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US4959935A Expired / Lapsed US ⏱️ 0.0 years remaining

Adjustable stairway

Assignee: Individual
•
Filing: 1989-09-25
•
Granted: 1990-10-02
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Expires: 2009-09-25
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Abstract

Abstract A prefabricated adjustable stairway having a pair of opposed stacked stringers supporting each step. A stair support bracket is pivotally attached to each top stringer and is connected by an associated link to the supporting bottom stringer. Each step is mounted on an opposed pair of brackets. Sliding movement of the top stringer on the bottom stringer is used to adjust each step to a horizontal plane regardless of the inclination of the stairway. The steps can then be fixed in this position.

Inventors

  • 👤 H. Richard Stob

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 04:19
CPC Classifications
E; E01; E01D; E01D15/00; E01D15/24; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; E04F11/0255; E06; E06C; E06C1/00; E06C1/02; E06C1/38; E06C1/387

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 166 words
A stairway having a plurality of steps that can be simultaneously adjusted to the horizontal plane regardless of the angle of inclination of the stairway comprising: a top stringer for each side of said stairway; a bottom support stringer for slidably supporting each top stringer on each side of said stairway; a plurality of spaced opposed brackets pivotally fastened to each top stringer; a link connecting each opposed bracket on each of said top stringers to said bottom support stringer; a plurality of steps, each step of said plurality of steps being mounted on a pair of said spaced opposed brackets on each of said top stringers; at least one guide attached to each of said bottom supports for maintaining said top stringers in sliding alignment with said bottom support; whereby said stairway can be placed at any desired angle of inclination and each step of said stairway can be simultaneously adjusted to the horizontal plane by sliding said top stringer on said bottom support stringer.
Claim 2
Dependent Claim 166 words
A stairway having a plurality of steps that can be simultaneously adjusted to the horizontal plane regardless of the angle of inclination of the stairway comprising: a top stringer for each side of said stairway; a bottom support stringer for slidably supporting each top stringer on each side of said stairway; a plurality of spaced opposed brackets pivotally fastened to each top stringer; a link connecting each opposed bracket on each of said top stringers to said bottom support stringer; a plurality of steps, each step of said plurality of steps being mounted on a pair of said spaced opposed brackets on each of said top stringers; at least one guide attached to each of said bottom supports for maintaining said top stringers in sliding alignment with said bottom support; whereby said stairway can be placed at any desired angle of inclination and each step of said stairway can be simultaneously adjusted to the horizontal plane by sliding said top stringer on said bottom support stringer.
Claim 3
Dependent Claim 29 words
A stairway as set forth in claim 1 wherein the top and bottom stringer on each side of the stairway are in a sliding contact position at all times.
Claim 4
Dependent Claim 25 words
A stairway as set forth in claim 1 wherein each of said guides has apertures therein on the edge and side adjacent said top stringer.
Claim 5
Dependent Claim 37 words
A stairway as set forth in claim 1 wherein said top and bottom stringers can be locked in position after the stair level is adjusted by using fasteners into the top slider through apertures in said guides.
Claim 6
Dependent Claim 14 words
A stairway as set forth in claim 1 which is completely assembled or prefabricated.
Claim 7
Dependent Claim 48 words
A stairway as set forth in claim 1 wherein: a pair of pipe supports are fastened to a pair of spaced steps on said stairway; an upstanding support is mounted in each of said pipe supports; and a handrail is pivotally fastened to each of said upstanding supports.
Claim 8
Dependent Claim 23 words
A stairway as set forth in claim 6 wherein said handrail maintains its position relative to said stairway as said steps are adjusted.
Claim 9
Dependent Claim 219 words
A stairway having steps that will adjust to the horizontal plane regardless of the inclination of the stairway comprising: a first and a second pair of stringers, each pair of stringers having an upper stringer in sliding contact with a lower stringer; a plurality of steps mounted between said first and second pair of stringers; a supporting bracket attached across the bottom at each end of each of said steps, said supporting bracket having a pair of spaced apertures therein with a first aperture near the front and a second aperture near the rear of each of said steps; a fastener for each of said brackets pivotally fastening each of said steps to the upper stringers of each of said pairs of stringers through the first aperture in each of said brackets; a link pivotally connected to each of said brackets at the second aperture and also pivotally fastened to the lower stringer of each of said pair of stringers whereby each step of said plurality of steps can be simultaneously adjusted to the horizontal plane regardless of the angle of inclination of said stringers, by sliding said upper stringer along said lower stringer thereby causing each of said links to pivot its associated bracket and step about said fastener on the upper stringer of each pair of stringers.
Claim 10
Dependent Claim 219 words
A stairway having steps that will adjust to the horizontal plane regardless of the inclination of the stairway comprising: a first and a second pair of stringers, each pair of stringers having an upper stringer in sliding contact with a lower stringer; a plurality of steps mounted between said first and second pair of stringers; a supporting bracket attached across the bottom at each end of each of said steps, said supporting bracket having a pair of spaced apertures therein with a first aperture near the front and a second aperture near the rear of each of said steps; a fastener for each of said brackets pivotally fastening each of said steps to the upper stringers of each of said pairs of stringers through the first aperture in each of said brackets; a link pivotally connected to each of said brackets at the second aperture and also pivotally fastened to the lower stringer of each of said pair of stringers whereby each step of said plurality of steps can be simultaneously adjusted to the horizontal plane regardless of the angle of inclination of said stringers, by sliding said upper stringer along said lower stringer thereby causing each of said links to pivot its associated bracket and step about said fastener on the upper stringer of each pair of stringers.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-10-01 1994-04-02 1994-10-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-10-01 1998-04-02 1998-10-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-10-01 2002-04-02 2002-10-02 $7700.00 Window Closed / Lapsed

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