Patent ID: 8474590

Claim:
A friction part ( 2 ) for a frictionally acting device, comprising an annular friction surface ( 30 ) which has an inner edge ( 32 ) and an outer edge ( 34 ), with the friction surface ( 30 ) having provided in it an encircling first groove ( 40 ) which extends in zig-zag or undulating form between radially inner and radially outer deflection points ( 44 , 42 ), a plurality of second grooves ( 54 ) which extend from the inner edge ( 32 ) to the outer deflection points ( 42 ) and a plurality of third grooves ( 56 ) which extend from the outer edge ( 34 ) into the encircling first groove ( 40 ) and which open into the encircling first groove ( 40 ) at opening-in points ( 58 ) between the radially inner and radially outer deflection points ( 42 , 44 ).