WO1998031295A1

WO1998031295A1 - Medical or dental handpiece for treating by chip-removal or abrasion preferably tissue from the human or animal body

Info

Publication number: WO1998031295A1
Application number: PCT/EP1998/000189
Authority: WO
Inventors: Burkhard Hugo; Walter Mössle
Original assignee: Kaltenbach & Voigt Gmbh & Co.
Priority date: 1997-01-14
Filing date: 1998-01-14
Publication date: 1998-07-23
Also published as: EP0959800A1; JP2001510373A

Abstract

The invention relates to a medical or dental handpiece for treating preferably body tissue by chip-removal or abrasion. Said handpiece comprises a holding device (26) for attaching a tool (5) to the handpiece and a drive (2) for oscillating the tool (5), wherein the holding device (26) has a latching device (101) with a latch element (102) for attaching the tool (5) and the latch element (102) is pressed down when the tool (5) is manually pushed in and pulled out.

Description

Medical or dental medical handpiece for machining or abrasive processing, preferably of tissue from the human or animal body

The invention relates to a handpiece according to the preamble of claim 1.

A tool of this type is described in WO 96/14024. It is a tool whose abrasive machining section is effective laterally and at the end and is suitable for working out an approximal cavity in the tooth with an oscillating drive which is transferred to the tool by a dental handpiece. The magnitude of the amplitudes of the oscillation movements is relatively small in the sense of a vibration, the frequency preferably being in the sound or ultrasound range. In this known embodiment, the machining section is a machining head which is thickened with respect to the tool shank and whose cross-sectional shape converges towards its free end. The tool has a smooth surface on the side opposite the side machining section. As a result, the known tool is suitable for incorporating a cavity in the approximal area of the tooth. In this incorporation process, the processing section is preferably sunk from occlusal to cervical but also from lateral to central. The cavity can already be pre-machined using a rotary tool, or it can also be machined with the machining section without pre-machining. The adjacent tooth remains unaffected, since the smooth surface opposite the machining section does not damage the adjacent tooth. The abrasiveness of the effective working surfaces of the machining section is created by a stocking of small grains of hard material, preferably of diamond, which lie against one another. In functional operation, the small, hard grains prove to be a multitude of cutting edges, with the working surfaces present in each case being essentially effective over the entire surface.

The amplitudes of the oscillating movements of the machining section in functional operation can be carried out by spatial circular or elliptical movements in the sense of vibration. In order to avoid jamming when the tool is pulled out of the cavity, the machining section can have a cross-sectional shape which is convergent towards its free end.

A tool or handpiece of the types described above differs from known dental files and associated handpieces in several respects. On the one hand the known files or handpieces are set up for machining with a movement parallel to the file surface and thus for surface processing. In addition, the known files or handpieces are set up for a stroke size of their reciprocating movement, which is relatively large and can be a few millimeters.

On the other hand, the tool according to WO 96/14024 has working surfaces oriented transversely to one another, e.g. at least one working surface extending in its longitudinal direction and one end surface extending transversely thereto, and due to a drive with spatial amplitudes, it is set up not only to work on surfaces, as is usual with files, but also holes or cavities, in particular blind holes to incorporate.

In another handpiece of the type specified at the beginning, which is described in DE 33 28 605 C2, the tool is not used to prepare a cavity on the tooth, but rather to treat the surface of the tooth, namely to remove tartar.

In the aforementioned known configurations, the tool is connected in one piece to the shaft, the shaft being releasably connected to the handpiece by a screw connection.

The known disadvantages have the following disadvantages. Should a e.g. Damaged tools are discarded and replaced by a new tool, then the assembly consisting of the tool and the shaft must be replaced. As a result, a considerable amount of material is required.

Another disadvantage of the known configurations is that the known construction can only be used to a limited extent with regard to the working positions of the tool required in the mouth of a patient, since only certain processing points can be reached in an easy-to-use position of the handpiece per instrument. It should also be borne in mind that in order to produce cavities in a mesial or distal position, spatially differently arranged tools must be available. This also applies to the production of cavities in the proximal area with tools that have a smooth outer surface on their side facing the adjacent tooth in order not to damage the adjacent tooth. In the known configurations a large number of different tools are therefore required in order to be able to carry out the usual work occurring in the patient's mouth.

For this reason, different processing tools are used in the functional operation of an existing handpiece, each of which must be replaced.

The invention is therefore based on the object of designing a handpiece of the type described in the preamble of claim 1 in such a way that handling-friendly and quick loading and, if appropriate, also replacement of the tool is possible.

This object is solved by the features of claim 1. In this embodiment according to the invention, the holding device for the tool has a latching device which can be manually overridden when the tool is inserted and removed. This enables easy and quick loading and replacement of the tools with one-hand operation. The tool only needs to be gripped and inserted or pulled out with the operating hand, the fixing or loosening of the tool taking place by means of an automatic locking or unlocking.

The invention is further based on the object of designing a handpiece of the type described in the preamble of claim 12 in such a way that it is possible to equip the handpiece with a tool or to exchange tools with less material. In addition, the handpiece should be easy to use in normal or difficult working positions.

This object is solved by the features of claim 12.

In the embodiment according to the invention according to claim 12, the tool is a separate component which is detachably connected to the shaft by means of a holding device. It is thus possible to equip the handpiece with a small and inexpensive tool, or to detach the tool on its own and replace it with a new tool, whereby the shaft can remain on the handpiece. The material required therefore only extends to the tool, while the shank can remain unchanged. This solution according to the invention then also serves a user-friendly one

Use of the handpiece if several tools are provided, the design of which is different and / or adapted to different working positions

Embodiment can be adapted to certain working positions by the selection of a specific tool or tool shape so that a user-friendly use is guaranteed

In this embodiment according to the invention, the tool is also a separate component which is independent of the shaft and which can be adjusted in its holder on the shaft by means of an adjusting device and preferably also in the respective adjustment position by means of a locking device.This makes it possible to relate the tool to the shaft or the handpiece to adjust and determine in various and favorable working positions, so that it is secured against unintentional adjustment. It is also possible to reach inaccessible work places in the mouth of the patient in a manageable position of the handpiece

The present position problem is also predetermined by the fact that the teeth are arranged on both sides of a vertical longitudinal center plane and thus different working positions for the tool and the handpiece are specified on both sides of the longitudinal central plane. To solve this problem, it is advantageous to cross the tool with its longitudinal central axis to the shaft and about this longitudinal central axis adjustable and lockable to arrange With such a configuration, it is possible to reach the upper and lower as well as the left and right rows of teeth with the handpiece from the mouth opening of the oral cavity in a manner that is easy to handle

The invention also relates to a cutting tool for the handpiece, which has the same advantages as far as the tool is concerned

Further individual working positions of the tool in the interdental areas can also be achieved in a user-friendly manner The invention is also suitable for tools which have an asymmetrical and / or non-circular shape with respect to their longitudinal center axis.

Another advantage of the configuration according to the invention is that, due to the adjustability according to the invention, one and the same tool not only for use in handling-friendly positions but also for use in different places, e.g. for performing dental medicine work on inner and outer positions of the row of teeth of the lower or upper jaw. As a result, the required number of different tools can be significantly reduced. It can be assumed that, in the embodiment according to the invention, only about 25% to 50% of the number of different tools needs to be present in order to be able to carry out normal work at the treatment site, in particular in the mouth of a patient. As a result, fewer different tools are required and, in addition, a larger number of identical tools can be produced, which can significantly reduce the manufacturing costs.

Furthermore, the invention is suitable for processing tools with different attachments as well as different purposes. The holding devices can be simple clamping devices, in particular by means of screws, or so-called quick-connect connections, which enable the tool to be released or clamped in a short amount of time. The tools can be those that are suitable for the preparation of tooth cavities, crown stump preparations, caries extractions, marginal and interdental preparation of restorations, root surface treatment and bone treatment.

The solution according to the invention contained in claim 7 makes it possible to swivel the handpiece during processing, the tool being able to remain in operation due to the restoring force of the swivel joint effective on it. This protects the tool against overloads. Such a function is particularly advantageous when processing in the tooth side area, as is the case with a preparation of a crown or a partial crown.

In particular in the aforementioned machining cases, it is advantageous for the tool to be rotatable in the holding device, so that the tool can adapt to the circumferential surface during machining on the circumference of the tooth. For certain work with the tool, which, if a relatively large amount of material has to be processed or the tool is opposed, there is a demand for one Tool holder that is not rotatable. Claims 8 and 9 contain configurations with a swivel joint in which the tool can either be rotated or fixed by means of a locking device. It is advantageous to design the locking device in such a way that it automatically functions when the tool is adjusted laterally and / or axially against a restoring force by a pressure greater than a certain size, see claim 10. The automatically acting restoring force enables to use the tool both in its starting position or middle position or in its laterally or axially adjusted working position, even forced in the latter working position, since the tool is locked

For various reasons, it is advantageous to supply a rinsing, cooling and / or treatment liquid to an abrasive tool in operation. As a result, the performance and service life of the tool can be improved and the treatment site can be rinsed and cleaned.

