Abstract: The invention relates to a staircase system featuring modular construction components, wherein the framework of the staircase itself is produced by assembly of modular components paired one with the next in sequence so as to form a bearing structure for the single stair treads. The modular components are prismatic in shape and slot together reciprocally in a number of positions one relative to the other so as to a give a variety of reciprocal positions--at least, in the vertical plane. Each modular component consists of a length of molding whose cross section has an elongated profile which remains constant throughout. The molding is disposed so that its main longitudinal axis is horizontal following assembly. The reciprocal type of connection between one component and the next is brought about by tongues and grooves formed on the vertical side faces of one component and on the mutually-opposed and inwardly-set vertical faces of the next component, between which the first component is partially inserted.
Abstract: The invention relates to a spiral staircase which features adjustable rise, and whose structure is obtained by the assembly in reciprocal fashion of identical modular components (1) fitted one on top of the next, each component comprising a cylindrical section (2), to which either a step (4) or the support (3) for a separate tread (4) is fixed direct. Each cylindrical section (2) consists of an upper part (6) and a lower part (7), these coaxially disposed and provided with means for their being paired by screwing, as well as with alignment-surfaces which enable the upper part of each component (1) to insert coaxially into the lower part (7) of any of the other components (1), thus remaining stably associated therewith following assembly and creating a single, solid structure in consequence. The type of pairing envisaged permits adjustment of the stair rise--that is, the distance between two successive treads, and therefore between the two modular components themselves, once assembled.