[0001] The present invention relates to a working center, specifically a working center for the processes of tenoning, drilling, milling and profiling of extended work pieces, preferably of wood, suitable for the manufacture of door and window frames .

[0002] Advantageously, the working center resulting from this invention enshrines the concept of numerous parallel axes with the aim of eliminating limitations to the processing of a great variety of cross-sections, profiles and types of machining process, as required by the world's door and window frame industry.

[0003] In particular, well-known in the art are working centers for machining door and window frames, preferably in wood, with a number of processes for each work piece.

[0004] Usually the work piece is held by grabbers and machined by various head-mounted tools.

[0005] Prior art solutions exhibit numerous disadvantages. [0006] In fact, there is no single work station that provides an ideal solution to problems relating to specific locking systems, such as: 1. total automation without set-up as processing varies;

[0007] 2. composition of tool heads; [0008] 3. tool magazines with a high number of tools, allowing for simultaneous picking, auto set-up and rapid tool change from magazines solid with the beam. [0009] In particular, the grabbers of working centers known in the art are so large they prevent ideal and continuous machining of the work piece due to the need to use one locking system for all machining phases . Therefore the work piece is grabbed and machined, grabbed and machined, and so on, or else is machined with countless limitations. [0010] The tool head cannot in fact machine the work piece continuously, either when tenoning, milling and drilling the work piece along its entire length, or when profiling, when the work piece is repeatedly released by the grabbers and picked up by a mechanical hand or other exchanger. This mechanical hand or other system repositions the work piece and returns it to the grabber which grips it in various places .

[0011] These continuous changes between the grabber and mechanical hand lengthen the time required for machining and hence increase production costs, in addition to restricting the ability to machine certain pieces required in the world's markets.

[0012] Furthermore, after each repositioning of the work piece on the grabber and the non-dedicated locking mechanism for each of the three phases, machining is imprecise because the work piece is no longer in the original position.

[0013] The loss of precision in the machining of the work piece leads to poor quality and finish for the end product as well as high levels of rejects and often assembly problems for the final wood product, requiring further operators to correct the fault before the varnishing process . [0014] In the art the need is therefore felt for a working center which reduces machining time whilst guaranteeing precision work, i.e. machining to very small tolerances, the ability to create cross-sections and profiles with small grip zones and end products with a finish that does not require further work. [0015] The problem faced by the invention is that of creating a working center without the above defects as known in the art .

[0016] These limitations and defects have been overcome by a working center in accordance with claim 1. [0017] Other embodiments of the working center according to the invention are described in later claims. [0018] Further features and advantages of this invention will be easier to understand from the description below of preferred embodiments, among others, in which: [0019] figures Ia-Ib show a perspective view of an overall working center in accordance with a possible embodiment of this invention;

[0020] figure Ic shows a perspective view of some details of the working center as shown in figures Ia-Ib, exploded;

[0021] figures 2-13 show partial side views of the working center as shown in figures Ia and Ib, in different phases of production; [0022] figure 14-27 show partial perspective views of the working center shown in figures Ia and Ib, during various phases of production.

[0023] The elements or parts of elements common to the embodiments described below are shown by using the same numbers . [0024] With reference to the above figures, 4 shows a working center for drilling, milling, tenoning and profiling operations for extended work pieces 8, with a prevalently S-S extension, in particular for the production of wooden door and window frames. [0025] The working center 4 includes a feed 12 for the work pieces 8 to be machined or which have been partially machined, and locking equipment 16 able to hold the work piece (s) in a longitudinal direction X-X so the prevalently S-S extension is in line i.e. is essentially parallel to the longitudinal axis X-X. [0026] The system allows for the continuous machining of work pieces such as to comprise one piece of length 3500 mm.

[0027] The locking tool 16 is also suitable for locking the work piece 8 along a first pair of locking surfaces 20 of the work piece 8, set against the longitudinal direction X-X.

[0028] Preferably the locking equipment 16 receives the work piece 8 from the feeder 12 , as described in detail below.

[0029] The working center 4 also includes a mechanical hand 24 able to grab the work piece 8, take it from the locking device 16 and return it to the locking device 16. In other words the mechanical hand 24 is able to grab the work piece 8 from the locking device 16, remove it and return it to the same position 16.

[0030] The working center 4 also includes at least one tool head 25 with at least one tool 26 for the machining of the work piece 8, such as a drill bit or milling machine. [0031] Advantageously, the mechanical hand 24 includes at least one grabber 28 fitted with a striker plate 32 fixed in relation to the transverse direction Y-Y, perpendicular to the longitudinal axis X-X, during the machining phases and movement of the work piece 8. In other words, during the machining and movement of the work piece, the striker plate 32, is in a constant position in relation at least to the transverse axis Y-Y so as to act as reference point or fixed and unvarying zero point of the working center 4. [0032] According to one embodiment, the locking device 16 moves along the transverse Y-Y axis so as shift the work piece 8 along that axis and exchange it with the mechanical hand 24; the work piece 8 is fixed to the locking device 16 by the locking surfaces 20 so that the profiling surfaces 36 of the work piece 8 face the machining heads 25 alternately and are in opposition to one another along the transverse axis Y-Y. [0033] The profiling surfaces 36 are essentially lateral surfaces of the work piece 8 extending in parallel to the main direction S-S of the work piece 8.

[0034] Preferably, the work piece 8 is grabbed by the locking surfaces 20 which are perpendicular to the profiling surfaces 36, so that the profiling surfaces 36 are always free and face the machining heads 25. [0035] In this way it is possible to profile the work piece in one operation without interruption, grab the work piece 8 at different points and then resume profiling. [0036] According to one embodiment, the mechanical hand 24 moves vertically along the Z-Z axis perpendicular to the longitudinal axis X-X and transverse axis Y-Y, keeping the distance of the striker plate 32 constant in relation to a reference point or the center zero point, along the transverse Y-Y axis.

[0037] Preferably, the vertical direction Z-Z is perpendicular to the floor on which the working center 4 rests .

[0038] According to one embodiment, the mechanical hand 24 includes at least one clamp 40, which is mobile in relation to the grabber 28 along the transverse axis Y-Y, so as to immobilize the work piece 8 between the clamp 40 and striking plate 32.

[0039] According to one embodiment, the transverse axis Y-Y is parallel to the locking surfaces of the work piece 20; in other words the mechanical hand 24 grabs the work piece 8 between the striking plate 32 and the clamp 40, along the profiling surfaces.

[0040] According to another embodiment, the transverse axis Y-Y is perpendicular to the locking surfaces 20 of the work piece 8; in other words the mechanical hand 24 grips the work piece 8 between the locking surfaces 20.

[0041] The clamp 40 includes a locking surface 44, able to interface with the work piece 8 to be immobilized, this locking surface 44 preferably being parallel to the striking plate 32. [0042] According to a preferred embodiment, each clamp 40 is substantially in line with the grab element 28, so they occupy the same axial space in relation to the longitudinal axis X-X.

[0043] Preferably, the mechanical hand 24 includes several grabber elements 28, each with a counter clamp 40, staggered along the longitudinal axis X-X in a comb formation, so as to be able to grab the work piece 8 simultaneously at different points along the longitudinal axis X-X. [0044] Preferably, the grabber elements 28 are set somewhat apart, at a regular distance, along the longitudinal axis X-X.

[0045] The clamps 40 can be powered hydraulically, pneumatically and/or electrically. [0046] The locking device 16 includes at least one support plane 48 fitted with a press 52, which is mobile in relation to the support plane 48, and able to lock the work piece 8 between the press 52 and support plane 48. [0047] Preferably, the support plane 48 and press 52 comprise flat, parallel walls to lock the work piece 8 into position.

[0048] According to one embodiment, the press 52 is axially mobile along the vertical axis Z-Z and the flat, parallel walls of the press 52 and support plane 48 are perpendicular to the vertical axis Z-Z. [0049] Preferably, the press 52 has a number of needles which fit into the work piece 8 to improve the grip. [0050] According to one embodiment, the pressure of the press 52 varies according to the size of the work piece 8, the geometry of the profile and the material of the work piece 8 , i.e. the type of wood .

[0051] In this way the functioning of the working center 4 is optimized, guaranteeing a stable grip on the work piece 8 and preventing damage to, or the marking of, the work piece 8.

[0052] According to one embodiment, each support plane 48 is substantially in line with the related press 52 along the transverse axis Y-Y so that they occupy the same space in relation to the longitudinal axis X-X. [0053] According to one embodiment, the press 52 has a ^X T' structure with a central element 56 and pair of cantilevered elements 60 in relation to the central element 56, facing their respective support planes 48, with parts in opposition to the central element 56, so that each can grab the work piece and hold it against its support plane 48.

[0054] Preferably the cantilevered elements 60 are parallel to the transverse axis Y-Y. [0055] The opposing set-up of the cantilevered elements 60 in relation to the central element 56 enables the work piece 8 to be locked in place alternately on each cantilevered element 60 so that a different profiling surface 36 faces the machining head 25.

[0056] According to one embodiment , the working center 4 includes several support planes 48, each with an opposing press 52, staggered along the longitudinal axis X-X in a comb formation, so as to be able to grab the work piece 8 simultaneously at different points along the longitudinal axis X-X. [0057] Preferably the support planes 48 along the longitudinal axis X-X are the same distance apart. [0058] According to a preferred embodiment, both the mechanical hand 24 and the locking device 16 are 2 comb- like structures which are slightly staggered along the longitudinal axis X-X so as to fit into their striker plates 32 and the support planes 48 grabbing the work piece 8 simultaneously along various parts of its axis, during operations involving the exchange of the work piece 8 between the mechanical hand 24 and locking device 16.

[0059] The presses 52 may be powered hydraulically, pneumatically and/or electrically.

[0060] Preferably, the locking device 16 includes at least one lateral press 64 able to press the work piece 8 to be machined against a guide 68, straightening it up. [0061] According to one embodiment, the pressure of the lateral press 64 varies according to the size and material of the work piece 8, for example the type of wood. [0062] In this way the functioning of the working center is optimized by straightening of the work piece 8 and hence greater precision machining and tighter tolerances for subsequent machining operations. [0063] The guide 68 may be associated with the frame of the working center 4 or with feed devices 12.

[0064] Preferably, the guide 68 is set parallel to the longitudinal axis X-X so as to enable the straightening of the work piece 8 and parallelism with the longitudinal axis X-X before machining of the work piece 8 begins. [0065] According to one embodiment, the lateral press 64 is set along the transverse axis Y-Y so as to press the work piece perpendicularly to the guide 68.

[0066] For example, the lateral press 64 may be powered hydraulically, pneumatically and/or electrically. [0067] Preferably, the locking device 16 includes an ejector 72 able to discharge the work piece 8 after machining .

[0068] According to one possible embodiment, the lateral press 64 also acts as ejector 72 when powered in opposition to the guide 68. [0069] The ejector 72 may include compressed air nozzles for the discharge of the work piece 8.

[0070] Preferably, the working center as embodied in this invention includes several machining heads 25 on a beam with controlled axis 80, for example in line along the longitudinal axis X-X.

[0071] The beam 80 may, for example, be supported and guided by a pair of uprights 84 which define, in relation to the longitudinal axis X-X, the area for the machining of work pieces 8. The uprights extend along the transverse axis Y-Y so as to allow for the transverse stroke 88 of the beam with controlled axis 80 and hence the machining heads 25 it supports.

[0072] Preferably, the machining heads 25 are fitted with independent movement capability and the heads 25 move at least parallel to the beam 80 and the longitudinal axis

X-X.

[0073] Preferably, at least one of the machining heads 25 is fitted with independent movement capability perpendicular to the beam 80, for example along the transverse axis Y-Y.

[0074] Still more preferably, at least one machining head

25 is fitted with independent movement parallel to the vertical direction Z-Z. [0075] According to one embodiment , the working center 4 includes at least one tool magazine 92 to allow for the automatic replacement of tools 26 on the machining head 25.

[0076] The following pages describe the functioning of the working center according to this invention.

[0077] In particular, the feed devices 12, such as, for example, a grabber used for tenoning and drilling, bring the work piece 8 in front of the locking device 16 used for profiling, leaving the work piece 8 on its supports (fig. 2,14) .

[0078] The locking device 16 advances with controlled axis along the transverse axis Y-Y until it takes the work piece 8 so as to manage the proper jut for subsequent machining (fig.3a) . [0079] The lateral presses 64 press the work piece 8 against the guide 68, straightening the work piece 8 (fig. 3b, 15) .

[0080] After straightening, the presses 52 lock the work piece against their support planes 48. [0081] The locking device 16 then draws back with controlled axis, along the transverse axis Y-Y, to a set position where the tool heads carry out the profiling of one surface 36 facing the guide 68 (fig.4, 16) . [0082] After this profiling operation on the first surface, the locking device 16 moves with controlled axis to the proper position, which varies according to the profile to be carried out, and then the mechanical hand 24 takes over (fig.5, 17) .

[0083] In particular, the locking device 16 moves with controlled axis along the transverse axis Y-Y, so as bring the profiled part exactly into position along the transverse axis Y-Y to opposite the striking plate 32 of the mechanical hand 24. [0084] Then the mechanical hand 24 moves with controlled axis along the vertical axis Z-Z to the height at which the profile will be grabbed and immobilized and the mobile clamps 40 close, locking the work piece 8 from the side (fig.6, 18) . [0085] Figure 6a shows a detail of how the work piece is immobilized by the gripping element 28 of the mechanical hand 24 and the work piece is held between the press 52 and support plane 48 of the locking device 16. [0086] The locking device 16 opens the presses 52 and disengages laterally from the work piece 8 (fig.7, 19) . [0087] The straightness of the work piece 8 is guaranteed by the mechanical hand 24 which blocks the work piece 8 laterally, including when the presses 52 open. [0088] The presses 52 then close and the mechanical hand lifts further with a controlled axis (fig.8, 20) . [0089] The locking device 16 advances with controlled axis passing under the work piece gripped by the mechanical hand (fig. 9, 21) .

[0090] The presses 52 of the locking device 16 reopen, the mechanical hand 24 lowers along the vertical axis Z-Z and brings the work piece 8 to the height of the work plane (fig. 10, 22) .

[0091] The locking device 16 moves with controlled axis towards the work piece held by the mechanical hand 24 to the correctly jutting position of the work piece for the machining of the profile of the second surface, opposed to the first which has already been machined (fig. 11, 22, 23) .

[0092] The mechanical hand 24 leaves the work piece 8 after the presses 52 of the locking device 16 have reached -the locking position. The mechanical hand 24 returns to the rest position and the second profiling surface 36 is machined by the tool head (fig. 12, 24, 25, 26) . [0093] The locking device 16 moves with controlled axis towards the output of the unit 4 and discharges the work piece 8. At the same time the feed devices 12 load the next work piece (fig.13, 27) .

[0094] As can be seen from the above, according to this invention, the working center overcomes the disadvantages known in the art. [0095] In fact, the working center as embodied in this invention enables the complete machining of extended work pieces, i.e. tenoning, drilling, boring, milling and profiling far quicker than in the working centers known in the art. [0096] In addition, the working center as embodied in this invention enables finished work pieces to meet far tighter tolerances in terms of dimensions, down to tenths of a millimeter, something unattainable by conventional working centers . [0097] The resulting work pieces have an uncommon quality, allowing for quick assembly and practically eliminating rejects.

[0098] In addition, the working center embodied in this invention is extremely versatile, since work pieces of different sizes can be loaded one after another, without concern for the precise loading sequence.

[0099] It is sufficient to input the management software with all the machining data and the working center automatically recognises the new work piece and adapts in real time to the new dimensions, locking the working piece into the correct position. [00100] This further reduces machining time. [00101] A further example of extreme versatility is the v fact that the pressure exercised by the various presses varies according to the size, profile and material of the work piece.

[00102] This optimizes the functioning of the working center and guarantees compliance with the strictest tolerance requirements, without damage to the work pieces .

[00103] For specific contingencies and needs, a technician in the field will be able to carry out numerous fine-tuning operations and create different versions of the working center described above, all within the framework of the invention as defined by the following claims .