EP3768479B1

EP3768479B1 - Part of a mold for ceramic articles

Info

Publication number: EP3768479B1
Application number: EP19721042.0A
Authority: EP
Inventors: Andrea FRANCESCHI
Original assignee: Siti B&T Group SpA
Current assignee: Siti B&T Group SpA
Priority date: 2018-03-19
Filing date: 2019-03-19
Publication date: 2022-10-19
Anticipated expiration: 2039-03-19
Also published as: IT201800003746A1; WO2019180613A1; EP3768479A1

Description

Technical Field

The present invention relates to a part of a mold for ceramic articles. More specifically, the present invention relates to a part of a mold for ceramic articles of complex shape, such as sanitary ware such as WCs, bidets and the like.

Background Art

The production of sanitary ware is carried out in lines in which the slip is cast under pressure inside modular molds: each of these molds comprises two or more parts that can be connected to each other to define a forming cavity, within which the slip is then cast under pressure, i.e., in jargon, a fluid mixture comprising an aqueous part and a ceramic part in suspension.
The number of parts that make up each mold may vary according to various factors.
Typically, this number varies according to the geometry of the article to be produced with reference, for example, to the presence or absence of portions or appendices in the undercut, openings, or other geometric particularities.
The parts that make up the mold are placed side by side in such a way as to be one on top of the other in certain joint areas, and they define the above cavity into which the fluid mixture is directly poured.
After the fluid mixture has been poured, it solidifies so as to create the article with the desired shape: the individual parts of the mold can then be separated from each other to allow the extraction of the article itself, which will then be fired to obtain the end product.
The parts of the mold can be made, e.g., in porous resin, which has replaced, over time, traditional plaster: the porous resin combines properties of high mechanical strength, long life, lightness, and good permeability to liquids, so as to allow, after casting, the elimination of the liquid part of the fluid mixture, thus promoting the rapid solidification of the same to obtain the desired article. In the various operating phases, the individual parts that make up the mold can be reciprocally brought closer together and positioned side by side, in order to delimit the forming cavity, or they can be separated from each other, to allow the extraction of the sanitary ware, once solidified, from the mold itself.
As mentioned above, in some cases - for example for reasons of particular complexity of the shape of the article to be produced, or for other reasons, for example for ease of extraction of the article itself - each mold may comprise a number of reciprocally movable parts greater than three, for example four or even five.
In a typical application, for the production of WCs, bidets, or the like, the mold comprises five parts, two of which are lateral, also known as flanks, an upper part also known as a piston or cap, a lower part also known as a foot, and a rear part also known as a fifth part or back.
A fundamental characteristic of these molds is, as mentioned, the porosity of the resin portions, which allows reaching the forming cavity with fluids necessary both for the operation and for the maintenance and/or cleaning of the assembly itself (e.g. compressed air or water), or also to create a vacuum inside the cavity itself.
The supply of the above fluids, or the maintenance and/or cleaning operations of the molds are made possible thanks to the presence, in each of the lateral, upper or lower parts, of a respective distribution plate, which comprises ducts and, if necessary, members to control and regulate the circulation of the fluids.
In these parts of the mold it is easy to install a distribution plate, as they normally have a flat face, or a substantially flat face, facing outwards.
It is not possible, however, to install a distribution plate in the rear or fifth part because this, normally, consists of a sort of movable insert completely integrated into the cavity formed by the other four main parts.
The rear part, or fifth part, is usually associated with a supporting tube, made for example of stainless steel, which in use comes out from the rear of the mold in closed configuration, i.e. when the main parts of the same are reciprocally brought side by side; more specifically, the above tube is partially embedded in the porous resin, at one end, so as to obtain a rigid connection that allows the same part to be moved to open and close the mold.
The supporting tube also has the important function of distributing the service fluids (e.g. water, compressed air) to the entire porous resin portion of the fifth part.
In this regard, it should be noticed that the geometric complexity of the rear part makes it essential to have an extremely detailed distribution system, in order to distribute the fluids uniformly throughout the entire resin portion.
At present, the supporting tube comprises, at the end intended to be embedded in the resin, a number of holes drilled along a same circumference, which allow the service fluids to be distributed in a radial direction.
The notable points of the rear part are therefore reached, by the service fluids, through a system of ducts oriented parallel to each other, and perpendicular to the median axis of the part itself; these ducts are placed in communication with each other, and with the main supply point (i.e., the end of the tube provided with the holes) through further small internal ducts.
The distribution system of the service fluids described above has a number of drawbacks.
Firstly, the distribution of the service fluids can, in practice, be inefficient and uneven; as a result, obstructions or section shrinkage, even of small magnitude, at certain points in the circuit, can prevent the service fluid from reaching certain areas of the porous resin portion.
Furthermore, the distribution circuit inside the rear part cannot be inspected.
In fact, if there are, for example, obstructions or other problems of fluid circulation within the circuit, it is not possible to intervene to try to remedy them, or in any case to carry out certain maintenance operations, without damaging the rear part or without compromising, in some way, the structural and functional integrity of the same.
In case of problems not immediately solvable, therefore, the rear part, or fifth part, must be eliminated and completely replaced.
JP S51 101019 A discloses a part of a mold for ceramic articles in accordance with the preamble of claim 1 and
WO 02/072327 A2 and DE 2641 975 A disclose molds for ceramic articles of the known type.

Description of the Invention

The technical aim of the present invention is to improve the state of the art in the field of molds for ceramic articles.
As part of this technical aim, it is one of the objects of the present invention to develop a part of a mold for ceramic articles that allows overcoming the problems mentioned above.
Another object of the present invention is to make available a part of a mold for ceramic articles in which the circulation of the service fluids is improved and made more effective.
A further object of the present invention is to make available a part of a mold for ceramic articles in which the circulation system of the service fluids can be easily inspected without compromising the integrity of the part itself.
Yet another object of the present invention is to provide a part of a mold for ceramic articles in which it is possible to carry out the maintenance operations concerning the circulation system of the service fluids in a practical and effective way.
Another object of the present invention is to create a part of a mold for ceramic articles that allows carrying out the previous objects with a simple and cheap constructive solution.
This aim and these objects are all achieved by the part of a mold for ceramic articles according to the attached claim 1.
The part of mold comprises at least one portion in porous resin, and at least one supporting tube, rigidly connected to the resin portion.
The supporting tube comprises a first portion, provided with at least one main duct through which the service fluids are fed through the resin portion; furthermore, the supporting tube comprises a second portion, at least partially embedded in the resin portion.
According to the invention, the second portion comprises at least one distribution chamber of the service fluids, communicating with the main duct and provided with a plurality of holes for delivering the fluids themselves through the resin portion.
The distribution chamber, embedded in the resin portion and provided with the delivering holes, ensures a more effective and uniform diffusion of the service fluids through the resin portion itself, so that all the areas of the latter - or at least its notable points - are reached by the fluids themselves.
The dependent claims refer to preferred and advantageous embodiments of the invention.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will be more evident from the description of a preferred, but not exclusive, embodiment of a part of a mold for ceramic articles, illustrated by way of an indicative, but nonlimiting example, in the attached tables of drawings in which:

Figure 1 is an axonometric view of a mold for ceramic articles comprising the part of mold according to the present invention;
Figure 2 is an axonometric view of the same mold with some parts removed for better clarity;
Figure 3 is an axonometric view of the part of mold according to the present invention;
Figure 4 is a detail of Figure 3;
Figure 5 is a detailed side view of the supporting tube of the part of mold according to the invention;
Figure 6 is a side partially sectioned detailed view of the part of mold according to the invention, at the supporting tube;
Figure 7 is an axonometric view of the supporting tube of the part of mold;
Figure 8 is a detailed axonometric view of a part of the distribution chamber provided for in the supporting tube.

