DEVICE FOR CHANGING A POLISHING WHEEL

Description

[0001] The invention relates to a device for replacing a polishing disc according to the preamble of claim 1.

[0002] The invention further relates to a device for exchanging a polishing disc according to the preamble of claim 15.

[0003] Polishing discs are used to finish the surfaces of workpieces. The polishing discs are made of a very soft material, such as foam, foam rubber, felt, or lambskin. They are attached to the backing plate of the polishing tool using fasteners, particularly Velcro fasteners.

[0004] The opposite working side of the polishing disc is usually provided with a high-viscosity polishing paste. It is important to ensure that when attaching the polishing disc to the backing plate, the polishing disc is attached to the backing plate with the correct side.

[0005] To make it easier to change the polishing disc, i.e. to make it easier to remove, the polishing disc extends beyond the backing plate at the edge.

[0006] For optimal polishing results, the amount of polishing compound applied to the working side of the polishing wheel is crucial. With a new polishing wheel, a larger amount of polishing compound is initially applied and worked into the polishing wheel. During subsequent polishing operations, only a small amount of polishing compound is applied for the respective polishing process. Flat workpieces are preferably polished using orbital, rotary, and vibration movements of the polishing tool.

[0007] To avoid polish splashes, precise positioning of the polishing disc or polishing paste, as well as its pattern on the polishing disc, are important. Furthermore, the contact pressure and polishing time are crucial for the polishing result.

[0008] The polishing disc needs to be changed if, for example, it is clogged with clear varnish or base coat with which the workpiece is coated, or if the service life of the polishing disc has expired or the polishing agent has dried out due to longer breaks.

[0009] Replacing the polishing disc is currently very time-consuming and requires extremely careful handling due to the contamination caused by operation. This clearly contradicts the ever-present need to optimize the cost of the entire polishing process.

[0010] Devices for exchanging grinding wheels are known from the publications WO 2017 / 210755 A1, CN 107 283 288 A, DE 10 2012 006 502 A1, WO 2015 / 125068 A1, and DE 20 2013 101 858 U1. Such grinding wheels differ significantly from the soft-material polishing wheels discussed here, particularly in their hardness and reduced thickness.

[0011] The invention is based on the object of further developing a device of the generic type in such a way that the replacement of a polishing disc is possible in a shorter time and automatically.

[0012] This object is achieved by a device having the features of claims 1 and 15.

[0013] Further advantageous embodiments of the invention are characterized in the subclaims.

[0014] By means of this device, the worn-out polishing disc held on the backing plate of the grinding tool is automatically changed, i.e. replaced with a new polishing disc.

[0015] To do this, the polishing tool, usually the arm of the robot in question, with the connected support plate, simply needs to be moved into the area of ​​a dispenser's removal opening until it comes into contact with the uppermost polishing disc, whereby the positive connection is created by the corresponding Velcro layers of the support plate on the one hand and the polishing disc on the other hand by applying appropriate pressure.

[0016] In this case, a sliding device arranged according to the invention on the side of the changing device opposite the removal opening, on which the stack of polishing discs rests, serves as an abutment.

[0017] After the corresponding polishing disc has been removed, the remaining stack is moved by the sliding device in such a way that the top polishing disc reaches a removal position.

[0018] According to a first embodiment, the removal opening is smaller in its clear dimension than the associated outer dimension of the polishing wheels, so that a stop is formed by which the displacement path of the stack is limited by means of the sliding device.

[0019] The outer dimensions of the backing plate, however, are smaller than the inside dimensions of the removal opening, allowing the backing plate to be inserted unhindered into the dispenser for connection to the polishing disc. The dispenser's capacity is designed to store a sufficient number of polishing discs for a single work shift. The sliding mechanism can be driven pneumatically, hydraulically, or electromechanically.

[0020] Upstream of the changing device is a puller, which removes the worn polishing wheel from the backing plate. This puller is equipped with a clamping device, which can consist of gripping pliers, finger pliers, or parallel grippers, and which pulls the polishing wheel, which protrudes beyond the edge of the backing plate, from the backing plate.

[0021] The clamping device has a base body with a circular opening serving as a toothed disc holder, wherein the base body has an inlet opening widening away from the toothed disc, into which the support plate of a polishing tool with a polishing disc adhering thereto can be inserted, and an outlet opening widening away from the toothed disc, through which a polishing disc detached from the support plate can be removed from the clamping device.

[0022] After the polishing tool has been moved into the effective range of the pull-off device, the clamping device is brought into a clamping position in a coordinate-dependent manner, preferably by laser detection, a mechanical contact, or a light barrier. The polishing tool is then moved, preferably vertically, into the area of ​​the changing device, releasing the Velcro connection between the polishing disc and the backing plate.

[0023] A collecting container can also be provided to hold the polishing disc once it has been removed from the backing plate. The collecting container, which can be lined with a garbage bag, is designed so that it can be moved from the working area of ​​the polishing tool to the area of ​​the changing device.

[0024] According to a further concept of the invention, the changing device comprises several dispensers arranged at equal distances from one another on a table. The table, designed as a circular or linear table, can be moved intermittently, and the respective dispenser can be brought into correspondence with the sliding device. A space can be provided below the table for storing dispensers pre-loaded with polishing discs.

[0025] Especially with polishing tools that perform orbital and / or eccentric movements, they can remain indefinitely in one position if the drive power is interrupted. Therefore, they must be aligned to the polishing disc to be mounted. For this purpose, an alignment station for the support pad is located above the changing device.

[0026] This alignment station features a prism-shaped holder that moves horizontally toward the support plate. It then positions the support plate in a center position, precisely aligned with the axis of the changer, through an orbital or eccentric movement. The prism-shaped holder then returns to a parking position.

[0027] The movements of the polishing tool, i.e. the robot, are computer-controlled, and the need to change the polishing disc is also detected by appropriate sensors.

[0028] The automated workflow also includes coating the polishing disc with a polishing agent, particularly a polishing paste. For this purpose, a dosing device is located downstream of the changer. This device is equipped with a nozzle tip that enables precise application to the working side of the polishing disc and seals it without dripping.

[0029] Alternatively, the polishing agent can be dosed via a polishing agent nozzle from the back into the polishing disc, which is preferably designed as a polishing sponge, or through the polishing disc.

[0030] This dosing device is equipped with a storage container that is connected to the nozzle tip via a supply line.

[0031] The nozzle tip can be arranged on the robot arm, in the area of ​​the support plate, whereby the polishing disc is provided with the polishing agent after a rotary movement in a time- and path-optimized manner.

[0032] Alternatively, the nozzle tip can be placed above the changing device, with the polishing tool then moving towards the nozzle tip.

[0033] The amount of material dispensed onto the polishing disc is also computer-controlled.

[0034] When the dispensers need to be refilled with polishing discs, an operator can do so; a visual, acoustic, or electrical signal will alert the operator. An electronic message can also be sent from the system control system, i.e., the computer. The operator can also supply multiple devices accordingly.

[0035] The computer can be used to solve logistical tasks or initiate orders, whereby the consumption of polishing wheels and polishing agents per workpiece processed, shift or time period is determined and reported, which ultimately contributes to a continuous improvement of the work process.

[0036] This also applies to the detection of the consumption of polishing discs and polishing agents, which can be used to identify maintenance measures, such as changing the backing pad due to wear.

[0037] Another idea is to separate the polishing tool work area from the setup area, i.e., the area where the changing device is loaded. The work area is secured by a protective fence, light barriers, light curtains, grilles, and / or doors. When the doors are opened, the polishing tool stops moving or is moved to a home position and shuts down.

[0038] The base is preferably firmly connected to a positioning rod which, when the polishing tool with the support plate arranged on it is lowered, can be moved relative to the stacked polishing discs until the support plate comes into contact with the uppermost of the polishing discs and can be locked in this position.

[0039] According to yet another alternative embodiment of the invention, the device has a changing device with at least one dispenser, wherein the dispenser has an inclined magazine shaft with an upper filling area for supporting at least one polishing disc, which can be brought along the magazine shaft into a removal station at a lower end of the magazine shaft, to which the support plate can be moved for attaching the polishing disc to the support plate.

[0040] In a preferred further development, the removal station has positioning pins for the exact positioning of the polishing disc.

[0041] Embodiments of the invention are described below with reference to the accompanying drawings.

[0042] They show: Fig. 1 and 2 the use of a device according to the invention in different schematic views Fig. 3 a detail of the device in a perspective side view Fig. 4 an enlarged section of the part according to Fig. 3 Fig. 5 a further detail of the device in a perspective view Fig. 6 a further detail of the device in a perspective view Fig. 7 an enlarged section of the detail according to Fig. 6, Fig. 8 a sectional view through an embodiment variant of a clamping device designed as a jaw tool, Fig. 9 a partially sectioned side view through a further embodiment variant of a clamping device, Fig. 10 a side view of an embodiment variant of a dispenser, Fig. 11 a sectional view through the Figure 10 shown dispenser, Fig. 12 a perspective view of a further embodiment of a dispenser, and Fig. 13 a perspective detailed view of the dispenser shown in Figure 12 section marked XIII.

[0043] In the Fig. 1 and 2 is a device for exchanging a sheet-shaped polishing disc 8, usually 10 - 20 mm thick, coated with a polishing agent during operation, which is attached to a support plate 4 of a polishing tool held on a robot 1 by means of connecting means.

[0044] According to the invention, the device comprises a changing device 2 positioned on a work table 6, which in the example comprises a plurality of dispensers 3 held on a rotary table, which can be brought into the transfer area with the support plate 4 at equal distances from one another in cycles.

[0045] A setup area 15 is separated from a work area 16 by a partition wall 5, wherein the robot 1 with a part of the changing device 2 is arranged in the work area 16, while the setup area 15 is intended to equip the changing device 2 with dispensers 3 by means of an operator 7.

[0046] A donor 3 is in the Fig. 3 shown as a detail. In the example, the dispenser 3 has several, specifically four, limiting rods 11, which form a lateral fixation for polishing discs 8 stacked in the formed interior space.

[0047] These polishing discs 8 have, in a manner known per se, a connecting surface and, opposite, a working surface, wherein the connecting surface is provided in particular with a Velcro layer which can be brought into connection with a Velcro layer of the support plate 4.

[0048] The polishing discs 8 are accommodated in the dispenser 3 in such a way that the connecting surface of the uppermost polishing disc 8 is exposed, while the lowermost polishing disc 8 is supported with its working surface on a sliding device 9 which is axially displaceable and thereby moves the stack far enough that after the uppermost polishing disc 8 has been removed, the following polishing disc 8 is brought into a removal position.

[0049] Especially in the Fig. 4It can be clearly seen that in the area of ​​removal, ie in the area of ​​the upper polishing wheel 8, stops 10 are attached to the projecting ends of the rods 11, which are arranged opposite one another at a clear distance which is smaller than the associated outer dimension of the polishing wheel 8, which is designed to be flexible, ie bendable.

[0050] To connect the polishing disc 8 with the facing side of the support plate 4, the latter is brought under pressure against the connecting surface of the polishing disc 8, wherein the outer dimension of the support plate 4 is smaller than the clear distance between the opposing stops 10. This results in an edge-side projection of the polishing disc 8 relative to the support plate 4.

[0051] In order to apply the pasty polishing agent to the working surface of the polishing wheel 8, a dosing device 12 is arranged downstream of the changing device 2, which is shown as a detail in the Fig. 5 is shown.

[0052] This dosing device 12 has a cartridge 13 filled with the polishing agent and a nozzle 14 with which the polishing agent can be applied to the working surface of the polishing disc 8 in a defined quantity and in a defined application pattern.

[0053] The dosing device 12 can be stationary, positioned in the area of ​​the changing device 2 or on the robot arm of the robot 1, wherein the support plate 4 is brought into the application area of ​​the nozzle 14 by a corresponding movement.

[0054] In the Fig. 6 an alignment station 17 can be seen, which has a prism-shaped holder 18 which can be moved horizontally in the direction of the dispenser 3 and by means of which the support plate can be brought into an axially co-ordinate position with respect to the dispenser 3 or the polishing wheels 8.

[0055] In the Fig. 7the upper area of ​​the alignment station 17, which has the prism-shaped receptacle 18, is shown in an enlarged view.

[0056] It can be seen that the holder 18 is slide-guided and can be moved by a pneumatic, hydraulic or electromechanical drive.

[0057] In operation, the support plate, whose base is circular, rests with its edge on the formed prism, which in this respect forms a centering point for the support plate.

[0058] According to a further embodiment variant, in which the polishing tool on the robot arm of robot 1 can be controlled electronically on the basis of an absolute encoder, the use of such an alignment station 17 can be dispensed with, since the robot arm of robot 1 can be positioned exactly centrally above the changing station via the angle measurement.

