Surgical shaft assembly, and surgical instrument comprising shaft assembly

Abstract

The invention relates to a surgical shaft assembly (6) of or for a surgical instrument (2) and to a surgical instrument (2), in particular a minimally invasive shaft-type electrosurgical instrument (2), comprising the shaft assembly (6), wherein the shaft assembly (6) has a proximal axial stop (36, 50, 52, 74), which is received on an instrument shaft (12) in an axially movable manner and which is axially pretensioned in the distal direction, for limiting a proximally oriented axial movement of an insulating sheath (16) relative to the instrument shaft (12). (Fig. 4)

Description

[0001] Surgical shaft assembly and surgical instrument with shaft assembly

[0002] Description

[0003] Technical area

[0004] The present disclosure relates to a shaft assembly for a surgical instrument or a surgical instrument, in particular an electrosurgical instrument of the minimally invasive shaft type. Furthermore, the present disclosure relates to a surgical instrument having such a shaft assembly.

[0005] (Electro-)surgical instruments, particularly of a minimally invasive design, are already known from the prior art. These instruments enable cutting, gripping, holding, and / or clamping of body tissue by means of a multi-part tool, for example, composed of two scissor-, jaw-, forceps-, or tweezers-shaped elements that are movable relative to / toward each other and, in particular, pivotable, in order to coagulate, cauterize, or sever it in a monopolar or bipolar manner by applying a high-frequency voltage. Such an instrument is known, for example, from EP 3 033 022 A1.

[0006] Also from DE 10 2010 016 538 A1 is an instrument with a surgical shaft assembly which has a tubular instrument shaft and a plastic insulation sheath which surrounds the instrument shaft and is movable relative to the shaft.

[0007] The tool is articulated (or articulateable) at a distal ( / far from the surgeon or near the patient) end of the instrument or shaft assembly, in particular at an instrument shaft of the shaft assembly, and is coupled to a handle at a proximal ( / far from the surgeon or near the patient) end of the instrument or shaft assembly for actuation ( / operation) of the tool via a transmission, preferably in the form of a pull / push rod arranged inside the instrument shaft, in particular a longitudinally displaceable pull / push rod.The handle has an actuating element corresponding to the actuation of the tool (for example in the form of a handle-Ztrigger, a button, a rotary knob, a scissor handle), the (particularly manual) actuation of which leads to a correspondingly implemented movement of the tool branches at the place of use-Zapplication, such as a cutting-Zgripping-Zholding-Zlocking movement andZor a rotating-Zpivoting movement on or in the tissue of a patient.

[0008] Electrosurgical instruments of the relevant design generally use a so-called pistol handle with a rigid, immovable grip shell, in particular in the form of a (gear) housing extending from distal to proximal, i.e. substantially along a shaft axis of the instrument shaft, and a fixed handle element extending at an angle transverse to the distal-proximal direction and formed (integrally) on a proximal end portion of the (gear) housing or fixed thereto (as a separate, firmly connected component).A manually operable, preferably finger-guided, actuating lever (trigger) is pivotally mounted on the handle. This lever can be held—for example, in a monkey grip—by several fingers of a gripping hand of an operator and manually pulled toward the handle, in particular toward the grip element, for actuation. This pulling movement of the actuating lever is transmitted to the tool via a gear housed in the (gear) housing, the transmission within the instrument shaft, which is coupled or can be coupled to the handle, in order to move it accordingly. In addition, a type of switch is preferably attached to the pistol grip, by means of which the application of the high-frequency voltage to the tool can be triggered.

[0009] At least one of the two tool jaws can be equipped with an electrode or row of electrodes, through which the high-frequency voltage can be selectively introduced into the grasped patient tissue. In this case, the instrument would be a monopolar electrosurgical instrument, in which a patient, for example, lies on a metal plate through which the high-frequency voltage is discharged. Alternatively, both opposing tool jaws can be equipped with a corresponding electrode or row of electrodes or be made of an electrically conductive material, so that the high-frequency voltage is only applied in a gap between the jaws. In this case, the instrument would be a bipolar electrosurgical instrument.

[0010] A high-frequency connector, particularly located at the proximal end of the shaft assembly, can be electrically connected to the tool via the instrument shaft, which is made of metal, preferably steel (or the pull / push rod arranged inside the instrument shaft). To prevent electrical contact between the instrument shaft and the patient, the instrument shaft is encased (enclosed / surrounded) by an insulating sheath (tube), preferably completely circumferentially and electrically insulating radially on the outside. For this purpose, the insulating sheath is made of a plastic, preferably PEEK.

[0011] In order to be able to (re-)use the shaft assembly or instrument, the shaft assembly, in particular its components that come into contact with the patient, such as the insulation sheath, as well as the tool attached to it, must be sterilized before (each) use. Sterilization can be achieved in particular by heating, whereby individual components of the shaft assembly can expand differently depending on their material-dependent thermal expansion behavior. The shaft assembly or instrument is sterilized in a (finally) assembled state to avoid subsequent contamination during assembly of the shaft assembly. Therefore, there must be a degree of play between interconnected, differently expanding components of the shaft assembly to allow / enable differential expansion in order to prevent damage to the components.In particular, the instrument shaft and the insulation sheath mounted on the instrument shaft expand to different extents due to their different materials with regard to thermal expansion behavior, which is why the insulation sheath is arranged on the instrument shaft in an axially movable manner. However, due to the axially movable arrangement (and the fact that the insulation sheath does not necessarily retract to its original position before heating during cooling after sterilization), an (axial) slippage of the insulation sheath relative to the instrument shaft can occur. In particular, this can result in an axial gap between the instrument shaft and the insulation sheath at the distal end of the shaft assembly, which must be avoided at all costs.

[0012] The present disclosure is therefore based on the object of providing a shaft assembly of or for a surgical instrument and a surgical instrument with such a shaft assembly that is sterilizable and meets the high safety requirements.

[0013] The problem is solved by a surgical shaft assembly of or for a surgical instrument, in particular an electrosurgical instrument, having the features of the independent patent claim and / or by a surgical instrument, in particular an electrosurgical instrument, having the features of the independent patent claim. Advantageous further developments are the subject of the dependent claims.

[0014] In particular, the object is achieved by a shaft assembly for a surgical, in particular electrosurgical instrument or a surgical, in particular electrosurgical instrument.

[0015] A tool is articulated or linked to a distal end (working end) of the shaft assembly or instrument, and a handle for actuating the tool is articulated or linked to a proximal end (actuating end) of the shaft assembly or instrument. The shaft assembly has an instrument shaft, made in particular from a metal, preferably steel, and an insulating sheath (tube) made from a different material (with regard to thermal expansion behavior) than the instrument shaft, in particular from plastic, preferably PEEK, which is arranged axially displaceably on the instrument shaft and encloses (encloses / surrounds) the instrument shaft radially on the outside, preferably completely circumferentially, to electrically insulate the instrument shaft.

[0016] According to one aspect of the present disclosure, the shaft assembly comprises a proximal axial stop, which is axially displaceably received (or arranged) on the instrument shaft and axially preloaded in a distal direction to limit a proximally directed axial movement of the insulation jacket relative to the instrument shaft. This means that the axial stop, against which the insulation jacket rests on its proximal side and is thus limited in its axial displacement (or axial extension) (by an axial position of the proximal axial stop) in a proximal direction, is axially movable relative to the instrument shaft (just like the insulation jacket). A distally directed preload force / axial force acts on the axial stop (and thus on the insulation jacket), so that the axial stop (and thus also the insulation jacket) is pressed in the distal direction ( / toward the tool).This allows an axial gap formed by the slipping of the insulation jacket to be closed.

[0017] In other words, the core of the disclosure lies in the fact that the proximal axial stop, particularly during or due to heat-induced expansion of the insulation jacket, can move axially on the instrument shaft in the proximal direction against the preload, in order to (then), particularly during cooling-induced shrinkage / contraction and the resulting slipping / uncontrolled displacement of the insulation jacket, be moved back in the distal direction by the preload and thereby displace the insulation jacket into its original assembly position. According to a preferred embodiment, the shaft assembly can have a distal axial stop for limiting a distally directed axial movement of the insulation jacket relative to the instrument shaft. Preferably, the distal axial stop can be axially fixedly connected to the instrument shaft.This has the advantage that the insulation jacket has a defined end stop for the displacement in the distal direction and thus cannot be displaced too far in the distal direction, i.e. beyond its original mounting position, by the axially preloaded proximal axial stop.

[0018] According to a preferred embodiment, the shaft assembly can comprise a preferably annular disc, which is mounted on the instrument shaft and forms the proximal axial stop. For example, an inner diameter of the (annular) disc can be (slightly) larger than an outer diameter of the instrument shaft. This allows for a particularly simple design for a guided, yet axially loose, mount of the proximal axial stop.

[0019] According to a preferred embodiment, the shaft assembly can comprise a pressure element that axially preloads the proximal axial stop, particularly in the form of a spring, preferably a helical spring. The pressure element can be arranged axially between the proximal axial stop and a spring stop that is axially fixed to the instrument shaft or formed directly / immediately on the instrument shaft. This allows the axial preload to be applied to the proximal axial stop.

[0020] According to a further development of the preferred embodiment, the pressure element can bear against the disk or directly against the insulation jacket. The pressure element can thus apply the axial preload to the disk acting as the axial stop and thus indirectly to the insulation jacket, which has advantages in terms of uniform force introduction, or alternatively, it can apply the axial preload directly to the insulation jacket and thus itself (or its axial end face) can act as the axial stop, which has advantages in terms of reducing the number of components. According to a preferred embodiment, the shaft assembly can have a capsule-like adapter that is preferably axially fixed to the instrument shaft, in particular is received on the instrument shaft and preferably electrically insulates the instrument shaft on the outside, (radially) within which the proximal axial stop, i.e.in particular the disc and / or the pressure element. This has the advantage that the axial stop and thus also the proximal end of the insulation jacket are enclosed and thus have no contact with the environment.

[0021] According to a further development of the preferred embodiment, the adapter can have a distal (disk) stop, in particular in the form of a radially inwardly extending section, for limiting a distally directed axial movement of the (axially displaceable) proximal axial stop, i.e., in particular of the disc and / or the pressure element. This has the advantage that the proximal axial stop has a defined end stop for displacement in the distal direction and thus cannot be displaced too far in the distal direction by the axially preloaded proximal axial stop, but is positioned at a predetermined position.

[0022] According to a further development of the preferred embodiment, an axial position of the distal (disc) stop can be determined depending on the thermal expansion behavior of the insulation jacket and / or the instrument shaft. In particular, the axial position can be determined such that the proximal end of the insulation jacket lies within the adapter when cooled, or such that the insulation jacket, when cooled, rests against both the distal axial stop (particularly the one fixed to the instrument shaft) and the proximal axial stop (and such that an axial gap does not arise between the insulation jacket and the distal or proximal axial stop because the proximal stop cannot be pushed sufficiently far in the distal direction due to its distal (disc) stop.

[0023] According to a further development of the preferred embodiment, the adapter can have a receiving shell with an insertion opening for inserting the proximal axial stop, i.e., in particular, the disc and / or the pressure element. The insertion opening can be formed on a proximal side or a distal side of the adapter. Preferably, the insertion opening can have an inner diameter that is larger than an outer diameter of the proximal axial stop, i.e., in particular, the disc and / or the pressure element. This ensures that the proximal axial stop can be mounted.

[0024] According to a further development of the preferred embodiment, the adapter can have a cap, which is formed separately from the receiving shell and can be plugged (or plugged onto) the receiving shell from a distal side, in particular screwed (or screwed onto), forming the distal stop. The multi-part design results in design advantages with regard to functionality and assembly.

[0025] According to a further development of the preferred embodiment, the distal stop can alternatively be formed directly / integrally on a distal side of the receiving shell. This means that the proximal axial stop, i.e., in particular the disc and / or the pressure element, are inserted from the proximal side into the receiving shell (through the proximally arranged insertion opening) and rest (directly / immediately) against a wall of the receiving shell. This has the advantage of allowing for a simple design of the adapter.

[0026] According to a further development of the preferred embodiment, the adapter can have a distal opening / through-opening whose outer diameter essentially corresponds to an outer diameter of the insulating sheath and through which the insulating sheath and the instrument shaft can be passed. Alternatively, the adapter can have a central opening / through-opening whose outer diameter essentially corresponds to an outer diameter of the instrument shaft and through which the instrument shaft can be passed axially, as well as a second through-opening through which the insulating sheath (for contacting the proximal axial stop) can be passed axially. This ensures the functionality of the proximal axial stop arranged within the adapter.

[0027] According to the further development of the preferred embodiment, the distal opening can alternatively be formed (directly / integrally) on an inner diameter / inner circumference of the receiving shell. This has the advantage that the distal side of the receiving shell can be formed essentially (with the exception of the distal / central opening) integrally closed ( / closed).

[0028] According to a further development of the preferred embodiment, the adapter can have an axial cover that closes the insertion opening and forms the distal / central opening on its inner circumference. This has the advantage that the distal side of the receiving shell is essentially closed (with the exception of the distal / central opening), so that the interior has no contact with the environment.

[0029] According to a further development of the preferred embodiment, the axial cover can be formed by the proximal axial stop, i.e., in particular, a disc. This allows for functional integration and thus a reduction in the number of components.

[0030] According to a preferred embodiment, the shaft assembly can have two proximal axial stops (mounted axially displaceably on the instrument shaft and axially preloaded in the distal direction), of which a first proximal axial stop serves to limit the axial movement of the insulation jacket with a first (smaller, e.g., 5 millimeters) diameter, and a second proximal axial stop serves to limit the axial movement of the insulation jacket with a second (larger, e.g., 10 millimeters) diameter. This has the advantage that the (same) shaft assembly is compatible with both an insulation jacket with a smaller diameter and an insulation jacket with a larger diameter. This means that the shaft assembly can be used universally and modularly. In particular, the shaft assembly can only ever be used with one insulation jacket.According to a further development of the preferred embodiment, the shaft assembly can have a first pressure element, in particular in the form of a spring, preferably a helical spring, which axially prestresses the first proximal axial stop, and a second pressure element, in particular in the form of a spring, preferably a helical spring, which axially prestresses the second proximal axial stop.

[0031] According to a further development of the preferred embodiment, the first pressure element and the second pressure element can have different spring hardnesses. This allows for a preload force adapted to the respective insulation jacket to be axially displaced by the preload. Preferably, the spring hardness of the second pressure element (for the larger insulation jacket) can be greater than the spring hardness of the first pressure element (for the smaller insulation jacket).

[0032] According to a further development of the preferred embodiment, the first pressure element and the second pressure element can be arranged radially nested. This allows for a space-saving arrangement. Preferably, the first pressure element can be arranged radially within the second pressure element. This has the advantage that, due to the greater spring stiffness, a larger pressure element is often required, so that the first pressure element can be arranged more easily within the second pressure element than vice versa.

[0033] According to a further development of the preferred embodiment, the shaft assembly can have a first disc, preferably annular, forming the first proximal axial stop, and a second disc, preferably annular, forming the second proximal axial stop.

[0034] According to a further development of the preferred embodiment, the first disk and the second disk can be arranged axially one behind the other, in particular adjacent to one another. Preferably, the second disk can be arranged proximal to the first disk. This allows for a space-saving arrangement. According to a further development of the preferred embodiment, the axial cover can be formed by the proximally arranged disk, in particular the second disk. This allows the function of the axial cover to be integrated into the proximally arranged disk.

[0035] According to a further development of the preferred embodiment, the distally arranged disc can have an inner diameter or a through-opening (in its annular portion) through which the insulating jacket of the corresponding diameter can be axially passed for axial contact with the proximally arranged disc ( / for contacting the corresponding proximal axial stop). This ensures that, despite the discs being arranged one behind the other, each disc can be contacted by the insulating jacket of the corresponding diameter.

[0036] According to a preferred embodiment, the shaft assembly can have a third proximal axial stop for limiting the axial movement of the insulation jacket with a third (average, for example, 8 millimeters) diameter. According to a further development, a third pressure element axially preloading the third proximal axial stop, in particular in the form of a spring, preferably a helical spring, can have a different spring hardness than the first and / or second pressure element. In particular, the third pressure element can have a greater spring hardness than the first pressure element and / or a lower spring hardness than the third pressure element. According to a further development, the third pressure element can be arranged radially nested with the first and / or second pressure element.In particular, the third pressure element can be arranged radially outside the first pressure element and / or the second pressure element (or radially between the first pressure element and the second pressure element). According to a further development, a third disc forming the third proximal axial stop can be arranged proximal to the first and / or second disc, axially between the first and second discs, or distal to the first and / or second disc. In particular, the third disc can be arranged axially between the first disc and the second disc. The object of the disclosure is also achieved by a surgical instrument, in particular an electrosurgical instrument of the minimally invasive shaft design, with a described shaft assembly.

[0037] Short description of the characters

[0038] Fig. 1 shows a perspective view of an instrument according to the present disclosure,

[0039] Fig. 2 shows a perspective view of a distal part of the instrument,

[0040] Fig. 3 shows an enlarged perspective view of a proximal part of the instrument,

[0041] Figs. 4 to 11 show a design or receptacle of an insulation jacket of the instrument;

[0042] Fig. 12 shows a longitudinal sectional view of a handle of the instrument;

[0043] Figs. 13 and 14 show longitudinal sectional views of the handle in a fully open and closed position (or actuated and unactuated position) of a tool of the instrument;

[0044] Figs. 15 and 16 show an overload protection function of the instrument;

[0045] Fig. 17 shows a longitudinal section of the handle of the instrument in a loading position;

[0046] Fig. 18 shows a longitudinal sectional view of a distal end portion of the instrument; and Fig. 19 shows a cross-sectional view in the region of a disassembly button of the instrument.

[0047] Description of preferred embodiments

[0048] Fig. 1 shows a perspective view of a surgical instrument 2 according to the present disclosure. Figs. 2 and 3 show enlarged perspective views of a distal part and a proximal part of the instrument 2, respectively. The instrument 2 is designed, in particular, as an electrosurgical instrument and intended for use in minimally invasive surgery or endoscopy, in particular laparoscopy. The instrument 2 is designed, in particular, as a minimally invasive shaft-type instrument 2.

[0049] The instrument 2 has a distally arranged tool 4, a shaft assembly 6 arranged proximally to the tool 4, and a handle 8 arranged proximally (to the tool 4 and the shaft assembly 6). This means that the tool 4 can be coupled or is coupled to a distal end ( / working end) of the shaft assembly 6, and a proximal end ( / actuating end) of the shaft assembly 6 can be coupled or is coupled / coupled distally to the handle 8. Proximal and distal are defined in relation to a surgeon ( / operator / operator / user) of the instrument 2.

[0050] The instrument 2 has the (distally arranged) tool 4. The tool 4 is in particular constructed in several parts and can, for example, be constructed from two scissor-, clamp-jaw-, pliers-, or pincer-shaped tool branches ( / elements) 10 that are movable relative to / in relation to one another and, in particular, can be pivoted relative to one another. When the tool 4 is actuated, the tool branches 10 pivot relative to one another, whereby they open or close. The tool 4 can be used or the tool branches 10 can be used to cut, grip, hold, and / or clamp body tissue. The tool branches 10 are in particular pivotably connected to the shaft assembly 6 about a tool pivot axis, such that at least one of the tool branches 10, preferably both tool branches 10, can be pivoted relative to the shaft assembly 6 and thus also relative to the other tool branch 10. The tool pivot axis is in particular transverse ororiented perpendicular to a distal-proximal direction. The distal-proximal direction corresponds in particular to a longitudinal axis of the shaft assembly 6 (hereinafter referred to merely as a shaft axis). The tool 4 is connected to the shaft assembly 6 in particular in a rotationally coupled manner about its longitudinal axis, so that the tool 4 (as a whole) can be rotated with the shaft assembly 6. The tool 4 is formed in particular from a metal, preferably from steel.

[0051] The instrument 2 or the shaft assembly 6 has an instrument shaft ( / tubular shaft) 12, the longitudinal axis ( / tubular axis) of which corresponds in particular to the shaft axis. The instrument shaft 12 can preferably be translationally fixed and preferably rotatable about the shaft axis. The tool 4 can be coupled to the instrument shaft 12 such that a rotation of the instrument shaft 12 (about the shaft axis) causes (forces / actuates) a rotation of the tool 4 (about the shaft axis). In particular, the tool 4 and the instrument shaft 12 can be connected to one another, preferably directly, in a rotationally fixed manner about the shaft axis. The instrument shaft 12 is made in particular of a metal, preferably steel.

[0052] The instrument 2 or the shaft assembly 6 has a transmission, preferably a pull / push rod 14 mounted (received / arranged) inside the instrument shaft 12, the longitudinal axis (rod axis) of which corresponds in particular to the shaft axis or substantially to the distal-proximal direction. The transmission (pull / push rod 14) can be translationally displaceable, preferably axially / longitudinally movable / displaceable, i.e. translationally displaceable along the shaft axis, and preferably rotationally fixed. The tool 4 can be coupled to the transmission (pull / push rod 14) such that a translational movement, in particular a longitudinal movement (along the shaft axis), causes (forces / actuates) an actuation of the tool 4, in particular a pivoting movement (or opening and closing) of the tool branches 10 (about the tool pivot axis).In particular, the tool 4 and the pull / push rod 14 can be connected to one another, preferably via a coupling mechanism. This means that the pull / push rod's longitudinal movement in a distal direction / pushing direction causes ( / forces / actuates) the opening (or closing) of the tool 4 or the tool branches 10, and in a proximal direction / pulling direction causes ( / forces / actuates) the closing (or opening) of the tool 4 or the tool branches 10. The pull / push rod 14 is in particular made of a metal, preferably steel.

[0053] The instrument 2 or the shaft assembly 6 has an insulating jacket 16, which is arranged in particular on the instrument shaft 12 and whose longitudinal axis ( / jacket axis) corresponds in particular to the shaft axis. The insulating jacket 16 can be accommodated so as to be axially / longitudinally movable / displaceable, i.e., translationally displaceable along the shaft axis, and preferably (freely) rotatable, in particular relative to the instrument shaft 12 and / or the pull / push rod 14. The insulating jacket 16 is hollow, preferably tubular, and serves for the (radially) external electrical insulation of the instrument shaft 12 and / or the pull / push rod 14, in particular between a distal end region and a proximal end region of the instrument shaft 12 and / or the pull / push rod 14. The insulating jacket 16 is made of a different material than the instrument shaft 12, in particular of a plastic, preferably PEEK. An education orThe insulating jacket 16 is described in more detail below.

[0054] The instrument 2 or the shaft assembly 6 has a cap 18, preferably annular in cross-section, arranged particularly on the instrument shaft 12. The instrument shaft 12, the pull-Z-push rod 14, and / or the insulating sheath 16 can be axially guided through a (central) opening in the cap 18. The cap 18 can be held firmly in translation and preferably firmly in rotation, particularly relative to the instrument shaft 12. The cap 18 serves as an axial stop for the shaft assembly 6 on the handle 8.

[0055] The instrument 2 has the (proximally arranged) handle 8. The handle 8 is designed, in particular, in the manner of a pistol grip or as a pistol-shaped handle. The handle 8 has a gear housing 20, which extends, in particular, from distal to proximal, i.e., in the distal-proximal direction or substantially parallel to / along the shaft axis.

