Patent US4623619A successfully refreshed from Google Patents.
Patent JPS628105A successfully refreshed from Google Patents.
US3674110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wound filament ladder
Assignee: Cooper Industries LLC
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Filing: 1970-06-01
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Granted: 1972-07-04
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Expires: 1990-06-01
Abstract
Abstract Several embodiments of ladder construction, fabricated by a filament winding process are shown, wherein a continuous glass filament is wound at a controlled helical angle on suitable mandrels and bonded with an epoxy or polyester resin system. Circular, elliptical or rectangular cross-section members can be developed for the rungs and rails and glass fabric or longitudinal fiber members may be combined therewith for additional strength. The rungs and rails are machined and joined with a resin bonding agent and the assembly cured in single section, extension ladder, or section ladder configurations. In the latter, reinforcement of the notched ends is made with plies of resin impregnated glass strips filling the rail cavity in conformity with the notch.
Inventors
- 👤 Robert F Cooke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:52
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/08; B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
A fiberglass ladder, comprising a pair of rails, a plurality of rungs disposed between and interconnecting said rails at spaced locations, said rungs and said rails being formed of windings of single filament fiberglass material and having hollow cross-sections, means for bonding said rungs to said rails to provide a rigid structure, said rails being inclined slightly with respect to said rungs for interlocking with a further section ladder of the same configuration, each said rail having a notch at one end for engaging the ruNg of said further section ladder, and further comprising a plurality of resin impregnated glass strips filling said one end of said rail and conforming to the shape of said notch, said strips being bonded to said rails by curing of the resin.
Claim 2
Dependent Claim
128 words
A fiberglass ladder, comprising a pair of rails, a plurality of rungs disposed between and interconnecting said rails at spaced locations, said rungs and said rails being formed of windings of single filament fiberglass material and having hollow cross-sections, means for bonding said rungs to said rails to provide a rigid structure, said rails being inclined slightly with respect to said rungs for interlocking with a further section ladder of the same configuration, each said rail having a notch at one end for engaging the ruNg of said further section ladder, and further comprising a plurality of resin impregnated glass strips filling said one end of said rail and conforming to the shape of said notch, said strips being bonded to said rails by curing of the resin.
Claim 3
Dependent Claim
115 words
A fiberglass ladder comprising a pair of hollow rails, a plurality of hollow rungs disposed between and interconnecting said rails at spaced locations, said rungs and said rails being formed of plural overlapped windings of single filament fiberglass material, said rails further including a layer of fiberglass fabric bonded within and adjacent the filament windings thereof, with said fabric comprising woven fiberglass strands having a greater number of strands in the longitudinal direction than in the transverse direction, said rails being apertured for receipt of said rungs, with the latter bridging the void within said rails, and means for bonding said rungs to said rails to reinforce said rails and provide therewith a rigid structure.
Claim 4
Dependent Claim
115 words
A fiberglass ladder comprising a pair of hollow rails, a plurality of hollow rungs disposed between and interconnecting said rails at spaced locations, said rungs and said rails being formed of plural overlapped windings of single filament fiberglass material, said rails further including a layer of fiberglass fabric bonded within and adjacent the filament windings thereof, with said fabric comprising woven fiberglass strands having a greater number of strands in the longitudinal direction than in the transverse direction, said rails being apertured for receipt of said rungs, with the latter bridging the void within said rails, and means for bonding said rungs to said rails to reinforce said rails and provide therewith a rigid structure.
Claim 5
Dependent Claim
43 words
A ladder as set forth in claim 2 wherein said rails are of rectangular cross-section each further including a pair of ribs bonded on interior opposing sides of said fiberglass fabric and extending substantially the full length of said rails for reinforcing same.
Claim 6
Dependent Claim
30 words
A ladder as set forth in claim 3 wherein each of said ribs comprise a bundle of fibers extending longitudinally of said rails, said ribs having a segmented arcuate cross-section.
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) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |