A PLANT FOR AUTOMATICALLY STACKING AND ORDERLY ARRANGING PACKS OF PANELS OF DIFFERENT SIZES

Abstract: The plant according to the invention causes the packs of panels coming from the dividing machine to reach a first transport runway, said packs being arranged either side by side or in end-to-end sequence depending upon their size and stacking requirements. Ranged on a line beside said runway, there are lifting platforms to which the packs are supplied by common means and onto which there are stacked packs of panels of the same size. Thereafter, suitable means will transfer the stacks of panels to stations adjacent said lifting platforms where said stacks are orderly arranged either end to end or, if desired, side by side to form parallelepiped assemblies which are then transferred to a discharge station after being, optionally, arranged on a pallet or other supporting or protecting means.

Description: The present invention relates to a plant for stacking automatically, on respective lifting platforms, packs of panels of different sizes coming, in any succession, from either a dividing machine or any other processing machine. The plant according to the invention, subsequently, orderly arranges the stacks of panels from each stacking station adjacent to each other, at respective stations, so as to form parallelepiped assemblies which are then transferred to a discharge station, for example to a strapping station or to a plastics film wrapping station, after having been arranged on a pallet or other supporting or protecting means. The characteristics of said plant and the advantages resulting therefrom will be apparent from the following description of a preferred embodiment thereof, shown merely by way of non-limiting example in the figures of the accompanying sheets of drawings, in which: Figure 1 is a diagrammatic top plan view of the plant; Figure 2 shows the constructional details of the station indicated at A in figure 1, said station being shown in its operative working condition and as seen from the section line II-II of figure 1; Figure 3 is a side elevational view of the stations A-A'; Figure 4 is an elevational view of the rear side of I0 the abutment or stop bar which operates at the station A, said stop bar being shown in the active working position thereof; Figure 5 is a side elevational view of the stop bar of figure 4; Figure 6 is a front elevational view of the powered rollers of the station A'; Figure 7 is an enlarged side elevational view of one of the spring-loaded rollers of the presser device at the stations A-A'; Figure 8 is a side elevational and partly sectional 2b view of the presser device at the stations A-A'; Figure 9 shows some constructional details of the presser device of figure 8, on the section line IX-IX; Figure 10 is a top plan view showing other I constructional details of the presser device/stop bar assembly at the station A; Figure 11 is a front elevational view of one of the stations designated B-B', B'', B''' in figure 1, said station being shown in an intermediate step of its working cycle; Figure 12 is a fragmentary side elevational view of the rocking structure with idle rollers of one of the I0 stations B; Figure 13 is a side elevational view of the rocking structure with the powered rollers of one of the stations B; Figure 14 is a front elevational and partly sectional view of the rocking structure with powered rollers of one of the stations B, and showing partially the underlying lifting platform; Figure 15 is a side elevational view of the mechanism for the synch synchronous actuation of the discharge comb­ -like members of the station B; Figure 16 is a front elevation of a detail of the mechanism of figure 15; Figures 17 and 18 are side elevational and top plan views, respectively, of the powered rollers at the stations C, C', C'', C''' of figure 1, for transferring the packs of panels between the stations B-B'-B''-B'''; Figure 19 is a side elevational view of one of the lifting platforms which operate at the stations B of the plant; Figure 20 shows a details of the lifting platform of figure 19, taken on the section line XX-XX; Figure 21 is a side elevational view of the plurality of means operating in the lower portion of the stations B I0 and in the adjoining stations D-D'-D''-D''' of figure 1; Figure 22 shows a detail of the means of figure 21, taken on the section line XXII-XXII; Figure 23 is a side elevational view of the movable table which operates at each of the stations E-E'-E''-E'''; Figure 24 shows some details of one of the carriages for the table of figure 23, taken on the section line XXIV-XXIV; Figure 25 is a front elevational view of the drive shaft for actuating the table of figures 23 and 24; Figure 26 is a front elevational view of a portion of the border area between the stations B-E of the plant, as seen from the section line XXVI-XXVI of figure 1; Figure 27 is a side elevational view of the means operating in the upper portion of the station E of the plant; Figures 28 and 29 show further constructional details of the means of figure 27, both taken on the section lines XXVIII-XXVIII; Figure 30 is a side elevational view of the retaining bar which is operative at the border area between the stations D-E of the plant; Figure 31 is a front elevational view of the bar of figure 30; Figures 32 and 33 show further constructional details of the bar of figure 30, as seen on the respective section lines XXXII-XXXII and XXXIII-XXXIII; Figure 34 is a fragmentary side elevational view of one of the end carriages of the bar of the preceding figures, shown at the bottom end of its stroke; Figure 35 is a side elevational view of the bed with powered belts which operates at the stations E of the plant, said bed being shown in its bottom position at the beginning of a cycle; Figure 36 is an enlarged view of a detail of the bed of figure 35; Figure 37 is a side elevational view of the bed with its idle rollers which operates at thestations E of the plant; Figure 38 is a top plan view of the assembly of beds of the figures 36-37; Figure 39 is a front elevational view of the assembly of figure 38; Figure 40 is a diagrammatic front elevational view of the relative arrangement of the frames with the idle rollers, of the frames with the powered belts and of the teeth on the comb-like abutment of the pallet at the stations E of the plant; Figure 41 is a side elevational view of the retractable sensor which operates at the stations E of the plant; Figure 42 is a fragmentary top plan view of the means operating at the stations G-G'-G''-G''' of the plant; Figure 43 is a diagrammatic front elevational view of the power means for the rollers of the stations G of the plant; Figure 44 is a front elevational view of the stations G; Figure 45 is a side elevational view of the roller frame of the stations G and its power means; Figure 46 is a side elevational view of the bed with powered belts which operates at each of the stations G of the plant. In figure 1, the numeral 1 indicates a transport runway with parallel co-planar belts, which advances the packs of panels coming from a dividing machine in the direction of the arrow F; downstream of the latter machine there are arranged, preferably, devices of conventional design (not shown) for changing, if necessary, the orientation of said packs of panels by a 90° rotation, so that, on said runway 1, said packs will be arranged either side by side or in end-to-end sequence depending upon whether or not they have been rotated by 90°. Usually, the 90° rotation is imparted to the packs of panels having an elongated rectangular base, so that the longer dimension thereof will be transverse to the runway 1. With reference to figures 2 and 3, it will be noted that the powered belts of the runway 1 are mounted on vertically-movable frames and that said belts are arranged between fixed planar and co-planar supports 2 which, preferably, are coated with suitable material to avoid marring the panels. When the belts of the runway 1 are activated, they are lifted from said supports 2 which, thus, are prevented from contacting the packs of panels being transported. The transport runway 1 joins with an operative station A, where said runway 1 is characterized in that it comprises, instead of said supports 2 and co-planar therewith, small idle wheels 3 supported by stationary frames having their axes oriented in the direction F in figure 1. The packs of panels to be stacked by the installation of the invention, are stopped at the station A by abutting with their front sides aganist a transverse stop or abutment bar 4 (see also figures 4 and 5) which, usually, is in a lowered position and which is lifted only when scraps are present on said runway 1 and are to be transported beyond the station A towards collecting means (not shown here). The abutment bar 4 comprises a vertical face to be contacted by the packs of panels P, and a rear face provided, in symmetrical arrangement, with a tern of vertical rods 5 slidable in guide supports 6 which are secured to a support beam 7 forming a part of a carriage structure (described hereinafter) rotatably mounting, by means of bearings 8, a shaft 9 which, through end pinions 10-10', meshes with racks 11-11' which are formed on or attached to the end racks of said rods 5. Secured to said beam 7 are two cylinder-and­ -piston units 12-12' of the pressurized fluid and double acting type, the piston rods of which are connected to said abutment bar 4 which, due to said parts 9-10-11, will be moved by said units though remaining in a horizontal position. It will be noted in figure 4 that said abutment bar 4 is formed with recesses 13 in the lower side thereof to avoid interfering with the underlying members of the plant. It will be noted in figures 2 and 3 that when the pack, or packs, of panels will abut against the abutment bar 4, a suitable sensor (not shown) detects this condition and, at least, causes the powered belts of said runway 1 to be lowered, whereby said packs P will rest on the idle wheels 3. Under the side of the packs P abutting against the abut= ment bar 4 there is provided a horizontal runway of rubber­ -coated rollers 14, similar to each other and having their axes parallel to those of the wheels 3, said rollers being rotatably mounted in cantilever fashion on respective supports 15 which are fixed to the top side of a frame 16 the ends of which are pivotably connected, through parallel links 17, to a structure 18 comprising adjustable limit switches 19-19' co-operating with said links. Pivotably connected o said structure 18 are the body portions of fluid-operated double-acting cylinder-and­ -piston units 20-20', the piston rods of which are connected to end extensions 16' of said frame 16. The rollers 14, thus, may be raised and lowered while remaining in a horizontal condition. The hubs mounting said rollers 14 have keyed to their end portions protruding from the rear side of said supports 15, sprockets 21 having the same characteristics and driven, via a chain 22 and idle sprockets 23 with chain­ -stretcher 24, by a sprocket 25 which is keyed on the shaft of a motor-reducer 26 mounted on the frame 16. A torque limiter 27 is associated with the motor-reducer 26. By activating said motor-reducer 26, all the rollers 14 will be rotated at the same speed and in the proper direction to move the packs of panels P in the direction indicated by the arrow F1 in figure 1. During the working cycle at the station A, as explained with more detail hereinafter, the frame 16 with rollers 14 will be lifted up to a level equal or slightly higher than the sliding plane or path of movement defined by the rollers 3. Co-planar with the rollers 14 in rectilinear extension therefrom, when in the upper working position (figures 3 and 6), there are provided further identical rubber-coated rollers 28 which, unlike the former rollers, are rotatably mounted in a cantilever fashion on a frame 29 which is fixed to said structure 18. The rollers 28 concern the station A', which is adjacent the station A and connects the latter to the successive station B of the plant. The rollers 28 are kinematically connected, by a sprocket-and-chain drive system 30-31, to a drive unit 32 which, under command, causes said rollers to rotate in the same direction as the rollers 14 with the same surface speed. Above the edge of the packs of panels P contacting against the abutment bar 4, and opposed to said powered rollers of both the stations A-A', there is provided a row of parallel and grooved rollers 33 which are, preferably, coated with rubber or any other suitable material and are rotatably and elastically mounted, as indicated at 34, on a presser 35 which is parallel to said abutment bar 4 and is provided at the ends thereof with plates 36 which, through rollers 37, slide on vertical guide plates 38 which are fixed to said beam 7 rotatably supporting a longitudinal shaft 39 which is actuated by a motor-reducer unit 40 rotatable in both directions and which is provided at the ends thereof with pinions 41-41' in mesh with vertical racks 42-42' secured to said plates 36. At one side of the presser there is mounted parallelly, through an articulated parallelogram comprising links 43, a small bar 44 which is provided at the lower side thereof with idle rollers 45 parallel to the rollers 33 and normally protruding downwards beyond said rollers 33. Adjustable abutments 46 (figure 8) define the rest position of the bar 44, said position being also detected by a sensor 47. The structures 7-38 and 18-29 are fixed to a powered carriage structure (not illustrated because of conventional design) which, under command, can move the assembly of the members of figure 2 along the length of the runway 1, as indicated by the arrows K. The stations A-A' operate as follows. When the pack or packs of panels contact against the abutment bar 4, the belts of the runway 1 are lowered and, at due time, the structure 16 is raised whereby the rollers 14 will engage the lower side of said packs and will be located either co-planar or slightly above the path of travel or sliding plane formed by the idle wheels 3 supporting said packs. At due time the presser 35 is lowered to engage said pack with its rocking rollers 33 and press them properly by the action of the springs 34 and is stopped when the feeler 44 also engaging said packs through its small wheels 45, is lifted to modify the status of the sensor 47 that, automatically, disactivates the motion unit 40. The assembly of members of figure 2 is now moved through a short stroke in the direction of the arrow K in order to move the packs of panels clamped between the rollers 14-33 away from the packs possibly resting on the runway 1, so as to avoid any interference therewith. In the next step, the rollers 14 and 28 are activated, whereby the packs of panels P will be transferred in single file in the direction of the arrow F1, from the station A to the station A' and then toward the station B. The presence of the torque limiter in the drive of motor-reducer 26 eliminates undesired accelerations and de-celerations in the handling of the packs of panels, which might disassemble said packs. When the front side of the leading pack P co-operatingly engages a sensor 48 (figure 3), the motor-reducer 26 is stopped and the rollers 14 are lowered, while the rollers 28 of the station A' will remain activated to feed the pack (properly spaced from the following pack) to the station B of the plant. When the leading pack has moved past the sensor 48, if permitted by the operating program of the plant, the rollers 14 are lifted again and the motion unit 26 is re­ activated automatically to repeat said cycle. When the row of packs of panels at the station A has been exhausted, the presser 35 is lifted, the rollers 14 and 28 are stopped and the former of these rollers are lowered, whereafter the assembly of members of figure 2 is moved in the direction of the arrow K' back to the original position thereof, while at due time the belts of the runway 1 will be lifted again, which will feed new packs of panels to the station A to repeat said cycle. The positioning of the sensor 48 at the station A' is such as to avoid always a simultaneous clamping of two packs of panels between the rollers 28 and the rollers 33 of the presser 35 thereabove. According to a minor constructional modification, the cyclical stopping of the packs of panels at the station A, while they are being transferred to A' and then to B, might be effected by the motion unit 26 and, therefore, with the aid of the torque limiter 27, without lowering the rollers 14. In this instance, the rollers 14 or some of these rollers that are in proximity of A', will be driven by the chain 22 free trip connections, whereby when the motor 26 is stopped, those rollers 14 supporting the pack that engages the station A' may have a free idle rotation. With reference to figure 11, we will describe one of the stations B-B'-B''-B''' receiving the packs of panels from the stations A-A' in single file and suitably spaced apart. In line with the presser 35 there is provided a similar presser 49 associated with all the stations B-B',B''' and provided with rubber-coated and spring-loaded rollers 50 similar to those of the preceding presser, and actuated by a vertical guide/slide system, with pinion/rack device and with oppositely-rotatable motor-reducer, similarly to the presser 35 described above. The presser 49, through a sensor (not shown) mounted thereon, detects the level position of the presser 35 upstream thereof and automatically adjusts itself to said position. At each station B of the plant, below the respective rollers 50 of the presser 49, there are provided parallel and identical rubber-coated rollers 51 constituting a runway which is in line and coplanar with that of the rollers 28 at the station A', said rollers 51 being supported by a frame 52 which is pivoted at 53 to a stationary structure 54 and, therefore, can oscillate parallelly to the direction of movement indicated by the arrows F1, said frame being connected to fluid-operated double-acting cylinder-and-piston units 55 which, in turn, are secured at 56 to a stationary frame 57, the arrangement being such that, under command, the assembly 51-52 may be moved from the position shown with solid lines to the position shown with broken lines in figure 11, and vice versa. The rollers 51 are powered by means of a sprocket­ -and-chain drive 58-59 and a motor-reducer unit 60 mounted on the rocking frame 52, as shown in figures 13 and 14. The side of the pack of panels that is opposite the side which is clamped between the rollers 50-51 is supported by rubber-coated idle rollers 61 journaled on a comb-like frame 62 (figure 12) capable of oscillating parallelly to said support structure 64 having also connected thereto fluid­ -operated double-acting cylinder-and-piston units which are diagrammatically symbolized by the arrow 65 whereby, under command, said assembly 61-62 may be moved from the position shown with solid lines to the position shown with broken lines, and vice versa. The structure 64 is a carriage structure and can slide on stationary guides 66 which are normal to the direction of movement F1 of the panels at the stations B and have mounted thereon racks meshing in conventional manner with the end pinions of a shaft which is rotatably supported by said structure 64 and is connected to a motor-reducer unit having a double direction of rotation (not shown), the arrangement being such that the distance between the rollers 51-61 changes automatically depending upon the size of the packs of panels entering the stations B of the installation. The frame 62 provided with idle rollers 61 has affixed thereto vertical wings 67 which, viewed from above, have a substantially V-shaped configuration and which are in line with each other so as to form a grid-like barrier that, when the frame 62 is in its active position, is disposed on an imaginary vertical plane which is parallel to the direction of movement F1 of the packs of panels at the stations B of the installation. Opposed to said grid­ -like barrier and parallel thereto, there is provided (solidary with the stationary structure 54 mounting the rocking frame of the powered rollers 51) a guide 68 which at the bottom is also of grid-like formation to ensure the required reedom of movement to said rollers 51 (see also figures 11 and 14). With reference again to figure 11, it will be seen that suitably spaced between the rollers 51-61 there are the flat-shaped ends of the teeth 69-69' of respective comb-like structures 70-70', which are supported at the ends thereof by pairs of links 71-71' which are pivoted to supports 72-72' integral with the structures 54-­ 64. The body of the comb-like structures 70-70' has pivoted thereto, in the appropriate number and position, as shown at 73-73', connecting rods 74-74' the top ends of which are connected to cranks 75-75' (see figure 15), the crank 75 being keyed to the end of a shaft 76 which is rotatably supported, through bearings 77, by the structure 54 and which is parallel to the guides 66. The crank 75', on the other hand, is keyed to a bushing 78 which is rotatably supported, through bearings 79, by the structure 64 and which is so formed in the inner side thereof as to co­ operate with the longitudinal splined portion 76' of said shaft 76. Said bushing 78 and shaft 76 have normally secured thereto two levers 80-80' which are pivotably connected to the piston rods of respective fluid-operated double-acting cylinder-and-piston units 81-81' having their body portions secured to the structures 54-64. This solution permits a synchronous actuation of the comb-like frames 70-70' which, following the actuation of the units 81-81', may be moved from the position shown with solid lines to the position shown with broken lines in figure 11, and vice versa. Figures 11 and 12 that is pivoted at 82-82' to the structure 64, through parallel links 83-83', so as to be pivotable parallelly to F1, there is a further comb-like frame 84 having teeth 84' located between the teeth of the frame 62 and fixedly provided at the ends thereof with vertical plates 284 exactly aligned with each other, said frame 84 being connected to one or more cylinder-and-piston units which are diagrammatically symbolized by the arrow 85, and which hold it normally in the broken line position of figure 11 and which, under command, move it to the solid line position to operate on the side of the pack of panels which is opposite to that facing the stationary guide 68. With reference to figure 1, it will be seen that depending upon the size of the pack of panels reaching the station B and depending upon the operative stage of the installation, the programming device controlling the operation of the installation establishes at which of the four stations B a pack must be stopped to be stacked on an underlying lifting platform as discussed below. Arranged downstream of each station B-B'-B''-B''' are respective mechanical abutments indicated at 86-86'-86''-86''' in figure 1, the first­ -mentioned three are of retractable type and the last­ mentioned one is stationary and constantly operative. One of the retractable abutments 86 is shown in figure 13, and it will be seen that it comprises a slide 86 which is vertically movable on a stationary guide 87 located below the runway defined by the powered rollers 51, said slide being connected to a fluid-operated double-acting cylinder­ -and-piston unit (not shown) which, under command, will move it from the solid line position to the lifted broken line position, or vice versa. Micro-switches 88, only one of which is shown in figure 13, reveal the rest and the active positions of the slide 66 to the programmer. Again in figure 13, it will be seen that said guide 87 is at a small angle Z with respect to the vertical, whereby when the slide 86 is lowered after the latter has stopped the pack of panels at the desired station B, said slide 86 will move slightly away from the front side of said pack P, so as to avoid disordering and marring it. The front side of the slide 86 facing the stations A-A of the installation is such as to present a perfectly vertical face when said slide is in its operative top position, regardless of said inclination Z of the assembly 96-87. Before the pack of panels P reaches the lifted abutment 86 (see figure 1), the front side of said pack is detected by a first sensor 89 which controls the decrease of the speed of advance of said pack (see motor-reducer unit 60 in figure 13) so that said pack is not put out of order when engaging against the abutment 86 and a second sensor 90 which stops said motor-reducer unit 60 definitively. Similar sensors 89'-90', 89''-90'' and 89'''-­ 90''' are provided for the stations B'-B''-B'''. When the pack of panels has been properly stopped at one of the stations B (see figure 11), the teeth 69-69' of the comb-like structures 70-70' are already in their lifted position, below the pack, ready to take over the rollers 51-61 when, at due time, they will be lowered and moved away. Thereafter, said comb-like structures 70-70' are also moved away from the pack which will be softly transferred onto either a lifting platform 91 or a pack of panels previously deposited thereon. The jacks 85 (figure 11) are then activated and urge the grid-like formation constituted by the vertical small plates 284 against the adjacent side of the discharged pack of panels P whereby to force said pack to be positioned uniformly with its opposite side against the stationary guide 68. The stack of panels which is progressively built up on the lifting platform 91 is thus quite orderly arranged. Thereafter, the lifting platform 91 is lowered by the same extent as the pack transferred thereonto and the station B will be again in a condition permitting a new operative cycle as described above. Figures 17 and 18 show one of the sets of rubber­ -coated rollers 92 arranged at the stations C-C'-C'' of the installation, in line and co-planar with the rollers 51 when in their active working position, said rollers being rotatably supported by a stationary structure 93 and being actuated by a respective motion unit 94 with a sprocket-and­ -chain drive 95, so as to be rotated concurrently and at the same speed as said rollers 51. The rollers 92 constitute a bridge permitting an appropriate transfer of the pack of panels from a station B to a next following station. Rollers which are similar to the rollers 92 though freely rotatable (not shown), may be provided on the opposite side of the stations C and may be supported by a structure which is secured to the carriage 64 to beter support the pack while being transferred between said stations B. It will be seen in the figures 19 and 20 that each lifting platform 91 has a loading plane which is formed by a plurality of horizontal arms 91', disposed normally to the direction of movement indicated by the arrow F2, and parallel and suitably spaced apart from each other, said arms being suitably shaped to permit the platform to reach the highest level when it is empty, as shown in figure 14. The arms 91' of said platform are secured in cantilever fashion at an end thereof to a common carriage beam 96 provided at the ends thereof with wheels 97 sliding within a pair of U-shaped uprights 98 and comprised in the fixed framing of the stations B of the installation, said carriage beam provided at the ends thereof with sliding members 99 which are adapted to slide with enough precision on rectilinear vertical guides 100 secured to said uprights 98. At the two ends of the carriage 96 there are connected at 101 the ends of the two chains 102 only one of which is shown in figure 19, said chains being passed around sprockets 103 keyed on a shaft 104 which, in turn, is rotatably supported at the top of the stationary framing of the station B and is actuated by an oppositely-rotating motor-reducer unit 105. The outer end of the chains 102 is connected to counterweights 106 keeping said chains in a suitably taut condition and slidably guided within stationary housing 107. Sprockets 103' ensure a correct co-operation of the chains 102 with the sprockets 103 and a correct guidance of said counterweights into the respective guide housings. At the stations B-B'-B''-B''' the packs of panels of different sizes are stacked on each other over the underlying lifting platforms 91, according to the principle requiring panels of the same size on each platform to form a stack of a pre-established height, whereafter said lifting platform 91 is moved automatically to its lowest position as shown with broken lines in figure 19. In this figure, the platform 91 is shown with solid lines in its highest position, and P indicates the bottom of the pack of panels when it is about to be deposited on the lifting platform. In figure 21 it will be noted that when the platform 91 is completely lowered, the stack of panels P' built up thereon will engage and will be supported by a bed 108 extending both in the station B and adjacent station D and formed by a plurality of rectilinear, parallel and co-planar frames 109 which are suitably spaced apart and are disposed with their longitudinal axes in the direction of the arr F2 and which are provided thereover with small idle wheels 110 so disposed as to permit the stack P' to be moved in the direction of the arrow F2. Said frames 109 comprise at an end thereof integral extensions 111 pivoted at 113 to a common transom 112 which is secured to said uprights 98. The pivot 113 is parallel to the direction indicated by the arrow F1. At the opposite end thereof, said frames 109 are secured, through depending extensions 114, to a common transom 115 connected to fluid-operated double-acting cylinder-and-piston units 116 by means of which said bed 108 with the idle wheels may be moved from the solid line position to the broken line position of figure 21, and vice versa. When the stack of panels P' is positioned on the bed 108, the latter is in the raised horizontal position and the arms 91' of the platform 91 will be lowered below the sliding plane constituted by the small wheels 110. Between said frames 109 and the teeth or arms 91' of said platform 91 there will be left sufficient spaces to permit the longitudinal movement therebetween of the teeth 117 of a pusher that, prior to said lowering step of the stack P', has moved automatically to the position shown with solid lines in figure 21, the arrangement being such that said teeth will protrude, by an aligned portion of suitable extent, from the bed 108, said teeth being secured to a common beam 118 (see also figure 22) which is provided at the ends thereof with carriages 119-119' slidable in horizontal U-shaped guides 120-120' located below said bed, parallelly to the direction of the arrows F2 and bridging the stations B-D. Said carriages 119-119' are connected to the ends of respective chains 121-121' passed around sprockets 122-122', the latter being keyed to a shaft 123 rotatably supported by the baseplate of the installation and connected through a sprocket-and-chain drive 124 to a motor­ -reducer unit 125 which, when activated, moves said pusher 117 from the solid line position to the broken line position of figure 21, and vice versa, with resulting movement of the stack of panels P' from the station B to the station E of figure 1 (see arrows F2). Thereafter, when said pusher 117 has moved back to its rest position (the lifting platform 91 having already moved back to its top position), said bed 108 will be lowered to the broken line position to avoid interfering with the movable surface of station E during a following working step of this component, as will be explained more completely below. On completion of the operative cycle of this component, said bed 108 moves back to its horizontal position to repeat the cycle described above. While being transferred from the station B to the station E, said stack of panels P', preferably, is guarded at the sides thereof by suitable containing and guiding structures, not shown on the drawings because they are obvious and easily construed by those skilled in the art. At the station E (see figures 23-24-25), the stack of panels P' will be positioned on the surface - coated with protective material, such as synthetic velvet - of a steel table 126 which is secured with two opposite sides thereof on two carriages 127 which are slidable through wheels having horizontal and vertical axes 128 within guide channels 129 having composite cross section and fixed above the guides 120-120' and parallel thereto. Sliding blocks 129' of a material having a low-friction coefficient, such as nylon, engage the lower surface of the table 126 so as to improve the required stretching and planarity thereof. The ends of said carriages 127 are connected at 130-130' to the ends of respective chains 131 passed around pairs of sprockets 132-132', the latter being keyed on a shaft 134 (see also figure 21) journalled on the uprights 98 of the station B and connected through a sprocket-and-chain drive 135, to a motor-reducer unit 136. The operation of these components will be discussed further hereinafter. If the length of the table 126, in the direction of the arrow F3 of figure 1, is longer than the length of the stack of panels P', one or more stacks will be normally arranged after each other on the same table 126, by as many strokes of the pusher 117. During these steps, the stack of panels that cyclically is pushed onto the table 126 will push forward the stack or stacks which are located already on said table. In the embodiment shown in figure 1 of the table 126 operating at the stations B'''-D''', the operative cycle of the pusher unit 117 is completed after three operative strokes. Conversely, in the embodiment of the table 126 operating at the stations B""-D"", the operative cycle of the pusher unit 117 is completed after two operative cycles. The latter example also emphasizes that the stacks of panels positioned on the table 126 of one of the stations E of the installation may have a width which is smaller than that of said table 126, whereby a plurclity of rows of said stacks may be arranged side by side thereon; in the example being considered, two rows of said stacks P' are arranged thereon. This last-mentioned arrangement of the rows of stacks on the table 126 is effected by a pusher 137 that, normally, in the position shown with solid lines in figure 1, at one side of the station E and that, under command, is activated in the direction indicated by the arrows F3 to sweep the table 126 transversely and to displace the first row of stacks P' leftwards of the table (when looking at figure 1), until the front side thereof abuts against the feeler 138 of figure 26, which is slidable in a stationary guide 139, against the action of a spring 140, the displacement of said feeler being progressively detected by a plurality of micro-switches 140-140'-140''. When the micro-switch 140 is activated, the pusher 137 is stopped and is returned to its rest position. In the next step, said pusher moves the new row of stacks against the previously displaced row to cause a further displacement of this first row, such as to be detected by the second micro­ -switch 140' whereafter, in the previously considered example, the pusher is returned to its rest position having thus completed its operative cycle. In the example illustrated in figure 1 in connection with the station E', the respective pusher 137 completes its operative cycle after three complete strokes, involving the actuation, additionally, of the third micro-switch 140' of figure 26. With reference also to figures 27-28 and 29, it will be seen that each pusher 137-137'-137''-137''' of the stations E-E'-E''-E''' is supported at an intermediate portion by the lower end of a vertical carrier forming therewith an inverted T-shaped structure, the top end of said carrier being secured to a transom 142 which is provided at the ends thereof with carriages 143-143' slidable in horizontal guides 144-144' which are secured to the framing 145 of the station E. Secured to each carriage 143-143' are the ends of respective chains 146 passed around pairs of sprockets 147-147', the latter of which are keyed to a shaft 148 journalled on the structure 145 and connected to a motor-reducer unit 149 through a sprocket-and-chain drive. In figure 19, 150 indicates an opening in the transom 142 to allow the passage of the upper stretch of the chain 146. Components similar to those described above, indicated by the same number with a different suffix, are provided at the station E'-E'' and E''' of the installation. When the rows of the stacks of panels have been orderly arranged at the stations E of the installation, a retaining bar 151 (shown with broken lines in figure 1) is lowered at the border area between the stations E-D, extend close to or in substantial contact with said table 126. When said bar has reached its bottom operative position, the motion unit 136 is activated to remove the table 126 from the station E and transfer it temporarily to the station D which, as stated above, has been prepared for this occurrence. Said bar 151 retains the assembly of stacks of panels P' at the station E, and obliges said assembly to softly come to rest onto a plane which substitutes for the said table and which may be formed by a pallet, a protecting panel or merely a roller sliding plane, as will be discussed more fully below. Figures 30-31-32-33 and 34 show various constructional and operating details of the retaining bar 151. This bar is provided at the ends thereof with carriages 152-152' which, through bearings 153, slide within rectilinear guide channels 154-154' which are fixed to the uprights 155 of the framing of said station E, said channels being characterized in that their lower portions are inclined toward the station E, so that said bar 151, during the final portion of its descent stroke, will approach the base of the assembly of stacks P' to be retained, and will move away therefrom when it is lifted. The carriages 152-152' are connected to the ends of respective chains 155-155' passed around sprockets 156-156' keyed to a shaft 157 which is journalled on the structure 145 and is actuated by a motor­ -reduce 158. The other ends of said chains are connected to counterweights 159 contained by stationary guides 160. Adjustable abutment 161 (figure 34) control the bottom end of the stroke of said bar 151. With reference to figures 35-36-37-38-39, it will be noted that below said table 126, when positioned at the stations E of the installation, is provided a bed 162 with parallel co-planar belts 163 which are directed as indicated by the arrow F2, the upper stretches of said belts being passed around respective rows of idle grooved rollers 164 supported by parallel frames 165 which are fixed to said bed 162. The belts 163, at their ends, are passed around pulleys 166-166' keyed to shafts rotatably supported by said bed 162, one of which is connected, through a sprocket­ -and-chain drive 167, to an oppositely-rotatable motor­ -reducer unit 168. The bed 162 is provided at the bottom with four vertical nut-screws 169 arranged at the corners of an imaginary rectangle and co-operating with respective lead-screws 170 rotatably supported by a stationary frame 171 mounting an oppositely-rotatable motor-reducer unit 172 that, through a sprocket-and-chain drive 173, co-operates with sprockets 174 keyed on said lead-screws, the arrangement being such that upon activation of said unit 172 said bed with its belts will be raised and lowered, always in a perfectly horizontal condition. As shown also in figures 38 and 39, said bed 162 vertically movably mounts thereon, through four guide slide 175, an additional bed 176 which may be either raised or lowered with respect to the bed 162 by means of four suitably arranged fluid-operated double­ -acting cylinder-and-piston units 177. The bed 176 mounts frames 178 which are disposed parallelly and equally spaced between the frames 165 and are provided on the upper side thereof with co-planar, parallel, idle wheels 179 which constitute a sliding plane in the direction of the arrow F2 of figure 1 and which, under command upon the activation of said units 177, may be positionaed at a higher or at a lower level with respect to the handling plane constituted by the belts 163. The components described above operate as follows. If the parallelepiped assembly of the stacks arranged previously on the table 126 is to be unloaded onto a pallet R or onto a protecting panel, the bed 162 is initially in its lower position and the bed 176 is also in its lowest position, whereby the powered belts 163 will move in the direction indicated in figure 1 by the arrows F4 and will introduce the pallet under the table 126, against comb-like stationary abutments 180 (see figures 35-­ 36-40). Upon this occurrence (see also figure 26), micro­ switches 181-181' will detect the appropriate presence of the front side of the pallet and communicate this presence to the programmer of the installation. The motion unit 172 is then operated and raises the bed 162 and the pallet R thereon. Prior to this operation, a feeler 182 (see figure 4) carried by a rocking arm 183 controlled by a cylinder­ and-piston unit 184 is moved from its rest position (shown with broken lines) to its active position (shown with solid lines) so that said feeler will engage the upper surface of the lowermost portion of the table 126 which, in the central area thereof, not supported by underlying members, forms a camber of few millimeters. The lifting movement of the pallet is automatically stopped when it engages said table 126 and brings the central area thereof on the planarity line 185, which causes the feeler 182 to be raised against the action of the spring 186 so as to trip a micro-switch 187 to stop the motivating unit 172 (figure 35). Thereafter, said feeler 182 is moved back to its rest position away from the table 126. It is to be understood that the retractable feeler may be embodied otherwise or may be replaced by any other suitable means. The operation described above is effected at the beginning of the operative cycle of the stations E of the installation, when no stacks of panels have been transferred onto the table 126, so that when said transfer will be effected said table 126 will be supported thereunder due as well to the intimate bearing relationship with the pallet. When the table 126 is withdrawn from the station E and is translated temporarily to the adjoining station D, the assembly of stacks P', previously arranged on said table and held by the retaining bar 151, will be softly deposited onto the underlying pallet R. In the next step, the motion unit 172 will be re-activated to lower the bed 162, whereafter said belts 163 are activated in the direction of the arrow F2 (figures 35-1) to transfer the assembly of pallet and stacks to a station G which will be described hereinafter. If the assembly of stacks is to be discharged from the station E with no underlying protection, the installation operates as follows. The feeler 182 of figure 41 remains in its rest position, the bed 176 with the rollers 179 is raised so as to emerge from the plane of the now stopped belts 163, whereafter the main bed 162 is lifted to an extent which is controlled by a stationary sensor (not shown) whereby the rollers 179 will substantially bengage the undersurface of the table 126. When the table 126 is withdrawn from the station E, the assembly of stacks orderly arranged thereon and retained by the bar 151 will be deposited onto the bed with the rollers 179 that have efficiently supported said table throughout the operative cycle. In the next step, the bed with the rollers is lowered so that the assembly