This is made possible by the configuration according to claim 32, which is characterized by a simple and inexpensive to produce configuration, the connection of the feed line for the medium being ensured in a simple and easy-to-use manner even when the tool is changed. These advantages apply to both the handpiece and the tool.

The known tools and handpieces have the problem in common that if the tool is prevented from executing its oscillatory movement, it can be overloaded and damaged or break off due to an impact effect. This applies in particular to tools that have a small cross-section and can easily break off. The above-mentioned difficulty applies in particular to root canal files, which are sensitive to breakage due to their small diameter, in particular when a root canal file is overloaded in the bent state, in which it adapts, for example, to the bent root canal. A previously described impact effect is also given for a root canal file if the file tip incorporates a depression in the sense of a step in the outer curvature wall of the root canal and this step prevents the root file from penetrating further into the root canal. In particular, if the root canal file stands at such a step, there is a risk of it breaking off particularly easily in the event of loading or overloading or of causing lateral perforation of the root canal, which is of course undesirable. A comparable risk also exists if, in particular, apical parts of the root canal file are stuck in the root canal and attempts are made to move the root canal file into different directions Pull out directions. In the case of a root canal file, weakening can also occur as a result of the overloading described above, which can lead to breakage when used later.

The invention is further based on the object of designing a handpiece or a tool of the types specified in the preamble of claim 35 or 41 in such a way that the stresses on the tool resulting from the drive, in particular shock loads, are reduced.

This object is solved by the features of claim 35 or 41.

In this embodiment according to the invention, a damping means is provided which is integrated in the drive connection of the handpiece or in the tool above its processing section. It is possible within the scope of the invention to arrange the damping element in the chain of drive connecting links present in the handpiece or on the tool as a loose part or as a connecting medium or connecting part which connects the adjacent parts of the drive connection with one another and thus to excite vibrating both by abutment and by train can The damping means transmits the driving force unchanged, but the power transmission is resilient so that when the tool is prevented from oscillating, e.g. when it abuts a wall extending transversely to the movement amplitude, the drive force peaks are damped. In the case of an existing tool, it must be taken into account that it consists of hard material and that suddenly occurring load peaks are particularly suitable for breaking the tool. Since the power transmission is flexible in the embodiment according to the invention and the load peaks are damped, the tool is also subjected to more flexible loads, so that tool breakage occurs much less frequently or is avoided.

Depending on the configuration, the damping means can dampen in one or more load force directions which are or are directed radially or laterally and / or axially and / or in the circumferential direction and can also be caused by a tilting or bending movement.

If the damping means is arranged in the drive connection of the handpiece, it only needs to be arranged once, and it applies to all tools. If, on the other hand, the damping means is integrated in the tool, such a damping means integration is required for each tool. The latter is advantageous because Integration into the confined space of the head area of the handpiece is difficult and complex. The arrangement of the damping means in the region of the shank of the tool can be formed simply and inexpensively in the course of its manufacture. It should be taken into account that the design of the damping means in the shaft area of the tool can also be integrated in a confined space, but the tool is an easily accessible single part during its manufacture, which can be handled simply and conveniently in the design and arrangement of the damping means .

If the damping means is arranged in the region of the handpiece, the damping means can be an intermediate element between the machining section and the tool shank or between two tool shank parts. It is also possible for the damping means to be formed as an intermediate member surrounding the tool shank, in particular in the form of a sleeve which can be surrounded by an additional outer sleeve as an elastically deformable element and which can form a manual grip or which can be used as a connecting means with the handpiece or whose handpiece shaft can serve. In the context of the invention, it is also possible to arrange the damping means on a separate additional part which can be connected to the tool shaft and can serve as an intermediate member for connection to the handpiece or the handpiece shaft.

These advantages also apply to a handpiece, on the one hand for the preparation of a cavity and on the other hand for the preparation of a root canal in a tooth, and for an associated tool.

Features are contained in the subclaims which enable simple, small and inexpensive designs, ensure secure attachment and easy-to-use attachment and detachment of the tool, and enable the delivery of an in particular liquid treatment agent to the treatment site.

The invention also relates to cutting tool for a handpiece.

The invention and further advantages which can be achieved by means of preferred exemplary embodiments and drawings are explained in more detail below. It shows Fig. 1 shows a handpiece according to the invention with a tool according to the invention in the

Side view and in partial vertical longitudinal section;

2 shows the tool in an enlarged side view;

Fig. 3 shows the front end of a handpiece or its handpiece shaft in the

Top view;

Figure 4 shows the front end of a handpiece or handpiece shaft in a modified embodiment in a plan view.

5 shows the front end of a handpiece or handpiece shaft in a further modified configuration in a top view;

6 shows the front end of a handpiece or handpiece shaft in a further modified embodiment in a top view;

7 shows the front end of a handpiece or handpiece shaft in a further modified configuration in an axial longitudinal section;

8 shows the front end region of a handpiece or handpiece shaft in a further modified configuration in a vertical longitudinal section;

9 the front end region of the handpiece or handpiece shaft according to FIG. 8 in a further modified embodiment in a side view;

Fig. 10. The front end of a handpiece or handpiece shaft in a further modified configuration in a vertical longitudinal section;

11 shows the individual parts of the embodiment according to FIG. 10 in a so-called exposure representation; 12 shows the front end region of a handpiece or handpiece shaft in a further modified embodiment in a side view;

13 shows the front end region of a handpiece or handpiece shaft in a further modified embodiment in a side view;

14 shows the front end region of a handpiece or a tool held thereon in a further modified configuration in a partial vertical longitudinal section;

15 shows the partial section XV-XV in FIG. 14;

16 shows the front end region of the handpiece according to FIG. 14 in a side view and in a working position in the proximal intermediate tooth region;

17 shows the front end region of a handpiece or a tool held thereon in a further modified configuration, in particular for external tooth processing, preferably in its root region or for bone processing;

18 shows the front end area of a handpiece or a tool held thereon in a further modified embodiment in a side view;

19 shows a tool according to the invention in the form of a root canal file in a modified configuration and enlarged view;

20 shows the tool according to FIG. 9 in a further modified embodiment;

21 shows the front end region of a handpiece or a tool held thereon in a further modified embodiment;

22 shows the front end region of a handpiece or a tool held thereon in a further modified embodiment; 23 shows the front end region of a handpiece or a tool held thereon in a further modified embodiment;

24 shows the front end region of a handpiece or a tool held thereon in a further modified configuration, partially axially cut;

25 shows the front end region of a handpiece or a tool held thereon in a further modified configuration, partially cut axially.

The handpiece consists of an elongated handle or an elongated, essentially round handle sleeve 1, in which a vibration generator 2 is arranged, which is positioned in the handle sleeve 1 on an inner sleeve 3, which is the front end of the handle sleeve

I protrudes and thus forms a shaft 4 which carries a tool 5 at its front end. After switching on the vibration generator 2 by means of a hand or

Foot switch, the inner sleeve 3 and thus the shaft 4 and the tool 5 are set in vibration.

In the case of the tool 5, all of the configurations of the handpiece 1 to be described can be for machining a cavity in the tooth, also in the approximal area between two teeth, or for preparing a root canal.

The main direction of the relatively small amplitudes is directed transversely to the shank and along the tool. But there are also changing, i.e. generated spatial amplitudes.

