Abstract: A rotary drill bit for drilling wells in earth formations is produced by a casting technique using a plastic foam, combustible casting form. The bit includes a tapered drill body having a plurality of passageways therein which form jets for introducing liquid between the earth and a plurality of selectively arranged, cutting members extending outwardly from the drill body. The combustible form is molded in a shape substantially identical to that of the drill body. The cutting members are mounted on the form in the selective arrangement thereof, and the assembly of the form and cutting members are then coated with a mold material to form a mold body. A cavity is created in the form for receiving a molding mandrel which defines the longitudinal passageway of the completed bit. Molding pins are introduced through the mold body into the mandrel to precisely hold the mandrel relative to the mold body. The cutting members are precisely held by the mold body after the form is removed by combustion.

Abstract: A blade or vane structure for a gas turbine engine comprises a hollow aerofoil member and a cooling air entry tube within the hollow aerofoil member, the aerofoil and the tube comprising a unitary cast structure. To make this structure it is proposed that a lost wax casting process should be utilized, with the internal cavities formed using ceramic cores formed with the aid of temporary, disposable pieces which define the space eventually occupied by the tube.

Abstract: A process for preparation of support tooling for extruding dies is described in which a substantial reduction in machining is experienced by utilizing a pattern destroying precision casting system in which the pattern is adjusted to shrinkage and provided with a die orifice opening staged up in size to suit the particular support role of the tooling as in a backer or bolster. This is significant because such support elements are regarded as one-of-a-kind structures. Finish machining and treatment requires minimal time and at substantial energy reduction. The pattern is prepared from a destructible or vaporizable plastic material replaced by the molten metal conforming to the mold configuration.

Abstract: Process for making a multiple unit fixed prosthesis. A conventionally prepared wax bridge is separated into a plurality of segments, a plurality of brace members are partially interconnected between the segments, and an anchoring member having the general configuration of the wax bridge is prepared for attachment to the segmented bridge by first securing a different support member to each pontic and coping of the bridge and by temporarily securing the anchoring member to a preselected one of the pontics or copings. All of the support members are then permanently secured to the anchoring member by an adhesive that does not introduce distortion into the bridge as it hardens.

Abstract: A method of casting a blade or vane for a gas turbine engine which enables the production of more complex internal shapes than those which may be made by prior art methods. The method of the invention includes the steps of:making a temporary filler piece from a disposable material,holding the filler piece in place in a die,injecting the core material into the die and causing it to solidify round the filler piece,removing the core from the die,causing the filler to be removed from the core to leave within the core a cavity having the shape of the filler, andusing the core thus produced in an investment casting process to form the blade or vane shape.

Abstract: A method of making a form of a desired shape, for use in an investment casting technique which comprises forming a first sheet of formable material to a shape which approximates to the desired shape of the form, disposing the formed shape around a layer of deformable hardenable material, applying a compressive force to the formed shape to deform the underlying hardenable material to a desired shape, hardening the hardenable material to produce a form precursor, removing the formed shape from the hardened form precursor and utilizing the hardened form precursor to form a second sheet of formable material into the form of the desired shape. The invention also includes a method of making crowns by an investment casting technique utilizing the form produced by this method.

Abstract: A metal casting system including novel process and apparatus wherein the shape of the casting is defined by a thin thermal degrading film supported by a particulate bed. A pattern having the shape of the desired casting is surrounded by the tight fitting film with one end of the pattern exposed. A particulate bed is tightly packed about the film-surrounded pattern. A reduced fluid pressure is established within the particulate bed relative to the pattern so that the surrounding film is tightly held by atmospheric pressure against the particulate bed and slightly released from the pattern. The pattern is removed from the surrounding film and leaves therein a cavity bounded by the film with the shape of the desired casting. The cavity is filled with molten metal for forming the desired casting simultaneously with the vaporization of the film. The present metal casting system is especially useful for the casting of cylindrical shapes using unique molds and a novel flask is provided for such a casting process.

