Abstract: A chuck for clamping workpieces or tools is provided. The chuck has a chuck body and at least two clamping jaws are radially displaceably guided in the chuck body and are operable, via wedge surfaces, by a driven chuck piston that is axially displaceable. The chuck piston is in the form of a closed, first annular piston having an outer surface that is guided all the way around in a bore of the chuck body, with a forward region of the outer piston surface being provided with tangentially extending wedge surface, the number of which corresponds to the number of clamping jaws, with these wedge surfaces cooperating with correspondingly shaped counter-surfaces of the clamping jaws. A second annular piston, which operates in an opposite direction, is disposed in the chuck body concentric to the first annular piston. The second annular piston is also provided with tangentially extending wedge surfaces that cooperate with corresponding counter-surfaces of the clamping jaws.

Abstract: A power-operated chuck having a chuck body and clamping jaws that are displaceably guided in radial guides of the chuck body and that are adapted to be actuated by at least one drive element, which is displaceably guided in the chuck body and is actuated by a force producer that is operated with pressure medium. At least one chamber for receiving lubricating grease is provided in the chuck body, with lubricating bores establishing communication between the chamber and at least some glide surfaces provided for the chuck. At least one chuck component is provided that is moved during actuation of the clamping jaws, with this at least one chuck component extending into the chamber for the production of a pump movement that presses lubricating grease into the lubricating bores.

Abstract: An arrangement for mounting a power-operated clamping device for workpieces or tools on a hollow machine-tool spindle in which is disposed a securing rod that is adapted to be coupled with a drive member of the respectively mounted clamping device, and that is adapted to be actuated by a hydraulic or pressurized cylinder secured to the rear end of the spindle. Secured to a flange on the front end of the spindle is an intermediate ring to which the body of the clamping device is adapted to be secured via at least two securing pins. To provide a structurally straightforward design that requires no additional pressure medium cylinder, the securing pins are secured to the clamping device body and are axially oriented, with each securing pin being provided with a notch that has a tightening surface. Key rods are displaceably guided in the intermediate ring, with each key rod having a key that is introducible into a respective notch of the securing pins.

Abstract: A machine tool having a work spindle with an electrically actuated clamping unit including a three-phase motor with a stationary stator. The motor is supplied with electricity from a control unit operating with frequency conversion, and the control unit is alternatingly also used for triggering a spindle drive motor. A sensor detects clamping force applied to a workpiece, and produces a signal used to reduce motor speed of the three-phase motor until a predetermined clamping force is achieved.

Abstract: An apparatus for the adjustment of the tension in rotating gripping devices, which are operable with variable power outputs and follow (hysteresis) distinct tension-characteristics for build-up and withdrawal. In order to make possible a stabilization of the tension which is independent from the rotational speed, a desired value for the tension and an internal tolerance allotment for an upper and a lower desired adjustment value are presupposed in a control apparatus. In the control apparatus a leading regulated quantity is produced digitally for the changing of power outputs. The leading regulated quantity is reduced when the desired value approaches a presupposed amount, so that the actual value in presupposed intervals lessens regularly through the regulated quantity reduction under the desired value and is again increased.

Abstract: A chuck with two oppositely disposed clamping jaws, each of which includes a base jaw and a top jaw. The base jaws are guided in an annular chuck body that has a central clamping space in such a way as to be movable in a radial direction. Each base jaw is driven by a wedge-type member that is mounted in the chuck body in such a way as to be essentially axially movable. In order to provide such a centrally clamping two-jawed chuck with a small overall axial length and a large clamping space, each wedge-type member is driven by a piston of a pressure-medium cylinder. The stroke movements of the two pistons are automatically synchronized by a mechanical coupling element that is disposed in the chuck body parallel to the clamping axis of the two clamping jaws. The coupling element is preferably a coupling shaft. Each base jaw can be provided with a rotatably mounted intermediate jaw, but at least one of the latter being mounted in such a way as to be rotatable via a pivot drive.

Abstract: An electromechanical apparatus for producing an axial force for the actuation of a clamping device, such as a chuck that rotates with the arbor of a machining tool. The apparatus includes an electric motor that has a stator and a rotor, with the relative movement between the rotor and stator being transferable, via a gear system and a shaft drive as an axial movement, to a tie rod which is preferably hollow. In order to have a small overall size, and to reduce the frictional forces that occur during actuation, the rotor is connected with a gear wheel in which meshes at least one pinion that is secured to a shaft that is mounted in a housing in such a way that it cannot shift axially. Disposed on the shaft is a nut that in turn is connected to the tie rod, which is axially movably mounted in the housing.

Abstract: A power-operated chuck that is provided with a plurality of clamping jaws that are disposed in a chuck body in such a way as to be radially movable. The radial clamping movement of the clamping jaws is produced by a gear mechanism disposed in the chuck body and via an axial movement of a drive member. Radial positioning of the clamping jaws relative to the starting position of the drive member is adjustable, prior to carrying out a clamping stroke, for shifting the clamping stroke within the clamping range, with adjustment being effected by an adjustment member that acts simultaneously upon all of the clamping jaws. Via an additional axial movement, the drive member can be conveyed to a position that is beyond the clamping range, and in which position the clamping jaws are uncoupled from the drive member. An additional adjustment member is axially movably disposed in the chuck body.

Abstract: An apparatus for rapidly changing the top jaws of a power-operated chuck having several jaws which are movably guided in a radial direction in a chuck body. Each chuck jaw is formed by a base jaw, and by a top jaw which is exchangeably mounted on the base jaw. After an arresting mechanism has been released, each top jaw can be removed from its base jaw by a relative movement with respect to the latter. The exchange of the top jaws is effected with the aid of a changing apparatus which can be converted from a rest position into a changing position in front of the chuck. The changing apparatus is provided with guide rails which are adapted to correspond with guide surfaces of the base jaws. At least one top jaw is supported on these guide rails, and can be exchanged for the top jaw presently on the base jaw by being displaced by a pusher, which is provided with engaging elements.

Abstract: A rotary chuck having a plurality of clamping elements for clamping a respective workpiece. The clamping elements are interchangeable for adaptation of different dimensions of the workpieces, and can be actuated by a force operation via a direction-changing chuck or drive. At least one of the clamping elements is provided with a tension detector.

Abstract: A method for selecting the proper clamping force to be applied by a rotatable chuck against a workpiece of known rigidity comprises the steps of inserting a transducer of known rigidity into a chuck of known rigidity, measuring the clamping force under conditions of a stand-still and rotation to obtain a change in clamping force induced by rotation, and multiplying the change of force by a correction factor involving the foregoing rigidities to obtain a predicted change of clamping force which would be experienced upon insertion of the workpiece in the chuck. The predicted change in clamping force enables an operator to select a sufficient amount of clamping force for safely retaining a workpiece in the chuck during rotation.

Abstract: A chuck with T-slots to receive slot blocks for the attachment of stops or rests on the chuck body or on clamping jaws guided for radial movement within the chuck body by at least one attachment screw which engages into a slot block. In order to prevent throwing off of the clamping jaws even if the attachment screws are not properly tightened, the T-slot opens at its radially inward end into a continuous bore having a diameter corresponding to the width of the slot at the base of the slot and at least the base of the slot terminates at a radial distance from the outer periphery of the chuck body at the radially outward end of the slot or the base of the slot is inclined away from the face of the chuck in a direction toward the outer periphery.

Abstract: A power-operated chuck, for turning machines, having at least one jaw which is radially movably guided in a chuck body and which is actuated by a pressure medium piston which is movably guided in the chuck body and the working chamber of which is connected to a source of pressure medium via a releasable check valve. The working chamber of the pressure medium cylinder is connected with the pressure chamber of a centrifugal force compensating cylinder, the compensating piston of which is designed as a centrifugal weight and is radially movably guided in the chuck body. The radially outer end of the compensating piston projects into the pressure chamber. So that the system is effective independent of the level of the working pressure, the radially inner end of the compensating piston projects into a relief chamber which is directly connected, i.e. by-passing the check valve, with the source of pressure medium via a short-circuit line.

Abstract: The present invention relates to a method and apparatus for determining a working range of a double-acting clamping cylinder for actuation of operating devices, such as supporting, centering or chucking devices, respectively on machine tools, particularly replaceable chucks on lathes, giving consideration to a post-tightening distance and controlling of the drive for effecting of the machining of the workpiece.

Abstract: A device measures the force occurring on radially inwardly movably guided clamping elements of clamping devices. In order to create, with a simple construction, the ability to place the device directly at the corresponding clamping points of the clamping elements without the clamping elements having to be shifted or turned, there is arranged in fixed position in a housing at least one force pickup of substantially radial alignment which rests at its inner end against the housing and is provided on its outer end with a connection for a replaceable pressure piece. At least one similar pressure piece furthermore can be applied to another place on the housing.

Abstract: A clamping force relates to a clamping-force transducer for rotating clamping devices which has at least two opposite pressure pieces adapted to be placed on the clamping elements of the corresponding clamping device and arranged in a support member, at least one of which pressure pieces acts on a force transducer the measurement values of which are taken from the rotating clamping-force transducer housing via a stationary transfer housing. To adapt the clamping-force transducer simply to clamping devices having a different number of clamping elements and to different clamping diameters without the rigidity of the clamping-force transducer being changed thereby, the pressure pieces are arranged replaceably but fixed on the arms of a multi-arm measurement member, at least one arm of the measurement member being developed as the force transducer. The measurement member preferably has a star shape with six arms, each of which has a connection for a pressure piece.

Abstract: The present invention relates to a power-actuated chuck having a plurality of clamping jaws which are radially guided in a chuck body and are connected, via wedge receivers which extend at an angle to the axis of the chuck and wedge pieces extending into said wedge receivers, to an adjustment member which is axially displaceable in the chuck body and whose operating stroke is limited by form-locking and can be lengthened by turning a ring mounted coaxial to the chuck axis in the chuck body in order to disengage the clamping jaws from the adjustment member. In order to be able to disengage the clamping jaws from the adjustment member by an additional stroke of the latter without additional transmission elements being necessary for this, the ring is developed as a synchronizing ring (6) for controlling at least two stop pins (7) which are mounted in the chuck body (1) and are displaceable into the path of movement of the adjustment member as stops limiting the operating stroke (A) of the adjustment member (4).