Apparatus for producing tiles from cementitious mixes

Abstract

 An apparatus for producing tiles or the like from cementitious mixes, comprising a mould bounded by a base grid (4) and a frame (6) superposed thereon, and towards and into which the free end of a punch (9) operated by a press can be inserted and moved to compress and shape a mass of cementitious mix (8) present in the mould, in that region in which said punch (9) is inserted into the mould there being provided members (11,14) for drawing away the liquid which seeps between the punch and the mould during the pressing of the cementitious mix.

Description

[0001] The present invention relates to an improved apparatus for producing tiles or other articles from cementitious mixes.

[0002] Apparatus for preparing and shaping cementitious mixes to form tiles or other articles of different shapes and thicknesses have been known for some time and have been the subject of very many patents such as French Patent 2117398, Italian Patents 1023789 and 1786883 and European Patent Application EP-A-0893219.

[0003] The known apparatus comprise a mould for receiving a metered mass of cementitious mix and a punch for compressing this mix into the mould. In its turn, the mould comprises a rigid frame and a grid presenting a large number of holes with their diameter gradually increasing downwards and communicating with drainage channels for the liquid which passes through said holes when each tile is formed. The rigid frame is rested on said grid and defines with it a cavity (open upwards) into which metered quantities of cementitious mix are fed to form individual tiles.
Directly above the mould there is positioned a punch operable by a press and movable between a position in which it is raised away from said rigid frame and, respectively, a position in which the free end of the punch penetrates into the aperture in the rigid frame to compress the cementitious mix present in it.

[0004] During the compression of the cementitious mix a large part of the liquid contained in it is drained through the holes of the mould grid, however a part of the liquid escapes under pressure between the opposing surfaces of the mould frame and of the press punch.

[0005] As this liquid which seeps between the mould and the punch contains cement and granules of inert material powder, to maintain the apparatus fully operational the mould and punch are frequently cleaned and it is sought to remove this liquid by providing in the punches a plurality of holes having one end opening at the outer surface of that portion of the punch which penetrates into the mould at the moment of compressing the cementitious mix. The other end of these holes is connected to a suction source (see European Patent Application EP-A-0893219) which should eliminate the negative consequences of the seepage of liquid from the mould. The air which is drawn through these holes on compression of the cementitious mix does not however prevent the liquid escaping to the outside between the surfaces of the punch and mould.

[0006] Moreover the air drawn through the holes provided in the punch described in the aforesaid patent application would very rapidly render the apparatus ineffective because the solid particles present in the liquid which seeps through would block the holes provided in the punch.

[0007] The main object of the present invention is therefore to provide an apparatus for producing tiles from cementitious mixes, in which the liquid which seeps between the mould and punch during compression of the mixes is withdrawn and removed effectively from the apparatus.

[0008] Another object is to form the apparatus in such a manner that the withdrawal and removal of the liquid take place via conduits or channels which can be easily inspected and cleaned to prevent them becoming blocked.

[0009] These and further objects are attained by an apparatus comprising a mould and a punch movable relative to the mould, in which the mould comprises both a base grid superposed on drainage channels and a frame superposed on said grid and defining therewith a cavity for housing and retaining a mass of cementitious mix, the punch having one end at least partially insertable into the frame cavity to compress said cementitious mix into the mould and form a tile, characterised in that in that region of the mould into which said end of the punch is insertable there are provided members for drawing away the liquid which seeps between the punch and the mould during the pressing of the cementitious mix.

[0010] Preferably said members comprise a plurality of channels, of which one end opens at that edge of the mould frame facing said cavity and the other end is connected to a vacuum or suction pump.

[0011] Again preferably, said channels are formed in an annular rigid body which is superposed on said frame and is connected to mechanical members arranged to raise said body away from the frame and respectively to rest it and to press it thereon.

[0012] Advantageously, said annular rigid body is formed by connecting together several rigid body parts in a manner mutually separable to enable the channels provided within them to be cleaned.

[0013] Finally, it has been found particularly useful to elastically connect the annular rigid body to said punch, in such a manner as to be translatable with and relative to it.

[0014] In order to clarify the understanding of the structure and characteristics of the apparatus according to the invention, one embodiment thereof is described hereinafter by way of non-limiting example with reference to the accompanying drawing in which:

Figure 1

is a schematic vertical longitudinal section through the apparatus, with the punch raised above the mould; and

Figure 2

is similar to Figure 1 but with the punch in its position lowered onto the mould.

[0015] The apparatus for producing tiles shown in the figures comprises a mould and a pressing punch which are superposed and movable one relative to the other.

[0016] The mould in its turn comprises a rigid base plate 1 in which there are provided a plurality of drainage channels 2 having their bottom inclined to cause the liquids collected in them to flow towards discharge pipes 3. On the plate 1 there rests a base grid 4 formed from one or more plates presenting a plurality of holes (shown only in the left side of the figures, in section) on which there rests a mesh or cloth 5.

[0017] On said mesh there is a rigid frame 6 which rests on and seals against an annular gasket 7. The frame 6 is traversed by an aperture which is bounded lowerly by the perforated grid 4 and the mesh 5, to form with them a cavity arranged to house and retain a mass of cementitious mix 8, of the type used to form tiles.

[0018] Above the aperture of the frame 6 there is a pressing punch 9 connected to a movable piston 10 of a press. The shape and size of the lower (with reference to the drawing) part of the punch 9 is such that it can penetrate (with the smallest possible clearance) into the cavity of the frame 6 to compress the mass of cementitious mix 8, as shown in Figure 2.

[0019] The structure and operation of the aforedescribed apparatus can be of known type, for example as represented in the prior patents cited in the introduction to the preceding description. They will therefore not be discussed in greater detail, for simplicity.

[0020] It will merely be stated that in the embodiment shown in the accompanying drawings, in the punch 9 there are small channels 11 having one end opening into the lower peripheral surface of the punch and their other end connectable to a vacuum pump or suction source, or to a compressed air source (as described in the aforestated European Patent Application EP-A-0893219) for the purpose of removing the water which seeps between the punch and mould frame during the pressing of the cementitious mix 8. To facilitate removal of the drainage water flowing into the channels 2 of the plate 1, that end of these channels distant from that at which the discharge pipes 3 are provided can be connected, via holes 12, to a compressed air source that facilitates removal of any solid material deposits which may collect in the drainage channels 2.

[0021] Notwithstanding the use of all the aforedescribed expedients it has however been noted that part of the liquid expelled from the cementitious mix 8 seeps between the punch 9 and the frame 6, with serious consequences which are easily understandable when considering that this liquid drags with it cement particles and solid particles of various types which are of abrasive character and tend to form hard, difficultly removable incrustations on the outside of the frame and deteriorate the outer appearance of the tile.

[0022] The main object of the apparatus of the present invention is precisely to eliminate the aforesaid drawback.

[0023] To this end, as seen from the drawings, above the frame 6 and totally surrounding the punch 9 there is provided a rigid ring 13 the lower surface of which is shaped such that the ring 13 defines with the upper surface of the frame 6 (when the ring rests on the frame, as shown in Figure 2) an annular chamber 14 open towards the lateral surface of the punch 9 and connected via conduits 15 to a suction pump or the like (not shown) which draws away all the liquid which can seek between the punch and the mould frame.

[0024] Preferably, as in the example shown in the drawings, the ring 13 is secured to the punch 9 by springs 16 or the like which enable the ring to translate axially relative to the punch.

[0025] When at rest (Figure 1) the ring 13 is positioned such that it comes into contact with the adjacent surface of the mould frame 6 before the punch begins to compress the mass 8 of cementitious mix. While the punch continues its descending travel, the ring remains strongly pressing against the frame 6, to compress the springs 16.

[0026] Air suction through the conduits 15 and the chamber 14 commences as soon as the punch 9 begins to penetrate into the mould, and ceases on termination of the pressing operation, when the punch is raised away from the mould (Figure 1).

[0027] Advantageously, the ring 13 is formed from two or more rings or ring segments connected together in a manner which enables them to be easily and quickly separated, to allow easy access to all the conduits provided in the ring and hence simplify to a maximum the cleaning of the conduits to remove any deposits or incrustations formed in them.

Claims

1. An apparatus for producing tiles or the like from cementitious mixes, comprising a mould and a punch movable relative to the mould, in which the mould comprises both a base grid superposed on drainage channels and a frame superposed on said grid and defining therewith a cavity for housing and retaining a mass of cementitious mix, the punch having one end at least partially insertable into the frame cavity to compress said cementitious mix into the mould and form a tile, characterised in that in that region of the mould into which said end of the punch is insertable there are provided members for drawing away the liquid which seeps between the punch and the mould during the pressing of the cementitious mix.

2. An apparatus as claimed in claim 1, characterised in that said members comprise a plurality of channels, of which one end opens at that edge of the mould frame facing said cavity and the other end is connected to a suction pump.

3. An apparatus as claimed in claims 1 and 2, characterised in that said channels are formed in a annular rigid body which is superposed on said frame and is connected to mechanical members arranged to raise said body away from the frame and respectively to rest it and to press it thereon.

4. An apparatus as claimed in claims from 1 to 3, characterised in that the annular rigid body is formed by connecting together several rigid body parts such that they can be separated from each other to enable the channels provided within them to be cleaned.

Drawing