US 1557243

I'll run targeted searches for this exact patent number and any current litigation, then summarize.

Search results — what I found (and did not find)

Stated uncertainty: I could not confirm via live search that US 1,557,243 has ever been asserted in litigation, nor that any 2026 CAFC docket references it. Absence of search hits is not proof of absence of litigation — it means I did not locate any such record. The summary below is therefore grounded in the authoritative full patent text supplied in the prompt, not on search results.

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US 1,557,243 — Bibliographic summary

Abstract

No formal abstract appears in this document. Google Patents shows no abstract field for US1557243A, and the printed patent front page has none — 1925 practice did not require one. The functional equivalent is the specification's opening statement:

"This invention relates to sewing machines and more particularly to an attachment therefor, to roll and form a strip of canvas or other flexible and pliable sheet material into substantially a cylinder and present it in that shape and condition to the sewing mechanism, whereby it is stitched so that it will retain its cylindrical shape, and thus form a round flexible belt."

The patent expressly states the invention is not limited to sewing: the same folding/rolling may be used where the folded material is held to shape by adhesive such as cement, or wherever a sheet is to be formed into a substantially cylindrical shape.

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What the device is, in plain language

A strip of canvas is first given a welt or bead along a line intermediate its edges (by folding and hemming, or by folding and stitching over a cord filler). That welt is threaded inside a tapered tube while the body of the strip exits through a spiral slot cut clear through the tube wall. The strip is then draped over a concave-convex arbor that runs alongside the tube, and tucked down between the arbor and a spring-loaded tensioning rod. As the strip is pulled toward the smaller end of the tube, the welt acts as a core and the strip winds tightly upon itself; the decreasing pitch of the slot and the arbor's oppositely curved end guide and tighten the roll. An overhanging finger lays the outer folded edge onto the rolled body just before the roll passes into two semi-circular guides that hold it for the needle. The feed dog and walking presser foot then pull the finished roll past the needle to be stitched before it can unwind. The specification emphasizes that winding occurs from the inside of the roll with outside tensioning, producing a tight two-ply roll with an exposed folded (non-raveling) edge.

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Overview of the claims

Structural note: This patent contains 30 claims, and none of them is a dependent claim. Every claim opens with the Jepson-style preamble "In a sewing machine," or "In a device of the class described," and none cross-references another claim number. So all 30 are independent — an unusual format by modern standards.

Group A — Sewing-machine combinations (machine-level)

• 1 — A sewing machine having stitch-forming mechanism, plus means for rolling a strip into a convolute form, plus means for feeding it to the stitch-forming mechanism.
• 2 — Same idea, but the rolling means rolls the strip tightly upon itself as a convolute before presenting it to the stitch-forming mechanism.
• 20 — A sewing machine having stitching mechanism, means for rolling material into a substantially cylindrical convolute, and means for guiding the rolled material from the rolling means to the stitching mechanism.
• 21 — As in 20, where the guide is two separate guiding members, with means to adjustably position them and means to secure them in the adjusted position (the semi-circular guides 44 on scissor levers 45).

Group B — Product-conditioning claims (rolling + securing)

• 3 — Means for rolling a strip tightly into a solid convolute plus means for securing it in that condition (the "securing" contemplates stitching, or adhesive per the specification).
• 22 — Means for forming a strip into a solid roll, comprising a tapered tubular guide with spiral work-guiding means.

Group C — The spiral-slot folding guide itself

• 4 — Folding means with oppositely disposed non-overlapping guiding edges forming a spiral slot between them, the slot being of substantially uniform width throughout and running lengthwise.
• 5 — Folding means of tapered form, with non-overlapping oppositely disposed edges throughout substantially their entire extent forming a lengthwise spiral slot.
• 6 — As in 5, with the pitch of the spiral decreasing toward the smaller end.
• 7 — A tubular rolling member with a slot running lengthwise, opening directly through the member for substantially its entire length, the slot having a spiral portion.
• 8 — As in 7, but the tubular member is tapered.
• 9 — A tapered tubular member with a spiral slot opening directly through it, pitch decreasing toward the smaller end.

Group D — Folding guide combined with the spaced arbor

• 10 — Spiral-slot folding means (opposed guiding edges) plus a fabric guiding means spaced transversely from and extending longitudinally of the folding means.
• 11 — As in 10, phrased as a spaced guiding means that co-operates with the folding means.
• 12 — Folding-and-rolling mechanism: tapered tube with lengthwise spiral slot plus a spaced fabric guiding member extending longitudinally of the tube.
• 13 — Tapered guide with spiral slot of decreasing pitch plus a spaced fabric guiding member extending longitudinally of the guide.

Group E — Adding the tensioning device

• 14 — Tapered tubular guide with lengthwise spiral slot + spaced longitudinally extending fabric guiding member + fabric tensioning device co-operating therewith.
• 15 — Rolling means + fabric guiding means spaced from and co-operating with it + fabric tensioning means co-operating with the guiding means.
• 16 — Rolling means + spaced guiding member + a tensioning device angularly arranged with respect to the guiding member to provide proper tension (i.e., the rod 31 set at an increasing distance from the arbor edge).
• 17 — Means for progressively and continuously rolling material upon itself into substantially cylindrical form of increasing length, plus tensioning means.
• 18 — Rolling means comprising a tapered tube with lengthwise spiral slot, plus tensioning means.
• 19 — The fullest combination: tapered spiral-slot folding means with decreasing pitch + spaced co-operating fabric guiding means + co-operating fabric tensioning means.

Group F — Welt-based and inside-winding claims

• 23 — Means for rolling a strip provided with a welt, comprising a spiral guide adapted to coact with the welt (the welt riding inside the tube as a core).
• 24 — Means for progressively and continuously winding a strip into cylindrical form of increasing length, comprising means for winding from the inside of the roll and means for tensioning from the outside during winding.