In the grip sleeve 1, two medium lines 6a, 6b (coolant or treatment agent or energy line) extend from the rear to the front, which lead through connection lines 7 of a connection piece 8 arranged at the end of the grip sleeve 1 remote from the tool to a supply line 9 leading to a medium source (not shown) are connected in a flexible supply hose

II extend, with which the connector 8 is connected. Between the connector 8 and the grip sleeve 1, a screw coupling or a freely rotatable, quickly releasable and quickly assembled quick coupling in the form of a rotary / plug-in coupling 12 is arranged, which in the present embodiment by a hollow cylindrical Coupling recess 12a is formed in the rear grip sleeve 1 and a cylindrical coupling pin 12b which can be inserted therein with movement play and which projects from the connecting piece 8. The coupling recess 12a and the coupling pin 12b can be designed with a cross-sectional step tapered towards the front. The connecting lines 7 pass through the hollow cylindrical division joint 13 between the coupling pin 12b and the coupling recess 12a in a Z-shape radially from the inside out, and they are then continued as the medium lines 6a, 6b, which is shown in simplified form. At the points at which the radial sections 7a of the connecting lines 7 radially penetrate the division joint, an annular groove 14 is arranged in the outer surface of the coupling pin 12b or in the inner surface of the coupling recess 12a. As a result, the handle sleeve 1 is guaranteed relative to the connector 8, the liquid passage at all possible rotational positions. For sealing purposes, sealing rings 15 are provided on both sides of the annular grooves 14, which are seated in receiving grooves in the wall surface of the coupling pin 12b or in the inner lateral surface of the coupling recess 12a. For axially securing the coupling position, a latching device 16 is provided with a radially resiliently arranged latching element, for example in the form of a ball or a latching ring, which elastically engages behind a latching edge in the coupling position, which is formed by an annular groove. The locking ring is arranged in an annular groove in the other part. To release the rotary / plug-in coupling 12, the latching device 16 can be overpressed in a manner that is easy to handle.

The rear end region of the inner sleeve 3 is connected in the region of a resonance device 17 to a bearing sleeve 18 which is mounted on the inner wall of the grip sleeve 1. In the front end region of the grip sleeve 1, the inner sleeve 3 is free of play and with the possibility of slight radial movement in a bearing ring 19 which is fastened to the latter in the front end region of the grip sleeve 1 and can be formed by a ring made of elastic material which can be formed in one Inner groove sits.

The coolant or treatment agent line 6a extends by means of a conduit 22 from the back to the front into the inner sleeve 3 to the front end region of the grip sleeve 1, where the conduit 22 is mounted or held in the inner sleeve 3 by means of a spacer sleeve 23.

The tool 5 has a shank 25 which is arranged transversely by means of a releasable fastening device or holding device 26

Receiving hole 27 of the shaft 4 is attached to the front end of the handpiece shaft 4.

The holding device 26 is formed by a locking screw 28 which with respect to the Receiving hole 27 is screwed radially into the shaft 4, here from the front in an approximately coaxial threaded hole 29, and has a rotary engagement element. The tool shank 25 can be inserted into the correspondingly large receiving hole 27 with little movement play and can be secured by tightening the locking screw 28. The tool shank 25 preferably has one or more notches 31 or a waist which are arranged distributed over the circumference and into which the locking screw 28 is able to engage. The notch 31 is preferably formed by an annular cross-section, in particular wedge-shaped, in the tool shank 25, in the area of which a feed channel 4a opens into the shank 4. In this embodiment, on the one hand, an optional rotation adjustment and locking of the tool 5, optionally in steps or infinitely variable, is ensured by an optional turning and locking by means of the locking screw 28. On the other hand, when the screw 28 is not tightened, the tool shank 25 is freely rotatably mounted in the sense of a swivel joint and is axially positively secured by the screw 28.

Arranged in the tool shank 25 is an angular channel with a radial channel section 32a, which extends from the supply channel 4a for a coolant or treatment agent, preferably from the notch 31. The axial channel section 32b extends into the tool 5 and opens into an outlet opening 32c, e.g. 1 to 16 and 24 and 25 for working out a cavity on the underside, on an optionally inclined step surface and optionally also on the lateral surface of the tool 5 and forming a machining section 5a on the working surfaces thereof. These are abrasive work surfaces that are coated with an abrasive material, particularly in the form of an applied grain. This can be a known diamond coating.

For the purpose of clarifying the working position, a tooth 35 is indicated in FIG. 2, in which the tool 5 incorporates an approximally open cavity from the occlusal direction. For the proximal tooth area, the or another tool 5 can have a non-abrasive, i.e. have a smooth surface so as not to damage the adjacent tooth. A tool 5 for the preparation of a root canal, see. e.g. 19 to 23 is adapted to the convergent dimension of the root canal, and because of its flexibility it can follow a curvature of the root canal.

It is advantageous to arrange a preferably annular material thickening 4b on the handpiece shaft 4 in the region of the holding device 26 or the receiving hole 27 in order to stabilize the fastening point. This makes it possible to handpiece shaft 4 in the remaining area extending to the grip sleeve 1 to be thinner, which improves the view of the treatment site.

The configurations according to FIGS. 4 to 6, in which the same or comparable parts are provided with the same reference numerals, differ from the configuration described above only in that the transverse hole 27 and the tool shank 25 are designed in the sense of a regular polygon, whereby the locking screw 28 , which not only forms an axial but also a rotation lock, is exempt from the rotation lock function, since this is fulfilled by the polygon. In the embodiment according to FIG. 4, a hexagonal, in the FIG. 5 an octagonal and in the FIG. 6 a multi-tooth cross-sectional shape is realized.

In the embodiment according to FIG. 7, the holding device 26 is likewise formed by a screw connection, but in a modified embodiment. Here, the transverse hole 27 is arranged in the foot region of a threaded bolt 41 forming the free end of the shank 4, which projects coaxially forward in the present embodiment and on which a threaded nut 42 is screwed, which protrudes against the portions of the tool shank projecting on both sides of the threaded bolt 41 25 is exciting.

Instead of or in addition of channels 32a, 32b for liquid extending through the tool 5, an outlet opening opening on the circumference of the shaft 25 can be provided in the shaft 4, from which the liquid flows along the lateral surface of the tool shaft. 7, e.g. A notch or groove 32al is provided on the rear side of the receiving hole 27, which extends outward from the feed channel 4a and through which the medium flows on the outside of the tool 5 to the machining section 5a.

8, the holding device 26 has a quick-connect connection 45. It is formed by a pressure member that is tensioned by the force of a spring against the tool shank 25 and can thereby secure it axially and against rotation. The effectiveness of the pressure member 46 can be increased by enclosing it in a notch or flattening on the tool shank 25. The spring force is preferably only dimensioned so large that the pressure member can be pulled back manually against the spring force from the tool shank 25 and the connection can thereby be released. In the embodiment according to FIG. 8, the pressure member is formed by a sleeve 46 which can be displaced with play on the handpiece shaft 4 and which is acted upon by a compression spring 48, here a helical spring, which is supported on a rear shoulder surface 47 of the shaft thickening 4b, here a helical spring. in the In the area of the ring wall of the sleeve 46, the tool shank 25 has two flats 49 of equal depth, against which the flat end face of the sleeve lies. The inner radial boundary surfaces of the flats 49 form shoulder surfaces 49a, which overlaps the sleeve. As a result, the tool shaft 25 is axially positively locked, while the existing rotation lock is formed by the form-fitting and at the same time non-positive engagement of the sleeve 46 in the flats 49.

7 and 8, the cross-sectional shape of the transverse hole 27 and the tool shank 25 can also be round, non-circular or polygonal. In the embodiment according to FIG. 8, however, care must be taken that, in the case of a polygonal design, the flats 49 in the respective position of the tool shank 25 extend parallel to the end face of the sleeve 46 facing them. In the case in which the rotation lock is formed by a polygonal shape as described above, the pressure member 46 does not need to secure the rotation, but only an axial lock. It is therefore possible, instead of flattening 49, to provide ring depressions in the tool shank 25, on the lateral surfaces of which the sleeve 46 abuts and thereby overlaps the shoulder surfaces 49a which are also formed.

The above-described quick-connect 45 can be operated very quickly and easily.

The handpiece shank 4, the tool 5 with the tool shank 25 and the parts of the holding device 26 or quick-action connection 45 are preferably made of corrosion-resistant metal, e.g. made of alloy steel.

7 and 8, the tool 5 can also have the angular channel 32a, 32b for cooling or treatment liquid.

For ergonomic reasons, it is advantageous to bend the shank toward the side facing away from the tool 5. This angle W is approximately 10 to 20 °, in particular approximately 15 °.

The distance a of the tool 5 from the apex 51 of the bend is preferably smaller than the distance b between the bend of the grip sleeve 1 and is approximately 1 to 3 cm, in particular approximately 1 to 2 cm.

With a tool 5, because of the handpiece 1 forming a relatively long lever arm, considerable torque can be applied to the treatment site or tooth 35 are exercised. There are limits to such a torque in two ways. On the one hand, the torque must not be so great that the treatment site or tooth 35 is overloaded, for example so heavily loaded that part of it could break off or the tooth root is overloaded. On the other hand, the avoidance of an overload also applies to the tool 5, which is to be protected against overloads and breakage, particularly when the tool is small or thin.

It is therefore advantageous to assign an overload protection coupling 55 to the tool holder, which opens automatically and thus the connection between the tool shaft

25 and the shaft 4 releases when a certain power transmission or a moment is exceeded. The quick-connect connection 45 according to FIG. 8 is a

Embodiment of such an overload safety clutch 55, which is the present

Embodiment is effective when the handpiece 1 moves about the central axis of the tool 5. If, in the embodiment according to FIG. 8, the handpiece 1 is pivoted about its longitudinal central axis in the case of a stuck tool 5 and a torque determined by the force of the spring 48 is exceeded, the pressure member formed by the sleeve 46 is pushed back against the force of the spring 48, whereby the connection is broken and the shaft 4 can be rotated without the tool shaft 25 on the latter.

Another problem is that the quick-release connection 45 can be released due to the required tension of the spring 48 and only with a considerable amount of force, which affects the ease of use. 8, it is e.g. then difficult to withdraw the sleeve 46 against the force of the spring 48 when the force of the spring exceeds a certain size.

In the embodiment according to FIG. 9, a reduction gear 56 is assigned to the existing opening mechanism of the rotary driving connection between the shank 4 and the tool shank 25 in such a way that the connection or the overload protection coupling 55 can be released with less manual effort. In this embodiment, the reduction gear 56 has an inclined plane or a wedge gear, with at least one inclined or curved surface 57, which is effective when the sleeve 46 rotates between it and the shaft 4, preferably on a projection 58, in particular on the outer surface of the shaft 4. In the present embodiment, at least one wedge-shaped, preferably sawtooth-shaped projection 59 is provided on the annular end face of the sleeve 46 facing away from the spring 48, the inclined or curved surface 57 of which is arranged and designed such that in the The clamping position of the sleeve 46 of the projection 58 is located in the foot region of the inclined or curved surface 57 and has an axial distance therefrom and in the clamping position of the sleeve 46 the projection 59 is located near the head region of the inclined or curved surface 57. Two lugs 59 are preferably arranged diametrically opposite one another and having the same effect on the sleeve 46 in the circumferential direction.

10 and 11, in which the same or similar parts are also denoted by the same reference numerals, the holding device 26 and quick-connect connection 45 for the tool 5 is formed by a so-called collet 61, with an in the free end region of the shaft 4 arranged external thread 62 onto which a clamping nut 63 can be screwed in the form of a union nut. The end of the shaft 4 is divided by several diametrically opposed axial slots 64 into segments 65, the outer surfaces of which are conical section surfaces 66, against which, when the clamping nut 63 is screwed on, an inner surface 67 arranged in its free end region presses and the segments 65 against the between the Segments 64 inserted tool shaft 25 is stuck. The inner surfaces of the segments 65 are section surfaces of a hollow cylinder which is adapted to the dimension of the cylindrical tool shank 25. To additionally secure the tool shaft 25 against rotation in this quick-action connection 45, a polygon 68a, e.g. a square, hexagon or octagon can be provided which fits into a correspondingly polygonal recess 68b in the shaft 4. This creates a rotary position adjusting device 69, which enables the tool shank 25 to be positively secured to the shaft 4 in different rotary positions.

In this embodiment, the central axis of the collet 61 is arranged transversely to the longitudinal central axis of the handpiece shank 4, wherein there may be an essentially right or acute or obtuse angle, preferably an angle W1 of approximately 90 ° to 105 °. The collet 61 can also be arranged axially to the longitudinal center axis of the handpiece shaft 4. In the present angular shape, the free end of the handpiece shaft 4 is curved in accordance with the angle W1. The channel section 32 extends axially continuously in the tool shank 25, so that in this embodiment, too, treatment or cooling liquid can flow from the supply channel 4a through one or more channel sections 32d to one or more outlet openings 32c in the abrasive working surface (s) of the tool 5.

In the embodiment according to FIG. 12, in which the same or comparable parts are also provided with the same reference symbols, the handpiece shaft 4 is at a separation point 71 in divides two handpiece shaft parts 4c, 4d, which can be connected to one another by a screw coupling 72. The separation point 71 is in the vicinity of the grip sleeve 1 of the handpiece.

The screw coupling 72 has a threaded hole 73 on a shaft part into which a

Threaded pin 74 can be screwed onto the other shaft part and can be tightened against a shoulder surface 75. In the present embodiment, the threaded hole 73 is in the in the

Handle sleeve 1 of the handpiece mounted shaft part 4c. The threaded pin 74 is formed on the front shaft part 4d in the form of a tapered fitting

Threaded pin 74. The resulting step surface at the foot of the threaded pin 74 forms the shoulder surface 75 lying against the end face of the shaft part 4c. At the foot of the threaded pin 74 and at the edge of the threaded hole 73, matching conical surfaces 75a can be arranged. In addition, the front shaft part 4d has a rotary grip element for screwing in and unscrewing, here two key surfaces SF. This configuration enables the handpiece 1 to be assigned several different shaft parts 4d and optionally coupled to the handpiece 1. These shaft parts 4d can differ from each other, e.g. by the angle W or by a different holding device 26. It is thus possible to implement and use a desired holding device optionally with a preferred tool 5 and / or different shapes of the front end of the handpiece shaft 1 by retrofitting the handpiece.

This screw coupling 72 is preferably designed in accordance with a screw coupling on an applicant's dental calculus removal device that is already on the market, e.g. is described in the publication DE 33 28 605 C2. This configuration makes it possible to mount the handpiece shaft part or parts 4d on handpieces on the market or to mount the known tartar removal tools or tips on the present handpiece 1 and thus the known handpieces and the present handpiece 1 optionally with tartar removal tips or to equip existing shaft parts 4d and thus to use them both for removing tartar and for the present abrasive treatment.

In the embodiment according to FIG. 13, in which the same or comparable parts are also provided with the same reference numerals, a shaft 4 is provided, which in its from the Handle sleeve 1 of the area projecting from the handpiece has a lateral connection device 81 for a supply hose 82 which extends at least in the front area of the handle sleeve 1, the rear end of the hose 82 in a suitable manner with the associated media line 6a, 6b or 7 or 9 connected is. In the present embodiment, the handpiece shaft 4 has a lateral connection pipe socket 83, into or onto which the hose 82 can be plugged in or plugged on. A hollow section 4a runs axially from this pipe socket 83 in accordance with the previously described configurations for the holding device 26 and the tool 5, the shaft 4 being able to extend straight or bent or angled by the angle W.

The handpiece shaft 4, the tool 5 with the tool shaft 25 and the parts of the fastening device 26 or quick-action connection 45 preferably consist of corrosion-resistant plastic or metal, e.g. made of alloy steel.

In the embodiment according to FIG. 14, in which the same or comparable parts are also provided with the same reference numerals, the tool 5 is assigned a lateral support leg 85, which is located on one side of the tool 5, preferably on a broad side, and is over the entire width this side and / or length of the tool 5 can extend. In the embodiment according to FIG. 14, the support leg 85 is arranged on the front of the tool. The support leg 85 can, however, also be arranged laterally on one or the other side or on the back of the tool 5 or the holder provided therefor. The support leg 85 is maintained according to a first embodiment, independently of the holding means 26 for the tool 5 on the handpiece shaft 4, wherein it can be integrally ^'in two parts connected or so, for example, may be formed in one piece. The support leg 85 protects and stabilizes the tool 5 on the side on which it is arranged. The side surface of the tool 5 facing the support leg 85 is not abrasive but smooth. It is advantageous to profile the contact surface 86 of the support leg 85 facing the tool and the side surface 87 of the tool 5 resting thereon in a cross-section to the longitudinal axis of the tool 5, for example convex or roof-shaped, so that this profiling also provides support for the tool 5 results, which is effective with respect to lateral loads that extend at right angles to the direction of support of the support leg 85. In the embodiment according to FIG. 15, the contact surface 86 of the support leg 85 is profiled in a roof-shaped manner, the contact surface 87 of the tool 5 being correspondingly profiled in a trough-shaped manner.

In the embodiment according to FIG. 15, the tool 5 has a trapezoidal cross-sectional shape with convergent side surfaces 5c, the support leg 85 being arranged on the base surface of the trapezoidal shape with any profiling that may be present. In this embodiment too, the tool 5 or its shank 25 is connected by branching channel sections to the supply for treatment, processing and / or cooling liquid running in the handpiece shank 4, this connection being able to take place in the sense of one of the previously described embodiments. At least one channel section with an opening 32c in the region of the contact surfaces 86, 87 or above, e.g. in a waist of the tool 5, in order to also supply liquid between these axially parallel contact surfaces 76, 77. The flat side surface 5b of the tool 5 opposite the support leg 85 is designed to be convergent downwards. The side surfaces 5c can also be designed to be convergent downwards. This also applies to tools 5 without support leg 85. On the underside, the tool 5 has an inclined surface 5d which extends only over part of the depth of the tool 5 and then continues transversely.

