Abstract: A ceramic investment mold is disposed in a casting chamber and communicates with a pour cup melt reservoir connected to the mold and having a reservoir volume for holding enough melt to fill the mold. The melt pour cup reservoir is communicated to the mold via an inverted loop feed gate so that the melt is fed from a lower region of the reservoir through the inverted loop feed gate to the mold upon gas pressurization of the reservoir. The loop feed gate is configured to have a loop region above the melt level in the reservoir so as to prevent melt flow from the reservoir to the more mold cavities in the absence of reservoir pressurization. While residing in the pour cup reservoir, oxides and other inclusion-forming particles in the melt can float to the upper surface of the melt, whereby the melt fed from the lower region of the reservoir to the mold via the inverted loop melt feed gate includes reduced amount of inclusion-forming particles.

Abstract: In a low pressure die casting apparatus, the properties of the rising pipe of sintered ceramic material for light metal melts is improved by a covering of heat-resistant material surrounding the upper part of the rising pipe.

Abstract: The casting apparatus has a holding furnace for holding a reservoir of molten material, at least one smaller pumping furnace also for holding a reservoir of molten material and a casting cavity connected to the pumping furnace by one or more feed pipes. The pumping furnace is provided with a pressurizing assembly for applying a pressure to force the molten material from the pumping furnace into the casting cavity. The pumping furnace and holding furnace are contiguous and are connected by a non-return valve which prevents the flow of molten material from the pumping furnace to the holding furnace during pressurization but which allows the flow of molten material from the holding furnace to the pumping furnace after pressurization.

Abstract: A mold for gravity casting vehicle wheels having reusable thermally insulative linings attached to the interior of the gate and ball riser cavities. After filling the mold with molten metal, the gate cavity can be pressurized to assure that the mold cavity is completely filled. The ball riser cavity also can be pressurized subsequent to the gate cavity pressurization. The pressure on the gate and ball riser cavities forces molten metal from the cavities into the mold cavity as the metal cools and solidifies.

Abstract: A method of manufacturing a low melting-point metal core is provided, which consists of fitting a loose piece 6 having a built-in heater 5 in a mold 4, casting molten metal by pushing it up from a furnace into the cavity of the mold 4 to fill it, keeping the mold in a filled state for a given time, and stopping the casting step at a time at which the molten metal at the central part of the cavity is still unsolidified, so as to have the unsolidified molten metal fall freely into the furnace.

Abstract: A cylindrical element (14) with a through-going passage (15) is retained in the mold in such a manner that a part of the element (14) protrudes from the outside of the mold, and so that the passage (15) opens into a part of the runner (8) of the mold, the internal terminal surface of element (14) lying opposite a plane surface (16) in the runner (8). During casting, the nozzle (13) of a casting device is brought into tight-fitting abutment against the outer end of the element, and the molten metal alloy is cast into the mold through the nozzle (13), the passage (15) in the element (14) and the runner (8) of the mold.

Abstract: Molten metal is delivered from a master furnace to the molten metal holding chamber of a low pressure casting machine by a launder assembly having a unitary, quickly replaceable, valve assembly including a valve which, when closed, prevents flow of the molten metal from the master furnace to the holding vessel. The valve has a plug mounted for rotation in a valve body which may be made from graphite. In a modification, the valve has a port centered in a valve plate and a movable plug which may be made from aluminum titanate. In operation, the valve is opened to permit the molten metal within the master furnace and the holding vessel to seek a substantially uniform level and closed when the low pressure casting process is initiated. While the valve is closed, a pressurizing gas is introduced into the holding vessel above the level of the molten metal therein so that molten metal will rise up a riser tube into the cavity of a mold or other molten metal-receiving member.

Abstract: After casting a mould (1) through a bottom inlet (2) with liquid metal (4) under pressure through a mouthpiece (5) of a casting device, the inlet (2) is closed by a closing element (8) being pressed by the mouthpiece (5) into sealing abutment against a seat in the mould (1). Subsequently, an inert gas is introduced into a passage (6) in the casting mouthpiece from a source (9) through a pressure reducing valve (11), a shut-off valve (12) which is capable of being selectively opened, a gas chamber (13) and a bore (14) in the mouthpiece (5). The inert gas is introduced such that the casting device can suck the liquid metal (4) from the closing element (8) a distance backwards in the mouthpiece (5). The effect of this is that oxidation of the liquid metal in the mouthpiece (5) or in the nozzle (7) is avoided, and a faster suction of the metal back from the closing element (8) and the nozzle (7) into the passage (6) of the mouthpiece (5), is achieved.

