TOOL FOR EXTRUDING TUBES Russian patent published in 2000 - IPC

FIELD: plastic metal working, namely extruding two tubes (one tube inside another) with predetermined wall thickness from one-piece billet of aluminium alloys, possibly in single-action presses. SUBSTANCE: tool includes heated container, extrusion ram, chamber-type die set having outer die with welding chamber, flat divider with protrusion for defining intertube space. Tool also includes embedded needle for setting inner size of less tube. Said needle is provided with system of supplying ducts of welding chamber for forming wall of less tube. Extrusion of two separate tubes is achieved due to design of divider having no grooves for forming intertube ribs in zone of forming tube walls. EFFECT: enhanced efficiency due to simultaneously extruding two separate tubes. 3 dwg