Surgical instrument having a coupling device

Abstract

The invention relates to a surgical instrument (100) comprising a hollow shaft (1) defining a longitudinal axis (A), a handle (5) arranged at the proximal end (1.1) of the shaft (1), and a force-transmission element (6) mounted in the shaft (1) and connected to a tool (7) on the distal side and to the handle (5) on the proximal side. The surgical instrument (100) has a coupling device for detachably connecting the shaft (1) and the handle (5), the coupling device being an engaging device (10) with an engaging element (3) which can move between an engaging position in which the engaging element (3) engages with at least one recess (1.2) at the proximal end (1.1) of the shaft (1) and a release position in which the engaging element (3) does not engage with the recess (1.2). The engaging element (3) has at least one wedge-like engaging section (3.2) with an engaging plane (E), the length of which corresponds to a length of the recess (1.2) along the longitudinal axis (A) so that the engaging section (3.2) is received in the recess (1.2) up to the engaging plane (E) in the engaging position.

Description

[0001] Surgical instrument with coupling device

[0002] The invention relates to a surgical instrument with a coupling device for releasably connecting its shaft to a handle.

[0003] Medical or surgical instruments are known from the prior art, comprising a hollow shaft, a handle arranged at the proximal end of the shaft, and a force transmission element mounted in the shaft, at the distal end of which a tool is arranged that can be controlled by actuating the handle via the force transmission element. A handle is, for example, a handle with at least one movable and one immovable grip part. To improve the cleanability and sterilizability of the instruments, the shaft and the handle can be detachably connected to one another via a coupling mechanism. Furthermore, the proximal end of the shaft can be mechanically rigidly connected to a rotary grip part that is rotatably mounted on the handle in order to be able to rotate the shaft relative to the force transmission element and the handle.EP 3 351 191 B1 discloses a locking bracket for coupling a shaft assembly of a forceps attachment to a special handle. The locking bracket is pivotably mounted on the shaft assembly via a sleeve-like bearing piece and has a holding section that can engage the handle with a circumferential collar, so that the shaft assembly is pulled against a cone on the handle. The elastic design of the locking bracket ensures that this connection is free of play. However, such a locking bracket is a relatively expensive component that, due to the increased space requirement, is only of limited use and therefore not suitable for all types of surgical instruments. For example, adaptation to a pistol-shaped handle, for example, is not readily possible. Furthermore, this type of coupling does not allow for shaft rotation.

[0004] EP 1 196 097 B1 relates to a connection between the handle and shaft of a surgical instrument, wherein the shaft is fixed in a sleeve-like housing part of the handle by radially movable spherical locking bodies penetrating into recesses in the shaft. A spring-loaded retaining means secures the spherical locking bodies in the recesses and holds a displaceable stop element in a release position that allows the radial movement of the locking bodies outward into the recesses. This construction, enclosed in the housing part, requires a high number of parts and has a relatively large space requirement, whereby the large enclosed area presents a challenge for reprocessing, including cleaning and sterilization.

[0005] The same applies to a coupling known from EP 0 820 256 B1 for the detachable connection of a handle to a shaft tube, which is connected at the proximal end to a shaft receiving part. Between a rotating sleeve arranged around the shaft receiving part and the shaft receiving part, there is arranged an axially movable locking sleeve which receives at least one spherical locking element that is movable outwardly. The rotating sleeve and / or the handle has / have a conically shaped recess, so that by locking the locking element into the recess, the handle is connected to the shaft tube. EP 1 191 888 B1 also discloses a coupling of shaft and handle with spherical locking elements that are positioned between two conical surfaces.

[0006] DE 10 2011 001 890 A1 discloses a surgical instrument with an instrument shaft whose shaft end has a connecting pin protruding radially to the instrument axis for connection to the handle. This pin is divided by a slot into two resilient arms, at the free ends of which two locking lugs are formed. The housing of the handle has a corresponding through-bore for forming a locking engagement with the connecting pin, which is engaged behind by the locking lugs, thus securing the connection between the handle and shaft in one direction of force. However, since the pin with the locking lugs protrudes from the housing of the handle, inadvertent release of the locking connection during use is possible.

