UNIT FOR DEBURRING AND ROUNDING EDGES IN A SURFACE GRINDING MACHINE

Abstract

The present invention relates to an edge machining unit for a surface grinder, comprising: a plurality of cylindrical rotary brushes with a cylindrical surface and a plurality of brushes on said cylindrical surface, wherein each cylindrical rotary brush has a first axis of rotation, which corresponds to a central longitudinal axis of the cylindrical rotary brush, a first drive unit for driving each rotary brush in a rotational movement about its first axis of rotation, a plurality of second axes of rotation, which plurality is not parallel to the first axis of rotation, wherein each first axis of rotation is disposed so as to rotate about one of the second axes of rotation, a second drive unit for moving every first axis of rotation in rotation about its second axis of rotation, and a third axis of movement, wherein the second axes of rotation are guided for a movement guided by the third axis of movement, and a third drive unit for moving the second axes of rotation in a movement guided by the third axis of movement.

Claims

1. An edge machining assembly for a wide grinding machine, comprising: a plurality of cylindrical roller brushes having a cylindrical surface and a multiplicity of brushes on this cylindrical surface, wherein each cylindrical roller brush has a respective first axis of rotation which corresponds to a center longitudinal axis of the cylindrical roller brush, a first drive unit for driving each roller brush in a rotational movement about its first axis of rotation, a plurality of second axes of rotation which are not aligned parallel to the first axis of rotation, wherein each first axis of rotation is mounted so as to be rotatable about one of the second axes of rotation, a second drive unit for rotating each first axis of rotation about its second axis of rotation, a third movement axis, wherein the second axes of rotation are guided for a movement guided by the third movement axis, a third drive unit for moving the second axes of rotation in a movement guided by the third movement axis, wherein the third movement axis is in the form of a closed guideway and the second axes of rotation are moved along the closed guideway by the third drive unit.

2. The edge machining assembly as claimed in claim 1, wherein one or more of the following: the second axes of rotation are perpendicular to the first axes of rotation, the closed guideway is in a plane which is perpendicular to the second axes of rotation, and the closed guideway is in a plane which is parallel to the first axes of rotation.

3. The edge machining assembly as claimed in claim 1, wherein a second axis of rotation extends through a respective roller brush.

4. The edge machining assembly as claimed in claim 1, further comprising a workpiece support surface; and a workpiece conveying device for conveying the workpiece support surface in a workpiece conveying direction.

5. The edge machining assembly as claimed in claim 4, wherein the workpiece support surface has a support width perpendicular to the workpiece conveying direction and the closed guideway extends in the direction of the support width over an extent which is greater than or equal to the support width.

6. The edge machining assembly as claimed in claim 1, wherein the second drive unit comprises a hollow shaft and the first drive unit comprises a drive shaft extending through the hollow shaft.

7. The edge machining assembly as claimed in claim 1, wherein one or more of the following: the first drive unit and the second drive unit comprise an integral drive motor, the second drive unit and the third drive unit comprise an integral drive motor, and the first drive unit and the third drive unit comprise an integral drive motor.

8. The edge machining assembly as claimed in claim 1, wherein the first drive unit comprises a first drive motor, the second drive unit comprises a second drive motor and the third drive unit comprises a third drive motor, and the first, second and third drive motors are connected in signaling terms to a control unit which is configured to actuate the first, second and third drive units independently of one another.

9. The edge machining assembly as claimed in claim 1, wherein at least one of the roller brushes comprises a first and a second roller segment which are arranged axially next to one another in relation to the first axis of rotation and the two segments are mounted so as to be rotatable about the first axis of rotation, and wherein the first and the second roller segment are driven by the first drive unit in a matching direction of rotation, or the first and the second roller segment are driven by the first drive unit in different directions of rotation.

10. The edge machining assembly as claimed in claim 1, wherein the second axes of rotation are arranged one behind another along the guideway and each second axis of rotation guides a first axis of rotation of a roller brush, wherein two adjacent roller brushes are driven by the first drive unit to rotate in mutually opposite directions of rotation about their respective first axis of rotation.

11. The edge machining assembly as claimed in claim 1, further comprising a sensor device for detecting one or more workpieces, wherein the sensor device is arranged upstream of the edge machining assembly in relation to a conveying direction of the one or more workpieces through the edge machining assembly and is connected in signaling terms to a controller which is in turn connected in signaling terms to one or more of the first, second and third drive units and is configured to actuate the one or more of the first, second and third drive units based on a signal from the sensor device.

12. The edge machining assembly as claimed in claim 11, wherein the sensor device is a sensor strip which extends transversely to the conveying direction over a width of the edge machining assembly to optically scan the one or more workpieces and is configured to detect one or more properties selected from one or more of a dimension and an alignment of a recess in a workpiece, a region of the workpiece that is bent out of a workpiece plane lying in the conveying direction, a width dimension of the workpiece that extends in the width of the edge machining assembly, and a workpiece thickness, and to actuate the one or more of the first, second and/or third drive units based on the one or more detected properties.

13. The edge machining assembly as claimed in claim 1, further comprising an adjustment device for setting the spacing of the first axes of rotation from a workpiece support surface, wherein the adjustment device is connected in signaling terms to an adjustment controller which is configured to control the adjustment device to set a spacing or a contact pressure between the roller brush and a workpiece supported on the workpiece support surface.

14. The edge machining assembly as claimed in claim 13, wherein the adjustment controller is configured to actuate the adjustment device based on one or more of a drive parameter of the first, second or third drive unit, a workpiece thickness and a wear state of the roller brushes.

15. The edge machining assembly as claimed in claim 1, further comprising a sensor device for detecting an edge rounding on one or more workpieces, wherein the sensor device is arranged downstream of the edge machining assembly in relation to a conveying direction of the workpieces through the edge machining assembly and wherein the sensor device is connected in signaling terms to a controller which in turn is connected in signaling terms to a conveying device for conveying the workpieces and is configured to actuate the conveying device based on the edge rounding detected by the sensor device.

16. The edge machining assembly as claimed in claim 15, further comprising an optimizing unit which is configured, for a first edge that is to be deburred on a workpiece that is characterized and stored in memory by the sensor device according to its position, length or spacing from another edge, based on a comparison of a first edge radius, ascertained after carrying out a first deburring operation performed with a first control data set, with a second edge radius, ascertained after carrying out a second deburring operation performed with a second control data set, wherein each of the first control data set and the second control data set describes one or more of (i) an adjustment force between the roller brushes and the workpiece, (ii) one or more of a direction, a sequence of changes in direction, and a speed of rotation of the roller brushes about the first axis of rotation, (iii) the rotation of the first axes of rotation about the second axes of rotation, and (iv) the movement of the second axes of rotation along the guideway, to store in memory, as an optimized control data set, the first or the second control data set or a third control data set formed from the first and the second control data set by extrapolation or interpolation, if the comparison has produced a correspondingly better deburring operation as a result of the first or the second control data set or allows a better deburring operation to be expected as a result of the third control data set, and to carry out a deburring operation at a subsequent time on a second edge, which is characterized similarly or correspondingly to the first edge according to its position, length, or its spacing from another edge, using the optimized control data set.

17. A wide surface grinding machine, comprising a workpiece support surface, a conveying device for conveying workpieces on the workpiece support surface, and a plurality of grinding assemblies which are arranged one behind another in a row and are intended for the sequential machining by grinding of a workpiece conveyed by the conveying device, wherein one of the grinding assemblies is an edge machining assembly as claimed in claim 1.

18. The use of an edge machining assembly as claimed in claim 1 for one or more of deburring and/or rounding edges on a periphery or at recesses of a workpiece.

19. A method for deburring and/or rounding edges on a workpiece, comprising steps of: rotating a multiplicity of roller brushes about a respective first axis of rotation, rotating each of the first axes of rotation about a respective second axis of rotation which is assigned to the respective first axis of rotation and is not aligned parallel, to the first axis of rotation, and moving the second axes of rotation along a closed guideway.

20. The method as claimed in claim 19, wherein a position, alignment and/or a radius of an edge on the workpiece is ascertained as a measurement parameter by a sensor device before and/or after the deburring operation and wherein the direction and/or speed of rotation of the roller brushes about one or more of the first axes of rotation, the rotation of the first axes of rotation about the second axes of rotation, and the movement of the second axes of rotation along the guideway is controlled based on the measurement parameter.

21. The method as claimed in claim 19, wherein the respective first axis of rotation is parallel to a surface of the workpiece, the respective second axis of rotation is aligned perpendicularly to the first axis of rotation, and the closed guideway is in a plane aligned parallel to the first axes of rotation or perpendicularly to the second axes of rotation.

22. The edge machining assembly as claimed in claim 3, wherein each second axis of rotation extends through a respective roller brush.

23. The edge machining assembly as claimed in claim 3, wherein the second axis of rotation intersects a first axis of rotation.

24. The edge machining assembly as claimed in claim 3, wherein each second axis of rotation intersects a respective first axis of rotation.

25. The edge machining assembly as claimed in claim 4, wherein one or more of the following: the workpiece support surface is parallel to the first axes of rotation, and the workpiece support surface is parallel to a plane in which the closed guideway extends.

26. The edge machining assembly as claimed in claim 9, wherein each of the roller brushes comprises a first and a second roller segment which are arranged axially next to one another in relation to the first axis of rotation and the two segments are mounted so as to be rotatable about the first axis of rotation, wherein the first and the second roller segment are driven by the first drive unit in a matching direction of rotation, or the first and the second roller segment are driven by the first drive unit in different directions of rotation.

27. The edge machining assembly as claimed in claim 9, wherein the first and the second roller segment are driven by the first drive unit in the matching direction of rotation at different rotational speeds.

28. The edge machining assembly as claimed in claim 15, wherein the controller is configured such that if an edge rounding is found that results in an edge radius which is smaller than a predetermined minimum edge radius, the controller actuates one or more of: the conveying device to perform conveying in reverse to convey the workpiece back into the edge machining assembly and to control another machining operation by the edge machining assembly, the first, second or third drive unit with a modified drive parameter, and an adjustment device for setting the spacing of the first axes of rotation from a workpiece support surface to increase a contact pressure between the roller brushes and a workpiece supported on the workpiece support surface.

29. The use of an edge machining assembly as claimed in claim 18, wherein the workpiece is a plate-like workpiece.

Description

[0049] A preferred embodiment of the invention will be explained on the basis of the appended figures, in which:

[0050] FIG. 1 shows a frontal view of a detail of a grinding machine according to the invention comprising an edge machining assembly according to the invention installed therein,

[0051] FIG. 2 shows a perspective view, obliquely laterally at the top front, of an edge machining assembly according to the invention, and

[0052] FIG. 3 shows a perspective partial view of a first embodiment of a satellite of the edge machining assembly according to FIG. 2;

[0053] FIG. 4 shows a perspective partial view, obliquely from below, of a second embodiment of a satellite of the edge machining assembly according to FIG. 2 with the option of receiving two roller brushes; the two roller brushes are masked for better understanding,

[0054] FIG. 5 shows a perspective partial view, obliquely from above, of the satellite according to FIG. 4, the two roller brushes being illustrated,

[0055] FIG. 6 shows a perspective partial view, obliquely from above, of a third embodiment of a satellite of the edge machining assembly according to FIG. 2 with the option of receiving two roller brushes, and

[0056] FIG. 7 shows a perspective partial view, obliquely from above, of a fourth embodiment of a satellite of the edge machining assembly according to FIG. 2 with the option of receiving two roller brushes.

[0057] FIG. 1 shows a detail of a grinding machine comprising two machining assemblies inserted therein. Arranged on the right-hand side is a longitudinal grinding assembly L which has a contact roller KW and can perform surface machining on a workpiece 31 which passes through on a machine table 30 in a horizontal plane. For this purpose, the longitudinal grinding assembly has an endless belt grinding body, which is brought into linear contact with the workpiece by the contact roller KW.

[0058] An edge machining assembly 60 according to the invention is arranged on the left, next to the longitudinal grinding assembly. This edge machining assembly 60 can perform edge machining on the workpiece 31.

[0059] The workpiece 31, supported on the machine table 30, is conveyed through the grinding machine in a conveying direction F from right to left in FIG. 1. The machine table 30, the longitudinal grinding assembly L and the edge machining assembly 60 are fastened to a machine housing 10 and as a result are positioned in their positions relative to one another in a stiff structure. Also arranged on the machine housing 10, on a extension arm, is an operating unit 20, which comprises both a control unit in the form of a programmable computer unit and a corresponding user interface for inputting and outputting parameters and information.

[0060] FIG. 2 perspectively depicts an isolated view of the edge machining assembly. In this view, the longitudinal grinding assembly and parts of the machine table and of the machine housing are not depicted for the sake of better presentation of the edge machining assembly.

[0061] The edge machining assembly comprises a multiplicity of roller grinding bodies in the form of roller brushes 40a, b, c, . . . . Each of the roller brushes 40a, b, c is mounted so as to be rotatable about a respective first axis of rotation 41a, b, c, . . . . The first axes of rotation 41a, b, c are aligned parallel to the upwardly facing surface of the workpiece 30 to be machined, which is mounted on the machine table 30. Each of the roller brushes 40a, b, c therefore forms a theoretically linear line of contact with the workpiece 31.

[0062] The roller brushes 40a, b, c are occupied by a multiplicity of brush elements which extend radially outward from a cylindrical central core. In the figures, the roller brushes 40a, b, c are depicted only symbolically.

[0063] Each roller brush 40a, b, c is mounted in a U-shaped holder 42a, b, c so as to be rotatable about the first axis of rotation. Each holding profile is connected on its upper side to a hollow shaft 130a, b, c extending in the vertical direction. These hollow shafts 130a, b, c are each mounted on a suspension frame 45a, b, c so as to be rotatable about a second axis of rotation 44a, b, c.

[0064] Each suspension frame 45a bears two guide rollers 46a at its upper end and likewise two such guide rollers 47a at its lower end. These guide rollers make it possible to move the suspension frame 45a in translation on a corresponding upper guide rail 60 and lower guide rail 61. These upper and lower guide rails 60, 61 each extend in a horizontally aligned plane and form a guideway in the shape of a closed lame oval in these planes.

[0065] A respective roller brush 40a, its U-shaped holder 42a, the hollow shaft 130a fastened thereto, and the suspension frame 45a with the guide rollers 46a, 47a fastened thereto form the main constituent parts of a structural unit in the form of a satellite 110a. The edge machining assembly comprises multiple such satellites and each of the satellites is guided on the upper and the lower guide rail 60, 61 for a translational movement along the closed guideway defined by these two guide rails 60, 61.

[0066] Three endless toothed belts, the ribbed sides of which face radially outward and which likewise extend in the same lame oval as the upper and the lower guide rail, are arranged between the upper and the lower guide rail.

[0067] A central toothed belt 90 is made to move in circulation relative to the upper and lower guide rails by a traction drive unit 70. Each of the suspension frames 45a, b, c is fastened to this central toothed belt 90, with the result that the satellites 110a, b, c are moved one after another along the lower and upper guide rails in a closed guideway as a result of the circulating movement of the central toothed belt 90.

[0068] A lower toothed belt 120, which is arranged underneath the central toothed belt and likewise extends in a closed oval guideway, interacts with a sprocket 150 which is arranged on each of the satellites and is connected fixedly in terms of torque to the hollow shaft 130a of the satellite. The toothed belt 120 may be stationary, that is to say not move in circulation, with the result that the circulating movement of the satellites causes the lower sprocket 150 to roll on the toothed belt and the U-shaped holder to rotate about the respective second axis of rotation 44a, b, c of the satellite via the hollow shaft. This second axis of rotation 44a extends concentrically to the hollow shaft 130a and extends in the vertical direction. The second axis of rotation 44a, b, c extends through the respective roller brush 40a, b, c. It preferably intersects this roller brush centrally between the two end faces of the roller brush and also preferably intersects the first axis of rotation 41a, b, c.

[0069] If the roller brush thus rotates about the first axis of rotation, a rotation of the roller brush about the second axis of rotation in the center of the roller brush does not cause the relative speed between the outer circumference of the roller brush and the workpiece to change, the relative speed is increased on a side of the roller brush that is radially on the outside in relation to the second axis of rotation by a superposition of the rotational speeds of the roller brush about the first and the second axis of rotation, and the relative speed of the outer circumference of the roller brush that is in contact with the workpiece is reduced on an opposite side of the roller brush that is radially on the outside in relation to the second axis of rotation by the same superposition. These kinematics result in a variable relative speed along the line of contact between the roller brush and the workpiece, the variable relative speed being favorable for edge machining and achieving effective machining of edges of any alignment and with any spacing from other edges.

[0070] An upper toothed belt 100, which interacts with an upper sprocket 140, extends underneath the central toothed belt. The upper sprocket 140 is fastened fixedly in terms of torque on a drive shaft 131a, which extends through the hollow shaft 130a and the upper region of the U-shaped holder.

[0071] FIG. 3 shows a first embodiment of a satellite which comprises a roller brush, its holder and bearing arrangement, and part of its drive unit. A pulley 141, which may be in the form for example of a V-belt pulley, poly V-belt pulley or toothed belt pulley, is arranged at the lower end of this drive shaft. A drive belt 160 is wound around this pulley 141. The rest of the course of the drive belt is guided laterally out of the U-shaped holder, deflected by 90? and looped around a pulley 142 which is connected fixedly in terms of torque to the brush roller and rotates about the first axis of rotation together with the brush roller. In this way, a rotation, brought about by the toothed belt 100, of the upper sprocket 140 can be transmitted to the brush roller 40a and the brush roller as a result can be driven in a rotational movement about the first axis of rotation 41a.

[0072] In principle, it should be understood that the toothed belts 100 and 120 may be in the form of stationary toothed belt segments and produce the rotation of the roller brushes about the second axis of rotation and about the first axis of rotation as a result of the rolling movement of the upper sprocket 140 and the lower sprocket 150 on the upper toothed belt 100 and the lower toothed belt 120. In this case, both the movement of the satellites 110 along the guideway and the two rotational movements about the first and the second axis of rotation can be performed by a single motor drive, by means of which the central toothed belt 90 is moved in circulation along the oval guideway.

[0073] Both the upper and the lower toothed belt 100, 120 or the two of them may, however, also be in the form of drivable toothed belts, which can similarly move in circulation and as a result generate an individual rotational movement about the first axis of rotation and an individual rotational movement about the second axis of rotation. In this case, one, or two, additional motor drive(s) for driving the upper and the lower toothed belt is/are correspondingly necessary and an independent movement shape in terms of the circulating movement of the satellites along the closed guideway, the rotation about the second axis of rotation and the rotation about the first axis of rotation can be generated by providing three such drive motors. This makes it possible to individually adapt the kinematics for certain edge machining operations. In the exemplary embodiment illustrated, a first drive motor 70 which makes the upper toothed belt 100 move in circulation is arranged above the upper guide rail. Furthermore, a third drive motor 80 which makes the central toothed belt 90 move in circulation is arranged above the upper guide rail. The lower toothed belt is stationary, and therefore the rotational speed about the second axis of rotation and the movement speed along the guideway are proportional to one another. As an equipment variant, the lower toothed belt could, however, likewise be made to move in circulation by a transmission on the first drive motor or by a second drive motor.

[0074] On the machine housing 10, it is also the case that a first sensor strip 200 is arranged in the run-in region and a second sensor strip 210 is arranged in the run-out region. The two sensor strips 200, 210 extend over the entire width of the run-in region and completely scan a workpiece 31 or multiple workpieces, which runs/run through underneath the sensor strips, by means of an optical scanner.

[0075] In this respect, the sensor strip 200 in the run-in region serves to detect the side and alignment of recesses and the edges formed there and also the outline with the corresponding edges of workpieces which are conveyed on the machine table to the edge machining assembly and to forward these data to the controller in the operating unit 20. The drive motors of the edge machining assembly can then be correspondingly actuated on the basis of these data.

[0076] The sensor strip 210 in the run-out serves to optically detect a workpiece machined by the edge machining assembly and in the process ascertain the edge rounding. This is also achieved by optical scanning. If this measurement by means of the sensor strip 210 determines that the edge rounding is sufficient, the workpiece can continue to run through the grinding machine and optionally be fed for further machining steps. By contrast, if the edge radius is below a desired minimum value, the workpiece is conveyed back to the edge machining assembly and undergoes edge machining again in order to produce the desired edge radius. In the process, the drive motors of the edge machining assembly can be actuated such that optionally such post-machining takes place only in certain regions in which the edge radius was found to lie below what is desired.

[0077] The entire edge machining assembly is supported or suspended in the vertical direction within the machine frame 10 by means of hydraulic cylinders, wherein other configurations with a spring-mounted suspension/support or a pneumatically assisted suspension or support are also possible. The suspension force or supporting force of this suspension or support, respectively, can be set in order to be able to set a contact pressure of the roller brushes on the workpiece as a result.

[0078] FIG. 4 shows a second embodiment of a satellite. In this embodiment, the satellite is designed to receive two roller brushes 210a, b. Here, the two roller brushes 210a, b lie concentrically on the first axis of rotation and both rotate about this first axis of rotation.

[0079] For this purpose, at the lower end the internal drive shaft 131a bears a toothed wheel 241, which meshes on either side with two sprockets 248a, b. The two sprockets 248a, b are mounted rotatably in the upper plate of the U-shaped holder 242 and on the top side of this upper plate bear a respective pulley 220a, b. These pulleys 220a, b are to the side of the hollow shaft 130a and the drive shaft 131a of the satellite that extends in the hollow shaft 130a.

[0080] A drive belt 260a, which is deflected downward by 90? at the right-hand periphery of the upper plate of the U-shaped holder and extends to a pulley 242a, which is fixed in terms of torque with a receiving portion 280a for one of the two roller brushes 210a, is looped around the right-hand pulley 220a. Correspondingly, a drive belt 260b extends from the pulley 220b to a pulley 242b, which is connected to a second receiving portion 280b for the second roller brush 210b. The pulleys 242a, b and the receiving portions 280a, b are coaxial with the first axis of rotation. The two receiving portions 280a, b are connected to one another by means of a freewheeling support shaft 290, as a result of which the two receiving portions 280a, b are centrally supported and axially centered on one another.

[0081] The two receiving portions 280a, b are designed to receive the two roller brushes 210a, b fixedly in terms of torque.

[0082] In the exemplary embodiment illustrated according to FIGS. 4 and 5, the drive force for the rotation of the two roller brushes about the first axis of rotation is distributed to two sides of the U-shaped holder 242 and distributed to the roller brushes 210a, b by the drive belts 260a, b. In the exemplary embodiment, this division is performed by means of the force distribution from the toothed wheel 241 to the sprockets 248a, b and via the pulleys 220a, b and the drive belts 260a, b to the pulleys 242a, b. In principle, this distribution of the drive force to the two roller brushes can also be performed in another way. According to the invention, the first drive unit generally comprises a mechanical division of the drive force for the rotation of two roller brushes about a shared first axis of rotation, by means of which the two roller brushes are driven separately.

[0083] FIGS. 4 and 5 depict a configuration in which the two roller brushes 210a, b rotate about the first axis of rotation in opposite directions of rotation and at the same rotational speed. In other embodiment variants, it can be provided to drive the two roller brushes 210a, b at different rotational speeds, for example by selecting a different number of teeth for the sprockets 248a, b or by selecting a different effective diameter for the pulleys 220a, b or effective diameter for the pulleys 242a, b or a combination of several of these measures. Furthermore, in other embodiments, the two roller brushes can also be driven about the first axis of rotation in the same directions of rotation. This can be achieved, for example, by crossing over one of the belts 260a or 260b.

[0084] In principle, it should be understood that, instead of the division of the drive force via the toothed wheel 241 and the sprocket 248a, b, it would also be possible to perform a force distribution in the case of which, for example, instead of the toothed wheel 241, two coaxial and mutually adjacent pulleys are arranged and the drive belts 260a, b after deflection are guided through corresponding openings in the side walls of the U-shaped holder and loop around these pulleys, as illustrated for example in the embodiment shown in FIG. 3.

[0085] FIG. 6 shows a third embodiment of a satellite. This third embodiment is likewise equipped with two mutually coaxial roller brushes 310a, b in a U-shaped holder.

[0086] The embodiment according to FIG. 6 differs from the embodiment according to FIGS. 4 and 5 in the manner in which the two roller brushes are driven in rotation about the first axis of rotation. In the embodiment according to FIG. 6, a transfer gearbox 340 is arranged between the hollow shaft and the U-shaped holder. This transfer gearbox may for example be in the form of a bevel gear mechanism having a sprocket placed on the drive shaft 131a and two ring gears.

[0087] The rotational force about the second axis of rotation is transmitted from the hollow shaft to the U-shaped holder via the housing of this transfer gearbox 340.

[0088] The drive shaft, extending through the hollow shaft, for the rotation of the roller brushes about the first axis of rotation enters the transfer gearbox 340 as input drive shaft and there is deflected by 90? and divided up into two drive shafts 330a, b, which are connected for example within the bevel gear mechanism to a respective one of the two ring gears.

[0089] The two drive shafts 330a, b extend parallel to the first axis of rotation on both sides of the U-shaped holder. Arranged at the end of the two drive shafts 330a, b in turn are pulleys which transfer the rotational movement to corresponding pulleys 343a, b by means of respective drive belts 360a, b. These two pulleys 343a, b drive the two roller brushes 310a, b in the same way as in the embodiment according to FIGS. 4 and 5. It is also possible in this embodiment to select the same or different rotational speeds for the two roller brushes 310a, b and the same or opposite directions of rotation for the two roller brushes 310a, b by correspondingly designing and dimensioning the transfer gearbox 340 and the pulleys and optionally by crossing over one of the two belts 360a, b.

[0090] FIG. 7 shows a fourth embodiment of a satellite for the edge machining assembly according to the invention. In this embodiment, the hollow shaft 130a on the toothed wheel 450 together with the drive shaft 131a, extending therein, on the toothed wheel 440 extends as far as the region between the two roller brushes 410a, b and is connected to a transfer gearbox 460 there.

[0091] The drive force about the second axis of rotation is in turn transmitted directly via the hollow shaft to the housing of this transfer gearbox 460 and the housing transmits this rotational movement to the first axis of rotation. The drive force of the drive shaft 131a extending in the hollow shaft 130a is distributed from the transfer gearbox 460 directly to the two roller brushes 410a, b, which are on the left-hand and the right-hand side of this transfer gearbox.

[0092] The transfer gearbox 460 therefore in principle has the same structure as the transfer gearbox 340, but in the fourth embodiment no U-shaped holder is provided and, owing to the position of the transfer gearbox 460 at the level of the first axis of rotation, it is not necessary to convey the drive force from the first drive unit by means of pulleys and drive belts in this embodiment variant. It is also the case in this embodiment that the same or opposite directions of rotation are selected for the two roller brushes 410a, b and/or the same or different rotational speeds are selected for the two roller brushes 410a, b by correspondingly dimensioning and selecting the transfer gearbox 460.