US 2214350

I'll verify the record against live sources before summarizing, since you asked specifically for USPTO/CAFC checks.

Verification note first

I searched for the exact identifier 2214350. The only hits returned were unrelated to this patent:

• EP 2214350 A1 — a European publication (appears in a PCT search report; the OCR attributes it to "HUAREI/HUAREI TECHNOLOGIES CO., LTD.") — a different jurisdiction and number, not US 2,214,350.
• 2214350 ALBERTA INC — an Alberta corporate registry number.
• Tribunal administratif de Paris n° 2214350 (2022) and STJ AgInt no AGRAVO EM RECURSO ESPECIAL Nº 2214350 (Brazil) — unrelated case numbers.

No CAFC 2026 docket, ITC, or district court activity for US 2,214,350 appeared in any query. I cannot treat that as an authoritative negative — absence of search hits is not proof of no litigation — but there is no evidence of any 2026 CAFC appeal involving this patent. Note also that US 2,214,350 issued in 1940 and expired 1957-09-10, so an appeal would have to concern a much later patent claiming priority to it (none is recorded).

I am treating the supplied Google Patents full text as authoritative. I am not auto-correcting any identifiers below; where the OCR is corrupt I say so explicitly.

Bibliographic record — US 2,214,350

Abstract: There is no abstract of record. The document is a 1940 patent predating abstract requirements, and the Google Patents record contains none. Anything labeled an "abstract" for this patent would be a modern editorial summary, not part of the original grant.

Third-party citations (Cited By, 3): US2415608A (1944-06-19 → 1947-02-11, Grant Oil Tool Company, "Hydrostatic bailer for wells"); US6695053B2 (Esp Environmental Service Products, "Bailer discharging device…"); US20090101746A1 (Lanz, "Winder for a material web…" — evidently spurious).

References made in the specification: Erwin and Sweet Nos. 2,059,629 (1936-11-03) and 2,133,383 (1938-10-18), and, as examples of alternative actuators, Erwin 2,059,631 (1936-11-03) and Santiago 2,098,520 (1937-11-09).

Certificate of correction (Oct. 15, 1940): directs striking out the words "tubular body comprising two separable portions with opposing" from page 1, first column (OCR reads "lines 25 and 2h."). The certificate number is OCR-corrupted as "12,21%550" and the date as "191m/19140" — artifacts I am not correcting.

Plain-language overview of the claims

The structural core: an upper low-pressure (atmospheric) chamber sealed by a frangible disk 14; the disk is held between an upwardly facing seat on tubular sleeve 21 and a downwardly facing, screw-adjustable seat ring 15; a union coupling 25 with interrupted threads 31/32 draws the two body halves together; a side opening 13 in connector member 12 serves double duty as disk-insertion port and discharge port; and a ball check valve 44 sits below, on seat 43, opening upward toward the chamber. A hammer plunger 46 (with bottom shoe 55) is pushed up by the well bottom; it lifts ball 44, which lifts the passaged plunger 60 (serrated head 63) to break the disk. All 13 claims are independent and cover variations on these themes.

1. Broadest claim. Tubular body, one end a low-pressure chamber; a removable closure forming an end wall of that chamber; a check valve located toward the other end that opens to pass fluid toward the closure and closes against reverse flow; means to open the valve; and the closure is removed by the check valve's opening movement (the valve and the closure-remover move together).
2. Same as claim 1, but the closure-removing means is specifically a longitudinally passaged plunger reciprocable between valve and closure, moved by the valve's opening stroke.
3. Oriented vertically: upper portion is the low-pressure chamber, the closure is its lower end wall, and there is an upwardly facing valve seat below the closure; the valve seats downwardly to block downward flow; reciprocable means below the valve lifts it off the seat; a passaged plunger resting on the valve between valve and closure is lifted to engage and remove the closure.
4. Two-part body genus: the body has two relatively longitudinally movable portions whose opposing ends carry opposing seats; one portion forms the low-pressure chamber; the closure is held between the facing seats; releasable means holds the portions in opposition with the closure between them; a check valve prevents flow away from the low-pressure chamber; plus means to remove the closure.
5. Claim 4 plus the specific holder: a tubular member attached to one body portion, running longitudinally over the opposing seated ends, with a side-wall opening through which the closure is inserted onto one of the body ends (i.e., opening 13).
6. Claim 4 with the check valve in the other body portion, closing by movement away from the low-pressure chamber and closure; means to open it; and reciprocable means between valve and closure moved by the valve's opening stroke to remove the closure.
7. Claim 6 where the reciprocable means is a tubular plunger.
8. Combines the side-wall-opening tubular holder of claim 5 with the check valve and valve-actuated closure-remover of claim 6 (note: the printed text of claim 8 in this record is OCR-garbled, with a duplicated fragment — the corrected reading is the one per the certificate of correction).
9. Detailed apparatus claim: upper body portion closed at top, with a tubular coupling member at its lower end having a side-wall opening; an adjustable-downwardly-facing annular seat in the coupling member; lower body portion with an upwardly facing annular seat on its upper end; union means to draw the two portions together endwise; a removable closure disk seated and held between them; an upwardly opening check valve preventing downward flow; and means to remove the closure.
10. Claim 9 refined: the downwardly facing seat is vertically adjustable; the check valve is in the lower body portion below the closure; means for raising the valve; and the closure is removed by virtue of the valve's upward opening movement.
11. Restates claim 1 in "movable with" language: a check valve element that opens by moving toward the closure and closes by moving the opposite way, with means within the body movable with the valve element in the opening direction to remove the closure.
12. Narrowest-structure/broadest-scope variant: two movable body portions with opposing seats, closure held between them, releasable holding means, and means to remove the closure — no check valve required at all.
13. Claim 12 plus the tubular holder with the side-wall insertion/discharge opening.

Observation worth flagging: every one of the 13 claims is drafted as an independent claim ("A well tool of the character described, comprising…"). There are no dependent claims, and claim 12 notably omits the check valve entirely, making it an outlier in scope.

Uncertainties (stated explicitly)

• Assignee conflict. The printed patent says "assignor to John Grant, Los Angeles, Calif.," while the Google Patents metadata says "Individual" for original and current assignee. I do not have an authoritative chain of title. The later US2415608A (Grant Oil Tool Company) is cited by this patent and shares the "Grant" name, but I will not assert a corporate lineage from that alone.
• OCR corruption in the supplied text (apparent "Filed Feb. 20, 1959"; "lines 25 and 2h"; "12,21%550"; garbled claim 8). These are transcription artifacts; the authoritative filing date is 1939-02-20.
• No litigation found. I found no CAFC 2026 (or any other) docket activity. Because a number-only search surfaces several unrelated entities that share the digits "2214350," I want to be clear: I did not conflate those with US 2,214,350, and I have no authoritative confirmation that litigation records were exhaustively searched.

Source for the full text and metadata: https://patents.google.com/patent/US2214350/en

I'll search litigation-focused sources for this patent number before answering.

Those hits all concern unrelated patents sharing the "'350" shorthand. Let me search the litigation-specific databases and try the patent's actual subject matter.

Litigation search result: US 2,214,350 — NO LITIGATION FOUND

Bottom line: I found no litigation of any kind involving US Patent 2,214,350. No district court case, no CAFC appeal, no ITC investigation, no PTAB proceeding, and no PTO litigation-related filing. I am reporting this as a documented negative result on the searches I ran, not as a certified exhaustive clear.

What I searched and what came back

Critical disambiguation — the "2214350" trap

This number collides with several unrelated entities that I explicitly did not conflate with US 2,214,350:

• EP 2214350 A1 — European publication, Huarei Technologies (per the PCT search report OCR citation)
• CA 2214350 A1 — "Polyol ester compositions with unconverted hydroxyl groups"
• RU 2214350 C1 — spacecraft two-phase heat-transfer filling method
• DE 2214350 A1 — winding apparatus for webs/films
• 2214350 ALBERTA INC — Alberta numbered corporation (No. 2022143503)
• U.S. Pat. No. 8,759,350, 10,401,350 — Otsuka and Sysmex/Roche patents, constantly abbreviated "'350" in briefs

Every litigation-looking hit traced to one of the above or to unrelated serial numbers. None is US 2,214,350.

Why a null result is expected here

Three structural reasons, stated plainly:

1. The patent expired on 1957-09-10 — 17 years from the 1940-09-10 issue date, consistent with the pre-1995 term. An expired patent cannot support an injunction and is a poor damages vehicle.
2. No post-1957 continuation/priority chain is recorded. The Google Patents record shows only one family member (US257428A → US2214350A) and no domestic priority descendants. The three "Cited By" documents (US2415608A, US6695053B2, US20090101746A1) are forward citations, not family members — and US20090101746A1 (Lanz, "Winder for a material web") is plainly a spurious match to the digit string.
3. The Art Unit / classification is E21B37/00 (borehole cleaning), pre-1995 vintage. Reconstruction of 1930s–40s litigation would require paper-era court records, which are essentially absent from the online databases I queried.

Important caveat on this null: a number-only search is exactly the scenario where false negatives hide. The 1950s would predate PACER entirely (PACER coverage is generally 1988–present for most districts, with scattered earlier data), and pre-1982 patent appeals went to the regional Courts of Appeals or the Court of Customs and Patent Appeals — none of which are reliably indexed in modern litigation databases. So I can say with reasonable confidence that no modern (online-database-era) litigation exists, but I cannot rule out a 1940s–50s infringement suit that was never digitized. I have not searched those paper records.

Recommendation if you need a definitive negative

If this is for a clearance or diligence opinion where the null must be airtight, the authoritative sources would be:

• Docket Navigator or RPX Insight (paid; both index pre-1988 data to varying degrees)
• The USPTO Patent Assignment Search at assignment.uspto.gov — to trace any recorded transfer from James J. Santiago / John Grant, which is where a suit defendant would typically first surface
• Westlaw / Lexis full-text case databases for the 1939–1960 window
• The Court of Customs and Patent Appeals published volumes, if an appeal is suspected

One litigation-adjacent fact worth flagging from the record, though it is not litigation: US2415608A, "Hydrostatic bailer for wells," was filed 1944-06-19 and issued 1947-02-11 to Grant Oil Tool Company. It cites your patent. The printed patent names the assignee as "John Grant, Los Angeles, Calif." That naming coincidence, combined with the "Grant" corporate assignee on the later bailer patent, hints at a commercial relationship worth investigating for context — but I have no evidence it produced any lawsuit, and I am not asserting a corporate lineage from the name match alone.

Sources checked: Google Patents US2214350A (https://patents.google.com/patent/US2214350/en); search results surfaced from Justia, CourtListener/RECAP, RPX Insight, and PTAB/USPTO document repositories, all of which returned only the unrelated matches enumerated above. The Unified Patents litigation caselist query returned no records for this number.

I'll verify the "no PTAB activity" default against live sources before writing.

Let me run additional targeted checks to be thorough.

PTAB proceedings on file — verification note

I sourced the canonical list from the structured "PTAB proceedings on file" block supplied for this working session, which reports that the USPTO Open Data Portal API returns no AIA trial proceedings for US 2,214,350 as of the most recent ingest. I then ran live searches to try to surface anything the ODP hadn't indexed.

Result: the structured block is confirmed. No IPR, PGR, or CBM proceeding number could be located for this patent. Every search hit on the digits "2214350" resolved to a different patent or a different number entirely, and I did not conflate them:

I am not treating any of those as activity on this patent. The absence is a genuine negative as to the sources I could reach, not a fabricated one.

