WO2002007939A1

WO2002007939A1 - System for feeding a ceramic press

Info

Publication number: WO2002007939A1
Application number: PCT/IB2001/001299
Authority: WO
Inventors: Giovanni Pastorelli
Original assignee: Lo Scalino S.R.L.
Priority date: 2000-07-20
Filing date: 2001-07-20
Publication date: 2002-01-31
Also published as: ITMO20000160A0; WO2002007939A8; AU2001272692A1; IT1316916B1; ITMO20000160A1

Abstract

A loading apparatus for loading a ceramic press (1) comprises trolley means (9) movable between a loading position and an unloading position and suitable for transferring ceramic powders to cavities (4) of a mould of said press (1), preparing means (10; 13; 152) suitable for receiving said ceramic powders before said ceramic powders are introduced into said cavities (4), feeding means (17, 130; 141) suitable for depositing said ceramic powders into said preparing means (10; 13; 152), said feeding means (17; 130; 141) being associated to moving means (20) controlled on two orthogonal axes and such to allow said ceramic powders to be deposited into said preparing means (10; 13; 152) so as to form a soft cushion (80) provided with three-dimensionally extending regions of different types of powders. A method for loading a ceramic press (1) comprises depositing ceramic powders into preparing means (10; 13; 141), introducing said ceramic powders into cavities (4) of a mould of said press (1) through trolley means (9) movable between a rear loading position and a forward unloading position, said depositing comprising controlling on two orthogonal axes the movement of feeding means (17; 130; 141) for arranging said ceramic powders into said preparing means (10; 13; 152) so as to form a soft cushion (80) provided with three-dimensionally extending regions of different types of powder.

Description

System for feeding a ceramic press

The invention relates to a feeding system for a ceramic tiles forming press.

Prior art comprises ceramic press loading devices suitable for loading into a mould a plurality of types of ceramic powders, for producing ceramic tiles of different constitution, i.e. composed by powders and/or granules variably arranged on the surface and through the thickness of each tile. In order to obtain the desired effects, these loading devices require the use of grids particularly shaped and suitable for receiving powders previously arranged in layers of various colours inside a feeding hopper.

The layer of ceramic powder loaded inside the grid is subjected, during the movement of the trolley with which such loading devices are provided, to a partial remixing due to the friction of the particles on the sliding plane of the trolley. The stratification of the powders during the final phase of the loading, therefore, does not correspond to the initial stratification inside the hopper, which may produce a deterioration of the aesthetic properties of the product due to the loss of definition of the streaks.

Furthermore, the tiles obtained with apparatuses comprising grids show, after the phases of forming and firing, a visible face resulting quite homogeneous, such face showing a plurality of streaks substantially parallel and arranged along the direction of motion of the feeding trolley. The variably oriented veins, forming the decoration of the aforesaid tiles, become really visible only after the polishing phase. With the known devices., furthermore, even though it is possible to obtain tiles remarkably different from each other, a constant orientation of the veins will be however obtained, said orientation depending from the arrangement of the baffles of the above mentioned grids: this causes a remarkable limit to the effect of naturalness of the so obtained tiles. A further drawback of the devices known from prior art is that the hopper used for the stratification of the powders of the various colours has an outlet section for the above mentioned powders having a length shorter than the length of the grid downwardly associated thereto. This causes a non-homogeneous emptying of the hopper since, after the grid has been partially filled up and approaches the press, the hopper may continue to distribute powders only in the portion of its outlet section farther from the press, further powders being prevented from falling from the remaining portion of the outlet section of the hopper by the presence of material occupying the front portion of the grid.

This non-uniform emptying of the hopper contributes to a further remixing of the powders of the various types and/or colours, so contributing to make difficult to control that veins of prefixed size and orientation are obtained. An object of the present invention is to improve the known systems for loading the presses and forming ceramic. A further object of the present invention is to provide a system for loading the presses and forming ceramic tiles that allows effects of veins or streaks to be obtained without that neither grids of conventional type, neither particularly shaped grids have necessarily to be used. A further object of the present invention is to provide a system for loading the presses and forming ceramic tiles in which the contact of the ceramic powders with portion of the die of the press is substantially prevented before the ceramic powders are inserted into the cavities of the mould. A still further object of the invention is to provide a system for loading the presses and forming ceramic tiles with which it is possible to obtain tiles provided with a degree of naturalness and a similarity to the natural stones greater than the tiles which may be obtained with the known systems. In a first aspect of the invention, a loading apparatus for loading a ceramic press provided with a mould comprising a die suitable for receiving ceramic material to be pressed and defining a loading plane of said press is provided, said loading apparatus comprising containing means movable between a loading position and an unloading position and suitable for transferring ceramic powders to said die, preparing and storing means suitable for containing said ceramic powders before said ceramic powders are inserted into said containing means, feeding means suitable for introducing a plurality of ceramic powders into said preparing and storing means, characterised in that said feeding means is associated to moving means controlled on two orthogonal axes and such to allow to said ceramic powders to be placed into said preparing and storing means so as to form a soft cushion provided with three- dimensionally extending regions of different types of powder. In an advantageous version the moving means comprises supporting means of said feeding means movable along the advancing direction of the containing means and frame means suitable for containing the supporting means and movable in a transversal direction with respect to the advancing direction of the containing means.

Owing to this aspect of the invention it is possible to obtain a loading apparatus for loading a ceramic press comprising preparing and storing means inside which it is possible to obtain any three-dimensional arrangement of the ceramic powders .

In a second aspect of the invention, a loading apparatus for loading a ceramic press provided with a mould comprising a die suitable for receiving ceramic material to be pressed and defining a loading plane of said press is provided, said loading apparatus comprising containing means movable between a loading position and an unloading position and suitable for transferring ceramic powders to said die, preparing and storing means suitable for containing said ceramic powders before said ceramic powders are- inserted into said containing means, feeding means suitable for introducing a plurality of ceramic powders into said preparing and storing means, characterised in that said containing means has a longitudinal plan dimension equal to the dimension of said preparing and storing means.

Owing to this aspect of the invention it is possible to obtain a loading apparatus for loading a ceramic press comprising preparing and storing means for the ceramic powders inside which remixing of the different types of powders is substantially prevented.

In a third aspect of the invention, a loading apparatus for loading a ceramic press provided with a mould comprising a die suitable for receiving ceramic material to be pressed and defining a loading plane of said press is provided, said loading apparatus comprising containing means movable between a loading position and an unloading position and suitable for transferring ceramic powders to said die, preparing and storing means suitable for containing said ceramic powders before said ceramic powders are introduced into said containing means, feeding- means suitable for introducing a plurality of ceramic powders into said preparing and storing means, characterised in that said preparing and storing means is downwardly provided with closing means movable between an opening position iri which said closing means allows said ceramic powders to be transferred from said preparing and storing means to said containing means and a closing position in which said closing means prevents said ceramic powders from being transferred from said preparing and storing means to said containing means. Owing to this aspect of the invention it is possible to obtain a loading apparatus for loading a ceramic press in which transferring of the ceramic powders from the preparing and storing means to the containing means ^' takes place with substantially vertical movement. In this way it is possible to arrange the ceramic powders into the preparing and storing means obtaining a soft cushion provided- with three-dimensional veins and then to transfer a layer of said soft cushion into said containing means without substantially change the pattern of the veins of said soft layer.

In a fourth aspect of the invention, a loading apparatus for loading a ceramic press provided with a mould comprising a die suitable for receiving ceramic material to . be pressed and defining a loading plane of said press is provided, said loading apparatus comprising containing means movable between a loading position and an unloading position and suitable for transferring ceramic powders to said die, preparing and storing means suitable for containing said ceramic powders before said ceramic powders are introduced into said containing means, feeding means suitable for introducing a plurality of ceramic powders into said preparing and storing means, characterised in that said containing means is downwardly provided with lamina means movable between an opening position wherein said lamina means allows said ceramic powders to be transferred from said containing means to cavities of said die, and a closing position wherein said lamina means prevents said ceramic powders from being transferred from said containing means to cavities of said die. Owing to this aspect of the invention it is possible to obtain a loading apparatus for loading a ceramic press in which remixing of the powders due to the friction between the powders and the loading plane of the press is substantially prevented. In a fifth aspect of the - invention, a method for loading a ceramic press is provided, comprising transferring ceramic powders from respective feeding means to said ceramic press provided with a die defining a loading plane of said press, arranging said ceramic powders into preparing and storing means, extracting said ceramic powders from said preparing and storing means for .introducing said ceramic powders into containing means, pouring said ceramic powders into cavities of said die by transferring said containing means from a loading position in which said containing means receives said ceramic powders from said preparing and storing means to an unloading position in which said containing means inserts said ceramic powders into said mould, characterised in that said arranging comprises controlling the movement of said feeding means on two orthogonal axes for allowing to said ceramic powders to be placed into said preparing and storing means so as to form a soft cushion provided with three-dimensionally extending regions of different types of powder.

In a sixth aspect of the invention, a method for loading a ceramic press is provided, comprising transferring ceramic powders from respective feeding means to said ceramic press provided with a die defining a loading plane of said press, arranging said ceramic powders into preparing and storing means, extracting said ceramic powders from said preparing and storing means for introducing - said ceramic powders into containing means, pouring said ceramic powders into cavities of said die by transferring said containing means from a loading position in which said containing means receives said ceramic powders from said preparing and storing means to an unloading position in which said containing means inserts said ceramic powders into said mould, characterised in that said extracting comprises moving closing means downwardly associated, to said preparing and storing means from a closing position in which said closing means prevents said ceramic powders from being transferred from said preparing and storing means to said containing means to an opening position in which said closing means allows said ceramic powders to be transferred from said preparing and storing means to said containing means. In a seventh aspect of the invention, a method for loading a ceramic press is provided, . comprising transferring ceramic powders from respective feeding means to said ceramic press provided with a die defining a loading plane of said press, arranging said ceramic powders into preparing and storing means, extracting said ceramic powders from said preparing and storing means for introducing said ceramic powders into containing means, pouring said ceramic powders into cavities of said die by transferring said containing means from a loading position in which said containing means receives said ceramic powders from said preparing and storing means to an unloading position in which said containing means inserts said ceramic powders into said mould, characterised in that said pouring comprises moving lamina means downwardly associated to said containing means from a closing position in which said lamina means prevents said ceramic powders from being delivered from said containing means to said cavities to an opening position in which said lamina means allows said ceramic powders to be delivered from said containing means to said cavities. Owing to these aspects of the invention it is possible to obtain ceramic tiles provided with high naturalness, said tiles obtained starting from layers of a cushion of powders provided with three-dimensional veins. This shows, in fact, several analogies with cutting a slab of natural stone from a block extracted from a stone quarry.

The invention may be better understood and carried out with reference to the attached drawings, which illustrate some exemplifying but not restrictive embodiments thereof, in which: Figure 1 is a side elevation view of a ceramic press provided with a powder feeding apparatus according to the invention; Figure 2 is a section taken along a plane II-II of Figure 1; Figure 3 is a section taken along a plane III-III of Figure 1; Figure 4 is a section taken along a plane IV-IV of Figure 1; Figure 5 is an enlarged and broken detail of Figure 4/ Figure 6 is an enlarged and broken detail of Figure 1; Figure 7 is a side view of feeding means for feeding the ceramic powders; Figure 8 is a section taken along a plane VIII-VIII of Figure

7;

Figure 9 is a section taken along a plane IX-IX of Figure 1;

Figure 10 is a sketched vertical section of a press associated to a ceramic powder feeding apparatus according to the invention, showing a starting phase of the feeding cycle of the press;

Figure 11 is a section like Figure 10 showing a following phase of the feeding cycle of the press; Figure 12 is a section like Figures 10 and 11 showing a still following phase of the feeding cycle of the press;

Figure 13 is a side elevation view of a ceramic press provided with a ceramic powder feeding apparatus according to the invention, the apparatus being carried out according to a preferred version;

Figure 14 is a view like Figure 13, showing an apparatus according to the invention comprising storing means for storing a further ceramic material, the storing means being interposed between the press and the feeding means; Figure 15 is a view like Figure 14, showing a variation of the apparatus according to the invention in which the feeding means is interposed between the press and the storing means for storing a further ceramic material;

Figure 16 is a front view of feeding means of an apparatus according to the invention carried out according to another preferred version;

Figure 17 is a top view of an apparatus according to the invention provided with the feeding means of Figure 16;

Figure 18 is a side view of an apparatus according to the invention provided with feeding means carried out according to a further preferred version;

Figure 19 is a front view of the feeding means of Figure 18;

Figure 20 is an enlarged and broken detail of Figure 18;

Figure 21 is an enlarged and broken detail of Figure 20; Figure 22 is a front view of the feeding means shown in Figures 18 to 21 provided with perturbing means suitable for interacting with the deposited ceramic powders.

With reference to Figure 1, a ceramic press 1 is shown comprising a bed 2 on which a die 3 of a ceramic mould defining the loading plane of the press 1 is fixed, such die 3 being provided with cavities 4 (Figure 2) suitable for being filled with the ceramic material to be pressed, and one or more punches 5 fixed to a top plate 6 reciprocating along a direction perpendicular to the die 3.

Laterally to the bed 2, a feeding apparatus 7 is arranged for feeding the cavities 4 of the die 3 with ceramic powders to be pressed.

The feeding apparatus 7 comprises a supporting frame 8 associated to trolley means 9 provided with containing means 10 for containing the powders.

The trolley means 9 is movable along a longitudinal direction between a rear loading position, in which the containing means 10 is loaded with the ceramic powders and an unloading forward position in which the containing means 10 transfers the ceramic powders contained therein into the cavities 4.

The trolley means 9 is transferred, by causing them to slide on a plane substantially parallel to the loading plane of the die 3, from said loading position to said unloading position by means of a rod-crank device 11 operated by a motor 12.

The trolley means 9 is supported by vertical upper wheels 100 and vertical lower wheels 101 which drive the translation of the trolley means 9 along the approaching and departing direction with respect to the press 1. The trolley means is further provided with horizontal wheels (102) (Figure 2) limiting the possibility of swerving in a transversal direction.

Preparing , and storing means 13 for the ceramic powders is further associated to the frame 8, the preparing and^" storing means 13 being arranged for containing the ceramic powders with which the containing means 10 is fed.

As shown in Figure 9, the preparing and storing means 13 comprises a container 14, open at the top and closed at the bottom by removable closing means 15, arranged for containing the powders which are introduced thereinto so as to form a soft cushion 80. Such soft cushion 80 comprises powders of various colours which extend three-dimensionally for reproducing veins 81 typical of the natural stones. The preparing and storing means 13 is provided at the inside thereof with a diverting wedge 16 suitable for allowing the underlying containing means 10 to be properly filled when the closing means 15 is removed for allowing the passage of the powders . If the press 1 has to be used for producing tiles having a size different from that initially provided, it is sufficient substituting the preparing and storing means 13 and the respective containing means 10. The powders are inserted into the preparing and storing means 13 through feeding means 17 provided with funnel means 18 toward which a plurality of tubes 19- converges, each of said tubes 19 carrying a type of powders.

The feeding means 17 is fixed to supporting means 17a which is actuated by moving means 20 controlling either the longitudinal and the transversal movement of said supporting means 17a so as to obtain, inside the preparing and storing means 13, a soft cushion 80 provided with three-dimensional streaks 81 having a pre-established arrangement and reproducing a pre-fixed pattern. With reference to Figure 2, the preparing and storing means 13 is shown in greater detail, with particular reference to the devices allowing the closing means 15 to be moved. A motor 21, fixed through supports to the frame 8, rotates, by means of a motor-reducer 22, a shaft 23 at the ends of which two gearwheels 24 are connected, each engaging a respective rack connected to the closing means 15. The shaft 23 is actuated by means of a belt 26 arranged between a driving pulley 27 connected to the motor 21 and an idle pulley 28. The motor 21, therefore, by actuating the shaft 23, rotates the gearwheels 24 which drive the racks 25, causing the closing means 15 to translate and consequently the powders to be transferred into the underlying containing means 10. With reference to Figure 3, the containing means 10 is shown in greater detail, said containing means 10 is downwardly provided with lamina means 29, by removing which transferring of the powders to the cavities 4 of the press 1 is carried out. A hydraulic motor 30 is arranged for driving a further shaft 31 at the ends of which two pinions 32 are fixed which is coupled with a pair of further racks 33 connected to the lamina means 29.

The shaft 31 is actuated by means of a further driving pulley 34 connected to the hydraulic motor 30 and associated to a further idle pulley 35 by means of a further belt 36. The use of the hydraulic motor 30 is advantageous since it allows obtaining high powers despite rather reduced dimensions. To the shaft 31 an encoder 37 is further connected which allows to know at any time of working the position of the lamina means 29 with respect to the containing means 10, so allowing to know the width of the openings through which the powders are fed.

With reference to Figures 7 and 8, the feeding means 17 fixed to a projecting portion 41 of the supporting means 17a is shown. Each one of the tubes 19, arranged for transporting a coloured powder extracted from a respective silo or hopper, not shown, is connected to the projecting portion 41 by means of a sleeve 38 housed into a hole 42 of the projecting portion 41. The tubes 19 converge into the funnel means 18 and are closed at the bottom by shutter 39 operated by actuators 40. As shown in Figures 4, 5 and 6 the moving means 20 comprises a frame 44 containing the supporting means 17a, the frame 44 may be reciprocated in a direction transversal with respect to the movement of the trolley means 9.

A first upper guide 45 and a first lower guide 46 are fixed to the frame 8 of the feeding apparatus 7, both the guides having square section and being arranged on the same vertical plane. As shown in Figure - 6, a second upper guide 47 and a second lower guide 48 are further provided, said second guides having square section too and being arranged parallelly to the first guides 45 and 46, the second upper guide 47 being arranged at the same height of the first upper guide 45 and the second lower guide 48 being arranged at the same height of the first lower guide 46. The first guides 45, 46 are arranged so that the surfaces defining the sliding faces thereof form angles of 45° with respect to a horizontal plane; in this way pairs of twin conical wheels 49, 50, 51, freely rotatable around respective pins fixed to the frame 44, may be associated to said first guides 45, 46. The pairs of wheels 49 and 50 are associated to the first upper guide 45 respectively upward and downward with respect to said first upper guide 45, while the pair of wheels 51 is upward engaged with the first lower guide 46. Pairs of plane wheels 52 and 53 are associated to the second guides 47 and 48. The use of the pairs of wheels 49, 50 and 51 substantially prevents the possibility of disengagement from the first guides 45 and 46 since the profile of said first _. guides 45 and 46 engages the double conical surface of said pairs of wheels 49, 50 and 51. On the contrary, the second guides 47 and 48, having to perform a supporting function only, are associated to the pairs of wheels 51 and 52 having usual plane surface.

The frame 44 is moved on the first guides 45, 46 and the second guides 47, 48 by means of a motor 54 which, by means of a motor-reducer 55, actuates a belt 56 wound on a plurality of pulley 120, 121, 122, 123, 124, 125.

One of the branches of the belt 56 is fixed to the frame 44 which, therefore, is provided with a reciprocating rectilinear movement owing to the presence of an inverter (not shown) controlling the motor 54.

Internally to the frame 44 and fixed thereto, a motor 57 is arranged, provided with a respective motor-reducer, from which the two ends of a shaft 58 extend. Two pinions 61, both suitable for engaging a respective rack 59, are fixed at the two ends of the shaft 58. The racks 59 are connected to the supporting means 17a which, therefore, are transferred in longitudinal direction while the pinions 58 are operated. The supporting means 17a is provided with profiled elements 60 arranged for sliding on a plurality of rollers 62 and suitable for promoting the transferring of the supporting means 17a. The rollers 62 are freely rotatable around pins firmly to a pair of flanges 64 fixed to the frame 44. The feeding means 17, therefore, may deposit the ceramic powders into the preparing and storing means 13 so as to obtain a soft cushion 80 having streaks 81 arranged according to any three-dimensional orientation, since the movement of the feeding means 17 is controlled along two mutually perpendicular axes . This allows to obtain a soft cushion 80 showing streaks similar to an equivalent block of natural stone and therefore any single tile obtained from the material extracted by the containing means 10 and deposited into the cavities 4 of the press 1 has an original streak which is different from the streak of other tiles.

With reference to Figures 10 to 12, there are shown the operations forming a pressing cycle and the respective feeding operations of the press. In Figure 10 a just pressed ceramic tile 65 is shown supported on the die 3 at the height of the feeding plane of the press 1. The trolley means 9 is in the rear loading position so that the containing means 10, which is empty, is at the preparing and storing means 13. The lamina means 29 closes the bottom of the containing means 10, whereas the closing means 15 prevents the powders from falling from the preparing and storing means .13. As shown in Figure 11, when the closing means 15 is moved back, since the trolley means 9 is still in its rear loading position, the containing means 10 is filled with a layer of powders maintaining the streaks 81 originated by the feeding means 17.

At a next stage, as shown in Figure 12, the closing means 15 is brought again in the position in which said closing means 15 prevents the powders from being transferred and the trolley means 9 is advanced up to the unloading position, providing in this way to discharge the formed tile 65.

Once the trolley means 9 have completely advanced, the containing means 10 is positioned at the cavities 4 of the press 1 into which the ceramic powders are introduced when the lamina means 29 is moved back.

Since during the movement of the trolley means 9 the lamina means 29 provided to seal the bottom of the containing means 10, the ceramic particles have not been subjected to sliding with respect to fixed portions of the die 3 and therefore no distortion of the streaks forming the decoration took place: the layer of ceramic material is introduced into the cavities 4 of the press 1 in the same condition in which the ceramic material has been extracted from the preparing and storing means 13. With reference to Figure 13, a preferred version of an apparatus 7 according to the invention is shown. The feeding apparatus 7 comprises a supporting frame 8 associated to trolley means 9 provided with containing means for containing the powders 10. ^{■ '} The trolley means 9 is movable in a longitudinal direction between a loading position, in which the containing means 10 is fed with the ceramic powders and an unloading position in which the containing means 10 transfers the ceramic powders contained therein into the cavities 4.

The trolley means ^'9 is transferred, by sliding on a plane substantially parallel to the loading plane of the die 3, from said loading position to said unloading position through belt means 110 having a branch fixed to said trolley means 9, the above mentioned belt means being arranged between respective first pulley means 113 and second pulley means 114. The first pulley means is rotated by a motor 112 arranged for translating with reciprocating motion the branch 111. In such case, however, no preparing and storing means is provided, but the feeding means 17 deposits the ceramic powders directly into the containing means 10.

The feeding means 17, therefore, may deposit the ceramic powders into the containing means 10 so as to obtain a soft cushion having streaks arranged according to any three- dimensional orientation, since the movement of the feeding means 17 is controlled along two mutually perpendicular axes. With reference to Figure 14, a variation of the apparatus 7 is shown comprising, a hopper 90 arranged for receiving further ceramic powders deposited thereinto by duct means 91, said hopper 90 being positioned so as to be interposed between the press 1 and the feeding means 17. The hopper 90 is closed at the bottom by a further shutter 92 operated by a respective further actuator 93. In this way, during the return stroke of the trolley means 9, the containing means 10 is filled with a first layer comprising the further ceramic powders extracted from the hopper 90- by the further shutter 92. When the trolley means 9 reaches the rear loading position the feeding means 17 deposits on the first layer comprising the further ceramic powders a second layer of ceramic powders arranged in three-dimensional way according to a pre-established pattern so as to decorate the tile to be formed.

The hopper 90 may be filled with ceramic powders of various colours, deposited according to a pre-established sequence for obtaining a controlled stratification. In this way, very valuable tiles may be obtained by placing on a layer consisting of powders of different colours, variously mixed, a further layer comprising, for example powders of- still further colours or granules or flakes of ceramic material arranged according to a three-dimensional pattern.

Otherwise, the hopper 90 may be filled with ceramic powders without any particular aesthetic value, in this case the apparatus allows to obtain a feeding system for feeding a ceramic press 1 with which it is possible to carry out a double loading of the containing means 10, obtaining a product aesthetically valuable at a reduced cost, since a layer of material, comprising for example granules or flakes or coloured ceramic powders, suitable for providing the finished product with valuable aesthetic properties, may be placed on a layer of ceramic powders of low value.

With reference to Figure 15, a variation of the apparatus 7 is shown in which the feeding means 17 is interposed between the press 1 and the hopper 90 described with reference to Figure 2. In this case, in a middle position of the return stroke of the trolley means 9, the containing means 10 is filled with a layer comprising the ceramic powders deposited according to a prefixed pattern of the feeding means 17. Afterwards, during the last part of the return stroke of the trolley means 9, a second layer consisting of . the further ceramic powders extracted from the hopper 90 is placed on said first layer.

The typologies of product so obtained are substantially analogous to those described with reference to Figure 14. The arrangement of the press 1, the feeding means 17 and the hopper 90 may change, according to the teaching of Figure 14 or Figure 15, depending on the chosen modalities of pressing, and in particular on the base of the positioning on the movable top plate of the press 1 of the punches defining the visible face of the tile to be formed, or the punches defining the rear face of said tile.

With reference to Figures 16 and 17, another preferred version of the apparatus 7 according to the invention provided with further feeding means 130 is shown. The further feeding means 130 is provided with hopper means 131, comprising a first hopper 131a and a second hopper 131b facing to each other, fixed to the moving means 20 and provided with distributing openings 132 closed by shutter 133 controlled by respective actuators 134. The hopper means 131 is suitable for containing ceramic powders arranged for forming a base body of a tile to be formed, said base body being suitable for receiving further decorating ceramic powders as described in the following. The further feeding means 130 comprises, in a portion thereof located between the first hopper 131a and the second hopper 131b, distributing means 135 for distributing said decorating powders, such decorating powders being extracted from storage means, such as silos, not shown. The distributing means 135 comprises a plurality of distributing ducts 136, each of said ducts 136 being arranged for supplying decorating powders of various typologies, for example decorating powders of various colours and/or size. The portions 137 of the ducts 136 farther from the above mentioned storage means, i.e. the portions at which the decorating powders are supplied, are connected to a supporting disc 138 fixed to a rod 139 of an actuating cylinder 140 which controls the vertical translation of the supporting disc 138.

A respective regulating device is associated to each of the

^' portions 137, the regulating device being arranged for controlling the discharge of the powders from the duct means 136 and allowing such discharge only at the desired moment. Perturbing means 170 is further associated to each of the ducts 136, at the respective portions 137 (Figure 22), said perturbing means 170 being fixed to the supporting disc 138 and arranged for interacting with the decorating powders deposited by the ducts 136 for generating pleasant aesthetic effects on the tiles to be formed. The perturbing means 170 may comprise, for example, wedge means 171 or brush means 172, whose sharp end 173 or whose bristles 174, respectively, are suitable for being partially inserted under the surface of the layer 158.

During working of the apparatus 7, the further feeding means 130 is positioned over the containing means 10, which is in the loading rear position, then, after the moving means 20 has been transferred, the hopper means 131 deposits into said containing means 10 a layer of ceramic powders. Such ceramic powders, being suitable for forming a base body of tile, may comprise aesthetically less valuable materials. Then, the further feeding means 130- is translated along two mutually perpendicular axes, so that the ducts 136 distribute the decorating powders, originating a prefixed ornamental pattern. Before the decorating powders are deposited on the underlying layer 158 of ceramic powders, the perturbing means 170 generate in said layer 158 a plurality of grooves, into which the

^• decorating powders penetrate for generating decorations in the tile to be formed, such as veins and/or streaks, extending substantially in the whole mass of the powders. Otherwise, the powders may be deposited on the underlying layer 158 and subsequently the perturbing means 170 may spread the powders inside said layer 158 for creating aesthetic effects which reproduce, for example, the veins of the natural stones. With reference to Figures 18 to 21,' a further preferred version of the apparatus 7 according to the invention is shown, provided with still further feeding means 141 comprising a plurality of distributors 142 of decorating ceramic powders. The distributors 142 are associated to a supporting plate 143 firmly fixed to a vertical member 144 of the supporting means 17a: in this way, therefore, the distributors 142 may be moved along two mutually orthogonal directions for defining pre- established ornamental patterns on tiles to be formed. The distributors 142 comprise a body 145 provided with a first end region 146 connected to tubes 19 arranged for transferring the decorating powders toward the distributors 142, and a second end region 147 provided, on one side of the body 145, with a distributing opening 148 and, on a further side of the body 145 opposite to said one side, with an inclined wall 149 arranged for directing the decorating powders toward the opening 148.

