System and method for trimming ceramic powder articles

Abstract

System (1) for trimming an article (2) made of compacted ceramic powder comprising: a transport device (3) for transporting the article (2) in an advancing direction (A); a fixed main frame (9); a secondary frame (10) which is connected to the main frame (9) in the advancing direction (A) in a sliding manner; a trimming assembly (11) which, in turn, comprises two transverse support structures (13) carried by the secondary frame (10); at least two abrasive tools (14) for trimming the edges (B1, B2, B3, B4) of the article (2) and each coupled to a support structure (13) in a sliding manner; two drive assemblies (16) so as to position and / or move the respective abrasive tool (14) along a trimming trajectory (T); detectors (17) to detect the development / outline of the edge (B1, B2, B3, B4) to be trimmed; two deflection units (12) to deflect the ring-shaped transport device (3) so as to define a work space (W); and a control assembly (CU) to control the actuation of the various components as a function of the data detected by the detectors (17) and the format of the article (2) to be trimmed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority of Italian patent application no. 102024000016897 filed on July 22, 2024, the content of which are incorporated herein by reference.FIELD OF THE ART

[0002] The present invention relates to a system and method for trimming articles made of compacted ceramic powder (i.e. made of compacted ceramic powder) for the manufacture of ceramic products, such as ceramic slabs and tiles.BACKGROUND OF THE INVENTION

[0003] In the field of the production of ceramic products, in particular of ceramic slabs and tiles, production plants are known that provide for feeding (typically, in a substantially continuous manner) semi-dry ceramic powder (i.e. with a moisture content of less than 10%, in particular between 5% and 6%) along a determined path through a continuous compacting assembly, which subjects the ceramic powder to a compacting pressure, so as to obtain a layer of compacted ceramic powder in the form of a continuous strip of compacted ceramic powder, which is subsequently cut to obtain a plurality of articles of compacted ceramic powder, which will then be dried, possibly decorated, and fired to obtain the final ceramic products.

[0004] During cutting operations, imperfections may arise along the edges of the compacted ceramic powder articles, typically of the portions of the compacted ceramic material in excess that protrude relative to the edges of the articles, the so-called burrs, due to inaccuracies during cutting. The well production plants for ceramic products therefore include trimming stations, also called deburring or finishing stations, where the edges of the compacted ceramic powder articles are trimmed (i.e. finished or deburred) to eliminate the aforementioned burrs. In detail, the trimming operations are generally carried out by means of the abrasive tools that intercept the edge to be treated, remove any excess material and smooth the edges of the corners itself.

[0005] The well production plants for ceramic products therefore include finishing stations, also called deburring or trimming stations, at which the edges of the compacted ceramic powder articles are finished (i.e. deburred or trimmed) to eliminate the aforementioned burrs. In this regard, documents IT201900003337A1 and EP4023392A1 describing two different examples of trimming assemblies of known type are reported.

[0006] In detail, for trimming (i.e. deburring or finishing) all the edges of each compacted ceramic powder article, the trimming assembly generally provides for two abrasive tools mounted on two linear guides arranged parallel to the advancing direction of the compacted ceramic powder articles to trim (i.e. finish or deburr) the lateral edges of each compacted ceramic powder article while it advances in the advancing direction; and at least one further abrasive tool mounted on a further linear guide arranged transversely to the advancing direction to trim the front edges of the same article, when it is in a first position, and the rear edges of the article, when it is in a second position. The trimming operations, especially those of the transverse edges, therefore often represent a real bottleneck for the production plant of ceramic products, since the machine stops at least for the time necessary to trim the front edge and the rear edge of each article.

[0007] To try to solve this problem, plants are known that provide multiple transverse trimming stations, so as to finish several compacted ceramic powder articles at the same time. This solution, however, only partially solves the problem and involves a considerable increase in the overall dimensions, which is not always compatible with the structural constraints of the premises intended to accommodate these plants.

[0008] To these drawbacks must be added the fact that such systems often require a very accurate positioning of the ceramic articles entering the deburring station in order to function efficiently. Which instead do not always arrive at the aforementioned finishing station perfectly aligned with each other and with the longitudinal edges perfectly parallel to the advancing direction and with the transverse edges perfectly perpendicular to the advancing direction, due to inaccuracies in the movement system and / or in the cutting system, in particular due to problems of cutting inaccuracy, the tile could have a rhomboidal or trapezoidal shape. This could compromise the success of the trimming operations as the abrasive tool would risk removing different amounts of material along the same edge based on the inclination with which each article arrives at the finishing station.

[0009] More recently, automatic trimming systems have been developed, also by the same Applicant, which have, for example, deburring tools mounted on robots capable of acting simultaneously both on the longitudinal edges and on the transverse edges. However, these systems, in addition to being very expensive, are not always adaptable, for reasons of overall space and safety, to the plants for the production of ceramic products of known type and, in any case, require times for the execution of operations that are incompatible with the needs of the most modern plants for the manufacture of ceramic products.

[0010] Aim of the present invention is to provide a system and a method for trimming articles made of compacted ceramic powder, which allow to overcome, at least in part, the drawbacks of the prior art.SUMMARY

[0011] In accordance with the present invention there is proposed a system and a method for trimming articles made of compacted ceramic powder and a method and an apparatus for producing ceramic products, as described in the appended independent claims, and preferably, in any one of the claims directly or indirectly dependent on the aforementioned independent claims.

[0012] The claims describe preferred embodiments of the present invention forming an integral part of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will now be described with reference to the accompanying drawings, which show some non-limiting examples of embodiments, wherein: Figure 1 is a perspective view of a trimming system in accordance with a first embodiment of the present invention during the trimming process of a ceramic article; Figures 2 and 3 are, respectively, a front view and a side view of the trimming system of Figure 1 to better illustrate some parts thereof; Figure 4 is a perspective view of a trimming system in accordance with another embodiment of the present invention and shows the trimming system that has just trimmed a longitudinal edge of a first ceramic article; Figure 5 is a side view of the trimming system of Figure 4 to better illustrate some parts thereof; Figure 6 a perspective view of the trimming system of Figure 4 in a subsequent step of the trimming process of the ceramic article, during which the trimming system trims the transverse edges of the ceramic article; Figure 7 is a side view of the trimming system of Figure 6 to better illustrate some parts thereof; Figure 8 a perspective view of the trimming system of Figures 4 and 6 in a subsequent step of the trimming process of the same ceramic article, during the trimming step of the other longitudinal edge of the same ceramic article; Figure 9 is a side view of the trimming system of Figure 8 to better illustrate some parts thereof; Figure 10 is a perspective view of the trimming system of Figures 4, 6 and 8 during a step of transverse trimming of another ceramic article advanced through the trimming station after the first ceramic article; and Figure 11 is a side view of the trimming system of Figure 10 to better illustrate some parts thereof. DETAILED DESCRIPTION

[0014] In the attached figures, number 1 denote as a whole a system for trimming articles 2 made of compacted ceramic powder (hereinafter for the sake of brevity only "articles"); more advantageously but not in a limiting manner, the present invention refers to the trimming of substantially flat articles 2 intended (once subjected to at least the known heat treatments) to form ceramic slabs or tiles.

