Abstract: Method and investment shell mold for casting comprising introducing molten metallic material into an investment shell mold to fill a mold cavity and provide an upper surface of the molten metallic material above the mold cavity. An initially closed, destructible region of the mold then is broken to provide an entry opening through which exothermic material is placed on the upper surface of the molten metallic material to provide a source of molten metallic material to accommodate shrinkage of a casting as it solidifies in the mold cavity.

Abstract: A riser sleeve apparatus (10) for preparing and insulating a passage (14) within which molten metal is accumulated prior to its movement into a mold cavity which includes an inner surface (12) which longitudinally extends between a first end (16) and a second end (18) wherein the inner surface bounds the passage. The riser sleeve further includes an annular lip (20) which is positioned adjacent the second end and extends inward into the passage. When the riser sleeve is positioned about a plug of a pattern, the annular lip deforms to seal the passage at the second end. A process for forming a cast metal article using said riser sleeve apparatus. A process for forming the riser sleeve apparatus.

Abstract: A foundry exothermic assembly is formed by mixing hollow glass microspheres and an inorganic or organic binder with matrix forming constituents including an oxidizable metal, an oxidizing agent, a foundry refractory aggregate and, optionally, a pro-oxidant, and shaping and curing the mixture. The hollow glass microspheres are dispersed and embedded in the assembly matrix.

Abstract: The invention relates to exothermic sleeve compositions comprising (a) an oxidizable metal where the oxidizable metal comprises aluminum dross, and (b) an oxidizing agent capable of generating an exothermic reaction. The invention also relates to sleeve mixes prepared with the sleeve compositions, the use of the sleeve composition to prepare sleeves, the sleeves prepared with the sleeve compositions and the use of the sleeves to prepare metal castings.

Abstract: A riser sleeve apparatus (10) for preparing and insulating a passage (14) within which molten metal is accumulated prior to its movement into a mold cavity which includes an inner surface (12) which longitudinally extends between a first end (16) and a second end (18) wherein the inner surface bounds the passage. The riser sleeve further includes an annular lip (20) which is positioned adjacent the second end and extends inward into the passage. When the riser sleeve is positioned about a plug of a pattern, the annular lip deforms to seal the passage at the second end.

Abstract: A process of positioning a riser sleeve about a plug of a mold cavity pattern. The riser sleeve is positioned to engage the plug to prevent sand from entering the interstitial space between the riser sleeve and the plug. The riser sleeve may comprise a deformable annular lip for engagement with the perimeter of the plug. The riser sleeve may engage the plug in sealing relationship.

Abstract: A riser sleeve has a sleeve body and an evaporative pattern fit into the sleeve body to pass through a side wall thereof. The evaporative pattern is shaped to enable the casting, integrally with the riser cast by the sleeve body, of a projecting portion capable of receiving a wedge blade of an openable wedge blade type riser breaker. Even a top riser can therefore be broken off of the main casting at a neck portion by an opening force applied to the wedge blades of the riser breaker without the use of a special jig.

Abstract: The method of casting of the present invention is capable of making volume of a feeder head can be small and making cooling rate of the feeder head can be easily made lower than that of a cavity. The method is executed in a casting machine, which includes a casting die, in which the feeder head is provided between a metal inlet and the cavity and in which heat insulating of the feeder head is greater than that of the cavity so as to make cooling rate of the feeder head lower than that of the cavity. The method comprises the steps of: pouring a molten metal into the cavity; reacting the molten metal on a deoxidizing compound in the cavity so as to deoxidize an oxide film formed on a surface of the molten metal; and supplementing the molten metal in the feeder head to the cavity when the molten metal in the cavity is solidified and shrinked.

Abstract: A filter unit for use in metal casting including a filter adapter, a filter adapter per se, and a mold for use in metal casting utilizing the filter unit, as well as a method of producing a metal casting, facilitate or practice direct pouring in a manner which provides for greater flexibility, being applicable to a wider range of castings. The apparatus elements and method are particularly suitable for the manufacturing of castings of relatively high modulus and low pour weight, and for the manufacture of high volume castings of low modulus. The mold includes a mold cavity and a sprue, a filter unit located in the sprue, and the filter unit comprising an adapter of refractory material having one or more ledges o10 for mounting a filter, and a filter (e.g. ceramic foam filter) supported by one of the ledges.

Abstract: This invention relates to exothermic and insulating sleeve mixes comprising (1) a sleeve composition comprising stabilized hollow aluminosilicate microspheres, and (2) a chemically reactive binder. Sleeves are formed from the sleeve mix and are cured in the presence of a catalyst by the cold-box or no-bake curing process. The invention also relates to a process for casting metal parts using a casting assembly where the sleeves are a component of the casting assembly. Additionally, the invention relates to the metal parts produced by the casting process.

Abstract: Apparatus and methods of die casting which reduce waste, by providing heated channels to feed solidification shrinkage. The channels are heated to a temperature which prevents solidification in the channels, thus allowing the channels to be substantially smaller than conventional risers. An insulating layer in the mold prevents excessive heat loss from the channels to the mold cavity area.

Abstract: Flask-bound molds include two molding-flask halves, which have means (15) for the transport thereof on automatic mold systems. The molding flask receives a bound sand mold (8), which has cores (13), a pouring funnel (6) and a feeder passage (9). In order to be able to cast complicated castings also out of aluminum in such molds and to avoid the expensive finish work for the feeder and pouring funnel and in order to guarantee at the same time good core ventilation, the molding flask (4) has in the area of its parting plane a recess extending over at least a portion of the length and width of one side of the molding flask, whereby the pouring funnel (6) and the feeder (9) end in the area of the recess and the feeder is constructed within the sand mold (8) of the mold (1).

Abstract: A riser sleeve apparatus (10) for preparing and insulating a passage (14) within which molten metal is accumulated prior to its movement into a mold cavity which includes an inner surface (12) which longitudinally extends between a first end (16) and a second end (18) wherein the inner surface bounds the passage. The riser sleeve further includes an annular lip (20) which is positioned adjacent the second end and extends inward into the passage. When the riser sleeve is positioned about a plug of a pattern, the annular lip deforms to seal the passage at the second end. A process for forming a cast metal article using the riser sleeve apparatus. A process for forming the riser sleeve apparatus using a vacuum forming technique.

Abstract: A method and machine for forming an open riser in a mold includes a resiliently compressible plug received into the upper end of a riser sleeve, which projects above the riser sleeve and cope sand level so as to be advanced into the riser sleeve during squeezing of the mold sand. The plug is fixed to the upper squeeze plate to be withdrawn from the riser sleeve as the squeeze plates are separated, creating an open riser.

Abstract: Insulating sleeve mixes that contain hollow aluminosilicate microspheres, an organic binder, and boric acid and/or a phosphate, and their uses.

Abstract: A method for producing light metal castings, in particular cylinder heads, cylinder blocks and/or crankcases for internal combustion engines, includes a sand mold which forms a mold cavity for the casting. The sand mold includes outer mold parts, at least one core and at least one feeder for forming a riser, wherein the mold is provided with an in-gate for receiving the metal melt and the metal melt is filled into the mold cavity under the effect of gravity. A cover core (5) is fitted onto the mold that is at least in partial regions designed to be impermeable to gas and which contains at least one feeder, and wherein immediately after the filling operation, the feeder filled with metal melt is admitted with a pressure via a pressurized gas.

Abstract: This invention relates to riser sleeves which contain markings and concentric grooves. The markings are used to as a guide so one can customize the size of the sleeves and the concentric grooves are used to help hold the sleeve in place when it is placed in the mold where it surrounds the riser. The invention also relates to the use of the riser sleeves in the making of metal castings.

Abstract: A mold for metal casting contains a bonded refractory composition comprising hollow alumina-containing microspheres in which the alumina content is at least 40% by weight. The mold may be an ingot mold and the bonded refractory composition may be in the form of a sleeve or boards located in the top of the mold or in the head box thereto. The mold may be a sand mold and the bonded refractory composition may be in the form of a sleeve or boards located in a feeder cavity or in the form of a board or pad located so as to constitute a metal casting surface where it is desired to promote directional solidification in cast metal. The bonded refractory composition may also be in the form of a breaker core. In a preferred composition the microspheres contain alumina and silica and the composition may also contain one or more other particulate refractory materials, a readily oxidizable metal, an oxidizing metal, an oxidizing agent for the metal and a fluoride salt.

Abstract: A method of forming an open riser in a mold includes telescoping a heat consumable tapered plug into the upper end of a riser sleeve, which projects above the riser sleeve and cope sand level so as to be advanced into the riser sleeve during squeezing of the mold sand. The plug is vaporized or consumed by hot metal during casting, creating an open riser.

Abstract: The sprue/riser sleeve 40 has a tubular, preferably cylindrical wall 42 extending between an inlet end 48 and an outlet end 50. The sleeve 40 has a woven mesh filter extending across a central passageway 51 with a periphery 54 of the filter 52 embedded into the wall 42. The periphery 54 has three or more, evenly spaced tabs 56 formed thereon that project further into or through the wall to secure the filter to the wall without materially weakening the wall. Preferably, the filter has a square-shaped periphery 54 with corners 64 that define the tabs 56. The main portion of the periphery extends into the wall less that one-half the thickness of the wall, whereas the tabs extend into the wall a distance greater than one-half the thickness.

Abstract: A riser sleeve with a breaker core comprises a sectionally V-shaped riser sleeve having a bottom opening and a breaker core having a central opening and attached to the bottom of the riser sleeve. The inner diameter D.sub.3 of the central opening of the neck-down core is substantially the same as the inner diameter D.sub.2 of the bottom opening of the riser sleeve, and the outer diameter D.sub.5 of breaker core is substantially the same as or larger than the outer diameter D.sub.4 of the bottom of the riser sleeve. The riser sleeve with breaker core greatly reduces the amount of finishing that the cast product requires after casting.

Abstract: A mould for metal casting which is vertically parted into two parts, comprises one or more mould cavities and a plurality of feeder cavities each communicating with a mould cavity, and has a feeder unit comprising a plurality of interconnected feeder sleeves therein, each of the feeder sleeves surrounding one of the feeder cavities. The mould may be a vertically parted permanent mould or die, or particularly a vertically parted sand mould.

Abstract: Apparatus and method for countergravity casting a melt employs a particulate mass disposed in a container about a mold having a mold cavity, an ingate passage communicated to the mold cavity for supplying the melt to the mold cavity, and a separate, preformed riser-forming member connected to the mold so as to communicate to an isolated and/or enlarged region of the mold cavity needing additional melt supply during solidification in the mold. The mold ingate passage and a source of the melt are communicated to conduct the melt through the ingate passage to the mold cavity to fill the mold cavity with the melt and form a riser of melt in the particulate mass. The riser of melt provides a source of additional melt for supply, as necessary, to the isolated and/or enlarged region during solidification of the melt in the mold cavity to accommodate melt shrinkage thereat.

Abstract: A paper sleeve and system for application as an insulated riser in a sand mold used to cast metal articles is disclosed. The sleeve, preferably cylindrical, is formed from a plurality of sheets of paper wrapped around one another with, preferably, a space between the edges of each sheet to provide a plurality of spaces or openings extending through the sleeve. Each sheet is treated with a precise amount of fire retardant. The sleeve for a given time period acts as an insulator keeping metal therein liquid until the metal solidifies in the article forming cavity of the sand mold and thereafter decomposes or reduces itself to a harmless carbon ash. The sleeve can function to both feed liquid metal to the article forming cavity in a sand mold and also to supply additional liquid metal to the article cavity upon solidification of the metal therein to eliminate the need for separate risers as now required in conventional foundry practice.

Abstract: A long thin metal article having a thick portion is cast with a stress free interconnection between the thick and thin portions of the article. A heat transfer wall is provided around at least a portion of a mold in which the article is cast. To preheat the mold, heat is radiated from an inner side surface of a furnace wall to an outer side surface of the heat transfer wall. Heat is radiated from an inner side surface of the wall to the mold. Molten metal is conducted into the long thin portion of the article mold at a location other than along the length of the long thin portion of the article mold. During solidification of the molten metal, heat is radiated from the thick portion of the article mold to the inner side surface of the heat transfer wall. As the mold structure is withdrawn from the furnace chamber during solidification of the molten metal in the article mold cavity, heat is radiated from the outer side surface of the heat transfer wall to locations outside of the furnace.

Abstract: A paper sleeve and system for application as an insulated riser in a sand mold used to cast metal articles is disclosed. The sleeve, preferably cylindrical, is formed from a plurality of sheets of paper wrapped around one another with, preferably, a space between the edges of each sheet to provide a plurality of spaces or openings extending through the sleeve. Each sheet is treated with a precise amount of fire retardant. The sleeve for a given time period acts as an insulator keeping metal therein liquid until the metal solidifies in the article forming cavity of the sand mold and thereafter decomposes or reduces itself to a harmless carbon ash. The sleeve can function to both feed liquid metal to the article forming cavity in a sand mold and also to supply additional liquid metal to the article cavity upon solidification of the metal therein to eliminate the need for separate risers as now required in conventional foundry practice.

Abstract: A gravity poured foundry mold having a gating system and at least one complete mold casting cavity, the gating system allowing castings to be made in more compact molds, using less metal at lower temperature, obtaining less solidification strained castings, and requiring less fettling work and less pattern work. The gating system combines the use of a strainer such as a skin-strainer with any of several fluid restraining devices including but not limited to skin-strainer covers, restraining floating pieces, non-floating restraining pieces and blind floating pieces. Also disclosed are applications in which a skin-strainer is omitted. There is disclosed apparatus which may be standardized, thereby greatly increasing the ease, accuracy and confidence with which the gating system may be used in foundries which would have available to them sets of different sizes of standardized, interchangeable and prefabricated elements as disclosed herein.

Abstract: A riser for a mold includes a riser body formed of an exothermic material. A cavity is located in the riser body and is adapted to contain an associated molten metal. An opening is provided in the riser body for communicating the riser body cavity with a cavity of an associated mold. The riser body exothermic material consists essentially of a reactive mixture which includes, in weight percent, from about 25% to 65% silica, from about 5% to 18% sodium nitrate, from about 1% to 8% sodium hexafluorosilicate, from about 15% to 40% aluminum, and from about 2% to 20% iron oxide.

Abstract: A feeder sleeve (1') for use in the casting of molten metal has a cavity (8) whose cross-sectional area at the bottom of the cavity (8) is greater than the cross-sectional area at the top of the cavity (8) such that a line joining a point (11.1) on the inner surface (11) of the sleeve at the bottom of the cavity (8) and the nearest point (11.2) on the inner surface (11) of the sleeve at the top of the cavity (8) is less than 80.degree. to the horizontal. The inner surface of the sleeve may taper from the bottom of the cavity to the top of the cavity uniformly or in at least one step (12).

Abstract: A gravity poured foundry mold having a gating system and at least one complete mold casting cavity, the gating system allowing castings to be made in more compact molds, using less metal at lower temperature, obtaining less solidification strained castings, and requiring less fettling work and less pattern work. The gating system combines the use of a strainer such as a skin-strainer with any of several fluid restraining devices including but not limited to skin-strainer covers, restraining floating pieces, non-floating restraining pieces and blind floating pieces. Also disclosed are applications in which a skin-strainer is omitted. There is disclosed apparatus which may be standardized, thereby greatly increasing the ease, accuracy and confidence with which the gating system may be used in foundries which would have available to them sets of different sizes of standardized, interchangeable and prefabricated elements as disclosed herein.

Abstract: A breaker pad which is formed with a star-shaped orifice, with inwardly extending formations, which, when viewed from the side, are tapered, reducing in dimension towards the center of the orifice.

Abstract: Molten metal is cast in a mould having a feeder cavity, which may be defined by a feeder sleeve, whose surface has a plurality of elongate projections or ribs spaced apart around its perimeter, the number and dimensions of the ribs being such that the volume of the feeder cavity is reduced by at least 20% compared to a feeder cavity of generally the same size and shape but without the ribs. Preferably the ribs extend substantially the full length of the inner surface of the feeder sleeve. The sleeve may have for example four ribs whose shape and size is such that the horizontal cross-section of the feeder cavity defined by the sleeve is cruciform. The ribs may be formed of material having an exothermic, an exothermic and heat-insulating, or a heat-insulating composition. The ribs enable a given casting to be fed from a smaller quantity of feeder metal than is usual.

Abstract: In casting metals for dental prosthetic use, superior dental castings free from shrinkage cavities can be obtained by delaying the cooling and solidification of molten metal in mold members such as a sprue, runner and gate and, if necessary, a molten metal reservoir into which the molten metal is poured. Such delay in cooling and solidification can be achieved either by forming the sprue and the like from a heat resisting ceramic tubular body or by further forming a heat insulating layer on the outer periphery of the tubular body.

Abstract: A riser sleeve has at its end which is uppermost when the sleeve is located in the mould a holding member which can be engaged by a mechanical holding device so as to adapt the sleeve to automatic handling. The holding member may be for example a disc, ring or solid or hollow cylinder and may be formed integrally with the sleeve or formed separately and fixed to the sleeve. By adopting a standard shape and size for the holding member for a wide range of sleeve shapes and sizes the same holding device can be used to handle the whole range of sleeves.

Abstract: A blind feeder sleeve for use in the casting of metals comprises a sleeve body and a cover having a Williams core, and optionally an opening for ventilation, the Williams core being formed integrally with the feeder sleeve and comprising a rib extending across the inner surface of the cover and projecting downwardly from that surface in a wedge like shape. Preferably the rib is formed integrally with the inner surface of the cover at each end of the rib, and when the feeder sleeve is circular in cross-section the rib preferably extends across a diameter of the sleeve.

Abstract: A no-fume riser neck for use in molding the connecting neck between the riser cavity and general mold cavity in the production of metal castings. The neck is generally cup-shaped and preformed of sheet metal with a closed and substantially sealed upper end and an open flared and grooved lower end which is positioned open-end down on the face of a foundry pattern so that the sealed upper end is gas tight and separates the open riser cavity from the mold cavity and prevents extraneous material from entering and contaminating the mold cavity, and also prevents the unrestricted escape of objectionable gases and fumes from the mold cavity to the environment during the pouring cycle.

Abstract: An improved casting riser is provided of two different materials, an upper portion having a low thermal conductivity for retaining the heat of the metal in the riser liner and a lower portion having a high thermal conductivity to allow transfer of heat between the molten metal in the riser liner and the molten metal in the mold.

Abstract: A breaker core for use in metal casting is described. The core is located in a casting mould between a riser and the cavity corresponding to the casting. The core consists of a base having an aperture (which defines a neck between the casting and the solidified metal in the riser) and means for frictional engagement with a casting riser lining sleeve or with a casting riser cavity. The base may have a recess which receives a projection extending from the sleeve or an upstanding lip at or somewhat spaced from the edge of the base for engagement with an inner or an outer wall of the riser sleeve.

Abstract: A feeding unit comprising a breaker core and a riser sleeve. In a first embodiment the breaker core has a thickness of 10% of the diameter of the riser sleeve and the opening in the breaker core is from 20% to 35% of the riser sleeve diameter.In another embodiment of the invention the breaker core opening is tapered inwardly and downwardly in a generally v-cross sectional shape and one embodiment of the invention will have a symmetrical v-cross sectional area.

Abstract: An improved method of forming a shell mold for casting having a shrink bob is provided. A tubular frusto-conical shrink bob, or riser, is first formed from sand and a plastic or resin binder such that both the apex and base of the riser are open. The riser is then inverted and positioned on a casting pattern with the apex of the riser abutting against the casting pattern. The entire pattern is then cast with a thermosetting material, such as sand and a binder, such that the thermosetting material bonds to both the pattern and the riser. After hardening, the thermosetting material with the attached riser forms a shell mold which is subsequently utilized in a foundry casting operation.