US Patent 7350306 Easy stairs

Easy Stairs is an L-shaped device having a diagonal sliding rod attached to the two sides. Connectors with locking devices allow the diagonal rod to firmly affix to the sides at various locations. To use Easy Stairs, a user adjusts the diagonal rod along the edge of a stringer. When it is in the correct position for the proper size stair, the lock lever is activated. A line can then be drawn on the inside edge of the device on both sides, forming the shape of the stair. The same stair size is then repeated as many times as is necessary to make a staircase of appropriate size.