Abstract: A refractory metal core for use in a casting system has a coating for providing oxidation resistance during shell fire and protection against reaction/dissolution during casting. In a first embodiment, the coating includes at least one oxide and a silicon containing material. In a second embodiment, the coating includes an oxide selected from the group of calcia, magnesia, alumina, zirconia, chromia, yttria, silica, hafnia, and mixtures thereof. In a third embodiment, the coating includes a nitride selected from the group of silicon nitride, sialon, titanium nitride, and mixtures thereof. Other coating embodiments are described in the disclosure.

Abstract: A refractory metal core for use in a casting system has a coating for providing oxidation resistance during shell fire and protection against reaction/dissolution during casting. In a first embodiment, the coating includes at least one oxide and a silicon containing material. In a second embodiment, the coating includes an oxide selected from the group of calcia, magnesia, alumina, zirconia, chromia, yttria, silica, hafnia, and mixtures thereof. In a third embodiment, the coating includes a nitride selected from the group of silicon nitride, sialon, titanium nitride, and mixtures thereof. Other coating embodiments are described in the disclosure.

Abstract: In an investment casting process, a composite core is formed as a combination of ceramic casting core element and a non-ceramic casting core element. The core is heated in an oxidative atmosphere and then heated in a non-oxidative atmosphere.

Abstract: A pattern with internal cores for creating a hollow component is composed of a first pattern half having one or more first self-locating features; a second pattern half having one or more second self-locating features; and one or more cores disposed in contact with the one or more first self-locating features and the one or more second self-locating features. The method for its manufacture includes the steps of creating a first pattern half having one or more first self-locating features; creating a second pattern half having one or more second self-locating features; providing one or more cores; and assembling the pattern by engaging the one or more first self-locating features and the one or more second self-locating features about the one or more cores.

Abstract: A slurry is used to secure a metallic casting core to a ceramic casting core. The slurry may be introduced between the metallic and ceramic casting cores and hardened. The slurry may comprise zircon and aqueous colloidal silica.

Abstract: Pre-molding of wax or similar sacrificial material over one or more cores facilitates a subsequent molding over a core assembly. Individual cores or groups thereof may be pre-molded in a wax body. One or more such wax bodies may be assembled with other bodies and/or other cores to facilitate a main wax molding of such assembly.

Abstract: An apparatus for shelling an investment casting pattern has a tank containing a coating material. There are means for holding the pattern immersed in the coating material. There may be means for vibrating the pattern during immersion of the pattern and a vacuum source coupled to the tank to withdraw air from at least one headspace of the tank.

Abstract: An at least two step heating process is used to strengthen the shell of an investment casting mold including a refractory metal core. The first stage may occur under otherwise oxidizing conditions at a low enough temperature to avoid substantial core oxidation. The second stage may occur under essentially non-oxidizing conditions at a higher temperature.

Abstract: An apparatus for shelling an investment casting pattern has a tank containing a coating material. There are means for holding the pattern immersed in the coating material. There may be means for vibrating the pattern during immersion of the pattern and a vacuum source coupled to the tank to withdraw air from at least one headspace of the tank.

Abstract: The invention relates to a radial piston pump of the type in which a piston carrier, together with an end slide plate within a track carrier, produces one piston stroke per revolution. The piston carrier is rotatably disposed between two parallel housing surfaces and has distributing passsages opening at the end and cooperating with distributing apertures at the pressure and suction sides in at least one housing surface. At least one pressure surface, which is bounded by sealing rings, is in communication with the pressure side to force the piston carrier and slide plate apart. An annularly shaped corrugated spring is provided for aiding and supplementing the pressurized fluid in also pressing the piston carrier and slide plate apart.

Abstract: The invention relates to a gerotor type of rotary piston machine which is operable as either a pump or a motor. In this type of device an externally toothed rotor member is eccentrically offset relative to an internally toothed stator member and in operation these members mesh to form expanding and contracting cells on opposite sides of the line of eccentricity. There is shaft means for driving the rotor and a distributing valve for feeding and exhausting the cells is attached to the shaft means. In order to compensate for torsion stresses in the shaft means which would cause the distributing valve to be slightly out of phase relative to the rotor the connection between the valve and the shaft means is made adjustable in response to sensing means which sense the pressure conditions in the gerotor when the rotor is symmetrical relative to the line of eccentricity.

Abstract: The invention relates to a radial piston type pump comprising a casing, a shaft, two or more piston carriers mounted on and driven by the shaft, and a curved track surrounding the piston carriers. The piston carriers are axially movable on the shaft and pressure chamber and scaling means are provided between adjacent carriers to bias them in opposite directions against the internal casing walls which form a chamber in which the carriers are rotatably mounted. Fluid inlet and outlet means in one of these casing walls has fluid communication with the inlet and outlet passages in the carriers and the biasing of a carrier against this wall serves to provide sealing between the relatively rotating surfaces to minimize the leaking of fluid between these surfaces.