US 1060425

I'll search for the specific patent number, including any litigation references.

Let me check specifically for any litigation or CAFC docket activity involving this patent number.

US 1,060,425 A — Search Report and Summary

Scope/caveat on the search itself

I ran targeted searches for the literal string 1060425 (and US1060425) restricted to patent and litigation sources. Two things must be flagged up front:

1. No CAFC docket activity exists or can exist for this patent. US 1,060,425 issued in 1913 and its own record shows it expired April 29, 1930 (Google Patents legal status: "Expired – Lifetime"). The Court of Appeals for the Federal Circuit was not created until 1982, and a 1913 patent cannot be the subject of a 2026 CAFC appeal absent some extraordinary revival event, for which I found no evidence whatsoever. My search returned no CAFC, ITC, district-court, or IPR/PTAB proceeding referencing this patent number. I cannot rule out an obscure 19th/early-20th-century infringement suit, but nothing surfaced, and I will not invent one.
2. The string "1060425" is not unique to this patent. Searches for the bare number also return EP 1060425 A1 / B1 (wavelength division multiplexer/demultiplexer optical device, Corning Inc., inventor Louay Eldada), GB 1060425 A (photographic printing machines, Gretag A.G.), FCC antenna structure No. 1060425 (Effingham, Illinois), and a PCT application number PCT/US1060425. Per your instruction not to auto-correct identifiers, I am reporting these literally as distinct documents — none of them is US 1,060,425. I excluded them from the summary below.

I do not have direct API access to USPTO PatentCenter or the CAFC docket system; results come from web-indexed patent and court-record sources. Where I lack authoritative confirmation, I say so below.

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Bibliographic data (from the patent text, corroborated by Google Patents)

Assignee uncertainty note: the record says "Individual" for both original and current assignee. There is no evidence of assignment to a pottery, brick, or kiln company. Because this is a 1912 filing, pre-AIA assignment records may exist in USPTO microfilm/Assignment Center that are not reflected in the modern index; I could not verify the chain of title beyond the indexed "Individual" entry.

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Abstract

There is no formal abstract. The document predates the statutory abstract requirement (the Patent Act of 1952, 35 U.S.C. § 112, first introduced abstracts for US patents). Google Patents accordingly displays no abstract field for US 1,060,425. The closest authoritative substitute is the specification's own statement of objects:

"to improve the construction of drying apparatus of this type, to obtain a more uniform distribution of heat through the drying chambers, and to utilize the heat present in the drying chambers after the material in the latter has been fully dried."

Structure of the machine (from the specification and Figs. 1–3): eight drying chambers (1–8) arranged around a central hot-air chamber B and a saddle-shaped moist-air collecting chamber C; conduits a (valved at a₁) connect B to each drying chamber and open via transverse slots/orifices at different points along the chamber length; conduits b (valved at b₁) connect each drying chamber to C, leading to a chimney or exhaust blower E via connection D; openings l at alternating ends of adjacent chambers (valved at d) connect chambers in series; dampers c separate chambers 1/2 and 5/6; each chamber has an outer charging door f; bridge pipes g link adjacent chambers. Hot air enters from pipe K.

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Plain-language overview of each independent claim

All nine claims begin "Drying apparatus comprising…" and are therefore all independent — there are no dependent claims in this patent.

Claim 1 — Buried conduits + closely-spaced central chambers.
Central hot-air and moist-air chambers; several drying chambers arranged around them; conduits routed beneath the drying chambers that connect each drying chamber to both central chambers; and those conduits open into the hot-air and moist-air chambers close to one another. Practical effect: the central chambers can be small, saving floor space.

Claim 2 — Distributed hot-air injection.
Same central-chamber / surrounding-drying-chamber layout; the hot-air supply conduits open into each drying chamber at different points along its length (the slots/orifices), giving more even heat distribution. Notably, this claim does not require the conduits to be beneath the chambers.

Claim 3 — Series connection with alternating-end openings.
Central hot-air and moist-air chambers with surrounding drying chambers and connecting conduits; the drying chambers have interconnecting openings located at alternating ends so they can be linked in series successively, plus valves to control those openings. Effect: hot air is forced end-to-end through each chamber, heating it uniformly.

Claim 4 — Series connection + doors + bridge pipes.
Everything in claim 3 (alternating-end valved openings) plus an air-admission door on each drying chamber and bridge pipes joining adjacent drying chambers. The bridge pipes are the heat-recovery feature: opening a chamber's door admits cold air, which is warmed by residual heat and transferred to the next chamber.

Claim 5 — Buried conduits + closely-spaced openings + series/valves.
Combines claim 1's feature (conduits beneath the chambers, opening into the central chambers close together) with claim 3's feature (alternating-end connecting openings and controlling valves).

Claim 6 — Buried conduits + series/valves + distributed injection.
Combines the buried-conduit layout and alternating-end valved openings of claim 3/5 with the claim 2 feature that hot-air conduits open into the drying chambers at different points in their length.

Claim 7 — Buried conduits + distributed injection + doors + bridge pipes.
Conduits beneath the drying chambers, hot-air conduits opening at different points along the chamber length, an air-admission door per chamber, and bridge pipes between adjacent chambers. (Heat-recovery combination without the alternating-end series openings.)

Claim 8 — Buried conduits + series/valves + doors + bridge pipes.
Conduits beneath the drying chambers; alternating-end connecting openings with valves; an air-admission door per chamber; and bridge pipes between adjacent chambers. (The claim-4 combination plus buried conduits — but without the distributed-injection feature.)

Claim 9 — Full combination (narrowest).
The cumulative claim: central hot-air and moist-air chambers; surrounding drying chambers; conduits beneath the drying chambers connecting them to both central chambers; hot-air conduits opening into the drying chambers at different points in their length; drying chambers with alternating-end connecting openings for successive series connection; valves for those openings; an air-admission door per chamber; and bridge pipes between adjacent chambers. This claim requires every disclosed feature at once and is therefore the most easily designed around.

Claim-drafting observation: claims 1–9 form a nested family in which the later claims incrementally add the three disclosed innovations (buried/closely-spaced conduits; distributed slot injection; alternating-end series connection with valves, doors and bridge pipes). US 2,538,363 and US 2,542,607, both cited-by entries from 1946 filings, indicate this disclosure was treated as prior art by later drying-apparatus applicants.

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Confidence and open items

• High confidence on title, inventor, filing date, issue date, application/serial number, expiry, claim set, and classifications — all read directly from the patent specification and the Google Patents record you supplied.
• Medium confidence on assignee: the index says "Individual"; I found no assignment instrument and cannot exclude an unreported transfer.
• No authoritative confirmation of any litigation. I found zero CAFC 2026 (or any-year) docket entries, district-court actions, ITC investigations, or PTAB proceedings involving US 1,060,425. Given the 1930 expiry, that absence is expected rather than surprising. If you have a specific docket number or case caption in mind, supply it and I will search that identifier directly rather than the patent number.

I'll search for litigation involving US patent 1060425.

Let me run a few more targeted searches against litigation databases.

Litigation Search Results: US Patent No. 106,0425

Bottom line: I found no record of any litigation involving US Patent No. 106,0425.

What I searched

I ran targeted queries against general web search plus patent-litigation-oriented sources, using the literal identifiers "1060425," "US1060425," and "10,604,25":

• Unified Patents litigation portal queries (no results returned)
• CourtListener / RECAP and Justia federal docket material
• CAFC / Federal Circuit opinion databases
• General queries pairing the patent number with "litigation," "infringement," "lawsuit," "case," and "docket," and with the inventor name (Jacob Buehrer / Buehrer) and title ("Apparatus for drying pottery and the like")

Every hit that matched the string "1060425" was either (a) the patent itself (Google Patents, PatentHub), (b) unrelated third-party material that merely contains that number (e.g., EP 1060425 A1/B1, a Corning wavelength-division multiplexer patent; a Brazilian government document control code; a Swedish auction lot number; an unrelated PCT application number "PCT/US1060425" cited in US 9,159,635), or (c) unrelated patent cases that happened to surface for other reasons. None involved US 106,0425 as an asserted patent.

Case-by-case table

Why the absence of litigation is unsurprising here

This is a historical patent, and the prosecution history in the record supports the conclusion that no litigation exists:

• Grant/publication: US 106,0425 was granted April 29, 1913, on Application Serial No. 720,722, filed September 17, 1912, to Jacob Buehrer of Constance, Germany (assignee listed as "Individual").
• Expiration: The Google Patents legal-status record shows "Anticipated expiration" on 1930-04-29 — i.e., the full ~17-year term from the 1913 grant ran out, and the patent has been "Expired – Lifetime" for roughly 96 years.
• Prosecution record: The only "citations" in the file are prior-art keyword/classification tags; the only citing documents are three later patents (US 2,538,363; US 2,540,607; US 5,685,710) that cite it as background art. There is no interference, reissue, reexamination, IPR/PGR, or district-court entry associated with the number.

Any infringement suit on a patent that expired in 1930 would have had to have been filed on or before that date and would now be nearly a century old. Old circuit-court patent decisions of that era are partially indexed online, but coverage is incomplete — so I cannot rule out the theoretical existence of a 1913–1930 judgment in a source that has never been digitized.

Caveats on methodology

• Full-text docket databases are not comprehensively searchable for pre-1930 federal cases. CourtListener/RECAP, Unified Patents, and similar tools are built primarily around modern electronic dockets (roughly 2000s onward, with some historical scanned opinions). A 1913–1930 equity suit would only appear if someone had separately digitized the opinion.
• Number-collision risk is high for a 7-digit patent number. As the searches show, "1060425" also matches an EPO publication number, administrative control codes, and unrelated PCT application fragments. I excluded all of those and did not auto-correct the number.
• No contrary evidence was found. Nothing in the search results contradicts the conclusion of "no known litigation"; there simply is no record either way.

Recommended next steps if you need a definitive negative

1. USPTO Patent Assignment Search and the Patent and Trademark Assignment records for Reel/Frame entries naming Serial No. 720,722 or Patent 1,060,425 — assignments often reference co-pending or subsequent litigation.
2. Federal Reporter / Federal Supplement / Federal Cases volumes (F. 1913–1930; F.2d thereafter) via a full-text legal database such as Westlaw, Lexis, or HeinOnline — these are the only reliable way to catch a pre-1930 circuit-court patent decision.
3. Google Books / HathiTrust full-text of volumes covering the 1913–1930 period for the inventor name "Buehrer," since German-owned US patents of that era were sometimes litigated alongside related foreign patents.

If you have a specific case number, court, or party name you believe is associated with this patent, provide it and I will verify it directly — that is the fastest way to confirm or rule out a match, given how poorly pre-1930 dockets are indexed.

PTAB Proceedings — US 1,060,425 ("Apparatus for drying pottery and the like")

Analyst note up front: The structured block in this prompt is dispositive: the USPTO Open Data Portal returns no AIA trial proceedings for US 1,060,425. My independent web checks surfaced none either. Everything below is therefore a "no-activity" report with the doctrinal reason why that result is not merely a database gap — it is structural.

Proceedings overview

Total AIA trial proceedings on file: 0 (0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials). This patent is a 1913 grant — filed 1912-09-17, issued 1913-04-29, statutory term expired 1930-04-29 (Google Patents legal status: "Expired - Lifetime") — which predates the AIA trial regime by a century. There is no defensive posture to compute in the usual sense: no defendant can be asserted against on this patent today, because it has been expired for roughly 96 years and the § 286 six-year damages lookback reaches back only to 2020. The practical relevance of US 1,060,425 in 2026 is as prior art, not as an assertion vehicle.

Proceedings

None. There is no {PROCEEDING_NUMBER} to report, and I will not synthesize one.

For completeness, the following were checked and are not PTAB proceedings:

False-positive warning for anyone replicating this search: the string "the '106 patent" appears constantly in modern PTAB records — e.g., IPR2020-00027 and the Dolby v. Intertrust proceeding over the Intertrust patent that the Federal Circuit addressed on remand (claims 4, 7, 15, 18 held obvious under § 103 over Linjama, Lehrmann, and Tosaki; CAFC appeal noticed 2021-11-05). Those hits concern US 8,370,106 (and, in the Dolby/Intertrust matter, a different '106 altogether). They have no relationship to US 1,060,425. Do not cite them.

Strategic summary

Claim status of US 1,060,425. All claims — 1 through 9, as granted — are UNTESTED in any AIA trial, and simultaneously unenforceable and unassertable because the patent expired 1930-04-29. That is not the same as "sustained": a claim is only "sustained" when a panel has adjudicated it and left it standing. Nothing has been canceled either. The correct characterization is that the entire claim set is a century-old public-domain document. For a defendant, the absence of proceedings here is not the "well-asserted patents eventually attract IPRs" signal — it is the opposite signal: nobody has ever needed to file one, because the patent has been dead since the Hoover administration. The specification's description of the invention (central hot-air chamber B, saddle-shaped moist-air collecting chamber C, conduits a and b beneath the drying chambers, alternating-end valved openings d, bridge pipes g, exhaust blower E) is now, however, citable printed publication art under § 102(a)(1)/pre-AIA § 102(b) for anything filed later.

Estoppel landscape. There is no § 315(e)(2) estoppel of any kind, because no IPR, PGR, or CBM was ever instituted. No petitioner, privy, or real party in interest is barred from anything arising out of this patent. Any ground a modern defendant wants to raise — including grounds that were available in 1913 and never raised — remains available in the district court, subject only to the ordinary rules. Note also that § 315(e)(2) estoppel is a one-way ratchet: it constrains IPR petitioners, not defendants. Here it constrains nobody.

Pattern signals. No repeat petitioner (there is no petitioner at all). No PTAB appeal, so no CAFC docket number to report; I checked CourtListener-adjacent search results and found no Federal Circuit decision involving Jacob Buehrer or this patent. No defensive aggregator — no Unified Patents, RPX, or similar entity has any traceable involvement, and none would have a reason to appear: there is no live infringement campaign to defend against. The only "family" record is the single application US 720,722 and its own publication US 1,060,425 A (Family ID 3128673), with no continuations, divisionals, reissues, or foreign counterparts surfaced.

Recommended next steps

1. If a demand letter cites US 1,060,425, treat it as a fraud/mistake indicator, not an infringement claim. The patent expired 1930-04-29. Any live damages theory would need infringing acts between 1924 and 1930 (35 U.S.C. § 286) and is time-barred many times over. Preserve the letter and consider fee-shifting or § 285/state-law exposure for the sender.
2. If you are defending a modern patent and want to use '425 as art, cite it by its own terms: US 1,060,425 A, published 1913-04-29, at https://patents.google.com/patent/US1060425/en. The strongest passages for a § 103 combination are the alternating-end valved openings d and the series-connection/bridge-pipe g disclosure, which anticipate a great deal of recirculating multi-chamber dryer architecture. There is no IPR estoppel to worry about on that art, but note that art you could have raised in a prior IPR on a different patent is unaffected by this patent entirely.
3. Verification trail if you need to confirm the null result yourself: USPTO PTAB E2E (https://ptacts.uspto.gov/ptacts/) and the PTAB Decisions page (https://www.uspto.gov/patents/patent-trial-and-appeal-board/decisions) — search by patent number 1060425 and by inventor Jacob Buehrer. The ODP structured field is the canonical source and is authoritative here.
4. Do not invent a proceeding number to fill the template. The prompt's "for each proceeding" loop has zero iterations. If you are running this template programmatically, the correct output is an explicit no-activity flag — the same flag the prompt itself instructs you to treat as the default.

Caveat on confidence: I state the 1930-04-29 expiration from the Google Patents "Anticipated expiration" entry for this record and from the 17-years-from-grant term in force for 1913 applications; I did not independently verify a maintenance/lapse record, and pre-1952 patents had no maintenance fees. If you need a litigation-grade expiry date, pull the certified copy from the USPTO PatentCenter linked on the record. The "no PTAB proceedings" conclusion, by contrast, is high-confidence: it rests on the ODP structured data plus two independent web searches, neither of which produced a single AIA petition naming this patent.

I'll verify the assignment-record situation before writing anything up.

Inventors

Additional names on the document that are not inventors: witnesses August Oosterman and Anna Buehrer (name coincidence with the inventor — likely a relative, but the record does not say so; do not treat as a co-owner).

Pattern notes:

• Not a team filing. A single named inventor with no assignee is the classic 1912-era independent-inventor filing. There is no "all inventors departed the assignee within 12 months" signal to evaluate, because there was never an assignee.
• Likely (but unverified) identity match. A 2018 article in Ziegelei-Museum (vol. 35) profiles Jacob Bührer (1828–1914), a Swiss-born brick-industry pioneer from Hofen near Schaffhausen who built the "Zickzackofen" (zig-zag kiln) and ran a Tonfabrik; the article calls him "der schnelle Brenner vom Bodensee" — e-periodica.ch. Same given name, same Swiss citizenship, same Lake Constance geography, same ceramics/brick field. I flag this as probable but not proven: the article's birth year of 1828 would make him 84 at filing, and I have not verified that the Constance "engineer" of the patent is the same person. Treat the biographical color as context, not as an ownership fact.
• Do not rely on the Google Patents OCR fragments for the prosecuting attorney. The scraped text includes garbled strings ("Luger France Attorney", "Bratao & Brondia") that are OCR noise from the printed drawing sheets, not a reliable attorney or correspondent name. I will not treat them as a correspondent of record.

Original assignee

None. The patent issued to Jacob Buehrer as an individual.

• Google Patents lists Original Assignee: Individual and Current Assignee: Individual — US1060425A.
• No company, partnership, or other legal entity is named on the face of the patent, and the specification contains no assignment recital.
• Product embodying the claims: the patent describes a multi-chamber drying plant for pottery, bricks and tiles — eight drying chambers around central hot-air and moist-air chambers, under-floor conduits, alternating-end valved openings, bridge pipes — which is a plant installation, not a shipped article of manufacture. If the inventor is the Hofen/Zickzackofen Bührer, his line of business was brick and clay products (an operating, family-scale manufacturer), not patent licensing. That is consistent with, but not proof of, an operating-company origin.
• Current status of the "assignee": the individual inventor is long deceased (the trade-press biography gives 1914, the year after grant). There is no successor entity of record. The patent expired 1930-04-29 at the end of its full 17-year term — Google Patents legal events list "Anticipated expiration 1930-04-29," i.e. it did not lapse early for non-payment. Public domain since 1930; nothing has been enforceable for ~96 years.

Assignment timeline

USPTO Assignment Center has no recorded assignments for US 1060425. I searched the same records indexed at assignmentcenter.uspto.gov and assignment.uspto.gov/patent for patent 1,060,425 and for application 720,722:

Zero records. No reel/frame, no assignor, no assignee, no conveyance type, no execution date, no recording date, and therefore no correspondent of record on this patent.

• Google Patents' legal-events table for this patent shows only: 1912-09-17 Application filed, 1912-09-17 Priority to US72072212A, 1913-04-29 Application granted, 1913-04-29 Publication of US1060425A, 1930-04-29 Anticipated expiration. It contains no assignment, security-interest, merger, change-of-name, license, or release event at any point.
• The Google Patents "Family" and "Country Status" tables likewise show a single US member with one application and no transferee fields — US1060425A.

Why the absence is expected here and is not itself evidence of anything hidden:

1. The patent is from 1912/1913. The USPTO's automated Patent Assignment Search index is generally understood to cover recordings from 1980 forward; pre-1980 recordings exist only on microfilm/paper and are largely not retrievable through the online index. Absence of a hit is therefore a coverage artifact, not a finding of non-transfer.
2. The patent expired in 1930. Any post-1930 transfer would have conveyed a dead asset; there is no commercial or litigation reason for one to have been recorded.
3. The invention issued to an unassigned individual, so the baseline expectation is that the original owner held it (or that it simply lapsed into the public domain with him).

A caveat I want to state explicitly rather than paper over: an unrecorded, un-indexed, or paper-era transfer cannot be ruled out from the sources available to me. The honest finding is "no assignments are of record in the retrievable databases," not "no assignment ever occurred."

Per the stop rule for this section, the assignment-chain analysis terminates here. The remaining sections are completed only to the extent the (empty) record permits.

Timeline diagram

timeline
    title Ownership of US 1060425
    1912 : Filed by Jacob Buehrer as an individual
         : No assignee named on the application
    1913 : Patent issued 29 April
    1930 : Full 17 year term expires
         : No assignment on record at any point

NPE / troll-pattern signals

All eight signals are assessed against zero assignment records. Every "not present" below is a statement about the absence of evidence in the retrievable record, never a negative finding about history.

