US 4127765

I'll run a couple of targeted searches, then summarize against the authoritative patent text provided.

Search conduct and scope notes

I ran two web searches (Google Patents / uspto.report / Justia-indexed sources) for the literal string 4127765. Two caveats up front, per your strict rules:

• I do not have direct API access to USPTO PatentCenter, PAIR, or the CAFC docket system. I could only reach them indirectly through general web search. Treat the litigation finding below as "nothing surfaced," not as a certified negative.
• A number-similarity trap: DE 41 27 765 A (Liechtenstein, "DE 4127765") surfaced in my second search. It is a different document — a German application, not US 4,127,765 — and I am not reporting it as a result. Likewise US 4,260,876 and US 7,340,907 appeared only because they cite US 4,127,765 in their prior-art listings.

CAFC 2026 dockets: No 2026 (or any-year) CAFC appeal involving US 4,127,765 surfaced. That is consistent with the record: the patent shows "Expired – Lifetime," anticipated expiration 1998-02-17, roughly 28 years before the current docket year. No infringement suit or IPR involving it appeared in search results. I cannot state this with high confidence as an exhaustive check.

Bibliographic data — US 4,127,765

Assignee note: The record shows only security interests (Manufacturers Hanover Trust 1987, Chemical Bank 1995, First National Bank of Boston 1997), each terminated in 1999. No assignment of title appears. The "Current Assignee" field still reads Anthony's Manufacturing Co Inc. Later citing patents list "Anthony, Inc." as assignee, which suggests a corporate renaming, but I flag that as inference, not record.

Abstract (as printed)

"A system is described which permits the electrically heated door of a refrigerated display cabinet to be operated selectively at a plurality of power settings, providing respectively higher and lower levels of electrical heating. A switching means is used to alter the electrical interconnection of the door window heating elements with the door frame heating elements from a series connection to a parallel connection. In one embodiment, an automatic electrical controller actuates the switch in response to changes in the ambient humidity and temperature."

Independent claims — plain language

There are 9 claims total; two are independent (1 and 9), and claims 2–8 depend from claim 1.

Claim 1 — the switching apparatus

For a refrigerator door that has both a heated door frame (a frame heating element) and a heated window (a window heating element), the claim covers an apparatus comprising switching means electrically connectable to both heaters. The switch selectively changes how the two heaters are interconnected — from series to parallel (and back) — thereby changing the effective resistance of the combined load. Because resistance changes, multiple distinct heating power levels become selectable when the combination is run off a voltage source.

The technical hook is the arithmetic: for two heaters of resistance R₁ and R₂, P_parallel / P_series = (R₁+R₂)² / (R₁R₂), which has a minimum value of 4 (equal when R₁ = R₂). So the patent's stated effect is a ≥4× jump in heating power by flipping series→parallel, at constant line voltage.

Claim 9 — the improvement-format claim

Drafted as a Jepson-style "improvement" claim for a refrigerator door having a frame and a window, each with its own heating element. The improvement is simply: an electrical switch for selectively connecting the door-frame heating element and the window heating element in either series or parallel. Claim 9 is notably broader/simpler than claim 1 — it recites the switch and the two connection modes, but omits the "alter the effective resistance" and "plurality of levels" functional language of claim 1.

Dependent claims 2–8 (summary)

• 2 — the switching means is a double-pole double-throw switch (the FIG. 4 preferred embodiment, with conductor 80 tying terminals 76 and 78).
• 3 — adds a selectable "off" setting (no current to either heater).
• 4 — the switch is a double-pole triple-throw switch (implements claim 3).
• 5 — the switching means is manually actuated (FIG. 4 / FIG. 5).
• 6 — adds control means with a dew-point sensor for air outside the refrigerator adjacent the door, actuating the switch on predetermined dew-point changes.
• 7 — same, but sensing humidity.
• 8 — same, but sensing temperature of a part of the refrigerator door.

FIG. 6 corresponds to the automated embodiments (differential relay 84 driven by controller 82); the specification cites Heaney U.S. Pat. No. 3,859,502 as a suitable controller.

Context worth noting

• The problem solved was inventory, not physics. The background section is explicit: doors were built once as either "series-wired" (normal humidity) or "parallel-wired" (high humidity), and "the interconnection was not thereafter alterable without disassembling the door to a considerable degree." Distributors had to stock both SKUs. The invention collapses two SKUs into one field-configurable door.
• Prior art heating elements: the window heater is an optically transparent conductive coating (per Stromquist, US 3,724,129) on the inward-facing pane surface, with metallic strip electrodes; the frame heater is an insulated resistive conductor in a groove in the metal frame.
• Specification text quirks (transcription artifacts, reproduced literally): "Ohn's law" (for Ohm's), "configuratin," "(now shown)" (presumably "not shown"), and "1/R 1 + R 2" where the denominator grouping is ambiguous. These are OCR/typo issues in the fetched text, not substantive.
• Forward-citation footprint is large (Google Patents lists ~135 citing documents, including US 4,260,876 to the same assignee, US 8,250,873 to Anthony, Inc., and US 10,178,918 to Hussmann). That is evidence of the concept's durability in commercial refrigeration anti-sweat design, but I did not verify any of those citations against the original documents.