[0056] In addition, the handle 8 has a fixed grip element ( / grip part) 21. The grip element 21 extends, in particular, at an angle, i.e., transversely, to the distal-proximal direction. The grip element 21 can be fixed to a proximal end portion of the gear housing 20 or, in particular, can be formed on the gear housing 20, i.e., can be integrally connected to the gear housing 20. In particular, the gear housing 20 and the grip element 21 are firmly connected to one another.

[0057] Furthermore, the handle 8 has an actuating lever 22 which is articulated on the gear housing 20 and is in particular finger-guided or finger-guideable. The actuating lever 22 is in particular manually operable and has an engagement point for applying an actuating force (by the surgeon). The actuating lever 22 can have a preferably closed or substantially ring-shaped loop for receiving the fingers (preferably not a thumb) of the surgeon, which loop forms the engagement point for the actuating force. The actuating lever 22 can be pivotably received. The actuating lever 22 is in particular pivotally articulated on the gear housing 20 about an actuating lever pivot axis, so that the actuating lever 22 can be pivoted relative to the gear housing 20, i.e., towards the grip element 21 or away from the grip element 21. The actuating lever pivot axis is in particular transverse or perpendicular to the shaft axis, i.e.,the distal-proximal direction. By manually actuating the actuating lever 22, i.e., by applying the actuating force to the actuating force application point, in particular the loop, a pivoting movement of the actuating lever 22 (relative to the gear housing 20) is caused ( / forced / actuated). The pivoting movement of the actuating lever 22 toward the handle element 21, actuated, for example, by the surgeon closing his hand / pressing the actuating lever 22 and handle element 21 together, is referred to below simply as pivoting / pivoting movement in an actuating direction or actuation of the actuating lever 22. The pivoting movement of the actuating lever 22 away from the handle element 21, actuated, for example, by opening one hand of the surgeon / pushing apart the actuating lever 22 and the handle element 21, is referred to below merely as pivoting / pivoting movement in a return direction or returning the actuating lever 22.

[0058] The instrument 2 or the handle 8 has a gear 24 that converts the pivoting movement of the actuating lever 22 (actuated by manual actuation) into a translational movement of the transmission, in particular into a longitudinal movement of the pull / push rod 14. This means that the gear 24 couples the pivoting movement of the actuating lever 22 with the longitudinal movement of the pull / push rod 14 (and thus (indirectly) with the actuation of the tool 4 or the opening and closing of the tool branches 10). In other words, actuating the actuating lever 22 actuates the longitudinal movement of the pull / push rod 14 in the pushing direction (or pulling direction), and returning the actuating lever 22 actuates the longitudinal movement of the pull / push rod 14 in the pulling direction (or pushing direction) (which in turn causes the actuation (or opening or closing) of the tool 4).The gear 24 can preferably be arranged largely or entirely within the gear housing 20 or be covered from the outside by the gear housing 20. A design of the gear 24 is described in more detail below.

[0059] The instrument 2 or the handle 8 has a rotating star 26, arranged in particular at a distal end of the handle 8, the longitudinal axis (star axis) of which corresponds in particular to the shaft axis. The rotating star 26 can be mounted, in particular relative to the gear housing 20, preferably translationally fixed and preferably rotatable about the shaft axis. The instrument shaft 12, the pull / push rod 14 and / or the insulating sheath 16 can be or can be axially guided through a (central) opening of the rotating star 26. The rotating star 26 can be or can be coupled to the instrument shaft 12 in such a way that a rotation of the rotating star 26 (about the shaft axis) causes (forces / actuates) the rotation of the instrument shaft 12 (about the shaft axis) (which in turn causes the rotation of the tool 4).In particular, the rotary star 26 and the instrument shaft 12 can be connected to one another in a rotationally fixed manner about the shaft axis, preferably directly or via a component that is (fixedly) connected to the instrument shaft 12.

[0060] The instrument 2 or the handle 8 has a disassembly button 28, upon actuation ( / pressing) of which the shaft assembly 6 and the handle 8 can be disassembled, ie, the shaft assembly 6 can be decoupled from the handle 8. The design of the disassembly button 28 is described in more detail below.

[0061] The instrument 2 or the handle 8 has a high-frequency connection, in particular an HF pin 30, through which the tool 4, in particular the tool branches 10, can be subjected to a high-frequency voltage. The HF pin 30 can be held, particularly relative to the gear housing 20, preferably in a translationally fixed and preferably rotationally fixed manner. The HF pin 30 can be in contact with the instrument shaft 12 and / or the pull / push rod 14 or can be brought into contact in order to transmit the high-frequency voltage through the material of the instrument shaft 12 and / or the pull / push rod 14 to the tool 4. The HF pin 30 can be designed as a bipolar or a monopolar HF pin.

[0062] The handle 8 has a locking mechanism 32, by which a pivoting position of the actuating lever 22 can be locked in predetermined locking positions. The locking mechanism 32 can be constructed from a locking bracket (fixed) attached to the handle element 21 and a detent (fixed) attached to the actuating lever 22.

[0063] The handle 8 has a button 34, which can be used to trigger the application of the high-frequency voltage to the tool 4. Alternatively, the button 34 can be used to unlock the locking mechanism 32.

[0064] The design or receptacle of the insulating sheath 16 is described with reference to Figs. 4 to 11. Fig. 4 shows a longitudinal sectional view of a proximal receptacle of the insulating sheath 16 according to a first embodiment. Fig. 5 shows a longitudinal sectional view of a proximal receptacle of the insulating sheath 16 according to a second embodiment. Figs. 6 and 7 show exploded views of individual parts of the proximal receptacle of the insulating sheath 16 according to the second embodiment. Fig. 8 shows a longitudinal sectional view of a proximal receptacle of the insulating sheath 16 according to a third embodiment. Figs. 9 to 11 show different embodiments of a distal section of the insulating sheath 16 and a distal receptacle of the insulating sheath 16.

[0065] As described above, the insulation sheath 16 is mounted axially displaceably ( / freely floating) on ​​the instrument shaft 12. A proximal axial stop 36 is formed on the instrument 2 to limit a proximal axial movement (toward the handle s) of the insulation sheath 16.

[0066] According to one aspect of the disclosure, the proximal axial stop 36 is axially displaceably received / arranged on the instrument shaft 12. The proximal axial stop 36 is axially preloaded distally / in a distal direction. This means that the proximal axial stop 36 applies a distally directed axial force to the insulation jacket 16, or the proximal axial stop 36 is pressed distally / in the distal direction by an axial preload.

[0067] When cooled, the insulation jacket 16 is in its assembly position and rests axially against the proximal axial stop 36. When heated, for example during sterilization of the instrument 2 and / or the shaft assembly 6, the insulation jacket 16 and the instrument shaft 12 expand to different extents due to their different thermal expansion coefficients, resulting in axial slippage of the insulation jacket 16 on the instrument shaft 12. The proximal axial stop 36 is displaced in a proximal direction due to the expansion of the insulation jacket 16, whereby the axial preload on the proximal axial stop 36 increases. When the insulation jacket 16 cools down again and contracts, the insulation jacket 16 is pushed back into its assembly position by the axial preload of the proximal axial stop 36. Fig.4 shows a first embodiment of the proximal receptacle of the insulating sheath 16. The proximal axial stop 36 is preferably formed on an annular disk 38, which is received in particular on the instrument shaft 12 (e.g., placed / attached to an outer circumference of the instrument shaft 12). The axial preload of the proximal axial stop 36 is preferably realized by an axially preloading pressure element, in particular a spring 40, preferably in the form of a helical spring, arranged in particular on the instrument shaft 12. The spring 40 can preferably bear directly on the disk 38. Alternatively, the spring 40 can preferably bear directly on the insulating sheath 16, so that an axial end face of the spring 40 forms the proximal axial stop 36. The proximal axial stop 36 (ieThe spring 40 (the disc 38 and / or the spring 40) can preferably be arranged within a capsule-like adapter 42, which is particularly received on the instrument shaft 12. The adapter 42 can serve for the (radially) external electrical insulation of the instrument shaft 12 and / or the pull / push rod 14. The adapter 42 can preferably be axially fixedly connected to the instrument shaft 12.

[0068] The adapter 42 can preferably have a distal stop 44 for limiting a distally directed axial movement (in the direction toward the tool 4) of the axially displaceable proximal axial stop 36 (i.e., the disc 38 and / or the spring 40). An axial position of the distal stop 44 can preferably be determined as a function of a thermal expansion behavior of the insulation jacket 16 and / or the instrument shaft 12. In particular, the axial position can be determined such that the insulation jacket 16, in the cooled state, axially abuts the proximal axial stop 36 (as well as a distal axial stop 80 described later) (i.e., the insulation jacket 16 should not retract further in the distal direction due to its thermal expansion behavior than the proximal axial stop 36 can be pushed in the distal direction due to the distal stop 44).The distal stop 44 can be formed, in particular, on a portion of the adapter 42 extending radially inward (in particular, further inward beyond an outer circumference of the proximal axial stop 36 / the disk 38). The adapter 42 can preferably have a receiving shell 46 with an insertion opening for the (axial) insertion ( / pushing in / inserting) of the proximal axial stop 36, in particular the disk 38 and / or the spring 40. The insertion opening can, in particular, have a larger outer diameter than the proximal axial stop 36, in particular than the disk 38 and / or the spring 40. The insertion opening can preferably be formed on a proximal side of the adapter 42. The receiving shell 46 can preferably form the distal stop 44 directly / integrally.

[0069] The adapter 42 can preferably have a distal opening 48, which is in particular substantially as large as an outer diameter of the insulation jacket 16 (or slightly larger to ensure the axial displaceability of the insulation jacket 16), through which the insulation jacket 16 (as well as the instrument shaft 12 and / or the pull / push rod 14) is or can be axially passed. The distal opening 48 can be formed (directly / integrally) on an inner circumference ( / diameter) of the receiving shell 46.

[0070] Figs. 5 to 7 show a second embodiment of the proximal receptacle of the insulating jacket 16. The proximal receptacle according to the second embodiment can be used universally for (two) insulating jackets 16 of different diameters. The second embodiment differs from the first embodiment in particular in that two proximal axial stops 36 are provided. A first proximal axial stop 50 serves to limit the axial movement of the insulating jacket 16 with a first (smaller) diameter, while a second proximal axial stop 52 serves to limit the axial movement of the insulating jacket 16 with a second (larger) diameter, wherein the first proximal axial stop 50 and the second proximal axial stop 52 each correspond essentially in structure to the proximal axial stop 36 of the first embodiment.

[0071] The first and second proximal axial stops 50, 52 are preferably formed on an annular first disc 54 and second disc 56, respectively, which are received in particular on the instrument shaft 12 (e.g., placed / attached to an outer circumference of the instrument shaft 12). The axial preload of the first and second proximal axial stops 50, 52 is preferably realized by an axially preloading pressure element, in particular a first spring 58 and second spring 60, respectively, preferably in the form of a helical spring, arranged in particular on the instrument shaft 12. The first and second springs 58, 60 can preferably bear directly against the first and second discs 54, 56, respectively. Alternatively, the first or second spring 58, 60 may preferably bear directly against the first or second insulation jacket 16, so that an axial end face of the first or second spring 58, 60 forms the first or second proximal axial stop 50, 52.

[0072] In particular, only a first or second insulating jacket 16 is ever inserted into the proximal receptacle. Fig. 6 shows an exploded view (viewed from left to right) of the insulating jacket 16 with the first (smaller) diameter, the second disc 56 (forming the second proximal axial stop 52), the second spring 60, the first disc 54, and the first spring 58. Fig. 7 shows an exploded view (viewed from left to right) of the insulating jacket 16 with the second (larger) diameter, the second disc 56 (forming the second proximal axial stop 52), the second spring 60, the first disc 54, and the first spring 58.

[0073] Preferably, the first spring 58 and the second spring 60 can have different spring hardnesses. In particular, the second spring 60 can have a greater spring hardness than the first spring.

[0074] Preferably, the first spring 58 and the second spring 60 can be arranged radially nested / interleaved. In particular, the first spring 58 can be arranged radially inside the second spring 60.

[0075] Preferably, the first disk 54 and the second disk 56 can abut one another axially. In particular, the first disk 54 can be arranged proximal to the second disk 56. Preferably, the first disk 54 and the second disk 56 can have different inner diameters. In particular, the distally arranged disk 54, 56, here the second disk 56, can have a larger inner diameter than the proximally arranged disk 54, 56, here the first disk 54, so that the respective insulating jacket 16 can be passed axially through the distally arranged disk 54, 56, here through the second disk 56, for axially abutting the proximally arranged disk 54, 56, here the first disk 54. Alternatively, the distally arranged disk 54, 56 can have a through-hole through which the respective insulating jacket 16 can be passed for axially abutting the proximally arranged disk 54, 56.

[0076] The first and second proximal axial stops 50, 52 (i.e., the first and second discs 54, 56 and / or the first and second springs 58, 60) can preferably be arranged within a capsule-like adapter 62, which is particularly received on the instrument shaft 12. The adapter 62 can serve for the (radially) external electrical insulation of the instrument shaft 12 and / or the pull / push rod 14. The adapter 62 can preferably be axially fixedly connected to the instrument shaft 12.

[0077] The adapter 62 can preferably have a distal stop 64 for limiting a distally directed axial movement (in the direction toward the tool 4) of the axially displaceable first or second proximal axial stop 50, 52. An axial position of the distal stop 64 can preferably be determined as a function of a thermal expansion behavior of the insulation jacket 16 and / or the instrument shaft 12. In particular, the axial position can be determined such that the insulation jacket 16, in the cooled state, axially abuts the first or second proximal axial stop 50, 52 (as well as a distal axial stop 80 described later) (i.e., the insulation jacket 16 should not retract further in the distal direction due to its thermal expansion behavior than the first or second proximal axial stop 50, 52 can be pushed in the distal direction due to the distal stop 64).The distal stop 64 can be formed in particular on a portion of the adapter 62 extending radially inward (in particular further inward beyond an outer circumference of the first or second proximal axial stop 50, 52).

[0078] The adapter 62 can preferably have a receiving shell 66 with an insertion opening for the (axial) insertion ( / insertion / insertion) of the first or second proximal axial stop 50, 52, in particular the first or second disc 54, 56 and / or the first or second spring 58, 60. The insertion opening can in particular have a larger outer diameter than the first or second proximal axial stop 50, 52, in particular than the first or second disc 54, 56 and / or the first or second spring 58, 60. The insertion opening can preferably be formed on a distal side of the adapter 62.

[0079] The adapter 62 can preferably have a distal opening 68, the outer diameter of which is in particular substantially equal to that of the insulating sheath 16 (or slightly larger to ensure the axial displaceability of the insulating sheath 16), through which the insulating sheath 16 (as well as the instrument shaft 12 and / or the pull / push rod 14) is or can be axially passed. Alternatively, the distal opening 68 can be substantially as large as an outer diameter of the instrument shaft 12 if the insulating sheath 16 extends through the through-hole to contact the distally arranged disc 54, 56, here the first disc 54.

[0080] The adapter 62 may have a cap 70, preferably formed separately from the receiving shell 66, which can be plugged, in particular screwed, onto the receiving shell 66 from the distal side. The cap 70 may preferably directly / integrally form the distal stop 64. The adapter 62 may preferably have an axial cover 72, which closes the insertion opening on the receiving shell 66 and forms the distal opening 68 on its inner circumference ( / diameter) (directly / integrally). The axial cover 72 can preferably be formed by the first disk 54 or the second disk 56, in particular by the proximally arranged disk 54, 56, here the second disk 56. Alternatively, the distal opening 68 can be formed (directly / integrally) on an inner circumference ( / diameter) of the cap 70 if the insulating jacket 16 extends through a through hole in the cap 70 to contact the distally arranged disk 54, 56, here the first disk 54.

