Patent GB-650683-A (GB)
Title: Improvements in and relating to centrifugal casting and to forming a mold for use therewith
IPC: B22D13/02
Filed: 1947-01-24
Abstract: 650,683. Moulding-machines; centrifugal casting-machines. HERMAN PNEUMATIC MACHINE CO. Jan. 24, 1947, No. 2256. Convention date, Feb. 18, 1946. [Class 83 (i)] Apparatus for making a mould for centrifugally casting hollow articles comprises a flask open at each end, means for rotating the flask about its axis, means for introducing moulding material into the flask, compacting means movable firstly axially through the flask and then transversely so as to compact the material to form a cylindrical mould as the flask rotates. After the mould has' been completed, molten metal is introduced at one end and the cast article is removed from the other end. The base 2 of the apparatus has uprights 3, Fig. 5, carrying coaxial bearings 4 and 5. In the bearing 4 is a shaft 6 adapted to be rocked from a cylinder 10 through a piston-rod 9 and arm 7. Through the bearing 5 passes a shaft 14 adapted to be driven from a motor 17 through a reduction gear 15. The flask 20 is carried by a support 19 having legs 18 pivotally mounted on the inner end of the shaft 6, to which one leg is keyed, and on a sleeve 13 carried by the shaft 14 on the inner end of which is a bevel pinion 22 meshing with a similar pinion on a shaft 24. A pulley 26 on this latter shaft is coupled to a pulley 27 on the flask by a belt 28 so that the flask may be rotated about its axis by means of the motor 17 and may be turned from the horizontal to the vertical position by the cylinder 10 as indicated in Fig. 1. The flask has radial cooling fins 30 and is rotatably mounted in bearings 29. Mounted on a track 31 above the flask are trucks 32, 33 rigidly connected by a bar 34 and adapted to be moved by a cylinder 37 so that in one position the carriage 32 which has a bin 38 is beneath a hopper 39 while the carriage 33 which has a vertically movable ejector 43 is aligned with the axis of the flask when the latter is in its vertical position. In the other position of the carriages, mould material may be discharged into the flask from the bin 38. Mounted on tracks 46 beyond the flask is a carriage 47 which may be traversed by means of a motor 49, pinion 51 and stationary rack 48. Movable transversely on the carriage by a cylinder 55 is a member 52 from which project towards the flask, a mandrel 60 and a tube 61 within which is a screw conveyer driven by a motor 65. In operation, the flask is moved into its vertical position and receives a charge of mould material from the bin 38, the lower end of the flask having been closed by a slidable plate 94. The flask is then rotated, restored to the horizontal position, the closure plate moved, and carriage 47 and member 52 operated so that the tube 61 is passed axially through the flask, any surplus material being removed by the conveyer. The tube is then withdrawn and the mandrel 60 passed through the tube so that its end 77 is journalled in a support 72 carried by a slide 71. By means of stops 85, 86 carried by a rockable shaft 80, the slide 71 and member 52 are positioned to give the mandrel a predetermined eccentricity relatively to the flask so that the mould material is smoothed and compacted to the required diameter, the mandrel being rotated by frictional contact with the material. Portions 69b and 69c on the tube 61 and 89 on the mandrel form a bell-mouth at the end of the mould. The mandrel is then withdrawn, a cone 90, Fig. 6, inserted in the end of the mould and molten metal is poured in from the other end to form the pipe shown at 107. After the molten metal has solidified, the flask is turned into its vertical position and the member 43 is moved downwardly to eject both the casting and the mould material from the flask. In a modified form of apparatus, the motor for rotating the flask is mounted on the flask support 19 thereby eliminating the bevel gearing 22, 25.