Abstract: A method of making a hollow-shaped green ceramic article by pressure slip casting in a slip casting mold having a porous mold part with porosity channels opening at the surface of the mold cavity. A slip composition is formed having solid phase components with an average particle size distribution less than the cross-sectional dimension of mold porosity channels, and also having a flocculating agent to cause agglomeration of the solid phase particles into floccules larger than the porosity channel dimension.The molding cavity is filled with the slip composition, and the same is then hydrostatically pressurized while withdrawing slip filtrate from the mold cavity via the mold porosity channels for a time sufficient to deposit to a desired thickness a layer of solids. Excess slip is then removed from the molding cavity to provide an exposed interior surface on the deposit layer.

Abstract: A torch jet spark plug is provided which is suitable for use in a torch jet-assisted spark ignition system for an internal combustion engine. The torch jet spark plug is configured to ignite an air/fuel mixture within a combustion prechamber formed integrally within the body of the spark plug, such that a jet emanates from the prechamber and projects into the main combustion chamber of the engine, so as to enhance the burning rate within the main chamber. More particularly, the spark plug is configured so as to be relatively unsusceptible to pre-ignition, and also substantially eliminates the occurrence of internal short circuits to ground due to deposits accumulating within the prechamber. The spark plug achieves each of the above objects while having a relatively uncomplicated structure, requiring a minimal number of discrete components so as to enhance its manufacturability.