Abstract: A tubular sand molding chamber having two conventional movable walls one mounted on a piston for compacting and expelling the cake and the other pivotably mounted on a displaceable hinge arm for opening the chamber, but having side walls that are also movable is disclosed. Each movable side wall includes a plate (11) mounted on a respective plate-holder (12) that is connected to guides (13) for sliding the side wall on a fixed support (14) through the action of a respective hydraulic cylinder (15), in such a manner that the effective width of the chamber be adapted to different cake sizes, in order to minimize the consumption of sand. However, the movable end wall that are mounted on a faceplate (20) affixed to a hydraulic cylinder and pivotably mounted on the hinge arm, respectively, for the compacting and expelling the sand cake, have replaceable plate assemblies.

Abstract: A relatively hard sand cake, containing a metal casting cavity, is formed in a flask comprising cope and drag frame sections by filling and compacting sand in the drag against the drag half of a cavity-forming pattern, then arranging the drag with the cavity opening upwards, applying the cope upon the drag and filling and compacting sand in the cope against the cope half of the cavity-forming pattern. The sand-filled cope is lifted from the drag for removal of the pattern and is re-applied to form the casting cavity in the sand cake. Next, selected wall corner joints of both the cope and the drag frames are separated and opened to laterally expand the walls of the frames away from the sand cake surfaces. This releases the sand cake from the cope and drag so that it may be removed from the flask for later casting molten metal in its casting cavity. At least two of the corners of each of the cope and drag frames include a separate corner piece against which the adjacent ends of the frame walls are abutted.

Abstract: An apparatus for the preparation of a dental casting from a dental pattern utilizing an exothermic investment material which expands upon curing which comprises a base having a top surface for supporting the dental pattern and a container having a first and a second open end. The container and the base partially enclose the dental pattern when the first open end of the container is disposed upon the top surface of the base. The second end of the container enables the introduction of the exothermic investment material to compeletly encompass the dental pattern. The container comprises a first and a second container portion with each of the first and second container portions having a first and a seond terminating edge. The first and second terminating edges of the first container portion respectively cooperate with the second and first terminating edges of the seocnd container portion for retaining the uncured exothermic investment material within the container.

Abstract: The apparatus comprises an expandable investment ring having a removable base. Formed on the top surface of the base, and within the void defined by the ring, is an indexed sprue former. A curved runner bar having an indexed coping is formed at one end thereof in mating relation to the sprue former. The curved full arch runner bar comprises a proximal end portion and distal end portion with the distal end forming a first and second curved configuration portion which together approximates the curved configuration of the jawbone of a patient. The first and second curved configuration portions are interconnected thereby resulting in extremely accurate full arch base metal castings. The apparatus is also useful for preparing precious metal castings.

Abstract: The apparatus comprises an expandable investment ring having a removable base. Formed on the top surface of the base, and within the void defined by the ring, is an indexed sprue former. A curved runner bar having an indexed coping is formed at one end thereof in mating relation to the sprue former. By virtue of this apparatus extremely accurate base metal castings may be obtained. The apparatus is also useful for preparing precious metal castings.