SURGICAL TOOL WITH STORAGE

Description

Technical field

[0001] The present disclosure relates to a surgical instrument with storage. Background of the invention

[0002] Surgical tools, such as surgical milling tools or drills, are known from the prior art. These tools have a shank with a proximal and a distal end section, the latter being a working end with an effector. The proximal end section of the tool is coupled to a drive unit within a housing via a coupling structure, ensuring rotational and axial rigidity. This allows the drive unit to transmit a rotational movement to the tool, which then rotates about its longitudinal axis when the device is actively operated. The housing incorporates a fixed rotary bearing to support the tool. The tools are typically interchangeably connected to the housing, allowing the housing to be reused and fitted with different or varied tools. State of the art

[0003] Such a tool is known, for example, from US RE 29 736, where the tool is designed as a surgical drill. The tool shank has a circumferential raceway near its proximal end, in which balls, fixedly held in a multi-part housing, can rotate to support the tool shank relative to the housing. The tool shank is axially displaceable relative to the housing. If the balls are defective, the portion of the housing in which the balls are held must be replaced.

[0004] Furthermore, a surgical instrument with bearings is known from US 9,175,723 B2. In this instrument, the proximal end section is rotatably mounted in a housing shaft by several ball bearings. At its distal end section, the instrument is mounted in the housing shaft by needle bearings. All rotating bearings are fixedly integrated into the housing shaft or the housing.

[0005] Furthermore, WO 2018 / 075 925 A1 shows a system for intramedullary preparations with a tool having a flexible drive shaft having a proximal and a distal end, and a cutting head which is operationally connected to the distal end of the flexible drive shaft.

[0006] This creates the problem that such rotary bearings, which support tools within the housing and are wear parts, are subjected to significant stresses inside the housing, such as corrosion, contamination, and overloading. At the same time, the housings in which the rotary bearings are integrated are used repeatedly. This can lead to damage to the rotary bearings, resulting in a defective condition that requires repair or replacement. During the repair or replacement period, the housing or handpiece cannot be used for its intended purpose, resulting in time and expense for the tool user.

[0007] It is therefore an objective of the invention to increase the availability of a housing with a drive that can be coupled to a surgical tool, with respect to the at least one bearing which supports the tool in the housing. Summary of the invention

[0008] To solve the stated problem, a surgical tool according to claim 1 is provided. That is, a surgical tool, in particular a surgical milling or drilling tool, is provided with a tool shank that has an effector at its distal end section and a coupling structure at its proximal end section. The coupling structure is designed to be optionally coupled to a drive in a rotationally and axially fixed manner in order to transmit rotation of the drive to the tool shank. Furthermore, the surgical tool has at least one rotary bearing, which is provided for rotatably supporting the tool shank on a housing, preferably a handpiece. The rotary bearing is connected to the tool shank to form a unit that, as a whole, can be inserted into the housing for coupling with the drive and withdrawn from the housing for uncoupling from the drive.

[0009] In other words, a surgical tool, in particular a surgical milling or drilling tool, is provided with a tool shank having an effector at its distal end section and a coupling structure at its proximal end section. This coupling structure is designed and adapted to be selectively coupled to a drive housed in a housing (or housing shank), preferably a handpiece, in a rotationally and axially fixed manner, in order to transmit rotation of the drive to the tool shank. For this purpose, at least one rotary bearing is arranged between the tool shank and the housing, preferably a handpiece, for rotatably supporting the tool shank on the housing, preferably a handpiece. According to the invention, the rotary bearing is connected to the tool shank to form a unit that, as a whole, can be inserted into the housing for coupling with the drive and withdrawn from the housing for uncoupling from the drive.

[0010] In other words, a surgical tool, in particular a surgical milling tool, is provided, comprising a tool shank and distal and proximal end sections. The tool is inserted into a housing / handpiece at its proximal end section in a replaceable manner and is coupled to a drive within the housing in a rotationally and axially fixed manner, enabling it to execute the rotational movement generated by the drive about its longitudinal axis. The tool is supported in the housing by at least one bearing / rotary bearing / bearing element. The rotary bearing is detachably connected to the housing, preferably by a snap-fit ​​or plug-in connection, and (axially) fixedly connected to the tool, such that the rotary bearing and the tool shank form a single unit.

[0011] This allows the rotary bearings to be replaced independently of the handpiece or housing, along with the tool itself, and they do not need to be replaced during the housing's service interval. This significantly reduces rotary bearing failure. If a rotary bearing fails, the tool, with its permanently integrated rotary bearing (which is in this case permanently attached to the tool shaft), is replaced, thus ensuring the continued use of the corresponding handpiece. Users can easily and quickly replace the tool with the rotary bearing for the handpiece themselves with each tool change, as needed. This guarantees high availability and reliability of the handpieces. The fact that the rotary bearing can be replaced independently of the handpiece results in cost and / or time savings for the user of the surgical tool according to the invention.

[0012] Preferably, rolling bearings are used as rotary bearings. These bearings have an inner section with a guide, an outer section with a guide, and a cage containing rolling elements located between them. The rolling elements are arranged between the guides of the inner and outer sections. The rolling bearings, particularly ball bearings, are usually ring-shaped and mounted on the tool shank in such a way that the rotary bearing and the tool shank are coaxial. Alternatively, plain bearings without rolling elements between their inner and outer sections can also be used as rotary bearings.

[0013] According to the invention, the rotary bearing is integrally formed with the tool shank, in particular pressed onto the tool shank, so that the tool shank or tool and rotary bearing form an inseparable unit and the tool is preferably a disposable tool.

[0014] If the rotary bearing is integrally formed with the tool shank, it can advantageously be replaced with each tool change, making the tool a single-use tool. One way to permanently connect the rotary bearing to the tool shank is to press the inner bearing section onto the tool shank. In cases where the rotary bearing and tool form a single, inseparable unit, the rotary bearing can achieve improved running characteristics, and no slippage occurs between the rotary bearing and the tool shank. Furthermore, the load-bearing capacity and thus the load-bearing capacity of the rotary bearing are increased.

[0015] Not part of this invention is an alternative embodiment to a rotary bearing integrally formed with the tool, in which the rotary bearing can be formed separately from the tool shank, in particular can be pushed onto the tool shank, so that the tool shank or tool and rotary bearing form a detachable unit.

[0016] The advantage of this design is that the tool is independent of wear on the rotary bearing and can be used multiple times. Furthermore, a user can easily replace the rotary bearing themselves if necessary, for example using a ball bearing magazine.

[0017] In a further embodiment, the tool shank can have at least one radially circumferential, and in particular coaxially and / or thus integrally designed, projection between the proximal and distal end sections for axially securing the rotary bearing. The projection, with its side facing the proximal end section, directly contacts the rotary bearing.

[0018] The projection serves as protection for the rotary bearing and prevents unwanted axial displacement of the rotary bearing towards the distal end section. Such a projection is particularly necessary when the rotary bearing is formed separately from the tool shank, for example, when it is pushed on. Furthermore, if a rolling bearing is used as the rotary bearing, the projection prevents the loss of the rolling elements.

[0019] Preferably, the projection can be conical in the axial direction, with the radial dimension of the projection increasing from the distal end section towards the proximal end section, preferably until the radial dimension of the projection is at least as large as the outer radial dimension of the rotary bearing. Alternatively, the projection can be flat. Furthermore, the projection can be at least as large as its radial dimension corresponds to the radial dimension of an inner bearing section. The larger the projection, the more effectively it secures the rotary bearing.

[0020] Preferably, the tool shank, which is inseparably connected to the rotary bearing, has at least one radially circumferential running groove that accommodates the rotary bearing, so that the running groove is part of the rotary bearing.

[0021] Forming a raceway on the tool shank as part of the rotary bearing is an alternative to pressing the inner bearing section onto the tool shank. With such a raceway, the inner bearing section of the rotary bearing is eliminated, and the rotary bearing is not interchangeable on the tool but can only be replaced when the tool is changed. In the case of a rolling bearing, the rolling elements are mounted directly onto the tool shank along with the outer bearing section. The absence of an inner bearing section offers the advantage that the rotary bearing has one less component that cannot wear or break, thus resulting in a longer service life and increased reliability. The production costs for such a rotary bearing are also lower compared to conventional rotary bearings with an inner bearing section. In this space-optimized design, the rotary bearing is an integral part of the tool.In cases where the raceway takes over the function of the bearing's inner section, the size of the rotary bearing can be reduced compared to a conventional rotary bearing, resulting in slimmer working ends. Alternatively, the load rating of the rotary bearing can be increased, contributing to extended bearing life and stability. A higher load rating also allows for a greater distance between the rotary bearing and the distal end section. Thus, both the size reduction and the increased load rating of the rotary bearing are advantageous for access and visibility when using the surgical instrument.

[0022] Furthermore, the running groove can be formed in the form of a groove-like depression in the outer circumferential surface of the tool shank or as an area between two radially circumferential lips spaced apart from each other in the axial direction, which rise from the outer circumferential surface of the tool shank, for example vertically.

[0023] Such a groove can be easily and cost-effectively machined into the tool shank (e.g., by turning). At the point where the groove is formed, the thickness of the tool shank is less than in the adjacent area. This means the groove can represent a weak point for the tool shank, or at least minimize the tool's load-bearing capacity. Alternatively, the groove can be designed so that two radially circumferential lips rise from the surface of the tool shank, spaced apart along the axial direction of the tool shank. The groove is thus formed in the area enclosed by these two lips. In this case, the tool shank has a constant material thickness radially below the groove and in the axially adjacent area. In any case, the groove must be designed to fulfill the function of guiding an inner bearing section.

[0024] In a preferred embodiment, the rotary bearing has at least one first detent section on its outer circumferential surface, the housing provides a second detent section which interacts with the at least one first detent section, and the first and second detent sections interlock in a detent state and thus contribute to the support of the tool shank relative to the housing.

[0025] The first detent section can be a detent lug, and the second detent section can be a recess, or vice versa. The purpose of this detent connection is to prevent the rotational movement of the drive or tool from being transmitted to the outer bearing section. This prevents the outer bearing section from rotating. When the tool with the fixed rotary bearing is inserted into the housing, the detent lug engages in the designated recess. To release the detent connection between the housing and the bearing, only a pulling force needs to be applied to the tool. This contributes to quick and easy tool installation and removal.

[0026] Furthermore, the rotary bearing can be a single-, double-, or multi-row rotary bearing. In addition, the rotary bearing can also be a single-, double-, or multi-row plain bearing, which, unlike rolling bearings, does not have rolling elements.

[0027] Multi-row rotary bearings have a higher load-bearing capacity and therefore a longer service life and greater durability than single-row rotary bearings. Plain bearings are particularly suitable for low-speed applications (low tool rotation speeds).

[0028] According to the invention, a surgical tool system is further provided with a housing and a surgical tool which can be coupled to a drive in the housing in a rotationally and axially fixed manner in order to take over a rotational movement generated by the drive, and has a rotary bearing on its tool shaft which is fixedly connected to it and which supports the tool relative to the housing. Brief description of the characters

[0029] The following describes in detail embodiments of the surgical instrument according to the invention with reference to the accompanying drawings. The same reference numerals are assigned to identical elements. The embodiments are only examples, and the invention is not limited to them. Fig. 1A shows a surgical tool with a swivel bearing attached to the tool; Fig. 1B is an excerpt from Fig. 1A and shows a rotary bearing and part of a tool shank that supports the rotary bearing; Fig. 2A shows part of a tool shank with a rotary bearing attached to it and with a projection adjacent to the rotary bearing; Fig. 2B shows part of a tool shank with a rotary bearing attached to it and with a modified projection adjacent to the rotary bearing; Fig. 2C shows part of a tool shank with a rotary bearing attached to it and with a further modified projection adjacent to the rotary bearing; Fig. 2D shows part of a tool shank with a rotary bearing attached to it and with a further modified projection adjacent to the rotary bearing; Fig. 3A shows part of a tool shank with a rotary bearing and a running groove designed as a slot; Fig. 3B shows part of a tool shank with a rotary bearing and a running groove formed between two lips; Fig. 4 shows part of a tool shaft with a double bearing Description of the exemplary implementations

[0030] The following are examples of embodiments of the present disclosure based on the accompanying figures.

[0031] Fig. 1A Figure 1 shows a surgical milling tool 1 with a tool shank 2 having a main section 3, an effector 4 at the distal end section, and a coupling structure 6 at the proximal end section. The effector 4 is designed here as a milling cutter, but could also be a drill. The tool shank 2 tapers conically towards its distal end section. The coupling structure 6 is narrower in its radial dimension than the tool shank 2 to allow for easy insertion into a housing or handpiece (not shown). The housing contains a drive (not shown) to which the tool 1 can be coupled via the coupling structure 6 so that it receives a rotational movement generated by the drive. In the event of rotation of the tool 1, a bearing between the tool 1 and the housing is required. According to the invention, a rotary bearing 8 is therefore located on the tool shank 2 and is rigidly connected to it.The rotary bearing 8 is arranged here on or near the central transverse axis of the tool shank 2, but in any case in its main section 3.

[0032] Fig. 1B shows an excerpt from Fig. 1A The rotary bearing 8, which is connected to the tool shank 2 to form a unit, is designed as a ball bearing in this embodiment, but can alternatively also be another type of rolling bearing or a plain bearing. The rotary bearing has an inner bearing section 10, a guide 12 on the inner bearing section, balls (rolling elements) 14 and an outer section 16. In all figures ( Fig. 1A, 1B and Fig. 2A - 2D In the figures where the ball bearing 8 with bearing inner section 10 mounted on the tool shank 2 is shown, the rotary bearing 8 can either be pushed onto the tool shank 2 (releasable connection) or pressed onto it (permanent connection). In the other cases ( Fig. 3A, 3B und Fig. 4 ), in which the ball bearing 8 is mounted on the tool shank 2 without an inner bearing section 10 via a raceway, this raceway is part of the ball bearing 10 and replaces its inner bearing section 10.

[0033] The ball bearing 8, as it is in Fig. 1B The ball bearing 8, as shown, has an axially extending locking lug 18 on its outer circumferential surface. However, it is conceivable that the ball bearing has several locking lugs 18. The locking lugs 18 are designed to engage in corresponding recesses (not shown) in the housing to prevent the outer section 16 of the ball bearing 8 from taking over the rotational movement of the drive and contributing to the bearing between the tool and the housing. The inner bearing section 10 is fixedly connected to the tool shank 2: either the inner bearing section 10 is pushed onto the tool shank 2, thus making the rotary bearing 8 detachable / separate from the tool 1, or the inner bearing section 10 is pressed firmly onto the tool shank 2, so that the tool 1 and the rotary bearing 8 are permanently / integrally connected. In either case, the tool 1 or the tool shank 2 and the ball bearing 8 form a single unit.

[0034] Fig. 2A Figure 1 shows a section of the tool shank 2, which includes the ball bearing 8. A projection 20 adjoins the ball bearing 8 directly towards the distal end section of the tool 1. The projection 20 is designed such that its maximum radial dimension on the side in contact with the ball bearing 8 is equal to the outer radial dimension of the ball bearing 8. In this embodiment, the projection 20 is flange-shaped. When the milling tool 1 is used as intended, the projection 20 serves as a safeguard against unwanted displacement of the rotary bearing towards the effector 4. The projection 20 can protect rotary bearings that are pushed onto the tool shank (thus forming a separate component) and those that are pressed onto it (thus forming an integral component) from slipping towards the effector. Furthermore, the projection 20 prevents the balls 14 from being lost. Thus, the projection 20 provides protection for the ball bearing 8.The projection 20 is integrally formed with the tool shank 2 and contacts the rotary bearing 8 with an end face (facing the proximal end section).

[0035] Fig. 2B Figure 1 shows the projection 20 in an alternative embodiment. Here, the projection 20 is planar and its radial dimension is the same over its entire height and corresponds to the radial dimension of the outer circumference of the ball bearing 8.

[0036] Fig. 2C Figure 1 shows another alternative embodiment of the projection 20. Here, the projection 20 is conically shaped, such that its radial dimension tapers continuously from the radial dimension on the side in contact with the ball bearing 8, which is as large as the outer radial dimension of the ball bearing 8, to a radial dimension at the distal end section that is only slightly larger than the radial dimension of the tool shank 2.

[0037] Fig. 2D Figure 20 shows a modified projection 20 compared to the previously described embodiments. Its radial dimension is only as large as the outer radial dimension of the inner bearing section 10, and thus secures not the entire rotary bearing 8, but only the inner bearing section 10 against axial displacement towards the distal end section. Such a shortened projection compared to the other embodiments can be flange-shaped, planar, or conical.

[0038] Fig. 3A Figure 1 shows a portion of the tool shank 2 with a running groove in the form of a radially circumferential groove 22, which serves as a guide 12 for the balls 14 of the ball bearing 8. The inner bearing section 10 of the ball bearing 8 is therefore unnecessary and omitted. The groove 22 is formed as a recess relative to the outer surface of the tool shank 2, so that the tool shank 2 is narrower at this point than in the remaining main section 3 of the tool shank 2.

[0039] Fig. 3B shows part of the tool shaft 2 with a opposite Fig. 3A An alternative embodiment of the running groove is defined as the area between two radially circumferential lips 24 spaced apart from each other in the axial direction of the tool shank 2. The hummock-shaped lips 24 rise from the outer surface of the tool shank 2 and are designed and spaced apart such that they can accommodate the balls 14 of the rotary bearing 8. Thus, the tool shank 2 has the same thickness at the point of the running groove as in the rest of the main tool shank section 3 and is even reinforced at the level of the two lips 24.

[0040] Although not shown, the tool shank 2 can have several integrally or separately formed rotary bearings 8 and thus also several identically or differently formed projections 20 or running grooves.

[0041] Fig. 4Figure 2 shows a portion of the tool shank 2, which forms a unit with a double ball bearing 26. The double ball bearing 26 is a double-row ball bearing. For guiding the balls 14, the tool shank 2 has two radially circumferential and axially spaced-apart raceways in the form of two grooves 22, in each of which a set of balls 8 rotates. The double ball bearing 26 therefore does not have an inner bearing section 10. Although not shown, a three-row or multi-row rotary bearing can be used. It is also conceivable that the two- or multi-row rotary bearings have an inner bearing section and are pushed or pressed onto the tool shank 2 and protected by a projection 20.

[0042] It is generally possible to combine the embodiments shown here, as long as this makes technical sense. List of reference symbols:

[0043] 1: Surgical instrument 2: Tool shank 3: Tool shank main section 4: Effector at the distal end section of the tool 6: Coupling structure at the proximal end section of the tool 8: Rotary bearing 10: Inner bearing section 12: Guide for rolling elements at the inner bearing section 14: Rolling elements (balls) 16: Outer bearing section 18: Detent lug 20: Projection 22: Groove 24: Lip 26: Multi-row bearing

Claims

1. A surgical tool (1), in particular a surgical milling or drilling tool, including a tool shaft (2), which has an effector (4) at its distal end portion, and a coupling structure (6) at its proximal end portion, said coupling structure being adapted to be selectively coupled to a drive in a rotationally and axially fixed manner in order to thus transmit rotation of the drive to the tool shaft (2), and at least one pivot bearing (8) provided for rotatably supporting the tool shaft (2) on a housing, preferably a handpiece, the pivot bearing (8) being connected to the tool shaft (2) to form a unit that can be inserted into the housing in its entirety for coupling to the drive, and that can be withdrawn from the housing for decoupling from the drive, characterized in that the pivot bearing (8) is integrally formed with the tool shaft (2), in particular is pressed onto the tool shaft (2), so that the tool shaft (2) of the tool (1), preferably a disposable tool, and the pivot bearing (8) are connected to form an inseparable unit.

2. The surgical tool (1) according to claim 1, characterized in that the tool shaft (2), between the proximal and the distal end portion, has at least one protrusion (20) radially circumferential and, in particular coaxial and / or integrally formed therewith for axially securing the pivot bearing (8) such that the protrusion (20) directly contacts the pivot bearing (8) with its side facing the proximal end portion.

3. The surgical tool (1) according to claim 1, characterized in that the protrusion (20) is conical in the axial direction, with the radial dimension of the protrusion (20) increasing from the distal end portion toward the proximal end portion.

4. The surgical tool (1) according to claim 1, characterized in that the tool shaft (2) has at least one radially circumferential running groove that is part of the pivot bearing (8).

5. The surgical tool (1) according to claim 4, characterized in that the running groove is formed in the shape of a slot (22) or as an area between two radially circumferential lips (24) spaced apart from each other in the axial direction, which rise from the outer circumferential surface of the tool shaft (2).

6. The surgical tool (1) according to any of preceding claims 1 to 5, characterized in that the pivot bearing (8) has at least one first locking section on its outer circumferential surface, the housing provides a second locking section interacting with the at least one first locking section, and the first and second locking sections can engage with each other in a locking state and thus contribute to supporting the tool shaft (2) relative to the housing.

7. The surgical tool (1) according to any of preceding claims 1 to 6, characterized in that the pivot bearing (8) is a two-row or multi-row pivot bearing (8).

8. A surgical tool system including a housing, a drive in the housing and the surgical tool (1) according to any of preceding claims 1 to 7, characterized in that the tool (1) can be coupled to the drive in the housing in a rotationally and axially fixed manner in order to take over a rotational motion generated by the drive, and has a pivot bearing (8) on its tool shaft (2) firmly connected to it, which pivot bearing supports the tool (1) relative to the housing.