A spindle includes a housing including a first opening, a bearing housed in the housing, a main shaft rotatably supported by the bearing, a collet chuck in a first through hole defined in the main shaft to grip a machining tool and being movable in an axial direction of the main shaft, a draw bar connected to the collet chuck, and a cover covering the first opening and including a second through hole through which the main shaft is disposed. The main shaft and the cover are disposed at a distance from each other.

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.

Provided is a method for evaluating tool installation when fastening a tool to a main shaft of a machine tool, wherein the method includes a storage step for storing a reference location of a draw bar at the time when the tool is contacting a mounting seat of the main shaft, in a state in which foreign matter has been removed from the surface of the mounting seat and from the contacting surface of the tool. The method for evaluating tool installation includes a measuring step for measuring a measurement location of the draw bar when the tool is installed on the main shaft, and a determination step for determining the installation state of the tool to be abnormal if a measurement-location error with respect to the reference location exceeds a predetermined determination range.

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.

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.

This device is provided with: a main shaft (20) onto which a tool (100) is detachably mounted; a rod (30) slidably supported by the main shaft (20) and configured to attach or detach the tool (100) to or from the main shaft (20) through a sliding action; a fluid channel (32) formed in the rod (30); fluid feed device (51, 70) configured to feed a fluid into the fluid channel (32); a plurality of fluid channels for seating detection (24) for detecting when the main shaft (20) and the tool (100) are in a seated state, the fluid channels for seating detection (24) being formed in the main shaft (20) so as to communicate with the fluid channel (32) when the rod (30) is positioned at a first position; and a plurality of fluid channels for cleaning (25) for cleaning seating portions of the main shaft (20) and the tool (100), the fluid channel for cleaning (25) being formed in the main shaft (20) so as to communicate with the fluid channel (32) when the rod (30) is positioned at a second position different from the first position.

A clamping device includes a first clamping segment which has a first mounting flange and a tubular member extending axially away therefrom. A first bore extends through the first mounting flange and the tubular member. The first mounting flange is configured for attachment to a rotatable spindle of a machine tool. The clamping device includes a draw bar assembly which has an axially extending elongate shaft. The elongate shaft extends through the first bore of the first clamping segment. A biasing unit is mounted on or in the tubular member. A locking member is removably secured to the elongate shaft such that the biasing unit is compressed between the locking member and a portion of the first clamping segment. The biasing member remains compressed when the first clamping segment is separated from the spindle of the machine tool.

An electrospindle device includes at least one electrospindle extending about a vertical axis, the electrospindle including a motor, a shaft that rotates for transmitting motion, and an engagement portion for a toolholder in which a tool rotatably actuated by the shaft is mounted, the tool being actuated directly by the shaft; at least one toolholder support element including at least two toolholders; and at least one device for rotating the at least one toolholder support element, wherein operation of the at least one device for rotating the at least one toolholder support element brings a selected one of said at least two toolholders into vertical alignment with the engagement portion and extending in the vertical axis.

A machine tool clamping device for releasably holding a tool holder having a tapered shank and a knob protruding from the tapered shank, the clamping device having: a spindle, rotatable about an axis, and having a tapered socket at a lower end thereof and an axial passage, the tapered socket being complementary in shape to the shank of a tool holder. Clamping members are pinned to the spindle and extend into the axial passage, the clamping members being pivotal between a clamped position in which the clamping members clamp the tool holder knob, and an unclamped position in which the clamping members release the tool holder knob. A drawbar is slidable within the spindle axial passage between the clamping members, the drawbar having a surface that acts to pivot the clamping members between the clamped and unclamped positions depending on the position of the drawbar within the axial passage. A spring is arranged between the drawbar and the spindle to bias the drawbar to the clamped position.