Patent US3690407A successfully refreshed from Google Patents.
US3690407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extension scaffold
Assignee: Individual
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Filing: 1971-03-15
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Granted: 1972-09-12
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Expires: 1991-03-15
Abstract
Abstract A portable scaffold which is extendable in height as well as length, the device being comprised of a pair of base ladder units held in upright vertical position by means of criss-crossing braces and a horizontal platform across the upper ends, and each of the base ladder units being adaptable for supporting thereon an extension at an adjustable elevation, and the horizontal platform in one form of the invention being telescopic in length.
Inventors
- 👤 Eugene Francis Cullison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:14
CPC Classifications
E; E04; E04G; E04G1/00; E04G1/18; E04G1/20; E04G1/15; E04G1/152; E04G1/22; E04G2001/157
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
205 words
In an extension scaffold, the combination of a pair of spaced apart ladder base units, each one of said base units being comprised of a pair of parallel, spaced apart runners which are inter-connected by transverse extending rungs, a pair of crisscrossing braces being provided for erecting said base units in an upright position, each one of said braces having a hook at its opposite ends for being hooked around said rungs, and a horizontal extending platform being supported between said base units, said platform at its opposite ends being provided with strong metal hooks for fitting around said rungs, said scaffold including a pair of extensions, each one of said extensions being adaptable for being adjustably secured to said base units, each of said base units having a semi-cylindrical guard rail secured to each one of said runners, each said extension comprising a ladder member including extensions receivable into said guard rails, said runners being inter-connected by transverse extending rungs, a pivotable hook secured to a lower end of each one of said runners of said extension being adaptable for being hooked selectively around one of said rungs of said base unit, and said platform being telescopic by comprising a pair of interslidable units.
Claim 2
Dependent Claim
205 words
In an extension scaffold, the combination of a pair of spaced apart ladder base units, each one of said base units being comprised of a pair of parallel, spaced apart runners which are inter-connected by transverse extending rungs, a pair of crisscrossing braces being provided for erecting said base units in an upright position, each one of said braces having a hook at its opposite ends for being hooked around said rungs, and a horizontal extending platform being supported between said base units, said platform at its opposite ends being provided with strong metal hooks for fitting around said rungs, said scaffold including a pair of extensions, each one of said extensions being adaptable for being adjustably secured to said base units, each of said base units having a semi-cylindrical guard rail secured to each one of said runners, each said extension comprising a ladder member including extensions receivable into said guard rails, said runners being inter-connected by transverse extending rungs, a pivotable hook secured to a lower end of each one of said runners of said extension being adaptable for being hooked selectively around one of said rungs of said base unit, and said platform being telescopic by comprising a pair of interslidable units.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |