Mandrel conveying device for a tube rolling mill

A mandrel conveying device for a multi-stand tube rolling mill with mandrel, defining a rolling axis, the conveying device comprising a rack device and a hooking and releasing device, for hooking and for releasing a tang of the mandrel, the hooking and releasing device comprising at least a head and a lever hinged to said head, wherein said lever being adapted to move with an angular oscillation between a hooking position and a releasing position of the tang of the mandrel, wherein the lever engages a locking pin of another head on an opposite side of the rolling axis when in the hooking position, said angular oscillation being performed on a plane transversal to the rolling axis, said lever being shaped in a part with a groove complementary with the shape of said tang of the mandrel, said lever acting in connection of said tang of said mandrel in said hooking position, wherein the rack device comprises two racks side-by-side and parallel to the rolling axis, each of said two racks has two respective gear teeth, the hooking and releasing device being arranged at one end of the two racks.