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US3732609A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making curved staircase

Assignee: STILE KING STAIRS Inc
•
Filing: 1970-03-02
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Granted: 1973-05-15
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Expires: 1990-03-02
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Abstract

Abstract Right-angle braces are formed of two sections of angle iron mitered together. One leg of the brace is adapted to receive the riser of a stair; and the other leg is adapted to receive the tread of the stair. A number of these braces, each designed to define one side of a step in a curved staircase, are mounted on a flat metal bar to form a flat string for the staircase. A similar flat metal bar is place in a jig at the pitch and curvature the finished staircase is intended to assume; and the formed string is placed in the jig with the two flat bars engaging each other throughout their lengths. The two bars are then welded together to form a lamination while in the jig to provide the curved horse for one side of the staircase with the laminated bars retaining the desired curve and pitch after removal from the jig. Another metal horse is similarly formed for the other side of the staircase, but in a separate jig of different curvature. After the two curved horses are installed, the treads and risers are attached to a pair of associated braces by screws inserted from beneath the metal frames.

Inventors

  • 👤 A Cirgenski
  • 👤 V Stilles

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 11:54
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 93 words
A method of making a frame for a curved staircase comprising: mounting a plurality of right-angled braces along an elongated first metal bar to define the riser portions and tread portions of one side of the stairs of said staircase, forming said first metal bar into a desirable shape defined by the curvature and pitch of the staircase, contacting said first metal bar and its attached braces with a second elongated metal bar substantially throughout their lengths, and securing said first and second metal bars together along the length of the contacting bars.
Claim 2
Independent Claim 93 words
A method of making a frame for a curved staircase comprising: mounting a plurality of right-angled braces along an elongated first metal bar to define the riser portions and tread portions of one side of the stairs of said staircase, forming said first metal bar into a desirable shape defined by the curvature and pitch of the staircase, contacting said first metal bar and its attached braces with a second elongated metal bar substantially throughout their lengths, and securing said first and second metal bars together along the length of the contacting bars.
Claim 3
Dependent Claim 50 words
The method of claim 1 wherein said steps of forming and contacting comprise: placing said second bar in a jig providing a curved surface defined by the desired curve of said staircase, and then contacting said second metal bar with said first metal bar substantially along their entire respective lengths.
Claim 4
Dependent Claim 48 words
The method of claim 1 wherein said step of securing comprises: welding said first and second elongated metal bars together at spaced intervals along their lengths whereby when said framework is removed from said jig, it retains the desired shape defined by said curved surface of said jig.
Claim 5
Dependent Claim 22 words
The method of claim 1 further comprising the step of forming said braces by mitering angle-irons together to provide a right-angle brace.
Claim 6
Dependent Claim 80 words
A method of forming a staircase comprising: forming first and second side metal frames according to claim 1 wherein each of said braces define at least one aperture along the tread portion thereof and an aperture along the riser portion thereof, and securing the risers and treads to their respective brace portions of said first and second metal frames by inserting a wood screw through the proper apertures of said brace and securing the same to the riser and tread.
Claim 7
Dependent Claim 72 words
In a method of fabricating a framework for a curved staircase, the steps of contacting a first metal bar formed in a curve defined by the curvature of said staircase with a second elongated metal bar substantially throughout their respective lengths; and securing said first and second metal bar together in said curved relationship substantially throughout their lengths whereby when said bars are released, they will cooperate to maintain said curved relation.
Claim 8
Dependent Claim 72 words
In a method of fabricating a framework for a curved staircase, the steps of contacting a first metal bar formed in a curve defined by the curvature of said staircase with a second elongated metal bar substantially throughout their respective lengths; and securing said first and second metal bar together in said curved relationship substantially throughout their lengths whereby when said bars are released, they will cooperate to maintain said curved relation.

References Cited (Backward Citations)

US1229482A Cited
US2826157A Cited
US2822841A Cited
US2863531A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-14 1976-11-13 1977-05-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-14 1980-11-13 1981-05-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-14 1984-11-13 1985-05-15 $7700.00 Window Closed / Lapsed

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