AUTOMATIC APPARATUS FOR THE SURFACE TREATMENT, IN PARTICULAR FOR SURFACE POLISHING, OF COMPONENTS INTENDED FOR THE MANUFACTURE OF WEARABLE ORNAMENTAL OBJECTS, IN PARTICULAR OF COMPONENTS INTENDED FOR THE REALIZATION OF WATCHES

Abstract

 Automatic apparatus (1) for the surface treatment of components (C) for the manufacture of ornamental objects, in particular watches, comprising:
- a surface treatment tool (2) for the components (C) operatively connected to electrical rotation means (3);
- a gripping and movement group (4) for hooking one of the components (C);
- processing means (5) operatively connected to the electrical rotation means (3) and to the gripping and movement group (4) so as to control the rotation speed of the surface treatment tool (2) and so as to move the component (C) based on a predefined trajectory.
The apparatus comprises a guide station (6) of an abrasive paste (PA) in the solid state, the processing means (5) being operatively connected to the guide station (6) so as to command the approach of the abrasive paste (PA) towards the surface treatment tool (2), in order to apply an amount of the abrasive paste (PA) on the circumferential surface (22) of the tool.

Description

[0001] The present invention concerns an automatic apparatus for the surface treatment, in particular for surface polishing, of components intended for the manufacture of wearable ornamental objects, in particular of components intended for the realization of watches. In particular, such components could be, by way of example, straps, watch cases, as well as wristband meshes and clasps.

[0002] The invention also concerns a method for performing such surface treatment, in particular such surface polishing, by using the automatic apparatus of the invention.

[0003] It is known that, at least in the production of high-end watches, it is provided to carry out surface treatments of the various components, in particular a polishing operation of the cases, the wristband and all the external components of the watch, in order to guarantee a finished product with a very high quality finish.

[0004] It is also known that these operations, both in the past and still today, are carried out by highly specialized people who, manually and consciously, manipulate the component so as to bring it into contact, for example, with a polishing brush, so as to obtain a surface polishing treatment with an aesthetic effect of the highest quality.

[0005] However, carrying out these operations manually requires, as already mentioned, personnel with very high experience and specialisation. This entails, disadvantageously, an objective difficulty in finding suitable personnel capable of carrying out such activities in industrial contexts, or at least in contexts with medium/high production figures of high-end ornamental objects. Hence the disadvantage emerges relative to the fact that the production of such manually processed ornamental objects requires long timing and that, as a result, productivity is obviously reduced.

[0006] Furthermore, a further disadvantage is due to the fact that, although the aforesaid personnel present a very high level of professionalism, it is still true that it is not always possible to guarantee a perfect repeatability of the result of these processing among the various objects of the same type, intrinsically due to human nature.

[0007] To overcome these disadvantages of manual processing, in recent years automatic apparatuses have been proposed which are capable of carrying out such surface treatments, in particular the polishing operation of the aforesaid components of wearable ornamental objects, replacing human personnel.

[0008] In particular, such automatic apparatuses provide a gripping and movement group, such as for example an anthropomorphic robot, capable of grasping and moving in space, according to a predefined trajectory, a component of a wearable ornamental object so as to bring the various surfaces of said component into adherence to a surface treatment tool, in particular to a rotating polishing brush, substantially simulating the movements that the expert personnel would have performed to carry out said polishing operation. The aforesaid evolution, therefore, allows to speed up the execution of the surface treatments of the components and at the same time allows an objective repeatability of these treatments for all the components of the same type.

[0009] As regards the definition of the trajectories that the gripping and movement group must make the component travel, they can be pre-set by a technician manually, by properly programming the same gripping and movement group, or they can be acquired automatically, by means of adequate automatic acquisition and processing means, from the observation of the processing carried out by a specialized human operator.

[0010] However, even with the use of these automatic apparatuses, carrying out the surface treatments of the various components still requires the presence of a human operator, since, for example, in the case of polishing, in addition to the adequate movement of the component, it is necessary to control and appropriately adjust additional variables that are not currently managed autonomously and automatically by the current automatic apparatuses.

[0011] In particular, two important variables not negligible during the execution of a polishing treatment are the variation of the radius of the polishing brush and the amount of abrasive paste present on the circumferential surface of said polishing brush.

[0012] In fact, as regards the radius of the polishing brush, it may vary, in particular decrease, during the use of the polishing brush itself, following the wear that the latter undergoes. This aspect is not to be considered secondary, since, as the trajectory of the component by means of the gripping and movement group is pre-programmed, it does not take into account the possible variation of the radius of the polishing brush and therefore, if not suitably adjusted following this variation, a different final polishing result would be disadvantageously obtained for the same type of components.

