Abstract: A seal assembly having a backup ring through which a piston reciprocates. There is a seal sleeve made of a non-abrading, extrusion resistant material that surrounds the piston at a location forwardly of the backup ring. The backup ring has an opening to receive the piston, and the opening is formed to define a radially and rearwardly expanding gas between the piston and backup ring to receive and discharge any seal material which may extrude into the gap. There is a positioning flange integral with the backup ring that surrounds the seal sleeve to press the seal sleeve into engagement with the piston, and there is an outer seal portion to form a seal between the positioning flange (or the outer portion of the backup ring) and the cylinder.

Abstract: An abrasivejet system for cutting brittle materials is disclosed. One feature of the disclosed system is a jet-producing nozzle assembly which includes means for inducing turbulence in the jet-forming liquid during the period in which the jet initially impacts on the brittle material so that impact stress on the material is reduced. A second disclosed feature is a supplementary suction device, preferable in the form of a second nozzle dimensioned for maximum suction, which maintains a generally constant feed rate of abrasive into the cutting nozzle assembly during the turbulence-inducing phase of operation.

Abstract: A catcher for use in liquid and abrasive-laden liquid jet cutting apparatus that includes a separate fluid-filled chamber for reducing noise. The catcher also provides for increasing the speed of return flow to reduce the length of fluid required to absorb the kinetic energy of a jet.

Abstract: A method and apparatus for producing a coherent stream of high velocity abrasive laden liquid. The method includes allowing the particles to assume the direction and velocity of a high velocity jet of liquid. This method also allows concentration of particles in the center of the flow of liquid to reduce nozzle wear and increase cutting efficiency. The apparatus includes a nozzle having a converging section attached to a straight section that is sufficiently large that the abrasive particles approach the velocity of the fluid jet before exit of the nozzle.