A clamping device is arranged for releasably holding a tool holder shank and includes a housing, a wedge engagement member reciprocally mounted inside the housing, and a wedge having a first pressure receiving surface and first and second wedge surfaces. An aperture extends radially through a wall of the housing and the wedge engagement member extends radially outwards into the aperture. The first wedge surface acts upon a wedge engagement slide surface on the wedge engagement member and the second wedge surface acts upon an aperture slide surface. The wedge is arranged between a surface of the housing and a surface of a member securely arranged to a drawbar to effectuate a displacement of the drawbar when the wedge is moved inwards, to clamp the tool holder shank. A sleeve is arranged around the peripheral surface of the housing for moving the wedge inwards when the sleeve is moved.

A clamping unit includes a drawbar having an interior surface defining a fluid transport channel. A fluid transport pipe is at least partially disposed within the interior of the drawbar and is in fluid communication with a fluid transport adapter and a fluid transport channel to enable high pressure fluid to be provided directly to a toolholder. The clamping unit further comprises at least one spring-like member positioned around the outer surface of the drawbar to provide a biasing force against an end plate. The drawbar is movable along a longitudinal axis between a locked position and a tool release position by applying and not applying hydraulic pressure against the end plate, thereby providing a quick-change feature of the invention.

A workholding apparatus (2) having jaws (5) comprising interchangeable adapter blocks (12) that enable a single workholding apparatus (2) to accommodate workpieces (22) having a range of inner bore diameters.

A coupling device for coupling a hollow shaft taper to a receiver provided on the machine tool, having a collet and a tension rod by means of which the collet can be brought into a release position or a clamping position. The collet is embodied in one piece and has several clamping segments extending in its longitudinal direction. Upon moving the collet into the clamping position, said clamping segments are moved in a radial direction against spring forces exerted by the spring element. The spring elements are an integral part of the collet. Each spring element between two adjacent clamping segments is provided to extend in the longitudinal direction of the latter.

In one aspect tool holder assemblies are described herein. Such tool holder assemblies can employ outer and inner spring-like members. For example, a tool holder assembly described herein comprises a drawbar having an outer diameter surface and an inner diameter surface defining an interior of the drawbar. The drawbar is movable or actuatable along a longitudinal axis between a locked position and an unlocked position. The tool holder assembly can further comprise a first spring-like member positioned around the outer diameter surface of the drawbar and a second spring-like member positioned in the drawbar interior.

A clamping unit includes a drawbar having an interior surface defining a fluid transport channel. A fluid transport pipe is at least partially disposed within the interior of the drawbar and is in fluid communication with a fluid transport adapter and a fluid transport channel to enable high pressure fluid to be provided directly to a toolholder. The clamping unit further comprises at least one spring-like member positioned around the outer surface of the drawbar to provide a biasing force against an end plate. The drawbar is movable along a longitudinal axis between a locked position and a tool release position by applying and not applying hydraulic pressure against the end plate, thereby providing a quick-change feature of the invention.

A clamping device for releasably holding a tool holder shank includes a spindle rotatably mounted inside a housing, a drawbar axially moveable in a bore in the housing between an advanced releasing position and a retracted locking position, engagement members moveable under the effect of the drawbar into locking engagement with the tool holder shank, an actuating member slidably mounted to the spindle, a motion transferring mechanism for transferring an axial movement of the actuating member into a movement of the drawbar, and a cylinder housing and an associated piston member for moving the actuating member in relation to the spindle. The cylinder housing is arranged in the housing in an axially floating manner. The actuating member is rotatable in relation to the cylinder housing and the piston member together with the spindle.

To provide a clamp device which is designed to shorten a spindle than before, thus enabling the downsizing of a spindle device.

In a clamp device for removably mounting a tool holder to a spindle of a rotary spindle device, a clamp mechanism is placed in a clamp state by a reciprocation drive mechanism producing a rearward movement in which a draw-in sleeve (9) engaged therewith via steel balls (13) is moved rearward to bring through-holes (12) thereof to rearward large diameter portion (4d) in a bore region of a spindle body (4) and further rearward to a position where the steel balls (13) are retained between the rearward large diameter portion (4d) and a jig large diameter portion (14a), while the retreated draw-in sleeve (9) moves rearward a draw-in bolt (8) and a clamp sleeve (5) by means of a biasing force of an elastic member (10).

A spindle apparatus according to the present disclosure includes a housing, a spindle rotatably installed in the housing, a tool releasably engaged with one end of the spindle and having an insert tip movable in a radial direction of the tool, a first draw-bar movably mounted in the spindle, and a second draw-bar movably mounted in the first draw-bar. The tool and one end of the first draw-bar are releasably engaged with the one end of the spindle by a movement of the first draw-bar, and the insert tip is configured to move in the radial direction by a movement of the second draw-bar.

A counter bearing for machining spindles of machine tools has at least one expansion bushing with an elastically deformable wall that delimits at least one pressure chamber. The pressure chamber accommodates a pressure medium. A supply line for the pressure medium opens into the pressure chamber. A pressure conduit opens into the pressure chamber. A mechanically actuatable pressure element is disposed in the pressure conduit and actuated by an actuating tool. A piston is slidably arranged in the pressure conduit and actuated by the pressure element, wherein the piston loads the pressure medium.