Patent GB-632867-A (GB)
Title: Improvements in or relating to mold and pattern separating and actuating mechanism
IPC: B22C17/00
Filed: 1947-06-09
Abstract: 632,867. Foundry moulding machines. HERMAN PNEUMATIC MACHINE CO. June 9, 1947, No. 15116. Convention date, June 14, 1946. [Class 83 (i)] Mechanism for separating moulds and the patterns on which they have been formed, comprises a hollow piston 9 within a cylinder 10 and having an extension integral with a larger piston 12 within a cylinder 11, means to supply pressure fluid to the interior of the hollow piston and thence by way of an opening 13 in the larger piston, into the cylinder 11 so as to raise the pistons and cause fluid from an annular space 32 between the cylinder 11 and the extension to flow along a conduit 29 so as to raise at the same speed a third piston 27, the pistons 9 and 27 carrying members 3 adapted to engage and raise the mould or pattern to be moved. The mould and pattern are mounted on a support 2 and separation is effected by the movement of four arms 3, normally positioned in slots in the support 2 but being secured in pairs to heads 4 and 5 adapted for upward movement. Depending from the hollow head 4 is a tubular piston 9 within a cylinder 10 and terminating in a piston 12 movable within a cylinder 11. Upstanding from the base of the cylinder is a speed control member comprising a lower cylindrical part 15 of smaller diameter than an opening 13 in the piston 12, a part of smaller diameter 20 and an upper part 17, of the same diameter as the part 15. Surrounding this member and normally resting on the piston 12 is a ring 21. Depending from the head 5 is a hollow closed piston 27 operating in a cylinder 25, the effective area of the piston being equal to the area of the annular space 32 between the extension of the piston 9 and cylinder 11, which annular space is permanently connected with the cylinder 25 by a pipe 29. The cylinder 25, pipe 29, space 32, a space 16 below the piston 12 and the greater part of the interior of the piston 9 are filled with an incompressible fluid, preferably oil. A pipe 33 connects the pipe 29 to the space 16 by way of a valve 34 which may be closed by admitting compressed air to a pipe 41 from a manually-controlled valve 37. In operation and starting from the position shown in Fig. 1, compressed air is admitted to the pipe 41 to close the valve 34 and by way of a pipe 38 to the space above the oil in the piston 9. Oil is thus forced between the ring 21 and part 15 and through the piston 12 so that the pistons and head 4 begin to rise, at first slowly, then with increasing speed as the ring 21 reaches the smaller diameter part 20 of the speed control member and finally moves slowly again before being stopped by the operation of the valve 37. During this movement oil from the annular space 32 is forced along the pipe 29 to the cylinder 25 so that the piston 27 and head 5 move together with the pistons 9 and 12 and head 4. On opening the pipe 38 to exhaust, the pistons 9 and 12 descend, oil passing back from the space 16 into the piston 9 and during this movement the ring 21 no longer serves to obturate the opening between the piston base and the speed control member. The head 5 also descends at the same rate, oil passing back through the pipe 29 into the space 32. Finally, the valve 34 is allowed to open. The purpose of this valve is to ensure that at the beginning of a stripping operation all the conduits and spaces are filled with oil and do not contain entrapped air. In a modification, the apparatus is operated by compressed air instead of by a liquid and in this case the pipes 33 and 35 and valve 34 are omitted.