DE20309776U1 - Hand-held surgical instrument has a form/fit link to the handgrip and operating shaft - Google Patents

Abstract

A surgical instrument (10) has a shaft (12) with a handgrip (34) at its proximal end with an axial link (78, 80). In the engaged presentation, the axial link has a form/fit link to the handgrip (34) and shaft.

Description

A 57 466 u Applicant: AESCULAP AG & Co. KG

20 June 2003 At Aescuiap Square

z-286 78532 Tuttlingen

Surgical instrument

The present invention relates to a surgical instrument with a shaft, with a handle connectable to a proximal end of the shaft and with a coupling device for axially connecting the shaft to the handle in a coupling position.

Surgical instruments of the type described above are known in many different ways. In many of these instruments, the handle is connected directly to the shaft, for example by gluing or soldering. It is also known to connect the handle to the shaft using a coupling device, whereby here too the coupling device is connected to the shaft and the handle by gluing or soldering. However, creating such a connection is extremely complex.

It is therefore an object of the present invention to improve a surgical instrument of the type described above so that individual parts of the instrument can be assembled easily and safely.

This object is achieved according to the invention in a surgical instrument of the type described at the outset in that the coupling device is positively and/or non-positively connected to the handle in the coupling position and that the coupling device is positively and/or non-positively connected to the shaft in the coupling position.

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Such a design has the advantage that the parts of the instrument can be simply put together to connect them. Due to the positive and/or force-fitting connections between the handle, shaft and the coupling device, material-bonded connection methods such as gluing or soldering can be completely dispensed with. In addition, it is conceivable to assemble parts of the instrument in such a way that they can be transferred from a separate state into the coupling position, but cannot be separated from this again. This has the particular advantage that when disposable instruments are manufactured, they can be assembled in a simple manner, but their individual parts cannot be separated from one another and therefore cannot be used.

It is advantageous if the coupling device comprises at least one coupling element that at least partially, preferably completely, surrounds a section of the shaft and the handle in the circumferential direction. This results in a particularly stable connection between the shaft and the handle, because both the shaft and the handle can be supported on the coupling element or vice versa.
20

A particularly secure connection can be made if the coupling device comprises at least one two-part coupling element comprising essentially two half-shells. The two-part design of the at least one coupling element makes it possible to completely enclose both a distal end of the handle and a proximal end of the shaft, thus ensuring an optimal connection between the three parts. A double half-shell-shaped design of the coupling

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The coupling element can be assembled in a simple manner, for example the shaft or the handle can be inserted into a half-shell and by adding the second half-shell a connection can be made between the handle and the shaft by means of the coupling element.
5

It is advantageous if the coupling device is connected to the shaft in a rotationally fixed manner in the coupling position. This allows the shaft to be rotated together with the coupling device.

According to a further preferred embodiment of the invention, it can be provided that the coupling device is rotatable relative to the handle in the coupling position. In this way, the coupling device can be rotated relative to the handle and, for example, if the coupling device is connected to the shaft in a rotationally fixed manner, the shaft can also be rotated relative to the handle.

It is advantageous if the coupling device comprises at least one coupling receptacle and one coupling projection and if the at least one coupling receptacle is arranged on the handle or on the at least one coupling element and if the coupling projection is arranged on the at least one coupling element or on the handle. This results in a secure connection in the direction of the longitudinal axis of the shaft when the coupling projection engages in the coupling receptacle in the coupling position.

For the desired axial fixing of the handle to the coupling device, it is advantageous if the at least one coupling projection extends in the radial direction relative to the longitudinal axis of the shaft from a release position in which

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it is disengaged from the coupling receptacle, it can be moved into a coupling position in which it is engaged with the coupling receptacle. This can be done, for example, by the coupling projection being moved together with the coupling element or the coupling projection being movable relative to the coupling element. In both cases, axial fixing is achieved when the coupling projection engages in the coupling receptacle.

The construction of the instrument is particularly simple if the coupling receptacle is formed by a groove on the handle and the coupling projection by a projection pointing radially in the direction of the longitudinal axis of the shaft. It would also be conceivable to attach the coupling projection to the handle and a groove to at least one coupling element.

In order to prevent the coupling device from coming loose from the handle and/or the shaft, it is advantageous if at least one locking element is provided to hold the coupling device in the coupling position. In the coupling position, the coupling device cannot be detached from either the handle or the shaft. The locking element ensures that all parts of the coupling device that are engaged in the coupling position remain engaged with the handle and the shaft.

According to a preferred embodiment of the invention, it can be provided that the at least one securing element at least partially, preferably completely, surrounds the at least one coupling element in the circumferential direction. In this way, radial detachment of the at least one coupling element from the handle and/or the shaft is prevented.

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Preferably, the securing element is rotatable relative to the shaft and/or relative to the handle. This has the advantage that forces acting on the securing element in the circumferential direction are merely transformed into a rotary movement of the securing element, but do not cause the handle to rotate relative to the shaft. However, the handle can be rotated relative to the shaft by rotating the securing element if the latter is only rotatable relative to the handle or the shaft.

It is advantageous if the at least one coupling element is fixed axially relative to the securing element in the direction of the longitudinal axis of the shaft in the coupling position. This means that the securing element cannot be accidentally released from the coupling device. This design therefore allows the instrument to be assembled from its individual elements and a connection between the handle and the shaft to be secured by means of the securing element. In particular, the securing element can be designed in such a way that after it has been joined to the coupling device it is fixed in the direction of the longitudinal axis, but can no longer be released from this coupling position.

In order to enable a rotational movement about the longitudinal axis to be transmitted from the securing element to the coupling device, it is advantageous if at least one coupling position is non-rotatable about the longitudinal axis relative to the securing element.

Both for axial fixing and to prevent rotation of the coupling device relative to the locking element, it can be advantageous

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if the at least one coupling element is positively and/or non-positively connected to the securing element in the coupling position.

In order to prevent an axial relative movement between the coupling device and the securing element, it is advantageous if the securing element comprises at least one distal and at least one proximal stop for preventing an axial movement of the at least one coupling element relative to the securing element in the coupling position.

According to a preferred embodiment of the invention, it can be provided that the at least one coupling element has a connecting projection and that the securing element has a receptacle corresponding to the connecting projection. Due to this design, it is possible to prevent a relative axial movement between the coupling element and the securing element if, for example, the connecting projection protrudes in the radial direction and it is also possible to prevent a rotation of the securing element relative to the coupling element if, for example, the connecting projection protrudes parallel to the longitudinal axis of the shaft.

The coupling device and the securing element can be connected to one another particularly easily and safely if a locking connection is provided between the at least one coupling element and the securing element for axially fixing the at least one coupling element relative to the securing element in the coupling position. In this way, when the instrument is disassembled, the securing element can be moved in the axial direction relative to the at least one coupling element until

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the coupling position is reached and the locking position, for example a locking lug in conjunction with a locking edge on one of the two elements engage with each other and thereby the coupling element is axially fixed relative to the securing element.
5

According to a preferred embodiment of the invention, an angular positioning device can also be provided for setting and varying a rotational position of the handle relative to the shaft about the longitudinal axis of the shaft. This design has the advantage over free rotation of the shaft relative to the handle that a desired rotational position between the handle and the shaft can be maintained or transferred to other positions predetermined by the angular positioning device. These are each discrete positions.

A particularly simple construction of the instrument is achieved if the angle positioning device comprises at least one radial toothing and at least one rotary catch corresponding to the toothing. An angular position can then be fixed, for example, by the rotary catch engaging in a specific recess in the toothing.

It would be conceivable that the toothing or the at least one rotary catch is arranged on the handle or that the at least rotary catch or the toothing is arranged on the shaft. However, it is advantageous if the toothing or the at least one rotary catch is arranged on the handle and if the at least one rotary catch or the toothing is arranged on the at least one coupling element. This design allows a discrete angle to be set with a fundamentally free rotation between the coupling element and the handle.

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positioning between the handle and the shaft when the shaft is non-rotatably connected to the coupling device.

In order to be able to transfer the shaft relative to the handle from a first rotational position to a second, different rotational position, it is advantageous if the at least one rotary detent in the coupling position is immersed in the radial toothing in a detent position and is disengaged from the toothing in the coupling position in the rotational position.

In order to hold the at least one rotary detent in the locking position, it is advantageous if the at least one rotary detent is spring-loaded in the direction of the toothing.

In order to achieve a particularly stable structure of the instrument, it is advantageous if a distal end of the handle has a receptacle for the proximal end of the shaft and if the distal end of the handle at least partially, preferably completely, surrounds the proximal end of the shaft in the circumferential direction. For example, the handle could have a hole into which the shaft can be inserted axially. This results in particularly good support and force transmission from the handle to the shaft.

It is advantageous if the at least one coupling element clamps a proximal end region of the shaft. In this way, no additional connecting elements are required on the shaft for connection to the coupling device.

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For a particularly secure connection between the shaft and the coupling device, it is advantageous if a projection or a corresponding recess is provided on a proximal end region of the shaft and on at least one coupling element to produce a positive connection between the shaft and the coupling device. This could be implemented, for example, in the form of radial projections or grooves which engage with one another when assembled after the coupling position has been reached.

It is advantageous if a distal end region of the handle, which is positively and/or force-lockedly connected to the coupling device in the coupling position, is designed as a single piece or one-piece. This design of the handle significantly simplifies the structure of the instrument. In known instruments, the handle is designed as a two-piece in the connection area with the shaft, which allows a connection to be made between the handle and the shaft. However, the special coupling device also makes it possible to fix the shaft to the handle in the desired manner if the proximal end of the handle is designed as a single piece or one-piece.

The following description of a preferred embodiment of the invention serves to explain it in more detail in conjunction with the drawing. They show:
25

Figure 1: a longitudinal sectional view of a pair of scissors according to the invention;

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Figure 2: an enlarged longitudinal sectional view of the transition area between handle and shaft;

Figure 3: a sectional view taken along line 3-3 in Figure 2;

Figure 4: a second longitudinal sectional view parallel to that shown in Figure 2 of a securing element;

Figure 5: a cross-sectional view taken along line 5-5 in Figure 4;
Figure 6: a side view of a coupling element;

Figure 7: a view of the coupling element in the direction of arrow A in Figure 6; and

Figure 8: a view of the coupling element in the direction of arrow B in Figure 7.

Figure 1 shows a longitudinal sectional view of a pair of bipolar scissors, designated overall by the reference numeral 10, designed as an endoscopic tubular shaft instrument.

The bipolar scissors 10 comprise an elongated, tubular shaft 12, at the distal end of which two scissor blades are pivotable relative to one another.

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blades 14 and 16 are mounted on a bearing pin 18 which penetrates the shaft 12 on both sides and transversely to a longitudinal axis 20 of the shaft 12.

To move the scissor blades 14 and 16, a drive body 24 is arranged at a distal end of a push and pull rod 22 which is longitudinally displaceable in the direction of the longitudinal axis 20 in the shaft 12. The drive body 24 is provided with two guide slots 26 into which bearing pins 28 projecting transversely to the longitudinal axis 20 from the scissor blades 14 and 16 are inserted and are positively guided as a result of an axial displacement of the drive body 24, whereby the scissor blades 14 and 16 are opened or closed.

At its proximal end 30, the shaft 12 is received in a longitudinal bore 32 of a fixed handle part 34, from which a fixed branch 36 with a finger opening 38 extends away from the longitudinal axis 20 essentially transversely. On the handle part 34, a second branch 40 is pivotally mounted in a recess 42 open in the proximal direction about a bearing pin 44 passing through the recess 42 transversely to the longitudinal axis 20 and has a further finger opening 46 at its free end.

A proximal end of the push and pull rod 22 is provided with a short cylindrical head 48, which positively engages in a single-stage widening bearing groove 50 of a bearing cylinder 52 and is held therein. The push and pull rod 22 protrudes from the bearing groove 50 and is covered with an electrical insulating layer 54. A longitudinal axis of the bearing cylinder 52 runs transversely to the longitudinal axis 20. The bearing cylinder 52 is held on the branch 40 near the bearing bolt 44 in a bearing bore 56, which

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which extends transversely to the longitudinal axis 20 and comprises a slot 58 which widens from the center of the bearing bore 56 in the distal direction.

Like the push and pull rod 22, the shaft 12 is also surrounded by an electrically insulating layer 60. Both the shaft 12 and the push and pull rod 22 are connected in a manner not shown in detail to a bipolar connection 62, via which the bipolar scissors 10 can be connected to an electrical power supply unit by means of cables. An electrical connection is made to one of the two scissor blades 14 and 16, which are insulated relative to one another, via both the push and pull rod 22 and the shaft 12. This makes it possible, for example, to conduct a high-frequency current over the scissor blades 14 and 16 to coagulate tissue and to sever the coagulated tissue following the coagulation process.

Furthermore, a rotary knob 64 is provided which is rotationally fixed relative to the shaft 12, but which can be rotated relative to the handle part, so that the distal end of the bipolar scissors 10 with the two scissor blades 14 and 16 can be rotated about the longitudinal axis 20 relative to the two branches 36 and 40.

In connection with Figures 2 to 8, the connection between the handle part 34 and the shaft 12 is explained in more detail below.

A proximal end of the handle part 34 is provided with a receiving bore 66 which concentrically surrounds the longitudinal axis 20 and into which the shaft 12 can be inserted parallel to the longitudinal axis 20. Furthermore, an outer diameter of the distal end 34 tapers in one step from a first section 68

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and increases in the distal direction in one step so that an annular groove 70 is formed. The annular groove 70 is delimited on the distal side by an annular flange 72, which borders on a radial toothing 74 on the proximal side. Further distally, the toothing 74 is adjoined by a sleeve section 76, the outer diameter of which corresponds to the outer diameter of the annular groove 70 and the length of which in the axial direction corresponds approximately to the total length of the annular groove 70, the annular flange 72 and the toothing 74.

To connect the handle part 34 to the shaft 12, two identical bearing shells 78 and 80 are provided, which are shown in three views in Figures 6 to 8. On the proximal side, the bearing shell 78 is in the form of a length
after split half cylinder sleeve and thus designed as a half shell 82 which has a semi-cylindrical recess 84 whose inner diameter is the same as or alternatively slightly smaller than the outer diameter of the shaft 12. Furthermore, an inner surface 86 of the recess 84 is provided with fine teeth running transversely to the longitudinal axis 20. One of the two cutting surfaces 88 and 90 of the half shell 82, which are parallel to one another and to the longitudinal axis 20, is provided with a cylindrical connecting pin 92, the other cutting surface 90 with a blind hole 94 corresponding to the connecting pin 92. In the assembled state, the bearing shells 78 and 80 thus form a hollow cylindrical section with their half shells 82, with a cutting surface 88 in each case resting against a cutting surface 90 without a gap and the connecting pins 92 engaging positively in the blind holes 94.

On the proximal side, a central retaining tab 96 is symmetrically connected to the half-shell 82 and on both sides of this along the circumference of the half-shell

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shell 82 each have a locking tab 98. The retaining tab 96 is essentially elongated and L-shaped with a radially inward-pointing locking projection 100, the width of which in the direction of the longitudinal axis 20 corresponds to the width of the annular groove 70. Furthermore, the shape and radial extent of the locking projection 100 corresponds to the annular groove 70 and its shape in the radial direction. The locking tabs 98 in the form of cylinder wall sections each have a locking nose 102, which is shaped to correspond to recesses formed by the teeth 74.

The retaining tab 96 has an outer side 104 which is curved radially outward away from the half-shell 82 and which carries a catch 106 with a catch edge 108 pointing in the proximal direction. Furthermore, recesses 110 extending in the direction of the longitudinal axis 20 are formed on both sides of the half-shell 82, which recesses form two diametrically opposed, radially outward-pointing longitudinal grooves 112 when the bearing shells 78 and 80 are assembled.

The rotary knob 64 has a central shaft receptacle 114 in the form of an axial bore coming from the distal side. The shaft receptacle 114 has an inner diameter that corresponds to the outer diameter of the shaft 12. On the proximal side, a hollow cylinder section 116 with an inner diameter approximately three times as large adjoins the shaft receptacle 114, so that an annular stop 118 pointing in the proximal direction is formed. On the proximal side, the hollow cylinder section 116 is adjoined by an expanding hollow cone section 120, which is delimited on the proximal side by an annular edge 122 that projects radially inwards in the distal direction.

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The shape of the hollow cone section 120 is essentially adapted to the outside 104 of the retaining tab 96 and its shape. Two radially inwardly projecting rectangular drivers 124 extend parallel to the longitudinal axis 20 from the hollow cylinder section 116, the shape of which corresponds to the longitudinal grooves 112 formed by two recesses 110. The distance between the stop 118 and the ring edge 122 corresponds to the length of a distal end edge 126 of the bearing shell 78 or 80 and the locking edge 108. In cross section, the rotary knob 64 has a pentagonal, rounded shape.

The connection between the handle part 34 and the shaft 12 is explained in more detail below.

In a first step, the shaft 12 is inserted into the central receiving bore 66 of the handle part 34. The bearing shell 78 is then guided laterally to the shaft 12 and the handle part 34 so that the locking projection 100 is inserted into the annular groove 70. The annular flange 72 then penetrates between the locking projection 100 and the end faces 128 of the locking tabs 98 and is held there in a form-fitting manner. The bearing shell 80 is guided in the opposite direction in the same way to the handle part 34 and the shaft 12 until the connecting pin 92 of the bearing shell 80 is completely inserted into the blind hole 94 of the bearing shell 78 and vice versa the connecting pin 92 of the bearing shell 78 is inserted into the blind hole 94 of the bearing shell 80. The two half shells 82 thus enclose a

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section of the shaft 12 completely and thus form a two-part coupling element for connecting the handle part 34 to the shaft 12.

In order for the two bearing shells 78 and 80 to be held by the shaft 12, the rotary knob 64 with its hollow cone section 120 open in the proximal direction is pushed from the distal end over the two bearing shells 78 and 80 that surround the shaft 12. To do this, the rotary knob 64 must be rotated about the longitudinal axis 20 until the two drivers 124 can engage in the longitudinal grooves 112. The rotary knob 64 is pushed over the bearing shells 78 and 80 until their front edges 126 rest against the stop 118. As the rotary knob 64 is pushed forward, the catch 106 slides on an inward-pointing ring flange 130 forming the ring edge 122 at the proximal end of the hollow cone section 120, whereby the retaining tab 96 is moved radially inward. As soon as the ring edge 122 engages behind the locking edge 108, the retaining tab 96 springs radially outward so that the two bearing shells 78 and 80 are held axially between the ring edge 122 and the stop 118. In this coupling position, the outer side 104 of the retaining tab 96 essentially rests against the hollow cone section 120 so that the two bearing shells 78 and 80 cannot easily be released from the handle part 34. If the diameter of the recess 84 of the bearing shells 78 and 80 is slightly smaller than the outer diameter of the shaft 12, the toothed surface 86 is pressed against the shaft 12 due to a corresponding fit of the outer contour of the bearing shells 78 and 80 and the rotary knob 64 so that the shaft 12 is held axially and rotationally fixed in the two recesses 94. However, such a press fit can also be dispensed with. The shaft 12 is also securely inserted into

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the two recesses 94 if the outer diameter of the shaft 12 corresponds to the inner diameter of the recesses 94.

The locking lugs 102 of the locking tabs 98 form rotary detents which, in the coupling position, penetrate into recesses in the toothing 74. If the shaft 12 is to be rotated relative to the handle part 34, this can be done by rotating the rotary knob 64 relative to the handle part 34. Due to the clamping of the shaft 12 between the two bearing shells 78 and 80, the shaft 12 is connected in a rotationally fixed manner to the coupling device formed by the two bearing shells 78 and 80, whereas the coupling device can be rotated relative to the handle part 34. If the rotary knob 64 is now rotated about the longitudinal axis 20, the locking lugs 102 slide on the toothing 74, causing the locking tabs 98 to spring radially outwards until they spring back and engage in the next recess in the toothing 74. In this way, an angle of rotation between the handle part 34 and the shaft 12 and thus the tool arranged at the distal end of the shaft 12 in the form of a pair of scissors formed from the two scissor blades 14 and 16 can be adjusted step by step.

Claims (26)

1. Surgical instrument ( 10 ) with a shaft ( 12 ), with a handle ( 34 ) that can be connected to a proximal end of the shaft ( 12 ), and with a coupling device ( 78 , 80 ) for axially connecting the shaft ( 12 ) to the handle ( 34 ) in a coupling position, characterized in that the coupling device ( 78 , 80 ) is positively and/or non-positively connected to the handle ( 34 ) in the coupling position and that the coupling device ( 78 , 80 ) is positively and/or non-positively connected to the shaft ( 12 ) in the coupling position. 2. Instrument according to claim 1, characterized in that the coupling device comprises at least one coupling element ( 78 , 80 ) which at least partially, preferably completely, surrounds a portion of the shaft ( 12 ) and the handle ( 34 ) in the circumferential direction. 3. Instrument according to claim 2, characterized in that the coupling device comprises at least one two-part coupling element ( 70 , 78 ) comprising essentially two half-shells ( 82 ). 4. Instrument according to one of the preceding claims, characterized in that the coupling device ( 78 , 80 ) is connected to the shaft ( 12 ) in a rotationally fixed manner in the coupling position. 5. Instrument according to one of the preceding claims, characterized in that the coupling device ( 78 , 80 ) is rotatable relative to the handle ( 34 ) in the coupling position. 6. Instrument according to one of claims 2 to 5, characterized in that the coupling device comprises at least one coupling receptacle ( 70 ; 100 , 128 ) and one coupling projection ( 72 , 100 ) and that the at least one coupling receptacle ( 70 ; 100 , 128 ) is arranged on the handle ( 34 ) or on the at least one coupling element ( 78 , 80 ) and that the coupling projection ( 72 ; 100 ) is arranged on the at least one coupling element ( 78 , 80 ) or on the handle ( 34 ). 7. Instrument according to claim 6, characterized in that the at least one coupling projection ( 100 ) is movable in the radial direction relative to the longitudinal axis ( 20 ) of the shaft ( 12 ) from a release position in which it is disengaged from the coupling receptacle ( 70 ) into a coupling position in which it is engaged with the coupling receptacle ( 70 ). 8. Instrument according to one of claims 6 or 7, characterized in that the coupling receptacle is formed by a groove ( 70 ) on the handle ( 34 ) and the coupling projection ( 100 ) is formed by a projection pointing radially in the direction of the longitudinal axis ( 20 ) of the shaft ( 12 ). 9. Instrument according to one of the preceding claims, characterized in that at least one securing element ( 64 ) is provided for holding the coupling device ( 78 , 80 ) in the coupling position. 10. Instrument according to claim 9, characterized in that the at least one securing element ( 64 ) surrounds the at least one coupling element ( 78 , 80 ) in the circumferential direction at least partially, preferably completely. 11. Instrument according to one of claims 9 or 10, characterized in that the securing element ( 64 ) is rotatable relative to the shaft ( 12 ) and/or relative to the handle ( 34 ). 12. Instrument according to one of claims 9 to 11, characterized in that the at least one coupling element ( 78 , 80 ) is fixed in the coupling position axially relative to the securing element ( 64 ) in the direction of the longitudinal axis ( 20 ) of the shaft ( 12 ). 13. Instrument according to one of claims 9 to 12, characterized in that the at least one coupling element ( 78 , 80 ) is non-rotatable about the longitudinal axis ( 20 ) relative to the securing element ( 64 ) in the coupling position. 14. Instrument according to one of claims 9 to 13, characterized in that the at least one coupling element ( 78 , 80 ) is positively and/or non-positively connected to the securing element ( 64 ) in the coupling position. 15. Instrument according to one of claims 9 to 14, characterized in that the securing element ( 64 ) comprises at least one distal and at least one proximal stop ( 118 , 122 ) for preventing an axial movement of the at least one coupling element ( 78 , 80 ) relative to the securing element in the coupling position. 16. Instrument according to one of claims 9 to 15, characterized in that the at least one coupling element ( 78 , 80 ) carries a connecting projection and that the securing element ( 64 ) has a receptacle corresponding to the connecting projection. 17. Instrument according to one of claims 9 to 16, characterized in that a locking connection ( 108 , 122 ) is provided between the at least one coupling element ( 78 , 80 ) and the securing element ( 64 ) for axially fixing the at least one coupling element ( 78 , 80 ) relative to the securing element ( 64 ) in the coupling position. 18. Instrument according to one of the preceding claims, characterized in that an angular positioning device ( 74 , 102 ) is provided for adjusting and varying a rotational position of the handle ( 34 ) relative to the shaft ( 12 ) about the longitudinal axis ( 20 ) of the shaft ( 12 ). 19. Instrument according to claim 18, characterized in that the angular positioning device ( 74 , 102 ) comprises at least one radial toothing ( 74 ) and at least one rotary catch ( 102 ) corresponding to the toothing ( 74 ). 20. Instrument according to claim 19, characterized in that the toothing ( 74 ) or the at least one rotary catch ( 102 ) is arranged on the handle ( 34 ) and that the at least one rotary catch ( 102 ) or the toothing ( 74 ) is arranged on the at least one coupling element ( 78 , 80 ). 21. Instrument according to one of claims 19 or 20, characterized in that the at least one rotary catch ( 102 ) in the coupling position in a latching position dips into the radial toothing ( 74 ) and in the coupling position in a rotary position is disengaged from the toothing ( 74 ). 22. Instrument according to one of claims 19 to 20, characterized in that the at least one rotary catch ( 102 ) is resiliently preloaded in the direction of the toothing ( 74 ). 23. Instrument according to one of the preceding claims, characterized in that a distal end of the handle ( 34 ) has a receptacle ( 66 ) for the proximal end of the shaft ( 12 ) and that the distal end of the handle ( 34 ) at least partially, preferably completely, surrounds the proximal end of the shaft ( 12 ) in the circumferential direction. 24. Instrument according to one of claims 2 to 23, characterized in that the at least one coupling element ( 78 , 80 ) clamps a proximal end region of the shaft ( 12 ). 25. Instrument according to one of claims 2 to 24, characterized in that a projection or a corresponding recess is provided on a proximal end region of the shaft ( 12 ) and on the at least one coupling element ( 78 , 80 ) for producing a positive connection between the shaft ( 12 ) and the coupling device ( 78 , 80 ). 26. Instrument according to one of the preceding claims, characterized in that a distal end region of the handle ( 34 ), which is positively and/or non-positively connected to the coupling device ( 78 , 80 ) in the coupling position, is formed integrally or in one piece.