[0015] In the present discussion, the expression "trimming of articles 2" is intended to refer to the finishing operation, i.e. deburring of the edges B1, B2, B3, B4 of the articles 2, i.e. the operation of removing portions of material, the so-called "burrs", from the edges B1, B2, B3 and B4 (more in particular, from the upper and lower corners) of the articles 2. In detail, advantageously but not in a limiting manner, the removal of such portions of material is aimed at chamfering the upper and lower corners of the edges B1, B2, B3 and B4. Typically, such portions of material to be removed refer to a few millimetres of material on the upper and lower perimeter of the tile and, advantageously but not in a limiting manner, comprise (in particular, are formed by) parts of excess material (which may be created as a result of inaccuracies in the operations of manufacture of the articles 2; in particular in the cutting operations), and / or additional parts of the (body) of the article 2. Therefore, the trimming operations to which reference is made in the present discussion are to be understood as operations of removal of such portions of material from one or more edges B1, B2, B3 and B4 of an (in particular, of each) article 2 (even more in particular, from one or more corners of one or more edges B1, B2, B3 and B4 of each article 2).

[0016] It should also be noted that in the present discussion the terms such as "upper", "lower", "lateral", "right", "left", "front", "rear", are used with reference to the trimming system 1 arranged resting on a horizontal support plane. Therefore, for example, with the term "above" or "under", it is intended, respectively, "that it is located above" or "that it is located below" relative to another component of the trimming system 1 in use. In the context of the present disclosure, the term "second" component does not imply necessarily the presence of a "first" component. These terms are sometimes used as labels to improve clarity.

[0017] Advantageously, the trimming system 1 comprises a ring-shaped transport device 3 configured to define, with one of its upper branch, a transport surface S and to receive the articles 2 and transport them in an advancing direction A through at least one trimming station 4 by moving them in a first advancing direction (in particular, in a first advancing direction having a first direction / orientation / versor / way) going from the input 5 of the trimming station 4 towards the output 6 of said trimming station 4.

[0018] According to some advantageous but non-limiting embodiments, such as those shown in the attached figures, the ring-shaped transport device 3 comprises (in particular, is formed by) a plurality of belts 7 parallel to each other in the advancing direction A, which define with their upper branch the transport surface S and are operable in movement, for example by a pulley drive system 8 (per se known and not described in detail herein), to advance the articles 2 in the advancing direction A in the aforementioned first advancing way.

[0019] It is understood that, according to other advantageous but non-limiting embodiments, the transport device 3 could comprise (in particular, be formed by) a belt conveyor or a chain conveyor or a round track conveyor etc.

[0020] According to some advantageous but not limiting embodiments, the transport device 3 comprises a high-friction coating (not visible in the attached figures) arranged on the transport surface S at least at the trimming station 4 to improve the adhesion of the article 2 to the transport device 3 and, therefore, increase the stability of the article 2 while, in use, the article 2 itself is advanced in the advancing direction A (even when subjected to external actions, for example to the actions that are transmitted when trimming, as will be better explained below).

[0021] Advantageously, the trimming system 1 also comprises: a fixed main frame 9; a secondary frame 10 which is connected to the main frame 9 in a sliding manner and operable in translation in the advancing direction A, in the aforementioned first way (in particular, in the first advancing direction having a first direction / orientation / versor / way) or in a second direction (in particular, in a second advancing direction parallel - lying on the same straight line - and opposite to the first advancing direction and having a second direction / orientation / versor / way), opposite to the first direction, which second direction goes from the output 6 of the trimming station 4 towards the input 5 of the trimming station 4; a trimming assembly 11 carried by the secondary frame 10; two deflection units 12 carried by the secondary frame 10 spaced apart from one another by a determined distance D2 along the advancing direction A and each configured to deflect the ring-shaped transport device 3 so as to leave a work space W free (in particular, to be defined) between two successive segments of the transport surface S.

[0022] Advantageously but not in a limiting manner, the secondary frame 10 is configured to move relative to the main frame 9 with a second speed similar to the speed with which the transport device 3 advances the articles 2, at least when it moves in the same advancing direction of the articles 2 advanced by the transport device 3. Alternatively or in addition, the advancement speed of the secondary frame 10 relative to the main frame 9 may also be greater than the speed with which the transport device 3 advances the articles 2, at least when said secondary frame 10 moves in the direction opposite to that of advancement of the articles 2 carried by the transport device 3.

[0023] The trimming system 1 also comprises a control assembly CU (only schematically shown in Figures 1 and 9 e) configured (i.e. programmed) to control the actuation of the various components of the trimming system 1, as will be better explained below.

[0024] This control assembly CU, advantageously but not in a limiting manner, comprises a writable memory that contains at least geometric data on the articles 2 to be trimmed and a programming of the trimming operations that associates each article 2 with a certain sequence of edges B1, B2, B3, B4 to be trimmed, as a function of the type of trimming assembly 11 included in the trimming system 1, as will be better explained below.

[0025] With particular reference to the attached figures, advantageously, the trimming assembly 11 comprises: two support structures 13, which extend above the transport surface S along a direction B transverse (in particular, perpendicular) to the advancing direction A, and which are carried by the secondary frame 10 spaced apart from one another by a distance D1 along the advancing direction A; and at least two abrasive tools 14; more advantageously but not in a limiting manner four abrasive tools 14, 14', which can be operated so as to intercept and trim the (in particular, at least some; even more in particular, at least two) edges B1, B2, B3, B4 of the article 2 and are each coupled, by means of a slide 15 (as will be explained below), to one of the support structures 13 in a sliding manner so as to be operable in translation in the transverse direction B.

[0026] The trimming assembly 11 further comprises: at least one detector 17 for each abrasive tool 14, 14' configured to detect at least one quantity related to the development / outline of the edge B1, B2, B3, B4 to be trimmed (in particular, at the edge B1, B2, B3, B4 that the respective abrasive tool 14, 14' is intended to trim); and at least two first drive assemblies 16, each operatively interposed between support structures 13 and one of the aforementioned abrasive tools 14, 14' and that is operable to position and / or move the respective abrasive tool 14, 14' along a trimming trajectory T (only schematically and partially shown in Figures 4 and 10) so as to allow the movement of the abrasive tool 14, 14' along the trimming trajectory and to change the position of the abrasive tool 14, 14' relative to the edge B1, B2, B3, B4 of the article 2 to be trimmed as a function of the data detected by the detector 17 (while the respective abrasive tool 14, 14' moves along the aforementioned trimming trajectory T).

[0027] Advantageously but not in a limiting manner, each detector 17 is configured to transmit position data about the position of the edge B1, B2, B3, B4 to be trimmed (in particular, that the respective abrasive tool 14, 14' is intended to be trimmed) to the control assembly CU with a given frequency, which, in turn, is connected (in a manner known per se) to the detectors 17 so as to continuously receive the position data detected by said detectors 17 so as to be able to consequently control the respective abrasive tools 14, 14'.

[0028] According to some advantageous but non-limiting embodiments, each abrasive tool 14, 14' comprises (in particular, is formed by) a frusto-conical grinding wheel configured to allow, once in contact with the edge B1, B2, B3, B4 to be trimmed and actuated, the simultaneous trimming of both the lower corner and the upper corner of each edge B1, B2, B3, B4.

[0029] Advantageously, the trimming trajectory T along which the abrasive tools 14, 14' move, extends, at least partly, along the work space W, in particular at least for the abrasive tools 14 intended to trim also, or only, the transverse edges B1 and B3 of the various articles 2.

[0030] Advantageously but not in a limiting manner, each deflection unit 12 comprises: two first parallel and side-by-side idle rollers 18 which extend parallel to the transverse direction B carried by the secondary frame 10 and spaced apart from one another, along the advancing direction A, by a distance D2 that is sufficient to allow the passage of an abrasive tool 14 between them, and at least one central idle roller 19 (in the attached figures two central idle rollers 19, each) carried by the secondary frame 10, which is parallel to the first rollers 18 and is interposed between said rollers 18 at a lower height (i.e. at a greater distance from the transport surface S).

[0031] In other words, advantageously but not in a limiting manner, the deflection units 12 comprise at least two rollers 18 whose upper surface is aligned with the plane containing the transport surface S and at least another roller 19 (more advantageously two rollers 19, each) arranged under the rollers 18 so that each belt 7 of the transport device 3 by running (in particular, passing) above the idle rollers 18 and under the idle roller 19 (in the case shown with the two central rollers 19) defines a "U"-shaped segment, within which the aforementioned operating space W remains defined (see in particular Figures 1, 3, 5, 7, 9 and 11).

[0032] More advantageously but not in a limiting manner, the secondary frame 10 has lateral walls 20 that extend on the sides of the transport device 3 and the rollers 18, 19 are mounted on these walls 20 (see for example Figures 1, 3-11).

[0033] Even more advantageously but not in a limiting manner, the secondary frame 10 also has an adjustment system 21, for example in the shown case a screw adjustment system, interposed between the main frame 9 and the secondary frame 10 and capable of being operated so as to move said walls 20 towards or away from one another and, therefore, the deflection units 12 (in particular the rollers 18, 19) connected to them.

[0034] Alternatively or additionally, according to some advantageous but non-limiting embodiments (such as, for example, those of the embodiments shown) the adjustment system 21 is configured to also change the mutual distance D2 between the support structures 13 as a function of the format of the article 2.

[0035] With particular reference to the embodiments shown in the attached figures, advantageously but not in a limiting manner, the support structures 13 are also connected to the walls 20.

[0036] More in particular, advantageously but not in a limiting manner, the distance D1 between the deflection units 12 and the distance D2 between the support structures 13 are substantially similar; and, in any case, each of said distances D1, D2 is, advantageously but not in a limiting manner, at least equal to the extension of the article 2 in the advancing direction A.

[0037] According to some advantageous but non-limiting embodiments (such as, for example, those shown in the attached figures), each support structure 13 comprises (in particular, is formed by) a linear guide that extends from the secondary frame 10 (more in detail, from the walls 20) above the transport device 3 (in particular, the transport surface S) from one side to the other of the transport surface S to allow the movement of the trimming tools 14 along the direction B, in one way (in particular, in a first advancing direction that lies on the same straight line as the direction B and has a first direction / orientation / versor; more in particular, from a first end of the linear guide towards a second end of the same linear guide) or in a direction opposite to the previous one (in particular, in a further advancing direction that lies on the same straight line as the direction B and has a direction / orientation / versor opposite to that of the first direction; more in particular, from the aforementioned second end of the linear guide towards the aforementioned first end of the same linear guide).

[0038] In this case, advantageously but not in a limiting manner, the trimming assembly 11 comprises a pair of slides 15 each of which carries a respective abrasive tool 14, is coupled to one of the linear guides 13 in a sliding manner and is operable by means of a motor 22 (per se known) along said linear guides in one direction or the other, when the transverse edges B1, B3 of the article 2 are to be trimmed.

[0039] More in particular, in this case, each drive assembly 16 comprises at least: the aforementioned motor 22 and a motor 23 for causing the rotation of the abrasive tool 14 around a vertical rotation axis (therefore orthogonal to the transport surface S), so that, in use, it intercepts and trims an edge B1, B2, B3 and B4 of the article 2. According to some advantageous but non-limiting embodiments, such as for example those shown in Figures 4 to 11, each drive assembly 16 further comprises a positioning unit 24, interposed between the respective slide 15 and the respective abrasive tool 14 and having at least one positioning actuator 25, advantageously a linear actuator, configured to move the respective abrasive tool 14 (advantageously but not in a limiting manner together with the motor 23) relative to the slide 15 along a positioning path which extends along an adjustment direction, which is parallel to the plane on which the transport surface S lies and, in use, is substantially orthogonal to the edge B1, B2, B3, B4 to be trimmed.

