| 摘要 |
The sprue for a metal casting mould communicates directly with the mould cavity. A sleeve of refractory material is located in the sprue, and a cellular ceramic filter is fixed into the sleeve. The mould has no other running system, and may be a sand mould or a gravity metal die. The sleeve may be located by protrusions in the sprue, or its exterior may be flared. The filter may be located on a ledge or projection inside the sleeve. It may be glued in place, or filter and sleeve may be formed integrally. |
