Chucking means

A chuck apparatus for the fastening to a working spindle (2) of a tool machine, with a chuck body (8) comprising a receptacle (7) for the working spindle (2), with at least two chuck jaws (9) which can be adjusted radially to the body axis, and with a drive ring (10), for whose rotation taking place in the circumferential direction a drive (11) is provided, comprising a structure is formed on the drive ring (10) on its outer circumference or its inner circumference for each chuck jaw (9) and which serves for its adjusting. The invention furthermore relates to a rapid replacement system (1) with the chuck apparatus (3) as a base flange (4) and with a replacement flange (5).

The invention relates to a chuck apparatus for the fastening to a working spindle of a tool machine, with a chuck body comprising a receptacle for the working spindle, with at least two chuck jaws which can be adjusted radially to the body axis, and with a drive ring, for whose rotation taking place in the circumferential direction a drive is provided.

Such chuck apparatus are widely distributed in the technology under the designation plane spiral chuck, have been publicly previously used by the applicant and described by it, for example, in its total catalog for chucking technology.

Plane spiral chucks get their name from a plane spiral used as a drive ring and which comprises a drive toothing on its side facing away from the chuck jaws into which toothing the drive constructed as a gear engages. A thread is formed on the opposite side of the plane spiral into which thread the chuck jaws engage with drive teeth. These plane spiral chucks are distinguished in that the jaws can be adjusted over the entire chucking range so that workpieces with different chucking diameters can be chucked very rapidly and without displacing the jaws. It should furthermore be noted that these plane spiral chucks have a relatively low axial height in comparison to other chucking chucks, e.g. with wedge rods. However, there are applications in which an axial height which is reduced even further is desirable.

The invention therefore has the basic problem of constructing a chuck apparatus of the initially cited type in such a manner that the most compact structural form possible can be achieved.

This problem is solved in a tensioning means of the initially cited type in that the structure is formed on the drive ring on its outer circumference or its inner circumference for each chuck jaw and which serves for its adjustment.

In the plane spiral chucks known from the prior art there is an axially stacked arrangement of the four components drive, drive toothing, thread of the plane spiral and drive teeth of the chuck jaws which is necessary in this chuck type and opposes a reduction of the structural shape. The invention therefore leaves the known way and follows another way for adjusting the chuck jaws while renouncing the plane spiral in that the sides of the drive ring, which face away from one another, are not provided for adjusting the chuck jaws but rather the circumference of the drive ring is used. It is therefore sufficient to use the front side as the structure of the drive ring without an axial stacking of all corresponding structural components being necessary.

Furthermore, the chuck apparatus according to the invention is distinguished by its very simple construction in which a large receptacle can also be made available in the chuck body, which chuck apparatus is therefore in particular also suitable for chucking workpieces with a large diameter which extend into the working spindle constructed as a hollow spindle.

It is especially preferred in the framework of the invention if the structure is formed by a control curve formed on the outer circumference and with a control cam serving for adjusting each chuck jaw radially outward. In this embodiment the chucking of the workpiece or of the tool is provided by radially outwardly adjustable chuck jaws so that an inner chucking takes place in which the chucking force is increased by the action of the centrifugal force arising during the operation, that is, differently than that a lower boundary of the acting chucking force can always be indicated in the case of an outer chucking.

Furthermore, it is provided in the framework of the invention that the drive is formed by a drive wheel which can rotate about a radial axis and which engages in a drive toothing formed on the drive ring, and that a return curve is formed on the drive ring side comprising the drive toothing, into which curve the chuck jaw engages with a control member. This embodiment makes a forced guidance available which brings about an adjusting of the chuck jaw in the direction of opening when the control cam no longer makes contact with the associated chuck jaw by the rotating of the drive ring in the direction corresponding to the loosening.

Furthermore, it is preferred in the framework of the invention if an indicator curve is formed on the outer circumference of the drive wheel for cooperating with an indicator pin for displaying the rotary position of the drive ring.

With this indicator pin, the rotary position of the drive ring can be directly determined optically and if necessary also by sensors and it can be checked in particular with it whether the control cams rests on the chuck jaws and adjusts them radially outward or whether no reliable chucking and the replacement of the tool or workplace is possible due to the lacking contact.

It also proved to be advantageous in the framework of the invention if the chuck jaw has a basically L-shaped form on whose base shank the control member is arranged and if a pin receptacle which is open to the drive ring is formed in the second shank into which receptacle a contact pin is inserted. Furthermore, it is advantageous if the contact pin has a plane surface on the side facing the drive ring and if the contact pin comprises a pin foot. This design of the chuck jaw improves its guidance, which can take place on the one hand by the chuck body and on the other hand also by the drive ring, wherein in particular the base shank is also made available in order to carry the control member cooperating with the return curve. The plane surface of the contact pin brings about a good contact on the control curve of the drive ring, wherein the pin foot to be secured by a securing ring in the chuck jaw ensures the secure receiving of the contact pin in the chuck jaw.

It is furthermore favorable if the chuck jaw comprises a radially outside groove in order to make possible, if necessary, a real positive lock opposite the workpiece or tool to be chucked.

It is quite especially preferred in the framework of the invention if the chuck apparatus forms the base flange of a rapid replacement device which comprises a replacement flange which can be chucked by the base flange and can be connected to a workpiece chuck apparatus. It is often necessary in chucking technology that chuck apparatus fastened on the work spindle is to be replaced by another one in order to, for example, replace a wedge rod chuck by an expansion chuck for another application. To this end, three screws must conventionally be loosened as a rule by which the chuck body is fastened on the work spindle in order to subsequently loosen the air pipe connection for adjusting the chuck jaw. A complete chuck apparatus replacement takes about 30 to 40 minutes, so that correspondingly high equipment expenses are associated with this and it is desirable to make a more rapid replacement of the spiral chuck. This is made possible by the chuck apparatus according to the invention, which can remain continuously connected to the working spindle and forms, in cooperation with a replacement flange, a rapid replacement device with which the replacement flange carrying the workpiece chuck apparatus can be chucked by the chuck apparatus as base flange and therefore the workpiece chuck apparatus is reliably connected to the working spindle. Therefore, a replacement of the workpiece chuck apparatus is possible by the chuck apparatus according to the invention as part of a rapid replacement device in a very short time with a high concentricity and a high run-out as well as a very good repetition accuracy.

It is advantageous for the use of the chuck apparatus according to the invention as base flange if an air pipe which can rotate at least in a limited manner about the spindle axis is provided whose rotation can be derived by at least one coupling member from the rotation of the drive ring. This air pipe adapter ensures that an orderly functioning of the workpiece chuck apparatus is possible since the actuation of its chuck jaw is made available, for example, by the air pipe adapter.

At least one axially running groove is formed to this end on the air pipe adapter into which groove a sliding block arranged on a carrier ring engages wherein the coupling member is provided for rotating the carrier ring. This design has the special advantage that during the adjusting of the carrier ring for chucking the replacement flange, at the same time the air pipe adapter is also rotated so that only the activation of the drive is necessary in order to carry out the adjustments in the chuck apparatus as base flange which are necessary for a replacement of the workpiece chuck apparatus.

A possible alternative is formed in that the carrier ring comprises an outer toothing and the drive ring comprises an inner toothing into which a drive pinion engages as the coupling member.

It is furthermore conceivable that the coupling member is formed by a strut rigidly coupling the drive ring and the carrier ring. However, it is also advantageous if the coupling member is formed as a two-arm lever supported on a shaft and whose free lever ends are coupled to the drive ring and to the carrier ring. In particular when using the two-arm lever and the drive pinion a translation or gearing down is possible so that the rotation carried out on the drive ring can lead to a deviating angle of rotation of the carrier ring.

In order to actuate the workpiece chuck apparatus, substantially axially acting forces must be transferred by the air pipe adapter, to which end catch cams are formed on the air pipe adapter in the circumferential direction with a mutual distance.

A replacement flange for the connection to a chuck apparatus of the previously described type is also part of the invention, wherein a collar is formed on the replacement flange from which collar a radially inward protrusion projects. This protrusion is in particular suited for interacting with the radially outer chuck jaw comprising a groove, wherein it is advantageous if the walls of the groove of the chuck jaw and of the protrusion, which walls will make contact, are designed with an inclination in order to generate a downward traction effect.

Furthermore, it is advantageous if a coupling casing is provided on the replacement flange on which casing countercams are constructed in the circumferential direction with a mutual distance whose distance is measured in such a manner that upon a starting movement taking place in an axial direction whereby the one or more catch cams of the base flange can pass between the countercams. In this manner a covering of the catch cams with the countercams takes place during the rotation of the air pipe adapter brought about by the drive ring so that the transfer of the tractive forces acting in the axial direction is made readily possible.

FIG. 40shows a rapid replacement system1consisting in the exemplary embodiment shown of a chuck apparatus3fastened to the working spindle2of a tool machine which is not shown itself as a base flange4and of several replacement flanges5on which different workpiece chuck apparatus6can be fastened. The chuck apparatus3, the replacement flange5and the rapid replacement system1form independent aspects of the invention which is explained in the following.

FIG. 1shows the chuck apparatus3which is provided for the fastening to the working spindle2of a tool machine and has a chuck body8comprising a receptacle7for the working spindle2. Furthermore, the chuck apparatus3comprises at least two chuck jaws9which can be adjusted radially to the body axis and comprises a drive ring10for whose rotation in the circumferential direction a drive11is provided. In the exemplary embodiments shown in the drawings a total6of chuck jaws9arranged distributed uniformly over the circumference are provided and the drive11is basically formed by a drive wheel12which can rotate about a radial axis. However, even other drives11are conceivable which are suitable for rotating the drive ring10. For example, no drive11oriented radially to the drive ring10is shown to this end inFIG. 6but rather a spindle drive13oriented tangentially to the drive ring10in which the spindle casing engages via a drive tooth into a tooth receptacle of the drive ring10.

As can be recognized in particular fromFIG. 5andFIG. 7andFIG. 8, the drive ring10comprises on its outer circumference for each chuck jaw9a structure serving for its adjustment, namely, a control curve14formed on the outer circumference and with a control cam15serving for the radially outward adjustment of the chuck jaws9. It is pointed out for the sake of completion that in the case of a radially inward adjusting of the chuck jaws9the structure can also be formed on the inner circumference of the drive ring10.

A drive toothing16is constructed on the drive ring10on the side facing the working spindle2into which toothing the drive wheel12engages, whereby a return curve17is constructed on the side of the drive ring10facing the drive toothing16into which curve the chuck jaw9engages with a control member18(FIG. 8,FIG. 33).FIGS. 14 to 18show that the adjusting of the chuck jaws9does not necessarily have to take place via a control cam15in cooperation with a return curve17but rather that, for example, the drive ring10can also act on an eccentric44supported in the chuck body8on which eccentric the chuck jaws9are supported. The adjustment of the eccentric44can take place here according to theFIGS. 15 and 16via the cooperation of an eccentric cam pin and of a pin receptacle on the drive ring10or according toFIGS. 17 and 18via a toothing.

FIGS. 9 and 10show an embodiment in which an indicator curve19is formed on the outer circumference of the drive ring10for cooperating with an indicator pin20for displaying the rotary position of the drive ring20. The indicator pin is preferably arranged in a radial bore of the chuck body8so that its position can be recognized optically from the outside; a checking of the radial position of the indicator pin20is, however, also possible with a sensor for acting on the control of the tool machine.

FIGS. 11 to 13show that the chuck jaw9has an L-shaped base form on whose base shank21the control member18is arranged. A pin receptacle23open to the drive ring10is formed in the second shank22into which receptacle a contact pin24is inserted which comprises a plane surface25on the side associated with the drive ring10. The contact pin24furthermore comprises a pin foot26which is secured by a safety ring27in the pin receptacle23. It can be recognized in particular fromFIG. 13that the chuck jaws9comprises a groove28radially on the outside whose walls29are constructed with an inclination so that the groove28tapers toward the groove bottom.

As was already explained previously, the chuck apparatus3is suitable for forming the base flange4of a rapid replacement system1which comprises a replacement flange5as another constituting component which flange can be chucked with the chuck apparatus3as base flange4. The replacement flange5carries the workpiece chuck apparatus6. The jaws of this workpiece chuck apparatus6are adjusted in a customary manner by the air pipe associated with the tool machine so that when the chuck apparatus3is used as base flange4, an air pipe adapter30which can rotate at least in a limited manner about the spindle axis is associated with the chuck apparatus3, the rotation of which adapter can be derived by at least one coupling member31from the rotation of the drive ring10. To this end at least one axially extending adapter groove32is formed on the air pipe adapter30(FIG. 23) into which groove a sliding block34arranged on a carrier ring33engages. The coupling member31is provided for the rotation of the carrier ring33, wherein the embodiment shown inFIGS. 23 and 24shows a drive pinion35as coupling member31which engages in an outer toothing formed on the carrier ring33and into an inner toothing formed on the drive ring10.

Alternatively, the realizing of the exemplary embodiments shown in theFIGS. 25 and 26is possible, in which the coupling member31is formed by a strut36firmly coupling the drive ring10and the carrier ring33.

The embodiment shown in theFIGS. 27 to 30shows as coupling member31a two-arm lever37supported on a shaft and whose free lever ends are coupled to the drive ring10and to the carrier ring33. The free end of the two-arm lever37associated with the carrier ring33engages with a pin into a radially oriented groove while the end associated with the drive ring10is forked and extends over a forked cam38of the drive ring10.

Catch cams39are formed on the air pipe adapter30in the circumferential direction with mutual spacing while countercams41are formed on a coupling casing40associated with the replacement flange5and which are also spaced in the circumferential direction. The spacing is dimensioned in such a manner that upon a starting movement of the replacement flange5with the coupling casing40taking place in an axial direction, with the one or more catch cams39of the base flange4can pass between the countercams41so that a covering of the one or more catch cams39with the countercams40takes place upon the rotation of the air pipe adapter30.

FIG. 35shows that the replacement flange5has a collar42from which from which a protrusion43projects in a radially inward manner, wherein the walls of the groove28or chuck jaws9and of the protrusion43, which walls will make contact, are designed with an inclination in order to generate a downward traction effect.

The functioning of the invention is explained in the following.

Therefore, it is possible to connect the chuck body8one time to the working spindle2of the tool machine by the screws provided to this end as a replacement for a conventional tightening chuck. The chuck apparatus3connected in this manner to the working spindle2is already suitable for chucking workpieces or tools, wherein a replacement flange5can also be chucked. In order to carry out the chucking, at first the drive wheel12is actuated and the drive ring10is rotated in such a manner that the chuck jaws9are located in the open position, that is, the control cam15does not cooperate with the plane surface25of the contact pin24of the chuck jaws9. It is ensured at the same time by the coupling member31that the carrier ring33rotates the air pipe adapter30into the open position via the sliding block34. It is possible in this position to set the replacement flange5with this coupling casing40axially onto the base flange4, wherein the countercams41of the coupling casing40are moved past the catch cam39of the air pipe adapter30. Once this constellation has been reached, the drive wheel12is rotated so that the drive ring10is rotated out of the open position into the chucking position and the control cam15adjusts the chuck jaws9radially outward so that they surround with their groove28the protrusion43formed on the collar42of the replacement flange5. In this radially occurring adjustment of the chuck jaws9a downward traction effect is produced due to the inclination of the walls of the groove28and of the protrusion43and which brings about a defined axial position of the replacement flange5opposite the base flange4.

It should be noted that during the chucking of the replacement flange5, the rotation of the carrier ring33is also already being brought about via the coupling member31so that the one or more catch cams39which are arranged axially stacked opposite the countercams41are rotated with the air pipe adapter30and therefore an overlapping of countercams41and of catch cams39takes place in the manner of a bayonet closure. This completes the connection of the base flange4and of the replacement flange5and an axial adjustment of the coupling casing40can be brought about by the actuation of the air pipe of the tool machine via the air pipe adapter30in order to adjust, for example, the chuck jaws of a tightening chuck6mounted on the replacement flange5.

In order to loosen the connection of the replacement flange5and of the base flange4, the drive wheel12is merely rotated in the opposite direction so that the drive ring10is rotated out of the chucked position into the open position. This brings about on the one hand the rotation of the air pipe adapter30so that the one or more catch cams39and the countercams41no longer overlap. At the same time, the chuck jaws9are adjusted radially inward by the control member18resting on the return curve17so that the groove28of the chuck jaw9comes out of engagement with the protrusion43of the replacement flange5with the result that the replacement flange5can be axially removed from the base flange4. It is then possible to fasten another replacement flange5with a tightening chuck6with different qualities on the base flange4and therefore on the tool machine.

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