[0013] In the same way, a poor repeatability of the final polishing effect would be obtained if an adequate amount of abrasive paste was not maintained on the brush.

[0014] There is therefore a need to define an automatic surface treatment apparatus and a relative method for performing such surface treatment, which allow the operation of highly specialized human personnel to be totally replaced, in order to carry out these treatments, while guaranteeing a high quality and repeatability of the final results.

[0015] Therefore, it is an aim of the invention to define a totally autonomous automatic apparatus for surface treatment for carrying out surface treatments of the components for the manufacture of ornamental objects, in particular watches, which allows to guarantee at the same time a high quality and repeatability of the final results.

[0016] Another aim of the invention is the realization of an automatic apparatus that allows to increase productivity with respect to manual processing and processing performed with the known automatic apparatuses.

[0017] Therefore, it is an aim of the invention to define an automatic apparatus that allows to increase profitability, while maintaining a high quality of the results of such surface processing.

[0018] According to the invention, such aims are achieved by means of the automatic apparatus in accordance with claim 1.

[0019] Further characteristics of the apparatus of the invention are indicated in the dependent claims, the advantages of which will be clarified during the description of the preferred embodiment of the invention.

[0020] The method for performing such surface treatments by using the automatic apparatus is also part of the invention, in accordance with claim 8.

[0021] The task and the aforesaid aims, together with the advantages that will be mentioned hereinafter, are highlighted by the description of an embodiment of the invention, which is given by way of non-limiting example with reference to the attached drawings, where:

• in fig. 1 the automatic apparatus of the invention is represented as a whole;
• in fig. 2 the guide station belonging to the automatic apparatus of the invention of fig. 1 is represented in isolation, in side view;
• in fig. 3 and in the detail of fig. 3a the guide station of fig. 2 is represented in axonometric view, in isolation;
• in fig. 4 the guide station of fig. 2 on which the abrasive paste PA is applied is represented;
• in fig. 5 a first step of the method of the invention is represented;
• in fig. 6 and in the detail of fig. 6a a second step of the method of the invention is represented;
• in fig. 7 a third step of the method of the invention is represented;
• in fig. 8 an abrasive paste applicable on the guide station of fig. 2 is represented in axonometric view.

[0022] The automatic apparatus of the invention for the surface treatment of components C for the manufacture of ornamental objects, in particular watches, is schematically illustrated in fig. 1, where it is indicated overall with 1.

[0023] By way of non-limiting example, such components C may be straps, watch cases, as well as wristband meshes and clasps.

[0024] As can be observed in fig. 1, this automatic apparatus 1 of the invention comprises a surface treatment tool 2 for said components C, substantially discoidal or ring-wound tape in shape and operatively connected at its centre 21 to electrical rotation means 3, configured to rotate the same surface treatment tool 2 around this centre 21.

[0025] In particular, said electrical rotation means 3 are represented by an electric motor whose motor shaft 31 is keyed at the centre 21 of the aforesaid surface treatment tool 2.

[0026] As regards the surface treatment tool 2, according to the preferred embodiment, it is a polishing brush 7, configured to polish the metal surfaces of the components C of a wearable ornamental object, in particular of a watch. It is not excluded, however, that according to executive variants of the automatic apparatus of the invention such a surface treatment tool 2 may be of another type than a polishing brush, such as for example a grinding tool or an abrasive belt.

[0027] Returning to the preferred embodiment of the invention, the automatic apparatus 1 further comprises a gripping and movement group 4 comprising, at a free end thereof 4a, gripping means 41 for hooking one of the aforesaid components C.

[0028] This gripping and movement group 4 is also configured to move the aforesaid component C in space according to a predefined trajectory, so as to bring one or more surfaces S of the same component C into contact with the surface treatment tool 2.

[0029] Preferably, the gripping and movement group 4, as can be observed in fig. 1, is an anthropomorphic robot 8.

[0030] It is not excluded, however, that this gripping and movement group 4, according to executive variants of the invention, can be any other type of gripping and multiple-axis movement system, thus able to move the aforesaid component C in space according to a predefined trajectory.

