EA014087B1 - Elastically flexible coupling body - Google Patents

Abstract

The invention relates to a coupling body (26) that can convert a linear input movement into a linear output movement transversal to the input movement. Said coupling body comprises two parallel flexional arms (28, 30) of the same length, the ends of said flexional arms being connected by means of transversal connection arms (32, 34). The connection arms (28, 30) carry driving bodies (40, 42) which represent load bodies arranged at the same distance from the neutral lines of the connection arms, in the same direction.

Description

(57) The coupling element (26), which can convert linear motion at the input into transverse linear motion variables at the output, has two parallel bending levers (28, 30) of the same length, which are connected at their ends by transverse connecting levers (32, 34). On levers working on bending (28, 30), massive bodies are equally directed and equally remote from their neutral lines, which are leading bodies (40, 42).

The invention relates to an elastically bendable docking element for a high frequency working tool according to the preamble of claim 1.

High-frequency in the claims and in the description should be understood as a frequency component from a few kHz to 40 or more kHz. For conventional dental purposes, it may preferably be in the range of 15 to 25 kHz.

A high-frequency working tool for dental use is described in ΌΕ 4238384 A1. It includes an ultrasonic unified drive unit, which includes an elongated package of piezoelectric disks located one after another. This pack of discs is placed in the handle of the working tool. The docking tool is made in the form of an annular vibrator, which has four vibrational maxima equally distributed in the direction of the perimeter. One of the vibrational maxima is connected to the ultrasonic unified drive unit, one vibrational maximum shifted by 90 ° is connected to the instrument. Thus, it carries out a movement whose direction is shifted by 90 ° with respect to the direction of the working movement of the ultrasonic unified drive unit.

Working tools of the type described above find their application, first of all, in the dental field for cleaning the upper surface of the teeth or also for forming cavities in the teeth.

At the same time, the docking elements should be relatively small in order to allow the dentist also in a cramped environment to have a good overview of the corresponding workplace in the patient's mouth. According to the prior art, docking elements made in the form of a ring with a small diameter only work reliably when they are made with high precision and made of special, expensive materials. If these conditions are not met, cracks may occur in the connecting elements, which thereby entails the failure of the working tool.

The objective of the invention is to improve the docking element in such a way that it can be made easier and less prone to fracture of the material.

In accordance with the invention, this problem is solved by means of a docking element with the features given in claim 1.

In the docking element according to the invention, the excitation of natural vibrations occurs due to the fact that a torque is applied to a given position of the bending lever. The latter is formed by a force that acts under the lever arm on the bending lever / bending lever.

Preferred embodiments are set forth in the dependent claims.

According to claim 2, a particularly effective excitation of the natural vibrations of the bending lever operating is obtained if the driven tipping movement is applied to one point of the bending working lever, in which it has a natural vibration unit.

Another embodiment according to claim 3 has an advantage with respect to symmetrical vibrational relationships and the symmetrical load of the bending lever / bending lever.

In the embodiment according to claim 4, it is also achieved that the non-driven bending lever also oscillates symmetrically to the transverse middle plane of the lever and is loaded.

The docking element according to claim 5 has two bending levers with one-way directed, working bodies as massive bodies, each of whose centers of gravity is removed from the neutral line of the levers operating on bending, on which they are located. When a force is applied to the bending levers in the longitudinal direction, the massive bodies located at a distance as leading bodies then cause, due to their inertia, the equally directed bends of both leverage bending.

Because both driven ends and both free following the movement of the end of the bending levers are connected by connecting levers, at the ends following the movement of the ends, the movement of the connecting lever located there is located, which is perpendicular to the longitudinal direction of both bending levers, and thereby also perpendicular to the parallel movement of the actuator, which is superimposed on the connecting driven ends of the bending levers of the connecting lever.

According to claim 2, the docking element can thus be considered in the form of a frame with bendable parallel sides on which massive bodies made as leading bodies are located. Thus, the docking element forms elastically deformable parallelogram rods, which leads to the fact that the applied high-frequency linear motion variables at the input are converted to essentially linear motion variables developed at them at the output of the same frequency.

The embodiment according to claim 6 is preferable from the point of view of the possibility of establishing in relation to the same load and the ratio of motion in both bending levers.

In the connecting element according to claim 7, it is possible to obtain a benefit for the resulting moment of inertia of the masses of the driving bodies from the transverse dimensions fixed by means of various frame levers.

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Thus, the mass of one of the leading bodies can be chosen somewhat smaller.

Moreover, according to claim 8, in spite of the different masses of the leading bodies, it is possible to coordinate with each other the moments of rotation that the massive bodies acting as leading bodies exert when accelerating the frame formed by the bending levers and connecting levers.

An embodiment of the invention according to claim 9 is advantageous with respect to the compact dimensions of the docking element.

An embodiment of the invention according to claim 10 is advantageous with respect to the smooth bounding surfaces of the docking element.

The coupling element according to claim 11 is characterized in that the accelerations formed by the bending levers and connecting levers of the frame in the direction of the axes of the bending levers are converted especially effectively into vibrational bends.

Moreover, according to clause 12, it is possible to give the drive body located inside the frame particularly large sizes.

Also, the embodiment according to claim 13 is advantageous with respect to strong excitations of vibrational bends. Correspondingly strong are the tails formed from this movement in the direction of the tool axis, which are formed by the connecting lever located on the tool side.

Clause 14 describes a particularly simple and reliable possibility of connecting a waveguide-hub and a docking element.

The docking element according to claim 15 allows a particularly short implementation of the assembly formed by the docking element and the drive section of the hub-waveguide in a direction perpendicular to the plane of the frame.

Also, the embodiment of the invention according to clause 16 serves to evenly distribute mechanical loads to both working arm bends.

The embodiment of the invention according to claim 17 is advantageous with respect to the accurate and reliable insertion of the drive movement and with respect to the accurate and reliable movement of the tool.

The same is true in a reinforced form for the docking element according to p. 18.

In the connecting element according to claim 19, the geometry received without the application of force is a rectangle. The deflection of the bending levers occurs symmetrically on both sides by means of the edges of the rectangle formed by them, whereby the parallel component of the residual motion, which remains with a larger deviation of the bending levers, can be kept very small, or with small deviations, which The case of interest is practically zero.

The embodiment of the invention according to claim 20 is advantageous with respect to preventing local stresses in the material of the docking element.

In the docking element according to item 21, the massive body and the connecting levers can be located in the same plane without limitation, the leading deformation of the frame located inside the frame. As a consequence of this, it is possible to manufacture a docking element in a simple manner from a plane-parallel blank.

The embodiment of the invention according to item 22 is advantageous with respect to the simple and reliable fastening of the tool on the leading (received movement) parts of the docking element.

In the embodiment according to item 23, it is achieved that the docking element in the immediate vicinity of the tool has a particularly thin shape.

According to paragraph 24 receive a simple and capable of loading the connection of the docking element with a unified drive unit. The latter can simply be formed, for example, by means of an ultrasonic generator and a connected waveguide-hub.

The embodiment of the invention according to claim 25 is advantageous with regard to favorable ergonomics realized by means of a docking element of a working device.

The embodiment of the invention according to p. 26 is advantageous primarily in relation to the possibility of manufacturing a docking element from a plane-parallel blank. In addition, the rectangular prismatic geometry of the main form of the bending lever allows accurate preliminary calculation of the vibration frequencies. Finally, bending vibrations are precisely set by means of a rectangular shape. The vibrations induced in the bending levers are substantially free of torsion with respect to the longitudinal axis of the bending lever.

The above advantages are enhanced in the docking element according to clause 27 and the docking element according to clause 28.

The embodiment of the invention according to p. 26 is advantageous with respect to the compact form of the docking element and the handle containing it in the immediate vicinity of the workplace. This simplifies manipulation in tight spaces and optical contact with

- 2 014087 workplaces.

The invention will now be described in more detail with reference to the drawings, in which FIG. 1 is a side view of a dental ultrasonic handle, which schematically shows various main components of the handle;

FIG. 2 is a side view of a docking member that can be used in the dental ultrasonic handle of FIG. one;

FIG. 3 is a schematic view of a docking member according to FIG. 2 in a motion phase in which a pulling force directed to the right is applied to the docking element;

FIG. 4 - similar to FIG. 3 view, however, the compressive force applied to the docking element is directed to the left in the drawing;

FIG. 5 is a perspective view of a practical structural form of a docking element for the one shown in FIG. 1 working device;

FIG. 6 is a longitudinal section of the shown docking element;

FIG. 7 is a perspective view of another embodiment of a docking member;

FIG. 8 is a section through the center of FIG. 7 of the docking element together with the end of the drive of the waveguide hub, and FIG. 9 is similar to FIG. 7 is a view showing yet another embodiment of a docking member.

In FIG. 1, reference numeral 10 shows a generally ultrasonic handle that serves to drive a tool 12.

Tool 12 can be, for example, a flat tool made in the form of a lancet, which should be used to process the lateral surfaces of the tooth. The tool 12 moves in the direction of the arrow shown in the drawing 14. During operation with the tool 12, a jet of working fluid 18, which contains an abrasive medium suspended in water, is directed at it using a nozzle 16.

To form the one shown in FIG. 1 of the reciprocating movement of the tool 12, the amplitude of which is from 10 to 100 μm, is an ultrasonic generator 20, which is located inside the handle 22 of the handle 10. The ultrasonic generator 20 includes several axially stacked piezoelectric plates and connected located in FIG. 1 on the left, by the end of the drive with a waveguide-hub 24. The latter serves to concentrate ultrasonic energy through the funnel effect and to produce correspondingly increased amplitude of movement at the output.

The end of the waveguide-hub 24 is connected to the docking element 26. It converts the axial direction of the handle 22, in the drawing, the horizontal working movement of the waveguide-hub 24, perpendicular to the axis of the handle 22, in the drawing, the vertical movement of the tool 12.

In FIG. 2 shows a schematic construction of a docking member 26. It has two, parallel to each other, bending levers 28, 30 of equal length, each of which has a rectangular cross section, with the long side of the cross section being perpendicular to the plane of FIG. 2 drawings. The ends of the bending levers 28, 30 are connected by connecting levers 32, 34 to a rectangular frame 36, the inner edge of which has in the corners made in the form of a quarter of a rounding curve 38.

The connecting levers 32, 34 are perpendicular to the plane of FIG. 2 of the drawing have the same dimensions as the bending levers 28, 30, however, have a width B substantially greater than the width b of the bending levers 28, 30. Therefore, shorter connecting levers 32, 34 can also be considered with respect to the bending levers 28, 30 are substantially rigid.

In the middle of the connecting levers 32, 33 there are identical leading bodies made in the form of massive bodies (40, 42; 40, 42, 84), the centers of gravity of which are removed upward at the same distance And from the neutral lines of the bending levers 28, 30. Leading bodies 40, 42 also have the same dimensions perpendicular to the plane of FIG. 2 of the drawing, as well as the bending levers 28, 30 and the connecting levers 32, 34. Thus, the docking element 26 can be made by sawing from a plane-parallel workpiece.

Leading bodies acting in the form of massive bodies (40, 42; 40, 42, 84) are essentially cylindrical in shape and are connected via transition sections 44, 46 to adjacent connecting levers 32, 34.

The transition sections 44, 46 on their both sides are respectively connected to the bending levers 28, 30 by means of curvatures 48, 50.

Under operating conditions, the connecting lever 32 located on the left in the drawing is connected to the tool 12 by means of a collet not shown, while the connecting lever 34 in the drawing on the right is connected to the drive section of the waveguide hub 24 by means of a not shown connecting head.

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In FIG. Figures 3 and 4 show how the docking element deforms if a rightward pulling force or a leftward compressive force is applied to the connecting lever 34 in the right drawing.

If the connecting lever 34, as shown in FIG. 3, a rightward directed force is applied, the inertia of the driving body 40 causes the bending levers 28, 30 to bend downward. Because the driving bodies 40, 42 with respect to their geometry, their material and their weight are completely identical, both bending arms 28, 30 bend equally downward. Because their length remains constant and their free ends move equally, the connecting lever 32 located on the left in the drawing moves down parallel to the connecting lever 34.

On the contrary, when a force is applied to the right connecting lever 34 of a left-directed force, then, due to the inertia of the driving bodies 40, 42, this leads, similarly to the above, to the same direction and the same amount of bending upward on the bending levers 28, 30 and, therefore, to move the connecting lever 32 up in exactly parallel to the length of the connecting lever 34 direction.

It is understood that, by doing so, the connecting element 26 converts the alternating movement applied to the right-hand driven connecting lever 34, which occurs along the axis of the waveguide hub 24 and, therefore, along the axis of the ultrasonic generator 20 and the handle 22, into the movement of the tool, which occurs perpendicular to the axis of the waveguide - hub 24 and, thus, to the axis of the handle 22.

From FIG. 2-4, it is understood that the driving body 40, which is located inside the frame 36 and rests on the lower bending lever 32, is removed from the upper, outside the frame bending lever 34 so that its bending movement is not disturbed. Because both bending levers 28, 30 are deflected in the same direction by the same amount, the distance between the drive body 40 and the bending lever 30 can be small.

FIG. 5 and 6 show a practical example of the implementation of the docking element 26. Parts of the docking element 26, which in their functions correspond to the above with reference to FIG. 2-4 parts are again indicated by the same references and a description with respect to their fundamental properties is not given.

Docking member 26 according to FIG. 5 can be made of plane-parallel workpiece by the fact that in the region of the bending levers 28, 30, two longitudinal holes are made in it, which at each of their ends are bounded by a semicircular surface 48. In the jumper remaining between both longitudinal holes, a groove 52 is then milled, whereby the lower base of the driving body 40 is obtained.

Similarly, in the upper section of the workpiece, two other longitudinal holes are made, which are limited by flattened semi-cylindrical holes 50, and their left is open up and to the left so that the lower surface of the longitudinal hole extends to the free horizontal end of the docking element 26 and shortly before the end surface of the right elongated hole is oblong the hole opens up.

Similarly, by milling, the upper portion of the material above the right elongated hole is also removed so as to have a substantially T-shaped drive body 42.

On the right-hand connecting lever 34 of the docking element, a connecting head 54 is made, which has a threaded hole 56 open to the right, into which a threaded end portion of the waveguide-hub 24 can be screwed.

The upper bounding plane of the connecting head 54 and the lower bounding plane of this connecting head are located so that the hole 56 located in the middle of the connecting head is located approximately at the height of the upper bending arm 30. The transition surfaces from these upper and lower bounding surfaces are bent as shown in the drawing, with reference numerals 58 and 60. The edges of the connecting head 54 are rounded by chamfering 62.

Located in FIG. 5 to the left, the end portion of the docking element 26 has a middle vertical groove 64, which leads to a vertical hole 66. On the left side, each of the outer sides of the connecting levers 32, 34 is symmetrically to the longitudinal median plane and has a chamfer 68 so that clamp sections 70, 72 are formed left connecting lever 34.

Parallel to the hole 66 in the connecting lever 32, an axially split receiving sleeve 74 is inserted into which a tool shank can be inserted.

By means of a clamp screw not shown, the clamping sections 70, 72 can, counteracting the elastic force, move towards each other for rigidly securing the tool shank in the receiving sleeve 74.

The upper driving body 42 has a central vertical groove 78 open to its upper end surface, at the base of which a through hole 80 is provided. It is located on one straight line (coaxial) with the mounting hole 82 in the base 40 of the driving body.

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In the mounting hole 82, a massive rod 84 is rigidly fixed (welded), which extends with a lateral gap through the through hole 80 and the groove 80 so that when applied to the ultrasound connector 26, the massive rod 84 does not collide with the walls.

The end surface of the massive rod 84 and the upper surface of the driving body are essentially coplanar.

The geometry and mass of the base 40 of the driving body and the massive rod 84 are selected so that the combined moment of mass inertia with respect to the region adjacent to the bending lever 28 is substantially equal to the mass inertia of the driving body 42 to its adjacent region on the bending lever thirty.

With regard to operation, depicted in FIG. 5 and 6, the connecting element 26 corresponds to the connecting element shown in FIG. 2-4.

As the material for the docking element 26 and, if necessary, parts thereof, titanium is used.

In FIG. 7 and 8 show another variant of the docking element 26, which is made more compact in the perpendicular direction to the axis of the bending levers 28, 30. The components described with reference to the previous figures, in the case of their functional correspondence, are provided with the same reference positions, even if they are geometrically made somewhat differently.

The leading body 42 protruding outside the frame of the docking member 26 is reduced and protrudes only minimally into the frame. The leading body 40 protruding into the inside of the frame almost reaches its even end surface to the inside of the bending lever 30.

The driving body 40 serves as a docking portion for the waveguide hub 24. For this, a threaded hole 56 is provided therein. Also, a threaded hole 86 is provided in the connecting arm 32, through which the outlet portion 88 of the waveguide hub 24 can extend with a gap.

The axis of the hole 86 is parallel to and in the middle between the bending levers 28, 30 so that the drive section 88 under the lever arm acts on the bending lever 28. Due to this force-input geometry, the frame of the docking element formed by the bending levers 28, 30 and the connecting levers 32, 34, despite the fact that the driving bodies 40, 42 have a significantly reduced mass in comparison with other examples of structural forms.

The docking member according to FIG. 7 and 8 are characterized by a particularly compact design and a good change of direction of movement at the entrance to the drive movement located at an angle of 90 ° to it.

The docking member according to claim 9 is substantially similar to that of FIG. 7

In this case, the leading body 42 is absent and the end surface 40 is even closer to the inner surface of the bending lever 30 as close as the manufacturing technique allows.

The manufacturing process is such that the plate-shaped workpiece is milled to give the desired external contour and two openings with roundings 38, 48 are made in it, with the first continuous middle bridge remaining, which later forms the leading body 40. In the intermediate product thus obtained, the shape of which essentially corresponds to form 8, then a through hole 86 is drilled and a threaded hole 56 located along with it is made.

Then, as close as the manufacturing technique allows, a groove 52 is made on the inside of the bending lever 30 by milling with a narrow disk mill.

The bending lever 28 due to the driving body 40 located on it has a different oscillation pattern than a bending lever having the same cross section without a mounted driving body.

To smooth out the differences, located in FIG. 9 below, the bending working lever is approximately 25% wider than the bending working lever 28. In this way, both bending working levers 28, 30 have the same natural frequency and oscillate with their end located next to the connecting lever 34 in phase with the same amplitude .

In a practical embodiment of the invention, the docking member 26 has a longitudinal dimension (horizontal in the drawing) of 24.2 mm, and in the transverse (vertical) direction, the lower bounding surface of the docking member 26 has a distance from its longitudinal axis of 4 mm, while the upper outer surface of the docking element 26 has a distance from the longitudinal axis of only 3.6 mm. The difference in distance corresponds to the increased transverse dimension of FIG. 9 below the bending lever 30.

In this practical embodiment, the thickness of the plate from which

- 5 014087 pouring the connecting element 26, is 5 mm, the diameter of the through hole is 86-4 mm, and the diameter of the threaded hole is 56-3.5 mm.

As the material for the docking element 26, titanium is used.

Claims (18)

CLAIM 1. An elastically bendable docking element for docking a standardized drive unit (20, 24) with a tool (12) that converts the input movement along the input axis into the output movement along one of the output axes different from the input axis, characterized in that it has two parallel bending levers (28, 30) of equal length, which are connected at their ends by transverse connecting levers (32, 34), and that at least one of the two bending levers (28, 30) under shoulder leverage butt a high-frequency bending force. 2. The connecting element according to claim 1, characterized in that the bending force is applied to the unit of natural vibrations of the bending lever (28), driven by this bending force. 3. A connecting element according to claim 2, characterized in that the bending lever (28) driven by a bending force is substantially symmetrical to the transverse middle plane of the lever and a bending force is applied in the middle plane of the lever. 4. The connecting element according to claim 3, characterized in that the second bending lever (30) is also essentially symmetrical to the transverse middle plane of the lever. 5. The connecting element according to one of claims 1 to 4, characterized in that on the bending levers (28, 30) there are equally directed, transversely eccentric massive bodies representing leading bodies (40, 42; 40, 42, 84) . 6. The connecting element according to claim 5, characterized in that the moments of inertia of the masses of the massive bodies, which are the leading bodies (40, 42; 40, 42, 84), are essentially the same with respect to their connecting sections on the corresponding working bending levers (28, 30). 7. The connecting element according to claim 5 or 6, characterized in that the centers of gravity of the massive bodies, which are the leading bodies (40, 42, 84), are removed from each of the related bending levers (28, 30) at a different distance. 8. The connecting element according to one of claims 5-7, characterized in that the massive bodies, which are the leading bodies (40, 42, 84), are transversely nested one into the other. 9. The connecting element according to one of claims 1 to 4, characterized in that one leading transverse body (40) arranged transversely on one (28) of the bending levers is provided with connecting means (56) adapted to interface with the drive section ( 88) waveguide concentrator (24). 10. The connecting element according to claim 9, characterized in that the first (32) of the connecting levers (32, 34) is provided with a through hole (86) located parallel to the bending levers (28, 30), made with a through passage through drive section (88) of the waveguide hub (24). 11. The connecting element according to one of claims 1 to 10, characterized in that the bending levers (28, 30) have such an edge contour and / or such a cross section that they have the same oscillation frequency and their lateral ends oscillate in phase. 12. The connecting element according to one of claims 1 to 11, characterized in that the connecting levers (32, 34) have greater bending strength compared to the bending strength of the bending levers (28, 30), preferably they are essentially tough. 13. The connecting element according to one of claims 1 to 12, characterized in that the driving bodies (40, 42) are connected to the sides of the bending levers (28, 30) by means of curved transition surfaces (48, 50). 14. The docking element according to one of claims 1 to 13, characterized in that the massive body (40) located on one (28) of the bending levers (28, 30) directed inside the docking element ends at a small distance from the inside of the other working on a bend of the lever (30). 15. The connecting element according to one of claims 1 to 14, characterized in that the connecting lever (34) facing the tool side is made in the form of a collet clamp (64, 74). 16. The connecting element according to one of claims 1 to 15, characterized in that the main shape of the bending levers (28, 30) corresponds to a rectangular cross section of the prism formed. 17. The connecting element according to clause 16, characterized in that the width of the cross section of the prism is substantially greater than its height. 18. The connecting element according to one of claims 1 to 13, characterized in that it is made of titanium.