Patent attributes
A hammer mechanism including: a motor; a piston reciprocatingly driven by the motor; a ram reciprocatingly driven by the reciprocating piston via an air spring; a beat piece supported in an axially slideable manner within a beat piece support structure which, during the normal operation of the hammer mechanism, is repetitively struck by the ram and which transfers the impacts to a cutting tool when held by the tool holder; wherein the beat piece comprises a first impact surface and the beat piece support structure including a second impact surface, the first and second impact surfaces coming into contact with each other when the beat piece axially slides to its furthest position away from the ram; and wherein the shape of the two surfaces relative to each other is arranged so that there is a non-uniform amount of contact between the first and second surfaces around the longitudinal axis.
