Patent ID: 8262055

Claim:
An adjustable stair forming apparatus, to form, in an inverted condition, a flight of stairs of a settable material, each stair of said flight including a tread and a riser, each having a width, said apparatus comprising; a frame, a plurality of abutting forming units to receive the settable material, each forming unit reconfigurably mounted from said frame in: (a) a pivotal manner about a first axis parallel to pivot axes of the other forming units, said axis extending in a direction parallel to the width direction of the flight of stairs to be formed, and (b) a translational manner in a direction perpendicular to the width direction, each of said forming units comprising; (i) a tread forming member defining a tread forming surface with an upper edge, and (ii) a riser forming member defining a riser forming surface of a fixed shape and that includes a. a first edge bearing on the tread forming member at or toward said upper edge of said tread forming member, and b. a bearing edge parallel to and distal from said first edge, said riser forming surface at least in part co-extending in said width direction with said tread forming surface, said plurality of forming units each arranged relative said frame with said bearing edge of one said forming unit located by an adjustable support at said tread forming surface of an adjacent said forming unit, adjustment of said support rotationally positioning said riser forming member relative said tread forming member to allow an angle between said riser forming surface and said tread forming surface to be varied to set a desired amount of tread protection, wherein prior to receiving said settable material, said forming units can be configured to a desired configuration, adjustment of said forming units relative each other allowing forming of differently shaped flights of stairs.