Sliding roof, particularly for lorries, semitrailers and the like, with carriages made of extruded aluminium alloy

The sliding roof (10) comprises: a pair of guide sections (12) arranged parallel to each other so as to define a sliding direction (x), a plurality of intermediate cross-members (16) mounted on the guide sections (12) so as to be able to slide along the sliding direction (x), and a tarpaulin secured to the intermediate cross-members (16). A pair of intermediate carriages (20) by means of which the intermediate cross-member (16) is guided along the guide sections (12) are fixed to the opposite ends of each intermediate cross-member (16). Each intermediate carriage (20) comprises a body (24) and a plurality of guide bearings (26, 28) carried by the body (24). The body (24) of each intermediate carriage (20) comprises a first piece (30) of extruded aluminium alloy having a first extrusion direction (x1), a second piece (32) of extruded aluminium alloy having a second extrusion direction (x2), and fixing screws (46) for fixing the first piece (30) and the second piece (32) to each other. The first and second pieces (30, 32) are arranged in such a manner that the first extrusion direction (x1) is oriented parallel to the sliding direction (x), whereas the second extrusion direction (x2) is oriented perpendicular to the sliding direction (x).