Abstract: In a high-pressure shut-off valve, in particular for a hydraulic pressure system having a relatively high liquid delivery rate, the pressure device of the valve body has a plurality of back support rings arranged as a stack and moveable essentially in the axial direction, i.e., in the direction of the shut-off pressure, forces the valve body onto the valve seat, such that neighboring back support rings bear against one another, causing the valve body to lift from the valve seat, whereas in the shut-off position, the neighboring back support rings inside the hydraulic system, which is under a relatively high shut-off pressure, are at a slight spacing from one another.

Abstract: A method of erosive cutting of a hard material such as rock utilizes two spaced clusters of jets for high-pressure discharge of fluid in the course of their movement along the same longitudinal path over the hard material. One of the jet clusters has a fixed orientation for multiple-jet discharge at the hard material, while the other cluster of jets is subjected to oscillating excursions transverse to the direction of the path that both clusters are caused to follow. A cooling medium is directed at the working site between the two clusters. The result is a faster working rate and a more cleanly defined groove in the hard material, along the path of movement.

Abstract: In particular for cutting working of especially hard rock such as granite, an additional cooling medium is supplied to a pressure medium which is at a high pressure of especially more than 1500 bar. The pressure medium is ejected particularly in the form of discrete narrow jets from a nozzle head (5) and the directional jet (5g) of the cooling medium is directed towards at least some of the jets (5b) of the bundle of jets of the pressure medium so that together with the pressure medium a cooling effect is caused on the object to be worked, thus resulting in an improved crushing effect.

Abstract: In order to increase the delivery pressure of the reciprocating pump-actuating mechanism of hydraulic feed pumps having a high pumping capacity, stacks of thin spacer discs are provided on either side of a sealing ring sealingly engaged in a sealing position between the plunger and the cylindrical bushing, said stacks of spacer discs being axially movable along the plunger in the normal non-sealing position. A pressure-distributing bushing is disposed between the stack of spacer discs which faces the free end face of the plunger and the sealing ring, said pressure-distributing bushing rapidly compensating the pressure between said stack of spacer discs and the end face of the pressure-distributing bushing facing the sealing ring.

Abstract: To cut, bore or similarly machine rock, ore, stratified coal or other objects, a medium is delivered under high pressure through a supply pipe to a nozzle. The supply pipe is designed as a pendulum-type pipe, in particular in the form of a flexible high-pressure hose, and executes, together with the nozzle, rapid, for example oscillating and/or circular, movements along a guide. In this way, straight cuts and/or holes can be made very rapidly and simple in rock. The cut width can be controlled by the arrangement and fitting in particular of a plurality of nozzles, depending on the rock and pressure medium. In particular, an eccentric element which functions as a drive mechanism permits a circular movement of the nozzle.

Abstract: A process is disclosed for cutting rock by means of discharging a medium under high pressure from a nozzle head at a fixed oscillating angle. A nozzle head on the end of the pressure hose is set in a freely pulsating movement through the discharge of a medium under high pressure. The movement of the nozzle head is controlled by a guide with stops. An apparatus for carrying out this process is also disclosed. The apparatus comprises a suitable nozzle head on a delivery line 1 for discharging a medium under high pressure and with a fixed oscillating angle and a guide 6 with stops 4. A flexible high-pressure hose is used as the delivery line 1.