GB489388A - Improvements relating to draw benches - Google Patents

Abstract

489,388. Drawing. ACCLES & POLLOCK, Ltd., and HACKETT, G. Feb. 20,1937, No. 5115. [Class 83 (iv)] A device for drawing metal tubes, rods, strips, or the like through the die of a drawbench comprises a carriage travelling horizontally along the bed of the machine, gripper jaws in one end of the carriage, a hook pivoted at the other end of the carriage and adapted to engage the drawbench chain, means actuated by the hook for closing the jaws on the work, and a catch for holding the hook out of action. In a machine wherein two benches are mounted in parallel relation, each workpiece r is drawn through a die a by a carriage b having wedgeshaped jaws g sliding in inclined ways f and a hook adapted to engage a drawing chain m. A catch t holds the hook j in the raised position. The jaws g are moved into gripping engagement with the work by a lever h which is rocked on downward movement of the hook j through an arm n and a spring p engaging a nut q on a rod o. At the end of the return movement of the carriage b the catch t is released upon engagement with a hand-operated removable abutment v, and the hook j falls into engagement with the chain, the jaws g thereby being moved into gripping engagement with the work. The tension of the chain causes the hook to be moved again to the raised position, the adjacent parts of the chain being raised with it, and the catch t again engages the hook to maintain it in raised position. When the work leaves the die at the end of the operation, the tension in the chain is relieved, and the chain falls free of the hook. Disengagement is ensured by projections x adapted to ride up inclined portions of the track. Return movement of the carriage is effected by the descent of a two-part weight 11, 12, the part 11 engaging an abutment 16 towards the end of the descent so that the movement is completed under the action of the weight 12 only. The weight 12 is adjustably secured to a rod 13 by a spring-pressed pawl 19 co-operating with a series of recesses 18. A relatively short movement of the weight produces the required return movement through a rope 5, a pulley 3, a large pulley 2 and a rope y connected to the lever h. Lateral spring-pressed friction pieces bring the carriage to rest without shock.