摘要 |
Sand 23 in a space defined by a squeeze plate 5, a drag up-set frame 1, a drag moulding flask 16 and a pattern plate 17 is made to conform properly to the shape of the pattern plate by means of gas passed through holes 7 in the squeeze plate. Gas escapes through holes 21 in the pattern plate 17. Firstly, the pressure of gas lifts the sand upwards into the recesses of the pattern plate 17, and then the pressure of gas is increased to consolidate the sand in the recesses. Then, the squeeze plate 5 is raised to mechanically compact the whole of the sand. The pattern plate 17 may be shaped on both of its sides to produce a drag mould below and a cope mould above. <IMAGE> |