[0081] Fig. 8 shows a third embodiment of the proximal receptacle for the insulating jacket 16. The proximal receptacle according to the third embodiment can be used universally for (three) insulating jackets 16 of different diameters. The structure of the proximal receptacle according to the third embodiment essentially corresponds to that of the second embodiment. In addition, a third proximal axial stop 74 is provided, which is formed by a third disk 76 and is axially preloaded in a distal direction by a third spring 78. The three disks 54, 56, 76 abut one another axially. The three springs 58, 60, 78 are arranged in a radially nested manner.

[0082] Figs. 9 to 11 show different embodiments of a distal portion of the insulation jacket 16 and a distal receptacle of the insulation jacket 16.

[0083] On the instrument 2, in particular on the instrument shaft 12 (or a component connected thereto (in a translationally fixed manner)), in particular a distal axial stop 80 is formed for limiting a distally directed axial movement (in the direction of the tool 4) of the insulating sheath 16. The distal axial stop 80 can be received in an axially fixed manner to the instrument shaft 12, in particular axially fixedly connected to the instrument shaft 12 or formed on the instrument shaft 12. In Fig. 9, the insulating sheath 16 lies with the first (smaller) diameter, in Fig. 10 the insulating sheath 16 lies whose diameter tapers at its distal end from the second (larger) diameter to the first (smaller) diameter, and in Fig. 11 the insulating sheath 16 lies with the second (larger) diameter against the distal axial stop 80.

[0084] Fig. 12 shows a longitudinal sectional view of the handle 8, which explains the design of the gear 24 in more detail. As described above, the gear 24 is designed to transmit the pivoting movement of the actuating lever 22 into the translational movement of the transmission, in particular the longitudinal movement of the pull-push rod 14. This means that the gear 24 couples the pivoting movement of the actuating lever 22 (actuated by manual actuation) with the longitudinal movement of the pull / push rod 14 (and thus (indirectly) with the actuation of the tool 4 or the pivoting movement of the tool branches 10).

[0085] The actuating lever pivot axis, about which the actuating lever 22 is pivotally connected to the gear housing 20, is arranged in particular between the translational axis of the translational movement of the transmission, in particular the shaft axis (i.e., the longitudinal axis of the instrument shaft 12 or the pull / push rod 14), and a proximal end region of the actuating lever 22 (i.e., the actuating force application point for applying the actuating force). In other words, the actuating lever pivot axis (when the instrument 2 is used in the vertical direction) is located below the shaft axis.

[0086] According to one aspect of the present disclosure, the transmission 24 is configured such that a pivoting movement of the actuating lever 22 toward the handle element 21 is transformed into a translational movement of the transmission 14 in the proximal direction. This means that the pivoting movement of the actuating lever 22 toward the handle element 21 (the actuation of the actuating lever 22) is converted into a proximally directed longitudinal movement of the pull / push rod 14 (a pulling movement of the pull / push rod 14).

[0087] In particular, the gear mechanism 24 is designed in two or more parts. Preferably, the gear mechanism 24 forms a power transmission line (from the actuating lever 22 to the transmission (pull / push rod 14)).

[0088] The power transmission cable has a first rotating part ( / adjusting lever) 82. The first rotating part 82 is operatively engaged with the actuating lever 22. This means that the pivoting movement of the actuating lever 22 is coupled to a rotation of the first rotating part 82. The first rotating part 82 is pivotally connected to the gear housing 20 about a first axis of rotation. The first axis of rotation is, in particular, transverse or perpendicular to the shaft axis. The first rotating part 82 is, in particular, formed separately from the actuating lever 22, but can alternatively also be formed on the latter (i.e., on a portion of the actuating lever 22), even if this is not shown.

[0089] The power transmission cable has a second rotating part (receiving element / closing element) 84. The second rotating part 84 is operatively engaged, preferably toothed, with the first rotating part 82, reversing the direction of rotation. This means that the rotation of the first rotating part 82 is coupled to a rotation of the second rotating part 84, and the first rotating part 82 and the second rotating part 84 rotate in different directions. The second rotating part 84 is pivotally connected to the gear housing 20 about a second axis of rotation. The second axis of rotation is, in particular, transverse or perpendicular to the shaft axis. The second axis of rotation is preferably offset parallel to the first axis of rotation. The second rotating part 84 preferably has a coupling section 86 for the transmission (pull / push rod 14). The coupling section 86 is, in particular, operatively engaged or can be brought into operative engagement with the transmission (pull / push rod 14).This means that the rotation of the second rotating part 84 is coupled or can be coupled via the coupling section 86 with the translational movement of the transmission, in particular the longitudinal movement of the pull / push rod 14.

[0090] For this purpose, the first rotating part 82 and the second rotating part 84 can have teeth that mesh with one another. The toothing can be designed, for example, as an involute toothing. Due to the toothing, the first rotating part 82 and the second rotating part 84 rotate in different directions of rotation. As a result, the pivoting movement of the actuating lever 22 in the actuating direction causes ( / forces / actuates) the longitudinal movement of the pull / push rod 14 in the pulling direction, and the pivoting movement of the actuating lever 22 in the return direction causes ( / forces / actuates) the longitudinal movement of the pull / push rod 14 in the pushing direction.

[0091] Preferably, the instrument shaft 12 in the coupled state can serve as a stop for the pivoting movement of the actuating lever 22, i.e. as a pivoting limiter for the actuating lever 22, or as a rotation limiter for the first rotating part 82 and the second rotating part 84 or as a translation limiter for the transmission, in particular as a longitudinal limiter for the pull / push rod 14. This means that the actuating lever 22 is pivotable (only) within a pivoting range that is preferably limited on both sides, or the first rotating part 82 and the second rotating part 84 are (only) within a rotation range that is preferably limited on both sides, or the transmission ( / pull / push rod 14) is (only) longitudinally movable within a translation range ( / longitudinal range / working range) that is preferably limited on both sides, i.e. it has a maximum stroke of the longitudinal movement.Due to the coupling between the transmission (pull / push rod 14) and the gear 24 (in particular the second rotating part 82), the power transmission within the gear 24 (in particular the second rotating part 82 and the first rotating part 82) as well as the coupling between the gear 24 (in particular the first rotating part 82) and the actuating lever 22, the stop on the instrument shaft 12 can serve for all coupled (or couplable) movements.

[0092] Figs. 13 and 14 show end positions of the translation range / working range of the transmission, in which the tool 4 is fully opened or closed.

[0093] Preferably, the gear 24 can have a gear ratio of 1:1. In particular, the teeth of the first rotating part 82 and the second rotating part 84 can be arranged on the same diameter. Alternatively, the teeth of the first rotating part 82 and the second rotating part 84 could be arranged on different diameters to realize a reduction or a transmission, although this is not shown.

[0094] Preferably, the teeth of the first rotating part 82 and / or the teeth of the second rotating part 84 can be formed (only) in sections on the circumferential side, i.e., not over the entire circumference. In this case, a number of teeth of the first rotating part 82 and / or the second rotating part 84, i.e., a dimensioning of the circumferential section formation, can preferably be determined as a function of the maximum stroke of the longitudinal movement / the limited longitudinal range of the pull / push rod 14. In particular, the first rotating part 82 and / or the second rotating part 84 can have two to five teeth, preferably two, three, or four teeth. Alternatively, the teeth of the first rotating part 82 and / or the second rotating part 84 could be formed over the entire circumference, even if this is not shown.

[0095] Preferably, the coupling section 86 of the second rotary part 84 can be designed as an axially undercut recess 88, into which the transmission (pull / push rod 14) can engage or engages in an axially undercutting manner in order to couple the rotation of the second rotary part 84 with the translational movement (longitudinal movement of the pull / push rod 14). For this purpose, the pull / push rod 14 can have a radial thickening (enlarged compared to an axially adjacent region) at its proximal end (end region), particularly in the form of a ball thrust piece 90, which engages in an axially undercutting manner in the recess 88 of the second rotary part 84.

[0096] Preferably, the gear unit 24 can have a guide dome 92 that is (rotatably) articulated to the second rotating part 84. The guide dome 92 is, in particular, articulated to the second rotating part 84 so as to be rotatable about a dome rotation axis, such that the second rotating part 84 and the guide dome 92 can be rotated relative to one another. The dome rotation axis is, in particular, transverse or perpendicular to the shaft axis. Preferably, the dome rotation axis can be offset parallel to the second rotation axis (and / or the first rotation axis). The guide dome 92 is longitudinally guided, i.e., displaceable (only) along its longitudinal axis, in the gear unit housing 20. The longitudinal axis of the guide dome 92 can, in particular, be offset parallel to the shaft axis. Preferably, the guide dome 92 is received in the gear unit housing 20 so as to be spring-loaded via a spring 94. Preferably, the spring preload of the guide dome 92 of the pivoting movement of the actuating lever 22 towards the handle element 21 (ieof the operation).

[0097] Preferably, the handle 8 can have an outer handle 96 and an inner handle 98 that is firmly connected to the outer handle 96, for example, screwed on. The inner handle 98 can preferably be covered on the outside by the outer handle 96. In particular, the second rotating part 84 can be rotatably connected to the inner handle 98. In particular, the guide pin 92 can be rotatably connected to the inner handle 98. In addition, the guide pin 92 can be longitudinally guided in a recess 100 in the inner handle 98.

[0098] According to one aspect of the present disclosure, the transmission 24 comprises the first rotary part 82, which is particularly pivotally connected to the transmission housing 20, as well as an elastic overload protection element 102 that couples the pivoting movement of the actuating lever 22 with a rotation of the first rotary part 82 (see also FIGS. 15 and 16 in particular). This means that the overload protection element 102 is arranged in the force flow / force transmission line between the actuating lever 22 and the first rotary part 82. The overload protection element 102 can be designed, in particular, as a spring element, preferably as a helical spring.

[0099] Preferably, the actuating lever 22 and the first rotary part 82 can be pivotally or rotatably connected to the gear housing 20 about the same axis. This means that the actuating lever pivot axis preferably corresponds to the first rotation axis.

[0100] Preferably, the actuating lever 22 can have a recess 104 in which the overload protection element 102 is received. In particular, the overload protection element 102 can be arranged entirely within the recess 104. This means that the overload protection element 102 is preferably covered on the outside by the actuating lever 22.

[0101] Preferably, the overload protection element 102 can be loosely received in the recess 104, i.e., not rigidly connected to the actuating lever 22 and / or the first rotating part 82. In particular, the overload protection element 102 can be longitudinally guided, i.e., (only) displaceable or elastically compressible or bendable along its longitudinal axis, in the recess 104.

[0102] As described above, the actuating lever 22 can be pivoted, ie actuated and reset, in the actuating direction, ie in the direction from the actuating lever 22 towards the handle element 21, actuated for example by closing a hand of the surgeon / pressing the actuating lever 22 and the handle element 21 together, and in the resetting direction, ie in the direction from the actuating lever 22 away from the handle element 21, actuated for example by opening a hand of the surgeon / pressing the actuating lever 22 and the handle element 21 apart.

[0103] The overload protection element 102 can preferably be arranged such that it acts (only / exclusively) in the actuation direction (and not in the return direction). This means that the overload protection element 102 only limits / damps / secures / protects against overload the pivoting movement of the actuation lever 22 toward the handle element 21. In particular, an actuation transmission surface 106 of the actuation lever 22 and a return transmission surface 108 of the actuation lever 22 can be formed separately from one another, i.e., on different surfaces.This means that the actuating lever 22 and the first rotary part 82 are not firmly connected to one another, and a force transmission when the actuating lever 22 is actuated takes place via the actuating transmission surface 106 coupled to the first rotary part 82 via the overload protection element 102, and a force transmission when the actuating lever 22 is returned takes place (directly) via the coupled return transmission surface 108 adjacent to the first rotary part 82.

[0104] In addition, the overload protection element 102 can preferably be arranged and dimensioned such that an initial (initially in the sense of actuation, i.e., starting from the pivoting movement from a non-actuated position of the actuating lever 22) force transmission via the overload protection element 102 between the actuating lever 22 and the first rotating part 82 exhibits a substantially linear transmission behavior. This means that the coupling via the overload protection element 102 is quasi-rigid / inelastic during the initial force transmission, in particular during force transmission within the "normal" working range (and without resistance on the tool 4).

[0105] In particular, the overload protection element 102 can preferably be arranged and dimensioned such that the overload protection element is only compressed when an actuating force of greater than 200 N, preferably greater than 300 N, is applied via the actuating lever 22 (but only when an actuating force of 1000 N is applied via the actuating lever 22).

[0106] According to one aspect of the present disclosure, the instrument shaft 12 can be coupled or can be coupled to the handle 8 and, in the coupled state, serve as a stop for the pivoting movement of the actuating lever 22 (and the components coupled thereto in the power transmission train). This means that, in the coupled state, the instrument shaft 12 serves as a pivoting limiter for the actuating lever 22, as well as a translation limiter for the transmission or longitudinal limiter for the pull / push rod 14, and thus as a travel limiter for the tool 4. This also means that, in a decoupled state of the instrument shaft 12, the stop function for the pivoting movement of the actuating lever 22, as well as the translation limiter for the transmission or the longitudinal limiter for the pull / push rod 14, and thus the travel limiter for the tool 4, are omitted, so that the movably guided or articulated components of the power transmission train of the gear 24 orof instrument 2 can move freely (with regard to their degree of freedom / their movement possible due to appropriate storage / receiving or attachment).

[0107] The instrument shaft 12 can serve as a stop such that decoupling of the transmission (pull / push rod 14) from the gear 24 is only possible when the instrument shaft 12 is decoupled from the handle 8, due to the loss of its stop function. This means that decoupling of the transmission (pull / push rod 14) from the gear 24 is blocked when the instrument shaft 12 is coupled to the handle 8, due to its stop function.

[0108] As described above, the stop formed by the instrument shaft 12 can preferably be designed as an axial stop that limits the translational movement of the transmission ( / the longitudinal movement of the pull / push rod 14), in particular on both sides. For example, the stop can be formed in that the transmission ( / pull / push rod 14) has a pin 110 that is received in a slotted guide 112 on the instrument shaft 12, so that when the pin 110 rests against the slotted guide edge, further translational movement (in the direction of the slotted guide edge) is prevented (see Fig. 18). The stop can preferably be formed on a distal end region of the instrument shaft 12.

[0109] Preferably, the gear 24 can have the second rotating part 84 operatively connected to the actuating lever 22, the rotation of which can be coupled or is coupled to the translational movement of the transmission (or the longitudinal movement of the pull / push rod 14) via a (first) axial positive connection. The first axial positive connection is formed in particular by the axially undercut recess 88 in the second rotating part 84, into which the transmission, in particular the ball pressure piece 90 of the pull / push rod 14 (in the coupled state of the instrument shaft 12 and thus of the pull / push rod 14), engages in an axially undercutting manner.

[0110] Preferably, the transmission (pull-push rod 14) can be translationally displaceable, in particular longitudinally movable, in the decoupled state of the instrument shaft 12, and (due to the coupling between the transmission and the second rotating part 84 or the gear 24), in particular the second rotating part 84 can be rotatable in the decoupled state of the instrument shaft (12) to such an extent that the axial positive connection between the transmission and the second rotating part 84 is releasable. This position of the second rotating part 84 is also referred to below as a disassembly position of the second rotating part 84 or as the loading position of the instrument 2 (see in particular Fig. 17). In particular, the transmission (pull-push rod 14) (together with the instrument shaft 12 or the entire shaft assembly 6) can be pulled in the distal direction (out of the handle 8).

[0111] In addition, the second rotating part 84 can be received in the handle 8, in particular the gear housing 20, with spring preload. In particular, a spring preload of the second rotating part 84 can press the second rotating part 84 into the disassembly position, in which the first axial positive connection between the transmission (pull / push rod 14) and the second rotating part 84 can be released. The spring preload can be realized in particular via the spring 94 preloading the guide dome 92. The disassembly position can in particular correspond to an unactuated, overextended position of the actuating lever 22, i.e. a position in which the actuating lever 22 is positioned further away from the handle element 21 than in the unactuated position.

[0112] In particular, the instrument shaft 12 can be axially fixedly coupled to the handle 8 in the coupled state and axially displaceable relative to the handle 8 in the uncoupled state. This means that a coupling between the instrument shaft 12 and the handle 8 corresponds in particular to an axially fixed connection.

[0113] As described above, the instrument 2 or the handle 8 can preferably have the disassembly button 28, upon actuation ( / pressing) of which the shaft assembly 6 / the instrument shaft 12 and the handle 8 can be disassembled, i.e. the shaft assembly 6 / the instrument shaft 12 can be uncoupled from the handle 8. The disassembly button 28 can in particular be manually actuated. By actuating the disassembly button 28, the instrument shaft 12 can be axially decoupled from the handle 8. This means that the disassembly button 28 can block an axial displacement of the instrument shaft 12 relative to the handle 8. In other words, the instrument shaft 12 and the handle can be freely axially displaced relative to one another when the disassembly button 28 is actuated and can be or be axially connected to one another when the disassembly button 28 is not actuated.

[0114] The disassembly button 28 can preferably have a closing slide 114 which is received in the handle 8 for (longitudinal) displacement and whose longitudinal axis corresponds in particular to a radial direction of the instrument shaft 12. This means that the closing slide 114 can be displaced transversely or perpendicularly to the shaft axis. The closing slide 114 can preferably be coupled or coupled to the instrument shaft 12 via a second axial positive connection. The second axial positive connection can preferably be released by a (longitudinal) displacement of the disassembly button 28 (relative to the handle 8). In particular, the closing slide 114 can be received in the handle in a spring-loaded manner. The (second) axial positive connection can preferably be released counter to a spring preload of the closing slide 114. This means that a spring preload of a spring 116 pushes the closing slide 114 into an unactuated position orinto axially positive engagement with the instrument shaft 12.

[0115] For example, the second axial positive connection can be formed by a slot-like slotted connection 118 formed in the closing slide 114, with which the instrument shaft 12 (when the disassembly button 28 is actuated) is out of axially positive engagement and can thus be guided axially through the slotted connection 118 and (when the disassembly button 28 is not actuated) is in axially positive engagement and thus cannot be moved axially relative to the slotted connection 118 (and thus to the handle 8). For this purpose, the instrument shaft 12 can preferably have a radial groove 120 (approximately running circumferentially) into which an end region / edge of the link 118 engages in the unactuated position of the disassembly button 28 (and thereby prevents an axial movement of the instrument shaft 12 (in the direction through the link)) and is received in a central region / center of the link 118 in an actuated position ( / longitudinally displaced position) of the disassembly button 28 (cf. Fig.19).

Claims

Claims 1. Surgical shaft assembly (6) of or for a surgical instrument (2), in particular an electrosurgical instrument (2) of the minimally invasive shaft type, to the distal end of which a tool (4) is coupled or can be coupled and to the proximal end of which a handle (8), in particular in the manner of a pistol handle for actuating the tool (4), can be coupled, with - an instrument shaft (12) made in particular of a metal, preferably of steel; and - an insulating jacket (16) made of a material different from the instrument shaft (12), in particular of plastic, preferably of PEEK, which is arranged axially displaceably on the instrument shaft (12) and encloses the instrument shaft (12) radially on the outside for electrical insulation of the instrument shaft (12), preferably completely on the circumference, characterized by a proximal axial stop (36, 50, 52, 74) which is received axially displaceably on the instrument shaft (12) and is axially prestressed in a distal direction for limiting a proximally directed axial movement of the insulating jacket (16) relative to the instrument shaft (12).

2. Shaft assembly (6) according to claim 1, characterized by a preferably annular disc (38, 54, 56, 76) forming the proximal axial stop (36, 50, 52, 74).

3. Shaft assembly (6) according to claim 1 or 2, characterized by a pressure element (40, 58, 60, 78) which axially prestresses the proximal axial stop (36, 50, 52, 74), in particular in the form of a spring, preferably a helical spring, which preferably bears against the disc (38, 54, 56, 76) or directly against the insulating jacket (16).

4. Shaft assembly (6) according to claim 3, characterized in that the pressure element (40, 58, 60, 78) bears against the disc (38, 54, 56, 76).

5. Shaft assembly (6) according to claim 3, characterized in that the pressure element bears directly against the insulation jacket (16).

6. Shaft assembly (6) according to one of claims 1 to 5, characterized by a capsule-like adapter (42, 62) which is preferably axially fixed to the instrument shaft (12), in particular received on the instrument shaft (12), within which the proximal axial stop (36, 50, 52, 74) is arranged.

7. Shaft assembly (6) according to claim 6, characterized in that the adapter (42, 62) has a distal stop (44, 64), in particular in the form of a radially inwardly extending portion, for limiting a distally directed axial movement of the proximal axial stop (36, 50, 52, 74).

8. Shaft assembly (6) according to claim 7, characterized in that an axial position of the distal stop (44, 64) is determined as a function of a thermal expansion behavior of the insulation jacket (16) and / or the instrument shaft (12).

9. Shaft assembly (6) according to one of claims 6 to 8, characterized in that the adapter (42, 62) has a receiving shell (46, 68) with an insertion opening for inserting the proximal axial stop (36, 50, 52, 74).

10. Shaft assembly (6) according to claim 9, characterized in that the insertion opening is formed on a proximal side of the adapter (42).

11. Shaft assembly (6) according to claim 9, characterized in that the insertion opening is formed on a distal side of the adapter (62).

12. Shaft assembly (6) according to one of claims 9 to 11, characterized in that the adapter (62) has a distal side on the Receiving shell (68) has a cap (70) which can be plugged on, in particular screwed on, and which forms the distal stop (64).

13. Shaft assembly (6) according to one of claims 7 to 11, characterized in that the distal stop (44) is formed integrally on a distal side of the receiving shell (46).

14. Shaft assembly (6) according to one of claims 1 to 13, characterized by two proximal axial stops (50, 52), of which a first proximal axial stop (50) serves to limit the axial movement of the insulation jacket (16) with a first diameter and a second proximal axial stop (52) serves to limit the axial movement of the insulation jacket (16) with a second diameter, 15. Shaft assembly (6) according to claim 14, characterized by a first pressure element (58) axially prestressing the first proximal axial stop (50) and a second pressure element (60) axially prestressing the second proximal axial stop (52).

16. Shaft assembly (6) according to claim 15, characterized in that the first pressure element (58) and the second pressure element (60) have different spring hardnesses.

17. Shaft assembly (6) according to claim 15 or 16, characterized in that the first pressure element (58) and the second pressure element (60) are arranged radially nested.

18. Shaft assembly (6) according to one of claims 14 to 17, characterized by a first disc (54) forming the first proximal axial stop (50) and a second disc (56) forming the second proximal axial stop (52).

19. Shaft assembly (6) according to claim 18, characterized in that the first disc (54) and the second disc (56) are arranged axially one behind the other, in particular adjacent to one another.

20. Shaft assembly (6) according to claim 19, characterized in that the distally arranged disc (56) has such an inner diameter or such a through-opening through which the insulating jacket (16) can be passed axially for axial contact with the proximally arranged disc (54).

21. Surgical instrument (2), in particular electrosurgical instrument (2) of the minimally invasive shaft type, with a shaft assembly (6) according to one of claims 1 to 20.

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