Abstract: A clamping chuck for securing a tool in a drilling device can be used for transmitting rotary and/or percussion motion to the tool. Independently adjustable guide jaws and at least one engaging element are mounted in the chuck. The guide jaws can hold a tool shank in a frictional engagement while the engaging element can fit into a recess in the surface of the tool shank. With such separate adjustment, the guide jaws can be used alone or in combination with the engaging element for holding the tool shank.

Abstract: In a tool holder for securing a tool in a hammer drill in a form-locking manner, locking elements are radially displaceably mounted in a guide member. An adjustment ring is threaded onto the guide member and by rotating the adjustment ring relative to the guide member, the locking elements can be adjustably tightened or loosened. The locking elements seat in closed end recesses in the shank of the tool to be secured. The adjustment ring can be locked in different rotational positions by an interlocking tooth arrangement. Teeth are provided on the adjustment ring and on a fixing sleeve axially slidably positioned on the guide member. The fixing sleeve can be moved axially between a position for locking the adjustment ring and another position permitting the adjustment ring to be rotated relative to the guide member.

Abstract: In a motor operated hand-held tool, such as a hammer drill, a drive train transmits driving force from a motor to a drive spindle. The drive train includes a safety clutch positioned on a shaft for interrupting the transmission of driving force if a torque overload occurs. The safety clutch has a hub encircled by a gear ring with spring-biased balls releasably interengaging the hub and ring for transmitting the driving force. The hub is engaged with a thread on the shaft and under normal operation a spring prevents the hub from being rotated relative to the shaft and being displaced axially along the shaft. During torque overload conditions the hub acting against the spring moves axially along the shaft until the hub and gear ring are released.

Abstract: In a device which can be used as a hammer drill or a chipping hammer, a percussion mechanism is located within a working cylinder in the housing of the device. A tool can be placed in one end of the working cylinder and the tool can be rotated without any percussive action or it can be given a combined rotative and percussive action. The percussive action is transmitted over a driving mechanism to an actuating piston which reciprocates a percussion piston through an intermediate air cushion. The drive mechanism includes a driving shaft with a disk pivotally connected to the shaft and in engagement with the actuating piston for selectively effecting the percussive action on the tool.