Modular staircase system

Abstract

A modular staircase system configured to form a curved staircase, support extremely heavy finishing materials, having higher design tolerances, and can be achieved at a relatively moderate cost. A plurality of stair modules are configured to secure to one another to form a complete staircase system, each which has an elaborate stringer of significant strength and moderate weight configurable to create floating staircases at an affordable cost.

1 . A stair system comprising:
 a plurality of steps each having a riser portion and a tread portion, each of the steps having a first end and a second end;   a first stringer secured to the first end of each said step, the first stringer extending generally transverse to each of the steps; and   wherein the first stringer is comprised of frame elements defining stringer spaces therebetween, and further comprises a face flange secured to the frame elements proximate the stringer spaces.   
   
   
       2 . The stair system as specified in  claim 1  wherein the frame elements comprise at least two stringer flanges extending generally parallel to each other. 
   
   
       3 . The stair system as specified in  claim 2  further comprising at least one riser flange extending between the two stringer flanges, wherein one of the stringer flanges is positioned closely proximate one of the step tread portions. 
   
   
       4 . The stair system as specified in  claim 3  wherein the riser flange extends transverse from a midsection of one of the stringer flanges to the other stringer flange. 
   
   
       5 . The stair system as specified in  claim 4  further comprising at least two said riser flanges extending between the two stringer flanges to form a generally rectangular stringer frame portion. 
   
   
       6 . The stair system as specified in  claim 5  wherein the face flange is secured directly to the two stringer flanges and the two riser flanges. 
   
   
       7 . The stair system as specified in  claim 5  further comprising a lower flange extending beneath, and secured to, a lower portion of the stringer frame portion. 
   
   
       8 . The stair system as specified in  claim 2  wherein the face flange is generally planar. 
   
   
       9 . The stair system as specified in  claim 2  wherein the stringer flanges are generally planar. 
   
   
       10 . The stair system as specified in  claim 2  wherein the riser flanges are generally planar. 
   
   
       11 . The stair system as specified in  claim 2  wherein the face flange has a major outer surface that is curved. 
   
   
       12 . The stair system as specified in  claim 2  wherein the stair system has a securing portion configured to securely join the stair system to another said stair system. 
   
   
       13 . The stair system as specified in  claim 2  wherein the steps of each said secured staircase systems are in line with each other to form an ascending or descending stair. 
   
   
       14 . The stair system as specified in  claim 2  wherein the stair system has a securing portion configured to securely join the stair system to a landing member. 
   
   
       15 . The stair system as specified in  claim 2  wherein the securing portion comprises an opening configured to receive a fastener securingly extending to another said stair system. 
   
   
       16 . The stair system as specified in  claim 2  wherein the first stringer further includes a railing mounting portion configured to receive and support a railing. 
   
   
       17 . The stair system as specified in  claim 2  wherein the railing mounting portion includes a plurality of openings configured to receive a railing system. 
   
   
       18 . The stair system as specified in  claim 2  wherein the first stringer is comprised of a metal material. 
   
   
       19 . The stair system as specified in  claim 2  wherein the riser portion and the tread portions are comprised of a planar metal material. 
   
   
       20 . The stair system as specified in  claim 2  wherein the riser portion and tread portion are comprised of metal strips. 
   
   
       21 . The stair system as specified in  claim 2  wherein the face flange comprises a singular planar piece of metal. 
   
   
       22 . The stair system as specified in  claim 19  wherein the riser portion is a riser extending the width of the tread. 
   
   
       23 . The stair system as specified in  claim 19  wherein the tread portion is a tread extending the width of the tread. 
   
   
       24 . The stair system as specified in  claim 19  wherein the riser portion and the tread portion each extend the width of the tread and are also a unitary member. 
   
   
       25 . The stair system as specified in  claim 22  wherein the riser is curved. 
   
   
       26 . The stair system as specified in  claim 22  wherein the thread is curved. 
   
   
       27 . The stair system as specified in  claim 1  further comprising a t-astragal extending from the first stringer. 
   
   
       28 . The stair system as specified in  claim 18  wherein the first stringer is comprised of steel. 
   
   
       29 . The stair system as specified in  claim 28  wherein the stringer frame elements are welded together. 
   
   
       30 . The stair system as specified in  claim 4  wherein the at least one riser flange is generally perpendicular to one of the stringer flanges. 
   
   
       31 . The stair system as specified in  claim 2  wherein at least one of the stringer flanges extends the width of two said steps. 
   
   
       32 . The stair system as specified in  claim 2  wherein the stringer flanges extend parallel of one said step.