Abstract: A transfer system for delivering molten metal against gravity from a pressurized furnace to a mold, comprising: a ceramic lined refractory metal gatebox adapted to sit on or above the furnace, the gatebox having one or more openings at its top for communicating with the mold and having a plurality of metal transfer openings along its bottom; a stalk tube depending from each of the gatebox bottom openings, each stalk tube being effective to extend into at least the upper region of the molten metal within the furnace; a sealing gasket between the stalk tube and gatebox; imposing a first fluid pressure on the molten metal in the furnace to gradually force the molten metal up through the stalk tubes into the gatebox to substantially fill same, said stalk tubes promoting a convection circulation of metal between molten metal between the furnace and gatebox to retain the temperature of the molten metal in the gatebox at a difference of no greater than 15.degree.-15.degree. F.

Abstract: A casting mold for a low-pressure casting apparatus can be opened and closed and is closed to form therein a cavity which is filled with molten metal to form a cast product. The casting mold includes an upper mold of metal, a lower mold of metal and a sand mold which is disposed between the upper and lower molds and forms a part of the cavity. A top wall of the cavity is formed by a lower surface of the upper mold, at least a part of a side wall of the cavity is formed by the sand mold so that the upper mold contacts with the molten metal filled in the cavity in a larger area than the lower mold.

Abstract: The subject invention is characterized by a mechanism for moving the tilt plate (45) laterally of the guide posts (38) to a loading position outside the operating area within the assembly so that the attachment surface faces sufficiently upwardly to allow a cope (36) and drag (34) defining a mold to rest thereon under the force of gravity. A plurality of crank arms (48) are fixed to and extend upwardly from one lateral edge of the tilt plate (45) to a distal end. A pair of hydraulic cylinders (51) are disposed above the movable platen (43) with a first connection (52) to the distal ends of the crank arms (48) and a second connection (53) to the movable platen (43) for rotating the crank arms (48) to thereby rotate the tilt plate (45) about a tilt axis (50) between an operating position within the assembly and the loading position outside the assembly and facing upwardly.

Abstract: The invention is characterized by a rack mechanism (60) interconnecting a fixed platen (41) and a movable platen (43) for preventing the movable platen (43) from cocking relative to its guide posts (38) during vertical movement thereof. The rack mechanism (60) includes a gear rack (61) paired with each of the guide posts (38) with the bottom end of each gear rack (61) secured to the movable platen (43), and a spur gear (71) in meshing engagement with each of the gear racks (61) and supported on the fixed platen. A box-like framework interconnects the gear racks (61) and a synchronizing drive system simultaneously rotates the spur gears (71) in unison and includes parallel shafts (72) on opposite sides of the framework with two of the spur gears (71) supported on each of the shafts (72) and in meshing engagement with two of the gear racks (61). The running tolerances between the spur gears (71) and the gear racks (61) can be adjusted by pillow blocks (76) supporting the shafts (72).

Abstract: The movable upper portion of a mould is positioned in a first position. Molten metal is forced upwardly into the mould cavity through an opening in a stationary lower mould portion. The upper portion is lowered to a position below the first position to force molten metal into all regions of the mould cavity and to force excess metal back into the furnace. A stop is moved downwardly through an upper opening defined in the upper mould portion to close the lower opening. The upper portion is lowered to a second position, and an external downward force is applied on the upper portion to compress the metal within the mould. The method is particularly suitable for forming vehicle wheel rim castings with reduced subsequent surface processing.

Abstract: In a low-pressure casting in which molten metal is introduced into a cavity of a casting mold under a pressure applied to the surface of the molten metal according to a preset reference pressurizing pattern, the reference pressurizing pattern is corrected when that the cavity has been filled with molten metal is detected and the pressure applied to the molten metal surface is controlled according to the reference pressurizing pattern after the correction. The pressure difference between a set pressure at a predetermined time in the reference pressurizing pattern after the correction and a set pressure at the corresponding time in the reference pressurizing pattern before the correction, is calculated and a set pressure for the period up to the time the cavity is filled with molten metal in the reference pressurizing pattern for the next casting cycle is corrected on the basis of the calculated pressure difference.

Abstract: The apparatus comprises a vessel having an interior. A mold is disposed within the interior of the vessel. A casting material is contained in the interior of the vessel. The apparatus also comprises a mechanism for providing the casting material to the mold in a manner such that vapors of the casting material are prevented from communicating with the interior of the vessel. The providing mechanism is in communication with the vessel. The providing mechanism comprises an inner chamber within which the mold and casting material are contained in. The providing mechanism further comprises a mechanism for heating the inner chamber, such as heating coils. The heating mechanism is disposed within the interior of the vessel adjacent to the inner chamber. Preferably, the inner chamber has a tube extending therefrom having a filter element, disposed therein for catching vapors of the casting material.

Abstract: A method and system for producing a continuous supply of low volume fraction composite material that can be fed continuously into one or more molds. Composite inputs are fed into a mixing device such that a continuous supply of mixed composite material is available from the output side of the mixing device. The operation removes the step of creating master ingots and removes the need for a two step process in which the material is melted twice. This invention reduces the cost of producing composite components, reduces batch-to-batch variations, and allows for a continuous production flow. In addition, the invention allows for a much greater flexibility in the selection and optimization of material systems.

Abstract: The machine for filling moulds with metal to be cast, in which a casing is provided comprises a fixed body and a mobile body. The mobile body is driven by a cylinder. The casing can be provided with a vacuum chamber which when closed houses, with the ability to rotate, a sand mould clamped in a central turning body of a support which can be moved by another cylinder towards a lower injector which supplies the mould with the appropriate quantity of cast metal from a lower metering store. A pressure gas is inserted into the metering store through a connection. The metering store receives the cast metal from a larger tank with the assistance of a seal controlled by a level sensor. The machine also includes a metering ladle positioned between a filling plate and the mould itself. The metering ladle has heating elements.

Abstract: In a vacuum casting method, a molding cavity is reduced in pressure to a vacuum, and when a gate is opened, a molten metal which has been raised to a molten metal retaining dome is charged into the molding cavity at a high speed. When a portion of a molten metal held in a molten metal holding furnace is raised to the molten metal retaining dome via a stalk, (1) the rising speed of a portion of the molten metal is set at 5-10 cm/sec, or (2) the rising speed is varied between an early stage of the rising motion and a later stage of the rising motion. In the latter method, the rising speed at the early stage of the rising motion is set at a speed higher than 10 cm/sec, while the rising speed at the later stage of the rising motion is set at 5-10 cm/sec. Due to the rising speed control, air involvement by the rising molten metal is effectively prevented.

Abstract: In a method of vacuum casting wherein when the molten metal previously introduced into a molten metal reservoir is fed into a cavity, the lowest head of the molten metal in the molten metal reservoir is held to be higher than the level of a sprue, so that the cycle time of casting may be shortened and the quality of cast products may be improved. To this end, the interior of the molten metal reservoir is held gas tight while the sprue is opened by a gate member of straight tubular shape.

Abstract: A vacuum casting apparatus includes a plurality of pressure pins arranged in a molding cavity, and at least one pressure pin is located in a portion of the molding cavity farthest from a gate. The pressure pins are operated to pressurize the molding cavity in an order from the pressure pin located farthest from the gate to a pressure pin located nearest to the gate. A cross-sectional area reduced portion can also be formed in a portion of a runner connecting the molding cavity and the molten metal retaining dome. A molten metal in the molding cavity is thereby suppressed from flowing backward into the molten metal retaining dome when being pressurized by the pressure pins, so that the quality of the cast products is improved.

Abstract: In a method of vacuum casting molten metal sucked from a molten metal reservoir into a cavity held under a reduced pressure by opening a gate having been blocking the communication between the molten metal reservoir and the cavity, the trapping of gas and foreign matter in the cavity is effectively prevented. To this end, an accommodation space for accommodating gas and foreign matter is provided in the molten metal reservoir. The accommodation space is provided at a position from which the accommodated matter is not sucked into the cavity.

