• Closest art: US 5,219,378 (Arnold) — same field, same application (molding/emblem removal from vehicle body panels via an air hammer), and shares the claim-1 structural preamble — but its metal two-part adapter cannot satisfy the "specific gravity less than about 1.84" limitation of claim 1, and the record does not show it meets the mass limit of claim 10 or the molding step of claim 19.
• Secondary/background art: US 833,869; US 2,264,374; US 2,335,872; GB 844,416; US 3,782,482 — all non-analogous implements cited for isolated features (thin flexible blade; molded plastic handle around metal). Each anticipates no claim.
• Net: the novelty of US 5,469,623 rests on the low-specific-gravity / low-mass adapter (polymeric or polymer-plus-rod) and the molding method for it — none of which the cited art discloses in a single reference.

4. Flags and caveats

• The § 102 conclusions above rest on the claim language (via the authoritative full text and the FPO/Justia claim mirrors) and the face-of-patent citation list; I could not directly execute a USPTO Patent Public Search session, so a formal examiner's citation set (including any references cited only in the file wrapper, not printed on the patent) should be confirmed in PatentCenter.
• One family citation appears in the record — DE 4,222,250 C2 (Berthold Thieme, "Cutting device for severing glass panes glued to motor vehicle body parts," priority 1992-07-07, published 1995-04-13) — but it is listed under "Family Cites Families," not as a citation on US 5,469,623 itself, and post-dates the 1994-04-29 filing for its publication date; I have not treated it as § 102 art against this patent.
• No litigation/PTAB/CAFC record for US 5,469,623 was surfaced (consistent with the earlier litigation-inquiry section); treat "no known proceedings" as unverified.

I'll research the cited prior-art references to ground the obviousness analysis, then build the § 103 combinations.

Obviousness Analysis — US 5,469,623 A under 35 U.S.C. § 103

Patent: US 5,469,623 A ("Cutting tool and method for manufacture")
Applicant/assignee: Minnesota Mining and Manufacturing Co. (now listed as 3M Co)
Inventors: Roeker, Manor, Crosby
Filing/priority date: 1994-04-29 — pre-AIA patent, so pre-AIA § 103 governs
Source of truth: the full text you supplied from https://patents.google.com/patent/[US5469623A](/patent/US5469623A)/en

Builds on prior sections: I do not repeat the bibliographic summary, claim breakdown, or litigation inquiry already generated. One cross-reference flag is noted in § 10 below.

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1. Framework and critical date

Because the application was filed 1994-04-29, § 103 is applied under pre-AIA law: the inquiry is whether the claimed subject matter as a whole would have been obvious to a person having ordinary skill in the art at the time of invention. Graham v. John Deere Co., 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).

The four Graham factors:

1. scope and content of the prior art;
2. differences between the prior art and the claims;
3. level of ordinary skill in the pertinent art; and
4. secondary considerations (objective indicia).

The reference date for the prior art is 1994-04-29. Anything published after that date cannot be § 102(a)/(b) art. This matters for one family citation (see § 3.7).

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

A PHOSITA here would be a mechanical tool designer or tooling engineer with roughly 2–5 years of experience in the design of hand-held power-tool accessories (particularly pneumatic/air-hammer attachments), or a journeyman tool-and-die maker, with working knowledge of:

• thin spring-steel blade fabrication and hardening;
• air-hammer shank geometry and retention (the patent's collar part 47, engagement part 46, and spring retention are conventional);
• injection molding / over-molding of thermoplastics onto metal inserts and the resulting cost, weight, and dimensional characteristics.

Notably, all of these skills are in the same field of endeavor — hand and power cutting tools and their manufacture — so the second Graham factor (analogous art) is satisfied broadly across hand-tool, cutlery, and scraper art.

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3. The prior art of record — what each reference teaches

These are the six U.S./GB references cited on the face of US 5,469,623 plus the family citation listed on the page.

3.1 What Arnold (US 5,219,378) already discloses

Reading Arnold against claim 1, the following elements are present in Arnold:

• a blade of thin resiliently flexible metal (clock spring steel) with a sharpened distal cutting edge and an opposite fixed/proximate end that functions as the driven edge — this is exactly the blade recited in the 5,469,623 background section ("a blade of thin resiliently flexible clock spring steel having a first sharpened edge, and an adapter including a blade holding portion engaging a portion of blade along a driven edge opposite its sharpened edge");
• a blade holder portion with a rear part abutting the driven edge (the retainer-member shoulder closing the blade receiver, in abutment with the blade's proximate edge) and front parts extending along portions of the major surfaces (the base-member inner face and retainer-member inner face clamp the blade faces);
• means for retaining the blade portion in the holder (the mechanical fasteners/screws and clamping shoulder);
• an elongate shank with a portion adjacent its rear end shaped for engagement by an air hammer (annular retainer flange / spring-retained pneumatic-hammer shank), whose front end attaches to the blade holder, and which extends away from the sharpened edge;
• the tool is for the same purpose (separating molding/emblems from vehicle body panels) by the same mechanism (air-hammer reciprocation).

The point of departure is materials and mass, not structure. Arnold's holder is a two-part metal assembly; the 5,469,623 specification says so directly: "its blade holder portion is of two part metal construction which makes it expensive to manufacture and gives it a significantly high mass and specific gravity."

3.2 What Sears Roebuck (US 2,335,872) already discloses

Sears is the keystone secondary reference. It teaches, decades earlier:

• permanently molding/flowing a polymer around a metal blade portion to form a handle — "the tang and blade are united to a handle by flowed-in bonding material … the handle is preferably formed of a plastic material";
• retention through the blade itself — the blade tang is perforated at 29 and the handle at 28, so that the bonding material flows through and congeals into interlocking rivets 29; grooves 30/31 and bores strengthen the union. This is structurally the same retention mechanism recited in claim 9 (polymer extending through blade through-openings 45 to help hold the blade);
• an express design rationale for replacing metal with polymer: "economy of metal and also lightness of weight and proper balance. Reduction in quantity of bonding metal facilitates rapid cooling because of the relatively low quantity of total heat to be dissipated." This is precisely the rationale the 5,469,623 specification repeats (low mass, low specific gravity, and — for the rod embodiment — "allowing the polymeric material in the shank to freeze or solidify more quickly when it is molded because of its reduced thickness").

Sears is analogous art (hand cutting implements, blade-to-handle unions) and is not limited to a particular handle resin.

3.3 Note on the § 112(f) "means for retaining" element

Claim 1 recites "means for retaining said portion of said blade … in said blade holder portion." That is a means-plus-function limitation; the corresponding structure disclosed in the specification is (a) the permanently molded polymeric layer and (b) the through-openings 45 with polymer extending through them (claim 9; spec: "through which extend portions of the layer 27 of polymeric material that join the front parts 30 … and help hold the blade 16 in place"). For § 103 purposes, the prior art need only disclose structure performing the identical function that is the same as, or equivalent to, that disclosed structure. Sears' flowed-in bonding material plus interlocking rivets 29 through the perforated tang is at minimum an equivalent, and it performs the identical function (retaining a blade portion against a holder). This closes the "means" element against a § 112(f) narrowing argument.

3.4 Henschell (US 2,264,374)

Henschell is cumulative to Sears but adds two points: (i) a thin flexible metal blade rigidly secured to a handle is conventional in hand scraping tools, and (ii) the specification anticipates plastic as the handle material, reinforcing that polymer handles on bladed hand tools were an established option by the 1940s.

3.5 GB 844,416 (Polycell)

I could only verify the citation metadata, not the specification. On its face it is a decorator's tool — a hand cutting/scraping implement with a blade and handle — and is therefore cumulative to the general teaching that bladed hand tools conventionally use molded handles. I am not relying on it as a primary or necessary reference, and I flag it as a factual gap.

3.6 US 3,782,482 and US 833,869

Both are remote, old hand tools. Neither adds anything not already in Sears/Henschell. They do, however, support the general proposition that attaching a thin blade to a handle is a mature, predictable art.

3.7 DE 4,222,250 C2 (Thieme) — likely NOT prior art

This reference appears on the page only under "Family Cites Families," with publication date 1995-04-13 and priority 1992-07-07. As a foreign printed publication, its § 102(a)/(b) date is its publication date, not its foreign priority date — and 1995-04-13 is after the 1994-04-29 filing date of US 5,469,623. It therefore cannot be used against the claims of US 5,469,623.

Actionable flag: German applications are laid open 18 months after filing, which would put the A1 laid-open version (≈1994-01-13) on the books before 1994-04-29. If an examiner wanted to use Thieme, the correct citation would be DE 4,222,250 A1, not the C2. I could not verify the A1 publication date in this session — treat as a lead, not a fact.

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4. Independent claim 1 — element-by-element obviousness

Conclusion on claim 1: Prima facie obvious over Arnold in view of Sears Roebuck, optionally with Henschell and GB 844,416.