Proceedings overview

Total AIA trial proceedings on US 2,214,350: zero. Breakdown: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials — and the bottom line for a defendant is that this is not a defensive-posture question at all: the patent issued 1940-09-10, expired 1957-09-10 ("Expired – Lifetime," anticipated expiration per the Google Patents record), and its last possible infringement-recovery window under 35 U.S.C. § 286 closed in 1963 — roughly 49 years before the first AIA petition could be filed (2012-09-16). There is nothing left to assert and no one with standing to petition against it. If you have received a demand letter citing "2214350," the cited number is almost certainly not this patent.

Per-proceeding analysis

There are no proceedings to analyze, so I will not manufacture the per-proceeding template. Instead, here is the closest thing to an evidentiary record, and why the null result is structural rather than incidental.

No proceeding — canonical list empty (USPTO ODP)

• Type: N/A — no Inter Partes Review, Post-Grant Review, or CBM proceeding on file
• Filed: N/A
• Status: N/A (structured block: "returns no AIA trial proceedings for this patent as of the most recent ingest")
• Judge panel: None — no panel has ever been assigned
• Petition grounds: None. No petition has ever challenged claims 1–13, so there is no § 102, § 103, or § 112 ground of record to report.
• Institution decision: None. No § 314(a) or § 324(a) determination has issued.
• Final Written Decision: None. No claim of US 2,214,350 has ever been canceled in an AIA trial, and none has ever been sustained in one. Claims 1–13 stand exactly as the certificate of correction left them (the Oct. 15, 1940 certificate striking "tubular body comprising two separable portions with opposing" from page 1, col. 1 — OCR-fouled as certificate no. "12,21%550").
• Settlement / termination: N/A — no proceeding existed to terminate.
• Appeal: No Federal Circuit appeal. I found no CAFC docket, opinion, or CourtListener entry for US 2,214,350. Consistent with the earlier section of this analysis, there is no 2026 CAFC activity.
• Defensive value: None accrues from PTAB, because none exists. The defense here is expiration, which is categorically stronger than any IPR: a patent that expired 1957-09-10 cannot support a live infringement claim against a 2026 product, so there is no case in which an IPR-based defense would need to be deployed. Confirm the demand letter's patent number before spending anything on this.

Why the empty docket is structural, not luck

Three independent reasons no petitioner could ever have filed:

1. Temporal impossibility. The AIA created IPR/PGR/CBM effective 2012-09-16. This patent expired 1957-09-10 — 55 years earlier. The pre-AIA inter partes reexamination statute (35 U.S.C. §§ 311–318, 1999 version) postdates it by 42 years, and I found no ex parte or inter partes reexamination certificate (e.g., a "B2" or "C2" number) for it either.
2. No case or controversy. Even after Apple Inc. v. Gesture Technology Partners, LLC, 127 F.4th 364 (Fed. Cir. Jan. 27, 2025) (precedential) — which confirmed that the PTAB does have jurisdiction over expired patents because an IPR is a "second look" at a public-rights grant and the patentee retains limited rights such as past damages — the petitioner's standing rests on the possibility of past-infringement liability. Here that possibility ended with the § 286 six-year bar in 1963. Gesture does not help a petitioner who faces zero exposure.
3. No commercial incentive. There is no product, no license, and no entity collecting royalties on a 1940 well bailer. Contrast the Cited By trail — US2415608A ("Hydrostatic bailer for wells," Grant Oil Tool Company, 1947) — which shows this was an influential patent, not a asserted one.

If, contrary to all of the above, a demand letter purports to rest on a live "2214350," the discrepancy is worth raising directly: the AIA trial regime has never touched this patent, and it could not have.

Strategic summary

Claim status across the patent: 100% UNTESTED. None of claims 1–13 has been canceled, none has been narrowed by a PTAB adverse judgment, and none has been confirmed over art. There is no "surviving claims" list to give you, because nothing was ever removed. That is not a statement that the claims are strong — it is a statement that the Board has never evaluated them. The earlier section of this analysis correctly flagged that claim 12 omits the check valve entirely and is the scope outlier; that observation remains an academic one, since the patent is unassertable.

Estoppel landscape: none exists, and § 315(e)(2) is irrelevant. No FWD has issued, so no petitioner, real party in interest, or privy is estopped. Conversely, there is no estoppel benefit to inherit — a defendant today cannot point to a prior petitioner's win because there is no prior petitioner. Any invalidity position you might want to run would have to be built from scratch in district court, which is procedurally meaningless here given expiration. Note also that the practical estoppel question is moot: you cannot be sued on a patent that expired 1957-09-10.

Pattern signals: all negative. No serial petitioner (there is no petitioner). No PTAB appeal history on the owner's side (the inventor, James J. Santiago, and the recorded assignee, John Grant of Los Angeles, are long out of the picture; the 1957 expiration predates every defensive-aggregator model). No Unified Patents, RPX, or similar entity in any chain, and no reason one would ever have engaged — a defensive aggregator challenges asserted patents. The one genuinely interesting downstream datum is US2415608A, cited by Google as a third-party citation assigning to Grant Oil Tool Company — the same "Grant" surname that appears in this patent's printed assignment line ("assignor to John Grant, Los Angeles, Calif."). I flag it only as a coincidence worth noting, not as an established corporate lineage; the earlier section of this analysis reached the same restraint on the assignee conflict, and I do not resolve it here.

Recommended next steps

1. Verify the patent number in any demand letter. Given that four separate, unrelated patents numbered "…350" (6,553,350; 8,880,350; 10,401,350; and this one) appear in the search corpus, and that "2214350" also surfaces as an Alberta corporate registry number, a Paris tribunal docket, and a Brazilian STJ docket, misidentification is the most likely explanation for any 2026 assertion. A demand citing "US 2,214,350" is a demand citing an article of history.
2. If the patent number is confirmed as US 2,214,350, you are done. Do not file a PTAB petition — you cannot: no petition could be filed in 2026 against a patent whose infringement window closed in 1963, and there is no live controversy to support standing. The response is expiry, not invalidity.
3. If the real number is a different '350, the analysis restarts from that patent's own docket. Three of the four candidates above have live PTAB history: U.S. 6,553,350 (CBM2012-00001 — claims 17 and 26–29 canceled under § 101, affirmed in Versata, so those specific claims are dead; the CBM program has since sunset); U.S. 8,880,350 (IPR2019-00164 — claims 1–14 held obvious, affirmed in Caris MPI v. Foundation Medicine, Nos. 2020-1886/2020-1887 (Fed. Cir. Nov. 9, 2021)); and U.S. 10,401,350 (Beckman Coulter IPR filed 2020-08-20). For any of those, the § 315(e)(2) estoppel and surviving-claim analysis would need to be run properly.
4. If no proceeding exists for the number you actually hold — say so plainly. The absence of PTAB activity is itself a signal: well-asserted patents eventually attract IPRs. A "…350" patent with no PTAB docket either expired before the AIA (this one), is too recently issued to have been challenged yet, or has never been asserted against anyone with the resources to file.

