Abstract: The present invention is directed for use in a valve assembly including a housing having an axis and defining an interior, with fluid provided in the housing and substantially filling the housing interior, a valve stem disposed in the housing interior and a piston attached to the valve stem, wherein the piston and valve stem are moveable along the housing axis within the housing interior between first and second positions. The present invention includes a valve actuation control device disposed in the housing interior, the valve actuation control device allowing the fluid to freely flow from one side of the piston to the other side during at least a portion of the piston's movement between the first and second positions.

Abstract: For use in a valve assembly including a housing having an axis and defining an interior, with fluid provided in the housing and substantially filling the housing interior, a valve stem disposed in the housing interior and a piston attached to the valve stem, wherein the piston and valve stem are moveable along the housing axis within the housing interior between first and second positions, a valve actuation control device is provided which is disposed in the housing interior, the valve actuation control device allowing the fluid to freely flow from one side of the piston to the other side during only a first portion of the piston's movement between the first and second positions.

Abstract: The present invention is directed for use in a valve assembly including a housing having an axis and defining an interior, with fluid provided in the housing and substantially filling the housing interior, a valve stem disposed in the housing interior and a piston attached to the valve stem, wherein the piston and valve stem are moveable along the housing axis within the housing interior between first and second positions. The present invention includes a valve actuation control device disposed in the housing interior, the valve actuation control device allowing the fluid to freely flow from one side of the piston to the other side during at least a portion of the piston's movement between the first and second positions.

Abstract: A system for manufacturing metal matrix composites, each including a porous preform infiltrated with molten metal, includes a programmable, automated arrangement for handling preforms for sequential introduction into a die caster of the system. A preform loader includes a reciprocable loading head which receives each preform from an associated stack, and delivers each preform to a horizontally reciprocable carrier of a preform shuttle. The preform shuttle effects indexed movement of each preform along a substantially horizontal path, through a preheating furnace, and into the die caster. Efficient operation of the system is promoted, while undesirable damage to the relatively brittle porous preforms is avoided.