SYSTEM FOR ON-SITE ASSEMBLY AND INSTALLATION OF A QUARTER TURN METAL STAIRCASE IN A KIT

The invention relates to a jig for assembling a kit staircase including stringers and steps in separate parts， the jig being of generally prismatic shape with a triangular base， and comprising a working face (20) serving as a support to the staircase， configured to， in a lying position of the jig resting on a first face (22) adjacent to the working face， maintaining the stringers and the steps in a configuration corresponding to that of the finished staircase; and a second face (24) adjacent to the work face， forming with the first adjacent face (22) an edge (P) which is located substantially in line with the center of gravity of the finished staircase in the lying position， from which it follows that the template supporting the finished staircase can be tilted to a raised position resting on the second adjacent face by exerting a small force compared to the weight of the staircase.