US 3424176

I'll search for the specific patent number as requested.

Let me check for any CAFC/litigation activity and confirm the assignee status.

Let me try to recover the full claim set (the header indicates 4 claims) from another source.

US 3,424,176 — Summary

Important scoping note on identifiers (interpreted literally, no auto-correction):

• The query ID 3424176 is ambiguous across offices. As a US patent number, 3,424,176 is the 1969 Hale hair-dyeing patent. As an EP number, EP 3424176 B1 is a completely unrelated patent ("Systems and methods for distributed data sharing with asynchronous third-party attestation," priority 2016). These are different documents; only the US patent is summarized below.
• I did not find any CAFC 2026 docket or litigation record referencing U.S. 3,424,176. That is consistent with (not proof of) the patent's status: it expired decades ago, so it cannot be asserted in a current infringement suit.

Bibliographic data (from Google Patents, Justia, and the issued patent PDF)

Abstract (as printed in the patent)

"This invention relates to hair dyeing apparatus and in particular, to wet combs and brushes for applying developers, dyes, tints, bleaches, wave-set solutions and the like to the hair."

Cited prior art

US 1,263,693 (Mathews, fountain-comb); US 1,707,665 (Murphy, comb for coloring or dyeing hair); FR 773,486 (device for projecting/distributing liquid on and in hair); US 2,228,213 (Hillsberry, hair dye applicator); US 2,617,431 (Gaspari, hair-treating implement); US 3,147,757 (Hofmann, hair treatment comb with a resilient handle reservoir). The specification singles out Hofmann '757 as the closest known device.

Independent claim — plain-language overview

Claim 1 is the only independent claim in the patent's textual set. It claims, as a combination, a hair-treatment device comprising:

1. a comb having a handle at one end;
2. a plurality of blending tufts of narrow cross-section depending from the other end (i.e., a thin, segmented line of brush bristles on the non-handle end); and
3. a dye applicator removably mounted on the comb that includes means for delivering dye directly to the scalp.

The dependent claims narrow the delivery structure rather than the comb:

• Claim 2 — the delivery means are soft rubberized "nobs" whose delivery ends are substantially adjacent the blending tufts (specification: the nobs are slightly biased toward the tufts so liquid can be applied between pairs of tufts right at the part, with the tufts already positioned to blend immediately).
• Claim 3 — the applicator further includes a thumb bulb for holding dye solution that is a component separate from the comb, positionable relative to the handle so the operator can apply thumb pressure independently of the hand's grip on the handle.

Claim 4 — uncertainty flagged. The printed patent states "4 Claims," but the full text of claim 4 did not come through in any source I could retrieve (Google Patents' claim block ends at claim 3; the patentimages PDF and Justia mirrors likewise surfaced only claims 1–3 in the extracted text). Based on the specification's process passage (bleach with ammonium chloride/hydrogen peroxide → dry → section the hair with the comb side → apply dye along the part → blend into the new growth with the tufts, repeating until only new growth is tinted), claim 4 is most plausibly a method claim covering that sectioning/applying/blending sequence — but I cannot state its wording authoritatively. Treat claim 4 as unverified from the sources I could reach.

Practical significance

The patent's stated point of novelty is the combination in one tool of (a) a sectioning comb, (b) a narrow line of blending tufts replacing the cotton swab used for touch-up blending, and (c) a detachable, thumb-actuated rubber bulb applicator whose discharge nobs sit immediately adjacent the tufts — minimizing the time between applying dye at the part and blending, which the specification identifies as the critical step. It is a ~1969 mechanical grooming patent, expired since 1986 and in the public domain.

Sources

• https://patents.google.com/patent/US3424176/en (bibliographic data, description, claims 1–3, citations, family/legal status)
• https://patentimages.storage.googleapis.com/a8/01/ab/4926c63321ec59/US3424176.pdf (issued patent PDF, front page confirming "4 Claims," U.S. Cl. 132–112, Int. Cl. A45D 25/08)
• https://patents.justia.com/patent/D640470 and https://patents.justia.com/patent/D1000000 (later design patents listing "3424176 | January 1969 | Hale" as prior art)
• http://data.epo.org/gpi/EP3424176B1-... (confirming the unrelated EP 3424176 B1 is a different patent, not this one)

Limitations of this search

I have no direct query access to USPTO PatentCenter/PAIR, the PTAB, or the CAFC docket system; results came from public web search. No CAFC 2026 docket entry, district-court case, or PTAB proceeding for U.S. 3,424,176 appeared in any search. Because the patent's term ended in 1986, litigation over it in 2026 would be legally implausible, but I cannot affirmatively certify that no historical suit ever named it.

I'll research litigation involving US patent 3,424,176 across litigation-tracking sources.

Let me run more targeted searches on litigation-specific sources.

Let me do a final verification search on litigation databases and the Federal Circuit.

Litigation Search: US Patent 3,424,176

Bottom line: No litigation is known involving US Patent 3,424,176 ("Hair dyeing apparatus," Edith A. Hale). I could not identify any district court, ITC, or Federal Circuit proceeding in which this patent was asserted or challenged.

What I searched

Why the negative result is credible here

• The "hits" were false positives from different patents. Searches for a "'176 patent" repeatedly returned U.S. 7,818,176 (VoiceBox/VB Assets v. Samsung and Amazon, e.g. IPR2025‑00867), U.S. 5,085,176 (MercExchange v. eBay, E.D. Va. 2:01‑cv‑736), and a Mentor Graphics '176 patent in Synopsys v. Mentor. None of these is US 3,424,176.
• The patent is long expired. Filed November 2, 1966; granted January 28, 1969; anticipated expiration January 28, 1986. Google Patents lists legal status as "Expired – Lifetime." A patent that lapsed four decades ago has no live infringement cause of action (damages recovery is generally limited to six years pre-suit under 35 U.S.C. § 286), which is consistent with the absence of any electronic docket record.
• No successor/assignee trail. The patent records show an individual inventor assignee (Edith A. Hale, New York, NY) with no corporate assignment history — the profile of a patent that was never commercially enforced.
• Technology context. It is a mechanical hairdressing tool (detachable thumb-bulb dye applicator clipped to a comb/brush with blending tufts). Its only "forward citations" are later patents that cite it as background art (e.g., US 5,146,936 Charlene Products; US 3,563,250; USD 1,000,000), which is citation activity, not litigation.

Important caveats — please read

1. Pre‑1989 litigation may be invisible to me. PACER electronic docketing did not begin until the late 1980s/early 1990s, and CourtListener/RPX/Unified coverage of pre‑1990 cases is incomplete. It is therefore possible — though I found no evidence of it — that a 1969–1980s infringement suit existed that no online database preserves. Given the patent's expiry in 1986, any such case would be historical only.
2. No litigation activity is shown in any post‑grant proceeding. There is no IPR, PGR, CBM, or ex parte reexamination record surfaced for this patent (the PTAB records returned by search all relate to other patents).
3. I did not access PACER directly. My searches surface litigation aggregators and PACER-derived documents indexed by search engines; I could not run a live Docket Alarm / Unified Portal patent-number query returning a case list. If you need a certified negative, I recommend a direct Docket Alarm or Lex Machina patent-number search and a PACER "party name" search for "Hale, Edith A." in the 1969–1990 window.

Summary table

If you have a lead suggesting this patent was litigated (e.g., a specific company or decade), tell me and I'll run targeted follow-up searches, but based on the searches completed I cannot report any case with plaintiff, defendant, jurisdiction, case number, and filing date, because no such case was found.

Sources checked: Google Patents – US3424176A · Unified Patents Litigation Portal · CourtListener · Justia Patents – D1000000

I'll verify the structured data with a quick search before reporting.

Proceedings overview

Total AIA trial proceedings on file: 0. No IPR, PGR, or CBM proceeding has ever been instituted or even filed against US 3,424,176 — the structured ODP block reports no AIA trial proceedings, and independent web searching surfaced none. Bottom line for a defendant: there is no PTAB record at all, but that is not because the patent is a hardened survivor — it is because the patent expired on 1986-01-28, roughly 26 years before the AIA trial regime existed. Do not treat the silence as a validity signal; treat it as an expiration signal. If a demand letter cites claims 1–4 of this patent, the sender is asserting a patent that has been in the public domain for four decades.

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No proceedings to report

The required per-proceeding cards are omitted because the canonical list is empty. Verified against:

• Structured data (authoritative): "The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest." Status breakdown: active 0 / claims invalidated 0 / claims sustained 0 / settled 0 / institution denied 0.
• PTAB E2E / PTAB Decisions search — no petition, institution decision, FWD, or termination naming Hale or U.S. Patent 3,424,176 (PTAB E2E, USPTO PTAB Decisions).
• Federal Circuit / CourtListener — no appeal docket identified (CourtListener search for "3,424,176"). No CAFC opinion and therefore no Rule 36 or precedential disposition to cite.
• Web search — the only "342" PTAB hits are a different patent (US 7,908,342, IPR2018-01131, RPX v. patent owner). Flagging as a false-positive disambiguation so it isn't mis-cited in an invalidity chart. Google Patents likewise lists no adversarial-proceeding history for 3,424,176 (US3424176A).

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Why there is structurally no PTAB story here

• AIA trials post-date this patent by decades. IPR/CBM jurisdiction opened 2012-09-16; PGR applies only to patents with an effective filing date on or after 2013-03-16. This patent was granted 1969-01-28 on an application filed 1966-11-02 (Ser. No. 591,457). No CBM was possible either — CBM is limited to covered business-method patents in financial-services contexts, which has no application to a hair-dyeing comb.

• Term already expired. Google Patents records the anticipated expiration as 1986-01-28 (17-year pre-URAA term from grant). Status is "Expired – Lifetime." That means any damages case would be confined to pre-1986 conduct, which is barred by the six-year limitation of 35 U.S.C. § 286 and, independently, by laches.

• Prosecution art, not PTAB art. The only prior-art record on this patent is the examiner-cited set listed in the "References Cited" section, none of which was ever tested in a contested proceeding:

  • US1263693 — Mathews, Fountain-comb (1918-04-23)
  • US1707665 — Murphy, Comb for coloring or dyeing the hair (1929-04-02)
  • FR773486 — Device for projecting or distributing any liquid on and in the hair (1934-11-19)
  • US2228213 — Hillsberry, Hair dye applicator (1941-01-07)
  • US2617431 — Gaspari, Hair-treating implement (1952-11-11)
  • US3147757 — Hofmann, Hair treatment comb with a resilient handle reservoir (1964-09-08)

  Hofmann is expressly named in the specification as priorly known like devices over which the applicator is "believed to afford distinct advantages."

• One data caveat, flagged not resolved. The printed front page recites "4 Claims," but the full-text "What is claimed" listing rendered on Google Patents shows only claims 1, 2, and 3. I cannot verify claim 4's text from the available source; treat the existence/content of claim 4 as unverified rather than assuming it was canceled or never issued.

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Strategic summary

Claim status: no claim has been canceled, sustained, or tested at the PTAB — because nothing was ever filed. Under the ODP data there are zero canceled claims, zero sustained claims tried in an AIA forum, and all claims are technically untested by the Board. The distinction that matters for a defendant is not "tested vs. untested" but "in force vs. expired." Claims 1–3 (and a possibly-unrecited claim 4) lapsed with the term on 1986-01-28 and are unenforceable as a practical matter; there is no narrowing through IPR to point to, because there is no IPR. Any argument that "the patent survived PTAB scrutiny, so it's hardened" would be a fabrication.

Estoppel landscape: no § 315(e)(2) estoppel attaches, because no IPR was ever instituted. That is a purely theoretical benefit — every invalidity ground under §§ 102/103/112 remains formally available in district court, including the examiner-cited Hofmann and Gaspari references and the 1934 French publication, none of which has been the subject of an estoppel-generating final written decision. In practice, the operative bars are temporal: § 286's six-year damages lookback combined with the 1986 expiration means there is no live infringement window to litigate.

Pattern signals: none. No repeat petitioner (there is no petitioner), no PTAB appeals, no defensive aggregator such as Unified Patents or RPX in the chain — the assignee of record is the individual inventor, Edith A. Hale. The cited-by list (13–16 forward citations, e.g., US5146936 Charlene Products, US5289833 McDonald, US8967156 Skidmore, US8770207 Kao) shows the patent was cited as prior art by later hair-dyeing filings, which is a prior-art signal against third parties, not against this patent. That is the mirror-image risk a defendant should note: this patent is old art that can be used to invalidate newer claims, not a weapon that can be used against anyone today.

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Recommended next steps

• If you are a defendant and received a demand citing this patent: do not spend budget on prior-art work. The dispositive point is that the patent's term ended 1986-01-28 (US3424176A, Google Patents, "Anticipated expiration 1986-01-28," status "Expired – Lifetime"). Assert the § 286 six-year bar and laches in your first responsive filing and demand the asserted claims and infringement dates be identified with specificity. I cannot link to a Final Written Decision here because none exists — there is no FWD to quote.
• Do not represent to a court or client that any claim has been invalidated by the PTAB. The correct statement is narrower and stronger: zero AIA proceedings were ever filed or instituted, the patent expired 1986-01-28, and no Federal Circuit appeal exists.
• No trial-stage milestones to track. There is no institution decision deadline, no oral hearing, and no statutory one-year FWD deadline (35 U.S.C. § 316(a)(11)) running against anyone, because there is no pending or instituted trial.
• If the demand letter is paired with a reissue, continuation, or later-family member: check that patent separately. 3,424,176 is pre-URAA and cannot have continuations still in force, but the forward citations (Kao US8770207, Skidmore US8967156, Charlene US5146936) indicate an active hair-coloring patent space where the real assertion risk sits.
• Verification path if you need a belt-and-suspenders record: query PTAB E2E by patent number at https://ptacts.uspto.gov/ptabweb/#/patentSearch and the ODP proceedings endpoint, and pull assignment history via USPTO Assignment to confirm no successor has acquired the lapsed rights.

Confidence note: I have high confidence in the "no PTAB proceedings" conclusion — the structured ODP block is authoritative and both targeted searches corroborated it. I have lower confidence only on the claim-4 recitation gap (front page says 4 Claims; the rendered claim listing shows 1–3), which I have flagged rather than resolved.

I'll start by checking the authoritative record and cross-referencing.

Inventors

Only one inventor is named. The patent issued Aug. 28? no — Jan. 28, 1969 from application Ser. No. 591,457, filed 1966‑11‑02, with no assignee stated on the front page. Google Patents records both "Original Assignee" and "Current Assignee" as Individual, which is the index's placeholder for a patent that issued to its named inventor with no assignment on record.

Unusual-pattern check: not applicable / no finding. There is no original corporate assignee, so the "all inventors depart within 12 months of filing" heuristic (which presumes employment-based ownership) cannot be run. The only notable observation on the record is drafting quality: the specification and claims carried into the granted patent contain uncorrected typographical errors ("com'b teeth," "nobs," "fnorn," "acompanying"), which is consistent with an unrepresented or lightly represented independent inventor rather than a corporate patent department filing. That is an observation about the prosecution record, not evidence of business status or of any later transfer.

Original assignee

None — the patent issued to the inventor, Edith A. Hale, as an individual. There is no company named as assignee on the face of US 3,424,176, and no change‑of‑ownership data appears in the Google Patents legal‑events record (see below).

• Product embodying the claims: No evidence found of any commercial product. The claims recite a hand‑held beautician's tool (a comb/brush with blending tufts plus a detachable thumb‑actuated bulb applicator for delivering bleach and dye along a hair part, claims 1–4). No manufacturer, catalogue, trademark, or sale of such a device surfaced in searching. I cannot affirmatively rule out that Hale or a small salon-supply operation made and sold it locally — but nothing in the public record supports a finding either way.
• Primary line of business: Not determinable from the patent or the indexed records; the inventor's address is a residential/manhattan street address, not a corporate address of record.
• Current status: Individual inventor; patent expired 1986‑01‑28 (17 years from grant). No corporate successor, acquisition, dissolution, or bankruptcy proceeding involving this patent was found.

Assignment timeline

There are no recorded assignments for US 3,424,176 — no reel/frame entries exist to report.

I did not fabricate any. What the underlying records show:

• Google Patents legal events for US3424176A list exactly four entries, all prosecution/lifecycle events, zero assignment (reel/frame) events: 1966‑11‑02 "Application filed by Individual"; 1969‑01‑28 "Application granted"; 1969‑01‑28 "Publication of US3424176A"; 1986‑01‑28 "Anticipated expiration." Google Patents sources its ownership/legal‑events data from USPTO assignment and PEDS/ODP feeds, so the absence of an assignment event is meaningful.
• Front page of the printed patent: inventor name and address only; no assignee, no "assignors to" line, no attorney of record for the applicant, and no security interest recorded.
• Cited-by and citation data: US 3,424,176 is cited as prior art by later patents (e.g., US 5,146,936, Charlene Products, Inc.; USD 566,485; USD 1,000,000) and itself cites US 1,263,693 (Mathews), US 1,707,665 (Murphy), FR 773,486, US 2,228,213 (Hillsberry), US 2,617,431 (Gaspari) and US 3,147,757 (Hofmann). Citation is not transfer — none of those citing or cited documents is an assignee or successor in the chain, and the reference to US 3,147,757 in the specification is an applicant‑acknowledged prior‑art citation, not a link in the ownership chain.
• Litigation/assertion cross‑checks: no infringement suit, PTAB proceeding, ITC action, or SEC filing referencing patent 3,424,176 or Ser. No. 591,457 was found. There is therefore no "first suit" event against which a pre‑litigation transfer could be dated.
• Caveat on verification method: the Assignment Center at assignmentcenter.uspto.gov is an interactive query interface that I could not query programmatically during this analysis; the "no records" finding rests on the mirrored assignment/legal‑events data in the authoritative patent record and on the negative results of targeted searches for any recorded conveyance, litigation, or corporate successor. A human should confirm by running the patent number directly in Assignment Center (see link in Verdict) before relying on this for a portfolio opinion.

Because the chain is empty, there is no correspondent of record to flag and no recurring‑attorney pattern to analyze in this chain.

Timeline diagram

timeline
    title Ownership of US 3424176
    1966 : Filed by Edith A Hale
    1969 : Patent issued to inventor
    1986 : Expired 17 years after grant
         : No assignment ever recorded

NPE / troll-pattern signals

Verdict

Insufficient data (the "no records / only the original assignment" branch).

Justification: the assignment record for US 3,424,176 is empty end‑to‑end. The Google Patents legal‑events record contains only four non‑ownership entries — 1966‑11‑02 filed by Individual, 1969‑01‑28 granted, 1969‑01‑28 published, and 1986‑01‑28 "Anticipated expiration" — with no reel/frame postings whatsoever, and the printed patent names Edith A. Hale as sole owner with no assignee line. With no transfer events, no correspondent of record, and no assertion or litigation history, every NPE indicator above is necessarily "not present," and there is no evidentiary basis for any of the positive NPE verdicts. The practical ownership conclusion is that the patent remained with the inventor until it expired by operation of law on 1986‑01‑28, before the patent‑assertion era in which the NPE framework is meaningful.

Verify at: USPTO Assignment Center (search patent number 3424176; the legacy index is at assignment.uspto.gov) and cross‑check the Google Patents legal‑events record — the latter is the source of the "no assignment entries" call above.

I'll research US Patent 3,424,176 and each of its cited references against USPTO and patent databases.

Prior-Art Analysis — US 3,424,176 ("Hair dyeing apparatus," Edith A. Hale)

1. The patent number was located — and not confused with a similar number

A USPTO/Google Patents record was retrieved for exactly US 3,424,176 (I did not return results for the look‑alike numbers that dominate "176" searches — e.g., US 7,818,176, US 5,085,176, or the D‑variant family member):

Note on the claims: the operative text reproduced for me shows only claims 1, 2 and 3, even though the header states "4 Claims." Claim 4 is not reproduced in the available OCR. My anticipation analysis below therefore covers claims 1–3, all of which were analyzed against every reference.

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2. The references of record (the only true prior art for this patent)

There are two ways the citations appear, and they do not match perfectly:

A. Printed "References Cited" (as OCR'd from the patent face):

B. Structured citation data (Google Patents "Citations (6)"):

⚠ Contradiction to flag (do not auto-correct)

The printed reference list names a "Julien" (4/1929, class 132‑112). The structured citation data instead lists US 1,707,665 to Charles S. Murphy (filed 1928‑05‑29, published 1929‑04‑02) at that same slot, same date, same class. Both are dated 4/1929 and class 132‑112. I cannot reconcile "Julien" vs. "Murphy" from the sources I have; treat the identity of this reference as unverified and pull the physical copy (or the "References Cited" image) to confirm whether it is US 1,707,665 or a different 1929 patent.

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3. Legal framework that governs this analysis

The patent was filed 2 Nov 1966 and granted 28 Jan 1969 — i.e., pre‑AIA, so pre‑AIA 35 U.S.C. § 102 applies. Two consequences:

1. Every cited reference predates the 1966 filing by 2–48 years, so each is available as a § 102(b) statutory bar (printed publication/patent more than one year before filing). FR773486 (published 1934‑11‑19) is likewise a § 102(b) printed publication and, because it was filed and granted before the US filing date, also a § 102(d) reference.
2. Anticipation is a single‑reference test — a reference anticipates only if it discloses each and every element of the claim, arranged as in the claim (Net MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1369 (Fed. Cir. 2008)). Anything less is, at most, § 103 evidence.

Claim elements to test:

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4. Reference‑by‑reference analysis

4.1 US 1,263,693 — Lewis C. Mathews, "Fountain‑comb"

• Citation: US 1,263,693; filed 1917‑06‑01; published 1918‑04‑23; US Cl. 132‑114.
• Description: A self‑feeding ("fountain") comb that carries a liquid supply and feeds it through the comb to the scalp. (Note: my retrieval for this call returned content for a different number, US 1,256,386 — a fountain comb with a compressible tube/pouch in a hollow handle, a geared ball feeder, and hollow teeth that distribute liquid "directly onto the scalp without excessive wetting of the hair." I did not retrieve the text of US 1,263,693 itself; the description above rests on its title/class only.)
• § 102 anticipation potential: None. It may touch C1‑b and C1‑e (liquid delivered toward the scalp), but it discloses no brush/tuft blending structure (C1‑c) and no remountably attached applicator (C1‑d). It cannot anticipate any of claims 1–3. Relevance is § 103 background only.

4.2 US 1,707,665 — "Comb for coloring or dyeing the hair" (1929) — identity disputed v. "Julien"

• Citation: US 1,707,665 (per structured data), filed 1928‑05‑29, published 1929‑04‑02, inventor listed as Charles S. Murphy; printed patent face instead shows "Julien," 4/1929, class 132‑112.
• Description: By title, a comb adapted for applying coloring/dyeing material to hair; class 132‑112 places it in the same art as the Hillsberry/Gaspari references (dye‑applicator combs). I could not retrieve the specification text.
• § 102 anticipation potential: Indeterminate; likely none as to any full claim. On title alone it is a dyeing comb, not shown to have (i) narrow‑cross‑section blending tufts, (ii) a removable applicator, or (iii) a separate positionable thumb bulb. Because the reference itself is identified inconsistently, I expressly withhold an anticipation finding. Verify the document first.

4.3 FR 773,486 — "Device for projecting or distributing any liquid on and in the hair"

• Citation: FR 773,486 A; priority/filing 1934‑05‑22; published 1934‑11‑19; status Expired. Source: https://patents.google.com/patent/FR773486A/en
• Description: Only the front‑page/bibliographic data was retrievable. It is a liquid‑projecting/distributing device for hair. No drawing or claim text retrieved.
• § 102 anticipation potential: Not established. A general "projecting/distributing liquid on and in the hair" device does not, on the record available, disclose the blending tufts, the removable applicator, or the thumb bulb. It is a § 102(b)/§ 102(d) prior‑art reference of general relevance only. Its 1934 date means it is prior art regardless.

4.4 US 2,228,213 — Lillie M. Hillsberry, "Hair dye applicator" — the closest reference

• Citation: US 2,228,213; filed 1940‑05‑16 (Ser. No. 335,641); published 1941‑01‑07; 4 claims, Cl. 132‑9 (now 132/112, 132/120); Int. Cl. A45D19/02, A45D24/24. Sources: https://patents.google.com/patent/US2228213 and https://www.freepatentsonline.com/2228213.html
• Description (full text retrieved): An elongated brush head 11 with bristles 12; a comb 13 integral with the brush head ("secured to or formed integral with the brush head"), projecting perpendicular to the bristle side so it can part the hair so "the bristles 12 may be positioned close to the scalp for applying the dye to the roots of the hair." A hollow handle 19 houses a bottle of dye 28; passages 16/17 lead via ports 18 that open into the bristles; a valve 30 with an external stem regulates flow; a stopper 23 seals the bottle neck. The stated object is to apply dye "to the root portions of the hair adjacent the scalp" without dripping.
• Element mapping:

• § 102 potential: Strongest candidate, but likely does not anticipate claim 1 as a whole, because the "removably mounted applicator" limitation (C1‑d) is absent — Hillsberry's applicator is unitary with the comb/brush. Claims 2 and 3 are clearly not anticipated (no rubber nobs; no separate positionable thumb bulb). Hillsberry is best used as the primary § 103 reference, combined with Hofmann (thumb‑bulb reservoir) and/or Mathews (scalp‑direct fountain comb).

4.5 US 2,617,431 — Gaspari Joseph, "Hair‑treating implement"

• Citation: US 2,617,431; filed 1951‑01‑29; published 1952‑11‑11; Cl. 132‑112 (per the printed face).
• Description: A hair‑treating implement in the same class as the subject applicator combs. Full text was not retrieved (search budget exhausted); description rests on title/class/date only.
• § 102 potential: Not established. As a § 102(b) reference it is unquestionably prior art, but on the record available I cannot show it discloses blending tufts, a removable applicator, or the thumb‑bulb structure. No anticipation finding.

4.6 US 3,147,757 — Mary K. Hofmann, "Hair treatment comb with a resilient handle reservoir" — the reference the applicant expressly distinguished

• Citation: US 3,147,757; filed 1962‑08‑14; published 1964‑09‑08; Cl. 132‑1.
• Description: A hair‑treatment comb in which the liquid reservoir is a resilient (squeezable) handle — i.e., squeeze‑the‑handle dispensing. The specification of the '176 patent singles this reference out: the applicator of the invention "is believed to afford distinct advantages over priorly known like devices such as are shown, for example, in Patent No. 3,147,757."
• Element mapping: It is directly material to claim 3 — it shows a resilient/squeeze reservoir. But it is a comb with the reservoir in the handle, i.e., the reservoir is integral with and not separately positionable relative to the handle, which is precisely the limitation claim 3 recites ("being a component separate from said comb, said bulb is positionable relative to the handle thereof … independently of the pressure of the hand on said handle").
• § 102 potential: None as to any claim. It does not disclose a separately mounted, positionable thumb bulb, nor the blending tufts of narrow cross‑section in the claimed arrangement. It is § 103 evidence, and the patent's own remarks frame it as the closest known art to be improved upon.

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5. Summary matrix — claim vs. reference

✔ = disclosed; ~ = partially/analogously disclosed; ✘ = absent; ? = not retrievable.

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6. Bottom line

1. No single cited reference anticipates claim 1. The combination of (a) a comb, (b) narrow‑cross‑section blending tufts, (c) a removably mounted dye applicator, and (d) delivery directly to the scalp is not met in one reference. The missing element in every case is the removable mounting (C1‑d) and/or the specific nob/tuft geometry.
2. US 2,228,213 (Hillsberry) is the most relevant prior art — it is the only reference that comes close to a brush‑and‑comb dye applicator feeding dye to the roots/scalp through the bristles. Its fatal gap is that everything is integral, not removably mounted.
3. US 3,147,757 (Hofmann) is the reference the applicant specifically distinguished, and it bears on claim 3 (thumb‑squeeze reservoir) — but its reservoir is in the handle, not a separate positionable bulb, so it does not anticipate.
4. The real risk to validity is § 103 obviousness (Mathews' scalp‑direct fountain feeding + Hillsberry's comb/brush/bristle applicator + Hofmann's squeeze‑reservoir handle), not § 102 anticipation on any one reference.
5. Forward citations ("Cited By": US 3,563,250; US 3,960,154; US 5,146,936; US 5,289,833; WO 96/04814; US 7,337,352; US 7,647,933; US 8,220,469; US 8,967,156; US 8,770,207; USD 566485; USD 640470; USD 1,000,000) are NOT prior art — they post‑date the 1966‑11‑02 filing and cannot be cited under § 102 against this patent.

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7. What I could not verify (please treat as open items)

• Full text of three of the six cited references was not retrieved — US 1,707,665 (identity also disputed, see §2), US 2,617,431 (Gaspari), and FR 773,486. Their brief descriptions and anticipation findings above are correspondingly qualified; I did not fabricate specification detail for them.
• My search for US 1,263,693 surfaced a different patent number (US 1,256,386) — a fountain comb with a compressible tube/pouch and geared ball feeder. I did not auto‑attribute its disclosure to US 1,263,693; if you want a definitive Mathews analysis, pull the US 1,263,693 PDF directly.
• Claim 4 (the patent recites 4 claims) is not reproduced in the available text; it should be checked, as an independent or method claim (possibly directed to the sectioning/bleaching/blending steps described in the specification) could change the § 102 picture.
• I did not run a live PACER/Docket Alarm patent‑number query; consistent with the earlier litigation analysis, no assertion of this patent was located.

I'll research the six prior-art references cited on the face of US 3,424,176 to ground the § 103 analysis.

Now let me research the remaining three references — Gaspari, Mathews' fountain-comb, Murphy's coloring comb, and the French reference.

Obviousness Analysis — US 3,424,176 (Hair Dyeing Apparatus, Edith A. Hale)

Note: I build on the prior "Litigation summary" only at the points where it matters — specifically that no litigation/PTAB record exists, so there is no binding claim construction and no litigated secondary-considerations record to weigh. I do not repeat that section.

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1. Governing framework

The application was filed November 2, 1966 and granted January 28, 1969. It is therefore governed by pre‑AIA 35 U.S.C. § 103(a) (obviousness at the time the invention was made, to a person of ordinary skill in the art), applied through the Graham v. John Deere factors and the Supreme Court's decision in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007). Because no prosecution history is reproduced on the Google Patents page beyond the granted text, I analyze the claims as granted, not as narrowed by any argument of record.

The KSR rationales most relevant here (MPEP 2143 examples A–F) are:

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2. The claims as granted (and a record discrepancy to flag)

The granted text (as reproduced) recites three claims, although the abstract line on the page says "4 Claims":

• Claim 1 — combination: a comb with a handle at one end; a plurality of blending tufts of narrow cross-section depending from the other end; and a dye applicator removably mounted on said comb having means for delivering dye directly to the scalp.
• Claim 2 — the claim 1 means are soft rubberized nobs whose delivery ends are substantially adjacent said blending tufts.
• Claim 3 — the applicator has a thumb bulb for dye solution, is a component separate from said comb, and is positionable relative to the handle so that thumb pressure is applied to the bulb independently of the pressure of the hand on the handle.

Two record anomalies I will not auto-correct, per instruction, but which materially affect the analysis:

1. Claim 4 is missing from the text I have. The "4 Claims" statement is inconsistent with the three enumerated claims. Either claim 4 was cancelled/not printed, or the text is truncated. This does not change the § 103 outcome for claims 1–3.
2. Numerals collide. The specification says the applicator "is formed as a single component attachable to the brush by clips 14" and, in the next sentence, "the applicator is provided with a thumb operated bulb 14." One of these numerals is corrupt (likely clips 13/14). I treat reference numerals as unreliable in the OCR and rely on the descriptive words.

Claim-construction point with § 103 consequences: Claim 1 says the tufts depend "from the other end" of the comb, but the specification says the handle has "upper comb teeth 8 and lower dye blending brush tufts 10 in one end thereof." Read in light of the specification and FIG. 3, the two working surfaces are opposite sides near one end, not opposite ends of the handle. Under either the broadest reasonable construction or an ordinary Phillips construction, claim 1's "handle at one end / tufts at the other end" is at best imprecise, and probably means "a handle, with comb teeth and tufts on opposite faces of the working head." That reading — the narrower, more defensible one — is precisely the structure of the Hillsberry reference discussed below. The ambiguity thus does not save the claim; it broadens the prior-art coverage.

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3. The prior-art record actually available

The "Prior Art" material on the page divides into three groups. Only the first is usable as § 103 art.

3(a) The six examiner-cited references (all pre‑1966 — these are the § 103 art)

3(b) The "Cited By" list — NOT available as § 103 art

Every document in the "Cited By" table post-dates Hale's November 2, 1966 filing (US 3,563,250 filed 1967‑07‑12; US 3,960,154 filed 1975; US 5,146,936 filed 1990, etc.). Under § 102(a)/(b) and § 103 as they stood in 1966, a reference must predate the invention/filing date to be prior art. These later documents are therefore unavailable, except conceivably as evidence of the ordinary skill level or of the state of the art nunc pro tunc — a use courts disfavor. Anyone who cites the "Cited By" art as an obviousness combination for the '176 patent has made a date error. This is worth flagging because a casual reading of the page invites exactly that mistake.

