NZ200321A - Post-tensioned spiral staircase with newel post support and additional tread support risers - Google Patents

Description

2 003 I I Priority Date{s): ... fv.tp .

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P.O. Jouma!, Mo: ..... !?£? t t K. J. P. & S. 1e'V<} m/L NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION STAIRWELL DESIGN t; ■> * APR i982 ' ■] \\Ta *I; / WWe, SPIRAL MANUFACTURING, INC. of 17251 Jefferson Highway, Baton Rouge, Louisiana, U.S.A. 7 0895-, United States of America, a c*rfer*Jtu>n pC -tkc Qktt Lou^i'amt U*iieJ StffcS 0-t Atnevnt* hereby declare the invention for which ^./ we pray that a patent may be granted to sm/ue, and the method by which it is to be performed, to be particularly described in and by the following statement: - I ■I 2 3 4 t: 7 8 S 11 1 2 rfM 14 1 5 16 1 7 J 21 ^2 2 1 24 26 27 28 29 2 0032 j SPECIFICATION I BACKGROUND OF THE INVENTION Field of the Invention. The present invention relates generally to spiral staircases and more particularly to central column or pole staircases as opposed to center well type spiral staircases.

Prior Art. The development of spiral staircases has taken several directions utilizing both the center well type staircase and the central column, or pole type staircase in both singular and sectional modes, as illustrated in the following patents: I Patent Number Inventor Issued Title ~ U.S. 3491498 Wm.J.Hughes,Jr. 01/27/70 Spiral Staircases U.S. 3207259 Dave F. Gebhart 09/21/65 Spiral Stairway U.S. 424533-^ Reuben 0. Belles 04/01/1890 Spiral Stairway (oh There are various problems encountered by each type of staircase. The center pole type typically requires either a very large diameter center pole or a tread which is so narrow at its end adjacent to the center pole that it is unsafe and inconvenient. Additionally, unless the center pole is very wide there can be no center handrail .

The center well type typically requires wasted space for the center well which increases the overall diameter of the staircase and limits its applications particularly with smaller area constructions becoming more common. Center well type systems also tend to be springy and thus less safe. Finally, with the sectional mode center well systems, the riser column sections reduce the available tread space.

SUMMARY OF THE INVENTION Therefore, one object of this invention is to provide a center pole staircase which utilizes a small diameter center pole but retains treads of sufficient width adjacent to the pole for convenience and safety and allows for the incorporation of an inner hand 200 321 rail.

Another object of this invention is to provide a staircase which minimizes wasted center space and hence reduces the diameter of the entire system, thus enlarging its applications.

Another object of this invention is to provide a sectional mode staircase which is rigid, thus minimizing the spring effect.

Still another object of this invention is to provide a sectional mode staircase which maximizes available tread area.

Other objects and advantages of this invention shall become apparent from the ensuring descriptions of the invention.

Accordingly, a spiral staircase is provided comprising a center pole, a plurality of treads which are spirally placed around said center pole in an ascending mode, a plurality of riser support sections which are placed between the treads and a tension means which traverses the riser support sections and the treads through coordinated openings placed in each.

More particularly the present invention consists in a dual support spiral staircase comprising: (a) a center support pole with at least two tread attachment means; (b) a plurality of treads spirally mounted around said center support pole and having at least three strategically placed holes in each tread; (c) a plurality of riser supports each traversed by an opening and having at least two strategically placed pegs extending from both the top and bottom of each riser support, which said riser supports are placed between said treads so that said openings and pegs in the riser 1 Tfc 7sEPl984n 200321 supports correspond with the holes in said treads; and (d) a tensioning means which extends through the treads and risers and which tightens the entire construction around said support pole.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded view of a preferred embodiment of the invention.

Figure 2 is an exploded view of a preferred embodiment of the center pole of the invention.

Figure 3 is a side view of a preferred embodiment of the riser support section of the invention.

Figure 4 is an overhead view of the invention.

PREFERRED EMBODIMENTS OF THE INVENTION Without limiting the scope of this invention, the preferred features will be described using a particular preferred embodiment of this invention.

Referring to Figure 1, starter riser support section 1 is rigidly attached to floor 2 by attachment means 3. Tread 4 is placed on starter riser support section 1 so that hole 5 coordinates with opening 6 in starter riser support section 1 and holes 5a and 5b in tread 4 coordinate with pegs 6a and 6b respectively in starter riser support section 1. Center pole 7 is attached to tread 4 at its near interior corner and is extended up to landing 8.

Referring now to Figure 2, and in a preferred embodiment, tread 4 is attached to center support pole 7 by means of a screw 7a which traverses attachment dowel 4a into tread 4. Attachment dowel 4a is 4 200321 routed at the top to give it a smaller diameter to correspond with that of center pole 7 so that center pole 7 can tightly fit around attachment dowel 4a at its top end. In like fashion intermediate tread 13 can be attached to center pole 7 by means of attachment dowel 13a which is routed at both ends to allow center pole to fit snugly around both ends of attachment dowel 13a which is in turn attached to tread 13 by means of screw 7b. In like fashion attachment dowel 8a is fastened to landing 8 by means of screw 7c. Similarly attachment dowel 8a is routed at its bottom end to allow center pole 7 to snugly fit around attachment dowel 8a.

Now referring back to Figure 1 riser support sections 9, 10, and 11 are placed in succeeding steps between treads 4, 12, 13 and 14 respectively so that holes 5, 15, 16 and 17 correspond with openings 18, 19 and 20 to allow tension means 21 to traverse the entire assembly and so holes 15a, 15b, 16a, 16b, 17a and 17b correspond with pegs 18a, 18b, 19a, 19b, 20a and 20b respectively. As can also be noted, treads 12, 13 and 14 are lined up adjacent to center pole 7 at the near interior corner where grooves 22, 23 and 24 have been placed in treads 12, 13 and 14 respectively for that purpose.

Now referring to figure 3, riser support section 1, which is identical to riser support sections 1, 9, 10 and 11 in Figure 1, is angled at 60 degrees from the horizontal in this particular preferred embodiment .

Additionally, as can be seen in Figure 4, treads 25, 26 and 27 are rotated around center pole 7, so that interior edges 28, 29 and 30 of each succeeding tread form ah angle of 30 degrees.

Referring back to Figure 1, the positioning procedure is repeated / 19114 20032! with additional treads and riser support sections until landing tread 8 is reached. After proper alignment is completed, tension cable 21 is tightened by means already current in the art thus pulling the entire invention together in a rigid fashion.

There are, of course, many obvious alternate embodiments and modifications to this invention which are intended to be included within the scope of this invention as described by the following claims. 6 200

Claims (4)

WHAT WE CLAIM IS:

1. A dual support spiral staircase comprising: (a) a center support pole with at least two tread attachment means; (b) a plurality of treads spirally mounted around said center support pole and having at least three strategically placed holes in each tread; (c) a plurality of riser supports each traversed by an opening and having at least two strategically placed pegs extending from both the top and bottom of each riser support, which said riser supports are placed between said treads so that said openings and pegs in the riser supports correspond with the holes in said treads; and (d) a tensioning means which extends through the treads and risers and which tightens the entire construction around said support pole.

2. A dual support spiral staircase system according to Claim 1 wherein the sides of the riser supports are angled at sixty degrees from a horizontal plane.

3. A dual support spiral staircase system according to Claim 2 wherein the included angle formed by the leading or trailing edge respectively of each succeeding tread with that of its neighbor is thirty degrees, when seen in plan view.

4. A dual support spiral staircase as herein described with reference to any of the accompanying drawings. By yjS7Their authorised Agents, A. J. PARK & SON k ^