WO1999005984A2

WO1999005984A2 - Tool operating device, in particular for use in dentistry

Info

Publication number: WO1999005984A2
Application number: PCT/EP1998/004758
Authority: WO
Inventors: Karl Behr; Erich Kratzmaier; Axel Oswald
Original assignee: Karl Behr; Erich Kratzmaier; Axel Oswald
Priority date: 1997-08-01
Filing date: 1998-07-30
Publication date: 1999-02-11
Also published as: DE19733501A1; WO1999005984A3; AU9255998A

Abstract

The invention relates to an identification system of a tool or intermediate piece, for use in a tool operating device. Said tool operating device also has means for automatic detection of this identification, and an automatic drive which is actuated in accordance with the identification information received. The inventive device is preferably used in dentistry.

Description

Tool operating equipment. especially for the dental field

Description:

This invention relates generally to the field of power tools. In particular, but not exclusively, the dental field, that is to say dental or dental technology tools, is intended.

In the case of motor-driven tools, a tool operating device with the motor and a control device for operating the tool are generally equipped with a removable tool. This tool can be exchanged for another tool, for example, in the event of wear or before a different type of work. Normally, the removable tool is therefore not only to be exchanged for another identical tool, but rather there is also a choice of different tool types for the same tool operating device.

In addition, intermediate pieces between the tool and the tool operating device are also used, which in turn can be removed from the tool operating device and may be interchangeable with other types. The intermediate pieces can have different functions, for example as an adapter between different connection devices on the part of the tool operating device and the tool. Gearboxes with torque or speed ratios can also be available. Furthermore, an intermediate piece can also be used to adapt the geometry of the tool operating device to a specific application, for example as an extension or angled piece. Of course, these functions can also be fulfilled at the same time; intermediate pieces can also be used in series. In the following, the term "attachment" is to be used in summary for such intermediate pieces and the previously mentioned tools. An attachment piece is therefore generally an additional part that can be placed or attached to the tool operating device for indirect or direct use of tools.

However, as soon as more than one attachment piece comes into consideration, it makes sense to operate the tool operating device in accordance with the specific type of attachment piece actually installed, for example with a specific maximum motor torque, a specific nominal speed range, a fixed preset machining program sequence from such operating parameters or also including one Workpiece / tool relative movement etc. Various attachments are therefore linked to certain operating parameters which are important for the operation of the tool operating device or for the operation and use of the tool itself.

Whenever more than one attachment for a tool operating device comes into question, i.e. with different types of tools or intermediate pieces to choose from, there is a risk that the operator incorrectly recognizes the attachment used when operating the tool operating device or an automatic program control of the tool operating device or inadvertently initiates incorrect surgical steps despite correct detection.

In this regard, the invention is based on the technical problem of reducing the possibility of errors when operating a tool operating device with an attachment piece and thus improving the reliability and safety of the device and of working with it.

According to the invention, this problem is solved by a tool operating device with an automatic recording device for recording information from a marking of a marked attachment and with a control device for controlling the tool operating device. device in response to the information with these assigned operating parameters.

Furthermore, the problem described is solved by an attachment for a tool operating device with an immediately attached and information-bearing identification, the information being detectable for a detection device of the tool operating device and being implementable by a control device of the tool operating device.

The invention also relates in particular to a tool system comprising the above tool operating device and the above attachment.

In addition, to solve its problem, the invention also relates to a method for operating such a tool system, in which the tool operating device is actuated with the associated operating parameters in response to information acquired from the identification of the marked attachment.

Finally, the invention also includes an advantageous device in connection with the aforementioned marking according to the invention for attaching a depression to an attachment piece for a tool operating device with a motor, a milling or drilling head driven by the motor, and a receptacle for the attachment piece, which essentially mechanically is designed as a standard counterpart for a standardized connection of the extension.

The basic idea of the invention thus consists in the combination of an individualization of the end pieces by an identification that can be read by the tool operating device, ie generally ascertainable, with an automatic machine detection of this identification by the tool operating device itself the operator reliably detects at least the type of attachment. In addition, of course, the conversion of this information into a control of the tool operating device is also carried out automatically, at least to the extent that the operator is possibly offered a number of operating parameter or work program options that are possible with the detected tool type. However, operating errors are largely excluded because the selection only contains permissible options from the outset.

However, it is preferable to automate the control device in such a way that the operating parameters corresponding to the detected information enter the control of the tool operating device directly and without further intervention by the operator.

How far the automation goes depends essentially on which operating parameters are specified via the information contained in the labeling. Of course, these are preferably those whose incorrect setting has the most critical consequences for the tool operating device, the tool, the workpiece, or even the patient in the case of a medical system.

The term “tool” is to be understood in a broad sense in connection with this invention and also includes machines. For example, saw attachments for universal motor drive systems are also included in this term.

According to a preferred embodiment of the invention, the identification is read out without contact. Problems with contact wear or other wear on the marking or the detection device as a result of the detection process are thus avoided. Furthermore, without touching the part bearing the identification, it is particularly easy to access the identification even when the parts bearing the identification are moved and would interfere with a contact or mechanical connection. This also applies if these parts are (currently) relative to Detection device are fixed, but movable in themselves and thus are not completely fixed in their relative position to the detection device.

It should be emphasized that there are fundamentally different detection techniques for both contactless and "touching" detection. It is just as much a matter of mechanical detection and identification by positive or non-positive engagement (for example by means of tapped shapes) as it is purely electrical (about resistance measurement) to think purely magnetic or electromagnetic technology, the details being readily clear to the person skilled in the art.

An elegant variant, in particular contactless detection, which has been tried and tested according to experimental experience with the invention, is an optical detection of the marking. This can be done by measuring a color serving as a code, so that depending on the resolution of the color measuring device with a single marking or marking surface, that is to say without the need for further geometric structures and their detection, numerous different codings can be distinguished in a simple manner.

Another advantage of color coding is the relatively low susceptibility to contamination. A common contamination affects the brightness of the color coding rather than its color, because the contaminations themselves are generally not very colored, ie essentially "gray". This means that the colors can still be detected reliably, even at lower brightness or intensity, due to contamination a coding in brightness values might no longer be traceable.

A further advantageous possibility consists in querying a binary code which is constructed, for example, as a bar code, that is to say as a result of lines to be scanned (for example light and dark). As further illustrated in the exemplary embodiment, this results in above all cheap ones Possible solutions for the marking of moving parts of attachments, specifically in the exemplary embodiment by a line sequence in the circumferential direction of a rotating cylindrical shank of a tool. In the case of a lifting movement, the tool can also have a line sequence parallel to the axis.

Laser marking is a permanent and technically simple and inexpensive way of producing these line sequences or other binary codes. This means a change in the surface of the surface to be marked caused by the energy of an irradiated laser, for example a blackening of a metal surface of a tool shank.

When using one or more intermediate pieces, it is preferred according to the invention to provide a coupling between the detection device on the part of the tool operating device and the identification of a tool or of an intermediate piece not itself used directly on the tool operating device. In the case of optical detection, this can be done primarily by installing or mounting a correspondingly designed light guide in or on the intermediate piece or pieces. In particular, a simultaneous consideration of the information from the identification of the tool and of the intermediate piece (s) can be achieved in this way. The gear ratio of a transmission intermediate piece and the tool type can thus be taken into account.

In the case of the described and also other possible designs of the marking on the extension piece, it is fundamentally advantageous to attach the marking so that it cannot be detached, that is to say, for normal operation of the tool system, there is no separation between the marking and the marked tool. This is the case, for example, with laser inscription or a largely abrasion-resistant paint application (in contrast to, for example, a sticker). This is the only way to ensure that identifiers that are inadvertently loosened are lost or incorrectly reattached, thereby impairing the safety function of the invention. In the same sense, it is advantageous for the marking to be as protected as possible. For example, a colored surface can be provided in a recess and / or under a transparent protective cover in order to protect it against scratching or dirt or to facilitate cleaning.

As already mentioned, the “operating parameters” can be various variables that are relevant for the operation of the tool or the tool operating device. In a narrower sense that is also preferred according to the invention, however, these are engine parameters, such as torque or speed, as well as setpoints, under- or Upper limits or time functions.

The invention is particularly aimed at the area of tool operating devices in which at least one motor drive unit is to be held in the hand. Such devices also occur in particular in the dental field and in other medical technology. This is a particularly interesting field of application of the invention, because the technical requirements for maintaining certain operating parameters are particularly critical here. Errors in the correct motor speed for a specific gear ratio, for example a so-called contra-angle handpiece of a dental handpiece, can lead to a defect in the contra-angle handpiece or the tool or even serious damage to the tooth being treated.

In the field of dental spacers, a further advantageous embodiment of the invention relates to an embodiment of a receiving head with a holder for receiving a dental tool in such a way that a gear for driving the tool lies away from the tool, from the detection end of the described light guide of the coupling device. Then, as further clarified in the exemplary embodiment, the optical detection of an identification of the tool can be carried out particularly easily.

Another aspect of the invention relates to the application of the marking on the attachment, which is protected by a recess, such as the application of a color in a recess a special device for making such a recess. According to the invention, such a device has a motor drive and a milling or drilling head. It is essential that the adjustment of the relative position between the device and the piece to be processed, that is to say labeled, and simple and safe handling during processing are ensured by a special receptacle for the attachment piece. For this purpose, this receptacle is modeled on a standard counterpart to the connection of the extension piece, it being assumed that such connections are generally standardized. Such standard couplings often also determine the angular position between the attachment piece and the coupling counterpart, in this case the machining device.

In the aforementioned standard coupling, an ISO standard coupling of a dental handpiece is primarily intended, which is essentially mechanically simulated in the device for attaching the recess, but without taking into account the internal connections of such couplings for electricity and the like.

The following is a description of a non-limiting exemplary embodiment, which is shown in the figures. The individual features disclosed can also be essential to the invention, either individually or in combinations other than those shown.

In detail shows:

1 shows a dental handpiece according to the invention,

2 is a sectional and cross-sectional view of FIG. 1 with the structure of the tool holding head of an intermediate piece according to the invention and a tool shaft mounted therein, 3 shows an illustration of a bar code according to the invention for identifying a tool,

Fig. 4 shows an inventive device for making a recess on the intermediate piece from Figs. 1 and 2 and

Fig. 5 is a plan view of the receptacle of the device of Fig. 4 for an intermediate piece.

1 shows a dental handpiece 5 according to the invention, specifically a motor drive unit 5 to be held in the hand with an attached intermediate piece 4. (With regard to further details of the construction of the dental handpiece, not particularly explained here, in particular the housing of the motor drive unit 5 and intermediate piece 4 and the Assembly of the latter on the former is referred to patent application 197 14 248.6 by the same applicants dated 7.4.1997.)

The motor drive unit 5 is supplied with operating media, for example with electricity for an electric motor 10, with pressurized fluid for dental treatment and the like, through a connecting line which is shown in the lower region of the figure and is not of particular interest here. Electrical signal lines for feedback signals about the operating state of the motor 10 are also included. A compressed air line for a compressed air motor could also be provided.

