Tool for designing stair stringers

Abstract

An apparatus includes a base having a horizontal member and a vertical member substantially perpendicular to each other and wherein the horizontal member and the vertical member are substantially rectangular in shape, a first stop on a distal end of the horizontal member and a second stop on a distal end of the vertical member and wherein the horizontal member has a second end on the opposite side of the vertical member from the first stop and wherein a bottom edge of the second end is substantially aligned with a bottom edge of the horizontal member.

1 .- 2 . (canceled) 
     
     
         3 . The apparatus of  claim 9  wherein the first extendable arm and the horizontal member are securable in a fixed position relative to each other by a securing mechanism. 
     
     
         4 . The apparatus of  claim 3 , wherein the securing mechanism comprises a screw which passes through a slot defined through the first extendable member and is secured to the horizontal member by tightening the screw. 
     
     
         5 . (canceled) 
     
     
         6 . The apparatus of  claim 9  wherein the second extendable arm and the vertical member are securable in a fixed position relative to each other by a securing mechanism. 
     
     
         7 .- 8 . (canceled) 
     
     
         9 . A stair stringer design apparatus, comprising:
 a base having a horizontal member and a vertical member substantially perpendicular to each other, the base having a top side and a bottom side, wherein the horizontal member and the vertical member are substantially rectangular in shape, and the bottom sides of the horizontal member and the vertical member lie in a base plane;   a first extendable arm having a top side and a bottom side, the bottom side of the first extendable arm being slidably connected to the top side of the horizontal member wherein edges of the first extendable arm are substantially aligned with edges of the horizontal member;   a first stop integrally formed with a distal end of the first extendable arm, the first stop extending from the bottom side of the first extendable arm and through the base plane;   a second extendable arm having a top side and a bottom side, the bottom side of the first extendable arm being slidably connected to the top side of the vertical member wherein edges of the second extendable arm are substantially aligned with edges of the vertical member; and   a second stop integrally formed with a distal end of the second extendable arm, the second stop extending from the bottom side of the second extendable arm and through the base plane.   
     
     
         10 . (canceled) 
     
     
         11 . The apparatus of  claim 9  wherein the horizontal member has a notch on a top edge adjacent to a point of intersection with the vertical member sized in accordance with a width of a riser board. 
     
     
         12 . The apparatus of  claim 9  wherein the vertical member has a notch on an edge adjacent to a point of intersection with the horizontal member sized in accordance with a width of a decking board. 
     
     
         13 . A method for using a tool for designing a stair stringer board wherein the tool has an intersecting horizontal member and vertical member and wherein the horizontal member has a first stop on a distal end of the horizontal member and the vertical member has a second stop on a distal end of the vertical member, comprising:
 a. Sizing the horizontal member such that a distance from the intersection to the first stop is substantially equivalent to a desired depth of a tread board;   b. Sizing the vertical member such that a distance from the intersection to the second stop is substantially equivalent to a desired height of a riser board;   c. Positioning the tool on the stair stringer board such that the first stop and the second stop are adjacent to an edge of the stair stringer board;   d. Tracing a first line along a first edge of the vertical member;   e. Tracing a second line along a first edge of the horizontal member; and   f. Tracing a third line along a width of the horizontal member at the distal end of the horizontal member.   
     
     
         14 . The method of  claim 13 , further comprising:
 Moving the tool along the edge of the stair stringer board to align the first edge of the vertical member with the third line;   Repeating steps d, e, and f until a desired number of stairs have been drawn.   
     
     
         15 . The method of  claim 14  further comprising tracing a bottom line on a bottom edge of the horizontal member wherein the bottom edge of the horizontal member extends to the opposite side of the intersection. 
     
     
         16 . The apparatus of  claim 6  wherein the securing mechanism comprises a screw which passes through a slot defined through the second extendable member and is secured to the vertical member by tightening the screw. 
     
     
         17 . The apparatus of  claim 9  wherein longitudinal axes of the horizontal member and the vertical member intersect and define four quadrants, the edges of the first extendable arm comprise a first edge and the edges of the second extendable arm comprise a second edge, the first stop extends from the first edge of the first extendable arm into a first quadrant, and the second stop extends from the second edge of the second extendable arm into the first quadrant.