Abstract: In a vacuum casting method, a mold cavity is reduced in pressure to a vacuum, and when a gate is opened, a molten metal which has been raised to a molten metal retaining dome is charged into the cavity at a high speed. When a portion of a molten metal held in a molten metal holding furnace is raised to the molten metal retaining dome, an upper surface of the molten metal is moved downwardly and upwardly through at least one cycle in the molten metal retaining dome, or a swirl flow is generated in the molten metal in a stalk. Such a unique motion as the downward and upward motion or the swirl flow effectively operates to detach solid metal pieces from an inside surface of the molten metal retaining dome or the stalk to push them to an upper portion of the molten metal. As a result, the detached metal pieces are prevented from being charged into the mold cavity to thereby cause defects in a cast product.

Abstract: Metal is cast by melting it in a crucible over a hole too small to enable gravity to make the molten metal pass through the hole and with a diameter to length ratio greater than one, after which increased pressure is applied to the metal to drive it through the hole into a mold.

Abstract: A casting method wherein casting cycles are continuously performed with respective molds and a common mass of molten metal accommodated in a container, such that in each casting cycle, the mold cavity is filled with the molten metal through a pouring tube connected at one end to a sprue hole of the mold and immersed at the other end in the molten metal mass, due to a difference between pressures to which the mold and the container are exposed, and wherein the molten metal temperature is estimated from the detected amount of consumption of the immersed tube, and the actual molten metal temperature is regulated, on the basis of a difference between a predetermined desired temperature of the molten metal, and the estimated temperature which changes with the actual temperature.

Abstract: A multi-stage sand mold 4 defines a plurality of casting impressions or cavities 31 fed with molten metal from a tubular central chamber 28 via a pair of parallel intermediate ducts 30A, 30B extending horizontally outwardly from opposite sides of the chamber, and ingates 32A, 32B extending between the ducts and the impressions. All of the ingates fed by a single intermediate duct open into the same impression, thus implementing a balanced and uniform distribution of molten metal to the impressions.

Abstract: A low pressure chill casting method for casting metal components such as cylinder heads or engine blocks of combustion engines or the like, which cast components have wall portions which are locally predominently thinner than in their other regions. In this method, by means of gas pressure, liquid metal is forced from a melt container through a riser tube into a mold. According to the invention, the mold is so arranged that therein the thicker wall portion of the cast component is cast upwardly remote from the gating and the thinner wall portion is cast downwardly in the vicinity of the gating, the liquid metal being introduced at or near the lower region of the mold in the vicinity of the gating into the mold cavity region forming the thinner wall portion.

Abstract: A counter pressure casting and a counter pressure casting device in which the pressures in a furnace side and a casting mold side are set to be lower than the maximum pressure of the process at a stage of the molten metal charging and increased to the maximum after the molten metal charging step. This technique provides a casting having less casting defects and improves the productivity.

Abstract: The apparatus for casting comprises a pressure vessel and a device for pressurizing the vessel. The pressurizing device is in fluidic connection with the vessel. The apparatus is also comprised of a chamber disposed in the pressure vessel within which material is melted. There is a mold adapted to contain a preform disposed in the vessel and in fluidic connection with the chamber by a passage such that melted material in the chamber can be forced down into the mold through the passage as the pressurizing device pressurizes the vessel. A heating device is disposed in the vessel. There is also a device for directionally solidifying the material in the mold. Additionally, there is a method comprising the steps of loading the pressure vessel by disposing a material within the chamber whereby the material is in fluidic connection with the mold adapted to contain a preform through the passage. The passage has a filter disposed therein.

Abstract: A multi-stage sand mold 4 defines a plurality of casting impressions or cavities 31 fed with molten metal from a tubular central chamber 28 via intermediate ducts 30A, 30B extending horizontally outwardly from opposite sides of the chamber, and ingates 32A, 32B extending between the ducts and the impressions. At each stage the sum of the cross-sectional areas of the ducts at their inlets is substantially less than the cross-sectional area of the central chamber, and the sum of the cross-sectional areas of the ingates fed by a given duct is at least equal to its cross-sectional area. This results in delivery rate reductions at the entrances to the ducts and in pressure reductions at the entrances to the ingates, which enhances the uniformity and integrity of the castings.

