Patent ID: 6732815
Filing Date: 2004-05-11
Classification: B25D

Abstract:
An electrically powered hammer comprising:a hollow spindle including a tool holder portion at its forward end in which a tool can be releaseably mounted for limited reciprocation; a piston mounted within the spindle for reciprocating motion; a ram of an air cushion hammering mechanism; a beatpiece including a first increased external diameter mid-portion located within the spindle between the ram and the tool for transmitting repeated impacts from the ram to the tool; a two part sleeve arrangement located within the spindle and having an increased internal diameter mid-portion for receiving the increased external diameter mid-portion of the beatpiece and a reduced internal diameter forward and rearward portions for guiding the forward and rearward ends respectively of the beatpiece in all working positions of the beatpiece; and wherein the two part sleeve arrangement comprises a forward sleeve and a rearward sleeve which are both guided with tight radial tolerances and with slight axial play within and by the spindle and in which the forward axial movement of the forward sleeve is limited by a reduced internal diameter portion of the spindle and the forward axial movement of the rearward sleeve is limited by the forward sleeve.