Abstract: An apparatus for processing semiconductor wafers includes: a wafer support with a first positioning system that can rotate the wafer support coaxially with a wafer; at least one processing apparatus, which can be moved with a second positioning system such that a processing tool proceeding from the processing apparatus can be guided radially over the wafer; and at least one position determining apparatus for determining a wafer position on the basis of features of the wafer. Alignment marks of the wafer are found and points to be processed, such as laser fuses, are moved by rotation of the wafer and movement of at least one processing apparatus in the radial direction above the wafer.

Abstract: An apparatus for processing semiconductor wafers includes: a wafer support with a first positioning system that can rotate the wafer support coaxially with a wafer; at least one processing apparatus, which can be moved with a second positioning system such that a processing tool proceeding from the processing apparatus can be guided radially over the wafer; and at least one position determining apparatus for determining a wafer position on the basis of features of the wafer. Alignment marks of the wafer are found and points to be processed, such as laser fuses, are moved by rotation of the wafer and movement of at least one processing apparatus in the radial direction above the wafer.

Abstract: A mining tool with a rotary body carrying a number of peripherally spaced cutters has a water channel terminating in the vicinity of each cutter at a spray nozzle for the irrigation of particles such as coal dust detached from the mine face. The water supply for each nozzle is controlled by the associated cutter so as to be unblocked only when its working edge encounters resistance sufficient for a limited swing of the cutter shank about a pivotal axis against the force of a biasing spring, thereby opening a valve normally held closed by that spring.

Abstract: A water nozzle, particularly for dust suppressing for example at cutting rollers, has a housing with a central opening, a guiding sleeve received at least partially in the central opening of the housing and having an inner passage which is stepped in an axial direction, and a piston stepped in the axial direction and displaceable in the passage of the guiding sleeve to a position in which a narrow gap is formed between the piston and the guiding sleeve so as to prevent solid particles entrained in a flow of water from entering the nozzle. The piston is spring biased in a direction opposite to the direction of the flow of water, so that upon termination of the latter the piston dislodges the solid particles accumulated at the nozzle.