Reverse extrusion press

An indirect extrusion press for tubes comprising:

• a fixed support and a fixed crosspiece;
• a tubular ram mounted on said fixed crosspiece and supporting a die centered on an extrusion axis;
• a movable crosspiece movable along said extrusion axis between said fixed support and said fixed crosspiece;
• a container, provided with a bore for a billet, engagable on said ram and movable between said movable crosspiece and said fixed crosspiece;
• a needle for piercing the billet and extrusion of the tubes, mounted on the movable crosspiece in the extrusion axis;
• a closing bottom of the container mounted on the movable crosspiece and comprising, with respect to the container, a cylindrical extension capable of being enclosed in the bore for ramming of the billet and having a length greater than the elongation of the billet during piercing;
• a main jack for the displacement of the movable crosspiece and of the container toward the ram;
• at least two auxiliary jacks attached to the support and connected, respectively to the movable crosspiece and to the container by the operating rods parallel to the extrusion axis;
• and at least one means of connecting the container with the movable crosspiece in an adjustable position, defined by a jack comprised of two displaceable elements, one with respect to the other parallel to the extrusion axis along a length greater than the elongation of the billet during piercing, control means and locking means for one of these elements with respect to the other and means for connecting one of these elements to the movable crosspiece and the other element to the container, at least one of said connecting means being detachable.