Bottom line: US 4,127,765 is a 1978 Heaney/Anthony's Manufacturing patent on making a heated refrigerator door field-switchable between series and parallel heater connections — roughly a 4× heating-power step — to eliminate dual series/parallel door inventories. Two independent claims (1 and 9); seven dependents covering switch type, manual actuation, an off position, and automatic dew-point/humidity/door-temperature control. It is long expired (1998), and no CAFC 2026 activity connected to this number was located.

I'll run targeted searches for litigation on the literal patent number 4127765.

Let me try more targeted litigation-database searches.

Let me run a few final checks on litigation-specific sources.

Bottom line

I found no litigation — district court, CAFC, ITC, PTAB, or foreign — involving U.S. Patent No. 4,127,765.

That is an expected null result, and it is the answer, not a failure of the search: the patent shows "Expired – Lifetime," anticipated expiration 1978-02-17 + 20 years = 1998-02-17, on the face of the Google Patents record you supplied. A patent that expired in 1998 cannot be asserted today and was never a candidate for the 2026 docket you asked about.

What I searched, and what I found

Note the one near-miss I want to flag explicitly, because it is the kind of thing that gets mis-reported:

• ControlTec LLC v. Anthony, Inc., No. 1:24-cv-00883 (D. Del.) — a real, recent anti-sweat/anti-condensation patent suit against Anthony. But the asserted patents are U.S. '181 and U.S. '847, accused instruments are the "Anthony Energy Controllers," and neither asserted patent is US 4,127,765. This is not a '765 case. I mention it only so you don't mistake it for one.

Also confirm the naming trap: DE 4127765 (German document, cited as prior art in a PTAB petition about a flashlight) and US 4,127,765 are different documents. I am not reporting anything under the German number.

Why there is no litigation (record-based reasoning)

• Expiry: Anticipated expiration 1998-02-17; status "Expired – Lifetime." As of your stated date of April 26, 2026, the patent has been in the public domain for ~28 years. There is no enforceable right left to litigate.
• No title-assignment activity. The Legal Events list shows only security interests — Manufacturers Hanover Trust (1987), Chemical Bank (1995), First National Bank of Boston (1997) — each terminated in 1999. No assignment of title appears. (As flagged in the earlier bibliographic section, later citing patents name "Anthony, Inc.," which suggests a rename, but that is inference, not record.)
• No post-issuance proceedings in the file. The Google Patents record shows no reissue, reexamination, IPR/PGR, or disclaimer entries.
• The forward-citation footprint (~135 citing documents) is evidence of the concept's durability in commercial anti-sweat design — it is not evidence of litigation. Citations are examiner/third-party references, not assertions.

Confidence and caveats (stated plainly, per your rule)

• High confidence that the '765 patent is expired and unassertable, based on the authoritative record you supplied.
• Moderate confidence that no historic suit was ever filed on it. I could not reach PACER, the CAFC docket, Docket Navigator, or Darts-IP directly — only indirectly through general web search. Several of those databases are paywalled and not fully web-indexed, so a pre-1998 infringement action (if any) could in principle exist outside my reach. I am reporting "none surfaced," not a certified exhaustive negative.
• No fabrication: I have no case caption, court, case number, or filing date to give you, because none exists in anything I retrieved. I will not invent one to fill the table.

I'll verify the null result from the ODP block with targeted PTAB-specific searches before finalizing.

Proceedings overview

Total AIA trial proceedings on US 4,127,765: 0. The canonical USPTO Open Data Portal block supplied with this prompt returns no IPR, PGR, or CBM for this patent, and my independent web searches surface none either — so the breakdown by status is 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution-denied.

Bottom-line defensive posture: the patent is not "hardened," it is expired. There is no PTAB record to attack or to hide behind. US 4,127,765 issued 1978-11-28, shows "Expired – Lifetime," and reached its anticipated expiration on 1998-02-17 — roughly 13 years before the AIA created IPR/PGR on 2012-09-16, and ~28 years before the filing date assumed for this analysis. Any defendant holding a demand letter citing claims 1–9 should be asking a different question than "which claims survived IPR": no enforceable claims remain at all. (Per the earlier section, the only live anti-sweat litigation I found involving the successor entity — ControlTec LLC v. Anthony, Inc., No. 1:24-cv-00883 (D. Del.) — asserts different patents, not the '765. Do not let that case be reported as a '765 case.)

Per-proceeding detail

None exists. I am not going to manufacture proceeding numbers, panels, or claim-level dispositions to fill this template. There is no FWD to quote, no institution decision to characterize, no settlement to describe, and no Federal Circuit appeal to cite. The required subsections (### {PROCEEDING_NUMBER}) are therefore empty by design, not by omission.

Strategic summary

Claim status under the AIA trial regime: 0 canceled / 0 sustained / 9 untested — and untested for a structural reason. Claims 1–9 have never been through an IPR, PGR, or CBM. But that is not because the patent is robust; it is because the window for doing so never really opened. The AIA trial provisions (IPR at 35 U.S.C. § 311 et seq., PGR at § 321) took effect in 2012, and the patent had already been expired for ~14 years. An expired patent technically can still be the subject of an IPR — the Board has instituted on expired patents where the petitioner had a concrete stake (e.g., pending district court damages exposure within the § 286 six-year lookback, or a live dispute over pre-expiry infringement) — but that scenario requires a controversy worth funding, and none surfaces for a 1978 door-heater patent. Note also that CBM review was unavailable here: it was limited to covered business methods and was sunset in 2020, and this patent's claims (a series/parallel heater switching circuit) are not a "financial product or service" claim in any event.

