US4219102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallic ladders
Assignee: SARL DITE FMC FABRICATIONS METALLIQUE DE CIZELY
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Filing: 1979-01-02
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Granted: 1980-08-26
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Expires: 1999-01-02
Abstract
Abstract A metallic ladder includes stiles (or side rails) of U or I section and rungs which are supported at each end by a reinforcing plate. The stiles have, in section on each longitudinal wall a flange which is spaced inwardly with respect to a free edge of the respective longitudinal wall so as to form a ridge. The reinforcing plates rest on the flanges and are restrained laterally by the ridges. The reinforcing plates are held at the flanges by a tab and opening arrangement. Each rung has a shoulder adjacent each end which contacts either the reinforcing plate or the web of the stile and the extreme end portion of the rung engages correspondingly in the web or the plate.
Inventors
- 👤 Pierre Ducresot
- 👤 Catherine Archer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:40
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/08; E06C7/082; E06C7/085
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
139 words
A metal ladder comprising two spaced stiles of open section, a plurality of rungs extending between the stiles, and having a shoulder at each end, and reinforcing plates each receiving an end portion of a rung in an opening thereof, and each including tab means, each said stile having a web, with openings for the rungs, two longitudinal walls, one wall extending from each edge of the web, and each longitudinal wall having a flange spaced inwardly from the free edge of the longitudinal wall so as to define a ridge, each said flange having apertures therein spaced along its length, each said rung being fitted in a said opening of the web and in a said opening of a said reinforcing plate, and the tab means of the reinforcing plates being secured in the apertures of the flanges.
Claim 2
Dependent Claim
139 words
A metal ladder comprising two spaced stiles of open section, a plurality of rungs extending between the stiles, and having a shoulder at each end, and reinforcing plates each receiving an end portion of a rung in an opening thereof, and each including tab means, each said stile having a web, with openings for the rungs, two longitudinal walls, one wall extending from each edge of the web, and each longitudinal wall having a flange spaced inwardly from the free edge of the longitudinal wall so as to define a ridge, each said flange having apertures therein spaced along its length, each said rung being fitted in a said opening of the web and in a said opening of a said reinforcing plate, and the tab means of the reinforcing plates being secured in the apertures of the flanges.
Claim 3
Dependent Claim
34 words
A ladder according to claim 1, wherein each reinforcing plate is disposed on the inside of each stile, so that the rungs first traverse the reinforcing plate, and then the web of the stile.
Claim 4
Dependent Claim
20 words
A ladder according to claim 1, wherein the tab means have the same width as the apertures in the flanges.
Claim 5
Dependent Claim
22 words
A ladder according to claim 1, wherein transverse edges of the reinforcing plate comprises a fold portion substantially perpendicular to the plate.
Claim 6
Dependent Claim
16 words
A ladder according to claim 1, wherein the reinforcing plate comprises stiffening ribs arrayed substantially diagonally.
Claim 7
Dependent Claim
28 words
A ladder according to claim 1, wherein the opening in the reinforcing plate is formed by a recess having a depth greater than the thickness of the plate.
Claim 8
Dependent Claim
42 words
A ladder according to claim 1, wherein each shoulder is constituted by a reduced section portion formed at each end of the rung over a length somewhat in excess of the distance separating the reinforcing plate from the web of the stile.
Claim 9
Dependent Claim
21 words
A ladder according to claim 1, wherein a common said reinforcing plate extends over at least two rungs of the ladder.
Claim 10
Dependent Claim
40 words
A ladder according to claim 1, comprising a blanking piece which extends between two said reinforcing plates and is engaged in the corresponding stile, the length of this blanking piece being equal to the space between the two reinforcing plates.
Claim 11
Dependent Claim
37 words
A ladder according to one of claim 1 wherein each end of the rung has a reduced section portion, with a longitudinal depression in each of its parts corresponding to a substantially plane part of the rung.
Claim 12
Dependent Claim
49 words
A ladder according to claim 1, comprising a spacer of which the thickness is substantially equal to the distance between the reinforcing plate and the web of the stile and is disposed between the reinforcing plate and the web and is threaded on the end portion of the rung.
Claim 13
Dependent Claim
30 words
A ladder according to claim 11, wherein the upper faces and lower faces of the spacer have a width substantially equal to the spacing between the stiles of the ladder.
References Cited (Backward Citations)
US2618427A
Cited
US3004625A
Cited
FR1459289A
Cited
US3608256A
Cited
US3653697A
Cited
US3997027A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |