Patent ID: 6866343
Filing Date: 2005-03-15
Classification: E21C,Y10S

Abstract:
1. In a chisel holder changing system having a base element with a chisel holder receiver, into which a chisel holder equipped with a chisel is insertable, wherein a holder shaft of the chisel holder is inserted into the chisel holder receiver and is maintained within the chisel holder receiver with a bracing screw, and wherein the bracing screw can be screwed into a threaded receiver of the base element while being supported under tension in a bracing receiver of the holder shaft of the chisel holder, the improvement comprising: a surface of at least one of an outer screw thread ( wherein the metallic layer is applied by at least one of a dipping process, a centrifuging process and a spraying process, is dried thereafter and is finally burned in at approximately 300° C.