GB691887A - Improvements in tube-drawing benches - Google Patents

Abstract

691,887. Drawing tubes. RHEINISCHE ROHRENWERKE AKT.-GES. Mav 22. 1951, No. 11962/51. Class 83 (iv). A tube drawing bench for the production of seamless tubes from tube blooms having a greater internal diameter than the drawn tube and in which the mandrel and tube bloom are externally guided during drawing, is characterized in that a tubular spacer is arranged between the tube bloom and the mandrel, said spacer surrounding the entire length of the mandrel in part of the entry side of the die, the spacer together with the external guides ensuring a steady and straight travel of the moving parts exactly on the drawing axis. A tube bloom 3 to be drawn is guided by blocks 2 on the draw-bench 1, said blocks also serving as guides for a mandrel 4 and a tubular spacer 5 which surrounds the mandrel. The spacer has an end cap 6 for preventing folds in the tube during drawing and rests on a slide 8 actuated by a fluid-pressure cylinder 7. A gripper 10 is arranged in front of a die 9 for gripping the mandrel 4 and the tube 3 and drawing them through the die. The guide blocks adjacent a roll supporting table 12 may be swung upwardly to receive tube blooms from the table 12. The end of the spacer 5 remote from the die 9 is slotted top and bottom to enable the pressure-plate of a fluid-pressure device 11 to force the tube and mandrel initially through the die to enable the gripper to engage the mandrel and tube. The gripper 10 has a chain drive and is provided with slides or rollers 14 operating in rails 15 to prevent displacement of the gripper carriage during drawing. The invention is applicable to cold-drawing and hotdrawing operations. The tube to be drawn may be heated electro-inductively just in front of the drawing die.