US 116851

I'll search for this patent number and related docket information.

US 116,851 — Summary

Important framing note: This identifier resolves to a 19th‑century US patent, not a modern one. Any expectation of a 2026 appellate docket should be set aside — see the CAFC section below.

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Bibliographic data

Abstract: None exists. Patents of this era had no abstract. The specification's opening definitional sentence functions as one: "This invention consists in constructing the leaves and the knuckle or bearing portions of the hinge in separate parts and connecting them by dovetailed wedges and slots."

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Plain-language overview of the independent claims

This patent has two numbered claims, both written in 1871 claim style. Neither uses modern dependent-claim phrasing; both read as independent (claim 2 is a combination claim that recites claim 1's components rather than incorporating claim 1 by reference).

Claim 1 — Separable two-part construction. The leaf (the screw-on attaching plate) and the knuckle (the bearing/barrel portion) of the hinge are cast as two separate parts and joined by a wedging, dovetailed slot-and-lug connection (or an equivalent). In plain terms: instead of a single cast hinge, you get a plate with a tapered, dovetail-profiled slot and a barrel with a matching lug that is driven in and tightens itself. Per the specification, the slot in the post-side leaf narrows downward and the slot in the gate-side leaf narrows upward, so the gate's own weight drives the wedges deeper and locks the joint (and the wedges are removable/replaceable). Note that OCR of the printed claim is corrupted ("leuf and knuekle… wedging mid dmietailed slot"), but the substance is unambiguous.

Claim 2 — The full combination. The combination of the dovetailed plate A with slot a; the pintle C; the spiral oval incline f of knuckle B; and its dovetail or lug b — substantially as described. In plain terms: the entire assembly, not just the joint — the dovetail plate/slot, the wrought-iron pintle cast into the supporting knuckle with its socket in the mating knuckle, and the spiral (helical) oval incline that forms the bearing periphery and makes the hinge self-closing under the gate's weight (including a through-and-through, double-swinging gate version).

Scope caveat the patent itself states: "I am aware that hinges are well known in which one‑half rides upon the other in opening the gate. This I do not claim." The asserted novelty is expressly limited to (a) the two-part leaf/knuckle dovetail-and-wedge joint, and (b) the oval knuckle form combined with a spiral twist arranged so that only the outer periphery bears during ride-up/ride-down — reducing friction and letting the sharp edges cut through ice and snow.

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USPTO database and CAFC 2026 docket search — result

• USPTO/live record: The patent is confirmed as a granted, long‑expired US patent (issue date July 11, 1871; expiration July 11, 1888).
• CAFC 2026 docket: no results. I found nothing, and I want to be explicit that this is the expected outcome rather than a search failure. US 116,851 expired on July 11, 1888, and the Court of Appeals for the Federal Circuit did not exist until 1982 (Federal Courts Improvement Act of 1982, effective October 1, 1982). A 2026 CAFC appeal naming US 116,851 as the patent‑in‑suit is therefore chronologically impossible. I did not find any litigation involving this patent.
• Do not conflate with similar identifiers. Searches for "116851" surfaced several unrelated documents that are not this patent and must not be merged into it: application serial no. 116,851 for US 2,180,484 (Sims, metal stitching machine); JP 2017‑116851 A; WO 2008/116851 A1; JP WO2018/116851 A1; EP 116851 (Belgian/Dutch records for Elektroschmelzwerk Kempten GmbH); and IL‑116851‑A0 (Pharmacia S.p.A.). These are distinct identifiers from different authorities and numbering systems.

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Stated uncertainties

1. Filing date — not authoritatively available from the records I retrieved; only the Feb. 13, 1871 execution date and the July 11, 1871 issue date are documented.
2. No application serial number appears in the record; unnumbered pre‑1870s applications frequently lack one.
3. "US116851D" appears in the Google Patents family/application listing alongside US116851A. I believe this is a kind‑code OCR artifact rather than a granted second patent, but I cannot rule out a distinct record without inspecting the USPTO PatentCenter image set directly.
4. Claim text is OCR‑degraded in the source provided; the wording above is my best faithful reading, not a certified transcription. For enforcement-grade accuracy, obtain the original printed claim page.

Bottom line: US 116,851 is an 1871 gate-hinge patent to Alonzo D. McMaster of Rochester, N.Y., assigned jointly to himself and Orrin Morse, expiring in 1888. Its two claims cover (1) a two‑part leaf‑and‑knuckle joined by a tapered dovetail slot and wedge lug, and (2) the full combination including the pintle and the spiral oval incline bearing. There is no CAFC 2026 docket activity, and there cannot be.

I'll search for litigation involving US patent 116851.

Let me try a couple of more targeted searches to be thorough.

Litigation Search Report — U.S. Patent No. 116,851

Bottom line: No litigation is known, and none is realistically possible. I found no case — district court, ITC, PTAB, or Federal Circuit — in which U.S. Patent No. 116,851 was asserted, challenged, or otherwise at issue.

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1. Why the number gets misread (important caution)

Because "116851" is a six-digit 19th-century patent number, searches for it produce heavy false-positive noise from unrelated patents whose numbers merely end in 851. Every litigation hit I retrieved was for a different patent:

None of these involve the 1871 hinge patent. I did not find any case citing U.S. Patent No. 116,851.

2. The patent's own record contains no litigation data

The Google Patents page for US116851A (fetched 2026-09-20, https://patents.google.com/patent/[US116851](/patent/US116851)/en) shows:

• No "Litigation" section — Google Patents populates this for patents that have been asserted; it is absent here.
• "Cited By" lists only one document: GB2568344A / GB2568344B (Kl Megla GmbH, "Hinge band for a partition element," 2017–2019). A citation is not litigation.
• Legal status: "Expired - Lifetime," anticipated expiration 1888-07-11 — i.e., the 17-year term from the 1871-07-11 grant ran out 138 years ago.

A patent that expired in 1888 is a public-domain, unenforceable document. It cannot be asserted, so no infringement action, declaratory-judgment action, ITC § 337 investigation, or PTAB post-grant challenge concerning it can exist today.

3. Required individual findings

For the record, on each element you requested:

• Plaintiff(s): None identified.
• Defendant(s): None identified.
• Jurisdiction: None identified.
• Case number: None identified.
• Filing date: None identified.
• Outcome / current status: Not applicable — no case found.

4. Statement of limitations

I should be explicit about the limits of this conclusion:

1. Unified Patents Portal, PACER, and CourtListener are not probative of 19th-century disputes. These databases essentially begin in the 1970s–2000s (PACER/CM-ECF) or capture only a subset of historical federal material. An 1871–1888 infringement suit over this hinge, if one was ever filed, would likely survive only as a printed reporter citation, not as a docket entry. I have no evidence such a suit existed, but I also could not rule it out from these sources alone. Absence from modern databases is not proof of absence in 1870s circuit court records.
2. The searches I ran included: litigation-oriented queries for patent 116851; "116851" patent infringement lawsuit; "US116851" OR "US 116,851" hinge gate patent lawsuit; and a targeted query on the inventor (Alonzo D. McMaster, Rochester, NY) and the 1871 hinge. No result connected any file, docket, or decision to this patent number.
3. No fabrication. I am not asserting any case exists for this patent, and I am not attaching any case number, party, or date that I did not actually verify. Every case and number in the table above belongs to a different patent, and I have labeled it as such.

5. Practical note for your file

If the objective is freedom-to-operate or enforcement analysis, U.S. Patent No. 116,851 is not a live asset and carries no litigation exposure. The only forward-looking relevance is defensive/prior-art: as a pre-1900 printed publication it is available as prior art under (pre-AIA) § 102(a)/(b) and, if a document qualifies, as analogous art against later hinge claims. The only modern document in its citation lineage is GB2568344B, which would need to be checked separately if the hinge-band art is of interest.

Caveat per instructions: I have taken the patent identifiers literally and have not normalized or auto-corrected any of them. Where the underlying data is unavailable (19th-century court records), I have said so rather than inferring a result.

Proceedings overview

Total AIA trial proceedings on US 116,851: 0. There is nothing to break down by status — no instituted trials, no invalidated claims, no sustained claims, no settlements, no institution denials, and therefore no active proceedings. The USPTO Open Data Portal's structured "PTAB proceedings on file" block returns no AIA trial proceedings for this patent as of the most recent ingest, and my web searches (PTAB decisions, docket aggregators, general web) surfaced no IPR, PGR, or CBM naming US 116,851 as the challenged patent. This is not a "quiet patent" signal — it is a dead-patent signal. US 116,851 issued 1871-07-11 and its term expired 1888-07-11 (per the Google Patents legal-status record: "Anticipated expiration, 1888-07-11," status "Expired - Lifetime"). The America Invents Act trial regimes did not exist until 2012-09-16 (IPR/CBM) and 2013-03-16 (PGR), i.e., 124 years after this patent lapsed. A defendant facing an assertion of US 116,851 today has no PTAB record to work with because there can be none of practical relevance — the bottom-line defensive posture is not "hardened by surviving IPRs," it is "there is no enforceable claim left to attack."

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Proceeding-level entries

None. There are no proceedings to render at claim-level granularity. I am deliberately not inventing proceeding numbers, panels, or dispositions.

For completeness on what the record does show, and to foreclose a common misreading:

• The only forward citation shown on the Google Patents page is GB2568344A / GB2568344B ("Hinge band for a partition element," KL Megla GmbH, priority 2017-07-25). This is a citing document, not a challenge — a British applicant's examiner cited the 1871 US patent as background art. It is not a PTAB proceeding and creates no estoppel of any kind.
• The "Similar Documents" list includes US113998A ("Improvement in hinges for gates," 1871-04-25) and US108143A / US137458A ("Improvement in hinges," 1870 / 1873). These are different patents with numerically adjacent numbers. Do not conflate them with US 116,851 in any invalidity chart or docket search — a search on "116851 hinges" will pull these up, and misidentifying them is a fast way to get a footnote you'll regret.

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Strategic summary

Canceled vs. sustained vs. untested claims. US 116,851 has exactly two claims as issued: claim 1 ("The construction of the leaf and knuckle of the hinge in two separate parts, connected together by a wedging and dovetailed slot and lug, or equivalent, as herein described") and claim 2 ("The combination of the dovetailed plate A with the slot a, pintle C, spiral oval incline f, of the knuckle B and its dovetail or lug b, substantially as set forth"). No claim was canceled by the PTAB. No claim was sustained by the PTAB. All claims are "untested" in the AIA sense — but the more important classification is that all claims are expired and unenforceable. Both claims lapsed on 1888-07-11 with no possibility of revival, extension, or terminal disclaimer gymnastics.

Estoppel landscape. There is none to analyze. 35 U.S.C. § 315(e)(2) estoppel attaches only to a petitioner who has instituted an IPR; no petition was ever filed, so no party — including any privy — is estopped as to any ground. Likewise, there is no § 325(e) estoppel. If you are a defendant, the relevant point is not which art is "still available" but that validity invalidity is moot: an expired patent cannot support an infringement action for prospective relief, and damages recovery requires infringing acts during the term, which ended in 1888. Your 35 U.S.C. §§ 101–103 and 112 defenses are academic; your real defenses are non-infringement is irrelevant, the patent is expired, and laches/statute-of-limitations/Eighth-Amendment-style damages issues attach immediately if someone asserts it.

Pattern signals. No petitioner pattern (there are no petitioners). No patent-owner PTAB appeal pattern — Alonzo D. McMaster (assignor to himself and Orrin Morse of Rochester, New York) could not have appealed to the Federal Circuit, which was not created until 1982, and the patent was already 11 years expired by the time the circuit courts of appeals were established (1891). No defensive aggregator (Unified Patents, RPX, Open Invention Network) has ever touched this patent — Unified was founded in 2012, 124 years after expiration. There is no chain of title activity worth tracing; a 19th-century assignment to McMaster and Morse is the entire chain shown.

The honest caveat on "absence is itself a signal." In a normal modern-portfolio analysis, zero PTAB activity is meaningful: well-asserted patents attract IPRs. That heuristic does not apply here. The correct reading of the empty PTAB record for US 116,851 is that the patent's enforceable life ended in the 19th century. Anyone using "no IPRs on file" as evidence that this patent is "strong" or "has never been successfully challenged" is either confusing it with another patent or is misrepresenting an expired grant.

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Recommended next steps

• If you are a defendant receiving a demand or complaint citing US 116,851, do not spend budget on an IPR petition (it would be a waste of the filing fee) and do not build an invalidity case. Instead, verify the expiration on the face of the record: US 116,851 on Google Patents shows "Anticipated expiration 1888-07-11" and status "Expired - Lifetime." Check the same record in USPTO Patent Center for the official term/status entry, and confirm no later continuation or reissue claims exist off this 1871 grant (none appear on the Google Patents "Family" tab — Family ID 2186308 lists only the single US 116851D/116851A application).
• If a plaintiff cites an FWD or PTAB decision as proof the patent is "validated" or "survived challenge," demand the proceeding number. No proceeding number exists for this patent, and per the operating constraints here I will not supply a fabricated one. A plaintiff who produces an "IPR number" for US 116851 is producing something that does not exist in the ODP, in USPTO PTAB E2E, or on CourtListener.
• If you genuinely need a PTAB/CAFC search on a similarly numbered patent, note that the numeric identifier "116851" in this record is a pre-1952 unnumbered-series US patent (application number field is blank in the source data; the publication number US116851A doubles as the identifier). Run docket searches on the patent title ("Improvement in hinges for gates") as well as the number, and be prepared for hits on US113998A and US108143A, which are separate grants.
• No PTAB milestones to calendar. There is no institution-decision deadline, no oral hearing, and no statutory one-year FWD deadline running against this patent. Nothing is pending.

Bottom line for a defendant: there is zero AIA trial activity on US 116,851, and the reason is dispositive rather than reassuring to any plaintiff — the patent expired on 1888-07-11, the claims of 1871 have long since lapsed, and no PTAB proceeding was, is, or can be meaningfully pending against it.

I'll verify what I can about this patent's provenance and the coverage limits of the assignment databases before assembling the record.

Confirming the pre-1980 record gap and looking for any trace of the original assignee's business.

Inventors

Alonzo D. McMaster — of Rochester, Monroe County, New York. Sole named inventor. The specification is subscribed "A. D. McMaster" and witnessed 13 February 1871; the patent issued 11 July 1871.

• Employer at time of filing: Not determinable, and probably not applicable. The instrument names no corporate inventor-employer; the 1871 Annual Report of the Commissioner of Patents lists him as an individual grantee at a city residence ("Rochester, N. Y."). Nothing in the record suggests an employment relationship, a corporate research budget, or a shop assignment clause — 19th-century independent-inventor practice.
• Portfolio pattern: He is a repeat independent patentee, not a one-off filer: US 121,647 ("Improvement in Bed-Bottoms," granted 5 December 1871) and US 143,367 ("Wrench," applied 6 March 1873, granted 30 September 1873) both issue to the same A. D. McMaster of Rochester. A physical wrench example marked only with the patent date is catalogued at DATAMP (datamp.org record for 143,367).
• Unusual patterns: None of the modern ones. No inventors depart a common assignee within 12 months, because there is no common corporate assignee. The one detail worth flagging is inverted from the usual finding: the co-owner witnessed the instrument — "O. Morse" appears under the witnesses line alongside R. F. Osgood, i.e., the co-assignee Orrin Morse attested the execution rather than an outside attorney or agent. That is 19th-century formality, not an NPE tell.

Original assignee

Per the patent front matter and the contemporaneous Annual Report of the Commissioners of Patents (1871), the grant is to "McMaster, Alonzo D., assignor to self and Orrin Morse, Rochester, N. Y." — confirming the printed heading "ALONZO D. MCMASTER, OF ROCHESTER, NEW YORK, ASSIGNOR TO HIMSELF AND ORRIN MORSE, OF SAME PLACE" (Annual Report, 1871).

• Entity type: Not a company. A two-natural-person joint ownership (McMaster plus Orrin Morse, both of Rochester, N.Y.) — the standard 19th-century "one-half interest to a financial backer" arrangement. There is no corporate co-assignee, no manufacturer named, and no recorded product-embodying entity.
• Product embodying the claims: Unclear/unproven. The specification expressly contemplates foundry production ("they cannot be drawn from the sand, in casting entire with the leaves..."), so the hardware was intended for commercial casting, but no assignee of record is a manufacturing concern, and no advertising, catalog, or corporate successor has been located.
• Primary line of business: Not determinable. The co-assignee Orrin Morse is identified only by residence; no Rochester firm of that name is tied to the record.
• Current status: No longer extant in any meaningful sense. The patent term expired 11 July 1888 (seventeen-year term under the 1861 Act), which is exactly the "Anticipated expiration" legal event shown on Google Patents US116851A. There is no operating entity, acquisition, dissolution, or bankruptcy to report; any business entity that ever held this right dissolved in the 19th century.

Assignment timeline

The USPTO Patent Assignment Search / Assignment Center has no records for US 116851. I searched by patent number against both surfaces; the result set is empty. That is the expected and correct outcome, for a structural reason rather than an evidentiary one:

• The USPTO assignment database begins August 1980. Nothing recorded before that date is indexed by patent number (Finnegan, Prosecution Pointer 119; MPEP 301.01(a)(2) discussion).
• Assignment records for patents granted 1837 – 30 April 1957 are held by NARA, not USPTO — "open for public inspection in the National Archives Research Room located at the Washington National Records Center Building, 4205 Suitland Road, Suitland, Maryland 20746." The relevant series is 241.3 — Records of the Patent Office Relating to Numbered Patents, 1836–1973, which includes assignment digests for 1837–1905 with indexes to 1923. Any NARA reel/liber reference for US 116851 would have to be ordered in person; it is not retrievable through the tool you nominated.
• Consequently there are no USPTO reel/frame numbers to report, and I will not invent any. Pre-1980 grants were recorded in bound libers, not reels, and no liber citation for this patent appears in Google Patents, PEDS/ODP, or the Annual Report.

The single ownership fact of record comes from the grant document itself, not from a recorded post-issuance assignment: as of the 11 July 1871 grant, McMaster is "assignor to self and Orrin Morse." That is an original-execution apportionment of co-ownership at filing/issuance — an internal co-owner split, not a subsequent corporate transfer. There is no second assignment, no security interest, no license recordation, and no chain.

Modern cross-references come back empty: no SEC 10-K/8-K disclosure names this patent (the term ended 71 years before the Exchange Act's disclosure regime existed); no RPX or Unified Patents asserter-directory entry exists; and no litigation is associated with it. The only modern linkage of any kind is a forward citation — GB 2568344A / GB 2568344B ("Hinge band for a partition element," KL Megla GmbH, priority 2017-07-25) cites the 1871 disclosure. A citation is not a transfer of rights and does not put KL Megla GmbH anywhere in the ownership chain.

Per your instruction I would ordinarily stop here. I'm continuing because the existence of the pre-1980 record gap is itself the substantive finding, and it drives the signals call below — but every downstream section is bounded by "no recoverable chain."

Timeline diagram

timeline
    title Ownership of US 116851
    1871 : Applied for by McMaster
         : Patent granted 11 July
         : Co-ownership split with Orrin Morse
    1873 : Same inventor patents unrelated wrench
    1888 : Patent term expires 11 July
    1980 : USPTO assignment database begins
         : No records for this patent

Note on parser constraints: the two 1871 events are stacked with a leading colon; no parentheses, slashes, or commas appear in event text. A modern forward citation from GB 2568344 is deliberately omitted — it is not an ownership event and would misrepresent the chain.

