US 1920774

I'll verify the patent details and check for any litigation/docket references.

US Patent 1,920,774 — "Trolley for conveyer systems"

Verification note on scope: I searched for US 1,920,774 specifically. No CAFC 2026 docket entry or any post‑issuance litigation involving this patent number was found. That is expected: the patent's term ended decades before the Federal Circuit existed, and Google Patents' legal‑status record shows "Anticipated expiration 1950‑08‑01 / Expired – Lifetime." I also encountered the bare number 1920774 in unrelated records — Madrid international trademark registration IR 1920774 (Yuzawaya Shoji Co., Ltd.) and EP 1920774 A1 (Suntory Ltd.) — and those are not the US patent; they are coincidental identifier matches, not related documents.

Bibliographic data

Abstract

Caution: this 1933 patent was published without a formal abstract — abstracts were not required in US practice at that time. What Google Patents displays is a machine‑generated "Definitions" excerpt from the specification, not an applicant‑supplied abstract. A faithful paraphrase of that summary text is:

A trolley device for conveyer systems used in manufacturing plants, comprising a one‑piece load‑carrying frame with flangeless horizontal supporting wheels and auxiliary vertical rollers, in which the supporting wheels and the point of application of the propelling force are arranged relative to the load so that tilting is obviated and the center of gravity lies substantially directly vertically beneath the point of propelling‑force application, reducing frictional wear and maintenance and eliminating flanged wheels.

The independent claim, in plain language

The patent has exactly one claim, and it is independent:

"A load carrying trolley assembly of the type wherein a plurality of flangeless load carrying trolley wheels mounted to rotate upon horizontal axes and supported in juxtaposition to a conveyer chain upon a pair of parallel spaced supporting tracks are maintained against excessive movement laterally to said tracks by auxiliary rollers rotating upon vertical axes and located between the opposed edges of said tracks characterized by said wheels and rollers being mounted upon a one piece frame having formed integrally therewith a pair of bearings for said trolley wheels, a pair of spaced lugs located below each of said bearings and providing bearings for the axles of said auxiliary rollers, and said frame also being provided with an upward extension midway between said trolley wheels for engagement by said conveyer chain and means for securing a load to said frame located in vertical alignment with said extension."

Plain‑language breakdown of the elements that must all be present:

1. Flangeless trolley wheels on horizontal axles — the load‑carrying wheels roll on a pair of parallel, spaced tracks and deliberately have no flanges (the stated point of novelty over the prior art).
2. Lateral restraint by vertical‑axis auxiliary rollers — instead of flanges, small rollers turning on vertical axles sit between the opposed inner edges of the two tracks and keep the trolley from moving sideways.
3. "Characterized by" a one‑piece frame — the claim transitions to its distinguishing feature: both the horizontal wheels and the vertical rollers are mounted on a single integral frame. That frame must have:
   • a pair of integral bearings for the trolley‑wheel axles,
   • a pair of spaced lugs below each of those bearings, forming the bearings for the vertical roller axles (i.e., two lugs per wheel bearing, per the specification's "pair of laterally extending arms 25" bored at 26),
   • an upward extension located midway between the trolley wheels for engagement by the conveyer chain (the head 14 engaged by a depending dog 15), and
   • means for attaching the load (the opening 17 receiving hook 18) positioned in vertical alignment with that upward extension.

Element 3's last two sub‑parts encode the second stated object of the invention: putting the load attachment directly under the chain‑engagement point so that the center of gravity hangs beneath the thrust line and the trolley does not tilt on the track.

Comment on claim style: the claim is a single, extremely long means‑plus‑function‑flavored composition reciting the track, the chain, and the trolley as one assembly, with the novelty carried in the "characterized by" clause. There are no dependent claims narrowing details such as the frusto‑conical tread shape or the ball bearings described in the specification (elements 19, 30, 31), so those features are not separately claimed.

Context and downstream references

• The specification emphasizes three advantages: elimination of flanged wheels (and their chipping/rail‑wear problems), quiet operation on curves, and the center‑of‑gravity/thrust‑line alignment noted above.
• Google Patents lists ~14–18 citing documents, notably US 4,464,997 and DE 3300991 A1 (Jervis B. Webb Company, 1982, "Conveyor trolley and track"), along with later Webb applications such as US 2,485,215 and US 2,510,318, and design registrations USD 982,875 / USD 982,876 (2023).

Uncertainty disclosure

• There is no applicant‑filed abstract in the original printed patent; the abstract above is a derived summary, clearly labeled as such.
• I did not retrieve an assignment record showing a corporate assignee during the patent's life; the bibliographic sources list the assignee as the inventor himself (or "Individual"). If a corporate assignment exists, it is not reflected in the databases I searched.
• I cannot confirm there was ever any litigation or CAFC proceeding on this patent number; my search of 2026 CAFC docket material returned nothing, and given the 1950 expiry I would treat any such claim as unverified without a docket citation.

I'll search for litigation records involving US patent 1920774.

Let me search more targeted litigation databases.

Let me try a few more targeted searches on litigation-specific sources.

Litigation Search Results: US Patent 1920774

Bottom line: I found no litigation — past or present — involving US Patent 1920774 ("Trolley for conveyer systems," Jervis B. Webb, filed November 2, 1931; granted August 1, 1933; expired August 1, 1950).

I was unable to identify any case in which this specific patent was asserted, challenged, or otherwise at issue. I could not populate the requested table (plaintiff, defendant, jurisdiction, case number, filing date, outcome/status) because no responsive case exists in the sources searched.

What I searched

• General web queries for "US patent 1920774 litigation" and "1920774 patent lawsuit defendant."
• Unified Patents litigation caselist (portal.unifiedpatents.com/litigation/caselist) and PTAB caselist references.
• CAFC opinions/orders.
• Queries combining the patent title, inventor name (Jervis B. Webb), and "infringement suit."

The searches produced only:

1. Patent-office/registry records for the '774 patent itself (Google Patents, FreePatentsOnline) — no litigation tab entries.
2. Unrelated hits on the number "1920774" in other registries — specifically an EU/international trademark registration 1920774 (Yuzawaya Shoji Co., Ltd.) and a Brazilian Superior Tribunal de Justiça proceeding "AgR no Recurso Especial nº 1920774." These are not the US patent and I have flagged them rather than treating them as responsive. Per the strict rule, I did not auto-correct them; I confirm they are distinct identifiers.
3. Webb-company conveyor cases involving different patents — none of which cite or assert the '774 patent:
   • Jervis B. Webb Co. v. Southern Systems, Inc., 742 F.2d 1388 (Fed. Cir. 1984) — asserted U.S. Patent No. 3,451,352 (W.D. Tenn. Civ. No. 80-2465-M); claims held invalid for obviousness (affirmed in part, vacated in part).
   • Mid-West Conveyor Co. v. Jervis B. Webb Co., 92 F.3d 992 (10th Cir. 1996) — license-scope dispute concerning U.S. Patent No. 4,616,570 ("wide dog" transfer).

Important caveats

• Practical age limit. The '774 patent issued in 1933 with a 17-year term and, per the Google Patents record, its anticipated expiration was August 1, 1950. Any enforcement litigation would predate modern electronic docketing, so digitized litigation databases (Unified Patents, PACER, CourtListener, Docket Alarm) generally do not reach the relevant era. My "no litigation found" conclusion is therefore based on searchable records and may not capture pre-1950 paper-era suits.
• No claim of exhaustiveness. I did not obtain a direct, verified "zero results" confirmation from a litigation-database query on the exact patent number; the absence is based on the search evidence available to me. If pre-1950 federal district court filings are of interest, that would require archival (non-electronic) research, which I cannot perform here.

If you'd like, I can attempt additional targeted searches (e.g., specific reporters or archival indexes) that might reach pre-1950 enforcement actions.

I'll verify the canonical "no PTAB activity" signal against public sources, running several targeted queries in parallel.

Proceedings overview

Zero AIA trial proceedings have ever been filed on US Patent 1,920,774. The canonical USPTO Open Data Portal (ODP) PTAB record returns no IPR, PGR, or CBM for this patent, and my independent web verification (PTAB-related queries, the patent's Google Patents/FreePatentsOnline records, and Unified Patents' patent portal) surfaced no petition, institution decision, Final Written Decision, or appeal citing it. The breakdown is therefore 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials — a complete absence, not a partial result. Plain-English defensive posture: this is not a "hardened" patent and it is not a "killed" patent — it is an expired patent (term ended 1950-08-01) that no one ever bothered to challenge at the Board, because by the time AIA trials existed it had been dead for 61 years. Any demand letter invoking US 1,920,774 is facially worthless for a reason far more basic than PTAB estoppel: there is no enforceable claim left to infringe. (And note the patent has exactly one claim — the prior section's plain-language breakdown confirms a single independent claim, so a demand letter citing "claim 5" of this patent would be wrong on its face.)

---

No proceedings to report

Because the structured "PTAB proceedings on file" block is empty and my searches produced nothing, I cannot populate the per-proceeding template without inventing proceeding numbers, which the task constraints forbid. I will not fabricate an IPR20XX-XXXXX caption. Instead, here is the negative finding in the template's shape:

(none) — No Petitioner v. Jervis B. Webb (Individual)

• Type: N/A — no Inter Partes Review, Post-Grant Review, or Covered Business Method proceeding exists.
• Filed: N/A
• Status: No AIA trial proceeding on file (per USPTO ODP PTAB record as of ingest; corroborated by web search on 2026-09-29).
• Judge panel: N/A — no panel ever convened.
• Petition grounds: N/A
• Institution decision: N/A
• Final Written Decision: N/A — no claim of the '774 patent has ever been canceled, confirmed, or construed by the PTAB.
• Settlement / termination: N/A
• Appeal: N/A — no FWD, hence no Federal Circuit appeal, no Director Review request, no Arthrex remand.
• Defensive value: None derived from PTAB history. The defense is statutory, not adversarial: the patent's anticipated expiration is 1950-08-01, per Google Patents' legal-status record (US1920774A). Sole claim 1 — the only claim in the patent — cannot be asserted against anyone today regardless of what the Board might have done.

Why the absence is expected, not anomalous. § 311(c) IPRs became available 2012-09-16; PGRs only for patents with an effective filing date on or after 2013-03-16; CBM only for covered business-method patents. A 1931-filed, 1933-issued, 1950-expired mechanical conveyor trolley satisfies none of the economic or statutory predicates for an AIA petition. The heuristic that "well-asserted patents eventually attract IPRs" is inapplicable: this patent was never asserted in the searchable litigation record either (see the prior Litigation summary in this analysis, which likewise returned zero cases).

Contradiction check / identifier-collision warnings (important). Repeatedly during verification, the bare string 1920774 resolved to documents that are not US Patent 1,920,774. I did not auto-correct these; they are distinct identifiers:

• EP 1920774 A1 — Suntory Ltd. immunostimulator application (cited as prior art in unrelated US 10,874,700 and US 10,806,769).
• International trademark registration IR 1920774 — Yuzawaya Shoji Co., Ltd. (CIPO application 2,479,473; EUIPO provisional partial refusal dated 2026-06-17).
• CN 1920774 A — Inventec Corp "Automatic Installation Method and System of Driver" (surfaced on Unified Patents' own portal, which is exactly the kind of false positive that could be mistaken for a PTAB hit).

None of these are AIA proceedings against the '774 patent.

---

Strategic summary

Claim status. US 1,920,774 has a single claim — claim 1 — and it is UNTESTED at the PTAB. There are no canceled claims, no surviving claims, and no claims narrowed by certificate. That said, "untested" should not be read as "risky": the patent expired 1950-08-01, and the specification's own framing (flangeless frusto-conical wheels plus vertical-axis guide rollers on a one-piece frame, with the load attachment vertically aligned under the chain-engagement head 14) describes mid-century overhead trolley-conveyor hardware. There is no live right to assert.

Estoppel landscape. There is no § 315(e)(2) estoppel to map, because there has never been a petitioner. No party is barred from raising any ground, and equally, no party benefits from a prior petitioner's work product or from an institution/FWD record. For a defendant today, the § 315 estoppel question is moot — the § 271 infringement question is answered by expiration and by the fact that no claim exists to be infringed. If someone is nonetheless asserting this number, the first move is not an IPR petition but a demand for the plaintiff's chain of title and an explanation of how to infringe a patent that expired in 1950.

Pattern signals. None available: no repeat petitioner (there is no petitioner at all), no patent-owner appeal activity on this number, and no defensive aggregator involvement — Unified Patents' portal indexes this patent only as prior art cited against third-party patents such as US 4,464,997 and US 10,478,737, and the only "1920774" that appears there is the unrelated CN reference above. Family size is US-only (one application, serial 572,806; one publication), so there is no international counterpart to challenge at the EPO either.

---

Recommended next steps

1. There is no PTAB activity to act on — say it plainly. The absence is the answer. Do not budget for an IPR; there is no FWD to link to, no disposition to quote, and no trial-stage milestone calendar (no institution deadline, no oral hearing, no 1-year FWD clock) because no petition exists. Per the structured ODP block, the default is and remains no PTAB activity on file.

2. If a demand letter cites US 1,920,774, treat it as a red flag, not a threat. Two independent, verifiable defects: (a) the patent's anticipated expiration was 1950-01-01... correction: 1950-08-01 (Google Patents legal status), and (b) it contains one claim, so any letter referencing multiple claims of this number misidentifies the patent. Require the sender to identify the asserted claim number and the live patent right.

3. If archival diligence is ever needed, go to paper-era, not electronic, records. Pre-AIA reexamination existed only from 1981 (ex parte) and 1999 (inter partes), and this patent's term ended long before either; if you need to rule out 1933–1950-era validity contests, those are paper-era district court filings requiring archival (non-electronic) research, which I cannot perform here. For the modern record specifically, verify via the USPTO PTAB Center / PTAB API at ptacts.uspto.gov using application number 572,806 and patent number 1,920,774.

4. Watch the number collisions. When monitoring or docketing, disambiguate 1920774 from EP 1920774 A1 (Suntory), IR 1920774 (Yuzawaya Shoji), and CN 1920774 A (Inventec) — all three surfaced as false positives during this analysis and could contaminate a conflict check or a PTAB-monitoring feed.

Uncertainty disclosure. The "zero proceedings" conclusion rests on (i) the canonical structured ODP block stating no AIA trial proceedings are on file, and (ii) my web searches, which uniformly returned patent-registry and unrelated-identifier hits rather than any Board document. I did not obtain a screen-captured "0 results" page from PTAB E2E itself, and searches for this era of patent on PTAB databases are inherently sparse; I flag that rather than overstate exhaustiveness. I found no PTAB proceeding number, panel, institution decision, FWD, settlement, or appeal, and I have deliberately not supplied any.

I'll verify the assignment record via USPTO sources and cross-reference the assignee's corporate history.

Ownership-chain analysis — US Patent 1,920,774

Methodology / access caveat (read first). I do not have interactive browser access to assignmentcenter.uspto.gov, so I could not execute a live query against the Assignment Center. What I can establish is definitive and is enough to resolve this patent: the USPTO Patent Assignment Search database ("Assignments on the Web," covering both assignmentcenter.uspto.gov and the legacy assignment.uspto.gov/patent/index.html index) contains recorded patent assignment information only from August 1980 to the present. This is stated in the USPTO's own assignment-database training material ("This searchable database contains all recorded Patent Assignment information back to August 1980"), in Finnegan's practitioner guidance, and in MPEP 301.01(a)(2), which directs that all assignment records for patents recorded before May 1, 1957 are held by the National Archives and Records Administration (NARA), not by the USPTO's searchable system. US 1,920,774 issued 1933-08-01 and reached anticipated expiration 1950-08-01 — seventeen years, pre-1995 term rules, and no maintenance-fee regime existed. It therefore cannot appear in the Assignment Center as a chain-of-title record, and any pre-1950 transfer of it would be a NARA paper record, not a reel/frame entry.

---

Inventors

• The patent names exactly one inventor. The specification is written in the first person throughout ("I am aware that there have been various types of trolleys…"), and the grant is printed in the inventor's own name without an assignee line.
• Pattern assessment — no unusual inventor signals. There is one inventor, not a team; no co-inventor departures are possible. The inventor is the founder-owner of the operating company, and the company outlived him and remained under family control for another ~70 years. There is no evidence of a within-12-months break between inventor and company — the opposite is true, since the corporate successor (Daifuku-owned Jervis B. Webb Company) still cites this patent family in later filings (e.g., US 4,464,997, DE 3300991 A1, both 1982, Jervis B. Webb Company).
• Note on inventor continuity: Jervis B. Webb was succeeded at the company by his sons Jervis C. Webb and George H. Webb, and then by his granddaughter Susan M. Webb (President/CEO 2003–2008) — confirming continuous family/operator ownership, not an inventor-detachment pattern.

Original assignee

• On the face of the patent: none — the patent issued to the inventor as an individual. Sources differ only in how they render that absence: Google Patents lists the original assignee as "Individual" (and the current assignee as "Individual"), while FreePatentsOnline renders the assignee field as "Webb, Jervis B." — i.e., the inventor personally. There is no assignee name in the printed grant, and no corporate assignment is reflected at issuance. This is consistent with a 1931 filing by a company founder who owned his own patents personally rather than assigning them to his (privately held) corporation.
• Did the original owner ship a product embodying the claims? Yes. The claimed subject matter — a flangeless-wheel overhead trolley with vertical-axis guide rollers on a one-piece frame — is the load carrier for the overhead power-chain conveyors that were Jervis B. Webb Company's core product line. Daifuku's own acquisition release records that Webb "played an important role in establishing the Ford system (a mass production method using chain conveyors to move automobile bodies through the assembly and finishing process)," that Webb sold its first overhead system to Ford in 1922, and that "chain conveyors remain one of Webb's leading products to this day." This is an operating-company patent, not a paper asset.
• Primary line of business: design, engineering, manufacturing, installation and service of material handling systems — overhead and in-floor chain conveyors, airport baggage handling systems, automatic guided vehicles, and automated storage/retrieval systems.
• Current status of the original owner: Operating. Jervis B. Webb Company remains an active entity; it has been a wholly owned subsidiary of Daifuku Co., Ltd. (Osaka; TSE:6383) since the 2007 share purchase, wrapped in Daifuku Webb Holding Company (2011) → Daifuku North America Holding Company (2015) → Daifuku North America, Inc. (2024). No bankruptcy, no dissolution, no portfolio fire-sale. Critically, these were share purchases of the company — a change of control that does not generate a recorded patent assignment (no assignor/assignee reel/frame) even in periods the USPTO database covers.

Assignment timeline

The USPTO Assignment Center has no records for US 1,920,774, and it structurally cannot have any. Stating that plainly, as the stop rule directs:

• The Assignment Center / Assignments on the Web database covers recorded patent assignments from August 1980 onward. US 1,920,774 expired nineteen years before the start of that coverage window (1950-08-01), so it will return zero entries regardless of whether any transfer ever occurred.
• Pre-May 1, 1957 assignment records for US patents are held by NARA (MPEP 301.01(a)(2)); retrieving them requires an archival request to the National Archives, which I cannot perform here. I therefore cannot supply reel/frame numbers, execution dates, recording dates, or correspondent-of-record entries for this patent, and I will not invent them. Any table of reel/frame entries for this patent would be fabrication.
• Correspondent-of-record finding: unavailable by construction. Because there is no post-1980 recordation and no NARA pull, no recording attorney/agent can be identified. I note for completeness that the pre-1980 USPTO assignment practice did not use the modern EPAS/electronic correspondent fields at all, so the "repeat correspondent" tell — the single most useful NPE-family indicator in this methodology — is not recoverable for this vintage of patent.

Corroborating absence evidence, none of which is an assignment record:

• SEC filings cross-reference: not applicable. Jervis B. Webb Company was privately and family-owned throughout the patent's life and after; Daifuku Co., Ltd. is Tokyo-listed and files no 10-K/8-K. There is no SEC disclosure trail to mine for this asset. (Daifuku's 2007 acquisition was disclosed via news release/JP disclosure, not SEC filings.)
• RPX / Unified Patents asserter directories: no entry associated with US 1,920,774 (consistent with the finding in the previously generated sections that no assertion, litigation, or CAFC docket entry exists for this patent number).

Per the task's stop rule after this section, the recorded-chain analysis terminates here. Because you asked for a required verdict, I have completed the remaining sections below and marked each signal accordingly — but every NPE signal is unresolvable on the record, and I have labeled them that way rather than inferring.

Timeline diagram

timeline
    title Ownership of US 1920774
    1919 : Jervis B. Webb Company founded in Detroit
    1931 : Application filed by Jervis B. Webb
    1933 : Patent issued to inventor personally
    1950 : Patent term expired
    2007 : Webb company shares sold to Daifuku
         : No patent rights conveyed
    2011 : Webb folded into Daifuku Webb Holding
    2015 : Renamed Daifuku North America Holding
    2024 : Renamed Daifuku North America Inc

The 2007 and later entries document corporate change of control only. They are included for completeness and convey no rights in US 1,920,774, which had been expired for 57 years at that point.

NPE / troll-pattern signals

Verdict

Insufficient data (the "no records / original assignment only" branch).

Justification: US 1,920,774 issued to Jervis B. Webb personally on 1933-08-01 and reached anticipated expiration on 1950-08-01, roughly thirty years before the USPTO Patent Assignment Search window opens (August 1980). There is therefore no reel/frame entry to cite — no shell-entity transfer, no asserter, no correspondent, no cascading chain — and any pre-1950 recordation would have to be pulled from NARA under MPEP 301.01(a)(2). The affirmative evidence that is available points away from an NPE pattern in every respect: the property was owned by a founder-operated material-handling manufacturer whose successor entity (now Daifuku North America, Inc.) still exists as a going concern and still cites this patent family in later filings, and no assertion, litigation, or CAFC docket entry ties to this number. I cannot responsibly return an NPE verdict on an empty record, and I have not fabricated reel/frame data to fill it.

Verification links:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/
• Legacy Assignments on the Web index: https://assignment.uspto.gov/patent/index.html
• Patent document (assignee data of record on the face): https://patents.google.com/patent/US1920774/en and https://www.freepatentsonline.com/1920774.html
• Assignment-database coverage statement: https://www.uspto.gov/sites/default/files/documents/Assignment%20Database%20Webinar_20150120.pdf

If you need the actual paper chain: the next step is a NARA request for the pre-1957 assignment records (Records of the Patent Office relating to numbered patents, 1836–1973), searching for any 1933–1957 assignment from Jervis B. Webb to Jervis B. Webb Company. That would settle whether the inventor later assigned the patent to his own corporation — a routine internal transfer that, if it occurred, would still be a not-present on every NPE signal here.

I'll verify the patent record and check whether it lists any cited prior-art references.

Let me check the official USPTO record and the patent's own front-page references.

The face of the patent shows no cited references. Let me examine the pre-1931 "similar documents" and Webb's earlier work, plus the examiner citations in the citing family patents.

Prior-Art Analysis — US Patent 1920774

1. Record verification (USPTO / public databases)

Sources: USPTO patent print (OCR) https://patentimages.storage.googleapis.com/85/52/f8/e5bfe53d1f2fc8/US1920774.pdf; Google Patents https://patents.google.com/patent/US1920774/en; FreePatentsOnline https://www.freepatentsonline.com/1920774.html.

2. Critical finding: US 1,920,774 has no cited prior-art references

This is the single most important result of the search, and it should not be glossed over:

• The face of the patent contains no "References Cited" / "Citations" block. The printed patent runs from "Application November 2, 1931. Serial No. 572,806 / 1 Claim. (CL 105—155)" directly into the specification. There is no examiner-cited art listed between the serial number and the body text — consistent with 1931–1933 USPTO practice, in which cited references were generally not printed on the face of the patent.
• Google Patents' record for US1920774A likewise has no "Citations" section — only a "Cited By" section. Verified in two separate fetches of the page (the rendering variously shows "Cited By (13)" and "Cited By (17)" — see §6, inconsistency note).

Consequence: there is no set of "patent citations for 1920774" in the sense of prior art cited against it. The only citation data that exists for this number is forward citation data (later documents that cite 1920774). A forward citation cannot anticipate US 1,920,774 under 35 U.S.C. §102, because every one of those documents post-dates the '774 filing date (Nov. 2, 1931) — most by decades. The arrow points the other way: '774 is prior art against them.

Anyone who presents the "Cited By" list as "prior art for 1920774" is applying the citation direction backwards. I will not do that, and I am flagging it explicitly.

3. Documents that cite US 1,920,774 (forward citations — not §102 prior art to '774)

For completeness, the "Cited By" set (dates are the citing documents' own dates):

§102 mapping for this table: none of these anticipates claim 1. Each is dated after Nov. 2, 1931, so none qualifies as §102(a), (b), or (e) art against '774. Their value is reverse-direction: e.g., US 4,464,997 (Webb) and DE 3300991 A1 expressly list US 1,920,774 among their own cited references, and the design application behind USD 982,876 ("Wheel trolley") lists "1920774 — August 1933 — Webb" in its Referenced Cited block — confirming that '774 is treated as background art by later actors, not that it has prior art of its own.

4. Candidate prior art (pre‑Nov. 2, 1931) — identified from the record, not examiner citations

Because no references were cited on the face of '774, the only pre-1931 documents I can identify are those surfaced by the databases as "Similar Documents" and those appearing in the reference lists of later Webb-family patents. I flag clearly: these are my candidates, not citations of record against '774.

Details and §102 assessment

US 1,572,941 A — "Trolley conveyer" (McBride / Palmer Bee Co.), filed Jan. 2, 1923, pub. Feb. 16, 1926 — the most substantive candidate.

• Disclosure (per retrieved claim text): a power-propelled trolley suspended from a single I-beam track, with supporting rollers riding the lower flanges; anti-friction rollers on the trolley engaging the underside of the track "for limiting the upward movement of said trolley relative to said track"; side frames (claim 7 recites "rollers upon said side frames engaging the lower flanges, said rollers having their axes in the same plane, rollers upon said side frames below said track"); shelves below the track to catch dirt/metallic dust.
• §102 assessment: available under §102(a)/(b). However, it discloses a monorail I-beam environment, not the "pair of parallel spaced supporting tracks" of claim 1, and its auxiliary rollers are lift-restraint rollers about horizontal axes, not vertically-axled rollers positioned between opposed edges of two tracks for lateral restraint. It does not anticipate claim 1. It is realistic §103-type background (and mirrors '774's own anti-friction/quiet-operation rationale).
• Caveat: I retrieved only a partial text/claim set; I could not read the full specification and drawings.

US 1,876,904 A — "Trolley conveyer" (Earle V. Francis), filed May 11, 1931, granted Sept. 13, 1932.

• Disclosure: combination with a track and wheeled trolley of a bar above the track engageable by the trolley — including by the tops of the trolley wheels — to restrain lifting tendencies.
• §102 assessment: published after the '774 filing date, so it is not §102(a)/(b) art. It is a §102(e) candidate only (US application filed May 11, 1931, before Webb's Nov. 2, 1931 filing), and only if its filing precedes Webb's date of invention. Even then it addresses anti-lift, not flangeless lateral guidance or the integral one-piece frame — no anticipation of claim 1.

US 1,662,093 A — Conveyer-bar construction (1928); US 1,585,605 — Amusement device (1926); US 870,704 (1907); US 1,127,753 (1915); US 833,326 A — Gravity-conveyer (1906).

• These are pre-1931 and therefore §102(a)/(b)-eligible, but I have not verified their disclosures. US 833,326 is a gravity conveyor (no overhead power chain), which is structurally remote from the claimed assembly; US 870,704 and US 1,127,753 are listed in the FreePatentsOnline reference block of US 2,593,699 without titles, so I cannot characterize them. Treat all five as unverified background candidates.

Why none of the above anticipates the sole claim

Claim 1 requires, in combination: (a) flangeless load wheels on horizontal axles on a pair of parallel spaced tracks; (b) lateral restraint by auxiliary rollers on vertical axles located between the opposed edges of those tracks; and (c) a one-piece frame with integral wheel-axle bearings, a pair of spaced lugs below each bearing forming the vertical-roller axle bearings, an upward chain-engagement extension midway between the wheels, and load-securing means in vertical alignment with that extension. No candidate identified above is shown to disclose (b) or (c) — i.e., the "characterized by" clause in which the patent's novelty resides. On the present evidence, no reference anticipates claim 1 under §102, and there are no dependent claims to analyze separately.

5. What the search does not establish

• No examiner-cited prior art exists in the public record for this number. That does not mean the examiner considered nothing — it means the citations (if any) are not printed on the face of the 1933 patent and are not captured in the digitized Google/FPO records.
• No verified anticipation. Element-by-element anticipation would require reading the full specifications and drawings of US 1,572,941 and the untitled candidates; I could not do that within this search.
• No litigation. This is consistent with the earlier litigation section: the patent's 17-year term ended Aug. 1, 1950, before modern docketing.

6. Inconsistencies / flags to carry forward

1. Forward-citation count varies across fetches — Google Patents renders "Cited By (13)" and "Cited By (17)" (and earlier renders of the same page text showed 14 and 18). The membership of the list is stable in substance (same 13–18 documents); the discrepancy is a rendering/indexing artifact, not evidence of additional references to '774.
2. Cited-reference direction. The task's premise ("look at each patent citation for 1920774") appears to conflate forward citations with prior art. I have separated the two explicitly rather than relabeling forward citations as §102 art.
3. Identifier collisions. As previously flagged, the bare string 1920774 also matches an international trademark registration (Yuzawaya Shoji) and EP 1920774 A1 (Suntory). Per the strict rule I have not auto-corrected these; they are not US 1,920,774 and are excluded from this analysis.
4. Abstract. The Google Patents "Definitions" text is a machine-generated excerpt, not an applicant-filed abstract (1933 practice required no abstract). This does not affect the prior-art analysis but must not be mistaken for claim-construction material.

Bottom line: US 1,920,774 has zero cited prior-art references of record. The citation graph runs only forward. The best pre-1931 candidates I could identify — chiefly US 1,572,941 A (McBride/Palmer Bee, 1926) and, as a §102(e) candidate only, US 1,876,904 A (Francis, filed 1931‑05‑11) — are background art that does not disclose the flangeless-wheel-plus-vertical-roller-plus-one-piece-frame combination of the single claim, and therefore none anticipates claim 1 under 35 U.S.C. §102.

I'll ground the analysis by pulling what these listed references actually disclose before reasoning about combinations.

Obviousness Analysis of US 1,920,774 under 35 U.S.C. § 103

Patent analyzed: US 1,920,774 A, "Trolley for conveyer systems" (Jervis B. Webb; App. US 572,806, filed 1931‑11‑02; issued 1933‑08‑01; expired 1950‑08‑01). One claim.
Source of record: https://patents.google.com/patent/US1920774/en
Prior art used: the "Cited By" and "Similar Documents" listings on that page, as instructed.

---

0. Threshold caveats (read these first — they materially qualify everything below)

0.1 — § 103 did not legally apply to this application. The Patent Act of 1952 (Pub. L. 82‑593) created § 103, and its validity/obviousness provisions apply to applications filed on or after January 1, 1953. US 572,806 was filed November 2, 1931. This patent was therefore never subject to § 103 as a matter of positive law; the 1933 Examiner, and any pre‑1950 court, would have applied the judicially created "invention" requirement (Hotchkiss v. Greenwood, 52 U.S. (11 How.) 248 (1851)), later phrased as requiring more than "the skill of the calling" and, after 1941, a "flash of genius" (Cuno Eng'g Corp. v. Automatic Devices Corp., 314 U.S. 84 (1941)). What follows is therefore a retrospective/hypothetical § 103 analysis — useful for prior‑art landscape, litigation‑hold history, and genealogy work, but not a statement of the law that governed this patent. I flag the anachronism rather than silently importing modern doctrine.

0.2 — Validity is moot. The claim expired August 1, 1950. There is no live infringement or invalidity controversy (consistent with the earlier Litigation section: no case identified, and pre‑1950 paper‑era dockets are not electronically searchable).

0.3 — Source limitation. The fetched page does not reproduce the patent's own front‑page "References cited in the file of this patent" list, i.e., the art the Examiner actually had before him. The "Cited By" and "Similar Documents" lists are Google's forward‑citation and algorithmic‑similarity outputs, not the Examiner's citations. My analysis is confined to those lists as instructed, but no inference should be drawn that the Examiner saw any of them.

0.4 — Dates control the § 103 analysis, and most of the list is unusable. Every "Cited By" document (1945–2025) and most "Similar Documents" post‑date the 1931 filing and are legally irrelevant as § 103 art. Only four listed documents survive as potentially citable art, one of them only under a 1926 doctrine:

On US 1,876,904: because it issued after Webb's November 1931 filing, old‑law § 102(a) ("patented … before the invention thereof") would not reach it unless its filing pre‑dated Webb's invention date. However, Alexander Milburn Co. v. Davis‑Bournonville Co., 270 U.S. 390 (1926) — decided five years before this filing, and the doctrinal ancestor of § 102(e) — held that a US patent's application filing date, not its issue date, is its effective prior‑art date as against a later applicant. US 536,614 was filed 1931‑05‑11, roughly six months before Webb. I therefore treat it as available § 103 art, clearly labelled as such, and not as § 102(a) art.

Everything else on the page — US 2,485,215, US 2,510,318, US 2,586,264, US 2,593,699, US 2,621,609, US 2,844,105, US 4,464,997, DE 3300991 A1, EP 3 636 563 B1, US 10,105,564, US 10,213,699, US 11,376,513, USD 982,875/982,876, US 2012/0067246, US 8,807,044, US 10,478,737, US 1,949,691, US 2,059,804, US 2,279,207, US 2,286,666, US 2,552,897, US 2,601,610, US 2,620,580, US 2,649,080, US 2,809,146, US 2,947,264, US 2,971,474, US 3,018,584, US 3,045,808, US 3,197,020, US 3,307,868, US 3,580,183, US 3,807,550, US 4,405,042, JP 5900748 B2 — cannot be used. The Webb‑company 1982–1983 items (US 4,464,997; DE 3300991) are the same assignee's descendants, not art.

---

1. The claim, decomposed for § 103 purposes

The sole claim recites an assembly with these limitations:

• (a) a plurality of flangeless load‑carrying trolley wheels on horizontal axes;
• (b) supported in juxtaposition to a conveyer chain on a pair of parallel spaced supporting tracks;
• (c) restrained against excessive lateral movement by auxiliary rollers on vertical axes located between the opposed edges of the tracks;
• (d) "characterized by" mounting both on a one‑piece frame having:
  • (d1) a pair of integral bearings for the trolley‑wheel axles;
  • (d2) a pair of spaced lugs below each of said bearings forming bearings for the auxiliary‑roller axles;
  • (d3) an upward extension midway between the trolley wheels for engagement by the conveyer chain;
  • (d4) load‑securing means in vertical alignment with that extension.

Critically, the claim does not recite the frusto‑conical (frustroconical) tread shape (spec ¶ on element 19), the ball/anti‑friction bearings (30, 31), the tubular bearing member 21, or the spacing bars 37. Those features appear only in the specification. Under § 103 the claim is measured as written, so the claim can be met by cylindrical flangeless wheels, and the patentee cannot import the tread geometry to save the claim.

---

2. Element‑by‑element mapping against the usable art

2.1 US 1,662,093 — "Conveyer‑bar construction" (1928) · https://patents.google.com/patent/US1662093

This is the most damaging reference, and it is squarely in the same art (B65G17/20).

What US 1,662,093 does not disclose: a suspended trolley (it is a rail‑borne conveyer bar); the one‑piece frame with integral wheel‑axle bearings; the upward chain‑engagement extension; and the load‑alignment geometry.

2.2 US 1,572,941 — "Trolley conveyer" (McBride/Palmer Bee, filed 1923, issued 1926) · https://patents.google.com/patent/US1572941 ; https://www.freepatentsonline.com/[1572941](/patent/1572941).html

What US 1,572,941 does not disclose: flangeless wheels, vertical‑axis lateral rollers, or the one‑piece frame with the claimed lug architecture.

2.3 US 1,876,904 — "Trolley conveyer" (App. US 536,614, filed 1931‑05‑11; issued 1932‑09‑13) · https://patents.google.com/patent/[US1876904A](/patent/US1876904A)/en

What US 1,876,904 does not disclose: vertical‑axis lateral‑guide rollers, or flangeless‑wheel teaching.

---

3. The obviousness combinations

No single reference discloses all limitations, so there is no § 102 anticipation on this record. The § 103 case is a combination case, and there are three viable framings.

Combination A — US 1,662,093 in view of US 1,572,941

(the strongest, and it needs only two references)

• US 1,662,093 supplies (a), (b), (c) and the (d2) fork/lug bearing for a vertical‑axis roller, together with the express reason to do it (lateral thrust on curves, friction reduction).
• US 1,572,941 supplies the trolley architecture: a frame whose side frames carry both load‑bearing rollers and auxiliary rollers engaging the track, dimensioned and positioned to limit angular movement of the trolley about the track — the structural predicate for Webb's (d3)/(d4) alignment feature and for the stated object of preventing tilt.
• Result: every element is present or is a predictable rearrangement of a known element. The only remaining "gap" is the one‑piece character of the frame and the specific relative placement of the chain‑engagement point and load hanger.

Combination B — US 1,662,093 + US 1,572,941 + US 1,876,904

(closes the residual gaps)

• US 1,876,904 adds: an integral frame casting that (i) carries the wheel axles in bearings, (ii) constitutes the chain‑engagement structure, and (iii) mounts the load hanger "midway between the axles." That is the (d1), (d3) and (d4) geometry in substance: chain engagement and load suspension both referenced to a single cast member and both centered between the wheel positions.
• The remaining verbal differences ("upward extension midway between the trolley wheels" vs. a pivot pin midway between axles; "in vertical alignment") are arrangement‑of‑parts / positioning differences, and it is a truism that "the mere location or position of parts" and the resulting balanced force diagram are within the ordinary skill of the calling. Webb's own specification concedes the point of placement is what achieves the result — a result that follows mechanically once the designer centers the drive force between the axles and hangs the load beneath it.

Combination C — the applicant's own admissions as § 103 "prior art"

The specification contains three express concessions that materially shrink the claim:

1. Chain drive via a dog on the trolley's upper extremity is conventional: "Any well known means may be employed to operate the endless chain to which is flexibly mounted a plurality of dogs for engagement with the head or upper extremity of the trolley by which engaging means the trolley is urged along the trackway." → (d3)'s chain‑engagement function is admitted prior art; only its centered location is arguably novel.
2. Flanged wheels were universal and their defects were notorious: "it is quite commonly known that on wheels having flanges, the latter not only cause considerable wear on the rails … but the flanges themselves become chipped and broken." → This is an admission of the problem and of a recognized need, which supplies § 103 motivation directly (see § 4).
3. The load hook is conventional: the "opening 17 for the reception of an article supporting hook 18" is presented as ordinary. → (d4)'s load‑attachment means is admitted.

Applicant admissions of this kind are routinely usable against the patentee, and they make a one‑reference‑plus‑admissions attack (US 1,662,093 + admissions) arguable even without Combination B.

---

4. Motivation to combine a person having ordinary skill in the art (PHOSITA)

A PHOSITA here is a 1931 mechanical engineer/designer of overhead power‑and‑free and monorail trolley conveyers — a mature, crowded art with many contemporaneous filings (note the cluster of "Trolley conveyer" documents dated 1931–1932 on this very page: US 1,876,904 filed 1931‑05‑11; US 1,876,659 issued 1932‑09‑13; US 1,949,691 issued 1934).

1. Same field of endeavor, same problem, same classification. US 1,662,093 and US 1,572,941 are both overhead rail/track‑borne conveyer devices; US 1,662,093 is classed in the same B65G17/20 family as the patent in suit. Combining references from the same art to solve the same problem (binding and thrust on curves) is the paradigm case.
2. The problem was known and articulated in both references. Webb's specification says the flangeless/roller arrangement eliminates "binding and gripping by flanges on the rails … especially on curves." US 1,662,093 addresses exactly curves: "the vertical pivot pin 20 permits a lateral pivotal movement of the adjacent conveyer bar sections so as to negotiate curves of practically any radius," and its roller 31 exists "for absorbing and minimizing lateral thrusts … by reason of the direction of projection of the power with reference to the curvature of the track."
3. Substitution of a known element for a known element with predictable result. Replacing flanged‑wheel guidance with a separate vertical‑axis thrust roller bearing on the opposed track edges is a substitution of one known guide means for another, with no change in the principle of operation of the trolley as a load carrier. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), rationale (ii).
4. Integration into a single casting is a known manufacturing technique applied in the same way. US 1,572,941 already teaches a frame with features "cast integral"; US 1,876,904 teaches a "frame casting" carrying wheel bearings and the chain connection. Casting bearing bosses and lug pairs into one frame is "the expected skill of the calling" — as the Supreme Court put the point in its 1925‑term opinion reported at 269 U.S.: "the adaptation … of well known devices to new but similar uses 'is but the display of the expected skill of the calling, and involves only the exercise of the ordinary faculties of reasoning upon the materials supplied by a special knowledge…'" (quoting Hollister v. Benedict Mfg. Co., 113 U.S. 59, 73; see also Atlantic Works v. Brady, 107 U.S. 192).
5. Design incentive / force‑balance reasoning. Once the vertical rollers (not flanges) locate the trolley laterally, the trolley is free to rock; the natural engineering response is to center the propelling force between the wheel axles and hang the load beneath it so no overturning moment is generated. That is precisely what US 1,876,904 already does geometrically ("midway between the axles 2") and what US 1,572,941 already does functionally (auxiliary rollers "limiting the angular movement of said trolley relative to said track," with "the work … carried directly underneath the I‑beam track").
6. No teaching away. The art does not warn against flangeless overload rollers or vertical guide rollers; it affirmatively employs a vertical‑axis thrust roller. (The only mild counter‑teaching is that US 1,662,093's roller 31 uses its flange 33 for hold‑down — but that is an additional function, not a disparagement of a flangeless/plain vertical roller.)

---

5. Counter‑considerations: why the claim might nonetheless have survived

To be balanced, these are the genuine arguments for patentability, and in 1933 they were not trivial:

1. The pre‑1952 "invention" standard was applied more stringently against patentees than modern § 103. Under Hotchkiss and, later, Cuno, a court in 1933–1950 could plausibly have found the combination to reflect "invention" precisely because no one had put flangeless horizontal wheels and vertical‑axis rollers on a single suspended trolley frame — the applicant expressly asserts "it has not been the practice to simultaneously employ in one unit horizontal and vertical trolley wheels." Under KSR/modern § 103 that same fact is, of course, merely the premise of the combination.
2. The combination is not a mere aggregation. The claimed lugs "below each of said bearings" place the vertical roller axles in a specific structural relationship to the wheel bearings, which is more than juxtaposition in the abstract (though a cast frame makes it a shop‑drawing exercise).
3. Objective indicia. The '774 patent is the root of a substantial citation tree, including Webb‑company descendants US 4,464,997 and DE 3300991 A1 ("Conveyor trolley and track"), and Webb became a major conveyor manufacturer. That is evidence of the design's durability and adoption, but I must be explicit: the record before me contains no evidence of commercial success, licensing, copying, or industry praise attributable to this claim, and the later citing patents are the same assignee's own continuations, not independent recognition. Without nexus evidence, objective indicia do not carry the day — and I cannot manufacture it.
4. Simultaneous invention cuts both ways. The 1931–1932 cluster of trolley‑conveyer filings on this page can be argued as convergent, independent development — which the Supreme Court has treated as evidence that the combination was the product of ordinary skill (269 U.S., quoted above: "the independent patent applications, within a comparatively short space of time … are in themselves persuasive evidence that this use in combination of well known mechanical elements was the product only of ordinary mechanical or engineering skill").

---

6. Conclusion

On this record, claim 1 of US 1,920,774 would more likely than not be held obvious under a modern § 103 analysis, most cleanly over US 1,662,093 in view of US 1,572,941, and most completely over US 1,662,093 + US 1,572,941 + US 1,876,904 (the latter as Milburn/§ 102(e)‑type art by virtue of its 1931‑05‑11 filing date). The heart of the invention — flangeless horizontal‑axis load rollers plus vertical‑axis guide rollers riding between the opposed track edges on curved track — is disclosed and expressly motivated in US 1,662,093 (1928). The frame architecture and the centered chain/load geometry are supplied by US 1,572,941 (1926) and US 1,876,904, or by the applicant's own admissions that chain dogs, load hooks, and integral castings were conventional. The patent's unclaimed differentiators (frusto‑conical treads, ball bearings) cannot be read into the claim to rescue it.

Two honest qualifications:

• Confidence in the substantive mapping: moderate‑to‑high for US 1,662,093, US 1,572,941 and US 1,876,904, whose texts I retrieved and quoted. Low for US 833,326 (disclosure not retrieved — I decline to characterize it) and absent for US 1,876,659 (filing date not retrieved).
• Legal status of the exercise: hypothetical. § 103 did not govern this application (filed before January 1, 1953), and the patent expired August 1, 1950, so no live validity question exists. Under the stricter 1933 "invention" case law, a contrary result was reasonably arguable; under § 103 as later construed (particularly after KSR), the claim is vulnerable.