Patent US4143742A successfully refreshed from Google Patents.
US4143742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ladder extension apparatus
Assignee: Individual
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Filing: 1978-07-20
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Granted: 1979-03-13
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Expires: 1998-07-20
Abstract
Abstract A ladder extension device for enabling a ladder to stand upright upon uneven or inclined surfaces is disclosed which is composed of a pair of diametrically opposed side members, preferably L-shaped, connected by hinges and secured about a ladder leg by bolts or other means.
Inventors
- 👤 Albert Fernandez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:53
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
A ladder rail extension device comprising: a. at least three bolts; b. a pair of diametrically disposed L-shaped side members which together form a U-channel, one L-shaped member has at least three threaded holes sized to receive the bolts and the other L-shaped member has an equal number of larger holes, sized so as to permit a bolt to hang loosely from the side member when not engaged in a threaded hole; c. a keeper attached to each bolt to prevent the bolt from slipping out of the oversized hole; and d. a hinge member attached to the side member to permit the U-channel to be opened in order to insert the ladder rail.
Claim 2
Dependent Claim
114 words
A ladder rail extension device comprising: a. at least three bolts; b. a pair of diametrically disposed L-shaped side members which together form a U-channel, one L-shaped member has at least three threaded holes sized to receive the bolts and the other L-shaped member has an equal number of larger holes, sized so as to permit a bolt to hang loosely from the side member when not engaged in a threaded hole; c. a keeper attached to each bolt to prevent the bolt from slipping out of the oversized hole; and d. a hinge member attached to the side member to permit the U-channel to be opened in order to insert the ladder rail.
Claim 3
Dependent Claim
26 words
The ladder rail extension device in claim 1 having a resilient pad attached to an inside face of each side member which grips the ladder rail.
Claim 4
Dependent Claim
49 words
The ladder rail extension device in claim 1 wherein the hinge member is of the type having leaves which are slotted so that the hinge may be adjustably attached to the side members premitting an expansion of a width of the U-channel to accommodate ranging widths of ladder rails.
Claim 5
Dependent Claim
127 words
A ladder rail extension device comprising: a. at least three bolts; b. a pair of diametrically disposed L-shaped side members; c. a pair of L-shaped flanges each extending from an L-shaped side member one flange having at least three threaded holes sized to receive the bolts and the other flange having an equal number of larger holes sized so as to permit a bolt to hang loosely from the flange when the bolt is not engaged in a threaded hole; d. a keeper attached to each bolt to prevent the bolt from slipping out of the oversized hole; and e. a hinge member attached to the side members to permit the side members to move for ease of insert of the ladder rail between the side members.
Claim 6
Dependent Claim
127 words
A ladder rail extension device comprising: a. at least three bolts; b. a pair of diametrically disposed L-shaped side members; c. a pair of L-shaped flanges each extending from an L-shaped side member one flange having at least three threaded holes sized to receive the bolts and the other flange having an equal number of larger holes sized so as to permit a bolt to hang loosely from the flange when the bolt is not engaged in a threaded hole; d. a keeper attached to each bolt to prevent the bolt from slipping out of the oversized hole; and e. a hinge member attached to the side members to permit the side members to move for ease of insert of the ladder rail between the side members.
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) | 1982-03-12 | 1982-09-11 | 1983-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-12 | 1986-09-11 | 1987-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-12 | 1990-09-11 | 1991-03-13 | $7700.00 | Window Closed / Lapsed |