Patent ID: 8074734
Filing Date: 2011-12-13
Classification: B25D

Abstract:
1. Powered hammer comprising: a housing, a tool holder mounted on the housing, a percussion mechanism arranged within the housing which mechanism includes a ram reciprocating in a longitudinal direction and being adapted to apply impacts on a tool bit supported in the tool holder, a dampening mass which is slidably mounted in the longitudinal direction within the housing, wherein the dampening mass is biased towards a neutral position by a biasing element and wherein the dampening mass may be deflected from the neutral position against the biasing force of the biasing element, wherein the dampening mass is formed of a ferromagnetic or paramagnetic material or comprises a permanent magnet, and wherein a solenoid is arranged within housing adjacent to the dampening mass such that the solenoid applies a force in the longitudinal direction on the dampening mass when being in the neutral position if a current is flowing through the solenoid, the powered hammer further comprising a control unit which applies a current to the solenoid depending on a signal which is a measure for the acceleration of the housing in the longitudinal direction.