[0040] The control assembly CU, in this case, is configured to operate the positioning actuator 25 of each drive assembly 16 as a function of the data detected by the respective detector 17 so as to adjust, continuously, the mutual distance between each abrasive tool 14 and the edge B1, B2, B3, B4 to be trimmed of the article 2.

[0041] More advantageously but not in a limiting manner, the positioning actuator 25 has a limited excursion, i.e. the positioning path has a variable limited extension of + or - 3mm. In fact, this adjustment path must only have an extension such as to allow the precise adjustment of the position of the abrasive tool 14 relative to the edge B1, B2, B3, B4 that it is intended to trim on the basis of the position and the actual development / outline of the edge B1, B2, B3, B4 itself detected by the detector 17.

[0042] According to some advantageous but non-limiting embodiments, such as for example those shown in Figures 1 to 3, the trimming assembly 11 comprises, four abrasive tools 14, 14', two abrasive tools 14 carried by the support structures 13 in a sliding manner and operable to trim the transverse edges B1 and B3 of the articles 2 and other two abrasive tools 14' carried by the secondary frame 10 so as to extend on opposite sides of the ring-shaped transport device 3 to intercept and trim the longitudinal edges B2, B4 of the article 2.

[0043] As already mentioned above, in this case, the trimming assembly 11 further comprises: two further detectors 17, each carried by the secondary frame 10 so as to extend on opposite sides of the ring-shaped transport device 3 upstream of the respective abrasive tools 14' along the advancing direction A in the aforementioned first way (direction) and each configured to detect at least one quantity related to the development / outline of the edge B2, B4 to be trimmed; two positioning units27, each operatively interposed between one of the abrasive tools 14' and the secondary frame 10 and each having a positioning actuator 28, advantageously similar to the positioning actuators 25, and also this configured to move the respective abrasive tool 14' (advantageously but not in a limiting manner together with the motor 23) relative to the transport device 3 along a positioning path which extends perpendicular to the advancing direction A. In this case, the control assembly CU is configured to also actuate the further abrasive tools 14' and the further positioning units 27 as a function of the data detected by the respective detector 17 to trim the longitudinal edges B2, B4 of the article 2, while this advances on the transport surface S along the advancing direction A in the area of the trimming station 4. This solution, in view of the need for two further abrasive tools 14', allows all four edges B1, B2, B3, B4 of the article 2 to be trimmed more quickly without having to provide a rotary actuator 26 to rotate the positioning unit 24 relative to the slide 15, as will be better described below, thus also simplifying the drives and in general the structure of the machine.

[0044] Alternatively, according to some advantageous but non-limiting (simplified) embodiments of the present invention, such as those shown in Figures 4 to 11, the trimming assembly 11 comprises (in particular, is formed by) only two trimming tools 14. In this case, advantageously but not in a limiting manner, to allow the trimming tools 14 described above to trim both the longitudinal edges B2, B4 and the transverse edges B1 and B3 of each article 2, the drive assembly 16 actually comprises a main rotary actuator 26, which can be operated so as to rotate the positioning unit 24 relative to the slide 15 by an angle equal to at least about 90°, clockwise or counterclockwise.

[0045] The control assembly CU is advantageously, but not in a limiting manner, configured to control the activation of the rotary actuator 26 as a function of the edge B1, B2, B3, B4 to be trimmed so that, in use (i.e. during trimming operations), the adjustment direction is always substantially orthogonal to the edge B1, B2, B3, B4 to be trimmed. For example, compare Figure 1, where the abrasive tools 14 are in position to trim the longitudinal edges B2, B4 together with Figure 3, which shows the same positioning unit 24 rotated by 90 degrees counterclockwise so that the abrasive tools 14 assume a position suitable for trimming the transverse edges B1 and B3.

[0046] According to some advantageous but non-limiting embodiments, said rotary actuator 26 comprises a cam system. Alternatively, the rotary actuator 26 is (in particular, comprises) a gearmotor, or a cylinder with a respective lever.

[0047] The presence of the rotary actuator 26 allows the entire positioning unit 24 to be rotated as the edge B1, B2, B3, B4 to be trimmed changes, advantageously allowing, with a single positioning actuator 25, the adjustment of the position of the abrasive tool 14 in both possible positioning directions (i.e. parallel to the advancing direction A or parallel to the transverse direction B).

[0048] According to still other advantageous but non-limiting embodiments not shown, the positioning unit 24 comprises two linear positioning actuators 25 (for example two linear actuators) which are selectively operable to move the respective abrasive tool 14 (advantageously but not in a limiting manner, together with the motor 23) relative to the slide 15 along two positioning paths that extend along two positioning directions orthogonal to each other, one parallel to the advancing direction A and one parallel to the transverse direction B. In this case, the control assembly CU is configured to cause the actuation of one or the other positioning actuator 25 as a function of the edge B1, B2, B3, B4 to be trimmed to allow, in use, the movement of the abrasive tool 24, advantageously but not in a limiting manner, together with the motor 23 orthogonally to the edge B1, B2, B3, B4 to be trimmed.

[0049] In both embodiments described above, however, the positioning actuators 25, 28 are provided to continuously adjust the position of the abrasive tool 14, 14' while it moves along the trimming trajectory T so as to adapt this position to the real development / outline of the edges B1, B2, B3, B4 of the article 2, through precisely the data provided by the detector 17.

[0050] According to some advantageous but non-limiting embodiments, such as those attached, each detector 17 is connected to the secondary frame 10 (in particular to the support structures 13) independently of the respective abrasive tool 14, 14'. More advantageously but not in a limiting manner, in this case, each of the detectors 17 intended to move upstream of the abrasive tools 14 is connected to a support structure 13 in a sliding manner so as to be operable in translation in the transverse direction B independently of the respective abrasive tool 14, 14' and is configured to detect, continuously, the position of an edge B1, B2, B3, B4 to be trimmed and the trimming assembly 11 comprises second drive assemblies 29, each operatively interposed between the detector 17 and the respective support structure 13 and operable to move the detector 17 relative to the respective abrasive tool 14, 14' so that the detector 17, in use, is, at all times upstream of the respective abrasive tool 14, 14' along the trimming trajectory T.

[0051] More advantageously but not in a limiting manner, according to some non-limiting embodiments, such as those shown in the attached figures, the detector 17 is mounted on the same slide 15 that carries the respective abrasive tool 14, 14' and is connected to said slide 15 by means of an arm 30 that is rotatable to rotate the detector 17, as a function of the development / outline of the edge B1, B2, B3, B4 to be trimmed by an angle of at least about 90 degrees. In other words, in this case, advantageously but not in a limiting manner, the second drive assembly 29 comprises the aforementioned arm 30 connected to the slide 15, thus partly coinciding with the first drive assembly 16.

[0052] According to other advantageous but non-limiting and non-embodiments shown, the detectors 17 are connected to the secondary frame 10, through the same support structures 13, and, when provided, the same positioning units27 that carry the abrasive tools 14, 14'. This allows to facilitate the movement of the detectors 17.

[0053] Even more advantageously but not in a limiting manner, in this case, the detectors 17 intended to move upstream of the abrasive tools 14 are integral with the aforementioned positioning unit 24. In this case, advantageously but not in a limiting manner, each drive assembly 29 is comprised in (more in particular coincides with) the drive assembly 16; even more advantageously coincides with the motor 22.

[0054] Alternatively or additionally, advantageously but not in a limiting manner, when four abrasive tools 14, 14' are provided, the detectors 17 intended to move upstream of the abrasive tools 14' are integral with the aforementioned positioning unit 27.

[0055] Advantageously, the control assembly CU is configured to continuously receive the position data detected by the detector 17 and to control, consequently, and always continuously the respective abrasive tool 14, 14'.

[0056] Even more advantageously but not in a limiting manner, the detector 17 comprises (in particular, is) a position sensor, for example a photocell and is configured to detect the actual development / outline of the edge B1, B2, B3, B4 to be trimmed and transmit the data to the control assembly CU which will thus actuate consequently the actuators 25, 28 to adjust the position of the abrasive tool 14, 14' as this moves along the trimming trajectory T.

[0057] According to some advantageous but non-limiting embodiments, each drive assembly 29 intended to operate the detector 17 in motion comprises (in particular, is formed by) at least one secondary rotary actuator 31 operable to rotate the detector 17 by an angle of at least 180° relative to a vertical axis (in particular, orthogonal to said transport surface S).

[0058] Advantageously but not in a limiting manner, the trimming system 1 also comprises a detection system 32 (only schematically shown in Figures 1 and 9) configured to detect the presence and the position of the article 2 at the trimming station 4 and to transmit the data to the control assembly CU so that it can consequently operate the trimming assembly 11 and the deflection units 12.

[0059] In particular, this detection system 32 (known per se and not described in detail) is configured to detect the entry of the front of the article 2 into the trimming station 4 and to transmit such data to the control assembly CU, which will then operate the different components (in particular, at least the secondary frame 10, the deflection units 13, each abrasive tool 14, 14', each drive assembly 16, 29 also as a function of the data detected by the detection system 32; in particular, at least as a function of the data detected by the detection system 32, the format of the article 2 to be trimmed (more advantageously of the aforementioned programming) and of the data detected, instant by instant, by the detectors 17.

[0060] According to another aspect of the present invention, a trimming method for trimming an article 2 using a trimming system 1 of the type described above is proposed.

[0061] With particular reference to Figures 1 to 8, when the trimming method is implemented using a trimming system 1 having (as better explained above) only two abrasive tools 14, the trimming method advantageously provides for the following steps: a preparatory step, during which the control assembly CU operates the drive assemblies 16 so as to position the abrasive tools 14 on one side of the ring-shaped transport device 3 and are spaced apart from one another, along the advancing direction A, by a first distance D1 substantially similar to the length of the article 2 (see, for example, Figure 1) and each arranged downstream of the respective detector 17 along the advancing direction A in the aforementioned first direction.

[0062] The trimming method further comprises a first longitudinal trimming step, during which, while the article 2 is advanced along the advancing direction A in the first direction through the trimming station 4, the abrasive tool 14 located most upstream along the advancing direction A (in the aforementioned first direction) is operated (in particular, by operating the aforementioned motor 23) so as to trim a first longitudinal edge B2 or B4 of the article 2; a second trimming step, which is subsequent to the first trimming step, during which (once the trimming of the first longitudinal edge B2 or B4 has been completed and once the detectors 17 and the abrasive tools 14 have been correctly positioned), the abrasive tools 14 trim the transverse edges B1, B3 of the article 2 while they translate along the support structures 13 in the transverse direction B carried by the secondary frame 10 with the respective detectors 17 arranged upstream of the abrasive tools 14 along the trimming trajectory T, and, at the same time, the secondary frame 10 advances relative to the main frame 9 along the advancing direction A in the first direction with a speed, which according to some advantageous but non-limiting embodiments is similar (at least in this case) to the speed with which the transport device 3 advances the articles 2 in the advancing direction A. The trimming method also provides for a third trimming step, during which the abrasive tool 14 located most downstream (along the direction A in the aforementioned first direction (versor / way)) is operated so as to trim the other longitudinal edge B4 or B2 of the article 2 while the secondary frame 10 moves, relative to the main frame 9, along the advancing direction A in a second direction (versor / way), opposite to the first direction (versor / way), with a speed that can be similar to or greater than the speed with which the transport device 3 advances the articles 2 in the advancing direction A.

[0063] The trimming method further comprises an adjustment step for each of the aforementioned trimming steps, which is simultaneous with the respective trimming step and during which the position of each active abrasive tool 14 is adjusted, relative to the respective edge B1, B2, B3, B4 to be trimmed, as a function of the data detected by the respective detector 17.

[0064] Advantageously but not in a limiting manner, the above trimming method (i.e. when implemented with a trimming system 1 having only two abrasive tools 14) further comprises a first positioning step, which is subsequent to the first trimming step and prior to the second trimming step, during which the above-described main rotary actuator 26 of both abrasive tools 14 is operated and rotates the positioning unit 24 relative to the respective slide 15 by about 90° in a counterclockwise direction and the second drive assemblies 29 each move the respective detector 17 and place it so as to detect the position of the transverse edges B1, B3 (compare the attached figures 1 and 3 together).