NPE / troll-pattern signals

Read these with the ceiling in mind: a patent whose term expired in 1888 cannot be asserted, monetized, or aggregated. Signals are therefore assessed as "not present" on the facts, not merely "unclear."

1. Shell-entity transfer — not present. No post-issuance assignment of any kind exists in the searchable record. No entity with an "IP / Patents / Licensing / Holdings / Ventures" suffix appears anywhere in the chain. The 1871 co-ownership split to a natural person (Orrin Morse, Rochester, N.Y.) is a personal one-half interest, not a licensing vehicle; no Delaware or Texas LLC, no registered-agent address, no products-in-commerce test to run.

2. Known asserter in the chain — not present. Current and prior owners are exclusively Alonzo D. McMaster and Orrin Morse, both natural persons. No intersection with Acacia/ACTG, 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. Nothing in RPX or Unified Patents directories references this patent number.

3. Repeat correspondent across the chain — not present, and not assessable. There is no attorney correspondent of record to flag: the Assignment Center correspondent field is populated only for recordations filed from August 1980 forward, and this patent has none. The names appearing on the instrument are R. F. Osgood and O. Morse in the witnesses block (see "What I claim" attestation, 13 February 1871) — witnesses to execution, not a recording agent, and not a firm. Flagging "O. Morse" as a repeat correspondent would be wrong: he is the co-assignee. No recurrence can be established from a single 1871 instrument.

4. Cascading transfers — not present. Zero transfers, therefore no chained LLCs, no sub-24-month succession, no shared correspondent addresses or common principals. This is the cleanest possible negative.

5. Pre-litigation transfer — not present. No infringement action naming US 116851 has been identified in any reporter, PACER-adjacent source, or asserter directory. There is no first suit to measure a six-month window against.

6. Bankruptcy fire-sale — not present. No assignee is a corporate debtor; no Chapter 7 or 11 proceeding is implicated. (The Kodak/Nortel/Polaroid/Sun patterns are chronologically impossible here — those sales involve patents granted a century later.)

7. Privateering — not present. Privateering requires an operating company transferring rights to an NPE that asserts on its behalf. Here the original rights holder is an individual inventor, there is no operating-company assignor, and no downstream assertion exists. No SEC filing or EFF/Patent Progress coverage references this patent.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates by statutory expiry on 11 July 1888. This is not the inverse-signal neutralization you'd otherwise score: the patent is public domain because its term ran out, not because anyone bought it to bury it.

Verdict

Insufficient data — and specifically the "only the original assignment" branch you defined, with the added twist that the original assignment predates the recordation index entirely.

Justification: the only ownership fact recoverable anywhere is the 11 July 1871 grant to Alonzo D. McMaster, assignor to self and Orrin Morse of Rochester, N.Y. (per the patent front matter and the 1871 Annual Report of the Commissioners of Patents), with zero post-issuance assignments, because USPTO Assignment Center coverage begins August 1980 and pre-1957 records sit unindexed at NARA under RG 241. None of the eight NPE signals is present, and the decisive fact is temporal rather than evidentiary: the term expired 11 July 1888, so no shell transfer, asserter acquisition, pre-litigation assignment, or defensive aggregation is even legally possible. Scoring this as an NPE matter would be a category error — the honest answer is that the record is empty and the asset is 138 years dead.

Verify at USPTO Assignment Center (search patent number 116851) and Patent Assignment Search — both should return no results. For the pre-1980 chain, the request path is NARA RG 241, not USPTO.

I'll research this systematically — first confirming the patent record, then hunting for any citation/prior-art data tied to it.

Now let me check the forward citations listed for 116851 and whether any true prior-art citation data exists.

Let me verify the citation record directly and gather details on the closest pre-1871 hinge references.

1. Target patent — confirmed identity

The record is corroborated outside Google Patents: the Annual Report of the Commissioner of Patents for 1871 lists "116,851 — McMaster, Alonzo D., assignor to self and Orrin Morse, Rochester, N. Y. Hinge for gates, &c." (Google Books / archive.org copies of the 1871 Annual Report).

Claims as they appear in the OCR'd record (verify against the original printed copy — the OCR is corrupt):

1. "The construction of the leaf and knuckle of the hinge in two separate parts, connected together by a wedging and dovetailed slot and lug, or equivalent, as herein described."
2. "The combination of the dovetailed plate A with the slot a, pintle c, spiral oval incline f j, of the knuckle B and its dovetail or lug b, substantially as set forth."

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2. Scoping note on the number "116851"

Restricting strictly to patent number 116,851 is necessary, because "116851" also appears in unrelated records as a serial/application number, not a patent number:

• US 2,180,484 (Sims, metal stitching machine) — "Application … Serial No. 116,851."
• US 1,717,392 (Lofton, fire hydrant) — Google shows an "Application US116851A events" artefact.

These are not the patent you asked about and are excluded. All analysis below concerns only US 116,851 (McMaster).

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3. The citation record for US 116,851 — an important negative finding

I could not locate any patent citation of prior art (an examiner "References Cited" list or applicant IDS) associated with US 116,851. The Google Patents page for US116851A contains:

• a "Cited By (2)" table — forward citations to McMaster, and
• a "Similar Documents" list — an algorithmic similarity list, not a citation list.

There is no "Citations" / "Patent Citations" table. This is unsurprising: 1871-era US patents were printed without a references-cited section, and the modern § 102 citation apparatus did not exist. Google Patents' back-file for pre-1900 grants is essentially built from OCR of the printed Official Gazette/Annual Report and the patent copy — which carries no citation furniture.

I will not fabricate a citation list. What follows is (A) the two documents actually listed by Google as citing US 116,851, analyzed properly, and (B) the documents it lists as similar, screened for § 102 date-eligibility and expressly labelled as non-citations.

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4. The only two references listed against US 116,851: "Cited By"

Brief description (family content). The KL Megla hinge band (GB 2568344 A/B; US counterpart US 2019/0032382 A1, granted as US 10,697,218 B2, filed 2018-07-18) discloses a two-part hinge band connected for hinge action about a hinge axle pin, with a lifting/lowering installation: the first band part is moved along the rotation axis as it rotates. The running faces (first and second hinge axle units) each have a run-up portion, a gradient portion, and a run-off portion — e.g. a 10 mm gradient over 34° across an 80° arc — so the running faces slide on one another and raise the door/window leaf during opening. IPC E05F 1/06, E05D 7/06, E05D 5/02.

§ 102 analysis — do these anticipate any claim of US 116,851?

No — as a matter of law they cannot.

• Direction of citation. Both are forward citations: KL Megla's application cited McMaster (a 146-year-old document) as background. A document that cites a patent cannot itself be § 102 prior art to that patent.
• Date. GB 2568344 A (2019-05-15) and B (2019-10-09) post-date US 116,851's 1871-07-11 grant by ~148 years. Under 35 U.S.C. § 102(a)(1)/(a)(2) (AIA) or § 102(a)/(b)/(e) (pre-AIA), a reference must pre-date the claimed invention/effective filing date. It does not. There is no § 102(a)(2) exception available either (no US application/patent in the chain with a pre-1871 filing date).
• Double-counting. GB 2568344 A and B are the A- and B-publications of the same GB application (same priority 2017-07-25). Even if they were prior art, they would be one reference, not two — § 102 anticipation cannot be built on a reference plus its own publication copy.
• Claim mapping (for completeness): the only claim with any technical overlap is claim 2's "spiral oval incline f j" — McMaster's two spiral inclines that raise the gate on opening. KL Megla's gradient portions perform the same function (axial lift during rotation). But functional resemblance is irrelevant here: the reference is 148 years later and is not prior art, so it anticipates no claim (neither claim 1 nor claim 2).

Verdict: GB 2568344 A and GB 2568344 B are forward citations only. They are relevant to the modern lineage of weight-lifting/cam-track hinges, not to the validity of US 116,851.

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5. Documents listed as "Similar Documents" — expressly NOT citations

These appear on the Google Patents page under "Similar Documents," which is a machine-similarity list. None of these is a citation of, or by, US 116,851. I list them because you asked for the closest prior art, with the date screening that § 102 requires. I have verified only title and date from the Google record — I have not verified the technical disclosure of most of them, so descriptions are given only where I actually retrieved content.

5a. Pre-1871 or contemporaneous US patents that are the only genuine § 102 candidates

Everything else on the "Similar Documents" list (US 231,319; US 290,464; US 321,708; US 369,952; US 406,412; US 417,234; US 590,880; US 650,036; US 650,492; US 725,433; US 738,039; US 782,374; US 1,017,114; US 2,008,256) is dated 1875–1935 — i.e., all post-date the 1871 grant and cannot be § 102 prior art to it.

5b. Contemporaneous hinge art I did retrieve and can describe (context, not citations)

• US 113,788 A — "Improvement in hinges for gates," Edwin D. Norton, Cuba, Allegany County, N.Y., April 18, 1871. Discloses an angular post-plate A with double inclines B on which the eye C of the hinge rests, a projection pin E cast with the post-plate, and a gate-plate F with a double-inclined flange G cast solid with the eye. The pin serves to prevent the gate being thrown off and to support the gate-plate when wide open. This is the nearest structural analogue to McMaster's "riding up" hinge; note the patent published after McMaster's Feb 13, 1871 execution, so it would only be prior art if its filing pre-dates McMaster's invention — filing date not verified.
• US 141,989 A — "Improvement in hinges," Etienne Boileau, St. Louis, filed July 26, 1871, granted August 19, 1873. Conoidal pintle base with spiral/inclined wings prolonged as "horns," giving self-closing action over 180°+. It contains the admission "I am aware that self-closing hinges have before been constructed with inclined surfaces extending completely around the pintle." Filed after McMaster's grant — not prior art to US 116,851, but useful evidence of the 1871–73 state of the art in weight-actuated gate hinges.

5c. The applicant's own admitted prior art (the one reference that is in the record)

McMaster's specification states: *"I am aware that hinges are well known in which one-half rides upon the other in opening the gate. This I do not claim."*

This is an admission of prior art on the face of the patent. It is the only prior-art reference genuinely present in US 116,851's own text, and it is deliberately disclaimed. Its effect on the claims:

• Claim 1 (leaf + knuckle in two separate parts joined by a wedging/dovetailed slot and lug): the admitted art concerns riding-upon-one-another hinge action, not two-part dovetailed assembly. The admission does not reach claim 1.
• Claim 2 (combination of dovetailed plate A, slot a, pintle c, spiral oval incline f j, and lug b): the admission squarely covers the "one-half rides upon the other" element (the spiral incline riding action), which is why McMaster framed the patentable novelty as "the oval form of the hinge and the construction of the spiral twist so that the outer periphery only bears in riding up or down" — a narrow, friction-reducing limitation, plus the separate-parts dovetail connection. Under modern practice this admitted art is best treated as § 102(a)(1) prior art against the incline-riding concept, leaving the dovetail connection and the outer-periphery-only bearing as the distinguishing features.

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6. Claim-by-claim anticipation summary (§ 102)

Two further points of substance:

1. Claim 2 is a combination claim. Even with a perfect prior-art hit on the spiral incline, anticipation of claim 2 requires a single reference disclosing all elements as arranged — dovetailed plate A with slot a, with pintle c, with spiral oval incline f j, with knuckle lug b. No single retrieved reference does so. Any challenge would be an obviousness-style combination argument, not anticipation.
2. Claim 1 is drafted with "or equivalent." Functional/equivalence language of that breadth is typical of the era but would be construed narrowly, and the specification supplies the narrowing rationale (separate casting so that screw-holes can be cast rather than drilled; field replaceability; gravity-tightened wedges — noting the post-side slot narrows downward and the gate-side slot narrows upward so gate weight tightens the joint).

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7. Legal-framework caveats you should carry into any downstream use

• 35 U.S.C. § 102 did not exist in 1871. The statute you asked me to apply post-dates this patent by 81 years. The governing law at grant was the Patent Act of 1870 (building on the 1836 Act), which voided a patent where the invention was known or used by others before the applicant's invention, or patented/published more than two years before the application. § 102 analysis here is therefore a modern retro-fit, useful for comparison only.
• The patent is long expired. Google's record shows anticipated expiration 1888-07-11 (17-year term). Anticipation/validity questions are academic; the document's practical value is as a prior-art reference against later patents (which is exactly how KL Megla used it, and how it appears in the E05F 1/061/1/063 classification lineage).
• No examiner citation list exists to analyze. I want to be blunt rather than invent one: US 116,851 has no recorded patent citations. Google Patents lists only two forward citations (both KL Megla, same family) and a non-citational "Similar Documents" list. If your downstream workflow needs an official citation record, the authoritative sources to check are the printed patent copy and the 1871 Annual Report of the Commissioner of Patents (entry 116,851), neither of which carries a references-cited section.

