US3908796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-levelling accessory for ladders
Assignee: Individual
•
Filing: 1974-10-04
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Granted: 1975-09-30
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Expires: 1994-10-04
Abstract
Abstract A self levelling accessory for extension ladders to accommodate to uneven terrain includes a pair of sockets secured to a cross member and adapted to be mounted on the lower end of a ladder. Two independently adjustable legs are slidably received, each in a respective socket. When the legs are relieved of the weight of the ladder the legs will self adjust to the terrain and when the weight of the ladder is again imposed on the legs, the legs lock by friction within their respective sockets, in adjusted positions.
Inventors
- 👤 Mathew Hurwitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:01
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
149 words
A self levelling and self locking accessory for supporting an extension ladder having a pair of side rails and rungs extending between said side rails, said accessory comprising a pair of open ended sockets, each adapted to be secured outwardly of and in close proximity to a respective side rail, a pair of ground engaging legs, each leg having a lower portion outwardly offset from an upper portion with the upper portion of each leg being received in a respective socket and freely independently slidable therein, said sockets and legs being substantially quadrilateral in cross-section, said legs when the weight of the ladder is removed from the legs being independently freely movable in said sockets to accommodate to the terrain on which the ladder is rested, said legs being automatically self binding and locked in adjusted positions when the weight of the ladder thereafter is imposed on said legs.
Claim 2
Dependent Claim
149 words
A self levelling and self locking accessory for supporting an extension ladder having a pair of side rails and rungs extending between said side rails, said accessory comprising a pair of open ended sockets, each adapted to be secured outwardly of and in close proximity to a respective side rail, a pair of ground engaging legs, each leg having a lower portion outwardly offset from an upper portion with the upper portion of each leg being received in a respective socket and freely independently slidable therein, said sockets and legs being substantially quadrilateral in cross-section, said legs when the weight of the ladder is removed from the legs being independently freely movable in said sockets to accommodate to the terrain on which the ladder is rested, said legs being automatically self binding and locked in adjusted positions when the weight of the ladder thereafter is imposed on said legs.
Claim 3
Dependent Claim
14 words
The invention as defined in claim 1 including a cross member connecting said sockets.
Claim 4
Dependent Claim
28 words
The invention as defined in claim 1 including a cross member and means associated with said sockets for securing said sockets to opposite ends of said cross member.
Claim 5
Dependent Claim
70 words
The invention as defined in claim 3 including clamping engaging said side rails and a pair of U-bolts associated with said clamping means and embracing said cross member and the lowermost rung of said ladder and in which the clamping means comprises vertically extending channel members engaging opposite end edges of said side rails and laterally extending members secured to said channel members and having apertures to receive said U-bolts.
Claim 6
Dependent Claim
43 words
The invention as defined in claim 1 including means for securing said accessory to the side rails of said ladder whereby the stresses imparted by said accessory to said ladder are distributed over an area sufficient to prevent injury to said side rails.
Claim 7
Dependent Claim
31 words
The invention as defined in claim 1 including a liner in each of said sockets providing a higher coefficient of friction with said legs and the material of said socket liners.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |