Molten metal admission control in casting

Abstract

Balance beams are pivotally mounted on and crosswise of an elongated rack extending parallel to a trough over a series of mold cavities, valve closure devices are suspended from corresponding first end portions of the beams to throttle valve openings in the trough, float sensors are suspended from points on the opposing second end portions of the beams to contact the surfaces of molten metal columns brought to a state of equilibrium in the cavities, and the rack is elevated in relation to the cavities as molten metal is delivered to the trough, so that as the first end portions impose a desired value on the rate at which the surfaces escalate up the axes of the cavities, the second end portions elevate the suspension points for the sensors at a rate commensurate therewith, to assure that the input signals transmitted to the first portions through the fulcra for the beams, are consistent with the imposed value. Alternatively, non-contact sensors are suspended from the rack, and the input signals thereof are transmitted through an electronic controller to balance beams on the trough, either electrically to motor driven linear actuators for the balance beams, or through a device which converts the signals to pneumatic signals for pneumatically driven actuators for the beams. The desired value is imposed on the actuators from the controller, and the rack is elevated to raise the signal generation points at a rate commensurate therewith; or the opposite is done.