[0031] As regards the predefined movement trajectory for each type of component, as already mentioned above, it can be pre-set by a technician manually, by properly programming the same gripping and movement group 4, or it can be acquired automatically, by means of adequate automatic acquisition and processing means, from the observation of the processing carried out by a specialized human operator. Clearly, even in this second case, this acquired trajectory, suitably processed, is transmitted to the gripping and movement group 4 so that the latter is able to replicate it accordingly.

[0032] Furthermore, the automatic apparatus 1 comprises processing means 5 operatively connected to the electrical rotation means 3 and to the gripping and movement group 4 so as to control the rotation speed of the surface treatment tool 2 and so as to move the component C based on the aforesaid predefined trajectory.

[0033] In particular, said processing means 5 can be a PLC or any other type of electronic control system capable of performing the aforesaid control activities of the remaining electromechanical components of the automatic apparatus 1 of the invention.

[0034] According to the invention, the automatic apparatus 1 comprises a guide station 6 of an abrasive paste PA in the solid state. This guide station 6 is represented in isolation in figs. 2 and 3, in a configuration in which such abrasive paste PA in fig. 4 is applied thereon and inserted into the same automatic apparatus 1 in figs. from 5 to 7.

[0035] As regards the abrasive paste PA in the solid state, it, as can be observed in fig. 8, has an essentially longitudinal development, in particular a cylindrical shape in which a proximity end PAa and a distal end PAb, opposite said proximity end PAa, are identified.

[0036] Said guide station 6 is configured to move the abrasive paste PA along a displacement axis X, incident on the circumferential surface 22 of the surface treatment tool 2, in particular said displacement axis X is defined in a radial direction with respect to the surface treatment tool 2.

[0037] The processing means 5 are operatively connected to the guide station 6 so as to command the approach of the abrasive paste PA, during surface treatment, towards the surface treatment tool 2, in order to apply an amount of the abrasive paste PA on the circumferential surface 22 and, also, so as to command the distancing of the same abrasive paste PA from the surface treatment tool 2.

[0038] In this way, advantageously, also the management of the distribution of the abrasive paste on the surface treatment tool 2 is performed automatically by the automatic apparatus 1 of the invention, without therefore requiring the presence of a human operator while carrying out the surface treatment operations of a component C.

[0039] As can be observed in figs. 2 and 3, according to the preferred embodiment of the invention, the guide station 6 is provided with an actuator 61 for moving the abrasive paste PA along the displacement axis X and with a movement detection element 62 for determining the position of the actuator 61 along the same displacement axis X and therefore, as will be seen in detail shortly, the position of the proximity end PAa of the abrasive paste PA along the displacement axis X.

[0040] Even more in detail, preferably but not necessarily, the actuator 61 comprises:

• an electric motor 611;
• a worm screw 612 associated with the rotation shaft 611a of the electric motor 611 and arranged along the displacement axis X;
• a pusher 613 driven by the worm screw 612 and configured to be associated with the proximity end PAa of the abrasive paste PA so as to be able to move the latter along the displacement axis X.

[0041] In this case, the movement detection element 62 is a rotary encoder, operatively connected to the electric motor 611 and capable of determining the position px of the pusher 613 and therefore of the proximity end PAa of the abrasive paste PA along said displacement axis X.

[0042] It is not excluded, however, that according to different embodiments of the invention such actuator 61 and the movement detection element 62 may be of another type, for example a hydraulic or pneumatic actuation system and e.g. a linear encoder.

[0043] Furthermore, again according to the preferred embodiment of the invention or according to alternative embodiments thereof, the guide station 6 comprises a presence sensor 63 arranged at a predefined point p1 along the displacement axis X between the actuator 61 and the circumferential surface 22 of the surface treatment tool 2, so that said presence sensor 63 is configured to detect the passage of the distal end PAb of the abrasive paste PA, at said predefined point p1.

[0044] Preferably but not necessarily, the presence sensor 63 is a photocell 631.

[0045] This advantageously allows to calculate in real time, by means of the processing means 5, the length L of the abrasive paste PA arranged on the guide station 6, based on the position px of the actuator 61, and therefore of the proximity end PAa of the same abrasive paste PA, detected by means of the movement detection element 62, at the instant t_x1 at which the presence sensor 63 detects the passage of said distal end PAa of the same abrasive paste PA, as represented in fig. 6.

[0046] In other words, by calculating the difference between the point p1 and the point px along the displacement axis X at the instant t_x1, the actual length of the abrasive paste PA is determined.

[0047] Advantageously, this operation automatically allows to the automatic apparatus 1 of the invention to check the consumption status of the abrasive paste PA, and when said length is less than a predefined minimum length the same automatic apparatus 1 is able to provide an alarm signal for non-presence of the abrasive paste PA and/or to stop its operation until said abrasive paste PA is replaced.