The intermediate piece 4 is a conventional dental angle piece with an internal transmission gear. It is driven by the motor 10 in the motor drive unit 5 via a clutch 11, the internal gear being drawn here as an angled and otherwise continuous shaft 12 for the sake of simplicity of illustration. In addition to these conventional features, the intermediate piece 5, however, has an identification 2 according to the invention in the form of a flat color code on the connection surface to the motor drive unit 5 and an optical fiber 6 as a coupling device. The color coding 2 of the intermediate piece 4 is detected via a further light guide 13 within the motor drive unit 5 as part of the detection device 1 according to the invention, that is to say read out. An additional light guide 14 in the motor drive unit 5, which is also part of the detection device 1, serves together with the coupling device light guide 6 already mentioned in the intermediate piece 4 for reading out the identification 2 of a tool 3 mounted on the end of the intermediate piece 4 facing away from the motor drive unit 5 , here a common dental drill. This marking 2 consists of a line sequence generated by laser inscription as a binary code and is described in more detail below.

The signals guided by the described light guides 13 and 14 in the motor drive unit, i.e. the light-dark sequences from the bar code identification 2 of the tool 3 and the color signal from the color identification 2 of the intermediate piece 5, are also formed by light guides which form part of the detection device 1 15 in the connection line already mentioned for evaluation of a stationary base station, not shown. In the opposite way, the two labels are illuminated for reading.

Since, in particular, the air gap between the light guides 6 and 13 at the transition from the motor drive unit 5 to the intermediate piece 4 provides for a damping of the light signals transmitted over it, which increases with the width of the air gap, the light guide 6 can, for example, be spring-mounted in the intermediate piece 4. As a result, when the intermediate piece 4 is mounted on the motor drive unit 5, it sits directly on the counter surface of the light guide 13 in the motor drive unit and springs back somewhat to the tool in the longitudinal direction of the dental handpiece. On the tool side, a certain distance is required anyway between the corresponding end of the light guide 6 and the tool shank 3 due to the rotation of the drill 3 during operation, which has a tolerance that is sufficient for this resilience. This base station also contains the control device according to the invention for converting the acquired information into operating parameters and for controlling the tool operating device. In the case shown, this means the control of the electric motor 10 with motor parameters, namely a maximum motor torque and a target speed (which is ramped up and down in a time-controlled manner). For this purpose, the control device contains a parameter memory, from which the motor parameters corresponding to the information acquired from the described descriptions are taken.

The evaluation of the color code is based on a decomposition of the reflection light (with white light illumination) into its three primary colors. The primary colors are measured separately with regard to their respective intensity or output. The ratio of the primary colors is used for coding, regardless of the overall performance, overall color intensity or brightness. The direction of the three-component color vector, not its length, is evaluated, so to speak. This results in a largely insensitivity to surface and brightness changes due to wear or dirt and a distance independence with regard to the distance between the exit of the light guide 6 and the shank of the tool 3 (analogously for other geometries).

FIG. 2 shows a section and cross-sectional view of the structure of the tool-side end of the intermediate piece 4. The already mentioned shaft 12, which can be the output shaft of a transmission gear in the intermediate piece, drives a clamp holder 17 via a bevel gear 16. This clamp mount 17 holds the shank of the tool 3 and, in the manner indicated in FIG. 2 in the left half of the shank, engages in a recess in the shank in order to transmit the drive torque. The clamp holder also forms a socket for detachable assembly of the tool.

The shaft of the tool 3 is mounted in two ball bearings 18 at the top together with the clamp holder 17. Between these ball bearings 17 and in the

n Figure under the bevel gear 16, the light guide 6 of the coupling device already described in connection with FIG. 1 opens into the intermediate piece 4 shortly before the shank of the tool 3. A sleeve is provided between the shank and the ball bearings 18, which is used to minimize the entry of Lubricants and abrasion in the treated area (under the tool 3) are extended in the direction of the axis of the tool up to the actual read-out area of the light guide 6.

On the circumference of the shaft, a binary bar code 2, indicated in FIG. 2, is attached as a laser inscription marking, which can be read out by lighting and measuring the reflected power when the tool 3 is rotated, for example when the set speed is increased, and thereby information to the currently mounted tool. This form of identification 2 is preferred in the case of a tool 3 with a cylindrical shaft, because the creation of a depression described below would be more complex and would only allow a smaller amount of information given the small area available. In addition, the tool shank is a problematic point of wear due to abrasion, in which blackening by laser inscription is more permanent than a paint application. The binary bar code is described in more detail with reference to FIG. 3.