Estoppel landscape: no § 315(e)(2) estoppel attaches to anyone. Estoppel is petitioner-specific and arises only from a petition that reaches a final written decision. With no petitioner and no FWD, there is no estoppel bar — but that is cold comfort, because it also means there is no prior-art record to leverage. For a defendant, the operative bars are not estoppel but the statute of limitations (§ 286 damages lookback), laches/§ 282 defenses if an old suit were resurrected, and the threshold reality that an expired patent supports no prospective injunctive relief and only historically-accrued damages. The most useful defense-side prior art here is the same art the examiner already considered: US 2,858,408 (Barroero), US 3,724,129 (Anthony S Mfg Co), US 3,859,502 (Anthony S Mfg Co), plus family-cited US 4,004,370. That art is available to a defendant unencumbered by IPR estoppel precisely because no IPR happened.

Pattern signals: none internal to this patent; one adjacent signal worth watching. There is no repeat petitioner on the '765, no PTAB→Federal Circuit appeal chain, and no defensive aggregator (e.g., Unified Patents) in the record. The patent does show a large forward-citation footprint (~135 citing documents per the Google Patents record), but those are examiner and third-party citations, not petitions — they evidence the concept's durability in commercial anti-sweat design, not validity contests. The one genuinely relevant pattern signal is on the successor entity: Anthony, Inc. now appears as a petitioner rather than a patent owner in recent anti-sweat proceedings — e.g., IPR2025-00636, Anthony Inc. v. ControlTec, LLC, instituted on all 20 challenged claims of US 7,421,847 on § 103 grounds (source: third-party case-law aggregator, https://cases.arcticinvent.com/us/patent/us/institution-decision-grant/ipr2025-00636/). That tells you the corporate family descended from the '765 assignee is IPR-active against anti-sweat patents today; it says nothing about the '765 itself, and I have not verified that aggregator entry against the PTAB E2E docket.

Recommended next steps

• If you are a defendant being asserted against US 4,127,765: stop arguing validity and argue expiry. There is no PTAB FWD to link to because there is no proceeding. Point the other side to the face of the record — "Expired – Lifetime," anticipated expiration 1998-02-17 — and to the absence of any assignment of title (the Legal Events list shows only security interests from Manufacturers Hanover Trust (1987), Chemical Bank (1995), and First National Bank of Boston (1997), each terminated in 1999). There is no live right to enforce.
• No PTAB milestones exist to track. Because no petition was ever filed, there is no institution deadline, no 1-year § 316(a)(11) trial clock, no oral hearing, and no FWD due date. Nothing is pending.
• The absence of PTAB activity is a weak-to-neutral signal here — read it with care. The usual heuristic ("well-asserted patents eventually attract IPRs") presupposes an asserted, unexpired patent. For a patent that expired in 1998, the absence of IPRs is fully explained by expiry and should not be mistaken for a validity endorsement. Do not argue the null result as evidence of strength, and do not rely on it as evidence of weakness either — it is simply non-probative on validity.
• Verify before relying. The ODP block is the canonical source and it reports zero. I attempted to corroborate via general web search rather than direct PTAB E2E / PTAB API queries, and my searches returned no '765 proceeding. A number-similarity trap persists: DE 4127765 (a German document) and US 4,127,765 are different documents, and hits on ControlTec v. Anthony concern US '181/'847, not the '765. If you need a certified negative, pull the PTAB E2E docket and the ODP API directly; I flag this as none surfaced, not as a court-grade exhaustive negative.

I'll research the ownership chain and corporate history, then build the record from the authoritative legal-events data in the patent text.

Let me probe the USPTO assignment records directly and check the correspondent-of-record details.

Inventors

James J. Heaney — sole named inventor (the patent face and Google Patents both list a single inventor, "James J. Heaney"; his portfolio entries at the original assignee also render him as "Heaney James J" / "Heaney James Joseph").

• Employer at filing: Anthony's Manufacturing Company, Inc. This is determinable from the record, not merely inferred from his address: the '765 application was assigned to Anthony's Manufacturing Company, Inc. (the "Current Assignee" field still reads that entity, and uspto.report states the grant "is currently assigned to Anthony's Manufacturing Company, Inc."). Heaney is the single most prolific inventor in the Anthony's portfolio — GoodIP tallies 26 patents for "Heaney James J" at Anthony's Mfg Co — which is consistent with a senior in-house design engineer rather than a one-off contributor.
• No departure / fire-sale pattern. Heaney kept filing for the same employer well after 1978 (e.g., the 1980-09-15 application that issued as US 4,382,177, "Substantially transparent insulating anti-condensation structure"). There is no evidence of inventor exit within 12 months of filing. The only wrinkle worth flagging is that US 4,382,177 is indexed with "Heaney James J" himself as the listed assignee, whereas '765 is indexed to Anthony's — i.e., at least one later Heaney case appears to have been filed in his own name first. That is a filing-practice curiosity, not an NPE signal, and I have not verified the underlying assignment documents for it.
• One-inventor structure means the "all inventors departed" red flag is structurally inapplicable.

Original assignee

Anthony's Manufacturing Company, Inc. (also rendered in the record as "ANTHONY S MANUFACTURING COMPANY, INC., A CA. CORP." and "ANTHONY S MANUFACTURING COMPANY, INC., CALIFORNIA" — the apostrophe-s is truncated in the USPTO/Google rendering; this is a transcription artifact, not a different entity).

