WO1996004090A1

WO1996004090A1 - Chuck

Info

Publication number: WO1996004090A1
Application number: PCT/EP1995/003016
Authority: WO
Inventors: Horst Nespeta; Franz Pfob; Friedrich SCHÖLER; Werner Fleschutz
Original assignee: Zettl GmbH CNC Präzisions- und Sonderwerkzeuge
Priority date: 1994-07-29
Filing date: 1995-07-28
Publication date: 1996-02-15
Also published as: DE4427051A1; DE29521475U1

Abstract

The chuck as per the invention comprises a base body unit and, rotatably mounted thereon, a clamping jaw taper sleeve in which clamping jaws can be displaced in such a way that they are radially adjusted by means of axial displacement relative to the clamping jaw taper sleeve, a worm drive that axially displaces the clamping jaws and is actuated by rotation of the clamping jaw taper sleeve, and a gear for increasing the clamping force, wherein the worm drive has a first threaded body which is connected with the clamping jaws and is moved axially and a second threaded body which meshes therewith, the screw action providing that when the clamping jaw taper sleeve is rotated the first threaded body effects an axial movement which is transmitted to the clamping jaws. The chuck as per the invention is characterized in that the clamping force gear has a gear output member coupled to one of the threaded bodies and, meshed therewith, a gear input member which can be rotated about an axis to actuate the clamping force gear so as to exert a torque on the threaded body coupled to the gear output member, this torque being transformed into an axial force on the first threaded body.

Description

CHUCK

The invention relates to a chuck with a base body unit set up for mounting on a chuck receptacle, in particular a machine tool, a clamping jaw constricting sleeve arranged in the center of the base body unit and rotatable relative to the base body unit about its longitudinal axis, in which a plurality of circumferentially offset clamping jaws axially are slidably received and guided in such a way that they can be adjusted radially by axial displacement relative to the clamping jaw constricting sleeve in order to clamp a tool shaft between the clamping jaws, a spindle drive coupled to the clamping jaw constricting sleeve and operable by rotation of the clamping jaw constricting sleeve and axially displacing the spindle drive for radial approximation of the Clamping jaws on a tool shank to be clamped, and with a clamping force increasing gear acting on the spindle drive for exerting a clamping force on the approximated clamping jaws on d A tool shank to be clamped, the spindle drive having a first threaded body that is axially movably guided in a force-transmitting connection with the clamping jaws and a second threaded body that is in screw engagement therewith, one of which is designed as an externally threaded spindle body and the other as an internally threaded sleeve body that is formed both extend along the axis of the base body unit and, when the clamping jaw narrowing sleeve rotates, cooperate by means of the screw engagement in such a way that the first threaded body executes an axial movement which is transmitted to the clamping jaws. In the case of a chuck of the type mentioned above, the spindle drive actuated by rotation of the clamping jaw narrowing sleeve is used as a clamping jaw approximation gear, with which the clamping jaws can be approximated to a tool shaft to be clamped or can be lifted radially from the tool shaft over a comparatively large radial feed path. If a previously clamped tool with a large shank diameter is to be replaced by another tool with a considerably smaller shank diameter, the corresponding radial adjustment of the clamping jaw adjustment can be achieved by a few turns of the clamping jaw constriction sleeve. However, if the transmission ratio with respect to the rotation of the clamping constriction sleeve to the axial drive of the first threaded body is selected to be comparatively large, so that a correspondingly large axial stroke of the threaded body takes place at a small angle of rotation, it is difficult to achieve the necessary for securely clamping the tool shank Apply clamping forces by turning the jaw constriction sleeve. General safety requirements, however, require that the respective tool shank is clamped firmly and reliably. In practice, moreover, there is often the need to have the chuck as an add-on part of a rotating machine tool spindle rotate in different directions. In such a case, the secure clamping of a tool shank requires particularly strong clamping forces that withstand the tendencies to loosening that can occur when the chuck is rotated in one of the two directions of rotation.

In a chuck of the type mentioned at the outset, the clamping force increasing gear is used to apply a high clamping force corresponding to the clamping force requirements mentioned, after the clamping jaws are approximated to the tool shaft to be clamped by the clamping jaw approximation gear and, if necessary, are pre-tensioned by a clamping force already exerted . The clamping force increase drives should be designed in such a way that the resulting increase in clamping force can be achieved with little actuation effort.

A generic chuck is known from DE 41 10 894 AI. In this known chuck, the first threaded body is designed as an internally threaded sleeve body which is rotatably and axially displaceably mounted in a guide sleeve. The internally threaded sleeve body is connected via interlocking profiles to the respective clamping jaws for axial entrainment in both axial directions and furthermore in rotary entrainment engagement. The clamping jaws are in turn connected to the clamping jaw constricting sleeve via a conical expanding cage, the expanding cage being connected to the clamping jaw constricting sleeve for common rotation. Rotation of the clamping jaw constricting sleeve therefore leads to a rotation of the inner threaded sleeve body, which is screwed axially relative to the second threaded body of the spindle drive designed as an external threaded spindle body. The external thread spindle body in the chuck according to DE 41 10 894 A1 is non-rotatable, but is displaceably mounted in the base body unit over a small axial movement distance.

The clamping jaws are guided on a conical inner circumferential surface of the clamping jaw constricting sleeve and on the expanding cage in such a way that an axial movement of the clamping jaws is accompanied by a radial movement. In this way, the radial feed of the clamping jaws takes place via their axial displacement by means of the internally threaded sleeve body when the clamping jaw constricting sleeve rotates. The clamping force increasing gear mechanism described in DE 41 10 894 AI consists of an eccentric shaft which is mounted essentially radially to the axis of the base body unit in the base body unit and has an eccentric body which is the end of the external threaded spindle body removed from the clamping jaws acted upon. When the eccentric shaft rotates, starting from an ineffective rotational position, into an effective rotational position, the eccentric body exerts an axial force on the externally threaded spindle body of the spindle drive, which is transmitted via the screw engagement between the threaded bodies to the internally threaded sleeve body and from there to the clamping jaws is released in order to increase the clamping force exerted by the clamping jaws. Thus the radial approach of the clamping jaws to a tool shank to be clamped can be effected by rotating the clamping jaw constriction sleeve with comparatively simple turning effort, after which the clamping force increasing gear can then be used to apply the desired higher clamping forces.

In the known chuck, the clamping jaw constriction sleeve is fixed axially immovably on the base body unit by a snap ring. This snap ring acts as a friction brake between the clamping jaw constricting sleeve and the base body unit when the clamping jaw constricting sleeve is axially loaded when the clamping jaws are axially propelled during clamping.

In the chuck explained in more detail in DE 41 10 894 AI, only an axial stroke of the spindle drive corresponding to the eccentricity of the eccentric body of the spindle drive can be used to increase the clamping force via the clamping force increase gear. This means that the operator must always ensure that the clamping jaws are brought so close to the tool shank to be clamped that the axial stroke of the spindle drive that is possible by actuating the clamping force increase gear is sufficient to actuate the clamping jaw approach gearbox to achieve the minimum clamping force required for safe operation to apply. The operator will therefore always be required to generate a preload by rotating the clamping constriction sleeve in order to ensure that the clamping force increasing gear is sufficiently effective. In extreme cases, it could happen that the operator causes the clamping jaws to approach the tool shank inadequately when the clamping force approximation gear is actuated, and then relies on the fact that after actuation of the clamping force increase gear, a sufficiently secure clamping has taken place, although by actuation the eccentric shaft has only undergone a further radial approach of the clamping jaws, which however has not led to a sufficiently high increase in clamping force. If an attempt were now made to increase the eccentricity of the eccentric body in order to achieve a greater axial stroke of the spindle drive when the clamping force increasing gear was actuated and thus to make the above-mentioned case less likely, normally a very large actuating torque would always be present the actuation of the clamping force increasing gear is necessary, which runs counter to the requirement for safe and simple handling. But even in the event that the operator is instructed to use the reaction torque when actuating the clamping force increasing gear small eccentricity of the eccentric body to estimate whether the applied clamping force is sufficient, the known chuck cannot be handled better, since the necessary corrections always result in the necessary corrections reciprocal actuation of the clamping jaw constriction sleeve and the clamping force increase gear necessary.

In DE 41 10 894 AI is already referred to the fact that a worm gear can be used to increase the thrust. However, DE 41 10 894 AI does not provide any further information on how to arrange a worm gear and how to use it effectively. From the overall context of the disclosure of DE 41 10 894 AI, the person skilled in the art could at best have been considered to use a worm gear which comprises a thrust body which acts on the end face of the non-rotatable external thread body which is remote from the clamping jaws. From WO 92/17 305, which emerged as a subsequent application to DE 41 10 894 AI, a non-generic chuck is known which has a worm gear. The latter known chuck has only one gear for the delivery of the tensioning jaws and the application of the required clamping force ^"on. This transmission umf SST a in a Grundkörper¬ unit axially slidably but non-rotatably mounted internally threaded sleeve body, the above interlocking profiles for axial entrainment with The clamping jaws are guided in an expanding cage which is fixed non-rotatably on the base body unit and on the conical inner circumference of a corresponding clamping jaw constricting sleeve, the clamping jaw constricting sleeve also being fixed non-rotatably on the base body unit The external threaded spindle body has a worm gear toothing provided on its circumference, which meshes with a worm shaft rotatably mounted tangentially to it in the basic body unit f The worm shaft can be rotated using a hexagon wrench in order to set the externally threaded spindle body in rotation. If this happens, then there is an axial screwing of the non-rotating internal thread sleeve body, this axial movement being transmitted to the clamping jaws, which are controlled radially by means of their guidance. The radial approach movement of the clamping jaws to a tool shank to be clamped and the exertion of the required clamping force is achieved solely by actuating the worm gear. If the gear ratios of this gear system are now selected so that strong clamping forces can be generated by a small torque that is to be applied manually, it is impossible to also achieve rapid radial infeed over larger feed paths with little turning effort using this gear system. The person skilled in the art will find in WO 92/17 305 the above-described solution according to DE 41 10 894 AI with the indication that it would be desirable, in the case of a chuck, on the one hand, and the possibility of rapid radial infeed of the clamping jaws over correspondingly large feed paths on the other hand to provide for the application of a clamping force sufficient for all clamping force needs. In connection with a worm gear in chucks, WO 92/17 305, however, only offers a specific solution in which the possibility of rapid delivery of the clamping jaws cannot be realized.

The same applies to a chuck, which is described in DE 30 48 274 AI and shown in Figure 2. The last-mentioned known chuck also has an axial spindle drive which is actuated by a worm gear and which acts on non-rotatably mounted but axially and radially displaceable clamping jaws. In contrast to the worm gear solution according to WO 92/17 305, in the object according to DE 30 48 274 AI an externally threaded spindle body is designed as an axially displaceable but non-rotatable feed element, while the internally threaded sleeve, which is in engagement therewith, is rotatable and a worm gear toothing is on ¬ has a circumference that can be actuated by a screw.

A further chuck is known from DE 32 22 399 A1, which provides for the possibility of rapid delivery of the clamping jaws by means of a spindle drive and the re-tensioning by means of a clamping force increasing gear. The chuck according to DE 32 22 399 AI comprises a spindle drive with an internally threaded sleeve body which can be rotated by hand relative to the basic body unit and the clamping jaw constriction sleeve fixed thereon and which is fixed axially immovably on the basic body unit. The internally threaded sleeve acts in a screwing manner with an externally threaded spindle body which is non-rotatable but axially is slidably mounted in the base body unit and is connected to the relevant jaws for axial entrainment in both axial directions. Rotation of the internally threaded sleeve body can thus bring the clamping jaws closer to a tool shaft to be clamped. The inner thread sleeve body is provided with a circumferential toothing on its circumference. Tangentially to this extends a toothed rack mounted in the base body unit, which is slidably guided in its longitudinal direction, but is non-rotatably mounted. The toothed rack is biased towards an ineffective position by a return spring and has a tooth-free axial area which, in the inactive position, lies opposite the outer circumferential toothing of the internally threaded sleeve body, so that there is no meshing engagement between the toothed rack and the circumferential toothing when the toothed rack is in the ineffective position. Only in this case can the jaw approach by direct rotation of the female threaded sleeve body. A toothed axial region of the toothed rack can be brought into meshing engagement with the external toothing of the internally threaded sleeve body in order to increase the clamping force by axially displacing the toothed rack. This takes place after the clamping jaws have approached the tool shank in question by actuating a pressure screw against which the toothed rack is supported against the spring prestressing force. The rotation of the pressure screw thus leads to an axial displacement of the rack, which thereby comes into engagement with the internally threaded sleeve body and rotates it in the sense of an increase in the clamping force. In the chuck according to DE 32 22 399 AI, the problem discussed in connection with the subject matter according to DE 41 10 894 AI occurs analogously due to the design that only a small axial stroke of the clamping jaws can be achieved by the clamping force increasing gear concerned. This is due to the fact that only a comparatively short axial region with teeth can be provided on the toothed rack, unless one wishes to prevent that the rack protrudes outward beyond the outer circumference of the chuck, and that there is only a relatively small amount of axial movement for this toothed area, since it must be ensured that in the inactive position of the rack a sufficiently large one preventing mutual engagement toothing-free area lies opposite the external thread of the internal thread sleeve body. The only limited possible axial stroke of the external threaded spindle body and thus the clamping jaws when the clamping jaw increasing gear is actuated, as already described with reference to DE 41 10 894 AI, now harbors the risk that the stroke possible by the clamping jaw increasing gear has already been used without one to have caused sufficient tension on the tool shank to be clamped.

The invention has for its object to provide a chuck of the type mentioned which, regardless of the degree of radial proximity of the clamping jaws caused by turning the clamping jaw sleeve to a tool shank to be clamped, always enables the tool shaft to be securely clamped by actuating the clamping force increasing gear.

To achieve this object, it is proposed according to the invention that the clamping force increasing gear unit has a toothed round body coupled with one of the threaded bodies for common rotation and arranged coaxially therewith as a gear output member and a round body designed with a toothing for engaging the toothing of the gear output member as a gear input member has which can be rotated about its axis for actuating the clamping force increasing gear, so that a torque can be exerted on the threaded body coupled to the geared output member by rotating the gear input member, which torque is applied to the first threaded body by means of the screw engagement of the threaded body of the spindle drive. kend force and transmitted to the jaws is transformed.

The chuck according to the invention thus provides the possibility of bringing the clamping jaws closer to a tool shaft inserted into the chuck by rotating the clamping jaw constriction sleeve, and then by turning the gear input element of the clamping force increasing gear to exert a sufficiently large clamping force on the tool shaft for all clamping force needs ¬ practice. By rotating the transmission input member, the threaded body of the spindle drive, which is in a force-locking connection with the clamping jaws, can be further axially displaced, the clamping jaws also carrying out a corresponding axial movement. Due to the guidance of the clamping jaws, the axial movement is accompanied by a radial movement or by a force acting radially on the clamping jaws, which force is used to firmly clamp the respective tool shank. The axial stroke of the threaded body that is in positive connection with the clamping jaws by actuating the clamping force increasing gear is not subject to any narrow restrictions, so that regardless of the presetting of the clamping jaws caused by rotation of the clamping jaw constriction sleeve, an adjustment movement sufficient for the application of a sufficiently high clamping force is always carried out Actuation of the tension power transmission can be achieved. There is therefore not the risk outlined above that the stroke of the clamping jaws that can be generated by the clamping force increasing gear has already been exhausted without having applied the required clamping force. Even if the clamping jaws are only roughly approximated to the tool shank to be clamped by rotating the clamping jaw constriction sleeve, the further approach and corresponding application of clamping force can then be brought about by actuating the clamping force increasing gear, even if several revolutions of the gear input element should be required. The ratio of the clamping force increasing gear is selected so that a large clamping force can be exerted on the tool shank to be clamped by a comparatively small actuating torque applied from the outside or with little force.

The concept according to the invention permits various designs of the spindle drive with an integrated tension force increase gear. For example, the first threaded body of the spindle drive can be connected to the clamping jaw constricting sleeve while the second threaded body is fixed on the base body unit so that it cannot rotate and is axially immovable. In this case, the transmission output member of the tension-increasing transmission is in rotary connection with the first threaded body.

According to another embodiment, the first thread body could be fixed axially movably, but non-rotatably, in the base body unit, while the second thread body is in rotationally driving connection with the clamping jaw constricting sleeve and has the transmission output member of the clamping force increasing gear. A solution is particularly preferred in which the first threaded body and the z .. e threaded body can be rotated about the axis of the base body - eir.h -_._ t; are stored and the second threaded body is held axially immobile. In this preferred embodiment, the transmission output element is provided on the second thread decor. In this solution, it is in particular not necessary to ensure that the toothing of the transmission output element of the tension-increasing transmission can shift relative to the transmission input element.

According to one variant, the first threaded body is designed as an internal threaded sleeve body, while the second threaded body is the external threaded spindle body. In an alternative embodiment, the first threaded body is designed as an externally threaded spindle body, while the second threaded body is the internally threaded sleeve body.

According to a development of the invention, the second threaded body is connected to the transmission output member and is rotatably and axially movably mounted in the base body unit, the second threaded body being in screw engagement with a thread carrier fixed in relation to the base body unit, in particular with the base body unit Has threaded part, so that a rotation of the second threaded body by means of this screw engagement is forcibly transformed into an axial displacement of the second threaded body.

This solution enables two screwing movements to be superimposed in an additive sense, triggered by actuation of the clamping force increasing gear. The first screwing movement results from the screwing of the first thread body with respect to the second thread body, whereas the second screwing movement results from the screwing of the second thread body with respect to the base body unit. For example, an initially inadequate radial approach of the clamping jaws to the tool shank to be clamped can be remedied by actuating the clamping force increasing gear with comparatively little turning effort in order finally to exert the required clamping force. This aspect is of independent importance within the scope of claim 29 to.

It has proven to be expedient to adjust the friction between the clamping jaw constricting sleeve and the basic body unit such that when the clamping force increasing gear is actuated, the constricting jaw constricting sleeve is prevented from rotating with the screwing of the first threaded body relative to the second threaded body. To For this purpose, it is proposed that when the spindle drive is actuated by turning the clamping constriction sleeve, the clamping constriction sleeve is fixed in the axial direction by an axial securing device, in particular by one or more snap rings, and that this axial securing device is loaded when the clamping jaws are loaded axially tion sleeve through the jaws due to the action of the jaw increasing gear on the jaws as a brake between the jaw narrowing sleeve and the base unit is effective. This measure ensures that when the clamping force increasing gear is actuated, there is always an axial screwing of the first threaded body with respect to the second threaded body, the operator not having to take care that the clamping constriction sleeve is prevented from rotating. The operator therefore has both hands free so that, on the one hand, he can hold the tool shank in position if necessary and, on the other hand, he can actuate the clamping force increasing gear.

The clamping jaws are preferably guided within the clamping jaw constriction sleeve by a conical expansion cage, which ensures a radial retraction movement of the clamping jaws from the relevant clamping part with corresponding axial movement of the first threaded body. In this context, it is proposed that the expansion cage is connected to the clamping jaw constriction sleeve for common rotation and that the clamping jaws form a rotational driving connection between the expansion cage and the first threaded body. In this way, a simple rotary driving connection between the clamping jaw constriction sleeve and the first threaded body is realized, which does justice to the space conditions in the chuck.

Each of the two threaded bodies, externally threaded spindle body and internally threaded sleeve body, is preferably mounted radially in the base body unit independently of the mutual thread engagement. In this context It is proposed that the first threaded body be guided on an inner circumferential surface of a guide sleeve which centers it with respect to the base body unit and which forms the expansion cage in the region of the clamping jaw constriction sleeve and in a subsequent area as a centered on the base body unit with an outer peripheral surface Sleeve extension is formed, and that the inner circumferential surface centering the first threaded body is provided on the guide sleeve both in the area of the sleeve extension and in the area of the expansion cage. With regard to the second threaded body, it is proposed that this engages with a guide part in a centering hole in the base body unit and is rotatably mounted there with the base body unit. The independent centering of the two threaded bodies allows freedom in the design of the interlocking threads, since the thread engagement is not used for centering. In particular, thread play can be provided.

According to a preferred embodiment, the tension-increasing gear is a worm gear, the gear output element being designed as a worm wheel and the gear input element being designed as a worm, which is preferably arranged tangentially to the worm wheel and can be rotated in the base body unit but is not displaceable.

To facilitate handling of the clamping force increasing gear, it is proposed that the worm, which is preferably rotatably mounted tangentially to the worm wheel in the base body unit, has engagement means for a rotary actuating tool that can be applied from the outside.

According to another embodiment, the clamping force increasing gear is designed as a bevel gear.

For mounting the clamping jaw constriction sleeve on the base body unit, in particular for axially fixing the Clamping jaw constricting sleeve is proposed according to a development of the invention to provide a spherical ring. This enables excellent concentricity of the clamping constriction sleeve compared to the base body.

According to a further particularly preferred embodiment of the invention, the first threaded body is mounted rotatably about its axis relative to the base body unit and coupled for common rotation with the clamping constriction sleeve, the second threaded body being fixed to the base body unit non-rotatably and axially immovably. In this embodiment, the transmission output member of the clamping force increasing gear is preferably formed by a toothing of the clamping jaw constricting sleeve, which toothing is expediently formed on the rear face of the clamping jaw constricting sleeve opposite the tool insertion side of the clamping jaw constricting sleeve. The main body unit has a bearing that rotates the gear input element of the clamping force increasing gear for engaging the gear output element on the basic body unit, so that the gear input element is supported on the basic body unit when the clamping force increasing gear is actuated.

The first threaded body of the spindle drive is preferably designed as an external threaded spindle body, which extends into an axial sleeve bore of the base body unit, the second threaded body of the spindle drive being formed in a simple manner in that the peripheral wall of the sleeve bore of the base body unit engages with the thread of the Has externally threaded spindle body engaged thread. The second threaded body is thus an integral part of the basic body unit.

The chuck realized according to the last-mentioned embodiment of the invention is characterized by comparatively few moving parts in the base body unit , whereby overall a reduction in the fit clearance is achieved and overall there are more favorable friction conditions. The radial centering of the first threaded body on the base body unit can be realized with sufficient accuracy by the mutual thread engagement between the two threaded bodies of the spindle drive. The above-mentioned arrangement of the clamping force increasing gear also enables a short design of the chuck, since no elements of the clamping force increasing gear that extend the thread body have to be accommodated in the interior of the base body unit. Furthermore, there are greater degrees of freedom in the dimensioning of the diameter dimensions, in particular of the base body unit, so that the base body unit can be designed to conform to small diameters and / or short overall lengths. According to a further development of the embodiment of the invention explained above, the base body unit has a tapered hollow shaft according to DIN 69893, for example with the nominal size 50.

The clamping force transmission can be designed, for example, as a bevel gear or a crown gear. The transmission input member can be rotatably fixed to the base body unit, the axis of the transmission input member preferably running radially with respect to the axis of the base body unit and the transmission input member having engagement means for an externally applicable rotary actuating tool.

According to a variant, the transmission input member of the tension-increasing gear can be removably engaged with the transmission output member and further combined with a rotary actuating tool to form an actuating element for the tension-increasing transmission.

Further preferred aspects of the invention are given in claims 35 to 39. Preferred exemplary embodiments of the invention are explained in more detail below with reference to the drawings, in which

FIG. 1 shows a first exemplary embodiment of a chuck according to the invention in longitudinal section, the first thread body being an internally threaded sleeve body and the second thread body being an externally threaded spindle body,

FIG. 2 shows a section through the expansion cage along line II of FIG. 1,

FIG. 3 shows a second embodiment of a chuck according to the invention, similar to the first embodiment, in longitudinal section,

FIG. 4 shows a third exemplary embodiment of a chuck according to the invention in longitudinal section, the second threaded body designed as an externally threaded spindle body being screwed into the base body unit,

FIG. 5 shows a fourth embodiment of a chuck according to the invention, the first threaded body being an externally threaded spindle body and the second threaded body being an internally threaded sleeve body,

FIG. 6 shows a chuck according to a further aspect of the invention,

FIG. 7 shows a further exemplary embodiment of a chuck according to the invention in longitudinal section, the transmission output member being integrally connected to the clamping constriction sleeve,

FIG. 8 shows a variant of the exemplary embodiment shown in FIG. 7, FIG. 9 shows a further exemplary embodiment of a chuck according to the invention in longitudinal section, the transmission output member of the clamping force increasing transmission being an integral part of the base body unit,

Figures 10 u. 11 show variants of the exemplary embodiments shown in FIG. 7 and FIG. 9,

12 shows a further exemplary embodiment of the invention in longitudinal section,

13 shows a variant of the exemplary embodiment according to FIG. 12,

Fig. 14 shows a further embodiment of the invention in longitudinal section and

FIG. 15 shows a cross-sectional illustration of the exemplary embodiment according to FIG. 14 with the sectional plane identified by 15-15 in FIG. 14.

A basic body unit is generally designated by 10 in FIG. This basic body unit 10 comprises an attachment 12 in the form of an outer cone for insertion into a chuck receptacle of a rotating spindle. A flange 14, which has a gripper groove, is also attached to the outer cone 12. The gripper groove serves for gripping and transporting the chuck by means of a handling device.

A clamping jaw constriction sleeve 16 is also rotatably mounted on the base body unit 10 and is axially secured by one or more snap rings 18. The jaws constriction sleeve 16 has a substantially conical inner circumference, and in the region of this conical inner circumference guide surfaces or constriction tracks 20 are formed which converge in the axial direction A of the chuck. Clamping jaws 22 with radially outer sliding surfaces 24 are guided on these guide surfaces 20. By axially displacing the clamping jaws 22 in the axial direction A to the left (based on FIG. 1), the clamping jaws 22 can be moved radially inward, with the result that their radially inner tool clamping surfaces 26 act on a tool shank (not shown) to be clamped. Several, for example three, clamping jaws are distributed over the inner circumference of the clamping jaw constriction sleeve 16. These individual clamping jaws 22 are fixed in their distribution around the axis A by an expansion cage 28. The expansion cage 28 is fixed radially immovably on the clamping constriction sleeve 16 by a pin 30. The expansion cage 28 has a sleeve extension 32 which is rotatably mounted in a bore 34 of the base body unit 10.

2 shows a partial section through the expansion cage 28. The expansion cage 28 has slots 36 in which the clamping jaws 22 are guided. The slots 36 are widened to a guide groove 36a at their radially outer ends. T-shaped back regions 22a of the clamping jaws 22 are guided in these guide grooves 36a in such a way that the contact of the radially outer sliding surfaces 24 of the clamping jaws 22 with the guide surfaces 20 is constantly ensured, regardless of the position of the clamping jaws 22 in the longitudinal direction of the axis A.

An inner threaded sleeve body 38 is mounted radially fixed and axially displaceable within the sleeve extension 32. This internally threaded sleeve body 38 is integrally connected at its left end in FIG. 1 to a shear force application body 40. As can be seen from the lower half of FIG. 1, the pushing force exercising body 40 lies with pushing force exercising surfaces 42 on the pushing force absorption. surfaces 44 of the jaws 22. The shear force application surfaces 42 are part of L-shaped profile grooves 46 of the shear force application body 40, which receive complementary profiles 48 at the right ends of the clamping jaws 22 in FIG. 1. In the embodiment shown in FIG. 1, the shear force application surfaces 42 of the shear force application body 40 and the shear force absorption surfaces 44 of the clamping jaws 22 are arranged orthogonally to the axis A.

1, the clamping jaws 22 are also moved to the left along the guide surfaces 20, the complementary profiles 48 in the profile grooves 46 moving essentially radially inwards.

If c .r S:.; Ubkraftausübungskorper 40 moves in the axial direction A gerr.ä:! - Figure 1 to the right, the jaws 22 are carried along by the shear force exercising body 40 to the right, by means of the profile grooves 46 and the Complementary profiles 48. The radially outer sliding surfaces 24 of the clamping jaws 22 remain on the guide surfaces 20 thanks to the guidance of the back regions 22a in the guide grooves 36a. This means that the clamping jaws 22 move radially outward when axially displaced to the right and lift off with their tool clamping surfaces 26 from the shank of the respective tool. The radial outward movement of the clamping jaws 22 means that the complementary profiles 48 likewise move essentially radially outwards in the L-shaped profile grooves 46.