of stacks will be deposited on the plane formed by the belts 163, whereafter the general bed 162 is lowered to bring the belts in line with the station G, which is necessary for discharging said assembly of stacks. With reference to figures 1-42-43-44-45-46, it will be noted that the stations G-G'-G''-G''' are equipped with common co-planar parallel rollers 188 which are disposed with their longitudinal axes in the direction of the arrow F2 and are arranged on an imaginary horizontal plane located appropriately below the plane formed by the belts 163 of the station E when it is in the lower position thereof. The rollers 188 are supported by a stationary frame 189, are provided at an end thereof with sprockets 190 of the same diameter and, through additional idle sprockets 190', are connected to a single chain 191 driven by a motor-reducer unit 192 (figure 43), the arrangement being such that said rollers will move the articles deposited thereon, in the direction indicated by the arrows F5 in figure 1. At each station G-G'-G''-G''' there are provided respective beds 193-193'-193''-193''' vertically guided by suitable guide slide means 194 (figure 46) and either raised and lowered by fluid-operated cylinder-and-piston units 195. Mounted on said beds are frames 196 positioned parallelly between the rollers 188 and equally-spaced therefrom, each frame having mounted thereon small, idle, grooved wheels 197 supporting the upper stretch of belts 198 passed around end pulleys 199-199' which are keyed on respective shafts 200-200' one of which is connected to an oppositely-rotatable motivating unit 201. The linear speed of the belts 198 is the same as that of the belts 163 of the stations E. The frame 193 is normally in a lifted up condition so as to present lifted up belts 198 above the rollers 188. In this condition the belts 198, suitably moved in the direction of the arrow F4, will first introduce the pallet or panel R into the stations E of the plant, and thereafter, by a movement in the direction of the arrow F2, will withdraw from said stations E said pallet or panel having thereon the assembly of stacks, or the simple parallelepiped assembly of stacks of panels. The beds 193 with the belts 198 are then lowered whereby the assemblies of stacks with, if desired, a pallet or panel at the bottom will be deposited onto the rollers 188 which, when activated, will discharge said assemblies in the direction indicated by the arrow F5. Downstream of the transport runway formed by the rollers 188 there may be provided a strapping station or a plastics film wrapping station, or any other means for collecting and disposing the articles processed by the plant according to the invention. The pallets or, if desired, the protecting panels R are inserted into the stations G from respective stations H-H'-H''-H''' comprising powered belts which are co-planar and in line with respect to those of the belts 198 of said stations G when in the raised working position thereof, and which are moved at the same speed and in the direction of the arrow F4. No further constructional details of the stations H of the installation are illustrated here, since they are obvious and easily construed by those skilled in the art. The activation of the stations H may beeither manual or, advantageously, automated. It is to be understood that this description relates to a preferred embodiment of the invention, omitting the constructional details concerning the various control and safety circuits of the plant, as well as the various electrical circuits and fluid-operated circuits, since they are easily conceivable and can be easily constructed by those skilled in the art.

Claims: 1. A plant for stacking automatically on respective lifting platforms packs of panels of different sizes coming from a dividing machine and for orderly arranging said stacks adjacent to each other, to form parallelepiped assemblies which are then transferred to a discharge station after being, optionally, arranged on a respective pallet or a protecting or supporting panel, characterized in that it comprises: a) a transport runway (1) whereon the packs (P) of panels from the dividing machine may be arranged and may be moved side by side or in sequence; b) at least a row of lifting platforms (91),located laterally and perpendicularly to said transport runway and so that the top side of said platforms is below the imaginary horizontal plane on which said transport runway is located; c) means (A-A') operating transversely on the end portion of said transport runway, in line with the row of lifting platforms (91) and stopping the pack or packs of panels from the dividing machine and feeding said packs, in a single file and suitably spaced apart, to transport means operating longitudinally and above the row of lifting platforms, receiving the spaced apart packs of panels in single file from the previously-mentioned means, and effecting the sorting, soft stacking and orderly arrangement of said packs on the lifting platforms, so that panels of the same size will be discharged onto each platform at each particular operation; d) means transferring the stacks (P') of panels from said lifting platforms to adjacent stations (E) where said stacks are arranged either after each other or side by side so as to form parallelepiped assemblies of a pre-established size; e) means for softly depositing each assembly of stacks, optionally, onto a pallet or a protective panel (R), or directly onto discharging means operating at the lower portion of the same station (E) whereon said assembly is formed; f) means (H-G) for feeding automatically to the preceding I0 stations (E) the optional pallets or protective and supporting panels of the assemblies of stacks; g) means (G) for moving away, to an optional strapping or wrapping station, or to any other collecting and processing means, the assemblies of stacks arranged on said optional pallet or coming from the stations mentioned above. 2. A plant according to claim 1, characterized by the fact that said transport runway (1) feeding the packs of panels from the dividing machine to said plant, comprises horizontal stationary beds (2) of longitudinal grid-like formation, preferably coated with low-friction material, while in the void spaces of said beds there are arranged longitudinal powered belts co-planar with each other mounted on respective beds that, under command, may be either lowered and raised so that said belts may protrude from said stationary beds or may be retracted below said beds, in order to either advance or stop the packs of panels, wherein at the end portion of said transport runway, where the packs of panels are stopped and arranged for being transferred toward the row of lifting platforms to be stacked thereon, the stationary portions of the bed whereon said packs would rest, are replaced by a co-planar structure formed by small idle wheels (3) having their axes disposed so as to facilitate said transfer of the packs; wherein at said end portion of the feeding runway (1) is operatively provided an abutment bar (4) for stopping said packs and for lowering, in co-operation with suitable sensors, said transport belts, said abutment bar being connected to vertically movable means (5-6-9-10-11-12) which will raise automatically said bar when cut-offs or other parts to be conveyed beyond said plant to collecting means are coming from said feeding runway. 3. A plant according to claim 1, characterized by the fact that at the abutment bar (4) for stopping and guiding the packs of panels there are provided means whereby when the belts of the feeding runway (1) are lowered, the side of the pack or packs of panels contacting against said abutment bar will be clamped between a pair of rows of parallel rollers (14-33) which are rubber-coated and are disposed with their axes perpendicularly to the imaginary plane containing said abutment bar, the upper one of said rows being formed by spring-loaded and preferably grooved rollers (33) which are idlingly supported by a presser (35) carried by vertically-moving means (36-37-38-39-40-41-42) and provided with a feeler (44) and with sensors (47) to stop said presser automatically when it has a proper interference engagement with said packs of panels; while the other or lower row of rollers (14) is powered by suitable means (21-22-23-24-25-26-27) to make the packs of panels advance in single file towards the line of lifting platforms; said assembly of means formed by the roller-clamp and abutment bar being supported at their ends by a powered carriage structure of such construction whereby when the two rows of rollers have clamped one or more packs of panels abutting against said abutment bar, this assembly will be moved to a short extent in the same direction of