In currently common turning tools, embodiments are also in use, in which an individual cut ting insert is fixed in a receiving and/or working position on a tool holder and, by the move ment of the same, is advanced toward the workpiece. After the active cutting edge of the cut ting insert is worn down, it must be either replaced in the case of simple cutting inserts, or, if indexable inserts are used, these plates have to be released, turned and/or tilted and be fixed anew on the tool holder. All this is done manually and leads to a longer disruption of the ma chining operation. Even the known approach to provide multiple turning tools around the workpiece and to advance a new tool after one is worn down, brings about only a minor im provement as the entire arrangement has to be shut down and the tool has to be changed man ually for replacing any consumed tool.

In systems having multiple machining operations happening simultaneously on multiple ma chining spindles in one housing, replacement operations of consumed cutting inserts also cause a dramatic reduction of productivity as all other stations must be shut down, too, for the replacement on one machining station.

The object of the present invention was to overcome the disadvantages of the prior art and to provide a device, by means of which the change of the cutting insert can be performed as quickly as possible and with minimal user intervention, and which also allows and optimiza tion of the production time.

This object is achieved by a device according to the claims.

The device according to the invention is based on a turning tool for lathes, preferably for met alworking, comprising a cutting insert and a tool holder having a recess for receiving the cut ting insert in a working position, which is located at an end of the base body which can be ad vanced toward a workpiece. In the working position, the tool protrudes beyond the tool carrier such that it can perform the required machining of the workpiece, without the tool carrier or any other machine part coming into contact with the workpiece.

In order to achieve the stated object, such a turning tool is characterized in that the base body has an elongated recess leading to the working position, in which recess a plurality of cutting inserts are received one after the other and aligned in the same orientation and are mounted to be movable along the recess in the direction toward the working position. The recess, which can principally have any cross-section, but which preferably has a circular cross-section, is preferably straight and leads to the working position such that the cutting inserts have to be moved purely translationally, without the necessity of a turning, tilting or similar rotatory po- sitionings. The recess could also be arcuate and/or could consist of connected arcuate or straight segments. This way, elaborate and time-consuming rotation and turning operations can be avoided and the replacement of the individual cutting inserts, too, takes place rapidly as the replacement inserts for worn down cutting inserts are already kept available in the base body and do not have to be supplied from outside.

Preferably, a guide structure extending in the longitudinal direction in the recess engages with a complementary guide structure on the cutting inserts. This way, the exact orientation of the cutting inserts on any position in the circumferential direction, the unimpeded movement in the direction of the working position as well as the already optimally aligned reaching of the working position can be ensured. Most preferably, the complementary guide structure on the cutting inserts is also extending in the longitudinal direction of the inserts.

A simple yet effective embodiment of such a guide arrangement can, for example, be given by a group of guide pins extending in the longitudinal direction of the recess in a straight line and protruding into the clear opening of the recess and engaging with a guide slot on the cutting inserts.

The exact orientation of the cutting inserts in the recess transversely to its longitudinal axis is preferably achieved by the cross-section of the cutting inserts or its envelope being circular across a circumferential angle of more than 180 degrees, coaxial with respect to a center axis of the recess and having the same size as the cross-section of the recess. Hence, one the one hand, the good mobility of the cutting inserts along the recess is secured while also having an optimally predefinable orientation and preventing movements that are transverse with respect to the longitudinal axis.

The necessity of the intervention by a user is further reduced, if, according to a preferred ex emplary embodiment of the invention, each cutting insert can be at least indirectly subjected to a force in the direction toward the working position by means of a controllable drive.

Hence, an automated change of the cutting inserts is possible without manual user interven tion.

Preferably, a fluidic drive or an electric drive is provided for this. In respect of the available space and also the energy supply and the connection to control signals and sensor signals, this drive is preferably positioned on the base body end opposing the working position. An em bodiment having a pneumatic drive, for example a pneumatic working cylinder, is particularly preferred here.

In addition to the drive, a latching mechanism is advantageously effective between the base body and at least one cutting insert for the exact and reproducible positioning of the cutting insert on the working position, wherein a latch is displaceable against an elastic spring force transversely to the longitudinal axis of the base body, and, when in the latching position, abuts the side of a cutting insert facing away from the working position in a fixating manner. Of course, other arrangements and mechanisms are also possible for the fixation of the or each cutting insert, for example by means of a drive also serving for infeed, which can be stopped at an exactly definable position.

In this, the latch preferably has an oblique flank on its side facing away from the working po sition, which flank runs onto the side of a cutting insert facing the working position.

In order to achieve the initially stipulated object, a tool holder for a turning tool for lathes is provided, as well, having a base body and a recess for receiving a cutting insert in a working position, which is located at an end of the base body which can be advanced toward a work- piece. The features according to the invention are based in the fact that the base body has a recess leading to the working position for receiving a plurality of cutting inserts. Said recess is de signed such that the cutting inserts can be received therein one after the other and so as to be displaceable in the longitudinal direction of the recess.

For the optimum orientation and guidance of the cutting inserts, there is a guide structure ex tending in the longitudinal direction of the recess, which guide structure is configured for en gaging, in a longitudinally displaceable manner, with a complementary guide structure of the cutting inserts.

This is preferably provided by a group of guide pins extending in the longitudinal direction of the recess in a straight line and protruding into the clear opening of the recess.

In order to make an automated change of the cutting inserts possible, a preferred embodiment of the invention provides that a controllable drive is present for subjecting cutting inserts lo cated in the recess to a force in the direction of the working position.

The drive is preferred to be a fluidic drive, preferably a pneumatic drive or an electric drive.

A latching mechanism between the base body and at least one cutting insert is effective for the purpose that an exact positioning of the cutting inserts can be ensured. In this regard, a latch is displaceable against an elastic spring force transversely to the longitudinal axis of the base body and, when in the latching position, abuts the side of a cutting insert facing away from the working position.

A further optional embodiment is also preferred, in which the latch has an oblique flank on its side facing away from the working position, which flank runs onto the side of a cutting insert facing the working position and can displace the same against the effect of the elastic spring force.

Finally, a cutting insert arrangement for a turning tool for lathes, in which a plurality of cut ting inserts are connected to one another for forming an integral, oblong rod, also serves for achieving the initially stipulated object. All these cutting inserts present in the same orienta- tion are preferably formed and/or connected to be integral with one another, wherein the indi vidual cutting inserts are preferably delimited from one another by sections having a reduced cross-section, seen in the direction of the axis of the oblong rod. This allows the simple and rapid refitting with a high number of cutting inserts at the same time.

One embodiment of a cutting insert arrangement according to the invention, in which the sec tions having a reduced cross-section are formed as slits, wherein the open side of said slits are preferably inclined in the direction toward the working position, allows to create a simple and effective catching mechanism which allows the exact positioning of the individual cutting in serts.

The exact and reproducible orientation of every cutting insert in the circumferential direction about the longitudinal central axis of the arrangement of cutting inserts can be ensured by a guide structure being provided, which extends in the longitudinal direction, for engaging with a complementary guide structure of the tool holder in a longitudinally displaceable manner. For this, an embodiment is preferably provided in which, in each cutting insert and/or in the rod of cutting inserts, a guide slot is formed which extends in the longitudinal direction of the rod, which guide slot is designed for receiving the guide pins of the tool holder in a longitudi nally displaceable manner.

For the purpose of better understanding of the invention, it will be elucidated in more detail by means of the figures below.

These show in a respectively very simplified schematic representation:

Fig. 1 a side view of a tool according to the invention with the interior, non-visible com ponents represented in dashed lines;

Fig. 2 an oblique view from the upper front of the tool of fig. 1, again with the interior, non-visible components represented in dashed lines;

Fig. 3 a detail of the view of fig. 2, namely the front end with the cutting insert in working position, again with the interior, non-visible components represented in dashed lines;

Fig. 4 a front view of the tool of fig. 1, from the direction of the workpiece; Fig. 5 a view as in fig. 4, only with the interior, non-visible components represented in dashed lines;

Fig. 6 a side view of an integral cutting insert according to the invention;

Fig. 7 an enlarged detail on the front end of the cutting insert of fig. 6;

Fig. 8 a rod according to the invention with cutting inserts arranged one after the other;

Fig. 9 the front end of the rod of fig. 9 in an enlarged scale, and Fig. 10 a view of the rod of fig. 8 from a direction perpendicular to that of fig. 9 on the level of the latching element.

First of all, it is to be noted that in the different embodiments described, equal parts are pro vided with equal reference numbers and/or equal component designations, where the disclo sures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.

By way of example, one of a plurality of embodiments according to the invention of a turning tool for lathes, preferably for metalworking, is represented in fig. 1. In the following and for further embodiments, equal reference numbers and/or component designations are used for equal parts and reference is made to the detailed description above.

The turning tool comprises a cutting insert 1 which is inserted in a working position P on the front end of an oblong tool holder 2 and fixed in this position. In addition, the tool holder 2 has a correspondingly-shaped socket for the cutting insert. The remaining structure of the tool holder 2 can be designed as desired and be embodied as it is in conventional constructions. In the drawings and in the following description, an oblong tool holder 2 having a rectangular and/or square cross-section is represented and/or explained purely by way of example. Prefer ably, the front end 23 of the tool holder 2 facing the workpiece is formed to be conical, py ramidal or the like, so that it does not touch the workpiece. This can be seen very well in fig. 2, in which drawing coordinate axes are also included, to which reference will be made below for the purpose of a simpler description of movements and/or their fixations. In the base body 21 of the tool holder 2, a cylindrical recess 22 is formed, preferably drilled, in which recess 22 a plurality of cutting inserts 1 are received in most preferably a straight line, one after the other and aligned in the same orientation. The cutting insert 1 and/or any of the group of the cutting inserts can be designed to be right-handed, left-handed, neutral or having any desired angle.

Other cross-sectional shapes of the recess 22 are possible, such as rectangular, square, gener ally polygon or also having a round journal for connecting to the lathe. All these cutting in serts 1 are mounted to be movable preferably in x-direction or in an acute angle to this direc tion toward the working position P - represented on the far left in fig. 1 -, in which the cut ting edge and the cutting corner of the cutting insert 1 at the very front protrudes beyond the front end of the base body 21 of the tool holder 2. The recess 22 is preferably formed to ex tend in the longitudinal direction of the base body 21. This way, the tool holder 2 can keep a great number of replacement cutting inserts 1 available and does not have to be disassembled, for example, for the replacement of consumed inserts 1. Naturally, the tool holder 2 can be filled with a new group of cutting inserts 1 and used again once the last cutting insert 1 is used up.

In order to avoid elaborate readjusting when replacing a cutting insert 1 with the next insert 1 in the row, on the one hand, a guide structure extending in the longitudinal direction in the re cess 22, i. e. again in X-direction here, is provided. For example, a group of guide pins 24 (please refer to fig. 3, 5 and 9, in particular, on this), which extends in the longitudinal direc tion of the recess 22 in a straight line, protrudes into the clear opening of the recess 22. This guide structure on the tool holder 2 cooperates with a complementary guide structure on the cutting insert 1 or the entire group of cutting inserts, in order to ensure the exact orientation of the cutting inserts at each position in the circumferential direction of the recess 22 preferably having a circular cross-section. This complementary structure is, for example, a straight guide slot 13 on the cutting inserts 1, with which the guide pins 24 engage in a displaceable manner. For the depicted embodiment having a round cross-section of the recess 22, the cross-section of the cutting inserts 1 or its envelope is circular over a circumferential angle a of more than 180 degrees. The cross-section is arranged to be at every position coaxial to a center axis of the recess and has the same size as the cross-section of the recess 22. This ensures the easy displaceability of the cutting inserts 1 in the recess 22 and arranges for an accurately defined location in all directions transversely to the longitudinal axis of the recess 22. Due to the more than 180 degree envelopment, the cutting inserts 1 and/or the integral cutting insert arrange ment is therefore fixed in the y-direction and in the z-direction, regardless of the cross-sec tional shape. The contact between the inner wall of the recess 22 in the tool carrier 2 and the cutting inserts 1 is given across a circumferential angle a of more than 180 degrees, whereby the fixation in the y-direction and z-direction occurs automatically. The fixation in the cir cumferential direction is accomplished by means of the guide structures, for example the guide slots 13 and guide pins 24.

Preferably, a plurality of cutting inserts 1 are connected to each other for forming an integral, oblong rod, wherein the plurality of cutting inserts 1 is preferably designed to be integral. The individual cutting inserts 1 effective for machining the workpiece are delimited from one an other by sections 8, 9 having a reduced cross-section and held together by means of an oblong connecting part 12 extending along all cutting inserts 1 of the rod. The previously described guide slot 13 of the cutting inserts 1 can also be formed in the connecting part 12 as a slot run ning continuously from the first to the last cutting insert 1.

The reductions of the cross-section and/or notches, which delimit the individual cutting in serts 1 from one another, are preferably designed as slits 8, 9, oriented perpendicular or at an obtuse angle to the longitudinal axis of the plurality of the cutting inserts 1 or the oblong rod, respectively. In this regard, the open side of these slits 8, 9 is preferably inclined in the direc tion toward the working position P. This results in an front face 17 that is oblique with respect to the longitudinal axis of the cutting insert 1, to the longitudinal axis of the entire arrange ment of the cutting inserts 1 and the longitudinal axis of the recess 22, as well as in a rear side 18 facing away from the working position P on each cutting insert 1 (please refer to fig. 7, in particular, on this). The reductions of the cross-section and/or the notches between the indi vidual cutting inserts 1 can generally have any shape and can be adapted to the requirements of the respective machining process or the specific kind of separation of wom-down cutting inserts 1 and/or of the latching mechanism.

The exact and reproducible positioning of the cutting insert 1 on the working position P is ef fected or at least advantageously supported by a latching mechanism between the base body 21 and at least one cutting insert 1. An advantageous embodiment is represented in fig. 9 and 10 and comprises a latch 4 which is displaceable against the force of a spring 5 transversely to the longitudinal axis of the base body 21. In the latched position, a latching flank of the latch 4 is parallel with respect to the rear face 18 of one of the cutting inserts 1, and the cutting in sert 1 rests on this latch 4 toward the rear, away from the working position P, and thereby fix ates the cutting insert 1 with respect to movements away from the working position P.

The opposing flank of the latch 4 is slanted with respect to the front face 17 of the cutting in serts 1, and can therefore slide off on said face 17 if the cutting inserts 1 are moved toward the working position P on the front end of the tool carrier 2 and are thereby pushed radially out wardly against the impact of the spring 5. Only once next cross-section constriction 8, 9 reaches the position of the latch 4, the spring 5 again pushes the latch 4 radially toward the central axis of the recess 22 and the latching mechanism can take effect again.

In order to effect the automated infeed of the cutting inserts 1 without operating staff being required, each cutting insert 1 can be at least indirectly subjected to a force in the direction to wards the working position P by means of a controllable drive 6. For this, a fluidic drive by means of a hydraulic or a pneumatic working cylinder, which is independent of different vis cosities of hydraulic oil, is preferred, whose piston and/or piston rod is connected to prefera bly the last cutting insert 1 of the group located in the socket 22 or with the rear end of the in tegral rod of cutting inserts 1. If necessary, the rear end of the rod of cutting inserts 1 can per se be the piston or the piston rod of a fluidic working cylinder. In that case, the rear end of the recess 22 is preferably used as working space. Of course, electric, magnetic or electromag netic drives can also be put to use. The control and sensor lines from and to the drive 6 are symbolized by the connections 61. The drive arrangements can, additionally or alternatively to possible latching mechanisms, arrange for the exact positioning and/or locking of the cut ting inserts 1, in particular for the cutting insert 1 which is currently located at the working position P. Particularly with drives which engage on the rear end of an integral rod of cutting inserts 1, the positioning can thus also take place from the rear side of the cutting inserts 1. Finally, it should be mentioned that, with the aid of the arrangement according to the inven tion, changing the cutting insert 1 can be performed completely autonomously and without the necessity of operator intervention. Due to the typically brittle materials of the cutting inserts and/or of the cross-section constrictions 8, 9 between the individual cutting inserts 1, the con sumed cutting inserts 1 can be broken off simply by the impact of a radial force. In order to do so, a suitable tool can act on the cutting insert 1, in an automatically controlled manner, either radially with respect to the longitudinal axis of the arrangement of the cutting inserts 1 and/or radially with respect to the longitudinal axis of the tool holder 2. As an alternative to this, the tool holder 2 can also be moved to a fixed stop by means of its manipulation system, at which stop the consumed cutting insert 1 is radially broken off by means of a movement radial to the axis of the tool holder 2. Manually breaking off the cutting insert 1 would also be conceiva ble. The worn down, consumed cutting insert 1 is preferably moved in x-direction by means of the drive 6 and pushed beyond the working position P. Subsequently, the tool carrier 2 is moved against a stop in any direction in the y-z plane, which stop can also be the workpiece itself, wherein then, the first consumed cutting insert 1 breaks off at the point of the cross-sec tion constrictions 8, 9, due to the weakening of the arrangement of the cutting inserts 1. Then, the next, not yet consumed cutting insert 1 is moved up into the working position P by means of the drive 6 and is fixated there.

The monitoring of the wearout of the cutting inserts 1 can be fully integrated into the automa tion and/or control system of the machining station. The decision of when to change the cut ting insert 1 — meaning breaking off the consumed cutting insert 1 and moving the new cut ting insert 1 up to the working position P out from the inside of the tool holder 2 - can also be made with the aid of artificial intelligence, so that the machine itself decides and controls when and how the cutting insert 1 should be replaced, which is particularly advantageous at times when the machine is not supervised, for example during the night shift, operation at the weekend etc. Thus, this technology is prepared for the requirements of Industry 4.0.

The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment vari ants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the teaching for technical action pro vided by the present invention lies within the ability of the person skilled in the art in this technical field.

Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size. List of reference numbers

1 cutting insert

2 tool carrier

3

4 latching element

5 spring

6 actuator

7

8 slit

9 slit 0 tappet 1 tappet 2 connecting part 3 guide slot 4 5 sliding flank 6 latching flank 7 front face 8 rear face 9 0 1 base body 2 recess 3 conical section 4 guide pin 5 a circumferential angle P working position