Modular curvilinear staircase

Abstract

Provided is a curved staircase installed between upper and lower levels of a building structure. The curved staircase may be configured as an “outside radius free-standing” version, an “inside radius free-stranding” version, or as an “entirely free-standing” version using a plurality of step modules disposed in stacked relationship to one another. The step modules may be configured in single-step and/or dual-step versions. Each one of the step modules has at least one side panel and at least one riser assembly which comprises a tread ledger and a front riser. A tread is mounted on the tread ledger and side panel of each of the step modules. Each of the treads is also supported by the front riser of the immediately lower adjacent one of the step modules. Inner and outer reinforcing panels are disposed in overlapping relationship to the side panel to interconnect the step modules.

1 . A step module for a staircase, comprising: 
 at least one side panel;    a front riser and a tread ledger extending laterally outwardly from the side panel.    
   
   
       2 . The step module of  claim 1  wherein the side panel is fabricated from a plurality of laminated members.  
   
   
       3 . The step module of  claim 1  wherein the side panel is arcuately shaped.  
   
   
       4 . The step module of  claim 1  wherein: 
 the side panel and tread ledger is formed at a riser height and each having upper edges that are generally flush with one another;    the front riser having an upper edge that extends upwardly past the side panel upper edge to a level equal to that of the riser height.    
   
   
       5 . The step module of  claim 1  wherein the front riser and tread ledger are disposed in abutting relation to one another.  
   
   
       6 . The step module of  claim 1  wherein at least one of the front riser and tread ledger is configured to be attachable to a building structure for supporting the staircase.  
   
   
       7 . The step module of  claim 1  wherein the step module is configured to be arranged in stacked relationship to an adjacent one of the step modules.  
   
   
       8 . A staircase, comprising: 
 a plurality of step modules each including: 
 a spaced pair of side panels; and  
 a front riser and a tread ledger extending between the side panels;  
 wherein the step modules are disposed in stacked relationship to one another and defining a plurality of module joints therebetween;  
   a plurality of treads mounted on the side panels and tread ledger of a respective one of the step modules and on the front riser of the immediately lower adjacent one of the step modules;    a plurality of inner reinforcing panels disposed in overlapping relationship to the side panels of adjacent ones of the step modules for interconnection thereof and forming a plurality of inner panel joints disposed in staggered relationship to the module joints; and    a plurality of outer reinforcing panels disposed in overlapping relationship to the inner reinforcing panels for interconnecting adjacent ones thereof and forming a plurality of outer panel joints disposed in staggered relationship to the inner panel joints.    
   
   
       9 . The curved staircase of  claim 8  wherein at least one of the side panels, inner reinforcing panels and outer reinforcing panels are fabricated from a plurality of laminated members.  
   
   
       10 . The curved staircase of  claim 8  wherein at least one of the side panels is arcuately shaped and having an outer convex surface and an inner concave surface and defining a radius of curvature.  
   
   
       11 . The curved staircase of  claim 8  wherein the side panels of each one of the step modules comprises an inner side panel and an outer side panel having non-concentric radii of curvature.  
   
   
       12 . The curved staircase of  claim 8  wherein: 
 the side panels and tread ledger of each one of the step modules are formed at a riser height and having upper edges that are generally flush with one another;    the front riser having an upper edge that extends upwardly past the side panel upper edge to a level equal to that of the riser height.    
   
