Abstract: A hammer tool such as a rotary hammer, hammer drill or the like includes a motor housing and a gear case secured to the motor housing forwardly of the motor housing. A motor in the motor housing has a shaft projecting into the gear case and a pinion formed on the end of the motor shaft. A first set of ratcheting teeth is formed on a body rotatably journaled in the gear case. An output spindle for holding a tool bit is provided and has a longitudinal axis. The output spindle is rotatably journalled in the gear case so as to be also slideable in the direction of said longitudinal axis. A second set of ratcheting teeth is mounted on the output spindle so as to be in confronting relation to the first set of ratcheting teeth. A spring provides a resilient force for holding the first and second sets of ratcheting teeth in spaced apart relation to each other.

Abstract: The invention is directed to a removable guard arrangement for a power tool having a rotating head for performing work on a workpiece and includes a guard member and a mounting member which is fixedly attached to the tool for accommodating the guard member thereon. The guard member and the mounting member are configured so as to facilitate the removable bayonet engagement of the members. A locking device is provided for locking the guard member in place on the mounting member.

Abstract: The invention is directed to a bearing arrangement for the shaft of the armature of an electric motor disposed in a support frame and subject to axial thrust. The bearing arrangement includes a bearing housing disposed so as to receive an end portion of the shaft therein and defining a bearing wall for receiving the axial thrust of the shaft. The bearing housing has a structure formed thereon for mounting the bearing housing to the support frame. A bearing at the interface of the bearing wall and the end portion transmits the axial thrust of the shaft to the bearing wall. A shaft bearing rotatably engages the end portion of the shaft and elastic material interposed between the structure and the support frame deforms elastically in response to the axial thrust applied to the bearing wall.

Abstract: The invention is directed to a speed-changing device for a tool having a gear-box housing and a gear assembly arranged in the housing. The gear assembly has a gear cluster which is movable between at least two positions for changing the gear ratio of the gear assembly. The speed-changing device includes an annular guide member adapted to snap into an opening in the gear-box housing for firmly holding the device in the housing. A cylindrical member is rotatably mounted in the annular guide member and defines a longitudinal axis of rotation. A head piece is securely mounted on the cylindrical member and has an elongated projection extending therefrom eccentric to this axis. The elongated projection engages the gear cluster to move the same from one position to another in response to a manual actuation of the cylindrical member. The cylindrical member is configured to contact the guide member to conjointly define therewith a sealing interface.