Patent ID: 7331407
Filing Date: 2008-02-19
Classification: B25D,F16F

Abstract:
1. A vibration reduction apparatus for a power hammer apparatus comprising a housing, a motor arranged in the housing, a piston, a reciprocating drive drivable by the motor to drive the piston in reciprocating motion in a bore, and a flying mass arranged in the bore such that said reciprocating motion of said piston in said bore in use causes reciprocating motion of said flying mass relative to the housing to impart impacts to a working member of the hammer apparatus, the vibration reduction apparatus comprising a driveable mass surrounding at least part of the bore, a cam rotatable by the reciprocating drive and engagable to the drivable mass, and a first biasing member for urging the drivable mass into driving engagement with the cam and wherein the driveable mass is caused by the motor to execute reciprocating motion to at least partially cancel vibration of said housing caused by reciprocating motion of the flying mass relative to the housing.