[0048] According to the preferred embodiment of the invention, the same processing means 5 are configured to detect also the variation of the intensity of electric current absorbed by the electrical rotation means 3, during the rotation of the surface treatment tool 2; which variation is essentially due to the contact of the abrasive paste PA with the circumferential surface 22 of the surface treatment tool 2, when the same abrasive paste PA is advanced towards the latter, as represented in fig. 7. This allows the processing means 5 to determine in real time the value of the radius r of the surface treatment tool 2, based on the position of the actuator 61 at the instant t_x2 at which this variation in the value of absorbed electric current is detected and based on the length L of the abrasive paste PA, previously detected.

[0049] In fact, the processing means 5, by knowing in advance the position C₂₁ of the centre 21 of the surface treatment tool 2, by knowing the position px of the actuator 61 and therefore of the proximity end PAa of the abrasive paste PA, and by knowing the length L of the same abrasive paste PA are able to calculate the actual value of the radius of the surface treatment tool 2 with the following formula:

[0050] Still, preferably but not necessarily, the automatic apparatus 1 provides that the processing means 5 are configured to modify the rotation speed of the electrical rotation means 3 based on the calculated value of the radius r, so as to keep the peripheral speed of the circumferential surface 22 of the surface treatment tool 2 aligned with the peripheral speed defined in a predefined surface treatment program for said component C.

[0051] In fact, since also the peripheral speed of the circumferential surface 22 of the surface treatment tool 2, which actually comes into contact with the component C to be treated, is a further important aspect for the optimal success of the treatment on the aforesaid component, and since as known the peripheral speed is directly proportional to the angular speed of rotation imposed by the rotation electric means 3 for the radius r of the surface treatment tool 2, in order to maintain this peripheral speed adequate and aligned with the aforesaid predefined treatment program, it is necessary to vary this angular speed following the variation of the radius r of the surface treatment tool 2. Therefore, advantageously, by means of the aforesaid feature, the automatic apparatus 1 of the invention is able to manage, automatically and therefore without the help of a human operator, also this aspect, in order to obtain an optimal and as constant as possible final result of the treatment carried out on the various components C.

[0052] Furthermore, again according to the preferred embodiment of the invention, the processing means 5 are also configured to modify the predefined trajectory of the component C, performed by the gripping and movement group 4, based on the value of the radius r previously calculated.

[0053] In fact, also in this case, the variation of the radius r of the surface treatment tool 2, with the same trajectory of the component C, results in a variation of the points of contact of this component to the circumferential surface 22 of the surface treatment tool 2. This, therefore, would disadvantageously result in a non-constancy in the final result of the treatment on components C of the same type.

[0054] However, the solution implemented with the automatic apparatus 1 of the invention advantageously allows to overcome this disadvantage, making also in this sense the same automatic apparatus 1 of the invention totally autonomous from the presence of a human operator.

[0055] According to the preferred embodiment of the invention, the guide station 6 comprises a second actuator 64, in particular a second electric motor 641, arranged at the pusher 613 and configured to rotate the abrasive paste PA around the aforesaid displacement axis X, so that, when the distal end PAb of the same abrasive paste PA comes into contact with the circumferential surface 22 of the surface treatment tool 2, the rotation of this abrasive paste PA results in a homogeneous consumption of the same over its entire surface at the distal end PAb, avoiding therefore the appearance of irregularities on this surface which would consequently result in a worsening of the distribution of the same abrasive paste PA on the circumferential surface 22 of the surface treatment tool 2.

[0056] As mentioned above, the method for the surface treatment of a component C for the manufacture of ornamental objects, in particular watches, by using the automatic apparatus 1 of the invention is also part of the invention.

[0057] In particular, the method provides for arranging the actuator 61, in particular the pusher 613, in the most retracted position, as is visible in fig. 5.

[0058] Furthermore, as visible always in fig. 5, the method provides for preparing an abrasive paste PA in the solid state in the guide station 6, associating said abrasive paste PA to the same pusher 613, so that the distal end PAb of the abrasive paste PA is on the opposite side of the predefined point p1 and of the presence sensor 63 with respect to the surface treatment tool 2.

[0059] Once the abrasive paste PA has been prepared, the method provides for activating the actuator 61 so as to move the abrasive paste PA towards the surface treatment tool 2 and for detecting, by means of the presence sensor 63, when the same abrasive paste PA passes at the predefined point p1, as well as for detecting at the same instant the position of the pusher 613 by means of the movement detection element 62, as represented in fig. 6.

