Abstract: The pattern is surrounded by packed unbound molding medium within a container. The gaseous material resulting from the evaporation of the pattern is removed from within the container as the gaseous material permeates through the packed unbound molding medium. The outflow of the gaseous material is regulated to control the rate of displacement of the pattern by the molten metal. The removed gaseous material is cleaned and cooled, thereby forming condensate and detoxified gas. Thereafter the condensate, and detoxified gas are discharged.

Abstract: A molding medium and process for making it, preferably for use in the evaporative pattern casting process, is disclosed. The molding medium comprises, in one embodiment, a base granular molding material having spherically shaped grains wherein the individual grains of the material are coated with a refractory material. Preferably the grains are coated first with a binding agent and then mixed with a refractory material, which may be zirconium oxide. After coating, the material is fired at a high temperature, crushed and screened to size, according to one method. Alternatively, the base molding material may itself be a refractory material, in which case the refractory material is mixed with a binding agent to agglomerate the base material into substantially spherical particles and a refractory coating need not be applied. In either embodiment, substantially spherical free-flowing particles are produced having a low angle of repose.

Abstract: The method and apparatus are based on the use of a casting process in which expendable patterns are made of a low density material, then evaporated by molten metal as the metal advances into the cavity created by the evaporation of the pattern material. The outer supporting material of the cavity is an unbonded granular material of sufficient grain size distribution. This unbonded material is vibrated in defined partial volumes of the whole volume of a holding vessel called a pouring container and compacted to a predetermined density around the expendable pattern so that it fills all cavities of the expendable pattern prior to the introduction of molten metal into the container to displace the pattern. The compacting vibration is performed in several independent zones to achieve uniform compaction and to prevent pattern deformation. The pouring container follows a loop via a conveyor system preferably through four operation stations.

Abstract: A molding medium and process for making it, preferably for use in the evaporative pattern casting process, is disclosed. The molding medium comprises, in one embodiment, a base granular molding material having spherically shaped grains wherein the individual grains of the material are coated with a refractory material. Preferably the grains are coated first with a binding agent and then mixed with a refractory material, which may be zirconium oxide. After coating, the material is fired at a high temperature, crushed and screened to size, according to one method. Alternatively, the base molding material may itself be a refractory material, in which case the refractory material is mixed with a binding agent to agglomerate the base material into substantially spherical particles and a refractory coating need not be applied. In either embodiment, substantially spherical free-flowing particles are produced having a low angle of repose.

Abstract: A new and improved mixer apparatus is especially adapted for use in a program controlled system for making foundry molds and includes a mixing device for dispensing a mixture of molding sand and binder onto a mold forming pattern in a flask. The device includes a mixing chamber having an inlet for receiving sand adjacent an upper level and a discharge outlet for dispensing a mixture adjacent a lower level. A rotor is mounted on a central axis of the chamber and includes an elongated shaft extending between the inlet and outlet. A flow metering unit divides the chamber into upper and lower sections and is operable for controlling the flow rate of material toward the discharge outlet. The rotor includes upper and lower sets of blades pivotally mounted on axes parallel and spaced radially outwardly of the central axis of the chamber.

Abstract: Apparatus of the invention includes a dispenser for mixing an discharging layers of the molding material onto the mold forming pattern, and means for producing selectively controlled relative movement between the dispenser and the pattern including a control system for varying the ratio of sand and binder in the mixture being dispensed in accordance with the relative position of the dispenser and the pattern. The apparatus may thus be controlled to provide for selectively variable ratios of sand and binder in accordance with the strength required of the mold at a particular position. The system also provides a selectively variable control of the thickness of each layer of molding material as the mixing head or pattern moves on a three axis coordinate system.

Abstract: An impact scrubber for removing coating materials from the surfaces of particulate matter such as foundry sand and the like comprises a lift tube open adjacent upper and lower ends for containing a high velocity fluidized stream of said particulate matter. A fluid injector is mounted adjacent the lower end of the lift tube for moving the particulate matter into the lift tube to form an upwardly flowing, high velocity turbulent fluidized stream. An adjustable inlet valve is provided adjacent the fluid injector for regulating the flow of sand into the high velocity stream of fluid moving into the lift tube. A target is spaced above the open upper end of the lift tube providing an impact area for receiving the flow of high velocity fluidized particulate matter which impacts against the target. The coating material is loosened from the sand grains by the impact at the target and during the turbulent flow.

Abstract: A program controlled customized method for making molds comprises the steps of dispensing a layer of molding material including a mixture of sand and binder over a mold forming pattern by means of relative movement between a dispensing device and the pattern while selectively varying the ratio of sand and binder in the mixture dispensed in predetermined areas of the pattern or in successive layers to provide a mold of the desired strength in certain critical areas while conserving the amount of binder needed for the completed mold.