The axial movement of the thrust body 40 is brought about by a spindle drive 37. This spindle drive 37 includes, in addition to the already mentioned internal threaded sleeve body 38, an external threaded spindle body 54 which is rotatably and axially immovably received in the base body unit 10. The external threaded spindle body 54 and the internal threaded sleeve body 38 are referenced to FIG Axis A is arranged coaxially and is in screw engagement via a particularly flat thread 56, for example with threads having a rectangular cross section. The external threaded spindle body 54 engages with its right-hand, cylindrical end 60 in FIG. 1 in a guide bore 62 which extends axially to the right in the base body unit 10, starting from the bore 34. The outer circumferential surface 64 of the cylindrical end 60 forms with the inner circumferential surface 66 of the guide bore 62 an exact guidance of the external threaded spindle body 54, as a result of which the external threaded spindle body 54 is rotatably mounted with great centering accuracy with respect to the axis A and from this a high concentricity of the external surface threaded spindle body 54 results. In this context, it should be remembered that the internal thread sleeve body 38 is centered independently of the external screw spindle body 54, namely by the inner peripheral surface 68 of the sleeve extension 32. This ensures that the thread engagement point 56 does not have to serve for centering.

When the clamping jaw constricting sleeve 16 is rotated, the expanding cage 28 is also rotated, and thus the clamping jaws 22 are also rotated via the expanding cage 28. Due to the engagement of the L-shaped complementary profiles 48 in the L-shaped profile grooves 46, the clamping jaws 22 take the pushing force exerting body 40 with them in the direction of rotation and thus also the internally threaded sleeve body 38. If the clamping jaw constricting sleeve 16 is rotated clockwise, for example, it is also rotated Internally threaded sleeve body 38 rotates relative to the externally threaded spindle body 54, which is prevented from rotating in the manner to be described. In the event that the thread 56 between the internally threaded sleeve body 38 and the externally threaded spindle body 54 is, for example, a left-hand thread, this means that a rotation of the clamping jaw constricting sleeve 16 and therefore also of the internally threaded sleeve body 38 in a clockwise direction to an axial movement of the internally threaded sleeve body 38 and thus also the thrust Force body 40 leads to the left according to Figure 1, with the result that the jaws 22 are moved radially inward. The reverse applies to a rotational movement of the clamping constriction sleeve 16 counterclockwise. By rotating the clamping jaw constricting sleeve 16, the approach movement of the clamping jaws 22 and the retracting movement of these clamping jaws 22 to and from the respective tool shank can thus be carried out in a manner that is customary and customary for the practitioner — it should be recalled the clamping jaws of simple hand drills ¬ the. By means of a corresponding design of the thread 56, the feed movement of the clamping jaws 22 can take place very quickly with relatively little turning effort on the clamping bench constriction sleeve 16.

After the main approach movement of the clamping jaws 22 to a tool shaft to be clamped has been carried out by rotating the clamping jaw constricting sleeve 16, a clamping force increasing gear can be effective in order to exert a clamping force sufficient for all clamping force requirements on the relevant tool shaft.

In the embodiment shown in Figure 1, the clamping force increasing gear comprises a worm wheel 54b, which is arranged coaxially to the external threaded spindle body 54 and is integrally connected thereto.

The clamping force increasing gear further comprises a worm 70 which extends tangentially to the worm wheel 54b and is in engagement with the toothing thereof. The worm 70 is rotatably mounted in a tangential receiving channel of the base body 10 and is immovably received in its longitudinal direction. The worm 70 also has an internal hexagon head 72 which is accessible from the outer circumferential surface of the base body unit 10 for receiving a turning tool (not shown). In the already described Sehnell clamping process by rotating the clamping constriction sleeve 16, the self-locking engagement between the worm 70 and the worm wheel 54b prevents the externally threaded spindle body 54 from rotating as well when the internally threaded sleeve body 38 rotates, so that the relative screwing already described between the internally threaded sleeve body and the outer threaded spindle body leads to the axial movement of the inner threaded sleeve body 38.

To actuate the clamping force increasing gear, the worm shaft 70 can be rotated by means of a turning tool attached to it, in order to exert a torque on the worm wheel 54b and thus on the externally threaded spindle body 54. As a result of the screw engagement of the threaded bodies 38, 54, this torque is transformed into an axial force acting on the internal threaded sleeve body 38, which is transmitted to the clamping jaws 22 via the engagement of the profiles 46, 48. The radial force components occurring on the clamping jaws 22 by means of the jaw guide act - depending on the selected direction of rotation of the worm 70 - as a clamping force on the tool shaft in question or as a releasing force for detaching the clamping jaws 22 from the tool shaft.

So that a screw connection between the external threaded spindle body 54 and the internal thread sleeve body 38 which is in rotational engagement with the clamping jaw constricting sleeve 16 via the clamping jaws 22 and the expanding cage 28 takes place when the clamping force increasing gear is actuated, care must be taken to ensure that the clamping jaw unit constriction sleeve 16 does not rotate with respect to the base body 10. Such co-rotation can be prevented, for example, by the clamping jaw constriction sleeve 16 being gripped by hand and held in position while the clamping force increasing gear is actuated. In the chuck according to the invention, however, measures are preferably taken to hold the chuck in place. Make the jaw constriction sleeve 16 superfluous during the actuation of the clamping force increasing gear. In the exemplary embodiment of the invention shown in FIG. 1, these measures consist essentially in the fact that the friction between the clamping jaw constriction sleeve 16 and the base body 10 compared to the entraining effect between the external thread of the external threaded spindle body 54 and the internal thread of the internal threaded sleeve body 38 is that when the worm 70 is actuated, the clamping constricting sleeve 16 remains non-rotatably relative to the base body 10, while the external threaded spindle body 54 is screwed relative to the internal threaded sleeve body 38. According to the exemplary embodiment shown in FIG. 1, the clamping jaw constriction sleeve 16 is supported on the base body unit 10 in the axial direction by the snap rings 18. If a force is now exerted on the internally threaded sleeve body 38 by the clamping force increasing gear, the clamping jaw restricting sleeve 16 is likewise subjected to a force with respect to the base body unit 10. This force is transmitted from the clamping constriction sleeve 16 to the base body 10 through the snap ring 18. The snap rings 18 then act as a friction brake between the clamping jaw constricting sleeve 16 and the base body unit 10, as a result of which a rotation of the clamping jaw constricting sleeve 16 when the clamping force increasing gear is actuated is reliably counteracted. As a further measure to prevent the internal thread sleeve body 38 from rotating when the tension-increasing mechanism is actuated, a corresponding design of the intermeshing threads can be selected.

As a result of the measures mentioned, the operator is freed from holding the clamping constriction sleeve 16 and therefore has both hands free in order to actuate the clamping force increasing gear and possibly to hold the tool shaft in position. To clamp a tool shank, in practice, the clamping jaws 22 are first brought closer to the respective tool shank by turning the clamping jaw constriction sleeve 16 and then the clamping force increasing gear is used by turning the worm 70 by means of a hexagon key ¬ sels twisted. Conversely, to loosen a tool, the clamping force increasing gear is first used by rotating the worm 70 in the corresponding reverse direction, after which the clamping jaws 22 can be lifted off the respective tool shank by actuating the clamping constriction sleeve 16.

With the chuck according to the invention, such high clamping forces can be applied between the clamping jaws 22 and the respective tool shank that every torque requirement is satisfied, irrespective of the direction of rotation of the tool spindle.

It should also be pointed out that the independent guidance of the external threaded spindle body 54 on the one hand and the internal threaded sleeve body 38 in the base body unit 10 gives degrees of freedom with regard to the design of the thread formation on the threaded bodies 38, 54, since the thread engagement does not provide for the radial centering of the two threaded bodies 38, 54 must serve. In this way, the threads can be designed with play in terms of ease of movement, which has no effect on the radial centering of the threaded bodies 38, 54.

FIG. 3 shows a second exemplary embodiment of the invention, which is identical to the exemplary embodiment shown in FIG. 1 except for the axial fixing of the clamping jaw constriction sleeve to the base body. Parts of the exemplary embodiment according to FIG. 3 which correspond to parts of the exemplary embodiment shown in FIG. 1 are identified by the same reference numerals plus 100. draws, so that reference can be made to the description of Figure 1. In contrast to the exemplary embodiment shown in FIG. 1, the chuck according to FIG. 3 comprises a spherical ring 118 instead of a snap ring for axially fixing the clamping jaw constricting sleeve 116. The spherical ring 118 ensures excellent concentricity and running accuracy of the clamping jaw constricting sleeve 116 compared to the base body 110. In the exemplary embodiment 3, care has also been taken to ensure that the friction between the clamping constriction sleeve 116 and the base body 110 is adjusted in comparison to the entraining effect between the external thread of the external threaded spindle body 154 and the internal thread of the internal threaded sleeve body 138 so that when the worm 170 is actuated, the Clamping jaw narrowing sleeve 116 does not rotate with respect to the base body 110.

FIG. 4 shows a third exemplary embodiment of the invention. Parts of the third exemplary embodiment which correspond to parts of the exemplary embodiment shown in FIG. 1 are identified in FIG. 4 with the same reference numerals plus 200, so that reference can be made to the description of the exemplary embodiments according to FIGS. 1 and 2.

In a departure from the exemplary embodiments already described, the end 260 of the external threaded spindle body 254 received in the bore 262 of the basic body unit 210 has a screw thread which is screw-engaged with an internal thread 266 of the basic body 210. This ensures that when the clamping force is increased by rotating the worm shaft 270, the externally threaded spindle body 254 is inevitably and necessarily screwed to the base body 210. It depends on whether a screwing is also carried out between the threaded bodies 238 and 254 at the start of the increase in the clamping force or whether the internal thread sleeve body 238 also rotates due to the friction of the threads between the threaded bodies 254 and 238 again on the coordination of the friction in the threaded engagement 256 on the one hand and between the clamping jaw restriction sleeve 216 and the base body unit 210, in particular in the bearing 218, on the other hand. In principle, both are acceptable, since there is definitely a screw connection between the threaded spindle body 254 and the base body unit 210, which leads to an increase in the clamping force, regardless of whether a screw connection occurs simultaneously between the threaded bodies 254 and 238. For this purpose, the external threaded spindle body 254 is axially displaceable over a movement distance indicated by way of example at 280. In the exemplary embodiment shown in FIG. 4, however, the friction ratio has been set so that when the tension-increasing mechanism is actuated, a screw connection between the threaded bodies 238 and 254 also occurs. The thread directions in question are selected so that the two screwing movements when screwing the external thread spindle body 254 with respect to the base body unit 210 and when screwing the internal thread sleeve body 238 with the external thread spindle body 254 overlap with respect to a direction of movement and thus add up. In this way, the reduction ratio is correspondingly smaller, with a rotation of the worm 270 corresponding to a greater advance of the internally threaded sleeve body 238 and thus the clamping jaws 222.

In the chuck according to the invention shown in FIG. 4, the clamping jaw constriction sleeve 216 is axially fixed to the base body unit 210 by a spherical ring 218, as was already the case in the exemplary embodiment according to FIG. 3. Of course, as an alternative or in addition, the solution of axially fixing the clamping constriction sleeve shown in FIG. 1 by means of snap rings is also possible.

A further exemplary embodiment of the invention is shown in FIG. Parts of the exemplary embodiment shown in FIG. 5, which correspond in part to the parts of the chuck according to FIG. 1, are identified by corresponding reference numerals plus 300, so that the description of the exemplary embodiment according to FIG. 5 is limited to the differences from the exemplary embodiments already described can.

In contrast to the exemplary embodiments already described, in the case of the chuck shown in FIG. 5, the externally threaded spindle body 354 instead of the internally threaded sleeve body 338 is in rotary engagement and pushing engagement with the clamping jaws 322. For this purpose, the internally threaded sleeve body 338 has on its circumference the worm gear teeth 338b, which is in engagement with the tangential worm shaft 370.

In accordance with the exemplary embodiments already described, in the chuck shown in FIG. 5, the expansion cage 328 is connected in a rotationally fixed manner to the clamping jaw sleeve 316 via the coupling pin 330. The rotation of the clamping jaw constricting sleeve 316 therefore causes the external threaded spindle body 354 to be driven via the expanding cage 328 and the clamping jaws 322, which body is screwed in the axial direction relative to the internal threaded sleeve body 338. The clamping jaws 322 are controlled radially inward during this axial movement of the externally threaded spindle body 354 when the clamping jaw constriction sleeve 316 is rotated. In this way, by rotating the clamping jaw constriction sleeve 316, the radial setting of the radial clamping jaw can be rapidly adapted to the diameter of the tool shank in question. Tensioning with high clamping force is then carried out by actuating the clamping force increasing gear. In the exemplary embodiment shown in FIG. 5, this means that by rotating the worm shaft 370 and the associated rotation of the internally threaded sleeve body 338, strong axial forces are exerted on the externally threaded spindle body 354 can be exercised by means of the screw engagement 356 with a correspondingly selected ratio of the clamping force increasing gear, which act on the tool shank to be clamped as correspondingly high clamping forces via the clamping jaws 322.

Thus, by actuating the clamping jaw constriction sleeve 316, the radial adjustment of the radial clamping jaw to the shank of a tool to be clamped in can be carried out quickly and then by actuating the clamping force increasing gear, a clamping force sufficient for all clamping force needs can be exerted.

FIG. 6 shows a chuck according to the invention which, in terms of the gear system for the clamping jaws, has similarities to the exemplary embodiment shown in FIG.

In the chuck according to FIG. 6, however, deviating from the previous exemplary embodiments, the clamping constriction sleeve 416 and the expansion cage 428 are fixed non-rotatably and axially immovably on the base body unit 410. The clamping jaws 422 are connected to the first threaded body 438 designed as an internally threaded sleeve body for axial entrainment in both axial directions. The latter is mounted in the guide sleeve 431 in a non-rotatable but axially displaceable manner in order to be able to control the axial movement of the clamping jaws 422. The radial guidance of the clamping jaws 422, which is accompanied by the axial displacement, takes place via the conical guide surface 420 of the clamping jaw constriction sleeve 416.

The external thread spindle body 454, which is in screw engagement with the internal thread sleeve body 438, has the worm gear teeth 454b, which is in engagement with the tangentially guided worm spindle 470. A rotation of the worm 470 thus leads to a screw connection between the threaded bodies 438 and 454, which turns out to be Axial movement of the internally threaded sleeve body 438 expresses. The external thread spindle body has the threaded part 460, which has an external thread 467 which is in screw engagement with the internal thread 466 of the base body unit 410. As shown in FIG. 6, the arrangement is such that the rotation of the worm 470 also inevitably results in the external threaded spindle body 454 being screwed relative to the main body unit 410 by means of the threaded engagement 466, 467. The thread directions of the gear system 437 'are selected such that the axial screwing movements during the screwing between the threaded bodies 438,454 and during the screwing between the second thread body 454 and the base body unit 410 are superimposed in one direction of movement . In this way it is achieved that by rotating the worm 470 a comparatively rapid delivery of the clamping jaws 422 in the sense of an approach to a tool shank to be clamped in is possible and nevertheless a sufficiently strong clamping force can be exerted on the tool shank. The operator therefore only has to actuate one actuating element, namely the worm shaft 470.

480 in FIG. 6 denotes a distance by which the external threaded spindle body 454 can be moved axially. This route can be made larger or, if necessary, also smaller.

The inventive idea expressed in the chuck according to FIG. 6 can also be applied to an embodiment, as shown in FIG. 5, by taking appropriate adaptation measures. In such a case, the internally threaded sleeve body would be designed to be axially screwable relative to the base body unit.

A further preferred exemplary embodiment of a chuck according to the invention is shown in FIG. Parts of the exemplary embodiment shown in FIG. 7, which correspond in part to the parts of the chuck according to FIG. 1, are identified by the same reference numerals plus 500, so that the description of the exemplary embodiment according to FIG. 7 is limited to the differences from the exemplary embodiments already described can.

In the chuck in FIG. 7, the first threaded body 554 of the spindle drive 537, which is connected to the clamping jaws 522 in a force-transmitting manner, is designed as an external threaded spindle body which is screwed in the axial direction A with respect to the base body unit 510 when the clamping constriction sleeve 516 rotates. The second threaded body 538 of the spindle drive 537, which is designed as an internally threaded sleeve body, is an integral part of the basic body unit 510. To form the second threaded body 538, the axial bore 534 'provided in the basic body unit 510 is provided on its inner circumference with a thread which is provided with the Thread of the first threaded body 554 is in screw engagement.

In contrast to the exemplary embodiments already described, the transmission output element 516b of the clamping force increasing gear is coupled for common rotation with the first threaded body 554 and is designed as an integral part of the clamping jaw constricting sleeve 516, the gear output element 516b of the clamping force increasing gear via the clamping jaw constricting sleeve 516, the clamping jaws 522 and the expanding cage 528 are in rotary driving engagement with the first threaded body 554 of the spindle drive 537.

To form the transmission output element 516b of the clamping force increasing transmission, the clamping jaw constricting sleeve 516 has on the end face 585 of the basic body unit 510 which extends radially inward from the circumference guided annular bearing extension 586 a circumferential toothing 588. A gear 570, which is combined with a rotary actuating tool 592 to form an actuating element 594 for the clamping force increasing gear, serves as the gear input element of the tension-increasing gear. The actuating element 594 can be attached to the chuck for actuating the clamping force increasing gear, a bearing pin 596 extending coaxially to the gear 570 engaging in a bearing bore 598 provided in the basic body unit 510 and extending radially to the axis A of the chuck. With the actuating element 594 attached in this way, the gear 570, which is small compared to the ring gear 588, is in meshing engagement with the crown gear toothing 588 on the clamping jaw constriction sleeve 516, so that by turning the rotary actuating tool 592 with comparatively little effort, a relatively large torque is applied to the Clamping jaw constriction sleeve 516 can be exerted in order to twist the clamping jaw constriction sleeve 516 relative to the base body unit 510 about the axis A and thus exert the required clamping force on a tool shank to be clamped.

After actuation of the clamping force increasing gear, the actuating element 594 can be removed from the base body unit 510.

The toothing of the spindle drive 537 is also selected in the exemplary embodiment shown in FIG. 7 so that the clamping jaws 522 can be brought quickly closer to a tool shaft to be clamped by directly turning the clamping jaw constricting sleeve 516 and the external threaded spindle body 554 thus engaging in rotation. After the clamping jaws 522 have been sufficiently brought close to the tool shank, the clamping force increasing gear 516b, 570 can be used, the bearing journal 596 of the actuating element 594 being inserted into the bearing bore 598 in order to To bring wheel 570 with the crown gear teeth 588 into engagement, whereupon the re-tensioning process can take place by turning the rotary actuating element 592.

The exemplary embodiment shown in FIG. 7 is characterized in that fewer moving parts are accommodated in the basic body unit 510, as a result of which the bearing play can be reduced overall. The radial centering of the external threaded spindle body 554 can take place via the mutual tooth engagement of the elements 538, 554 of the spindle drive 537. The external thread spindle body 554 is also guided within the expansion cage 528 on the guide surface 568. The exemplary embodiment shown in FIG. 7 is further distinguished by the fact that it is of comparatively short construction in axial direction A, as a result of which inner parts are more easily accessible. Since the gear parts accommodated in the base body unit are designed to be very space-saving, the outer diameter of the chuck can also be kept small, for example in order to meet certain standards. For example, the preferred embodiment according to FIG. 7 has a hollow taper shank (HSK) according to DIN 69893-A for mounting on a chuck holder.