1. Shell-entity transfer — not present. No transfer of any kind is recorded. There is no "IP / Holdings / Licensing / Ventures" assignee, no registered-agent address, and no single-purpose LLC anywhere in the chain — Google Patents shows Current Assignee: Individual for the entire life of the patent. The only entity-like designation on the document is the boilerplate "Individual."

2. Known asserter in the chain — not present. No assignee of record to compare against the Acacia / Marathon / Intellectual Ventures / Wi-LAN / Conversant / Vringo / Pendrell / Round Rock / Spangenberg lists. The patent's own priority date (1912) precedes every entity on those lists by roughly seventy years, and the patent expired in 1930, long before the modern NPE model existed.

3. Repeat correspondent across the chain — not present. A correspondent of record is a property of a recorded assignment; with zero recorded assignments there is no correspondent, and therefore no recurrence to test. I specifically decline to treat the garbled OCR strings on the drawing sheets ("Luger France Attorney") as an attorney of record — that would be fabricating a correspondent.

4. Cascading transfers — not present. No consecutive transfers at all, let alone chained LLCs within 24 months.

5. Pre-litigation transfer — not present. No assignment, and no infringement litigation is identifiable. (Any 1913–1930 enforcement would predate modern docketing systems and would not appear in the modern sources I can reach — an evidentiary gap, not a negative finding.)

6. Bankruptcy fire-sale — not present. The original "assignee" is a natural person, not a company; individuals do not file Chapter 7/11 patent-sale proceedings of the Kodak/Nortel type. No bankruptcy, receivership, or estate sale appears in the record.

7. Privateering — not present. Requires an operating company transferring to an NPE to assert on its behalf. There is no transfer and no operating-company assignor.

8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at a deceased individual inventor and then at expiry.

One genuinely inverse observation worth recording: the patent was cited by three later US patents — US2538363A (Drying apparatus, 1951), US2542607A (Dehydration apparatus, 1951) and US5685710A (tobacco curing barn, 1997). Those are citations to the 1913 disclosure, not conveyances, and they confer no ownership. They do show the patent remained meaningful as prior art decades after expiry — which is why it is in the databases at all.

Verdict

Insufficient data (specifically: no assignment records of any kind exist in the retrievable databases).

Justification: the USPTO Assignment Center returns zero entries for US 1,060,425 / app. 720,722 — no reel/frame, no assignor, no assignee, no correspondent — and Google Patents' legal-events table for the same patent shows only filing (1912-09-17), grant and publication (1913-04-29) and term expiry (1930-04-29), with no transfer event ever recorded. With no assignment, there is no shell-entity link, no asserter, no repeat correspondent, and no pre-suit transfer to cite, so no NPE signal can be marked present on evidence. The chain consists solely of an unassigned individual inventor filing in 1912 and a patent that ran its full seventeen-year term and entered the public domain in 1930 — the "no records" outcome the instructions anticipate, and not an NPE scenario.

Verification: search patent number 1060425 at USPTO Assignment Center or USPTO Patent Assignment Search — expect an empty result set. The authoritative document text and legal events are at patents.google.com/patent/US1060425/en.

I'll search for the specific patent and its citation records.

Let me verify the citation records from additional sources.

1. Patent identified (literal match, no auto-correction)

US 1,060,425 A — "Apparatus for Drying Pottery and the Like"

• Inventor: Jacob Buehrer (spec body also printed as "JACOB BHRER"; OCR of the original is inconsistent — I have not "corrected" it)
• Serial No. 720,722; Application No. US72072212A
• Filed: 1912‑09‑17 · Granted/Published: 1913‑04‑29
• Assignee: Individual (Constance, Grand Duchy of Baden, German Empire)
• Legal status: Expired – Lifetime (anticipated expiration 1930‑04‑29)
• Source: https://patents.google.com/patent/US1060425/en (fetched 2026‑09‑27)

Claims 1–9 are all apparatus claims (claim 1 = central hot‑air + moist‑air chambers with under‑floor conduits opening into those chambers in close proximity to each other; claim 2 adds hot‑air conduit openings at different points along the chamber length; claim 3 adds alternating‑end connecting openings + valves; claim 4 adds air‑admission door + bridge pipes; claims 5–9 are combinations of these features).

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2. Mandatory framework note before the citation list

There is an important asymmetry you must not gloss over:

• The public record for US 1,060,425 contains no examiner‑cited prior‑art list and no "References Cited" (backward) section. This was a 1912 ex parte grant; the printed specification (Vol. "Copies of this patent may be obtained for five cents each…") contains no citation block at all.
• What the databases do show is a "Cited By (3)" list — i.e., forward citations (later patents that cite this one), plus a "Similar Documents" list of same‑classification patents.

Therefore the three "patent citations for 1060425" that you asked me to work through all post‑date US 1,060,425 and legally cannot anticipate it under 35 U.S.C. § 102(a)/(b) or pre‑1952 law. The correct § 102 direction for these three is reversed: US 1,060,425 is potential prior art against them. I give the mapping for both directions below so the record is complete.

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3. The three recorded citations of US 1,060,425 (forward citations — "Cited By")

Source for all three: the "Cited By (3)" table at https://patents.google.com/patent/US1060425/en

Bottom line for this group: zero of the three cited references anticipates any claim of US 1,060,425. None is prior art to it at all.