movement as the feeding runway (1), so as to move the clamped packs away from the packs that possibly follow them, so that when the clamped packs will be moved toward the line of lifting platforms, they will not interfere with any packs that might have remained on the feeding runway, the lower powered rollers (14) being divided in two groups (14-28) arranged after each other, the former group (14) that first engages the packs of panels stopped against the abutment bar being mounted on a support structure (16) which, under command, may be raised and lowered by suitable means (17-20) and being powered by a motion unit (26) with the intermediary of a torque limiter (27) to ensure a soft handling of the packs, and the latter group of powered rollers (28) being mounted on a stationary structure (29), a sensor (48) being provided between said rollers to cause, upon detection of the front side of a pack, the temporary lowering of the former group of rollers, whereby the packs of panels will be fed to the line of lifting platforms spaced apart as necessary to stop them selectively on the lifting platform selected at each particular operation; and, finally, the arrangement being such that when the rear side of the pack being handled is detected by said sensor and if permitted by the operative program of the installation, the former group of rollers (14) is raised and re-activated if it had been previously stopped, and beingsuch that after discharging all the packs that have reached said abutment bar, in proper time relationship with the lifting up of the belts of the feeding runway (1), the assembly of the transfer rollers and abutment bar is returned automatically to the original position, with a movement opposite to the advancing movement of the packs on said feeding runway. 4. A plant according to claim 3, characterized in that the operative cycle of the roller-clamp (14-28-33) for transferring the panels towards the line of lifting plat­ forms, is such that when the front side of the pack (P) is detected by the sensor (48) arranged between tha latter group of powered rollers (28), the former group of rollers (14) is softly stopped by the respective motion unit comprising said torque-limiter (27) with no need of lowering these rollers, the arrangement being such that these rollers (14) or a part of the rollers in proximity of the latter group of powered rollers (28) is connected to its motion unit (26) through the intermediary of at least one free-trip coupling, so that said rollers, still engaged by a pack being transferred, may have a idle rotation to avoid hindering said pack. 5. A plant according to claim 1, characterized by the fact that the transport means operating longitudinally above the line of lifting platforms and receiving the packs of panels coming in single file from said transferring clamp, comprises a similar roller-clamp in line with the preceding one and which, more particularly, comprises idle, grooved, spring-loaded upper rollers (50) mounted on a common presser (49) which may be either raised and lowered by suitable means, to conform with the level of the presser (35) of the preceding operative unit, the lower rollers (51) of said means being powered at the same speed and in the same direction as the preceding rollers (28) and being rotatably supported in a cantilever fashion by rocking structure (52) controlled by cylinder-and-piston units (55) and provided in the number of one at each lifting platform (91); similar and respective rocking structures (62) being provided opposite said rocking structures (52) and parallelly thereto and carrying in a cantilever fashion idle rollers (61) adapted to support the pack of panels on the side opposite to that which is clamped by the roller-clamps for transferring the packs along the line of lifting platforms, said rocking structures being supported by a powered carriage (64) slidable on stationary guides (66) normal to the longitudinal axis of the transport runway comprising said mears and controlled by devices which are actuated by the programmer of the plant so that the width of said transport runway will be adapted each time automatical­ ly to the width of the packs to be handled (P); the rocking structures carrying the idle rollers (61) being controlled by fluid-operated cylinder-and-piston units (65) whereby when a pack has been stopped suitably above the selected lifting platform (91) either the powered rollers and the idle rollers may be moved laterally away from said pack which will be supported by the teeth(69-69') of comb-like structures (70-70') which are parallelly swingably mounted on the same parts supporting the rocking structures of said rollers (51-61); said structures (70-70') being controlled by centrally-controlled mechanisms enabling the synchronous actuation thereof, such that, successively to the operations mentioned above, said comb-like structures may be also moved away laterally from the pack of panels which will softly come to rest by gravity onto the loading plane (91') of the underlying lifting platform which in the next step will be lowered by the same extent as the thickness of the pack deposited thereon, whereafter said rocking structures (52-62-70-70') will be all returned to their active position to repeat a new operative cycle. 6. A plant according to claim 1, characterized by the fact that the means for actuating synchronously said comb-like structures (70-70') supporting through their teeth (69-69') the packs of panels while being transferred onto the respective lifting platforms (91) comprises rods (74-74') which are connected at an end to said rocking structures and at the opposite end to a shaft (76) provided with telescopic members (78) and rotatably supported by the same fixed parts (54) and movable parts (64) carrying said rocking structures, said shaft being operatively connected to one or more fluid-operated double-acting cylinder-and­ -piston units (81-81') which through the means mentioned herein will transmit the required synchronous movement to said rocking comb-like structures. 7. A plant according to claim 1, characterized by the fact that the carriage (64) carrying said rocking structures with the idle rollers (61) has pivoted thereto, parallelly to each of said structures, a further comb-like structure (84) having teeth which are provided at the ends with vertical aligned small plates (284), which are usually in a retracted position to avoid interferring with the packs of panels being fed to the lifting platforms, these comb­ -like structures being also controlled by respective fluid­ -operated double-acting cylinder-and-piston units (85), which when a pack has been unloaded onto the respective lifting platform are activated whereby said vertical aligned small plates (284) of said rocking structures will push the top of the stack on a side thereof, to force the opposite side thereof to come in line against a stationary, grid-like vertical structure (68) which has such a height as to perform its guiding function even when the packs of panels are moved along the transport runway operative above the lifting platforms, while said packs are controlled at the opposite side by a grid-like guide structure (67) which is formed by plates secured to the rocking frames (62) carrying said idle rollers (61). 8. A plant according to claim 1, characterized by the fact that the means for stopping each pack of panels properly above the selected one of the lifting platforms (91) whereon the packs are being stacked, comprises sensors (89-90) which detect the front side of the pack and which firstly slow down and then stop the powered group of rollers (51) associated to the selected lifting platform, and which comprise retractable abutments (86) connected to means for vertical and selective handling, the guiding means (87) of said abutments being suitably at an angle to the vertical, whereby when said abutments will be lowered, after stopping a pack, they also have a horizontal movement away from said pack so that the latter will not be put out of order at all; the active surface of said abutment, designed to engage the pack of panels, being exactly vertical when said abutment is in the upper operative condition. 9. A plant according to claim 1, characterized by the fact that said lifting platforms (91) have a comb-like loading plane (91') supported in a cantilever fashion by a carriage structure (96) which may be moved vertically by suitable driving and guiding means (96 to 107), the arrangement being such that when a platform is to be cleared from the stack of panels built up thereon, the loading plane of said platform is lowered to a pre-set stop device so as to insert its teeth through the void longitudinal spaces of a frame (108) which is usually in a horizontal position and is provided with a plurality of small idle and co-planar wheels (110) which take over in supporting said stack; said frame (108) being disposed with its longitudinal axis parallelly to the axis of the main feeding runway (1); said plant comprising a carriage (118-119) longitudinally reciprocatable below said frame (108) by the action of suitable guiding and driving means (120 to 125) and provided with a comb-like pusher (117) which may be moved through the longitudinal void spaces of said sliding plane (110) and which, under command, pushes the stack to be discharged from said plane to an adjacent co-planar station, whereafter said pusher is returned to its rest position to repeat a new operative cycle; said sliding plane formed by the idle wheels (110) beingconnected, at the end proximate to the adjacent station to which said stack is to be transferred, to suitable handling means (116), while the other end of said plane is pivoted horizontally (113) to a stationary supporting structure (112), the arrangement being such that, if desired, said plane may be moved from the horizontal position to a longitudinally-inclined position, such that means (126) of the adjacent operative station (E) may be transferred temporarily above said plane (108). 10. A plant according toclaim 1, characterized by the fact that the stacks (P') of panels discharged from the idle-roller sliding plane (110) located below each lifting platform (91), are transferred onto a horizontal steel table (126) the upper face of which is coated with material which facilitates the sliding movemer of the stack and avoids marrying said stack, said table being secured at two parallel sides to respective carriages (127-128) connected to suitable drive means (130-136) and longitudinally slidable within guides (129) which are parallel to the longitudinal axis of said idle-roller sliding plane and are located partly laterally to said plane, on a stationary supporting structure (120); the arrangement being such that means of a plurality of strokes of said pusher (117) operating below each lifting platform (91), there may be arranged on said table even a plurality of stacks successively to one another. 11. A plant according to claim 1, characterized by the fact that arranged at each stack build up table (126) there is a pusher (137) which when at rest is located at one side of said table, parallelly to one of the carriages of said table, and which is connected to its own guide and drive means (143 and 149) which, under command, will move said pusher horizontally and transversely to the direction of the stacks reaching said table so that the stacks will be arranged on said table either in sequence and side by side to each other so as to form a parallelepiped assembly of pre-established dimensions; suitable sensors (138-139-140) being provided to detect the position of the rows of stacks which are being moved transversely on said table and to cause the building-up to return to its rest position. 12. A plant according to claim 1, characterized by the fact that at and above the side of the build-up table (126) that is facing towards the adjacent station (D) where= from said stacks are coming, there is arranged, parallelly to said side, a carriage bar (151) which may be either lifted and lowered with a guillotine-like movement on said table by the action of suitable means (152 to 159), so that when said bar is lowered and said table is withdrawn from the build-up station and moved toward the stack-feeding station (D), where the idle-roller bed (108) has been suitably lowered, the assembly of stacks (P') will be retained at said build-up station and obliged to softly come to rest onto a pallet or onto a protecting panel (R) or directly onto any underlying supporting structure for subsequent transfer. 13. A plant according to claim 1, characterized by the fact that the guides (154) controlling the up-and-down movement of the retaining bar (151) are at an angle at the lower portion thereof whereby when said bar is raised after the assembly of stacks (P') has been discharged from the table (126), said bar will be moved away from said assembly with a horizontal component of displacement, thus avoid interfering with said assembly. 14. A plant according to claim 1, characterized by the fact that at said station (E) where the stacks are built-up there is provided below said movable table (126) a horizontal bed (165) with powered belts (163) which are parallel and co-planar to each other and are oriented in the same direction as the feeding d rection of the stacks of panels toward said build-up table (126), said bed being mounted on a main frame (162) which may be either lifted and lowered by suitable guiding and driving means (169 and 172); wherein mounted on said frame through the intermediary of guiding and lifting lowering means (175-177) is a further bed (176) provided with rows of idle and co-planar small wheels (179) which depending upon the position of the last­ -mentioned bed may either emerge or be located below the transport plane formed by said belts, said rows of wheels being located in the hollow longitudinal spaces between said belts (163), further means provided whereby said station may operate as follows: the main frame (162) with its belts is in the lower position thereof and the bed with the idle rollers (176) is also in the lower position thereof; the belts (163) are activated to insert below said table a pallet or a protecting panel (R) to be moved against a stationary front abutment (180); the main frame (162) is lifted and this lifting movement is stopped automatically by suitable sensors when the pallet or panel will be in substantial engagement with the lower face of the table (126) where the stacks are built-up, the arrangement being such that when the assembly of stacks has been transferred onto said pallet, after said withdrawal of said table (126), the main frame (162) will be lowered to the cycle-start position and the belts (163) will be activated to discharge the combination pallet assembly of stacks and to be re-set to repeat a new operative cycle. 15. A plant according to claim 14, characterized in that the means located below the build-up table (126), in case that the assembly of stacks is to be discharged without being deposited onto a pallet or protecting panel, operate as follows: the idle-roller bed (179) is lifted so that said rollers will emerge from the belts (163); the main frame (162) is lifted by a fixed stroke so as to bring said rollers (179) in contact with the lower surface of the build-up table thereabove (126); when the assembly of stacks has been discharged onto the idle-roller bed (179), this bed will be lowered whereby said assembly will be placed onto the underlying belts (163); the main frame (162) is lowered to the cycle-start position and the belts (163) will be powered to discharge the assembly of stacks and to re-set the components to repeat a new operative cycle. 16. A plant according to claim 1, characterized by the fact thatthe means for stopping the lifting movement of said main frame (162) located below said table (126) where the stacks are built-up, comprises a feeler (182) which is mounted on means (183-184) for positioning it, under command, at the point of maximum camber of said table (126) to detect when the pallet or protecting panel (R) engages said table and makes it become planar, whereafter said sensor (182) is moved away to leave said table unhindered. 17. A plant according to claim 1, characterized by the act that the means for feeding the pallets or panels (R) to the stack build-up station (E), comprises beds (193) having powered parallel belts (198) which are in line with the belts (163) of said build-up station, said beds (193) being provided with lifting and lowering means (195) whereby the respective belts will be lifted or lowered with respect to a transport plane formed by rollers (188) parallelly arranged between said belts, supported by a stationary structure (189) and connected to drive means (192), the arrangement being such whereby when the assembly of stacks eitner with or without a supporting pallet or panel has reached the belts (198) of the subject means, said belts may be lowered to transfer said assembly to the powered rollers (188) to be moved away to disposal. 18. A plant according to claim 1, characterized by the fact that said pallets or protecting panels (R) are selectively fed to the respective stations (G) for automatic insertion into the stations (E) where the stacks of panels are built-up, by the action of respective beds with powered belts (H), adapted for either manual or automatic activation.

Inventors: BENUZZI, GINO
Applicants: GIBEN IMPIANTI S.P.A.
Application year: 1986
Main classification: B65G57
IPC codes: B65G57