Abstract: The lower mold which forms the external side of the vehicle wheel is water-cooled by water-cooling pipes. The rib-forming portions of the upper mold which forms the internal side of the vehicle wheel are forcibly air-cooled by the air passages provided along the rib-forming portions. Since water-cooling has better cooling capacity than air-cooling, the molten material inside the cavity between the lower mold and the upper mold is solidified from the external side thereof, and no defects such as shrinkage cavities occur on the external side thereof. When the internal side is solidified, the rib portions are solidified not much later than the other portion of the internal side, thereby shortening the casting cycle time. The split molds which form the cavity for forming therein the rim portion of the vehicle wheel are opened earlier than the upper mold, at the time when the surface layer portion of the molten material in the cavity has been solidified.

Abstract: A split mold is closed to define a cavity. The mold has in its lower portion a gate communication with the cavity. A stoke is connected at its upper end to the gate, while its lower end is immersed in a bath of molten metal in a holding furnace. The pressure of the bath is increased, or the pressure of the cavity decreased, whereby the molten metal is introduced into the cavity. The molten metal in the cavity is allowed to solidify to yield a cast product. The product is cooled and removed from the mold. The stoke and the cavity are filled with an inert gas before the molten metal is introduced into the cavity. In order to introduce the molten metal into the cavity, a pressure difference is created between the bath and the cavity at a rate of 0.001 to 0.006 kgf/cm.sup.2 /s. The molten metal is kept at a temperature which is higher than its melting point by 50.degree. to 80.degree. C., or the mold is kept at a temperature of 350.degree. to 430.degree. C.

Abstract: A pressure molding method and apparatus uses a mold with a casting cavity and a pouring gate through which a molten metal is fed into the casting cavity. After feeding a molten metal into the mold through the pouring gate to fill the casting cavity and pouring gate, a cap member is placed on the mold to bring its open end into contact with a dead head of the molten metal in the pouring gate of the mold so as to form an air-tightly sealed chamber between the cap member and dead head of the molten metal. Pressure is supplied into the sealed chamber to force the molten metal in the mold through the dead head.

Abstract: A porous preform is placed in a nonporous mold chamber of a pressure vessel. A material is placed in a crucible of the pressure vessel. The pressure vessel is evacuated through a snorkel fluidically connected to the mold chamber and extending therefrom out of the pressure vessel. The material in the crucible is melted. The crucible is placed in fluidic communication with the mold chamber such that the melted material fluidically seals the inside of the mold chamber and the snorkel from the interior of the pressure vessel to fluidically isolate the mold chamber from the interior of the pressure vessel so that a pressure differential exists therebetween.

Abstract: The present invention pertains to an apparatus for casting comprised of a pressure vessel and means for evacuating and pressurizing the vessel. The evacuating and pressurizing means is in fluidic connection with the vessel. The apparatus is also comprised of a crucible disposed in the pressure vessel within which material is melted. There is a mold disposed in the pressure vessel. Additionally, the apparatus is comprised of means for heating material in the crucible and the mold in the mold chamber such that material is melted in the crucible and stays melted as it is drawn up to the mold chamber while the evacuating and pressurizing means evacuates the vessel, and when it is forced into the mold while the evacuating and pressurizing means charges the vessel. The heating means is disposed in the vessel. The pressurizing means comprises at least one chill line which serves to chill the mold as the vessel is pressurized. The present invention also pertains to a method for casting.

Abstract: The sum of the areas of the sections of the operational ingates 30 of the mold 4 is, at least at the time of casting, greater than the area of the section of the vertical casting chamber 28, or at least approximately equal to it. This makes it possible to slow the molten metal as it flows into the ingates, and thus to obtain a non-turbulent filling of the impressions or cavities 29.

Abstract: Flat metal products are pressure cast in a mould having two lateral walls each consisting of a support and of a graphite block as well as several spacers, including an upper spacer interposed between the blocks. The ends of the upper spacer and of the front spacer are inserted between two half-shells intended to receive a header of molten metal at the end of the cast. Elastic members carried by the supports exert during the cast, a clamping force of the half-sheels on the spacers. After the start of solidification of the slab, the clamping force is reduced by lateral jacks which eliminate any resistance to contraction of the slab and thus prevent the formation of cracks at the slab/header transition.

Abstract: A metallurgically improved metal casting (10) is made with increased productivity, wherein molten metal is quiescently fed upwards into a molding chamber (14) which is then inverted. An assembly of refractory cores (12) is used that defines the molding chamber (14) with riser channels (16). A metal entrance (18) to the molding chamber (14) through a mold side wall (20) requires feeding molten metal against gravity to fill the molding chamber (14), and quiescently pressure feeding molten metal through a metal launder (26) to fill the molding chamber (14) and the riser channels (16). A mold/nozzle connection between the metal launder (26) and the source of molten metal delivered under pressure is rotationally flexible and axially compliant. The feeding of molten metal is interrupted and the assembly is rotated about an axis passing through the mold/nozzle connection (28) to invert the assembly while maintaining the mold/nozzle connection.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permeability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core.

Abstract: A wear-resistant cast iron rocker arm or similar machine element is formed by differential pressure, countergravity casting an iron melt of low superheat into a ceramic investment shell mold maintained initially at room temperature and rapidly solidifying the melt therein to provide a wear-resistant, as-cast microstructure throughout the body of the element. The as-cast microstructure comprises a dendritic constituent of austenite or transformed austenite (e.g., pearlite) depending on alloy composition and an interdentritic carbide constituent. Interdendritic ledeburite will also be present if the austenite remains untransformed. The as-cast microstructure of the rocker arm is devoid of graphite.

Abstract: The apparatus for casting comprises a pressure vessel and a device for evacuating and pressurizing the vessel. The evacuating and pressurizing device is in fluidic connection with the vessel. The apparatus is also comprised of a chamber disposed in the pressure vessel within which material is melted. There is a mold with a passage such that the melted material in the chamber can be forced down into the mold through the passage as the pressurizing device pressurize the vessel. The passage contains a filter such that the melted material is prevented from entering the interior of the mold prior to pressurization. Additionally, the apparatus is comprised of a device for heating material in the chamber and the mold such that material is melted in the chamber and stays melted as it is forced down into mold while the pressurizing device pressurizes the vessel. The heating device is disposed in the vessel.

Abstract: A porous preform is placed within a permanent, nonporous, thin walled mold chamber. The mold chamber is disposed within a pressure vessel. A material is placed in a crucible of the pressure vessel. The pressure vessel is evacuated through a snorkel fluidically connected to the mold chamber. There is means for cooling the snorkel in thermal communication with the snorkel. The material is melted within the crucible. The crucible is placed in fluidic communication with the mold chamber such that the melted material seals the inside of the mold chamber from the pressure vessel to isolate a vacuum within the mold chamber.

Abstract: A method and apparatus for countergravity casting of molten metal with exclusion of air in a gas-pervious mold sealed in an evacuable chamber having a free end of a fill pipe for the mold cavities projecting therefrom. The fill pipe is moved relative to an enclosed crucible containing the molten metal under an air-free atmosphere of inert gas to project the fill pipe free end into the crucible enclosure to a position below the molten metal so that evacuation of the chamber produces filling of the mold. Entry of air into the crucible enclosure is prevented by maintaining the surface of the molten metal and the ambient atmosphere a sufficient distance apart prior to insertion of the fill pipe to prevent circulating air currents from drawing air down to the metal or by blocking entry into the crucible enclosure. Entry of air can be further prevented by maintaining a sufficient pressure of inert gas in the crucible enclosure and by sealing the upper portion of the fill pipe between the chamber and the mold.

Abstract: A body frame for a motor bicycle includes a main frame, a head tube provided at a front end of the main frame and down tubes extending rearward from the main frame. The main frame, head tube and down tubes are cast with a light alloy into an integral form of a hollow and thin-wall structure. A production process of the body frame, wherein an integrally-formed core, which is formed into a shape similar to that of the body frame, is hollow and has good permability. A molten metal is charged into the mold and a vacuum is applied to the interior of the core. The molten metal is charged into a cavity defined between the core and the molding surface of the mold by a low-pressure casting method, and the molten metal is solidified so as to cast the body frame.

Abstract: A metallic mold (1) comprises two mold halves (3,4) which define between them a mold cavity connected to blowing means (56). The mold (1) is vertically movably mounted on a chassis (18) rigidly supporting an aspiration channel (16). To aspirate the metal, the mold is sealingly applied against the channel which is immersed in the bath (62). After filling of the mold cavity, the material solidifies in a constriction (26) of the channel. This permits raising the chassis (18) without the mold cavity emptying. Then, the mold (1) is raised relative to the channel (16) to break the material in the constriction and to let fall back into the bath the material (68) which was in the channel. Demolding is effected by separating the mold halves from each other.

Abstract: The invention relates to a method and apparatus for sand molding composite articles formed of a light alloy metal and fibrous insert. A sand mold is formed containing a fibrous preform separated from the walls of the mold cavity. The mold is fed by means of a tube dipping into a liquid metallic bath therebelow. In the molding process, the pressure in the mold cavity and above the bath are reduced, and the pressure above the bath is increased to create a positive pressure differential .DELTA.P, thereby forcing molten metal from the bath into the mold cavity. The pressure in the mold cavity and above the bath are then increased to above atmospheric, and the pressure differential .DELTA.P is maintained until the metal in the mold cavity solidifies.

Abstract: A light metal alloy such as an aluminum alloy is cast into a casting such as an automobile engine cylinder head under low pressure. A fluid pressure is applied to the surface of a light metal alloy stored in a closed container to introduce the light metal alloy from the closed container through a transfer tube and a sprue into a mold cavity defined in a mold assembly. The introduced molten metal alloy is brought into contact with molds of the mold assembly which have different thermal conductivities, respectively. The time in which the molten metal alloy is solidified is controlled by the molds of different thermal conductivities. The molds may forcibly be cooled by a cooling medium passing therethrough or cooling blocks mounted thereon.

Abstract: A countergravity casting process involves holding an inherently unstable mass of particulate mold material in an open bottom container around a destructible pattern therein by exerting external fluid pressure, such as atmospheric pressure, on a bottom side of the particulate mass in excess of internal pressure in the container. The container and an underlying molten metal pool are relatively moved to place the bottom side of the particulate mass in the pool. Molten metal is drawn through an ingate to the pattern to destroy and replace the pattern in the particulate mass. When the container and pool are relatively moved to extract the bottom side from the pool after casting, the particulate mold material is held in the container around the metal replacing the pattern by the external/internal pressure differential between the bottom side of the particulate mass and interior of the container.

Abstract: A low-pressure die casting process in which gaseous pressure is applied to molten metal in a bath (C) in three stages from three pressure applying circuits. The first circuit applies pressure to lift molten metal to the charging aperture of the die. When the presence of the metal at that die is detected by a sensor (8), a datum pressure is established and the further application of gaseous pressure to the molten metal is taken over by a second circuit. When the pressure applied to the molten metal differs from the datum pressure by a predetermined amount, an after pressure is applied to the molten metal by the third circuit.

Abstract: Method of and apparatus for making metal castings using a polystyrene pattern 10 embedded in unbonded sand 20 which is consolidated to form a mould M in which is defined a mould cavity C. Molten metal is fed into the cavity C and permitted to solidify to form a casting 11. The metal is aluminum or an aluminum alloy and at least part of the mould is formed of sand which comprises at least 50% zircon sand, or other particulate material suitable for making a mould and having a bulk density lying in the range 2-3 grams/cc. The mould M may have a moulding feature 9 having upper and lower surfaces for contact with the metal and which projects inwardly of the mould cavity C from the main wall thereof and the length of any one section of the molding feature 9 being at least twice the thickness of the thinnest part thereof by which the section is connected to the main wall of the mould cavity.

Abstract: An apparatus and method for counter-gravity casting of molten metal, in a gas permeable mold with a fill passage upper end above the lateral communication of the passage with other mold cavities. The mold is filled by low pressure in a chamber sealed about the mold while the mold fill passage is communicated with the molten metal. Provision is made for maintaining, during filling, the upper part of the mold fill passage at a lower pressure than that in the chamber external to the mold.