US Patent 8376309 Adjustable form for a concrete stairway

An apparatus for forming steps within a concrete stairway, wherein each step has a rise and a run. The apparatus includes a stringer rail, one or more riser brackets and a plurality of fasteners. The stringer rail has a lengthwise-extending channel. Each riser bracket has a panel leg and a support leg, wherein one end of the support leg is attached to panel leg. The fasteners are selectively slidable within the rail channel. One of the fasteners attaches the panel leg to the rail and another of the fasteners attaches the support leg to the rail. Each fastener is configurable in a first mode where the fastener is slidably attached to the rail. Each fastener is configurable in a second mode where the fastener is fixedly attached to the rail.