Invalidity dossier

US 3074572

Added 8/27/2026, 7:34:30 AM

IndustryIndustrial Manufacturing (IM)
At a glanceNo PTAB challengesNo litigation on fileIndustrial Manufacturing (IM)

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Patent summary

Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.

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US Patent 3,074,572 — Search Summary

Verification note on searches

I searched for the literal patent number 3074572 (and variants "3,074,572", "US3074572A", "US-3074572-A"). The results confirm this patent — no similar-number matches were substituted. I found no CAFC 2026 docket entries, district-court cases, or other 2026 litigation records referencing this patent. Given that the patent expired in ~1980 (see status below), the absence of current CAFC docket activity is expected, but I cannot rule out older or non-indexed proceedings.

Bibliographic data

Field Value
Patent / publication number US 3,074,572 (US3074572A)
Title Lever lift
Inventor Bronislaus I. Ulinski, Flossmoor, Illinois
Assignee (original) The Yale and Towne Manufacturing Company, Stamford, Connecticut (a Connecticut corporation) — listed on third-party sites as "Yale & Towne Mfg Co"
Application Ser. No. 10,954 (US10954A), filed February 25, 1960 — a divisional application of Ser. No. 700,369, filed December 3, 1957, which issued as US Patent 2,953,264 ("Industrial Truck") on September 20/29, 1960
Priority date December 3, 1957
Issue / publication date January 22, 1963 (the patent front page itself reads "Patented Jan. 22, 1963"; one aggregator lists Jan. 21, 1963, but the patent document is authoritative)
Status Expired — Lifetime (USPTO/Google record; anticipated expiration ~January 22, 1980, consistent with the then-standard 17-year term from grant)
Classification International: B66F9/065 (non-masted lift trucks); US Class: 214-140 (per the patent), later 414/712
Cited references US 2,345,620 (Bucyrus-Erie, "Tractor propelled implement") and US 2,563,974 (Thierry, "Toy excavator"); foreign reference SE129142A noted by one source

Source: patent text (Google Patents US3074572A), FreePatentsOnline 3074572, Unified Patents US-3074572-A.

Abstract

The Google Patents/USPTO record for this patent does not include a formal published abstract (this era of patents generally had none). The invention, as disclosed in the specification, is: an industrial truck leverage system for elevating/lowering a load carriage (fork) in a substantially vertical straight-line path and tilting the carriage at any elevation, using a minimum number of parts. It improves on the inventor's earlier lifting mechanism (US 2,980,271) by eliminating two supporting arms and two tilting links: the same ram that tilts the carriage also forms part of the mounting structure that lets the carriage-supporting levers shift longitudinally, compensating for the arc motion of the levers so the fork travels vertically. The truck also features a low, accessible battery compartment beneath the leverage system, improving stability and service access.

Independent claims — plain-language overview

The patent has 3 claims, all independent (claims 1–3).

Claim 1 — A truck with a load carriage and a pair of levers pivoted at one end to the carriage (spaced apart) and at the other end to an arm at the same spacing, forming a parallelogram (carriage + levers + arm). A lift mechanism connected to the levers and the truck swings the levers vertically about their pivots on the arm to raise/lower the carriage. A lever and a ram, each pivoted at one end to the arm (spaced) and at the other end to the truck (same spacing), allow the arm and levers to move bodily fore-and-aft so the carriage travels in a substantially straight vertical path; operating that ram also pivots the arm to tilt the carriage. A control link, pivoted to one of the levers and to the truck, is sized/positioned so that it drives the bodily movement of the levers and arm (through swinging of the ram and lever) in the direction and amount needed to keep the carriage on the substantially vertical straight-line path during raising/lowering.

Claim 2 — Everything in claim 1, plus: the parallelogram keeps the carriage at a particular angular position relative to the truck while it is raised/lowered; and ram means pivoted to the truck at one end and to the control link at the other pivot the link, simultaneously producing both the vertical swinging of the levers and the bodily longitudinal movement of the levers/arms. (This corresponds to the single bell-crank/lift-ram arrangement doing both jobs.)

Claim 3 — Substantially the same combination as claim 1, but phrased more broadly with "link means" (rather than "a control link") connected to one of the levers and to the truck, positioned and dimensioned so that it effects the bodily movement of the levers and arm through the swinging of the ram and lever, keeping the carriage on the substantially vertical straight-line path as the levers are raised and lowered.

Uncertainty / caveats

  • No CAFC 2026 docket or current litigation found — searches of site:cafc.uscourts.gov and general 2026 docket queries returned nothing. I cannot affirmatively rule out an appeal filed under an abbreviation or a PACER-only record not indexed by search engines.
  • The formal abstract is not present in the USPTO/Google record; the summary above is drawn from the specification's own language.
  • Minor discrepancies between aggregators (e.g., grant date Jan. 21 vs. Jan. 22, 1963; filing date Feb. 24 vs. Feb. 25, 1960) exist; I relied on the patent document and Google Patents record (Jan. 22, 1963; Feb. 25, 1960) as authoritative.
  • The OCR in the fetched patent text contains artifacts (e.g., "Feb. 25, 1969" for the divisional filing, "lever 1?" for lever 17, "3,d7t,572") — these are scanning errors, not substantive.

Generated 8/27/2026, 7:35:00 AM

Cases on file (0)

Specific litigation cases in our database that name US patent 3074572. The free-form analysis below may also discuss cases beyond this list.

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Litigation summary

Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.

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Proceedings on file (0)

All PTAB activity →

AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.

No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.

PTAB challenges

AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.

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Assignment history

Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.

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Prior art

Earlier patents, publications, and products that may anticipate or render the claims unpatentable.

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Obviousness

Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.

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Extensions

Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.

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Derivative works

Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.

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