US 150262

I'll verify the patent record against live sources before summarizing.

US 150,262 — Verified Record

Identifier check: The number as given, 150262, maps to US 150,262 (Google Patents renders it US150262A). All facts below are for that specific number. I did not substitute results for any neighboring number (e.g., 150,262 is not the same document as US 200,909, which is a visually similar OCR result from the "Similar Documents" list and is a different patent number with a similar title — see caveats).

1. Bibliographic data

2. Abstract

There is no abstract. US patents of 1874 were not required to (and did not) include an abstract, and Google Patents displays no abstract field for this document. The closest authoritative substitute is the inventor's own statement of object and the single claim:

"My invention has for its object to furnish an improved cap for glass syringes, which shall be so constructed that it cannot be pushed into the barrel of the syringe, and which shall at the same time be convenient in use. The invention consists of the cap formed of the cork, and the metallic tube having a flange formed upon its upper end, the end of which is spun over to clasp the upper end of the said cork and form a lip, and having the lower end spun outward to overlap the inner end of the said cork…"

The drawing is described as "a side view, partly in section, of a glass syringe to which my improved cap has been applied, the cap being also shown in section."

3. The sole independent claim — plain-language analysis

Claim 1 (independent, and the only claim):

"The syringe-cap C D, formed of the cork C and the metallic tube D, having a flange formed upon its upper end, the edge of which is spun over to clasp the upper end of the said cork C and form a lip, and having its lower end spun outward to overlap the inner end of the said cork C, substantially as herein shown and described."

Element-by-element, in plain language:

1. What is claimed is a two-piece cap subassembly — a cork (C) plus a metal tube (D). The claim is directed to the cap, not to the syringe.
2. The cork C is sized to fit into the glass barrel (A) and has a longitudinal hole through its center.
3. The metal tube D passes through that hole and is dimensioned so the piston rod (B) "can work in it freely" — i.e., the tube is a guide/bushing for the rod, not a fluid seal itself.
4. Upper-end flange: the tube's top end carries an outward flange sized so its edge projects a little beyond the sides of the cork.
5. Spun-over edge → lip (first function): that flange edge is spun over (roll-formed) so it turns against and clasps the upper part of the cork, creating a lip. The lip rests against the edge/rim of the barrel (A) and thereby prevents the cap from being pushed down into the barrel — the stated failure mode being that the piston then strikes the syringe shoulder and breaks the glass.
6. Spun-out lower end (second function): the tube's lower end is spun outward to overlap the inner (i.e., lower/inner-facing) end of the cork. This mechanically prevents the tube from being drawn out of the cork when the cork is compressed by being forced into a syringe that is "a little too small."

Net scope in one sentence: A syringe cap consisting of a cork with a metal guide tube through it, where the tube is swaged at both ends — flanged and spun over at the top to clasp the cork and form a barrel-rim-engaging lip, and spun out at the bottom to lock under the cork — with the two deformations together permanently locking cork and tube into one unit.

Claim-drafting notes relevant to construction: This is a pre-1952 single-claim ("I claim as new and desire to secure by Letters Patent") format with a "substantially as herein shown and described" closer, which imports the disclosed structure/function. The claim is a combination claim requiring both the spun-over top flange/lip and the spun-out bottom end; a cap with only one of the two deformations would arguably fall outside the literal claim.

Expressly not claimed: The barrel (A) and piston rod (B). The specification states "about the construction of which there is nothing new." I found no dependent claims, no method claims, and no apparatus claims to the syringe as a whole.

4. Litigation / docket check

• CAFC 2026 dockets: I found no Court of Appeals for the Federal Circuit docket activity, and no district-court activity, involving US 150,262. This is expected: the patent's term expired April 28, 1891, roughly 135 years ago, and the Federal Circuit did not exist until 1982.
• USPTO: No live prosecution, reissue, reexamination, IPR/PGR, or assignment record surfaced. Google Patents lists the status simply as "Expired – Lifetime."
• "Cited By" list — treat with caution. Google Patents shows 7–8 forward citations (e.g., US 4,832,695 Tamper evident injection syringe; US 5,417,661 Safety syringe; and five Dentsply dental-polymer patents, e.g., US 5,876,210, US 5,998,499, US 6,353,061, US 6,369,164, US 2005/0043490 A1). These are algorithmic/third-party citations from later patents, not examiner citations against this patent, and the Dentsply dental-resin cluster in particular has no apparent substantive relationship to an 1874 cork syringe cap. They should not be read as evidence of scope or validity impact.

5. Explicit uncertainty / limitations of this record

• No abstract exists in the source document. Anything labeled "abstract" for this patent is a modern database construct.
• No assignee is recorded on the face of the grant. In the 1870s, assignments were recorded separately at the USPTO rather than printed on the patent; I did not retrieve an assignment reel/frame, so I cannot rule out a later-recorded assignment to a third party. As issued, the patent is inventor-owned.
• OCR/transcription variance: The Google Patents text and the OCR of the front page disagree on names and reference characters. The specification text uses cork C and cites witnesses James T. Graham and T. B. Mosher; the OCR'd drawing sheet renders the same reference letter as "0"/"(l"/"G" and shows inconsistent names ("H. M. Langvird," "O. S. Baroni"). The authoritative PDF text is the one that reads "cork C" throughout. I flag this rather than silently normalizing it.
• Filing vs. execution date: April 4, 1874 is the filing date stated on the face of the specification ("application filed April 4, 1874"). No separate execution/oath date is printed.
• Related-looking but distinct document: the "Similar Documents" list includes US 200,909, also titled "Improvement in caps for glass syringes" (1878-03-05). That is a different patent number and a different document; I did not verify its inventor or content, and nothing in this summary should be attributed to it.
• Search coverage: I could not query PACER, the CAFC docket system, or USPTO PatentCenter/Assignment directly in this session. The no-litigation finding rests on public web search results and the Google Patents status field, not on a primary docket query.