Sources checked

• Canonical source: structured "PTAB proceedings on file" block (USPTO Open Data Portal ingest) — empty
• PTAB P-TACTS / E2E case tracking: https://ptacts.uspto.gov/ptacts/ui/home — no AIA review case for US 2,214,350
• Patent record: https://patents.google.com/patent/US2214350/en (expiration field: 1957-09-10, "Expired – Lifetime")
• Expired-patent IPR jurisdiction: Apple Inc. v. Gesture Tech. Partners, LLC, 127 F.4th 364 (Fed. Cir. 2025) — opinion accessible via the Federal Circuit's opinions page and https://www.courtlistener.com/ (search "Apple v. Gesture Technology Partners")
• Unrelated "…350" PTAB matters (excluded from this patent's count): Versata/SAP CBM2012-00001; Caris MPI IPR2019-00164; Beckman Coulter IPR re U.S. 10,401,350

Caveat, stated explicitly: absence of search hits is not proof of a universal negative. USPTO ODP, however, is the authoritative registry for AIA trials, and it reports none; combined with the 1957 expiration, I assess the probability of any undiscovered proceeding as negligible.

Assignment & Ownership Analysis — US 2,214,350 (Santiago, "Well cleaning tool")

Tooling and scope note — read first

I attempted live retrieval from the USPTO Assignment Center and its legacy mirror (assignmentcenter.uspto.gov, assignment.uspto.gov/patent/index.html) for patent number 2214350. My queries returned no usable results, and I have no API/database access to the Assignment Center from this session. Consequently:

• I cannot cite reel/frame numbers for this patent, and I will not invent them. Any reel/frame in a report on this patent that I have not seen is fabricated.
• Everything below that is evidenced comes from the four corners of the printed grant (the authoritative text provided) plus one web source on Grant Oil Tool Company's 1947 product line.
• Where the record is silent, I mark it not determinable rather than inferring.

There is also a substantive point about the record itself: this patent issued 1940-09-10 and expired 1957-09-10. Its ownership is therefore a historical question, and the modern assignee-LLC mechanics the task asks about (shell transfers, cascading LLCs, pre-litigation venue transfers) postdate the patent by four decades. I run the signals anyway, as instructed, but the base rate for them is zero by construction.

Consistency check against the prior section: no contradiction. The earlier summary flagged the assignee conflict — printed patent says "assignor to John Grant, Los Angeles, Calif." while Google Patents metadata says "Individual." Those two are consistent: an individual assignee. Nothing here overrides that; I confirm it.

Inventors

Notes:

• Single inventor. No joint-inventor pattern, so the "all inventors departed within 12 months" fire-sale precursor is structurally inapplicable — there is only one inventor.
• He was already an established oil-tool inventor in this exact art. The specification cites Santiago 2,098,520 (1937-11-09) as an example of alternative means for actuating the closure-removing member, i.e. the inventor's own earlier patent on a related well-cleaner actuator. I could not verify the assignee of US 2,098,520 — do not treat it as Santiago-owned or Grant-owned without checking that record separately.
• Ownership posture at filing: Santiago was an assignor, not the owner. The grant is printed "assignor to John Grant," which means Santiago had parted with his rights before issuance. He is not the patentee of record in the ownership sense.

Original assignee

John Grant, Los Angeles, Calif. — an individual.

Circumstantial link, explicitly labeled as circumstantial: US 2,415,608, "Hydrostatic bailer for wells," filed 1944-06-19, issued 1947-02-11, is assigned to Grant Oil Tool Company and is the first-listed third-party citation against this patent. Same city, same surname, same product category ("hydrostatic bailer"). That is suggestive that the individual "John Grant" and Grant Oil Tool Company are related, but the ordinary evidence of legal identity (articles of incorporation, assignment of this patent to the company) is not in my retrievable record. I am not asserting the corporate lineage. The earlier section reached the same conclusion independently.

Assignment timeline

The USPTO Assignment Center returned no records to me for this patent. Stating it plainly, as instructed.

What is documented, and where:

1. On or before 1939-02-20 (execution date not stated on the patent) / recording date not determinable — Reel/Frame not retrievable

   • Conveyance: Assignment (pre-issuance)
   • Assignor: James J. Santiago, Los Angeles, Calif.
   • Assignee: John Grant, Los Angeles, Calif.
   • Correspondent: not determinable
   • Context: ordinary inventor-to-funder assignment of rights in an unissued application. It must have been recorded with the Patent Office, because the grant is printed in the assignee's name ("assignor to John Grant"). This is the only assignment evidenced anywhere in my retrievable record.
   • Evidence: printed grant, "Patented Sept. 10, 1940 … James J. Santiago, Los Angeles, Calif., assignor to John Grant, Los Angeles, Calif."

2. No post-issuance assignment found. I found no conveyance after 1940-09-10, and none is suggested by the metadata. For a patent that expired 1957-09-10, that is unremarkable.

Interpretation caveat on "no records": assignment-database coverage at USPTO is uneven for pre-1950s grants — older conveyances live in the recorded-assignment microfilm/paper indexes and are not uniformly surfaced in modern search. I am only moderately confident in that coverage claim and state it as a caution rather than a finding. The correct reading is: no post-issuance chain is evidenced, not no post-issuance chain exists.

Timeline diagram

timeline
    title Ownership of US 2214350
    1939 : Application filed by James J Santiago
         : Rights assigned to John Grant
    1940 : Patent issued naming Grant as assignee
    1957 : Patent expired

NPE / troll-pattern signals

Verdict

Insufficient data — the chain consists of the original assignment only.

Justification: the sole evidenced conveyance is the pre-issuance assignment from James J. Santiago to John Grant, shown on the face of the grant ("assignor to John Grant, Los Angeles, Calif."), executed on or before the 1939-02-20 filing date; USPTO Assignment Center returned no retrievable records to me, so no reel/frame, correspondent, or post-issuance link can be cited. US 2,214,350 expired 1957-09-10, which independently forecloses every modern NPE signal — there is no live right to transfer, no infringement suit to set venue for, and no asserter directory that would list it. I found no shell entity, no known asserter, and no cascading or pre-litigation transfer, and I am not treating the surname coincidence between individual assignee "John Grant" and the later Grant Oil Tool Company (assignee on US 2,415,608) as a legal link, because no record in my retrieval establishes it.

Verify directly at the USPTO Assignment Center — search by patent number 2214350: assignmentcenter.uspto.gov (legacy mirror: assignment.uspto.gov/patent/index.html). Patent text and metadata used above: https://patents.google.com/patent/US2214350/en.

I'll verify the patent and each candidate reference against live sources before analyzing anticipation.

Both queries returned unrelated material. Let me search the individual references by their exact numbers.

Search hits are noisy. Let me query the exact Google Patents records directly.

Prior-Art Analysis — US Patent 2,214,350 ("Well cleaning tool")

0. Verification status and a correction to the framing

I was unable to complete every planned retrieval in this session (the search budget was exhausted mid-run), and the searches I did run were noisy. So let me be blunt about what is verified and what is not:

• Verified: The patent itself, its specification text, its 13 claims, its issue/filing dates, and the references it names in the body of the specification. These come from the authoritative full text at https://patents.google.com/patent/[US2214350](/patent/US2214350)/en.
• Verified indirectly: That US2059629A is titled "Well bailer" — it appears as a listed reference in the Google Patents record for US2155601A ("Bailer," Glenn D. Johnson, Baash-Ross Tool Company).
• NOT verified: I did not retrieve the full text or claim sets of 2,059,629, 2,133,383, 2,059,631, 2,098,520, 2,415,608, or 6,695,053. My claim-mapping below is therefore a provisional, reasoned mapping based on how Santiago himself characterizes each reference — not a claim-by-claim anticipation finding. I will not dress it up as more than that.
• A literal-ID caution: Searches for the bare string "2214350" surface several unrelated entities that share those digits — EP 2214350 A1 (a European publication), 2214350 Alberta Inc (a Canadian corporate registry number), Tribunal administratif de Paris n° 2214350, and STJ AgInt no AGRAVO EM RECURSO ESPECIAL Nº 2214350 (Brazil). None of these is US 2,214,350. I have not conflated them. Correspondingly, I did not retrieve a live USPTO PatentCenter/PatFT page for 2214350 in this session; the grant text as mirrored on Google Patents is the record I am working from.

Important reframing of the task. The instruction "look at each patent citation for 2214350" needs splitting into two categories that Google Patents presents side-by-side but that have completely different legal weight:

Category (B) is a trap. Three documents appear in the Google "Cited By" list, and none of them can anticipate US 2,214,350 because all three were filed years or decades after 1939-02-20.

Also worth stating plainly: the record contains no examiner-cited "References Cited" list. For a 1940 grant this is normal (front-page citation listing was not customary). So the only true citations connected to 2,214,350 are the specification-named patents in Category (A). Everything in the "Similar Documents" pane is Google's algorithmic adjacency, not prior art of record.

Statute caveat. US 2,214,350 was filed 1939-02-20, thirteen years before the Patent Act of 1952. Strictly, it was examined under R.S. §4886, where the printed-publication bar ran to the date of invention (with no one-year grace) and a two-year bar applied to public use/sale. The task asks for 35 U.S.C. §102, so I give that mapping below, but I flag the mismatch rather than silently applying modern law to a 1939 application. Under old §4886 the analysis is if anything harsher on the applicant for the 1936 and 1937 references.

Date contradiction (flagged per cross-reference instruction): the previously generated summary is written against a 2026 CAFC-checking frame, and this task states "Current Date: April 26, 2026," while my operating environment reports 2026-09-30. This is immaterial to the prior-art analysis but I am noting it rather than papering over it.

1. USPTO record for 2214350 (as located)

2. Category (A) — References cited in the patent (true prior art)

A-1. US 2,059,629 — Erwin & Sweet, "Well bailer"

• Full citation: US 2,059,629 (Erwin and Sweet), granted 1936-11-03; application number and filing date not verified in this session.
• Description as characterized by Santiago: He calls his invention an improvement on "the type of well cleaning tool or bailer shown in the patents to Erwin and Sweet Nos. 2,059,629 and 2,133,383." This is the primary starting-point reference — a hydrostatic-type bailer with a low-pressure charge chamber and a breakable closure.
• §102 status: Granted 1936-11-03, i.e. more than one year before the 1939-02-20 filing → §102(b) statutory bar. Under pre-1952 R.S. §4886 it is prior art if published before Santiago's invention date, which 1936 almost certainly is.
• Claims potentially affected: Claim 12 is the exposure point. Claim 12 requires only: two relatively movable body portions with opposing seats, a removable closure held between them, releasable holding means, and means to remove the closure — with no check valve and no valve-actuated breaking. Any prior bailer of this general family that holds a closure between two opposed body seats would bear directly on claim 12. Claims 1, 2, 3, 11 (the low-pressure-chamber + frangible-closure + check-valve combination) are also potentially implicated if this reference discloses a check valve whose opening stroke removes the closure. I could not verify that it does, and Santiago's own framing (§below) suggests his contribution is precisely the valve-coupled breaker — so I read claims 1–3 and 11 as probably distinguishing.
• Claims probably NOT anticipated: 5, 8, 9, 10, 13 — all of which require the single side-wall opening that serves both as discharge port and disk-insertion port, a feature Santiago expressly claims as his own point of departure ("whereby a single opening serves both as a discharge opening and as an opening for insertion of the breakable disks").

A-2. US 2,133,383 — Erwin & Sweet

• Full citation: US 2,133,383 (Erwin and Sweet), granted 1938-10-18; filing data not verified here.
• Description: Named alongside 2,059,629 as the same class of bailer the invention improves upon — likely a later case in the same Erwin/Sweet line.
• §102 status: Granted 1938-10-18, which is less than one year before 1939-02-20 → no §102(b) bar. It is available only under §102(a) (before Santiago's invention date) — and since it issued only ~4 months before filing, its §102(a) status depends entirely on when Santiago actually conceived. This is the weakest of the four as prior art, notwithstanding that it is the closest in subject matter.
• Claims potentially affected: Same profile as A-1 (claims 12, and conditionally 1–3/11). Weaker because of the §102(a)-only posture.

A-3. US 2,059,631 — Erwin

• Full citation: US 2,059,631 (Erwin), granted 1936-11-03; filing data not verified.
• Description as characterized by Santiago: Cited as an instance showing "suitable and typical means of actuating a closure removing member upwardly by virtue of means operated by contact with the wall of the hole." In other words, a wall-engaging actuator for a closure-removing member — not a bottom-engagement (hammer-shoe) actuator.
• §102 status: 1936-11-03 → more than one year pre-filing → §102(b) statutory bar.
• Claims potentially affected: It maps onto the "means for moving the check valve in its opening direction" element of claims 1, 3, 6, 10 and the "means within the body adapted to be actuated to remove said closure" element of claims 4, 5, 12, 13. Note that Santiago's own claims are deliberately broad ("means for moving…", "means… adapted to be actuated"), so a second reference teaching an alternative actuator is more of a §103 obviousness concern than a clean §102 anticipation. On its own, an actuator reference cannot anticipate a claim that also requires the low-pressure chamber, frangible closure, and seat-holding structure.

A-4. US 2,098,520 — Santiago (the inventor's own earlier patent)

• Full citation: US 2,098,520 (Santiago), granted 1937-11-09; filing data not verified.
• Description as characterized by Santiago: Cited together with Erwin 2,059,631 as showing "suitable and typical means of actuating a closure removing member upwardly by virtue of means operated by contact with the wall of the hole."
• §102 status — worth calling out: This is the inventor's own prior patent. Granted 1937-11-09, roughly 15 months before the 1939-02-20 filing → under the 1952 Act it falls inside §102(b) (more than one year before filing), and an inventor's own earlier patent is available as a §102(b) bar against his later application. This is a real, if easily overlooked, exposure.
• Claims potentially affected: Same element — the actuator "means" of claims 1, 3, 6, 10, 12, 13. Again, §103 rather than §102 is the more realistic attack, since 2,098,520 does not appear to disclose the check-valve-actuated closure removal or the single-opening holder.

A-5. Summary table — Category (A)

3. Category (B) — "Cited By" forward citations: NOT prior art

These appear on the Google record and must be excluded from any §102 analysis of 2,214,350. I list them so the exclusion is explicit and auditable.

Substantive note on US 2,415,608: although legally irrelevant as prior art, it is the most informative document in the whole family picture. It is a Grant Oil Tool Company hydrostatic bailer citing Santiago's patent — which is consistent with the printed patent's "assignor to John Grant, Los Angeles, Calif." I am not asserting a corporate lineage from the shared "Grant" name alone (see the assignee-conflict uncertainty already flagged in the prior section), but the citation direction supports the idea that the Grant entity carried this line of technology forward.

4. Non-of-record "Similar Documents" — leads, not citations

Google's similarity pane lists documents that were not cited against or by 2,214,350. Those predating 1939-02-20 are worth a manual pull if a validity opinion is being prepared, because they are potential §102 art the examiner apparently never had before him. I flag them as leads only — I could not verify their contents:

• US 1,958,915 A — "Desander or vacuum bailer" (1934-05-15)
• US 1,875,414 A — "Washing and cementing device for well casings" (1932-09-06)
• US 2,050,631 A? — not in the list; note US 2,059,631 A ("Well cleaning device," 1936-11-03) is in the list and is a different patent from the Erwin 2,059,631 discussed above. Do not merge these two numbers.
• US 2,073,126 A — "Well cleaning system" (1937-03-09)
• US 2,090,616 A — "Fishing tool" (1937-08-24)
• US 2,092,062 A — "Apparatus for testing oil wells" (1937-09-07)
• US 2,096,444 A — "Filling cap and strainer device" (1937-10-19)
• US 2,117,534 A — "Well cementing device" (1938-05-17)
• US 2,145,842 A — "Bypass assembly for packers" (1939-01-24) — five weeks before Santiago's filing; §102(a)-only exposure at best

5. Bottom line

1. There are exactly four genuine prior-art references associated with US 2,214,350, and all four are cited by the applicant in his own specification — 2,059,629, 2,133,383, 2,059,631, and 2,098,520. There is no examiner-cited art of record.
2. Three of the four (2,059,629, 2,059,631, 2,098,520) carry a §102(b) statutory bar under the 1952 Act's one-year rule, and the same three are prior art under the pre-1952 R.S. §4886 publication bar. 2,133,383 is §102(a)-only because it issued less than a year before filing.
3. The most exposed claim is claim 12, which is the broadest in the patent — it requires no check valve at all, only two body portions, opposing seats, a closure between them, releasable holding means, and means to remove the closure. Any same-field bailer holding a closure between opposed seats bears on it.
4. Claims 5, 8, 9, 10, and 13 are comparatively well insulated, because they recite the single side-wall opening serving double duty as discharge and disk-insertion port — the feature Santiago expressly identifies as his own contribution over the cited art. An anticipation case on those claims would have to come from art outside the four cited references.
5. The "Cited By" trio is legally inert for §102 purposes; all three postdate the patent, one by nearly seven decades, and one (the Lanz web winder) is plainly spurious.
6. My claim mapping is provisional. I did not obtain the claim text of any of the four references in this session, so I have not done a true element-by-element §102 comparison. What I have given is a reasoned, source-grounded targeting of which claims are worth testing against which reference — the next step would be pulling the full text of 2,059,629 and 2,133,383 (the two Erwin & Sweet bailers) and comparing their claims against claim 12 and claim 1 element by element.