Embodiments of the Invention

With particular reference to these figures, reference numeral 1 globally indicates a part of a mold for ceramic articles. For a better understanding of the characteristics of the invention, Figures 1, 2 schematically show a mold S for ceramic articles comprising the part of a mold 1 according to the present invention.
More particularly, Figures 1, 2 show a mold S comprising an upper part 2, a lower part 3 and two lateral parts 4, 5; these parts 2-5, mutually placed side by side, define a forming cavity 6, into which the liquid mixture can be poured, which, when solidified, will give rise to the ceramic article 7.
The forming cavity 6 is also defined by the part of a mold 1 according to the present invention.
In a particularly practical embodiment of the invention, the part of a mold 1 is the rear part of mold S (also known as the fifth part).
Nevertheless, this does not constitute a limitation to the objects of the present invention: in other embodiments, in fact, the part of mold 1 could be any other part of mold S, and not necessarily the rear part which is usually completely integrated between the remaining parts 2-5.
In Figure 2, in which from the mold S the upper part 2 and one of the lateral parts 4 have been removed for greater clarity, both the ceramic article 7, formed inside the cavity 6, and the part of mold 1 (or rear part, according to the present invention) can be seen.
In greater detail, the part of mold 1 - see e.g. Figure 3 - according to the invention, comprises at least one supporting tube 8.
Furthermore, the part of mold 1 comprises at least one porous resin portion 9; the resin portion 9 is rigidly connected to the supporting tube 8.
The shape and size of the resin portion 9 can be any, depending on the shape and size of the ceramic article 7 to be made inside the forming cavity 6.
In an embodiment of the preferred, but not exclusive, invention, the mold S is adapted to make a ceramic article 7 of complex shape, such as a sanitary ware, or the like.
For example, the ceramic article 7 may consist of a WC, a bidet, or the like; it cannot however be ruled out that the ceramic article 7 can be of another type, without any limitation.
As can be seen in Figure 2, the part of mold 1 according to the present invention, which in the illustrated embodiment constitutes the rear part of the mold S, is completely enclosed in use by the remaining parts 2, 3, 4, 5 of the mold S itself; for example, the part of mold 1 can be used to delimit the forming cavity 6 so as to create, in the ceramic article 7, a rear chamber or recess.
The supporting tube 8 is preferably, but not exclusively, made of a metal material.
According to the invention, the supporting tube 8 comprises a first portion 10 and a second portion 11.
The first portion 10 is substantially cylindrical tubular; the first portion 10 comprises at least one main through duct 12, for the supply of at least one service fluid to the resin portion 9.
The main duct 12 is characterized by a first diameter D1.
Furthermore, the first portion 10 comprises a free end extremity 13 for the connection to supply means of at least one service fluid (not shown in the illustrations).
The end extremity 13 is, for example, threaded; alternatively, the end extremity 13 can be provided with other types of connection members.
The same first portion 10 (and/or the same end extremity 13) can be used to move the part of mold 1, e.g., to allow the extraction of the ceramic article 7 from the mold S once it has been fully formed, or to carry out maintenance or cleaning operations on the part of mold 1 itself.
The second portion 11 of the supporting tube 8 is, at least partially, embedded in the porous resin portion 9, as shown for example in the Figures 3, 4, 6.
The second portion 11 communicates with the main duct 12, and is shaped so that the service fluid from the main duct 12 flows through it to reach different areas of the resin portion 9.
According to the invention, the second portion 11 comprises, in turn, a distribution chamber 14 of at least one service fluid.
More particularly, the distribution chamber 14 communicates with the main duct 12 for the supply of the service fluid.
With reference to the longitudinal axis A of the supporting tube 8, the distribution chamber 14 has the transversal dimension larger than the first diameter D1.
More in particular, the distribution chamber 14 has cylindrical symmetry, and is characterized by a second inner diameter D2 larger than the first diameter D1 of the main duct 12.
The distribution chamber 14 can also have different shapes, not symmetrical, depending on the conformation of the resin portion 9.
Therefore, in the passage between the main duct 12 and the distribution chamber 14, a section enlargement is provided.
At this section enlargement, the service fluid undergoes a slow-down and therefore an increase in pressure, which facilitates the effective distribution of the resin portion 9 towards the peripheral areas.
According to the invention, the second portion 11 comprises a first element 15 and a second element 16, mutually connected to each other in a separable way.
The first element 15 and the second element 16 define the aforementioned distribution chamber 14.
According to the invention, therefore, the distribution chamber 14 can be fully inspected, thanks to the fact that the first element 15 and the second element 16 can be separated.
In more detail, the first element 15 and the second element 16 are connected to each other by removable connecting members 17.
The first element 15 comprises a first flange 18.
The first flange 18 is rigidly connected to the first portion 10; e.g., the first flange 18 is connected to the first portion 10 by welding.
The second element 16 comprises a second flange 19.
As shown in Figure 4, the first flange 18 can be completely embedded in the resin portion 9, so as to obtain a substantially flat and uniform outer surface, or the first flange 18 can be protruding from the outer surface of the resin portion 9, and therefore not embedded in the resin, for easier removal.
The first flange 18 of the first element 15 and the second flange 19 of the second element 16 can be mutually coupleable to each other by means of the aforementioned removable connecting members 17.
The first element 15 also comprises a tubular extension 20; the first tubular extension 20 extends from the first flange 18 along the longitudinal axis A of the supporting tube 8.
The second element 16 comprises a substantially bell-shaped portion 21, to which the second flange 19 is fixed (see in particular Figure 8).
The tubular extension 20 engages in a corresponding annular seat 22 provided in the inner surface of the bell-shaped portion 21.
Furthermore, in the tubular extension 20, a groove is provided for housing a gasket 23, which abuts on the surface of the annular seat 22 so that the coupling between the first element 15 and the second element 16, which as has been said is removable, is fluid-tight.
The removable connecting members 17 can comprise, e.g., a plurality of screws engaged in their respective threaded holes 24 provided in the second flange 19; the heads of these screws 17 engage, on the other hand, in respective recessed seats 25 provided, correspondingly, in the first flange 18 (see, for example, Figure 7).