[0059] According to a further embodiment, in which the polishing tool on the robot arm of robot 1 can be controlled electronically incrementally, the use of the alignment station 17 is only necessary if the power supply to the robot arm of robot 1 has been interrupted.

[0060] According to the invention, a removal device is arranged upstream of the changing device 2, with which a polishing disc 8 can be removed from the support plate 4.

[0061] For this purpose, the pulling device is provided with a clamping device with which, according to one embodiment variant, an edge region of the polishing disc 8 protruding relative to the support plate 4 can be clamped.

[0062] The clamping device can be actuated to close by means of laser detection, a mechanical contact or a light barrier, depending on the position of the support plate 4, depending on the coordinates.

[0063] A collecting container can be arranged below the clamping device, which serves to hold the polishing disc 8 detached from the support plate 4.

[0064] According to a preferred embodiment, as in Figure 8 shown, the clamping device of the puller is designed as a jaw tool 19.

[0065] The jaw tool 19 has, as shown in Fig. 8 shown, a base body 20 with a preferably circular receiving opening for receiving the polishing disc 8.

[0066] To remove the polishing disc 8 from the support plate 4, the polishing disc 8 attached to the support plate 4 is pressed into the opening of the jaw tool 19.

[0067] Subsequently, a piston tip 22 of at least one preferably pneumatically displaceable piston is pressed laterally into the polishing disc 8 and thus holds the polishing disc 8 firmly in engagement with the jaw tool 19.

[0068] It is also conceivable to arrange several such pistons 21 with piston tips 22 for fixing the polishing disc 8.

[0069] After the piston tip 22 or the piston tips 22 are pressed laterally into the polishing disc 8, the support plate 4 is moved away from the polishing disc 8 perpendicular to the fixing surface of the support plate 4 and the polishing disc 8 is thus released from the support plate 4.

[0070] The pistons 21 are then returned to their original position. The piston tip 22(s) moves back out of engagement with the polishing disc 8.

[0071] The polishing disc 8 can then preferably be disposed of downwards into a collecting container positioned below the jaw tool 19.

[0072] According to a further embodiment, as in Fig. 9 shown, the clamping device is provided with a toothed disc 25.

[0073] As in Fig. 9As shown, the clamping device shown here has a base body 26 serving as a toothed disk holder with a circular opening, wherein above the toothed disk 25 there is an inlet opening 27 widening towards a polishing tool 24 and below the toothed disk 25 there is an outlet opening 28 widening downwards, ie away from the toothed disk 25.

[0074] Here too, in order to detach the polishing disc 8, the polishing disc 8 is moved by moving the polishing tool 24 in the direction of the toothed disc 25 until the polishing disc 8 is pressed through the inlet opening 27 into the toothed disc 25.

[0075] The diameter of the toothed disc 25 is slightly smaller than the diameter of the polishing disc 8.

[0076] The polishing tool 24 is then moved out of the inlet opening 27 back to its starting position, in Fig. 9upwards. The polishing disc 8 engages the teeth of the toothed disc 25, so that upon further upward movement of the support plate 4 together with the polishing tool 24, the polishing disc 8 detaches from the support plate 4.

[0077] The polishing disc 8 remains hooked in the teeth of the toothed disc 25 until the next polishing disc 8 is pushed through the inlet opening 27 and the toothed disc 25 and the previously stuck polishing disc 8 is released from engagement with the toothed disc 25.

[0078] In this embodiment, a collecting container can also be positioned below the clamping device to collect the used or worn polishing disc 8.

[0079] As in the Fig. 8 and 9 As further shown, the polishing disc 8 has a channel 23 which preferably extends centrally and perpendicularly to the polishing surface of the polishing disc 8.

[0080] This channel 23 serves to accommodate an application nozzle 29, which is centrally located in the support plate 4 and connected to a polishing agent reservoir. The polishing agent can be metered into the polishing disc 8 through this polishing agent nozzle 29.

[0081] Further special design variants of a dispenser 31, 42 are described in the Fig. 10 to 13 shown.

[0082] In the Figs. 10 and 11 In the embodiment shown, the dispenser 31 has a similar design to the embodiment of Fig. 3 several limiting rods 11, which form a lateral fixation for polishing discs 8 stacked in the formed interior space.

[0083] The limiting rods 11 of the dispenser 31 are mounted on a base 32 and extend through an intermediate base 33 on which the polishing discs 8 can be stacked. The length of the portion of the limiting rods 11 projecting upward from the intermediate base 33 is designed to be adjustable to the stacking height of the polishing discs 8.

[0084] In addition, the floor is 32, as well as in Fig. 11 can be seen, is firmly connected to a positioning rod 34.

[0085] This positioning rod 34 has at its upper end, near the polishing machine 24, a pressure surface 35 which, when the polishing tool 24 with the support plate 4 arranged on it is lowered relative to the stacked polishing wheels 8, in Fig. 11 downwards, until the support plate 4 comes into contact with the uppermost polishing disc 8 and thus the uppermost polishing disc 8 is adhesively connected to the support plate 4, preferably via a Velcro connection.

[0086] The vertical displacement of the positioning rod 34 is accompanied by a lowering of the limit rods 11.

[0087] The polishing discs 8 are not stacked on the base 32 to which the limiting rods 11 are attached, but on an intermediate base 33 arranged above the base 32 through which the limiting rods 11 are guided.

[0088] In contrast to the floor 32 to which the limit rods 11 are attached, this intermediate floor 33 always remains at the same height relative to the initial position of the support plate 4.

[0089] The positioning rod 34 is designed, at least in the lower area below the base 32, as a locking shaft with locking teeth 36.

[0090] A locking pawl 37, which is attached to a lower base 38 which is connected to the base 32 via connecting rods 39, engages in these locking teeth 36 and locks the positioning rod 34 in the respective position in which the polishing wheel 8 previously received by the support plate 4 was received.

[0091] This enables the distance between the pressure surface 35 of the positioning rod 34 and the upper edge of the uppermost polishing disc 8 to always remain the same until all polishing discs 8 have been removed from the dispenser 3.

[0092] In order to refill the dispenser 31 with polishing discs 8, the locking pawl 37 can be released by rotating the positioning rod 34, for example by means of an actuating lever 41 attached to it perpendicular to its longitudinal extent, and can be moved back into its starting position by spring force from springs 40 which are arranged on the connecting rods 39 of the base 32 with the lower base 38.

[0093] The limiting rods 11 are moved upwards relative to the intermediate floor and thus form a cage which can be filled with new polishing discs 8 until the stack of polishing discs 8 again reaches the upper edge of the limiting rods 11.

[0094] In the alternative design variant, as described in the Figs. 12 and 13 As shown, the dispenser 42 has an inclined magazine shaft 43 into which polishing discs 8 can be inserted in an upper filling area 44.

[0095] The polishing discs 8 then slide along the magazine shaft 43 to a removal station 47.

[0096] At this Figure 13 Positioning pins 48 are provided for the exact positioning of the polishing wheels 8 at the removal station 47, shown in detail. The polishing tool 24 with the support plate 4 arranged thereon can be moved to this removal station 47 and thus pick up a respective polishing wheel 8.

[0097] As in Fig. 12 As further shown, the magazine shaft 43 extends through a protective wall 45 with an opening 46, wherein a setup area 44 of the magazine 42 is positioned on the side opposite the protective wall 45 as the removal station 47.

[0098] In order to prevent more than one polishing wheel 8 from being present one above the other at the removal station 47, a monitoring element, for example in the form of a light barrier, is preferably provided in the area of ​​the removal station 47. List of reference symbols

[0099] 1 Robot 2 Change device 3 Dispenser 4 Backing plate 5 Partition 6 Work table 7 Operator 8 Polishing disc 9 Slide device 10 Stop 11 Limit rod 12 Dosing device 13 Cartridge 14 Application nozzle 15 Setup area 16 Work area 17 Alignment station 18 Mount 19 Jaw tool 20 Base body 21 Piston 22 Piston tip 23 Channel 24 Polishing tool 25 Toothed disc 26 Base body 27 Inlet opening 28 Outlet opening 29 Polishing agent nozzle 30 Velcro pad 31 Dispenser 32 Base 33 Intermediate base 34 Positioning rod 35 Pressure surface 36 Ratchet teeth 37 Locking pawl 38 Base 39 Connecting rod 40 Spring 41 Operating lever 42Dispenser 43Magazine shaft 44Setup area 45Protective wall 46Opening 47Removal station 48Position pin

Claims

1. Device for replacing a polishing disc (8) made of a very soft material, in particular foam, foam rubber, felt or lambskin, which in function is coated with a polishing agent and is attached to a support plate (4) of a polishing tool held by a robot (1) by means of connecting elements, with a exchanging device (2) with at least one dispenser (31) in which a stack of polishing discs (8) is arranged, wherein the dispenser (31) has a removal opening whose clear width is greater than the associated dimension of the support plate (4) and wherein an axially movable sliding device (9) is provided on the side facing away from the removal opening, on which the stack rests, wherein the dispenser (3) has limiting rods (11) fixed to a floor (32) and an intermediate floor (33) passing through the limiting rods (11), on which the polishing discs (8) can be stacked, characterized in that the length of the limiting rods (11) forming a receiving cage for the polishing discs (8) is adaptable to the stack height of the polishing discs (8), wherein the exchanging device (2) is preceded by a removal device with which a polishing disc (8) can be removed from the support plate (4), wherein the removal device is provided with a clamping device with which the polishing disc (8) can be clamped laterally, wherein the clamping device has a toothed pulley (25) with a main body (26) serving as a toothed disc holder with a circular opening, wherein the main body (26) has an inlet opening (27) widening away from the toothed pulley (25), into which the support plate (4) of a polishing tool with the polishing disc (8) adhering thereto can be inserted, and an outlet opening (28) widening away from the toothed pulley (25), through which a polishing disc (8) released from the support plate (4) can be removed from the clamping device.

2. Device according to claim 1, characterized in that the clear width of the removal opening of the dispenser (3) is smaller than the corresponding dimension of the polishing disc (8).

3. Device according to claim 1 or 2, characterized in that the clamping device can be actuated for closing in a coordinate-dependent manner by laser detection, a mechanical contact or a light barrier, depending on the position of the support plate (4).

4. Device according to one of the preceding claims, characterized in that a collection container is arranged below the clamping device to receive the polishing disc (8) released from the support plate (4).

5. Device according to one of the preceding claims, characterized in that an alignment station (17) is provided upstream of the exchanging device (2) for the precise positioning of the support plate (4), wherein the alignment station (17) has a prism-shaped receptacle (18).

6. Device according to one of the preceding claims, characterized in that a dosing device (12) is arranged downstream of the exchanging device (2), with a storage container for polishing agent and an application nozzle (14) connected thereto.

7. Device according to one of the preceding claims, characterized in that several dispensers (3) are positioned on a table that can be moved in cycles.

8. Device according to claim 7, characterized in that the table is designed as a rotary table or linear table.

9. Device according to claim 7 or 8, characterized in that the dispensers (3) are arranged at equal distances from each other.

10. Device according to one of the preceding claims, characterized in that the exchanging device (2) is enclosed.

11. Device according to claim 10, characterized in that the enclosed exchanging device (2) has a removal opening for changing the dispensers (3).

12. Device according to one of the preceding claims, characterized in that the exchanging device (2) and / or the dosing device (12) and / or the robot (1) and / or the removal device and / or the alignment station (17) are connected to a computer.

13. Device according to one of the preceding claims 5 to 12, characterized in that sensors are provided for controlling the robot arm and the exchanging device (2), the removal device, the dosing device, and the alignment station (17).

14. Device according to one of the preceding claims, characterized in that the floor (32) is firmly connected to a positioning rod (34) which, when the polishing tool (24) is lowered, can be moved relative to the stacked polishing discs (8) together with the support plate (4) arranged thereon until the support plate (4) comes into contact with the uppermost of the polishing discs (8) and can be locked in this position.

15. Device for replacing a polishing disc (8) made of a very soft material, in particular foam, foam rubber, felt or lambskin, which in function is coated with a polishing agent and is attached to a support plate (4) of a polishing tool held on a robot (1) by means of connecting means, characterized by a exchanging device (2) with at least one dispenser (42), wherein the dispenser (42) has an inclined magazine shaft (43), with an upper set-up area (44) for supporting at least one polishing disc (8), which can be moved along the magazine shaft (43) into a removal station (47) at a lower end of the magazine shaft (43), to which the support plate (4) can be moved for attaching the polishing disc (8) to the support plate (4).

16. Device according to claim 15, characterized in that the removal station (47) has positioning pins (48) for the exact positioning of the polishing disc (8).