• Primary line of business: commercial refrigeration hardware — specifically glass refrigerator and freezer doors, lighting, shelving and display systems for supermarkets and convenience stores.
• Did they ship a product embodying the claims? Yes. The company's own history page confirms it built exactly the product the claims describe: a glass division (Anglass Industries, formed 1965 at the Sylmar/San Fernando plant) "was producing tempered insulated glass units and a proprietary heated glass — making Anthony the only door manufacturer to possess this high-tech process." A heated-glass door with a heated frame is the literal subject matter of claims 1 and 9. So this is an operating-company invention in the company's core product line, not an acquired paper asset.
• Founder/prior-art overlap worth noting: the company was founded in 1958 as Anthony's Refrigeration Service Company by Gerald Anthony Linglebach and Michael Stromquist. The '765 specification cites US 3,724,129 to Stromquist, assigned to Anthony S Mfg Co — i.e., the cited prior art is the co-founder's own earlier work. That reinforces the "in-house, continuous R&D" character of this patent family.
• Current status: operating, as a Dover Corporation subsidiary. The corporate chain is documented: sold to The Northern Group in 1986; American Securities investment year 1998; sold to Aurora Capital Group (Sept./Oct. 2004, ~$121.4M); sold to Avista Capital Partners (June 2011, undisclosed); acquired by Dover Corporation (NYSE: DOV) for $602.5M on 2012-11-30; SCHOTT Gemtron glass-door business added 2015. Today it trades as Anthony, Inc. / "Anthony International," Sylmar CA, within Dover's Refrigeration & Food Equipment segment (parent listed as Hillphoenix, a Dover company). This corroborates and upgrades the earlier section's inference that "Anthony, Inc." reflects a renaming of Anthony's Manufacturing Company, Inc. — PitchBook lists "Anthony Manufacturing, Anthony International" as former names, and an EPO/OEPM filing names "Anthony, Inc., 12391 Montero Avenue, Sylmar, CA 91342."

Assignment timeline

Five post-issuance records are surfaced for US 4,127,765. Every one of them is a security interest or the termination of one. There is no assignment of title anywhere in the chain. Correspondent-of-record fields were not retrievable in this pass — Google Patents legal events do not publish correspondents, and I could not open the Assignment Center / legacy-assignment reel PDFs. I am leaving "Correspondent" explicitly blank rather than guessing; see the caveat under Signal 3.

• 1986-12-19 (executed) / recorded 1987-01-02 — Reel 004661/0501

  • Conveyance: Security Interest (security agreement)
  • Assignor: Anthony's Manufacturing Company, Inc., a California corporation
  • Assignee: Manufacturers Hanover Trust Company
  • Correspondent: not retrievable
  • Context: securitization. Executed ~2 weeks after the company's 1986 sale to The Northern Group; consistent with acquisition/recapitalization financing collateralized in part by the patent portfolio (inference).

• 1995-03-31 (executed) / recorded 1995-04-18 — Reel 007437/0368

  • Conveyance: Security Interest
  • Assignor: Anthony's Manufacturing Company, Inc.
  • Assignee: Chemical Bank (New York)
  • Correspondent: not retrievable
  • Context: securitization/refinancing. Chemical Bank had absorbed Manufacturers Hanover in 1991, so this plausibly continues/replaces the 1987 facility.

• 1997-02-21 (executed) / recorded 1997-05-12 — Reel 008545/0385

  • Conveyance: Security Agreement
  • Assignor: Anthony's Manufacturing Company, Inc.
  • Assignee: The First National Bank of Boston (Massachusetts)
  • Correspondent: not retrievable
  • Context: securitization/refinancing with a new lender, ~9 months ahead of the 1998 American Securities investment.

• 1998-12-21 (executed) / recorded 1999-01-21 — Reel 009719/0230

  • Conveyance: Termination of Security Interest (release)
  • Assignor: Chase-Manhattan Bank, successor by merger to Chemical Bank, SBM Manufacturer's Hanover Trust Company
  • Assignee: Anthony's Manufacturing Company, Inc. (California)
  • Correspondent: not retrievable
  • Context: lien release — payoff/clearing of the Chemical/MHT facility; the successor language reflects the 1991 MHT→Chemical and 1996 Chemical→Chase mergers.

• 1998-12-22 (executed) / recorded 1999-02-03 — Reel 009737/0089

  • Conveyance: Termination of Security Interest and Quitclaim
  • Assignor: BankBoston, N.A. f/k/a The First National Bank of Boston
  • Assignee: Anthony's Manufacturing Company, Inc. (California)
  • Correspondent: not retrievable
  • Context: release + quitclaim — extinguishes any residual bank interest, clearing title around the 1998 recapitalization.

Missing link I must flag rather than fill: the original inventor→company assignment (Heaney → Anthony's Manufacturing Company, Inc.) does not appear in the surfaced legal-events list. That is an omission of the Google Patents event feed, not evidence that no assignment exists — the granted patent carries Anthony's as assignee, which normally means an assignment was recorded during 1977–78 prosecution (a low reel number in that era). I could not retrieve its reel/frame. Do not read this gap as a finding.

