| 摘要 |
Molten metal is cast in a mould having a feeder cavity, which may be defined by a feeder sleeve, whose surface has a plurality of elongate projections or ribs spaced apart around its perimeter, the number and dimensions of the ribs being such that the volume of the feeder cavity is reduced by at least 20% compared to a feeder cavity of generally the same size and shape but without the ribs. Preferably the ribs extend substantially the full length of the inner surface of the feeder sleeve. The sleeve may have for example four ribs whose shape and size is such that the horizontal cross-section of the feeder cavity defined by the sleeve is cruciform. The ribs may be formed of material having an exothermic, an exothermic and heat-insulating, or a heat-insulating composition. The ribs enable a given casting to be fed from a smaller quantity of feeder metal than is usual. |
