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 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: The present invention provides means for the improved positioning of a strongback in a pattern mold for formation of expendable patterns thereon. Investment casting molds formed around the assembly of strongback and patterns are characterized as having the strongback precisely and reproducibly suspended therein. Articles, such as turbine blade halves, cast in such investment molds have mating surfaces in close dimensional relationship and can be bonded one to any mating other to form a finished product.In particular, a strongback having bonding locators near the opposite ends thereof is provided with additional locators to be used in suspending the strongback in the pattern mold. According to the invention, these pattern mold locators are colinear with and in close proximity to the bonding locators and are engaged by locating means in the pattern mold for establishing precise positioning of the strongback therein.

Abstract: The present invention provides a method for improved positioning of a strongback in a pattern mold for formation of expendable patterns thereon. Investment casting molds formed around the assembly of strongback and patterns are characterized as having the strongback precisely and reproducibly suspended therein. Articles, such as turbine blade halves, cast in such investment molds have mating surfaces in close dimensional relationship and can be bonded one to any mating other to form a finished product.In particular, improved positioning of the strongback in the pattern mold is achieved by suspending the strongback from the bonding locators by expendable locating means; that is, locating means which are incorporated into the patterns formed on the strongback surfaces. The use of expendable locating means enables the bonding locators to also serve as locators for positioning the strongback in the pattern mold and essentially eliminates errors in strongback positioning due to tolerances associated therewith.

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: For use in the lost pattern process of investment casting, an improved pattern assembly of the type having a pattern supporting center tree or sprue member including a rigid tube surrounded by a sleeve made of a flexible material, characterized by longitudinally spaced, thin bands of pattern material extending around the sleeve at those locations where the patterns are to be attached.

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: Precision investment casting of small parts with fine detail and free of air inclusions is achieved by the use of flat sided blocks of a relatively high melting point plastic material received upon elongated tubes or rods of the same or similar material. The shape and size of the blocks permit a large number of small parts to be cast at the same time and provide reservoirs for the molten casting metal close adjacent the casting cavity.

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: Hollow "lost plastic" patterns for metal casting molds are built up from plastic plate or sheet material bonded to internal supporting framing; the elements being formed of substantially ashless plastic solid or foam rod sheets or laminates easily sculptured or bent to desired shape when heated to provide even large and complex hollow patterns with a comparatively small expenditure of pattern material and labor.