Abstract: A method for manufacturing rubber molds using a mold making apparatus having first and second discs of rubber mold material with models of articles to be cast positioned therebetween includes a bottom plate having a centrally located portion which engages the first sheet of rubber mold material and an outer reduced thickness flange, and a top plate which overlies the bottom plate. The top plate has a centrally located portion which engages the second sheet of rubber mold material and an outer reduced thickness flange corresponding to the flange of the bottom plate when disposed over the bottom plate. A plurality of thumb turn members are provided for tightening the top plate towards the bottom plate by hand. The arrangement is such that the models disposed between the first and second discs of rubber mold material form mold cavities therein.

Abstract: A two-stage investment removal apparatus for removing investment material from an investment casting includes first and second stage sub-assemblies operative for different impacting actions. The first stage sub-assembly includes spaced drive rollers for rotating the investment flask on its side, and a pneumatic hammer which engages the side wall of the investment flask for imparting impact energy to the investment flask while the flask is being rotated. The flask is placed in a protective sleeve which more evenly distributes the impact forces around the side wall of the flask during rotation. The second stage sub-assembly includes a tubular chamber, and a spring-biased seat in the chamber for receiving the bottom end of the central casting trunk when the flask is positioned on the seat. The chamber includes radial spring arms for centering the flask and casting trunk on the seat.

Abstract: The apparatus for removing investment material from an investment flask casting includes a spring-biased seating assembly, a centering assembly having spring-biased shoulder mounts, a vertical impact assembly, and a pair of opposing horizontal impact assemblies. The vertical and horizontal impact assemblies work simultaneously and in combination with the spring-biased seating assembly and the spring-biased shoulder mounts to transmit linear dynamic and high frequency vibratory impact energy to the investment flask casting wherein the apparatus effectively and quickly removes virtually all of the investment material therefrom. The investment apparatus further includes an investment collection system for collecting waste investment material for subsequent disposal.

Abstract: A self-leveling shim for centrifugal casting apparatus of the type wherein piston means maintain two-part elastomer molds in pressurized engagement with each other during the molding operation, said shim comprising an inflatable bladder positioned between said piston means and said molds, said bladder being inflatable only at selected portions thereof, so as to apply shim pressure at the portions of the molds where such pressure is required.

Abstract: Multi-mold centrifugal casting system comprising basically conventional centrifugal casting apparatus except that instead of receiving a single mold, i.e., one pair of mold halves, a plurality of molds are mounted in the apparatus in stacked relation, with all mold halves having central openings to define a plurality of ring-like molds. A manifold member is positioned in the center of the stacked ring-like molds for receiving and simultaneously feeding molten metal to each of the stacked molds.