Patent US4098372A successfully refreshed from Google Patents.
US4098372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collapsible ladder
Assignee: Individual
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Filing: 1977-03-03
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Granted: 1978-07-04
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Expires: 1997-03-03
Abstract
Abstract A collapsible ladder made of non-combustible material, which can be used for example as a fire escape, comprises two flexible strings with rungs threaded thereon at spaced distances, and these rungs have divergent limbs dimensioned so that, when the ladder is collapsed, the rungs seat on one another leaving a space between them for stowage of the parts of the strings.
Inventors
- 👤 Wilhelm Luckey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:34
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/52; E06C1/56
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
85 words
In a collapsible ladder of non-combustible material having two flexible lines and a plurality of rungs spaced along and between said lines, the rung improvement comprising a tread section having divergent limbs extending therefrom to form a U-shaped cross section for nesting astride adjacent rungs relative to one another in spaced fashion, and to provide intermediate spaces for receiving and uncovering said two flexible lines in stowage position, and said lines pass through and are respectively held in openings proximate the ends of each rung.
Claim 2
Dependent Claim
85 words
In a collapsible ladder of non-combustible material having two flexible lines and a plurality of rungs spaced along and between said lines, the rung improvement comprising a tread section having divergent limbs extending therefrom to form a U-shaped cross section for nesting astride adjacent rungs relative to one another in spaced fashion, and to provide intermediate spaces for receiving and uncovering said two flexible lines in stowage position, and said lines pass through and are respectively held in openings proximate the ends of each rung.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein said rungs further comprise an upward bend at each end part.
Claim 4
Dependent Claim
21 words
The apparatus of claim 1 wherein said flexible lines are crossed between respective rungs in said intermediate spaces in stowage position.
Claim 5
Dependent Claim
20 words
The apparatus of claim 1, wherein said rungs are made of a plate material of less that 1 mm thickness.
Claim 6
Dependent Claim
12 words
The apparatus of claim 1 wherein the rungs are made from aluminum.
Claim 7
Dependent Claim
28 words
The apparatus of claim 1, wherein the rung openings each further comprise two opposed crescent-shaped edges which are pressed out of said rung tread section in opposite directions.
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) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |