"MIRROR-LIKE DIE FOR MAKING CERAMIC TILES WITH SPACERS,THE TILE BEING PLACED WITH ITS EXPOSED SURFACE^UPWARDS Present state of the art Ceramic tiles are generally made in dies of a certai _iape to ^" be put into special hydraulic or other types of presses. When working the controls of the press the dies are opeiεd, loaded with clay or other material and then closed again to produce, ^" by means of suitable pressure and heating, a tile of the chosen shape.

Tiles are generally of two kinds:

- with spacers,

- without spacers.

These spacers are very slight lateral projections, of a few tenths of a mm, rising from the ^" base of the tile up to about half its thickness and is there for functional, pro _, tective and aesthetic purposes all at once. The die is usually made of two main parts, the upper and the lower, one opposing the other, each part consisting of a shaped plug, one shaped for one side of the tile and the other shaped for the other side, placed within a flame called a matrix.

The upper die also has a part called a block fitting at the back against the plug for supporting and moving it, generally fixed to the plug and to the matrix.

If the tile is made with its "finished" surface, namely the one that will show when the tile is mounted, upper¬ most, the upper plug will be shaped to make said finished surface, and the lower plug will be shaped to make the back of the tile. When pressing is finished and the die is opened, the tile must be extracted generally done by ma¬ king the lower plug rise till the tile is out of 1he lower

matrix.

Where there are spacers, to enable the tile to be extrac- ted its wider part, namely the part where there are the spacers, must be uppermost and therefore the "finished" surface must be downwards as otherwise, since extraction is done by movement of the lower plug, said extraction would be hindered by that part of the matrix correspond¬ ing to the part over said spacers. Unfortunately, placing the tile with its "finished" sur- face downwards leads to several drawbacks.

When the tile is being extracted from the lower plug to T placed in boxes, especially if transfer of the tile js mack at the same level, when being slid along, the finished sur fact of the tile, under its own weight, may become marked or scratched or similarly damaged.

There is also the risk of roughening, actually on the fi¬ nished surface itself, due to pressure and movements; the force of gravity, then, means that many impurities which are heavier or, in any case, heterogeneous to the mixture, tend to sink down through the clay to the bottom and thus reach the finished surface.

On the whole, therefore, the finished surface is often da¬ maged which means a great many rejected tiles, or at any rate tiles which are imperfect or defective. In dies made to have the finished aurface upwards, these difficulties do not arise but it means doing without spa¬ cers and having to face the consequences of this. The subject invention makes it possible to produce tiles with spacers and with the finished surface placed upper- most in the die as will be explained below.

Description of the Invention

Subject of the invention is a mirror-like die for shaping ceramic tiles with spacers.

The upper plug is shaped to correspond with the upper fi- nished surface of the tile.

The sides of the upper matrix are shaped , starting from its edge, to correspond with the short sides of the upper part of the tile or, in other words, with that part which from the upper surface extends downwards to where the spa- cers begin to project.

The upper plug is mobile in relation to the matrix for a distance at least equal to the thickness of the upper part of the tile. The lower plug is shaped to correspond with the back sur- face of the tile.

The sides of a lower matrix are shaped, starting from its edge, to correspond with the short sides of the lowerpart of the tile or, in other words, with that part which from the back surface extends upwards for the whole height of the spacers. Said lower plug is mobile in relation to the lower matrix for a distance at least equal to the height of said lower part of the tile. When formed, extraction is done by an outward movement of both plugs in relation to their respective matrixes. By the rising movement of the upper part of the die, including the upper matrix and and upper pl ^* u g, the tile is completely freed and remains resting on its back surface. It is thus possible to extract the tile without scratching it or touching its finished front surface in any way, thus avoiding any harm to it. When out of use the edge of the upper plug is kept prac¬ tically flush with the edge of the upper matrix by an elastic means.

This means gives_way under pressure exerted on said plug by the material of which the tile is made a_jιd, due to the effect of closure of the die, creates in the upper matrix, fixed _. to the biock, the volume corresponding to the upper part of the plate.

When the operation terminates and the upper part of the die rises, _, said elastic means causes the plug to slide in relation to the_ atrix, and externally to the same, and cau ses extraction of the upper part of the tile. In one type of execution the elastic means consists of a Belleville spring placed round a central bolt, and the like, connecting the upper plug to the block. Said bolt allows an amount of play between block and plug equivalent to the movement made by said plug, needed to allow space both for the volume corresponding to the up¬ per part of the plate and for extracting said plate. The characteristics and purposes of the invention will be made even clearer by the following example of its execu¬ tion illustrated by drawings. Example of execution

Fig. 1 Plan view of'the upper block Fig. 2 Cross section of the upper block Fig. 3 Plan view of the upper matrix Fig. 4 Cross section of the upper matrix Fig. 5 Plan view of the upper plug

Fig. 6 Cross section of the upper plug Fig. 7 Cross section of the die when open Fig. 8 Cross section of the die during pressing Fig. 9 Enlarged detail of the cross section of a tile at the moment of pressing

The upper matrix 10 is fixed to the upper block 11 by bolts and the like, lodged in the seats 16, screwed into the

holes 17 in the block.

Said block has a lower recess 18, cylindrical in shape and concentric with the hole 19 made in the centre of the block itself. The upper plug 12 is fixed to the block by a device 40 in¬ cluding the bolt 20 (Fig. 7, 8) lodged in the hole 19, the end 21 of which is screwed into the threaded hole 22 made in the centre of the plug itself. The hexagonal head 23 of the bolt is in contact with the bottom of the upper recess 24 of the block.

Inside the lower recess 18, the pair of Belleville springs 25, 26 and the washer 27 are placed round the bolt 20. The dimensions of the bolt are such that, due to effect of pressure by the springs, the plug when idle appears as in Fig.7 with the lower edge 28 practically flush with the lower edge 29 of the matrix 10.

Between the upper surface 30 of the plug 12 and the oppo¬ sing lower surface 31 of the block 11 there is a remaining space of a height (a") corresponding to the stroke (a) of the plug (Fig.8) during pressing, and therefore correspon¬ ding to height (a') of the upper part 33 of the tile 32 (Fig. 9) which extends to the point where the spacers 35 begin, to project. The lower part of the die comprises the lower matrix 13 inside of which the lower plug 14 can move for a stroke (b) (Figs. 8, 9) corresponding to height (b')of the lower part 34 of the tile supplied with laterally projecting zones 35, called spacers, extending for the whole of the aforesaid height. Said spacers project for the value C (Figs. 8, 9).

Plan dimensions of the lower matrix 13 exceed those of tie upper matrix 10 to the extent of the spacer projections.

The lower surface 36 of the upper plug, mirror-like for making the "finished" face of the tile, is hollowed out to a height (d) joined by the sloping sections 37 to the edge of the tile. At the edges of the upper matrix 10 there is a pair of bevels 38 and 39 joining the spacers 35 to the upper part 33 of the tile. Operation At the start of each working sequence the die appears as shown in Fig. 7.

After the tile material is loaded, the upper part of the die approaches the lower part causing the matrixes 10 and 13 (Fig. 8) to come together and causing formationof the tile 32 by pressure and heating. As Fig. 8 clearly shows, pressure has caused compression of the Belleville springs and mating of the upper surfe.ce 30 of the upper plug 12 with the lower surface 31 of the block 11. Between the two plugs 12 and 14 a space is thus created corresponding to that of the tile 32 and formation ofthe upper part 33 and lower part 34 of said tile. Having completely formed the tile the upper part of the die rises up while simultaneous release of the Belleville springs hold the upper plug, in relation to the tile,in the position seen in Fig. 8 until the lower edge 29 of the matrix 10 has reached the lower edge 28 of the plug (see Fig. 7 as well).

In this way extraction of the upper part 33 of the tile is completed. The upper part of the die continues to rise, removing the upper plug still further from the tile , while the lower plug rises extracting the lower part 34 of 1te tile

with the spacers 35 on it, from the matrix 13 . The tile can therefore be moved to its place of storage. Advantages

The advantages are clear. The tile is made with its finished face uppermost even though it has its spacers.

All the drawbacks caused by friction, contact and blows of one kind and another on the finished face are avoided, these drawbacks occurring when the finished face is laid downwards, and happening to the tile during transfer and storage, so that the finished face lying uppermost dra¬ stically reduces rejects and considerably improves qua¬ lity compared with the usual methods of production. All this achieved by simple and highly reliable means. As applications of the invention have been described as examples only not limited to these it is understood that any equivalent application of the inventive concepts ex¬ plained and any product made and/or operating according to the characteristics of the invention will be covered by its field of protection.