Patent Publication Number: US-2022219272-A1

Title: Mobile device for machining a workpiece

Description:
RELATED APPLICATIONS 
     This application is a continuation of International Patent Application PCT/EP2020/025385 filed on Aug. 28, 2020 claiming priority from German Patent Application DE 10 2019 123 119.1 filed Aug. 28, 2019, both of which are incorporated in their entirety by this reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a mobile device for machining a workpiece, 
     BACKGROUND OF THE INVENTION 
     The mobile device according to the invention is particularly suited for chipping machining of a work piece to be provided with a circular arc shaped surface contour. Thus, the device can be used for chipping machining of any type of work piece, thus e.g., for processing a metal work piece as well as a wooden work piece. The device is also suitable for chipping machining of a non-machined work piece as well as for finishing a surface that has been previously machined. 
     The mobile device according to the invention is useable e.g; for machining valve seats. Valve seats are typically configured trumpet shaped, including a surface contour of the valve that is oriented towards an interior and configured circular arc shaped. Typically, the valve seats have to be refinished after a certain time period. For large size valves used e.g. in power plants, removing the valves and transporting them to a shop is complex and expensive. Therefore, mobile devices are typically used to finish the valve seats in place. 
     Known mobile devices thus operate driven by computerized numeral control (CNC). These devices typically include individually controllable motors that facilitate moving a cutting tool along a preprogrammed path in a direction of plural typically perpendicular axes. A device of this type is disclosed in FR 2 751 901 A1 which describes a device for machining valve seats including a machining tool that is movable by two separately controllable positioning devices. This way the desired contour of the valve seat becomes achievable. 
     DE 600 00 215 T2 describes a device for machining valve seats. The valve seats are machined by a cutting tool which includes an end contour corresponding to a desired contour of the valve seat, therefore a separate tool contour is required for each valve contour. 
     Typically, devices of this general type are expensive. Furthermore, it has proven to be a problem that the programmable devices can only be operated by trained personnel that is familiar with CNC programming. Therefore, operators have to be trained before using the device. Therefore, there is long felt need for a mobile device, that is operable without programming skills and that facilitates machining a multitude of possible work piece contours. 
     BRIEF SUMMARY OF THE INVENTION 
     Thus, it is an object of the invention to provide a mobile device which is simple to handle and facilitates freedom to machine different work pieces. 
     Improving upon the devices recited supra the object is achieved by a mobile device for machining a workpiece, the mobile device including a shaft rotatable about a rotation axis; a carriage rotatable with the shaft about the rotation axis and axially, or radially displaceable relative to the rotation axis; a tool support for a cutting tool, the tool support connected to the carriage and displaceable along a carriage axis and in a direction perpendicular to the carriage axis; and a transmission that couples the shaft to the tool support and the carriage so that the tool support is displaceable along a path that includes an axial and a radial movement component relative to the shaft. 
     The device according to the invention has many advantages. In particular, the device is operable without any programming knowledge. This advantageously reduces training time of an operator of the device. The mobile device only has a small number of components and thus can be transported in a particularly simple manner and can also be disassembled simply and quickly. 
     The coupling of the shaft with the tool support and the carriage described supra furthermore facilitates moving the tool support and thus the cutting tool along a path that is configured to machine the work piece so that a surface contour of the work piece is configured as a circular arc in cross section. The carriage and the tool support connected therewith perform a rotating movement about the rotation axis of the shaft. When the carriage is axially movable along the rotation axis of the shaft the cutting tool connected with the tool support is movable on a path that is determined by a distance between the rotation axis of the shaft and the cutting tool. Due to the coupling of the shaft with the carriage of the device that is movable axially along the rotation axis an axial movement component of the cutting tool is facilitated in a direction of the rotation axis of the shaft. 
     In an embodiment where the carriage is radially movable with respect to the rotation axis of the shaft the cutting tool is movable on a path that is determined by a displacement of the cutting tool along the rotation axis of the shaft. Due to the coupling of the shaft with the carriage that is radially movable relative to a direction of the rotation axis of the shaft a radial movement component of the cutting tool with respect to the rotation axis of the shaft is facilitated. 
     It is also conceivable that the carriage is movable with a radial and an axial component with respect to the rotation axis of the shaft. Put differently the carriage is movable in this embodiment at a slant angle relative to the rotation axis of the shaft. Overall, the tool support is also movable in this case with an axial and a radial component along the path relative to the shaft. 
     The device according to the invention can thus be used for machining a work piece configured as a valve. Advantageously the rotation axis of the shaft corresponds to a longitudinal axis of a work piece, thus the shaft is aligned centric and parallel to a longitudinal axis of the valve. In an operating condition of the device the cutting tool, e.g. a turning steel is moved along a path. Thus, it is advantageously provided that the shaft is coupled with the tool support and the carriage so that the cutting tool moves along a circular path in a plane that is parallel to the shaft, wherein the circular path is transferred to the work piece to be machined. Advantageously, the device according to the invention facilitates producing a concave as well as a convex surface contour of the work piece to be machined. 
     By the same token the device according to the invention is also configured to machine a flange or a diffusors where faces have to be machined so that the faces are circular in a cross section along a symmetry access of the flange. 
     In any case it can be particularly advantageous when the rotation axis of the tool corresponds to a longitudinal axis of a work piece. This way the work piece can be machined rotation symmetrical with respect to the rotation axis. In particular when machining a valve seat or a flange it can be advantageous when the shaft is arranged within the work piece and the rotation axis of the shaft corresponds to or coincides with the longitudinal axis of the work piece. 
     According to another embodiment of the invention the transmission is a mechanical transmission and/or the coupling between shaft, tool support and carriage is a forced coupling. A mechanical transmission facilitates mechanically transposing a predetermined path of the cutting tool by the device without computer-based control. Thus, it has become apparent that the mechanical configuration of the transmission is particularly advantageous with respect to a simple handling of the device. Thus, acquiring programming skills that are required for operating known devices is redundant. By the same token operator errors due to programming errors can be precluded for the device. Furthermore, also replacing components of the device e.g: due to wear is simpler and more economical since no electronic components (actuators, sensors and controllers etc.) are being used. When configuring a forced coupling of the shaft, the tool support and the carriage a common drive can be used for operating the device. 
     According to an advantageous embodiment of the invention, the transmission includes a lever arrangement and/or a slotted link and/or gears, and/or traction devices. It has become apparent that the coupling of the shaft with the tool support and the carriage can be performed in a particularly simple manner by a lever arrangement and/or a slotted link and/or by gears and/or traction devices. In any case the coupling is performed purely mechanically so that no programming skills of the operator of the device are required to operate the device. Additionally, the components recited supra can be replaced particularly easily when worn. 
     In particular when using a slotted link, the cutting tool can be moved along any path wherein the path is predetermined by the slotted link. This can facilitate e.g: to turn a tulip shape into a surface. In particular when machining tubular sections fabricating tulip shapes is often required. Essentially a tulip shape is a transition that is essentially semi-circular. When machining the tubular section, the tulip is to be machined into a face of the typically rotation symmetrical work piece so that the work piece is provided with a circular transition along a circumference of the work piece. Thus, it can be particularly advantageous when the tulip is arranged in a center portion of the face and adjacent portions are arranged at an angle of less than  90  degrees with reference to the longitudinal axis of the work piece. This contour can be transferred to the work piece by a slotted link. 
     Advantageously the mobile device can include a support block that is connected torque proof to the shaft wherein the transmission is linked at the support block. The support block advantageously cooperates with the carriage of the mobile device. Advantageously the support block functions as a fixed point wherein the carriage is moved relative to the fixed point by the transmission in an axial and/or radial direction relative to the shaft. 
     According to an advantageous embodiment of the invention at least one connection lever is provided which is rotatably coupled with the support block and also rotatably coupled with the tool support so that the tool support moves along a circular path viewed in a plane that is parallel to the shaft wherein a center of the circular path is a first axis of rotation of the connection lever at the support block and wherein a radius of the circular path corresponds to a distance between an axis of rotation of the connection lever and a second axis of rotation of the connection lever at the tool support. 
     Advantageously the mobile device facilitates chipping machining of the work piece so that the work piece has a circular arc shaped surface contour in a sectional view parallel to the shaft wherein the circular arc shaped surface contour corresponds to the path traveled by the tool holder. Thus, the mobile device is particularly suited for chipping machining of valve seats and flanges and diffusers. 
     The radius is particularly advantageously adjustable by adjusting the distance described supra. It is conceivable for example that the connection lever includes a groove for this purpose. However, it is also conceivable that the radius is adjusted by adjusting a length of the connection lever. 
     According to an advantageous embodiment of the invention the tool support is connected to the carriage by a linear support. The linear support advantageously cooperates with the connection lever of the mobile device described supra. A particularly advantageous embodiment of the device according to the invention provides that two support rods of the linear support of the tool support are respectively arranged at one side of the shaft and at an opposite side of the shaft. 
     Advantageously, the linear support is connected with the connection lever so that the movement of the carriage in the axial and/or the radial direction of the shaft is transferred to the connection lever due to the coupling of the carriage with the linear support. 
     Another embodiment of the invention provides a groove that extends in the axial direction of the shaft wherein a coupling element of the carriage and/or of the support block engages the groove so that a torque proof connection is provided. Advantageously a controlled movement of the tool support is provided relative to and in a direction of the carriage axis which is exclusively predetermined by the rotating movement of the shaft. 
     Another advantageous embodiment of the invention provides a spindle that cooperates with a threaded nut that is connected with the carriage, wherein the spindle advantageously extends parallel and/or radially relative to the shaft and is rotatable about its own longitudinal axis so that a relative movement of the carriage with respect to the shaft in an axial and/or radial direction of the shaft is generatable. Thus, an advantageous embodiment of the invention includes a coupling device that couples the spindle to the shaft so that a rotating movement of the spindle is generatable from the rotating movement of the shaft. 
     Advantageously the coupling of the spindle with the shaft is a forced coupling. Advantageously the movement of the tool support along the path can be controlled by a multi-stage coupling of the individual components which is controlled exclusively by the rotating movement of the shaft. A size of the relative movement of the carriage with respect to the shaft is thus adjustable by the coupling element so that a precision of the path to be traveled by the cutting tool is variable. Thus, the spindle can perform a partial revolution caused by a full revolution of the shaft. It is also conceivable that the spindle performs a full revolution caused by the full revolution of the shaft. The coupling of the carriage with the linear support of the tool support which is also coupled with the connection lever facilitates adjusting the radial movement component of the cutting tool as a function of the relative movement of the carriage. 
     According to an advantageous embodiment of the invention the carriage and/or the support block are assembled from two half shells which respectively envelop approximately half of the shaft and which are connected by disengagable fasteners. 
     Advantageously the carriage and/or the support block are removable from the shaft in a particularly simple manner and/or mountable on the shaft in a particularly simple manner. It is also conceivable that the carriage and/or the support block are provided with a pass-through bore hole into which the shaft is insertable. It is appreciated that simple assembly of the device is very advantageous for transporting the device to a job site. 
     According to another embodiment of the invention, the device includes a rotating arm that is connected torque proof with the shaft, wherein a longitudinal axis of the rotating arm is advantageously oriented perpendicular to the shaft. Thus, it can be particularly advantageous when the carriage and/or the tool support are movable along the longitudinal axis of the rotating arm. This embodiment is particularly suitable for a movability of the carriage in a radial direction relative to the rotation axis of the shaft. Thus, it can be particularly advantageous when the spindle runs parallel to the pivot arm. Advantageously the spindle is then coupled with the carriage so that a rotating movement of the shaft causes a linear displacement of the carriage along the longitudinal axis of the pivot arm so that the radial movement component of the tool support is generated while the axial movement component of the tool support is advantageously caused by the coupling with the connection lever. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is subsequently described based on two embodiments with reference to drawing figures, wherein: 
         FIG. 1  illustrates a perspective view of the device according to the invention; 
         FIG. 2  illustrates the device according to  FIG. 1  in a second operating position; 
         FIG. 3  illustrates the device according to  FIG. 2  in a third operating position; 
         FIG. 4  illustrates a schematic detail of a cutting tool of the device according to the invention according to  FIG. 1  and a work piece; 
         FIG. 5  illustrates a perspective view of a second embodiment of the device according to the invention; 
         FIG. 6  illustrates the device according to  FIG. 5  in a second operating position; 
         FIG. 7  illustrates the device according to  FIG. 6  in a third operating position; 
         FIG. 8  illustrates the device according to  FIG. 5  and a work piece; 
         FIG. 9  illustrates a front view of another embodiment of a slotted link of a transmission; and 
         FIG. 10  illustrates a front view of another embodiment of a slotted link. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The first embodiment of the invention illustrated in  FIGS. 1-4  includes a first mobile device  1  according to the invention. 
       FIG. 1  illustrates a perspective view of the device  1 . The device  1  includes a shaft  2 , a carriage  3 , a tool support  4  and a transmission  5 . 
     The shaft  2  of the device  1  is rotatable about a rotation axis  6  which also forms a longitudinal axis  7  of the shaft  2  and provided with a groove  8  at a top side wherein the groove extends in an axial direction  9  of the shaft  2 . 
     The carriage  3  of the device is assembled from the two half shells  10 ,  11  which are respectively provided with two pass through bore holes  12  in a portion that is oriented away from the shaft  2 . The half shells  10 ,  11  of the carriage  3  respectively envelop half of the shaft  2  and are disengageably connected by fastening bolts. Thus, the carriage  3  is displaceable in the axial direction  9  of the shaft  2 . One of the half shells  10 ,  11  of the carriage  3  is provided with a coupling element at an inside. Due to an engagement of the coupling element in the groove  8  of the shaft  2 , the carriage  3  is connected torque proof with the shaft  2 . 
     The tool support  4  includes a receiving element  16  which includes a cutting tool  17  configured as a turning steel configured for machining metal. Thus, the tool support  4  is movable along a carriage axis  47  and in a direction perpendicular to the carriage axis  47 . Thus, the carriage axis  47  corresponds to the rotation axis  6  of the shaft  2 . 
     The transmission  5  of the device  1  includes a linear support  13  and two connection levers  21 . The linear support  13  in turn includes four support rods  14 . Thus, the support rods  14  are respectively supported by two coinciding pass through bore holes  12  of the half shells  10 ,  11  of the carriage  3 . The tool support  4  and a support plate  15  are respectively arranged at ends of the support rods  14 . Each of the connection levers  21  respectively includes three pass through bore holes  22  at an end whereas the other end is provided with a groove  23 . The transmission  5  furthermore includes two transmission elements  18  which are respectively connected at two adjacent support rods  14  on both sides of the shaft  2  by bolts. 
     The device  1  further includes a support block  19  which is also assembled from two half shells  20  that substantially envelop half of the shaft  2  respectively and which are connected with each other in a disengageable manner by connection elements configured as bolts. The support block  19  is attached at the shaft  2  so that the half shells  20  of the support block  19  are arranged at the shaft  2  approximately perpendicular to the half shells  10 ,  11  of the carriage  3 . 
