Abstract: A chuck has a chuck body formed centered on an axis with a rearwardly open hole adapted to receive a drill spindle and with a plurality of axially forwardly and axially rearwardly open guide passages, an adjustment ring axially fixed but rotatable about the axis on the chuck body and formed with an internal screwthread, and respective jaws displaceable in the passages between axially front and radially closely spaced positions and axially back and radially widely spaced positions and having teeth meshing with the screwthread. The jaws project in the back positions rearward from the chuck body axially rearward past the hole receiving the spindle so that rotation of the ring in a forward direction on the chuck body displaces the jaws axially forward and radially inward and opposite rotation of the ring in a reverse direction on the chuck body displaces the jaws axially rearward and radially apart.

Abstract: A drill has a drill housing and a drive spindle centered on and rotatable about an axis, projecting axially outward from the housing, and having an outer end. A chuck element is fixed on the spindle outer end and an annular formation is axially fixed on the housing, centered on the axis, and extends axially to the chuck element. The formation defines with the chuck element an annular chamber. An adjustment ring element is axially fixed but rotatable about the axis on the chuck element. One of the elements is formed with a plurality of axially forwardly open guide passages open axially rearward into the chamber and the other of the elements is formed with a screwthread centered on the axis. The elements both are rotatable about the axis relative to the formation.

Abstract: A spindle assembly has inner and outer coaxial shafts having front and rear ends and extending along a common axis with the inner shaft axially displaceable in the outer shaft, a holding assembly on the front ends adapted to grip a tool or workpiece in an axially forwardly displaced position of the inner shaft relative to the outer shaft, a coupling ring fixed on the rear end of the outer shaft, and an actuator having a piston axially engageable with the rear end of the inner shaft and operable to axially shift the inner shaft in the outer shaft. In accordance with the invention complementarily interengaging formations on the actuator and the coupling ring including a groove and a projection are displaceable between a holding position axially securing the ring on the actuator and a freeing position allowing the ring to be axially separated from the actuator.

Abstract: A drill has a drive unit having a front end and an output shaft projecting from the front end and centered on and rotatable about an axis, and a fan associated with the shaft for creating a moving stream of air traversing a location at the drive-unit front end. A chuck body fixed on the shaft is formed with a rear end juxtaposed with the drive-unit front end, an axially forwardly open tool recess on the axis, a plurality of angularly spaced and angled guides opening into the recess, and at least one passage extending between the chuck rear end and the recess. Respective jaws displaceable in the guides have front ends in the recess. An adjustment sleeve is rotatable about the axis on the body and interengaging formations on the sleeve and on the jaws displace the jaws radially on rotation of the sleeve about the axis.

Abstract: An actuator has a cylinder centered on an axis and a piston axially displaceable in the cylinder, defining therein axially opposite front and rear compartments, and having an axially rearwardly projecting stem. A distributor is axially fixed but rotatable about the axis on the stem offset from the cylinder. The piston and distributor are formed with passages for pressurizing and depressurizing the compartments. At least one control element is fixed on the distributor offset from the cylinder. A sleeve coaxially surrounds the piston stem and forms a rear abutment against which the piston engages in a rearmost position of the piston. Formations on the cylinder and on the sleeve can axially displace the sleeve on the cylinder and fix the sleeve on the cylinder in any of a multiplicity of axially offset positions thereon. Respective front and rear control members extending axially rearward from front and rear bearings on the cylinder and sleeve are engageable with the control element to operate same.

Abstract: A holder for a tool or workpiece has a tubular working spindle centered on and rotatable about an axis, an elongated pulling element axially displaceable in the spindle and having a front end provided with holder jaws and a rear end with a forwardly directed face perpendicular to the axis. An actuating body axially displaceable in the spindle forward of the element face has an outwardly directed and rearwardly inwardly inclined face. A spring between the spindle and the body urges the body continuously backward. At least one wedge in the spindle between the body and the element face has a rear end face flatly abuttable with the element face, an inclined inner face flatly abuttable with the body face, and a forwardly outwardly inclined front end face.

Abstract: A drill chuck has a chuck body centered on an axis, a plurality of jaws radially displaceable on the body and each having a row of teeth, and an adjustment ring rotatable about the axis on the body but axially fixed thereon and formed with a screwthread meshing with the teeth of the jaws so that rotation of the ring on the body in a forward tightening direction displaces the jaws radially toward each other and opposite rotation displaces them radially away from each other. The adjustment ring is formed centered on the axis with an annular row of recesses having flanks and open in a predetermined direction. A holding ring is axially fixed on the body and abutments on the holding ring and body permit the holding ring to rotate on the body about the axis between a pair of angularly offset end positions. A return spring engaged between the holding ring and the body can be loaded to urge the holding ring in the forward direction on the body.

Abstract: An operation control device is provided for a chuck by which the rotary drive for the chuck is disengaged when the clamping motion leading to clamping of the workpiece in the chuck has not been provided or is not sufficient. The clamp jaws of the chuck are adjustable by a drive member guided axially in the chuch body which is connected to a clamping piston. The operation control device comprises a control piston which is acted on by a compressed medium against the force of a restoring spring and is locked by the drive member against the sliding caused by the compressed medium in a locked position disconnected from the rotary drive if the drive member is positioned in the end safety region of its axial displacement.

Abstract: The clamp jaws radially adjustable by a drive member each comprise a jaw base guided in the chuck body and a mounted jaw member replacably attached with it as well as at least one connecting pin which is mounted pivotable about the pin axis in the jaw base. According to rotary position the attachment between the jaw base and the mounted jaw member is released or locked. At least one control rod guided longitudinally slidable in the jaw base is coupled with the connecting pins by gear teeth so that the motion of the control rods relative to the jaw base converts to a rotation of the connecting pin and vice versa. The feed of the control rods in the jaw base runs parallel to the feed of the jaw base in the chuck body. For the control rod a controlling member is provided by which the control rod is held fixed from motion relative to the chuck body. The jaw base is slidable for rotation of the connecting pins by its drive member with the control rods held fixed in position.