US4448283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable fold-up ladder
Assignee: ANDRAL CORP
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Filing: 1983-05-06
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Granted: 1984-05-15
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Expires: 2003-05-06
Abstract
Abstract A portable and convertible ladder comprising a series of u-shaped modules each movably connected to the other by hinge means, said modules having progressively decreasing widths as they approach the top of the ladder when in an open mode, said modules having a base or rung portion and upright sections, each module having locking means movably positioned in their lower portion, and adapted to form a substantially rigid ladder when in an open mode, each module except for the uppermost module having hinge means at substantially the upper portion of said upright sections, said locking means having a locking member positioned in said lower portion adapted to fit and mate with complimentary male or female member positioned in an adjacent portion of said upright sections, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided in said overlapping portions.
Inventors
- 👤 Salvador A. Marques
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:45
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/04; E06C1/08; E06C1/12
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
164 words
A portable folding lean to ladder comprising a plurality of u-shaped modules comprising a rung and two vertical portions, said modules movably connected to each other, and when opened becoming progressively narrower as they approach the top of said ladder, when folded said narrower modules fitting inside of the next wider modules, said modules except for said widest base module comprising in their lower portions a complete module locking means and a module hinge means, said locking means fixing said modules in a rigid manner when said ladder is extended and open, said locking means integral with said modules and comprising latches adapted to movably fit into and mate with an aperture located in the upper sections of said vertical portions of said modules, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided within said overlapping portions.
Claim 2
Dependent Claim
164 words
A portable folding lean to ladder comprising a plurality of u-shaped modules comprising a rung and two vertical portions, said modules movably connected to each other, and when opened becoming progressively narrower as they approach the top of said ladder, when folded said narrower modules fitting inside of the next wider modules, said modules except for said widest base module comprising in their lower portions a complete module locking means and a module hinge means, said locking means fixing said modules in a rigid manner when said ladder is extended and open, said locking means integral with said modules and comprising latches adapted to movably fit into and mate with an aperture located in the upper sections of said vertical portions of said modules, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided within said overlapping portions.
Claim 3
Dependent Claim
26 words
The portable ladder of claim 1 wherein said locking means are adapted to lock with the upper portion of the next adjacent and wider lower module.
Claim 4
Dependent Claim
29 words
The portable ladder of claim 1 wherein said hinges are located in the upper portion of said u-shaped modules, and the lower portion of the sequentially adjacent smaller module.
Claim 5
Dependent Claim
32 words
The portable ladder of claim 1 wherein said locking means comprise latches adapted to fit into and lock with an aperture located adjacent it in the side rails of said u-shaped modules.
Claim 6
Dependent Claim
21 words
The portable ladder of claim 4 wherein said hinges are positioned above said latches in each of said vertical side rails.
Claim 7
Dependent Claim
35 words
The portable ladder of claim 1 wherein said locking means comprises spring loaded latches that are adapted to mate with and lock into an aperture located in the adjacent portion of said vertical side rails.
Claim 8
Dependent Claim
29 words
The portable ladder of claim 1 wherein said vertical side rails comprise grooves into which the side rails of the next adjacent module slides when in an unlocked mode.
Claim 9
Dependent Claim
27 words
The portable ladder of claim 1 wherein said outer vertical side rails are in juxtaposition with the inner vertical side rails of the next wider u-shaped module.
Claim 10
Dependent Claim
42 words
The portable ladder of claim 1 wherein said locking means comprise latches, latches release means, and latch receiving apertures, said latch release means connected to said latches and said latches adapted to be moved into and out of said latch receiving apertures.
Claim 11
Dependent Claim
165 words
A portable and convertible ladder comprising a series of u-shaped modules each movably connected to the other by hinge means, said modules having progressively decreasing widths as they approach the top of the ladder when in an open mode, said modules having a base or rung portion and upright sections, each module having locking means movably positioned in their lower portion, and adapted to form a substantially rigid ladder when in an open mode, each module except for the uppermost module having hinge means at substantially the upper portion of said upright sections, said locking means having a locking member positioned in said lower portion adapted to fit and mate with complimentary male or female member positioned in an adjacent portion of said upright sections, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided in said overlapping portions.
Claim 12
Dependent Claim
165 words
A portable and convertible ladder comprising a series of u-shaped modules each movably connected to the other by hinge means, said modules having progressively decreasing widths as they approach the top of the ladder when in an open mode, said modules having a base or rung portion and upright sections, each module having locking means movably positioned in their lower portion, and adapted to form a substantially rigid ladder when in an open mode, each module except for the uppermost module having hinge means at substantially the upper portion of said upright sections, said locking means having a locking member positioned in said lower portion adapted to fit and mate with complimentary male or female member positioned in an adjacent portion of said upright sections, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided in said overlapping portions.
Claim 13
Dependent Claim
31 words
The ladder of claim 10 wherein said hinges are positioned in and connect the lower portion of said u-shaped module and in the upper portion of the adjacent wider u-shaped module.
Claim 14
Dependent Claim
22 words
The ladder of claim 10 wherein said hinges are positioned above said locking means in all except the upper most u-shaped module.
Claim 15
Dependent Claim
49 words
The ladder of claim 10 wherein said locking means comprise a latch male member, a latch release means and latch receiving female member, said latch release means movably connected to said latches and adapted to move said latches into and out of locking relationship with said latch receiving members.
Claim 16
Dependent Claim
25 words
The ladder of claim 13 wherein said latch release means are located externally of the terminal portions of said base sections of said u-shaped modules.
Claim 17
Dependent Claim
45 words
The ladder of claim 10 wherein said locking means are below said hinges in each of said modules and are adapted to lock with the upper portion of the next adjacent and wider u-shaped module to thereby form a ladder having a substantailly rigid configuration.
Claim 18
Dependent Claim
26 words
The ladder of claim 10 wherein said modules are adapted to be unlocked to form a step ladder having substantially rigid equal or unequal leg sections.
Claim 19
Dependent Claim
30 words
The ladder of claim 10 wherein the inner surface of said upright sections fit over and are in juxtaposition to the lower surface of the next adjacent narrower u-shaped module.
Claim 20
Dependent Claim
24 words
The ladder of claim 10 wherein said ladder is adapted to be extended and locked in position to form thereby a substantially rigid ladder.
Claim 21
Dependent Claim
16 words
The ladder of claim 10 wherein the outside vertical surfaces of said upright sections are grooved.
Claim 22
Dependent Claim
21 words
The ladder of claim 10 wherein said ladder is adapted to be compacted and reduced in size when not in use.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |