US 7421847

I'll search for authoritative information on this patent, including any 2026 CAFC activity.

Let me dig into the litigation and current ownership details.

Let me do one final check for any appellate activity.

Search results for US 7,421,847 — scope note

I searched the USPTO/Google Patents record and litigation/PTAB/appellate dockets. Summary of what I found, with confidence levels flagged.

Caution on dates: the stated current date is April 26, 2026. My live searches returned materials dated as late as ~July 2026 (unrelated Federal Circuit orders). I flag this inconsistency rather than resolving it. Also note that I found no Federal Circuit docket for 7,421,847 — I cannot rule out something filed very recently, but no CAFC 2026 appeal of this patent surfaced.

Bibliographic data (high confidence)

Uncertainty flags: (1) The Google Patents assignee field says "Individual," which conflicts with ControlTec, LLC being identified as patent owner in the Delaware suit and in PTAB filings — this suggests an unrecorded or later assignment. (2) On expiration, Google Patents' "anticipated expiration" is March 1, 2025, while a Finnegan/Lexology article on the IPRs states the patents "would be expired by July 8, 2025." I am not resolving that discrepancy; both figures appear in the record and may reflect differing assumptions about term adjustment.

Abstract (as published)

"Apparatus, systems and methods are disclosed for efficient elimination of door and frame condensation at widely utilized commercial freezer/refrigeration display cases. The apparatus includes a local controller unit connected with an array of case sensors including an internal case temperature sensor, an external case frame temperature sensor and a dew point sensor. The case frame temperature sensor and dew point sensor are housed to thermally isolate sensing elements thereof from effects of frame temperature changes and ambient air temperature in the vicinity of a sensing element, and to limit heat transfer by the housing to the sensing elements thereby improving sensing accuracy and apparatus performance."

Plain-language overview of the independent claims

Claim 1 — networked proactive heater control (single case). A method with four steps: (1) monitor the display case frame temperature and produce first output data; (2) monitor ambient air temperature and relative humidity outside the case and produce second output data; (3) process both data sets locally at the display case to anticipate condensation and, based on that, turn the frame/door heater on and off; and (4) communicate the temperature/humidity data and a record of heater activation/deactivation to a remote centralized processing location.

Claim 8 — core sensing/control method (device-level). A method with three steps: (1) place a temperature sensing unit in contact with the display case frame to monitor frame temperature; (2) mount a dew point sensing unit on the display case to monitor ambient air temperature and relative humidity outside the case; and (3) use those monitored values to anticipate condensation and activate/deactivate the frame/door heater accordingly. This is the broadest independent claim and, per the Delaware complaint analysis, the claim asserted against the accused "Anthony Energy Controller" products.

Claim 14 — multi-case array management. A method for any of a plurality of display cases: (1) monitor selected parameters at each case and produce output data; (2) collect that data; (3) anticipate condensation-formation status at any of the cases and produce an output indicating it; (4) establish measures to address that status (e.g., heater control) responsive to the output; and (5) compile a record of both the data and the measures.

Dependent-claim highlights: claim 2 (wireless data/record transfer across multiple cases), claim 3 (thermal isolation of sensing units to reduce data inaccuracy), claims 4–6 (data accumulation, viewing/reporting, efficiency reports, remote recalibration), claim 7 (constantly updatable on-site automated control parameters); claims 9–10 (thermal isolation of the dew-point unit from frame/door temperature swings, and of the frame sensor from ambient air), claim 11 (internal case temperature sensing), claims 12–13 (stored data, wireless access); claims 15–16 (activate/deactivate heater on set points above a dew-point value derived from ambient temp and RH), claim 17 (internal case temperature records), claim 18 (communicate record remotely), claim 19 (thermal isolation), claim 20 (updatable automated control parameters).

Notable feature across the disclosure: the claimed architecture is proactive — heaters are switched on at a set point above dew point (before moisture forms) and off at a second set point above dew point, with the specification expressly criticizing reactive moisture-detector systems such as those in U.S. 5,899,078.

Prior art cited on the face (per Google Patents): US 3,939,666; 4,127,765; 4,261,179; 4,862,701; 5,778,147; 5,778,689; 5,899,078; 6,301,913; 6,470,696; 6,550,261; and US 2004/0050072 A1.

Litigation and PTAB posture (moderate-to-high confidence; see caveat)

• District court: ControlTec, LLC v. Anthony, Inc. et al., No. 1:24-cv-00883 (D. Del.), filed July 26, 2024, Judge Jennifer L. Hall. Defendants Anthony, Inc. and Hill Phoenix, Inc. Cause: 35 U.S.C. § 271 infringement. The complaint's Rule 3 report lists both 7,207,181 B2 and 7,421,847 B2; the '847 patent's independent claim 8 is among the asserted claims.
• PTAB: IPR2025-00636, petitioner Anthony Inc., filed Feb. 24, 2025, against 7,421,847, challenging all 20 claims; instituted Sept. 30, 2025; status "Pending – Instituted." A companion petition, IPR2025-00559, challenges sibling patent 7,207,181 (filed Jan. 30, 2025; instituted Aug. 25, 2025).
• Grounds: §103 obviousness. The Board/portal summaries indicate the primary reference is "Carter" (found analogous to condensation control in refrigerated equipment), with "King" also considered despite its automotive context.
• Director decision (Paper 9, July 16, 2025): Acting Director Coke Morgan Stewart declined to exercise discretionary denial under §325(d) despite the patents being expired/expiring, finding petitioner showed a "material error by the Office" in overlooking Carter during examination; the petitions were referred to the Board.
• No Federal Circuit docket found for 7,421,847. A final written decision in IPR2025-00636 would be expected roughly one year after institution (~Sept. 2026), so any appeal would post-date the stated current date.

Conflicting source warning: one aggregator page (Arctic Invent) contains internally inconsistent text, at one point describing the Director as having "den[ied] institution" while also stating the proceeding was instituted on all 20 claims. That page's summaries appear partially garbled/AI-generated and should not be relied on. The more reliable primary-style sources (the Director's decision as posted by Finnegan, and the Unified Patents PTAB case list) support: discretionary denial denied → referred to Board → instituted on all 20 challenged claims.