Timeline diagram

timeline
    title Ownership of US 4127765
    1978 : Filed by Heaney
         : Assigned to Anthonys Manufacturing
         : Patent issued
    1986 : Sold to The Northern Group
    1987 : Lien recorded to Manufacturers Hanover
    1995 : Lien recorded to Chemical Bank
    1997 : Lien to First National Bank of Boston
    1998 : Liens terminated by Chase Manhattan
         : Liens released by BankBoston
    2011 : Sold to Avista Capital Partners
    2012 : Acquired by Dover Corporation

Note: the 1978, 1986, 2011 and 2012 rows are corporate/ownership context (Heaney's initial assignment and the operating company's M&A chain). Only the 1987, 1995, 1997, 1998/99 rows correspond to records actually filed against US 4,127,765 — all of them liens and lien releases.

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignee in the record carries an "IP / Patents / Licensing / Holdings / Ventures" suffix, and no single-purpose Delaware/Texas LLC appears anywhere. The only assignees ever recorded against this patent are two state-chartered banks (Manufacturers Hanover Trust, Chemical Bank, First National Bank of Boston / BankBoston) and the original California operating corporation. See reels 004661/0501, 007437/0368, 008545/0385.

2. Known asserter in the chain — not present. No entry matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity. I did not have direct access to the Unified Patents / RPX asserter directories, so this is "none surfaced," but the recorded assignee population (banks + one manufacturer) makes a match structurally implausible.

3. Repeat correspondent across the chain — unclear / not determinable (data gap). This is the one requested datapoint I could not obtain: the USPTO correspondent-of-record for these recordings is not published in the Google Patents legal-event feed, and I could not open the reel PDFs. I will not invent a name. Two observations, however: (a) all five records share a single assignor (Anthony's) over a 12-year window, so even a single recurring correspondent would be ordinary outside patent counsel behavior, not an NPE tell; and (b) the signal is defined by recurrence across NPE-to-NPE transfers, which do not exist here. No finding.

4. Cascading transfers — not present. Five recorded events spanning 1978–1999, zero of them transfers of title, none within 24 months of another as a chained assignment, and no shared-address LLC principals.

5. Pre-litigation transfer — not present. No infringement action on US 4,127,765 was located at any time (consistent with the earlier litigation section's null result), so there is no suit to precede. The nearest live case, ControlTec LLC v. Anthony, Inc., No. 1:24-cv-00883 (D. Del.), asserts U.S. '181 and '847 against Anthony — i.e., Anthony is the accused defendant here, not the asserter, and '765 is not in suit.

6. Bankruptcy fire-sale — not present. No Chapter 7/11 appears for Anthony's Manufacturing. The company's ownership changes were solvent M&A transactions (Northern Group 1986; American Securities 1998; Aurora ~$121.4M 2004; Avista 2011; Dover $602.5M 2012). The 1998/99 lien terminations are payoffs, not distress liquidations.

7. Privateering — not present. No operating company → NPE transfer exists to be a privateering vehicle, and neither Anthony's nor Dover ever asserted this patent against competitors.

8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates with a Dover Corporation operating subsidiary.

Verdict

Defensive / non-asserting — with the caveat that the "defensive aggregator" prong of that label does not apply; the operative fact is non-asserting ownership that never left the operating company.

Justification: all five records against this patent — reels 004661/0501 (1987), 007437/0368 (1995), 008545/0385 (1997), 009719/0230 (Jan 1999) and 009737/0089 (Feb 1999) — are security interests and their terminations, i.e., collateral liens and releases, not conveyances of title. The patent was never transferred to any NPE, and the owner throughout has been the same Sylmar, CA door manufacturer, now Anthony, Inc. under Dover Corporation (a $602.5M operating acquisition, 2012-11-30), which shipped heated glass refrigerator doors embodying the claims. Zero of the eight NPE signals is present; the patent expired 1998-02-17 and is today unassertable public-domain art.

Verify at the USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (mirror: https://assignment.uspto.gov/patent/index.html), searching Patent Number 4127765 — where the reel/frame entries above can be pulled directly, including the correspondent fields I could not retrieve here.

Flagged contradiction/correction to the earlier sections: the earlier bibliographic section summarized the two 1999 events as liens "each terminated in 1999." Precisely, both were executed in December 1998 (1998-12-21 and 1998-12-22) and recorded in January/February 1999 — a nuance that matters because it places the lien clean-up in the 1998 American Securities recapitalization window rather than in 1999.

I'll verify each cited reference against live sources before analyzing, per the ground-truth rule.

Prior-art analysis — US 4,127,765 (Heaney, "Anti-condensation system for refrigerator doors")

Scope note: what counts as a "citation for 4127765"

I searched for the literal string 4127765 and restricted analysis to the prior-art cites appearing on the face of US 4,127,765. The record yields exactly three U.S. patent citations (all examiner-cited) plus one family-cited reference. I am not importing near-number hits:

Because the '765 application was filed 1978-02-17, the pre-AIA version of 35 U.S.C. applies. Every reference below published more than one year before that filing date, so each is prior art at minimum under pre-AIA §102(b), and each is also a "patent … by others" under §102(a).

The four references, at a glance

Sources: US2858408 PDF · FPO 2858408 · US3724129 · US3859502 (full claims/description) · US4004370 · canonical record for the patent under analysis: US4127765

A. US 2,858,408 — Barroero (1958-10-28)

Full citation: US 2,858,408, Louis F. Barroero, "Refrigerated freezer cabinets having heated door frames and doors therefor," filed 1957-10-25, issued 1958-10-28 (no assignee of record).

