Patent ID: 7819343

Claim:
A tool for cutting up coke, comprising a housing mounted on a drill stem in the operating condition, and wherein at least one cutting nozzle for cutting and one boring nozzle for boring coke by means of a water jet, and a switchable valve arranged in a flow-through channel for alternatively feeding water to flow channels in a flow body for paths to the cutting and boring nozzles, and a switching apparatus manually or water-pressure-controlled operable at switching pressure of the water within the flow-through channel, for switching the switchable valve, are arranged, the switchable valve comprising a distribution apparatus rotatably supported above the flow body, with at least one valve body for closing off at least one opening of the flow channels, wherein depending on the angular position of the distribution apparatus with respect to the flow body, the flow path of the water to the boring nozzle or the flow path to the cutting nozzle is free or obstructed, wherein the valve body has means for compensating the pressure within the flow channel below the valve body to switching pressure as in the flow-through channel, the pressure compensating means comprising a closure body and a communication between the underside of the closure body facing the flow channel and an operating-pressure side of closure body exposed to the operating pressure of the water in operation for pressure compensation, and means for opening the communication for pressure compensation as soon as the operating pressure is reduced to switching pressure.