A significant difference from a conventional construction of this end of the intermediate piece 4 consists, in addition to the additional light guide 6, in the arrangement of the bevel gear 16 facing away from the tool exit side. As a result, the bevel gear 16 lies directly with the clamp holder, which transmits the torque to the tool 3. Correspondingly, the light guide 6 lies in the lower area in the figure.

In the conventional arrangement (the bevel gear 16 would be in the figure below), an additional sleeve is used for mechanical coupling with the clamp holder 17, which would interfere with the optical detection in the present case. This sleeve could also be provided with a detection window. hen, however, which would be more complex in terms of production technology and would reduce the part of the circumference of the tool shank available for bar code 2.

For the rest, the housing of the “receiving head” of the intermediate piece shown - as illustrated in the figure by the different hatching - consists of three parts, namely a push button for releasing or mounting a tool 3 by actuating the clamp holder 17 in the figure above, and two further housing elements , an inner and an outer, which are put together before the installation of the remaining ("long") part of the intermediate piece 4.

3 shows a roll of the circumferential surface of the tool 3 in the area of the bar code identification 2. The dashed lines are only drawn in to clarify the boundaries of the individual fields. In addition, some guidelines are only drawn to indicate the dimensions. In fact, only the two filled black rectangles can be found on the cylindrical tool shank as elements of bar code 3.

Typical dimensions are a width b of 5 mm parallel to the shank axis of the tool 3, a total circumference u corresponding to the total length of the strip drawn in FIG. 3 of 5 mm (more precisely 1.6 mm) and lengths (in the circumferential direction) a, x and e of the three different drawn lines of 0.55 mm, 0.37 mm and the remaining length, that is about 1.1 mm.

The relatively large width b of the lines of 5 mm in the present case has the function of ensuring the identification of the identification even with a certain axial tolerance when the tool 3 is inserted into the corresponding chuck of the intermediate piece or the motor operating device itself.

In the case of another shaft diameter, in the case of the dental tools on which the exemplary embodiment is based, for example 3.0 mm instead of the above 1.6 mm, the above numerical values preferably change proportionally, depending on the hold the approximate numerical ratio a: x: e = 1, 5: 9 * 1: 3. The same applies to numbers other than 9 (8 + 1 bit) for the narrow stripes.

The first line of length a drawn in has the function of an initial character for the beginning of the bar code, on the basis of which the reading electronics recognize the start of the 8 + 1 bit code by the increased length compared to the following lines and start or synchronize it. This is followed by eight information bits and an additional parity bit for simple error checking. If a readout error is recognized on the basis of the parity bit, the readout process is simply repeated. The stroke sequence ends with an end character with a length e that is greater than the previous strokes. The bit numbers for information and error control can of course also be selected differently. In the case shown, 256 (or fewer) different tools can be distinguished and simple but no double read errors are recognized.

The end character and the start character always have the same binary value, in the present case "dark" for the start character and .hell "for the end character. The nine dashes in between carry the information regarding the tool and the associated operating parameters and the error detection code with individual binary values.

In the present case, the line sequence with lines parallel to the axis of the tool 3 is for reading out during a tool rotation. In the case of a tool working with a stroke movement, a line sequence rotated by 90 °, so to speak, can also be used, that is to say with a side parallel to the axis with the designation u in FIG. 3. This is appropriate, for example, in the case of dental files with corresponding special angle pieces.

Fig. 4 shows the device for making a recess in an intermediate piece designed as a dental angle piece. Via a gear transmission, a drive motor 7 drives a milling head 8 which, when an intermediate piece 4 is placed on the device for milling a depression, for a subsequent color application. The milling head is mounted in a chuck 20, which can be pressed upwards against a return spring 21 by a lever mechanism 22, to be precise according to the depth of the depression to be milled in the intermediate piece 4. The motor 7 is powered by an electrical power supply

22 supplied with the other components together in one housing

23 is housed.

The housing 23 has, according to the invention, on its upper side a receptacle 9 designed as an approximate standard counterpart for the dental ISO coupling connection of the intermediate piece 4, with a pin 25 for plugging the intermediate piece 4 and a recess 24 corresponding to the orientation lug of the ISO coupling for receiving it in the correct orientation . On the surface of the orientation lug in the recess 24 facing the described device, the recess for the subsequent application of paint for producing a marking 2 according to the invention is made by the milling head 8. The label 2 then lies in the circumferential direction with respect to the longitudinal axis of the intermediate piece 4 next to the exit of the light guide 6 of the intermediate piece 4 already described.

Fig. 5 illustrates the structure of the receptacle 9 with a centrally located pin 25 and next to the pin 25 on a peripheral part of the connecting surface of the intermediate piece 4 opposite recess 24. Inside the recess 24, the top of the milling head 8 is shown. In the figure above the milling head 8 and within the recess 24, the light guide 6 (not shown, see FIG. 4) comes to rest.

Claims

Expectations:

1. Tool shop facility with:

- An automatic detection device (1) for detecting information from a label (2) of a marked attachment (3, 4) and

with an automatic control device for controlling the tool operating device in response to the information with the operating parameters assigned to it.

2. Tool operating device according to claim 1, wherein the detection device (1) works without contact.

3. Tool operating device according to claim 2, wherein the detection device (1) operates optically.

4. Tool operating device according to claim 3, wherein the detection device (1) detects a color code (2).

5. Tool operating device according to claim 3, wherein the detection device (1) detects a binary code (2), in particular a stroke sequence.

6. Tool operating device according to one of the preceding claims, in which the operating parameters are motor parameters, in particular for torque and / or speed.

7. Tool operating device according to one of the preceding claims with a motor drive unit (5) for holding in hand.

8. Tool operating device according to claim 7 with a dental handpiece (5) as a motor drive unit.

9. attachment (3, 4) for a tool operating device with an immediately attached and information-bearing identification (2), the information for a detection device (1) of the tool operating device can be detected and implemented by a control device of the tool operating device.

10. extension (3, 4) according to claim 9, wherein the label (2) is attached non-detachably.

11. extension (3, 4) according to claim 9 or 10, wherein the marking (2) consists of a colored area.

12. extension (3, 4) according to claim 9 or 10, wherein the marking (2) consists of a stroke sequence, in particular over the circumference of a cylindrical tool shank (3).

13. extension (3, 4) according to claim 12, wherein the marking (2) consists of a laser inscription.

14. Extension piece (3, 4) according to one of claims 9 to 13 as an intermediate piece with a coupling device (6) for the detection device (1) for detecting information from the identification (2) of an attachment piece (3, 4) mounted on the intermediate piece. .

15. extension (3, 4) according to claim 14, wherein the coupling device comprises a light guide (6).

16. extension (3, 4) according to claim 15 as a dental adapter with a receiving head with a socket (17) for receiving a dental tool (3), with a gear (16) for driving the tool (3) facing away from the detection end of the light guide (6).

17. Tool system from a tool operating device according to one of claims 1 to 8 and at least one extension piece (3, 4) according to one of claims 9 to 16.

18. A method for operating a tool system according to claim 17, in which the tool operating device is controlled in response to information acquired from the identification (2) of the marked attachment (3, 4) with these assigned operating parameters.

19. Apparatus for attaching a recess to an extension piece (3, 4) for a tool operating device with a motor (7), a milling or drilling head (8) driven by the motor (7) and a receptacle (9) for the extension piece ( 3, 4), which is designed mechanically essentially as a standard counterpart for a standardized connection of the extension piece (3, 4).

20. The apparatus of claim 19, wherein the receptacle (9) corresponds to a dental handpiece ISO coupling.