| 摘要 |
1,132,373. Making moulds and cores. LITTON INDUSTRIES Inc. 17 May, 1966 [21 May, 1965], No. 21973/66. Heading B3F. In the production of moulds and cores in which the mould or core material is caused to set by heat generated by the application of micro-wave energy, a mould box or core box 54, is located in a curing chamber which is constituted by a conductively bounded micro-wave cavity 26, the mould or core material being blown into the core base from a blowing head 18 and the micro-waves being directed into the cavity 26 through a tube 46. The mould box or core box is made from a material lossless to micro-wave energy, such as plaster, polypropylene, silicone rubber or similar plastics material so that substantially all the microwave energy is concentrated within the mould or core material. In an alternative embodiment the surface of the core box cavity is coated with a material such as ferrite, which is heated by the micro-wave energy and the heating of the mould or core material is effected by conduction from the ferrite coating. Alternatively, ferrite may be added to the moulding composition. In a further embodiment the mould box or core box 58, 60, is provided with hollow cavity walls to which a fluid 62 is supplied and which produces rigidity in the core box halves while the setting and curing of the core takes place therein and whereby the removal of the fluid facilitates collapsing of the core box to permit removal of the finished core. Control means for repetitive production of the cores may be provided. |