[0065] Furthermore, the above trimming method (i.e. when implemented with a trimming system 1 having only two abrasive tools 14) also comprises a second positioning step, which is subsequent to the second trimming step and prior to the third trimming step, during which the main rotary actuator 26 of both abrasive tools 14 is operated and rotates the positioning units 24 relative to the respective slide 15 by 90° in a counterclockwise direction and the second drive assemblies 29 each move the respective detector 17 and place it so as to detect the position of the longitudinal edge B2, B4 (compare, between them, the attached figures 3 and 5).

[0066] According to some advantageous but non-limiting variants of the present invention, during the aforementioned first and second positioning step the secondary rotary actuator 31 of the respective detectors 17 is also operated and rotates the respective detectors 31 so as to position them to detect, respectively, the transverse edges B1, B3, in the first positioning step, and the longitudinal edges B2, B4, in the second positioning step.

[0067] Alternatively, with particular reference to Figures 9, 10 and 11, when the trimming method is implemented using a trimming system 1 comprising four abrasive tools 14, 14', the trimming method provides for the following steps: a preparation step, during which the control assembly CU operates the drive assemblies 16 so as to position the abrasive tools 14 so that they are spaced apart from one another, along the advancing direction A, by a first distance substantially similar to the length of the article 2 and each positioned so as to be able to intercept and trim a transverse edge B1, B3 of the article 2; in other words, with the positioning actuator 25 arranged so as to be able to move the respective abrasive tool 14 parallel to the advancing direction A and with the respective detector 17 placed upstream along the trimming trajectory T.

[0068] Advantageously, in this case (i.e. when implemented with a trimming system 1 having four abrasive tools 14, 14'), the trimming method then comprises: a longitudinal trimming step, during which, while the article 2 is advanced along the advancing direction A through the trimming station 4 in the aforementioned first direction, the further abrasive tools 14' are operated (by means of the respective motor 23) and intercept and trim the longitudinal edges B2, B4 of the article 2; and a transverse trimming step, which is subsequent to the longitudinal trimming step and the preparation step, during which, once the trimming of the longitudinal edges B2, B4 is finished and once the detectors 17 and the abrasive tools 14 are correctly positioned (as will be better explained below), the further abrasive tools 14' trim the transverse edges B1, B3 of the article 2 while they translate along the support structures 13 in the transverse direction B carried by the secondary frame 10, with the respective detectors 17 upstream the trimming trajectory T, and at the same time the secondary frame 10 advances along the advancing direction A in the first direction with a second speed, which advantageously but not in a limiting manner, in this case (i.e. when the frame 10 advances in the first direction), is similar to the speed with which the transport device 3 transports the articles 2.

[0069] Advantageously but not in a limiting manner, the trimming method also in this case (i.e. when the trimming is carried out with a trimming system 1 having four abrasive tools 14, 14') also comprises an adjustment step, which is simultaneous with the transverse and longitudinal trimming steps, respectively, and during which the position of each active abrasive tool 14, 14' is adjusted relative to the respective edge B1, B2, B3, B4 to be trimmed as a function of the data detected by the respective detector 17.

[0070] In this second case, i.e. when the trimming is carried out with a trimming system 1 having four abrasive tools 14, 14', the abrasive tools 14 move along the respective support structures 13 in the transverse direction B with a similar speed but in opposite directions to each other; in other words, they move in phase opposition to each other. This ensures greater stability and reduces the risk of inadvertent movement of the article 2 by the action of the abrasive tools 14, 14'.

[0071] According to some advantageous but not limiting embodiments of the trimming method, during the aforementioned first, second and third trimming steps (when the trimming method is implemented with a trimming system 1 having only two abrasive tools 14), or during the aforementioned transverse trimming and longitudinal trimming steps (when the trimming method is implemented with a trimming system 1 having only four abrasive tools 14, 14'), the positioning actuators 25, 28 of the active abrasive tools 14, 14' (in particular, operated by the respective motors 23) are controlled by the control assembly CU to continuously change their activation as a function of the data detected by the respective detector 17 in order to adjust, in real time, the position of the respective abrasive tool 14, 14' relative to the edge B1, B2, B3, B4 to be trimmed, thus ensuring a precise trimming regardless of the actual development / outline of the edge B1, B2, B3, B4, that is, regardless of any geometric and / or orientation errors that may have occurred in the previous steps of manufacture of the article 2.

[0072] The trimming system 1 and the trimming method of the present invention have numerous advantages, among which we mention the following.

[0073] First of all, they allow a fast and extremely precise trimming of all the edges B1, B2, B3, B4 of the article 2 without the need to have to act on these edges B1, B2, B3, B4, through orientation systems that would risk damaging the articles 2. In fact, thanks to the presence of the detectors 17, which continuously detect the real development / outline of the edges B1, B2, B3, B4 (thus taking into account any defects and / or misalignments of the article 2), and the particular structure of the drive assemblies 16, the trimming system 1 of the present invention allows a continuous adaptation of the position of the abrasive tools 14, 14' relative to the edges B1, B2, B3, B4 to be trimmed.

[0074] In addition, the presence and the configuration of the secondary frame 10 and of the deflection units 12 described above allows a trimming on the fly, that is, while the article 2 continues to advance in the advancing direction A, with a considerable reduction in the time required for trimming operations.

Claims

1. A trimming system (1) for trimming at least one article (2) made of compacted ceramic powder; the trimming system (1) comprises: a ring-shaped transport device (3) configured to define a transport surface (S), with one of its upper branch, to receive and transport the compacted ceramic powder article (2) in an advancing direction (A) through at least one trimming station (4) with a first speed; a main frame (9); a secondary frame (10), which is connected to the main frame (9) in a sliding manner and is operable to translate in said advancing direction (A), in a first direction (versor / way) or in a second direction (versor / way), which is opposite to the first direction (versor / way). a trimming assembly (11), which, in turn, comprises: two support structures (13), which extend above said transport surface (S) along a direction (B) transverse (in particular, perpendicular) to said advancing direction (A) and are carried by said secondary frame (10) spaced apart from one another by a first distance (D1) defined along said advancing direction (A); at least two abrasive tools (14), which can be operated so as to intercept and trim the edges (B1, B2, B3, B4) of said at least one compacted ceramic powder article (2) and are each coupled to one of said support structures (13) in a sliding manner; two first drive assemblies (16), each operatively interposed between one of said support structures (13) and the respective abrasive tool (14) and operable so as to position and / or move the respective abrasive tool (14) along a trimming trajectory (T); and at least one first detector (17) for each abrasive tool (14), each configured to detect at least one quantity related to the development of the edge (B1, B2, B3, B4) to be trimmed; two deflection units (12) carried by said secondary frame (10) spaced apart from one another by a second distance (D2) determined along said advancing direction (A) and each configured to deflect said ring-shaped transport device (3) so as to leave a work space (W) free between two successive segments of said transport surface (S); said trimming trajectory (T) at least partly extending along said work space (W); and a control assembly (CU) configured to control the actuation of said secondary frame (10), of each deflection unit (12), of each abrasive tool (14) and of each drive assembly (16) as a function of at least the data detected by the respective first detector (17) and of the format of said at least one compacted ceramic powder article (2) to be trimmed.

