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US4143740A Expired / Lapsed US ⏱️ 0.0 years remaining

Modular stairway system for installation on structures having non-linear walls

Assignee: Individual
•
Filing: 1977-12-27
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Granted: 1979-03-13
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Expires: 1997-12-27
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Abstract

Abstract This application disclosed a modular stairway system for circular structures or other structures having non-linear walls. The invention comprises a plurality of first stringer means, a plurality of first connecting means for joining the first stringers, a plurality of second stringer means horizontally spaced from and parallel to the first stringer means, and a plurality of adjustable second connecting means for adjustably joining the second stringers such that the first and second stringers conform to the curvature of the structure. A plurality of stairs are horizontally interposed between the first and second stringers, and a stair mounting means for securing the stairs to the first and second stringers are provided. Also provided are mounting bracket means securing the first stringers to the structure and brace means for supporting the second stringer to the structure, whereby there is obtained a reversible sectional stairway system which can be easily installed on circular structures or other structures having non-linear walls.

Inventors

  • 👤 Wesley D. Matthews

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 14:24
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; Y; Y10; Y10T; Y10T403/00; Y10T403/57; Y10T403/5761; Y10T403/5766; Y10T403/5781

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 133 words
A modular stairway system for structures having non-linear walls comprising: a plurality of first stringer means; a plurality of first connecting means for joining the first stringers; a plurality of second stringer means horizontally spaced from and parallel to the first stringer means; a plurality of adjustable second connecting means for adjustably joining the second stringers such that the combination of first and second stringers conform to the curvature of the structure; a plurality of stairs horizontally interposed between the first and second stringers; a stair mounting means for securing the stairs to the first and second stringers; mounting bracket means for securing the first stringers to the structure; and brace means for supporting the second stringer to the structure, whereby the stairway system may be easily installed on structures having non-linear walls.
Claim 2
Dependent Claim 133 words
A modular stairway system for structures having non-linear walls comprising: a plurality of first stringer means; a plurality of first connecting means for joining the first stringers; a plurality of second stringer means horizontally spaced from and parallel to the first stringer means; a plurality of adjustable second connecting means for adjustably joining the second stringers such that the combination of first and second stringers conform to the curvature of the structure; a plurality of stairs horizontally interposed between the first and second stringers; a stair mounting means for securing the stairs to the first and second stringers; mounting bracket means for securing the first stringers to the structure; and brace means for supporting the second stringer to the structure, whereby the stairway system may be easily installed on structures having non-linear walls.
Claim 3
Dependent Claim 23 words
An apparatus, as claimed in claim 1, wherein the ends of the side portions of the first and second stringers have spaced holes.
Claim 4
Dependent Claim 33 words
An apparatus, as claimed in claim 2, wherein the adjustable second connecting means comprises a metal plate having spaced slots that align with the spaced holes in the ends of the second stringers.
Claim 5
Dependent Claim 32 words
An apparatus, as claimed in claim 2, wherein the first connecting means comprises a metal plate having spaced holes that align with the spaced holes in the ends of the first stringers.
Claim 6
Dependent Claim 25 words
An apparatus, as claimed in claim 4, wherein spacing of the spaced holes conform to the normal bolt spacing on standardized structures having non-linear walls.
Claim 7
Dependent Claim 50 words
An apparatus, as claimed in claim 1, further comprising: a platform section; a platform connecting means for joining the platform section to the first and second stringers; a platform mounting bracket means for securing the platform to the structure; and platform brace means for supporting the platform to the structure.
Claim 8
Dependent Claim 42 words
An apparatus, as claimed in claim 6, further comprising: a plurality of balusters secured to the second stringers and platform section; a plurality of adjustable handrail splices secured to the balusters; and a plurality of handrails adjustably secured to the handrail splices.

References Cited (Backward Citations)

US1173074A Cited

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

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