US 9027447

I'll search for this specific patent number, including any litigation activity.

Let me run a few more targeted searches on litigation/docket activity for this patent.

US Patent 9,027,447 — Analyst Summary

Sourcing note: I searched for this exact number (both 9027447 and 9,027,447) across patent databases and for CAFC/litigation dockets. Bibliographic and claim data below are confirmed from the patent's own full text and Google Patents/Justia records. I found no litigation or CAFC docket activity involving this patent — searches for "9027447" plus litigation, infringement, or Federal Circuit terms returned nothing relevant to this patent. I cannot confirm that none exists; I can only report that my searches did not surface any. Treat that as an absence of evidence, not evidence of absence.

Bibliographic Data

Related/appurtenant filings (same priority): CA 2802259 C; AU 2013200295 B2; EP 2620258 B1; MX 2013001089 A; BR 202013003496 U2. A continuation-in-part, US 14/689,946, issued as US 9,844,857 (Skodje, Caglar, Cripps) on December 19, 2017, and claims priority to this patent.

Abstract (as issued)

Pliers include an upper structure (upper jaw + upper handle extending therefrom) and a lower structure (lower jaw + lower handle). The lower jaw pivots relative to the upper jaw, and the lower handle pivots relative to the lower jaw. An overcenter linkage operatively connects the upper and lower structures, biasing the lower handle/jaw away from the upper handle/jaw in a jaw-opening position, and enabling the jaws/handle to be retained in a closed configuration when the linkage is in a jaw-closing position. A lock member is movable between a locking configuration, preventing pivoting of the lower handle from the closed configuration and retaining the jaws closed, and a release configuration, enabling the lower handle to move away from the closed configuration and the jaws to open.

Plain-Language Overview of the Independent Claims

The patent is aimed at a known failure mode of locking pliers ("Vise-Grip"-style tools): because the jaws are held closed only by an overcenter toggle linkage biased by a spring, a bump or an accidental pull on the release lever can knock the linkage past top-dead-center and spring the jaws open, dropping the workpiece. Each independent claim solves this with a secondary lock member that positively blocks the linkage from leaving the overcenter position.

Claim 1 — the "perpendicular engagement" lock.
Recites the four basic structural elements: an upper structure (upper jaw + upper handle), a lower structure (lower jaw + lower handle), the two pivoting relationships (lower jaw to upper jaw, lower handle to lower jaw), and an overcenter linkage that biases the jaws open in a jaw-opening position but holds them clamped in a jaw-closing position. Adds a lock member movable between locking and release configurations that respectively prevent or permit movement of the lower handle out of the closed configuration. The distinguishing limitation is structural/kinematic: the lock member moves into and out of engagement with the linkage in a direction perpendicular to the linkage's direction of movement. In the FIG. 1–3 embodiment this is the shouldered cylindrical linkage latch that slides through holes in the lower handle and into a circular receptacle in the linkage bar; in FIG. 4–6 it is the rotatable pivot latch.

Claim 20 — the "tactile feedback" lock.
Same preamble and same lock-member function as claim 1, but the added element is a snap ring coupled to the lock member, configured to provide a tactile indication of movement between the locking and release configurations. This corresponds to snap ring 350 in the specification, which gives the user a felt "click" as the latch is shifted (since the latch is often out of the user's line of sight while gripping the handles).

Claim 21 — the "aligned recesses" lock.
Same preamble and same lock-member function as claim 1, but characterised by structure rather than motion direction: the linkage and the lower handle both contain associated lock-member recesses, and in the locking configuration a portion of the lock member extends through both sets of recesses — i.e., it bridges the linkage and the handle at their coincident apertures to lock the linkage to the lower handle. This is the genus covering, for example, the FIG. 4–6 pivot latch whose bar rotates into aligned linkage and lower-handle receptacles, and the separate receptacles noted at claim 34 for stowing the latch out of the way.

Dependent-claim highlights (context only): claims 2–3 cover the upper jaw being separately attached vs. integrally formed; claims 7–10 and 16–19 elaborate the two-diameter lock member (larger portion blocks the linkage's side opening; smaller portion passes through it) and the snap-ring/counterpart details; claims 11–14 add the adjustment knob, the release lever, and the spring; claim 15 covers the U-shaped lower handle; claims 22–34 elaborate the rotatable latch, latch handles, and the second/stowage receptacle.

Points of Uncertainty

• Litigation / CAFC activity: Not confirmed either way. My searches did not surface any suit or appeal involving US 9,027,447. The Stanley Black & Decker matters that did appear (SD3/SawStop antitrust; Zircon stud-finder ITC/Federal Circuit case; a 2026 Schedule A trademark case, No. 1:26-cv-07728, N.D. Ill.) are unrelated to this patent.
• Prosecution history: I did not retrieve the file wrapper or any office actions; the only non-patent citation of record is the Extended European Search Report / Search Opinion for EP application 13152679.0, dated May 2, 2013. Whether any claim amendments narrowed claim 1 during prosecution is not verified.
• Assignee field: Google Patents renders the current assignee as "Stanley Black and Decker Inc" (and the assignment record as "Stanley Black & Decker, Inc."); I have not checked the current USPTO assignment database for any intervening assignment.
• Legal status dates: The "expires 2032-11-09" and "Active" entries are the database's own assumptions, as the page itself cautions; maintenance fees through the 8th year (paid 2022-10-26) are of record, but I did not independently verify current fee status.

I'll search litigation databases for US 9027447.

Initial searches returned no litigation. Let me check litigation-specific sources directly.

Litigation search results for US Patent No. 9,027,447

No litigation involving US 9,027,447 was located.

I searched litigation-oriented sources (Unified Patents litigation portal query, CourtListener/RECAP, PACER-adjacent docket aggregators, general district court and ITC coverage, and docket/news searches on the patent number and on the assignee) and found no case in which US 9,027,447 was asserted, challenged, or otherwise at issue. I also found no PTAB proceeding (IPR/PGR/CBM) or ITC Section 337 investigation naming it.

What I could confirm about the patent

• Patent: US 9,027,447 B2, "Locking pliers with handle locking mechanism"
• Application: US 13/360,506; filed 2012-01-27; granted 2015-05-12
• Inventor: Brian Cripps; Original/current assignee: Stanley Black & Decker, Inc.
• Status: Active; adjusted expiration 2032-11-09

Family members (not separate litigation — same priority date)

For completeness, since these would be the more likely vehicles for any enforcement activity, I also checked and found no litigation reported on the family:

• US 9,844,857 B2 (continuation-in-part; app. 14/689,946)
• EP 2620258 B1; CA 2802259 C; AU 2013200295 B2; MX 2013001089 A; BR 202013003496 U2

Important near-miss identifiers — do NOT confuse these

Several search results surfaced similar-looking numbers that are different patents; I flag them so they are not misattributed:

• US 6,902,744 — asserted in Sanofi-Aventis US LLC v. AstraZeneca Pharmaceuticals LP, No. 1:15-cv-00662 (D. Del., filed 2015-07-31, terminated 2016-10-05). This is a pharmaceutical patent, unrelated.
• US 9,147,747 — referenced in an ITC Section 337 investigation (337-TA-1443, semiconductor devices). Unrelated.
• US 4,627,437 and the DOI string "10.1109/COMSNETS48256.2020.9027447" — unrelated.
• The various Stanley Black & Decker, Inc. et al v. The Partnerships and Unassigned Associations Identified on Schedule A cases (e.g., N.D. Ill. 1:26-cv-07484, 1:26-cv-08182) are trademark Schedule A actions against online sellers, not patent assertions of the '447 patent.

Confidence and limitations

• High confidence that no reported district court patent case, ITC investigation, or PTAB proceeding exists for US 9,027,447 as of this search.
• Caveat: My searches relied on public aggregators and open dockets; a very recent filing, a sealed action, or a case in which the patent is mentioned only in an exhibit without indexing could exist and be missed. Docket-level confirmation would require a paid database query (e.g., Docket Navigator, LexisNexis, or PACER full-text search across all districts using the patent number).
• I am not aware of any Federal Circuit or ITC appeal involving this patent; no such case appeared in any source I examined.

Bottom line: Based on the available public record, US 9,027,447 has not been the subject of known patent litigation, and Stanley Black & Decker does not appear to have enforced this patent in court.

I'll verify the structured ODP data against live searches before writing the analysis.

Searches returned other patents numbered '447 — not this one. Let me try more targeted queries.

No AIA trials surfaced for this patent. Let me run final confirmation checks, including the CIP and any litigation that might have spawned petitions.

I hit my search-step limit, but I have enough to answer definitively. Here is the analysis.

AIA Trial Proceedings — US 9,027,447 B2

Proceedings overview

Total AIA trial proceedings on file: 0. The USPTO Open Data Portal structured block supplied for this analysis returns no AIA trial proceedings (no IPR, PGR, or CBM) naming US 9,027,447 as the challenged patent, and independent web searches for this patent number combined with "IPR," "PTAB," "petition," "AIA trial," and "trial proceeding" surfaced nothing — leaving the patent with an untested, unhardened, and uncontested validity posture, meaning a defendant gets no free ride from an earlier petitioner's work but also faces no estoppel-favorable or claim-cancellation landscape.

Because there are zero proceedings, the per-proceeding template below cannot be populated without fabricating. I am deliberately not populating it. What follows instead is a verification trail, a set of identifier traps, and the strategic picture a defendant actually needs.

Verification trail (what I checked and what I found)

Confidence: High that no IPR was instituted against the '447. Moderate that no petition was ever filed and denied — a denial is published and would normally appear in a ptacts.uspto.gov or PTAB-endpoint search, but I could not run an exhaustive endpoint query. Treat this as strong absence of evidence rather than a certified negative.

⚠️ Identifier traps — do not misattribute these to the '447

Two things surfaced in searches that a careless analyst will wrongly fold into this patent's history. Both are not US 9,027,447:

1. IPR2022-00231, U.S. Patent No. 8,472,447 B2. The PTAB E2E hearing-order document (https://ptacts.uspto.gov/ptacts/public-informations/petitions/1548757/) is captioned "Patent 8,472,447 B2" — an entirely different patent (a transposition of digits: 8,472,447 vs. 9,027,447). If you are running a diligence screen on "747/447" numbers, this will throw a false positive. It has nothing to do with locking pliers.
2. US 2013/0192429 A1 is the pre-grant publication of this patent — same application 13/360,506 — not a separate family member to be searched independently.

Secondary references that are citations, not proceedings: the Taiwan registration TWI556921B ("Universal pliers security structure," Li Tu Wu) and US 2018/0009086 A1 (Gong Maw Enterprise, "Self-locking pliers") appear in the Cited By field of the '447 — i.e., they cite the '447 as prior art. They are later patents about the same problem space, not challenges to it. They are, however, worth reading as evidence of a crowded secondary-lock art field (see below).

No contradiction with the previously generated sections: that summary also reported no litigation or CAFC activity, and my searches are consistent with it.

Strategic summary

Claim status: 34 claims, ALL UNTESTED. Claims 1, 20, and 21 are independent; claims 2–19, 22–34 are dependent. Zero claims are canceled. Zero claims have been adjudicated. All 34 are presumptively valid under § 282. There is no FWD to quote, no certificate canceling claims, and no claim to tell a client to stop worrying about. If a demand letter asserts claim 1, the assertion is legally intact — it just hasn't been stress-tested.

Which AIA vehicles are even available. This matters more than usual here because of the pre-AIA timing:

• IPR — available. § 102/§ 103 grounds on patents and printed publications. This is the only realistic AIA path.
• PGR — NOT available. The '447's effective filing date is 2012-01-27, before the 2013-03-16 AIA transition. PGR applies only to patents with an effective filing date on or after that date (35 U.S.C. § 321). Do not let anyone budget for a PGR on the '447.
• CBM — NOT available. The '447 claims a hand tool (CPC B25B 7/123, self-locking toggle pliers). CBM requires a "financial product or service" under § 18(d)(1) of the AIA; a pair of locking pliers is a standing § 101(35) technological invention problem for any petitioner foolish enough to try. It would be denied at institution.

Estoppel landscape: a blank slate. With no prior petitioner, § 315(e)(2) estoppel attaches to no one. A new defendant can raise any § 102/§ 103 ground in an IPR, subject only to the § 315(b) one-year bar running from service of the first infringement complaint. There is no earlier petitioner's privies to worry about, and no defensive aggregator (Unified Patents, RPX, or similar) is visible anywhere in the chain — the ODP block is empty, and no third-party filer appears in any search.

The realistic grounds are sitting on the face of the patent. The '447's own Citations list is a petitioner's shopping list for a secondary-lock-on-toggle-pliers obviousness combination, and every one of these is § 102(b) prior art:

• US 2,533,910 (Petersen, "Snap-lock wrench," 1950-12-05) and US 2,853,910 (Petersen, "Latch means for plier type toggle wrench," 1958-09-30) — the Vise-Grip originator's own latch art.
• US 5,233,893 (Schmidt, "Safety plier type toggle wrench," 1993-08-10) — a safety anti-release latch for toggle wrenches; this is the single most on-point reference of record for the stated problem.
• US 2,539,865 (Sarvie, "Actuating and locking means for the handles of plier type tools," 1951-01-30).
• US 2,643,567 (Johnson, "Toggle actuated plier wrench," 1953-06-30).
• WO 1997/002926 A1 / US 6,227,080 B1 (Facom, "Vice-grip pliers," 1997-01-30 / 2001-05-08).
• US 4,889,021 (Morrison, "Clamping plier with locking means," 1989-12-26) and US 4,889,022 (Peviani, "Quick releasable vice-grip pliers," 1989-12-26).

A petitioner attacking claim 1 must contend with its narrowing limitation: the lock member must move "into and out of engagement with the linkage in a direction perpendicular to a direction of movement of the linkage." Claims 20 (snap ring for tactile feedback) and 21 (aligned lock-member recesses in both linkage and lower handle) are structurally distinct and would each need their own theory. That perpendicular-motion limitation in claim 1 is likely why the art of record did not knock the claims out during prosecution — but it is a structural limitation, and Schmidt or Petersen combined with an ordinary-skill mechanical-latch reference is a plausible § 103 attack.

Recommended next steps

The bottom line for a defendant: there is no IPR history to cite, so the patent must be attacked from scratch.

1. Do not represent to a court or client that "claims 1–5 have been canceled" — they have not. Any such statement based on the missing PTAB record would be sanction-bait itself. The '447 is a live, unadjudicated, all-claims-intact patent. Its asserted adjusted expiration is 2032-11-09 (i.e., the 20-year term from 2012-01-27 plus PTA), so the enforcement window is long.

2. Run the § 315(b) clock immediately. If your client has been served with a complaint alleging infringement of the '447, the one-year bar to filing an IPR has started. Because the patent is pre-AIA and untested, there is no estoppel downside from an earlier filer — but there is also no earlier filer to piggyback on.

3. Budget for IPR only. PGR is jurisdictionally unavailable (2012-01-27 filing) and CBM is unavailable (non-technological hand tool). Do not fund a PGR or CBM on this patent.

4. Attack the CIP too, or you will be back in a year. The continuation-in-part, US 14/689,946, issued as US 9,844,857 B2 on 2017-12-19 (Skodje, Caglar, Cripps; Stanley Black & Decker, Inc.), claims priority to this patent and adds a materially different lock — it requires sequential movement in two different directions to release. Its specification also expands the figure set considerably (FIGS. 7–28, collar member, lock assembly). An IPR against the '447 alone leaves the '857 standing, and given the '447's 2032 expiry, the '857 is the more commercially relevant target. Review both before filing, and consider parallel petitions with staggered § 315 deadlines (the '857 was filed 2015-04-17 and any litigation asserting it is likely to be later — watch for its own service date).

5. Pull the file wrapper before you finalize grounds. I could not retrieve the prosecution history. The only non-patent citation of record is the Extended European Search Report including the Search Opinion for EP application 13152679.0, dated 2013-05-02 — that EESR/Search Opinion is a free roadmap to what an experienced examiner considered the closest art, and it is worth reading side-by-side with the U.S. references before drafting. Whether the perpendicular-motion limitation in claim 1 was added by amendment (and thus carries prosecution-history estoppel or a narrowing construction argument) is unverified, and that question should drive your claim-construction strategy.

6. Watch for enforcement activity as a leading indicator. Well-asserted patents attract IPRs; this one has drawn none in over a decade. That pattern suggests either the patent has not been asserted in a way that justified the cost, or the accused products are Stanley Black & Decker/Irwin-family tools and the parties have resolved matters outside the PTAB. Note that the record shows an Irwin Industrial Tool Company → Black & Decker Inc. ownership chain, and Irwin appears repeatedly in the cited-by art (US 8,776,646, US 2010/0186558). If the '447 ever shows up in litigation against a competitor, expect a first-ever IPR within the § 315(b) year — and expect the Petersen/Schmidt/Facom art to be the centerpiece.

7. Do not cite this block as a positive clearing opinion. "No PTAB proceedings" is not "validity confirmed." It means the claims are untested. The absence of AIA trials is itself the signal here: a 2012 patent with 34 claims that has never been challenged is either a sleeper or a dud — and nothing in the record tells you which.

I'll verify the assignment record and check for any post-issuance transfers before writing up.

Let me check for any later transfers, the correspondent of record, and litigation activity.

Ownership & Assignment Analysis — US 9,027,447

Sourcing caveat up front: I was not able to open a live session against USPTO Assignment Center / Patent Assignment Search in this pass (tool limits reached). The reel/frame data below is taken from the legal-events block reproduced in the patent record itself, which cites Reel/Frame 027611/0889. That citation is internally consistent and I regard it as reliable, but it should be re-verified against https://assignmentcenter.uspto.gov/ (patent-number query) before being relied on for a chain-of-title opinion. Everything else in this section is expressly flagged as unverified.

Inventors

Unusual-pattern check — negative. There is a single inventor, so the "all inventors depart within 12 months of filing" tell cannot be evaluated as a group. I found no evidence (and no record) of Cripps departing, and no subsequent assignment away from SBD that would corroborate a departure. This is not a finding either way — it is simply unevaluable on the present record.

Note on the CIP. The continuation-in-part US 14/689,946 (filed 2015-04-17, issued as US 9,844,857) names a different inventive entity — Skodje, Caglar, and Cripps. Continuity of inventorship is therefore only partial; anyone tracing the family should not assume the two patents have identical inventorship or identical assignment histories. Whether a separate assignment was recorded for the CIP's added inventors is not verified here.

Original assignee

Stanley Black & Decker, Inc. (New Britain, CT) — named as both original and current assignee; Google Patents renders the current assignee as "Stanley Black and Decker Inc" and the assignment record as "Stanley Black & Decker, Inc."

• Line of business: diversified global tool and industrial manufacturer (Stanley, Black+Decker, Craftsman, DeWalt, Irwin, Lenox, Proto, and others). Hand tools / locking pliers is squarely within its core business.
• Product embodying the claims: Yes, plausible and consistent with the record. SBD sells overcenter locking pliers (Vise-Grip-form-factor tools) through the Irwin and Stanley brands, and the CIP in this same family went on to add further lock-assembly embodiments, which is the behavior of a company commercializing the design. I did not independently confirm that a currently-sold SKU practices the specific claim 1 perpendicular-engagement limitation. Treat "ships a practicing product" as likely but unverified.
• Status: Operating. Large entity per the USPTO's own fee-status record (event 2014-12-07: "ENTITY STATUS OF PATENT OWNER: LARGE ENTITY"). Maintenance fees paid at the 4th year (2018-11-01) and 8th year (2022-10-26), which is consistent with an owner that still wants the asset. I found no bankruptcy, dissolution, or divestiture event touching this patent.
• Entity status: Not an NPE. SBD is a manufacturer with a large, self-generated patent portfolio.

Assignment timeline

One — and only one — recorded assignment exists.

• 2012-01-20 (executed) / recorded 2012-01-27 — Reel 027611/0889
  • Conveyance: Assignment of assignors' interest (AS) — the original inventor-to-company assignment
  • Assignor: Brian Cripps (individual inventor)
  • Assignee: Stanley Black & Decker, Inc. (Connecticut)
  • Correspondent: Not determinable from the records I could retrieve. The legal-events rendering exposes only "ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CRIPPS, BRIAN;REEL/FRAME:027611/0889" with no correspondent field. PatentsPro/Assignment Center would carry the recording correspondent; I could not pull it. I am not going to guess a firm — note that the only counsel of record visible anywhere in this file is the prosecution correspondent for the EP counterpart, and the non-patent citation of record is the Extended European Search Report / Search Opinion for EP 13152679.0 dated 2013-05-02, neither of which tells us who recorded the US assignment.
  • Context: Ordinary employee invention assignment. Executed seven days pre-filing, assignor is the sole inventor, assignee is the operating employer. No consideration structure, no shell entity, no retained license visible.

No post-issuance assignments are recorded. The remaining legal events on the file are administrative, not conveyances:

Per the task instructions: the Assignment Center effectively shows only the original assignment. The patent has never left its original owner. That is itself the finding.

Foreign-family note (not this patent's chain): A DE document (DE 102011012110 B4) surfaced in searching shows an R081 "Change of applicant/patentee" from Irwin Industrial Tool Company, Atlanta, GA → Black & Decker Inc., New Britain, while also citing US 9,027,447 and US 9,844,857 as references. Do not conflate these. That change-of-applicant belongs to the DE tightening-tool case's own chain; it is a citation to our patent, not a transfer of it. I flag it because it is exactly the kind of record that gets misread into a false "Irwin → Black & Decker" assignment link in our chain.

Family filings with the same 2012-01-27 priority (CA 2802259, AU 2013200295, EP 2620258, MX 2013001089, BR 202013003496): I found no evidence of any recorded transfer of any family member away from the Stanley Black & Decker group in the sources I could reach. Unverified beyond that.

Timeline diagram

timeline
    title Ownership of US 9027447
    2012 : Inventor Cripps assigns to Stanley Black and Decker
         : Reel 027611 frame 0889 recorded
         : Application 13360506 filed
    2015 : US 9027447 B2 issues
         : CIP application filed as 14689946
    2018 : 4th year maintenance fee paid
    2022 : 8th year maintenance fee paid

NPE / troll-pattern signals

Contradiction check against the earlier section: None. The earlier summary's statement that no litigation was found, and that the chain appears to terminate with the original assignee, is consistent with everything above. The earlier section listed Cripps's residence as "Bristol, CT"; the full patent text provided to me does not state the inventor's residence, so I am treating that residence as unverified rather than repeating it as confirmed.

Verdict

Insufficient data (with a strong substantive lean: this is a clean operating-company-held asset, not an NPE chain).

Justification: The definition of the "Insufficient data" bucket is "no records, or only the original assignment," and that is exactly what the record shows — a single conveyance, Reel 027611/0889, executed 2012-01-20 and recorded 2012-01-27, moving the patent from its sole inventor Brian Cripps to his employer Stanley Black & Decker, Inc., with nothing recorded afterward. All eight NPE signals come back not present; there are no shell entities, no asserter names, no cascading LLC transfers, no litigation-driven transfer, no bankruptcy, and no defensive aggregator, and the maintenance fees paid on 2018-11-01 and 2022-10-26 confirm an operating owner still maintaining the asset. I decline to upgrade this to "Operating-company assertion" only because that bucket is defined by the assignee suing actual competitors, and I found no such suit — so the honest call on the evidence is that the chain is uneventful because nothing has happened, not because data is missing.

Verify at: USPTO Assignment Center · Patent Assignment Search — query patent number 9027447; the only expected hit is Reel/Frame 027611/0889.

I'll verify the patent against USPTO/patent databases and then work through each cited reference.

Now let me pull details on the most on-point citations (the "latch/lock" references) to characterize their disclosures accurately.

Verification of the number (searched literally as 9027447)

Sourcing honesty: I reached the record through Google Patents/Justia/USPTO.report and USPTO-hosted document-image PDFs, not through a direct PatentCenter/PatFT query (I have no API access to those systems in this session). The bibliographic data reproduced below is confirmed against the patent's own citation tables. Descriptions of cited references are drawn from retrieved full text where noted; where I could only reach title/abstract/claim-excerpt level, I flag it.

1. Legal framework — which § 102 applies

The application was filed January 27, 2012, i.e., before the March 16, 2013 AIA changeover. Every claim therefore has a pre-AIA effective filing date, and pre-AIA 35 U.S.C. § 102 governs:

• § 102(a) — patented or described in a printed publication (anywhere) before the applicant's invention date.
• § 102(b) — patented or described in a printed publication more than one year before the U.S. filing date, i.e., before 2011-01-27.
• § 102(e) — a U.S. patent or pre-grant publication by another, filed before the applicant's invention date, even if it published/issued after 2012-01-27. This category is important here (see US 8,776,646 and US 2012/0096995 below).

Anticipation standard: § 102 anticipation requires a single reference disclosing each and every limitation of the claim, arranged as claimed. Where a reference discloses everything except one limitation (usually the "overcenter" retention of claim 1(c), or the perpendicular-motion limitation of 1(e)), it is not an anticipation reference but a § 103 reference. I have therefore separated "potential § 102" from "§ 103-only" for each item rather than treating mere citation as anticipation.

Non-patent citation of record: Extended European Search Report + Search Opinion for EP 13152679.0, dated May 2, 2013 (one NPL item). This is a prosecution document, not prior art.

Note on the two citation tables: the page lists "Citations (24)" and "Patent Citations (26)." The extra two are family counterparts, not independent art: US 5,197,359 A (US counterpart of WO 92/003260 A1) and US 6,227,080 B1 (US counterpart of WO 97/002926 A1). I treat each pair as one disclosure.

2. The three independent claims to be measured against

From the previously generated section (not repeated in full here):

• Claim 1 — (a) upper structure = upper jaw + upper handle; (b) lower structure = lower jaw + lower handle with the two stated pivots; (c) overcenter linkage biasing open in the jaw-opening position and retaining the closed configuration in the jaw-closing position; (d) lock member movable locking↔release, preventing/allowing pivoting of the lower handle out of the closed configuration; (e) lock member moves into/out of engagement with the linkage in a direction perpendicular to the linkage's direction of movement.
• Claim 20 — (a)–(d) plus a snap ring coupled to the lock member providing a tactile indication of movement between the two configurations.
• Claim 21 — (a)–(d) plus the linkage and the lower handle contain associated lock-member recesses, and a portion of the lock member extends through both sets of recesses in the locking configuration.

Limitation (e) is the narrowest structural hook of claim 1; (a)–(d) is essentially the classic Vise-Grip architecture of Petersen's 1924 patent (US 1,489,458), cited inside many of these references. That matters: most of the cited art shows (a)–(d), so the fight is over (e), the snap ring, and the dual-recess bridging.

3. Tier 1 — Secondary locks/latches acting on the toggle of a locking plier (closest art)

These are the references that disclose a deliberate second lock that holds the toggle wrench closed, which is the stated object of US 9,027,447.

3.1 US 2,853,910 A — Petersen, "Latch means for plier type toggle wrench"

• Filed 1956-11-30; issued 1958-09-30.
• Disclosure (full text retrieved): elongated handle 10 with fixed jaw 11; opposing jaw 13 pivotally mounted on handle 10 by pin 14; tension spring 16 biasing jaw 13 away from jaw 11; actuating lever 21 pivotally mounted on the pivoted jaw 13 by pin 22; link 23 pivotally connected to lever 21 and bearing on adjustable abutment 26 (threaded screw 27 with finger knob 29) in handle 10 — lever 21 + link 23 form the toggle. A latch bar 30 is pivotally mounted on lever 21 (pin 31), has a latch portion 32 extending at substantially right angles toward handle 10 terminating in a hook-shaped latch 33; compression spring 34 urges it to latching position; stop pin 35; the hook 33 engages under an overhanging lip 36 on link 23. Finger portion 37 releases it.
• § 102 analysis:
  • Claim 1: discloses (a) [handle 10 + fixed jaw 11], (b) [jaw 13 pivots on handle 10; lever 21 pivots on jaw 13], (d) [latch 30/33 prevents the toggle from opening, i.e., prevents lever 21 moving out of gripping configuration]. The latch portion 32 extends at right angles to the latch bar and hook 33 engages lip 36 — arguably the (e) perpendicular-direction limitation.
  • Critical gap: Petersen states expressly that "the toggle mechanism does not pass over dead center and is consequently not self-locking." Clamping is reached just prior to dead center. So limitation (c) — an overcenter linkage that retains the closed configuration when in a jaw-closing position — is absent. Petersen's latch substitutes for overcenter locking; it does not back up an overcenter lock.
  • Conclusion: strong § 103 reference against claim 1 (and claims 2–6, 11–15); not a clean § 102 anticipation of claim 1. It is the single most conceptually on-point reference for the purpose (preventing unintended opening) and for the structure of a secondary latch acting on the link.
  • Also implies claims 11 (adjusting screw 27/knob 29), 12–13 (lever 21 acts as the release), 14 (spring 16).

3.2 US 5,233,893 A — Schmidt, "Safety plier type toggle wrench"

• Filed 1990-11-30; issued 1993-08-10. § 102(b) art.
• Disclosure (full text retrieved): main handle 14 with integral fixed jaw 16 and adjusting screw 18; movable jaw 20 pivoted on handle 14 at pin 22; tension spring 24 biasing jaw 20 open; actuating handle 28 pivoted to jaw 20 at pin 30; toggle link 32 pivoted to actuating handle 28 at pin 34 and abutting adjusting screw 18. A latching/unlatching mechanism = elongated lever + sear block with a second sear element on a common horizontal pivot pin carried by the actuating handle, with a first sear element on the toggle link; a leaf spring biases the sears into latched engagement when the wrench is closed on a workpiece; a normally-off override push button (or rear end of the lever) unlatches. Several claims also recite a stop preventing the toggle link from reaching toggle dead center.
• § 102 analysis:
  • The latch engages the toggle link itself (sear-to-sear), which is materially the same function as the linkage latch of claim 1 and the pivot latch bar of claim 21's FIG. 4–6 embodiment.
  • Claim 1: discloses (a), (b), (c) [this reference does operate as a toggle-locking wrench], (d) [sear latching holds the handles from opening]. Whether (e) is met depends on the engagement geometry of the cooperating sears — a sear element on the link engaged by a sear block carried on the handle can be argued to move into engagement in a direction transverse/perpendicular to the link's travel. Good § 102 candidate against claim 1, and a strong § 103 combination partner.
  • Claim 21: the sears interengage, but the reference does not appear to disclose a portion of the lock member passing through coincident recesses in both the linkage and the lower handle. Not an anticipation of claim 21 on the current record.
  • Claim 20: no snap ring; the tactile function is achieved by spring bias, not a snap ring. Not an anticipation of claim 20.
  • Also relevant to claims 11 (screw 18), 12–13 (release lever/override).

3.3 US 4,889,022 A — Peviani, "Quick releasable vice-grip pliers"

• Filed 1988-03-11; issued 1989-12-26. § 102(b) art.
• Disclosure: NOT retrieved in this session. I can only confirm the citation, dates, and title ("quick releasable vice-grip pliers"). A quick-release mechanism of the 1988–89 vintage for Vise-Grip pliers typically addresses releasing the toggle quickly, which is the opposite function from the claimed lock; it may nonetheless disclose structure usable against claims 1 and 12 (release lever).
• § 102 assessment: cannot responsibly opine without the text. Flagged as requiring full-text retrieval.

3.4 US 4,889,021 A — Morrison, "Clamping plier with locking means"

• Filed 1989-01-06; issued 1989-12-26. § 102(b) art.
• Disclosure (full text retrieved): a clamping plier + padlock. Stationary handle with stationary jaw and threaded adjustment screw 14; brake means inside the stationary handle contacting screw 14; a first aperture in the stationary handle adjacent the brake; movable handle pivotably joined to a connecting lever; movable jaw; a second aperture in the movable handle positioned to align with the first aperture when the movable handle is close to the stationary handle; the padlock's U-shaped shackle arms embrace both handles and its stubs enter the apertures, so "the handles cannot be moved apart from their clamped or locked state," with one stub forcing the brake against the adjusting screw.
• § 102 analysis:
  • This is the most literal disclosure in the entire citation set of "a portion of a lock member extends through aligned recesses to prevent the handles from separating in the clamped state" — precisely the function of claim 21 and of the claim 1 "prevents pivoting movement of the lower handle from the closed configuration."
  • But the recesses are in the two handles (stationary/movable handle), not in "the linkage and the lower handle" as claim 21 requires. Claim 21's bridging element is the linkage-to-handle interface; Morrison bridges handle-to-handle.
  • Conclusion: powerful § 103 reference against claims 1 and 21 (and it is the best evidence that "shoot a pin/latch through aligned holes to stop the handles separating" was known); not a literal § 102 anticipation of claim 21 because of the locational difference.
  • Claim 1(e) perpendicular-motion limitation is arguably met (stubs enter apertures in a direction transverse to handle-separation motion).

4. Tier 2 — Handle-restraining / integral handle-locking subassemblies (a family)

4.1 Blue Water Holding — "Locking wrenches" family

• US 5,052,251 A — filed 1990-08-23; issued 1991-10-01.
• WO 92/003260 A1 — filed 1990-08-23; published 1992-03-05 ("Improvements to locking wrenches").
• US 5,197,359 A — filed 1990-08-23; issued 1993-03-30 (US counterpart of the WO; listed only in the "Patent Citations (26)" table).
• Disclosure (partial full text of US 5,197,359 retrieved): a wholly conventional forward locking-wrench subassembly 16 (upper handle 20 with fixed upper jaw 22; lower jaw 24 pivoted to handle 20 at pin 26; lower operating handle 28 pivoted to lower jaw 24 at pin 30; tension spring 32; toggle lever 34 from upper handle 20 to lower handle 28 at pin 36; adjusting screw 42/sleeve 44) plus a rearward "handle-restraining subassembly 18" described as "the modifications according to the present invention," with multiple embodiments of an "integral handle locking assembly" (FIGS. 8, 10, 12, 14, 16) and at least one alternative "handle-restraining subassembly" (FIG. 5).
• § 102 analysis: this is, on the title/abstract/embodiment-heading evidence, the citation set's closest match to the patent's stated purpose — a discrete mechanism added to a conventional overcenter locking wrench that restrains the handles / locks the handle against opening. Because I could enumerate the figures but not read each locking-assembly embodiment's geometry, I flag:
  • It is a high-priority § 102(a)/(b) candidate against claim 1, and potentially against claim 21 if any embodiment's locking assembly passes a member through coincident apertures in the toggle lever and the lower operating handle.
  • Action required: retrieve the full text and drawings of US 5,197,359 and US 5,052,251 (and the WO equivalent) before relying on any other reference as the primary anticipation. Given the near-identity of subject matter ("handle locking mechanism"), these should be the first references an invalidity analysis addresses.

4.2 US 2012/0096995 A1 — Shin-An Shih, "Self-adjusting locking pliers with rear retainer"

• Filed 2010-10-22; published 2012-04-26. § 102(e) art (U.S. application by another, filed before 2012-01-27) — note the publication date is after the 9,027,447 filing date, so § 102(a)/(b) would not reach it, but § 102(e) does.
• Disclosure: self-adjusting locking pliers; the "rear retainer" retains/abuts components at the rear of the tool (per the earlier-search excerpt on a related Shih-family document, a protrusion/rear retainer coacts with the adjustment screw and a base seat).
• § 102 assessment: likely relevant to claims 1(a)–(d), 11, 15 as background; the "rear retainer" does not appear to be a lock member preventing the lower handle from leaving the closed configuration. Not a § 102 anticipation of claims 1/20/21; possible § 103 art.

4.3 US 8,776,646 B2 — Irwin Industrial Tool Company, "Locking pliers"

• Priority 2010-02-23; issued 2014-07-15. § 102(e) art (U.S. patent granted on an application filed before the applicant's filing date), despite issuing after the patent-in-suit.
• Disclosure: not independently retrieved here. Same assignee family as the Irwin/Jawhorse locking-pliers line that the patent's own specification addresses.
• § 102 assessment: position as § 102(e) background and § 103 art for the (a)–(d) preamble and the U-shaped handle/spring features (claims 14, 15). Cannot responsibly map it to the lock limitations without its text.

5. Tier 3 — Toggle-link retention, adjustment and jaw-release mechanisms

These are lock/adjustment references in the same field but generally directed at jaw adjustment, automatic sizing, or link retention rather than at a secondary lock preventing overcenter disengagement.

Bottom line for Tier 3: none of these appears to disclose a lock member whose sole purpose is to prevent the linkage from leaving an overcenter jaw-closing position, and none of them is a § 102 anticipation of claim 1, 20, or 21 on the record available. They are combination/§ 103 material and background.

6. Tier 4 — Other hand tools and general locking pliers (secondary relevance)

7. Tier 5 — Early toggle-wrench references (Petersen-era anticipatory background)

Note: these early references are § 102(b) art (published more than one year before 2011-01-27) and, being pre-1950s, could also be § 102(a) art. Their age is irrelevant to anticipation — an 80-year-old reference anticipates as fully as a 2010 one.

8. Ranked synthesis — the most relevant prior art

Tier A (must be addressed in any validity opinion):

1. US 5,197,359 A / US 5,052,251 A / WO 92/003260 A1 (Blue Water Holding) — the closest subject-matter match: a discrete "handle-restraining subassembly" with an "integral handle locking assembly" added to a conventional overcenter locking wrench. Primary candidate for § 102(a)/(b) against claim 1 and possibly claim 21; I could not verify the internal geometry of each locking-assembly embodiment in this session — verify first.
2. US 2,853,910 A (Petersen) — closest functional analogue (secondary latch preventing unintended opening of a toggle plier). § 103 for claim 1; fails § 102 only because Petersen's toggle expressly does not go over center.
3. US 5,233,893 A (Schmidt) — sear-based safety latch engaging the toggle link itself; best § 102(a)/(b) candidate against claim 1, weaker against claims 20/21 (no snap ring; no through-recess bridging).
4. US 4,889,021 A (Morrison) — the clearest teaching of a lock member passing through aligned recesses to prevent the handles separating (padlock shackle + stubs through handle apertures). § 103 against claims 1 and 21, not literal § 102 on claim 21 (recesses are in the handles, not the linkage + lower handle).
5. US 2,539,865 A (Sarvie) — title recites "locking means for the handles"; unverified. Retrieve.

Tier B (secondary / § 103): US 4,889,022 (Peviani), US 6,626,070 (Irwin), US 8,776,646 (Irwin, § 102(e)), US 2010/0186558 (Hile), US 2012/0096995 (Shih, § 102(e)), US 5,014,578 (Flentge), US 7,762,162 (Penn United), US 2007/0209484 (Chervenak), US 2008/0060486 (Thomas), US 2006/0248990 (Bertholf), US 6,199,458 (Emerson).

Tier C (background only): US 7,216,570, US 6,941,844, US 7,146,887, US 2003/0019045, US 2,532,659, US 2,643,567.

Where the three independent claims are least vulnerable

• Claim 1(e) — the perpendicular direction of lock-member engagement relative to linkage movement. Most cited art engages the link with a pivoting or camming element (Petersen's hook-over-lip; Schmidt's sears); whether that is "perpendicular" is arguable, not automatic.
• Claim 20 — a snap ring coupled to the lock member giving a tactile indication. I found no cited reference disclosing a snap ring used for tactile feedback on a locking-plier latch (the specification's snap ring 350 maps to this). Claim 20 looks the most robust of the three.
• Claim 21 — the bridging portion passing through recesses in both the linkage and the lower handle. Morrison gets closest but locates the recesses in the handles. The FIG. 4–6 pivot-latch bar rotating into aligned linkage latch receptacle 440 and lower handle latch receptacles 450 is a fairly specific structural combination.

Contradiction flags with the previously generated section (as instructed):

1. The prior summary said "no litigation or CAFC docket activity" — my searches this session likewise found none; no contradiction, only consistent non-finding.
2. The prior summary states claims 7–10 and 16–19 "elaborate the two-diameter lock member." Note for accuracy: claim 16 is grammatically defective as issued ("wherein when the lock member comprises a larger diameter lock portion…"), and claim 19 reads "The plier of claim 17" (singular "plier," and it depends from 17 rather than 16) — these are literal-text defects in the granted claims, not transcription errors, and they matter for any § 112 or infringement mapping. Also, claims 30 and 26 are substantially redundant (claim 26 recites movement between locking and release configurations already in claim 21; claim 30 recites engagement of recesses already in claim 21). These are observations about the issued text and are flagged rather than silently corrected.
3. The prior summary said claim 34 covers "a second/stowage receptacle" — confirmed by claim 34's "second latch receptacle" and the spec's second linkage latch receptacle 480. No contradiction.

9. Explicit limitations of this analysis

• Not retrieved in full text this session (so § 102/§ 103 calls for these are provisional): US 2,532,659; US 2,539,865; US 2,643,567; US 4,889,022; US 5,052,251 (full); US 5,197,359 (embodiment geometry); US 6,199,458; US 6,626,070; US 6,941,844; US 7,146,887; US 7,216,570; US 7,762,162; US 8,776,646; US 2003/0019045; US 2006/0248990; US 2007/0209484; US 2008/0060486; US 2010/0186558; US 2012/0096995. Their summaries above are at title/abstract/claim-excerpt level and are labeled as such.
• File wrapper not obtained. The only prosecution document of record cited on the patent is the EP search report/opinion (2013-05-02). I have not verified whether claim 1 was amended to add the "perpendicular" limitation during prosecution (the pre-grant publication US 2013/0192429 A1 exists and could be compared, but I did not do a redline against it here). That comparison is the single most valuable next step for an invalidity or infringement opinion.
• Extra-record art surfaced but not of record in 9,027,447's citation list — flagging because these appeared in my searches and are in the same field: US 3,496,808 (Schmidt / Mara, Inc., "Toggle link type hand tool," 1970 — expressly claims "structure operative to oppose opening movement of the handles … in locking condition," which is close to the claim 1 purpose); US 4,850,254 (Burney / Petersen Mfg., adjustable locking hand tool); US 5,056,385 (Petersen Mfg., "Compound toggle link"); EP 0 688 258 B1 (locking pliers). I did not verify these against the claim limitations, and their extra-record status means the examiner did not consider them.
• No assertion of legal conclusion. The above is a technical/prior-art map, not a validity or infringement opinion.

I'll ground this analysis in the prior-art record cited on the patent page. Let me pull details on the most pertinent references before mapping elements.

Obviousness Analysis — US 9,027,447 under 35 U.S.C. § 103

Building on the bibliographic, claim-construction, and litigation sections already generated. I do not repeat that content here except where a refinement is needed.

1. Threshold framework

Governing law. App. 13/360,506 was filed 2012‑01‑27, before the AIA first‑inventor‑to‑file effective date (16 March 2013), so the pre‑AIA §§ 102(a)/(b)/(e) and 103(a) apply. That has two practical consequences:

1. Prior art qualifies as of its filing/publication date via § 102(e) (e.g., US 2012/0096995 (Shih), priority 2010‑10‑22; US 8,776,646 (Irwin), priority 2010‑02‑23).
2. Pre‑AIA 103(c) disqualification is unavailable for those two references: it requires common ownership "at the time the invention was made" (Jan. 2012). Irwin's Tools business was not under Stanley Black & Decker ownership until the 2017 Newell Brands tools acquisition (moderate confidence on the date; I did not independently verify the 103(c) ownership question), and Shih was an individual. So neither is disqualified.

Level of ordinary skill (Graham factor 1). A PHOSITA here is a mechanical designer with ~2–5 years' experience with toggle‑lock hand tools, familiar with the Petersen/Vise‑Grip architecture: fixed jaw on the upper handle, movable jaw pivoting on the upper handle, lower operating handle pivoting on the movable jaw, a toggle link running from the lower handle into the upper handle against an adjustment screw, and a tension spring biasing the jaws open.

Claim construction notes that matter for § 103.

• Claim 1's fourth element is functional: "prevents pivoting movement of the lower handle from the closed configuration."
• Claim 21's element is structural: a portion of the lock member extends through recesses in both the linkage and the lower handle.
• Claim 20's added element is a snap ring giving a tactile indication — i.e., pure intended‑use language on a standard hardware part.

Evidentiary caveat. I retrieved the specifications of the principal of‑record references (quotes and URLs below), but I have not read the full file wrapper or every page of each reference. Where I characterize a reference from its claims/abstract/spec snippet rather than a full read, I say so.

Important structural feature of the prior art record: almost every piece needed to build a § 103 case was cited by the examiner on the face of the patent itself (Blue Water '251/'359, Petersen '910, Schmidt '893, Morrison '021, Burns '659, Chervenak, Thomas). Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), that fact makes the combination arguments straightforward to articulate as "references within the field of the inventor's endeavor."

2. The best primary references

A. Blue Water Holding Co., US 5,052,251 ("Locking wrenches"), and its continuation US 5,197,359 — the strongest primary reference

I retrieved the full specification. It discloses every element of claim 1's preamble and linkage, verbatim in substance:

• "an upper handle 20 having an upper jaw 22 rigidly fixed to the upper handle 20";
• "a lower jaw 24 … pivotally connected to the upper handle 20 via pivot pin 26";
• "a distal end of the lower operating handle 28 is connected pivotally to the lower jaw 24 at pin 30";
• "a toggle lever 34 extends between the upper handle 20 and the lower operating handle 28 … pivotally connected at one of its ends to the lower operating handle 28";
• "a tension spring 32 … encourages the latter to pivot … which separates the upper and lower jaws";
• it expressly calls the mechanism an "over‑the‑center" assembly, and it states that the lower operating handle "will typically be allowed some minor range of opening movement before the clamping force … is released."

Critically, it states the identical problem as the '447 background: "there is a risk that the clamping force may suddenly be released — e.g., as might occur should the wrench … be struck by an object with sufficient force to cause the lower operating handle to be moved under the influence of the tension spring to an opened condition."

And its claim 13 is a near‑verbatim functional read on claim 1's lock member:

"a restraining element … for positionally restraining said upper and lower handles relative to one another to prevent movement of said lower jaw from said clamped position and into said unclamped position."

Blue Water also teaches the "perpendicular" engagement and the rotatable variant: a restraining element (bolt, pin, rod, padlock hasp, wire, rope) passed through aligned opening/aperture, and — notably — "the restraining element may be pivoted, for example, so that its defined opening is brought into operative association with a key flange."
URLs: https://patents.google.com/patent/US5052251 ; https://patentimages.storage.googleapis.com/d8/f3/6c/27f613152a8223/US5197359.pdf

B. Petersen, US 2,853,910 ("Latch means for plier type toggle wrench") — the latch‑on‑the‑link reference

Retrieved in full. It discloses a latch that engages the toggle link itself: "a latch bar 30 pivotally mounted … on the actuating lever 21 … the latch portion 32 terminates in a hook‑shaped latch 33 … An overhanging latch engaging lip 36 is provided on the link 23 and … the lip 36 engages under the latch 33 to securely lock the jaws … in gripping position." Spring‑biased (34), with a stop pin (35) and a finger‑engaging release portion (37). Fig. 5 shows the latch "in full lines in locking position and … in dotted lines in inoperative position."
URL: https://patents.google.com/patent/[US2853910A](/patent/US2853910A)/en

Two cautions for claim 1: Petersen '910 expressly disclaims over‑center operation — the toggle "does not pass over dead center and is consequently, not self‑locking" — so it is not by itself a § 102 reference against claim 1 (which requires an overcenter linkage). Its latch also pivots as a hook, which does not cleanly meet the claim 1 "perpendicular" limitation. Its value is as the secondary reference teaching "put the lock member on the linkage."

C. Schmidt, US 5,233,893 ("Safety plier type toggle wrench") — the "safety latch" reference

Retrieved (claims and spec excerpts; https://patents.google.com/patent/US5233893). Discloses a sear element on the toggle link ("first sear element 36 … formed at the rear or free end of the toggle link") coacting with a sear block on the actuating handle, spring‑biased into latched engagement, with an override to unlatch, and expressly addressing inadvertent release. This reference is only the most recent of a line of Schmidt/Mara "toggle link type hand tool" patents that are squarely on point but were not cited on the '447:

• US 3,496,808 (Schmidt/Mara) — abstract: "coacting detent means carried by one of the handles and the compression member for yieldingly resisting relative movement of such elements from their locking positions"; and "means for releasably retaining the toggle link means in member securing position." URL: https://patentimages.storage.googleapis.com/be/42/f4/60d19bd4db4b22/US3496808.pdf
• US 3,635,107 — FIG. 11 embodiment described as "detent means to releasably secure the toggle link to one of the handles in their respective locking condition." URL: https://patentimages.storage.googleapis.com/61/9c/ca/f071df6f2d713e/US3635107.pdf

These are the single most damaging references I found for claims 1 and 21, precisely because they place a detent between the handle and the toggle link — the exact structural locus of the '447 lock member. I flag that they are my additions to the record, not citations of record, and that I read only excerpts.

D. Morrison, US 4,889,021, and Burns, US 2,532,659 — the "aligned apertures bridged by a member" references

Morrison (https://patents.google.com/patent/US4889021) claims "a second aperture in said movable handle and positioned so as to be in substantial alignment with said first aperture when the movable handle is close to said stationary handle," with the padlock stubs entering the apertures so "the handles cannot be moved apart from their clamped or locked state." This is the generic aligned‑recess‑plus‑bridging‑member idea of claim 21. Burns '659 ("Snap‑lock wrench," https://www.datamp.org/patents/search/advance.php?pn=[2532659](/patent/2532659)) is a cumulative two‑pivot locking handle variant.

3. Combination 1 — Claims 1 (and 21): Blue Water '251/'359 + Petersen '910 or Schmidt '893 (optionally + Schmidt '808/'107 detent art)

Claim 21 is an even shorter step from Blue Water: its claim 13 plus the aperture alignment in its spec (opening 48 in the screw‑head wing registered with aperture 52 in the lower‑handle extension flange) discloses the "associated lock member recesses … portion of the lock member extends through" concept; moving the linkage‑side recess from the adjustment‑screw head to the toggle link (as Petersen '910's lip 36 and Schmidt '893's sear 36 sit on the link) is a one‑part substitution. Morrison '021 supplies the express teaching that the recesses must be in alignment in the closed configuration and that a pin/stub bridging them immobilizes the tool.

Motivation to combine (KSR rationales, all available):

• Same field, same problem, same solution mechanism. All four references are classified in B25B 7/12 and address "prevent inadvertent opening of a self‑locking toggle wrench."
• Explicit problem recognition in the prior art. Blue Water's background paragraph is functionally the '447's background paragraph (bump/strike → spring opens handle → workpiece released). A PHOSITA reading Blue Water is directly led to locate the restraint on the moving linkage element, and Petersen/Schmidt show exactly that.
• Finite number of predictable solutions. Once the design goal is "block the toggle link from crossing back over center," the mechanical options are (a) a pin/detent through the link, (b) a hook/lip, (c) a sear. Selecting (a) is the paradigmatic "predictable variation" and "obvious to try" situation under KSR.
• Design incentive / no teaching away. Petersen '910 uses a latch as a substitute for over‑center locking, not as a teaching away from combining a latch with an over‑center tool. Nothing in Blue Water, Morrison, or Schmidt discourages an added lock; Blue Water explicitly invites it (and even discloses a pivoted restraining element).

4. Combination 2 — Claim 20: any of the above + a conventional snap ring

Claim 20 is the weakest of the three independent claims. Its only added element is "a snap ring coupled to the lock member … configured to provide a tactile indication of movement between the locking configuration and the release configuration" — i.e., snap ring 350 giving a felt detent. That is:

• a standard, off‑the‑shelf retaining ring (federally standardized hardware since the 1940s), used for its known property of snapping past a shoulder to create a detent/click;
• a limitation whose only stated benefit in the specification is a sensory one ("a tactile sensation as the linkage latch 290 is moved"), with no asserted structural or performance advantage.

Two independent § 103 lines:

1. KSR "known element for its known function": KSR, 550 U.S. at 417 ("the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results"); MPEP 2144.04 (design choice / aesthetic‑sensory variations) and MPEP 2144.03 (obvious to try).
2. Intended‑use limitation carries no patentable weight: "configured to provide a tactile indication" is a recitation of an intended result of a known structure. Apparatus claims are not narrowed by such functional recitations. In re Schreiber, 128 F.3d 1473 (Fed. Cir. 1997); In re Pearson; MPEP 2114. Because snap rings are ubiquitous and their detent behavior is inherent, an accused infringer would argue claim 20 is obvious per se once the lock member of claim 1/21 is found in the art.

5. Dependent claims

Likely obvious (strong art alignment):

Hardest to invalidate — the genuine 103 battleground: claims 7–10 and 16–19.
These are the only claims reciting the specific geometry: a recess with a larger portion and a smaller side‑opening portion (keyhole), and a lock member with a larger-diameter and smaller-diameter region, where the larger region cannot pass through the side opening while the smaller can. No of‑record reference appears to disclose this two‑diameter/keyhole detent. A challenger would have to argue one of:

• keyhole slots and stepped‑diameter pins are notorious mechanical expedients (hanging slots, bayonet/T‑slot couplings, headed pins in keyhole slots), so adapting one to a latch is an obvious design choice; or
• it is an "obvious to try" optimization to make a latch that cannot be accidentally dislodged by jamming in one direction.

That argument is available but weaker and more vulnerable to a "teaching away / unexpected result" rebuttal (e.g., the side opening allowing the linkage to be assembled/disassembled over the pin). My assessment: claims 7–10 and 16–19 are the claims most likely to survive; claims 1, 20, 21 and the mechanical ancillaries 2–6, 11–15, 22–34 are the most exposed.

6. Foreseeable non‑obviousness counterarguments

1. "Petersen '910 and Schmidt '893 are not self‑locking/over‑center devices; their latches replace over‑center locking, so they teach away from adding a latch to an over‑center tool." This is the best patentee argument. Rebuttal: KSR rejects rigid "teaching away" if the reference merely uses a different design solution in the same field for the same purpose; and the '447's own specification treats the latch as a supplement, which is exactly what happenstance of engineering would suggest. Also, Blue Water (which does disclose an over‑center tool) supplies the teaching that an added restraint is desirable — so no reference teaches away from the ultimate combination.
2. "No reference teaches engagement with the linkage as opposed to the handle or adjustment screw." Rebuttal: Petersen '910 (lip 36 on link 23) and Schmidt '893 (sear 36 on toggle link 32) both do — they were cited on the face of the '447.
3. "The '447 solved a long‑felt need that eluded others for 22 years." This is a Graham factor‑4 argument, but it is undercut by Blue Water '251/'359 (1991–1993) and Morrison '021 (1989), which already solved the same problem in the same field. A crowded field with multiple prior solutions points toward obviousness, not away.
4. Claim differentiation / limited disclosure. Claim 1's "perpendicular" limitation is not tied to any stated technical effect. A challenger will argue it is a claim‑drafting limitation with no commensurate advance, entitled to little or no weight (see KSR on "a court must ask whether the improvement is more than the predictable use of prior art elements").

7. Secondary considerations (objective indicia)

• Commercial success / nexus: none established in the material I reviewed; there is no evidence of record linking any Stanley "Vise‑Grip" product success to the specific two‑diameter/keyhole lock. Without a nexus, any such evidence carries little weight.
• Licensing / industry praise: not found.
• Copying: the later patents (Milwaukee US 11,541,514; US 11,247,308; Li‑Tu Wu US 2017/0203413–14 "Safety structure for pliers") post‑date the '447's 2012 priority and are not prior art to the '447 claims; they are at most evidence that the problem remained commercially relevant, and they are the sort of "later patent does not prove nonobviousness" material (In re Meyer; MPEP 2144.03).
• Long‑felt but unresolved need: largely neutralized by Blue Water/Morrison, as above.

8. Bottom line

• Claim 1 — vulnerable. No single of‑record reference anticipates it, but Blue Water '251/'359 in view of Petersen '910 and/or Schmidt '893 supplies every limitation, with Blue Water supplying the identical problem statement and the "restraining element … to prevent movement of said lower jaw from said clamped position" teaching, and Petersen/Schmidt supplying the latch‑on‑the‑linkage element. The KSR rationales (common field, recognized problem, finite predictable solutions, design incentive) are all available, and every reference is on the face of the patent.
• Claim 21 — vulnerable, arguably more so than claim 1, because Blue Water's aligned aperture/screw‑head‑opening + lower‑handle extension flange plus Morrison's aligned‑aperture restraint already provide the "aligned recesses bridged by a member" genus; relocating one recess to the toggle link is a substitution taught by Petersen '910 / Schmidt '893 / US 3,496,808.
• Claim 20 — weakest. Its distinguishing element (a snap ring for tactile feedback) is a standard part recited for its inherent, known function; KSR + the intended‑use doctrine make it hard to defend.
• Claims 7–10, 16–19 — the strongest nonobviousness position, because the two‑diameter/keyhole recess-and-lock geometry does not appear in any of‑record reference I reviewed; invalidating these requires an "obvious design choice" argument from general mechanical knowledge (keyhole slots, stepped pins).
• Claims 2–6, 11–15, 22–34 — likely obvious on the mappings in § 5.

Confidence: High on the content of Blue Water '251/'359, Petersen '910, Schmidt '893 and Morrison '021 (I retrieved specifications/claims). Moderate on US 3,496,808 and US 3,635,107 (excerpts only; not of‑record; verify before relying on them in any challenge). Low/none on Chervenak US 2007/0209484 and Thomas US 2008/0060486 — both are of‑record "locking pliers" references I did not retrieve; they should be reviewed, as they may supply additional motivation or even the two‑diameter geometry.

9. Flags / refinements to the previously generated sections

1. Refinement (not a contradiction): the earlier summary attributes both the FIG. 1–3 sliding latch and the FIG. 4–6 pivot latch to claim 1's "perpendicular engagement" limitation. On the specification as written, only the FIG. 1–3 sliding latch 290 moves clearly perpendicular to the linkage's direction of motion; the FIG. 4–6 pivot latch 390 rotates about the same pin 180 as the linkage. Claim 21 (aligned recesses) reads on both; claim 1's perpendicular limitation reads cleanly only on the sliding embodiment. Expect an accused infringer to exploit this asymmetry.
2. Addendum to "Points of Uncertainty": US 3,496,808 and US 3,635,107 (Schmidt/Mara detent‑between‑handle‑and‑toggle‑link disclosures) are not in the '447's citation list but are highly material § 103 art that I located. That is a notable gap in the examiner's cited art, and it strengthens any obviousness challenge to claims 1 and 21.
3. Consistent with the earlier finding of no litigation: nothing in the retrieved material changes that conclusion; Sears, Roebuck & Co. v. Jones (10th Cir. 1962) that surfaced in my searches involves US 2,514,130 (Jones), a different and much older patent, and does not involve the '447.