GB761491A - Method of and apparatus for the production of cores, shell moulds or the like for casting purposes - Google Patents

Abstract

761,491. Moulding-machines. DEUTSCHE EDELSTAHLWERKE AKT.-GES. June 23, 1954 [June 24, 1953], No. 18401/54. Class 83 (1). [Also in Group XXX] In an apparatus for blowing cores, shellmoulds and cores &c., the compressed-air pipe introduced into the moulding-material container is directed towards a deflector which spreads the compressed-air and produces substantially uniform pressure on the material while suddenly expelling it. The part-spherical deflector plate 7 also serves as a valve for the charging-opening 8 of the container 3, being urged downwardly by a spring-loaded guide 12 while a spring 13 closes a valve 14 in the airpipe 6 to prevent mould-material entering during charging. When pipe 6 is subjected to pressure, the valve 14 lifts and thrusts the deflector-plate against the opening, sealing being completed by the following compressed air. Charging is effected via a filter 10 and a hopper 9. The container 3 is preferably supplied with a regulated quantity of compressed-air, and for this purpose a cylinder 4 containing a piston 15 is situated before the container 3 and connected thereto by the pipe 6 with a cock 23 therein, and to the compressed-air supply by pipes 16, 17 through a cock 18. The initial position of the piston is adjusted so that a predetermined volume of pressure-air is enclosed beneath it, cock 23 being closed and cock 18 open to pipe 17. As cock 23 is opened, cock 18 closes pipe 17 and opens pipe 16 so that the air beneath the piston discharges suddenly into the container 3, the discharge being assisted by pressure on top of the piston. Rubber-buffers 20-22 and a relief-valve 24 are fitted. At the core-box clamping-station, air-vents are provided in the clamping-plates 25, 26, since vents in a heated core-box as used for shell-moulding are stated to become clogged.