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: A flash control molding is provided for use in association with a pattern for forming a casting cavity in a metal casting mold. The flash control molding includes an elongated strip of pliable material having a predetermined cross sectional configuration to define a thick portion for forming a flash control chamber in the mold, and a thin edge along one side of the thick portion to form a restricted opening between the flash control chamber and the casting cavity so that a casting subsequently produced in the mold is formed with controlled shaped flash which has a built-in fracture line immediately adjacent the casting proper, thereby making the flash easily and cleanly removable from the casting.

Abstract: A precision investment casting ceramic mold of the self-casting type is made as a unitary mold by providing separately a pattern for a wax charge-holding assembly and a pattern for a wax article casting assembly, each including an alignment portion. The two patterns are secured together at the alignment portions and are supported and located one with respect to the other by a plurality of supporting and locating members. The assembled patterns then are used in the conventional manner to make a ceramic casting mold.

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 method for forming casting molds, comprising forming a flexible pattern composed of rigid plates and a flexible cloth, the rigid plates being adhered to the flexible cloth with intervals between plates, and the flexible pattern being made an air-tight construction, pouring a fluid into the flexible pattern or supplying the fluid under pressure to form any desired shape thereof, discharging the fluid from the flexible pattern after a sand mold has been cured, and then withdrawing the flexible pattern from the sand mold.