Patent ID: 6648079
Filing Date: 2003-11-18
Classification: B25D

Abstract:
A percussion device having a protective apparatus for preventing the infiltration of contaminants, said device comprising: a fluid-operated percussion device, having a striking tool that is guided to move in a housing by a striking tool guide, which has inner and outer axially spaced annular guide portions each having an inner surface that engages a portion of a circumferential surface of the striking tool, and is driven by a percussion piston in the striking direction, and a seal that is supported at least indirectly on one of the housing and the striking tool and has a securing portion that is fixedly disposed with respect to the other of the housing and the striking tool, with the seal being disposed between an inner end of the inner guide portion of the striking-tool guide and a theoretical striking plane of the percussive piston on the striking tool, when seen in the direction opposite the striking direction, and the support for the seal is a countersurface provided on said one of the striking tool and the housing, which countersurface moves relative to the securing portion of the seal, is in contact with the seal, and is unaffected by wear in that it is not engaged by the inner surface of the tool guide or the circumferential surface of the striking tool.