Abstract: Tooling includes an inflatable arbor for forming a backdraft cavity in a foundry sand core. A core handling device includes an inflatable arbor, similar to the one used for forming the backdraft cavity in the sand core, whereby the lifting device arbor, when in its deflated state, may be inserted into the backdraft cavity of the sand core and then inflated to grip and become locked to the sand core.

Abstract: In an apparatus for the compaction of foundry sand by the impact of pressurized gas on the foundry sand as filled into a flask over a pattern plate with a pattern therein, a specially designed diaphragm is used to get an even and constant hardness of the mold in every horizontal plane thereof and/or to put an end to the formation of shear cracks in the mold between different parts of the volume of the sand. This diaphragm is placed over the so far uncompacted surface of the foundry sand and it has a permeability to gas varying with the height of the sand to be compacted so that such permeability is less in the parts with high and/or plateau-like pattern contours than in parts where there is no pattern on the pattern plate.

Abstract: To compact a sand-binder mixture in a mould or core box and subsequently apply a hardening gas to the mixture, I apply to the open top of the box a fluid-pervious diaphragm backed by an impervious diaphragm, apply suction to the bottom of the box to draw the diaphragm against the top of the mixture and compact the mixture, and subsequently introduce the hardening gas between the diaphragms so that it passes through the first diaphragm and permeates the mixture within the box.

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 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: In a method of forming foundry sand moulds employing a cold-setting sand mixture pressed around a pattern by the use of pneumatic pressure acting on a flexible diaphragm, the sand is formed into a horizontal layer of approximately uniform thickness in a frame of which the bottom wall is formed by the diaphragm, the pattern is then pressed into that layer of sand, causing the diaphragm to bulge downwards, then the gas pressure (conveniently air pressure) is applied to compact the sand, which thereupon sets to allow separation of the resultant mould body from the diaphragm and pattern. During the initial formation of the layer the diaphragm can be supported by a further, stronger diaphragm, which is perforated to allow the gas pressure through, or by a rigid pad, or both.

Abstract: An improved method of producing a mould under a reduced pressure is described herein. In the improved method, after a main pattern (1) having a protrusion and a recess is inserted with an auxiliary pattern (8) having the same shape as said recess and having an air-tight film (9) tightly adhered on its outer peripheral surface into said recess, said main pattern (1) is fixedly placed on a surface plate (2) provided with evacuating means, and the surface of the main pattern (1) including the upper surface of said surface plate but excluding the upper surface of said auxiliary pattern (8) is covered with an air-tight film (3). Then, after said air-tight film (3) has been tightly adhered onto the surface of the main pattern (1) excluding the upper surface of said auxiliary pattern (8) and onto the upper surface of the surface plate (2) with the evacuating means of the surface plate (2), said auxiliay pattern (8) is extracted from the main pattern (1).