Apparatus for controlling the rate of filling of casting molds

Claim 1

Apparatus for controlling the rate of filling of a casting mold, comprising: a first chamber containing a crucible for the material to be cast and first pressure means operatively associated with the first chamber for supplying a pressure P 1 to the crucible; a second chamber adjacent said first chamber and containing a casting mold and second pressure means operatively associated with the second chamber for supplying a pressure P 2 to the mold; a tube extending between said chambers and connecting said crucible to said mold for conducting said material into said mold at a flow rate determined by the pressure differential P = P 1 - P 2 ; first signal-producing means connected to at least one of said chambers for producing a first signal representing the time derivative of one of said pressures; monitoring means connected to said signal-producing means for monitoring said first signal and controlling said one of said pressures to maintain the time derivative thereof substantially constant; second signal-producing means connected to said first signal-producing means for providing a second signal representing the time derivative of one of the parameters constituted by said pressure differential and the other of said pressures; comparison means connected to said second signal-producing means for comparing said second signal with a set-point value in accordance with a predetermined program; and control means connected to said comparison means for controlling said other pressure in response to a signal representing the comparison of said second signal and said set-point value.