Patent ID: 7950471

Claim:
A hand-held percussion power tool, comprising a guide tube ( 6 ); an anvil ( 8 ) axially displaceable in the guide tube ( 6 ) within limits defined by two, spaced from each other, stops ( 9 a , 9 b ) arranged in the guide tube ( 6 ), the anvil ( 8 ) having an outer radial collar ( 11 ); a percussion piston ( 5 ) for applying blows to the anvil ( 8 ); a pneumatic percussion mechanism ( 2 ) for driving the percussion piston ( 5 ); an air spring ( 3 ) for connecting the percussion piston ( 5 ) with the percussion mechanism ( 2 ); an impact ring ( 12 ) arranged in the guide tube ( 6 ) coaxially with the anvil ( 8 ) radially outwardly thereof, the impact ring ( 12 ) having an outer diameter smaller than a guiding inner diameter of the guide tube ( 6 ) and being freely displaceable, within limits, in the guide tube ( 6 ) relative to the anvil ( 8 ) for reducing an impact energy applied to the anvil during an idle blow applied to the anvil, wherein the impact ring ( 12 ) is formed of two parts, an inner ring formed of two half-shells [ 17 a , 17 b ] and a radially outer, circumferentially closed, mounting sleeve ( 19 ) surrounding the inner ring for securely holding the half-shells [ 17 a , 17 b ] together, and wherein the half-shells each has an outer thread ( 10 ), and the mounting sleeve ( 19 ) has an inner thread ( 20 ) cooperating with the outer thread ( 18 ) of the half-shells.