3(c) "Similar Documents" — mostly post-dating, mixed

A few of the "Similar Documents" predate 1966 (US 2,299,296 / 1942; US 2,617,431 / 1952; US 2,139,904 / 1938; US 2,299,295 / 1942; US 2,775,244 / 1956), but they are neither cited on the face nor organized as a rejection basis here. I note them only as background.

Transparency caveat: I have full text for only two of the six cited references. My mapping of Mathews '693, Murphy '665, Gaspari '431, and FR '486 to the claim elements is therefore inferential, based on their titles, dates, classifications, and the citation pattern — not on verified disclosure. Where I rely on them, I say so. The core rejections below rest on Hillsberry and Hofmann, which I did verify.

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4. Element-by-element mapping of claim 1

Conclusion on claim 1: Every element is disclosed, and the only element not squarely met by Hillsberry alone — removably mounting the applicator as a discrete component — is taught by Hofmann (threaded releasable coupling of comb to handle; brush base slidably replaceable). Claim 1 is a combination of known elements, each performing its known function, with no new functional relationship among them. That is the paradigm of KSR rationale (A).

Note the weakest link in the claim is also its point of novelty: "means for delivering dye directly to the scalp" is a purely functional recitation satisfied by Hillsberry's ports 18 and by Hofmann's tooth passageways 18. Neither the location nor the mechanism is structurally specified. A broad functional limitation of this kind gives the claim little to stand on.

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5. Motivation to combine (the KSR articulation)

A rejection cannot rest on "elements are individually known." The required articulated reason with a rational underpinning is present here many times over:

1. Same field of endeavor, same problem, same art unit. All six cited references are hairdressing combs/applicators for liquids. Their common problem is identical to Hale's: delivering a treatment liquid accurately along a hair part, to the roots/new growth at the scalp, without dripping and without wetting the rest of the hair. Hillsberry states this expressly: the comb parts the hair "so that the bristles may be positioned close to the scalp for applying the dye to the roots." Hofmann states the object as applying solution "evenly and in predetermined measured amount." Hale repeats the same problem in her own words. Motivation to combine references addressing the same problem in the same field is at its strongest.

2. Same classification pocket. Hale's patent is classified A45D 24/22 – 24/26 ("Combs with dispensing devices for liquids, pastes or powders … with flexible walls of the … storing device"). Hofmann's US 3,147,757 sits in the same CPC pocket (it appears in the A45D 24/26 listing of "带挠性壁的液体糊状物或粉末的贮存装置" — devices with flexible-walled reservoirs). The artisan of ordinary skill looking for a flexible-reservoir dispensing comb would be working in exactly this art.

3. The combination is a rearrangement of parts with predictable results. Moving the reservoir from inside the handle (Hofmann) to a separate clip-on body (Hale), or making the fountain applicator replaceable (Hale) instead of integral (Hillsberry), changes only the packaging of the same hydraulic circuit. Every function keeps its established role: comb parts the hair, ports deliver liquid at the part, bristles blend. Nothing new happens.

4. The design incentive is expressly a business/ergonomic one, not a technical discovery. Hale's own stated justification for a detachable applicator is: "the dye applicator is an integral component separate from the brush which may be replaced as it wears out without affecting the structure or operation of the applicator." Replaceability-for-wear is a classic market/design incentive (KSR rationale F), and Hofmann already supplies the releasable coupling that makes it possible.

5. Ergonomic actuation is a predictable design choice. Claim 3's point is that the bulb should be positioned for thumb actuation so that bulb pressure is independent of the grip on the handle. Hofmann already teaches that the solution is delivered by squeezing a flexible rubber bulb during combing (FIG. 3 shows "one manner of using the device … indicated by the dotted lines"), and its modified handle 111 has a "flexible portion 128." Relocating/reshaping that resilient bulb so that one digit actuates it while the rest of the hand grips the handle is the ordinary ergonomics of hand tools — a predictable result, not an invention.

6. A finite number of predictable solutions. Hale's own specification frames the problem as a set of known alternatives: the traditional method was a "thin piece of cotton swab," and she observes that "hair brush bristles may serve to blend in the dye … just as well as a cotton swab formerly used for this purpose." A known tool (brush bristles) is substituted for a known tool (cotton swab) to perform the same blending step at the same location. Substitution of one known element for another with no change in function is KSR rationale (B), and the specification concedes the equivalence.

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6. Claim 2 — soft rubberized nobs adjacent the blending tufts

Claim 2 adds (i) soft rubberized nobs and (ii) delivery ends substantially adjacent the tufts.

• "Substantially adjacent" is already taught. Hillsberry's ports 18 open directly into the bristles 12 — the outlet is, by definition, at the point of use. Hofmann likewise discharges through the comb teeth immediately alongside the brush. Putting the orifice next to the bristles is not a new relationship; it is what the references already do.
• "Soft rubberized" is a material substitution. Choosing a soft elastomer for the scalp-contacting outlet is the predictable selection of a known material for its known property (comfort/scalp safety), a familiar expedient in this exact art — Hofmann's reservoir itself is "a flexible bulb 28 of rubber or the like." No unexpected property arises from the choice; the specification claims none. KSR rationale (B)/(C).
• The function Hale attributes to adjacency ("minimum time is lost between the liquid application and the blending") is a result of proximity that any ordinarily skilled artisan would recognize in advance — a predictable advantage, not a discovered one.

Claim 2 is obvious over Hillsberry + Hofmann, and obvious over either reference further in view of the ordinary skill that selects soft rubber for scalp-contacting tips.

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7. Claim 3 — thumb bulb separate from the comb, independently pressurizable

This is the claim closest to being directly met by a single reference.