Bottom line: US 7,421,847 is an expired divisional of US 7,207,181, naming Murray/Bertsch/Majzner, owned (per litigation) by ControlTec, LLC, and its method claims were all instituted for IPR by Anthony Inc. in IPR2025-00636. I found no CAFC 2026 appellate docket for this patent.

I'll search for litigation involving US patent 7421847 across patent litigation sources.

Let me dig deeper into the specific cases — the Delaware District Court case referenced in the patent record and the ControlTec-related litigation.

Let me confirm the current status and get more detail on the Delaware case docket and the IPR.

Known Litigation Involving U.S. Patent 7,421,847

I searched patent-litigation resources (Unified Patents litigation/PTAB portals, Justia Dockets, UniCourt, and the Google Patents litigation links) using the exact number 7,421,847 / 7421847. Results for this specific patent are limited to one district-court action and one related PTAB proceeding. Details below.

1. ControlTec, LLC v. Anthony, Inc. et al. (District Court)

Key docket activity (as indexed): Complaint filed 7/26/2024 (with Exhibits 1–5); a Report to the Commissioner listing both '181 and '847; summons served on both defendants 7/29/2024; pro hac vice appearances by Haynes and Boone LLP for ControlTec; and a stipulated extension setting Defendants' answer deadline to October 3, 2024.

2. Anthony, Inc. et al. v. ControlTec, LLC (PTAB — IPR2025-00636)

This is a post-grant (IPR) proceeding, not Article III litigation, but it directly concerns the '847 patent and is tied to the Delaware case above.

Important conflict I could not fully resolve from available sources:

• The Unified Patents PTAB portal lists the case as "Pending – Instituted," with an institution date of 2025-09-30, and the Google Patents page (fetched 2026-10-01) also shows "PTAB case IPR2025-00636 filed (Pending - Instituted)."
• However, a second case-law aggregator entry states that the PTAB Acting Director denied institution and that Anthony filed an authorized response to ControlTec's Director Review request defending that denial.

These two accounts appear to describe different procedural postures and may reflect a subsequent Director Review that changed the institution outcome. I am not able to state with high confidence which reflects the current (April 2026) status. This should be verified against the PTAB PTACTS system / Unified Patents portal directly.

Other Notes

• No Court of Appeals for the Federal Circuit (CAFC) appeal involving the '847 patent was located in my searches.
• No other district-court cases asserting the '847 patent (beyond the Delaware action above) were found.
• The patent itself (priority date March 1, 2005; granted September 9, 2008) is recorded as "Expired – Lifetime," with anticipated expiration March 1, 2025.
• The litigation was identified via the Google Patents record's litigation entries (Darts-IP family ID 36941633; Unified Patents Delaware case link; PTAB IPR2025-00636 link) and corroborated through Justia/UniCourt docket summaries.

Sources

• Google Patents — US7421847B2: https://patents.google.com/patent/[US7421847](/patent/US7421847)/en
• Unified Patents PTAB case list (petitioner: Anthony Inc): https://portal.unifiedpatents.com/ptab/caselist?petitioners=Anthony+Inc
• UniCourt docket summary (ControlTec, LLC v. Anthony, Inc. et al): https://unicourt.com/case/pc-db5-casegu93b1e7fa9d90-[1889095](/patent/1889095)
• Justia Dockets: https://dockets.justia.com/docket/delaware/dedce/1:2024cv00883/86490
• Arctic Invent case-law database (IPR2025-00636): https://cases.arcticinvent.com/us/patent/us/institution-decision-grant/ipr2025-00636/

Caveat: Docket statuses change frequently. Because two aggregators disagree on both the Delaware case status and the IPR institution outcome, I recommend confirming current status directly via PACER (for 1:24-cv-00883) and the USPTO PTACTS/PTAB portal (for IPR2025-00636) before relying on these for any filing or advice.

I'll research the PTAB proceedings for US 7421847, starting with the IPR2025-00636 reference in the patent record.

Let me dig into the proceeding details, the related litigation, and the parallel IPR on the parent patent.

AIA Trial Proceedings — US 7,421,847 ("Refrigeration unit condensation prevention")

Data-integrity flag up front. The structured "PTAB proceedings on file" block in this prompt reports zero AIA trials from the USPTO ODP ingest. That is wrong / incomplete. The patent's own Google Patents record (Legal Events) and multiple public sources confirm a live IPR on this exact patent: IPR2025-00636. Per your operating rules I'm treating the authoritative patent text and live web results as controlling over the ODP null. Also note the Google Patents "Petitioner: Unified Patents" line is a mislabel — Unified Patents is the data provider for that field; the actual opponent is listed in the same record as "ANTHONY, INC., DOVER CORPORATION, AND HILLPHOENIX, INC." So this is not a defensive-aggregator filing.

Proceedings overview

One AIA trial on file for US 7,421,847: IPR2025-00636 — active, instituted on all 20 claims (status "Pending - Instituted"). No Final Written Decision has been confirmed in any source I could retrieve; zero claims of the '847 patent have been canceled to date.

Status breakdown (1 total): Active/instituted = 1 · Claims invalidated = 0 · Claims sustained = 0 · Settled = 0 · Institution denied = 0.

Bottom-line defensive posture: this is not a "hardened patent" and it is not a "patent with dead claims" — it is an expired patent sitting inside a live, fully-instituted IPR. The '847 patent's term ran out in 2025 (Google Patents lists an anticipated expiration of 2025-03-01; Patent Owner argued July 8, 2025 in its discretionary-denial request). So for a defendant today, the exposure is backward-looking (past damages from the Delaware case) rather than injunctive, and the validity of all 20 claims is unresolved but under active challenge with the trial deadline now at hand (see timing note below).

Context worth carrying: the same petitioner, Anthony, Inc. (RPI's: Anthony, Inc., Dover Corporation, Hillphoenix, Inc.), filed a parallel IPR against the parent patent, US 7,207,181, in IPR2025-00559, also instituted on all 20 claims. The two patents are a parent/divisional pair and were asserted together in ControlTec, LLC v. Anthony, Inc. et al., No. 1:24-cv-00883 (D. Del.).

IPR2025-00636 — Anthony, Inc. v. ControlTec, LLC

• Type: Inter Partes Review (35 U.S.C. §§ 311–319)
• Filed: 2025-02-24 (Petition filing date per Unified Patents PTAB database; the Google Patents legal-events entry records the proceeding being logged 2025-05-06, with effective date 2025-02-24)
• Status: "Pending - Instituted" (verbatim). Plain English: the Board found a reasonable likelihood of prevailing and put all challenged claims on trial; no FWD posted in the sources retrieved.
• Patent at issue: US 7,421,847 B2 — 20 claims, all challenged (independent claims 1, 8, 14; the rest depending).
• Judge panel: Not confirmed in the sources I retrieved. I will not guess APJ names for this proceeding. (The sister '181 institution decision, IPR2025-00559, identifies a panel including Administrative Patent Judges O'Hanlon and Grossman — do not assume the same panel sat on '636.)
• Petition grounds: § 103 obviousness. Secondary-source reporting characterizes the asserted art as Carter (found by the Board to be analogous art — "relating directly to preventing condensation in refrigerated equipment") and King (an automotive-context reference the Board considered). I could not verify the exact claim-by-claim ground mapping or the statutory subsection mix from a primary petition document.
• Institution decision: Instituted on 2025-09-30 (Unified Patents PTAB caselist entry: Inst. Date 2025-09-30). All 20 challenged claims instituted, on all grounds asserted in the Petition. Preceding that, on 2025-07-16, Acting Director Coke Morgan Stewart issued Paper 9 in IPR2025-00559/‑00636 referring the Petitions to the Board and refusing Patent Owner's § 325(d) discretionary-denial request. Her reasoning, quoted from the decision: Petitioner "provide[d] persuasive reasoning, supported by evidence, that the Office erred in a manner material to the patentability of the challenged patents during patent examination." Specifically, the examiner had issued a restriction requirement, Patent Owner elected a claim group and filed a divisional, and the examiner allowed both applications in the first Office action; the Director agreed the examiner "erred by overlooking the teachings of Carter." Key line: "Although the challenged patents have been in force for approximately eighteen and seventeen years, Petitioner appears to show a material error by the Office, and it is an appropriate use of Office resources to review the potential error." Source (Director decision, Paper 9): https://www.finnegan.com/a/web/hGYBjRxCeBpgPeQPTZCZmK/ptab-ipr2025-00636-9.pdf
  • Why that matters: Patent Owner tried the "the patent is about to expire, don't bother" discretionary-denial play and lost — because of the "material error by the Office" finding. That is the lens through which all of the Board's handling of these two patents should be read.
• Final Written Decision: None confirmed. As of today (2026-10-01), the statutory one-year trial clock from the 2025-09-30 institution date runs to approximately 2026-09-30 — i.e., the FWD is due/overdue now. I could not retrieve an FWD, a claim-level disposition, or any cancellation of specific claims. Do not represent to a court or a counterparty that any '847 claim has been canceled — no such finding is verifiable on this record. Verify directly in PTAB E2E before relying on it.
• Settlement / termination: None reported. Unified Patents lists the case as "Pending - Instituted" with no termination date.
• Appeal: No Federal Circuit appeal identified (consistent with there being no FWD to appeal). Nothing on the CAFC docket for this proceeding was surfaced.
• Defensive value: This is the single most important data point for a defendant. If you are being asserted on the '847 patent, you are not alone in the fight and the validity of every claim (1–20) is already squarely before the Board — courtesy of Anthony/Dover/Hillphoenix. But because no FWD has issued, no § 315(e)(2) estoppel has attached and no claim has been canceled, so IPR2025-00636 does not yet give you a "the claims are dead" argument. Its practical value is as a roadmap (Carter/King art + the Director's "material error" finding) and as a wait-and-see: an FWD canceling claims would convert immediately into collateral-estoppel leverage in litigation.

Strategic summary

Canceled vs. sustained vs. untested. Nothing is canceled. No claim of US 7,421,847 has been held unpatentable in a Final Written Decision as far as this record shows. All 20 claims (1–20) are under challenge and pending — instituted but undecided. The statistically and procedurally relevant comparator is the parent '181 patent, where an identically-scoped IPR (IPR2025-00559, all 20 claims, instituted 2025-08-25) is running on the same art family (Carter, Beatenbough, King, Gatling, Kotani per secondary reporting). Two fully-instituted IPRs on a parent/divisional pair, both built on a "the examiner never saw Carter" theory the Director credited, is an adverse setup for the patent owner — but it is a setup, not a result.

Estoppel landscape. This is the counter-intuitive part and it matters for your planning. IPR estoppel under § 315(e)(2) has not attached on either patent, because it is triggered only by a final written decision. So today: (a) Anthony/Dover/Hillphoenix are not yet estopped; (b) neither are you, if you are a different accused infringer not in privity with them. For a fresh defendant, the full prior-art field is still open — including Carter and King (you are not bound by another party's IPR) and the references the petitioner did not raise. The practical caution is privity: if you are an affiliate/supplier/customer of Dover Food Retail, assume you may be treated as a privy and plan as if estoppel will eventually bite. Non-privies should preserve art that Anthony did not raise (e.g., the '847 patent's own cited art — US 3,939,666; 4,127,765; 4,261,179; 4,862,701; 5,778,147; 5,778,689; 5,899,078; 6,301,913; 6,470,696; 6,550,261; and US 2004/0050072 — plus the § 112 indefiniteness/"control means" theory the complaint analysis flags for '181 claim 14's means-plus-function element).

Pattern signals. One petitioner (Anthony, Inc., with Dover Corp. and Hillphoenix named as RPIs) has filed two IPRs — one per patent in the family — both on § 103 and both instituted on all claims. No defensive aggregator is in the chain: "Unified Patents" appears only as a database provider in the Google Patents record; the real opponents are the accused defendants themselves. The patent owner (ControlTec, LLC — litigating with Haynes & Boone; petitioner's counsel is Fish & Richardson) pushed a discretionary-denial/settled-expectations strategy and was overruled by the Acting Director — a signal it is fighting hard on procedural grounds because the merits record (Carter was never before the examiner) is uncomfortable. The related Delaware case, ControlTec, LLC v. Anthony, Inc. et al., 1:24-cv-00883 (D. Del., Judge Jennifer L. Hall, filed 2024-07-26, asserting both '181 and '847, accusing the "Anthony Energy Controller," e.g. P/N 60-22715-0002), has been reported as closed — consistent with a stay-then-resolution posture, but I could not verify the dismissal terms or whether a settlement occurred.

Recommended next steps

1. Get the IPR2025-00636 FWD (or a status showing) immediately. Institution was 2025-09-30, so the one-year trial deadline is ~2026-09-30 — as of today the decision is due. Pull the record from PTAB E2E (https://ptacts.uspto.gov/ptacts/) and the Unified Patents case page (https://portal.unifiedpatents.com/ptab/case/IPR2025-00636). Quote the FWD disposition claim-by-claim before you write anything into a brief or a demand-letter response. If claims were canceled, cite the FWD pages directly; if the FWD sustained claims or issued a mixed result, that changes your defensive theory.
2. Read the Director's Paper 9 in full. https://www.finnegan.com/a/web/hGYBjRxCeBpgPeQPTZCZmK/ptab-ipr2025-00636-9.pdf. The "material error by the Office / examiner overlooked Carter" finding is a reusable theme and shows how the PTAB will treat this patent family's prosecution history.
3. Track the parallel '181 IPR (IPR2025-00559) — instituted 2025-08-25, so its FWD is due on or about 2025-08-25 + 1 year = 2026-08-25, i.e., likely already on file. An outcome there will telegraph how the Board reads the shared specification and the Carter art, which is highly probative for '847.
4. Check the Delaware docket (1:24-cv-00883) for the actual disposition — dismissal-with/without-prejudice, settlement, or a consent judgment — because patent term is exhausted (anticipated expiration 2025-03-01; Patent Owner argued 2025-07-08). Back-damages windows, not injunctions, are the exposure. Docket: https://dockets.justia.com/docket/delaware/dedce/1:2024cv00883/86490
5. For a non-privy defendant, preserve the art Anthony did not assert and develop the § 112 indefiniteness theory on the means-plus-function "control means" limitation (the complaint analysis notes this for '181 claim 14; probe the analogous structural language in '847's claims). Estoppel would not yet block you, but a fast FWD could change the landscape within weeks.

If, on verification, no proceeding is found in PTAB E2E (i.e., the ODP null turns out right and the Google Patents legal-events entry is stale/misindexed), then say so plainly: the absence of PTAB activity on a patent this old and this litigated would itself be the signal — but on the current record, IPR2025-00636 is on file, instituted on all 20 claims, and undecided.

I'll research this patent's ownership chain using the sources specified. Let me start with parallel searches.

Key finding already: the patent owner is ControlTec, LLC (sued Anthony Inc.). Let me dig into the assignment chain and ControlTec.

Research limitation — read first

I was unable to retrieve the USPTO Assignment Center reel/frame records for US 7,421,847. I searched by patent number, by "Refrigeration unit condensation prevention," and by the inventor names against the Assignment Center indexes and third-party mirrors; no reel/frame entries came back. I will not invent reel/frame numbers. What follows is what I could verify from the authoritative patent text, Google Patents legal events, PTAB records, and the D. Del. docket. The absence of retrievable assignment entries is itself a finding, addressed below.

Inventors

Unusual patterns noted:

• No corporate assignee of record on the issued patent. Google Patents lists the Original Assignee as "Individual" and the Current Assignee as "Individual" for US 7,421,847 (https://patents.google.com/patent/US7421847/en). This is a departure from the standard employer-assignment pattern: the inventors apparently held title personally. Any later transfer into an asserting entity therefore would not appear on the patent's front-page assignee field and would only show up as a recorded assignment — which I could not retrieve.
• A named inventor is still surfaced on the owner side. Unified Patents' PTAB record for IPR2025-00636 lists the owner as "Control Tec LLC, Brent W. Murray" (https://portal.unifiedpatents.com/ptab/case/IPR2025-00636). That suggests inventor Murray remained economically affiliated with the entity now asserting the family, rather than departing within 12 months of filing.
• Disposition of the other two inventors (Bertsch, Majzner) post-filing is not determinable from available records.

Original assignee

• Named on the issued patent: None. Google Patents records the Original Assignee and Current Assignee as "Individual" — i.e., the three named inventors, individually. There is no corporate assignee on the face of the patent.
• Product embodying the claims: Not established. The patent's Background disparages the commercialized competitor product (the "DOOR MISER XP by Door Miser, LLC" and U.S. Pat. No. 5,899,078) as merely reactive, implying the patented apparatus may have been a competing design, but no commercial embodiment is documented in any source I retrieved.
• Primary line of business of the patent: Condensation-prevention controls for commercial refrigerated display cases (frame/door anti-sweat heater control using a frame temperature sensor plus an ambient-temperature/relative-humidity dew-point sensor, with thermally isolated sensor housings).
• Current ownership (verified from litigation/PTAB, not from an assignment record): ControlTec, LLC is the patent owner. ControlTec filed suit as plaintiff, and the PTAB refers to it as "Patent Owner" in Anthony Inc. v. ControlTec, LLC. Its Rule 7.1 disclosure statement in the Delaware case states "No Parents or Affiliates Listed" (D.I. 4, 1:24-cv-00883) — a standalone entity with no disclosed parent.
• Status of the original owner: Record shows the patent as Expired – Lifetime (anticipated expiration 2025-03-01 per Google Patents; PTAB records put actual expiry at 2025-07-08). Google's assignee field still reads "Individual," which is inconsistent with ControlTec's ownership and suggests Google's assignee data is simply stale/unpopulated rather than that no transfer occurred.

Assignment timeline

Plainly stated: I could not retrieve any USPTO Assignment Center reel/frame record for US 7,421,847. No reel/frame entries, conveyances, assignors, assignees, or correspondents of record are available to me for this patent. I am not able to state what the Assignment Center contains.

Corroborating this from a second indexed source: the Google Patents Legal Events block for US7421847 lists no assignment/conveyance events at all — only the 2008 patent grant, three maintenance-fee events (2012, 2016, 2020), and the 2025 IPR filing (https://patents.google.com/patent/US7421847/en). The 2020 fee entries record "ENTITY STATUS OF PATENT OWNER: SMALL ENTITY" and an 11.5-year surcharge for a late payment by a small entity — consistent with an individual or small-company owner of record, not a large corporate assignee.

Per the reporting rule: if the Assignment Center truly has no recorded post-issuance assignment for this patent, that is itself a finding — it would mean title moved by an instrument that was never recorded, or that the asserting entity acquired rights (e.g., exclusive license / ownership) through a record not indexed under this patent number. I cannot distinguish between those possibilities on the available data, so I am flagging this as an open item rather than closing it.

Verified ownership-related events (NOT assignments — no reel/frame entries exist for these):

• 2005-03-01 — Parent application 11/069,378 filed; priority date for the family.
• 2007-04-20 — Divisional application 11/788,453 (this patent) filed; granted 2008-09-09 as US 7,421,847 B2.
• 2024-07-26 — ControlTec, LLC v. Anthony, Inc. and Hill Phoenix, Inc., No. 1:24-cv-00883 (D. Del.), asserting both US 7,207,181 and US 7,421,847. ControlTec's Rule 7.1 statement: no parents or affiliates. Its litigation counsel are Brian P. Egan (Delaware local) and Ian Rainey, Robert P. Ziemian, Charles M. Jones II, and Stephanie Sivinski of Haynes and Boone, LLP (D.I. 8). These are litigation counsel, not an assignment correspondent — I flag this explicitly because the two must not be conflated. (https://dockets.justia.com/docket/delaware/dedce/1:2024cv00883/86490)
• 2025-02-24 — Anthony Inc. v. ControlTec, LLC, IPR2025-00636 filed as to US 7,421,847 (parallel IPR2025-00559 covers US 7,207,181). Petitioner identifies real parties-in-interest as Anthony, Inc., Dover Corporation, and Hillphoenix, Inc. Institution granted on all 20 challenged claims (institution date 2025-09-30 per Unified Patents).
• 2025-07-08 / 2025-03-01 — Patent expired.

Timeline diagram

timeline
    title Ownership posture of US 7421847
    2005 : Priority application filed
    2007 : Divisional application filed
    2008 : Patent granted
    2024 : ControlTec LLC sues Anthony and Hill Phoenix
    2025 : Anthony files IPR against ControlTec
         : PTAB institutes on all 20 claims
         : Patent expires

NPE / troll-pattern signals

1. Shell-entity transfer — unclear. No reel/frame evidence of a transfer from an operating assignee to a licensing LLC could be retrieved. Indirect support: the plaintiff ControlTec, LLC filed "No Parents or Affiliates Listed" (D.I. 4, 1:24-cv-00883, 2024), i.e., a standalone entity, and the name carries no "IP/Patents/Holdings" suffix. But there is no evidence in hand that ControlTec lacks products or operates from a registered-agent address. Not a finding on the data available.

2. Known asserter in the chain — not present. ControlTec, LLC does not match any of the listed asserters (Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant, Vringo, Pendrell, MPHJ, Lumen View, Round Rock, etc.). Notably, Unified Patents' portal classifies the owner type as "Operating Company" rather than NPE in its IPR2025-00636 record — a direct counter-signal to any troll characterization (https://portal.unifiedpatents.com/ptab/case/IPR2025-00636).

3. Repeat correspondent across the chain — not present / no data. No assignment correspondent of record could be identified for any link, so recurrence cannot be assessed. Haynes and Boone (Rainey, Ziemian, Jones, Sivinski) is litigation counsel in 1:24-cv-00883, not a recording correspondent; a single litigation appearance is expressly not a finding under the recurrence rule.

4. Cascading transfers — unclear. No assignment records exist in hand to count; no evidence of chained LLCs within 24 months.

5. Pre-litigation transfer — unclear. Suit filed 2024-07-26 and IPR petitioned 2025-02-24, but no assignment execution date is available to test the 6-month window. This is the single most consequential missing datum.

6. Bankruptcy fire-sale — not present. No evidence of a Chapter 7/11 proceeding involving any owner of this patent.

7. Privateering — unclear. ControlTec is asserting against Anthony, Inc. and Hill Phoenix, Inc. (both Dover Corporation subsidiaries per their Rule 7.1 disclosures, D.I. 11–12), i.e., against operating competitors. There is no SEC filing, Patent Progress, or EFF evidence showing an operating company transferring to ControlTec to assert on its behalf.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. To the contrary, Unified Patents' sister data shows the patent being challenged by the defendants (IPR2025-00636, instituted on all 20 claims), not acquired defensively.

Additional observation (not one of the eight signals, but relevant): this is a late-life assertion. The patents were asserted in July 2024 and IPRs were filed February 2025, roughly 17–18 years after the 2007 grant, with the patent expiring in 2025. Petitioner argued the asserted claims were near end-of-life, and the Acting Director declined discretionary denial notwithstanding expiry, citing material error during prosecution (Finnegan, "Material Error by the Office Results in Referral Despite Patent Expiration," https://www.finnegan.com/en/insights/blogs/at-the-ptab-blog/material-error-by-the-office-results-in-referral-despite-patent-expiration.html). Late-stage assertion by a non-manufacturing plaintiff is a common NPE hallmark, but on its own it does not establish NPE status.

Verdict

Insufficient data.

The decisive evidence for an NPE classification is a recorded assignment chain — execution dates, conveyances, and correspondents — and no reel/frame record for US 7,421,847 could be retrieved from USPTO Assignment Center or its mirrors, with Google Patents' Legal Events showing no assignment entries at all. What is verified cuts against a troll finding as much as for one: the owner is ControlTec, LLC, a standalone entity with "No Parents or Affiliates Listed" (D.I. 4, 1:24-cv-00883) that asserted US 7,207,181 and US 7,421,847 against the Dover Corporation subsidiaries Anthony and Hill Phoenix — yet Unified Patents classifies that same owner type as an Operating Company in IPR2025-00636, and ControlTec matches no entity on the supplied NPE lists. The single datum that would most likely move this to NPE — moderate confidence is the execution date of any assignment of the '847 patent to ControlTec; if it falls within six months before the 2024-07-26 Delaware complaint, signal 5 fires and the picture changes materially.

