Patent GB-784492-A (GB)
Title: Improvements in lubricating extrusion billets
IPC: B21C23/32
Filed: 1955-02-24
Abstract: 784,492. Extruding. BABCOCK & WILCOX CO. Feb. 24, 1955 [Feb. 26, 1954; March 3, 1954; April 12, 1954], No. 5581/55. Class 83 (4). In the extrusion of a heated cylindrical metal billet using a refractory material, such as glass, as a lubricant, a uniform layer 60, 120, Fig. 3, of the refractory material is formed on a cylindrical surface of the billet 100 by rolling the latter towards the press while such cylindrical surface is in contact with a non-coherent mass of refractory material, to effect softening and flowing of the refractory material over the cylindrical surface. The billet is preferably of tubular form and is coated on both the external and internal surfaces with glass which is applied in powdered form or alternatively as randomly distributed (non-woven) fibres. Pierced billets heated to a temperature of 2300‹ F. in the case of steel, in a rotary furnace 20 are extracted therefrom by a billet handling device 21, Fig. 1, and placed on a transfer means 30 which transfers the billets into alignment with the bore 24 of a billet container 14 and ejects them into this bore. Before charging the container, however, one or more cylindrical plugs of glass fibre are placed in the container bore 24. A mandrel 18 is then extended through the hollow billet and into the orifice of a die 35 mounted on an axially movable die carrier 15 which presses the die against the front end of the container 14. A ram 17 then engages the end of the billet and extrudes it between the mandrel and die to form a tube. After extrusion the mandrel 18 and ram 17 are withdrawn and the container 14 is moved rearwardly away from the front platen 11 to allow the extrusion to be severed from the discard remaining in the container. The latter is then moved forwardly and the ram 17 is moved into the container to eject the discard which falls into a receptacle. The extruded tube passes along a run-out table and conveyer 26 and beneath a saw 27 which severs the extrusion into lengths which are moved against a stop 28. A pusher then moves the cut lengths on to skids 31. The heated billet 100, Fig. 3, received from the furnace 20, is supported in a trough 50 and a predetermined quantity of powdered glass 105 is deposited by a spoon 110, Fig. 4 (not shown), into the bore of the billet. The billet is then ejected from the trough 50 by fingers 61 actuated by a pressure fluid actuator 65, and rolls down a sloping surface 45 and along a horizontal surface 40 on which is disposed a blanket or sheet 210 of heat-resistant material, such as asbestos. Powdered glass 215 is spread over the sheet 210 and as the billet rolls over the surface the powdered glass adheres to it and forms the surface 120 thereon. Due to the rolling of the billet the pile of powdered glass 105 deposited in the bore of the billet also forms the internal layer 60 of glass. The rolling billet subsequently falls into a trough 75 and is ejected therefrom and into the container 14 by an ejector bar 78 actuated through linkage 88 by a pressure fluid actuator 90, Fig. 2 (not shown). The asbestos sheet 210 may alternatively be placed on the sloping surface 45. Specifications 607,285, 663,357 and U.S.A. Specifications 2,731,123 and 2,739,799 are referred to.