     The connection levers  21  are rotatably coupled with the support block  19  and rotatably coupled with the transmission element  18  of the transmission  5 . Thus, the connection levers  21  are respectively rotatably coupled with a half shell  20  of the support block  19  by a bolt  24  that is supported by one of the pass-through bore holes  22  of the connection lever  21 . Thus, each half shell  20  is provided with a groove into which a sliding block is inserted. A bushing is inserted through the pass-through bore hole  22 . Thus, the bushing is inserted flush into the pass-through bore hole  22  down to a protruding collar. The bolt  24  is run through the bushing and bolted together with a sliding block. A first rotation axis  25  of the connection lever  21  is formed by a longitudinal axis of the bolt  24 . 
     A T-bolt is respectively inserted into the groove  23  of each connection lever  21  wherein the T-bolt is bolted into a blind rivet nut. The transmission elements  18  of the transmission  5  are also provided with a pass-through bore hole wherein a diameter of the pass-through bore hole approximately corresponds to a diameter of the blind rivet nut. Placing the transmission element  18  onto the blind rivet nut forms a straight bearing which provides a rotatable coupling of the connection levers  21  with the transmission elements  18  whose rotation axis  26  runs parallel to the first rotation axis  25  of the connection lever  21 . 
     The device  1  further includes a spindle  27  that runs parallel to the shaft  2  rotatable about a longitudinal axis  28  of the spindle  27 . The spindle  27  cooperates with a nut that is arranged at a top side of a half shell  10  of the carriage  3 . The spindle  27  is coupled with the shaft  2  by accordingly configured devices so that the spindle  27  also performs a rotating movement due to the rotating movement of the shaft  2 . 
     In an operating condition of the device  1  the shaft  2  is caused by a drive to rotate. Due to the torque proof connection of the carriage  3  and of the support block  19  at the shaft  2 , all components rotate about the rotation axis  6  of the shaft  2 . Thus, the tool support  4  and the cutting tool  17  move with a radial movement component along a path  35  that will be described infra with reference to  FIG. 4  in more detail. A radius  29  of the movement of the cutting tool  17  viewed in a direction of the rotation axis  6  of the shaft  2  is determined by a distance  30  between the rotation axis  6  of the shaft  2  and the cutting tool  17 . 
     The coupling of the spindle  27  with the shaft  2  causes a rotation of the spindle  27 . Due to the coupling of the spindle  27  with the nut of the carriage  3  a movement of the carriage  3  relative to the shaft  2  is caused in an axial direction  9  of the shaft  2 . Thus, the carriage  3  is moved axially in a direction of the rotation axis of the shaft  2 , whereas the spindle  27  remains in place. The movement of the carriage  3  occurs in a direction of the support block  19 . Due to the coupling of the carriage  3  through the transmission elements  18  with the connection levers  21 , the connection levers  21  are moved in the axial direction  9  of the shaft  2  and simultaneously moved perpendicular to the axial direction  9 . Due to this movement a component of the movement of the connection levers  21  perpendicular to the rotation axis  6  of the shaft  2  is transmitted to the support rods  14  of the linear support  13 . This causes a linear displacement of the tool support  4  relative to the rotation axis  6  of the shaft  2  of the device  1 . This operating position is illustrated in  FIG. 2 . The axial displacement of the tool support  4  causes an increase of the distance  30  of the cutting tool  17  from the shaft  2 . 
     Further operation of the device  1  causes a continuous pulling of the carriage  3  along the shaft  2  in the axial direction  9  and therefore a corresponding increase of the distance  30  due to the forced coupling between the shaft  2 , the tool support  4  and the carriage  3  as shown in  FIG. 3 . Thus, a maximum distance  30  is reached when the connection levers  21  are oriented parallel to the shaft  2  and the support plate  15  contacts a half shell  10  of the carriage  3 . 