[0007] DE 103 57 104 A1 discloses a locking connection in which elastic tongues with engagement elements at the free end are provided as locking elements on the handle or the shaft insert. These engagement elements can engage with corresponding recesses or projections on the shaft insert or the handle. An axially displaceable locking sleeve, which acts as a locking element to maintain the engagement of the elastic tongues with the recesses or projections in a secured position, is held in the secured position by spring force.

[0008] DE 20 2004 019 174 U1 relates to a surgical instrument in which the handle can be connected to the proximal end of the shaft by means of an elastic snap connection. The shaft has two longitudinal slots at its proximal end. These slots contain locking recesses at the transition from a distal section of constant width to a proximal section that widens toward the proximal end. The handle has a receiving sleeve into which the proximal end of the shaft can be inserted, with a locking pin protruding from the receiving sleeve engaging one of the locking recesses. However, to secure this snap connection, an additional pin is required, which engages a transverse recess at the proximal end of the shaft.

[0009] Another coupling mechanism for detachably connecting the shaft and handle is known from EP 1 889 578 B1. The coupling mechanism is designed as a combined clamping and locking device, wherein a conical proximal end of the shaft is clamped in a correspondingly tapered counter-cone of a sleeve, which is mounted for axial displacement in a receiving bore in the handle. A locking element is mounted in the housing of the handle, transverse to the receiving bore, and is displaceable against the force of a spring element. The locking element consists of a locking member with a keyhole-shaped through-bore in cross-section for receiving the sleeve with the clamped proximal shaft end.The shaft is secured via two recesses in the proximal end of the shaft and two recesses in the sleeve, each of which is congruent with the locking element. The locking element engages into these recesses, securing the sleeve and shaft against axial displacement in the handle and also preventing rotation of the shaft. However, this locking connection is subject to play, as a certain amount of play must always be present between the locking element and its guide, as well as between the locking element and the recess in the sleeve, to ensure proper function in all conceivable tolerance ranges.

[0010] DE 100 64 623 CI describes a spring-loaded locking element for securing a bayonet connection between the distal end of the shaft and a pliers head at the tool tip. This locking element is mounted at the proximal end of the shaft in the handle in a bore running transversely to the shaft. The locking element has a keyhole-shaped through-bore with a round upper passage area and a narrow lower grip area. The drawbar has an engagement area with a rotationally asymmetrical, e.g., rectangular cross-section. When assembled, this engagement area is non-rotatably but longitudinally displaceably received in the grip area of ​​the locking element.

[0011] Based on this prior art, it is the object of the present invention to provide a surgical instrument with an improved coupling device for the releasable connection of shaft and handle.

[0012] This object is achieved by a surgical instrument having the features of claim 1.

[0013] Further developments are set out in the subclaims.

[0014] According to a first embodiment, a surgical instrument according to the invention has a hollow shaft which defines a longitudinal axis A of the surgical instrument, a handle arranged at the proximal end of the shaft, i.e. near the operator during use, and a force transmission element mounted in the shaft, which is connected to a tool on the distal side, i.e. at the end farthest from the operator, and to the handle on the proximal side. The surgical instrument has a coupling device for releasably connecting the shaft and the handle, which coupling device is designed as a locking device with a locking element which is movable between a locking position in which the locking element engages with at least one recess at the proximal end of the shaft, and a release position in which the locking element does not engage with the recess.According to the invention, the locking element has at least one wedge-like engagement portion having an engagement plane E, the length of which along the longitudinal axis A corresponds to a length of the recess along the longitudinal axis A, so that the wedge-like engagement portion is received in the recess up to the engagement plane in the locking position.

[0015] This locking device of a surgical instrument according to the invention reduces the play between the handle and shaft components because the wedge-like engagement section of the locking element compensates for tolerance differences due to its contour. "Wedge-like" is understood to mean a shape of the engagement section in which, like a wedge, two opposite side surfaces extending from a rectangular base surface are not parallel but converge towards one another, so that the distance between the side surfaces decreases over the height. However, the locking element or the engagement section of the locking element is not limited to the shape of a wedge, in which two opposite side surfaces starting from the rectangular base surface meet at a common edge, so that the wedge is triangular in profile.Alternatively, the shape of the wedge-like engagement section can also have a basic shape that deviates from the rectangular shape, as long as it has two parallel sides, from which the two side surfaces facing away from each other extend towards each other so that, like a wedge, the distance between the side surfaces decreases over the height. Furthermore, a "wedge-like" shape can also be a truncated wedge shape, in which the side surfaces do not converge at a common edge and which is created when the tip of a wedge is cut off with the edge. Furthermore, the two side surfaces of the wedge-like engagement section that converge can be designed with different inclination and profile. The side surfaces can be designed as flat surfaces with the same inclination so that the distance between the side surfaces decreases proportionally over the height.In principle, however, it is also conceivable for the two side surfaces to have a different inclination and / or for the inclination to vary over the height, so that at least one side surface can also be stepped or curved. Consequently, it is possible that the inclination of the converging side surfaces of the wedge-like engagement section is not constant over the height, so that the distance between the side surfaces does not decrease proportionally over the height.

[0016] In order to allow rotation of the shaft relative to the handle during use of the surgical instrument, the surgical instrument according to the invention can, in a preferred embodiment, have a rotary handle part that is rotatably mounted on the handle about the longitudinal axis A. In this advantageous embodiment, it is provided that the rotary handle part has the locking device for releasably connecting the handle to the shaft. The rotatability of the shaft is provided by the mounting of the rotary handle part on the handle, so that the locking engagement of the locking device with the shaft in the rotary handle part does not require rotatability and can therefore be designed to be non-rotatable. The non-rotatable connectability between the shaft and the rotary handle part contributes to reducing the axial play at the interface between the handle and the rotatable shaft.

[0017] In a further embodiment of the surgical instrument according to the invention, the rotary handle part, as part of the locking device, can have a receiving bore that extends along the longitudinal axis A and is designed to receive the proximal end of the shaft. Furthermore, the locking device in the rotary handle part can have a guide bore whose guide axis B runs in the rotary handle part transversely to the receiving bore, preferably at right angles to the longitudinal axis A. The locking element is arranged in this guide bore so as to be movable along the guide axis B.

[0018] In a preferred embodiment of the surgical instrument according to the invention, the wedge-shaped engagement section has a trapezoidal profile, which, corresponding to a trapezoidal shape, has a longer base side and a shorter upper side parallel thereto, which are connected by the non-parallel side surfaces. The length of the base side is greater and the length of the upper side is shorter than the length of the recess at the proximal shaft end, so that the engagement plane E of the wedge-shaped engagement section lies in the area between the longer base side and the shorter upper side of the trapezoidal profile.

[0019] A further embodiment of the surgical instrument according to the invention provides that the locking element is arranged in the guide bore such that the longer base side points away from the shaft and the trapezoidal profile lies in a plane spanned by the longitudinal axis A and the guide axis B or runs parallel thereto.

[0020] Particularly preferably, in a further embodiment of the surgical instrument according to the invention, the trapezoidal profile of the wedge-like engagement section can have a rectangular trapezoidal shape, wherein the side surface which represents the trapezoidal leg running at right angles to the base side and the top side defines a guide side which - like the non-converging side surfaces of the wedge-like engagement element - supports linear guidance of the locking element in the guide bore along the guide axis B. To further reduce the play between the handle and the shaft, a further embodiment of the surgical instrument according to the invention can provide that the locking device has a spring element by means of which the locking element is pretensioned in the direction of the locking position.

[0021] In a further embodiment of the surgical instrument according to the invention, such a spring element can be arranged between the base side of the engagement portion of the locking element and a bottom of the guide bore.

[0022] In order to transfer the locking element from the locking position to the release position for releasing the locking engagement with the shaft, the locking element in a further embodiment of the surgical instrument according to the invention can have an actuating section which can be designed differently depending on the design of the locking element.

[0023] In a preferred embodiment of the surgical instrument according to the invention, the locking element can have, in addition to the engagement portion, a through-bore for the shaft and an actuating portion, wherein the through-bore is arranged between the actuating portion and the wedge-like engagement portion. The through-bore can, for example, be cylindrical or keyhole-shaped in cross-section. Regardless of the shape of the through-bore, such a locking element with engagement portion, through-bore, and actuating portion can have a trapezoidal profile overall, i.e., the actuating portion can also have a trapezoidal profile that complements the trapezoidal profile of the engagement portion to form the overall trapezoidal shape of the locking element.Furthermore, a print head can be arranged on the actuating section, or the actuating section can be designed as a print head to facilitate the pressure actuation of the locking element along the guide axis B to release the locking engagement. In the locking position, the print head can preferably be located in a position in the guide bore in which it can be easily reached by an operator without protruding from the guide bore, in order to avoid unintentional release of the locking engagement.

[0024] In principle, however, it is also possible for the locking element, in an alternative embodiment to a locking element with a through-bore, to have an actuating section that extends from the wedge-like engagement section substantially at right angles to the longitudinal axis A and the guide axis B. Such an actuating section can extend in the manner of a slider into a guide groove running parallel to the guide bore, so that the locking element can be actuated to release the locking engagement by moving parallel to the guide bore.

[0025] Further embodiments, as well as some of the advantages associated with these and other embodiments, will become clearer and more easily understood from the following detailed description with reference to the accompanying figures. Items or parts thereof that are substantially the same or similar may be provided with the same reference numerals. The figures are merely a schematic representation of one embodiment of the invention.

[0026] Showing:

[0027] Fig. 1 is a schematic side view of a partially disassembled surgical instrument according to the invention,

[0028] Fig. 2 is a schematic longitudinal sectional detail view of a surgical instrument according to the invention with the locking device in the locking position,

[0029] Fig. 3 is a schematic longitudinal sectional detail view of the surgical instrument according to the invention from Fig. 2 with the locking device in the release position,

[0030] Fig. 4 is a perspective schematic detailed view of the locking element of the surgical instrument according to the invention from Figs. 2 and 3,

[0031] Fig. 5 is a schematic side view of a locking element with a pressure head according to a further embodiment of the surgical instrument according to the invention, Fig. 6 is a schematic side view of a locking element with an alternatively shaped actuating section according to a further embodiment of the surgical instrument according to the invention,

[0032] Fig. 7 is a schematic front view of a locking element with an alternatively shaped through-bore according to a further embodiment of the surgical instrument according to the invention,

[0033] Fig. 8 is a perspective schematic detailed view of a locking element without a through-bore and with an alternatively designed actuating section according to a further embodiment of the surgical instrument according to the invention.

[0034] The invention relates to a surgical instrument equipped with a low-play coupling device for detachably connecting the shaft and handle. Fig. 1 shows, by way of example, a surgical instrument 100 having a hollow outer shaft or shaft 1 defining a longitudinal axis A. At the distal end 1.3 of the shaft 1, a surgical tool 7 is arranged, which is connected to a rod-shaped force transmission element 6, also called a pull rod, which is mounted in the shaft 1 and extends through the shaft 1. At the proximal end 1.1 of the shaft 1, a handle 5 is arranged, which in this example has a stationary handle part 5.3 and a movable handle part 5.2, which is brought into operative connection with the force transmission element 6 for actuating the tool 7.For the detachable connection of the shaft 1 and the handle 5, the surgical instrument 100 according to the invention has a locking device 10 as a coupling device, which in the particularly advantageous embodiment shown by way of example in Figures 1 to 3 is accommodated in a rotary handle part 2, which is mounted on the handle 5 so as to be rotatable about the longitudinal axis A for the rotation of the shaft 1.

[0035] For the detachable connection of the handle 5 to the proximal end 1.1 of the shaft 1, the locking device has a locking element 3 which can be moved between a locking position shown in Fig. 2, in which the locking element 3 engages with a recess 1.2 at the proximal end 1.1 of the shaft 1, and a release position shown in Fig. 3, in which the locking element 3 does not engage with the recess 1.2, so that the shaft 1 can be detached from the handle 5 or joined thereto. According to the invention, the locking element 3 has a wedge-like engagement section 3.2 which, at an engagement plane E parallel to the longitudinal axis A, has a length which corresponds to the length of the recess 1.2 parallel to the longitudinal axis A, so that the engagement section 3.2 is received in the recess 1.2 up to the engagement plane E in the locking position. In the locking position, the shaft 1 is due to the wedge-like engagement section 3.2 of the locking element 3 is fixed against axial displacement in the rotary handle part 2, which is rotatably mounted on the handle 5.

[0036] The position of the engagement plane E in relation to the height of the engagement section 3.2 and thus the vertical position of the locking element 3 in relation to the shaft 1 varies depending on the dimensions of the recess 1.2 and the inclination of the wedge-like engagement section 3.2 - exaggerated for clarity in Figures 2 to 8. This advantageously compensates for manufacturing tolerances and thus reduces or even prevents axial play between the connecting partners, shaft and handle 5 or rotary handle part 2. To secure the shaft 3 by means of the locking element 3, the locking device 10 in the illustrated embodiment has two recesses 1.2 formed diametrically in the proximal end 1.1 of the shaft 1, wherein the locking element 3 engages with its engagement section 3.2 in one of the two recesses 1.2 in a locking manner. In principle, only a recess 1.2 at the proximal end 1 would be required to create the locking engagement.1 of the shaft 1 is required, however, the locking engagement can then only take place in a single rotational positioning of the shaft 1 if the circumferential position of the recess 1.2 corresponds to the position of the engagement section 3.2 of the locking element 3. With two recesses 1.2, the engagement can accordingly take place in two rotational positions of the shaft 1. Regardless of whether the shaft has one or two or more recesses 1.2, the shaft 1 is not only fixed in the axial direction by the locking element 3 without play, but is also connected to the rotary handle part 2 in a rotationally fixed manner. For this purpose, the width of the locking element 3 can correspond to the width of the recess 1.2.

[0037] In the example of a locking device 10 of a surgical instrument 100 according to the invention shown in Figs. 2 and 3, a receiving bore 2.1, which is open on the distal side and runs along the longitudinal axis A, is formed in the rotary handle part 2 for receiving the proximal end 1.1 of the shaft 1. The rotary handle part 2 is rotatably mounted on the handle 5, of which only a portion is shown in Figs. 2 and 3 with a radially inwardly projecting collar 5.1, which is in rotatable engagement with a flange portion 2.2 of the rotary handle part 2, which is offset by a neck portion 2.5. This schematically simplified representation of the rotatable mounting of the rotary handle part 2 on the handle 5 is to be understood only as an example and is in no way intended to represent a limitation. Technical solutions for the rotatable mounting of a component such as the rotary handle part 2 on a second component such as the handle 5 are known. For example, the flange portion 2.2, unlike the illustration, may be designed as a threaded ring separate from the rest of the rotary handle part 2. The rotary handle part 2 then has a corresponding counter thread on the neck section 2.5. During assembly, the collar 5.1 of the handle 5 is placed onto the neck section 2.5, then the threaded ring is screwed on and, after the play has been adjusted, is connected to the neck section 2.5 in a rotationally fixed manner, e.g. by welding or glue. The locking element 3, which is movable between the locked position and the release position and is also shown enlarged in Fig. 4, is guided in a guide bore 2.3, the guide axis B of which runs transversely to the receiving bore 2.1, here at right angles to the longitudinal axis A. In the example shown in Figs. 2 and 3, the locking element 3 is operatively connected to a spring element 4 supported on the bottom 2.4 of the guide bore 2.3 such that the locking element 3 is preloaded in the direction of the locked position. This creates the wedge-like engagement section 3.2 in the locked position, as can be seen in Fig. 2, is pressed into one of the recesses 1.2. To transfer the locking element 3 into the release position (Fig. 3), an actuating force F, represented by the block arrow, directed against the force of the spring element 4 and acting in the direction of the guide axis B, must be applied to the locking element 3 in order to press the engagement section 3.2 out of the recess 1.2 against the spring force. In the present example with the locking element 3, which is also shown in Fig. 4, the release position is reached when the shaft 1 is aligned with a cylindrical through-bore 3.1 formed in the locking element 3 between the wedge-like engagement section 3.2 and an actuating section 3.3. This actuating section 3.3 for actuating the locking element 3 by means of pressure from above extends along or parallel to the guide axis B. The concentric position of the longitudinal axis A with the through hole 3 shown in Fig. 4.1 therefore refers to the release position of the locking element 3. In the locking position, the position of the longitudinal axis A would be further down relative to the locking element 3, e.g. in the lower area of ​​the through hole 3.1.

[0038] The same applies to the variants of a locking element 3 shown in Figs. 5 and 6, which also have a cylindrical through-bore 3.1 for the shaft 1. The variant of a locking element 3 in Fig. 7 also has a through-bore 3.1, but which has a keyhole-shaped cross-section with an upper round area and a lower narrow area. The upper round area of ​​the keyhole-shaped through-bore 3.1 allows the passage of the shaft 1 for assembling or disassembling the instrument 100 when the locking element 3 is arranged in the release position. As soon as the recesses 1.2 formed in the proximal end 1.1 of the shaft 1 enter the through-bore 3.1, the locking element 3 is pressed upwards into the locking position by the spring element 4, whereby the proximal shaft end 1.1 enters the lower narrow area of ​​the keyhole-shaped through-bore 3.1 at the level of the recess 1.2.The variant of the locking element 3 shown in Fig. 8, however, has an actuating section 3.3 but no through-bore 3.1. This alternative actuating section 3.3 extends perpendicular to the guide axis B (as well as perpendicular to the longitudinal axis A) from the wedge-like engagement section 3.2, so that actuation of the locking element 3 to release the locking engagement can occur parallel to the guide bore 2.3 if the actuating section 3.3 extends through a parallel guide groove (not shown).

[0039] In each variant, the locking element 3 has the wedge-like engagement section 3.2, which allows for play-free engagement with the shaft 1. While a wedge is generally understood to be a body in which two side surfaces converge at an acute angle, a wedge-like shape is preferably understood to be a prismatic body whose geometric base is a trapezoid, preferably a right-angled trapezoid. In other words, the wedge-like engagement section 3.2 has a trapezoidal profile, with the locking element 3 being arranged in the guide bore 2.3 such that the trapezoidal profile lies in a plane spanned by the longitudinal axis A and the guide axis B or runs parallel to it.

[0040] The trapezoidal profile of the engagement section 3.2 is particularly clearly visible in the side views of Fig. 5 and 6 - however, the following explanations also apply, with appropriate adaptations, to the other embodiments shown in Fig. 2 to 4, 7 and 8. The trapezoidal profile of the engagement section 3.2 is defined by a longer base side as the base side 3.2.1 and a shorter base side as the head side 3.2.2, whereby the base side 3.2.1 is longer than the recess 1.2 in the proximal end 1.1 of the shaft 1 along the longitudinal axis A. The head side 3.2.2 is shorter than the recess 1.2, so that the engagement plane E (cf. Fig. 2 and 3), whose length corresponds to the length of the recess 1.2, lies between the base side 3.2.1 and the head side 3.2.2 of the wedge-like engagement section 3.2.

[0041] In the locking element 3 in Fig. 5 and also Figs. 2 to 4 and 7, not only the engagement section 3.2 has a trapezoidal profile, but also the actuating section 3.3, so that the locking element 3, apart from any print head 3.4 mounted on the head side 3.2.4, also has a trapezoidal profile. The locking element 3 from Fig. 6 also has an engagement section 3.2 with a trapezoidal profile, but the actuating section 3.3 has a rectangular profile, so that the head side 3.2.4 can also serve as a print head. In the examples shown, the trapezoidal profile of the wedge-like engagement section 3.2 has a right-angled trapezoidal shape; however, the engagement section can have a profile that deviates from the right-angled trapezoidal shape, unlike the examples shown. Due to the preferred rectangular trapezoidal shape, one side surface is advantageously used as a guide side 3.2.3, which is defined by the trapezoidal leg running perpendicular to the base side 3.2.1 and the head side 3.2.2. The guide side 3.2.3 supports the linear guidance of the locking element 3 in the guide bore 2.3. The other side surface is defined by the non-perpendicular trapezoidal leg as an inclined side 3.2.5, which provides the adaptability of the engagement plane E to the length of the recess 1.2.

[0042] In principle, the inventive arrangement of a wedge-like locking element 3 for the axial fixation of a shaft 1 is not limited to the rotary handle part 2. Alternatively, in a surgical instrument according to the invention, a locking device can also be arranged in the handle itself, for example, if no rotation of the shaft relative to the handle is intended. Such a surgical instrument, also according to the invention, is not shown, but can be transferred from the examples with the rotary handle part: For the arrangement of the wedge-like locking element for the play-free axial fixation of the shaft in the handle, the receiving bore for receiving the proximal shaft end is provided in the housing of the handle or a sleeve arranged there. Accordingly, the guide bore for the displaceable wedge-like locking element is also formed in the housing of the handle.

[0043] The present invention provides a surgical instrument 100 comprising a hollow shaft 1 defining a longitudinal axis A, a handle 5 arranged at the proximal end 1.1 of the shaft 1, and a force transmission element 6 mounted in the shaft 1, which is connected to a tool 7 on the distal side and to the handle 5 on the proximal side. The surgical instrument 100 comprises a coupling device for releasably connecting the shaft 1 and the handle 5, wherein the coupling device is a locking device 10 with a locking element 3 that is movable between a locking position, in which the locking element 3 engages with at least one recess 1.2 at the proximal end 1.1 of the shaft 1, and a release position, in which the locking element 3 does not engage with the recess 1.2. The locking element 3 has at least one wedge-like engagement section 3.2 with an engagement plane E, the length of which corresponds to a length of the recess 1.2 along the longitudinal axis A, so that the engagement section 3.2, in the locking position, is received in the recess 1.2 up to the engagement plane E. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into further meaningful combinations. LIST OF REFERENCE SYMBOLS.

[0044] 1 shaft

[0045] 1.1 Proximal end

[0046] 1.2 Recess

[0047] 1.3 Distal end

[0048] 2 rotary handle part

[0049] 2.1 Mounting hole

[0050] 2.2 Flange section

[0051] 2.3 Guide hole

[0052] 2.4 Bottom of the guide hole

[0053] 2.5 Neck section

[0054] 3 locking element

[0055] 3.1 Through hole

[0056] 3.2 Intervention section

[0057] 3.2.1 Base page

[0058] 3.2.2 Top

[0059] 3.2.3 Guide side

[0060] 3.2.4 Header

[0061] 3.2.5 Inclined side

[0062] 3.3 Operating section

[0063] 3.4 Print head

[0064] 4 spring element

[0065] 5 Handle

[0066] 5.1 Collar

[0067] 6 Actuating element

[0068] 7 Tools

[0069] 10 locking device

[0070] 100 Surgical Instruments

[0071] A Longitudinal axis

[0072] B Guide axis

[0073] E Intervention level

[0074] F Actuating force

Claims

PATENT CLAIMS E Surgical instrument (100) comprising a hollow shaft (1) defining a longitudinal axis (A), a handle (5) arranged at the proximal end (1.1) of the shaft (1), and a force transmission element (6) mounted in the shaft (1), which is connected to a tool (7) on the distal side and to the handle (5) on the proximal side, wherein the surgical instrument (100) comprises a coupling device for releasably connecting the shaft (1) and the handle (5), and wherein the coupling device is a locking device (10) with a locking element (3) which is movable between a locking position in which the locking element (3) engages with at least one recess (1.2) at the proximal end (1.1) of the shaft (1), and a release position in which the locking element (3) does not engage with the recess (1.2), characterized characterized in that the locking element (3) has at least one wedge-like engagement section (3.2) with an engagement plane (E) whose length corresponds to a length of the recess (1.2) along the longitudinal axis (A), so that the engagement section (3.2) is received in the recess (1.2) up to the engagement plane (E) in the latching position.

2. Surgical instrument (100) according to claim 1, characterized in that the surgical instrument (100) has a rotary handle part (2) which is mounted on the handle (5) so as to be rotatable about the longitudinal axis (A), wherein the rotary handle part (2) has the locking device (10) for the releasable connection of the handle (5) to the shaft (1). Surgical instrument (100) according to claim 2, characterized in that the locking device (10) in the rotary handle part (2) - a receiving bore (2.1) extending along the longitudinal axis (A) and designed to receive the proximal end (1.1) of the shaft (1), and - has a guide bore (2.3) whose guide axis (B) runs in the rotary handle part (2) transversely to the receiving bore (2.1), preferably at right angles to the longitudinal axis (A), wherein the locking element (3) is arranged in the guide bore (2.3) so as to be movable along the guide axis (B). Surgical instrument (100) according to at least one of claims 1 to 3, characterized in that the wedge-like engagement section (3.2) has a trapezoidal profile with a longer base side (3.2.1) and a shorter upper side (3.2.2) parallel thereto, wherein a length of the base side (3.2.1) is greater than the length of the recess (1.2) and a length of the upper side (3.2.2) is smaller than the length of the recess (1.2), so that the engagement plane (E) lies between the base side (3.2.1) and the upper side (3.2.2) of the wedge-like engagement section (3.2).Surgical instrument (100) according to claim 4, characterized in that the trapezoidal profile of the wedge-like engagement section (3.2) has a rectangular trapezoidal shape, wherein a trapezoidal leg extending at right angles to the base side (3.2.1) and the upper side (3.2.2) defines a guide side (3.2.3). Surgical instrument (100) according to claim 4 or 5, characterized in that the locking element (3) is arranged in the guide bore (2.3) such that the base side (3.2.1) points away from the shaft (1) and the trapezoidal profile lies in a plane spanned by the longitudinal axis (A) and the guide axis (B) or runs parallel thereto. Surgical instrument (100) according to at least one of claims 1 to 6, characterized in that the locking device (10) has a spring element (4), via which the locking element (3) is pretensioned in the direction of the locking position. Surgical instrument (100) according to claim 7, characterized in that the spring element (4) is arranged between the base side (3.2.1) of the engagement section (3.2) of the locking element (3) and a bottom (2.4) of the guide bore (2.3). Surgical instrument (100) according to at least one of claims 1 to 8, characterized in that the locking element (3) has a through-bore (3.1) for the shaft (1) and an actuating section (3.3), wherein the through-bore (3.1) is arranged between the actuating section (3.3) and the wedge-like engagement section (3.2), wherein preferably - the through hole (3.1) is cylindrical or keyhole-shaped in cross-section, and / or - the locking element (3) has a trapezoidal profile, and / or - a pressure head (3.4) is arranged on the actuating section (3.3) or the actuating section (3.3) is designed as a pressure head (3.4); Surgical instrument (100) according to at least one of claims 3 to 8, characterized in that the locking element (3) has an actuating section (3.3) which extends from the wedge-like engagement section (3.2) substantially at right angles to the longitudinal axis (A) and the guide axis (B).

Images