I'll ground this analysis in the actual prior-art references before drawing obviousness conclusions.

Obviousness Analysis — US 2,214,350 (Santiago, "Well cleaning tool")

Preliminary caveats (stated before the analysis, not buried in it)

1. Statutory anachronism. US 2,214,350 was filed 1939-02-20 and issued 1940-09-10. At that time there was no 35 U.S.C. §103. The governing test was the "invention" requirement of R.S. §4886, construed under the "flash of genius" standard of Cuno Engineering Corp. v. Automatic Devices Corp., 314 U.S. 84 (1941). § 103 was created by the Patent Act of 1952. This patent was still in force on 1953-01-01 (it expired 1957-09-10), but I do not have high confidence whether §4 of the 1952 Act applied §103 retroactively to patents already granted. I flag that rather than assert it. The analysis below is therefore a retrospective, hypothetical §103 analysis using the Graham v. John Deere, 383 U.S. 1 (1966), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), framework, as instructed. It is also academic in a practical sense: the patent expired 1957-09-10, so no live claim remains to invalidate.

2. Two "prior art" lists must be separated. The instruction is to use the prior-art section of this page — but that page mixes genuine pre-1939 art with material that is legally not prior art. For a 1939-02-20 filing date, only art dated before that date (or more than one year before, for the §102(b) bar) counts.

3. The single most important caution. US 2,415,608 (Grant Oil Tool Company, "Hydrostatic bailer for wells") is, on its face, extremely close to the patent in suit. Its Fig. 3 form shows a frangible disc 69 clamped between head 64 and the upper end of tube 61, a check valve 66, a disc breaker 81 projecting upwardly with a sharp end 83, a releasable threaded connection at 71 whose unscrewing drops the mandrel to uncover opening 57, and the specification states the disc may be inserted "through opening 5[7]" — i.e., the same dual-purpose side opening. That is nearly claim-for-claim the disclosure of claims 5–9 of US 2,214,350. It cannot be used as §103 art here because it was filed 1944-06-19. It is, however, powerful contextual evidence that the claimed arrangement was the direction the art was already moving. I will flag it as such and not treat it as a reference. A careless analysis that cites it as prior art would be wrong on the law. (FPO full text)

4. Date discrepancy in my inputs. The system header gives today as 2026-09-30 and the fetched-record timestamp is 2026-09-30T18:27:16Z, while the "Current task" block states April 26, 2026. I am not reconciling these; I note it for transparency.

5. Search limitations. My searches failed to retrieve the full text of Erwin & Sweet 2,059,629, Erwin & Sweet 2,133,383, and Erwin 2,059,631; the query for 2,059,629 returned an unrelated EP jarring-tool document and the query for 2,133,383 returned a gas-lift history page. I therefore rely on the admissions in the specification of US 2,214,350 itself for their content, and I say so explicitly.

1. Person having ordinary skill in the art (PHOSITA)

A 1939 mechanical/oilfield-tool engineer with several years of experience designing hydrostatic bailers and well cleaners — familiar with the Erwin/Sweet and Santiago line of tools, with frangible-disk closures, low-pressure charge chambers, upward-opening ball check valves, and bottom- or wall-actuated trip mechanisms. Not a visionary; an ordinary designer working from catalogues of known sub-assemblies (packing subs, ball-and-seat check valves, interrupted-thread unions, shear disks).

2. The real inventive content, decomposed

The 13 claims fall into five functional clusters. Separating them is essential, because obviousness is decided per claim, not per patent.

3. Claim-by-claim analysis

Claims 1, 3, 11 — "means actuated by the check valve … to remove said closure"

The starting point is admitted art: the specification states the invention "embodies improvements upon the type of well cleaning tool or bailer shown in the patents to Erwin and Sweet Nos. 2,059,629 and 2,133,383." Those patents are therefore admitted as disclosing the low-pressure chamber + frangible disk + check valve + disk-breaking combination. What remains is where the opening force comes from.

Three §103 rationales converge:

1. Express admission of equivalency of actuating means. The specification states: "any other suitable means may be used to actuate that plunger upwardly, either for bailing operations or for cleaning operations," naming Erwin 2,059,631 and Santiago 2,098,520 as "suitable and typical means." An applicant's own specification identifying actuators as interchangeable is close to dispositive on the motivation prong — the reference teachings are literally pointed to by the patentee as substitutes.

2. Design simplification motive supplied by the applicant's own earlier patent. US 2,098,520 (Santiago, assigned to John Grant) expressly criticizes the prior "load-and-fire" disk breakers because they required cocking before lowering and were "prematurely released while the apparatus is being lowered in the well due to sudden jarring." Eliminating the separate latch/spring/load-and-fire subassembly is a recognized problem in the field, which supplies the motivation to use the already-present, already-reciprocating hammer plunger 46 as the breaker actuator. (FPO full text)

3. Mere duplication / collocation of parts. The specification itself says the plunger "may be considered as if it were a part of or an upward projection from the ball valve 44, as it moves directly with the valve." Adding a rod that rests on the ball and rides with it is the addition of a part performing its established function with no change in the operation of the ball. KSR: "the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." Stacking the breaker on the valve is a predictable use of prior-art elements according to their established functions.

Conclusion: claims 1, 3, 11 obvious. Claim 3's added vertical orientation and "resting on the check valve" limitation are conventional and, again, conceded in the spec's own description of the parts.

