Coal-mining machine

摘要

An excavating machine, e.g. for the recovery of coal and its removal from a coal seam comprises a rotary excavating tool which consists of a plurality of neutrally articulated coal augers which are driven and are disposed against the face to be excavated. The coal augers are provided with nozzles for spraying water or some other fast settling and spark-inhibiting liquid, the nozzles being controlled by a valve which opens flow to the nozzles only when at least one auger is disaligned from an adjustive auger as is required for coal cutting operations with such tools.