Patent GB-715761-A (GB)
Title: Improvements in or relating to mechanism for casting hollow articles
Inventor: KOHL GEORGE CARLOS
IPC: B22D15/02
Filed: 1951-09-03
Abstract: 715,761. Extracting castings; moulds; cores. ALUMINUM CO. OF AMERICA. Sept. 3, 1951, No. 20737/51. Class 83 (1). A machine for casting pistons, e.g. of alloy of aluminium or magnesium, or other hollow articles, has mechanism, operating in timed sequence with the opening of the mould, for gripping the casting, holding it while an inner core is stripped, moving it to a new position and there releasing it. The core comprises an axially removable central section and side sections each removed from the casting, first in an inward direction along a straight path downwardly inclined. In a machine having two moulds for casting pistons P, Fig. 9, the mould halves 16 are separated by movement, along guides 24 on a plate 12, effected by fluidpressure cylinders 30 each acting through a lostmotion device 37 to jerk a core 40 from its casting before the lost motion of a second device is taken up and the mould half is withdrawn. Tapered core parts 53 are then withdrawn downwardly by a cylinder 138 acting through a rack 135, shaft 128, a lost motion coupling 131, Fig. 2, and two racks 124. A gantry 150, having jaws 172 for gripping the castings, which has been moving down by means of a pneumatic cylinder 157, reaches then its lowest position, shown in broken lines, and rests on spacing blocks 165 and an aligning pin 191. Pneumatic diaphragm devices 185 are then operated to move levers 181 and spring-returned slides 171 having inclined slots engaged by pins 173 of'the jaws 172, which thus grip the castings. Pneumatic vibrators 48, Fig. 9, are then started and the core parts 52 are moved inwardly along a downwardly inclined path by fluid-pressure cylinders 104 and inclined slides 80, all carried by a table 86 which is then moved down by a cylinder 112 to the position shown in Fig. 9, the cylinder 104 then being operated to return the cores 52 to outward position against stops 45. The cores 51 are then moved inwardly along a downwardly inclined path to the position shown in Fig. 9 by a slide 54 and a cylinder 72 (Fig. 1, not shown). The gantry 150 then moves up with the extracted castings, the cores 52 also being moved up and the cores 51 out to casting position, Fig. 10. A slide comprising pipes 203, carrying a trough 200 and air-water spray nozzle 218, is then moved inwardly to the position shown in Fig. 10, air and water being automatically supplied by pipes 219, 203 to cool the cores 51 ... 53. The grippers 172 then release the castings which fall into the trough 200, the slide 203 is moved back to its original position, the coolant is stopped, the cores 53 are moved up and the moulds 16 are closed ready for pouring. When the gantry 150 moves down, during the next cycle of operations, a projection 232 thereon engages a projection 230 on the trough 200 and tilts this about its pivot 226 to discharge the castings into a shoot 234. In an automatic arrangement described, all the cylinders and the devices 185 are controlled by solenoid-actuated valves, switches in the solenoid circuits being operated by movement of machine parts and by cams rotated by a motor which is started after an interval, controlled by an adjustable timing device, to allow the castings to cool. A warning light is also turned on by the hand switch initiating the cycle of operations and is automatically turned off when the cooling time has elapsed. The cooling water is turned on by another solenoid-actuated valve and the air by a valve 220 opened by a projection 222 of the slide 203 when it reaches the position shown in Fig. 10. It is stated that the cylinders could be replaced by rotary shafts and linkage members and that some or all the movements could be effected by hand.