| 摘要 |
A hammer drill with an air-cushion percussion mechanism (18) is proposed. The percussion mechanism (18) has a cylindrical skirt-type piston (39) reciprocating in a guide. Arranged in the bore of the skirt-type piston is a piston-like striker (41) which is carried along by the skirt-type piston (39) via a closed air cushion. In its frontmost position, the striker (41) strikes a coaxially arranged intermediate anvil (48) which transmits the energy delivered by the striker to the tool (5) of the hammer drill. The intermediate anvil (48) is located in a guide sleeve (46), which at its end remote from the tool (5) has an axial stop (53) for the intermediate anvil (48). The guide sleeve (46) is solidly supported to the front - in the direction of the tool - and elastically supported to the rear. The outside diameter of the guide sleeve (46) is less than the inside diameter of the inner space of the skirt-type piston (39). At least in its frontmost position facing the tool, the wall of the skirt-type piston (39) overlaps the guide sleeve (46). In this way, a hammer drill is created which is distinguished by a very compact type of construction and a very low weight. Lubricant losses and the ingress of dust are prevented by the arrangement of the intermediate anvil. Drilling impact effects on the housing and thus on the operator are reliably avoided. <IMAGE>
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