In a zero-point clamping device (1) for centred locking of an object (2) with repeat accuracy, in particular a workpiece, a tool or a pallet, or a carrier part (3) to which the corresponding object (2) is attached, the zero-point clamping device comprising: a housing (4), a receiving opening (5) worked into the housing (4), which has a centring axis (6) with which the axis of symmetry (2 or 3) of the object (2) or the carrier part (3) is coaxially aligned during the clamping process, at least two clamping slides (7, 8 or 9), each of which is mounted axially displaceably in a bore (10) provided in the housing (4) and which open into the receiving opening (5) during the clamped condition and thereby act on the object (2) or the carrier part (3) and secure them, and an actuating element (11) which is rotatably mounted in the housing (4) and by means of which the clamping slides (7, 8, 9) can be moved, one axis of rotation (12) of the actuating element (11) running tangentially and at a distance from the receiving opening (5),
on the one hand, this should enable a reliable, permanent and repeatable fixing of a large number of workpieces, tools, pallets or other objects (2) and, on the other hand, the housing (4) of the clamping device (1) should be extremely compact, i.e. its external dimensions can be kept extremely small in height and diameter.

This is achieved in that two spaced-apart threads (13, 14) are incorporated in the actuating element (11), the respective threads (13, 14) of which have identical pitches and are designed to be inclined in opposite directions with respect to one another, a drive pin (15, 16) is inserted in each thread (13, 14), this drive pin (15, 16) being in a driving operative connection with the respective thread (13 or 14) in such a way that the drive pins (15, 16) can be moved along the axis of rotation (12) of the actuating element (11) by means of the rotation of the actuating element (11), that at least two drive segments (21, 22 or 23) are mounted in a floating arrangement in the housing (4) and extend in an arc around the centring axis (6) of the receiving opening (5), that two of the drive segments (21, 22) are coupled in a driving arrangement to the actuating element (11) via one of the respective drive pins (15, 16), that a respective pivot pin (17, 18) is provided between th

Disclosed is a built-in type electric driving system of a machine tool. The system is capable of directly connecting a motor, which drives a spindle in a lathe which processes a workpiece, to an outer surface of the spindle without using a belt to rotate the spindle, and is capable of selectively transferring the power of the motor to a rotation system including a drawbar and a spindle for driving a chuck using a clutch device.

A collet assembly of improved stability has a collet, an axial limiting assembly, a cutter, a pin, and multiple damping elements. The collet has a containing space, a pin-receiving groove, a connecting groove, and multiple receiving grooves. The containing space is formed through the collet. The pin-receiving groove is formed through the collet. The connecting groove is recessed on the collet. The multiple receiving grooves are recessed in the collet. The axial limiting assembly is mounted to the collet. The cutter has a limiting groove and a mounting end. The limiting groove is recessed on the cutter. The mounting end abuts against the limiting assembly. The pin extends into the pin-receiving groove and abuts against the limiting groove of the cutter. Each one of the multiple damping elements is received in a respective one of the multiple receiving grooves of the collet. A collet of improved stability is also provided.

A cutting device in accordance with some example embodiments is provided for use with an arbor assembly. The cutting device includes a blade having a plurality of teeth, and a back plate at a proximal end of the blade. The back plate has an outer end surface in which a plurality of ramp surfaces and pin locking recess are provided. A central through hole extending through the back plate. The ramp surfaces only allow the cutting device to be rotated relative to the arbor assembly in one direction.

A chuck for a power tool includes a body extending along a longitudinal axis, a central bore extending along the longitudinal axis and configured to receive a tool bit, a plurality of angled passageways defined in the body, and a plurality of jaws at least received in the passageways and moveable between an axially forward and radially inward clamping position to clamp a tool bit and an axially rearward and radially outward retracted position. At least one jaw has a rear end lying in a first plane transverse to the longitudinal axis. A first key drive member is coupled to a tail portion of the body and configured to be engaged by a second key drive member on an output shaft of a power tool to non-rotationally couple the body to the output shaft. The first key drive member extends axially from a rearward end to a forward end that lies in a second plane transverse to the longitudinal axis. The second plane is axially forward of the first plane when the jaws are in the retracted position.

A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

A quick change tool includes a tool element, an elongate body having a drive shaft and attaching means for attaching the tool element to the body, and a receiving element for attaching to the tool element. The receiving element includes a through-hole for receiving the body by sliding through the receiving element in the longitudinal direction of the body. The receiving element is configured to co-act with the attaching means to lock the tool element relative to the body at least in an axial direction of the drive shaft. The attaching means includes a resiliently movable locking pin arranged spring-mounted in the body. The receiving element comprises a locking hole configured to receive the locking pin therein in a snapping manner. A pin guiding groove extends between a receiving opening of the through-hole and the locking hole for guiding the locking pin from the receiving opening to the locking hole.

A power tool chuck includes a body with a central bore extending along an axis and configured to receive a tool bit, a plurality of angled passageways, and a plurality of jaws received in the passageways and moveable between an axially forward and radially inward clamping position and an axially rearward and radially outward retracted position. At least one jaw has a rear end lying in a first plane transverse to the axis. A first key drive member coupled to a tail portion of the body is configured to be engaged by a second key drive member on a power tool output shaft to non-rotationally couple the body to the output shaft. The first key drive has a forward end lying in a second plane transverse to the axis. The second plane is axially forward of the first plane when the jaws are in the retracted position.

A surgical tool-piece and a coupling mechanism for a surgical tool-piece are provided. The surgical tool-piece is configured to be driving by a driving mechanism. The surgical tool-piece comprises a shaft having a longitudinal axis running from a distal end of the shaft to a coupling portion at a proximal end of the shaft. The coupling portion comprises a driving section comprising at least three indentations located around the circumference of the coupling portion, each indentation being configured to receive a corresponding driving element of the driving mechanism to secure the tool-piece both longitudinally and rotationally.

A cutting device in accordance with some example embodiments is provided for use with an arbor assembly. The cutting device includes a blade having a plurality of teeth, and a back plate at a proximal end of the blade. The back plate has an outer end surface in which a plurality of ramp surfaces and pin locking recess are provided. A central through hole extending through the back plate. The ramp surfaces only allow the cutting device to be rotated relative to the arbor assembly in one direction.