6. Sources

• US 150,262 granted specification (full text and drawing): https://patents.google.com/patent/[US150262A](/patent/US150262A)/en
• Front-page/OCR PDF of the original letters patent: https://patentimages.storage.googleapis.com/90/4b/2d/4b00b8f84bc546/[US150262](/patent/US150262).pdf

I'll search litigation-tracking sources for this specific patent number.

Initial searches returned only noise (unrelated patents with digit-sequence coincidences like AU2020356797, JP2004-150262, WO2009150262). Let me query litigation-specific sources.

Let me try court-record-specific sources.

Litigation Report — U.S. Patent No. 150,262

Bottom line: No litigation involving U.S. Patent No. 150,262 is known or discoverable. I found no district court action, no Court of Appeals (CAFC/Circuit) appeal, no ITC Section 337 investigation, no PTAB/IPR/PGR proceeding, and no reported decision naming this patent as an asserted or adjudicated patent.

1. The patent at issue (verified, not assumed)

Source: https://patents.google.com/patent/[US150262](/patent/US150262)/en (PDF: https://patentimages.storage.googleapis.com/90/4b/2d/4b00b8f84bc546/US150262.pdf)

Note the critical date structure: this is a pre-1952 Act patent with a term of 17 years from grant, expired April 28, 1891. It has been in the public domain for roughly 135 years and cannot support an infringement cause of action today.

2. Case table

There is no row to populate. Nothing was found.

3. Search log (what I actually checked)

Explicit caveat on method: I do not have direct PACER or CAFC docket access in this session; the sources above are indexed/aggregated web sources. PACER's electronic docket system only reaches back to the late 1980s–1990s for most districts, and 19th-century federal equity dockets (where a suit on this patent would have been filed, in a U.S. Circuit Court) are largely undigitized. I therefore cannot rule out, with certainty, a paper-only 1874–1891 infringement suit that was never digitized or was never reported in a case reporter. I found no trace of one in the searchable record.

4. Why litigation is effectively impossible in the current landscape

1. The patent has been expired for ~135 years (anticipated expiration April 28, 1891). Expiration terminates the exclusionary right; there is no live cause of action for infringement of an expired claim.
2. No standing. After expiration, no assignee or successor can assert Section 271 rights; the most that could arise is a pre-expiration damages action filed before April 28, 1891 — and the six-year limitations period plus laches would have extinguished any such action long ago, even assuming one existed.
3. No terminal disclaimer, extension, or revival under 35 U.S.C. §§ 154(b)/156. Note that patent term extension under § 156 was created by the Drug Price Competition and Patent Term Restoration Act of 1984 — 93 years after this patent expired and 54 years before this patent existed in its current statutory context. Even theoretically, at 85+ years past expiration no extension mechanism reaches it.
4. No Modern Tribunal Hook. The ITC, PTAB, and the AIA post-grant regimes cannot produce a meaningful proceeding against an expired 1874 patent. No such filing exists in the searchable record.

5. Practical relevance (why this matters for your file)

If the reason you are asking is a freedom-to-operate, validity, or prior-art question, this patent's significance is as prior art / historical antecedent art, not as an assertion instrument:

• It is best characterized as background art in the lineage of syringe plunger/piston seal and cap assemblies (its classification sits at A61M5/31511 — piston or piston-rod constructions).
• The later patents shown on the Google Patents "Cited By" list (notably US 4,832,695, Tamper evident injection syringe, and US 5,417,661, Safety syringe) reflect that practitioners in the modern syringe art have cited the 1874 Slavin disclosure. If your interest is invalidity or derivation-of-art, those citations — not litigation — are the usable trail.

6. Recommendation

Because the answer is negative, the appropriate deliverable is a "no litigation found" certification with the search parameters preserved above, worded as: "Counsels' searches of the public litigation indices, the Unified Patents litigation portal index, CourtListener, and general web sources on [date] disclosed no action in which U.S. Patent No. 150,262 was asserted, adjudicated, appealed, or made the subject of a post-grant challenge."

If you need affirmative negative clearance, the one gap to close is a manual PACER / Federal Archives (NARA) record pull for 1874–1891 U.S. Circuit Court (S.D.N.Y.) equity dockets naming Slavin as complainant. I have not performed that pull, and I will not state it as complete.

I'll verify the structured data against public sources before reporting.

Proceedings overview

Zero AIA trial proceedings on file. Total count: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. The USPTO Open Data Portal structured block returns no IPR, PGR, or CBM for US 150262, and targeted web searches returned no petition, institution decision, Final Written Decision, or Federal Circuit appeal naming this patent. The bottom-line defensive posture is therefore not "this patent survived two IPRs and is hardened" — it is the opposite of a hardened patent: US 150262 expired on 1891-04-28, and any infringement theory citing it is aimed at a patent that has been dead for over 134 years.

That is the whole story, so the remaining sections explain why the answer is categorical rather than empirical, and flag two things in the source record that are easy to misread as PTAB activity.

No proceedings to itemize

There is no {PROCEEDING_NUMBER} to report. I will not manufacture one. For completeness, the reason each AIA trial vehicle is unavailable or pointless here:

Term: the application was filed 1874-04-04 and the patent granted 1874-04-28. Under the pre-1995 seventeen-year term measured from grant, the patent expired 1891-04-28 — which is exactly the "Anticipated expiration" date the Google Patents record for US150262A carries. Status shown: "Expired - Lifetime." No AIA proceeding could post-date enforceable coverage; AIA trials themselves only became available on 2012-09-16, 121 years after expiry.

Non-proceedings that look like proceedings — do not cite these as PTAB activity

These appear in the Google Patents record for the same patent number and are not AIA trials:

• "Cited By" — 7–8 entries (US4832695A Tamper evident injection syringe; US5417661A Safety syringe; US5876210A, US5998499A, US6353061B1, US6369164B1, US6339114B1, US20050043490A1 — Dentsply dental-polymer family). These are forward citations, i.e., later patents whose examiners cited US 150262 as prior art. A "Dentsply G.M.B.H." assignee in that table is the citing patent's owner, not a petitioner.
• "Similar Documents" (US200909A, US258035A, USD13267S, etc.) — classification/CPC neighbors, not related proceedings.
• The US150262D and US150262DA identifiers in the family table — these are Google Patents' internal publication-kind aliases for the same 1874 grant, not separate challenges.

If a demand letter or an internal docketing entry points to a "PTAB proceeding on US 150262," verify the number first. Unverified hypotheses worth checking against the actual letter: an OCR/typo rendering of US 1,502,862 (a different patent), or confusion with a modern application number in the 15/026,2xx range. I have not confirmed either; treat them as number-verification steps, not findings.

Strategic summary

Claim status: UNTESTED and legally unenforceable. The patent has a single claim: "The syringe-cap G D, formed of the cork O and the metallic tube D, having a flange formed upon its upper end, the edge of which is spun over to clasp the upper end of the said cork (J and form a lip, and having its lower end spun outward to overlap the inner end of the said cork O, substantially as herein shown and described." No claim has been canceled, none has been held patentable in any contested proceeding, and none has been tested. The cancel/sustain/untested taxonomy simply does not engage: the entire right expired 1891-04-28, before any modern post-grant mechanism existed.

Estoppel landscape: nonexistent. Because no IPR or PGR ever reached a Final Written Decision, there is no § 315(e)(1) or § 315(e)(2) estoppel, no § 325(e) estoppel, and no petitioner/RPI/privy chain to trace. There is also no joinder history, no motion-to-amend record, and no claim-construction precedent. Practically, a defendant has all prior-art grounds nominally available — but that is a curiosity, not an advantage, since the real defense operates a century earlier in time than any prior-art reference could.

Pattern signals: none, and none expected. No serial petitioner, no defensive aggregator (no Unified Patents, RPX, or similar), no patent-owner appeal activity, no Director Review, no parallel ITC or district court docket I can identify. This is not the "well-asserted patents eventually attract IPRs" signal. It is a 19th-century artifact whose claim term ran out during the Benjamin Harrison administration. The absence of PTAB activity here carries no inference about litigation exposure.

Recommended next steps

1. If a demand letter or suit cites US 150262, the dispositive response is a term defense, not an invalidity defense. Filed 1874-04-04, granted 1874-04-28, expired 1891-04-28. There is no actionable infringement for any conduct after that date, and any pre-1891 damages theory is barred by the statute of limitations many times over. You do not need an FWD to quote, because no FWD exists.
2. Do not budget for an IPR. There is no claim whose cancellation would help you, and a petition would face the antecedent problem that the patent's term and any recovery window lapsed over a century ago.
3. Verify the patent number in writing against the asserting party. Ask for the patent's title, grant date, and a claim chart. If the reply identifies anything other than "Improvement in caps for glass syringes," granted 1874-04-28 to Patrick F. Slavin of New York, you are dealing with a number error and should re-run the analysis on the correct patent.
4. If you nonetheless want to confirm the null result independently, check USPTO PTAB E2E and the USPTO PTAB Decisions page by patent number, and search CourtListener for any Federal Circuit appeal. My searches returned no proceedings, no institution decisions, and no appeals; the ODP structured block agrees. I found no contrary evidence, and I am not aware of any proceeding I am withholding.

Confidence note: I am highly confident there are zero AIA trial proceedings on US 150262 — the patent's 1891 expiry makes the question categorical, and both the canonical ODP list and web searches are consistent and empty. I could not verify whether some other patent number is being conflated with this one in any particular live dispute, because I have no visibility into the specific assertion you may be facing.

I'll start by checking what's actually retrievable for this patent's assignment record.

Key structural finding already: the USPTO assignment database only covers records back to August 1980. Let me verify and check for any related filings by the same inventor.

Assignment & Ownership Analysis — US Patent 150,262

Scope note before anything else: US 150,262 issued 1874-04-28 and expired 1891-04-28 (17-year term then in force). The two databases named in the brief — USPTO Assignment Center (assignmentcenter.uspto.gov, successor to assignment.uspto.gov and assignments.uspto.gov) — contain recorded patent assignment data only from August 1980 to present; the USPTO states plainly that "Patent Assignments recorded prior to 1980 are maintained at the National Archives and Records Administration." A search of either portal by patent number therefore returns nothing for this patent by design, not by absence of activity. I found no fabricated or reconstructed reel/frame entries and will not invent any. Where the requested analysis is structurally impossible, I say so rather than filling the template.

Inventors

• Sole inventor. Patent granted in his individual name; the specification reads "I, PATRICK F. SLAVIN, of the city, county, and State of New York, have invented a new and useful Improvement in Cap for Glass Syringes."
• Employer is not discernible from the record. There is no corporate assignee on the face of the patent, no "assignor to" recital (compare contemporaneous US 208,062, Bliss & Davol, Providence, R.I., "said Bliss assignor to said Davol" — early patents do carry such recitals when a corporate or co-inventor transfer existed, so the absence here is meaningful, not merely an artifact of the era). Slavin appears to have been an independent inventor or mechanic working in New York.
• Unusual-pattern check: not assessable / not present. The "all inventors departing the original assignee within 12 months" pattern requires (a) an assignee and (b) a multi-inventor team. Neither exists — single inventor, no assignee. There is no acquisition, no portfolio, and no fire-sale window to measure.
• Attesting witnesses in the specification block: James T. Graham and T. B. Mosher (Google Patents OCR renders the second as "T. B. Mosnnn"). Note a conflicting OCR reading of the drawing sheet in the scanned PDF (patentimages.../US150262.pdf) garbles the witness/attorney line into "H. M. Langvird" / "O. S. Baroni / BY ATTORNEYS." I treat the specification attestation (Graham / Mosher) as authoritative and flag the sheet OCR as unreliable — no attorney-of-record inference should be drawn from it.

Original assignee

None. The patent was never assigned to a corporate assignee of record.

• The front page names no assignee, and Google Patents' legal-events record for US 150262A shows only: Application granted 1874-04-28, Publication of US150262A 1874-04-28, Anticipated expiration 1891-04-28, current status Expired – Lifetime. There is no Assignment, Merger, Change of Name, Security Agreement, or License legal event on the Google Patents record.
• Primary line of business: not applicable. Patrick F. Slavin, New York City, individual — no evidence of a manufacturing concern or company affiliation surfaced.
• Product embodying the claims: the invention is a syringe cap — a flanged and spun-over metallic tube (D) clasping a cork (C), the tube's upper flange forming a lip that seats against the barrel mouth so the cap cannot be driven into the barrel, and the lower end spun outward so the tube cannot be pulled out of the cork when the cork is compressed. Whether Slavin or any licensee manufactured it is not determinable from any source I retrieved (no corporate records, no 19th-century catalog match).
• Current status: the underlying invention is in the public domain; any 19th-century business around it is unknown / presumed long dissolved. The patent itself terminated 1891-04-28.

Assignment timeline

There are no recorded assignments for US 150,262 in any accessible USPTO assignment database. No reel/frame entries exist to cite, and I am not going to manufacture placeholder reels.

Two independent structural reasons, in order of importance:

1. Database coverage. Assignment Center / Patent Assignment Search begins August 1980. This patent expired 1891-04-28, i.e. 89 years before the first indexed record date. Any conveyance of this patent would have been paper-recorded in the 1870s–1890s and, if it survives at all, sits with NARA, not in the searchable portal.
2. No assignee chain ever appears on the face of the patent or in Google Patents legal events, which is consistent with an unassigned, individually held 1874 grant.

Because the Assignment Center has no records, per the brief's instruction I stop the timeline here — with the added note that this is a coverage boundary, not evidence of a clean title chain. The honest statement is: ownership history after 1874-04-28 is unverifiable through the named sources. It is possible Slavin assigned or licensed the patent between 1874 and 1891; that fact, if it exists, is not recoverable from USPTO Assignment Center, PEDS/ODP (which has no meaningful data for an 1874 grant), SEC EDGAR (no 19th-century filings of this type), or the RPX / Unified Patents asserter directories.

Disambiguation warning (worth flagging for whoever set up this query): the number "150262" also appears as the application serial number of US 3,142,326 (William L. Lindley, "Wheel rim attachment for a tubeless tire," filed 1961-11-06, issued 1964-07-28). A query run against an application-number or serial-number field will return the Lindley tire patent, a live-mid-20th-century asset with a real (searchable) chain of title — not this 1874 syringe cap. Do not merge the two records.

Timeline diagram

timeline
    title Ownership of US 150262
    1874 : Application filed April 4
         : Patent issued April 28 to P F Slavin
         : No assignee named on patent face
    1891 : Patent term expired April 28
    1980 : USPTO online assignment database begins
         : Zero records found for patent 150262
    2026 : Still no recorded assignments of record

NPE / troll-pattern signals

Global caveat that governs every row below: all eight signals are defined by recorded post-issuance transfers. This patent has zero recorded transfers in any searchable database, and its term ended in 1891. Accordingly each signal is marked not present in the sense of "no supporting record exists in any indexed source" — not as an affirmative forensic finding of good title. Signals 6 and 7 would require a 20th/21st-century operating company in the chain; none exists. Signals 1–5 require at least one recorded assignment; none exists. The 1980 coverage boundary means pre-1980 paper transfers are theoretically possible but unverifiable — I do not upgrade any row to "unclear" on that basis alone, because the same objection would apply identically to all eight rows and would make the rubric non-discriminating.

1. Shell-entity transfer — not present. No assignee of any kind is of record. No successor LO LLC, no Delaware/Texas single-member entity, no registered-agent address. The patent names the inventor personally.
2. Known asserter in the chain — not present. No assignee at all, therefore no match to Acacia, Marathon Patent Group, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg-linked entity. Note: the "Cited By" list on Google Patents is not evidence of a chain — the citing documents (US 4,832,695 Rosenberg Tamper evident injection syringe; US 5,417,661 Stringer Safety syringe; and the Dentsply dental-polymer family US 5,876,210 / US 5,998,499 / US 6,353,061 / US 6,369,164 / US 2005-0043490 A1) are downstream technical citations across unrelated owners. Treating that list as an assignment record would be an error.
3. Repeat correspondent across the chain — not present. With no recorded assignment, there is no correspondent of record in the Assignment Center sense (the correspondent field is populated by the recording party). The only names in the 1874 document are the attesting witnesses James T. Graham and T. B. Mosher, which are filing-era attestations, not recording correspondents, and they appear exactly once. No recurrence, no firm, no address, no Unified Patents / RPX / Patent Progress association. Not a finding.
4. Cascading transfers — not present. Zero consecutive transfers in any window, let alone multiple LLC-to-LLC hops in <24 months.
5. Pre-litigation transfer — not present. No infringement suit has ever named this patent; the patent expired 1891-04-28, 135 years ago. There is no litigation date to measure backwards from, and no assignment date to measure forwards to.
6. Bankruptcy fire-sale — not present. No operating-company assignee ever existed in the chain, so no Chapter 7/11 estate could have sold it. No Kodak/Nortel/Polaroid-style transaction record exists.
7. Privateering — not present. Requires an operating company → NPE transfer. No operating-company assignee of record; no SEC disclosure could exist for an 1874 individual grant.
8. Defensive aggregator — not present. Chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at statutory expiry on 1891-04-28.

Inverse-signal note: the practical analogue here is the strongest possible neutralization — not aggregation, but expiration plus public-domain dedication (pre-1883 grants were also subject to the era's abandonment/forfeiture doctrines for failure to pay issue fees, though nothing in the record indicates that occurred here). For assertion purposes the patent has been inert for over a century.

Verdict

Insufficient data — with a structural rather than evidentiary basis.

Justification: The only ownership fact of record is that Letters Patent No. 150,262 issued 1874-04-28 to Patrick F. Slavin as an individual, with no assignee named on the face and no assignment, merger, name-change, security, or license legal event on the Google Patents record; the patent expired 1891-04-28. USPTO Assignment Center cannot produce a reel/frame for this patent because its coverage begins August 1980 — 89 years after expiry — and pre-1980 records are held at NARA, so the absence of assignments is a database boundary and title after 1874 is simply unverifiable, not clean. Consequently no NPE signal can be grounded in a specific reel/frame entry, and the NPE/troll framework is inapplicable to a 152-year-old expired instrument: there is no chain, no assignee, no litigation, and no assertable right.

Verification links:

• USPTO Assignment Center (search patent number 150262 — expect zero results): https://assignmentcenter.uspto.gov/
• Legacy portal (retired 2026-02-02): https://assignment.uspto.gov/patent/index.html
• Google Patents legal events for this patent: https://patents.google.com/patent/US150262A/en
• Scanned original: https://patentimages.storage.googleapis.com/90/4b/2d/4b00b8f84bc546/[US150262](/patent/US150262).pdf

Process recommendation: if the live matter behind this request concerns active assertion of a patent numbered in the 150,000s, confirm whether the target is actually US 3,142,326 (Ser. No. 150,262) or a reexam/reissue descendant, and re-run the assignment pull against that number — an 1874 grant has no recoverable chain of title through any of the sources named in this brief.

I'll start by searching for the specific patent and checking for its citation records.

Let me verify whether the USPTO/Google Patents record lists any examiner-cited prior art (backward citations) for this patent, and check the related 1878 document.

Prior-Art Analysis — US Patent No. 150,262

1. Target patent (confirmed, interpreted literally)

2. Critical finding first: the record contains no examiner-cited prior art

The strict task is to "look at each patent citation for 150262." I checked the authoritative record (Google Patents / USPTO publication data) carefully, and the important, non-obvious result is:

• There is no "Patent Citations" / "References Cited" / §102 backward‑citation list on this patent's record. The Google Patents page for US150262A shows only two citation-adjacent tables: "Cited By" (forward citations) and "Similar Documents" — neither of which is prior art under §102. This is consistent with the fact that this is an 1874 pre‑examination-era U.S. patent: no prior-art references were printed on the face of such early patents, and none have been retro-added to the digital record.
• Therefore I cannot truthfully identify a genuine §102 anticipatory reference "cited by" this patent. Reporting one would require fabrication, which I will not do.

I want to be explicit about this rather than answer a different question than the one asked.

3. The "Cited By" table — every entry is forward citation, not prior art

The following 7–8 references appear on the record. Each postdates US150262 by roughly 110–130 years, so under 35 U.S.C. § 102(a)/(b) — which require the reference to predate the applicant's invention/effective filing date — none of them can anticipate or render obvious the 1874 claim. For completeness and per the request, each is listed with citation, dates, and description:

Interpretation of these forward citations:

• Entries 1–2 are genuine, topically-related downstream art (syringe improvements) that cite Slavin's 1874 cap as background/foundational art. They are relevant as evidence of the field lineage, not as §102 prior art.
• Entries 3–8 are Dentsply dental-polymer filings that are topically unrelated to syringe caps. Their appearance as "cited by" is almost certainly a citation/indexing artifact (shared family/citation data or an automated mapping), and they have no substantive bearing on the syringe-cap claim.

Anticipation conclusion for the sole claim: Because the claim requires (a) a cork C and (b) a metallic tube D with an upper flange spun over to clasp/lip the cork and a lower end spun outward to overlap the cork's inner end, no forward-cited reference above discloses this combination on its own effective date, and, more decisively, all of them postdate the 1874 filing, so §102 cannot be met by any of them.

4. "Similar Documents" — not citations, and not prior art

The record also lists documents such as US 200,909 ("Improvement in caps for glass syringes," 1878‑03‑05), US 193,023 ("Improvement in stoppers for mucilage-holders," 1877‑07‑10), US 258,035 ("Measuring bottle-stopper," 1882‑05‑16), etc. These are machine-generated textual/similarity neighbors, not citations by or against US150262. Note in particular that US 200,909 postdates US150262 (1878 vs. 1874) and therefore is not prior art to it either. These should not be reported as §102 references.

5. False-positive warning (identifier discipline)

A search for the number "150262" also surfaces US 3,142,326 A ("Wheel rim attachment for a tubeless tire," Lindley). That document's "Ser. No. 150,262" is an application serial number, not the granted patent number. Per the operating rule to interpret identifiers literally and not blend similar numbers, this is excluded — it is a different identifier, a different invention, and unrelated to syringe caps in every respect except the coincidental digit string.

6. Honest bottom line

• Genuine §102 anticipatory prior art cited by US150262: none on record. The digital record provides no examiner/backward citations, so there is no citation list to map against the sole claim under 35 U.S.C. § 102.
• All 7–8 "Cited By" references are forward citations issued 1989–2005 and are legally incapable of anticipating an 1874 claim under §102(a)/(b).
• Similar Documents are not prior art (and one of them, US 200,909, is itself later than 1874).
• To locate actual §102 prior art for this claim, one would need to search pre-April 1874 sources (contemporaneous 1860s–1874 U.S. patents on syringe pistons/corks, British/French syringe patents, and printed catalogues of Pravaz/glass-syringe makers). The available search tools did surface 19th-century syringe literature (e.g., a French-language article on the Lüer all-glass syringe at https://hal.science/hal-03592288, and the DPMA Erfinderaktivitäten survey describing US 686,451, US 718,979, US 723,588, etc.), but those items all postdate 1874 as well and are not tied to US150262's citation record.

If you can supply the USPTO PatentCenter/Global Dossier "References Cited" image for US150262 (if any examiner annotations were made), I can map each entry to the sole claim under §102 precisely. Based on the authoritative record I have accessed, however, no such citing prior art exists to analyze.

Primary source: Google Patents, US150262A — https://patents.google.com/patent/US150262A/en ; original specification PDF — https://patentimages.storage.googleapis.com/90/4b/2d/4b00b8f84bc546/US150262.pdf

I'll verify what prior art actually exists on this record before analyzing, since the page's "Prior Art" section is unusually sparse (the fetched text shows only a Cited By block and a Similar Documents block — no backward "Citations" block).

The record's "Prior Art" section is confirmed to contain only forward citations ("Cited By") and "Similar Documents" — no backward citations. Let me verify a few candidate references and the applicable legal standard.

§103 Obviousness Analysis — US 150,262 ("Improvement in caps for glass syringes")

Bottom line up front: I cannot produce a bona fide §103 analysis grounded in the record, because the Google Patents page for US 150,262 contains no prior-art citation block at all. What the page labels as related material — Cited By and Similar Documents — is (a) entirely forward-citing and post-dating, and (b) largely unrelated subject matter. I set out below what the page actually supplies, subject each entry to the statutory date test, and then give a clearly labeled constructive/hypothetical combination analysis. I also flag a threshold problem: §103 did not exist in 1874.

1. Threshold problems with applying §103 to this patent (must be stated first)

(a) Temporal inapplicability. US 150,262 issued April 28, 1874. 35 U.S.C. § 103 was enacted in the Patent Act of 1952 — 78 years later. For a patent granted in 1874 the governing invalidity standard was the pre-1952 judge-made "invention" requirement, canonically Hotchkiss v. Greenwood, 52 U.S. 248 (1851) ("ordinary skill and ingenuity" vs. "the work of the inventor"), later hardened into the "flash of genius" formulation of Cuno Engineering Corp. v. Automatic Devices Corp., 314 U.S. 84 (1941). (Caveat: my attempts to verify Hotchkiss and KSR in this session were cut off by a tool step-limit, so those citations rest on my training knowledge, not on a retrieved source — treat them as unverified for citation purposes.)

Applying § 103 here is best understood as a retrospective academic exercise, or as a proxy for the modern Graham/KSR framework used whenever an old patent's disclosure is asserted as prior art against a later filing.

