fig1 shows a schematic view of a medical instrument 10 with a proximal end 11 and a distal end 12 . the medical instrument 10 has , at the proximal end 11 , a manipulation device 18 with a plurality of movable grip parts and other actuating devices . a curved outer shaft 20 extends from the manipulation device 18 at the proximal end 11 to a grasping device 30 and a cutting device 50 at the distal end 12 of the medical instrument 10 . whereas in fig1 the manipulation device 18 is indicated only by its contours and the grasping device 30 and the cutting device 50 are shown in a side view , a substantially tubular section 23 of the outer shaft 20 is shown in longitudinal section . the tubular section 23 contains , in a coaxial arrangement , a transmission rod 40 , an internal inner shaft 60 and an external inner shaft 70 . the internal inner shaft 60 and the external inner shaft 70 are each tubular or hose - shaped . the transmission rod 40 , the internal inner shaft 60 and the external inner shaft 70 are each flexurally elastic , stiff in respect of longitudinal forces and torsionally rigid . the internal inner shaft 60 is arranged in an annular space between the transmission rod 40 and the external inner shaft 70 . the external inner shaft 70 is arranged in an annular space between the internal inner shaft 60 and the tubular section 23 of the outer shaft 20 . arranged immediately proximally of the grasping device 30 , a pivot joint 24 is provided which is connected mechanically to the tubular section 23 of the outer shaft 20 , either releasably or non - releasably , and in particular forms a component part of the outer shaft 20 . the pivot joint 24 permits a pivoting of the grasping device 30 and of the cutting device 50 about a pivot axis 25 perpendicular to the plane of the drawing of fig1 . the pivot joint 24 and the pivot axis 25 are rotatable , relative to the curved , tubular section 23 of the outer shaft 20 , about a rotation axis 28 in the plane of the drawing in fig1 . the rotation axis 28 is defined by a rotation joint not shown in fig1 . the proximal end 31 of the grasping device 30 is mechanically connected to the pivot joint 24 in a releasable manner . a stationary jaw part 32 and a pivotable jaw part 34 , which is pivotable about a pivot axis 35 perpendicular to the plane of the drawing of fig1 , form the distal end of the grasping device 30 . the solid line shows the pivotable jaw part 34 in an open position , spaced apart from the stationary jaw part 32 , and the broken line shows it in a closed position , bearing on the stationary jaw part 32 . together with the pivot axis 35 and the cutting device 50 , the grasping device 30 is rotatable about the longitudinal axis 38 of the grasping device 30 relative to the pivot joint 24 . fig2 shows a further schematic view of the medical instrument 10 from fig1 . the plane of the drawing of fig2 is perpendicular to the plane of the drawing of fig1 and parallel to the pivot axis 25 of the pivot joint 24 and to the rotation axis 28 about which the pivot joint 24 is rotatable relative to the tubular section 23 of the outer shaft 20 . in contrast to fig1 , the outer shaft 20 in fig2 is shown exclusively in an external and side view . fig3 shows a further schematic view of the medical instrument from fig1 and 2 . the plane of the drawing of fig3 is perpendicular to the plane of the drawing of fig1 , perpendicular to the plane of the drawing of fig2 , perpendicular to the longitudinal axis 38 of the grasping device 30 ( cf . fig2 ), perpendicular to the rotation axis 28 about which the pivot joint 24 is rotatable relative to the tubular section 23 of the outer shaft 20 , parallel to the pivot axis 25 of the pivot joint 24 and parallel to the pivot axis 35 of the pivotable jaw part 34 . comparing fig1 to 3 , it will be seen that the outer shaft 20 has a spatial curvature , i . e . not a planar curvature , and in particular has a configuration similar to a screw or a helix . fig4 shows a further schematic view of the medical instrument from fig1 to 3 . the plane of the drawing of fig4 corresponds to the plane of the drawing of fig1 . the view in fig4 differs from the views in fig1 to 3 in that component parts into which the medical instrument 10 can be dismantled without destruction , i . e . reversibly , by medical personnel without using tools , are shown separately . the flexurally elastic transmission rod 40 , the flexurally elastic internal inner shaft 60 and the flexurally elastic external inner shaft 70 are each shown in rectilinear form . dot - and - dash lines indicate how the component parts of the medical instrument are to be assembled . the flexurally elastic , torsionally rigid transmission rod 40 , which is stiff with respect to longitudinal forces , is mechanically connected to the grasping device 30 . as is explained in detail below with reference to fig5 , the distal end of the transmission rod 40 is mechanically coupled and electrically conductively connected to the pivotable jaw part 34 and is electrically insulated from the stationary jaw part 32 and from bayonet claws or catches 37 at the proximal end 31 of the grasping device 30 . as is likewise explained below with reference to fig5 to 7 , the grasping device 50 can be inserted from the proximal direction into a channel in the transmission device 40 and into the grasping device 30 . the tubular or hose - shaped internal inner shaft 60 has a lumen whose cross section is adapted to the cross section of the transmission rod 40 , such that the transmission rod 40 is guided with minimal play and minimal friction in the internal inner shaft 60 . at the distal end 62 , the internal inner shaft 60 has an l - shaped slit with an axial section 63 and a circumferential section 64 . the l - shaped slit 63 , 64 , a projection 56 on the cutting device 50 , and the function thereof , are likewise explained below with reference to fig5 to 7 . the external inner shaft 70 is mechanically connected to the pivot joint 24 . in particular , the distal end of the external inner shaft 70 is coupled to the pivot joint 24 in such a way that an axial translation movement of the external inner shaft 70 is associated with a pivoting movement of the distal part of the pivot joint 24 about the pivot axis 25 relative to the proximal part of the pivot joint 24 . at the distal end of the pivot joint 24 , l - shaped grooves 27 are formed which correspond to the catches 37 at the proximal end 31 of the grasping device 30 , for releasable mechanical connection of the tool 30 to the pivot joint 24 . the proximal end of the pivot joint 24 can be mechanically connected in a releasable manner to the distal end of the tubular section 23 of the outer shaft 20 by means of devices not shown in fig4 . in particular , bayonet coupling devices are provided at the proximal end of the pivot joint 24 and at the distal end of the tubular section 23 of the outer shaft 20 . the external inner shaft 70 is substantially tubular or hose - shaped . the cross section of the lumen of the external inner shaft 70 is adapted to the cross section of the internal inner shaft 60 in such a way that the internal inner shaft 60 is guided and movable in the external inner shaft 70 with minimal play and minimal friction . the cross section of the lumen of the tubular section 23 of the outer shaft 20 is adapted to the cross section of the external inner shaft 70 in such a way that the external inner shaft 70 is guided and movable in the tubular section 23 of the outer shaft 20 with minimal play and minimal friction . the proximal end 21 of the outer shaft 20 , or of the tubular section 23 of the outer shaft 20 , can be locked with a form fit in a corresponding recess in the manipulation device 18 by means of a locking device not shown in fig1 to 4 . in the arrangement shown in fig1 , the proximal end 41 of the transmission rod 40 , the proximal end 61 of the internal inner shaft 60 and the proximal end 71 of the external inner shaft 70 are mechanically coupled to actuating devices on the manipulation device 18 by way of devices not shown in fig1 to 4 . in particular , the proximal end 41 of the transmission rod 40 is coupled to a pivotable grip part of the manipulation device 18 in such a way that the transmission rod 40 is displaceable in its longitudinal direction , in order to pivot the pivotable jaw part 34 between the open position , shown by solid lines in fig1 , 3 and 4 , and the closed position , shown by broken lines in fig1 , 3 and 4 . moreover , the transmission rod 40 is coupled to a further actuating device , for example a rotary wheel , in such a way that the transmission rod 40 is rotatable about its longitudinal axis , in order to rotate the grasping device 30 about its longitudinal axis 38 together with the cutting device 50 . moreover , the proximal end 61 of the internal inner shaft 60 is coupled to a further actuating device of the manipulation device 18 in such a way that the internal inner shaft 60 can be displaced axially , i . e . in its longitudinal direction , in order to move the cutting device 50 parallel to the longitudinal axis 38 of the grasping device 30 . moreover , the proximal end 71 of the external inner shaft 70 is mechanically coupled to a further actuating device of the manipulation device 18 in such a way that the external inner shaft 70 can be displaced axially , i . e . in the longitudinal direction , in order to pivot the grasping device 30 and the cutting device 50 , together with the distal part of the pivot joint 24 , about the pivot axis 25 . moreover , the proximal end 71 of the external inner shaft 70 is mechanically coupled to a further actuating device of the manipulation device 18 in such a way that the external inner shaft can be rotated about its longitudinal axis , in order to rotate the pivot joint 24 , together with the pivot axis 25 , about the rotation axis 28 relative to the distal end of the tubular section 23 of the outer shaft 20 . fig5 shows a schematic axonometric view of the grasping device 30 , which is provided and designed to form a medical instrument , as is explained above with reference to fig1 to 4 . the grasping device 30 has a proximal end 31 and two jaw parts 32 , 34 , which form the distal end of the grasping device 30 . near the proximal end 31 , the grasping device 30 has two symmetrically arranged bayonet claws or catches 37 , of which one is arranged on a side facing away from the viewer and is therefore largely concealed . the grasping device 30 shown in fig5 differs from what has been explained above with reference to fig1 to 4 in terms of a slightly different arrangement of the catches 37 . otherwise , the grasping device 30 shown in fig5 corresponds substantially to the grasping device of the medical instrument explained above with reference to fig1 to 4 . the grasping device 30 is mechanically connected to the transmission rod 40 . the transmission rod 40 is movable , within a predetermined range , relative to the grasping device 30 , in particular relative to the proximal end 31 and to the stationary jaw part 32 , in the axial direction , i . e . parallel to the longitudinal axis of the transmission rod 40 and to the longitudinal axis 38 of the grasping device 30 ( cf . fig1 and 2 ). the distal end of the transmission rod 40 is arranged inside the grasping device 30 and is therefore not visible in fig5 , and it is coupled to the pivotable jaw part 34 in such a way that an axial movement of the transmission rod 40 is associated with a pivoting movement of the pivotable jaw part 34 . a groove 45 , which in particular has a narrow and deep rectangular cross section , is provided in the transmission rod 40 . at its distal end , not visible in fig5 , the groove 45 in the transmission rod 40 is continued by a channel of corresponding cross section which extends between the jaw parts 32 , 34 to almost the distal ends of the latter . parts of the grasping device 30 , in particular the catches 37 and the transmission rod 40 , are made of stainless steel or another metal . the catches 37 and the transmission rod 40 are electrically insulated from each other . the jaw parts 32 , 34 have metallic and therefore electrically conductive grasping surfaces , which are electrically insulated from each other when they are not bearing on each other as shown in fig5 . the catches 37 and the transmission rod 40 are each electrically conductively connected to the grasping surface of a jaw part 32 , 34 . in particular , the catches 37 are electrically conductively connected to the grasping surface of the stationary jaw part 32 , and the transmission rod 40 is electrically conductively connected to the grasping surface of the pivotable jaw part 34 . fig6 shows a schematic axonometric view of the cutting device 50 with a proximal end 51 and a distal end 52 . at the distal end 52 , the cutting device 50 has a cutting edge 53 . at the proximal end , the cutting device 50 has a projection 56 . between the proximal end 51 and the distal end 52 , the cutting device comprises a rod - shaped area 54 , which has substantially the configuration of a strip - shaped plate or of a rod with a rectangular cross section . between the projection 56 at the proximal end 51 and the cutting edge 53 at the distal end 52 , the cross section of the cutting device 50 corresponds substantially to the cross section of the groove 45 in the transmission rod 40 ( cf . fig5 ), such that the cutting device 50 is received completely , except for the projection 56 , by the groove 45 in the transmission device 40 and is guided in the latter with minimal play and minimal friction and can be moved in the longitudinal direction of the transmission rod 40 and of the cutting device 50 . the projection 56 is provided to protrude from the groove 45 in the transmission rod 40 . fig7 shows a further axonometric view of the grasping device from fig5 and of the cutting device 50 from fig6 . in the view in fig7 , the cutting device 50 is arranged in the groove 45 in the transmission rod 40 ( cf . fig5 ). the distal end 52 of the cutting device 50 ( cf . fig6 ) is arranged here in the grasping device and in particular between the jaw parts 32 , 34 . the projection 56 protrudes from the groove 45 . fig7 also shows the internal inner shaft 60 , which has substantially a tubular shape or the shape of a jacket of a circular cylinder . at its distal end 62 , the internal inner shaft 60 has an l - shaped slit with an axial or axially extending section 63 and a circumferential or circumferentially extending section 64 . the width of the axial section 63 of the l - shaped slit , measured in the circumferential direction , and the width of the circumferential section 64 of the l - shaped slit , measured in the axial direction , are adapted to the dimensions of the projection 56 on the cutting device 50 . after the transmission rod 40 has been inserted into the internal inner shaft 60 , the projection 56 can be guided by a relative movement in the axial direction through the axial section 63 and into the circumferential section 64 . when the projection 56 on the cutting device 50 is located in the circumferential section 64 of the l - shaped slit at the distal end 62 of the internal inner shaft 60 , the internal inner shaft 60 can be rotated relative to the grasping device 30 , the transmission rod 40 and the cutting device 50 , in a first direction 91 , as far as the configuration shown in fig7 . in the relative positioning of cutting device 50 and internal inner shaft 60 shown in fig7 , the cutting device 50 and the internal inner shaft 60 are rigidly coupled to each other in terms of axial movements ( except for play ). an axial movement of the internal inner shaft 60 is therefore associated with a corresponding axial movement of the cutting device 50 . thus , by means of the internal inner shaft 60 , a movement of the cutting edge 53 at the distal end 52 of the cutting device 50 ( cf . fig6 ) can be effected in said channel ( not shown in the figures ) between the jaw parts 32 , 34 , such that , for example , tissue that is grasped by the jaw parts 32 , 34 can be separated after electro - cauterization . the internal inner shaft 60 has an insulating jacket 69 , which has a distal edge lying near the l - shaped slit 63 , 64 , and which can extend to near the proximal end of the internal inner shaft 60 . fig8 shows a schematic sectional view of an example of how the mechanical coupling , explained above with reference to fig7 , between the projection 56 at the proximal end of the cutting device 50 and the l - shaped slit 63 , 64 at the distal end 62 of the internal inner shaft 60 is locked . the sectional plane in fig8 is perpendicular to the plane of the drawing of fig1 , perpendicular to the plane of the drawing of fig2 , parallel to the plane of the drawing of fig3 , and perpendicular to the plane of the drawing of fig4 . the sectional plane in fig8 lies immediately proximally of the distal end 62 of the internal inner shaft 60 in the area of the axial section 63 of the l - shaped slit ( cf . fig4 and 7 ). the internal inner shaft 60 has an axial , or axially extending , locking slit 67 which lies substantially opposite the l - shaped slit 63 , 64 . thus , in relation to the views shown in fig5 and 7 , the axial locking slit 67 lies on a side facing away from the viewer . the transmission rod 40 has a projection 47 , which corresponds to the axial locking slit 67 on the internal inner shaft 60 and which , for example , is in the form of a lug , an axially extending web or a pin . the angle position of the projection 47 relative to the groove 45 ( cf . fig4 and 7 ) in the transmission rod 40 and the angle position of the axial locking slit 67 relative to the l - shaped slit 63 , 64 in the internal inner shaft 60 are chosen such that the projection 56 on the cutting device 50 , arranged in the groove 45 in the transmission rod 40 , is held in the circumferential section 64 of the l - shaped slit at the distal end 62 of the internal inner shaft 60 when the projection 47 on the transmission rod 40 engages in the axial locking slit 67 on the internal inner shaft 60 , as is shown in fig8 . the projection 47 is arranged so far distally of the proximal end of the groove 45 in the transmission rod 40 ( cf . fig5 and 7 ) that , first of all , the cutting device 50 can be inserted into the groove 45 in the transmission rod 40 and can be coupled to the distal end 62 of the internal inner shaft 60 in the manner described above with reference to fig7 . thereafter , the internal inner shaft 60 is moved distally together with the cutting device 50 . it is only with this movement of the internal inner shaft 60 in the distal direction that the projection 47 on the transmission rod 40 engages in the axial locking slit 67 on the internal inner shaft 60 , as is shown in fig8 , in order to lock the mechanical connection between the cutting device 50 and the internal inner shaft 60 . fig9 shows a schematic sectional view of another example of how the internal inner shaft 60 is locked relative to the transmission rod 40 . the sectional plane in fig9 is perpendicular to the plane of the drawing of fig1 , perpendicular to the plane of the drawing of fig2 , parallel to the plane of the drawing of fig3 , perpendicular to the plane of the drawing of fig4 , and parallel to the sectional plane in fig8 . the transmission rod 40 has two flat surfaces 46 lying opposite each other . the internal inner shaft 60 has two openings lying opposite each other , in which a bolt 66 is in each case mounted so as to be radially movable . the bolts 66 are in particular movable between radially inward locking positions and the radially outward unlocking positions shown in fig9 . the bolts 66 can be held in the recesses in the internal inner shaft 60 by an o - ring made of an elastic material or by other devices not shown in fig9 and / or can be pressed radially inward into the locking positions . fig1 shows a further schematic sectional view of the example from fig9 . the sectional plane in fig1 corresponds to the sectional plane in fig9 . the view in fig1 differs from the view in fig9 in that the internal inner shaft 60 is rotated relative to the transmission rod 40 to the extent that the bolts 66 can assume their radially inward locking positions and in so doing can bear on the flat surfaces 46 on the transmission rod 40 . in the view in fig1 , the transmission rod 40 and the internal inner shaft 60 are arranged in the external inner shaft 70 . here , radially outer surfaces of the bolts 66 bear on the inner surface of the external inner shaft 70 . in this way , the bolts 66 are held with a form fit in their locking position shown in fig1 . thus , when the transmission rod 40 and the internal inner shaft 60 are arranged in the external inner shaft 70 as shown in fig1 , the transmission rod 40 is locked in terms of rotation about its longitudinal axis relative to the internal inner shaft 60 . the angle positions of the flat surfaces 46 relative to the groove 45 in the transmission rod 40 ( cf . fig5 and 7 ) and the angle positions of the openings in the internal inner shaft 60 , receiving the bolts 66 , relative to the l - shaped slit 63 , 64 at the distal end 62 of the internal inner shaft 60 are chosen such that , in the locked configuration shown in fig1 , the projection 56 of the cutting device 50 is held in the groove 45 in the form - fit connection shown in fig7 with the circumferential section 64 of the l - shaped slit at the distal end 62 of the internal inner shaft 60 . thus , in the configuration shown in fig1 , the mechanical connection between cutting device 50 and inner shaft 60 is locked . the locking between transmission rod 40 and internal inner shaft 60 , as has been explained with reference to fig9 and 10 , can be arranged near the distal end of the internal inner shaft 60 or , if the transmission rod 40 and the internal inner shaft 60 have a sufficiently torsionally rigid design , can be arranged at any other desired location as far as the proximal ends of the transmission rod 40 and of the internal inner shaft 60 . pivot joint at the distal end 22 of the outer shaft 20 l - shaped groove at the distal end 22 of the outer shaft 20 axial section of an l - shaped slit at the distal end 62 circumferential section of an l - shaped slit at the distal end 62
a medical instrument includes an outer shaft , a manipulation device at the proximal end of the outer shaft , a tool at the distal end of the outer shaft , with a first effecting device for a first function and a second effecting device for a second function , a first transmission device in the outer shaft for transmitting at least either a force or a torque for controlling the first effecting device , and a second transmission device in the outer shaft for transmitting at least either a force or a torque for controlling the second effecting device . the outer shaft is at least either curved or able to be curved or has a pivot joint . the first transmission device and the second transmission device are each designed to be flexible at least in sections .