Patent GB-417968-A (GB)
Title: Improvements in machines for casting metals under pressure
IPC: B22D17/32
Filed: 1933-09-25
Abstract: 417,968. Casting-machines. HAESSLER, P., (trading as PRAZISIONGUSS-FABRIK NURNBERG GEB. ECKERT), 19, Goethestrasse, Nuremberg, Germany. Sept. 25, 1933, Nos. 26411 and 26412. Convention dates, Sept. 24,1932 and Feb. 21, 1933. [Class 83 (i).] Castings, extracting ; clamping moulds.-A machine for casting metal under pressure comprises a cam shaft for controlling the valves which distribute pressure fluid to the cylinders for closing the mould, for charging the metal under pressure, and for inserting and removing the cores, the shaft being intermittently rotated by a hydraulic device. A mould comprises a stationary half 6 integral with a vessel 12 from which metal is charged under pressure into the mould by a plunger 11, and a movable half 5 which is controlled by a piston 2 in a cylinder 1. High pressure fluid is supplied and discharged by pipes 111, 106 respectively, and accumulators 21, 22 contain low and medium pressure air respectively. The control of fluid to the cylinder 8 is effected by valves 13, 14 actuated by cams on a hollow shaft 19, and that to the cylinder 1 by valves 15-18 actuated by cams on a hollow, coaxial shaft 20. A central shaft 34 is movable axially by a control 37, 43a to couple either or both of the shafts 19, 20 to it through clutches 30, 31. Intermittent rotation of the shaft 34 is effected by a hydraulic cylinder 41 through a rack 40, gear 38, and pawl and ratchet 39, 35. The supply of fluid to the cylinder 41 is controlled by valves 44, 45 which may be operated manually by a lever 46 to produce one part oscillation of the shafts 19, 20, semi-automatically by depressing and releasing a lever 65, or completely automatically by continued depression of the lever 65. On actuation of the lever 65 a clutch 57, 67 is coupled under the control of a spring 60 to drive a cam 54 from a motor 72 through gearing 71, variable friction gear 69, and gearing 51. If the lever is released the clutch is decoupled after one revolution which produces four actuations of the valves 44, 45 representing a complete cycle of operations. Upon the first actuation the piston 42 is moved to the left, valves 15 and 17 are opened, and valves 16 and 18 are closed. The piston 2 is thereby moved to the right to close the mould, the piston being initially under the control of low pressure water, the high pressure only becoming fully effective when the piston stops. During this movement a rod 82 is raised manually by a cam 86, or by an electrical control 87 on the cam 54 controlling the energization of a solenoid 88. This rod operates valves 80, 81 to move piston 92 and the cores 90 inwardly, passages 73, 74, 79 for the passage of the fluid being formed in the piston 2. The vessel 12 is charged after or during the closing of the mould. In the second actuation the piston 9 is moved to the left. In the third actuation the piston 2 is moved to the left while the piston 11 being still under control of the pressure medium from the vessel 22 follows it to act as an ejector, and the piston 92 and cores 90 are raised. In the fourth operation the piston 9 is returned. In a modification of the control for the valves 44, 45, the cam disc 54, Fig. 2, instead of operating the lever 46 directly, controls a clutch 57a to couple a shaft 126 to a constant speed shaft 58a so that the valves are operated through a cam 127 and lever 46 at a speed independent of the adjustment of the friction gear 68. The core 90, Fig. 3, may be secured to a plate 154 connected by rods 153 to a plate 152 directly mounted on the rod 151 of the piston slidable in the cylinder 147. A modification of the construction of the piston and cylinder 2, 1 is described.