The motivation to combine (KSR factors)

1. Same field, known problem, finite solution set. Arnold's own field (air-hammer cutting tools) and Sears' field (blade-to-handle unions for hand cutting implements) are the same art. Substituting a known, lighter, cheaper molded-polymer holder for a two-part machined metal holder is one of a small number of known options.
2. Explicit design incentive in the prior art. Sears expressly identifies "economy of metal and also lightness of weight and proper balance" as benefits of replacing metal with flowed-in plastic — the very advantages 5,469,623 claims for its low-specific-gravity adapter.
3. A recognized secondary benefit — marring. The 5,469,623 specification states the polymer contact surfaces give "less tendency to mark the paint on the surface of those panels." A PHOSITA knows a polymer is softer than paint/steel; choosing a soft, low-modulus material for the part of an automotive-finish tool that touches paint is a predictable use of a known material property (KSR: "a known material's properties").
4. Cost. The specification itself concedes Arnold's two-part metal holder is "expensive to manufacture." Cost reduction is a legitimate and well-recognized motivation.
5. Reasonable expectation of success. Over-molding polymer onto metal blades and tangs was mature, predictable technology (Sears 1943; Henschell contemplating plastics 1941). No unpredictable chemistry or new mechanism is required.

The numeric limitation ("less than about 1.84")

Under In re Woodruff, 919 F.2d 1575 (Fed. Cir. 1990), and In re Peterson, 315 F.2d 571 (CCPA 1963), a numerical range that is result-effective and within/adjacent to a range taught or rendered obvious by the art is not patentably distinguishing. Here, "1.84" is simply the specific gravity of magnesium, cited as a convenient threshold for "significantly less than metal" (spec: "less than a specific gravity of about 1.84 which is the specific gravity of magnesium"). Once a PHOSITA selects a molded polymer for the adapter, every conceivable polymer falls below 1.84, so the limitation adds no patentable weight. The same reasoning disposes of claims 5 and 18 (≤ 1.44), and of the mass limits in claims 10–13 and 17.

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5. Independent claim 10 — the mass-based claim

Claim 10 is the same apparatus, closed by: "mass of no greater than about 4.86 ounces per inch of length of the driven edge of the blade." It does not require polymeric material.

Two independent lines of attack:

(a) Obviousness by material substitution. Arnold + Sears produces a tool whose mass is a direct arithmetic consequence of substituting ~1.0–1.4 specific-gravity polymer for ~2.7–7.8 specific-gravity metal. The specification's own figures land at 0.74 oz/in (rod version) and 0.57 oz/in (all-polymeric) for a 4-inch blade — far inside the claim. A limitation that is inherently met by the obvious substitution is not a patentable difference.

(b) A much sharper point — the outer bound may not even distinguish Arnold. Claim 10's limit is 4.86 oz total for a 1-inch driven edge, i.e. 4.86 oz/in applied at any blade width. Working backwards from the specification's own comparative statement — that the "three times" tool (9 oz total at 4 inches ≈ 2.22 oz/in) "would be less than half the weight of the same cutting tool when the adapter was solid and made entirely of iron or steel" — a solid all-steel adapter tool at 4 inches would be ≈ 18 oz total ≈ 4.5 oz/in, which is below 4.86 oz/in.

That is potentially decisive: if the actual mass of the Arnold tool (or any conventional all-metal air-hammer cutting tool of this type) is under ~4.86 oz per inch of driven edge, then claim 10 reads on an all-metal prior-art tool and is anticipated or, at minimum, obvious. The specification's own numbers suggest this may be true at the 4-inch size.

Factual gap / recommended verification: I do not have Arnold's measured or calculated tool mass. Confirming the mass of the Arnold US 5,219,378 tool (and of the commercial air-hammer molding-removal tools of that era) would materially strengthen or weaken this attack on claim 10. This is the single highest-value factual inquiry in the analysis. The claim's use of "about 4.86" further widens the capture.

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6. Independent claim 19 — method of manufacture

Claim 19 requires: provide the metal blade; mold polymeric material to form (i) the blade holder portion with rear part and front parts and (ii) the elongate shank portion with an air-hammer-engageable rear end and a front end attached to the holder with axis in the same plane as the blade centerline; the molding performed so that at least the majority of the adapter is polymeric with adapter average specific gravity < about 1.84.

The method claim adds no step not already performed by Sears (mold plastic around a metal blade and let it congeal) combined with Arnold's structure. Under KSR, "a patent composed of several elements is not proved obvious merely by demonstrating that each of its elements was, independently, known in the prior art" — but where the combination is nothing more than the known method of over-molding applied to the known structure of Arnold, yielding only predictable, expected results, the method claim is obvious as a matter of law.

Claim 19 is obvious over Arnold + Sears.

