Patent US4388983A successfully refreshed from Google Patents.
US4388983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lightweight ladder
Assignee: Thomas and Betts Holdings Inc
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Filing: 1982-01-25
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Granted: 1983-06-21
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Expires: 2002-01-25
Abstract
Abstract A lightweight ladder includes a vertical member of flat sided tubing, rungs formed of angle metal, and ladder feet adapted to engage retaining clips mounted on a vertical structure. The ladder feed are designed to provide wedging between the clips and the vertical structure such that set screws are not required to keep the ladder in place and stable.
Inventors
- 👤 Leroy R. Bartels
- 👤 Arnold M. Milbright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:09
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/34; E06C1/38; E06C1/381
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
97 words
A ladder for use or a structure having vertically spaced apart retaining clips, said ladder comprising: a vertical member; a plurality of rungs on said vertical member; a leg extending substantially horizontal to said member; and a downwardly extending foot coupled to said leg and adapted to engage one of said retaining clips; said foot having a first portion substantially parallel to said vertical member for engaging the surface of said structure, and a second portion forming an angle with said first portion whereby when said first portion engages said structure, said second portion engages said clips.
Claim 2
Dependent Claim
97 words
A ladder for use or a structure having vertically spaced apart retaining clips, said ladder comprising: a vertical member; a plurality of rungs on said vertical member; a leg extending substantially horizontal to said member; and a downwardly extending foot coupled to said leg and adapted to engage one of said retaining clips; said foot having a first portion substantially parallel to said vertical member for engaging the surface of said structure, and a second portion forming an angle with said first portion whereby when said first portion engages said structure, said second portion engages said clips.
Claim 3
Dependent Claim
15 words
A ladder in accordance with claim 1 wherein said foot is of one piece construction.
Claim 4
Dependent Claim
19 words
A ladder in accordance with claim 2 wherein said second portion is intermediate said first portion and said leg.
Claim 5
Dependent Claim
31 words
A ladder in accordance with claim 3 wherein said foot includes a third vertical portion coupled to said leg, said third vertical portion being intermediate said second portion and said leg.
Claim 6
Dependent Claim
23 words
A ladder in accordance with claim 2 wherein said second portion is a tongue extending from said first portion at a predetermined angle.
Claim 7
Dependent Claim
37 words
A ladder in accordance with claim 5 wherein said first portion includes extending from said first portion in an angular direction away from said vertical member, said tongue extending in the opposite direction from said first portion.
Claim 8
Dependent Claim
20 words
A ladder in accordance with claims 1, 2, 3, 4, 5 or 6 wherein said vertical member comprises flat-sided tubing.
Claim 9
Dependent Claim
20 words
A ladder in accordance with claim 7 wherein each of said plurality of rungs is formed from a metal angle.
Claim 10
Dependent Claim
20 words
A ladder in accordance with claim 8 wherein the ends of each rung are bent upward by a predetermined angle.
Claim 11
Dependent Claim
15 words
A ladder in accordance with claim 9 wherein said foot comprises a flat sided tube.
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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) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |