Abstract:
A process and device are disclosed for positioning devices for temporarily fixing a workpiece in any desired angular position in a three-dimensional working space of which the coordinates are known, in particular when the workpiece requires a multidimensional support A computer-controlled machine with a tool movable in the direction of all co-ordinates is used for that purpose, together with a freely movable, vertically adjustable device or supporting column mounted on a base plate and upon which the supporting device for the multidimensional support of the workpiece is positioned. Based on the tool geometry or a C.A.D. programme, a coupling or an appropriately designed measurement head of a measurement machine is fixed on the tool with respect to a calculated plane of reference for the tool and to an axis inclined in relation thereto which cuts the plane of reference. The coupling parts designed as a coupling are then brought to a position at the tool or device which corresponds to the plane of reference, either directly by means of driven coupling parts or after a previous adjustment on an adjustment device placed on the base plate. The tool or measurement head is then moved into the precalculated position in space of the support of the workpiece and a supporting column with a corresponding supporting device is aligned with the position of the tool. The disclosed process steps and the positioning systems used to implement the process enable a three-dimensional supporting surface to be provided within a few minutes for a workpiece to be measured or machined, with an accuracy of more than 0.1 mm.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the invention 
     The invention relates to a method and a device for positioning a clamping device for workpieces within a predetermined working space. 
     The invention is described hereafter essentially with reference to a measuring machine and a positioning and clamping system provided for it, but is not restricted to measuring machines of this kind, instead being capable of being used in the same way for positioning systems with the aid of triaxially controllable robot systems for a tool. The system is, to that extent, suitable both for measuring machines and for processing machines. 
     2. Discussion of the Prior Art 
     Workpieces of any contour, in order to be accurately measured or processed, must be temporarily fixed within a specific three-dimensional space corresponding to the range of the measuring system or processing machine. Where measuring machines are concerned, this space is delimited in the plane by a measuring plate, a measuring table or a clamping plate, and the third dimension is determined by the range of the measuring tracer on a measuring bridge or a measuring boom (DE 22 32 858 A2 and DE 37 17 541 A1). 
     Adjustable columns, which can be locked with pin-point accuracy on the clamping plate, serve as clamping devices or seating columns for the workpiece. These include devices, such as are known, for example, from DE 44 24 765 A1 or U.S. Pat. No. 4,848,005. 
     A complete software-controlled measuring machine “TYPHOON” with a “Five Unique” clamping device was published in a prospectus of the same name by the company DEA-Brown-Sharpe SpA, Moncalieri, IT. 
     With the aid of the measuring machines or measuring robot, a reference point corresponding to a clamping point of the workpiece is approached in the three-dimensional measuring space surrounding the workpiece. A support or clamping column, which can be fixed on the measuring table, is then placed under this clamping point, as a rule by displacing the column as accurately as possible, manually or mechanically (U.S. Pat. No. 4,848,005), in the horizontal plane (XY-axis) and adjusting its height (Z-axis) vertically. The other clamping points are found and fixed in the same way. 
     A CAD program or a drawing of the workpiece, which are edited for software processing in the measuring machine, serves as an aid. In addition, the measuring rod or tracer of the measuring machine is replaced by a removable centering device which serves as a complementary simulated workpiece point at the clamping point of the column to be positioned. The centering device has a coupling element, for example a gripper or a ball catch, so that the column to be positioned can be coupled positively. This complicated positioning method is described in detail in DE 195 10 456 A1, as are some clamping means which can be used for fixing the workpieces. 
     Turntables with positioning accuracies of below +/−0.05° absolute accuracy, which are equipped with stepping motors or servomotors, are also known for positioning components at specific angles in one plane. The positioning accuracy is achieved by means of limit switches which utilize the Hall effect. Turntables of this kind bearing the type designation RTM are offered by the company Spindler &amp; Hoyer GmbH &amp; Co, Göttingen, Del. 
     Measuring columns movable on a measuring plate may be used, according to EP-B-0,216,041 for the automatic detection of individual measuring points even of very large components. 
     It is not possible, with the systems mentioned, to simulate a seating surface of any position and extent in the three-dimensional measuring space, that is to say working space, or to provide for a seating surface of this kind a column with a plane or curved clamping surface or otherwise spatial clamping surface; at least not when the position of the surface in the space assumes any solid angle which deviates from the angles standardized in grid systems, such as 15°, 30°, 45°, etc. 
     As regards the details of the clamping elements, centering balls and other details of the measuring machine, measuring plate and columns for the workpiece seatings and their functioning, reference is made to the publications mentioned here, and the description of these, by being quoted, is included in the disclosure of this invention. This applies insofar as other systems are not described for preference here. 
     SUMMARY OF THE INVENTION 
     The problem on which the invention is based, therefore, is to provide any clamping surface or multidimensional clamping and positioning device within the working space, so that a multidimensional clamping surface or correspondingly disposed clamping points for workpieces can be arranged on a corresponding positioning device. 
     The invention is based on the notion that, with the previous methods and positioning systems of the automatic or manual type, only point seatings or concrete points can be positioned accurately in order to seat the workpiece. In many cases, the workpiece surface, which serves for seating the workpiece or with which the workpiece is to be fastened to other parts, is not plane or does not have any horizontal extent in the working space, the coordinates of which are known. In these cases, for example if a seating surface has any solid angle, punctiform seating of the workpiece is inaccurate or leads to inaccurate temporary clamping of the workpiece. It was expedient, here, to find an economical, simple and cost-effective solution, using the hitherto conventional robot systems or measuring machines, in particular an arrangement for the measurement of workpieces. According to the prior art, it is necessary, in order to obtain a spatially arranged seating surface for the workpiece, to manufacture a special seating means which was capable of being placed on the punctiform supports, in particular seating columns on baseplates of measuring machines. In this case, there is the problem, inter alia, of accurately manufacturing this seating means which, under certain circumstances, can be used only once. Serious problems are also presented by prismatic workpieces or tubular workpieces or similarly shaped workpiece parts which, for measurement purposes, have to be positioned temporarily, in any axial position, below a spatial position known only from the finished product, or by devices for measuring methods, which require a controlled distance between a seating means and the workpiece, so that a uniform outer contour of the workpiece can be detected by means of a gage. 
     Proceeding from this, a method was developed for the accurate positioning of devices, such as seating columns and the like, for the temporary fixing of the workpiece in a known three-dimensional working space. It is presupposed, in this case, that the workpiece requires a multidimensional, that is to say spatially, randomly arranged seating and the tool or a measuring head with a measuring tracer can approach all the coordinate points, and the machine is equipped with a computer, as is the case, in particular, in three-dimensional measuring machines. The means made available by the measuring machine, such as collision protection or the transmission of electric control or power signals, can be used in the solution proposed here, in that they are employed, via a corresponding coupling system, on the head of the machine, for example the measuring head, for example as an exchange element for the measuring tracer. Opposite this measuring machine or processing machine, by which is meant, for example, a grinding device or a grinding tool and the like, and also, for example, an erosion tool, is located, as a rule, a baseplate, for example of the measuring plate of the measuring machine, and, on this, a vertically adjustable device freely movable in the X- and Y-axes, usually also designated as seating columns. In the prior art, these seating columns are, as a rule, provided with spherical or such like heads, so that the workpiece can be put in place there. 
     In the solution according to the invention, it is, of course, also possible to use such balls or standardized seating points unless, according to the invention, special seating means is to be used, which takes into account the multidimensional random spatial position of the workpiece. According to the invention, the seating column or similar device is equipped with a first coupling and the tool, that is to say the head of the machine, is equipped with a corresponding adapter having a second coupling, said device and said tool being movably connected in rotation through 360°. Each of these couplings consists of at least two coupling parts which are connected by means of lockable and pivotally movable intermediate joints, the two couplings temporarily being indirectly couplable to one another. This coupling may take place by means of a spacer piece between the freely movable coupling parts of the device and of the tool respectively or the coupling parts consist, at their free ends, of magnets, for example magnetic plates, which can thus indirectly couple the couplings of the device and of the tool to one another. 
     It is assumed that the workpiece configuration is available as a drawing or CAD program and that the spatial position of the seating surfaces of the workpiece can also be converted into coordinate points with the aid of the machine. The multidimensional seating thus determined is transposed to the system of coordinates of the working space and an arithmetic reference plane of the seating is then determined with respect to the multidimensional seating. This reference plane serves for fixing an axis which intersects this plane and according to which the entire positioning system can be oriented. The outer coupling parts on the tool are then aligned along the intersecting axis, and fixed, by the locking of the intermediate joint, and the tool is moved toward the arithmetically determined intersecting axis in the working space at a defined distance from the reference plane. This defined distance serves for receiving a spacer piece for coupling to the seating column, then to be aligned with the reference plane, and, if appropriate, for positioning a clamping means and a seating means on the seating column. After a seating column has been preadjusted approximately in the X- and Y-positions and the height (Z-axis) of the corresponding coupling part for the seating device subsequently to be mounted has then been aligned, the adjacent coupling parts of the device and of the tool are aligned so as to be axially true and are then fixed relative to one another. This fixing may take place by the intermediate coupling of a spacer piece of known length, while, at the same time, angular differences may be compensated for for the exact adjustment of the seating columns. 
     On the other hand, it is possible for the free ends of the coupling parts of the couplings to be equipped with magnetic elements which are then temporarily coupled to one another by means of magnetic forces in the position of the intersecting axis. 
     After this fine adjustment and alignment of the seating column or device on the baseplate has been carried out, the device is secured both on the baseplate and in terms of height. The couplings of the device and of the tool can then be uncoupled from the spacer piece, and a seating means complementary with the workpiece seating can be inserted into the then freed coupling part of the device or seating column and secured. It must be remembered, in this case, that both the spacer piece and the coupling parts are manufactured with high accuracy and have as little play as possible, so that a repetitive accuracy of &lt;0.1 mm can be guaranteed absolutely. The workpiece, for example an injection molding, can, as a rule, be manufactured with such narrow tolerances, so that a corresponding measuring machine or processing device must, of course, also be produced with similarly narrow tolerances. 
     In order to make the procedures and device parts used simpler and clearer, the positioning method and positioning system are based hereafter only on a three-dimensional measuring machine and a workpiece which is positioned in the space arranged within the range of the measuring machine and which is held by means of corresponding seating columns known per se. When the system is used with other machines, the average person skilled in the art can adapt to the operation and devices accordingly. Ideally, the number of components of the positioning elements to be used is to be kept as small as possible, on the one hand for reasons of cost and, on the other hand, so as to avoid inaccuracies being added together into relatively large positioning inaccuracies or measuring inaccuracies. One of the couplings to be used according to the invention, both on the head of the measuring machine, being inserted into the device used for the tracer, and on the head of the seating column, consists essentially only of the following elements: an adapter for coupling to the machine or the base of the seating column, an intermediate member allowing the coupling to move through 360°, although this degree of freedom in the X-Y-axis can be fixed by means of any angular lock, and a second coupling part which is to be arranged pivotally movably on this coupling part of the coupling and which is held so as to be pivotally movable relative to the first coupling part over somewhat more than +/−90° in a vertical plane relative to the axis of the latter, the pivot axis necessary for this purpose likewise being capable of being secured in a predefinable angular position. Lastly, it is also necessary, on this second coupling part, to have a fixing element arranged on the free end of the latter, so that an alignment of the complementary coupling part with the coupling of the seating column can be maintained in a defined angular position. Such fixing may be a sleeve which covers a defined spacer piece of known length between the two free coupling parts, or it may be a magnetic holding means, so that the coupling parts can be magnetically coupled to one another. The spacer piece used may, for example, be an accurately dimensioned cylindrical column provided, at both ends, with annular grooves, at which corresponding locking means of the coupling parts can hold this spacer piece. Ideally, the first coupling part and the adapter consist of a stepping motor or servomotor, in which one disk can turn rotationally relative to a second disk over a presettable degree of angle, for example according to an electric signal generated in the computer of a measuring machine. This stepping motor is provided with a forked piece at its end facing away from the machine, the forked piece having, at its ends, a pivot axis which receives in a pivotally movable manner a second motor designed in a similar way to the first stepping motor. This second motor is arranged pivotally movable about the pivot axis between the fork ends and, at its free end, carries a magnetic plate, for example a permanent magnet or else an electromagnet. If the seating is equipped in the same way, the magnets can be coupled to one another, so that the pivoted motors are coupled to one another, at the predefined angle, along the calculated intersecting axis. The joints of the couplings can then be fixed in this position, and the magnetic holding means is then separated. Since the measuring machine has locked on to the correct coordinate point, the seating column has been brought, after pre-adjustment, into a position such that, after coupling with the counterpiece, the pivotally movable motor is located on the seating column in the correct position, so that a workpiece can be supported at the desired location, with the seating surface being in the desired position. If appropriate, a seating means is placed onto the magnetic plate, said seating means being adapted to the contour of the workpiece and bridging a possible distance between the range of the seating column and the actual seating point of the workpiece. 
     Insofar as stepping motors of this kind cannot be used for the seating column and/or for the measuring head, for example because they are too expensive or too heavy, an auxiliary device, an adjusting device, can be used, which is positioned at a selectable reference location or reference point in the working space on the base plate. An adjusting device of this kind could then be equipped, in the same way as the movable seating column, with corresponding stepping motors, while the seating columns in the measuring machine itself have manual coupling systems. In this case, as described above, for this purpose the measuring machine is first used to determine the position of the workpiece in the working space, to calculate a reference plane and to determine an axis intersecting the reference plane. The adjusting device is then preset accordingly by the stepping motors being moved to the angular position complementary with the workpiece position, or its reference plane, and the intersecting axis. In a further step, one of the couplings described, but in a version to be operated manually, is positioned in the measuring head of the measuring machine, instead of the measuring tracer. This measuring head is then moved to a reference point of the working space, said reference point being located at a defined distance from the head face of the pivotally movable motor of the adjusting device. At the same time, the position of the intersecting axis at the reference point is approached and the coupling on the measuring head is then connected manually with the adjusting device, and the coupling, that is to say its pivot axis and axis of rotation, is subsequently fixed, so that the coupling no longer has any degrees of rotational freedom at the measuring point. After this preadjustment of the coupling, the measuring head is then moved to the desired location in the working space, and, as described above, the supporting column is positioned there, by the couplings being connected to one another and therefore the intersecting axis also being fixed in its X-Y-Z axial position on the supporting device. The couplings are then uncoupled manually, and the support means for the workpiece is inserted into the free coupling end of the supporting column. 
     If an adjusting device of this type likewise cannot be used, for example because the baseplate is very small or the stepping motors are still too expensive, in this case, too, the adjusting device may be equipped with a manual coupling device, either in the manner of couplings which are also present on the supporting column or on the measuring head or in that the adjusting device consists merely of a reference plinth which, in two or four reference directions, carries reference balls which can be connected by a centering means, in the manner of a union nut connection, to a couplable spacer piece relative to the measuring head. In this case, as described above, the measuring machine approaches the reference point of the adjusting device, and the centering element arranged on the reference ball with play, but positively, is then coupled to the manual coupling of the measuring machine by means of the union nut connection, using a spacer piece, and, in turn, the degree of rotational freedom and the degree of pivoting freedom are blocked on the measuring machine by appropriate locking means. Thereafter, as described above, the supporting column can be set up according to the model of axial inclination at the coupling of the measuring head. 
     Depending on the desired degree of automation or the outlay for such positioning systems according to the invention, both the measuring machine head, the supporting column and/or an adjusting device may be provided with an electrically or manually adjustable and lockable coupling, and the necessary angular settings on the couplings may be carried out manually or by electric control. In all cases, however, a reference plane or surface for the workpiece seating at a distance from the vertical axes of the supporting column or of the adjusting device, on the one hand, and of the measuring head, on the other hand, must first be defined according to the geometric dimensions of the supporting columns and support means used and with respect to the intersecting axis which, in the simplest case, is orthogonal to the reference plane. The right-angled axial position (in relation to a reference plane centrally between the vertical axes) is obtained automatically, using spacer pieces with parallel annular grooves and manually operable couplings of identical design. 
     The supporting element or support means, to be inserted into the supporting column, for the workpiece has, in relation to the supporting column, a reference plane, for example the top side of the support means, which is plane-parallel to a surface of the supporting column, so that, in the case of manual variation of the support means, the latter is not rotated or tilted out of the desired spatial position. 
     In a particular embodiment of the support means, the latter may be provided with a complementary surface to the workpiece surface, but this support means also acquires a further degree of rotational freedom, so that a workpiece contour deviating with respect to the reference plane can be taken into account. This is particularly expedient in the positioning of workpieces, such as pipelines or the like, which do not have two-dimensional seating edges and the support means therefore has to be designed as a multipoint support. It could be the same if the workpiece surface is provided with a three-dimensional structure at the seating point and the surface of the support means has to be aligned in the same way. If the surface of the support means has to be pivoted for this purpose, a bearing with a degree of rotational freedom is arranged on the support means itself, if appropriate with an indicator for the angular position or the arc dimension. 
     If nonmagnetic coupling parts are used for the above-described spacer piece or the support means, it is necessary for said coupling parts to be guided accurately, which is appropriately carried out by means of a corresponding design of the free end of the coupling part of the respective coupling. Since the spacer piece itself is to have a fixed dimension, adjustable coupling elements cannot be mounted there. For this reason, at least the coupling of the supporting column or the coupling on the measuring head must be equipped with a sleeve engaging over the spacer piece or with elements acting in a similar way, so that the spacer piece can be coupled and uncoupled. In order that the exact distances between the coupling parts can be adjusted with repetitive accuracy, the spacer piece may preferably be provided with annular grooves, in which locking means for the sleeves to be pushed into the spacer piece or coupling parts can be accurately fixed. The spacer piece is held centrally in the direction of the intersecting axis by appropriate centering means within the coupling parts. 
     Further advantages and details of the device according to the invention and of the positioning method may be gathered from the following description with reference to exemplary embodiments. By means of the measuring machine equipped in this way, a measuring point or a measuring surface can be approached with an accuracy of less than 0.1 mm and the workpiece positioned with corresponding accuracy. 
     The invention is described in more detail below with reference to a partly diagrammatic and partly concrete drawing in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a positioning device with adjusting device, tool and spacer piece; 
     FIG. 2 shows a positioning device with a supporting column, as a vertically adjustable device, as well as a tool and spacer piece, according to FIG. 1; 
     FIG. 3 shows the device according to FIG. 2 in the coupled state; 
     FIG. 4 shows the device according to FIG. 2 after the supporting column has been fixed; 
     FIG. 5 shows a supporting column with the support means to be inserted; 
     FIG. 6 shows a second form of the adjusting device and a second form of the tool; 
     FIG. 7 shows a third form of the adjusting device or supporting column; 
     FIG. 8 a  shows a concrete form of the adjusting device according to FIG. 1 in section; 
     FIG. 8 b  shows a concrete second form of the positioning system, similar to FIG. 3, in section; 
     FIG. 8 c  shows a concrete alternative plinth for a positioning system; 
     FIGS. 9 a-c  shows a second and third support means with clamping elements; and 
     FIGS. 10 d-f  shows different forms of support means. 
    
    
     Identical or identically acting components are given identical reference symbols below. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A positioning system according to FIG. 1, the parts of which consist essentially of light metal, shows the base of an adjusting device  2  provided with a coupling  1  which can be coupled via a spacer piece  3  to a coupling  4  of a tool/machine. A stationary part  11  is provided with a clamping ring  12 , by means of which a shaft  13 , rotatable through 360° with the degree of freedom F 1, can be locked at any desired angle of rotation relative to the fixed part  11 . The shaft  13  is connected to a coupling part  14  which is pivotally movable about the locking means  17  and which has a degree of freedom of about 180°, so that an angle of about +/−90° relative to the longitudinal axis of the part  13  can be set between the shaft  13  and the coupling part  14 . Arranged on this coupling part  14  is a part  15  which is designed in the manner of a union nut or slip-over sleeve and which is movable, in the position of rest, in the direction of the locking means  17  or the intermediate joint  13 , but, on the other hand, can be slipped over the spacer piece  3  and connected to the latter by the locking means  18 . The spacer piece  3  is secured, on the other hand, by a locking means  48 , designed identically to the locking means  18 , in a slip-over sleeve  45  which is designed in a similar way to the sleeve  15 . The sleeve  45  can, in turn, be displaced axially on the coupling part  44 , so that the spacer piece  3  can be extracted or inserted between the sleeves  45  and  15 . The coupling part  44  forms, with a further part  43  connected in a pivot axis of the locking means  47 , an angle which can be designed to be about +/−90° relative to the axis of the part  43  according to the degree of freedom F 2 which is exactly the same as the equivalent degree of freedom on the adjusting device  1 ,  2 . The part  43  is held on the machine side via an adapter  41 . The part  43  is capable of being moved with F 1 in rotation through 360° relative to the axis of the adapter  41 , but can be stopped by locking means  46  on the clamping ring  42 . The part  4  may also be designated, as a whole, as a tool, machine head or measuring head with coupling. 
     The parts of the positioning system which are illustrated in FIG. 1 make it possible to use a tool or measuring device, with the aid of a measuring machine which can be connected to the journal  40  with the adapter  41 , in order to calculate positions of supporting columns accurately in space with the aid of the adjusting device and tool and subsequently to align them. For this purpose, the measuring machine is brought to the illustrated position relative to the base  2 , the previously calculated spatial position of the axis being symbolized by a connecting line between the axes of the locking means  17  and  47 , previously also called an intersecting axis. The spacing of the axes of the components  41  and  13  is determined by the spacer piece  3  having a fixed length and by the overall lengths of the corresponding coupling parts  14  and  44 . 
     After the measuring machine together with the tool  4  has been moved into the position illustrated, the spacer piece  3  is coupled between the adjusting device  2  and the tool  4  and the locking means  48  and  18  are tightened, so that an accurate spacing of the vertical axes or an accurate length of the relevant portion of the intersecting axis is ensured. The locking means  46  is then actuated, in order to block the degree of freedom F 1, and the fastening means  47  is tightened, in order to block the degree of freedom F 2, after the degree of translational freedom, illustrated by the arrows parallel to the intersecting axis, has previously already been restricted by the fixing of the spacer piece with the aid of the locking means  18 ,  48 . 
     FIG. 2 shows, then, that the locking means  18  of the adjusting device (FIG. 1) or of the corresponding coupling part has subsequently been released, the annular groove  31  of the spacer piece  3  having been freed, so that the spacer piece  3  has been moved by the tool  4  relative to a supporting column with the coupling  6  and base  5 . The base of the supporting column has been preadjusted in the X- and Y-directions and displaced on a base plate (FIG. 8 b ) in such a way that, within the coupling  6  of the supporting column, a first height adjustment (FIG. 3) can take place in the direction Z of the coupling axis  63  and subsequently the column with the coupling part  64  can be pushed over the spacer piece  3 , so that the locking means  68  on the coupling part  64  can engage into the groove  31  of the spacer piece  3  and accurately adjust the connection between the workpiece and supporting column. For this purpose, it is initially unimportant whether the receptacle (part  64 ) for the spacer piece  3  is movable along the intersecting axis (arrow) and can be pushed over the spacer piece or whether, according to FIG. 8 b , the receptacle (part  65 ) for the spacer piece is fixed on the supporting column and is not designed as a slip-over socket. The advantage of this is that the version according to FIG. 8 b  is more accurate and allows less play. 
     The supporting column has a stationary part  61  and a clamping ring  62 , in which the shaft  63  is movable in rotation according to the degree of freedom F 1 and, at the same time, is adjustable in terms of its height, as shown by the arrow in FIG.  3 . The coupling parts  63 ,  64  are pivotable via the intermediate joint or the locking means  67 , movement being possible with a degree of freedom F 2 of +/−about 90°, preferably 2 to 5° in any direction. After the supporting column  5 ,  6  is coupled to the tool  4 , as illustrated in FIG. 3, the locking means  67  for the intermediate joint and a locking means, not illustrated, for the clamping ring  62  are actuated, so that the two degrees of freedom F 1 and F 2 are blocked and the part  64 , with its axis, more specifically the intersecting axis defined by the axes of the parts  44 ,  3 ,  64 , is fixed. During the mounting of the supporting column, the measuring machine with the adapter  41  was moved accurately into the position obtained as a result of the intersecting axis, and into the reference plane, defined by the spacer piece or, for example, its end faces, at a distance from the vertical axis of the adapter. 
     FIG. 4 shows that the locking means  68  is then released, so that the measuring machine together with the tool  4  and with the spacer piece  3  can leave the supporting column. Alternatively, the spacer piece  3  can initially remain in the supporting column and can be extracted later. 
     FIG. 5 then shows that this spacer piece is replaced by a support means  100 . The latter is equipped with a surface, its top side  103 , complementary with the seating of the workpiece, as well as with a journal  102  and a groove  101  which can be fixed in the exact desired position by the locking means  68 . 
     FIG. 6 shows, instead of an adjusting device  1 ,  2 , an alternative adjusting device  7  comprising a cross slide  72  arranged on a base plate which is not illustrated. Seated on the cross slide  72  are reference balls  71  provided with a union nut sleeve  73  for a spacer piece  33 . The tool  8  is designed, here, as a sleeve  80  which can be pushed over the measuring head  81  having a tracer  82 . The sleeve  80  has a journal  83 , on which are provided a rotational coupling unit  84 , with a degree of freedom of 360° about the vertical axis of the measuring head, and a forked piece  85  which is arranged on the coupling part and which itself, in turn, carries a pivoting unit  86  pivotable through +/−95° about the pivot axis  87 . Flanged to this pivoting unit  86  is a coupling part  88  provided with a box sleeve  89  for connecting this coupling  88  to the spacer piece  33 . In this case, the pivotings of the units through 360° and through +/−95° are executed by means of electrically operated stepping motors or servomotors which can be controlled by the computer of the measuring machine or the machine moving the measuring head  81 , with the result that the corresponding pivot angles or angles of rotation can be transmitted directly from the software program to the positioning means illustrated in FIG.  7 . Since the adjusting device  7  is equipped with the balls  71 , the axis of the measuring head  81  is freely movable relative to these balls  71  in the way illustrated, specifically with two degrees of rotational freedom, so that the connection from the ball center to the pivot axis  87  ultimately represents the intersecting axis according to the invention. 
     FIG. 7 shows an alternative adjusting means instead of the cross slide  72  and of the adjusting head equipped with balls, which alternative adjusting means can be arranged at a predetermined location on a measuring machine table or a baseplate  800 . To that extent, the device parts  800  to  880  represent a mirror-symmetric version of the above-described design of the tool bearing the reference numerals  80  to  88 . Fixed on the machine table  800  is a base unit  810  of an adjusting means, in which a programmable stepping motor is arranged so as to be movable through 360°, said stepping motor being adjustable over a predeterminable angle, for example with a limit switch function. A rotary head  840  holds in a fork  850 , at the joint  860 , a further rotary head with an integrated programmable stepping motor  870  which is pivotable through +/−100° about a rotary journal, as indicated by the angle scale marks. The stepping motor  870  carries, on its head side, a magnet  880 , by means of which, instead of the above-described coupling parts for a spacer piece  3 , this spacer piece is accurately fixed magnetically on the adjusting head. Alternatively, of course, the coupling means (FIG. 1) already described as part  1  may also be used on such a stepping motor or pivoting device. 
     FIG. 8 a shows in concrete form, as compared with FIG. 1, an adjusting device having the parts  1  and  2 . The part  2  comprises, here, a baseplate  21  and a fixing means  22  for the stationary part  11  of the coupling  1 . Two axial and radial bearings  111  are fixed on the threaded journal  131  in a sleeve shaped housing  110  by means of a spring ring  113  and a nut  132 . The threaded journal  131  belongs to the shaft  13  which is thus mounted freely movably in rotation, but, on the other hand, accurately and free of play, in the housing  110 . The clamping ring, designated as a whole by the numeral  12 , consists of a slotted torus  120  which is fixed, on one side, to the housing  110  by means of screws  121  while, on the other side, a clamping screw  16  passes through the slot  122 , in order to block the degree of rotational freedom of the shaft  13 . The shaft  13  terminates in the half shaft or the journal part  133  which is connected to a complementary journal part  141  over the part  14  by the locking means  17 . The locking means comprises a wing nut  171  having a sliding journal  172  which terminates in a threaded journal  173 . The sliding journal  72  is seated in a drilled bush  174  which bridges the two journal parts  133 ,  141 , while said sliding journal  172  can be screwed into a threaded bore of the journal part  141 , so that the coupling-side head of the wing nut  171  secures the journal part  133  by clamping against the journal part  141 . The part  14  terminates in a central guide part  142  having about half the diameter of the largest dimension of the journal  14 . Fixed to the head of the guide part  142  by means of a screw  143  is a collar disk  144 , so that the sleeve  15 , with its collar  151  sliding on the guide  142 , cannot fall off from the part  14 . The locking means  18  provided with a wing nut  181  having a threaded journal  182  passes through the sleeve  15  in a thread, not illustrated, and thus, according to FIG. 1, a spacer piece  3  can be fixed in the groove  31 . 
     FIG. 8 b  shows, in a design similar to that of the adjusting device, a device which is designed as a supporting column, the fixed part  5  comprising a plinth (base unit)  51  with an internal thread  510  which is capable of being fixed on a baseplate  21  with the aid of a clamping device  511  or  512 ,  513 . If required, an extension  52  having an external thread can be screwed into this base unit  51 , into the thread of the latter. The steel plates  53 ,  54 , which are fixed by means of screws  531 ,  541 , define surfaces for applying fork wrenches, so that the threaded parts can be tightened relative to one another. The extension  52  may be designed at any desired column height. The extension  52  also carries an internal thread  521  and can receive therein the stationary part  61 , having an external thread  611 , of the coupling  6 . The stationary part  61  of the coupling consists of a sleeve  610  with an inner guide bush  612  for the shaft  63  which is movable in the guide bush  612  both in rotation and in the axial direction of the shaft. The translational movement of the shaft in the Z-direction is limited by a spring ring  631  in interaction with the bash  612 . The largest diameter  630  of the shaft  63  can be fixed with a clamping effect, both in the direction of rotation and in the direction of translational movement, with the aid of the slotted ring  62  as well as the locking means  66  with the wing nut  661 . The journal  632  of the shaft  63  is locked no:positively, in the pivot angle position of said shaft, with a similarly designed journal  651  by the locking means  67  which is identical to the locking means  17 . The part  651  may be designed in a similar way to the part  14  or  64 , but it is more advantageous to dispense with a slip-over sleeve similar to the sleeve  15  and, instead, design the part  651  with rotationally symmetric inner centering as a flange of said part. A spacer piece  3  with grooves  31  can be fixed in this centering of the flange by a corresponding locking means  68  which is designed to be identical to the locking means  18 . It can be seen clearly that the pin  682  bears with its head on a flank of the groove  31  and thus ensures that the spacer piece  3  is clamped, free of play, relative to the locking device  48  in the groove  32  of said spacer. The sleeve  45 , coupling part  44  and locking means  47  are designed in the same way as the sleeve  15 , coupling part  14  and locking means  17 . The locking means  47  clamps to the coupling part  44  a shaft piece  43 , in which is centrally fixed by means of a screw  432  a shaft  431  which, on its larger collar  433 , supports an adapter  41  in a rotationally movable manner. The adapter  41  terminates in a connecting thread  40  connecting with a machine tool or measuring machine. The adapter  41  is connected to a clamping ring  42  by means of a screw  421 . This clamping ring  41  is slotted and can be clamped by the locking means  46  by means of a wing nut illustrated, so that the rotational movement of the shaft  431  in the adapter  41  is blocked. On the other hand, as has already been described above, the part  43  can be connected to the part  44  so as to be pivotally movable about the locking means  47 , previously also called an intermediate joint. The adapter  41  or the connecting thread  40  may, if appropriate, be adapted to a receptacle of a measuring machine head in such a way that a signal connection from the computer of the measuring machine or an electric line for drive energy can be fed into the tool generally designated as the part  4 . 
     The purpose of these connections is, for example, to make it possible to utilize further the collision sensors conventional in the case of measuring tracers or to drive energy for the stepping motors, which together form this tool  4  or are parts of this tool, or to transmit regulating commands to these. 
     FIG. 8 c  shows an alternative to the plinth  51  to be clamped or the clamping device  511  to  530  according to FIG. 8 b  on a baseplate  21 . The baseplate  21 , a plane clamping table with grooves or holes at grid intervals, serves for supporting and fixing the plinth  51  a of a column illustrated merely by the part  61 . The foot plate  514  can be positioned freely on the baseplate  21 . Said foot plate  514  has a perforation  519  which is partially congruent with the long hole  517  in the intermediate ring  515 . The intermediate ring  515  and an adapter ring  518  are both or individually freely movable in rotation, in the direction of the arrow, relative to the foot plate  514  and the column part  61 , respectively. It is thereby possible for the screw  516  to be displaced in the direction of the arrow in the long hole  517  and at the same time in the perforation  519 , until it can engage in a complementary nut, perforated block or tenon block, not illustrated, in the baseplate  21  and thus fix the column. 
     FIG. 9 a  shows a clamping means, provided as a whole with the numeral  9 , which is coupled to a support means  320  and which has a similar appearance to the spacer piece  3 , in particular is provided with an annular groove R, so that the support means  320  can be held with the locking means  68 . The actual supporting surface for seating a workpiece is designated by  321 . 
     FIG. 9 b  shows the clamping means  9  with the clip  91  for engaging round a support means  310  to  370  (FIG.  10 ), the support means being fixed to the clip by means of the screw  911 . A first lever  92  has a multiplicity of holes for a column  94  which is connected to the lever  92  in a pivotally movable manner by means of a rotary joint  93 . The lever  94  has itself, at its free end, a pivoting joint  941  with 360° of rotational freedom and is coupled, in the rotary joint, to a claw  95  which, at its free end, carries a clamping bolt  96  which can be displaced along the claw  95 , within the long hole or slot  951 , in such a way that said clamping bolt can be adjusted, in each case via the clip  91 , according to the offset of the center of a rotation  93 . 
     FIG. 9 c  shows another possibility for clamping workpieces with the aid of a tensioner  97  which is fastened on the head  890  of a device  870  (FIG. 7) by means of screw. The tensioner  97  is built on the base  973 , the base being itself fastened to the head  890  (in a similar way to FIG.  7 ). Depending on the movement of the lever  972 , the claw  971  or the tensioner  97  itself can be moved in the direction indicated by the arrows and, thus adapted, can in each case find the correct clamping point for the claw  971  relative to the support means  330 . 
     FIG. 10 a - 10   f  show various support means  310 - 370  which can be inserted into the coupling part  652 , and the support means  310  can be locked there, in its annular groove R, by the locking means  68 . If necessary, a further clamping means can be coupled to the annular groove  313 , with the aid of which clamping means the multidimensional support  311  of a workpiece not illustrated, for example a pipeline or a prism, can be additionally fixed.  312  designates a pivot mounting with angle scaling or a vernier, said pivot mounting making it possible for the journals of the multidimensional support points  311  to be adapted additively to the position of the workpiece after the support means  310  has been clamped. 
     The further support means for use with the supporting columns  5 ,  6  are shown in a similar way, the respective surfaces  331  to  371  being adapted to the corresponding contour of a workpiece. Thus, for example, annular workpiece faces can be supported by means of the surfaces  351  and  361 , while the surface  341  makes it possible to use any desired supporting contour adapted to the workpiece contour. At the same time, in this case, the circular top surface or underside of the support means may serve as a reference plane, while the vertical center line of this support means coincides with the intersecting axis.