| 摘要 |
<p>Process and machine use a box covered by an elastic sheet; and the box is located inside a moulding frame, which is raised when sand is fed onto the elastic sheet. The sand has a fine and controlled grain size, and is mixed with a binder. A pattern attached to an overhead plate is lowered by a work cylinder into the sand, and then compressed air is fed into the box to deform the elastic sheet, so the latter compacts the sand on the pattern. The sand is allowed to harden, and then the air pressure is removed and the pattern is raised. Ejector pins then push the shell mould obtd. off the pattern. Two shell moulds are pref. made which are then joined together. Rapid mfr. of consumable shell moulds is obtd.</p> |