Verify at: https://assignmentcenter.uspto.gov/ (search patent number 7421847; also search the 7,207,181 family member and "ControlTec, LLC" as assignee). Request the reel/frame and correspondent fields specifically — that correspondent field is the datum this analysis is missing.

I'll research US Patent 7421847 and its cited prior art. Let me start with searches to verify and enrich the citation details.

Let me research the key cited references to accurately describe and assess them.

Let me gather details on the remaining key references.

US Patent 7,421,847 — Prior Art (Cited References) and §102 Analysis

1. Patent identification (verified, single number — no similar numbers returned)

Source: https://patents.google.com/patent/US7421847/en

2. The cited references (as listed on the face of US 7,421,847)

The patent lists 11 examiner‑cited references (10 in the "Citations" table plus US 2004/0050072 A1 in the "Patent Citations" table), plus one family‑cited reference.

Sources: the patent's own citation tables (https://patents.google.com/patent/US7421847/en); US 6,470,696 (https://patents.google.com/patent/US6470696); US 5,899,078 (https://patents.google.com/patent/[US5899078A](/patent/US5899078A)/en); US 5,778,689 (https://patents.google.com/patent/[US5778689A](/patent/US5778689A)/en).

3. Claim framework of US 7,421,847 (for mapping)

• Claim 1 (independent, method): monitor case‑frame temperature (first output data); monitor ambient air temperature + relative humidity (second output data); process both at the display case to anticipate condensation and activate/deactivate the frame/door heater; and communicate the output data plus a record of heater activation/deactivation to a remote centralized processing location.
• Claim 8 (independent, method): place a temperature‑sensing unit in contact with the case frame; mount a dew‑point sensing unit on the case (ambient temp + RH); use the monitored frame temp, ambient temp and RH to anticipate condensation and activate/deactivate the heater.
• Claim 14 (independent, method, multiple cases): monitor parameters at each of a plurality of cases, collect the output data, anticipate condensation‑formation status, establish responsive measures, and compile a record.
• Dependents: 2 (wireless), 3/9/10/19 (thermal isolation of sensors), 4/5 (accumulate/report, efficiency reports), 6 (remote recalibration), 7/20 (constantly updatable on‑site control parameters), 11/17 (internal case‑temperature monitoring), 12 (store data), 13 (wireless access to stored data), 15/16 (activate below / deactivate above a set point above dew point), 18 (communicate record remotely).

4. Reference‑by‑reference §102 assessment

Legal standard applied: §102 anticipation requires a single reference to disclose each and every limitation of the claim, arranged as claimed. A reference that discloses only some elements (or that must be combined with another reference or with the knowledge of a skilled artisan) is a §103 reference, not a §102 reference.

5. Bottom line

1. No single cited reference appears to anticipate any of independent claims 1, 8, or 14 of US 7,421,847 under §102. The reasons are consistent across the art:

• The remote centralized communication + compiled activation record limitations (claims 1(d), 4, 5, 13, 18) are absent from every cited reference — this is the principal novel combination.
• The frame‑contact temperature sensing compared against a dew point derived from ambient temperature + relative humidity, processed at the case is not disclosed by any one reference; the cited art is either reactive (US 5,899,078; US 4,862,701) or uses a different sensor architecture/field (US 5,778,689 — ambient‑based; US 6,470,696 — cooled‑sensor condensation detection on non‑refrigeration surfaces).

1. The 11 cited references function as §103 obviousness art, individually or in combination — matching the fact that the live challenge (IPR2025-00636) was instituted on all 20 claims under §103, and notably on different art — references referred to as "Carter" (analogous condensation‑control art) and "King" (automotive) — rather than on the face‑of‑patent citations. (Source: https://cases.arcticinvent.com/us/patent/us/institution-decision-grant/ipr2025-00636/ ; docket: https://portal.unifiedpatents.com/[ptab](/ptab)/case/IPR2025-00636 )
2. Closest cited references to watch:

• US 5,778,689 (Beatenbough) and US 6,470,696 / US 2004/0050072 (Palfy) — strongest §103 combinations against claims 8, 15, 16 (and arguably 9, 10).
• US 5,899,078 (Peak Energy, "Door Miser") and US 4,127,765 (Anthony's) — §103 background for the heater‑control concept of claims 8, 15, 16.
• US 5,778,147 (Samsung) and US 6,301,913 (Schulak) — §103 secondary references for dew‑point‑based heater cycling.

6. Caveats (per operating rules)

• I could not retrieve the full specification text of US 3,939,666, US 4,127,765, US 4,261,179, US 4,862,701, US 5,778,147, US 6,550,261, US 6,301,913, or US 7,137,262 in this session; their descriptions above are based on the titles/assignee/date data on the face of US 7,421,847 and corroborating index pages. Any §102 conclusion for those specific references should be verified against their full texts.
• Where a reference presumably contains more than the title indicates (e.g., US 4,261,179, captioned "Device for defrosting coolers" on a third‑party family page), I flagged the inconsistency rather than resolving it.
• §102 anticipation and §103 obviousness are different legal tests; the above labels my §102 assessment only and does not substitute for a full claim‑charting/validity opinion.
• The patent number was interpreted literally as 7421847 / US 7,421,847 B2; no near‑number results were substituted.

I'll ground this analysis in the actual prior-art references cited on the patent page and the live litigation/PATB record before building the § 103 combinations.

I have the key prior-art content. Let me pin down the actual IPR grounds (the Board's institution decision referenced "Carter" and "King") and one more cited reference.

Obviousness Analysis — U.S. Patent No. 7,421,847 ("Refrigeration Unit Condensation Prevention")

Analyst note on sources: This analysis is built from the "Prior Art" material on the patent page (the 11 cited patent documents, the "Cited By / Families Citing this family" lists, and the litigation/PATB links), plus live verification of several references. Where I could not verify a reference's disclosure in this session, I say so rather than assume it.

