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.

This invention concerns a clamping device for firmly holding a part to be clamped at a clamping recess in which the clamping device is arranged. The clamping device comprises a collet with a first external protrusion for engagement with an internal recess in an inner peripheral area of the part that is to be clamped and with a second external protrusion for engagement with an internal recess in an inner peripheral area of the clamping recess. At least one of the first external protrusion or the second external protrusion comprises a first external taper or a second external taper for pulling the part to be clamped axially into the clamping recess by a radial outward movement of the collet or a section of the collet and an operation stud including an external tapered section for effecting the radial outward movement of the collet. The connection between the operation stud and the collet is self-locked and pre-loaded after a clamping movement of the operation stud in axial direction that locks and pre-loads the external taper of the operation stud and the collet or a part between the collet and the operation stud with each other. The invention includes a method for a part to be clamped in a clamping recess.

An ultrasonic spindle device with automatic tool changer is disclosed. The ultrasonic spindle device includes a housing member having an inner space along a longitudinal direction, a shaft member rotatably disposed in the inner space and having a hollow portion, an ultrasonic oscillation member disposed in the hollow portion and having a through hole, a drawbar member disposed in the hollow portion to move in a front-rear direction, a portion of the drawbar member being inserted into the through hole and passing through the ultrasonic oscillation member, a clamping member connected to a front end of the drawbar member and clamping a tool, a portion of the clamping member being disposed outside the housing member, a rotation means rotating the shaft member, and a cylinder member moving the drawbar member forward or backward along a longitudinal direction of the shaft member.

A spindle nose for a machine tool spindle. The spindle nose has a longitudinal axis and a receiving end at which a conical receiving area opens. The receiving area tapers conically away from the receiving end in the direction of the longitudinal axis for receiving a tool shaft cone. A circumferential wall surrounds the receiving area and forms a circumferential contact edge. The contact edge has flat contact surfaces on which contact surfaces of the tool shaft cone rest when the tool is clamped in the tool spindle. The spindle nose defines blind receiving bores leading perpendicularly to the flat contact surfaces and which end below the flat contact surfaces. The contact edge is divided into at least four segments with the same angle. At least one receiving bore is formed in each of the segments. A sensor is arranged in each receiving bore.

A machine tool comprising tool spindle (12) having a chuck (26) and a spindle motor, in which the chuck (26) can be actuated for the purpose of receiving and releasing a tool, a sealing air channel (40) is provided which extends at least partially radially outside the chuck (26). The sealing air channel (40) terminates in or at a protective cap (34).

A clamping device for releasably holding a tool holder shank includes a housing and a drawbar mounted reciprocally inside a bore of the housing and which in a forward end includes an engagement means, which is arranged to engage an engagement formation located at the end of the tool holder shank and in a rear portion is formed with a drawbar aperture. The clamping device further includes a clamping mechanism extending through the drawbar aperture, which is to impart an axial displacement of the drawbar to and fro in the direction of the longitudinal axis of the housing. The clamping mechanism includes a first and a second actuator and an actuator bolt interconnecting the actuators, extending through the drawbar aperture and arranged such that a rotation of the actuator bolt causes the actuators to move synchronously towards or apart from one another, imparting an axial movement of the drawbar.

A machine tool comprises a tool carrier, e.g. in the form of a turret disc (7) that is provided with receptacles (8) for tool holders (9), wherein each tool holder and tool carrier comprise support surfaces associated to each other and devices for fixing the tool holder at the tool carrier. At least one clamping element is provided at the tool carrier (7) that is adjustably supported between a clamping position and a release position in a direction transverse to a tie rod of a tool holder arranged on a slider (22) receptacle of the tool carrier. The clamping element is provided with a first clamping surface (24) that can be brought into engagement with a second clamping surface (35) at the tie rod of the tool holder in a self-locking and releasable manner.

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.

A clamping device for clamping a workpiece or a tool or, more specifically, a tool holding fixture in a machine part of a machine tool includes a tension rod slidably mounted within the machine part; a clamping set movable by the tension rod between clamped and released positions; a tension spring dedicated to the tension rod so as to generate the pull-in force of the clamping set; and a release mechanism, by which the clamping set can be moved against the force of the tension spring into the released position by the tension rod. To make possible effective clamping at optimum force, the tension spring is clamped between first and second rod parts of the tension rod. The second rod part can move relative to the first rod part, and, as the clamping set moves into the released position, is compressed on both ends by the release mechanism by moving the two rod parts in opposite directions.

A spindle unit for machine tools that includes a working spindle rotationally bearing-mounted in axially spaced spindle bearings in a spindle case, and an electric driving motor. The working spindle includes at its head side a clamping device for a tool and at its rear side a non-rotating ring cylinder for activating said clamping device via a rotating tie rod, and rotational bushing for supplying said tool with cooling and/or lubricating agents through a hydraulic conduit extending longitudinally through said working spindle. At least a segment of the non-rotating ring cylinder may be received in the rear end portion of said working spindle.