Description: A refrigerated freezer cabinet 10 with a metallic (aluminum) door frame 11. A plurality of resistance heating elements 51 are wound around the frame periphery and held in heating contact by insulating strip 47. Sliding doors 17, 18 each have a double-paned glass window 26 and, separately, heating means embedded in the door channel members — grooves 52–55 in wooden fillets 37–40.

The critical passage for our purposes:

"The heating elements 51 can be connected in series or parallel arrangement, again as desired, and are then connected to a suitable electric power source by suitable means (not shown)."

§102 assessment:

Net: Relevant to the environment and to the generic notion that heater elements may be series- or parallel-wired, but anticipates no claim. It is a background/§103 precursor, not a §102 killer. The one genuinely notable disclosure — explicit "series or parallel arrangement" for the heaters — is the piece a challenger would most want to lean on, and it still does not reach the switch-plus-two-different-heaters combination.

B. US 3,724,129 — Stromquist / Anthony's Mfg. Co. (1973-04-03)

Full citation: US 3,724,129, "Door and door mounting frame," filed 1970-12-14, issued 1973-04-03, assigned to Anthony S Mfg Co.

Description: A multi-door refrigerated display front with hinged doors 10–13, each having four rectangular frame members 50–53 surrounding a multi-pane glass unit 70, plus a plug-and-outlet power distribution scheme (door-mounted connector plugs 10P–13P engaging frame/mullion outlets 22A, 23A, 26A–28B wired to 120 V AC).

The critical passages: the specification states it is well known in the art to (i) run resistance heater cables through the length of the frame members 50–53 to prevent frame condensation, and (ii) coat one or more of the glass panels with a thin, optically transparent resistive coating, pass current through the coating, and thereby keep the glass clear.

§102 assessment:

Net: Anticipates no claim, but it is the strongest primary reference for the preamble of claims 1 and 9 (the "electrically heated door frame and electrically heated window" pair), because it is the reference the '765 specification itself credits for the transparent conductive coating technique. Combined with a switch-teaching reference, it is the natural §103 starting point.

C. US 3,859,502 — Heaney / Anthony's Mfg. Co. (1975-01-07)

Full citation: US 3,859,502, James J. Heaney, "Defrosting system for refrigerator doors," filed 1974-02-11, issued 1975-01-07, assigned to Anthony S Mfg Co. (the same inventor and assignee as the patent under analysis; the '765 specification expressly names it: "One suitable controller is described in Heaney U.S. Pat. No. 3,859,502.")

Description: A humidity-sensitive heat control for a supermarket glass-door refrigerator. Claim 1 is an apparatus with electrical heating means plus control means including a relative-humidity-sensing element, the control circuit connecting/disconnecting the heaters as ambient RH reaches dew point. Dependent claims add: resistive coating on the glass viewing area (claim 2), resistance element embedded in the door frame (claim 3), embedded in the jamb (claim 4), both (claim 5), frame plus glass coating (claim 6), the sensor being a humidity-variable resistance (7), a resistance bridge with adjustable balance leg (8), "switching means responsive to the bridge circuit for making and breaking an electrical path to the heating means" (9), and an isolating transformer supply (10).

§102 assessment:

Net: Anticipates no claim, but it is the most dangerous reference for dependent claims 6 and 7 in an obviousness posture, and it is the reference an examiner would pair with a series/parallel-switch teaching to reach claims 6–8. Note the symmetry the analysis must not miss: '502 supplies the control element; it does not supply the selector switch that claim 1 interposes between control and heaters. Also note claim 9 of '502 already introduces "switching means … for making and breaking an electrical path" — a challenger could argue this reads on claim 3's "off" setting, but claim 3 depends on claim 1 and therefore still requires the series↔parallel capability. That argument fails on the dependency.

D. US 4,004,370 — Heaney / Anthony's Mfg. Co. (1977-01-25) — family cite

Full citation: US 4,004,370, James J. Heaney, "Insulated door mounting frame structure," filed 1975-03-03, issued 1977-01-25, assigned to Anthony's Manufacturing Company, Inc. (listed in the '765 record under Family Cites Families).

Description: A door mounting frame combining a thermal barrier (insulated section) with electrical heating elements, using a divided thermal path (thick structural element + thin sealing-surface face plate). The stated aim is condensation-free operation at lower energy than prior heated frames.

§102 assessment: Anticipates no claim of '765. Its contribution is frame construction and heat-path management, not heater interconnection. It is relevant only as corroboration that (i) heated door frames with groove-embedded elements were conventional by 1975, and (ii) the field understood anti-condensation heating as an energy/condensation trade-off — the same problem '765 ultimately addresses via a low/high power setting.

Anticipation matrix

No cited reference anticipates any claim of US 4,127,765 under §102. That is a substantive conclusion, not a search failure, and it is consistent with the patent having issued with two independent claims over exactly these three references.

Where the art does come closest (for §103 mapping, not §102)

The limitation no cited reference discloses is the pivot of the whole patent: a means for selectively altering the interconnection of the frame heater and the window heater between series and parallel so as to change the combination's effective resistance (≈4× power step per the patent's own arithmetic, P_par/P_ser = (R₁+R₂)²/R₁R₂, minimum 4 at R₁=R₂).

Second-look leads (flagged as not on the face of '765, so outside your stated scope): the background of Barroero's own US 3,449,925 names US 2,811,406 (Moore et al.), US 3,038,319 (Kesling), US 1,710,405 (Copeman), US 1,915,704 (Warren), US 2,731,804 (Grubbs) as frame-heater art, and US 4,004,370's discussion references US 3,612,821 for a non-insulated heated door frame. If you want an exhaustive §102 sweep rather than a face-of-the-patent sweep, those are the next documents to pull — I have not verified them and do not rely on them here.

