A clamping device for releasably holding a tool holder shank formed with a bore includes a housing having a forwardly facing surface and a bore. A drawbar is mounted reciprocally movable inside the bore and in a forward end has engagement device, which is arranged to engage with an engagement formation inside the bore of the tool holder shank. The drawbar is, in a rear portion, formed with a drawbar aperture, and a cam shaft extending through the drawbar aperture and being rotatably journalled in the housing and arranged to impart an axial displacement to the drawbar in relation to the housing. The cam shaft includes first and second spaced apart cam formations and an intermediate circular cylindrical portion located between the cam formations, wherein the first and second cam formations are journalled in a first and second seating apertures, respectively, in the housing on opposite sides of the drawbar.

A clamping device is arranged for releasably holding a tool holder shank. The clamping device includes a housing, a drawbar mounted reciprocally movable inside a bore in the housing, and an actuator. An aperture extends along an actuator axis and is delimited by an aperture housing surface and a drawbar groove. A first locking pressure applying surface on the actuator acts upon a first locking pressure receiving surface in the drawbar groove to effectuate a displacement of the drawbar when the actuator is moved along the actuator axis in a first direction, resulting in clamping of the tool holder shank.

A clamping device for clamping a workpiece or a tool or a tool holder to a machine component of a machine tool, including an axially movable tension rod, a clamping assembly which can be moved by the tension rod between a clamped position and a released position, a spring assembly dedicated to the tension rod for generating the clamping and draw-in force of the clamping assembly, and a releasing unit by which the clamping assembly can be moved by the tension rod against the force of the spring assembly into the released position. The spring assembly has a minimum of one spring unit with a plurality of flexible spring members disposed between a first and a second spring holder, with the first and second spring holders being secured against torsion relative to the tension rod.

A clamping device for clamping a workpiece or a tool or a tool holder to a machine component of a machine tool, having an axially movable tension rod, a clamping assembly which can be moved by the tension rod between a clamped position and a released position, a spring assembly dedicated to the tension rod with a plurality of series-connected spring units for generating the clamping and draw-in force of the clamping assembly, and a releasing unit by which the clamping assembly can be moved by the tension rod against the force of the spring assembly into the released position. To ensure the most uniform load possible, the axial spring deflection of the spring units is limited by a stop when the spring assembly is compressed.

Disclosed is a clamping device (1) for clamping a toolholder of a drilling, milling or grinding tool in a balancing machine, comprising a receiver unit (2) having a receiving opening (9) for the coupling shaft of the toolholder and a collet (10), in which the shaft (20) of an actuator (18) for actuation of the collet (10) is slidably guided in a centrally located bore (19) of the receiver unit (2). The shaft (20) has at its one end a load-applying body (22) upon which a plurality of compression springs (30, 31) take support to enable the collet (10) to be tightened. The compression springs (30, 31) are arranged and/or configured in such a way that the spring loads acting on the load-applying body (22) with the collet (10) tightened act on the load-applying body (22) asymmetrically relative to the axis of the shaft (20).

A collet adaptor (10) including a body (11, 12) having forward and rear ends and an axial bore (17) extending through the forward and rear ends. A drawbar (13) disposed at least partly within the bore (17) for connection to a collet (14). The drawbar (13) is secured within the bore (17) and a biasing arrangement (42) acts on the drawbar (13) in a direction tending to shift the drawbar (13) rearwardly within the bore (17). The drawbar (13) is displaceable within the bore (17) against the biasing influence of the biasing arrangement (42) to shift forwardly within the bore (17).

A clamping device for releasably holding a tool holder shank includes a spindle rotatably mounted inside a housing. A drawbar is axially moveable in a bore in the housing between an advanced releasing position and a retracted locking position. A plurality of engagement members are moveable under the effect of the drawbar into locking engagement with the tool holder shank. An actuating sleeve is arranged around a peripheral wall of the spindle and axially moveable in relation to it. A motion transferring mechanism is arranged for transferring an axial movement of the actuating sleeve into a movement of the drawbar. A hydraulic cylinder arrangement is arranged for moving the actuating sleeve. The hydraulic cylinder arrangement includes a cylinder casing fixed to spindle and an annular piston head, which is fixed to or fixedly connected to the actuating sleeve and slidably received in an annular space inside the cylinder casing.

A clamping device for releasably holding a tool holder shank includes a spindle rotatably mounted inside a housing. A drawbar is axially moveable in a bore in the housing between an advanced releasing position and a retracted locking position. A plurality of engagement members are moveable under the effect of the drawbar into locking engagement with the tool holder shank. An actuating member is slidably mounted to the spindle. A motion transferring mechanism is arranged for transferring an axial movement of the actuating member into a movement of the drawbar. Two or more hydraulic actuators are arranged in or mounted on the housing on different sides of the spindle and configured to move the actuating member in relation to the spindle. A connecting element forms a connection in radial direction between the actuating member and piston members of the hydraulic actuators.

A clamping device for releasably holding a tool holder shank includes a housing, a drawbar axially moveable in a bore in the housing, engagement members moveable under the effect of the drawbar into locking engagement with the tool holder shank, and an actuating member rotatably arranged in the bore. Upon rotation of the actuating member, a contact surface on a motion transferring element fixedly connected to the actuating member achieves an axial movement of the drawbar by pressing against a contact surface on another motion transferring element fixedly connected to the drawbar. At least one of the contact surfaces includes two sections with mutually different pitch, such that the same angular displacement of the actuating member, when rotated in a first rotary direction, results in a longer axial movement of the drawbar in a first phase of the rotary movement than in a final phase thereof.

A spindle device includes a main spindle having a tapered hole that is positioned at one end and to which a tool is removably attached, and a spindle cylindrical portion that is positioned on the other end side with respect to the tapered hole and communicates with the tapered hole, a collet chuck that is disposed inside the spindle cylindrical portion and grips the tool, and a drawbar that is connected to the other collet end of the collet chuck and moves the collet chuck forward and backward along an axial direction of the main spindle. The collet chuck includes a plurality of collet clearances that extends from one collet end forming one end and having an annular shape toward the other end of the main spindle, and forms channels that guide air to the tapered hole. The spindle cylindrical portion has a housing space in which the other collet end is housed in a clamped state. The main spindle includes a plurality of spindle air supply channels for supplying air to the housing space in an unclamped state. The spindle device further includes an annular channel that communicates upstream sides of the plurality of spindle air supply channels.