APPARATUS FOR THE PRESSING AND REMOVAL OF PRESS-MADE CEMENT PRODUCTS

Abstract: The apparatus comprises a die with frame (24), a base (30) for closing the frame in its lower part, and a pressing pad able to be introduced into the cavity (24A) of the frame for the pressing; for the formation of through openings within the product (M), there is provided a member (38) with finger(s) (38A, 38B) intended to form said through openings below the base having through openings corresponding to said finger(s); at the beginning of the removal cycle control means (7A, 9, 10) cause a relative displacement between said member and the base for the withdrawal of the finger(s) from the formed piece (M).

Description: The invention refers to the manufacturing of products, like cement tiles or other, having through openings and holes or even recesses only. It relates to a pressing and removal apparatus to be combined with presses for this use and comprises a die with a frame, a bottom i.e. a base for closing the frame in its lower part, and a pressing pad able to be introduced in the frame cavity for the pressing, and means for determining relative displacements between the base, the frame, and a removal pad to allow the removal of the tile onto a shovel which is inserted between the frame and the base when they are spaced one from the other. When it is desired to produce holes, recesses or openings in the tile, this brings about several problems, due to the particular nature of the material used for the production of such article of manufacture. In fact, as well known to the skilled in the art, cement tiles are produced with cement grout, stone fragments and/or sand, together with a limited and dosed quantity of water. When producing the tile, care must be taken in order to avoid loss of water during filling up of the die and pressing. Moreover, the die must be designed in such a way as to avoid seizure of the various elements of the die, due to wedging of sand and/or stone fragments therebetween. From DE-A-2142570 there is known an apparatus for moulding articles formed by powdered material. This known apparatus comprises a mould formed by a central portion wherein a lower pad and an upper pad are introduced in order to define a moulding cavity. The lower pad is provided with a relatively long sliding seat for a finger which is made to pass through the whole volume of the cavity, in order to obtain an article of manufacture which is provided with a hole. This known apparatus is not suitable for the production of tiles of the above mentioned kind. In fact, the use of two pads which are inserted into a central portion of the mould, as well as of a finger which slides within a sliding seat of one of said two pads give rise to seizure between the moving portions of the mould. Moreover, if the finger is inserted in the sliding seat with clearance (in order to avoid seazure due to wedging of sand between the finger and the sliding finger), a loss of water is caused, so that the finished tile does not contain a sufficient amount of water and the necessary mechanical features are not obtained. It is the object of the present invention to develope an apparatus of the above mentioned type in such a way that tiles with holes, apertures or recesses may easily be formed. This is achieved by an apparatus of the above mentioned type, further characterized by the features of the characterizing portion of the enclosed claim 1. Further advantageous embodiments of the invention are set out in the dependent claims. The invention will be better understood by following the description and the attached drawing, which shows a practical, non limitative exemplification of the same invention, which relates to the production of flat tiles or slabs with holes. In the drawing: Figs. 1 to 6 are schematic vertical sections showing the various steps of a removal operation; and Fig.7 shows a perspective view of a product that can be manufactured by means of the illustrated die. According to what is illustrated in the attached drawing, numeral 1 indicates a main fixed structure which includes a column 3 intended to rotatingly engage a table 5 carrying a plurality of dies; each of these dies is subsequently transferred to various circularly distributed stations which include the loading station, vibration and pressing stations of the tiles being produced. A final removal station is provided with a lifting member 7 which is vertically guided in the structure 1 and is elastically urged downwards by compression springs 9 reacting between the fixed structure and the lower end heads of columns around which they are wound. Numeral 10 indicates a cylinder-piston system intended to control the lifting of member 7 against the counteracting action of springs 9 through a timely command. Member 7 has two columns 7A for the purposes to be indicated below. In the removal station, above table 5, a removal, i.e. an ejection system is provided on the structure 1, said system comprising a pad 12 vertically guided by columns 14 and controlled for the vertical displacements in either directions by a double-acting cylinder-piston system 16. In the arm 1B carrying said removal system, the structure 1 has also hooking members 18 articulated at 20 to said part 1B of the structure 1 and intended to perform the hooking of the frame in the manner described below; these hooking members 18 are controlled by double-acting cylinder-piston systems 22. Table 5 shows a plurality of dies, each of which comprises a frame 24 which defines a cavity 24A for the formation of the product M. This frame is carried by columns 26 which are able to slide in suitable seats of table 5 and which are part of double-acting cylinder-piston systems 28 apt to control the lifting and lowering of frame 24 with respect to the table. Each die is made up of frame 24 and a base 30 which is made to rest under the frame 24 in correspondence of the space 24A thereof, and is able to ensure, in a traditional manner, the sealing of cavity 24A for the pressing. The base 30 can be lifted and lowered through vertical columns 32 slidingly guided within table 5, urged downwards by springs 34 and capable of being lifted by the columns 7A of member 7, against the action of counteracting springs 34. Fig. 7 shows a product M that can be manufactured by the above described apparatus, which has a set of through openings like the larger central one, indicated by A1, and the smaller ones, indicated by A2 and located around said larger opening. The openings may be of various shapes to meet the requirements they are made for. To make a product of the above mentioned type on table 5 in correspondence of each die there is provided a support 36 on which a replaceable member 38 may be engaged having fingers 38A and 38B corresponding to the openings A1 and A2; these fingers 38A and 38B go through corresponding passages provided in the base 30 to extend into the cavity 24A of the die defined by frame 24 and base 30 in the position of Fig. 1. Obviously, the columns 32 for the movement of the base 30 pass through support 36 and member 38. A die which has been made to transit through the pressing station reaches the removal station (shown in Figs. 1 to 6) in the arrangement shown in Fig. 1, which is still the pressing arrangement. Under this condition, the die formed by the frame 24 and base 30 is still closed and the product M is crossed by fingers 38A and 38B provided in the apparatus. Pad 12 is in the lifted up position and the hooking members 18 wide open. It should be noted that the pad 12 is provided with recesses corresponding to the fingers 38A and 38B provided in the apparatus, in order to avoid interferences between pad and fingers. As soon as the die has reached the removal station in the condition shown by Fig. 1, the cylinder-piston system 10 is made to act on carrier 7 and lifts it thus causing the lifting of base 30 (through the co-action between columns 7A and columns 32) so that the said base 30 can also take up the frame 24; on the contrary, the member 38 with fingers 38A and 38B remains in its own position on support 36, being integral to table 5 and ― since it does not partecipate to the lifting ― it allows the withdrawal of fingers 38A and 38B from the product M without impairing said product as it is made to remain on the base 30; the fingers 38A and 38B slip out from the frame 30. In these conditions, the cylinder-piston systems 28 are inoperative. In the next phase (see Fig. 3) the cylinder-piston systems 28 are made to operate to lift the frame 24 with respect to base 30, so as to remove the product M from the base on which it has been formed and keep it adherent ― in a traditional way ― to the side wall of the cavity 24A of frame 24; the lifting is such as to draw the product close to the pad 12 and to form below the frame 24 a space which is sufficient for the insertion of a removal shovel of traditional type. The lifted frame 24 is hooked by the hooking members 18, which are timely driven by relevant cylinder-piston systems 22. Simultaneously (see Fig. 4), a removal shovel 40 is inserted according to arrow f40 of Fig. 4 below the frame and slightly lifted as far as to almost graze the lower edge of frame 24. The assembly is thus ready for the removal. In the subsequent phase (Fig. 5) the pad 12 is lowered by means of the cylinder-piston system 24A, to make it enter the through cavity 24A and act upon the product M thereby causing its removal from the walls of said cavity 24A, its resting on the shovel 40 and its further lowering together with shovel 40 until it is completely withdrawn from frame cavity 24A. During the lowering of the removal pad 12, an arm 12A thereof, provided with a tappet 12B, acts on the carrier of the shovel 40 causing a lowering thereof, synchronized with that of the pad 12; thus the removal of product M takes place while the product itself is kept between the shovel 40 and the pad 12 without any shock or falling down of said product, and thus without any damage thereof. The removal takes place while the frame is kept hooked by the members 18 and in a lifted position by the action of cylinder-piston system 28. During the phases shown in Figs. 3, 4 and 5, the member 7 may be lowered again so that the base 30 rests again on the assembly of support 36 and member 38 carrying the fingers like those indicated by 38A and 38B. In the successive phase (Fig. 6), the shovel 40 is moved forward again in a direction opposite to arrow f40 with the product resting thereon, the frame 24 is released from the hooking members 18 driven by the actuators 22 in the direction opposite to the preceding one, the pad 12 is lifted again by its own actuator 16 thereby allowing again the lowering of frame 24 due to its own weight or by means of the cylinder-piston systems 28 until the lower edge of said frame rests on the base 30. The table is thus ready for a new angular unitary advancement to repeat the cycle with the successive die reaching the removal station, while the die from which the product has been removed can reach the loading and the successive stations.

Claims: 1. Apparatus for the pressing and removal of cement tiles with holes or openings, to be combined to the presses intended for this use, comprising a die with a frame (24) a base (30) for closing the frame in its lower part, and a pressing pad (12) able to be introduced in the frame cavity (24A) for the pressing, and means (26, 28) for determining relative displacements between the base, the frame, and a removal pad (12) to allow the removal of the tile (M) onto a shovel (40) which is inserted between the frame and the base when they are spaced one from the other, said apparatus characterized in that, in order to obtain the formation of through openings (A1, A2) within the tile, it comprises: a member (38) with finger(s) (38A, 38B) intended to form the through openings, said member (38) being carried by the die-supporting structure (5), and being pressed against said die-supporting structure (5) by the frame (24) through the base (30); through openings in the base (30), corresponding to said finger(s) (38A, 38B); a member (7) carrying the base (30) and movable in the direction of the relative displacements in order to lift the base (30) and the frame (24) with respect to the supporting structure (5) for the withdrawal of the finger(s) (38A, 38B) from the formed tile (M), for determining, at the beginning of the removal cycle, a relative displacement between said member (38) and the base (30) for the withdrawal of the finger(s) (38A, 38B) from the formed piece; and the frame-lifting means (26, 28) being able to move the frame close to the lifted pad (12) while the base is lowered again. 2. Apparatus according to claim 1, characterized in that it comprises, for the removal operation, means (18, 20, 22) for hooking the frame to a structure (1B) for guiding and controlling the pad (12). 3. Apparatus according to the preceding claims, characterized in that it comprises elastic means (9, 34) counteracting the lifting runs of the base and of the base lifting members (7A, 10).

Inventors: GIANNELLI, UGO
Applicants: GIANNELLI, UGO
Application year: 1988
Main classification: B28B3
IPC codes: B28B3, B28B13