Patent US4744441A successfully refreshed from Google Patents.
US4744441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw-type ladder leveler
Assignee: Individual
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Filing: 1986-08-25
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Granted: 1988-05-17
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Expires: 2006-08-25
Abstract
Abstract A device for leveling a metal ladder comprising a mounting bracket which can be attached to the outside web of a ladder side rail, a threaded shaft embodied with a handle at its upper distal end and a convex semi-shperical head at its lower distal end which is sized to operate within a threaded bore hole in the distal member of said mounting bracket in order to provide means to raise or lower a pivotable ladder foot embodied with a concave semi-spherical surface within the raised center portion of said foot in order to provide a pivoting means for said foot with respect to said threaded shaft.
Inventors
- 👤 Bruce D. Sandstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:13
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44; E06C7/46
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
218 words
A device for leveling a ladder having side rails comprising: a mounting bracket with a back attached to said rail a base attached to said back to provide support for the lower end portion of said side rail and a lateral member extending from said back formed with a threaded longitudinal bore at is distal end; and a threaded shaft sized to fit in said threaded bore and embodied with a convex semi-spherical head at its lower distal end and a handle at its upper distal end; and a pivotable foot further comprising a raised member, a bottom and a concave semi-spherical cavity within said raised member which provides a uniform point of contact for said semi-spherical head of said shaft while in engaged position; and a keeper plate attached to the top of said raised member of said foot with a hole formed at its center sized to both prevent said shaft from detaching from said foot and to allow pivotability of said foot with respect to said shaft, the size of said semi-spherical head is such than when in disengaged position provides a clearance between said convex head and said concave cavity; and horizontal openings near the distal end of said raised member will allow the free exit of foreign material from said concave semi-spherical cavity.
Claim 2
Independent Claim
218 words
A device for leveling a ladder having side rails comprising: a mounting bracket with a back attached to said rail a base attached to said back to provide support for the lower end portion of said side rail and a lateral member extending from said back formed with a threaded longitudinal bore at is distal end; and a threaded shaft sized to fit in said threaded bore and embodied with a convex semi-spherical head at its lower distal end and a handle at its upper distal end; and a pivotable foot further comprising a raised member, a bottom and a concave semi-spherical cavity within said raised member which provides a uniform point of contact for said semi-spherical head of said shaft while in engaged position; and a keeper plate attached to the top of said raised member of said foot with a hole formed at its center sized to both prevent said shaft from detaching from said foot and to allow pivotability of said foot with respect to said shaft, the size of said semi-spherical head is such than when in disengaged position provides a clearance between said convex head and said concave cavity; and horizontal openings near the distal end of said raised member will allow the free exit of foreign material from said concave semi-spherical cavity.
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) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |