Medical tool system

Abstract

The invention relates to a medical tool system (1) comprising a tool receiving area (2) that is formed in a distal instrument section (4) adjoined by a proximal instrument section (6) which can be angled relative to the distal instrument section (4) and comprising a tool (8) which is received in the tool receiving area (2) and is rotatably mounted relative to the tool receiving area (2). A first coupling device (10) is arranged in the distal instrument section (4), and a second coupling device (12) is provided on the tool (8), said coupling device producing a coupling between the tool (8) and the distal shaft section (4) in a coupling state by engaging with the first coupling device (10) in order to fix the tool (8) in the distal shaft section (4) in the axial direction .

Description

[0001] Medical tool system

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a medical tool system comprising a medical, preferably shaft-shaped instrument having a distal shaft / instrument section and a proximal shaft / instrument section which are angled relative to one another, and a medical tool of the shaft type such as a drill, milling cutter, screwdriver, etc. which is insertable in the axial direction into a tool chuck of the distal instrument section and is rotatable relative to the tool chuck but is axially fixed.

[0005] Background of the invention

[0006] Such a (medical) tool typically comprises a distal tool head / effector and a tool shank that is received in the tool chuck. The tool head protrudes from the tool chuck and can be designed, for example, as a milling cutter, drill, cutting blade, or similar. The tool chuck, which in this case holds the tool relatively rotatably but does not rotate itself and is therefore also referred to as a tool holder for simplicity, is gripped (manually) by a user to guide the tool, preferably for surgery on a patient. Typically, the tool is rotated about its longitudinal axis relative to the tool holder. The rotational movement is transmitted to the tool shank by a drive unit / drive train that is arranged in or on the tool holder.

[0007] In surgical techniques, it is advantageous to angle the tool head of a medical hand instrument relative to its shaft. In other words, a distal section of the tool / tool ​​shaft should be able to be angled relative to a proximal section of the tool / tool ​​shaft. This allows operations to be performed in very tight spaces, for example, during spinal surgery.

[0008] State of the art

[0009] In the field of surgical robotics, instruments have long been known that allow the distal tool head to be angled relative to the rest of the tool shaft. This enables precise movement of the instruments in the tightest of spaces.

[0010] For example, milling tools with bendable tool shanks are known from the disclosures DE 10 2017 010 033 A1 and US 10 178 998 B2. The distal tool head of the milling tool can be bent relative to the proximal milling tool shank. The milling tool shank in DE 10 2017 010 033 A1 is inserted into a hand-graspable and guideable tool receiving section of a medical instrument and is axially secured against withdrawal from the tool receiving section by a push button enclosing the milling tool shank, which is provided in a proximal region of the tool receiving section.

[0011] A disadvantage of medical tools in which the tool head can be angled relative to the tool shaft, as defined above, is that the set angle between the tool head and the tool shaft often changes undesirably under load.

[0012] For this reason, a tool holder for a medical hand instrument was developed in which a distal instrument section can be angled relative to a proximal instrument section during operation and in which the angle between a longitudinal axis of the distal instrument section and a longitudinal axis of the proximal instrument section does not change even under load. In such a hand instrument, the tool shank of the tool is inserted into the tool holder and, together with the distal instrument section, can be angled relative to the proximal instrument section. In this way, the tool head can be angled relative to a proximal section of the tool shank, together with the tool holder. With such a medical hand instrument, however, there is a risk that the tool could become undesirably released from the tool holder, particularly under load.

[0013] The push-button safety device disclosed in DE 10 2017 010 033 A1 cannot be applied, or cannot be applied in a technically reasonable manner, to the above-described bendable tool holder of the medical hand instrument due to the different geometries of the respective tool holders.

[0014] Summary of Revelation

[0015] The object of the disclosure is therefore to overcome the disadvantages of the prior art and to provide a medical shaft tool, a correspondingly designed medical instrument, and a medical tool system, wherein the instrument has a bendable tool holder and a tool inserted therein, and wherein the tool does not undesirably detach from the tool holder. In particular, it is advantageous to couple the tool to the bendable tool holder in a particularly space-saving manner.

[0016] According to the disclosure, this object is achieved by a medical tool having the features of claim 1, a medical instrument having the features of claim 4, and a medical tool system having the features of claim 10. Advantageous developments of the disclosure are the subject of the appended subclaims.

[0017] The basic idea of ​​the present invention is essentially to operatively connect a rotary element arranged on the instrument via a slide to a coupling element on / in the tool holder, which coupling element acts radially on a tool shank, for axially holding a tool in a tool holder of a medical instrument, in such a way that upon a first predetermined rotation of the rotary element, the slide allows a release movement of the coupling element and upon a second predetermined rotation of the rotary element, different from the first rotation, the slide blocks the release movement of the coupling element.

[0018] If this basic functional principle is applied to a medical instrument which, as known from the cited prior art, has two instrument sections which are rotatable relative to one another about a tool shaft longitudinal axis and are angled relative to one another with respect to the shaft longitudinal axis, this rotation mechanism can be used outside the rotation range provided for the angling of the two instrument sections to actuate the aforementioned tool coupling.

[0019] In other words, a bendable instrument is conceivable in which the distal instrument section, which has a tool holder, can be bent by a specific angle relative to the proximal instrument section. For this, the proximal instrument section must be rotated by a specific angle relative to the distal instrument section from a design position (e.g., with the two instrument sections aligned straight) in a specific direction of rotation. This allows a rotational movement starting from the design position in the opposite direction to be used to release the coupling element and thus axially decouple the tool from the tool holder.

[0020] Specifically, a medical shaft tool is proposed, comprising a distal effector / tool ​​head and a tool shaft designed and constructed to be inserted into a tool chuck of a medical instrument, preferably a handheld instrument, in a rotatable but axially fixed manner. For this purpose, a coupling unit is provided, which is mounted or can be mounted on the tool shaft and has the following components:

[0021] - A ball or plain bearing for the rotating mounting of a coupling unit housing on the tool shank and - a locking / engagement geometry which is arranged or formed on an outer side of the coupling unit housing and defines an undercut acting in the axial direction, in particular in the proximal direction of the tool shank.

[0022] This undercut serves as an axially acting point of engagement of the instrument-side coupling locking element for axially holding the tool in the tool holder / tool ​​chuck.

[0023] Consequently, a medical instrument, in particular a hand instrument, is also proposed, with a tool chuck / tool ​​holder for selectively receiving a tool shank, in particular according to the above definition, which is characterized by the following components:

[0024] - an internal torque train designed and constructed to engage the tool shank in a torque-transmitting manner in order to drive the tool shank,

[0025] - an axially movable slider / lock / locking pin which is spring-loaded in a first axial direction, preferably the proximal direction,

[0026] - a locking engagement element, preferably a locking ball / locking ball, as the above-mentioned coupling element, which is in operative engagement with the slider / latch / locking pin in such a way that the locking engagement element is displaced radially outwards into a release position (axially releasing the tool shank) in a first axial position of the slider / latch / locking pin achieved by the spring preload, and the locking engagement element is displaced radially inwards into a locking position (axially holding the tool shank) in a second axial position of the slider / latch / locking pin achieved against the spring preload.

[0027] Preferably, an actuating housing section, in particular a sleeve-shaped actuating component, which is rotatable relative to the slider / latch / locking pin about the tool holder axis is provided with

[0028] - an axial end face or contact face facing that axial end section of the slider / bolt / locking pin on which the spring preload acts, so that the slider / bolt / locking pin is pressed against the end face or contact face, and with

[0029] - an axial recess or notch in the front or contact side into which the slide / latch / locking pin moves when the actuating housing section is rotated in order to move it from its locked position to its released position.

[0030] This design is particularly simple and resistant to manufacturing tolerances, contamination and / or wear.

[0031] Further preferably, the medical instrument has a distal instrument section which forms or has the tool chuck / tool ​​holder and holds the slider / latch / locking pin so as to be axially displaceable, and a proximal instrument section which forms or has the actuating housing section, wherein the distal and proximal instrument sections are in axial contact with one another in a relatively rotatable manner at the end faces, and the respective adjacent end faces of the distal and proximal instrument sections are inclined at an equal angle to one another of greater than 0°, preferably 22.5°, to the longitudinal axis of the tool, such that in the event of a relative rotation of the distal and proximal instrument sections, these angularly adjust to one another in the axial direction.

[0032] Advantageously, both the distal and the proximal instrument sections are bevelled by 22.5°, so that the angles add up to an adjustment angle of 45° at the maximum relative rotation to each other, more precisely at a relative rotation of 180° between the distal and proximal instrument sections.

[0033] In this case, the axial recess or notch in the front or contact side of the actuating housing section can be placed at such a circumferential position that when the angle of the distal and proximal instrument sections is adjusted by rotating the actuating housing section (in particular the entire distal instrument section) within the rotation range provided for this purpose, retraction of the slider / latch / locking pin into the axial recess or notch is excluded, but when the angle of the distal and proximal instrument sections is adjusted by rotating the actuating housing section (in particular the entire distal instrument section) outside the rotation range provided for this purpose, retraction of the slider / latch / locking pin into the axial recess or notch is possible.

[0034] The disclosure accordingly also relates to a medical tool system comprising an instrument (optionally with an integrated drive) that can be grasped in particular by a user for guiding the medical tool system, said instrument comprising a distal instrument section and a proximal instrument section that can be angled relative to one another with respect to the instrument's longitudinal axis by relative rotation about the instrument's longitudinal axis. Furthermore, the medical tool system comprises a tool that is received in the tool receptacle of the distal instrument section and is rotatably mounted relative to the tool receptacle. A first coupling device (as defined above) is arranged in the distal instrument section, and a second coupling device (as defined above) is provided on the tool.In a coupling state, the second coupling device fixes the tool in the axial direction by operative engagement / cooperation with the first coupling device.

[0035] Due to the interaction of the first coupling device in the distal instrument section and the second coupling device on the tool, the tool is securely held in the distal instrument section in the axial direction. This prevents the tool from accidentally becoming detached from the tool shaft. Particularly when the medical tool system is in operation, it is highly advantageous if the tool does not accidentally become detached from the tool holder, thus preventing injuries to a patient on whom the medical tool system is being used. Forces that can cause the tool to accidentally become detached from the tool holder are primarily tensile forces exerted on a distal end of the tool, in particular on its tool head.It is therefore particularly advantageous if the first coupling device is located in the distal instrument section (and not in the proximal instrument section), as this places the coupling between the tool and the tool holder in direct proximity to the location of the critical force and can counteract this (tensile) force. Accordingly, the coupling in the distal instrument section between the tool and the tool holder is particularly effective and counteracts the unintentional release of the tool from the tool holder.

[0036] In particular, the tool comprises a tool head and a tool shaft. The tool shaft is received in the tool holder. The tool head protrudes from the distal instrument section.

[0037] In this way, the tool head is exposed and can be used particularly effectively on a patient.

[0038] It is also very useful if a third coupling device is provided in the proximal instrument section and a fourth coupling device is provided on a proximal section of the tool, in particular the tool shaft, which, in a coupling state, transmits a driving force / torque to the tool, in particular the tool shaft, by operative engagement / cooperation with the third coupling device.

[0039] The coupling in the proximal instrument section (between the tool and the tool holder) serves to transmit a driving force, preferably within the proximal instrument section, to the tool or tool shaft. The coupling in the distal instrument section (between the tool and the tool holder), on the other hand, acts as an axial lock for the tool in the tool holder.

[0040] It is particularly advantageous if the first coupling device comprises a locking ball, and the second coupling device is an axial locking groove extending at least partially in the circumferential direction of the tool, preferably extending completely circumferentially, which engages with the locking ball in the coupled state. Such a coupling between the tool and the distal shaft section is particularly space-saving and can be accommodated in the smallest possible space.

[0041] The axial locking groove preferably has a semicircular or circular cross-section. The locking ball is dimensioned so that a portion of the locking ball rests completely against the cross-sectional inner surface of the axial locking groove. In other words, the locking ball and the axial locking groove match each other precisely in terms of geometry and dimensions. This ensures that the locking ball fits precisely into the axial locking groove, and the coupling between the tool and the tool holder is implemented particularly effectively.

[0042] It is particularly useful if the second coupling device, more precisely the axial securing groove, is formed on a bearing housing of a rolling bearing unit / housing of the tool shaft-side coupling unit, which is fixed to the tool in the axial direction, i.e. in the direction of the longitudinal axis (of a distal section) of the tool shaft, which is arranged in the distal instrument section and rotatably supports the tool relative to the distal instrument section, in particular to the entire tool holder.

[0043] A rotatable bearing of the tool in the tool holder is sensible because the tool is usually rotated relative to the tool holder when the medical tool system is in operation. The rotation is usually generated by the drive unit and transferred to the tool shaft. In terms of precise and effective bearing, it is particularly effective if the rolling bearing unit is provided for the rotatable bearing of the tool in the tool holder in the distal instrument section. If a rolling bearing unit is provided on the tool, in particular on the tool shaft, it is particularly efficient and space-saving if the bearing housing of the rolling bearing unit has the second coupling device, more precisely the axial locking groove. This is particularly relevant because the outer diameter of the tool holder shaft is usually 5.6 mm and the outer diameter of the rolling bearings is usually 3 mm.The tool coupling, i.e. the first and second coupling devices, must be accommodated in the remaining small installation space, minus the wall thickness of the tool holder.

[0044] The rolling bearing unit preferably has at least one distal rolling bearing, in particular a ball bearing, facing the tool head, and a proximal rolling bearing, in particular a ball bearing, spaced axially from the distal rolling bearing and facing the proximal end of the tool shank. Two ball bearings can support the tool shank in a particularly effective and low-friction manner relative to the tool holder shank for rotation. Furthermore, the bearing housing ensures secure and easy insertion of the tool into the tool holder shank when inserting the tool shank into the tool holder shank (coupling process).

[0045] In particular, the rolling bearing unit is fixed to a distal section of the tool shank in the axial direction (of the tool shank). To axially secure the rolling bearing unit to the tool shank, it can be provided that two stops are arranged on the tool shank, spaced apart from one another in the axial direction, preferably at least by the length of the rolling bearing unit, between which stops the rolling bearing unit is arranged. One of the two stops, in particular the one further away from the tool head than the other stop, can be integrally connected to the tool shank. The other stop is formed separately from the tool shank and, after the rolling bearing unit has been arranged around the tool shank, can be applied to the tool shank and connected to it. Alternatively, both stops can also be formed separately from the tool shank.The stops, which are formed separately from the tool shank, can be connected to the tool shank in a form-fitting, force-fitting or material-fitting manner.

[0046] Furthermore, it is preferred if the first coupling device further comprises a locking pin / slider fixed in the radial direction, which is movable in the axial direction between a coupling position / locking position, in which it holds the locking ball (in the radial direction) in the axial securing groove to realize the coupling state, and a release position in which it does not hold the locking ball in the axial securing groove. In other words, in the coupling position, the distal end of the locking pin / slider is opposite the axial securing groove. In the release position, the distal end of the locking pin / slider is not opposite the axial securing groove. In the release position, the distal end of the locking pin is opposite a section of the tool shank (without a recess) or a section of the bearing housing of the rolling bearing unit (without a recess).The locking pin / slider advantageously prevents the coupling between the tool and the distal instrument section from accidentally disengaging by keeping the locking ball in the axial locking groove. In the released position, the locking pin prevents the locking ball from being in the axial locking groove, allowing the tool to be removed from the tool holder shaft or still coupled to it.

[0047] It is also preferred that the locking pin / slider has at its distal end a first locking ball receiving recess, via which the locking pin holds the locking ball in the axial securing groove in the radial direction in the coupling position, and a second locking ball receiving recess which is (seen in the axial direction) closer to the distal end of the locking pin than the first locking ball receiving recess and is provided further away in the radial direction from the tool or the bearing housing of the rolling bearing unit than the first locking ball receiving recess and in the release position holds the locking ball in the radial direction on the tool or on the bearing housing but not in the axial securing groove.

[0048] The first and second locking ball receiving recesses can enclose the locking ball at least in sections and thus optimally hold it in the desired position. The first locking ball receiving recess is positioned on the locking pin such that it can optimally interact with the axial locking groove in the coupling position of the locking pin. The second locking ball receiving recess is positioned on the locking pin such that it can optimally interact with the tool shank or the bearing housing of the rolling bearing unit in the release position of the locking pin / slider. In particular, it is desirable for the two locking ball receiving recesses each to have a semicircular or circular arc-shaped cross-section. The locking ball is dimensioned such that at least a section of the locking ball rests completely in the cross-sectional inner surface of the first or second locking ball receiving recess.In other words, the locking ball and the two locking ball recesses match each other precisely in terms of geometry and dimensions. This ensures that the locking ball fits precisely into the first or second locking ball recess, and the adjustment of the coupling position or release position of the locking pin / slider is implemented particularly effectively.

[0049] It is further conceivable that the proximal instrument section has, at its distal end region, an edge which holds the locking pin in the coupling position, and a locking pin receiving recess which interrupts the edge and receives a proximal end of the locking pin in the release position, as already indicated above.

[0050] In other words, the proximal end of the locking pin contacts the edge in the coupling position and is received in the locking pin receiving recess in the release position. The locking pin receiving recess allows the locking pin to move axially toward the proximal instrument section. In this way, the distal end of the locking pin also moves axially away from the axial locking groove toward the proximal instrument section. As soon as the proximal end of the locking pin is received in the locking pin receiving recess, the distal end of the locking pin no longer faces the axial locking groove, and the locking pin has thus reached the release position. The locking pin receiving recess thus enables the realization of a non-coupling state between the tool and the tool holder. The edge, on the other hand, enables the maintenance of the coupling state.

[0051] Preferably, only one locking pin receiving recess is provided, interrupting the edge of the proximal instrument section. If more than one locking pin receiving recess is provided, there are also multiple positions in the circumferential direction in which the locking pin can be in the release position. Multiple locking pin receiving recesses would therefore impair the handling and usability of the medical tool system without improving the coupling between the tool and the tool holder.

[0052] Preferably, the locking pin has a projection at its proximal end that is smaller in diameter than the rest of the locking pin and is dimensioned and shaped such that it is received in the locking pin receiving recess in the released position. In this way, the locking pin receiving recess can be smaller than if the locking pin receiving recess had to accommodate the entire circumference of the locking pin instead of the (smaller) locking projection.

[0053] It is preferred that the edge at the distal end of the proximal instrument section (apart from the locking pin receiving recess interrupting it) be annular. The locking pin receiving recess interrupts this annular shape of the edge. If the edge is designed or shaped in this way, the axial positioning of the locking pin can be changed along with a rotation of the distal shaft section relative to the proximal instrument section between the release position and the coupling position, since the locking pin rotates together with the distal instrument section.

[0054] It is expedient if the first coupling device further comprises a pretensioning element, in particular a compression spring, preferably a spiral spring, which pretensions the locking pin in the direction of the proximal shaft section and thereby urges the locking pin, preferably locking projection, into the locking pin receiving recess and thus into the release position.

[0055] The preload element ensures that the locking pin, when the locking pin and the locking pin receiving recess are at the same height in the circumferential direction, actually moves from the coupling position in the axial direction toward the proximal instrument section into the locking pin receiving recess and thus into the release position. The preload element is therefore also part of the first coupling device. The coupling device thus comprises the locking ball, the locking pin, and the preload element (spring), and is composed in particular of these elements.

[0056] Preferably, the maximum adjustable angle between the longitudinal axis of the distal shaft section and the longitudinal axis of the proximal shaft section is 45°. Preferably, the predetermined angle for tool unlocking is 18°.

[0057] It is advantageous if the locking pin receiving recess has at least one bevelled flank.

[0058] The chamfered flank makes it easier for the plunger pin to transition between the release and engagement positions. In other words, the chamfered flank makes it easier for the plunger pin to exit / exit the plunger pin recess.

[0059] Furthermore, it is conceivable that an outer circumferential surface of the bearing housing of the rolling bearing unit, which is in contact with an inner circumferential surface of the distal shaft section, and / or the distal shaft section itself is provided with an adhesive surface coating, is roughened or has microgrooves, wherein such a structure can preferably partially absorb a distally directed tensile force and thus can relieve the locking engagement element.

[0060] Compressive forces acting on the tool head during operation of the medical tool system are transferred (in the radial direction) directly to the distal instrument section or its housing by the rolling bearing unit, in particular by the proximal rolling bearing. This means that the locking ball hardly has to absorb any compressive forces, but primarily counteracts tensile forces in the axial direction. The special design of the outer circumferential surface of the bearing housing of the rolling bearing unit increases the transmission of tensile forces to the inner circumferential surface of the distal instrument section, thus reducing the forces acting on the locking ball. Microgrooves, in particular, are perfectly suited to absorbing tensile forces. When used with the medical tool system, the tool is subjected not only to axial but also radial loads.Due to the radial force component, the microgrooves are in active engagement with the outer circumferential surface of the bearing housing of the rolling bearing unit, thus reducing the load acting on the first coupling device, in particular the locking ball. This improves the coupling between the tool and the tool holder shank and thus the axial securing of the tool in the tool holder shank.

[0061] Short description of the characters

[0062] Fig. 1 is a longitudinal sectional view of a medical tool system in which a tool holder of the tool system is straight and a coupling state between a tool and a distal instrument portion is shown;

[0063] Fig. 2 is a longitudinal sectional view of the medical tool system in which a distal instrument portion is angled at a 45° angle relative to a proximal instrument portion and a coupling state between the tool and the distal shaft portion is shown;

[0064] Fig. 3 is a perspective view of a tool with a rolling bearing unit mounted on the tool shank, which has a second coupling device;

[0065] Fig. 4 is a longitudinal sectional view of a medical tool system in which a distal instrument portion is angled at a predetermined angle a relative to a proximal instrument portion and a non-coupling state between the tool and the distal shaft portion is shown;

[0066] Fig. 5 is a side view of a locking pin; Fig. 6 is a perspective view of the distal end of the proximal instrument section;

[0067] Fig. 7 is a plan view of the distal end of the proximal instrument section; and

[0068] Fig. 8 is a perspective view of the tool and the tool holder.

[0069] Description of the aspects of revelation

[0070] Preferred aspects of the present disclosure will be described below based on the accompanying figures.

[0071] To simplify understanding, the following figures show the axial direction A and the radial direction R. Unless otherwise stated, the axial direction A and the radial direction R each refer to a distal instrument section with a tool holder of the medical tool system shown below.

[0072] Fig. 1 is a longitudinal sectional view of a medical tool system 1 in which a tool holder 2 of the tool system 1 runs straight. The tool holder 2 is accommodated in a distal instrument section 4, which is followed by a proximal instrument section e, which can be angled relative to one another. The medical tool system 1 also has a tool 8, which is designed here as a milling cutter. The tool 8 is received in the tool holder (tool chuck) 2 and is rotatably mounted relative to the tool holder 2. A first coupling device 10 is arranged in the distal instrument section 4. A second coupling device 12 is provided on the tool 8, which, in a coupled state, cooperates with the first coupling device 10 to create a coupling between the tool 8 and the distal shaft section 4 in order to fix the tool 8 in the distal shaft section 4 in the axial direction A. In Fig.1, a longitudinal axis S1 of the distal instrument section 4 and a longitudinal axis S2 of the proximal instrument section 6 enclose an angle of 0°. In other words, the tool holder 2 extends straight with respect to the proximal instrument section 6. Furthermore, Fig. 1 shows a coupling state between the tool 8 and the distal instrument section 4. This means that the first coupling device 10, which is mounted in / on the distal instrument section 4, and the second coupling device 12, which is provided on the tool 8, are engaged or interact with each other. The tool 8 has a tool head / effector 14, more precisely a milling head, and a tool shank 16. The tool head 14 and the tool shank 16 are connected to each other in a rotationally fixed manner.

[0073] Fig. 1 also shows that the tool shaft 16 is rotatably mounted in the distal shaft section 4 by means of a rolling bearing unit 18. A drive unit (not shown here) is housed in the proximal instrument section 6, which applies a torque to the tool shaft 16. As a result of this torque application, the tool shaft 16 rotates relative to the tool holder 2. The rolling bearing unit 18 has at least one, here exactly two, rolling bearings 20, more precisely ball bearings, which are spaced apart from one another in the axial direction A, but which can alternatively also be designed as plain bearings. The rolling bearings 20 are accommodated in a bearing housing 22, which is part of the rolling bearing unit 18. The second coupling device 12 is introduced into the bearing housing 22 and is therefore not provided directly on the tool 8. The rolling bearing unit 18 and thus also the bearing housing 22 are arranged fixedly on the tool shank 16 in the axial direction A.Alternatively, it would also be conceivable for the second coupling device 12 to be provided directly on the tool shank 16.

[0074] The second coupling device 12 is designed as an axial securing groove 24 that extends continuously or circumferentially around the bearing housing 22. The axial securing groove 24 preferably has a semicircular or circular segment-shaped cross-section. The first coupling device 10, which is provided in the distal instrument section 4, accordingly has a locking ball 26. The diameter of the locking ball 26 is selected such that the locking ball 26 can be received in the axial securing groove 24. The axial securing groove 24 preferably completely surrounds at least a portion of the locking ball 26 that contacts the axial securing groove 24. In the coupled state, the locking ball 26 is held in the axial securing groove 24 on its side opposite the axial securing groove 24 by a distal end of a locking pin / slider 28. The locking pin 28 is part of the first coupling device 10.The locking pin 28 is fixed in the radial direction R. The locking pin 28 is arranged in the distal shaft section 4 so as to be displaceable or movable in the axial direction.

[0075] In the coupling state, the locking ball 26 is received in the axial locking groove 24 and is held radially in the axial locking groove 24 by the locking pin 28. This position of the locking pin 28 in the axial direction A is referred to as the coupling position. An edge 30 at the distal end of the proximal shaft section 6 prevents movement of the locking pin 28 in the axial direction toward the proximal instrument section 6.

[0076] Fig. 2 is a longitudinal sectional view of a medical tool system 1 in which the shaft longitudinal axis S1 of the distal instrument section 4 is angled at a (+)45° angle relative to the shaft longitudinal axis S2 of the proximal instrument section 6, and a coupling state between the tool 8 and the distal shaft section 4 is shown. The 45° angle between the shaft longitudinal axis S1 of the distal instrument section 4 and the shaft longitudinal axis S2 of the proximal instrument section 6 is the maximum adjustable angle here due to the selected angle of attack (which each correspond to 22.5° to the instrument longitudinal axis) of the mutually facing end faces of the distal instrument section 4 and the proximal instrument section 6.The distal instrument section 4 is angled relative to the proximal instrument section 6 via a rotating mechanism not explained in detail here, wherein the torque train between the drive and the tool shaft allows this angling, as indicated in Fig. 2. It can be seen in Fig. 2 that the locking ball 26 is held in the axial securing groove 24 by the locking pin 28 in the radial direction R, even when the tool holder 2 is angled in the maximum adjustable angular position with respect to the proximal instrument section. In this way, the tool 8 is secured in the tool holder 2 by the engagement between the first coupling device 10 and the second coupling device 12, even in this angular position in the axial direction A.

[0077] The torque cable leading to the tool shaft 16, which is arranged in the transition area between the distal instrument section 4 and the proximal instrument section 6, is flexible. This flexible section of the torque cable allows the distal section of the tool shaft 16 with the tool head 14, together with the distal instrument section 4, to be angled relative to the torque cable in the proximal instrument section. At the same time, the flexible section of the torque cable is designed to transmit a torque exerted on a proximal section of the tool shaft 16 to the tool head 14.

[0078] Fig. 3 is a perspective view of the tool 8 with the rolling bearing unit 18 mounted on the tool shank 16. Here, the axial locking groove 24, which is formed in the bearing housing 22, can be clearly seen. The axial locking groove 24 extends over the entire circumference of the cylindrical bearing housing 22. The axial locking groove 24 is provided in a proximal half of the bearing housing 22, which faces the proximal end of the tool shank 16.

[0079] Fig. 4 is a longitudinal sectional view of the medical tool system 1, in which the distal instrument section 4 is angled at a predetermined angle a relative to a proximal instrument section 6, which angle is set when the proximal instrument section is rotated by approximately -18°, i.e., counter to the direction of rotation for a "proper" angling of the instrument shaft sections, whereby a release state between the tool 8 and the distal instrument section 4 is achieved. It can be seen that the first coupling device 10 and the second coupling device 12 are not in operative engagement with one another in the release state. More precisely, the locking ball 26 is not received in the axial securing groove 24. Instead, it is held by the locking pin 28 in the radial direction R against the outer peripheral surface of the bearing housing 22.

[0080] In order for the locking ball 26 to move from the coupling state shown in Fig. 1 out of the axial securing groove 24 into the release state, the locking pin 28 must move in the axial direction A towards the proximal instrument section 6. This is prevented in the coupling state by the edge 30 of the proximal instrument section 6. However, the edge 30 is interrupted at one point by a locking pin receiving recess 32 (see also Fig. 6). If the relative rotation of the two instrument sections about the longitudinal axis S1 of the distal instrument section 4 lies outside the rotation range for a "proper" angling, e.g., a (-)18° angle, then the locking pin 28 is positioned relative to the proximal instrument section 6 such that it is at the same height as the locking pin receiving recess 32 in the circumferential direction.A biasing element 34, which is part of the first coupling device 10, urges the locking pin 28 in the axial direction A toward the proximal instrument section 6. Thus, the biasing element 34 pushes the locking pin 28, more precisely its proximal end, which is formed as a locking projection 36, into the locking pin receiving recess 32. The position in which the locking pin 28 is when its locking projection 36 engages the locking pin receiving recess 32 is referred to as the release position.

[0081] In the release position, the distal end of the locking pin 28 no longer faces the axial locking groove 24. Thus, the locking ball 26 is no longer held in the axial locking groove 24 in the radial direction R. The tool 8 is thus no longer fixed in the axial direction A relative to the distal shaft section 4. If, starting from the coupling state, a tensile force (in the axial direction A) is applied to the distal end of the tool 8, the locking ball 26 is released from the axial locking groove 24. In this way, the tool 8 can be uncoupled from the tool holder 2.

[0082] Fig. 5 is a side view of the locking pin 28. The locking projection 36 can be seen at the proximal end of the locking pin 28. The locking projection 36 is finger-shaped to enable particularly secure and efficient engagement with the locking pin receiving recess 32 on the proximal instrument section 6. At its distal end, the locking pin 28 has, on the side facing the tool 8, a first locking ball receiving recess 38 and a second locking ball receiving recess 40. Both locking ball receiving recesses 38, 40 have a circular segment-shaped or hemispherical cross-section and are adapted to the diameter of the locking ball 26. More precisely, the two locking ball receiving recesses 38, 40 are dimensioned such that the locking ball receiving recesses 38, 40 completely surround the section of the locking ball 26 that is in contact with them.

[0083] The first locking ball receiving recess 38 is arranged on the locking pin 28 such that, in the coupling position of the locking pin 28, it is opposite the axial locking groove 24. In the coupling position, the first locking ball receiving recess 38 and the axial locking groove 24 thus close around the locking ball 26 or rest against it. The second locking ball receiving recess 40 is located closer to the distal end of the detent pin 28 in the axial direction A than the first locking ball receiving recess 38. The second locking ball receiving recess 40 is farther away from the bearing housing 22 in the radial direction R than the first locking ball receiving recess 38. Namely, the second locking ball receiving recess 40 is the locking ball receiving recess that holds the locking ball 26 against the outer peripheral surface of the bearing housing 22 in the release position.

[0084] Fig. 6 is a perspective view of the distal end of the proximal instrument section 6. The edge 30 protruding from the distal end of the proximal instrument section 6 in the axial direction A (of the proximal instrument section 6) can be seen. The edge 30 is generally annular. The annular shape of the edge 30 is interrupted by the locking pin receiving recess 32. The end face of the distal end of the proximal instrument section 6 is beveled at an angle to the longitudinal axis of the instrument. More precisely, the front surface of the distal end of the proximal shaft section 6 here has an angle of attack of 22.5°, which together with the 22.5° bevel of the opposite front edge of the distal instrument section defines the maximum adjustable angle between the longitudinal axis S1 of the distal instrument section 4 and the longitudinal axis S2 of the proximal instrument section 6.Furthermore, a plane E can be seen which bisects the proximal instrument section 6 lengthwise. This plane E simultaneously marks an angular position of 0° or 45° of the distal instrument section 4 to the proximal instrument section 6. More precisely, the angle between the distal instrument section 4 and the proximal instrument section 6 is a 0° angle to 45° angle when the locking pin 28 (not shown here) lies in the plane E. The locking pin receiving recess 32 is therefore positioned such that it does not lie in the plane E or does not intersect it. It can be seen that the locking pin receiving recess 32 has at least one bevelled flank 33 which facilitates the transition of the locking pin 28 between the release position and the coupling position or even enables it in the first place.

[0085] Fig. 7 is a plan view of the distal end of the proximal instrument section 6. Here, the essentially annular edge 30 can be seen. The annular shape of the edge 30 is interrupted by the circular segment-shaped locking pin receiving recess 32. Also visible is plane E, which can only be represented as a line here. In addition, a central axis M can be seen, which divides the circular segment-shaped locking pin receiving recess 32 into two equal halves. The plane E and the central axis M enclose the predetermined angle of rotation, which is, for example, (-)18°. The plane E divides the proximal shaft section 6 into two equal-sized instrument section halves 6.1 and 6.2. The locking pin receiving recess 32 is arranged in the right-hand instrument section half or shaft section half 6.2 shown here.

[0086] If a user wishes to change the angle between the longitudinal axis S1 of the distal instrument section 4 and the longitudinal axis S2 of the proximal instrument section 6 from the 0° angle or the maximum adjustable 45° angle while maintaining the coupling state, they should rotate the distal instrument section 4 relative to the proximal instrument section 6 such that the locking pin 28 remains in the instrument section half 6.1. If the user wishes to end the coupling state, they should rotate the distal instrument section 4 relative to the proximal instrument section 6 in exactly the other direction (i.e., in the minus direction), i.e., such that the locking pin 28 is moved into the instrument section half 6.2. The user must turn it until the locking pin 28 or its locking projection 36 can engage in the locking pin receiving recess 32.

[0087] Fig. 8 is a perspective view of the tool 8 and the tool holder 2. To assemble the medical tool system 1, the tool 8 is inserted with its proximal end into an opening 42 at the distal end of the distal instrument section 4. The opening 42 is large enough to accommodate the roller bearing unit 18 arranged on the tool shaft 16. The tool 8 is inserted into the tool holder 2 only far enough for the tool head 14 to protrude from the distal instrument section 4.

[0088] To couple the tool 8 to the distal instrument section 4, the predetermined angle of rotation between the distal instrument section 4 and the proximal instrument section 6 must be set, or the locking pin 28 (not shown here) must be positioned in the release position. As soon as the tool 8 or its tool shaft 16 is properly received in the tool holder 2, the angle of rotation between the distal instrument section 4 and the proximal instrument section 6 can be reset to the design position (straight alignment of the instrument). By rotating the distal instrument section relative to the proximal instrument section, the locking pin 28 is moved out of the locking projection receiving recess 32 via the beveled flank 33. The proximal end of the locking pin 28 or the locking projection 36 then rests against the edge 30.By rotating the distal instrument section 4 relative to the proximal instrument section 6, the locking pin 28 (rotated together with the distal instrument section relative to the proximal instrument section and thus) is moved from the release position to the coupling position, thus establishing the coupling state between the tool 8 and the tool holder 2. In this coupling state, the tool 8 is then axially secured or fixed in the tool holder 2.

[0089] List of reference symbols

[0090] 1 Medical tool system

[0091] 2 tool holders

[0092] 4 distal instrument section

[0093] 6 proximal instrument section

[0094] 6.1 left half of the instrument section

[0095] 6.2 right half of the instrument section

[0096] 8 Tools

[0097] 10 first coupling device

[0098] 12 second coupling device

[0099] 14 Tool head

[0100] 16 tool shank

[0101] 18 Rolling bearing unit / coupling unit

[0102] 20 rolling bearings

[0103] 22 bearing housings

[0104] 24 Axial locking groove

[0105] 26 locking ball

[0106] 28 locking pin / slider

[0107] 30 edge

[0108] 32 locking pin recess

[0109] 33 bevelled flank

[0110] 34 Preload element / spring

[0111] 36 locking projection

[0112] 38 first locking ball receiving recess

[0113] 40 second locking ball receiving recess

[0114] 42 Opening

[0115] A axial direction

[0116] E Level

[0117] M central axis

[0118] R Radial direction

[0119] S1 Longitudinal axis of the distal instrument section

[0120] S2 Longitudinal axis of the proximal instrument section

Claims

Claims 1. Medical instrument, in particular hand instrument, with a tool chuck (2) for optionally receiving a tool shaft (16) of a medical shaft tool (8), which is characterized by the following components: - an internal torque train which is designed and configured to engage with the tool shank (16) for torque transmission, - an axially movable slide or latch or locking pin (28) which is spring-loaded in a first axial direction, namely in the proximal direction, - a detent engagement element (26), preferably a locking ball, which engages with the slide or bolt or detent pin (28) such that the detent engagement element (26) is displaced radially outwards into a release position in a first axial position of the slide or bolt or detent pin (28) achieved by the spring preload, and the detent engagement element (26) is displaced radially inwards into a detent position in a second axial position of the slide or bolt or detent pin (28) achieved against the spring preload.

2. Medical instrument according to claim 1, characterized by an actuating housing section (6) rotatable about the longitudinal axis of the tool chuck relative to the slide or latch or locking pin (28), in particular a sleeve-shaped actuating component, with - an axial end face or contact surface (30) which faces that axial end section of the slide or bolt or detent pin (28) on which the spring preload acts, so that the slide or bolt or detent pin (28) is pressed against the end face or contact surface (30), and - an axial recess or notch (32) in the end face or contact side (30) into which the slide or bolt or locking pin (28) enters when the actuating housing section (6) is rotated to move it from its locking position to its release position.

3. Medical instrument according to claim 2, characterized by a distal instrument section (4) which forms or comprises the tool chuck (2) and holds the slide or latch or locking pin (28) axially displaceably, and CORRECTED SHEET (RULE 91) ISA / EP a proximal instrument section (6) which forms or comprises the actuating housing section (6), wherein the distal and proximal instrument sections (4, 6) are axially aligned with each other in a relative rotatable manner at their end faces and the respective adjacent end faces of the distal and proximal instrument sections (4, 6) are inclined at an angle greater than 0°, preferably 22.5°, to the longitudinal axis of the medical instrument, such that in the event of a relative rotation of the distal and proximal instrument sections (4, 6) they change angle to each other when viewed in the longitudinal direction of the instrument.

4. Medical instrument according to claim 3, characterized in that the axial recess or notch (32) in the end face or contact side (30) of the actuating housing section (6) is positioned in such a circumferential position that, when the distal and proximal instrument sections (4, 6) are angularly adjusted by rotating the actuating housing section (6) within the intended rotation range, the slider or latch or locking pin (28) cannot be inserted into the axial recess or notch (32), and when the distal and proximal instrument sections (4, 6) are angularly adjusted by rotating the actuating housing section (6) outside the intended rotation range, the slider or latch or locking pin (28) can be inserted into the axial recess or notch (32).

5. Medical instrument according to claim 4, characterized in that the distal and proximal instrument sections (4, 6) are angled by rotating the actuating housing section (6) in a first direction of rotation, preferably clockwise, and the slider or latch or locking pin (28) is inserted into the axial recess or notch (32) by rotating the actuating housing section in a second or opposite direction of rotation, preferably counterclockwise.

6. Medical instrument according to claim 5, characterized in that the rotation of the actuating housing section up to a retraction rotation position of the CORRECTED SHEET (RULE 91) ISA / EP The axial recess or notch (32) with respect to the slide or latch or detent pin (28) is smaller than the maximum rotation range of the actuating housing section (6) provided for angling the instrument sections and preferably is (-) 18° from a design position of the actuating housing section (6) in which the two instrument sections (4, 6) are angled 0° to each other.

7. Medical instrument according to one of claims 1 to 6, characterized in that the locking pin (28) with its distal end section is opposite a locking geometry (24) formed on the medical tool (8) and receiving the locking engagement element (26) in the coupling position and is arranged with its distal end section spaced proximally from the locking geometry (24) in the release position.

8. Medical instrument according to claim 7, characterized in that the locking pin (28) has a first locking element receiving recess (38) at its distal end section, via which the locking pin (28) holds the locking element (26) in the radial direction in the locking geometry (24) in the coupling position and which releases the locking element (26) in the radial direction in the release position.

9. Medical instrument according to claim 8, characterized in that the locking pin (28) further has a second locking element receiving recess (40) at its distal end section, which is closer to the distal end of the locking pin (28) in the axial direction than the first locking element receiving recess (38) and is further away from the medical tool (8) in the radial direction than the first locking element receiving recess (38) and, in the release position, holds the locking element (26) radially on the medical tool (8) and not in the locking geometry (24).

10. Medical tool system comprising a medical instrument according to any one of claims 1 to 9 and a medical shank tool (8) comprising a distal effector (14) and a tool shank (16) for this purpose CORRECTED SHEET (RULE 91) ISA / EP is designed and configured to be inserted into a tool chuck (2) of the medical instrument, preferably a hand instrument, in a rotationally and axially fixed manner, wherein the medical shaft tool (8) further comprises a coupling unit (18) which is mounted or attachable to the tool shaft (16) and which has the following components: - a rolling or sliding bearing (20) for rotating a coupling unit housing (22) on the tool shank (16) and a detent geometry (24) which is arranged or formed on an outer circumferential surface of the coupling unit housing (22) and defines an undercut acting in the axial direction, in particular in the proximal direction of the tool shank.

11. Medical tool system according to claim 10, characterized in that the tool chuck (2) forms a radially inwardly projecting, preferably annularly circumferential, stop against which the proximal bearing unit on the shank (16) of the medical tool (8) axially abuts upon reaching the intended receiving position in the tool chuck (2), in order to provide an axial force transmission bridge for a proximally directed compressive force originating from the effector (14) via the stop into the tool chuck (2).

12. Medical tool system according to claim 11, characterized in that the tool chuck (2) has or forms a receiving sleeve whose inner diameter is adapted to the outer diameter of the tool shaft-side coupling unit housing (22) for a substantially backlash-free insertion.

13. Medical tool system according to one of claims 10 to 12, characterized in that an outer circumferential surface of the coupling unit housing (22) of the coupling unit (18), which is in contact with an inner circumferential surface of the distal instrument section (4), and / or the distal instrument section (4) itself is provided with an adhesive surface coating, is roughened or has microgrooves. CORRECTED SHEET (RULE 91) ISA / EP 14. Medical tool system according to one of claims 10 to 13, characterized in that the rolling or sliding bearing (20) has two axially spaced bearing units between which a spacer bushing is arranged, wherein in the preferred case of a rolling bearing - the axially spaced bearing units each have an inner, outer and an intermediate ball ring, - the spacer sleeve is axially supported against the respective inner rings, and - the outer rings are inserted into the coupling unit housing (22).

15. Medical tool system according to one of claims 10 to 14, characterized in that the coupling unit housing (22) has a cylindrical shape and the undercut is formed by a groove (24) running around the outer surface of the coupling unit housing (22) as the detent / engagement geometry. CORRECTED SHEET (RULE 91) ISA / EP

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