Caveats

• Source of the citation set: the citations are taken from the Google Patents record you supplied and are corroborated by the individual reference pages fetched above (FPO/pdf for '408; Google Patents for '129 and '370; uspto.report for '502's claims and description). I did not reach USPTO PatentCenter or the file wrapper directly, so I cannot speak to examiner rejections/arguments during prosecution of '765.
• Dates: all three primary citations predate 1977-02-17 by more than a year and thus qualify under pre-AIA §102(b); no date relies on inference.
• Foreign members excluded deliberately: CA1077284A and JPS54112060A share the '765 priority date and applicant and are therefore not prior art against it.
• No fabricated references: every document named as prior art above is either literally on the face of US 4,127,765 or is explicitly identified as a second-order lead, labeled as such.

I'll verify the substance of the cited references before analyzing, since the §103 analysis turns on precisely what each reference discloses.

Obviousness analysis — US 4,127,765 under 35 U.S.C. § 103

Scope note on sources. This analysis uses the prior-art references listed in the Prior Art section of the Google Patents record for US 4,127,765 — the three "Citations" (US 2,858,408, US 3,724,129, US 3,859,502), the family-cited US 4,004,370, and the similar-document GB 1,481,441. I retrieved and quoted the descriptions of the first four directly. I did not retrieve the full claim sets of all of them; where I rely on a claim rather than the description, I say so.

Critical framing (this drives the whole analysis): the '765 specification contains an express admission that both connection schemes were already known in this exact field:

"Prior to the present invention, it has been known to connect the heating element in the door frame to the window heating element in either series or parallel connection depending on the environment in which the door would be operated. Parallel-wired doors were used in high-humidity environments, while series wired doors were used in less demanding environments."

That admission does most of the § 103 work. The only thing claim 1 adds over the admitted state of the art is (a) a switching means and (b) the recitation of the resulting property (altered resistance → plural heating levels). A § 103 rejection targets exactly that added matter.

1. What the prior art of record actually teaches

One record caution: the citing documents (US 4,260,876, US 4,584,043, etc.) and the ~135-item "Cited By" list are not § 103 prior art here — most post-date the 1978-02-17 filing, let alone the critical date. In particular US 4,260,876 ("Dew point differential power controller," Anthony's, filed 1978-12-11) is after the '765 filing and cannot be used. I mention this because it is the reference most likely to be mistakenly cited against '765.

2. Level of ordinary skill

A person having ordinary skill in the art (PHOSITA) at the 1978 critical date: a refrigeration-equipment or electro-mechanical design engineer with ~2–4 years of experience in commercial refrigerated-display doors, familiar with (i) anti-sweat heater practice and (ii) elementary DC/AC circuit theory — specifically that at constant line voltage, parallel connection of two resistors gives lower total resistance and therefore higher total power than series connection. The patent itself treats this as a matter of rote arithmetic:

"In accordance with Ohn's law [sic] … P_p/P_s = (R₁+R₂)²/R₁R₂ which has a minimum value of 4 when R₁ = R₂."

That formula is a tautology of circuit theory, not an invention. That is the crux of the § 103 case.

3. Combination A — the primary rejection against independent claims 1 and 9

US 3,724,129 in view of US 2,858,408, further in view of the ordinary skill of a circuit designer.

Motivation to combine (the § 103 "articulated reasoning")

1. Both references are in the same field, addressing the same problem. '129 and '408 are both commercial refrigerated-display/freezer door structures whose whole purpose is anti-condensation heating. Combining references from the same field of endeavor to solve the same problem carries the strongest presumption of obviousness (In re Keller; KSR).
2. '408 expressly points to the claimed result and leaves it to the designer. Barroero does not merely disclose series or parallel in the alternative — he says the choice is made "as desired." That is a teaching, suggestion, or motivation to select either arrangement; it is not a teaching away.
3. The applicant's own specification concedes the field was already doing this. Series-wired and parallel-wired doors were commercial products. A PHOSITA who has two known, environment-selected wiring configurations and a known electrical device (a selector switch) for choosing between configurations would see the substitution of a field-selectable switch for a fixed hardwired join as a routine design expedient — precisely the "known technique used to improve a similar device in the same way" scenario described in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007).
4. The motivation itself is stated in the specification, which is admissible evidence of what the PHOSITA would have perceived: reduced SKUs and inventory — "it was necessary to inventory both parallel-wired doors and series-wired doors… Because doors carried in inventory are unproductive investments, it is desirable to reduce inventory levels to the lowest practical point." Market pressure of this kind is expressly an obviousness-relevant motivation under KSR.

The predictable-result problem for the applicant

The alleged advance — a ≥4× power step — is not an unexpected discovery. It is the mathematically necessary consequence of a series→parallel change at constant voltage, computed by the applicant in the specification itself. The Federal Circuit's line of authority treating a claimed invention as obvious where it merely exploits an inherent property of a known structure applies: discovering why a known arrangement works is not a patentable contribution. Similarly, In re O'Farrell's "finite number of identified, predictable solutions" test is satisfied almost literally — here there are exactly two solutions (series and parallel), both identified in the prior art, one of them disclosed "as desired."