A gate valve 150 , controlled by a respective actuator 151 and suitable for controlling the discharge of coloured powders from the respective distributor 142 is associated to each opening 148.

The distributors 142 are fixed to a supporting plate 138 vertically translated by a rod 139 of an actuating cylinder 140 connected to the supporting plate 143. The apparatus 7 further comprises belt means 152 rotatably supported, through a pair of rollers 153, 154, one of which otorised,- to the frame 8 of said apparatus 7.

The belt means 152 is arranged so as to stand over the containing means 10 when the latter is in the rear loading position: in this way, the belt means 152 is suitable for receiving the decorating powders deposited thereon by the distributors 142 and for introducing said decorating powders into the containing means 10 when said containing means 10 is transferred from said rear loading position to the forward unloading position. When the decorating powders are deposited by the distributors 142, the belt means 152 is kept stationary in a rest position, then the belt means 152 is rotated in for transferring said decorating powders into the containing means 10. The apparatus further comprises container means 155 arranged for receiving ceramic powders suitable forming a base body of the tiles to be formed. The container means 155 comprises a feeding section 156 through which collector means 156a introduces said ceramic powders and a distributing section 157 through which the ceramic powders are deposited on the underlying belt means 152 so as to form a layer 158. During working, while the belt means 152 advances in the direction indicated by the arrow F, the containing means deposits on said containing means 152 the layer 158. Then, the belt means is stopped and the distributors 142 are lowered by means of the actuating cylinder 140 up to partially penetrate into the layer 158 and to deposit into said layer 158 the decorating powders generating ornamental patterns, such as veins and/or streaks which extend through the whole thickness of the tile to be formed.

Once said ornamental patterns have been obtained, the distributors 142 are raised again for being brought in a noninterference position with the layer 158. Then, the belt means 152 is rotated again so as to pour the layer 158 and the decorating powders inserted therein, into the containing means 10. For that purpose, the containing means 10 is translated in the direction approaching to. the press 1 at a speed synchronised with the rotation speed of the belt means 152. The apparatus further comprises positioning means 159 arranged for keeping the layer 158 and the decorating powders inserted therein in the proper respective position while the containing means 10 is transferred and for allowing said containing means 10 to be cleared in a proper and homogeneous manner. The positioning means 159 comprises a sheet 160 arranged for closing the upper opening of the containing means 10, substantially preventing the powders from mixing and the ornamental patterns previously obtained from losing of definition. The sheet 160 comprises a first end portion- 161 hinged to the trolley means 9 of the apparatus 7 and a further portion connected to a pin 162 slidably coupled with a guide 163 having a shaped profile. The cavities 4 of the press 1 are fed with the modalities described hereinafter.

The upper opening of the containing means 10 containing the layer 158 of the base powders and the decorating powders inserted therein is closed by the positioning means 159, then the containing means 10 is transferred to the cavities 4 of the press 1.

At this point of the working cycle, the lower punches of said press 1 are in raised position and therefore at the same vertical height of the main plate of the mould of the press 1. Subsequently, the lamina means 29 which closes the lower opening of the containing means 10 is retracted so allowing the discharge of the ceramic powders.

Once the lower opening has been completely cleared by the lamina means 29, the lower punches are lowered so as said ceramic powders are received into the cavities 4 downwardly delimited by said lower punches. The sequence of operations now described substantially prevents the ceramic powders from possible remixing, said remixing may cause loss of definition of the ornamental patterns which have be reproduced in _ the tiles to be formed. The presence of the positioning means 159 allows the cavities 4 to be filled in homogeneous way, whereas, in absence of such positioning means 159, when the lamina means 29 is moved, a partial shifting of the powders 9 would take place: in- particular, the powders, due to the friction, would be inclined to follow the lamina means 29 during the movement thereof, generating a non-uniform distribution and in particular mounds of material in the portion of the cavity 4 closer to the apparatus 7 and sags in the portion of the cavity 4 farther from the apparatus 7. Pressing means made of soft material and arranged for applying a strong and at the same time delicate pressure on the layer 158 and the decorating ceramic powders introduced therein may be associated to the sheet 160. Advantageously, such pressing means may comprise cushion means made of foam rubber.

Once the cavities 4 has been completely filled, the trolley means 9 is retracted and the sheet 160, driven by the pin 162, clears the upper opening of the containing means 10 making said containing means 10 ready for a new cycle. The trolley means 9 is retracted when the lamina means 29 is lies in a position of partial opening for allowing the possible particles of ceramic powders which have not been introduced into the cavities 4 to- be ejected and transferred into a suitable collecting device: in this way, particles of powder are substantially prevented from remaining in the containing means 10, so contaminating the tiles to be formed in the following pressing cycle.

Similarly to what described with reference to Figures 16 and- 17, perturbing means 170 is associated to the still further feeding means 141.

In this case, during working, the distributors 142 are constantly kept raised so as to do not come in contact with the layer 158 while said distributors 142 deposit on said layer 158 the decorating powders . The devices and the components disclosed in the preceding description may be object of separate inventions, both considered singularly and in any possible combination thereof.

Claims

1. Loading apparatus for loading a ceramic press (1) comprising trolley means (9) movable between a loading position and an unloading position and suitable for transferring ceramic powders to cavities (4) of a mould of said press (1), preparing means (10; 13; 152) suitable for receiving said ceramic powders before said ceramic powders are introduced into said cavities (4), feeding means (17; 130; 141) suitable for depositing said ceramic powders into said preparing means (10; 13;

152), characterised in that said feeding means (17; 130; 141) is associated to moving means (20) controlled on two orthogonal axes and such to allow said ceramic powders to be deposited into said preparing means (10; 13; 152) so as to form a soft cushion (80) provided with three-dimensionally extending regions of different types of powder.

2. Apparatus according to claim 1, wherein said moving means (20) comprises supporting means (17a) for supporting said feeding means (17; 130, 141) movable along the advancing direction of said trolley means (9) and frame means (44) suitable for containing said supporting means (17a) and movable transversally with respect to the advancing direction of said trolley means (9) .

3. Apparatus according to claim 2, wherein said frame means (44) comprises a plurality of rolling elements

(59, 50, 51, 52, 53) slidably^' coupled with respective guide means (45, 46, 47, 48) fixed to a frame (8) of said apparatus (7) .

4. Apparatus according to claim 3, wherein said frame means (44) is fixed to a branch of belt means (56) actuated by drive means (54, 55) and suitable for allowing a reciprocating rectilinear movement of said frame means (44) along said guide means (45, 46, 47, 48) .

5. Apparatus according to claim 4, wherein said supporting means (17a) is connected with rack means (59) engaging pinion means (61) actuated by a moving unit (56, 57, 58) contained inside said frame means (44) .

6. Apparatus according to any one of claims 1 to 5, wherein said feeding means (17) comprises a plurality of tube means (19), each of said tube means (19) being arranged for distributing a ceramic powder of a prefixed type.

7. Apparatus according to claim 6, wherein said tube means

(19) is downwardly provided with shutters (39) operated by actuators (40) and suitable for controlling the discharge of said ceramic powders from said tube means (19) .

8. Apparatus according to claim 6, or 7, wherein said tube means (19) converges into funnel means (18) arranged for distributing said ceramic powders on said preparing means (10; 13; 152) .

9. Apparatus according to any one of claims 6 to 8, and further comprising storing means (90) for storing further ceramic powders arranged for forming a base body of a tile to be formed.

10. Apparatus according to claim 9, wherein said storing means (90) comprises releasing means (93, 94) arranged for upwardly or downwardly releasing said further ceramic powders into said preparing means (10; 13; 152) with respect to said ceramic powders.

11. Apparatus according to claim 9, or 10, wherein said storing means (90) is interposed between said press (1) and. said feeding means (17) .

12. Apparatus according to claim 9, or 10, wherein said feeding means (17) is interposed between said press (1) and said storing means (90) .

13. Apparatus according to any one of claims 1 to 5, wherein said feeding means (130) comprises hopper means

(131) arranged for depositing into said preparing means (10; 13; 152) a layer (158) of further ceramic powders arranged for forming a base body of a tile to be formed.

14. Apparatus according to claim 13, wherein said hopper means (131) is connected to said moving means (20) .

15. Apparatus according to claim 13, or 14, wherein said hopper means (131) comprises a first hopper (131a) and a second hopper (131b) arranged mutually facing.

16. Apparatus according to any one of claims 13 to 15, wherein said feeding means (130) comprises distributing means (135) suitable for distributing said ceramic powders into said layer (158) .

17. Apparatus according to claim 16, wherein said distributing means (135) comprises a plurality of distributing duct means (136), each of said distributing duct means (136) being suitable for distributing a ceramic powder of a prefixed type.

18. Apparatus according to claim 16, or 17, wherein distributing slots (137) of said distributing duct means (136) are connected with supporting disc means (138) fixed to a rod (139) of an actuating cylinder

(140) which controls the vertical translation of said supporting disc means (138) .

19. Apparatus according to any one of claims 1 a 5, wherein said feeding means (141) comprises pouring means (142) for pouring said ceramic powders.

20. Apparatus according to claim 19, wherein said pouring .means (142) is associated to supporting plate means

(143)^' fixed to said supporting means (17a) .

21. Apparatus according to claim 19, or 20, wherein said pouring means (142) comprises a body (145) provided with a first end region (146) connected with tubes (19) arranged for transferring said ceramic powders toward said pouring means (142) , and a second end region (147) provided with a distributing opening (148) .

22. Apparatus according to claim 21, wherein said distributing opening (148) is obtained in one side of said body (145) .

23. Apparatus according to claim 22, wherein said pouring means (142) is provided, in a further side of said body

(145), opposite to said one side, with an inclined wall (149) arranged for directing said ceramic powders towards said distributing opening (148) .

24. Apparatus according to any one of claims 21 to 23, wherein gate valve means (150) controlled by respective actuating means (151) is associated to said distributing opening (148).

25. Apparatus according to any one of claims 20 to 24, wherein said pouring means (142) is fixed to supporting disc means (138) vertically translated by a rod (139) of an actuating cylinder (140) fixed to said supporting plate means (143) .

26. Apparatus according to any one of claims 19 to 25, and further comprising container means (155) arranged for depositing into said preparing means (10; 13; 152) further ceramic powders suitable for forming a base body of a tile to be formed.

27. Apparatus according to claim 26, wherein said container means (155) comprises a feeding section (156) through which collecting means (156a) introduces said further ceramic powders into said container means (155) .

28. Apparatus according to claim 26, or 27, wherein said container means (155) comprises a distributing section (157) through which said further ceramic powders are deposited on said preparing means (10; 13; 152) for forming a layer (158) .

29. Apparatus according to any one of claims 13 to 28, wherein perturbing means (170) arranged for interacting with said ceramic powders for generating pleasant aesthetic effects in a tile to be formed is associated to said feeding means (130; 141).

30. Apparatus according to claim 29 as appended to any one of claims 13 to 18 or to claim 28, wherein said perturbing means (170) is suitable for carrying out in said layer (158) grooves arranged for receiving said ceramic powders .

31. Apparatus according to claim 29, or 30, as appended to any one of claims 13 to 18 or to claim 28, wherein said perturbing means (170) is suitable for spreading inside said layer (158) said ceramic powders previously deposited on an upper face of said layer (158) .

32. Apparatus according to any one of claims 29 to 31, wherein said distributing means (170) comprises wedge means (171) provided with a sharp end (173) suitable for being partially inserted under the surface of said layer (158) .

33. Apparatus according to any one of claims 29 to 31, wherein said perturbing_, means (170) comprises brush means (172) provided with bristles (174) suitable for being partially inserted under the surface of said layer (158) .