Abstract: An improved method is utilized to make a mold for a cast product having a plurality of spaced apart surfaces. Although the method could be used for forming molds for different products, the method is advantageously used to form a mold for a cast product having a plurality of airfoils disposed in a circular array. To form the mold, a plurality of airfoil pattern segments are placed in a circular array with surfaces of the segments abutting at joints which are free of material interconnecting the segments. A coating of liquid ceramic mold material is applied over the airfoil pattern segments. Since the joints between the airfoil pattern segments are free of interconnecting material, the liquid ceramic mold material can flow into the joints. After the ceramic mold material has been dried and the airfoil pattern segments disposed of, the ceramic mold material which entered the joints between the airfoil pattern segments forms a plurality of relatively thin projections from the main wall of the mold.

Abstract: A method of and a device for the shipping of hot metal goods, such as hot steel ingots and slabs, in which the ingots or slabs are lowered into a container in which a granular insulating material, preferably porous vermiculite, is fluidized by a pressurized gas during the introduction of these metal goods. The particles of the insulating material, upon termination of the fluidization are then allowed to pack around and envelop the metal goods. The insulating material is again fluidized during withdrawal of the metal goods at the unloading site.

Abstract: A method of forming ceramic fiber and metal composite structures is disclosed. The method is particularly useful in forming such structures having a complex shape. Fibers are coated with an investment grade sticky wax as a fugitive organic binder. Aluminium oxide coated with a sticky wax binder have been found to have greater flexibility than the fibers alone or fibers coated with other binders. The coated fibers are then laid up into a preform of the desired shape. The preform is elevated to a moderate temperature prior to pressure compaction. The preform may be combined with other preforms to form a more complex shape. The preform is then installed in a casting mold and elevated to a temperature sufficient to remove the sticky wax binder. Molten metal is then introduced into the mold where it fills the voids created by the removal of the sticky wax. Subsequent to cooling, the fiber and metal composite material is removed from the casting mold.

Abstract: A method of manufacturing a casting mold includes the steps of forming a casting mold body of a flowable binder-free backfilling material, stabilizing the casting mold body by negative pressure, and providing in the body a lost form of synthetic plastic material, particularly foamed synthetic plastic material.

Abstract: Disclosed is a method and apparatus for fabricating thermoplastic patterns for investment casting. The patterns define hollow objects and have contained within a very precisely located ceramic core. Thermoplastic is injected into the pattern die on either side of the core, thereby avoiding distortion, movement or breakage of the core. Multiple sprues are used; the sprues are individually fed from a nozzle having a single central bore. The configuration of the nozzle tip and the cavity from which the sprues emanate is such that a gate or bridge is not formed at the entrance to the die assembly. Accordingly, removal of the pattern from the die may be effected by pulling the part coaxially with the sprues, thereby avoiding the necessity of splitting the die where the sprues are located.

Abstract: A method of producing a heat exchanger in which a fin block of porous metal and fin plates connected to the fin block are unitarily secured to a serpentine heat-transmitting pipe. A plurality of fin molds produced with the use of plastic patterns formed therein with continuous, three-dimensional cavities are assembled with the heat-transmitting pipe shaped beforehand into a serpentine form in such a manner that the fin molds enclose the heat-transmitting pipe with suitable spacing intervals defined between the fin molds themselves and between the fin molds and the heat-transmitting pipe. Molten metal of high thermal conductivity is cast into continuous cavities in the fin molds and into the spacing intervals, and the material of the fin molds is removed after the molten metal has solidified.

Abstract: A method for casting objects having complicated shapes from aluminum, zinc, non-ferrous metals and the like, for use in the industrial arts, comprises the steps of using a completely combustible and gasifiable foam material to constitute a form in which the objects are cast, removing a thin surface layer of the foam from those surface areas where a wall thereof could be damaged by flowing melted metal, where ornamental elements or profiles are to included in the objects prior to casting, or where the rate of flow of melted metal is to be decreased, substituting the removed foam layer by a protective layer of a material with a stronger structure, lower thermal conductivity, lower burning and gasifying rates than those of the material of the foam casting form, reconnecting the separated foam and protective layers by gluing, embedding the casting form into sand, pouring melted metal into a recess defined by the foam form while in the sand and delaying and regulating the burning of the foam during the pouring of

Abstract: A method of forming a mold for use in casting is disclosed. The method includes as a first step forming a positive pattern having a surface the shape of a part to be cast. Next a negative partial pattern is formed having a casting surface complimentary to a selected portion of the surface of the positive pattern and also having a reference surface in a fixed spatial relationship with the casting surface. The casting surface of the negative partial pattern is placed in complimentary engagement with the selected portion of the surface of the positive pattern to form a pattern assembly. A first mold section having a surface complimentary to the reference surface and to the surface of the part is formed by dipping the assembly formed in the preceding step in a ceramic material.

Abstract: The method of casting a representation of a photograph that includes forming an etched plate through a half-toned screen of the photograph, making a mold cavity of the plate, making a wax impression of the rubber mold with the wax impression not completely copying the rubber mold, forming a casting of the wax impression, coloring the surface of the casting and sanding and burnishing the surface to remove the coloring from the high areas to produce a cast surface having tonal and height contrasts.

Abstract: A method of manufacturing a mold adapted to be used for casting bodies of fiber-reinforced composites. A model of the body to be cast is prepared and coated with a one-piece dense shell of refractory metallic oxide deposited by plasma or flame spraying and the model is then separated from the shell by conventional physical or chemical treatment.

Abstract: A composite article and method of forming the same wherein an inner casting is separated from an outer casting by an insulative portion defining the pattern for the outer surface of the inner casting and the pattern for the inner surface of the outer casting. The insulative portion is captured between the castings to define a thermal barrier therebetween. The castings are formed by gasifying an expendable gasifiable pattern corresponding to the inner and outer castings, respectively. The patterns are assembled with the insulative portion of the article disposed therebetween and a mold is formed about the assembled patterns and insulative portion. Upon pouring of molten casting metal into the mold, the expendable patterns are gasified into the mold, permitting the inner and outer portions of the article to be cast about the insulative portion to form the desired final composite article.

Abstract: A casting process is disclosed including the steps of fabricating a multi-piece pattern from cellular plastic material, assembling the pieces to form a pattern, coating the pattern with a magnesium silicate ceramic coating and imbedding the pattern in dry, loose sand within a box or flask. The box includes a plurality of perforated side walls and a sprue is connected to the pattern.

Abstract: A three-dimensional network porous metallic structure is formed by filling the internal cavity of a mold, which has been prepared by making use of a three-dimensional network resin pattern, through driving the molten metal into the cavity by a pressure or through sucking the molten metal into the cavity by reducing the pressure in the cavity. The porous metallic structure thus obtained is characterized by a large specific surface area, as well as a reduced pressure drop of fluid passing through this structure, and, therefore, is fit for various uses such as the material of fins of heat exchangers, various filters and so forth.

Abstract: Castings are produced in a bed of production sand susceptible to both fluidizing and vacuumizing. The use of a vacuum at the time the molten metal is poured permits the use of thin shell molds made around styrene patterns, the vacuum maintaining mold shape and drawing out gases produced by the vaporizing pattern and otherwise. The produced casting is rapidly cooled in the bed while it is fluidized, the fluidized sand achieving good heat conduction. The casting is then heat stabilized while the bed is defluidized, the bed then becoming a good insulator. An austempering curve can be followed, thereby having the effect of heat treating in the same bed as used for casting production.

Abstract: An improved method incorporating investment burn out at a predetermined ideal temperature. The investment encasing the wax-like model of the desired casting is placed in an oven preheated to an ideal burn out temperature. The oven is maintained at that temperature while the pressure in the oven is increased to a predetermined pressure and maintained at that pressure for a given time. Following that time, the pressure is cycled between the predetermined pressure and atmospheric pressure or below for a second predetermined time.

Abstract: An internal combustion V-8 engine is disclosed having an aluminum semi-permanent mold head cast by a low-pressure die-cast process and an iron block cast by the evaporative casting method. The block and head have controlled thickness walls throughout to optimally lower the metal/working volume ratio of the engine. The block employs barrel cylinder walls cast integrally and unsupported except at the barrel ends and at a siamese connection between adjacent barrels; the barrels are maintained under a predetermined level of compression to eliminate fatigue failure and suppress sound. The block is sand cast and the head is totally formed with a three piece die and one sand core cluster, except for one passage which is drilled subsequent to casting. The engine is reduced in weight by at least 20% over conventional comparable engines; torque and horsepower is improved even though the cooling system capacity has been reduced to less than half that of a conventional cooling system.

Abstract: A method of making a composite consumable pattern for use in the cavityless type of metal casting is disclosed. At least two mateable pattern parts are formed entirely of a low density expanded closed-cell polymeric material which is ignitable upon contact with molten metal. The parts are brought together with predetermined mateable surfaces in contact under a pressure of 5-10 psi; one of the parts is vibrated with a frequency of 120-240 cycles per second and an amplitude of 0.03-0.10", to promote a controlled friction at the interface. A predetermined depth of the parts is melted and merged to create a water-tight bond between the mating surfaces upon relief of the vibration.

Abstract: A shell mold for producing directionally solidified single crystal metal castings in which use is made of a crystal selector of helical shape wound about a support of a non heat disposable material which eliminates the need for providing a crystal selector of sufficient dimension for self support or other supporting means which may form a part of the pattern assembly about which the shell mold is formed.

Abstract: The specification discloses a tooth-shaped member including a central insert which is removable from a facing in order to make the supporting framework for a dental bridge. An appropriate size and shape of a tooth-shaped member is selected and aligned in a gap between built up wax crowns of abutment teeth. The insert extends across the facing and is adhesively bonded at the ends thereof to the adjacent wax crowns. The facing is then removed from the insert. The wax crowns are cut down to the desired shape and the insert and crowns are removed as a single unit. The unit is then cast to form a bridge framework which is coated with porcelain to form artificial teeth.

Abstract: Method and apparatus for preparing a wax replica of a dental prosthesis is disclosed. The method of the invention is carried out by preparing a composite dental model which includes a base portion, an odontal die projecting from the base portion having a cavity in which the dental prosthesis is to be implanted, and an index pin embedded within the composite dental model. A complementary dental model having an odontal projection defining an occlusal surface for engaging the odontal die is also prepared. The index pin includes an anchor shank portion embedded within the odontal die, an alignment shank portion embedded in the base portion and a radially projecting collar portion disposed in the interface of the base portion and the odontal die. The odontal die and embedded index pin are removed from the base portion of the composite dental model and a die spacer is placed around the alignment shank portion of the index pin.

Abstract: A preform mold space is formed by two mold sections spaced from each other. A gem is positioned in the mold space, and a hardenable preform wax-like material is introduced into the mold space and into supporting contact with the gem to thereby form a preform model upon hardening of the wax-like material. The preform model is removed from the mold space and embedded in hardenable embedding material so as to form a mold cavity about the exterior of the preform model upon hardening of the embedding material. Simultaneously with the hardening process the wax-like material is melted and removed from the mold cavity while the gem remains embedded in the mold. A heated molten hardenable metal material is then introduced into the mold cavity. The hardened metal material supportingly engages different facets of the gem and fixedly anchors the latter in the article of jewelry formed by the disclosed method.

Abstract: A method of manufacturing a mold adapted to be used for casting bodies of ber-reinforced composites. A model of the body to be cast is prepared and coated with a one piece dense shell of refractory metallic oxide deposited by plasma or flame spraying and the model is then separated from the shell by conventional physical or chemical treatment.

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: Disclosed is an improved method for making molds and mold components for use in casting single crystal articles. According to the improved method, a preformed and reusable replica of a mold growth cavity and crystal selector passage is provided, the replica including a cylinder in the form of the desired growth cavity and a helical strand in the form of the desired crystal selector passage, one end of the strand being attached to an end of the cylinder such that their axes are coincident. In one embodiment, the replica is coated with a thin layer of wax or other removable material and then utilized in a variety of mold making processes, including investment molding, to form a growth zone and helical crystal selector in the mold.

Abstract: A core assembly is formed by fabricating a first core, molding a destructible plastic layer around the first core, and molding a second core around the plastic layer. The plastic layer is interlocked wth an irregular outer surface of the first core, and the second core is interlocked with an irregular outer surface of the plastic layer. The core assembly can be used for casting engine cylinder heads to eliminate the need for gluing cores together and the accompanying formation of fins within fluid conducting passages.

Abstract: A porous high-silica core is disclosed for use in directional solidification casting processes having exceptional thermal stability at temperatures above 1650.degree. C. and containing mineralizers which promote the formation of cristobalite. The cores may be made by mixing at least 75 parts of essentially pure fused silica particles with 1 to 25 parts of activating particles containing a mineralizer, such as an alkali metal or alkaline earth metal compound, may be fired at a temperature of 1000.degree. to 1300.degree. C. until they contain 35 percent or more of cristobalite and may then be cooled to room temperature. They may thereafter be incorporated in a shell mold in accordance with the "lost-wax" process and preheated with the shell mold at a temperature of 1300.degree. to 1600.degree. C. to provide a cristobalite content of 60 to 85 percent or more within a short period of time, such as 10 to 30 minutes, and before a molten superalloy is allowed to flow into the mold.

Abstract: A casting mold filled with free-flowing particulate matter such as sand, in which there is imbedded a vaporizable insert or pattern of wax, foam polymer or the like conforming to the shape of the desired casting, has at least two of its walls formed by flexible membranes exposed to the atmosphere for creating a more or less isobaric pressure upon the application of suction to its interior. One membrane may span the open top of a four-sided rigid shell whose perforated bottom is overlain by another such membrane; alternatively, with the sidewalls of the shell also perforated and/or vertically ribbed or fluted, five membranes may be combined into an open-topped bag lining the interior of the shell, the top of the bag being closed by a sixth membrane after introduction of the sand filling and its pattern insert.

Abstract: A synthetic sprue forming assembly comprises a base or preform adapted for engagement with a crucible former, a plurality of sprue formers, and one or more conduit forming shafts extending between the base and sprue formers. Each sprue former consists of a first portion connected to a shaft, a gate portion, and an enlarged reservoir portion therebetween. In one embodiment, there are a pluality of integral sprue pins seated in recesses in the base and each comprising a shaft portion and a sprue former portion extending at an angle to the longitudinal axis of the shaft. In another embodiment, there is one large shaft integral with the base, and the reservoir and gate portions are integrally formed and rotatably and detachably mounted to a conduit portion on the large shaft. In the method of making an investment mold, the base and sprue formers are assembled on a crucible former in an investment mold container.

Abstract: A casting mold filled with free-flowing particulate matter such as sand, in which there is imbedded a vaporizable pattern of foam plastic conforming to the shape of the desired casting, has at least two of its walls formed by flexible membranes exposed to the atmosphere for creating a more or less isobaric pressure upon the application of suction to its interior. One membrane may span the open top of a four-sided rigid shell whose perforated bottom is overlain by another such membrane; alternatively, with the sidewalls of the shell also perforated and/or vertically ribbed or fluted, five membranes may be combined into an open-topped bag lining the interior of the shell, the top of the bag being closed by a sixth membrane after introduction of the sand filling and its pattern.

Abstract: A segmented mold assembly is utilized to cast a turbine engine component having an annular inner wall and an annular outer wall which are interconnected by a plurality of struts or vanes. The mold assembly includes a plurality of sections which are formed of a ceramic mold material and are interconnected at flange joints. A pair of mold sections are advantageously formed simultaneously by repetitively dipping a single pattern in a slurry of liquid ceramic mold material to form a wet coating on the pattern. This wet coating of ceramic mold material is then dried. After a covering of the desired thickness has been built up by repetitively dipping and drying the coatings on the wax pattern, the wax pattern is destroyed. To facilitate separating the mold sections after destroying the wax pattern, at least some of the wet coatings are wiped away in an area between portions of the wet coatings which will eventually form the mold sections.

Abstract: A mold assembly for casting articles by the investment molding process. The assembly may include a wax center sprue element through which extends a center support. First and second wax end sprue elements are mounted in spaced relationship on the center support by means of expendable supports embedded in the sprue elements. A wax riser element extends between the spaced end sprue elements and carries wax patterns of articles to be investment cast by means of the mold. An expendable riser support may be embedded in the wax riser element and secured at spaced portions thereof to the end sprue element supports. A plurality of such wax risers may be provided in circumferentially spaced relationship to the center support, each of which may carry wax patterns. The wax riser elements may be provided with longitudinal, outwardly opening parallel grooves with the wax patterns being secured to the riser elements in the grooves.

Abstract: An improved method of making a ceramic mold having a cavity in which a cast product is accurately formed includes reinforcing relatively flexible wax pattern material having a configuration which corresponds to the configuration of the mold cavity. Supporting the flexible pattern material with a relatively rigid reinforcing member prevents the pattern material from deflecting during removal from the injection die, pattern storage, pattern and gating assembly and dipping of the pattern in liquid ceramic mold material. Between dipping steps, portions of a wet ceramic coating are wiped away in areas between portions of the wet coating which will eventually form mold sections. After the ceramic mold material on the pattern has been dried, the pattern material is destroyed by heating or other methods. The resulting mold sections are then separated and the rigid reinforcing member removed from between the mold sections.

Abstract: A pattern destructible on contact with a molten metal charge is given a composite coating consisting of a highly tacky viscous adhesive substantially devoid of solids and single particle thickness layer collection of ultra-fine refractory particles (carbon facing sand) aligned on the surface of said adhesive. The adhesive volatilizes on contact with the casting charge while the refractory particles remain unaffected. An ultra-smooth cast surface is produced without macro crevices inherent in the surface of a destructible pattern and the mold sand is reusable without contamination by a high portion of burned sand.

Abstract: A method of making a more economical and reliable treating agent for use in late metal treatment when pouring metal castings. The treating agent is defined as an essentially homogeneous solid cast block preferably containing alloying ingredients to nodulize or inoculant ferrous metal. Each block is designed to present a generally uniform reaction surface to molten metal to be treated. This is obtained by casting the block to a shape which snugly fits a prepared basin in the mold gating system over which the molten metal to be treated must flow, or to cast the block in an annular configuration through which the molten metal must flow. The latter block has contoured inner surfaces which maintain a generally constant reactive surface as the block is consumed. These blocks are preferably prepared by simultaneously casting a large number in closely nested relation.

Abstract: A pattern set-up especially useful for making prosthetic dental appliances is assembled by attaching a plurality of refractory casts to a support member so that adjacent casts along the length of the support member are circumferentially offset with respect to one another. The casts carry expendable patterns that are connected to the support member by gating systems laid down on faces of the casts. The support member has outward protrusions supporting the weight of the casts and may be formed by a plurality of segments fitted together in end-to-end relation.

Abstract: A method for producing sculptures which have a thin-walled outer metal shell and an internal soft core made of plaster, for example. A mold of the sculpture to be fabricated is constructed smaller by the thickness of the metallic outer shell. A substance which can withstand high temperatures when coming into contact with molten metal, such as plaster, is then poured into the mold. After the plaster cast is removed from the mold, a layer of wax is applied with a thickness exceeding the thickness of the final metallic shell. The final shape of the sculpture is then cut on the exterior surface of the wax, so that the wax layer has a thickness corresponding to the thickness of the outer metallic shell. The cut wax layer is then covered with plaster, and heat is applied to melt the wax and allow the wax to drip out through an opening in the outer plaster layer.

Abstract: Method of casting an alloy comprising copper, aluminum and indium utilizing lost wax process. After the wax process. After the wax is melted from an investment mold the mold temperature is normalized at 250.degree.F by placement in an autoclave. Thereafter the alloy is centrifugally cast at 2,000.degree.F while the mold is at 250.degree.F.

Abstract: Method and manufacture are provided for preparing a reticulated foam structure by: investing an organic reticulated foam structure with an inorganic composition, which composition is inert under the conditions for forming the reticulated structure; allowing the inorganic suspension to set to form an investment; removing the organic reticulated foam structure; filling the voids of the investment with a fluid composition to form a reticulated casting; and dissolving the investment so as to leave a reticulated foam structure casting.

Abstract: A core assembly is formed by fabricating a first core, molding a destructible plastic layer around the first core, and molding a second core around the plastic layer. The plastic layer is interlocked .[.wth.]. .Iadd.with .Iaddend.an irregular outer surface of the first core, and the second core is interlocked with an irregular outer surface of the plastic layer. The core assembly can be used for casting engine cylinder heads to eliminate the need for gluing cores together and the accompanying formation of fins within fluid conducting passages.