Piece-holding module, and feeding apparatus comprising the piece-holding module, for feeding a plurality of machining stations

Abstract

A piece-holding module (20) for a feeding apparatus (1) for feeding a plurality of machining stations (T1-Tn), said piece-holding module (20) comprising: - a front face (2A) comprising a clamping device (21) configured to hold a workpiece (A) to be machined by said machining stations (T1-Tn), and - a rear face (2B) comprising a centering interface (22) adapted to interact with at least one positioning device (9) for fixing the piece-holding module (20) in a machining position (W1) during the machining of the workpiece (A); wherein the centering interface (22) and the clamping device (21) are parts of a piece-holding body (26) so that the centering interface (22) and the clamping device (21) are rigidly connected to each other; the piece-holding module (20) comprising a frame (29) which supports the piece-holding body (26); wherein the piece-holding body (26) can move with respect to the frame (29), between: - a transport condition in which the piece-holding body (26) is rigidly fixed to the frame (29), and - a locking condition in which the piece-holding body (26) can be fixed in a machining position (W1-Wn) by means of a positioning device (9).

Description

[0001] PIECE-HOLDING MODULE, AND FEEDING APPARATUS COMPRISING THE PIECE-HOLDING MODULE, FOR FEEDING A PLURALITY OF MACHINING STATIONS

[0002] The present invention relates to a piece-holding module, and a feeding apparatus comprising the piece-holding module, for feeding a plurality of machining stations in a machining apparatus such as a machining line.

[0003] The present invention is useful in the field of industrial production and machining, especially in processes where a series of types of mechanical machining (such as chip removal) and / or other types of machining (such as surface treatments, laser machining etc.) are required.

[0004] Nowadays, it is common to clamp a workpiece in a clamping device arranged in a fixed position and then to machine it with one or more tools in a single machining station, when possible. In this manner there is no waste of displacement time, and precision is ensured by the single clamping in a fixed position.

[0005] When the production process requires different machining steps which cannot be executed in a single machining station, and thus a plurality of machining stations needs to be involved, it is necessary to move the workpiece from one machining station to another until all the machining steps are accomplished.

[0006] In these cases, a common solution is the use of a rotary transfer machine comprising a rotating round table that is surrounded by the machining stations. The rotating table is provided with clamping devices (for clamping the workpieces) evenly spaced along the circumference of the table. These clamping devices are commonly provided as fixed or rotating collets. In this solution, the workpieces being machined pass from one machining station to another by means of a rotation of the table. In this way all the machining steps are performed sequentially, without the need of changing tools, and as many workpieces as there are working stations can be machined at the same time in different working stations. However, production systems based on round table machines are not scalable, or only scantly scalable. In fact, the only way to make it possible to add more stations at a later stage is to design the system with more stations than initially needed, so that supplementary machining units can be added in the vacant stations. On the other hand, it is possible to remove non-used units, but the size of the machine and the number of clamping devices on the table remain the same. These are relevant drawbacks that the present invention sets out to solve.

[0007] Another drawback of rotary transfer machines is that many of the most important and complex parts of the apparatus (i.e. driving motor, indexing device, control systems) are placed in the area of the center of the table and hence maintenance and troubleshooting are normally quite difficult and inconvenient to perform.

[0008] According to an alternative known solution, the machining stations are spread out in an open area, typically arranged along an open line (e.g. in a row) and are fed by means of “pick and place” devices (manipulators or robots) typically provided with anthropomorphic robot arms or the like. Although functional, this solution has limitations, which are linked to the fact that the “pick and place” devices are generally very bulky, complex, and expensive, and the fact that, often, they hinder the accessibility to the machining line. In addition, in order to move all the workpieces at the same time, as many manipulators as there are working stations are required, and each one of these manipulators needs to be provided with its own actuation system and its own control system.

[0009] In some fields, such as the field of packaging, it is known to move the workpieces from one machining station to another by means of a conveyor belt, but this solution is not compatible with machining operations wherein the positioning of the workpiece with micrometric precision is required.

[0010] Another problem to be solved consists in the spreading of dirty processing residues (e.g., chips and fluids) from the units performing dirty operations, such as chip removal. In fact, in these cases, there is the need to isolate the machining stations, but this isolation is not possible, or is very complex, when the stations are fed with the known “pick and place” devices or conveyors.

[0011] On top of the above, the need to implement solutions to trace the production processes is growing, in particular the need to associate each workpiece with data relating to the machining to which the workpiece has been subjected. This kind of operation is not easy when the systems comprise several “pick and place” (or similar) devices, due to the integration effort required and to the fact that there are no components of the feeding system that are coupled with the same workpiece during all the machining operations.

[0012] The aim of the present invention is to provide a feeding system for a plurality of machining stations which solves one or more of the technical problems described above, obviates the drawbacks, and overcomes the limitations of the background art.

[0013] Within the scope of this aim, an object of the present invention is to provide a feeding system which is easily scalable and easily configurable for different working lines.

[0014] An additional object of the present invention is to provide a feeding system which is less bulky and / or less complex and / or less expensive with respect to the prior art.

[0015] A further object of the present invention is to provide a feeding system that requires less maintenance.

[0016] Moreover, an object of the present invention is to provide a feeding system that can perform the positioning of the workpiece with micrometric precision.

[0017] A further object of the present invention is to provide a feeding system that allows the isolation of the machining stations to be fed.

[0018] Another object of the present invention is to provide a feeding system that increases the speed and / or the efficiency of the machining apparatus.

[0019] Moreover, an object of the present invention is to provide a feeding system that makes it possible to associate each workpiece with tracking data.

[0020] Another object of the present invention is to also provide an alternative to known solutions.

[0021] This aim, these objects and others which will become better apparent hereinafter are achieved by a piece-holding module according to claim 1.

[0022] This aim and these objects are also achieved by a feeding apparatus according to claim 10.

[0023] Further characteristics and advantages will become better apparent from the description of a preferred but not exclusive embodiment of a pieceholding module, of a feeding apparatus comprising said piece-holding, and of a machining apparatus comprising the feeding apparatus, illustrated by way of nonlimiting examples with the aid of the accompanying drawings, wherein:

[0024] Figure 1A is a schematic side view of a machining apparatus comprising a feeding apparatus, according to the invention;

[0025] Figure IB is a schematic plan view from above of a machining apparatus comprising a feeding apparatus, according to the invention;

[0026] Figure 2 is a perspective view of part of a machining apparatus comprising a feeding apparatus, according to the invention;

[0027] Figure 3 is the same view of Figure 2 wherein more components of the apparatus are illustrated;

[0028] Figure 4 is a perspective view of the front face of a piece-holding module according to the invention;

[0029] Figure 5 is a perspective view of the rear face of the piece-holding module of Figure 4;

[0030] Figure 6 is a frontal view of the front face of the piece-holding module of Figures 4-5; Figure 7 is a cross-sectional side view, taken along the plane VII- VII identified in Figure 6, of the piece-holding module, wherein the module is in the transport condition and a positioning device is starting to engage the centering interface of the module;

[0031] Figure 7A is the same view of Figure 7 in a subsequent phase of the engagement with the positioning device, with the module still in the transport condition;

[0032] Figure 7B is the same view of Figure 7A in a subsequent phase of the engagement with the positioning device, with the module in the locking condition;

[0033] Figures 8A-8C are a sequence which shows the process of interaction between the piece-holding module and the positioning device, wherein the piece-holding module passes from the transport condition of Figure 8A to the locking condition of Figure 8C, and wherein the main body of the fixing device is shown in dotted lines;

[0034] Figures 8D and 8E correspond to Figures 8C and 8D, respectively, wherein the main body of the fixing device is shown in solid lines;

[0035] Figure 9A is a rear view of two piece-holding modules connected in a row;

[0036] Figure 9B is a frontal view of the two piece-holding modules of Figure 9A;

[0037] Figure 10 is a perspective view of an assembly comprising the first and the fourth driving devices of the feeding apparatus;

[0038] Figure 11 is a side view of part of the assembly of Figure 10;

[0039] Figure 11 A is a partially cross-sectional view of an enlarged detail of Figure 11 ;

[0040] Figure 12 is a perspective view of an assembly comprising the second driving device of the feeding apparatus;

[0041] Figure 13 is a perspective view of an assembly comprising the fourth driving device of the feeding apparatus. Before delving into the detailed description, it should be noted that the accompanying figures show parts of a machining apparatus according to the invention which, for the sake of clarity, have some parts removed (e.g., the machining stations) since these parts, in addition to being known to the person skilled in the art, are not useful for the comprehension of the invention itself and would only contribute to an overall crowding of the figures.

[0042] With reference to the cited figures, the piece-holding module, designated generally by the reference number 20, is adapted to be used in a feeding apparatus 1 for feeding a plurality of machining stations Tl-Tn (for example a plurality of machining stations arranged in a row so as to form working line).

[0043] The piece-holding module 20 comprises a front face 2A and a rear face 2B.

[0044] The front face 2 A comprises a clamping device 21 configured to hold a workpiece A to be machined by the machining stations Tl-Tn. The clamping device 21 can be any known clamping device and may comprise a collet (rotating or not rotating) and / or a pincer or any other clamping element 211 useful to keep a workpiece A in position.

[0045] The rear face 2B comprises a centering interface 22 adapted to interact with at least one positioning device 9 for fixing the piece-holding module 20 in a machining position Wl-Wn during the machining of the workpiece A.

[0046] The positioning device 9 can be part of the feeding apparatus 1 in which the piece-holding module 20 is used. The positioning device 9 is provided with an interface (the fixing interface 91) which is complementary to the centering interface 22 of the piece-holding module 20 in order to mechanically retain the piece-holding module 20 in a designated position.

[0047] In the preferred embodiments, the piece-holding module 20, overall, has the shape of a plate, or a tile, or a pallet, having the clamping device 21 protruding from one face and a centering interface 22 provided on the opposite face. In the illustrated example, the piece-holding module 20 has a substantially rectangular shape.

[0048] According to the invention, the centering interface 22 and the clamping device 21 are parts of a piece-holding body 26 (which is preferably a single rigid body) so that the centering interface 22 and the clamping device 21 are rigidly connected (coupled) to each other: their relative positioning does not change during operations. In other words, the pieceholding module 20 comprises the piece-holding body 26 which, in turn, comprises the clamping device 21 (at a first end) and the centering interface 22 (at another end which is opposite from said first end), so that the centering interface 22 and the clamping device 21 are integral with each other in any movement. It follows that the workpiece A, when retained by the clamping device 21, is integral with the centering interface 22 in any movement of the latter (while, obviously, in some embodiments, the workpiece A can be rotated, if required, during machining, independently of the centering interface 22).

[0049] The piece-holding module 20 further comprises a frame 29 which supports the piece-holding body 26.

[0050] Preferably, the piece-holding body 26 is arranged in a center region of the frame 29, and in practice is arranged in a window 222 provided in the frame 29.

[0051] The frame 29 should be understood, in a fully general manner, as being a supporting body which can have any suitable shape. In the illustrated example, the frame 29 is a plate-like frame in the center of which the pieceholding body 26 is arranged. In the preferred embodiments, the frame has a substantially rectangular shape, which is optimal for sliding along rails 51, 53.

[0052] The piece-holding body 26 can move (preferably by sliding) with respect to the frame 29, between a transport condition and a locking condition. Preferably, the piece-holding body 26 can slide transversally, with respect to the frame 29, between the transport condition and the locking condition.

[0053] In the transport condition (illustrated in Figures 7, 7 A and 8A), the piece-holding body 26 is rigidly fixed to the frame 29: that means that the piece-holding body 26 and the frame 29 are mechanically interlocked so that their relative positioning is fixed (preferably with micrometric precision) and that they are integral with each other in any movement. In the transport condition there is substantially no play between the piece-holding body 26 and the frame 29.

[0054] This interlocking, in the transport condition, is preferably achieved by means of mechanical locking elements, such as locking protrusions 48 which fit into complementary locking cavities 49. In the illustrated example, the piece-holding body 26 comprises one or more locking protrusions 48 which, in said transport condition, engage in complementary locking cavities 49 provided in the frame 29, but the possibility is not ruled out of an inverted arrangement.

[0055] Preferably, the locking protrusions 48 comprise one or more pins with a conical or truncated conical surface (preferably a conical or truncated conical end part which fits into a respective complementarity- shaped locking cavity 49). According to an optimal solution, the locking protrusions 48 are conical pins and the locking cavities 49 are conical cavities.

[0056] This condition is referred to as the “transport condition” because in this condition the piece-holding module 20 can be moved (for example from one machining position W1 to another W2) while the position of the clamping device 21 with respect to the frame 29 remains fixed, and ensured, preferably with micrometric precision.

[0057] In the locking condition (illustrated in Figures 7B, 8C and 8E) the piece-holding body 26 can be fixed in a machining position Wl-Wn by means of a positioning device 9.

[0058] In the preferred embodiments, in the locking condition, the interlocking between the piece-holding body 26 and the frame 29 is, at least partially, removed, i.e. the piece-holding body 26 and the frame 29 are, at least partially, disengaged.

[0059] In the illustrated example, in the locking condition, the locking protrusions 48 free the complementary locking cavities 49: in practice, the piece-holding body 26 is moved (translated) so that the locking protrusions 48 are moved at least partially out from the locking cavities 49.

[0060] In the locking condition there can be some play between the pieceholding body 26 and the frame 29, since the aim of this condition is to fix, without play and preferably with micrometric precision, the piece-holding body 26 to a positioning device 9 (and more precisely to a fixing device 91 comprised therein) so that the piece-holding body 26 (and thus the clamping device 21) is fixed in a predetermined position which is defined by the positioning device 9.

[0061] Preferably, the piece-holding module 20 comprises at least one elastic element 44 configured to return the piece-holding body 26 from the locking condition to the transport condition, preferably one or more springs that push or pull the piece-holding body 26 in the direction of the frame 29.

[0062] The centering interface 22 can be any known interface for fixing two elements to each other in a precise position.

[0063] Preferably, the centering interface 22 comprises protrusions and / or recesses 23, 24 adapted to engage, in the locking condition, complementary protrusions and recesses 92, 93 of a fixing interface 91 of the fixing device 90.

[0064] In the preferred embodiment, the centering interface 22 comprises a series of teeth 23 configured to mesh, in the locking condition, with complementary teeth 93 of the fixing interface 91 of the fixing device 90.

[0065] As can be seen from Figures 4-6, the piece-holding module 20 comprises two opposite lateral ends: a first lateral end 2C and a second lateral end 2D. In the preferred embodiment, these two lateral ends 2C, 2D are the longitudinal extremities of the piece-holding module 20 placed along a longitudinal direction along which the piece-holding module 20 is configured to slide.

[0066] As illustrated in Figures 9 A and 9B, the first lateral end 2C is adapted to face the second lateral end 2D of another piece-holding module 20, and the second lateral end 2D is adapted to face the first lateral end 2C of another piece-holding module 20.

[0067] In the operative condition illustrated in Figures 9 A and 9B, the first lateral end 2C of a first piece-holding module 20 is in contact with the second lateral end 2D of a second piece-holding module 20.

[0068] In greater detail, the first lateral end 2C comprises one or more pushing elements 41, such as cylindrical blocks, and the second lateral end 2D comprises a counter-pushing element 42, such as an anvil-shaped block; the counter-pushing element 42 is provided with an abutment surface 43 configured to be in contact with the pushing elements 41 of another pieceholding module 20.

[0069] These pushing elements 41 are passive pushing elements, in the sense that they do not actively exert a force, but rather merely transmit a pushing force by contact. In a possible example, the pushing elements 41 consist of monolithic bodies, having preferably a cylindrical shape, with one surface (e.g. a base of the cylinder) designed to come into contact with the abutment surface 43 of the counter-pushing element 42.

[0070] The counter-pushing element 42 is also a passive body.

[0071] In the preferred embodiments, the piece-holding module 20 further comprises engagement parts 57 for mechanical interaction with transmission means 331 of the feeding apparatus 1, so that the piece-holding module 20 can be moved by driving devices 31, 33.

[0072] In some embodiments, the piece-holding module 20 further comprises guiding protrusions 58 which are adapted to slideably couple the holding module 20 to rails 51, 53 or the like.

[0073] According to an optional feature, the piece-holding modules 20 comprise a data storage unit adapted to store data indicative of the machining and / or of the workpiece held by the piece-holding module 20 and adapted to be read by an electronic control apparatus. This data storage unit can record data coming from each machining station Tl-Tn, for example data indicative of the machining performed on the workpiece A and / or of machining parameters and / or of errors or problems, etc.

[0074] This data storage unit can be arranged in a slot provided in the frame 29 or in the piece-holding body 26, or externally attached to one of these.

[0075] This data storage unit can be an electromagnetic data storage device, readable remotely, such as an RFID (Radio Frequency IDentification) tag or the like.

[0076] The piece-holding module 20 described so far is designed particularly to be part of a feeding apparatus 1, such as the one illustrated in Figures 1-3.

[0077] Figures 1 and 2 show, schematically, the overall structure of a preferred embodiment of the feeding apparatus 1.

[0078] This feeding apparatus 1 is adapted for feeding a plurality of machining stations Tl-Tn which are arranged, in a row, along a working line XI at a machining elevation ql’.

[0079] It is useful to clarify that, in the present description and in the attached claims, “elevation” means a distance from a refence plane S. This reference plane may be, for example, a floor (or any other surface) on which the apparatus is placed. When referring to the illustrated example, wherein the apparatus is placed on a horizontal plane S, “elevation” means height from the plane S. However, alternative embodiments are conceivable wherein a vertical plane is chosen as the reference plane S.

[0080] The feeding apparatus 1 comprises one or more piece-holding modules 20 and driving elements 31, 32, 33, 34 configured to drive the piece-holding modules 20 along a closed path 11 (i.e., in a loop).

[0081] This closed path 11 comprises a working leg Ila that extends at a working elevation ql, from a start position Pl to an end position P2, and a return leg 11c that extends at a return elevation q2 which is different from said working elevation ql. That means that, in the preferred embodiments including the one illustrated, the working leg Ila and the return leg 11c lie on two different horizontal planes, at two different heights; this is particularly advantageous because the piece-holding modules 20 are always easily accessible from two opposite sides.

[0082] In this context, “leg” means a trajectory which is a portion of the closed path 11.

[0083] The driving elements 31, 32, 33, 34 comprise at least a first driving device 31 which is configured to induce the movement of the piece-holding modules 20 along the working leg I la, through a plurality of machining positions Wl-Wn. As can be seen in Figure 1A, the machining positions Wl- Wn are positioned between the start position Pl and the end position P2.

[0084] The feeding apparatus 1 is operatively connectable to the plurality of machining stations T1 -Tn in an operative configuration in which the working leg Ila is positioned in front of the working line XI, preferably, but not necessarily, with said working elevation ql substantially corresponding to said machining elevation ql’. In any case, in the operative configuration, the working leg Ila is positioned so that a workpiece A held by a piece-holding module 20 that is in one of the machining positions Wl-Wn can be machined by a designated machining station Tl-Tn arranged along the working line XI.

[0085] In this operative configuration (illustrated in Figures 1A-1B) one or more of the piece-holding modules 20 are in the working leg Ila, with the first face 2 A facing the working line XI.

[0086] When a plurality of piece-holding modules 20 are in the working leg Ila, they are aligned and mechanically connected to each other, so as to form a train or a chain, as shown in Figures 2 and 3.

[0087] The first driving device 31 is configured to drive the piece-holding modules 20 at least:

[0088] - from the start position Pl to a first machining position W1 in which, when in said operative condition, a workpiece A held by that piece-holding module 20 can be machined by a first machining station Tl,

[0089] - from said first machining position W1 to at least one second machining position W2 in which, when in said operative condition, the workpiece A held by the piece-holding module 20 can be machined by a second machining station T2, and

[0090] - from said second machining position W2 to the end position P2.

[0091] Obviously, the first driving device 31 can also be configured to move the piece-holding modules 20 to several intermediate machining positions W2, W3, ..., Wn, in sequence, before arriving at the end position P2.

[0092] Preferably, the machining positions W2-Wn are equally spaced apart from each other and the first driving device 31 is configured to move the piece-holding modules 20 along the working leg I la by single steps, each step corresponding to the distance between two machining positions W2-Wn, so that after each step each piece-holding module 20 passes from one machining position W2-Wn to the next and the piece-holding module 20 that was in the last machining position Wn arrives at the end position P2.

[0093] Preferably, each of the piece-holding modules 20 can be fixed in each of the machining positions Wl-Wn by means of a respective positioning device 9 (i.e., in the first machining position W1 by means of a first positioning device 9, in the second machining position W2 by means of a second positioning device 9, and so on).

[0094] In the preferred embodiments, the positioning devices 9 are arranged in line at a positioning elevation ql” which preferably substantially corresponds to the working elevation ql.

[0095] In the preferred embodiments, such as the one in Figures 1A-3, the driving elements 31, 32, 33, 34, in addition to the first driving device 31, further comprise a second 32, a third 33, and a fourth 34 driving device.

[0096] The second driving device 32 is configured to drive the piece-holding modules 20 (along a first connection trajectory 11b) from the end position P2 to the return leg 11c.

[0097] The fourth driving device 34 is configured to drive the piece-holding modules 20 (along a second connection trajectory l id) from the return leg 11c to the start position Pl . The third driving device 33 is configured to drive the piece-holding modules 20, along the return leg 11c, from the second driving device 32 to the third driving device 34.

[0098] In Figures 10-11 A a possible embodiment of the first driving device 31 is shown in detail.

[0099] Preferably, the first driving device 31 comprises a pushing device 331 (comprising an actuator) configured to push a first piece-holding module 20 from the start position Pl toward the end position P2, so that, in the operative condition, the pushing force is transmitted to a second piece-holding module 20 which is adjacent to said first one, and so on. In practice, in the condition shown in Figures 2 and 3, a pushing force of the pushing device 331 moves all the piece-holding modules 20 that are in the working leg Ila, inducing the sliding of each piece-holding module 20 to the next working position Wl-Wn (or, for the last module, to the end position P2).

[0100] In the illustrated examples, as visible in Figure 11 A, the first driving device 31 (and more precisely the pushing device 331) comprises a pushing shaft 332 which pushes against the counter-pusher element 42 of the first piece-holding module 20.

[0101] Optionally, a counter-pushing device 63 is provided on the other side of the working leg Ila (with respect to the pushing device 331), beyond the end position P2. This counter-pushing device 63 is a device configured to exert, on the piece-holding modules 20 that are in the working leg Ila, a pushing force opposite to the pushing force exerted by the pushing device 331, in order to better control the movement of the piece-holding modules 20 and to keep them in contact with each other.

[0102] Preferably, the second driving device 32 and / or the fourth driving device 34 (and more preferably both) comprise an elevator or a manipulator configured to lift or lower the piece-holding modules 20 from the working elevation ql to the return elevation q2, or vice versa.

[0103] In the non-limiting example of Figures 3 and 10, the fourth driving device 34 comprises a respective vertical conveyor 344 which lifts (or lowers) the piece-holding modules 20 from the return elevation q2 to the working elevation ql, until the piece-holding modules 20 is aligned with the pushing device 331 (in particular with the pushing shaft 332) of the first driving device 31.

[0104] In the optimal solution, this vertical conveyor 344 is provided with a lifting platform 342 configured to accommodate a piece-holding module 20 and to act as an elevator.

[0105] According to a particular solution illustrated in Figure 10, the first 31 and the fourth 34 driving devices are parts of an assembly 301, or first driving group, which is connected to a main structure 80 of the feeding apparatus 1 by means of a connecting structure 348.

[0106] In the non-limiting example of Figures 3 and 12, the second driving device 32 comprises a respective vertical conveyor 329 which brings the piece-holding modules 20 from the working elevation ql to the return elevation q2, until the transported piece-holding module 20 is aligned with the return leg 11c.

[0107] In the optimal solution, this vertical conveyor 329 is provided with a platform 328 which can slide along a vertical guide 323 and which is configured to accommodate a piece-holding module 20 and to act as an elevator. Preferably, the counter-pushing device 63 is arranged on this platform 328 and, more preferably, the counter-pushing device 63 is configured also to push the piece-holding modules 20 into the return leg 11c. As a possible alternative (not shown), a dedicated inserting device is present, preferably at the return elevation q2, and is configured to insert (e.g. by pushing) into the return leg the piece-holding modules 20 coming from the working elevation ql.

[0108] It is stressed that in the illustrated example the working leg Ila is at a working elevation ql that is higher than the return elevation q2 at which the return leg 11c is positioned, but it can be inverted (i.e. the working elevation ql can be lower than the return elevation q2). Obviously, in the latter case, the second 32 and the fourth 34 driving devices can be the same as the ones of the illustrated embodiment with the only difference that the second 32 driving device lifts the piece-holding modules 20 and the fourth driving device 34 lowers them.

[0109] In the preferred embodiments, the working leg Ila is defined by at least one first rail 51 (preferably a pair of parallel rails) along which the piece-holding modules 20 can slide.

[0110] Preferably, the return leg 11c is defined by at least one second rail 53 (more preferably a pair of parallel rails) along which the piece-holding modules 20 can slide.

[0111] The piece-holding modules 20 are thus preferably provided, on the second face 2B, with guiding protrusions 58 which are adapted to slideably couple the holding module 20 to the rails 51, 53.

[0112] In some embodiments where the return leg 11c is defined by at least one second rail 53, the fourth driving device 33 comprises a drive motor 330 configured to make the piece-holding modules 20 slide along the second rail(s) 53 by means of transmission means 331, 332, 334 which are operatively connected to the drive motor 333, for example as shown in Figure 13.

[0113] Preferably, these transmission means 331, 332, 334 comprise elongated dragging means 331, such as a chain or a belt or a wire or the like, configured to drag the piece-holding modules 20 along the second rail(s) 53.

[0114] These elongated dragging means 331 preferably comprise one or more engagement elements 332 designed to engage one or more complementary engagement parts 57 of the piece-holding modules 20. In the illustrated solution, the engagement elements 332 are pushing blocks which push against the engagement parts 57 which consist of abutment protrusions.

[0115] Optionally, the feeding apparatus 1 comprises a tensioning device 17 configured to tension the elongated dragging means 331. In the preferred and illustrated embodiment, the transmission means 331, 332, 334 further comprise a driving pulley (or toothed wheel) 334 which is driven in rotation by the drive motor 333 and is operatively connected to the elongated dragging means 331 in order to transmit motion thereto.

[0116] According to an optimal solution, the elongated dragging means 331 are tensioned between the driving pulley 334 and an idle wheel 335 which is pushed by the tensioning device 17. It should be understood that the elongated dragging means 331 extend along the whole of the return leg 11c.