Claim 9 is even more exposed. It recites only "an electrical switch for selectively connecting the door frame heating element and the window heating element in either series or in parallel connection" — no resistance-change language, no multi-level language. '129 supplies both heaters; '408 supplies the two connection modes; an electrical switch is conceded to be an "inexpensive" and ubiquitous component (the specification itself calls it "an inexpensive switch" and "the only additional component required"). Claim 9 is a textbook substitution of a known element (switch) for a known element (hardwired joint) to obtain a predictable result.

4. Combination B — alternative primary rejection using US 3,859,502

US 3,859,502 in view of US 2,858,408.

'502 is arguably the single most dangerous reference because it discloses almost all of claim 1 in one document:

• frame resistance heater (claims 3–5),
• transparent resistive coating on the glass viewing area (claim 6),
• "control means connecting the coating to the power source" (claim 6) and connecting the frame elements (claims 3–5),
• a humidity-sensing element (claim 7) and
• "switching means responsive to the bridge circuit for making and breaking an electrical path to the heating means" (claim 9).

So '502 discloses a refrigerator door with two heaters and a sensor-driven switching means. The only gap versus claim 1 is that '502's switch makes/breaks (on-off duty-cycle control) rather than reconfiguring series↔parallel. Barroero's express "series or parallel arrangement, as desired" fills that gap. The motivation is not merely that both references are in the same field — it is that '502 and Barroero solve the identical anti-condensation problem in the identical structure type, and the '765 background acknowledges that this field already selected series-vs-parallel by environment.

Note also that a rejection over the applicant's own earlier patents ('129 and '502 are both Anthony's Manufacturing) is fully proper, and the '765 specification expressly cross-references '502 as "one suitable controller." That is an admission that '502 is not only analogous art but designed to be used with the claimed door.

5. Dependent claims 2–5

These dependents add essentially no patentable weight: each is a claim to a type or operating mode of a switch, and the specification itself frames the switch as off-the-shelf.

6. Dependent claims 6–8 (automatic control) — US 3,859,502 is dispositive

Motivation: the specification itself directs the PHOSITA to '502 ("One suitable controller is described in Heaney U.S. Pat. No. 3,859,502"), and FIG. 6 of '765 is simply '502-style sensor → controller → relay, with the relay wired per '765's FIG. 4. An automated version is therefore the expressly suggested combination of '502's controller with the claim-1 switch. This is about as clean a "suggestion in the references" case as exists.

7. Likely applicant arguments, and why they probably fail

1. "No reference discloses a switch that reconfigures series↔parallel."
   Weak. This is a single-element difference. The combination of '129 ('both heaters) + '408 ("series or parallel arrangement, as desired") + a conventional switch leaves nothing inventive. KSR rejects the "each reference must teach the precise claimed structure" formulation.
2. "Unexpected four-fold power increase."
   Weak, and self-defeating. The applicant's own specification proves the 4× factor is an algebraic minimum, not an empirical surprise. An inherent, predictable consequence of a known circuit change cannot supply patentability.
3. "Secondary considerations: reduced inventory / commercial success."
   Unlikely to carry the day. Inventory reduction is a business benefit derived directly from the stated motivation to combine, not evidence of non-obviousness — it is the reason the PHOSITA would have combined, not proof that they could not have. There is also no nexus evidence here: the record shows the assignee already sold series-wired and parallel-wired doors, so any commercial success is at least as attributable to the pre-existing product line as to the switch. And the long-felt-need story is weak: the need (environment-matched heating) was already being met — expensively — by dual SKUs.
4. "Teaching away."
   None found. Barroero says the choice is "as desired"; '502 automates turning heaters on and off. No reference criticizes or discourages series/parallel selection or the use of a switch.

8. Proposed rejection summary

9. Confidence and caveats (stated plainly)

• High confidence in the content of the '129, '502, '408 and '370 teachings — the quoted passages were retrieved and are reproduced above.
• High confidence that the '765 background's admission ("it has been known to connect the heating element in the door frame to the window heating element in either series or parallel connection") is a fatal § 103 concession.
• Moderate confidence in the complete claim charts for claims 2–8, because I relied on the descriptions and quoted claim text of the references rather than a line-by-line reading of every claim of each reference. A full-text pull would let a rejection be mapped to specific reference claims rather than to the general disclosure.
• Not verified: the content of GB 1,481,441 ("Door with electrical heating means," 1977-07-27), which appears on the record as a similar document and, given its date, would be a statutory prior-art reference if it discloses a heated door with selectable heating. I flag it as the one unexplored reference that could strengthen or independently support a rejection.
• Explicit non-use: US 4,260,876 and the ~135 "Cited By" documents are post-filing and are not prior art against '765. I have not relied on them, and they should not be used in a § 103 rejection.
• No fabrication: where the record does not show a reference teaching a feature, I have said so rather than imputing it.

Bottom line: US 4,127,765 is vulnerable to a strong § 103 rejection. The prior art already contained every physical element — a refrigerator door with both a frame heater and a transparent window heater ('129, '502), an express teaching that such heater elements "can be connected in series or parallel arrangement, as desired" ('408), and a sensor-driven control circuit for those very heaters ('502). The patent's own background admits the field was already selecting series vs. parallel wiring by environment. Adding a switch to convert a fixed two-state choice into a field-selectable one — with the resulting ≥4× power change being an arithmetical certainty, not a surprise — is the paradigm of an obvious combination under KSR.