| 摘要 |
Two elongated gripping members (12,12) cooperate to form a closed pressure chamber about a waxed billet (61). The gripping members are reciprocated relative to an extrusion station (13), such reciprocation first moving the pressure chamber toward and past the extrusion station so as to extrude the billet through a die (66) at the extrusion station, and then returning the gripping members, in separated condition, to their initial positions to permit the immediate loading of another billet between the gripping members. Also disclosed are various additional systems, e.g., for feeding billets between the gripping members from a magazine; for coating the billets with wax; for automatically changing dies at the extrusion station; for providing soft, dummy billets to facilitate the complete extrusion of each successive billet, and to serve as soft, starting noses as each successive extrusion operation begins; for applying, along exterior surfaces of the gripping members, a pressure gradient increasing in the direction of the extrusion station, to match increasing pressure levels within each waxed billet during extrusion; and for so stressing and/or prestressing certain structural elements as to oppose high, extrusion-caused stresses.
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