Patent GB-1040430-A (GB)
Title: Drawing apparatus for tubes or the like
IPC: B21C1/02
Filed: 1965-06-08
Abstract: 1,040,430. Drawing; shearing. BLAW-KNOX CO. June 8, 1965 [July 22, 1964], No. 24166/65. Headings B3P and B3W. In a tube drawing machine a tube T is passed from a reel 7A, through a first draw head 5 mounted on a carriage 4A, around a positively rotating capstan 1 to a reel 7B and when the reel 7A is empty the tube T is passed back through a second draw head 5 mounted on a carriage 4B, around the capstan 1 to the reel 7A, this process being repeated using smaller dies for each cycle until the required tube size is reached. The reel 7A is mounted on a mandrel 2A which is mounted on a carriage 3A. The mandrel 2A is rotated by an electric motor which also drives a fluid pump which supplies pressure fluid to a piston and cylinder 54 which reciprocates the carriage 3A so that tubing T is always in line with the draw head 5 as it is unwound from the reel 7A. The reel 7B is driven in a similar manner. The reels 7 can be removed from the mandrels 2 and are loaded and unloaded from the mandrels 2 by a roller conveyer and lift assembly, the reels 7 being locked on the mandrels 2 by latches operated by cylinders 66. Piston and cylinders 105 (not shown) push the reels 7 from the mandrels 2 on to the lift and conveyer assembly. The capstan 1 is driven by an electric motor and has a gripper 26 which is operated through a toggle mechanism by a piston and cylinder (Fig. 5, not shown). Fluid operated plungers 41 remove the tube T from the gripper 26 when the gripper jaws are opened. Each carriage 4A and 4B carries a draw head 5 and a guide assembly 6 and can be reciprocated by a piston and cylinder so that either the draw head 5 or guide assembly 6 is in line with the tube T. Each draw head 5 includes straightening rolls, the upper roll of which can be raised by a piston and cylinder during threading of the tube T and a die box 8 having a guide die and a draw die. The guide assembly 6 has a fixed guide 159, a movable guide 163 and a guide roller which together with a guide channel 184 above the capstan 1, guides the end of the tube T when it has been released by the gripper 26 from the capstan 1 to an opening 85 in the reel 7B where it is gripped by a pair of jaws which are operated through a cam mechanism by piston and cylinder 67. In operation the tube T is first pointed by a conventional pointing device 187 and is fed manually through the draw head 5 to the capstan gripper 26. The capstan is then rotated until sufficient traction turns are wound on to the capstan when the gripper 26 releases the tube T and plungers 41 remove the tube from the gripper 26. Further rotation of the capstan causes the tube to pass through the guide 6 to the reel 7 where it is gripped in opening 85. The movable guide 163 is moved away from the tube and the capstan 1 is rotated at drawing speed, a plough 115 mounted on the carriage 4A engaging the first turn of the tube on the capstan to push the tubing axially so that it is wound on to the capstan in an even layer. When the end of the tube leaves the reel 7A a pair of knives (Fig. 12, not shown) mounted on rollers are actuated by a rack and pinion operated by a pneumatic piston and cylinder to sever the tail end of tube T. When the tube T is severed the draw head 5, which is pivoted to the carriage 4A, tilts under the action of a spring to operate a switch to stop the machine, the same result being achieved if the tube breaks. The capstan continues rotating until the traction turns are unwound. During the initial winding and unwinding stages the tube is held on the reels 7 by snubber rolls 107 and on the capstan 1 by snubber rolls 48. The above operations are then repeated to pass the tube T to the reel 7A.