(b) Mootness. The patent's term expired April 28, 1891 (Google Patents: "Anticipated expiration 1891-04-28"; "Expired – Lifetime"). It cannot be asserted, cannot be IPR'd, and no live validity controversy exists as to the claims of US 150,262 itself. The practical modern relevance of this document is the reverse of the task as framed: it is a §102 prior-art reference against later syringe-cap filings (e.g., the 1878 US 200,909 of the same title), not a target of §103 attack.

(c) §103 applies only to claims. Any analysis must be confined to the single claim identified in the prior section of this report — i.e., the combination requiring both (i) the spun-over top flange forming a lip, and (ii) the spun-out lower end overlapping the cork's inner end. Neither the barrel (A) nor the piston rod (B) is claimed ("about the construction of which there is nothing new").

2. Audit of the "Prior Art section" of the page — what is actually there

Critical finding: there are zero backward citations. No examiner-cited or applicant-cited prior art is recorded for US 150,262. Every reference on the page that is actually a reference postdates the patent. This is the central obstacle to the requested analysis and I will not manufacture a citation list to fill the gap.

3. Statutory date test applied to the only candidate references on the page

Only the Similar Documents block contains documents that could conceivably pre-date the April 4, 1874 filing / April 28, 1874 grant. Applying the date test literally (I have not verified any filing dates beyond those printed, and several entries show OCR year/content corruption):

Net usable prior art on the face of this page: at most two pre-1874 documents (US 105,104 and US 133,635), neither of which I could confirm discloses anything relevant to a syringe cap. That is not a sufficient evidentiary base for a prima facie §103 case, and I will say so rather than dress it up.

Also note: the seven/eight Cited By entries (US 4,832,695 Tamper evident injection syringe; US 5,417,661 Safety syringe; and the Dentsply dental-resin cluster — US 5,876,210, US 5,998,499, US 6,339,114, US 6,353,061, US 6,369,164, US 2005/0043490 A1) cannot support obviousness. They are later documents, so they are irrelevant to what a 1874 artisan would have known, and the Dentsply cluster (polymerizable dental compositions) has no apparent technical relationship to a cork-and-tube syringe cap. These are database artifacts of citation extraction.

(OCR caution observed in this session's results, consistent with the prior section's warning: the scanned US 208,062 sheet renders its own number variously as "208,062" / "205,062," and US 201,443 as "201,143." Numbers in this corpus must be read literally and not normalized — which is exactly why I have not merged US 200,909 into US 150,262.)

4. Graham v. John Deere analysis on the available record

A. Scope and content of the prior art. Two legs:

1. Self-admitted background art. The specification concedes the glass syringe barrel (A) and piston rod (B) are old, and implies the general practice of plugging the barrel with a cork having a longitudinal hole for the rod. This is the "admitted prior art" the claim must be measured against, and it supplies every element of the claim except the two swaged ends.
2. General state of the mechanical arts in 1874. The inventor's own language — "spun over," "spun outward" — describes spinning/lathe-swaging of sheet metal, a mature, ordinary workshop skill by 1874. Corroborating art surfaced in this session, though of mixed vintage: the Northern District of Illinois paint-can line (reported at 39 F. 544) describing flanged rings "interlocked" with folded and compressed cover flanges by "application of pressure," and US 1,033,196 (Roesch, 1912) attaching metal caps to glass syringe barrels by flanged engagement without screw-threading the glass. Both postdate 1874, so they are evidence of the durability of the technique, not prior art.

B. Differences between the prior art and the claim. Under the record as it stands, the differences are exactly the two swaged ends:

• top flange spun over to clasp the cork and form a barrel-rim-engaging lip (anti-push-in function); and
• bottom end spun out to overlap the cork's inner end (anti-withdrawal function).

Because the only defensible prior art here is the admitted background (unswaged cork + tube), the literal differences are the entire inventive contribution — which, standing alone, is a thin but non-zero record for validity.

C. Level of ordinary skill (PHOSITA, as of 1874). A mechanic or surgical-instrument maker familiar with (i) hand-blown/drawn glass syringe manufacture and its brittleness, (ii) cork as a compressible piston/plug material, and (iii) sheet-metal spinning and swaging on a lathe. Notably, the solver's toolbox includes spinning, because the inventor relied on no exotic step but the ordinary tinsmith's "spinning."

D. Secondary considerations. None of record. No commercial-success, copying, licensing, long-felt-need, or industry-praise evidence appears in the specification, the Google Patents record, or any source located in this session. For an 1874 patent that expired in 1891, such a record is effectively unavailable. Accordingly, there is no objective indicia to rebut a prima facie case — but equally no affirmative evidence to support nonobviousness. This neutralizes the factor on both sides.

5. Constructive §103 combinations (hypothetical — the record does not supply them)

I present these expressly as hypotheses built from what the page offers plus general mechanical-art knowledge. None is supported by a reference I have verified as disclosing the necessary elements, and a real examiner could not rest a rejection on them without such references.

Combination 1 — Admitted syringe art (primary) + sheet-metal can/cap seaming art (secondary).

• Primary: cork-plugged glass syringe with a central guide tube (admitted old).
• Secondary: US 133,635 (Delany, 1872-12-03, "Improvement in sheet-metal cans") — candidate only; I retrieved its bibliographic record but not its text. Also available as general knowledge: pre-1874 can/cover art in which a flange is folded or compressed over an edge to interlock two parts under pressure (the technique the 39 F. 544 opinion describes as long-standing).
• Motivation to combine: Both address the same mechanical problem — captivating a deformable or friable body within a metal shell so it cannot be displaced along its axis — and the fields are analogous under the "reasonably pertinent to the particular problem" test: a can closure and a syringe-barrel cap are both sheet-metal closures for a tubular body. A 1874 artisan seeking to keep a cork from separating from its guide tube would look to can/closure seaming as a known, cheap, tool-free method.
• Result: renders obvious the top spun-over flange/lip. Strongest as to that element.

Combination 2 — Combination 1 + the anti-withdrawal swage as an obvious design expedient.

• Once the artisan has swaged one end over (Combination 1), the second end's deformation is the natural complement: a body swaged over at the top only remains free to slide/fail at the bottom, and the specification's own rationale — tube "drawn out of the cork... should said cork be compressed by being forced into a syringe a little too small" — is a foreseeable consequence of single-ended swaging, discoverable by ordinary trial. This is the KSR "obvious to try" / "predictable variation" line: swaging the second end of the same tube, using the same tooling and technique, to bear against the same cork, is a variation a PHOSITA would implement with a reasonable expectation of success.
• Result: renders obvious the second swage and therefore the claim as a whole — if both references exist. This is the combination that defeats the claim, and it is the one I would expect an examiner to attempt.

Combination 3 — "Mere duplication of parts" / old-element aggregation. Both swaged ends perform the same generic function — axially retaining a member against displacement in one direction. An argument that the claim is an aggregation of two old expedients each performing its own independent function (lip prevents ingress; lower flange prevents egress) invokes the pre-1952 aggregation-of-old-elements doctrine. Weak on this record: the two deformations are structurally asymmetric, are formed in sequence on the same tube, and interact with the same cork through a thickness dimension (cork compression), which is more than bare juxtaposition.

Why the modern court would likely still uphold the claim (validity holding, for what it is worth):

1. No reference of record — indeed, none located this session — discloses a spun-over flange applied to a cork having a through-hole for a piston rod, or a spun-out tube end overlapping the inner end of a cork for anti-withdrawal.
2. The problem solved is narrow and specific (cork compression in an undersized barrel causing tube pull-out), and the reason for the second swage is not taught by can-seaming art, which addresses static sealed containers, not a cork that is deliberately radially compressed during use.
3. The claim's "substantially as herein shown and described" closer imports the illustrated structure (flange edge projecting "a little beyond the sides of the cork"; tube bore sized so the rod "can work in it freely"), narrowing the claim and making any rejection easier to distinguish.
4. The single claim is a true combination claim: a cap with only the top lip, or only the bottom flange, arguably falls outside it. A §103 case must therefore show both deformations, which on this record it cannot.

Net assessment: On the record actually available, the claim is not shown to be obvious — but only because no qualifying prior art exists in the citation record, not because the subject matter is technically deep. Were a §103 rejection to be attempted, the most likely basis is Combinations 1+2 above (analogous can-closure seaming art + predictable second-end swage). That is a plausible rejection in principle and unprovable on this page.

6. Explicit uncertainties / limitations of this analysis

• No backward-citation block exists on the page. My conclusion that the page supplies no §102/§103-qualifying reference is a statement about this page, not proof that no such art exists in the 1874 prior-art corpus. Class A61M and the 1870s "surgical instruments" and "tinware" classes almost certainly contain closer art I could not retrieve.
• US 133,635 (1872) and US 105,104 (1870) were verified only bibliographically (date, title, inventor for the former; I could not confirm the latter's content at all — my search returned unrelated firearm material). I therefore cannot and do not assert they disclose spun-over flanges or interlocks.
• Hotchkiss v. Greenwood, Cuno, Graham v. John Deere, and KSR were not verified by search in this session (tool step-limit reached). Cite them from primary sources before relying on them.
• Google Patents' "Similar Documents" are algorithmic, not evidentiary. They are not admissions, not citations, and not a prior-art statement by anyone. Several entries show OCR corruption (e.g., "sheet-wietal cans," "sheet-wietal," "spittoons," garbled inventor strings), and I treated titles literally per the operating rules.
• No assignment, prosecution, or litigation record was retrieved. The prior section's findings stand: no assignee on the face of the grant, no litigation, expired 1891.
• The Cited By Dentsply cluster remains unexplained. I did not verify why Google's citation extractor links five dental-resin patents to this document; I have treated them as noise and not as art.

7. Sources

• US 150,262 full text, Cited By, Similar Documents, and status fields (the source page for this task): https://patents.google.com/patent/[US150262A](/patent/US150262A)/en
• US 150,262 granted specification PDF (authoritative text; "cork C," witnesses James T. Graham and T. B. Mosher): https://patentimages.storage.googleapis.com/90/4b/2d/4b00b8f84bc546/[US150262](/patent/US150262).pdf
• US 133,635, "Improvement in Sheet-Metal Cans," John L. Delany, 1872-12-03 (bibliographic record only): https://texas.dp.la/item/17af482fb26a7e7d335d8f18a82c3e20
• Can-cover flange interlocking / double-seaming practice, N.D. Ill. opinion reported at 39 F. 544 (post-1874; cited as evidence of the technique's age, not as prior art): https://law.resource.org/pub/us/case/reporter/F/0039/0039.f.0544.pdf