2. The trimming system (1) according to claim 1, wherein said trimming assembly (11) comprises: two further abrasive tools (14') carried by the secondary frame (10) so as to extend on opposite sides of said ring-shaped transport device (3) to intercept and trim the longitudinal edges (B2, B4) of said at least one compacted ceramic powder article (2); two second detectors (17), each carried by the secondary frame (10) so as to extend on opposite sides of said ring-shaped transport device (3) and upstream of the respective abrasive tool (14') along said advancing direction (A) in said first direction (versor / way) and each configured to detect at least one quantity related to the development / outline of the edge (B2, B4) to be trimmed; two positioning units (27), each operatively interposed between one of said further abrasive tools (14') and said secondary frame (10) and each having a positioning actuator (28) configured to move the respective abrasive tool (14') relative to said transport device (3) along a positioning path extending perpendicularly to said advancing direction (A); said control assembly (CU) being configured to also actuate said further abrasive tools (14') and said further positioning units (27) as a function of the data detected by the respective second detectors (17) to trim the longitudinal edges (B2, B4) of said at least one compacted ceramic powder article (2) and said at least two abrasive tools (14) to trim transverse edges (B1, B3) of said at least one compacted ceramic powder article (2), while it advances on said transport surface (S) along said advancing direction (A) at said trimming station (4).

3. The trimming system (1) according to claim 1, wherein each first detector (17) is connected to one of said support structures (13) in a sliding manner to be operable in translation in said transverse direction (B) and is configured to continuously detect the position of an edge (B1, B2, B3, B4) to be trimmed; the trimming assembly (11) comprises two second drive assemblies (29), each operatively interposed between the respective first detector (17) and said support structure (13) and capable of being operated so as to move said first detector (17) relative to the respective abrasive tool (14) so that said first detector (17), in use, is upstream of said abrasive tool (14) along said trimming trajectory (T).

4. The trimming system (1) according to claim 3, wherein each second drive assembly (29) comprises at least one secondary rotary actuator (31), which is operable so as to rotate said detector (17) by an angle of at least 180° relative to a vertical axis.

5. The trimming system (1) according to any one of the preceding claims wherein: each first detector (17) and, when present, each second detector (17) is configured to transmit position data about the position of said edge (B1, B2, B3, B4) to said control assembly (CU) with a given frequency; said control assembly (CU) and said first and, when present, second detectors (17) are connected to one another so that said control assembly (CU) continuously receives said position data and, based on said position data, consequently controls the respective abrasive tools (14, 14').

6. The trimming system (1) according to any one of the preceding claims wherein: each support structure (13) comprises a respective linear guide; the trimming assembly (11) comprises a pair of slides (15), each coupled to one of said linear guides in a sliding manner and carrying one of said at least two abrasive tools (14); each first drive assembly (16) comprising: a first motor (23) for causing the rotation of the respective abrasive tool (14) of said at least two abrasive tools (14) around a rotation axis, orthogonal to said transport surface (S), and at least one second motor (22) for causing the translation of the respective slide (25) along said linear guide (13) in said transverse direction (B), in a first direction (versor / way) or in a second direction (versor / way), opposite to the first direction (versor / way).

7. The trimming system (1) according to claim 6, wherein: each first drive assembly (16) comprises a further positioning unit (24) interposed between the respective slide (15) and the respective abrasive tool (14) and having at least one positioning actuator (25) configured to move the respective abrasive tool (14) relative to said slide (15) along a positioning path, which extends along a third adjustment direction, which is parallel to the plane on which said transport surface (S) lies and, in use, is substantially orthogonal to the edge (B1, B2, B3, B4) to be trimmed; said control assembly (CU) being configured to operate said further positioning unit (24) (in particular, said positioning actuator (25)) of each first drive assembly (16) as a function of the data detected by the respective first detector (17) so as to continuously adjust the mutual distance between said abrasive tool (14) and said edge (B1, B2, B3, B4) to be trimmed of said at least one ceramic powder article (2).

8. The trimming system (1) according to claim 7, wherein each first drive assembly (16) comprises a main rotary actuator (26), which can be operated so as to rotate said further positioning unit (24) relative to the respective slide (15) by an angle of circa 90° clockwise, or counterclockwise; said control assembly (CU) being configured to control the activation of each rotary actuator (26) as a function of the edge (B1, B2, B3, B4) to be trimmed so that, in use, said third adjustment direction is substantially orthogonal to the edge (B1, B2, B3, B4) to be trimmed.

9. The trimming system (1) according to any one of the preceding claims, comprising an adjustment system (21) interposed between said main frame (9) and said secondary frame (10) and capable of being operated so as to move said support structures (13) and said deflection units (12) towards or away from one another in order to adjust said first distance (D1) and said second distance (D2) as a function of the format of said at least one compacted ceramic powder article (2); in particular, the first distance (D1) is similar to the second distance (D2).

10. The trimming system (1) according to any one of the preceding claims wherein: said transport device (3) is a belt conveyor; each deflection unit (12) comprises: two first parallel and side-by-side idle rollers (18), which extend parallel to said transverse direction (B) and spaced apart from one another, along said advancing direction (A), by a distance that is sufficient to allow the passage of one of said abrasive tools (14), and at least one central idle roller (19), which is parallel to the two first idle rollers (18) and is interposed between said two first idle rollers (18) at a lower height; each belt (7) of said belt conveyor running (in particular, passing) above said two first idle rollers (18) and under said at least one central idle roller (19) so as to define a "U"-shaped segment, within which the aforementioned operating space is defined.

