US4995474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety ladder
Assignee: Individual
•
Filing: 1990-01-22
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Granted: 1991-02-26
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Expires: 2010-01-22
Abstract
Abstract A safety ladder is disclosed. The safety ladder comprises at least two legs each of which containing a smooth longitudinal blind bore, a steel hollow pipe having an outer surface and being smoothly disposed in the longitudinal blind bore while providing additional strength to the at least two legs, a rod disposed concentrically in the steel hollow pipe and vacillating up and down therein without any hindrance so that its ease of operation is increased, a solid piece of steel drilled and tapped so as to contain a throughbore that will accommodate the steel hollow pipe, and a flat steel plate affixed to the solid piece of steel and containing a skewly drilled hole so that the skewly drilled hole lines up with the outer surface of the steel hollow pipe.
Inventors
- 👤 Edward Gauthier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:20
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/42; E06C7/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
An adjustable ladder, comprising: (a) at least two legs each of which containing a smooth longitudinal blind bore; (b) a steel hollow pipe having an outer surface and being smoothly disposed in said longitudinal blind bore while providing additional strength to said at least two legs; (c) a rod disposed concentrically in said steel hollow pipe and vacillating up and down therein without any hindrance so that its ease of operation is increased; (d) a solid piece of steel drilled and tapped so as to contain a throughbore that will accommodate said steel hollow pipe; and (e) a flat steel plate affixed to said solid piece of steel and containing a skewly drilled hole so that said skewly drilled hole lines up with said outer surface of said steel hollow pipe.
Claim 2
Dependent Claim
131 words
An adjustable ladder, comprising: (a) at least two legs each of which containing a smooth longitudinal blind bore; (b) a steel hollow pipe having an outer surface and being smoothly disposed in said longitudinal blind bore while providing additional strength to said at least two legs; (c) a rod disposed concentrically in said steel hollow pipe and vacillating up and down therein without any hindrance so that its ease of operation is increased; (d) a solid piece of steel drilled and tapped so as to contain a throughbore that will accommodate said steel hollow pipe; and (e) a flat steel plate affixed to said solid piece of steel and containing a skewly drilled hole so that said skewly drilled hole lines up with said outer surface of said steel hollow pipe.
Claim 3
Dependent Claim
25 words
A ladder as defined in claim 1, wherein said longitudinal blind bore is disposed on center of said each of said at least two legs.
Claim 4
Dependent Claim
18 words
A ladder as defined in claim 2, wherein said rod is made of steel for safety and strength.
Claim 5
Dependent Claim
14 words
A ladder as defined in claim 3, wherein said rod contains male external threads.
Claim 6
Dependent Claim
19 words
A ladder as defined in claim 4, wherein said steel hollow pipe is welded to said flat steel plate.
Claim 7
Dependent Claim
22 words
A ladder as defined in claim 5, wherein said steel hollow pipe enters said solid piece of steel at a skew angle.
Claim 8
Dependent Claim
34 words
A ladder as defined in claim 6; further comprising a turning collar, a pivot stem, and a ball, said turning collar, said pivot stem, and said ball are usually made as one homogeneous part.
Claim 9
Dependent Claim
37 words
A ladder as defined in claim 7; further comprising a lower portion of a pad, said lower portion of said pad is solid and contains a substantially spherical recess which receives said ball of said pivot stem.
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) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |