Wagstaff, Inc.

Aaron David Sinden

David Alan Salee

Frank E Wagstaff

An opening 206 is provided in a system for delivering molten metal to the mold cavity 18 of a molten metal casting apparatus. A valve closure device 192, 196 is mounted at 198 to be reciprocated in relation to the opening 206 to control the flow of molten metal therethrough, and the driven end 206 of a bellows motor 208 is connected with the valve closure device at 258 to reciprocate the device in relation to the opening. A pair of concentric relatively inside and outside thimble-shaped chambers 238 and 240, 264 is circumposed about the bellows motor so that the bight portions thereof are opposed to the driven end of the motor, and interconnected with one another by a restricted liquid flow passage 270 in the screw 268. When fluid input signals are generated in the relatively outside chamber 240, 264, for the actuation of the closure device through the bellows motor, each signal is transmitted to the end of the bellows motor through the restricted liquid flow passage 270 and the relatively inside chamber 238. But when suction occurs in the opening 206 of the molten metal delivery system, the restricted liquid flow passage 270 substantially resists the transmission of relatively low pressure feedback signals to the fluid input signals from the driven end 260 of the bellows motor because of the restriction in the passage.

Molten metal admission control in casting

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.

To control the admission of molten metal to a series of mold cavities through a series of valve openings in the downspouts of a trough thereabove, an elongated rack is arranged parallel to the trough, a set of balance beams is pivotally mounted on the rack, a set of valve closure devices is suspended from corresponding first end portions of the beams for throttling the openings, and a set of float sensors is suspended from points on the opposing second end portions of the beams for contact with the surfaces of the molten metal in the cavities. After an initial phase of the fill operation in which the surfaces of the molten metal reach a state of equilibrium at an intermediate elevation above the tops of the blocks, the rack is elevated in relation to the series of cavities so that as the first end portions of the beams impose a desired value on the rate at which the surfaces escalate up the vertical axes of the cavities, the second end portions raise the elevation of the suspension points for the sensors at a rate commensurate therewith so that the input signals transmitted to the first portions from the second portions through the fulcra for the beams, are consistent with the imposed value. In other versions using non-contact sensors hung from the rack, the input signals are developed electrically and transmitted through an electronic controller which either transmits them electrically to motor driven linear actuators for a set of balance beams on the trough from which the valve closure devices for the openings are suspended, or through a device which converts the electrical signals to pneumatic signals for pneumatically driven actuators for the set of trough mounted beams. In either of the latter versions, the desired value may be imposed on the actuators from the controller, and the rack elevated to raise the signal generation points of the sensors at a rate commensurate therewith, or the opposite may be done, in either case to assure that the imposed value and the input signals transmitted to the actuators for the balance beams are consistent with one another.

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Latah, WA, United States of America

Aaron David Sinden