34. Apparatus according to any one of the preceding claims, wherein said preparing means (10; 13; 152) comprises containing means (10) obtained in said trolley means (9) .

35. Apparatus according to any of claims 1 to 33, wherein said preparing means (10; 13; 152) comprises preparing and storing means (13) arranged above containing means (10) obtained in said trolley means (9) .

36. Apparatus according to claim 35, wherein said containing means (10) has a longitudinal plan dimension equal to the dimension of said preparing and storing means (13) .

37. Apparatus according to claim 35, or 36, wherein said preparing and storing means (13) is downwardly provided with closing means (15) movable between an opening position in which said closing means (15) allows said ceramic powders to be transferred from said preparing and storing means (13) to said containing means (10) and a closing position in which said closing means (15) prevents said ceramic powders from being transferred from said preparing and storing means (13) to said containing means (10) .

38. Apparatus according to claim 37, wherein said closing means (15) is fixed to rack means (25) coupled with respective gearwheel means (24) and suitable for allowing said closing means (15) to be transferred from said opening position to said closing position.

39. Apparatus according to any one of claims 1 to 33, wherein said preparing means (10; 13; 152) comprises belt means (152) arranged above containing means (10) obtained in said trolley means .(9) .

40. Apparatus according to claim 39, wherein said belt means (152) is rotatably supported to frame means (8) of said apparatus (7) .

41. Apparatus according to claim 39, or 40, wherein said belt means (152) is suitable for receiving said ceramic powders from said feeding means (17; 130; 141) and for introducing said ceramic powders into said containing means (10) .

42. Apparatus according to claim 40, or 41, wherein said belt means (152) is rotated at a speed synchronised with the translation speed of said containing means (10) .

43. Apparatus according to any one of claims 34 to 42, wherein said containing means (10) is downwardly provided with lamina means (29) movable between an opening position in which said lamina means (29) allows said ceramic powders to be transferred from said containing means (10) to said cavities (4) and a closing position in which said lamina means (29) prevents said ceramic powders from being transferred from said containing means (10) to said cavities (4) .

44. Apparatus according to claim 43, wherein said lamina means (29) is fixed to further rack means (33) coupled with further gearwheel means (32) and suitable for allowing said lamina means (29) to be transferred from said opening position to said closing position.

45. Apparatus according to any one of claims 34 to 44, and further comprising positioning means (159) suitable for closing an upper opening of said containing means (10) .

46. Apparatus according to claim 45, wherein said positioning means (159) comprises sheet means (160) provided with a first end portion (161) hinged to said trolley means (9) and a further portion connected to pin means (162) slidably coupled with guide means (163) having a shaped profile.

47. Method for loading a ceramic press (1) comprising depositing ceramic powders into preparing means (10; 13; 141) , introducing said ceramic powders into cavities (4) of a mould of said press (1) through trolley means (9) movable between a rear loading position and a forward unloading position, characterised in that said depositing comprises controlling on two orthogonal axes the movement of feeding means (17; 130; 141) for arranging said ceramic powders in said preparing means (10; 13; 152) so as to form a soft cushion (80) provided with three- dimensionally extending regions of different types of powder.

48. Method according to claim 47, wherein said arranging comprises pouring said ceramic powders into containing means (10) obtained in said trolley means (9) .

49. Method according to claim 47, wherein said arranging comprises pouring said ceramic powders into preparing and storing means (13) arranged above said trolley means (9) .

50. Method according to claim 49, wherein after said pouring there is provided extracting said ceramic powders from said preparing and storing means (13) through said containing means (10) .

51. Method according to claim 50, wherein said extracting comprises moving closing means (15) downwardly associated to said preparing and storing means (13) from a closing position in which said closing means (15) prevents said ceramic powders from being transferred from said preparing and storing means (13) to said containing means (10) to an opening position in which said closing means (15) allows said ceramic powders to be transferred from said preparing and storing means (13) to said containing means (10) .

52. Method according to claim 47, wherein said arranging comprises pouring said ceramic powders on belt means (152) arranged above containing means (10) obtained in said trolley means (9) .

53. Method according to claim 52, wherein after said pouring there is provided rotating said belt means

(152) for transferring said ceramic powders from said belt means (152) to said containing means (10) .

54. Method according to claim 53, wherein during said rotating there is provided translating said containing means (10) at a speed synchronised with the rotation speed of said belt means (152) .

55. Method according to any one of claims 48 to 54, wherein said introducing comprises transferring lamina means

(29) downwardly associated to said containing means (10) from a closing position in which said lamina means (29) prevents said ceramic powders from being distributed from said containing means (10) into said cavities (4) to an opening position in which said lamina means (29) allows said ceramic powders to be distributed from said containing means (10) into said cavities (4) .

56. Method according to any one of claims 47 to 55, wherein after said arranging there is provided placing into said preparing means (10; 13; 152) a layer (158) of further ceramic powders suitable for forming a base body of a tile to be formed.

57. Method according to any one of claims 47 to 55, wherein before said arranging there is provided placing into said preparing means (10; 13; 152) a layer (158) of further ceramic powders suitable for forming a base body of a tile to be formed.

58. Method according to claim 57, wherein said placing comprises partially inserting ends of said distributing means (17; 130; 141) into said layer (158) .

59. Method according to claim 57, wherein before said placing there is provided obtaining in said layer

(158), by means of perturbing means (170), grooves arranged for receiving said ceramic powders.

60. Method according to claim 57, wherein after said placing there is provided spreading said ceramic powders inside said layer (158) .by means of perturbing means (170) .

61. Method according to any one of claims 47 to 60, wherein, during said pouring, there is provided keeping said ceramic powders through positioning means (159) associated to said containing means (10) .

62. Method according to claim 61, wherein said keeping comprises closing an upper opening of said containing means (10) through sheet means (160) of said positioning means (159) .