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7. Dependent claims — disposition

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8. The named combinations, with motivation and expectation of success

Combination A — Arnold (US 5,219,378) + Sears Roebuck (US 2,335,872)

Renders obvious: claims 1, 2, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17, 19, 20, 24.

• Motivation: (i) reduce the weight of a hand-held, continuously reciprocated air-hammer tool; (ii) reduce manufacturing cost relative to Arnold's two-part machined metal holder; (iii) obtain a softer contact surface that will not mar the painted body panel; (iv) Sears explicitly supplies the weight/cost rationale.
• Expectation of success: high — over-molding polymer onto a metal blade is a mature, predictable technique taught by Sears itself.
• Result: a tool whose adapter, by construction, has an average specific gravity far below 1.84 and a mass far below the claim 10–13 limits.

Combination B — Combination A + a metal core through a polymer grip (Sears' own tang-in-hollow-handle; optionally US 3,782,482)

Renders obvious: claims 3, 4, 5, 15, 16, 18, 21, 22, 23.

• Motivation: a PHOSITA using a polymer shank in a percussive application would foresee deformation and dimensional drift at the air-hammer engagement end. The art already teaches running a metal tang/core through a hollow polymer handle to provide strength, stiffness, and dimensional stability (Sears), and the patent's own stated reasons — restricting shortening and deformation, increasing strength in cold weather, and faster polymer solidification due to reduced section thickness — are each predictable consequences of a metal core in a plastic handle, the last of which Sears states verbatim ("facilitates rapid cooling because of the relatively low quantity of total heat to be dissipated").
• Expectation of success: high. No new mechanism; only known reinforcement of a known molded part.

Combination C — Combination A + Henschell (US 2,264,374) [+ GB 844,416]

Reinforces obviousness of claims 1, 2, 6, 9, 14, 19, 20. Henschell adds the express teaching that a thin, flexible metal blade is rigidly secured to a handle, that this is done for economical manufacture, and that the handle may be plastic. GB 844,416 (decorator's tool) is cumulative. Caveat: GB 844,416 is characterized from its title only — I could not retrieve its specification.

Combination D — Combination A + the patent's own admitted range (for claims 7 and 24)

US 5,469,623 acknowledges that the shank axis "could be disposed at an angle somewhere between about 135 degrees and 180 degrees … such as about 160 degrees as is illustrated in U.S. Pat. No. 5,219,378." Selecting the 180° endpoint (parallel) is an obvious design choice from a disclosed range, and the resulting benefit (a straight, laterally compact tool that presents the blade flat to the panel) is predictable.

Combination E (not available) — Thieme DE 4,222,250 C2

Excluded on date grounds (§ 3.7) unless the A1 laid-open version is confirmed as published before 1994-04-29.

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9. The counterarguments — where non-obviousness could be defended

An honest analysis must identify where the applicant's best rebuttal lies.

1. Percussive service is the strongest non-obviousness argument. Air-hammer shanks are conventionally steel. A PHOSITA might have believed a polymer or polymer-cored shank could not survive percussive impact, fatigue, and the spring-retention clamping forces. The patent's own disclosure supplies ammunition for both sides:
   • It concedes the all-polymer shank "shorten[ed] slightly during use" and its engagement end enlarged, "making them increasingly more difficult to engage with and disengage from air hammers," and that large-diameter polymer shanks molded too slowly. If the prior art had recognized these problems and taught away from polymer shanks, that would support non-obviousness.
   • But the specification presents these as problems discovered by the inventors, not problems the art knew about. A difficulty encountered by the applicant, absent prior-art recognition, generally does not establish non-obviousness; it establishes the need for the rod (claim 3), not the patentability of the polymer holder (claim 1).
   • Critically, claim 1 does not require the rod, so the applicant's own specification shows that the subject matter of claim 1 (all-polymer shank) underperformed — a poor foundation for an "unexpected results" defense for claim 1.
2. Unexpected results. The patent asserts the tool is "surprisingly durable and effective" and marks paint less. These are conclusory. To carry weight they must be (a) unexpected relative to the closest prior art, (b) supported by objective evidence, and (c) commensurate with the claimed scope (nexus). A reduction in mass and a softer contact surface from substituting plastic for metal are expected, not surprising. The "surprising" durability claim is uncorroborated.
3. Commercial success / long-felt need. The 3M product line (the tool used with 3M "Overspray Masking Liquid") and the continuation-in-part US 5,640,772 are evidence of commercialization, but I found no evidence of a nexus between any commercial success and the specific claimed feature (adapter average specific gravity < 1.84 or the mass limits), and no licensing activity. As noted in the previously generated litigation section, no litigation was located at all. Unverified commercial success carries little weight without a nexus. A long-felt need could be argued (Arnold's expensive, heavy metal holder), but Arnold is only one year earlier (1993) — the "long-felt" window is short.
4. Teaching away. I found no affirmative teaching away in the prior art. To the contrary, Sears expressly promotes polymer substitution for metal in a blade handle. Absent a credible teaching-away, this defense is weak.
5. Claim 3's "not yet built" FIG. 7 metal embodiment is irrelevant to § 103 (the metal-tube embodiment would fail the < 1.84 limitation anyway) and does not create a "teaching away" from polymer.