11. The trimming system (1) according to any one of the preceding claims, wherein said transport device (3) comprises a high-friction coating arranged on said transport surface at least at said trimming station.

12. The trimming system (1) according to any one of the preceding claims, comprising: a detection system (32) configured to detect the presence and position of said at least one ceramic powder article (2) at said trimming station (4); said control assembly (CU) comprising a writable memory, which contains at least geometric data on said at least one ceramic powder article (2) to be trimmed and a programming of the trimming operations, which associates each ceramic powder article (2) to be trimmed with a sequence of edges (B1, B2, B3, B4) to be trimmed, so as to control the activation of said secondary frame (10), of each deflection unit (12), of each abrasive tool (14, 14'), of each drive assembly (25, 29) and, when present, of each further positioning unit (27) also as a function of the data detected by said detection system (32) and on the data contained in said writable memory.

13. A trimming method for trimming the edges of at least one ceramic powder article (2) by means of a trimming system (1) realized according to claim 1 or 3 or 4 or to one of the claims from 5 to 12, when they depend on claim 1; the trimming method comprises the following steps: a preparatory step, during which the control assembly (CU) operates the drive assemblies (16) so as to position said at least two abrasive tools (14) so that they arranged externally on one side of said ring-shaped transport device (3) and are spaced apart from one another, along said advancing direction (A), by a first distance substantially similar to the length of the ceramic powder article (2) to be trimmed and so that they are each arranged downstream of the respective first detector (17) along said advancing direction (A) in a first direction (versor / way) going from the input (5) of said trimming station (4) to the output (6) of said trimming station (4); a first longitudinal trimming step, during which, while said compacted ceramic powder article (2) is advanced along said advancing direction (A) in said first direction (versor / way) through said trimming station (4), the abrasive tool (14) located most upstream along said advancing direction (A) in said first direction (versor / way) is operated so as to trim a first longitudinal edge (B2, B4) of said at least one compacted ceramic powder article (2); a second trimming step, which is subsequent to said first trimming step and during which said abrasive tools (14) trim said transverse edges (B1, B3) of said compacted ceramic powder article (2) while they translate along said support structures (13) in said transverse direction (B) carried by said secondary frame (10) with the respective first detectors (17) located upstream along the trimming trajectory (T) and, at the same time, said secondary frame (10) advances along said advancing direction (A) in said first direction (versor / way) with a second speed similar to said first speed along said advancing direction (A); a third trimming step, during which the abrasive tool (14) located most downstream, along said advancing direction (A) in said first direction (versor / way), is operated so as to trim the other longitudinal edge (B2, B4) of said compacted ceramic powder article (2) while said secondary frame (10) moves, relative to the main frame, along said advancing direction (A) in a second direction (versor / way), opposite to the first direction (versor / way); and an adjustment step for each one of said first, second and third trimming steps, which is simultaneous with the respective trimming step and during which the position of each active abrasive tool (14) is adjusted, relative to the respective edge (B1, B2, B3, B4) to be trimmed, as a function of the data detected by the respective first detector (17).

14. The trimming method according to claim 13 implemented with a trimming system (1) realized according to one of the claims from 8 to 12, when they depend on claim 1; the method comprises: a first positioning step, which is subsequent to said first trimming step and prior to said second trimming step and during which said main rotary actuator (26) of both abrasive tools (14) is operated and rotates said positioning unit (24) relative to the respective slide by 90° in a counterclockwise direction and the second drive assemblies (29) each move the respective first detector (17) and place it so as to detect the position of said transverse edges (B1, B3); and a second positioning step, which is subsequent to said second trimming step and prior to said third trimming step and during which said main rotary actuator (26) of both abrasive tools (14) is operated and rotates said positioning unit (24) relative to the respective slide by 90° in a counterclockwise direction and the second drive assemblies (29) each move the respective first detector (17) and place it so as to detect the position of said longitudinal edge (B2, B4).

15. The trimming method according to claim 14 for trimming the edges of at least one ceramic powder article (2) by means of a trimming system (1) realized according to claim 2 or to any one of the claims from 3 to 12, when they depend on claim 2; the trimming method comprises the following steps: a preparation step, during which the control assembly (CU) operates the drive assemblies (16) so as to position said at least two abrasive tools (14) so that they are spaced apart from one another, along said advancing direction (A), by a first distance substantially similar to the length of the ceramic powder article (2) to be trimmed and so that they are each positioned so as to be able to intercept and trim a transverse border (B1, B3) of said at least one compacted ceramic powder article (2); a longitudinal trimming step, during which, while said compacted ceramic powder article (2) is advanced along said advancing direction (A) through said trimming station (4) in a first direction (versor / way) going from the input (5) of said trimming station (4) to the output (6) of said trimming station (4), said further abrasive tools (14') are operated and intercept and trim said longitudinal edges (B2, B4) of said at least one compacted ceramic powder article (2); a transverse trimming step, which is subsequent to said longitudinal trimming step and to said preparation step and during which said at least two abrasive tools (14) trim said transverse edges (B1, B3) of said compacted ceramic powder article (2) while they translate along said support structures (13) in said transverse direction (B) carried by said secondary frame, with the respective first detectors (17) located upstream along the trimming trajectory (T), while said secondary frame (10), in turn, advances along said advancing direction (A) in said first direction (versor / way) with a second speed similar to said speed along said advancing direction (A); and an adjustment step, which is simultaneous with said transverse and longitudinal trimming steps, respectively, and during which the position of each active abrasive tool (14, 14') is adjusted, relative to the respective edge (B1, B2, B3, B4) to be trimmed, as a function of the data detected by the respective first detector (17).

16. The trimming method according to claim 15, wherein, during said transverse trimming step, said at least two abrasive tools (14) move along the respective support structures (13) in said transverse direction (B) with a similar speed but in opposite ways.

17. The trimming method according to claim 14 or 15, wherein, during said first, second and third trimming steps or during said transverse trimming and longitudinal trimming steps, said positioning actuators (25, 28) of the active abrasive tool (14, 14') are controlled by the control assembly (CU) so as to continuously change their activation as a function of the data detected by the respective first or second detector (17) in order to adjust (in particular, in real time) the position of the respective abrasive tool (14, 14') relative to the edge (B1, B2, B3, B4) to be trimmed.

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