| 摘要 |
<p>A feed proportioning device for a vacuum moulding process, consists of a filling pipe at the bottom of a storage hopper which is closed by a sliding gate. A vacuum connection in the pipe above the gate can be used to produce a vacuum through holes which are closed by an air-permeable sleeve. This facilitates a very exact feed proportioning, and prevents the loss of overflow sand because the application of a vacuum solidifies the sand in the filling pipe and prevents its outflow.</p> |
