Method for manufacturing a plug-type chamber used in the cascade drawing of tubes, and device for implementing the method

A device for manufacturing a plug-type chamber to accommodate at least two floating plugs for use in the cascade drawing of tubes made of non-ferrous metal alloys, comprising:

• a clamping device disposable about a length of tube, said clamping device having radially movable fixing clamps for selectively fixing the clamping device to the tube, said clamping device further having attached thereto a denting tool for creating an indentation on the tube;
• a tool for expanding both the inner diameter and the outer diameter of a section of tube, said tool comprising a punch that is displaceable along the longitudinal axis of the tube towards the free end of the tube;
• and
• a necking down tool comprising a ring that is coaxial with the front of the tube and which is configured to be axially displaced along the axis of the tube so that it can be brought forward to the general position of the clamping device,
• wherein the punch serves to expand the inner diameter and the outer diameter of the tube, and the necking down tool serves to then reduce the outer diameter of the tube.

A method for manufacturing a plug-type chamber at the free end of a tube to accommodate at least two floating plugs for use in the cascade drawing of tubes made of metal alloys, comprising the steps of:

• expanding the inner diameter and the outer diameter of the tube at a portion of its free end;
• reducing the outer diameter of the tube along a portion of this section whilst not reducing the inner diameter of this section of the tube, thereby lengthening the tube and forming an expanded chamber within the tube;
• producing an indentation in the tube upstream from the front of the tube, thereby further delimiting the chamber from the remainder of the tube;
• inserting floating plugs into the chamber;
• and
• forming a drawing point onto the free end of the tube.

A device for manufacturing a plug-type chamber to accommodate at least two floating plugs for use in the cascade drawing of tubes made of non-ferrous metal alloys, comprising:

• a clamping device disposable about a length of tube, said clamping device having radially movable fixing clamps for selectively fixing the clamping device to the tube, said clamping device further having attached thereto a denting tool for creating an indentation on the tube;
• means for expanding both the inner diameter and the outer diameter of a section of tube;
• and
• means for reducing the outer diameter of the tube.

A device for manufacturing a plug-type chamber to accommodate at least two floating plugs for use in the cascade drawing of tubes made of metal, comprising:

• a clamping device disposable about a length of tube, said clamping device having radially movable fixing clamps for selectively fixing the clamping device to the tube, said clamping device further having attached thereto a denting tool for creating an indentation on the tube;
• a piston-driven tool for expanding both the inner diameter and the outer diameter of a section of tube, said tool comprising a punch that is displaceable by the piston along the longitudinal axis of the tube towards the free end of the tube;
• and
• a necking down tool comprising a ring that is coaxial with the front of the tube and which is configured to be axially displaced by a second piston along the axis of the tube so that it can be brought forward to the general position of the clamping device,
• wherein the punch serves to expand the inner diameter and the outer diameter of the tube, and the necking down tool serves to then reduce the outer diameter of the tube so as to create an expanded chamber within the tube, which is further delimited by the indentations made by the denting tool.