Article of furniture having a base fitted with castors

An article of furniture having a base fitted with castors, constituted by at least two bars substantially parallelepiped in form, each comprising an upper web and a lower web and side webs therebetween forming, respectively, the upper and lower and side surfaces of the bar, and each equipped with at least one castor, wherein each bar also has an intermediate web parallel to and situated between said upper and lower webs and extending between said side webs and having a cutaway portion in said bottom web and side webs and extending upward to said intermediate web at the ends of said parallelepiped for the accommodation of each castor each of said castors being fixed to said intermediate web in a said cutaway portion, said article of furniture further having two columns, one of said columns being fixed to one of said bars and the other of said columns being fixed to the other of said bars, said columns being connected together by at least one connecting element and supporting a tray or the like at their top, each of said columns being fixed to each of said bars by at least two barrel screws, the lower web and the intermediate web or each of said bars having corresponding apertures substantially of the same diameter as the barrel of said screw and the upper web of said bars having an aperture substantially equal in diameter to the threaded portion of said barrel screw, the barrel screw having a barrel at least equal in height to the distance between the upper web and the intermediate web.