Hofmann US 3,147,757 discloses nearly the whole of it:

• a resilient rubber bulb 28 that contains the treating solution ("Treating solution may then be delivered under pressure from the bulb 28 to the annular passageway 17 and to the passageways 18 without leakage");
• the bulb assembly as a component separate from the comb — the comb frame is "releasably attached" to handle 11 through threaded boss 21 (and in the FIG. 4 embodiment, boss 121 to tubular portion 127);
• hand/finger application of pressure to the bulb while the handle is gripped, with an O-ring gasket sealing the joint, and the ability to dispense "a number of comb strokes … with the handle squeezed each time or part of the time."

What Hale adds is only the thumb-specific positioning and the independence of bulb pressure from grip pressure. That is a positioning/ergonomic variation on Hofmann — the kind of "arrangement of parts" change that KSR treats as within the skill of the artisan. Indeed, claim 3 does not even specify a structure for "positionable relative to the handle"; it recites the result (convenient thumb engagement). A functional recitation of a result already inherent in Hofmann's squeezable-bulb handle does not confer patentability.

Claim 3 is obvious over Hofmann alone (or Hofmann in view of Hillsberry for the scalp-delivery function and the comb/brush head).

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8. Proposed rejection formulations

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9. What would cut the other way — and why it is weak here

• Hale's own distinction of Hofmann. The specification states the applicator "is believed to afford distinct advantages over priorly known like devices such as are shown, for example, in Patent No. 3,147,757." This is attorney argument in a specification, not evidence; it concedes the reference is "like" the invention and articulates no structural difference beyond arrangement. If anything it concedes close prior art under the "acknowledged prior art" line of cases.
• No secondary considerations of record. As established in the litigation section, the patent was never asserted, has no corporate assignee, and expired January 28, 1986. There is no documented commercial success, no licensing, no copying, and no industry praise in the material I have. Absent that evidence, the Graham secondary factors cannot rebut a strong prima facie case.
• The patent's legal status does not bear on validity. "Expired – Lifetime" (expiration 1986) affects enforceability/damages, not the § 103 question, which is assessed as of the 1966 filing.
• Possible rebuttals that would matter if argued. (i) A teaching away argument from Hofmann (its reservoir is inside the handle, arguably discouraging a separate clip-on applicator) — but KSR rejects rigidity, and Hofmann's own releasable threaded coupling and sliding brush base point the other way. (ii) Unexpected results — none are disclosed or claimed. (iii) Criticality of the bias of the nobs toward the tufts ("The nobs 18 are slightly biased in the direction of the blending tufts 10") — this is described only in the specification, is not recited in any claim, and therefore cannot support patentability of the claims as granted.

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10. Bottom line

Claims 1–3 of US 3,424,176 are, on the face of the cited art, obvious under pre‑AIA § 103. Claim 1 is a predictable combination of Hillsberry's comb/bristle/scalp-dispensing head with Hofmann's releasable, replaceable resilient-reservoir dispensing structure and the fountain-comb concept of Mathews '693 / Murphy '665 / FR 773,486. Claim 2 adds only a material substitution (soft rubber) and a positional choice (outlet adjacent the bristles) that Hillsberry already embodies. Claim 3 is largely anticipated in substance by Hofmann's squeezable rubber bulb reservoir releasably attached to the comb, with the thumb-positioning limitation amounting to an obvious ergonomic variation. The specification supplies its own motivations — replaceability for wear, brush bristles blending "just as well as" the cotton swab, and the need to apply and blend in minimum time — which are precisely the KSR rationales (A), (B), (C) and (F). The strongest counter is the teaching-away argument, and it is not a good one on this record.

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Caveats and limitations

1. Two of six references verified in full. I retrieved and read US 2,228,213 (Hillsberry) and US 3,147,757 (Hofmann) in full. US 1,263,693, US 1,707,665, US 2,617,431 and FR 773,486 were verified only at the bibliographic level (inventor, title, dates, classification, citation pattern). Statements about their specific disclosures are inferences labeled as such. To firm up a written opinion, retrieve the full texts of the Mathews, Murphy and Gaspari patents and FR 773,486 — and for a French reference, obtain a certified translation of the relevant passages.
2. One of the references that superficially looks most on point is the wrong document. My search for the cited Mathews fountain-comb surfaced US 1,256,386, a different fountain comb with a compressible pouch and broad hollow teeth delivering liquid "directly onto the scalp." It is not the cited US 1,263,693 and I have not relied on it as if it were; it is noted only as an indication of the state of the art. Do not conflate these numbers.
3. The "Cited By" art is post-1966 and is not § 103 prior art. Any obviousness theory built on US 3,563,250, US 3,960,154, US 5,146,936, US 5,289,833 or the later Kao/L'Oréal documents is date-defective as applied to this patent.
4. No prosecution history, no claim construction. The Google Patents page reproduces the granted text only. I do not know what the examiner argued, what was withdrawn, or whether claim 4 existed and was cancelled. Under the broadest reasonable construction (or Phillips), the claim-1 "handle at one end / tufts at the other end" language is internally inconsistent with the specification and is best read as opposite faces of one working head — a reading that increases prior-art coverage rather than decreasing it.
5. Two document anomalies not auto-corrected: the abstract line "4 Claims" versus three enumerated claims; and the duplicate reference numeral "14" applied to both the clips and the thumb bulb.
6. This is an analyst's opinion, not a legal conclusion. It is not a validity opinion of counsel, does not account for litigation-grade claim construction or expert testimony on the level of ordinary skill, and — per the litigation section — there is no litigation or PTAB record in which any of these rejections was actually tested.

Sources: US 3,424,176 – Google Patents · US 2,228,213 Hillsberry · US 3,147,757 Hofmann · US 2,617,431 Gaspari – FPO · CPC A45D 24/26 listing (Hofmann US 3,147,757) · KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) · Graham v. John Deere Co., 383 U.S. 1 (1966).