Shaft coupling and related mounting method

Abstract

To provide a shaft coupling for removably connecting a circular cylindrical shaft of medical equipment to a circular cylindrical reception part of a housing which holds an operation element for unlocking the shaft coupling such as a motor handpiece of the medical equipment.SOLUTION: A shaft coupling has at least one engaging body which is radially movably received by a guide opening of a circular cylindrical reception part and can be fixed in a lock posture that shape-fittingly engages a coupling recess of a shaft by a lock body movable in an axial direction at a first functional position. An engaging position of the engaging body can be unlocked by unlocking the coupling and moving the engaging body to a second functional position where the engaging body is movable outward in a radial direction away from engagement with the shaft along the axial direction against force of a compression spring.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a shaft coupling, in particular, a shaft coupling for one or more medical motor handpieces having a removable shaft carrying a motor-driven end effector.

[0002] In modern minimally invasive surgery, for example, in arthroscopic procedures, spinal surgery, the treatment of bone and cartilage in similar orthopedic / surgical treatments, and the treatment of organic matter in neurosurgery, motor handpieces for operating tools / instruments are used. Tools such as End end mills, rotary cutters, polishing heads, etc. End The effector is preferably attached to the distal end of the shaft of the tool / instrument. Such a motor handpiece having an interchangeable medical tool is shown in Document 10 2012 108 264 A1, D E 103 11 455 B3, and US5,893,851B. The coupling of the coaxial drive shaft portion is shown in Document US6,062,575B and US2017 / 0071608A1, in which latter document, the shaft for receiving the tool can be fixed to the handpiece via a bayonet connection. From Document DE 10 2015 110 415A1, a surgical handle for receiving the handpiece shaft without rotation is known, and a shaft coupling according to the preamble of claim 1 is provided. Such a shaft coupling is generally also known from Document US5,522,669. End Housing part of the housing

Figure 1

Figure 2

Figure 3

[0003] Depending on the purpose of use and the intended tool speed, a hydraulic, pneumatic, or electric motor drive unit is provided as the tool drive unit, and this tool drive unit is operatively connected to the tool head (

Figure 4

[0004] That is, since the components and mechanisms necessary for driving the end effector and controlling additional functions must be housed within a very limited radial space, the configuration of such a motor handpiece becomes very complex. Furthermore, the outer diameter of the handpiece is restricted in order to provide a good operating feel, and the central part of the handpiece is required for the drive train and, in some cases, the deployment mechanism for the end effector, so that only a very small radial installation space remains for accommodating the technical mimics for driving additional functions.

[0005] This problem is exacerbated by the fact that it is often desirable to be able to remove the shaft from the motor handpiece with a very simple operation, and here too, an operating mechanism should be provided that is as simple as possible and that the operator can operate intuitively and safely.

Summary of the Invention

[0006] Accordingly, the present disclosure is based on the problem of creating a shaft coupling that enables two coaxial cylindrical parts to be detachably connected with a minimum radial installation space and separated with a very simple operation, which is particularly suitable for connecting the shaft of a motor-driven end effector to a motor handpiece. A further problem is to provide a simple method of attaching such a shaft coupling.

[0007] This problem is solved by the features of claim 1 with respect to the shaft coupling and by the features of claim 10 with respect to the attachment method.

[0008] The special feature of the shaft coupling lies in the fact that all the necessary components can be accommodated in a very narrow radially installed space outside the cylindrical receiving part of the housing, such as the motor handpiece of a medical instrument. The locking body is configured as a locking sleeve guided outside the cylindrical receiving part together with a compression spring, so that even with a thin wall thickness, sufficiently good stability is imparted. The presence of a follower tongue on the side opposite to the shaft makes it possible to bridge a considerable axial distance to the operating element of the shaft coupling, which is well specified for operating purposes, for example, in the motor handpiece of a medical instrument. At the same time, at least one follower tongue has the function of fixing the locking sleeve in a specific rotational position and guiding it axially. Therefore, by simple assembly, the locking sleeve can be arranged or screwed outside the cylindrical receiving part in the first rotational position, and the locking sleeve can be fixed so as not to rotate in the second rotational position. The fact that the locking sleeve aligns with the guide opening only in the first rotational position of the locking sleeve and has a number of mounting recesses corresponding to the number of locking bodies means that at least one locking body can be inserted without loading the compression spring of the locking sleeve. This is because the mounting recesses are effective only in the first rotational position of the locking sleeve and lose their function in the second rotational position. This results in a special feature that the assembly of the shaft coupling becomes particularly easy, and most of the components of the coupling are protected and safeguarded during assembly.

[0009] The mounting method is the subject of claims 10 to 13.

[0010] Advantageous embodiments and arrangements of the mounting recesses are the subject of claims 8 and 9.

[0011] If at least one mounting recess of the lock sleeve is formed by an axially extending groove provided in the inner shoulder, the manufacture of the lock sleeve is particularly easy, and the groove has a depth sufficient to axially slide the shoulder of the lock sleeve on the corresponding locking body already mounted in the cylindrical receiving part. During assembly, it is only necessary to align the axially extending groove with the locking body that projects slightly from the outer surface of the cylindrical receiving part. The lock sleeve can be advantageously positioned in this rotational position using a follower tongue.

[0012] If at least one locking body is attached only when the lock sleeve is already screwed in, at least one mounting recess is formed by a filling opening assigned to each locking body, and each locking body (90) can be inserted radially through the filling opening into the guide opening of the cylindrical receiving part in the first rotational position of the lock sleeve. Here too, at least one follower tongue can be used to position the lock sleeve in the first rotational position.

[0013] An advantageous further development is the subject of the dependent claims.

[0014] The lock sleeve is

Figure 5

[0015] If at least one follower tongue extends through a corresponding opening provided in the ring flange of the cylindrical receiving part and can be fixed at the contact position on the side wall of the opening by a fitting part that can be inserted radially from the outside in the second rotational position, the lock sleeve can be fixed particularly effectively in its rotational direction. Since the fitting part can be inserted radially from the outside, the assembly is particularly simple. Furthermore, inserting the fitting part radially from the outside has the special advantage that the fitting part can be form-fitted to the side wall of the opening. In this way, only the shape of the fitting part ensures a clear lateral guide of the lock sleeve after insertion.

[0016] Advantageously, the lock sleeve forms, on the inside, two functional parts with different inner diameters that are axially continuous. In this way, the lock sleeve can ensure, by means of a simple manufacturing process of the inner contour, that a plurality of locking bodies spaced apart on the circumference are simultaneously released.

[0017] When at least one follower tongue extends away from the shoulder of the lock sleeve body forming the functional part and the shoulder radially inside the follower tongue forms a contact surface for the compression spring, a particularly good force transmission point or marking point is provided, so that the lock sleeve is effectively fixed against tilting.

[0018] In principle, one locking body and one follower tongue are sufficient for the shaft coupling. However, if a plurality of locking bodies and / or follower tongues are preferably provided evenly spaced apart on the circumference, the shaft coupling will exhibit better functionality.

[0019] If at least one locking body is configured as a ball, the shaft coupling can be moved particularly easily.

Brief Description of the Drawings

[0020] Hereinafter, the present disclosure will be described in more detail with reference to preferred embodiments using the drawings.

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

BEST MODE FOR CARRYING OUT THE INVENTION

[0021] Figure 1 shows a perspective view of a medical hand instrument 1 according to an embodiment of the present disclosure. In this medical hand instrument 1, the shaft coupling according to the present invention can be advantageously used. The medical hand instrument 1 has a medical motor handpiece 2 according to the present disclosure shown in Figures 3 and 4, and the handpiece 2 has a distal handgrip portion 4 coaxially connected to a drive unit 6. A cable for supplying power to the drive unit is indicated by 7.

[0022] Furthermore, the hand tool 1 comprises a distal tool (end effector / effector part) 8 which can be connected to or detached from the motor handpiece 2, in particular the handgrip part 4, via a (tool) shaft 10. The tool 8 may be configured, for example, as a milling cutter, a drill or a polishing head. The shaft coupling device provided for this purpose will be described in detail below. However, first, the design of the hand tool will be described in more detail.

[0023] When the shaft 10 is connected to the handgrip part 4, torque is transmitted from the drive unit 6 to the tool 8 via a torque transmission train arranged within the hand tool 1, in particular within the handgrip part 4 and the shaft 10, to rotate the tool 8. One particularity of the hand tool is seen in that the axis of the tool 8 can be inclined or bent relative to the axis of the shaft 10 (as indicated by the arrow C in FIG. 1). That is, the tool 8 and the shaft 10 can be inclined relative to each other such that the longitudinal axis S1 of the tool 8 and the shaft longitudinal axis S2 of the shaft 10 form an angle other than 180° with each other, in particular an angle smaller than 180° (see FIG. 1), as will be explained in more detail below.

[0024] For this purpose, as shown in FIG. 1, the hand tool 1 according to the present disclosure is provided with a sleeve-shaped operating element 12. The operating element 12 is arranged at the distal end of the handgrip part 4 and is rotatable in a first rotational direction A and in a second rotational direction B opposite to the first rotational direction A about the longitudinal axis of the handgrip part. In other words, the motor handpiece 2 comprises the handgrip part 4 and the distally arranged operating element 12, which are coaxially arranged relative to each other, and the operating element 12 is rotatable relative to the handgrip part 4.

[0025] When the tool 8 rotates the operating element 12 in the first rotational direction A from the neutral zero position where it is not inclined with respect to the shaft 10, as shown in FIG. 1, the axis of the tool 8 becomes inclined with respect to the shaft 10. In the hand tool 1 according to the present disclosure, the first rotational direction A is defined as the leftward rotation of the operating element 12 with respect to the hand grip portion 4. In other words, the first rotational direction A corresponds to the clockwise rotation of the operating element 12 in the distal plan view of the tool 8.

[0026] As shown in FIG. 2, in the hand tool 1 according to the present disclosure, the operating element 12 can also be rotated in a second rotational direction B opposite to the first rotational direction A with respect to the hand grip portion 4. That is, the second rotational direction B is defined as the counterclockwise rotation or the rightward rotation of the operating element 12 in the top view of the tool 8. When the operating element 12 is rotated in the second rotational direction B as indicated by the arrow B in FIG. 2, the connection between the tool 8 and the shaft 10 is released. Therefore, as will be described in detail below, by rotating the operating element 12 in the second rotational direction B, tool replacement can be performed easily and quickly.

[0027] Furthermore, as will be described in detail below, the hand tool includes a shaft 10, Exemplarily formed receiving part 、 and a device for removably connecting the shaft tube 50 to the motor handpiece 2. Hereinafter, this device will be referred to as a shaft coupling. The state in which the shaft having the drive shaft 20 inside is removed is shown in FIG. 5. 10 is shown in FIG. 5 with the shaft removed.

[0028] There is no particular need to explain here in detail the mechanism for tilting and deploying the tool axis. The decisive factor of the present disclosure is that, as can be seen in FIG. 6, the relatively complex mechanism required for this purpose is arranged inside the shaft tube 50 having the coupling hollow cylinder 52 or inside the distal housing portion 62 of the hand grip portion 4, leaving or providing a relatively small installation space for the shaft coupling and the mechanism forming its operating element.

[0029] The housing part 62 has a housing carrier body, which, as can be best seen from FIG. 8, Part rotatably supports the operating element 12 and comprises a ring flange 66 having two openings 67 opening radially outward, for a distal receptacle Exemplarily formed as a recess 64 is formed, on which an intermediate sleeve 68 of the housing part 62 additionally supporting the operating element 12 extends. Thus, a first ring space 70 for receiving a lock sleeve body 72 forming a first part of the shaft coupling is left on the distal side of the ring flange 66. This lock sleeve body 72 has two follower arms or follower tongues 74 spaced apart on the circumference, parallel to the axis, having sliding surfaces 81, and can be pressed by a compression spring 73 into the stop positions shown in FIGS. 6 and 7. In this way, the radial dimension of the lock sleeve body 72 is very small. At the same time, the lock sleeve body 72 functions as a carrier for a latch ring (see FIG. 7) indicated by reference numeral 85, which is for a mechanism not described in detail for determining the rotational movement of the operating element 12.

[0030] More specifically, the follower tongue 74 extends from a shoulder 75 of the hollow cylindrical lock sleeve body 72, and the shoulder 75 forms a contact surface 77 (see FIG. 13) for the compression spring 73 which is radially inside the follower tongue 74.

[0031] A further part of the shaft coupling is at least one locking body 90, which is Guide opening Exemplarily pushed into the coupling recess 94 (see FIG. 6) of the coupling hollow cylinder 52 beyond the inner surface of 64 so that Exemplarily Guide opening formed as such 64's Exemplarily corresponding Coupling is received in a form-fitting manner in 92.

[0032] In the illustrated embodiment, four locking bodies 90 are RecessFormed as balls, preferably evenly spaced on the circumference, and these are preferably arranged so as not to be lost, as shown in Fig. 13. Ring groove formed as a cup Radial opening or hole Ring recess Is accommodated within 92, within the hollow cylinder 52 for coupling Exemplarily formed as a slider Annular groove Actuating element Guide opening formed as a hole Cooperates with 94.

[0033] The rotationally symmetric inner contour KI of the lock sleeve body 72 has two functional parts KI1, KI2 with different inner diameters DKI1, DKI2, as best shown in Figs. 7 and 13 (see Fig. 13). The functional part KI2 with the smaller inner diameter DKI2 radially inwardly presses the ball 90 into the 2 or handgrip part Or handgrip part 4 94, and the inner diameter DKI1 of the functional part KI1 is large enough for the ball 90 to move radially outward without being hindered. The compression spring 73 biases the lock sleeve body 72 to the stop position or the biasing position where the functional part KI2 faces the ball 90.

[0034] The operation method and installation method of the shaft coupling will be described below.

[0035] Each of the follower tongues 74 extends through the opening 67 of the ring flange 66 into the second ring space 76 on the proximal side of the ring flange 66. Therefore, this second ring space 76 is radially inside the intermediate sleeve 68 of the housing part 62 and houses the train sleeve 78 that can be operated by the slider 80 via the pull rod 83 (see Fig. 8) and the follower projection 82. The train sleeve 78 can be hooked to the proximal end of the follower tongue 74, and as shown by the arrow ENT in Fig. 4 That is, within the housing part 62 of the embodiment Exemplarily formed receiving part When 80 is slid proximally, the lock sleeve body 72 resists the biasing force of the compression spring 73 and moves towards the motor handpiece 2It is pulled toward the proximal side so that the functional part KI1 faces the ball 90, allowing the ball 90 to move freely radially outward. In this way, the connected state of the shaft 10 shown in FIG. 7 can be released or invalidated.

[0036] To support the disconnection process, a catch - pressing body 98 may be additionally provided. The catch - pressing body 98 is biased by the deployment spring 96 and, in the connected state of the shaft 10 (see FIG. 7), contacts the end face of the coupling hollow cylinder 52 and follows the end - annular collar 95 when the end - annular collar 95 of the coupling hollow cylinder 52 moves beyond the ball 90. Thus, even if the hole is cylindrical throughout, the ball 90 Exemplarily does not fall out of 92. The shallow annular groove 97 of the catch - pressing body 98 fixes the latter so that it does not fall out within the motor handpiece.

[0037] As is clear from the drawings and the above description, the ring spaces 70, 76 are very limited radially due to a predetermined outer diameter related to the handling of the handpiece and the complex mechanism inside the motor handpiece Guide opening formed as such 4. In the case of a motor handpiece for a surgical instrument as shown, the radial dimensions of the ring spaces 70, 76 are at most in the millimeter range. Therefore, the components of the shaft coupling described above are configured to enable a very compact design radially, and this design is supported by the assembly of the components described below.

[0038] FIGS. 8 - 13 show how the individual components are assembled within the motor handpiece 2 Exemplarily formed receiving part inside. FIG. 8 shows the housing part 62 in a fully assembled state except for the intermediate sleeve 68 and the operating element 12, and the slider 80 is already housed within the housing together with the follower projection 82, the pull rod 83, and the train sleeve 78. Receiving part in it.

[0039] In this assembled state, first, the compression spring 73 (see FIG. 10), and then the lock sleeve body 72 are attached to or screwed into the Ring 64 of the housing carrier body. However, the following preliminary precautions are taken so that the ball 90 can be assembled without making the overall length of the compression spring 73 too long or applying a load to the compression spring 73 during assembly.

[0040] As can be seen from the front view of FIG. 9, on the inner surface of the lock sleeve body 72, there is a continuous groove 100 with sufficient depth formed at an angular distance and pattern corresponding to the pattern of the holes Part 62 92 for receiving the balls 90. As shown in FIGS. 10 and 11, the lock sleeve body 72 is first pushed onto the balls 90 that already protrude beyond the outer circumference of the Exemplarily formed as an insert part 64 in a certain rotational direction. The depth of the groove 100 is preferably selected such that, as shown in FIG. 11, the bottom of the groove coincides with the inner diameter DKI2 of the functional part KI2. Fitting part formed as such Fitting part

[0041] Fitting part At this stage, as shown in FIGS. 11 and 12, the follower tongue 74 engages through the corresponding opening 67 provided in the flange 66 of the housing carrier body. The side walls of the opening 67 are shown as 102 and 106. Preferably, the lock sleeve body 72 is positioned and guided in the initial rotational direction by the first side wall 106 of the opening 67. As shown in FIG. 11, the opening 67 extends over a central angle WZ67 that is larger than the central angle WZ74 swept by the follower tongue 74. As soon as the lock sleeve body 72 is screwed in to such an extent that the groove 100 passes over the ball 90 against a slight compression force of the compression spring 73, the lock sleeve body 72 rotates or twists as shown by the arrow S in FIGS. 11 and 12 until the follower tongue 74 hits the second side wall 102 of the opening 67. As a result, the groove 100 also moves circumferentially and is angularly offset from the ball 90, whereby the lock sleeve body 72 is attached to the housing Fitting part ​​It is axially fixed therein. Advantageously, this rotational movement of the lock sleeve body 72 may be used to hook the proximal end of the follower tongue 74 onto the train sleeve 78.

[0042] The follower tongue 74 is specially manufactured to fit precisely, Fitting part Fitting part and is fixed by 104 so as not to rotate on the housing carrier body of the housing part 62. The insert part 104 is inserted like a puzzle piece or like teeth into the other second side wall 106 of the opening 67. Side For the engagement between 104 and the side wall 106, Side 104 does not require additional fastening means, and the accurate and smooth axial guidance of the follower tongue 74 is ensured only by the fitting engagement with the side wall 106 of the opening 67. At the same time, Fitting part it has the special advantage of contacting the second side wall 102 of 104 and the opening 67 at the sliding surface 75.

[0043] Receiving cylinder Between 104 and the Guide opening formed as a hole wall 106 of the opening 67, a pair of precisely fitting engagement surfaces can be made with little effort, for example, in at least the region of the ring flange 66, by forming the engagement profile of the wall 106 using wire electrical discharge machining. Example By forming the engagement profile of the wall 106, it can be made with little effort.

[0044] As can be seen from FIGS. 6, 7 and 13, in this assembled state, the intermediate sleeve 68 can be screwed onto the housing part 62 thereby fixing 104 without the need for further assistance such as an adhesive. Exemplarily formed receiving part This makes assembly and disassembly very easy.

[0045] From the above description, it is clear that the compression spring 73 does not receive additional loads during the assembly of the shaft coupling, and it is possible to keep the axial mounting length of the compression spring 73 compact or small.

[0046] As an alternative to the assembly of the shaft coupling described above, while retaining the above advantages, at least one locking body 90 , i.e., in the illustrated embodiment, a locking body in the form of a ball 90 90 can also be inserted from the outside through the lock sleeve body 72 via the corresponding radial filling port 108. This modification will be described in more detail with reference to FIG. 14, which shows an enlarged front view of the lock sleeve body.

[0047] The lock sleeve body 172 of this modification has a corresponding number of radial holes 120 arranged in the same angular interval pattern instead of the groove 100 described above, and through these radial holes 120, a locking body, shown in dashed lines in FIG. 14 and in the form of, for example, a ball 90, can be filled. Filling from the outside is possible when the lock sleeve body 172 is pushed into 64 in the orientation of FIG. 10 until the radial holes 120 Exemplarily formed receiving part are in the same position as Exemplarily formed receiving part 92. At this time, the lock sleeve body 172 is in the axial position shown in FIG. 7 or FIG. 13 and in the rotational position shown in FIG. 11. In this assembled position, the ball 90 Exemplarily formed as a recess Guide opening can be inserted into 92 of 64, Exemplarily Guide opening formed as a recess and either the radial taper of 92 or the catch - pressing body 98 of 92 prevents the ball 90 from falling inward. Position Drive shaft Of the housing

[0048] In this axial position, the lock sleeve body 172 is rotated until the follower tongue 174 abuts against the first wall of the opening of the ring flange 66, as described in connection with FIGS. 10 - 12. As a result, the radial holes 120 are no longer aligned with the ball 90 and are no longer located on the movement paths of the lock sleeve 172 and the ball 90 that occur when the shaft coupling is disengaged.

[0049] ​​Of course, it is also possible to deviate from the described embodiments without departing from the basic concept of the present disclosure. The application fields of the shaft coupling described above are not limited to medical instruments. The design and mounting techniques of the shaft coupling are useful and applicable when it is necessary to accommodate the parts of the shaft coupling in a very limited radial installation space with a simple operation and minimize the mechanical stress during assembly.

[0050] For example, various changes are possible regarding the number, shape of the locking bodies and the follower tongue.

[0051] Thus, an object of the present disclosure is to provide a shaft coupling for removably connecting a cylindrical shaft of a medical instrument, for example, to a cylindrical receiving portion of a housing carrying an operating element for releasing the lock of the shaft coupling, such as a motor handpiece of a medical instrument. The shaft coupling has at least one locking body, which is received movably in the radial direction in a guide opening of the cylindrical receiving portion and is engaged in a form-fitting manner with a coupling recess of the shaft by an axially movable locking body in a first functional position. Part It can be fixed by a lock. The locking position of the locking body can be released by moving the locking body axially against the force of a compression spring to a second functional position where the coupling is unlocked, the locking body is disengaged from the engagement with the shaft and can move radially outward. In order to accommodate the parts of the shaft coupling in the smallest possible radial installation space and avoid applying stress to the compression spring during assembly, the locking body is configured as a locking sleeve guided outside the cylindrical receiving portion together with the compression spring, and has at least one follower tongue on the side opposite to the shaft that can be connected to the operating element. By means of the follower tongue, the locking sleeve is screwed onto the outside of the cylindrical receiving portion in a first rotational position and is fixed so as not to rotate in a second rotational position. The locking sleeve has a number of mounting recesses corresponding to the number of locking bodies, and the mounting recesses coincide in the circumferential direction with the guide opening or the locking body only in the first rotational position of the locking sleeve.

[0052] The specification at the time of international filing contains the following content. [1] A shaft coupling for removably connecting a circular cylindrical shaft (52) such as a medical instrument to a circular cylindrical receiving portion (64) of a housing (62) carrying an actuating element (80) for releasing the lock of the shaft coupling, such as a motor handpiece of a medical instrument, at least one locking body (90) that is received radially movably in a guide opening (92) of the circular cylindrical receiving portion (64) and can be fixed in a locking position in which it engages form-fittingly with a coupling recess (94) of the shaft (52) by an axially movable locking body (72) in a first functional position, wherein the locking position of the locking body (90) is released by moving the locking body (72) axially against the force of a compression spring (73) to a second functional position in which the coupling lock is released and the locking body (90) can move radially outward out of engagement with the shaft, and comprising a locking body (90). The locking body is configured as a locking sleeve (72) arranged to be guided outside the circular cylindrical receiving portion (64) together with the compression spring (73), and has at least one follower tongue (74) connectable to the actuating element (80) on the side opposite the shaft (52), and by means of the follower tongue, the locking sleeve (72) can be screwed onto the outside of the circular cylindrical receiving portion in a first rotational position and fixed so as not to rotate in a second rotational position. The locking sleeve (72) has a number of mounting recesses (100; 120) corresponding to the number of the locking bodies (90), and the mounting recesses coincide in circumferential position with the guide opening (92) only in the first rotational position of the locking sleeve (72). A shaft coupling, characterized in that. [2] The shaft coupling according to [1], characterized in that the locking sleeve (72) can be fixed so as not to rotate within the housing (62) in the second rotational position. [3]At least one of said follower tongues (74) extends through a corresponding opening (67) provided in a ring flange (66) of said circular cylindrical receiving portion (64), and in said second rotational position, can be fixed to a contact position on a side wall (102) of said opening (67) by a fitting portion (104) that can be inserted radially from the outside. The shaft coupling according to [2]. [4]The lock sleeve (72) has, on the inside, two axially continuous functional portions (KI1, KI2) having different inner diameters (DKI1, DKI2). The shaft coupling according to any one of [1] to [3]. [5]At least one of said follower tongues (74) extends away from a shoulder (75) of a lock sleeve body (72) forming said functional portion. Said shoulder (75) is radially inside said follower tongue (74) and forms a contact surface (77) for said compression spring (73). The shaft coupling according to [4]. [6]A plurality of locking bodies (90) and / or follower tongues (74) are preferably provided evenly spaced on the circumference. The shaft coupling according to any one of [1] to [5]. [7]At least one of said locking bodies is configured as a ball (90). The shaft coupling according to any one of [1] to [6]. [8]At least one of said mounting recesses of said lock sleeve (72) is formed on the inside by an axially extending groove (100) formed in said shoulder (75). Said groove (100) is deep enough to axially slide said shoulder (75) of said lock sleeve (72) on a corresponding locking body already attached to said cylindrical receiving portion (64). The shaft coupling according to any one of [5] to [7]. [9]At least one of the mounting recesses is formed by filling openings (108, 120) assigned to each locking body (90), and through this filling opening, in the first rotational position of the lock sleeve (72), each locking body (90) can be inserted radially into the guide opening (92) of the cylindrical receiving portion (64). The shaft coupling according to any one of [1] to [7], characterized in that.

[10] A method of attaching parts of the shaft coupling according to any one of [1] to [9], For example, a circular cylindrical shaft (52) of a medical instrument can be detachably connected to a circular cylindrical receiving portion (64) of a housing (62) such as a motor handpiece of a medical instrument, The housing carries an actuating element (80) for releasing the lock of the shaft coupling, The circular cylindrical receiving portion (64) receives at least one locking body (90) that can move radially in the guide opening (92), and can be fixed in a locking posture in which it engages in a form-fitting manner with the coupling recess (94) of the shaft (52) by an axially movable lock body (72) in the first functional position. The locking position of the locking body (90) can be released by moving the lock body (72) axially against the force of the compression spring (73) to a second functional position where the lock of the coupling is released and the locking body (90) can move radially outward out of engagement with the shaft. The lock body is configured as a lock sleeve (72) arranged to be guided outside the circular cylindrical receiving portion (64) together with the compression spring (73), and has at least one follower tongue (74) connectable to the actuating element (80) on the side opposite to the shaft (52). The lock sleeve (72) is screwed onto the outside of the circular cylindrical receiving portion at a first rotational position where the number of mounting recesses (100; 120) corresponding to the number of locking bodies (90) coincides with the circumferential position of the guide opening (92) together with the compression spring (73), and is fixed so as not to rotate at a second rotational position. A mounting method characterized by this.

[11] At least one of the locking bodies (90) is already inserted into the corresponding guide opening (92) before the lock sleeve (72) is screwed in. The lock sleeve (72) having a number of axially extending grooves (100) corresponding to the number of locking bodies (90) provided radially inward is axially pushed on the corresponding locking body (90) at the first rotational position, and then rotated to the second rotational position, and fixed at this rotational position through at least one of the follower tongues (74) by a fitting portion (104) inserted from the outside. The mounting method according to

[10] .

[12] At least one of the locking bodies (90) is inserted into the corresponding radially filling opening (108, 120) after screwing the lock sleeve (72) at the first rotational position. The lock sleeve (72) is then turned to the second rotational position and fixed at this rotational position through at least one of the follower tongues (74) by a fitting portion (104) inserted from the outside. The mounting method according to

[10] .

[13] The fitting piece (104) is radially fixed by an intermediate sleeve (68) screwed to the housing. The mounting method according to

[11] or

[12] , characterized by this.

Explanation of reference numerals

[0053] 1 Hand tool 2 Motor handpiece 4 Hand grip portion 6 Drive unit 7 Cable 8 Tool 10 Shaft S1, S2 Longitudinal axes of 8 and 10 12 Operating element 50 Body 52 Hollow cylinder for coupling 62 In an exemplary embodiment Distal housing part 64 Receiving Actuating element which is 66 Ring flange 67 Opening 68 Intermediate sleeve 70 First ring space 72 Lock In an exemplary embodiment KI1, KI2 Functional parts 73 Compression spring 74 Follower tongue part 75 Shoulder 76 Second ring space 77 Contact surface 78 Train sleeve 80 Locking body which is Slider In an exemplary embodiment, a recess or 81 Sliding surface 82 Follower protrusion 83 Tensile rod 85 Latch ring 90 Guide opening which is Ball In an exemplary embodiment, a ring groove 92 95 Annular collar Hole In an exemplary embodiment 94 Fitting part which is Coupling recess In an exemplary embodiment 96 Exhaust spring 97 Annular groove 98 Catch - pressing body 100 Groove 102 First side wall 104 Mounting recess which is Insert part In an exemplary embodiment 106 Second side wall 108 In an exemplary embodiment Filling opening ​ 120 ​ Mounting recess 172 which is a radial hole Deformation of the lock sleeve body 174 Follower Tongue WZ67 Central Angle WZ74 Central Angle

Claims

1. A shaft coupling for removably connecting a circular cylindrical shaft (10, 12, 52) of a medical device to a circular cylindrical receiving portion (64) of a housing portion (62) of a motor handpiece (2) of the medical device, which carries an actuating element (80) for releasing the lock of the shaft coupling, at least one locking body (90) that is received radially movably in a guide opening (92) of the circular cylindrical receiving portion (64) and can be fixed in a locking position in which it engages in a form-fitting manner with a coupling recess (94) of the shaft (52) by means of an axially movable locking body (72) in a first functional position, wherein the locking position of the locking body (90) is released by moving the locking body (72) axially against the force of a compression spring (73) to a second functional position in which the lock of the shaft coupling is released and the locking body (90) can move radially outward out of engagement with the shaft (52), the locking body (72) is configured as a locking sleeve that is arranged to be guided outside the circular cylindrical receiving portion (64) together with the compression spring (73), and has at least one follower tongue (74) that can be connected to the actuating element (80) on the side opposite the shaft (52), and by means of the follower tongue, the locking body (72) formed as the locking sleeve can be screwed onto the outside of the circular cylindrical receiving portion in a first rotational position and fixed so as not to rotate in a second rotational position, the locking body (72) formed as the locking sleeve has a number of mounting recesses (100; 108, 120) corresponding to the number of the locking bodies (90), and the mounting recesses coincide in circumferential position with the guide opening (92) only in the first rotational position of the locking body (72) formed as the locking sleeve, characterized by a shaft coupling.

2. The locking body (72) formed as the lock sleeve is fixable so as not to rotate within the housing portion (62) in the second rotational position, the shaft coupling according to claim 1.

3. At least one of the follower tongue portions (74) extends through a corresponding opening (67) provided in a ring flange (66) of the circular cylindrical receiving portion (64), and in the second rotational position, is fixable to a contact position on a side wall (102) of the opening (67) by a fitting portion (104) insertable radially from the outside, the shaft coupling according to claim 2.

4. The locking body (72) formed as the lock sleeve has, on the inside, different inner diameters (DKI1, DKI2) and forms two axially continuous functional portions (KI1, KI2), the shaft coupling according to claim 1.

5. At least one of the follower tongue portions (74) extends away from a shoulder portion (75) of a part of the locking body (72) formed as the lock sleeve forming the functional portions (KI1, KI2), The shoulder portion (75) forms a contact surface (77) for the compression spring (73) radially inside the follower tongue portion (74), the shaft coupling according to claim 4.

6. A plurality of the locking bodies (90) and / or the follower tongue portions (74) are provided equally spaced apart on the circumference, the shaft coupling according to claim 1.

7. At least one of the locking bodies (90) is configured as a ball, the shaft coupling according to claim 1.

8. At least one of the mounting recesses (100) of the locking body (72) formed as the lock sleeve is formed on the inside by an axially extending groove (100) formed in the shoulder portion (75), The shaft coupling according to claim 5, wherein the groove (100) has a depth sufficient to axially slide the shoulder (75) of the lock body (72) on the corresponding locking body (90) already attached to the cylindrical receiving portion (64).

9. The shaft coupling according to claim 1, wherein at least one of the mounting recesses (108, 120) is formed by a filling opening (108) or a radial hole (120) assigned to each of the locking bodies (90), and through the filling opening, in the first rotational position of the lock body (72) formed as the lock sleeve, each of the locking bodies (90) can be inserted radially into the guide opening (92) of the cylindrical receiving portion (64).

10. A method of attaching parts of the shaft coupling according to any one of claims 1 to 9, The circular cylindrical shafts (10, 12, 52) of the medical instrument can be detachably connected to the circular cylindrical receiving portion (64) of the housing portion (62) of the motor handpiece (2) of the medical instrument, The housing portion carries an actuating element (80) for releasing the lock of the shaft coupling, The circular cylindrical receiving portion (64) receives at least one locking body (90) that is radially movable in the guide opening (92), and can be fixed in a locking position in which it engages in a form-fitting manner with the coupling recess (94) of the shaft (52) by an axially movable lock body (72) in a first functional position. The locking position of the locking body (90) can be released by moving the lock body (72) axially along against the force of the compression spring (73) to a second functional position where the lock of the shaft coupling is released and the locking body (90) can move radially outward out of engagement with the shaft. The lock body (72) is configured as a lock sleeve that is arranged to be guided outside the circular cylindrical receiving portion (64) together with the compression spring (73), and on the side opposite to the shaft (52), it is provided with at least one follower tongue portion (74) that can be connected to the operating element (80). The lock body (72) formed as the lock sleeve is screwed outside the circular cylindrical receiving portion at a first rotational position where the number of mounting recesses (100; 108, 120) corresponding to the number of the locking bodies (90) coincides with the guide opening (92) in the circumferential direction together with the compression spring (73), and is fixed so as not to rotate at a second rotational position. A mounting method characterized by this.

11. Before the lock body (72) formed as the lock sleeve is screwed in, at least one of the locking bodies (90) is already inserted into the corresponding guide opening (92). The lock body (72) formed as the lock sleeve having a groove (100) extending in the axial direction corresponding to the number of the locking bodies (90) on the radially inner side is axially pushed on the corresponding locking body (90) at the first rotational position, and then rotated to the second rotational position and fixed at this rotational position through at least one of the follower tongue portions (74) by a fitting portion (104) inserted from the outside. The mounting method according to claim 10.

12. After screwing in the lock body (72) formed as the lock sleeve at the first rotational position, at least one of the locking bodies (90) is inserted into the corresponding radial filling opening (108) or radial hole (120). The lock body (72) formed as the lock sleeve is then turned to the second rotational position and fixed at this rotational position through at least one of the follower tongue portions (74) by a fitting portion (104) inserted from the outside. The mounting method according to claim 10.

13. The mounting method according to claim 11, characterized in that the fitting portion (104) is fixed in the radial direction by an intermediate sleeve (68) screwed to the housing portion (62).

Images