[0060] Therefore, the method provides for calculating the length L of the abrasive paste PA by determining the distance between the predefined point p1 and the position px detected for the pusher 613.

[0061] The method also provides for activating the rotation of the surface treatment tool 2 and for hooking, by means of the gripping and movement group 4, a component C and setting it into motion along a predefined trajectory so as to start the surface treatment.

[0062] It is also provided for keeping the actuator 61 active so as to continue the movement of the abrasive paste PA towards the surface treatment tool 2 and for detecting the variation of the intensity of electric current absorbed by the electrical rotation means 3 during the rotation of the surface treatment tool 2; variation due to the contact of the same abrasive paste PA with the circumferential surface 22 of the surface treatment tool 2, as visible in fig. 7.

[0063] Once this detection has been carried out, the method provides for calculating the value of the radius r of the surface treatment tool 2 based on the position px of the pusher 613 at the instant at which this variation is detected and based on the length L of the abrasive paste PA, as described above. Following the calculation of these values, the method provides for modifying the angular speed of rotation of the electrical rotation means 3 based on the calculated value of the radius r, so as to keep the peripheral speed of the circumferential surface 22 of the surface treatment tool 2 aligned with the peripheral speed defined in a predefined surface treatment program for the component C.

[0064] Finally, the method also provides for modifying the predefined trajectory of movement of the component C performed by means of the gripping and movement group 4 based on the same value of the calculated radius r.

[0065] As a result of what has been described, it can be understood that the automatic apparatus of the invention and the method for surface treatment performed by means of the aforesaid apparatus achieve all the intended purposes.

[0066] In particular, the aim of defining an automatic surface treatment apparatus and a relative method for performing such surface treatment which allow the operation of highly specialized human personnel to be totally replaced, in order to carry out these treatments, while guaranteeing a high quality and repeatability of the final results, is achieved.

[0067] Therefore, the aim of defining a totally autonomous automatic apparatus for surface treatment for carrying out surface treatments of the components for the manufacture of ornamental objects, in particular watches, which allows to guarantee at the same time a high quality and repeatability of the final results is achieved.

[0068] Another aim achieved by the invention is the realization of an automatic apparatus that allows to increase productivity with respect to manual processing and processing carried out with the known automatic apparatuses. Therefore, the aim of defining an automatic apparatus that allows to increase profitability, while maintaining a high quality of the results of such surface processing, is also achieved.

Claims

1. Automatic apparatus (1) for the surface treatment of components (C) for the manufacture of ornamental objects, in particular watches, of the type comprising:

- a surface treatment tool (2) for said components (C), substantially discoidal or ring-wound tape in shape, operatively connected at its centre (21) to electrical rotation means (3) configured to rotate said surface treatment tool (2) around said centre (21);

- a gripping and movement group (4) provided, at a free end thereof (4a), with gripping means (41) for hooking one of said components (C), said gripping and movement group (4) being configured to move said component (C) in space according to a predefined trajectory, so as to bring one or more surfaces (S) of said component (C) into contact with said surface treatment tool (2);

- processing means (5) operatively connected to said electrical rotation means (3) and to said gripping and movement group (4) so as to control the rotation speed of said surface treatment tool (2) and so as to move said component (C) based on said predefined trajectory;

- a guide station (6) of an abrasive paste (PA) in the solid state, said guide station (6) being configured to move said abrasive paste (PA) along a displacement axis (X), incident on the circumferential surface (22) of said surface treatment tool (2), said processing means (5) being operatively connected to said guide station (6) so as to command the approach of said abrasive paste (PA) towards said surface treatment tool (2), in order to apply an amount of said abrasive paste (PA) on said circumferential surface (22) and so as to command the distancing of said abrasive paste (PA) from said surface treatment tool (2);

characterized in that said guide station (6) is provided with:

- an actuator (61) for moving said abrasive paste (PA) along said displacement axis (X);

- a movement detection element (62) for determining the position of said actuator (61) along said displacement axis (X);

- a presence sensor (63) arranged at a predefined point (p1) along said displacement axis (X) between said actuator (61) and said circumferential surface (22) of said surface treatment tool (2), said presence sensor (63) being configured to detect the passage of the distal end (PAb) of said abrasive paste (PA) at said predefined point (p1);

said processing means (5) being configured to:

- calculate the length (L) of said abrasive paste (PA) along said displacement axis (X), based on the position (px) of said actuator (61) detected by means of said movement detection element (62) at the instant (t_x1) at which said presence sensor (63) detects said passage of said distal end (PAb) of said abrasive paste (PA);

- detect the variation of the intensity of electric current absorbed by said electrical rotation means (3) during the rotation of said surface treatment tool (2) due to the contact of said abrasive paste (PA) with said circumferential surface (22) of said surface treatment tool (2), said processing means (5) being also configured to determine in real time the value of the radius (r) of said surface treatment tool (2) based on the position of said actuator (61) at the instant (t_x2) at which said variation is detected and based on the length (L) of said abrasive paste (PA);

- modify the angular speed of rotation of said electrical rotation means (3) based on said calculated value of said radius (r), so as to keep the peripheral speed of said circumferential surface (22) of said surface treatment tool (2) aligned with the peripheral speed defined in a predefined surface treatment program for said component (C).

2. Automatic apparatus (1) according to claim 1, characterized in that said processing means (5) are configured to modify said predefined trajectory of said component (C) performed by means of said gripping and movement group (4) based on said calculated value of said radius (r).

3. Automatic apparatus (1) according to any one of the preceding claims, characterized in that said actuator (61) comprises:

- an electric motor (611);

- a worm screw (612) associated with the rotation shaft (611a) of said electric motor (611) and arranged along said displacement axis (X);

- a pusher (613) driven by said worm screw (612) and configured to be associated with said abrasive paste (PA) for the movement of said abrasive paste (PA) along said displacement axis (X);

said movement detection element (62) being a rotary encoder operatively connected to said electric motor (611) capable of determining said position (px) of said pusher (613) along said displacement axis (X).

4. Automatic apparatus (1) according to any one of the preceding claims, characterized in that said presence sensor (63) is a photocell (631).

5. Automatic apparatus (1) according to any one of the preceding claims, characterized in that said surface treatment tool (2) is a polishing brush (7).

6. Automatic apparatus (1) according to any one of the preceding claims, characterized in that said gripping and movement group (4) is an anthropomorphic robot (8).

7. Automatic apparatus (1) according to any one of the preceding claims, characterized in that said displacement axis (X), incident on said circumferential surface (22) of said surface treatment tool (2) is defined in a radial direction with respect to said surface treatment tool (2).

8. Method for the surface treatment of a component (C) for the manufacture of ornamental objects, in particular watches, by using the automatic apparatus (1) according to any one of the preceding claims, characterized in that it provides for the steps of:

- arranging said actuator (61) in the most retracted position;

- preparing an abrasive paste (PA) in the solid state in said guide station (6), associating said abrasive paste (PA) to said actuator (61) so that said distal end (PAb) of said abrasive paste (PA) is on the opposite side of said predefined point (p1) and of said presence sensor (63) with respect to said surface treatment tool (2);

- activating said actuator (61) so as to move said abrasive paste (PA) towards said surface treatment tool (2);

- detecting, by means of said presence sensor (63), when said distal end (PAb) of said abrasive paste (PA) passes through said predefined point (p1), and detecting at the same instant (t_x1) the position of said actuator (61) by means of said movement detection element (62);

- calculating the length of said abrasive paste (PA) by calculating the distance of said predefined point from said position of said actuator (61);

- activating the rotation of said surface treatment tool (2);

- hooking by means of said gripping and movement group (4) a component (C) and setting said component (C) into motion along said predefined trajectory so as to start the surface treatment;

- keeping said actuator (61) active so as to continue the movement of said abrasive paste (PA) towards said surface treatment tool (2);

- detecting the variation in the intensity of electric current absorbed by said electrical rotation means (3) during the rotation of said surface treatment tool (2) due to the contact of said abrasive paste (PA) with said circumferential surface (22) of said surface treatment tool (2);

- calculating the value of the radius of said surface treatment tool (2) based on the position of said actuator (61) at the instant at which said variation is detected and based on the length of said abrasive paste (PA);

- modifying the rotation speed of said electrical rotation means (3) based on said calculated value of said radius (r), so as to keep the peripheral speed of said circumferential surface (22) of said surface treatment tool (2) aligned with the peripheral speed defined in a predefined surface treatment program for said component (C).

9. Treatment method according to claim 8, characterized in that it provides for the further step of modifying said predefined trajectory of said component (C) performed by means of said gripping and movement group (4) based on said calculated value of said radius (r).

Drawing