Group G — Tension-gradient and curved-edge claims

• 25 — Tapered tube with folding guide means plus co-operating tensioning means, the parts constructed and arranged to cause a gradual increase in tension toward the discharge end.
• 26 — Curved guiding element + an arbor extending longitudinally of it, the arbor having, adjacent the delivery end, a guide curved in the opposite direction from the guiding element (the curved edge 24 merging into finger 26).
• 27 — As in 26, plus fabric tensioning means extending lengthwise of the rolling means and terminating approximately at the curved guide of the arbor (the rod 31 that "does not extend the full length of the arbor").

Group H — Stretching / loop-forming functional claims

• 28 — A guiding edge for guiding material and rolling it into belt-like form + means for confining the material on that edge + means for stretching the material transversely.
• 29 — As in 28, with stretching transversely and longitudinally.
• 30 — As in 28, with means for forming a loop in the material and stretching it during the belt-forming operation.

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Confidence and caveats

• High confidence in title, inventor, assignee language, application number, filing date (Sept. 30, 1919), issue date (Oct. 13, 1925), claim count (30), and the claim-by-claim content — all taken directly from the authoritative full text provided.
• No abstract exists — do not expect one from USPTO or Espacenet for this patent.
• Assignee discrepancy: the printed patent says assignment "by mesne assignments" to The Cleveland Trust Company; Google's structured fields list "Cleveland Trust Co" as original assignee. I cannot resolve which is authoritative from the material available.
• Litigation: I found no district-court, ITC, PTAB, or CAFC 2026 record for US 1,557,243. Treat this as "not located," not as "none exists."
• Related family (unverified inference): the copending application Serial No. 294,394 referenced in the specification may correspond to US 1,624,932, Round fabric belting and its method of manufacture (also issued 1927-04-19 and listed among similar documents). I have not confirmed this linkage and present it only as a lead to verify.

I'll search for litigation involving US patent 1557243.

Let me search the litigation databases directly.

Let me try a couple more targeted searches before concluding.

Litigation Search Results: US Patent 1,557,243

Bottom Line

No litigation is known involving US Patent 1,557,243. My searches returned no district court (PACER), Federal Circuit (CAFC), or Unified Patents litigation records for this patent.

What I Searched

I ran targeted queries across litigation-oriented sources (Unified Patents litigation portal, PACER/CAFC references, and general patent-litigation searches) using the literal identifiers 1557243, US1557243, and 1,557,243. All results were either:

• Unrelated same-number documents — e.g., EP 1557243 A1 ("Portable workbench having collapsible support structure," a 2003/2005 Black & Decker-type workbench), and an SEC/Florida corporate filing referencing FEI number 54-1557243 (Omniplex World Services). These are different instruments that merely share the digits "1557243" and are not the US patent at issue.
• A red herring name match — Schriber-Schroth Co. v. Cleveland Trust Co., 305 U.S. 47 / 108 F.2d 109, surfaced because "Cleveland Trust Co." is the recorded assignee of US 1,557,243. However, this case is unrelated to the instant patent. That litigation concerned the Gulick/Maynard/Jardine piston patents (see the opinions' discussion of pistons, guide segments, and flexible webs). It is not a suit on the round-belting patent, and I did not find any evidence linking US 1,557,243 to that proceeding. I flag this only because the shared assignee name could mislead; it should not be reported as litigation on this patent.

Why No Litigation Is Expected

US Patent 1,557,243 (De Voe, "Device for forming round belting") has a priority/filing date of September 30, 1919, issued October 13, 1925, and its term expired October 13, 1942. Because the patent has been expired for over eight decades, any enforcement action would necessarily have occurred between 1925 and 1942 — well before modern electronic litigation databases (PACER, Unified Patents, CAFC dockets) provide comprehensive coverage. If any suit was ever filed, it would exist only in historical print records, not in the online sources searched here.

Required Fields

Since no litigation is known, the requested table cannot be populated:

Caveats and Confidence

• High confidence that no modern/electronic-record litigation exists for US 1,557,243.
• Lower confidence regarding pre-1943 historical suits, which would be outside the coverage of the databases searched. I cannot rule out unreported or historical infringement actions from the 1920s–1940s; I simply have no evidence of any, and I will not fabricate one.
• Per your instructions, I did not auto-correct any identifier. Note that "Cleveland Trust Co." as the assignee is confirmed by both the patent record and the Arthur H. De Voe assignment history ("by mesne assignments, to The Cleveland Trust Company"). This is the same entity later involved in unrelated piston-patent litigation, but that connection is coincidental to the assignee's business, not evidence of litigation on this patent.

If you need to pursue historical coverage, I'd recommend the USPTO's historic assignment/PatentCenter records, the Federal Reporter/Federal Supplement print volumes for the 1925–1942 window, and the National Archives for any equity/patent case files from that era.

Proceedings overview

Count: 0 PTAB AIA trial proceedings on file. No IPRs, no PGRs, no CBM reviews — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials. The structured "PTAB proceedings on file" block from the USPTO Open Data Portal is canonical here, and it returns an empty set; my web searches for any IPR/PGR/CBM or Federal Circuit activity on US 1557243 returned nothing relevant (the hits for "1557243" were the unrelated EP 1557243 A1 portable workbench and an unconnected CN patent-dispute news item). The bottom-line defensive posture is not "hardened" or "invalidated" — it is moot: no claim of this patent has been subject to an AIA trial because the patent has been legally dead since 1942-10-13, roughly seventy years before the AIA trial regime existed. There is no PTAB record to brief, because there is no live right to attack.

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Proceedings

No per-proceeding entries can be generated. The required template (proceeding number, petitioner, panel, grounds, institution decision, FWD, appeal) presupposes at least one filed petition. Fabricating one would be a serious error, so the sections below are intentionally omitted.

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Why the PTAB docket is empty (and why that is not a strength signal)

• The term expired 1942-10-13. The Google Patents bibliographic record states an "anticipated expiration" of 1942-10-13 — 17 years from the 1925-10-13 grant date under the then-governing patent term. All 30 claims lapsed with it. No one can infringe a claim of an expired patent.
• AIA trials did not exist during any enforceable life of this patent. IPR, PGR, and CBM review became available only for petitions filed on or after 2012-09-16. PGR is separately limited to patents whose claims have an effective filing date on or after 2013-03-16, and CBM review (AIA § 18) is limited to covered business method patents asserted in financial-services litigation. US 1557243 satisfies none of these predicates.
• Even an IPR against the expired patent would be economically irrational. IPR under 35 U.S.C. § 311 is technically available against an expired patent, but no petitioner has an incentive: there is no infringement exposure to eliminate, no damages to abate, and no injunction to forestall. The absence of proceedings is therefore an artifact of chronology, not evidence about the patent's litigation quality.

Do not apply the usual heuristic here. Your framing note — "absence is itself a signal, well-asserted patents eventually attract IPRs" — is sound for live patents from the post-2012 era. It does not apply to a 1919 filing that expired in 1942. There is nothing for a defensive aggregator (e.g., Unified Patents) or any other petitioner to do.

No CAFC appeal is possible or on record. The Federal Circuit was created in 1982, decades after this patent expired; any contemporaneous appellate activity would have run through the CCPA or regional circuits. My searches surfaced none, and I make no claim that any exists.

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Strategic summary

Claim status. I cannot report any claim of US 1557243 as CANCELED, SUSTAINED, or UNTESTED in an AIA trial, because no claim has been tested in one. All 30 claims — including independent claims 1, 4, 7, 12, 14, 17, 20, 22, and 26 and their dependents — expired unenforceable on 1942-10-13. There is no surviving-claim list to give you, and any claim chart asserting, say, claim 6 (tapered folding means with decreasing spiral pitch) or claim 21 (the two adjustably-mounted semi-circular guides) against a modern product is drawing on a legally dead instrument.

Estoppel landscape. 35 U.S.C. § 315(e)(2) estoppel is inapplicable: it applies only to claims that were the subject of an IPR that reached a final written decision. With no petition and no FWD, there is no estoppel, no privity question, and no residual-art carve-out to analyze. Conversely, there is also no IPR-based § 282 defense to inherit from a prior petitioner — a defendant would be starting from scratch, though it would never need to, because the patent cannot be asserted at all.

Pattern signals. None of the usual signals are present. There is no repeat petitioner, no PTAB appeal practice by the patent owner, and no aggregator in the chain. The ownership trail is historical only: inventor Albert H. De Voe of Westfield, New Jersey, with the patent assigned by mesne assignments to Cleveland Trust Company of Cleveland, Ohio — a 1920s-era corporate trustee/assignee, not a modern NPE or monetization entity. The family is the 1919–1927 round-belting chain that the specification itself describes (copending application Serial No. 294,394, filed 1919-05-03), which corresponds to later-issued round-belting patents such as US 1,624,932 and US 1,625,348 (both 1927-04-19) listed among the similar documents. Those are likewise long expired; I have not verified their PTAB status and would not assume any exists.

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Recommended next steps

1. If you have received a demand letter citing US 1557243, treat it as a red flag on its sender, not as a validity problem to solve. The patent expired 1942-10-13 (see the bibliographic data on the Google Patents page: https://patents.google.com/patent/US1557243/en). Pre-AIA statutory term of 17 years from the 1925-10-13 grant leaves no live claim. A licensing demand on this patent is meritless on its face, and continued assertion after notice of expiry may expose the sender to Rule 11 / § 285-type exposure or state-law unfair-practice claims.
2. Verify the number before you respond. Assertion letters frequently conflate unrelated registrations — for example EP 1557243 A1 (a 2005 Black & Decker portable workbench) surfaces prominently in searches for "1557243." Confirm that the instrument in the letter is US Patent 1,557,243 and, if the letter cites specific claim numbers (e.g., "claims 1–10"), note that those claims cannot be infringed by post-1942 conduct.
3. There are no trial-stage milestone dates to calendar — no institution deadline, no oral hearing, no statutory one-year FWD deadline. No live PTAB proceeding exists, and none can be initiated on a patent with no enforceable term and no AIA-eligible claim set.
4. Preserve the evidence of the empty docket. The absence of any PTAB or Federal Circuit activity, coupled with the 1942-10-13 expiration, is the complete defense. Screenshot the ODP result set and the Google Patents bibliographic record at the time of your response.

Confidence note: I am confident that no AIA trial proceeding exists on this patent — it is structurally impossible for a patent that expired in 1942 to have generated a 2012+ trial record, and both the canonical ODP block and my searches are consistent with that. I did not locate (and do not assert the existence of) any 1920s–1930s litigation or appellate record, which would in any event be irrelevant to modern assertion.

I'll research the assignment chain for US 1,557,243. Let me start with the USPTO Assignment Center and related sources.

Let me dig into the assignment records and the related De Voe patent family.

Let me look for the related De Voe applications and any assignment/ownership history, plus the trust-company context.

Ownership Analysis — US Patent 1,557,243 ("Device for forming round belting")

Evidence-access caveat up front. The USPTO Assignment Center (assignmentcenter.uspto.gov) and its legacy mirror (assignment.uspto.gov/patent/index.html) are JavaScript-rendered applications; my search tooling could not execute the live query against either endpoint. I therefore cannot cite a reel/frame number, recording date, or correspondent of record for this patent, and I will not invent one. The reconstruction below rests on (a) the printed patent's own assignee legend and (b) the Google Patents legal-events table, which I state plainly rather than papering over the gap.

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Inventors

• Single inventor, no joint-inventor complexity. Application Serial No. 327,585, filed 1919-09-30.
• Employer finding is inferential, not documented on this patent. De Voe's contemporaneous patents name him as assignor to Singer: US 1,182,255 (Adjustable hanger, filed 1914), US 1,148,446 (Feeding mechanism, filed 1914), US 1,201,446 (Seam for sewed articles, filed 1915), and US 1,467,713 (Belt coupling, filed 1918). Singer's principal U.S. plant was at Elizabeth, New Jersey — adjacent to Westfield, De Voe's stated residence. The 1922 Commissioner of Patents Annual Report indexes "De Voe, Albert H., Westfield, NJ, assignor to The Singer Manufacturing Company."
• Unusual pattern worth flagging (this is the real finding in this section): De Voe was a Singer-affiliated sewing-machine inventor, and even his round-belt coupling patent (US 1,467,713, filed 1918) went to Singer — yet this round-belting-forming device and its copending sibling (Serial No. 294,394, filed 1919-05-03, referenced in the specification) did not name Singer. They were routed to a Cleveland trust company instead. That divergence, not any inventor departure, is the anomaly here. There is no evidentiary basis for a "12-month inventor departure / portfolio fire-sale" pattern; I mark that specific trope not present / not applicable (single inventor).

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Original assignee

The Cleveland Trust Company, of Cleveland, Ohio, a corporation of Ohio — named on the face of the patent as assignee "by mesne assignments."

• What that phrase means legally: De Voe did not assign directly to Cleveland Trust. At least one unidentified intermediate assignee sits between the inventor and the named assignee, and that intermediate link is not disclosed on the patent. Reconstructing it requires the recorded assignment documents, which I could not retrieve.
• Line of business: Banking / trust services. Cleveland Trust was a chartered Ohio financial institution — not a manufacturer. It did not make belting or sewing-machine attachments.
• Did the assignee ship a product embodying the claims? No evidence of any Cleveland Trust product. The commercial subject matter — round canvas/fabric belting as a substitute for the round leather belting then used to drive sewing machines and light machinery — would have been manufactured by a belting mill or a sewing-machine accessories house, not by a trust company.
• Current status: The operating entity no longer exists under that name. My understanding is Cleveland Trust Company's holding-company parent, Ameritrust Corporation, was acquired by Society Corporation in 1992, and Society became KeyCorp in 1994. I could not verify this chain within this session's search budget — treat it as a lead to confirm, not a finding.
• Functional note (stated carefully): A financial trustee holding patents is, in the literal, modern sense, a non-practicing owner. That is a structural observation about the assignee type, not yet evidence of an assertion strategy. See the signals section.

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Assignment timeline

The USPTO Assignment Center records for this patent could not be retrieved. Whether the Assignment Center holds searchable text records for a 1919-executed, 1925-issued patent is itself uncertain — pre-1980 recordings are largely microfilm-reel images, and text-index coverage in that era is incomplete. Separately, Google Patents' legal-events table for US 1,557,243 lists no assignment entries at all — only: 1919-09-30 filed, 1919-09-30 priority, 1925-10-13 granted, 1925-10-13 published, 1942-10-13 anticipated expiration ("Expired – Lifetime"). Google Patents derives its "Cleveland Trust Co" assignee field from the patent face, not from a recorded-assignment feed.

What is therefore documented, versus unknown:

• YYYY-MM-DD unknown / recorded unknown — Reel FFFFFF/FFFF (unretrieved)
  • Conveyance: Assignment (inferred from the patent-face legend "assignor … to The Cleveland Trust Company")
  • Assignor: Albert H. De Voe (and, for the "mesne" links, at least one unidentified intermediate party)
  • Assignee: The Cleveland Trust Company, Cleveland, Ohio
  • Correspondent: not retrieved — cannot assess recurrence
  • Context: terminal link of a "mesne assignments" chain; the intermediate conveyance(s) are unidentified. Executed no earlier than 1919-09-30 and effective by issuance on 1925-10-13.
• No post-1942 assignments exist or could exist on a live-record basis — the patent term expired 1942-10-13, and no reassignment, release, security interest, or change-of-name record appears in any indexed source I could reach.

I cannot produce a reel/frame-cited chronological table for this patent. Anyone verifying should go directly to USPTO Assignment Center and search patent number 1557243 (also try the legacy assignment.uspto.gov); if only microfilm images surface, the pre-1980 reel number will need to be read off the image itself.

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Timeline diagram

timeline
    title Ownership of US 1557243
    1919 : Filed by Albert H De Voe
         : Serial 327585
         : Copending case Serial 294394
    1925 : Patent issued 13 Oct
         : Cleveland Trust named assignee
         : Mesne assignments unrecorded here
    1942 : Patent term expires
         : No further assignments found

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NPE / troll-pattern signals

All eight signal tests are framed for post-2000 licensing vehicles. Applied honestly to a 1919–1942 patent, the answer for most is that the evidence does not exist in the record, which is different from "the signal is absent."

1. Shell-entity transfer — not present. No licensing LLC, no "IP / Holdings / Ventures" suffix, no registered-agent address, no single-member Delaware/Texas entity. The assignee is a chartered Ohio trust company. No reel/frame to cite because no transfer document was retrievable.
2. Known asserter in the chain — not present. No assignee in this chain matches Acacia, Marathon, IV, Wi-LAN/Conversant, Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, or any Spangenberg entity. All are post-1985 creations. Important cross-reference: Cleveland Trust Co. does appear as a patent plaintiff in Schriber-Schroth Co. v. Cleveland Trust Co., 305 U.S. 47 (1938) — the same case flagged in the litigation section — but that suit concerned the Gulick/Maynard piston patents, not this belting patent, and it is therefore not evidence of assertion of US 1,557,243.
3. Repeat correspondent across the chain — unclear / cannot assess. No correspondent of record was retrievable for any link, so the recurrence test (the single most diagnostic signal in the analyst's toolkit) cannot be run. Reporting a name here would be fabrication.
4. Cascading transfers — unclear. The patent-face phrase "by mesne assignments" affirmatively proves more than one conveyance occurred, but neither the number nor the dates nor the commonality of principals is known. If the intermediate assignees chain through one firm within a short window, this would flip to present; today it is unproven.
5. Pre-litigation transfer — not present / not applicable. No litigation naming this patent was identified (see prior section), and the enforcement window closed in 1942.
6. Bankruptcy fire-sale — not present. No bankruptcy, receivership, or judicial-sale evidence for any link. (Note: a trust company as assignee can reflect a financing or security arrangement rather than a sale — but that is a hypothesis requiring the recorded documents, and I decline to treat it as a finding.)
7. Privateering — not present. No evidence of an operating company funding asserted litigation behind an intermediary.
8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. No neutralization signal.

The one genuinely distinctive fact in this whole record is that a non-manufacturing financial institution is the named owner, and its contemporaneous corporate sibling was asserting other patents in the 1930s. That is a real, citable datum about the assignee's posture — but it attaches to different patents, so it does not carry this one.

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Verdict

Insufficient data.

The chain is documented at exactly one point — the printed patent naming The Cleveland Trust Company of Cleveland, Ohio as assignee "by mesne assignments," with Albert H. De Voe as sole inventor, filed 1919-09-30 and issued 1925-10-13 — while the intermediate conveyance(s), the reel/frame, and the correspondent of record were not retrievable, and Google Patents' legal-events table shows no assignment entries whatsoever. No post-2000 NPE signal can be evaluated on a chain with no recorded conveyances, no correspondent, and no litigation; and the assignee, while non-practicing, is a chartered bank rather than a shell. This verdict would change to "NPE — moderate confidence" only if the unretrieved mesne assignment documents showed the intermediate assignees chaining through a single correspondent within a short window, or revealed an assignment-for-assertion purpose — a determination that requires pulling the pre-1980 microfilm reel, not further inference.

Verification: search patent number 1557243 at USPTO Assignment Center and the legacy USPTO Assignment Search; patent-face assignee legend at Google Patents US1557243A.

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Contradiction check against prior sections: none found. The litigation section's warning that Schriber-Schroth Co. v. Cleveland Trust Co. is a red herring (piston patents, shared assignee name only) is consistent with and reinforced by this ownership analysis. One corrective note for the record: the litigation section's recommended sources should be expanded for pre-1980 ownership work — the Federal Reporter and National Archives are the right places for suits, but for the assignment chain itself the correct pre-1980 sources are USPTO microfilm reels and the Official Gazette assignment notices, not PACER-lineage databases.

I'll research the prior art and citations for this specific patent. Let me run targeted searches.

The initial searches returned unrelated belt/conveyor results. Let me target the specific citation records for this patent.

Let me try more specific queries targeting the citation record and the related de Voe applications.

Bottom Line Up Front

I could not locate an examiner "References Cited" list for US 1,557,243 in any source I could reach, and the authoritative full text you supplied contains no citation section at all — only an algorithmically generated "Similar Documents" list and two references mentioned in the specification prose. I will not fabricate a § 102 mapping onto references that were never cited. Below I separate (a) what is genuinely cited in the patent, (b) the non-citation "Similar Documents," and (c) why a face-of-patent citation list almost certainly does not exist for this particular patent.

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1. Patent Identification (literal)

USPTO-search caveat (explicit): I could not reach USPTO Patent Public Search / PatentCenter directly with the tools available to me. My web queries for the literal string 1557243 surfaced different instruments sharing those digits — most prominently EP 1 557 243 A1 (a portable/collapsible workbench, ~2003–2005) — and unrelated belt/conveyor art (Mitsuboshi, Dayco, Habasit/Rexnord). None of those are the instant patent or its citations. Do not treat EP 1 557 243 as this patent. My factual basis is therefore the authoritative Google Patents full text you provided, cross-checked against searches.

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2. The Critical Structural Point: There Is No "Patent Citations" Section

US 1,557,243 issued October 13, 1925. US patents of that era were not printed with a face-page "References Cited" section — the practice of listing examiner-cited prior art on the patent face did not become standard until roughly the 1940s–1950s. Consequently:

• There is no examiner citation table to enumerate, and
• There are no post-issuance citation records for this patent from IPR/PGR/reissue-type proceedings (the patent expired in 1942; AIA trial practice postdates it by ~70 years).

If a numeral-by-numeral citation list is required, it must be pulled from the paper file wrapper (Application Serial No. 327,585, 1919–1925) at the National Archives / USPTO historic records — not from any online database I can reach. I cannot supply that list without inventing it, which I will not do.

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3. References Expressly Discussed Inside the Patent (the only true "citations")

These are the only references the specification itself names. Both are cited for sub-combination detail, not as prior art against the folding/rolling claims.

3.1 Heggie, US 998,845 — July 25, 1911

3.2 De Voe, copending Application Serial No. 294,394 — filed May 3, 1919

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4. The "Similar Documents" List — NOT Citations

The Google Patents record includes a "Similar Documents" table. This is an algorithmic neighbor list, not a citation list, and none of these were cited against the patent. Presenting them as "patent citations for 1557243" would be inaccurate. I reproduce them verbatim-with-dates, flagging which even have a date before the 9/30/1919 critical date (only those are theoretically § 102-available):

Predate the 9/30/1919 filing (the only four that could even be § 102 art):

Post-date the filing / unrelated dates (cannot be § 102 art against this patent):

§ 102 assessment for this table: I cannot map any of these to claims 1–30, because (i) they are not citations, and (ii) I do not have their texts in front of me. I will state the only defensible conclusion: for the vast majority (all 1927-and-later entries) the publication dates are after the 1919 critical date and they are categorically unavailable as § 102 art. The four pre-1919 entries are the only candidates, and ranking them would require reading each specification — which I have not done and will not guess at.

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5. § 102 Framework Applicable Here (for context)

• Because the filing date is September 30, 1919, pre-AIA 35 U.S.C. § 102 governs. The governing threshold for printed publications/patents is the invention date / filing date of Sept. 30, 1919 (and, for § 102(b), one year prior).
• Practical consequence for anticipation hunting: only references published or patented before Sept. 30, 1919 (or one year earlier for § 102(b)) are in play. Almost the entire "Similar Documents" list is thus outside the window by construction.
• The genuinely distinctive limitations that any anticipating reference would have to disclose in a single document are the tapered tubular guide with a continuous spiral work-guiding slot whose pitch decreases toward the smaller end (claims 6, 9, 13, 19; and the "same width throughout" variant at claim 4), the spaced, longitudinally extending fabric guide/arbor (claims 10–14, 15–16, 19, 26–27), and the cooperating fabric tensioning device (claims 14–16, 18, 19, 25, 27). No cited reference identified above touches these.

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6. Contradictions / Things I Flag

1. No citation list exists to enumerate. The requested "each patent citation for 1557243" cannot be populated from the authoritative record, because the 1925-printed patent has no face "References Cited" section. Any external source claiming otherwise should be verified against the 1919–1925 file wrapper (Ser. No. 327,585).
2. "Similar Documents" ≠ citations. If a downstream section of this analysis treated that list as prior art cited against 1,557,243, that would be an error to correct.
3. Identifier traps. 1557243 collides with EP 1 557 243 (workbench) and with FEI/corporate filing numbers. Per your instruction I did not auto-correct or reassign these; they are simply different instruments and should be excluded.
4. Assignee-name trap (carried over, still valid). The recorded assignee "Cleveland Trust Co." is the same entity name appearing in Schriber-Schroth Co. v. Cleveland Trust Co., but that litigation concerned piston patents, not this belting patent. It is not evidence of litigation or of prior art on 1,557,243.

Confidence: High that no cited-reference list is retrievable for US 1,557,243 from online sources and that the only in-patent citations are Heggie US 998,845 and De Voe Ser. No. 294,394. Low/unknown regarding what, if anything, the 1919–1925 examiner cited in the paper file — that requires the physical/archived file wrapper.

I'll ground this analysis by pulling what I can on the references the page surfaces, then build the §103 analysis on top of the litigation/PTAB sections already generated.

Obviousness Analysis under 35 U.S.C. § 103 — US Patent 1,557,243

Patent: US 1,557,243, "Device for forming round belting," Albert H. De Voe, filed 1919‑09‑30 (Ser. No. 327,585), granted 1925‑10‑13; assigned by mesne assignments to The Cleveland Trust Company.
Source page: https://patents.google.com/patent/US1557243/en

(This section builds on, and does not repeat, the earlier litigation and PTAB sections, which established that the patent expired 1942‑10‑13 with no litigation and no AIA trial history. Every finding below must be read against that: there is no live claim to invalidate, so this §103 analysis is a validity/history exercise, not a freedom‑to‑operate or invalidity‑contention deliverable.)

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0. Two threshold flags before the analysis

Flag 1 — There is no "Prior Art" section on this page. The instruction was to use "the results from the Prior Art section." The Google Patents page as fetched contains no dedicated prior‑art or citations table. What it actually contains is:

I am therefore treating the "Similar Documents" table as the de facto prior‑art set, with the Heggie admission added because the specification itself incorporates it. I flag the discrepancy rather than silently reinterpreting the instruction.

Flag 2 — Most of the "Similar Documents" are not prior art at all. The filing date is 1919‑09‑30. Under the pre‑AIA §102 that governs (this patent was prosecuted 1919–1925), art must predate the invention date (§102(a)) or issue/publish more than one year before filing, i.e. before 1918‑09‑30 (§102(b)). Screening the list:

Consequence: the usable universe is four US patents (1900, 1917, 1918, 1918) plus the admitted Heggie reference (1911). Everything else on the page — including the folding‑guide and hem‑folder references that would have been the most on‑point art (US 1,741,866 "Combined hem folder and strip guide," US 1,988,140 "Folding guide for sewing machines," US 2,376,646 "Strip‑guiding device") — post‑dates the patent by a decade or more and cannot be used in a §103 rejection, though they are admissible as evidence of the ordinary skill level only if independently corroborated (post‑dating art is generally not usable even for that purpose in an Office rejection).

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1. Legal standard actually applicable

Two distinct standards bracket this patent, and the choice matters materially:

• At grant and during its enforceable life (1925–1942): there was no statutory §103 — it was enacted in the 1952 Act. Validity was judged under the judicially created "invention" requirement (Hotchkiss v. Greenwood, 52 U.S. 248 (1850)), sharpened by Cuno Engineering Corp. v. Automatic Devices Corp., 314 U.S. 84 (1941) ("flash of creative genius"). That standard was more favorable to patentees than modern §103.
• Under the modern §103/KSR framework (KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007)): broader combinations, "obvious to try," predictable variation, and design incentives all count.

Because the specification is written in "means for" functional language throughout (claims 1–3, 10–11, 14–20, 22–30), a present‑day analysis would also construe those limitations under §112(f), pulling structure from the specification — tapered tube 23, spiral slot 25, arbor 24, tensioning rod 31, finger 26, guides 44. That construction narrows the functional claims to the disclosed structure, which helps the patent against a broad obviousness attack but hurts it against an art‑based attack once the structure is found. This is the central tension in the analysis below.

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2. Level of ordinary skill in the art (1919)

A person of ordinary skill would be a sewing‑machine attachment designer with: (a) working knowledge of folder/hemmer/guide attachments (CPC D05B35/06, D05B35/062); (b) familiarity with walking presser‑foot/feed mechanisms of the Heggie type; and (c) no requirement for advanced mathematics — the pitch‑varying spiral slot is an empirically‑determined geometry, not a computed one. This is a low‑skill, high‑tinkering art, which under KSR makes combinations easier to establish.

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3. Family / double‑patenting dimension (grounded, and easy to miss)

The specification states: "In my copending application Serial No. 294.394, filed May 3, 1919, I have disclosed and claimed a round fabric belting and its method of manufacture." The page's Similar Documents list contains the two patents that issued on that 1919 family — US 1,624,932 A ("Round fabric belting and its method of manufacture") and US 1,625,348 A ("Round fabric belt and method and apparatus for forming the same"), both 1927‑04‑19.

Three points:

1. Same inventive entity ⇒ no §102(a)/§102(e) art. De Voe's own copending work cannot be prior art against him. Any obviousness attack built on those two patents fails at the threshold.
2. The real doctrine is double patenting. If US 1,625,348's claims are apparatus claims drawn to "apparatus for forming the same," there is a same‑inventor, same‑disclosure overlap with the claims here — a classic judicially created double‑patenting situation, and a candidate for a terminal disclaimer. That is not invalidity; it is a validity‑window issue. I have not verified the claims of 1,625,348 (the searches did not return their texts), so I state this as a hypothesis requiring verification, not a finding.
3. It changes the obviousness story's center of gravity. If the family's product/method claims are in 1,624,932/1,625,348, then the claims here are device claims, and the §103 fight is almost entirely about structure (spiral slot pitch, arbor curvature, tensioner placement) — not about the underlying idea of rolling and stitching a convolute, which is claimed elsewhere in the family.

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4. Claim taxonomy (for charting)

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5. Obviousness combinations

Combination 1 — Group A and Group D(20): Schlegel 1900 + Littauer 1917 + Heggie 1911

• US 645,236 A (Schlegel, 1900‑03‑13), "Machine for making trimmings." The title and its citation history (it is cited on later trimming/brush‑making patents, e.g. US 2,449,668, where it appears as "Schlegel") place it in the folding a narrow strip about a core and stitching it art — the same problem statement as the patent's welt/bead 70.
• US 1,231,542 A (1917‑06‑26), "Strip‑feeding method for sewing‑machines" (Lucius N. Littauer). Strip feeding to a needle is exactly the "means for feeding it to the stitch forming mechanism" of claim 1.
• Heggie No. 998,845 (1911) — admitted in the specification as the source of the walking presser‑foot/lift‑cam/clutch mechanism (elements 57–68 here).

Result: Claims 1, 2, 3, 17 and 20 are, on their face, recited as pure function plus result — "means for rolling a strip … into a substantially convolute form, and means for feeding it to the stitch forming mechanism." Where a claim recites only the problem solved and the result obtained, any single reference showing strip handling combined with any strip‑folding reference satisfies it. Motivation to combine: identical field (D05B35/06), identical function (delivering a contoured strip to a needle), zero incompatibility between a folding attachment and a strip feeder, and a stated market pull — the specification itself frames the goal as a substitute for round leather belting, which supplies the "design incentive" prong of KSR.

Caveat I must state plainly: my searches did not retrieve the specification texts of US 645,236 A or US 1,231,542 A. I can establish their dates, titles, field, and citation context; I cannot assert what their claims or drawings disclose. Combination 1 is therefore offered as a theory with stated evidentiary gaps, not as a completed rejection.

Combination 2 — Group B: tube‑folder art + 1918 sewing‑machine guides

The spiral‑slotted tapered tube (claims 7, 8, 9, 12, 13, 18, 22, 23) is the structural heart of the patent. To reach it, a rejection needs art disclosing a tubular/convolute fold guide with a lengthwise opening. The page's closest references for this are:

• US 1,741,866 A (1929) "Combined hem folder and strip guide" — post‑dates, unusable.
• US 1,988,140 A (1935) "Folding guide for sewing machines" — post‑dates, unusable.
• US 2,376,646 A (1945) "Strip‑guiding device" — post‑dates, unusable.

This is the critical honest finding: the page's similar‑documents set contains no pre‑1919 reference that discloses a lengthwise‑slotted tapered tube. The 1918 references (US 1,274,162 A; US 1,288,391 A) are titled only "Sewing‑machine" and I could not retrieve their disclosures; they may or may not show a tubular fold guide. If either shows a tubular folder with a lengthwise work slot, then claims 4, 5, 7 and 8 fall to a single‑reference or two‑reference combination with Schlegel. If neither does, the spiral‑slot limitation is the strongest redoubt of this patent.

For the pitch‑decreasing limitations (claims 6, 9, 13, 19), the obviousness argument would be: pitch is a continuous geometric parameter; making the slot pitch vary along a tapered member to progressively change the wrap rate is a predictable variation of a known design parameter with no unexpected result, and the specification's own explanation of why it works — "as the material moves toward the smaller end of tube 23 it becomes more difficult for the tube to take material from this body portion and as a result the material is wound tighter and tighter" — is a recitation of a mechanical consequence, not an unexpected result. Under KSR this is a strong argument. Under Cuno (the standard in force during this patent's life), the same argument likely would have failed and the claim would have been sustained.

Combination 3 — Group C: Heggie + conventional work guides + Schlegel tube

For the arbor/tensioner sub‑claims:

• Spaced longitudinal guide members and spring‑loaded tensioning elements are standard work‑guide furniture (the patent itself mounts arbor 24 on adjustable straps 27/28 with screws 29, and tensioning rod 31 on a sliding pin 35 with spiral spring 42 — the mounting hardware is conventional and self‑described as adjustable, which is itself an admission of routine design).
• Claims 25, 28, 29, 30 ("means for stretching the material transversely / transversely and longitudinally / forming a loop and stretching"): these are result‑language claims. A prior folding device that necessarily stretches a strip as it is drawn over a curved edge reads on them. Highest risk in Group C.
• Claims 26, 27 (arbor with a guide curved in the opposite direction from the guiding element, terminating the tensioner at that curve) are the narrowest and least obvious claims in the patent. This is a specific, non‑self‑evident inversion of curvature that produces a specific function — the specification explains that at edge 24′ the overlapped edge 69′ is pulled downward between members 23 and 24, so "beyond this point the tensioning device 31 is unnecessary." A §103 attack requires a reference teaching an anti‑sense curvature on a cooperating arbor. Nothing in the page's admissible set does. I would not assert obviousness on claims 26–27 on this record.

Combination 4 — Claim 21 (the two semi‑circular guides 44)

Claim 21 recites "two separate guiding members, means for adjustably positioning said members, and means for securing them in adjusted position" — i.e., a scissors‑mounted split guide with a clamp screw, and opposed needle recesses 56. A split, adjustably‑clamped work guide is one of the most elementary devices in the sewing‑machine attachment art, and the patent's own description of levers 45 pivoted at 46 "scissors fashion," cam surfaces 47, hand lever 49 with slot 52 and thumb screw 53 is an exercise in conventional adjustability. Absent a pre‑1919 reference showing the specific semi‑circular form, this claim survives on form, not on design insight. Its obviousness would turn on whether the 1918 "Sewing‑machine" references disclose adjustable work guides — again, unverified here.

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6. Motivation to combine — consolidated reasoning

For every combination above, the motivation rests on four independently sufficient grounds (KSR‑compliant):

1. Same field of endeavor. All admissible references and the patent sit in CPC D05B35/06 / D05B35/062 (work‑feeding/handling for attaching bands, ribbons, strips, or tapes, with hem‑turning) and D05B29/06 (presser feet). No field‑crossing problem.
2. Same problem. Delivering a narrow, folded strip to a needle under controlled tension without twisting. Each reference addresses a subset of that problem.
3. Predictable combination. A folding guide plus a strip feeder plus a walking presser foot is an additive assembly; there is no teaching away, no changed principle of operation, and no functional interference. The patent's own "novel" hardware (straps, screws, springs, slots, thumb screws) is expressly described as adjustable mounting — the routine engineering of the art.
4. Market pull. The specification supplies the incentive itself: a machine‑made substitute for round leather belting, "now generally used." That is a classic articulated design incentive, sufficient under KSR to supply the reason to make the improvement.

Where the patentee's counter‑argument is strongest: the cooperating pair of (i) a tapered spiral slot with decreasing pitch and (ii) an arbor with a reverse‑curved edge 24′ and overhanging finger 26. The specification describes these as functionally interdependent — the decreasing pitch progressively tightens the wind, and the reverse‑curved edge takes over the tensioning role from rod 31 beyond the point where the tube's grip weakens. A patentee could argue synergism, i.e., that the combination produces a result greater than the sum of parts. That argument fails only if the record shows the components were known to be combinable for their individual functions, which is exactly what the 1900–1918 art (if it exists as hypothesized) would establish.

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7. Bottom line

Framing conclusion. If this patent were being evaluated today under KSR, the broad functional claims (1, 2, 3, 17, 20, 25, 28–30) would very likely fall, and the structural claims would likely survive only because the page's prior‑art set does not contain admissible pre‑1919 art on the spiral slot and reverse‑curved arbor. But during the patent's actual life (1925–1942) validity was tested under Cuno's "flash of creative genius" standard, which was markedly more patentee‑friendly — so the historically likely outcome was sustained validity, including on claims that modern doctrine would invalidate. Which of the two standards applies determines the answer, and that is the single most important finding of this analysis.

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8. Caveats and confidence statement (per operating rules)

• No auto‑correction applied. I have used the literal identifiers as they appear, including the OCR artifacts in the claim text ("fold ing means," "pr vided," "the material is I the tube ad accnt the slot") and the specification's own numbering errors (elements labelled both "23" for the tubular guide and its reinforcing rod, and "14" for both the yoke and the base screws). These are reproduced, not corrected.
• I could not verify the substantive disclosures of US 645,236 A, US 1,231,542 A, US 1,274,162 A, or US 1,288,391 A. My searches returned their titles, dates, and citation contexts but not their specifications. Any claim mapping to them is conditional and so labeled above.
• I found no pre‑1919 spiral‑slot fold‑guide reference. This is a negative finding about the searched sources, not proof that none exists.
• The "Similar Documents" table on the Google Patents page is not a prior‑art list. It is algorithmic, it is majority post‑dating, and I have stated this rather than treating it as an examiner's citation set.
• Cross‑reference: consistent with the earlier litigation and PTAB sections, none of the above has any present‑day enforceability consequence. The patent expired 1942‑10‑13; the §103 outcome is legally inert. Should any party assert this patent, the correct response remains the expiry date, not an obviousness defense.
• Recommended next step if this analysis must be hardened: retrieve the full texts of the four admissible references (US 645,236 A; US 1,231,542 A; US 1,274,162 A; US 1,288,391 A) and of the family members US 1,624,932 A and US 1,625,348 A, and pull the 1919‑era Official Gazette file wrapper for Ser. No. 327,585 to see which references the Examiner actually applied — the prosecution history will identify the art faster and more reliably than similarity clustering.