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4. The references that actually could be prior art (the "Similar Documents" set)

These are the pre‑1912 publications surfaced by classification (F26B 7/00 / F26B) alongside US 1,060,425. These are the only candidates with a correct § 102 direction. I list dates and titles as they appear; I flag that I have not read the bodies of these documents, so the claim mapping is potential, not established.

Source: "Similar Documents" table, https://patents.google.com/patent/US1060425/en

Most probable § 102 anticipators, by claim (to be verified against the documents themselves)

• Claim 1 (central hot‑air + moist‑air chambers; ring of drying chambers; under‑floor conduits opening in close proximity): the "close proximity" limitation is the distinctive element. US 510,491 and US 634,916 are the best candidates; verification of their conduit routing is required.
• Claim 2 / claim 6 (hot‑air conduit discharging at different points along the chamber length): US 772,767 and US 996,943 are the candidates.
• Claim 3 / claims 5, 6, 8, 9 (alternating‑end connecting openings + valves): the alternating‑end geometry plus the series flow end‑to‑end limitation is the narrowest contribution. US 634,916 and US 837,547 are the candidates; no listed similar document is described as using strictly alternating ends.
• Claim 4 / claims 7, 8, 9 (air‑admission door + bridge pipes between adjacent chambers to scavenge residual heat): I found no listed pre‑1912 reference described as using bridge pipes for heat recovery between drying chambers — this appears to be the strongest novel element of the patent, consistent with the stated object "to utilize the heat present in the drying chambers after the material in the latter has been fully dried."

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5. Relevant contemporaneous art outside the patent citation record

One item in the search results is directly on point as background to the "series of drying kilns coupled by valved flues" concept and is worth logging for completeness, though it is a literature entry, not a patent citation of US 1,060,425:

"445,817, 13.6.23. — The units of a series of drying kilns are coupled to one another by a series of flues closed by valves which permit of the hot air and flue gases being led as required from one chamber to another or to the stack. The air used for drying is preheated." — A. R. Powell (1928 compilation), https://archive.org/download/1928A/1928_B.pdf (p. 445)

Note this is dated 1923 (or as compiled 1928) — later than the 1912 filing, so it cannot be § 102 art against US 1,060,425 either.

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6. Honest limitations of this answer

1. I could not retrieve a USPTO examiner citation list, because none exists for this patent in the available sources; the Google Patents record shows only "Cited By" (forward) and "Similar Documents."
2. I have not read the full text of the "Similar Documents" — the claim mapping in § 4 is inferred from titles, dates, and classification (F26B), and is expressly potential, not established.
3. I did not auto-correct any identifier: "US1060425", "US72072212A", "Serial No. 720,722", "US2538363A", "US2542607A", "US5685710A" are all reproduced exactly as retrieved. Note the OCR inconsistency in the specification between "Jacob Buehrer" and "Jacob Bhrer," and the examiner name in the CPC listing "BUEHRER JACOB" versus the FPO-style "Buehrer" — I have not harmonized these.
4. To convert § 4 from "potential" to "established," each of US 324,882; 510,491; 634,916; 554,743; 672,372; 772,767; 837,547; 996,943; 480,253 should be pulled in full text and element‑by‑element charted against claims 1–9. If you want, I can run that chart for the two closest-in-time references (US 996,943 and US 510,491) next.

I'll ground the analysis by checking a few of the listed references before reaching conclusions.

Two references are central to the strongest combinations, so let me confirm their disclosures.

Obviousness Analysis — US 1,060,425 A

"Apparatus for drying pottery and the like" — Jacob Buehrer, filed 17 Sep 1912, granted 29 Apr 1913, expired 29 Apr 1930. (https://patents.google.com/patent/US1060425/en)

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1. Preliminary caveats (read these first)

(a) The § 103 framework is anachronistic for this patent. 35 U.S.C. § 103 was not enacted until 1952. At the 1912–13 filing/grant date, patentability was judged under R.S. § 4886's "invention" requirement (Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1850)), and during this patent's 17‑year life the controlling combination-patent test was Great Atlantic & Pacific Tea Co. v. Supermarket Equipment Corp., 340 U.S. 147 (1950) (old elements must "coact" to produce a new result). Applying § 103 here is a retrospective exercise, governed today by Graham v. John Deere Co., 383 U.S. 1 (1966) and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007). The analysis below is conducted under the modern standard as requested.

(b) What the page actually supplies as prior art. The page gives no examiner-cited "References Cited" list. It supplies (i) prior-art keywords (air, chambers, drying, chamber, hot), (ii) a "Cited By (3)" list, and (iii) a machine-generated "Similar Documents" list. The two are not the same thing:

The six struck-out references are unusable in any § 103 ground; the three "Cited By" items in particular are later improvements on this disclosure, not prior art to it.

(c) Verification status. I verified the full text of only two references (US510491 and US634916, plus an incidental hit on US319562/Cohrs, which is not on the page). For the rest, the page supplies titles and dates only; my mapping from a title to a disclosure is an inference, and I flag every place where that inference carries the weight. I could not verify the disclosures of US996943 (the temporally closest reference), US837547, US324882, or US480253, because my searches for them were cut off. Statements below keyed to those references should be treated as unconfirmed.

(d) A classification anomaly worth noting. The page assigns this patent to D06F73/02 (garment smoothing/creasing apparatus, textiles) and F26B7/00. D06F is plainly an erroneous algorithmic assignment for a pottery drier; the operative art is F26B/F27B (driers and kilns). A searcher of ordinary skill in 1912 — or today — would search the brick, tile and ceramic kiln/drier art, which is exactly where the "Similar Documents" line up. This matters because it confirms the field of the invention is the brick/tile/pottery drying kiln, not textile finishing.

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2. The claims, decomposed

All nine claims are independent apparatus claims in cumulative form (standard 1913 drafting style). Reducing them to elements:

Claim 9 is the superset (E1+E2+E3+E5+E6+E7+E8). Claims 1 and 7 are the leanest combinations; claim 9 is the most cumulative.

The specification's own statement of purpose is critical to the § 103 analysis, because it concedes that each element produces only its own expected effect:

• under-floor conduits → "the conduits may open into the hot-air and moist-air chambers in close proximity to each other... thereby economizing space" (pure layout economy);
• multiple slots → "a better distribution of hot air in the drying-chambers is effected";
• alternating-end series dampers → "the hot-air is compelled to pass from end to end of each drying chamber and thus uniformly heat up the latter";
• doors + bridge pipes → "to utilize the heat present in the drying chambers after the material has been fully dried."

No element is described as producing a result different in kind from its individual contribution.

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3. Reference-by-reference mapping

US510491 — Brick-drier, Isaac Stripe, granted 12 Dec 1893 (verified; https://patents.google.com/patent/US510491, PDF at patentimages). Discloses: multiple brick kilns A; an underground pipe or conduit E located beneath the bottoms of the kilns, with branch pipes/openings F "connect[ing] with the bottoms of the kilns"; dampers in the underground pipes "between each two kilns, thereby providing a means for regulating the heat, or in other words, tempering the air conveyed to the drying kiln"; a slide K′ for tempering; each kiln having an "ordinary door or opening"; and branch pipes L "for passing or conveying the heat from a drying off kiln past, or by, the next adjacent kiln" — i.e., heat-recovery from a just-dried/finished chamber into the next chamber. Also expressly "utilizing all of the heat escaping from the cooling-off kiln."
→ Maps to E3 (partly), E6 (valved inter-chamber connections), E7, and the function underlying E8.

US634916 — Drying-kiln, George W. Sharer, granted 17 Oct 1899 (verified; https://patents.google.com/patent/US634916). Discloses: "a series of separate drying-chambers"; "a set of smoke-flues arranged below the floor of the chambers"; "means for conducting heated air directly into each drying-chamber at various points in its length" via ducts d, d′, d², d³, d⁴ that "terminat[e] in the floor a² of the chamber" at successively different points (d⁵, d⁶, c); offtake-flues communicating from the bottom of each chamber to a stack, with a vapor-chamber at the feed end and "means for cutting off the direct draft" so moist air is drawn off through the floor-level flues.
→ Maps to E3, E4 (co-located supply and offtake conduits), and directly to E5.

US324882 — Apparatus for the utilization or disposition of surplus or waste heat in pottery-kilns, 1885 (title only; unverified). Title alone establishes the pottery-kiln art's pre-existing concern with E8-type heat recovery and with the central-collection-of-heat concept.

*US837547 — Combined continuous kiln and drier, 1906; US672372 — Kiln for burning sewer-pipe, brick, &c., 1901; US480253 — Drying kiln, 1892; US772767 — Kiln for drying lumber, 1904* (titles only; unverified). These supply the continuous/series kiln background (E2, E6) — a bank of chambers about and across which a single induced draft is drawn serially through valved openings.

US996943 — Drier, 1911 (title only; unverified). Closest in time to the filing; I could not confirm its disclosure and therefore do not rely on it in any ground below.

Not on the page but located during verification: US319562, Cohrs, Drying Apparatus, granted 9 Jun 1885 — expressly discloses "a circular kiln for burning bricks, lime, or other goods, in which the drying-chambers surround the kiln in a circular series," with the stated object of "utilization, in an effective and economical manner, of the waste heat of kilns and furnaces for drying purposes." This is the single best reference for E1+E2 and I flag it as one an examiner should have found; since it is outside the supplied list, I keep it in a separate tier below.

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4. Grounds of rejection under § 103

Ground I — Claims 1 and 5: US510491 + US634916 (+ US324882/US837547 for E1/E2)

Rejection: Claims 1 and 5 are obvious over Stripe in view of Sharer, further in view of the central-chamber references.

• Stripe teaches the under-floor conduit network linking a bank of chambers, individually valved, with a door on each chamber, and with heat from a finished chamber transferred onward to the next (E3 in part, E6, E7, E8-function).
• Sharer teaches the same under-floor ducting convention with hot-air supply and moist-air offtake conduits both terminating at floor level, and supply at multiple points along the chamber (E3, E4, E5).
• The central hot-air/moist-air chamber with surrounding chambers (E1/E2) was a known kiln layout in the same art.

Motivation (KSR factors): (i) Same field of endeavor and same problem — drying green clay ware in chambers with ducted heated air. (ii) The patent's own asserted advantage for E4 — "enabling comparatively small central chambers to be employed, thereby economizing space" — is a design incentive/market force, not a technical discovery; KSR squarely holds that "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions." (iii) Both references address the recognized need to "regulate the heat, or in other words temper the air" (Stripe) and to distribute heated air "at various points in [the] length" (Sharer). (iv) The result is a mere rearrangement and co-location of conduits — MPEP 2144.04 (arrangement of parts, change of form, mere duplication of parts, a change in shape).

The only limitation not squarely met by a verified reference is the "in close proximity to each other" geometry of E4 — and that is a pure locational/space-economy expedient with no new coaction.

Ground II — Claims 2, 6, 7 and 9 (E5): US634916, alone or with US510491

Rejection: The E5 limitation is disclosed verbatim in substance by Sharer: "means for conducting heated air directly into each drying-chamber at various points in its length," with the several air-ducts terminating in the chamber floor at successive points. Stripe's adjustable slide K′ supplies the control aspect.
Motivation: Uniform distribution of heat through a drying chamber to avoid uneven drying, cracking and checking of pottery and brick was the recognized problem of the art; delivering the same air through multiple spaced orifices is the ordinary mechanical answer (MPEP 2144.04(IV), "change in arrangement"; In re Kerkhoven, 626 F.2d 846 (CCPA 1980)). The patent concedes the result is merely "a better distribution."

Ground III — Claims 3, 4, 5, 6, 8, 9 (E6, E7, E8): US510491 + the continuous-kiln references (US837547, US672372, US480253, US772767)

Rejection: Stripe discloses valved, individually controllable connections between each pair of chambers in an underground conduit, an access door per chamber, and branch pipes L that carry the hot exhaust of one chamber past/into its neighbor — the functional equivalent of the claimed bridge pipes. The alternating-end placement of those openings (E6) and the bridge-pipe form (E8) come from the continuous-kiln art, where drawing a single induced draft serially through a bank of chambers is the defining scheme.
Motivation: Connecting kiln chambers in series with dampers arranged so that the gas path traverses each chamber from end to end is the classic continuous-kiln teaching; it is the reason green ware is preheated and waste heat is not thrown away. One of ordinary skill would adopt alternating (serpentine) ends because that is the only arrangement that forces the air "from end to end of each drying chamber," which is precisely the result the patent attributes to it. Combining it with Stripe's heat-recovery branch pipes is a predictable aggregation.

I must flag candidly: I could not verify an "alternating ends" disclosure in a specific reference from the page's list, because my searches for US837547/US480253 were truncated. E6 is therefore the limitation with the weakest verified evidentiary support in this analysis; it is also the limitation most likely to have been the applicant's actual point of novelty.

Ground IV — Claims 4, 7, 8 and 9 (E7+E8 combination): US510491 is near-dispositive on the function

Stripe's express purpose is "utilizing all of the heat escaping from the cooling-off kiln," transferring it through the underground pipe and branch L to the adjacent chamber to be dried, with each chamber having a firing/drying door. The Buehrer specification states the identical object: "on opening the usual end charging door, cold air will enter and be heated in the drying chamber and from thence pass through the bridge pipe to the next drying chamber where it mixes with the hot air coming from the central hot air chamber." The difference is that Stripe's chambers are kilns in a row and Buehrer's are drying chambers around a central duct. That is a change of situation/location of parts with no change in operation — the paradigm of MPEP 2144.04 and of Anderson's-Black Rock, Inc. v. Pavement Salvage Co., 396 U.S. 57 (1969).

Ground V — Claim 9

Claim 9 is the cumulative superset of every limitation above. Under Kerkhoven and MPEP 2144.04(V)–(VI), adding further old elements to an already-obvious combination does not impart patentability where each added element performs its own independent function and there is no asserted or evidenced coaction. Claim 9 is the most vulnerable claim in the patent.

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5. The Graham secondary considerations do not rescue the claims

The record on this page shows no evidence of commercial success, long-felt but unmet need, failure of others, copying, unexpected results, industry praise, or licensing. To the contrary, the specification's recitation of objects reads as a list of ordinary, predictable advantages; and the alleged space-saving benefit of E4 is expressly a matter of "economizing space," not of any changed mode of operation.

The strongest argument available to a defender is the specific saddle-shaped moist-air chamber C "extending over and on both sides of the hot air chamber B." That argument fails at the claim-charting stage: none of claims 1–9 recites a saddle shape. The claims recite only a generic "central moist-air chamber." The unclaimed geometry cannot be read into the claims to supply non-obviousness.

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6. Bottom line

Framing note: novelty (§ 102) probably survives — no single reference on the page teaches the combination of a central hot-air chamber and a central moist-air chamber with drying chambers arranged around them and co-located under-floor conduits. That is precisely why the correct attack is § 103: the invention is a rearrangement of known ducting and valving parts, each performing its own well-understood function in the same art, in a new spatial relationship whose only asserted benefit is compactness. Under KSR, the combination is obvious; under the Great A&P Tea coaction test that actually governed during this patent's life, the absence of any new co-action among the elements points the same way.

Caveats to carry forward: (1) § 103 is an anachronism for a 1913 patent; (2) six items on the page's "Cited By" list are legally unavailable as prior art; (3) of the ~24 usable references on the page, I verified the disclosure of only two (US510491, US634916) — all mappings for US996943, US837547, US324882, US480253, US672372 and US772767 are title-based inferences and are unconfirmed; and (4) the Cohrs reference (US319562) that best supports E1/E2 is not on the page and would need to be added to the record.