Abstract: In a closed system a shock pressure wave of a burning gas is used for packing granular mold material loosely distributed around a model. Before the shock pressure is produced, the pore volume of the upper layer of the granular material exposed to the pressure is reduced. Through the pore volume reduction, the active surface of the granular material is increased, so that the gas pressure acts on an increased working surface and, consequently, greater mold hardness is achieved.

Abstract: A method of compacting particulate material includes providing a primary fuel mixture of air and natural gas in a closed chamber enclosing a surface of the material to be compacted. An additive gas, such as hydrogen, having a higher combustion velocity is added to the primary fuel/air mix and ignited, creating an exothermic reaction which compacts the material. The additive gas increases the gradient of the pressure rise curve of the combustion. Various fuels and additive gases and disclosed.

Abstract: To produce frozen casting moulds or core boxes the binder is cooled till freezing at least partly before or during the moulding process. This allows the production rate to be increased to such a level that the working rate of automatic machines for the production of casting moulds and core boxes can be fully obtained.

Abstract: In a molding machine for producing foundry sand molds the sand is compressed or packed by means of a pressure wave acting on the sand surface produced by explosive combustion of a mixture of fuel and air. The dosing of the fuel to be burned is carried out by a pressure regulated supply pipe, in which a dosing container is filled with fuel, e.g., gas, up to an exactly defined excess pressure. This fuel or gas is thereafter fed to the combustion chamber under relief of the gas pressure in the dosing container down to a lower pressure level.

Abstract: A cavity in a body of particulate moulding material has at least one rib-like formation for gripping an object received in the cavity. In the case of a metal casting mould a riser sleeve (1) is inserted into a cavity (9) in the top part of the mould and the cavity (9) is produced by means of a tapered former (5) the exterior of which has a plurality of radially spaced apart recesses (6) extending between the top and towards the bottom of the former and which has a negative taper from bottom to top. The depth of the recesses (6) is such that circles geometrically inscribed inside the base of the recesses (6) have diameters smaller than the corresponding mean outside diameters less three times the standard deviation of the riser sleeves (1) to be used. The recesses (6) form ribs (11) from the moulding sand and the ribs (11) grip the outer surface of the sleeve (1).

Abstract: A process for compacting moulding sand to form a casting mould comprises the steps of filling a moulding space located between a pattern plate and a pressure plate with moulding sand, pre-compacting the moulding sand, after the moulding space is filled with moulding sand and closed by the pressure plate, by an explosive-type shock pressure, and subsequently re-compacting the moulding sand by mechanically pressing the moulding sand between the pattern plate and the pressure plate.

Abstract: A binder and a hardener therefor for a foundry aggregate. The binder is a resin obtained by reacting phosphoric acid with a mineral silicate. The hardener is a linear alkali metal polyphosphate, ammonium polyphosphate, a source of polyvalent cations, potassium olivine phosphate and other metal silico-phosphates or aluminum dihydrogen phosphate or mixtures thereof. A process for manufacturing molds and cores from a mixture of said binder and hardener and foundry aggregate.

Abstract: A hydrogel binder for a foundry aggregate comprising, in combination, a metal silico-phosphate and as a hardener therefor a mixture of aluminum dihydrogen phosphate, water and phosphoric acid and a process for manufacturing molds and cores from same.

Abstract: A mold filling and compacting method includes forming a compact body of mold substance such as sand in an intermediate container and then abruptly opening the bottom closure of the container while releasing the sand, as a compact mass, so that it drops as a packet into the mold box, compacting itself effectively around a pattern arrangement. Specific techniques for releasing, including sudden lifting, sudden dropping and separating the container parts are disclosed as well as apparatus for performing the method.

Abstract: For packing granular materials, especially foundry moulding materials, by means of an exothermic reaction of a mixture of air and fuel in a combustion chamber (23), a relative movement between the combustible mixture and one or several pulse triggers (19), is produced during the exothermic reaction, preferably by a blower (20) disposed in the combustion chamber (23). Hence the measured amount of sand introduced into a moulding frame (11) and a filling frame (12) over a pattern (6) by means of a sand container (17) is packed to form a mould body.

Abstract: The specification discloses a strike off apparatus for leveling and compacting mounds of sand extending above the upper edges of open-top mold boxes of varying heights carried in succession along a pathway. A pair of pivotally supported rollers extend across the pathway. A sensor determines the height of a sand mound in a mold box before it reaches the rollers. An elevating mechanism responsive to the sensor adjusts the rollers to a height so that they level and compact the sand mound as the mold box is carried thereunder. A control system including electrical and hydraulic circuits is provided for automatically controlling the cyclical operation of the apparatus.

Abstract: An automatic method for producing molds using chemically bonded sands which consists of a molding machine adapted to produce either honeycomb (horizontally parted) or controlled contour (vertically parted) mold elements. The molding machine is provided with a venturi-type blow head having dual blow valves and an integral air chamber. Carriage means are provided to selectively move a sand magazine and catalyst manifold between their respective fill and work stations on the molding machine. A hydraulically actuated mold receiver, trunnion rollover and shuttle car means are provided to selectively receive the completed molds from the molding machine and transport them to associated mold finishing and closing means. A hydraulically actuated pattern clamp table is provided with an enclosed pattern and stripper pin stool having a separate hydraulically actuated stripper pin plate. The enclosed pattern and stripper pin stool is an integral catalyst exhaust manifold.

Abstract: A method of producing a mould of particulate material comprises admixing the particulate material with a controlled quantity of water, compacting the mixture to the required shape on a pattern or the like, removing the compacted mass from the pattern, and directing at at least the surface of the compacted mould to be contacted by molten metal a stream of coolant, whereby at least that surface is frozen to a depth sufficient to withstand the conditions imposed during the pouring of molten metal into the mould.

Abstract: A casting method and apparatus according to which a molten material is poured into a space occupied by a foam-plastic pattern which is at least partially embedded in a granular material. The foam-plastic pattern when contacted by the molten material decomposes and disappears, while a gas is generated from the contact between the molten material and the foam-plastic pattern. From this generated gas, by way of a suitable structure situated in a mold together with the pattern and granular material, an elevated pressure is created, and the molten material fills the space initially occupied by the foam-plastic pattern in the presence of this elevated pressure which is greater than atmospheric pressure.

Abstract: Tubular metal articles are produced by centrifugal casting in a rotary metal mold lined by centrifugally distributing a quantity of a dry finely particulate free flowing refractory material on the active mold surface with the quantity being in excess of that required for the lining, densifying the layer by rotating the mold at a rate such that the refractory layer is subjected to centrifugal force adequate to establish an equivalent specific gravity of at least 7.5, determined by multiplying the actual specific gravity of the refractory material by the number of gravities of centrifugal force, contouring the densified layer and removing the excess refractory material, rotating the mold at the casting rate and then introducing the molten metal for casting while continuing to rotate the mold at least that rate. Articles so cast have relatively smooth outer surfaces which require only finish machining.

Abstract: A self-hardening moulding mixture for making foundry moulds or cores, comprising moulding sand, orthophosphoric acid, a ferrous oxide-containing material, a water-soluble salt of an alkali metal or ammonium, and a carboxylic acid having one dissociation constant not exceeding 10.sup.-4 or a water-soluble salt of an alkali metal or ammonium, and an isopolyacid formed by a chromium subgroup metal, manganese oxide or urea.The self-hardening moulding mixture can also comprise a surface-active substance acting as a foaming agent in order to render the mixture to a fluid state and to avoid compacting when producing moulds and cores therefrom.The moulding mixture features an enhanced bench life (10-15 min) and ensures a sufficiently high hardening and strength rates (compression strength is equal to 10-25 kg/cm.sup.2) for the foundry moulds and cores produced therefrom.

Abstract: A mold forming machine for the production of casting molds wherein molding sand is compressed within mold flasks is provided with stabilizing means for counteracting the effects of the compressive forces generated within the mold flask during compression of the molding sand tending to cause distortion of the flask. The stabilizing means include a movable frame which is adapted to extend about a molding flask placed in the machine with the frame being positioned relative to the flask by lifting gears which move the frame in accordance with the various stages of operation of the machine. A plurality of fluid pressure actuated tensioning elements are mounted on the frame to be movable therewith. The tensioning elements are adapted to apply compressive forces inwardly of the mold flasks during application of the molding sand compressing forces.

Abstract: In preparation of a mold for metal casting, a thermosetting resin layer, preferably of a thickness in a range from 2 to 100 micrometers, is formed between the refractory filler in the molding box and a covering laminate such as a thermoplastic synthetic resin film for tightly covering the filler surface so that the thermosetting resin layer develops, during metal casting, a shell layer for reinforcing the cavity wall of the mold due to heat given by molten metal. Development of casting defects such as sand marks and blow holes and occurrence of mold crumbling can effectively be prevented by the presence of the shell layer.

Abstract: In a method for casting metal alloys, a molten metal alloy is introduced into a mold of a desired configuration containing a core material fabricated to a desired shape from titanium nitride while maintaining the mold under a vacuum. After allowing the mold to cool slowly to room temperature, the casted metal alloy with the core material exposed at one end is removed from the mold and immersed in a boiling caustic solution, thereby causing the titanium nitride core material to decompose. The casting so obtained has a smooth inner surface, an indication that no chemical reactions have occurred between the alloy and the core material.

Abstract: Foundry moulds and cores hardening at a room temperature which feature high strength can be produced from a moulding mixture comprising moulding sand, an organic binder capable of interacting with a hardening agent and causing the mixture to harden, the hardening agent being particulate material containing predominantly CaO and Cl.sub.2 O.sub.3 in a relative molar proportion of from 1.6:1 to 4:1 and from 40 to 98% by weight of the tricalcium aluminate.As to the organic binder, use may be made of lignosulfonate of an alkali, or an alkali-earth metal, or ammonium or mixtures thereof, a soluble resin produced by pyrolysis of wood pulp and processed with lime, and dextrin.The foundry moulds and cores can also be produced by pouring a fluid mixture comprising a foaming agent which is additionally introduced into it to render the mixture into the fluid state.

Abstract: In a method of forming foundry sand moulds employing a cold-setting sand mixture pressed around a pattern by the use of pneumatic pressure acting on a flexible diaphragm, the sand is formed into a horizontal layer of approximately uniform thickness in a frame of which the bottom wall is formed by the diaphragm, the pattern is then pressed into that layer of sand, causing the diaphragm to bulge downwards, then the gas pressure (conveniently air pressure) is applied to compact the sand, which thereupon sets to allow separation of the resultant mould body from the diaphragm and pattern. During the initial formation of the layer the diaphragm can be supported by a further, stronger diaphragm, which is perforated to allow the gas pressure through, or by a rigid pad, or both.

Abstract: In a system for the production of molds for casting, a pair of pattern plates are disposed in an opposed facing relationship with a frame located therebetween in a manner whereby the opposing pattern surfaces of the plates, together with the frame, define an enclosed cavity within which a casting mold section may be formed. The frame is preferably provided with an opening through which the cavity may be filled with molding material which, after hardening, forms a mold section. After separation of the pattern plates and frame, the mold section is conveyed into assembled relationship with one or more other mold sections in order to form a mold for casting. Pattern plates and frames may be arranged in a mass production facility to continuously form mold sections which, when assembled, will provide a mold stack for producing multiple castings.

Abstract: In an automatic mold part producing apparatus having a mold chamber which is filled with mold forming material that subsequently is compressed between a pair of opposite end walls, the mold forming material is forced into said mold chamber by means of pressurized air, the pressure of which is gradually or stepwise increased during the chamber filling operation, for the purpose of achieving uniform compactness or density of the mold forming material throughout the height of the mold chamber.

Abstract: A method of manufacturing a cast ferrous metal die wherein an initial die of non-ferrous metal is cast in a mould against a basic metal pattern having a melting point substantially not less than that of the non-ferrous casting metal, the basic metal pattern being preheated and coated with refractory material and the non-ferrous casting metal is cast against the preheated and coated basic pattern in a supercooled condition to minimise thermal shock and heat transference between the casting metal and basic pattern, and forming a further corresponding pattern of refractory material in the initial die, and then using the pattern of refractory material in a mould for casting a cast ferrous metal die from said refractory pattern, the cast ferrous metal die so obtained being of corresponding accuracy to the basic metal pattern.

Abstract: Moulding flask adapted to be used in a process for forming a mould comprising steps of disposing, at the opening of the moulding flask, a pattern having a shield membrane of synthetic resin on the outer surface thereof, filling the space defined between the moulding flask and the pattern with particulate filler material such as sand, and applying negative pressure to the filler material so that the filler material is subjected to an external pressure to make a mould, said moulding flask having at least one surface on an intermediate partition surface formed by an impervious resilient membrane which is supported by a support member whereby, when the filler material is subjected to the negative pressure, the external pressure is applied to the resilient membrance which then presses the filler material so as to enhance compacting of the mould thus producing a strong and precise casting mould.

Abstract: Tubular metal articles are produced by centrifugal casting in a rotary metal mold lined by centrifugally distributing a quantity of a dry finely particulate free flowing refractory material on the active mold surface with the quantity being in excess of that required for the lining, densifying the layer by rotating the mold at a rate such that the refractory layer is subjected to centrifugal force adequate to establish an equivalent specific gravity of at least 7.5, determined by multiplying the actual specific gravity of the refractory material by the number of gravities of centrifugal force, contouring the densified layer and removing the excess refractory material, rotating the mold at the casting rate and then introducing the molten metal for casting while continuing to rotate the mold at least that rate. Articles so cast have relatively smooth outer surfaces which require only finish machining.