       FIG. 4  shows the cutting tool  17  machining a work piece  31  configured as a valve  32 . The device  1  is used for finishing a contact surface  33  of the valve  32  so that the valve  32  has a circular surface contour in a cross section parallel to a longitudinal axis  34  of the valve. Overall, the cutting tool  17  moves on a circular path  35  determined by the axial and radial movement components caused by the forced coupling. Thus, the cutting tool  17  follows a circular movement of a first anchoring point  36  of the transmission element  18  at the connection lever  21 . A radius  38  of the movement path is thus determined by a distance  39  between the first anchoring point  36  and a second anchoring point  37  of the connection lever  21  at the half shell  20  of the support block  19 . 
       FIGS. 5-7  show a second embodiment of the device  1  according to the invention. The device  1  according to this additional embodiment differs from the first embodiment in that the carriage  3  of the device  1  is displaceable radially and not axially with respect to the rotation axis  6  of the shaft  2  which differs from the device  1  illustrated in  FIGS. 1-4 . 
     The second device  1  also includes a shaft  2 , a carriage  3 , a tool support  4  and a transmission  5 . The shaft  2  is thus rotatable about a rotation axis  6  wherein the rotation axis  6  of the shaft  2  is also the longitudinal axis  7  of the shaft  2 . 
     The device further includes a pivot arm  40  that arranged perpendicular to the shaft  2  and that is connected in a non-movable manner with the shaft  2  so that a rotating movement of the shaft  2  about its rotation axis  6  is transmitted to the pivot arm  40 . 
     The carriage  3  of the device  1  is arranged at the pivot arm  40  and displaceable in an axial direction of a longitudinal axis of the pivot arm  40 . The transmission  5  of the device  1  also includes a linear support  13  and a connection lever  21 . The linear support  13  includes a support rod  14  that is coupled with the carriage  3  of the device  1  and wherein a cutting tool  17  configured as a turning steel for machining metal is arranged at an end of the carriage  3 . The connection lever  21  is pivotable at one end about a first pivot axis  25  at a support block  19  of the device  1  wherein the support block  19  is fixed non-movable at the pivot arm  40  and the connection lever is coupled at a second end at the support rod  14  of the transmission  5  and rotatable about a second pivot axis  26 . The pivot axes  25 ,  26  of the connection lever  21  are thus oriented perpendicular to the rotation axis  6  of the shaft  2  and perpendicular to the longitudinal axis  41  of the pivot arm  40 . 
     The device  1  further includes a spindle  27  that is rotatably supported about its longitudinal axis  28 . The spindle  27  is coupled with the shaft  2  by suitable devices so that the spindle  27  also performs a rotating movement caused by the rotation of the shaft  2 . Furthermore, the spindle  27  is coupled with the carriage  3  of the device  1  by a nut. A rotation of the spindle  27  causes a linear displacement of the carriage  3  along the longitudinal axis  41  of the pivot arm  40 . 
     In one operating condition after device  1  the shaft  2  is caused to rotate by a drive. Due to the torque proof connection of the carriage  3  and of the support block  19  at the shaft  2  all components rotate about the rotation axis  6  of the shaft  2 . Thus, the tool support  4  and the cutting tool  17  are moved with an axial movement component along a path  35 . A radius  38  of the path  35  is determined by a distance  39  between the rotation axis  25 ,  26  of the connection lever  21 . 
     The coupling of the spindle  27  with the shaft  2  causes a rotating movement of the spindle  27  which causes the carriage  3  to move along the longitudinal axis  41  of the pivot arm  40  and thus in a radial direction relative to the shaft  2 . The carriage  3  thus moves as a function of a direction of rotation of the shaft  2  back and forth along the rotation axis  6  of the shaft  2 . 
     Thus, the connection lever  21  is moved in the longitudinal direction  41  of the rotation arm  40  due to the coupling of the carriage  3  with the connection lever  21 . Due to this movement a component of the movement of the connection lever  21  parallel to the rotation axis  6  of the shaft  2  is transferred to the support rod  14  of the linear support  13 . This causes a linear displacement of the tool support  4  in a direction of the rotation axis  6  of the shaft  2  of the device  1 . Due to the displacement of the tool holder  4  a distance between the cutting tool  17  and a work piece that is to be machined is reduced as evident from  FIGS. 5 and 6 . 
     Further operation of the device causes a continuous pulling of the carriage  3  along the longitudinal axis  41  of the pivot arm  40  and thus a corresponding reduction of the distance as illustrated in  FIG. 6  due to the forced coupling between the shaft  2 , the tool support  4  and the carriage  3 . A minimum distance is reached when the connection lever  14  is oriented perpendicular to the longitudinal direction  41  of the pivot arm  40 . During further movement of the shaft  2  and thus of the tool support  4  the tool support  4  is moved towards the work piece after reaching a maximum position where the distance is smallest. Overall, the tool support  4  performs a radial and an axial movement wherein the path  35  of the tool support  4  is circular wherein a radius  38  of the path  35  corresponds to a distance  39  between the first rotation axis  25  and the second rotation axis  26  of the connection lever  21 . 
       FIG. 8  illustrates the device  1  while machining a work piece  31  configured as a flange  43 . The shaft  2  of the device  1  is arranged in the flange  43  by suitable devices so that the rotation axis  6  of the shaft  2  coincides with a longitudinal axis  42  of the flange  43 . The goal of the machining is to fabricate a surface  44  of the flange  43  along a circumference of the flange  43  so that the surface  44  is configured semi-circular in top view. A face of the work piece  31  is shaped as a half-torus after machining. 
       FIG. 9  illustrates another configuration of a transmission  5  of the device  1 . Thus, the transmission  5  includes slotted link  45 . Thus, the slotted link  45  includes a contour  46  to be transferred to a work piece  41  wherein the cutting tool  17  is run along the contour  46 . Thus, the device  1  includes a support element  48  including a spherical contact element  49  which is preloaded e.g. by a spring against the slotted link  45  and a support arm  50  connected thereon. Thus, the support arm  50  is coupled with the support rod  15  so that a movement of the contact element  49  along the contour  46  of the slotted link  45  is transferred to the tool holder  4  and thus to the cutting tool  17 . Due to a coupling of the carriage  3  with the rotating movement of the shaft  2  the cutting tool  17  is moved towards the shaft  2  or away from the shaft  2  depending on the direction of rotation of the shaft  2 , while the cutting tool  17  is automatically run along the contour  46  so that the contour  46  is transferred to the work piece  31  during machining. 
       FIG. 10  illustrates another embodiment of the slotted link  45 . The contour  46  of the slotted link  45  is thus suitable for machining a work piece  31  that is to be provided with a notch along a circumference. 
     REFERENCE NUMERALS AND DESIGNATIONS 
       1  mobile device 
       2  shaft 
       3  carriage 
       4  tool support 
       5  transmission 
       6  rotation axis 
       7  longitudinal axis 
       8  groove 
       9  axial direction 
       10  half shell 
       11  half shell 
       12  pass through bore hole 
       13  linear support 
       14  support rod 
       15  support plate 
       16  receiving element 
       17  cutting tool 
       18  transmission element 
       19  support block 
       20  half shell 
       21  connection lever 
       22  pass-through bore hole 
       23  groove 
       24  bolt 
       25  rotation axis 
       26  rotation axis 
       27  spindle 
       28  longitudinal axis 
       29  radius 
       30  distance 
       31  workpiece 
       32  valve 
       33  contact surface 
       34  longitudinal axis 
       35  path 
       36  support point 
       37  support point 
       38  radius 
       39  distance 
       40  pivot arm 
       41  longitudinal axis 
       42  longitudinal axis 
       43  flange 
       44  surface 
       45  slotted link 
       46  contour 
       47  carriage axis 
       48  support element 
       49  contact element 
       50  support arm