Patent US4671383A successfully refreshed from Google Patents.
US4671383A
Expired / Lapsed
US
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Ladder leveller
Assignee: Individual
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Filing: 1986-06-23
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Granted: 1987-06-09
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Expires: 2006-06-23
Abstract
Abstract A ladder leveller includes an adjustable base having two adaptors suitable for receiving the ladder feet and a pair of telescopic legs respectively fixed under the two adaptors, wherein both the telescopic legs can be optionally adjusted their heights to allow the base and the ladder feet riding on the base horizontally standing on a rugged floor surface in a stable way.
Inventors
- 👤 Yeong-Maw Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:36
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/426
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
197 words
A ladder leveller comprising: an adjustable base having a first adaptor formed with a socket on its top portion, a right-arm portion transversely extending rightward from said first adaptor, and a second adaptor formed with a socket thereon, a left-arm portion transversely extending leftward from said second adaptor to be adjustably coupled by a coupling tenon inserted in said right-arm portion of said first adaptor, both sockets adapted for receiving the ladder feet; and a pair of telescopic legs each fixed under the bottom of any one said adaptor; each said telescopic leg including: a sleeve portion fixed under the bottom of any said adaptor, an inner cylinder movably jacketed in said sleeve portion having two rows of plural holes each row of holes longitudinally formed on either of the two sides of said cylinder, a pair of positioning latches each poking through a latch hole formed on said sleeve portion and through said hole on said cylinder for fixing said cylinder with said sleeve portion, a ball formed under said cylinder and a cushion having anti-slipping bottom surface for scratching the floor surface and a spherical socket for universal coupling of said ball of said cylinder.
Claim 2
Dependent Claim
197 words
A ladder leveller comprising: an adjustable base having a first adaptor formed with a socket on its top portion, a right-arm portion transversely extending rightward from said first adaptor, and a second adaptor formed with a socket thereon, a left-arm portion transversely extending leftward from said second adaptor to be adjustably coupled by a coupling tenon inserted in said right-arm portion of said first adaptor, both sockets adapted for receiving the ladder feet; and a pair of telescopic legs each fixed under the bottom of any one said adaptor; each said telescopic leg including: a sleeve portion fixed under the bottom of any said adaptor, an inner cylinder movably jacketed in said sleeve portion having two rows of plural holes each row of holes longitudinally formed on either of the two sides of said cylinder, a pair of positioning latches each poking through a latch hole formed on said sleeve portion and through said hole on said cylinder for fixing said cylinder with said sleeve portion, a ball formed under said cylinder and a cushion having anti-slipping bottom surface for scratching the floor surface and a spherical socket for universal coupling of said ball of said cylinder.
Claim 3
Dependent Claim
107 words
A ladder leveller according to claim 1, wherein any one said adaptor includes a parallelepiped portion having a socket formed thereon, at least a pair of adjusting screws transversely formed across said parallelepiped portion, and at least a pair of clamping panels each driven by the two adjusting screws, adapted for adjustably clamping the ladder foot as inserted into said sockets, each said adjusting screw formed with a leftward thread movably engaged with a clamping panel and a rightward thread movably engaged with a right clamping panel opposite to said left panel, whereby upon the driving of said screws, said panels will clamp the ladder foot therebetween.
Claim 4
Dependent Claim
57 words
A ladder leveller according to claim 1, wherein said positioning latch is tensioned by a spring held in a casing formed on one side of said sleeve portion to resiliently poke a latch tip through a latch hole of said sleeve portion and a hole of said inner cylinder for fixing the sleeve portion with the cylinder.
Claim 5
Dependent Claim
28 words
A ladder leveller according to claim 1, wherein said positioning latch is formed with a male-threaded portion to engage with a female-threaded hole formed on said sleeve portion.
References Cited (Backward Citations)
US2481581A
Cited
US2608336A
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US2830852A
Cited
US4095671A
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US3908796A
Cited
US3937298A
Cited
US4143742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |