Patent GB-562963-A (GB)
Title: Improvements in draw benches for drawing tubes and bars
IPC: B21C1/30
Filed: 1943-01-13
Abstract: 562,963. Drawing. VAUGHAN MACHINERY CO. Jan. 13, 1943, No. 603. Convention date, Jan. I, 1942. [Class 83 (iv)] A chain-operated draw bench, particularly for drawing tubes, has grippers attached to the chain that are automatically closed for a portion of the travel and opened at the end of such portion. The machine is of duplex construction, the chain on one side preferably effecting a draw whilst that on the other makes the idle return. The gripper carriages 14, Fig. 2, carry jaws 15, 16 sliding between bevel closing jaws attached to the carriage and connected by pins 17, 18 to a yoke 19, itself pivotally connected to a rod 21 passing through a boss on the arm 23 of a lever 31 pivoted to the carriage at 22 and attached at 32 to a specially extended pivot of the chain. Holders 9 at the end of the frame carry banks of four dies 10. Rollers 12, 13 run on a guideway 8 on one side of a beam 4 and a single roller runs on a way 7 on the other side to guide one carriage 14, similar rollers running on ways 5, 6 of the other beam 3 of the bench frame. The chains 26 run over sprockets 27 at the die end and over driving sprockets 28 at the other end ; idlers 29, 30 deflecting the lower run of the chain at this end. As the pivot 32 passes over the idler 30, the lever 31 is raised to draw back the jaws 15, 16 and release the work, the jaws remaining open during the passage of the pivot 32 along the upper and return run of the chain and closing again as the pivot passes round the sprocket 27. The sprockets 28 are mounted on the shafts of gears 79 mounted on casings pivoted about the driving shaft 75 to permit of tension adjustment at 83. To prevent damage to the work due to spring when the ends pull through the dies, jaws 44, 45 are closed to hold the work with a friction grip immediately prior to such release.. The jaws are carried by arms 32a loose on a shaft 34 and arms 33 fast thereon. The arms are connected by adjustable links 37, 38 to a lever 39. Piston-rods 42 of air cylinders 41 are connected to the arms 33 to move the jaws to and from the closed position, both positions being shown in Fig. 11. The jaw 44, Fig. 11a, is pivoted to the arm 32a and carries a single block 46 of rubber or rubber substitute, whilst the jaw 45 is integral with its arm 33 and carries sectional rubber blocks backed up by springs 46a and screws 46b. The valves controlling the cylinders 41 are actuated by solenoids connected to limit switches 47, Fig. 3, actuated by pivoted tappets on extensions 48 of the carriages 14. The tappets are connected to shouldered members 52 engaging the ends of yokes 51 carried by spring plungers 50. After actuating the limit switches, the tappets can thus yield and be spring returned to operative position. Should the grippers fail to open a cam surface 60, Fig. 2, engages a roller 58 on an arm 59 on the shaft 34 to provide a positive opening and prevent collision with the gripper carriage. The discharged tubes &c. fall on to arms 63 on shafts 62 rocked by manually. controlled cylinders when it is required to dump the tubes down an incline 72 to a trough 73. The C-shaped frame members 1 permit tubes from both sides of the bench to be delivered to a single trough.