Patent ID: 6763897
Filing Date: 2004-07-20
Classification: B25D

Abstract:
A hand held electrically powered hammer, comprising a housing within which is located:a motor; a hollow spindle within which is located for reciprocation therein a piston and a ram; a hammer drive arrangement which converts the rotary drive of the motor to a reciprocating drive to the piston; a tool holder body in which a tool may be mounted for reciprocation; wherein the reciprocation of the piston reciprocatingly drives the ram via an air cushion such that repeated impacts from the ram are transmitted to a tool mounted in the tool holder body, and wherein the hammer additionally comprises:a casing which encloses at least part of the spindle so as to define a chamber between the spindle and the casing; a damping mass which is located within the chamber which damping mass is connected to the hammer housing via a spring element so as to oscillate back and forth along the spindle; and at least one spacer element slideably mounted on the spindle for positioning the damping mass between the spindle and the casing so that a first gap is present between the damping mass and the spindle and a second gap is present between the damping mass and the casing.