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10. Faithfulness and data-quality flags

1. Claim 24 claim-type mismatch (previously flagged, confirmed). Claim 24 reads "A cutting tool according to claim 19 …" while claim 19 is a method claim. I have not auto-corrected this. For § 103 the effect is that claim 24's scope is ambiguous: read literally as depending from claim 19, it is a method claim incorporating the parallel-axis limitation; read as an apparatus claim, it is improperly dependent under 35 U.S.C. § 112 ¶ 4. Either construction is obvious for the reasons in Combination D, but the defect is chiefly a § 112 issue.
2. DE 4,222,250 C2 is not prior art to US 5,469,623 on its 1995-04-13 publication date (§ 3.7). It appears on the page as a family citation, not a patent citation.
3. Characterization confidence is uneven. I retrieved and reviewed the full text of Arnold (US 5,219,378), Sears (US 2,335,872), and substantial text of Henschell (US 2,264,374). For GB 844,416, US 3,782,482, and US 833,869 I verified only the citation metadata (number, title, assignee, date) from the patent page and could not retrieve specifications. I have not relied on those three as necessary references, and I say so explicitly rather than inferring their contents.
4. Arnold's tool mass is unknown. The strongest § 103/§ 102 argument against claim 10 (§ 5(b)) turns on a fact I could not verify. This should be checked against the Arnold specification and any physical specimens.
5. Cross-reference consistency. The previously generated section lists the maintenance-fee lapse as "effective 1993-11-28 (recorded as 2003-11-28)." The source Legal Events table gives the effective date as 20031128 ("Lapse for failure to pay maintenance fees," 2004-01-27; "Lapsed due to failure to pay maintenance fee," effective 2003-11-28). The "1993-11-28" figure appears to be a transcription slip; the record-consistent date is 2003-11-28. This does not affect the § 103 analysis.

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11. Bottom line

All 24 claims are, on this record, prima facie obvious under pre-AIA § 103.

• Primary combination: US 5,219,378 (Arnold) in view of US 2,335,872 (Sears Roebuck) — Arnold supplies every structural element of the apparatus claims except the polymer material and the low specific gravity; Sears supplies the express teaching of molding a polymer handle around a metal blade portion, the perforated-tang/interlocking-rivet retention that reads on claim 9 (and on claim 1's § 112(f) "means for retaining"), and — decisively for motivation — the express rationales of "economy of metal," "lightness of weight and proper balance," and rapid cooling from reduced section thickness.
• Secondary references: Henschell (US 2,264,374) reinforces thin-flexible-blade-plus-handle and plastic handles; GB 844,416, US 3,782,482, and US 833,869 are cumulative (metadata verified, specifications not retrieved).
• Claim 3/15/21 (metal rod in the shank): obvious over Arnold + Sears alone, because Sears' metal tang running through a hollow polymer handle is the same metal-core-in-polymer-shank architecture, and every advantage the patent attributes to the rod is a predictable consequence of reinforcement plus reduced section thickness.
• The numeric limitations (specific gravity < 1.84 / ≤ 1.44; mass 4.86 / 1.62 / 1.0 / 0.74 oz per inch) are result-effective-variable recitations that add no patentable weight once the polymer substitution is found obvious (In re Woodruff; In re Peterson).
• Strongest weakness in the obviousness case: claim 1 does not require the metal rod, and the specification concedes the all-polymer shank suffered shortening and end enlargement — the applicant's best (but, without prior-art recognition of the problem, likely insufficient) non-obviousness story. Strongest additional attack on claim 10: the specification's own arithmetic implies an all-steel-adapter tool at 4 inches weighs ≈ 4.5 oz/in, i.e. inside the 4.86 oz/in claim limit, subject to confirming Arnold's actual mass.

Confidence: high on the claim-vs-Arnold element mapping and on the Sears motivation teaching (both grounded in retrieved full texts and in the authoritative patent text). Medium on the dependent-claim dispositions that rest on routine-optimization reasoning. Low on anything requiring the contents of GB 844,416, US 3,782,482, US 833,869, or DE 4,222,250 — all flagged above and excluded from the operative combinations.