Although the clamping force increasing gear 516b, 570 is shown in FIG. 7 as a crown gear with a removable drive gear 570, the clamping force increasing gear according to a variant (not shown) can be fixed as a bevel gear with a correspondingly removable gear input member or with a rotatably fixed to the base body unit Drive bevel gear can be designed as a gear input element with engagement means for a rotary actuating tool. FIG. 8 shows a modification of the exemplary embodiment shown in FIG. 7 in a broken partial representation.

Parts in FIG. 8 which correspond in effect to parts of the exemplary embodiment shown in FIG. 7 are identified by corresponding reference symbols plus 100, so that reference can be made to the description of the exemplary embodiment according to FIG. 7.

In the chuck according to FIG. 8, the first threaded body 638 is designed as an internally threaded sleeve body. The second threaded body 654 of the spindle drive 637 is an external threaded spindle body which is connected in one piece to the base body unit 610. The internally threaded sleeve body 638 is guided on an inner circumferential surface 668 or 634 'of the expansion cage 668 or the base body unit 610 centering it relative to the base body unit 610.

The exemplary embodiment shown in FIG. 9 differs from the exemplary embodiment according to FIG. 7 in that the transmission output member 710b of the clamping force increasing gear is not formed on the clamping jaw constricting sleeve 716, but on the base body unit 710. The base body unit 710 instructs to form the gear output member 710b their ring-shaped end face 785 facing the clamping jaws 722 has a corresponding toothing 788. A guide channel 798 which passes radially through the clamping jaw constricting sleeve 716 and the expanding cage 728 is provided for receiving an actuating element 794 on which a gearwheel 770 which forms the transmission input element of the clamping force increasing transmission is formed.

To actuate the tension-increasing gear 770, 710b, the toothing of the toothed wheel 770 is brought into engagement with the toothing 788 of the transmission output element 710b in order to then rotate the actuating element 794. there the main body unit 710 is rotated relative to the clamping jaw constriction sleeve 716, with the result that the first threaded body 754 of the spindle drive 737 is screwed relative to the main body unit 710 in order to exert a clamping force on the tool shank to be clamped via the clamping jaws 722 coupled therewith. The exemplary embodiment shown in FIG. 9 has a hollow tapered shank (HSK) according to DIN 69893-A for mounting on a chuck holder. The radial pin coupling the clamping jaw constriction sleeve 716 for joint rotation with the expanding cage 728 lies in a plane which cannot be seen in FIG. 9.

FIGS. 10 and 11 show exemplary embodiments of the invention which differ from the exemplary embodiment according to FIG. 7 or from the exemplary embodiment according to FIG. 9 only by the shaft for mounting on a chuck holder. The chucks shown in Figures 10 and 11 have a taper shank SK according to DIN 69871-A. Parts in FIG. 10 which correspond to parts in FIG. 7 in effect are identified with the same reference numerals plus 300. Parts in FIG. 11 which correspond in part to parts in FIG. 9 are marked with the same reference numbers plus 200.

12 shows a further preferred exemplary embodiment of a chuck according to the invention. In FIG. 12, parts of the chuck which correspond in part to the parts of the first exemplary embodiment shown in FIG. 1 are identified by the same reference numerals plus 1000, so that the following description of the exemplary embodiment according to FIG. 12 essentially relates to the differences from the first Can limit embodiment.

The first threaded body 1054 of the spindle drive 1037, which is designed as an external thread spindle body in the exemplary embodiment according to FIG. 12, projects above the clamping jaws 1022 and the expanding cage 1028 in rotary driving connection with the clamping jaw constricting sleeve 1016. By rotating the clamping jaw constricting sleeve 1016, the externally threaded spindle body 1054 is screwed axially with respect to the internally threaded sleeve body 1038, around the clamping jaws 1022 - depending on the direction of the axial movement of the conical spindle body 105 To control the guide surface 1020 of the clamping constriction sleeve 1016 radially inwards or radially outwards.

The second threaded body 1038 of the spindle drive 1037, which is designed as an internally threaded sleeve body, is held axially immovable between the right end of the expanding cage 1028 in FIG. 12 and the basic body unit 1010. A special feature is that the internally threaded sleeve body 1038 is mounted on the basic body unit 1010 in this way that it is non-rotatable relative to the basic body unit 1010. For the purpose of the rotationally fixed coupling of the internal thread sleeve body 1038 to the base body unit 1010, the internal thread sleeve body 1038 has two cheek portions 1081 protruding axially to the right in FIG. 12, which engage in complementary groove portions 1083 of the base body unit 1010.

The inner thread sleeve body 1038 has on its outer circumference a worm gear toothing 1038b which forms the transmission output element of the clamping force increasing gear and is in engagement with a worm 1070 which represents the transmission input element of the clamping jaw approaching transmission. The worm 1070 extends tangentially to the worm wheel rim 1038b and is rotatably mounted in a tangential bearing bore 1085 of the clamping jaw constriction sleeve 1016.

It is pointed out that, in deviation from the exemplary embodiment shown in FIG. 12, two or a plurality of gear worms 1070 which are in engagement with the worm wheel rim 1038b can be provided, which are arranged separated from one another at corresponding angular intervals in corresponding bearing bores of the clamping jaw constriction sleeve 1016.

12 has a hollow taper shank (HSK) according to DIN 69893-A for mounting on a chuck holder.

To bring the clamping jaws 1022 closer to a tool shank to be clamped, the clamping jaw adjustment sleeve 1016 is rotated relative to the base body unit 1010 such that the external thread spindle body 1054 rotates via the thread engagement of its external thread with the internal thread of the sleeve body 1038 relative to the internal thread sleeve body 1038 and thus relative to it Base unit 1010 is screwed axially to the left in FIG. 12, whereby the clamping jaws 1022 on the guide surfaces 1020 are controlled radially inwards. After the clamping jaws 1022 have been brought sufficiently close to the tool shank (not shown), the clamping force increasing gear can be used. For this purpose, the worm 1070 is rotated with a suitable turning tool, which has the consequence that a further relative rotation of the clamping constriction sleeve 1016 with respect to the base body unit 1010 and thus a further axial screwing of the external threaded spindle body 1054 relative to the internal threaded sleeve body 1038 and the base body unit 1010 takes place in order to press the clamping jaws 1022 firmly against the tool shaft to be clamped.

The gear ratio of the clamping force increasing gear is selected such that sufficiently low clamping forces can be exerted on the tool shank to be clamped with little effort of torque. It should also be added that the gear worm 1070 rotates in its bearing bore 1085 in idle position during rotation of the clamping jaw narrowing sleeve 1016 during the approach of the clamping jaw to the tool shank or also during the radial removal of the clamping jaw 1022 from the tool shank.

In the exemplary embodiment according to FIG. 12, the inner threaded sleeve body, which is at least accommodated with its worm wheel section 1038b in the clamping constriction sleeve 1016, is designed to be exchangeable. For the exchange, the clamping jaw constriction sleeve 1016 can be separated from the base body unit 1010 in order to enable access to the spindle drive 1037 from the sleeve bore 1087 of the clamping jaw constriction sleeve 1016 adjacent to the base body unit 1010 in FIG. 12. The sleeve bore 1087 has an inner diameter which essentially corresponds to the outer diameter of the worm wheel rim 1038b.

The exemplary embodiment according to FIG. 12 is characterized by a simple structure and can be made compact in particular in the axial direction.

It is pointed out that with respect to the engagement profiles of the threaded body of the spindle drive, modifications in the sense of kinematic reversals are possible. It should also be noted that the clamping force increasing gear can alternatively be designed as a bevel gear.

FIG. 13 shows a variant of the embodiment according to FIG. 12. In FIGS. 12 and 13, the same reference numerals have been used for the same or equivalent elements, so that the explanation of the embodiment according to FIG Description of the embodiment of FIG. 12 can be referenced. The embodiment according to FIG. 13 differs from the embodiment according to FIG. 12 in that the internally threaded sleeve body 1038 is molded onto the base body unit 1010 and is an integral part of the base body unit 1010. As in the exemplary embodiment according to FIG. 12, the inner threaded sleeve body extension 1038 in the exemplary embodiment according to FIG. 13 also has a worm gear toothing 1038b on its circumference within the clamping jaw constricting sleeve 1016, the worm gear toothing 1038b being the transmission output member and the one in the Clamping jaw constricting sleeve 1016 supported worm 1070 form the transmission input element of the clamping force increasing transmission.

The chuck according to FIG. 13 is characterized by a compact structure with a small number of parts and has a high degree of centering reliability, concentricity and freedom from tension when clamped.

It must also be added that in the embodiment examples according to FIGS. 12 and 13 a ball ring 1018 is provided for axially fixing the clamping constriction sleeve 1016 with respect to the base body 1010, although other bearing elements can be provided in alternative embodiments.

Another embodiment of the invention is shown in FIG. 14 in longitudinal section and in FIG. 15 in a cross section along line 15-15 in FIG. 14.

Parts of the exemplary embodiment according to FIGS. 14 and 15, which correspond in effect to parts of the exemplary embodiment according to FIG. 1, are identified by corresponding reference numerals plus 1100, so that the following description essentially relates to deviations of the chuck according to FIGS. 14 and 15 can restrict compared to the chuck of FIG. 1.

14, the clamping jaw constriction sleeve 1116 is firmly screwed to the expanding cage 1128 and the expanding cage 1128 has an annular extension 1200 projecting axially to the right in FIG. 14 beyond the clamping jaw constricting sleeve 1116, which is centered in the base body unit 1110 is received so that the expansion cage 1128 with the clamping jaw constriction sleeve 1116 attached to it can be rotated about the axis A relative to the base body unit 1110. The spherical ring 1118 secures the expansion cage 1128 against axial displacement on the base body unit 1110.

The first threaded body 1154, which is connected in rotation with the clamping jaw constricting sleeve 1116 via the clamping jaws 1122 and the expanding cage 1128, is designed as an externally threaded spindle body. The internal thread sleeve body 1138, which is in screw engagement with the external thread spindle body 1154, is integrally formed on the base body unit 1110 and forms an integral part of the base body unit 1110.

By turning the clamping constriction sleeve 1116, the external threaded spindle body 1154 can thus be screwed in the axial direction relative to the base body unit 1110 in order to control the clamping jaws 1122 radially inwards or radially outwards.

The ring-shaped extension 1200 of the expansion cage 1128 has on its right-hand end in FIG. 14 a circumferential toothing 1200b which is designed as a spiroid toothing or an arch toothing and forms the transmission output element of the tension-increasing transmission. The gear input element of this spiroid clamping force increasing gear is driven by a screw Pinion 1170 formed with a constant pitch. The relative position of the pinion 1170 which is rotatably held in the base body unit with respect to the toothed ring 1200b meshing therewith can best be seen in FIG. 15. 14 and 15 is a helical gear designed as an angular gear, in which the engagement between the pinion 1170 and the ring gear 1200b takes place off-center, ie there is no maximum axle spacing the transmission members of the clamping force increasing gear was like a worm gear and there is no minimum center distance like a conventional bevel gear. Such a constellation of the transmission members of the tension-increasing transmission allows the transmission of large torques with a small size.

Details of the mounting of the pinion 1170 in the basic body unit 1110 as well as the means for the connection of a turning tool that can be used if necessary for turning the pinion 1170 are not shown in FIGS. 14 and 15, since such details can be provided at the discretion of the person skilled in the art.

The rotation of the pinion 1170, due to the screw engagement with the spiroid ring gear 1200b, causes the expansion cage to rotate and thus to transmit torque to the externally threaded spindle body 1154, so that the latter is axially screwed relative to the internally threaded sleeve body 1138 around the clamping jaws 1122 on the guide surface 1120 of the clamping jaw constricting sleeve 1116 can be controlled further radially inward and in doing so exert the required clamping force on a tool shaft to be clamped. In the embodiment according to FIGS. 14 and 15, the pinion 1170 is cylindrical.

In a variant of this embodiment, not shown, the spiroid pinion can be made conical with a constant pitch height. In this case, the ring gear 1200b is designed in the manner of a spiral toothed bevel gear which meshes with the conical spiroid pinion.

Claims

claims

1. Chuck, with a base body unit (10; 110; 210; 310, -510; 610; 710; 810; 910; 1010; 1110) set up for mounting on a chuck receptacle, in particular a machine tool, one centered on the base body unit arranged and relative to the base body unit about its longitudinal axis (A) rotatable clamping constriction sleeve (16; 116; 216; 316; 516; 616; 716; 816; 916; 1016; 1116), in which a plurality of circumferentially offset clamping jaws (22; 122; 222; 322; 522; 622; 722; 822; 922; 1022; 1122) are axially displaceably received and guided on the clamping jaw constriction sleeve in such a way that they are axially displaced relative to the clamping jaw constriction sleeve (16; 116; 216; 316; 516; 616; 716; 816; 916, 1016, 1116) are radially adjustable in order to have a tool shank between the clamping jaws (22; 122; 222; 322; 522; 622; 722; 822; 922; 1022 ; 1122) to be clamped, one coupled to the clamping jaw constriction sleeve (16; 116; 216; 316; 516; 616, -716; 816; 916; 1016; 1116) and by rotating the clamping jaw actuation sleeve, the clamping jaws (22; 122; 222; 322; 522; 622; 722; 822; 922; 1022; 1122) axially displacing spindle drive (37; 137; 237; 337; 537; 637; 737; 837; 937; 1037; 1137) for the radial approach of the clamping jaws to a tool shaft to be clamped and one of the Spindle drive (37; 137; 237; 337; 537; 637; 737; 837; 937; 1037; 1137) act on the clamping force increasing gear to exert a clamping force on the approximated clamping jaws on the tool shank to be clamped, the spindle drive having a force-transmitting connection with the jaws the axially movably guided first threaded body (38; 138, -238, -354; 554; 638; 754; 1054; 1154) and a second threaded body (54; 154; 254; 338; 538; 654) in screw engagement therewith ; 738; 1038; 1138), one of which is used as an externally threaded spindle body (54; 154; 254; 354; 545; 654; 754; 1054; 1154) and the other as an internally threaded sleeve body (38; 138; 238; 338; 538 ; 638; 738; 1038; 1138) is formed, which both coaxially along the axis (A) of the base body unit (10; 110; 210; 310; 510; 610; 710; 810; 910; 1010; 1110) this extend and, when the clamping jaw narrowing sleeve (16; 116; 216; 316; 516; 616; 716; 816; 916; 1016; 1116) rotates, cooperate by means of the screw engagement in such a way that the first threaded body (38; 138; 238; 354; 554 ; 638; 754; 1054; 1154) carries out an axial movement which is transmitted to the clamping jaws, characterized in that the clamping force increasing gear unit is common to one of the threaded bodies (54; 154; 254; 338; 554; 638; 754; 1038; 1154) rotation coupled and coaxially arranged, toothed round body (54b; 154b; 254b; 338b; 516b; 616b; 710b; 1038b; 1200b) as a transmission output member and a round body (70; 170; 270; 370) formed with an engagement profile for engaging the toothing of the transmission output member (54b; 154b; 254b; 338b; 516b; 616b; 710b; 1038b; 1200b) ; 570; 670; 770; 1070; 1170) as the transmission input element, which can be rotated about its axis to actuate the clamping force-increasing transmission, so that rotation of the transmission input element (70; 170; 270; 370; 570; 670; 770 ; 1070; 1170) on the threaded body (54; 154; 254; 338; 538; 654; 738, - coupled to the transmission output member (54b; 154b; 254b; 338b; 516b; 616b; 710b; 1038b) for common rotation 1038; 1154) a torque can be exerted, which by means of the screw engagement of the threaded body (38.54; 138.154; 238.254; 338.354; 538.554; 638; 654; 738, 754; 1038.1054; 1138.1154) of the spindle drive (37 ; 137; 237; 337; 537; 637; 737; 837; 937; 1037; 1137) is transformed into an axial force acting on the first threaded body (38; 138; 238; 354; 55; 638; 754; 1054; 1154).

2. Chuck according to claim 1, characterized in that the first threaded body (38; 138; 238; 354) is rotatably mounted about its axis relative to the base body unit (10; 110, -210; 310) and in rotary driving connection with the clamping constriction sleeve (16; 116; 216; 316) It stands that the second threaded body (54; 154; 254; 338) can be rotated about its axis relative to the main body unit, in particular axially immovably, and that the transmission output element (54b ; 154b; 254b; 338b) of the clamping force increasing gear is connected to the second threaded body (54; 154; 254; 338) of the spindle drive for common rotation.

3. Chuck according to claim 1 or 2, characterized in that the clamping force increasing gear is designed as a worm gear with a worm wheel (54b; 154b; 254b; 338b) as gear output member and a worm (70; 170; 270; 370) as a gear input member.

4. Chuck according to claim 3, characterized in that the worm (70; 170; 270; 370) of the Spannkrafter¬ increase gear extends tangentially to the worm wheel (54b; 154b; 254b; 338b) and in the basic body unit (10; 110; 210 ; 310) is rotatably and in particular immovably mounted and furthermore has engagement means (72; 172; 272; 372) for a rotary actuating tool that can be applied from the outside.

5. Chuck according to claim 1 or 2, characterized in that the clamping force increasing gear is designed as a bevel gear.

6. Chuck according to one of the preceding claims, characterized in that the first threaded body (38; 138; 238) is the inner threaded body and that the second threaded body (54; 154; 254) is the external threaded body.

7. Chuck according to one of claims 2 to 6, characterized in that the second threaded body (254) is axially movably gehal¬ th and a screw engagement with a with respect to the base unit (210) fixed thread carrier, in particular with the base unit (210 ), standing threaded part (260), so that a rotation of the second threaded body (254) by means of this screw engagement is forcibly transformed into an axial displacement of the second threaded body (254) relative to the base body unit (210).

8. Chuck according to one of claims 2 to 7, characterized in that the friction between the clamping constriction sleeve (16; 116; 216; 316) and the base body unit (10; 110; 210; 310) is set so that when the

Clamping force increasing transmission prevents the screwing of the first threaded body (38; 138; 238,354) relative to the second threaded body (54,154; 254; 338) from rotating the clamping jaw constricting sleeve (16; 116; 216; 316).

9. Chuck according to one of claims 2 to 8, characterized in that when the spindle drive (37; 137; 237; 337) is actuated by rotating the clamping constriction sleeve (16; 116; 216; 316), the clamping constriction sleeve by means of an axial securing device (18, 118) ; 218; 318), in particular through a Snap ring arrangement, is fixed in the axial direction and that this axial securing (18; 118; 218; 318) with axial loading of the clamping jaw constriction sleeve (16; 116; 216; 316) by the clamping jaws (22; 122; 222; 322) due to the action of the clamping force increasing gear on the jaws as a rotary brake between the jaw narrowing sleeve (16; 116; 216; 316) and the main body unit (10; 110; 210; 310 ^' ) is effective.

10. Chuck according to one of claims 2 to 9, characterized in that each of the two threaded bodies (38.54; 138.154; 238.254; 338.354) of the spindle drive in the basic body unit (10, -110; 210; 310) independently of that mutual thread engagement is mounted radially.

11. A chuck according to claim 1, characterized in that the first threaded body (554; 638; 754) can be rotated about its axis relative to the base body unit (510; 610; 710) and is connected in rotation with the clamping jaw constriction sleeve (516; 616; 716 ) stands and that the second threaded body (538; 654; 738) on the base body unit (510; 610; 710) is non-rotatable and in particular axially immovable.

12. Chuck according to claim 11, characterized in that the transmission output member (516b; 616b) of the clamping force increasing gear - in particular in one piece - is connected to the clamping jaw constriction sleeve (516; 616).

13. Chuck according to claim 11 or 12, characterized in that the base body unit (510; 610) a the gearbox input member (570, -670) of the clamping force increasing gear for engaging the gearbox output member (516b; 616b) Has a bearing (598; 698) rotatably mounted on the base body unit (510; 610).

14. Chuck according to one of claims 11 to 13, characterized in that the transmission output member (516b; 616b) of the clamping force increasing gear is formed by a toothing (588, -688), in particular crown gear toothing, of the clamping constriction sleeve (516; 616) is.

15. A chuck according to claim 13 or 14, characterized in that the teeth (588; 688) of the transmission output member (516b; 616b) of the clamping force increasing gear on the

Tool shank insertion side of the clamping jaw constricting sleeve (516, -616) opposite rear face (585; 685) of the clamping jaw constricting sleeve (516; 616) is formed.

16. Chuck according to one of claims 11 to 15, characterized in that the axis of the gear input member (516b; 616b) meshing with the gear input member (570; 670) of the clamping force increasing gear radially with respect to the axis A of the base body unit (510; 610) extends.

17. Chuck according to one of claims 11 to 16, characterized in that the clamping force increasing gear is designed as a bevel gear.

18. Chuck according to one of claims 11 to 16, characterized in that the clamping force increasing gear (516b, 570; 616b, 670) is designed as a crown gear.

19. Chuck according to one of claims 11 to 18, characterized in that the transmission input member (570, -670) of the clamping force increasing gear can be detachably engaged with the gear output member (516b; 616b) and with a rotary actuating tool (592; 692) to a rotary actuating element (594; 694) for the clamping force increasing ¬ drives is combined.

20. Chuck according to one of claims 11 to 19, characterized in that the second threaded body (538; 654) of the spindle drive (537; 637) is an integral part of the base body unit (510; 610).

21. Chuck according to one of claims 11 to 20, characterized in that the first threaded body (554) is the external threaded spindle body and that the second threaded body (538) is the internal threaded sleeve body.

22. Chuck according to claim 1, characterized in that the first threaded body (754) can be rotated about its axis relative to the basic body unit (710) and is in rotationally driving connection with the clamping jaw constriction sleeve (716), that the second threaded body (738) on the base unit (710) is non-rotatable and in particular axially immovably fixed, that the transmission output member (710b) of the clamping force increasing gear is connected in one piece with the base body unit (710) and that the gear input member (770) of the clamping force increasing gear for engaging the Transmission output member (710b) is supported such that the actuation of the transmission input member (670) causes the base unit (710) to rotate relative to the clamping jaw constriction sleeve (716).

23. A chuck according to claim 22, characterized in that the second threaded body (738) is an integral part of the base body unit (710).

24. Chuck according to one of the preceding claims, characterized in that the clamping jaws (22; 122; 222; 322; 522; 622; 722) within the clamping jaw constriction sleeve (16; 116; 216; 316; 516; 616; 716) are guided by a conical expansion cage (28; 128; 228; 328; 528; 628; 728) which causes the clamping jaws to move radially backward from the respective clamping part with corresponding axial movement of the first threaded body (38; 138; 238 ; 354; 554; 638; 754).

25. Chuck according to claim 24, characterized in that the expansion cage (28; 128; 228; 328; 528; 628; 728) for rotation together with the clamping constriction sleeve (16; 116; 216; 316; 516; 616; 716 ) and that the clamping jaws (22, 122; 222; 322; 522; 622; 722) have a rotary connection between the expansion cage (28; 128; 228; 328; 528; 628) and the first threaded body (38; 138 ; 238; 354; 554; 638; 754).

26. Chuck according to one of claims 24 or 25, characterized in that the first threaded body (38; 13β; 238; 354) on an inner circumferential surface (68; 168) centering it relative to the base body unit (10; 110; 210; 310) ; 268; 368) of a guide sleeve (31; 131; 231; 331) is guided, which forms the expansion cage (28; 128; 228; 328) in the area of the clamping jaw constriction sleeve (16; 116; 216; 316) and in one adjoining area is designed as a sleeve extension (32; 132; 232; 332) centered with an outer peripheral flat (82, -182, -282; 382) on the base body unit (at 34; 134; 234; 334), and that the inner peripheral surface (68; 38; -138; 238; 354) centering the first thread body (68; 168; 268; 368) both in the area of the sleeve extension (32;

132; 232; 332) as well as in the area of the expansion cage (28;

128; 228; 328) is provided on the guide sleeve (31; 131; 231; 331).

27. Chuck according to one of the preceding claims, characterized in that a thrust force receiving surface and a corresponding thrust force exerting surface are partial surfaces of interlocking profiles (46,48; 146,148; 246,248; 346,348; 546,548; 646,648; 746,748) which are the respective ones Connect the clamping jaw (22; 122; 222; 322; 522; 622; 722) to the first threaded body (38; 138; 238; 354; 554; 638; 754) in both axial directions for axial driving.

28. Chuck according to one of the preceding claims, characterized in that the clamping jaw constriction sleeve (116; 516, -616; 716) through a spherical ring (118; 518; 618, -718) on the basic body unit (110; 510; 610; 710) is mounted and secured against axial displacement.

29. Chuck, with a base body unit (410) set up for mounting on a chuck receptacle, in particular a machine tool, a clamping jaw constricting sleeve (416) centered on the base body unit, in which a plurality of circumferentially offset clamping jaws (422) are accommodated axially displaceably and are guided in such a way that they can be adjusted radially by axial displacement relative to the clamping jaw constriction sleeve (416) in order to clamp a tool shank between the clamping jaws (422), a combined clamping jaw approach and clamping force increasing gear (437 '), the a spindle drive (437) which axially displaces the clamping jaws (422) for the radial approach of the clamping jaws (422) to a tool shank to be clamped, the spindle drive (437) having an axially movably guided first threaded body (438) in force-transmitting connection with the clamping jaws (422) and a second threaded body in screw engagement therewith (454), one of which is designed as an external threaded spindle body (454) and the other as an internal threaded sleeve body (438), both of which extend along the axis (A) of the base body unit (410) and upon actuation of the combined clamping jaw approach and clamping force increase gear (437 ') cooperate by means of the screw engagement in such a way that the first threaded body (438) carries out an axial movement which is transmitted to the clamping jaws, characterized in that the combined clamping jaw approach and clamping force increasing gear unit is common to the second threaded body (454) Rotation, especially insert has a connected, coaxially arranged, driven gear member (454b) and an engaging driving gear member (470) which is rotatable about its axis for actuating the combined clamping jaw approach and clamping force increasing gear (437 ') that by turning the driving gear member (470) on the second threaded body (454) a torque can be exerted, which is transformed by means of the screw engagement of the threaded body (438,454) of the spindle drive into an axial force acting on the first threaded body (438), that the the second threaded body (454) can be screwed axially directly relative to the base body unit (410) by rotating the driving gear member (470) and for this purpose a thread (466) which is fixed in relation to the base body unit (410) Has thread (467) and that the thread between the threaded bodies (438, 454) of the spindle drive (437) and between Chen the second threaded body (454) and of the base body unit (410) are designed such that the screwing movements of the first thread body (438) relative to the second thread body (454) and the second thread body (454) relative to the base body unit (410) additively overlap in the axial direction.

30. Chuck according to claim 29, characterized in that the clamping jaw constriction sleeve (416) and the first threaded body (438) are fixed non-rotatably on the base body unit (410).

31. A chuck according to claim 29 or 30, characterized in that the driven gear member (454b) is a worm wheel and the driving gear member (470) is a worm of a worm gear.

32. Chuck according to claim 29 or 30, characterized in that the driven gear member and the driving gear member are bevel gears of a bevel gear.

33. Chuck according to one of the preceding claims, characterized in that it has a hollow taper shank (HSK) according to DIN 69 893 part 1 or part 2 for mounting on a chuck holder.

34. Chuck according to claim 33, characterized in that the tapered hollow shaft is an integral part of the basic body unit.

35. Chuck according to claim 1, characterized in that the first threaded body (1054) relative to the base body unit (1010) about its axis (A) is rotatable and has a rotational driving connection with the clamping jaw constriction sleeve (1016), that the second threaded body (1038) on the base body unit (1010) is non-rotatable relative to it and in particular is immovably fixed that the transmission output member (1038b) of the clamping force increasing gear is formed on the second threaded body (1038) and is received in the clamping jaw constriction sleeve (1016) and that the transmission input member (1070) of the clamping force increasing gear is rotatably held in the clamping jaw constriction sleeve (1016).

36. Chuck according to claim 35, characterized in that the first threaded body (1054) is designed as an external threaded body, that the second threaded body (1038) is designed as an internal threaded sleeve body and on its outer circumference the toothing of the transmission output member (1038b) of the clamping force increasing gear and that the axis of rotation of the gear input element (1070) is arranged tangentially to the gear output element (1038b).

37. Chuck according to claim 35, characterized in that the second threaded body (1038) for replacement is detachably coupled to the base body unit (1010) and is accommodated in the clamping jaw constriction sleeve (1016).

38. Chuck according to claim 35 or 36, characterized in that the second threaded body (1038) is integrally formed on the base body unit (1010) (Fig. 13).

39. Chuck according to one of the preceding claims, characterized in that the clamping force increasing gear (1200b, 1170) is designed as a spiroid gear.