According to the invention, the distribution chamber 14 comprises a plurality of holes 26a, 26b for the delivery of service fluids in the resin portion 9.
More in detail, the bell-shaped portion 21 of the second element 16 comprises a plurality of holes 26a, 26b, for the delivery of the service fluids in the resin portion 9.
In particular, first holes 26a are provided oriented in a substantially radial way with respect to the longitudinal axis A of the supporting tube 8.
In addition, there are second holes 26b oriented with respective axes parallel, or substantially parallel, to the longitudinal axis A of the supporting tube 8.
The bell-shaped portion 21 preferably has its lateral surface 27 cylindrical, or substantially cylindrical; the first holes 26a are therefore provided in the above-mentioned lateral surface 27.
The number and size of the first holes 26a can be any, depending on the different application requirements.
The same applies to the positioning of the first holes 26a along the lateral surface 27 of the bell-shaped portion 21.
According to a further aspect of the invention, the bell-shaped portion 21 comprises a frontal surface 28.
In use, the frontal surface 28 is opposite the first element 15.
The second holes 26b are provided in the aforementioned frontal surface 28 of the bell-shaped portion 21.
The positioning, number and size of the second holes 26b can also be any.
The bell-shaped portion 21 comprises, at its frontal surface 28, at least an appendix 29, adapted to be completely embedded in the resin portion 9, as schematically shown in Figure 6; this permits obtaining a more solid and secure coupling between the resin portion 9 itself and the supporting tube 8.
The appendix 29 can be made in various shapes.
For example, the appendix 29 may comprise a tubular portion 30 and a collar 31, fixed along the outer surface of the tubular portion 30.
The appendix 29 therefore provides an adhesion surface, between the supporting tube 8 and the resin portion 9, additional with respect to the bell-shaped portion 21, also comprising an undercut zone that prevents separation between the two parts when this is not required.
In the embodiment shown in the illustrations, the bell-shaped portion 21 is constructed by welding metal parts in a simple and economical way; however, it cannot be ruled out that the bell-shaped portion 21 can be made with other technologies.
In some embodiments of the invention, the whole supporting tube 8 might be made of a material other than steel: for example, the supporting tube 8 might be made of a polymeric material, or of a composite material, or others.
According to another aspect of the invention, the resin portion 9 comprises a plurality of ducts 32, 33; these ducts 32, 33 communicate with the holes 26a, 26b of the distribution chamber 14.
The ducts 32, 33 can be made in different directions, in relation to the shape and size of the resin portion 9 (and therefore in relation to the shape and size of the ceramic article 7 to be made).
The specific conformation/configuration of the ducts 32, 33 does not constitute, however, a limitation to the objects of the present invention.
For example, a number of first ducts 32 are provided that communicate directly with the first, second holes 26a, 26b, arranged in various directions; moreover, second ducts 33 are provided that intercept the first ducts 32.
The second ducts 33 extend in a direction substantially parallel to the longitudinal axis A of the supporting tube 8.
The method of using the part of mold 1 according to the present invention is, in the light of what has been described, completely intuitive.
As shown in Figures 1, 2, the part of mold 1 is assembled together with the other parts 2, 3, 4 and 5 that make up the mold S, to delimit the forming cavity 6, into which the fluid mixture for making the ceramic article 7 will then be poured.
The part of mold 1 is easily moved by means of the supporting tube 8, which is firmly anchored to the resin portion 9.
Through the supporting tube 8 - and more specifically through the main duct 12 - a service fluid, such as water, compressed air or others, can be fed into the resin portion 9.
The service fluid flows through the main duct 12 and reaches the distribution chamber 14, and from there it spreads through the holes 26a, 26b and the ducts 32, 33, in the various areas of the resin portion 9.
The distribution chamber 14, the holes 26a, 26b and the ducts 32, 33 can be sized in order to satisfy different application requirements, i.e., in order to optimize the pressure and the speed of the service fluid in the various areas of the resin portion 9 that have to be reached.
According to the present invention, the supporting tube 8 can be simply inspected, and maintenance, cleaning and similar operations can be easily carried out on it.
Consequently, any maintenance and cleaning operations on the resin portion 9 are also easier and more effective.
In fact, the first element 15 and the second element 16 are separable by means of the removable connecting members 17: while the second element 16 remains embedded in the resin portion 9, the first element 15 can be removed, together with the entire first portion 10 of the supporting tube 8.
The distribution chamber 14 can then be inspected and, if necessary, cleaned.
According to another interesting aspect of the invention, the first portion 10 and/or the first element 15 can also be replaced with others of different characteristics, or replaced with intact parts if those originally installed are damaged.
All these operations can be carried out while the second element 16 of the second portion 11 of the supporting tube 8 remains firmly anchored to the resin portion 9.
The resin portion 9, therefore, remains intact even after repeated inspection and/or maintenance jobs.
It should be noticed that the present invention also relates to the supporting tube 8 having the characteristics described above.
The present invention also relates to a mold S comprising the part of mold 1 having the characteristics previously described.
We have thus seen that the invention achieves its intended objects.
First of all, the diffusion of the service fluids through the resin portion 9 is uniform compared to known solutions, thanks to the presence of the distribution chamber 14; the various areas of the resin portion are therefore better reached by the fluids themselves, which perform their function more effectively.
The ease of inspection and/or maintenance, cleaning, or replacement of damaged parts, or in any case parts not suitable for the specific application, of the part of mold 1, and in particular of the supporting tube 8, is obtained, according to the invention, by means of a simple, effective and inexpensive constructive solution; the above constructive solution is also easily modifiable, to adapt the supporting tube 8 to different productive requirements.
In practice, the materials used, as well as the contingent shapes and dimensions, can be any according to the requirements without leaving the scope of protection of the following claims.

Claims

Part of a mold (1) for ceramic articles, comprising at least one porous resin portion (9), and at least one supporting tube (8) rigidly connected to said resin portion (9), said supporting tube (8) comprising a first portion (10), provided with at least one main through duct (12), for the supply of service fluids through said resin portion (9), and a second portion (11) at least partially embedded in said resin portion (9), wherein
that said second portion (11) comprises at least one distribution chamber (14) of service fluids, communicating with said main duct (12) and provided with a plurality of holes (26a, 26b) for the delivery of the fluids through said resin portion (9), characterized by the fact that said second portion (11) comprises a first element (15) and a second element (16), mutually connected to each other in a separable way through removable connecting members (17), said first element (15) and said second element (16) defining together said distribution chamber (14).
Part of a mold according to claim 1, wherein said first element (15) comprises a first flange (18) and said second element comprises a second flange (19), said first flange (18) and second flange (19) being mutually coupleable to each other by means of said removable connecting members (17).
Part of a mold according to claim 2, wherein said removable connecting members (17) comprise a plurality of screws engaged in respective threaded holes (24) provided in said second flange, the heads of said screws (17) engaging in respective recessed seats (25) provided, correspondingly, in said first flange (18).
Part of a mold according to one of claims 1-3, wherein said second element (16) comprises a substantially bell-shaped portion (21), in which said holes (26a, 26b) are provided for the delivery of the service fluids.
Part of a mold according to claim 4, wherein said first element (15) comprises a tubular extension (20) which engages in a corresponding annular seat (22) provided in the inner surface of said bell-shaped portion (21), said tubular extension (20) comprising a groove for housing a gasket (23), which abuts on the surface of said annular seat (22) so as to create a fluid-tight coupling between said first element (15) and said second element (16).
Part of a mold according to claim 4 or 5, wherein said bell-shaped portion (21) comprises a frontal surface (28), opposite said first element (15), comprising at least one appendix (29) adapted to be completely embedded in said resin portion (9) so as to define at least one undercut zone, that prevents the separation of said bell-shaped portion (21) from said resin portion (9).
Part of a mold according to claim 6, wherein said appendix (29) comprises a tubular portion (30) and at least one collar (31) fixed along the outer surface of said tubular portion (30).
Part of a mold according to one of the preceding claims, wherein said resin portion (9) comprises a plurality of ducts (32, 33) communicating with said holes (26a, 26b) of said distribution chamber (14).
Part of a mold according to claim 8, wherein said resin portion (9) comprises first ducts (32) that communicate with said holes (26a, 26b), and second ducts (33) that intercept said first ducts (32).
Part of a mold according to one of the preceding claims, wherein said main duct (12) has a first inner diameter (D1), and said distribution chamber has a second inner diameter (D2) larger than said first diameter (D1).
Mold (S), comprising at least one part of a mold (1) according to one of claims 1-10.