The above-described configuration with the support leg 85 is set up for a specific position of the tool 5. Within the scope of the invention, however, it is also possible and advantageous to fasten the support leg 85 to the handpiece shaft 1 with a special holder adjustable with the tool 5. Such a configuration makes it possible not only to move the tool 5 but also the support leg 85 into a specific treatment position and to fix it in this position.

A previously described rigid and adjustable support leg 85 can also be used advantageously in the intermediate tooth area, as shown in FIG. 16, in which a cavity K opening into the intermediate tooth area is worked out with the tool 5 and the support leg 85 forms a protective shield with a protective back surface for the adjacent tooth 35a . The handpiece and / or the tools 5, in particular the embodiment according to FIGS. 2 and 14 with the one without a support leg 85, are also suitable for preparing a tooth for a tooth crown.

In the embodiment according to FIG. 17, in which the same or comparable parts are also provided with the same reference numerals, a tool 5 is provided which is set up for bone or tooth surface treatment or bone removal, in particular inside or outside the gums. Root area of a tooth 35. This tool 5 is arranged or shaped in an angular manner, the shaft 25 being straight or angularly shaped with the angle W with a shaft part 25a provided for the holder and a shaft part 25b holding the tool 5. The angle W2 enclosed by the shaft parts can be approximately rectangular, obtuse or also acute, preferably in a range between approximately 75 ° and 105 °. In the present embodiment, a tool 5 in the form of a round head is provided, which is thickened with respect to the shaft part 25b which supports it. With this tool 5 too, it is advantageous to supply treatment or machining or cooling liquid through a supply channel 35b which extends longitudinally through the shaft parts 25a or 25b and which can branch out in the area of the tool head in one or more ways and can open out at outlet openings 32d of the spherical tool surface. The shaft part 25b and the tool 5 are preferably only so large that they can be inserted into the root region of a tooth for the purpose of machining it. The tool 5 can also have a different head shape instead of a spherical head, e.g. that of a file which extends in the longitudinal direction of the shaft 25 or shaft part 24a and which can have a round or flat cross-sectional shape.

A similar variant is shown in FIG. 18. In this embodiment, in which the same or comparable parts are also provided with the same reference numerals, the tool 5 extends straight, being arranged coaxially to the end region of the shaft 4 and thus extending in the longitudinal direction thereof. In this configuration, too, different tool head shapes can be provided, for example not an elongated file as shown, but a spherical head according to FIG. 17 or a cuboid head according to FIG. 2. In all of the above-described configurations, the tool 5 can have a smooth surface opposite to a working surface in the intermediate tooth area, so that the adjacent tooth remains undamaged during processing. One or more exit openings can be in the actual tool head or in the transition area between head and shaft 32d may be provided for processing or treatment or cooling liquid, which are connected to the liquid supply by one or more branching channels. Furthermore, it is advantageous to arrange at least one outlet opening 32d for liquid in the area of a smooth surface on the tool 5 as described above

It is also possible within the scope of the invention to arrange the at least one outlet opening for liquid in the region of the tool shank 25 or at the front end of the handle sleeve 1 such that it is directed towards the treatment site

Sterile or non-sterile liquids such as solutions, in particular salt solutions, for example sodium bicarbonate, are suitable as treatment or processing or cooling liquid. It is also advantageous to mix small, hard, preferably self-dissolving particles into the liquid in the sense of a self-accumulating abrasive suspension the performance of the processing is improved

Within the scope of the invention, it is possible to optionally combine all of the above-described design variants with one another. For example, it is possible to use all of the holding devices 26 or quick-connect connections 45 described. This is illustrated by an arrow in FIGS. 12 and the following, which indicates the holding device or quick-connect connection

When using the above-described tools 5 for machining surfaces, the shape of the tool or its working or jacket surface can be optionally determined, for example, taking into account the surface shape to be machined. On the other hand, if the tool 5 is used to machine a cavity K, then opposite tool surfaces are relevant the direction of incorporation in one or two dimensions to be convergent, so that the tool 5 can be removed from the cavity K again after the incorporation without clamping.

It is also advantageous to provide oblique edge surfaces on the tool 5, which incorporate corresponding inclined surfaces in the sense of chamfers in the region of the edge edge of the cavity at the edge of the cavity. In the embodiment according to FIG. 14, such an inclined surface is designated 5c as a partial surface of the associated side surface. Such inclined surfaces can also be arranged on the side surfaces extending in the longitudinal direction of the tool 5 (not shown).

The elongated tool 1 according to FIGS. 19 to 23 consists of a rod-shaped tool shaft 25 and a machining section 5a adjoining it coaxially in the form of a needle-shaped extension, on the lateral surface of which a plurality of cutting edges arranged next to one another are arranged or the lateral surface with grains of hard material lying next to one another , in particular diamond. The cross-sectional size of the processing section 5a, which is preferably round in cross-section, is adapted to the cross-sectional size of a tooth root canal WK in such a way that it can be inserted into the root canal WK, which is indicated, with little movement. In addition, the machining section 5a consists of an elastically flexible material, in particular steel, so that it can follow the curved shape of conventional root canals by bending.

In the context of the invention it is advantageous to assign several tools 5 of different shape and / or size to the handpiece, which are adapted to certain shapes and / or sizes of different cavities K. A number of so-called root canal files of different diameters can therefore be provided for root canal preparation.

The tool shank 25 and the machining section 5a can be made in one piece or consist of two parts which are firmly and permanently connected to one another. The tool 5 can have the shape of a commercially available root canal file, the

Tool shank 25 is made of plastic and has at least one circumferential groove or circumferential waist on its outer surface in order to enlarge the

Grip resistance in manual handling. 19 to 25, the tool 5 has a damping means 91 in the area of its tool shank 25 or the handpiece in the area of its drive connection, which dampens the load peaks resulting from the oscillation or oscillation drive and thereby the tool 5 from intermittent overloads protects, whereby the risk of breakage of the tool 5 is avoided or significantly reduced. The damping means 91 enables a relative movement in each case between two parts forming the drive chain between the drive in the handpiece and the machining section 5a. The relative movement can be based on elastic resilience or flexibility of the damping means 91. In this case, the damping means 91 can be arranged between two links of parts that are in chain connection with one another in drive connection, or the links can be connected to the damping means 91 in a non-detachable manner to form a component. In both cases, there is a flexible or floating mounting of the tool 5 or its processing body or processing section 5a, which ensures the above-described damping effect.

The damping means 91 can be implemented in all of the above-described and post-described embodiments of the handpiece and the tool 5.

When the damping means 91 is integrated into the tool 5, it is advantageous to arrange the damping means 91 between the tool shank 25 and the machining section 5a. 19 and 20, the damping means 91 can be arranged between an outer shaft shell 92 and a shaft core 93. The shaft core 93 can be cylindrical or for the purpose of positive engagement with the damping element 91 out of round and / or in its longitudinal direction a shape that deviates from a cylindrical shape, that is to say an unequal thickness, which results in a positive connection with the damping element 91. This is also possible between the damping element 91 and the outer shaft shell 92. In the present embodiment, the damping means 91 is an elastic filler material, for example an elastic filling material, which fills the cavity between the shaft core 93 and the shaft shell 92 and is thus embedded. B. rubber or plastic, which ensures an elastically flexible or floating mounting of the shaft core 93 in the shaft 25, namely radially, axially and in the circumferential direction. In the presence of elevations according to the invention and recesses receiving them between the shaft shell 92 and the shaft core 93, for example an annular groove in the outer surface of the shaft 25 or a waist of the shaft shell 92 and / or the shaft core 93, the positive connection between the damping means 91 and the shaft shell is provided 92 on the one hand and the shaft core 93 on the other hand, so that no further connection is required. However, it is possible to use the damping means 91 to firmly connect the inner peripheral surface of the shaft shell 92 and the outer peripheral surface of the shaft core 93 in another way, e.g. B. to glue. It is possible to inject the elastically deformable material of the damping means 91 between the shaft core 93 and the shaft shell 92 in a liquid or pasty state, which ensures particularly simple and quick production. In the context of the invention, it is further possible that the shaft shell 92 also covers the shaft core 93 on the front side facing and / or facing away from the machining section 5a and that the damping means 91 is arranged on the respective front side between the shaft shell 92 and the shaft core 93. However, it is also possible for the shaft shell 92, the damping means 91 and the shaft core 93 to terminate with one another on this end face and to form a common end face. In this embodiment, the damping means 91 is in the form of a sleeve or socket. The shaft shell 92 can be a sleeve or cap made of metal, whereby the shaft 25 is stabilized on the outside. The stresses emanating from the above-described fastening elements 28, 42, 46 can thus be absorbed by the tool shank 25 with a long service life. In the presence of an annular groove 31, the screw 28 can exert a positive and otherwise non-positive fastening effect on the tool shank 25. The cross-sectional dimension of the shaft shell 92 is adapted to the cross-sectional dimension of the transverse hole 27 or the plug-in recess 68b of the collet 61 with a slight amount of play, so that the tool 5 can be inserted and removed in a manner which is easy to handle.

Within the scope of the invention it is possible and, for reasons of simplification, also advantageous to design the tool shank 25 only with the shank core 93 and the damping element 91 in the form of an elastic sleeve, ie to omit the shank shell 92. Such an embodiment is also functional. Such a tool shank 25, the hollow cylindrical damping member 91 as a _solid. e.g. glued, attachment on and can be made with a small amount of movement and an axial locking or with a small cross-sectional oversize and thus can be elastically pressed into the shaft receiving hole, which due to the elastic radial clamping forces a tight fit and possibly an axial locking is ensured . A shaft shell 92 can also be dispensed with when using a collet 61.

It is advantageous within the scope of the invention for fine machining with a greater damping effect (high elasticity) and for rough machining with a lower one

Damping effect (small elasticity) to work. Tools or

Handpieces of different sizes damping are trained and provided. It is It is also advantageous to configure the damping means so that it can be adjusted between a larger and a smaller damping by means of an adjusting device 105.

In the embodiment according to FIG. 20, in which the same or comparable parts are provided with the same reference symbols, the cross-sectional size of the shaft shell 92 is variable in the manner of a cuff or bandage, as a result of which the elasticity of the damping element 91 is variable and adjustable. The adjustment mechanism for changing and adjusting the shaft strap designated 92a in FIG. 20 is not shown. It can be an adjustment mechanism, as is common with hose clamps.

21, the damping element 91 is not a part of the tool 5 but of the handpiece, here the handpiece shaft 4 and thus part of the drive connection for the tool 5. In the present embodiment, the damping element 91 is a receiving sleeve 94 made of elastic material such as Rubber or plastic, which is inserted into a correspondingly dimensioned transverse hole 95 in the shaft 4 and fastened therein, for. B. by gluing or by pressing against the receiving sleeve 94 or partially enclosing screw 28. The transverse hole 27 is arranged in this embodiment in the receiving sleeve 94, wherein it can be sized so that the tool shank 25 with little movement or can be inserted with a slight oversize and with an elastic compressive stress. In the first case and also in the second case, the screw 28 can take over the function of axially securing the tool shank 5 in that it presses radially inward against the receiving sleeve 94 and deforms it, thereby creating a non-positive connection or a deformation in the notch 31 or annular groove causes a positive locking of the tool shank 5 against axial displacement.

21 and 22 further exemplary embodiments for supplying the cooling, rinsing or treatment medium to the tool 5 are described, which can likewise be implemented in all of the above-described configurations. In the embodiment according to FIG. 22, the tool according to FIG. 19 or 20 is located in the receiving hole 27, the screw 28 engaging in the notch 31 or annular groove and forming an axial securing device 100 for the tool 5. In addition, the axial channel section 32b extends into the area of at least one machining surface on the machining section 5a or towards the front end of the tool shank 25 facing away from the machining section 5a, a detachable line connection 96 for a supply line 4e for the cooling pipe running outside the handpiece shank 4 at this outlet end. , Rinsing or treatment medium is provided. The end facing the machining section 5d can open out with one or more radial or oblique channel branches 32d in the transition region to the machining section 5a or in at least one machining surface, as has already been described.

21, one or more orifices 97 of the feed line are distributed around the transverse hole 27 or 95, which are connected by a bypass channel to the shaft cavity or feed channel 4a, which extends axially longitudinally through the handpiece shaft 4 according to FIG. 1 can extend or can be connected by a radial channel branch 4g and a detachable line connection 96 to the supply line running laterally next to the shaft 4.

It is also possible within the scope of the invention to design the receiving sleeve 94 in connection with the notch 31 or annular groove in the tool shank 25 as an axial securing device 100 and latching device 101, the tool shank 25 being insertable into the receiving hole 27 with little movement and the notch 31 or An elastically resilient or deformable latching nose 102 is provided opposite the annular groove, which engages in the notch 31 or annular groove and can be manually overpressed when the tool shank 25 is pushed in and out and expands automatically into the notch 31 or annular groove when inserted.

It is possible within the scope of the invention to form the latching lug 102 as a projection or as a ring on the inner wall of the receiving sleeve 94 or to bulge inwards by a radially inward pressure generated by the screw 28 on the receiving sleeve 94. The strength of the locking device 101 can be adjusted by screwing in the screw 28 to a greater or lesser extent.

The elasticity of the damping element 91 can also be changed and adjusted by means of the screw 28. The greatest elasticity is given when the screw 28 or the latching lug 102 presses only slightly against the receiving sleeve 94 or the shaft 25. The more the screw 28 is screwed in and the greater the contact pressure, the lower the elasticity of the damping element 91 and vice versa. Therefore, the screw 28 in connection with the reception of the shaft 28 in the receiving sleeve 94 also forms an adjusting device 105 for adjusting the elasticity of the damping element 91.

The tool 5 can also be freely rotated about its longitudinal central axis 10 in the tool holder. Such a swivel joint 106 is present when the tool shank 25 has little radial play in the receiving channel 27 of the handpiece shank 4 or in the receiving sleeve 94, so that it can be freely rotated therein and an axial fixing device is provided which axially fixes the tool shank but does not press radially inward against it. This can be achieved by engaging the locking lug 102, which is designed as a projection or as a ring, by engaging in the annular groove 31 with play. It is possible to form the latching lug 102 on the inside or to push it out of the elastic material of the receiving sleeve 94 by means of the screw 28 to such an extent that it fulfills the aforementioned features.

It is furthermore possible for the screw 28 to pass through the receiving sleeve 94 in a hole and to engage it in the annular groove 31 with its free, preferably rounded end.

A free or somewhat braked rotatability of the tool 5 has the advantage that no harmful torque can be exerted on the tooth or on the treatment site with the handpiece and with the tool 5 when rotating about the longitudinal central axis 10, since the tool 5 spins. On the one hand, this protects the tooth or the gums or the jawbone or the treatment site and, on the other hand, the tool 5 itself from overloading and damage. This is not only advantageous in the case of tools 5 whose processing section 5a or processing body have a non-round cross-sectional shape with which the torque can be exerted particularly prominently on the treatment site, but also have a round cross-sectional shape, especially if it is a ^' thin processing section acts that tends to break or bend, as is the case in particular with root canal files, as are exemplified in FIGS. 19 and 23. Such tools 5 are particularly at risk if they are stuck in the cavity K to be worked out or in the root canal WK. However, all other exemplary embodiments of the holding device 26 are suitable for root canal files.

The rotatability of the tool 5 according to the invention about its longitudinal central axis 10 in connection with the screw 28 thus also forms an overload safety device 111 which, due to the adjustable tension of a preferably elastic, radially inward adjustment element against the tool 5 or against the tool shaft 25, here the Latching lug 102 to which the respective requirement, in particular given by the strength of the tool 5, can be adapted.

Furthermore, the screw 28 forms a rotational position locking device 115 for the tool 5, which allows the tool 5 in certain rotational positions adjust, and which can be brought into and out of function by screwing the screw 28 in and out.

In the embodiment according to FIG. 23, in which the same or comparable parts are provided with the same reference numerals, the axial securing device 100 and the latching device 101 and a damping element 91 with a modified adjusting device 105 for the elasticity are assigned to the handpiece or the handpiece shaft 4. In this embodiment, the elastic receiving sleeve 94 is axially compressible between an abutment, here in the form of a step surface 95a of the receiving hole 95 and an adjusting element 105a, and is therefore more or less expandable, so that the inner wall of the receiving hole 27 presses more or less elastically against the tool shank 25 and thereby on the one hand determines the elasticity of the damping means 91 and on the other hand the size of the torque at which the overload protection device 111, which is also integrated, comes into operation and can turn the tool shank. The adjusting element can be formed by a hand nut with grip grooves screwed into the receiving hole 95. The latching device 101 is formed by an inner elastic latching lug 102 in the form of a projection or ring, which can be overpressed in the manner described above when the tool shank 25 is pushed in and out.

It is also advantageous to design the tool holder with a swivel joint 118, in which the tool 5 can be swiveled against an elastic restoring force about a swivel axis running coaxially or axially parallel in the region of the tool shank 25 or transversely to the handpiece shank 4 and transversely to the tool shank 25. Instead of a pivot axis, the pivot joint 118 can also be spatially pivotable about a pivot point 118a. In both cases, the swivel joint 118 is centered in each case on account of the elastic restoring force of the receiving sleeve 94. In this embodiment, the tool 5 can move sideways, making it less prone to breakage. This configuration is very advantageously suitable for machining in the lateral region of the tooth and tooth neck, as is the case with lateral cavities or crown preparations. In the present exemplary embodiments, the swivel joint 118 is formed by the elastic receiving sleeve 94, which enables pivoting against its elastic restoring force. The restoring force of the joint 118 can be reduced or increased by screwing in the screw 28 or the adjusting element 105a to a greater or lesser extent.

In the exemplary embodiments according to FIGS. 24 and 25, in which the same or comparable parts are provided with the same reference symbols, the tool holder is provided with a Swivel joint 106 assigned a locking device 121, which cancels the free rotatability when the lateral load on the tool 5 exceeds a predetermined force. This configuration is also particularly advantageous in the case of machining in the lateral tooth area, including the intermediate tooth area, as is also the case with a crown preparation. If, for example, the tool 5 should not be able to evade by turning, the swivel joint 106 can be locked by switching on the locking device 121, so that the tool 5 cannot evade and can perform cutting work in the respective rotational position. 24, this is achieved in that a first locking ring 122 is arranged on the tool holder, here on the handpiece shank 4, at a radial distance c around the tool 5, which, when the tool 5 is pivoted laterally, with an opposite second one Locking ring 123 of the tool 5, here on its shank 25, engages non-positively due to friction or positively due to a tooth engagement and thereby prevents the tool 5 from rotating.

It is possible within the scope of the invention and depending on the shape and purpose of the tool 5, it is advantageous to design the locking device 121 in such a way that the rotatability is blocked or canceled at a specific axial tool load. In this case, the locking ring 123 is arranged on its side facing away from the machining section 5a, on which it is also non-positively or positively designed as locking ring 123a, at axial distance d a locking ring 122a with which it interacts in the event of an axial displacement.

24 and 25 differs with respect to the design of the damping element 91 from the above-described exemplary embodiment in that the receiving sleeve 94 made of elastic material is part of the tool 5 and sits firmly on its shaft 25, e.g. is vulcanized or glued on. It thus forms an integral part of the tool 5. With this receiving sleeve 94 is the tool shaft

25 in the receiving hole 95 in the handpiece shaft 4 with play or easily inserted and axially secured, in the present embodiment by means of the screw

28, which in a notch 31 or preferably an annular groove in the lateral surface of the

Binding sleeve 94 surrounds. In this embodiment, too, there is an axial one

Security device 100 in the form of a locking device 101, a

Adjustment device for adjusting the elasticity of the damping element 91, an overload securing device 111, a rotational position determining device 115 and a

Swivel joint 118 is present, as already described. The tool 5 not only according to the exemplary embodiments according to FIGS. 1 to 9 but also according to the exemplary embodiments according to FIGS. 10 to 24 is suitable for working out a cavity in the lateral or approximal region of the tooth, the side surface of the tool 5 facing away from the tooth being smooth is so as not to injure the neighboring tooth in the proximal area when using the tool 1. This tool 5 is set up to be worked into the tooth from the side in the approximal area from the occlusal side and in the remaining side area of the tooth 35. The associated lateral work surfaces of the machining section 5a are designed to be convergent in the respective direction of incorporation in order to be able to easily pull the machining section 5 out of the machined cavity.

Within the scope of the invention it is possible and advantageous to use a liquid as a treatment agent in which there is a suspension with small hard and abrasive particles in order to increase the performance of the machining or abrasive processing.

3 and following, the tool 5 can have the angle channel 32a, 32b or the shaft 25 the channel 32al for the cooling, rinsing or treatment medium.

The distance a of the tool 5 from the apex 51 of the bend can be smaller or larger than the distance b between the bend and the grip sleeve 1. The distance a is preferably approximately 1 to 3 cm, in particular approximately 1 to 2 cm.

The vibration generator 2 generates short-stroke vibrations in the sense of a vibration with a frequency that is preferably in the sound or ultrasound range, wherein the vibrations or amplitudes can be linear or spatially directed transversely or longitudinally. Epsilon-shaped or circular spatial vibrations have also proven to be advantageous. In the present embodiment, depending on the working direction transverse or along the handpiece, the main direction of such vibrations can be transverse or along the

Shaft 4 run. The frequency of the vibrations is in the sound or ultrasound range and is approximately 4 to 8 kHz, preferably 6 kHz, the amplitude of the vibrations in the area of the tool 5 being approximately 0.05 to 0.2 mm, in particular approximately 0.1 mm.

It is also advantageous to equip the handpiece with a vibration generator 2, the power and / or frequency of which can be adjusted in order to use different ones Tools 5 and / or shaft parts 4c to achieve a favorable ratio between the vibrations and the respective mass. The adjustability can be provided continuously or in stages. For adjustability, a manually operated actuator on

Handpiece, in particular on the grip sleeve 1, may be provided.

The invention and the embodiments described above are also advantageous for a so-called laboratory handpiece for processing prostheses or samples of parts of the human or animal body in a medical or dental laboratory.

Claims

Expectations

1. Medical or dental medical handpiece for machining or abrasive processing, preferably of tissue of the human or animal body, with a holding device (26) for fastening a tool (5) on

Handpiece, and with a drive (2) for an oscillating movement of the tool (5), or handpiece according to one of the preceding claims, characterized in that the holding device (26) is a latching device (101) with a

Has locking element (102) for the tool (5), the locking element (102) being able to be pushed over during manual insertion and removal of the tool (5).

2. Medical or dental handpiece according to claim 1, characterized in that it has a projecting shaft (4) and the holding device (26) is arranged in the front end region of the shaft (4).

3. Medical or dental medical handpiece according to claim 1 or 2, characterized in that the latching device (101) one or more notches (31) arranged distributed around the circumference or an annular groove each with an axially cut or wedge-shaped cross section in the shaft (25 ) of the tool (5).

4. Medical or dental medical handpiece according to one of the preceding claims, characterized in that the latching element (102) is preferably assigned to the holding device (26) and is elastically resilient or elastically deformable.

5. Medical or dental handpiece according to one of the preceding claims, characterized in that the holding device (26) has a receiving sleeve (94) made of elastically deformable

Has material, the receiving hole (27) forms a plug hole for the shaft (25) of the tool (5), and that the locking element (102) on the wall of the Receiving hole (27) is formed or bulged by a screw (28) screwed into the shaft (4) of the handpiece and pressing against the receiving sleeve (94).

6. Medical or dental handpiece according to one of the preceding claims, characterized in that the strength or elasticity of the locking device (101) can be increased or reduced.

7. Medical or dental-medical handpiece for machining or abrasive processing, preferably of body tissue, with a holding device (26) for fastening a tool (5) to the handpiece, and with a drive (2) for an oscillating movement of the tool (5), or handpiece according to one of the preceding claims, characterized in that the holding device (26) has a swivel joint (118) in which the tool (5) is mounted so as to be pivotable about a pivot axis or spatially around a pivot point (118a) and in each case by a restoring force in its middle position is applied.

8. Medical or dental-medical handpiece for machining or abrasive processing, preferably of body tissue, with a holding device (26) for fastening a tool (5) to the handpiece, and with a drive (2) for an oscillating movement of the tool (5), or handpiece according to one of the preceding claims, characterized in that the holding device (26) has a rotary joint (106) or rotary bearing in which the tool (5) can be rotated about its longitudinal central axis (10)

9. Medical or dental handpiece according to claim 8, characterized in that the pivot joint (106) or pivot bearing is assigned a rotational position locking device (115, 121) with which the rotatability of the tool (5) in the pivot joint (106) can be blocked.

10. Medical or dental medical handpiece according to claim 9, characterized in that that the locking device (121) can be brought into engagement by a lateral and / or axial movement of the tool (5) and can be released by a movement in the opposite direction of movement, wherein preferably a tooth engagement is provided which is provided by mutually opposite, radial and / or toothed rings (122, 123; 122a, 123a) having an axial spacing (c, d) from one another is formed on the tool (5) or on the tool shank (25) and on the handpiece shank (4).

11. Medical or dental medical handpiece according to one of the preceding claims, characterized in that the holding device (26) has a round recess (27) into which the tool shank (25) can be inserted and secured against axial loosening.

12.Medical or dental medical handpiece for in particular machining or abrasive processing, preferably of body tissue, with a shaft (4) and a tool (5) arranged at its free end, which has one or more machining or abrasive work surfaces, and by a drive (2 ) can be driven in an oscillating manner, in particular for working out a cavity or a root canal in a tooth with an oscillating movement of the tool (5), or handpiece according to one of the preceding claims, characterized in that the tool (5) is a separate component and by a holding device ( 26) is detachably connected to the shaft (4) or is an adjustable component which is connected and lockable to the shaft (4) in the respective adjustment position by a locking device.

13. Handpiece according to one of the preceding claims, characterized in that the adjusting device or the holding device (26) round or non-circular or polygonal a receiving hole (27) arranged axially or transversely to the shaft (4)

Cross section in the handpiece shank (4) and the tool (5) has a corresponding shank shape (25) which can be inserted into the receiving hole (27) with movement.

14. Handpiece according to claim 13, characterized in that the locking device or the holding device (26) a clamping or

Has locking screw (28), which is preferably screwed from the front into a particularly coaxial threaded hole (29) in the handpiece shaft (4) and can be clamped against the tool shaft (25).

15. Handpiece according to claim 14, characterized in that the tool shaft (25) has a notch (31) preferably formed by an annular groove for the engagement of the clamping or locking screw (28).

16. Handpiece according to claim 12 or 13, characterized in that the receiving hole (27) is arranged in the foot region of a threaded bolt (41) which preferably projects forward from the handpiece shaft (4) and onto which a threaded nut (42) can be screwed and against which

Tool shank (25) can be clamped.

17. Handpiece according to one of the preceding claims, characterized in that the locking device or the holding device (26) by a

Quick-connect connection (45) is formed.

18. Handpiece according to one of claims 12 to 17, characterized in that on the handpiece shank (4) a pressure member (46) is mounted to be longitudinally displaceable, which can be clamped against the tool shank (25) by a spring force which can be suppressed manually or by means of a reduction gear (56) is.

19. Handpiece according to claim 18, characterized in that the pressure member is formed by a sleeve (46a) which is mounted on the handpiece shaft (4).

20. Handpiece according to claim 18 or 19, characterized in that a pressure spring (48) is provided to act on the pressure member (46) or the sleeve (46a), which is mounted on the handpiece shaft (4) and on one

Shoulder surface (47) of the handpiece shaft (4) is supported.

21. Handpiece according to one of claims 18 to 20, characterized in that a recess for the engagement of the pressure member (46) is provided in the tool shaft (25).

22. Handpiece according to claim 21, characterized in that the depression is formed by a flattened portion (49) or two flattened portions (49) having an axial spacing from one another with shoulder surfaces (49a) or annular grooves.

23. Handpiece according to one of claims 18 to 22, characterized in that between the pressure member (46) and the tool shank (25) a positive connection for axially fixing the tool shank (4) on the pressure member (46) is arranged.

24. Handpiece according to claim 22 or 23, characterized in that the pressure member (46) engages over one or both shoulder surfaces (49a) in a form-fitting manner.

25. Handpiece according to one of the preceding claims, characterized in that the holding device (26) has an overload coupling (55) is assigned, which releases the tool shank (25) in the event of overload.

26. Handpiece according to one of the preceding claims, characterized in that the central axis of the receiving hole (27) and / or the tool (5) with the

Include the central axis of the shaft (4) at an acute or right or obtuse angle (W), in particular an angular range of approximately 75 to 105 °.

27. Handpiece according to one of the preceding claims, characterized in that the shaft (4) is angled laterally, preferably to the side facing away from the tool (5), in particular by an angle (W) of approximately 10 to 20 °, preferably approximately 15 °.

28. Handpiece according to one of the preceding claims, characterized in that the tool (5) opposite a work surface has a smooth surface.

29. Handpiece according to one of the preceding claims, characterized in that a support leg (85) is provided on one side of the tool (5).

30. Handpiece according to claim 29, characterized in that the support leg (85) is held on the shaft (4) or on the tool shaft (25) and is adjustable, in particular rotatable, with the tool (5).

31. Handpiece according to claim 29 or 30, characterized in that the abutting contact surfaces (86, 87) of the support leg (85) and the tool (5) are profiled in the longitudinal direction of the tool (5), are shaped in particular roof-shaped.

32. Handpiece according to one of the preceding claims, characterized in that there is a media line (6a, 6b; 83) preferably for a machining or

Treatment or cooling liquid, which extends longitudinally through the handpiece (5) and is directed with an outlet opening onto the treatment site or a processing section (5a) of the tool (5) or which extends at least partially through the handpiece shaft (4), passing through the holding device (26) and the tool shank (2) and at at least one outlet opening (32c) in at least one working surface and / or in a smooth surface (5b) of the machining section (5a) and / or in the transition region between the tool shank (25) and a processing section opens.

33. Handpiece according to claim 32, characterized in that the at least one opening (32c) is provided above the machining section (5a) of the tool (5) or in the transition region between the machining section (5a) and the shaft (25).

34. Handpiece according to claim 32 or 33, characterized in that a lateral line connection (81) for a media line (82) is arranged on the shaft (4).

35. Medical or dental medical handpiece for machining or abrasive processing, preferably of body tissue, in particular for working out a cavity (K) or for preparing a root canal (WK) in a tooth, with a holding device (26) for fastening a tool (5) to the handpiece , and with a drive (2) for an oscillating movement of the

Tool (5), or handpiece according to one of the preceding claims, characterized in that a damping means (91) is arranged in the drive connection for the tool (5).

36. Handpiece according to claim 35, characterized in that the damping means (91) in the holding device (26) or in the tool shank (25) is integrated.

37. Handpiece according to claim 35 or 36, characterized in that an adjusting device (105) for increasing or decreasing the elasticity of the damping element (91) is provided.

38. Medical or dental medical handpiece according to one of the preceding claims, characterized in that the damping element (91) through a sleeve (94) made of elastically deformable

Material is formed, which surrounds the tool shank (25).

39. Medical or dental medical handpiece according to claim 38, characterized in that the sleeve (94) is fixedly arranged on the tool shank (25) or is held in the holding device (26).

40. Medical or dental handpiece according to one of the previous ones

Claims, characterized in that for axially securing the tool shank (25) in the sleeve (94) or the

Sleeve (94) in the holding device (26) a transversely directed fixing or clamping or screwing element or a locking device (101) is provided.

41. Medical or dental medical tool (5) for machining or abrasive processing of preferably body tissue, in particular for preparing a canal or root canal (35a) of a tooth (35), in particular for a handpiece according to one of the preceding claims, consisting of a

Processing section (5a), from one end of which a tool shaft (25) extends, with which the tool (5) can be connected to a holder of a handpiece, in which an oscillation drive is arranged, with which the holder with the Tool (5) fixed therein can be driven in an oscillating manner, or tool according to one of the preceding claims, characterized in that between the machining section (5a) and the tool shaft (25) or in the region of the tool shaft (25) or between the tool shaft (25) and a damping means (91) is arranged in a retaining ring (92) surrounding it or the damping means (91) forms the retaining ring (94).

42. Tool or handpiece according to one of the preceding claims 35 to 41, characterized in that the damping means (91) consists of elastically deformable material, in particular plastic or rubber.

43. Tool or handpiece according to one of the preceding claims 35 to 42, characterized in that the tool (5) or the drive connection is formed in two parts and the two parts (92, 93; 4, 94) are connected to one another by the damping means (91) are.

44. Tool or handpiece according to one of the preceding claims 35 to 43, characterized in that the tool shank (25) from a shank core (93) and the shank core (93) surrounding and with the shank core (93) e.g. firmly or positively or non-positively connected damping element (91) is formed.

45. Tool or handpiece according to claim 44, characterized in that the shaft core (93) has the shape of a pin and the damping element (91) has the shape of a seated thereon, optionally closed on the end face.

46. Tool or handpiece according to claim 44 or 45, characterized in that the damping element (91) has a shaft shell (92) made of a harder material than the damping element (91).

47. Tool or handpiece according to claim 46, characterized in that that the shaft shell (92) consists of metal.

48. Tool or handpiece according to one of the preceding claims 35 to 47, characterized in that the damping element (91) is formed by a bush (94) into which the

Tool shaft (25) can be inserted and fixed.

49. Tool or handpiece according to claim 48, characterized by a transversely to the socket (94) directed fixing or clamping or screwing element

Fixing the tool shank (25) in the socket (94).

50. Tool or handpiece according to one of the preceding claims, characterized in that the tool shaft (25) or the sleeve (94) or the switching shell (92) on the

The lateral surface has a preferably divergent or preferably wedge-shaped recess (31) in cross section, which in particular has an annular shape.