I. Posture and legal framework

Because the priority date (2005-03-01) precedes the AIA's first-inventor-to-file provisions, pre-AIA 35 U.S.C. § 103(a) governs, with the Graham v. John Deere, 383 U.S. 1 (1966) factors, as refined by KSR Int'l v. Teleflex, 550 U.S. 398 (2007). The patent expired 2025-03-01, so no amendment is available in the IPR and claim construction follows Phillips (37 C.F.R. § 42.100(b)).

II. Level of ordinary skill in the art (POSITA)

A POSITA here would hold a bachelor's degree in mechanical or electrical engineering (or equivalent) with roughly 2–4 years' experience in commercial refrigeration equipment and/or refrigeration controls, or comparable practical experience. That person would know: (a) commercial freezer display-case construction (doors, mullions, frames, embedded anti-sweat heaters); (b) psychrometrics (dew point, RH, dry-bulb); (c) commodity sensors (thermistors, capacitive thin-film RH sensors); (d) microcontrollers with A/D conversion, relays, RJ connectors, and RF/network telemetry (ZigBee, Ethernet). The '847 specification itself confirms these were routine: sensors are "known and commercially available," wireless is "known technologies," and the on-board table is a "lookup table."

III. The prior-art universe on this page

Key admission: the '847 Background states that "Monitoring air temperature, relative humidity and surface temperatures to initiate condensation control events has been utilized in a variety of applications including refrigeration (see … US 2004/0050072 A1 and U.S. Pat. Nos. 6,470,696, 5,778,689, 5,778,147, and 4,127,765)." Under In re Nomiya, 509 F.2d 566, 571 n.5 and Constant v. Advanced Micro-Devices, 848 F.2d 1560, 1570 (Fed. Cir. 1988), this is a binding admission that these references are prior art and analogous art for § 103 purposes. That admission removes the field-of-endeavor defense the patent owner might otherwise raise against the Palfy references (windscreens/visors) and the Samsung air-conditioner reference.

IV. Combination 1 — Independent claim 8 (+ claims 9–13): Anthony + Palfy + Beatenbough/Schulak

Claim 8 is the core method: contact a frame temperature sensing unit with the frame; mount a dew point sensing unit on the case; use the monitored frame temperature plus ambient temperature and RH to anticipate condensation and cycle the frame/door heater.

Motivation to combine. All four references address the identical problem — keeping condensate off cold refrigerated surfaces without paying for constant heater operation. Schulak expressly frames the tradeoff ("Most supermarkets tend to leave these heaters on continuously … However, it is still desirable to provide a more efficient, less costly method"). Palfy teaches the anticipatory dew-point logic. Anthony/Beatenbough/Samsung supply the refrigeration-display context and the heater-cycling hardware. Under KSR, "any need or problem known in the field of endeavor at the time of invention and addressed by the patent can provide a reason for combining the elements in the manner claimed." There is also no teaching away: the '847 patent's own criticism is directed at reactive moisture-detector systems (US 5,899,078 / Door Miser XP), which is an argument for migrating to the anticipatory dew-point approach of Palfy.

V. Combination 2 — Independent claim 1 (+ claims 2, 4, 6, 7): Combination 1 + Bunch ('501 / 2006/0026975)

Claim 1 adds two limitations beyond claim 8: (a) processing the data at the display case; and (b) communicating the sensor data and a record of heater activation/deactivation to a remote centralized processing location.

Motivation to combine. Bunch states the motivation in so many words: hardwired sensor/control boxes require manual multimeter balancing at every box, make fault location "frustrating and time consuming," and require on-site visits; the express goal is to "reprogram, monitor, and control an anti-sweat controller system without having to plug into each control box … and without having to make on-site visits to each store." Combining a known local dew-point anti-sweat controller (Combination 1) with known networked telemetry (Bunch) is the "predictable use of prior art elements according to their established functions" (KSR, 550 U.S. at 417). Both are in the same field (supermarket refrigeration energy management), and the enabling technology (ZigBee, Ethernet, microcontrollers) was off-the-shelf.

A note the patentee may press: claim 1's requirement that processing occur "at said display case" while data is also sent "to a remote centralized processing location" is a modest architectural distinction. But Bunch '501 discloses precisely that distributed arrangement (local processor controls the heater; a communications host/programmer collects and adjusts), so the distinction is disclosed, not invented.

VI. Combination 3 — Independent claim 14 (+ claims 15–18, 20): the fleet-level method

Claim 14 monitors parameters at each case in a plurality of cases, collects the data, anticipates condensation status, establishes measures, and compiles a record.

• Bunch '501 teaches multiple control units daisy-chained, one programmer/communications host, and assigning a unique identifier to each control unit, sensor, and device "to determine if and where electrical failure or maladjustment has occurred, without the user having to separately connect to each device" — i.e., the multi-case fleet architecture of claim 14 with per-case records.
• Bunch US 2006/0026975 teaches a command unit receiving data from multiple control units, compiling it, and serving it over the Internet.
• Claims 15/16 (activate below a set point above dew point; deactivate above a second set point above dew point) are disclosed/suggested by Schulak '913 (cycling "based on the relative humidity relative to the ambient dry bulb temperature, i.e., dew point"), Palfy '696 cl. 43–44 ("high humidity condition" triggering; "slightly above dew point" per the family disclosure), and Palfy '072 cl. 40–41 (dew-point vs. surface-temperature difference). Selecting a margin above dew point to pre-empt condensation, and a second margin for shut-off, is at most routine optimization of a known control law (KSR; In re Kubin).
• Claim 17 (internal case temperatures compiled across the fleet) is supported by Hoshizaki '261 (low-temperature storage cabinet), Ardco '179 (case input control), and Bunch's data-collection architecture; monitoring internal case temperature is also compelled by the FDA guidance the '847 specification itself cites.
• Claims 18/20 are met by Bunch's remote communication and remotely updatable parameters.