[0117] Optionally, the feeding apparatus 1 comprises a braking and shockabsorbing system 39 configured to make the piece-holding modules 20, which come from second driving device 32 along the return leg 11c, brake at the end of the return leg 11c when they reach the fourth driving device 34.

[0118] Preferably, the braking and shock-absorbing system 39 comprises a braking lever 391 which mechanically brakes the piece-holding modules 20.

[0119] Turning now to the possible embodiments of the positioning devices 9, preferably each of these positioning devices 9 comprises a fixing device 90 comprising a fixing interface 91 designed to be mechanically coupled to the centering interface 22 of the piece-holding module 20 (when the latter is in the locking condition) so as to fix the piece-holding module 20 in a respective machining position Wl-Wn. As said, this fixing interface 91 comprises teeth 93 (or other protrusions and / or recesses) configured to engage complementary teeth 22 (or other protrusions and / or recesses) of the centering interface 22.

[0120] In practice, at least when the piece-holding module 20 is stationary is one machining position Wl-Wn, the piece-holding body 26, together with the centering interface 22, can be moved, transversely with respect to the working leg Ila, towards the fixing interface 91, from the transport condition, in which the piece-holding module 20 is free to move, to the locking condition, by means of an actuation device 95 that pulls or pushes at least one of among (either or both ) the centering interface 22 and the fixing interface 91 toward the other.

[0121] In the preferred embodiments, the positioning device 9 comprises a pulling device 95 configured to pull the piece-holding body 26, so as to pull the centering interface 22 toward the fixing interface 91, into the locking condition, for example as shown in Figures 7A-7B, 8B-8C and 8D-8E.

[0122] In some of these embodiments, including the one illustrated, the pulling device 95 comprises a pulling shaft 97 comprising a grabbing end 98 configured to grab an engagement element 28 of the centering interface 22. Preferably, the grabbing end 98 comprises an inlet (or a niche) 99 and the engagement element 28 has a shape that is complementary to this inlet 99 so as to be able to slide inside the inlet 99 in order to engage it.

[0123] In the illustrated example, the inlet 99 has a female “T” shape and the engagement element 28 has a male “T” shape.

[0124] In greater detail, the fixing device 90 comprises a reference body 80 comprising the fixing interface 91. Conveniently, the fixing interface 91 faces the working leg Ila so as to face the rear face 2B of the piece-holding modules 20 positioned in the working leg Ila and thus so as to face the centering interface 22.

[0125] In the illustrated embodiment, the main body 80 is provided with a through hole 81 or passage through which the pulling shaft 97 passes.

[0126] Preferably, the main structure 80 of the feeding apparatus 1 comprises an internal housing 140 in which the positioning devices 9 are accommodated. According to an optimal solution, the first rails 51 are arranged on one side of the internal housing 140 so that the rear face of the piece-holding modules 20 that are in the working leg face inside the internal housing 140.

[0127] Optionally, the positioning devices 9 are covered and / or protected by the covering elements 19; for example, the covering elements 19 can form a covering structure enclosing the internal housing 140. The feeding apparatus 1 can be integrated in a machining apparatus 100 as shown in Figures 1A-1B. This machining apparatus 100 comprises:

[0128] - machining stations Tl-Tn which are arranged, in a row, along a working line XI at a machining elevation ql’, and

[0129] - the feeding apparatus 1 for feeding these machining stations Tl-Tn, which is arranged with the working leg Ila positioned in front of the working line xl.

[0130] The machining stations Tl-Tn can comprise any known machining station, such as a machining station comprising one or more tools for mechanical machining (e.g. chip removal), or a laser device, or a painting device, or stations for measuring or control procedures, etc.

[0131] Preferably, the number of piece-holding modules 20 in the feeding apparatus 1 is at least equal to the number of said machining stations Tl-Tn plus one, so that, while a piece-holding module 20 is fixed in front of each of the machining stations Tl-Tn, at least one further piece-holding module 20 is free to move along the return leg 11c.

[0132] The machining apparatus 100 can comprise a loading / unloading apparatus or system for loading the workpieces A onto the piece-holding modules 20 (before machining) and for unloading them (after machining). As an alternative, or in addition, a loading / unloading apparatus or system is provided which is configured to load the piece-holding modules 20, already holding a workpiece A, into the feeding apparatus 1 (before the machining executed by the machining stations Tl-Tn) and / or to unload, from the feeding apparatus 1, the piece-holding modules 20 together with the workpiece A held thereby (after machining).

[0133] Moving the workpiece A together with the piece-holding module 20 is advantageous from several points of view: the positioning of the workpiece A remains ensured, the piece-holding modules 20 with the workpiece A can be easily loaded into another feeding apparatus 1, the workpiece A remains coupled with the data storage unit (if present). These loading / unloading apparatuses or systems can be made in any manner known to those skilled in the art, for example comprising “pick and place” devices (manipulators or robots).

[0134] Advantageously, the loading / unloading apparatus or system is located and / or configured to load / unload the workpieces A and / or the piece-holding modules 20 from / into the return leg 11c (and / or from / into any of the connection trajectories 11b, 11c and / or at the start position Pl and / or the end position P2). Therefore, it is possible to perform the loading / unloading operations while the workpieces A in the working leg Ila are being machined, basically in parallel.

[0135] Advantageously, the machining stations Tl-Tn can be easily (at least partially) isolated, from each other and / or from the outside environment, by means of isolating structures, in order to avoid the dispersion of dirty residues of machining (such as fluids and chips) and to protect parts of the feeding apparatus 1 (such as the positioning devices 9, the rails 51, 53, and the driving devices 31, 32, 33, 34). For example, isolating structures can be fixed to the main structure 80, so as to form a tunnel or a closed environment in which one or more machining stations Tl-Tn (or parts thereof) are located. These isolating structures can comprise panels, walls, waterproof sheets or cloths, etc.

[0136] As an example, in the illustrated embodiment, the closed environment can be defined inside a tunnel-like chamber which is positioned symmetrically with respect to the internal housing 140, so that while the rear face 2B of a piece-holding module 20 faces the internal housing 140, the front face 2A faces the closed environment.

[0137] A plurality of feeding apparatuses 1 can be operatively linked in series (in a single machining apparatus 100 or as parts of different machining apparatuses 100 which are, in turn, linked).

[0138] The operation of the piece-holding module 20, as well as of the feeding apparatus 1 , is clear and evident from the foregoing description. In practice it has been found that the piece-holding module and the feeding apparatus according to the present invention achieve the intended aim and objects, since they provide a feeding system which is easily scalable and easily configurable for different working lines: the only modification needed is the variation of the length of the working leg and the number of the piece-holding modules (which can be easily added or removed).

[0139] Another advantage of the piece-holding module and of the feeding apparatus, according to the invention, lies in that they provide a feeding system which is less bulky, less complex, and less expensive with respect to the prior art.

[0140] A further advantage of the piece-holding module and of the feeding apparatus, according to the invention, lies in that they provide a feeding system that is able to ensure the positioning of the workpiece with the precision required in the precision mechanics.

[0141] Another advantage of the piece-holding module and of the feeding apparatus, according to the invention, is represented by the ease of isolating the machining stations to be fed.

[0142] Yet another advantage of the piece-holding module and of the feeding apparatus, according to the invention, consists in that they enable an increase in the speed and efficiency of the machining processes.

[0143] On top of the above, the piece-holding module and the feeding apparatus, according to the invention, provide a valid alternative to the known solutions.

[0144] The piece-holding module and the feeding apparatus thus conceived are susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.

[0145] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements.

Claims

CLAIMS1. A piece-holding module (20) for a feeding apparatus (1) for feeding a plurality of machining stations (Tl-Tn), said piece-holding module (20) comprising:- a front face (2 A) comprising a clamping device (21) configured to hold a workpiece (A) to be machined by said machining stations (Tl-Tn), and- a rear face (2B) comprising a centering interface (22) adapted to interact with at least one positioning device (9) for fixing the piece-holding module (20) in a machining position (Wl) during the machining of the workpiece (A); wherein said centering interface (22) and said clamping device (21) are parts of a piece-holding body (26), so that said centering interface (22) and said clamping device (21) are rigidly connected to each other; said piece-holding module (20) comprising a frame (29) which supports said piece-holding body (26); wherein said piece-holding body (26) can move with respect to said frame (29), between:- a transport condition in which the piece-holding body (26) is rigidly fixed to said frame (29) and- a locking condition in which the piece-holding body (26) can be fixed in a machining position (Wl-Wn) by means of a positioning device (9).

2. The piece-holding module (20) according to claim 1, wherein the piece-holding body (26) comprises one or more locking protrusions (48) which, in said transport condition, engage in one or more complementary locking cavities (49) provided in the frame (29), or vice versa.

3. The piece-holding module (20) according to claim 2, wherein said one or more locking protrusions (48) comprise one or more pins with a conical or truncated conical surface.

4. The piece-holding module (20) according to any of the precedingclaims, comprising at least one elastic element (44) configured to return the piece-holding body (26) from the locking condition to the transport condition, preferably one or more springs that push or pull the piece-holding body (26) in the direction of the frame (29).

5. The piece-holding module (20) according to any of the preceding claims, wherein said centering interface (22) comprises protrusions and / or recesses (23, 24) adapted to engage complementary protrusions and recesses (92, 93) of a fixing interface (91) of a fixing device (90) in said locking condition.

6. The piece-holding module (20) according to any of the preceding claims, wherein said centering interface (22) comprises a series of teeth (23) configured to mesh with complementary teeth (93) of a fixing interface (91) of a fixing device (90) in said locking condition.

7. The piece-holding module (20) according to any of the preceding claims, said piece-holding module (20) comprising:- a first lateral end (2C) adapted to face a second lateral end (2D) of another piece-holding module (20), and- a second lateral end (2D) adapted to face a first lateral end (2C) of another piece-holding module (20).

8. The piece-holding module (20) according to claim 7, wherein the first lateral end (2C) comprises one or more pushing elements (41), such as cylindrical blocks, and wherein said second lateral end (2D) comprises a counter-pushing element (42), such as an anvil-shaped block, provided with an abutment surface (43) configured to be in contact with the pushing elements (41) of another piece-holding module (20).

9. The piece-holding module (20) according to any of the preceding claims, comprising a data storage unit adapted to store data indicative of the machining and / or of the workpiece held by the piece-holding module (20), to be read by an electronic control apparatus.

10. A feeding apparatus (1) for feeding a plurality of machiningstations (Tl-Tn) which are arranged along a working line (XI) at a machining elevation (ql’), said feeding apparatus (1) comprising one or more piece-holding modules (20) according to any of the preceding claims, and driving elements (31, 32, 33, 34) configured to drive said piece-holding modules (20) along a closed path (11); wherein said closed path (11) comprises:- a working leg (Ila) which extends at a working elevation (ql), from a start position (Pl) to an end position (P2), and- a return leg (11c) which extends at a return elevation (q2) which is different from said working elevation (ql); wherein said driving elements (31, 32, 33, 34) comprise at least a first driving device (31) which is configured to induce the movement of the pieceholding modules (20) along said working leg (Ila), through a plurality of machining positions (Wl-Wn) which are located between said start position (Pl) and said end position (P2).

11. The feeding apparatus (1) according to claim 10, which is operatively connectable to said plurality of machining stations (Tl-Tn) in an operative configuration in which said working leg (Ila) is positioned in front of said working line (xl), and in which one or more of said piece-holding modules (20) are in said working leg (Ila), with the first face (2A) facing the working line (XI); wherein said first driving device (31) is configured to drive the pieceholding modules (20) at least:- from said start position (Pl) to a first machining position (Wl) in which, when in said operative condition, a workpiece (A) held by said pieceholding module (20) can be machined by a first machining station (Tl),- from said first machining position (Wl) to at least one second machining position (W2) in which, when in said operative condition, the workpiece (A) held by said piece-holding module (20) can be machined by a second machining station (T2), and- from said second machining position (W2) to said end position (P2).

12. The feeding apparatus (1) according to claim 10 or 11, wherein each of said piece-holding modules (20) can be fixed in each of said machining positions (Wl-Wn) by means of a respective positioning device (9).

13. The feeding apparatus (1) according to any of claims 10 to 12, wherein said driving elements (31, 32, 33, 34) further comprise:- a second driving device (32) configured to drive the piece-holding modules (20) from said end position (P2) to said return leg (11c),- a fourth driving device (34) configured to drive the piece-holding modules (20) from said return leg (11c) to said start position (P2), and- a third driving device (33) configured to drive the piece-holding modules (20), along said return leg (11c), from said second driving device (32) to said fourth driving device (34).

14. The feeding apparatus (1) according to claim 13, wherein said second driving device (32) and / or said fourth driving device (34) comprises an elevator or a manipulator configured to lift or lower the piece-holding modules (20) from said working elevation (ql) to said return elevation (q2), or vice versa.

15. The feeding apparatus (1) according to any of claims 10 to 14, comprising a plurality of piece-holding modules (20) according to claim 7 or 8, wherein, in an operative condition, a plurality of said piece-holding modules (20) are aligned with and mechanically connected to each other along the working leg (Ila).

16. The feeding apparatus (1) according to the preceding claim, wherein said first driving device (31) comprises a pushing device (331) configured to push a first piece-holding module (20) from the start position (Pl) toward the end position (P2), so that, in the operative condition, the pushing force is transmitted to a second piece-holding module (20) which is adjacent to said first one, and so on.

17. The feeding apparatus (1) according to any of claims 10 to 16,wherein:- said working leg (Ila) is defined by at least one first rail (51) along which the piece-holding modules (20) can slide; and / or- said return leg (11c) is defined by at least one second rail (53) along which the piece-holding modules (20) can slide.

18. The feeding apparatus (1) according to the preceding claim, wherein said third driving device (33) comprises a drive motor (330) configured to make the piece-holding modules (20) slide along said second rail (53) by virtue of transmission means (331, 332, 334) which are operatively connected to said drive motor (330).

19. The feeding apparatus (1) according to the preceding claim 18, wherein said transmission means (331, 332, 334) comprise elongated dragging means (331), such as a chain or belt or wire or the like, configured to drag the piece-holding modules (20) along said second rail (53); said elongated dragging means (331) preferably comprise one or more engagement elements (332) which are designed to engage one or more complementary engagement parts (57) of the piece-holding modules (20).

20. The feeding apparatus (1) according to any of the preceding claims, comprising a braking and shock-absorbing system (39) configured to make the piece-holding modules (20) that come from second driving device (32), along the return leg (11c), brake at the end of the return leg (11c) at the fourth driving device (34).

21. The feeding apparatus (1) according to any of claims 10 to 20, wherein each of said positioning devices (9) comprises a fixing device (90) comprising a fixing interface (91) designed to be mechanically coupled to said centering interface (22) in the locking condition so as to fix the pieceholding module (20) in a respective machining position (Wl-Wn).

22. The feeding apparatus (1) according to the any of claims 10 to 21, wherein said positioning device (9) comprises a pulling device (95) configured to pull the centering interface (22) toward the fixing interface (91)into said locking condition.

23. The feeding apparatus (1) according to the preceding claim, wherein said pulling device comprises a pulling shaft (97) which comprises a grabbing end (98) configured to grab an engagement element (28) of the centering interface (22); preferably, the grabbing end (98) comprises an inlet.

24. A machining apparatus (100) comprising:- machining stations (Tl-Tn) which are arranged along a working line (XI) at a machining elevation (ql’), and- a feeding apparatus (1) according to any of claims 10 to 23 for feeding said machining stations (Tl-Tn), which is arranged with said working leg (Ila) positioned in front of said working line (xl).

25. The machining apparatus (100) according to the preceding claim, wherein the number of piece-holding modules (20) in the feeding apparatus (1) is at least equal to the number of said machining stations (Tl-Tn) plus one, so that, while a piece-holding module (20) is fixed in front of each of the machining stations (Tl-Tn), a further piece-holding module (20) is free to move along the return leg (11c).

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