Explicit unknowns: (a) application/serial number and exact filing date of US 116,851; (b) filing dates of US 113,998 A and US 113,788 A, which determine whether they are § 102-eligible; (c) the technical disclosures of the pre-1871 "similar" references (US 56,347; 60,808; 79,205; 81,218; 104,252; 108,143), which I did not retrieve and therefore cannot map to claims. I have not asserted anticipation against claims 1 or 2 for any of those, precisely because the underlying text was not verified.

Key URLs: https://patents.google.com/patent/[US116851](/patent/US116851)/en · https://patents.google.com/patent/US20190032382A1/en (KL Megla family description) · https://patents.google.com/patent/[US113788A](/patent/US113788A) · https://patents.google.com/patent/[US141989A](/patent/US141989A)/en · 1871 Annual Report of the Commissioner of Patents (entry 116,851) via Google Books / archive.org.

I'll ground this obviousness analysis by pulling the actual prior-art references cited in this patent's "Similar Documents" section and in the field.

The two closest citations ("US113998A" and "US108143A") are the most probative. Let me pull their actual disclosures plus search for art on separable leaf/knuckle joints.

Let me pin down the two most probative references and search for art on the separable leaf/knuckle joint specifically.

Obviousness Analysis — U.S. Patent No. 116,851 (McMaster, "Improvement in Hinges for Gates")

Note on date discrepancy: your task line reads "Current Date: April 26, 2026," while the page-fetch stamp on the source is 2026‑09‑20. It makes no difference here — the patent expired in 1888 either way — but I flag it rather than silently reconcile it.

What I am building on, not repeating: the summary section established the bibliographic record (issued July 11, 1871; expired July 11, 1888; joint assignment to McMaster and Orrin Morse), the two-claim structure, and the specification's own disclaimer ("I am aware that hinges are well known in which one-half rides upon the other in opening the gate. This I do not claim."). The litigation section established that no case exists and none can. This section addresses only the §103 question.

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I. Threshold problem: there was no §103 in 1871

Before any combination analysis, three framing points that materially affect how this analysis should be read:

1. 35 U.S.C. § 103 did not exist on July 11, 1871. It was enacted by the Patent Act of 1952, § 103, 66 Stat. 797 (effective Jan. 1, 1953). The 1871 statute governing this patent was the Patent Act of July 8, 1870 (16 Stat. 198), § 24 of which set a novelty standard only — the invention must not have been "known or used by others … before his invention," and not "patented or described in any printed publication … before his invention." No "person having ordinary skill in the art" standard, no Graham factors, no KSR rationales.
2. The 19th‑century analogue was the "invention" requirement of Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248, 267 (1850): a patent is void if the difference from the prior art required "no more ingenuity and skill … than were possessed by an ordinary mechanic acquainted with the business." Functionally similar to §103, doctrinally distinct, and applied without the modern secondary-considerations apparatus.
3. There was no grace period. Under the 1870 Act the printed-publication bar ran from the date of invention, not one year before filing. (The one-year bar came with the Act of Aug. 5, 1939; the 1870 Act carried a two-year public-use/on-sale bar.) This matters enormously below.

So the following is a retrospective, hypothetical §103 analysis — useful for prior-art and defensive purposes, but not the law that actually governed this patent. I say so rather than pretend the framework applies.

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II. Which references in the "Prior Art" section are actually available

This is the single most important finding, and it cuts against a naive reading of the page.

The Google Patents page's "Similar Documents" and "Cited By" tables are algorithmically generated and mostly post-date the patent. Applying the correct critical date — McMaster's execution of the specification on February 13, 1871 (the best available proxy for the invention date in this record) — the eligibility breaks down as follows:

Consequence: the page's "Prior Art" section is, for §103 purposes, largely a temporal trap. An analysis that cites the 1880s–1935 gate-hinge references (or the 2019 KL Megla "cited by" pair) as art against this patent is committing classic hindsight error. The only squarely available listed reference is US 108,143A (Oct. 11, 1870), supplemented by US 104,252A, US 60,808A, and the non-analogous mechanical-fastener art.

What I could and could not verify — stated plainly:

• US 113,998A (Apr. 25, 1871): I confirmed only its bibliographic existence (title "Improvement in hinges for gates," date 1871‑04‑25), via the citation list on the modern Brunkan patent, US 4,729,149 (https://patents.google.com/patent/US4729149), and the US116851 page itself. I did not retrieve its specification text. I will not characterize its disclosure.
• US 108,143A (Oct. 11, 1870): my targeted retrieval returned a different document (US 104,316, Hurford) instead. I therefore have no verified disclosure for US 108,143A either. It is the most probative listed reference and the largest evidentiary gap in this analysis.
• US 113,788A (Norton, Apr. 18, 1871): retrieved in full text. Note an internal OCR inconsistency I am not auto-correcting: the document self-identifies as both "Letters Patent No. 113,758" and "No. 113,788" in the same text (contrast the PDF at https://patentimages.storage.googleapis.com/e7/01/32/c7ce954f704086/[US113788](/patent/US113788).pdf with https://patents.google.com/patent/US113788).
• US 104,316 (Hurford, June 14, 1870): retrieved in full text (https://patentimages.storage.googleapis.com/2f/ec/dd/3f4259f39bc575/[US104316](/patent/US104316).pdf). It shares the June 14, 1870 date that the US116851 page assigns to "US104252A — Improvement in spring-hinges." I cannot resolve whether that is coincidence or an OCR/numbering error, and I am not normalizing either number.
• Extra-record art I independently retrieved and can quote: the Lull v. Clark opinion, 13 F. 456 (C.C.N.D.N.Y. 1882) (https://law.resource.org/pub/us/case/reporter/F/0013/0013.f1.0456.pdf), which quotes the specification of Lull patent No. 10,477 (Jan. 31, 1854) in full and names several pre-1871 hinges; US 49,511 (Dummer, Aug. 22, 1865) (https://patents.google.com/patent/US49511); US 141,989 (Boileau, filed July 26, 1871, granted Aug. 19, 1873) (https://patents.google.com/patent/[US141989A](/patent/US141989A)/en); and a 1871 Scientific American hinge notice (https://babel.hathitrust.org/cgi/ssd?id=pst.000062999274;page=ssd;view=plaintext;seq=174;num=162).

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III. The claims, decomposed

Using the claim text as OCR'd on the page (still degraded; my reconstruction, unchanged from the summary section):

Claim 1 — "The construction of the leaf and knuckle of the hinge in two separate parts, connected together by a wedging and dovetailed slot and lug, or equivalent, as herein described."
Elements: (1.1) leaf and knuckle as separate cast parts; (1.2) joined by a tapered, wedging slot/lug; (1.3) the slot being dovetailed in cross-section; (1.4) "or equivalent" — a deliberately broad catch-all.

Claim 2 — "The combination of the dovetailed plate A with the slot a, pintle C, spiral oval incline f, of the knuckle B and its dovetail or lug b, substantially as set forth."
Elements: (2.1) dovetailed plate A + slot a [= claim 1's joint]; (2.2) pintle C in one knuckle, socket in the other; (2.3) spiral oval incline f forming the knuckle periphery; (2.4) the lug b.

Specification-supplied limitations that supply the function: the post-side slot narrows downward and the gate-side slot narrows upward so gate weight tightens the wedges; the knuckles when fitted are "oval or egg-form"; two spiral twists "gradually incline in a spiral from the center next the gate to the opposite side, the rear part being the steepest"; and — the crux — "the outer periphery only bears in riding up or down," which "greatly lessen[s] the friction," with "sharp edges [that] will easily cut their way free through ice and snow."

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IV. Combination A — The gravity-rise self-closing hinge (attacks claim 2, and the functional core of claim 2's incline)

References: McMaster's own admission in the specification + Lull patent No. 10,477 (1854) as quoted in Lull v. Clark + Norton US 113,788A (Apr. 18, 1871) + Boileau US 141,989A's admission.

The admission is the strongest single piece of evidence in the whole file. The specification states: "I am aware that hinges are well known in which one-half rides upon the other in opening the gate. This I do not claim." Under modern practice an applicant's specification admission of what is "well known" is usable as prior art without further corroboration, and it is binding on the patentee as to scope. It concedes elements (2.3)'s function (one knuckle riding up on the other under gravity) in its entirety.

Lull (1854) supplies the mechanism. The Lull v. Clark opinion quotes Lull's specification verbatim at 13 F. 456:

"There are several varieties of shutter and door hinges, the greater portion of which, in being opened, bring two inclined planes in action, causing the shutter or door to rise… The inclination of the planes should be about 45 degrees at the extreme outer end, and approach the vertical as they come nearer the center… I place them outside of the shoulder, and as remote from the center of the hinge as possible… The bottom of the planes A, A are brought to the top of the planes B, B … and the shutter is carried to the wall by its gravity on these inclined planes."

And Lull's own claim: "the so forming of a self-locking shutter hinge, cast in two pieces," with the strain "thrown onto cam arms" — i.e., onto a bearing surface remote from the spindle.

Two points follow directly:

• Lull (1854) is unambiguously pre-1871 art and squarely in the analogous field (gravity-actuated self-closing hinge with inclined bearing planes).
• Lull expressly teaches the outward displacement of the bearing contact — "as remote from the center of the hinge as possible" — which is precisely the concept McMaster asserts as novel when he claims that "the outer periphery only bears in riding up or down," thereby "greatly lessen[ing] the friction."

Norton US 113,788A (retrieved in full) adds a gate-specific embodiment: an angular post-plate A; "double inclines B upon which the eye of the hinge C rests"; a "projecting pin E cast solidly with or rigidly attached to the post-plate"; and a gate-plate F with a "double-inclined flange G … cast solid with the eye C." Norton's claim 2 is "the combination of the post-plate A, projecting pin E, eye of the hinge C, double-incline flange G, and gate-plate F." That is a pintle-and-socket gravity gate hinge with an inclined riding surface, published three months before McMaster issued.

Motivation to combine (as a PHOSITA in 1871): the problem was defined and public. Norton and McMaster were both New York inventors; the Scientific American notice of 1871 describes a hinge whose "top part … protects the working parts from snow and ice completely" — showing that the ice/snow failure mode McMaster invokes was a recognized, discussed problem in the very year of grant. A skilled mechanic seeking to reduce the friction and ice-binding of a known gravity-rise gate hinge had every reason to reach for Lull's 1854 teaching of relocating the bearing to the outer extremity.

Caveat I must state honestly: Norton's publication date (April 18, 1871) and US 113,998A's (April 25, 1871) postdate McMaster's February 13, 1871 execution date. If the invention date is the execution date, Norton is not §102 art and is usable only as evidence of the contemporaneous state of the art / level of ordinary skill. Norton's own execution date, January 23, 1871, is before McMaster's — suggesting near-simultaneous independent development, which is itself KSR-relevant evidence that the solution was the product of ordinary skill rather than invention. This near-simultaneity is a double-edged fact and I am not going to pretend it resolves cleanly.

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V. Combination B — The separable leaf-and-knuckle joint (attacks claim 1)

This is the weaker leg, and I want to be candid about why.

What the retrieved art actually shows: a separable fastener between hinge components, but not a dovetail-and-wedge one. Hurford, US 104,316 (June 14, 1870) claims "[t]he pins B, provided with flanges, and used in combination with the jaws C C, of one portion of the hinge provided with grooves e e" — removable flanged pins retained in grooved jaws, so the pin can be extracted without distorting the hinge. The stated production benefit is the same genus as McMaster's: cheapness, serviceability, and eliminating operations.

What I could NOT find, and will not fabricate: I retrieved no reference disclosing a tapered, dovetailed, wedging slot in a hinge leaf receiving a lug cast on the knuckle. The listed references that might have come closest (US 108,143A; US 113,998A) are exactly the ones whose full text I could not retrieve. On the record before me, element (1.3) — dovetailing the slot in cross-section — is not shown by any available reference.

How a §103 challenge would nevertheless be constructed (KSR-style):

1. Known technique applied to a known device. The dovetail-and-wedge is an ancient, universally known joint for resisting withdrawal along the joint axis (carpentry; machine-tool and foundry practice). The specification itself treats it as unremarkable: its stated advantages are (a) replaceability ("if any one portion becomes broken, it may be replaced"), (b) adjustability, and (c) casting-draw direction — the knuckle's "peculiar form" means the combined part "cannot be drawn from the sand … without drawing edgewise of the latter, in which case the screw-holes cannot be cast, but must be drilled." Casting the leaf separately "the other way" lets the screw-holes be cast rather than drilled.
2. Rationale 3 of KSR (design incentive / predictable result): a mechanic whose objective is a hinge that can be assembled from replaceable, individually-cast parts, and whose casting practice forces a particular draw direction, would predictably select a wedging dovetail. The specification supplies the business motivation itself.
3. Rationale 4 (obvious to try): the field was crowded with separable and adjustable hinge constructions — Hurford's removable grooved pins (1870), Dummer's pivoted locking bar (US 49,511, 1865), and the very existence of three near-simultaneous gate-hinge filings in early 1871.
4. Broadening: claim 1's closing "or equivalent" language materially enlarges the claim. Under well-settled construction, a claim reciting a specifically described joint plus "or equivalent" cannot be read to exclude alternative joining means — which expands the prior-art surface it must overcome.

Counter-analysis — where claim 1 plausibly survives: the combination of (i) a two-part hinge, (ii) a wedging taper, (iii) a dovetail cross-section, and (iv) oppositely oriented tapers on the post-side (narrowing downward) and gate-side (narrowing upward) leaves so that the gate's own weight tightens both wedges is a specific, non-trivial, functional arrangement. The opposed-orientation feature in particular is a genuine insight not shown in any reference I retrieved. A defendant attacking claim 1 would have to prove that the opposed-taper teaching was knowable, and I have no evidence of that.

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VI. Combination C — What the asserted point of novelty actually adds, and whether it is a "design choice"

McMaster expressly limits novelty to: "the oval form of the hinge and the construction of the spiral twist so that the outer periphery only bears in riding up or down." Taking each in turn:

• Oval (rather than circular) knuckle. This is a change in cross-sectional profile of a cast part. It changes the geometry of contact onset and the included angle of the incline. KSR Rationale 1 (predictable variation) and Rationale 4 (obvious to try) apply: the art already manipulated the inclination angle ("about 45 degrees at the extreme outer end, and approach the vertical as they come nearer the center" — Lull) and the radial placement of the bearing ("as remote from the center of the hinge as possible" — Lull). Moving from a simple double incline to a helically/spirally arranged incline on an oval body is a matter of degree, producing a predictable reduction in contact area.
• Outer-periphery-only bearing. Lull's specification already frames the problem in exactly these terms — bearing contact and strain diversion are the stated purpose of his "cam arms," and the Lull v. Clark opinion analyzes the invention in terms of where the load is thrown. A PHOSITA seeking lower friction and ice-clearing by definition seeks to minimize contact area; McMaster's solution does no more than the predictable result of that objective.
• Chilled/hardened bearing edges. McMaster's own words: "When chilled or otherwise hardened but very little wear comes at that point." Chilling cast iron for wear resistance was standard foundry practice well before 1871 (the patent presumes, rather than teaches, it). This is textbook Rationale 2 — a known technique applied to a known structure, with no unexpected result.

Where a validity defense retains the most traction: none of the retrieved references discloses an oval knuckle whose outer periphery alone constitutes the bearing surface throughout the ride-up/ride-down arc. Norton's flange and Lull's cam arms are inclined surfaces of conventional form. If claim 2's precise geometry is genuinely limited to "outer periphery only," claim 2's validity rests entirely on whether that limitation is treated as a quantitative design choice (obvious) or a change in principle of operation (not obvious). The patent's own framing — reduced friction and ice-clearing through minimized bearing area — reads as an optimization of a known parameter, which favors obviousness.

The self-limiting problem for the patentee: the specification disclaims the class ("hinges … in which one-half rides upon the other … This I do not claim"). That disclaimer concedes the entire functional class to the prior art and leaves claim 2 standing on geometry alone. Under a narrow construction sufficient to preserve validity, the claim is easily designed around; under a broad construction, it reads on the admitted prior art. This is the classic narrow-vs-anticipate squeeze, and it is why the patent, even if it were live, would be a weak assertion vehicle.

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VII. Bottom line

Claim 1 — probable but not clean obviousness. The concept of a two-part hinge joined by a wedging retainer is taught or suggested by Hurford (US 104,316, June 14, 1870) and by the general pre-1871 practice of separable/adjustable hinge construction, and the motivation is supplied by McMaster's own efficiency rationale (replaceability; casting the screw-holes rather than drilling them). The specific dovetailed cross-section with oppositely oriented tapers keyed to gate weight is not shown in any reference I could retrieve, and I have flagged the two listed references most likely to close that gap (US 108,143A and US 113,998A) as unverified. Verdict: likely obvious under a KSR-style expansion of the art; defensible if the opposed-taper feature is treated as the gist of the claim.

Claim 2 — probably obvious. Every element is individually established in pre-1871 or contemporaneous art: the pintle/socket (McMaster's own admission — "This is common in other hinges" — plus Norton's cast-in pin E); the gravity-rise incline (admitted prior art, plus Lull 10,477 of 1854, plus Norton's double inclines B); the outer placement of the load-bearing incline (expressly taught by Lull — "as remote from the center of the hinge as possible"); and the hardened bearing edge (routine foundry practice). The only genuinely unshown feature is the oval knuckle bearing solely on its outer periphery — and that is most naturally characterized as an optimization of contact geometry, i.e., predictable variation, not invention. Verdict: likely unpatentable as obvious, with residual strength only if the "outer periphery only" limitation is read as a change in principle of operation.

Strongest combination, stated formally: McMaster's specification admissions (self-closing ride-up class; pintle/socket as common) + Lull U.S. Patent No. 10,477 (1854) (gravity-actuated inclines; load thrown to cam arms remote from the spindle) + Hurford U.S. Patent No. 104,316 (1870) (removable flanged pins in grooved jaws for serviceability) + routine cast-iron chilling. Motivation: reduce friction and ice/snow binding in a known self-closing gate hinge while cheapening manufacture by casting separable parts — a problem the art had already identified and partially solved, as the 1871 Scientific American notice and the near-simultaneous Norton and US 113,998A filings demonstrate.

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VIII. Limitations of this analysis (stated, not buried)

1. § 103 did not govern this patent. The 1871 standard was Hotchkiss lack-of-invention. This analysis is analytic, not historical.
2. Two critical references are unverified. I retrieved neither US 108,143A (Oct. 11, 1870) nor US 113,998A (Apr. 25, 1871). Both are the most probative listed items and both have plausible disclosure bearing on claim 1's joint. The claim 1 conclusion is contingent on them.
3. No filing date exists in the record. Everything hinges on the February 13, 1871 execution date as a proxy for the invention date. If McMaster's invention date is later, US 113,788A and US 113,998A move into the prior art and both claims become materially weaker. If earlier, they move out.
4. The "Prior Art" section is not a prior-art list. Most of its entries — including the only "Cited By" documents — post-date the patent by decades to a century and a half, and are unusable.
5. OCR corruption persists in both the claim text and in reference numerals and numbers (e.g., "113,758" vs. "113,788" in the Norton document; "fj"/"j" for incline f). I have not auto-corrected any identifier, per instruction.
6. No fabrication. Everything attributed above to a specific reference is quoted from a document I actually retrieved, with a URL. Where I lack text, I have said so.