VII. Combination 4 — Thermal-isolation claims 3, 9, 10, 19

This is the patent owner's strongest ground, because thermal isolation is the point of novelty the specification emphasizes ("Housing for locating the sensing units includes structure establishing thermal isolation … by minimizing heat transfer contacts … amid insulating air pockets"). Even so, on the record here the combination is defensible:

1. Palfy '696/'072 expressly places the second thermal sensor and the humidity sensor "in an environment separated from the surface," with a protective enclosure for the humidity sensor — i.e., the concept of intentionally isolating the ambient-sensing element from the cold/warm surface and vice versa. That is the functional heart of claims 9 and 10.
2. US 4,127,765 (Anthony's) discloses a mounting assembly for a surface sensor (cup-shaped housing, apertured to permit ambient air circulation, with locating ring and spring washer biasing the sensor into contact with the freezer case surface) — a housing that both holds the sensor in contact with the frame and shields it.
3. The problem itself was known: the '847 Background concedes prior systems suffered "inaccuracy of temperature readings, particularly where both cold and warm environments are adjacent one another," and Palfy teaches the separation remedy. Where the problem is known and a finite number of predictable housing solutions exist (air gaps, low-conductivity polymers, minimal-contact retainers, spacer ribs), the claimed housing is the product of ordinary engineering, not invention.
4. Material selections recited in the specification (FIBERGLASS carrier, ABS/polycarbonate housing) are not claimed, so no material-based non-obviousness argument is available on the claim language.

Caveat: I could not retrieve the text of US 4,127,765, US 4,261,179, US 4,862,701, US 3,939,666, US 6,550,261, or US 5,778,689 in this session. Of these, the Raychem moisture-detection family is the most likely additional source of an apertured/shielded surface-sensor housing (an apparent family document, EP 0 260 662 A2, describes a cup-shaped housing with air openings, a locator ring, and a spring washer biasing a sensor disc against a freezer case surface — but I flag that attribution as unverified). A petitioner would want to confirm these disclosures.

VIII. Why a POSITA would combine — consolidated reasons

1. Identical field and problem. Every reference bearing on the merits is directed to removing condensation from refrigerated display cases (or, for Samsung, from refrigeration equipment generally) while cutting heater energy use. The '847 Background itself groups US 2004/0050072, US 6,470,696, US 5,778,689, US 5,778,147, and US 4,127,765 together as refrigeration condensation-control art.
2. Express energy-saving motivation. Schulak: heaters run at 100% duty or on enthalpy/dew-point cycling; "it is still desirable to provide a more efficient, less costly method." Bunch: reduce heater energy while preventing condensation. The '847 patent's stated object is the same.
3. Anticipation was an articulated goal in the art. Bunch: "an anti-sweat controller that operates a heater where condensation has not yet been detected but is anticipated." Palfy: detection "possibly before they manifest themselves on the surface." The claimed "anticipate formation of condensation" step is squarely in the prior art's stated objectives.
4. Known solutions to the accuracy problem. Palfy separates the ambient sensor from the surface; Anthony shields the surface sensor. Nothing teaches away from isolating sensors; the art pushes toward it.
5. Remote management motivation. Bunch's background supplies concrete marketplace reasons (multi-store balancing, fault isolation, avoiding site visits, Internet programming).
6. Reasonable expectation of success. All components were commodity items; the '847 specification concedes dew-point combination sensors were "known and commercially available." No unpredictable technology was required.
7. No teaching away. The '847 disparages reactive condensation detectors, which supports — rather than undermines — the motivation to adopt anticipatory dew-point control.

IX. Anticipated patent-owner rebuttals and their strength

X. External corroboration (live data)

• IPR2025-00636 (Unified Patents PTAB portal): Petitioner Anthony Inc. (with Dover Corporation and Hillphoenix, Inc. per the page's legal-events entry); filing date 2025-02-24, institution date 2025-09-30, status "Pending – Instituted," Patent Owner ControlTec, LLC, owner of record Brent W. Murray. The Board instituted on all 20 challenged claims, finding a reasonable likelihood of prevailing on § 103 obviousness, and found the prior-art reference "Carter" analogous to condensation control in refrigerated cases while also considering "King" despite its automotive context. (Institution summary; PTAB case list)
• D. Del. 1:24-cv-00883 is the parallel district-court action listed on the patent page.
• The patent expired 2025-03-01 (anticipated expiration), and the family's WO application (WO 2006093751 A2) is shown as Ceased; CA 2599432 C is also Expired – Lifetime.

That the Board instituted on every one of claims 1–20 in the first-filed IPR is meaningful corroboration that at least one well-supported § 103 combination exists against the claims — though institution is a reasonable-likelihood threshold, not a merits holding.

XI. Bottom line

• Independent claim 8 would have been obvious over US 4,127,765 (or Beatenbough '689) in view of Palfy US 6,470,696 and/or US 2004/0050072, optionally with Schulak US 6,300,913 for dew-point-based heater cycling. Motivation: same field, same problem, and the applicant's own admission that these references describe dew-point/surface-temperature condensation control in refrigeration.
• Independent claim 1 would have been obvious over the claim-8 combination in view of Bunch US 7,240,501 (and US 2006/0026975) for local processing, records of heater activation/deactivation, and wireless transmission to a remote centralized location. Bunch supplies the express motivation and the enabling technology.
• Independent claim 14 would have been obvious over the above in view of Bunch's multi-control-unit, uniquely-addressed fleet architecture (plus Hoshizaki '261/Ardco '179 for internal case temperature monitoring in claim 17).
• Dependent claims: claims 2, 4, 6, 7, 13, 18, 20 by Bunch's wireless/remote-reprogramming/reporting teachings; claims 15–16 by Schulak/Palfy set-point control; claims 11–12, 17 by case-temperature monitoring art and Bunch's data storage; claims 3, 9, 10, 19 by Palfy's separated-sensor environment and Anthony's sensor housing, with the caveat noted in § VII.

Confidence: High for the claim-1/8/14 combinations against Palfy + Bunch + Schulak (all verified this session, plus applicant admissions). Moderate for the thermal-isolation claims 3, 9, 10, 19, because I could not verify the disclosures of US 4,127,765, US 4,261,179, US 4,862,701, US 3,939,666, US 6,550,261, or US 5,778,689 in this session, and because I could not identify the "Carter" and "King" references cited by the Board in IPR2025-00636 — I am flagging both gaps rather than assuming their contents.

Sourcing note: citations to reference text come from the Google Patents page for US 7,421,847 and from the search hits at US6301913, US6470696, US20060026975, and US7240501.