Shot-blasting machine for cleaning a linear metal element

A shot-blasting machine for cleaning a surface of a metal rod, said machine comprising

• a) guiding means for said metal rod, and
• b) at least a rotor provided with vanes, said rotor being capable of projecting a jet of shots against said metal rod,
• c) said guiding means being capable of directing said metal rod in a field of action of said jet of shots at least a first and a second time, exposing in said field of action simultaneously at least a first and a second part, respectively, of said surface, a first portion of said metal rod turning said first part of said surface towards said jet of shots and a second portion of said metal rod turning said second part of said surface towards said jet of shots,
• characterized in that
• d) said guiding means comprise a first, a second, a third and a fourth snub pulley, said third and said fourth snub pulley being inclined one respect to the other by a prefixed angle (α),
• e) said third snub pulley supports said first portion of said metal rod and directs said metal rod downward, or upward, while said fourth snub pulley causes said metal rod to wind around said fourth snub pulley by an angle greater than 180°, so that said fourth snub pulley, or said third snub pulley, brings said second portion of said metal rod back to the side of said first portion,
• f) said at least a first and a second part of the surface are kept under said jet of shots practically on a same plane, side by side and at a prefixed close distance at least for the whole path travelled by said metal rod in said field of action of said rod under said jet of shots, and
• g) said second part of said external surface being opposite to said first part for placing the whole external surface of said rod under said jet of shots.