Patent GB-662746-A (GB)
Title: Improvements in or relating to the production of seamless steel tubes and apparatus therefor
IPC: B21C1/26
Filed: 1948-11-04
Abstract: 662,746. Making tubes; skew rolling. WELLMAN SMITH OWEN ENGINEERING. CORPORATION, Ltd., and BROOKS, C. Oct. 21, 1949 [Nov. 4, 1948], No. 28726/48. Classes 83 (ii) and 83 (iv). A method of producing seamless steel tubes from cast-steel billets comprises piercing a heated billet in a piercing-press 1 to form a solid - ended thimble 9, treating the thimble in a skew-roll type of elongator 11 to produce a closedended hollow, and treating the hollow on a mandrel in a continuous seamlesstube mill 34 consisting of sets of rolls. Billets of polygonal section are delivered to the piercing-press 1 from a furnace by a skidtable 7 and fed into a container 2 by a punch 3 actuated by hydraulic means 4. The punch 3 is forced into the billet which is displaced thereby to form the thimble 9. An ejector 5 on the press 1 projects through the base of the container 2 and is actuated by hydraulic means 6 to eject the thimble 9 from the container, a skid-table 8 then carrying the thimble on to a table 10 of the elongator 11. The latter preferably comprises three rolls 12 having their axes inclined and being driven by motors 13 through reduction gearing 14 and shafts 15 with universal joints. With the thimble retained by stop (not shown) on the table 10, a mandrel 17 on a roller-table 16 disposed adjacent the table 10 is advanced into the punch-hole in the thimble 9 by hydraulic means 18 and then caused to feed the thimble to the rollers 12 which advance it there-between so as to elongate the thimble on the mandrel. If desired, a gate 20 of the elongator 11, may be engaged on a catch 21 to retain the thimble 9 while the mandrel 17 is advanced to pierce the sealed end thereof and form an open-ended tube or, in order to improve the concentricity of the thimble as it is passed through the elongator, the mandrel 17 need not be used, in which case a ram of the hydraulic means 18 engages the thimble. Alternatively, the gate 20 may be located away from the elongator so that the thimble 9 is pierced by pressure from the hydraulic means after it has left the elongator. As the thimble, in the form of a hollow, and the mandrel 17 are passed through the elongator, they are received on a roller-table 19 which feeds them to a skidtable 22 for delivery to an extractor 24. The latter is of the kind having a gripper 29 mounted on a trolley 27 formed with a hook 26 to engage an endless chain driven by a motor 36. The gripper 29 extracts the mandrel from the hollow as the latter rests on a roller-table 23 and engages a stop 30. A skid-table 44 returns the extracted mandrel 17 to the roller table 16 while the hollow is fed along a skid-table 31 to a roller-table 32 disposed adjacent the tubemill 34. The latter comprises a number of rolls 33 having shaped edges, all or some of the rolls being driven by motors 35 or a single motor connected to each of the driven rolls. A mandrel 38 actuated by a carriage 41 which is disposed on runners 42 adjacent the mill 34 enters the bore of the hollow and feeds the latter through the mill where it is rolled into its final form and passed on to a roller-table 45, the carriage being operated either by hydraulic means or by a motor 40 connected thereto through a wire-rope. A stop 43 is disposed on the mill 34 to retain the hollow until the mandrel 38 has been inserted in the bore thereof. In its finished state, the hollow is passed from the table 45 along a skid-table 46 and on to a roller-table 47 where an extractor of the same kind as the one described above removes the mandrel 38 from the bore thereof, the mandrel then being returned to the roller-table 32 along a skid-table 48. The hollow is then delivered along the table 47 to a hot-saw and finishing apparatus.