Claim 2 — "longitudinally passaged plunger"

The passage is not a design choice; it is a functional necessity. A solid plunger resting on the ball would occlude the very flow path by which the charge enters the chamber. The spec makes this explicit: passages 62 "provide for fluid passage throughout the length of the tubular plunger," and note that the lower hammer plunger 46 is already hollow with openings 52 for exactly the same reason. Applying the same known hollow-plunger expedient one body-length higher is the paradigm of an obvious design modification.

Conclusion: claim 2 obvious.

Claims 4, 12, 13 — the two-part body genus (claim 12 omits the check valve entirely)

This is the weakest material in the patent, and claim 12 is the broadest claim of the set.

• Santiago's own US 2,098,520 describes the cleaner as "comprising relatively longitudinally movable body and sleeve portions B and S," with a mandrel M extending through the sleeve. That is, in substance, "two relatively longitudinally movable portions with opposing ends."
• Every tool of this class must (i) be assembled around a sealing disk and (ii) later be opened to discharge. Clamping a disk between two opposed annular seats and drawing the sections together with a threaded sub is the routine joinder technique of the art; a PHOSITA would not regard the choice of seat-clamping over, say, a shoulder-and-pin arrangement as inventive.
• Claim 12 requires no check valve whatsoever — only two movable body portions, opposing seats, a closure between them, releasable holding means, and means to remove the closure. On that scope, the claim is barely distinguishable from any number of ordinary two-section bailer couplings.

Conclusion: claims 4, 12, and 13 are the most vulnerable claims in the patent — claim 12 in particular.

Claims 5, 8, 13 — the dual-purpose side-wall opening

The specification itself states the object as "providing a single opening serves both as a discharge opening and as an opening for insertion of the breakable disks." Side-wall discharge ports in bailers are conventional in the art (see, e.g., the post-dated but structurally identical opening 57 in US 2,415,608; and the discharge openings conventional to the bailer art generally). Using one aperture for two temporally distinct operations (loading at the surface; discharging at the surface) is a classic new-use-for-an-old-element situation with a recognized advantage — simplicity of construction, which the patentee himself states is the object. KSR sanctions such "obvious to try" simplifications where the advantage is predictable.

Conclusion: claims 5, 8, 13 obvious. (Claim 8's printed text is OCR-garbled by a duplicated phrase; per the certificate of correction of Oct. 15, 1940, the words "tubular body comprising two separable portions with opposing" are struck out. I analyze claim 8 as corrected.)

Claims 6, 7 — check valve in the other body portion, closing away from the chamber

Same analysis as claims 1/2 with the two-part body of claim 4. The location of a check valve "in the other body portion" is dictated by the hydraulic function — it must be below the closure to admit flow upward toward the low-pressure chamber and to retain the charge. Functional placement is not inventive.

Conclusion: claims 6, 7 obvious.

Claims 9, 10 — the detailed apparatus claims (union coupling, adjustable seat, interrupted threads)

These are the most defensible claims, but still likely obvious:

• Interrupted threads: the specification concedes "the threads may be made continuous if so desired" — an admission that the thread form is a matter of design choice.
• Vertically adjustable downwardly-facing seat: when two seat surfaces must clamp a disk of variable thickness across manufacturing tolerances, making one seat screw-adjustable is the most obvious available expedient. The spec confirms the purpose ("The disk seat ring 15 having been adjusted in proper position…").
• Upwardly-opening check valve below the closure + means for raising it + closure removed by that upward movement: combines clusters A and B, analyzed above.
• The genuinely interesting unclaimed feature — the seal being formed between seats 17 and 21a independently of the thin disk, so the seal survives even if the disk rim breaks — is not claimed, which weakens claim 9 as a barrier and removes it from the obviousness question.

Conclusion: claims 9 and 10 are the hardest to invalidate, but a combination of the Erwin/Sweet bailer art with Santiago 2,098,520 plus ordinary mechanical skill (adjustable seat ring) supports an obviousness rejection.

4. Combination table (representative rejections)

5. Secondary considerations

There are none in this record. The patent expired 1957-09-10; no commercial success, long-felt need, or failure-of-others evidence is present, and none would be cognizable 86 years post-issuance. The one item that could cut either way is the near-simultaneous development of the same architecture by Grant Oil Tool Company in US 2,415,608 — independent, concededly later (1944), but reaching a strikingly similar arrangement. Courts and the USPTO have treated simultaneous independent invention as evidence that the advance was within the ordinary skill of the art; here the five-year gap and the assignee overlap ("assignor to John Grant") make it only weak, suggestive evidence. I would not lean on it.

6. Bottom line

• Most vulnerable: claims 12, 13, 4, 5, 8 — the two-part-body genus and the dual-purpose opening. Claim 12 omits the check valve, leaving only conventional coupling structure.
• Vulnerable: claims 1, 2, 3, 6, 7, 11 — the valve-actuated breaker. The specification's own statements (plunger is "as if it were a part of or an upward projection from" the ball; "any other suitable means may be used to actuate that plunger") are the applicant's near-admissions of obviousness. This is the strongest §103 attack in the file.
• Least vulnerable: claims 9 and 10, the detailed structural claims with the union coupling and adjustable seat ring — but still rejectable over the Erwin/Sweet + Santiago 2,098,520 combination.

The overall picture is of a genuine but narrow mechanical improvement: consolidating two previously separate sub-assemblies (the check valve and the disk breaker) into one moving column. Under R.S. §4886 and Cuno that might have survived; under §103 as later construed by Graham and KSR, most of these claims would likely fall.

Sources: US 2,214,350 on Google Patents (authoritative full text used throughout) · US 2,098,520 full text, FPO · US 2,415,608 full text, FPO — not prior art; cited as context only. Full text of US 2,059,629, US 2,133,383, and US 2,059,631 could not be retrieved; their content is taken from the admissions in US 2,214,350 itself, and any statement about them beyond those admissions should be independently verified before being relied upon.