   
       13 . A staircase, comprising: 
 a plurality of step modules each including: 
 a spaced pair of side panels, each one of the side panels having a main portion with a front extension protruding outwardly therefrom; and  
 a pair of riser assemblies extending between the side panels, each of the riser assemblies comprising a forward and an aft riser assembly disposed in staggered relationship to one another, each of the riser assemblies comprising a tread ledger and a front riser extending upwardly past the tread ledger;  
   wherein the step modules are disposed in stacked relationship to one another and defining a plurality of module joints therebetween;    a plurality of treads, each one of the treads being supported by the side panels and by a front riser and a tread ledger;    a plurality of inner reinforcing panels disposed in overlapping relationship to the side panels of adjacent ones of the step modules for interconnection thereof, adjacent ones of the inner reinforcing panels forming a plurality of inner panel joints disposed in staggered relationship to the module joints; and    a plurality of outer reinforcing panels disposed in overlapping relationship to the inner reinforcing panels for interconnecting adjacent ones thereof, forming a plurality of outer panel joints disposed in staggered relationship to the inner panel joints.    
   
   
       14 . The curved staircase of  claim 13  wherein at least one of the side panels, inner reinforcing panels and outer reinforcing panels is prefabricated of a plurality of laminated members.  
   
   
       15 . The curved staircase of  claim 13  wherein at least one of the side panels is arcuately shaped and having an outer convex surface and an inner concave surface and defining a radius of curvature.  
   
   
       16 . The curved staircase of  claim 15  wherein the side panels of at least one of the step modules comprises an inner side panel and an outer side panel having non-concentric radii of curvature.  
   
   
       17 . The curved staircase of  claim 13  wherein the front riser and tread ledger are disposed in abutting relation to one another.  
   
   
       18 . The curved staircase of  claim 13  wherein: 
 the front extension being formed at a riser height;    the main portion being formed at twice the riser height;    the tread ledger of the forward riser assembly having an upper edge that is generally flush with the front extension upper edge;    the front riser of the forward riser assembly having an upper edge that is generally flush with the main portion upper edge;    the tread ledger of the aft riser assembly having an upper edge that is generally flush with the main portion upper edge;    the front riser of the aft riser assembly having an upper edge that extends upwardly past the main portion upper edge to a level equal to that of the riser height.    
   
   
       19 . The curved staircase of  claim 13  wherein at least one of the side panels is formed of bonded particulate material.  
   
   
       20 . The curved staircase of  claim 13  wherein at least one of the front riser and tread ledger is fabricated of Versa-Lam material.  
   
   
       21 . The curved staircase of  claim 13  wherein at least one of the treads is fabricated of plywood.  
   
   
       22 . A staircase extending between upper and lower levels of a building structure having a plurality of spaced vertical wall studs, the staircase comprising: 
 a plurality of step modules each including: 
 a side panel having a main portion with a front extension protruding outwardly therefrom; and  
 a pair of riser assemblies extending laterally outwardly from the side panel and being connectable to the wall studs, each of the riser assemblies comprising a forward and an aft riser assembly disposed in staggered relationship to one another, each of the forward and aft riser assemblies comprising a tread ledger and a front riser extending upwardly past the tread ledger;  
   wherein the step modules are disposed in stacked relationship to one another and defining a plurality of module joints therebetween;    a plurality of treads being supported by the side panel and by a front riser and a tread ledger;    a plurality of inner reinforcing panels disposed in overlapping relationship to the side panels of adjacent ones of the step modules for interconnection thereof, adjacent ones of the inner reinforcing panels forming a plurality of inner panel joints disposed in staggered relationship to the module joints; and    a plurality of outer reinforcing panels disposed in overlapping relationship to the inner reinforcing panels for interconnecting adjacent ones thereof, adjacent ones of the outer reinforcing panels forming a plurality of outer panel joints disposed in staggered relationship to the inner panel joints.    
   
   
       23 . The curved staircase of  claim 22  wherein: 
 the front extension is formed at a riser height;    the main portion being formed at twice the riser height;    the tread ledger of the forward riser assembly having an upper edge that is generally flush with the front extension upper edge;    the front riser of the forward riser assembly having an upper edge that is generally flush with the main portion upper edge;    the tread ledger of the aft riser assembly having an upper edge that is generally flush with the main portion upper edge;    the front riser of the aft riser assembly having an upper edge that extends upwardly past the main portion upper edge to a level equal to that of the riser height.