Patent US3722622A successfully refreshed from Google Patents.
US3722622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Folding and collapsible ladders
Assignee: Individual
•
Filing: 1971-03-18
•
Granted: 1973-03-27
•
Expires: 1991-03-18
Abstract
Abstract A folding and collapsible ladder wherein the rungs are pivotally attached to the side rails and adjacent rungs are attached to the side rails in different planes, i.e., adjacent rungs are offset. To collapse or fold the ladder into a narrow but slightly longer mass, the rungs fold down like a closing parallelogram until the rungs are substantially parallel to the side rails. Rigidity of the ladder is provided by one or more braces pivotally attached at one end to one side rails and the opposed end of the braces provided with fastening means to removable secure the braces to the other side rail.
Inventors
- 👤 E Lauring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:30
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/38; E06C1/383
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
137 words
A folding and collapsible ladder comprising two sections; each section having oppositely facing channel-like members side rails; each of said rails having bottom, outwardly extending side walls and longitudinal extending rib-like member projecting from the bottom and being substantially parallel to side walls; one section of said ladder having one end of each channel-like side rails provided with one wall, part of bottom and rib, extending the distance between adjacent rungs in the other section, beyond the remainder of bottom and other sidewall, the bottoms of unequal length having rung receiving openings therein; rungs pivotally attached to side walls and ribs, adjacent rungs at least in one section attached to side walls and ribs in different planes whereby on collapsing the rungs fold down between side walls and ribs and means for maintaining ladder in uncollapsed position.
Claim 2
Dependent Claim
137 words
A folding and collapsible ladder comprising two sections; each section having oppositely facing channel-like members side rails; each of said rails having bottom, outwardly extending side walls and longitudinal extending rib-like member projecting from the bottom and being substantially parallel to side walls; one section of said ladder having one end of each channel-like side rails provided with one wall, part of bottom and rib, extending the distance between adjacent rungs in the other section, beyond the remainder of bottom and other sidewall, the bottoms of unequal length having rung receiving openings therein; rungs pivotally attached to side walls and ribs, adjacent rungs at least in one section attached to side walls and ribs in different planes whereby on collapsing the rungs fold down between side walls and ribs and means for maintaining ladder in uncollapsed position.
Claim 3
Dependent Claim
38 words
A collapsible ladder according to claim 1, in which said channel-like members are braced in opened position by brace pivotally attached at one end to said channels and opposed end of said brace detachable secured to another channels.
Claim 4
Dependent Claim
21 words
A collapsible ladder in accordance with claim 1, in which said means for maintaining ladder in uncollapsed position are cross members.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |