EP1226912A2

EP1226912A2 - Method and device for loading material into a mold for pressing ceramic articles

Info

Publication number: EP1226912A2
Application number: EP02001018A
Authority: EP
Inventors: Umberto Manfredini; Stefano Schianchi; Agostino Fiorentini
Original assignee: Manfredini E Schianchi Srl
Current assignee: Manfredini E Schianchi Srl
Priority date: 2001-01-24
Filing date: 2002-01-17
Publication date: 2002-07-31
Also published as: ITMO20010007A1; CN1367071A; EP1226912A3; BR0200167A; ITMO20010007A0

Abstract

A device for loading material into a mold for pressing ceramic articles comprises a frame (T) supporting a carriage (3) with at least one tray (4) supported thereon and at least one motorized conveyor belt (6) arranged in front of the tray (4), the carriage being slideable with reciprocating rectilinear motion between a feeder station (13, 17) for feeding material into the tray (4) and onto the upper portion of the belt (6), and a loading station for loading the mold (7) with. superimposed layers of the material (M, N) contained in the tray (4) and deposited on the upper portion. The mold loading method comprises depositing the material into the containment tray and on the upper portion of at least one motorized conveyor belt arranged in front of the tray; causing the simultaneous advancement of the tray and of the belt, which is kept stationary, above the mold, moving the tray so that it lies above the molding chambers of the mold and fills them by gravity, forming a first layer of material; simultaneously retracting the tray and the stationary belt, placing the belt at the downstream edge of the chambers; and causing the further retraction of the tray and of the belt, actuated so as to move, in order to release the material deposited on its upper portion into the chambers, so as to form a second layer which is superimposed on the first layer.

Description

The present invention relates to a method for loading material into a mold for pressing ceramic articles, particularly tiles, and to the corresponding loading device.
Loading devices are known which comprise a movable carriage, provided with a tray that is internally divided by a powder containment grid and is alternately actuated so as to perform a translational motion between a feeder station upstream of the mold of the press, in which the tray is filled with the powders, and a loading station at the press, in which the tray and the grid are aligned and superimposed on the recesses of the female part of the mold.
The tray and the grid are open in a downward region and rest on a sliding surface, which is co-planar to the plane of the press.
After filling the tray with a predefined quantity of powder, the tray is subjected to a translational motion from the feeder station toward the loading station while the upper male plugs of the mold are kept raised and the lower complementary male plugs are kept in a configuration that is raised to the same level as the plane of the press, so as to constitute a continuous sliding surface for the tray of the movable carriage.
When the tray is aligned and superimposed with respect to the recesses, the complementary male plugs are lowered, thus forming molding chambers, which are filled by the powder that falls from the grid.
While the carriage, with an empty tray and grid, is returned to the feeder station for the next operating cycle, the upper male plugs descend in order to press the powdered material loaded into the mold.
Furthermore, loading devices are known, which comprise a movable carriage that has, instead of a tray, a motorized conveyor belt on which a specific amount of powder is deposited.
The carriage performs a translational motion toward the loading station, placing the stationary belt above the recesses of the mold, and then returns to the feeder station: during this last stroke, the belt is actuated so as to move in order to release the powder into the recesses of the mold.
The above described devices allow to obtain ceramic articles constituted by a single layer of material.
As an alternative, the so-called double-loading devices are known, which allow to obtain articles having two superimposed layers, of which, for example, the lower one constitutes the body and the upper one constitutes the decoration.
These devices include those constituted by a main tray for containing the powder for molding the body of the tiles, in front of which an auxiliary tray for containing the powders for molding the decorative layer of the tiles is provided.
The two trays are supported by a same movable carriage and can be moved mutually closer or further apart.
From the feeder station, in which the two trays are filled with the respective powders, the carriage is subjected to a translational motion toward the loading station, so that the main tray is aligned and superimposed with respect to the recesses of the mold and the auxiliary tray is arranged downstream of said recesses.
The main tray, once the powder has fallen into the underlying chambers, retracts empty toward the feeder station; then the auxiliary tray also retracts and, during this retraction, deposits a second layer of powder onto the first one loaded earlier.
When both trays return upstream of the press, the upper male plugs of the mold are lowered in order to press the tiles.
These conventional double-loading devices are not devoid of drawbacks, including the fact that they are slow and quite complicated and difficult to operate; they in fact require two successive and independent return strokes, each of which requires significant times, which cause a disadvantageous slowing of production.
The aim of the present invention is to eliminate the above noted drawbacks of known devices, by providing a method and a corresponding device for loading material into a mold for pressing ceramic articles, which allow to reduce the time required to perform loading and to speed up and increase production.
Within this aim, an object of the present invention is to achieve the above aim with a structure that is simple, relatively easy to provide in practice, safe in use, effective in operation, and relatively low in cost.
This aim and this and other objects which will become better apparent hereinafter are achieved by the present method for loading material into a mold for pressing ceramic articles, characterized in that it consists in depositing the material into a containment tray and on the upper portion of at least one motorized conveyor belt arranged in front of said tray; in causing the simultaneous advancement of said tray and of said belt, which is kept stationary, above the mold, moving the tray so that it lies above the molding chambers of the mold and fills them by gravity, forming a first layer of material; in simultaneously retracting the tray and the stationary belt, placing said belt at the downstream edge of said chambers; and in causing the further retraction of the tray and of the belt, which is actuated so as to move, in order to release the material deposited on its upper portion into the chambers, so as to form a second layer which is superimposed on said first layer.
The device for loading material into a mold for pressing ceramic articles is characterized in that it comprises a frame for supporting a carriage for supporting at least one tray and at least one motorized conveyor belt arranged in front of said tray, said carriage being able to slide with a reciprocating rectilinear motion between a station for feeding the material into said tray and onto the upper portion of said belt, and a station for loading the mold, in which said tray is arranged above the molding chambers of the mold in order to fill them so as to constitute a first layer of material and said belt is kept stationary downstream of said chambers, the belt being actuated so as to move during the retraction stroke of the carriage for the release, into said chambers, of the material deposited on said belt so as to constitute a second layer superimposed on said first layer.
Further characteristics and advantages of the present invention will become better apparent from the detailed description of a preferred but not exclusive embodiment of a method and a corresponding device for loading material into a mold for pressing ceramic articles, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
Figure 1 is a schematic side view of a device according to the invention;
Figure 2 is a schematic plan view of the device of Figure 1;
Figure 3 is a partially sectional schematic view of a detail of the device of Figure 1 in a first active configuration;
Figure 4 is a schematic view of the detail of Figure 3 in a second active configuration;
Figure 5 is a schematic view of the detail of Figure 3 in a third active configuration.
With reference to the figures, the reference numeral 1 generally designates a device for loading material into a mold for pressing ceramic articles according to the invention.
The device 1 is arranged upstream of a press 2 for molding ceramic tiles P, and comprises a supporting frame T with which a carriage 3 is associated; said carriage supports a tray 4, which is provided with an internal grid 5 for containing molding material M.
A motorized conveyor belt 6 is arranged in front of the tray 4, and its upper portion is suitable to receive a predefined quantity of molding material N.
The press 2 comprises a lower mold part, which is constituted by a female mold part 7, in which recesses 8 are provided which are closed downward by complementary male plugs 9 which move vertically inside said recesses 8 in order to delimit chambers 10 for molding the tiles P, and by an upper mold part, which performs a vertical translational motion and supports male plugs 11 which are suitable to press the powders loaded into the chambers 10 in order to obtain the tiles P.
The structure of the press 2 is shown only schematically, since it is of a conventional type.
The frame T comprises two mutually opposite lateral plates 12, between which the carriage 3 is guided with a reciprocating rectilinear motion by way of rectilinear guiding means and motor means of a conventional type, which are not shown; the tray 4 and the belt 6 move rigidly with the carriage 3.
The carriage 3 moves between a feeder station, located upstream of the press 2, for feeding the molding and/or decorative material M and N respectively into the tray 4 and onto the belt 6, and a loading station, arranged at the press 2, for loading in superimposed layers the material M and N into the chambers 10.
The feeder station comprises a structure, formed by the frame T, for supporting a first hopper 13, the opening of which is controlled by fluidodynamic actuators constituted by first pneumatic cylinders 14; said hopper is suitable to fill the tray 4 with a predefined amount of material M.
The hopper 13 is provided with vibrating means, not shown, which are suitable to facilitate the discharge of the material M into the tray 4, and is filled from above by means of a dosage tube 15, which is actuated by a first motor 16 so as to slide along a rod that lies transversely to the device 1 and is not shown.
The feeder station further comprises a second hopper 17, which is also provided with vibrating means, not shown, and the opening of which is controlled by fluidodynamic actuators constituted by second pneumatic cylinders 18; said second hopper is suitable to deposit the material N onto the upper portion of the belt 6.
The hopper 17 is divided internally in portions by partitions, which allow to distribute in a differentiated manner the material N inside it, and is filled from above by three containers 19, which are supported by a frame 20 that is actuated so as to slide along a transverse bar 21 by a motor 22 and is suitable to place the containers 19 at the various portions into which the hopper 17 is divided in order to obtain polychromatic effects.
Each container 19 is individually able to slide along respective straight longitudinal guides 23, which are parallel and supported by the frame 20, and is actuated so as to move by respective actuation means constituted by a third pneumatic cylinder 24.
The outlet of each container 19 is closed, in a downward region, by a motorized roller 25 for the controlled dosage of the material N; the rollers 25 can be variously contoured.
For the sake of simplicity of illustration, Figure 2 does not show the first hopper 13 arranged above the tray 4 and the grid 5 and the second hopper 17 arranged above the belts 6 and below the containers 19.
Furthermore, the carriage 3 is provided with an auxiliary tray 26, whose opening is controlled; said auxiliary tray also has vibrating means, not shown, and is arranged in front of the belt 6 in order to contain an additional amount of molding material.
Advantageously, the device 1 comprises a pusher 27, which moves the molded tiles P away from the press 2, and a brush 28, a scraper, or the like, which is designed to clean residues of material from the pressing area.
The reference numeral 29 designates a sliding surface, which is co-planar to the upper surface of the female mold part 7, for the sliding of the tray 4 and of the grid 5 up to the recesses 8.
Conveniently, the device 1 (Figure 2) comprises a plurality of belts 6a, 6b, 6c and 6d, which are arranged side by side and parallel to each other in a number that corresponds to the number of chambers 10 for the independent and possibly differentiated loading thereof.
The feet 30 for ground support are provided with respective wheels 31, which allow the device 1 to move toward and away from the press 2.
The operation of the invention is as follows.
During the active step of the press 2, the carriage 3 is motionless in the feeder station, upstream of said press 2, in order to fill the tray 4 with the material M that exits from the first hopper 13 and deposit the material N that exits from the second hopper 17 onto the upper portion of the belts 6a, 6b, 6c, and 6d, which are actuated so as to move.
The feeding of the material M and N can be adjusted in various manners, in order to obtain different decorative effects thanks to the possibility to fill the hoppers 13 and 17 in a differentiated manner and thanks to the possibility to selectively distribute the material N on the belts 6, which are optionally engraved and contoured, by adjusting the speed of motion of said belts 6 and thanks to the presence of the dosage rollers 25.
After closing the first and second hoppers 13 and 17, the carriage 3 advances toward the press 2, in the active configuration, and arranges itself, in a parked condition, in the point that lies closest to said press.
Once pressing of the tiles P has ended, the male plugs 11 are lifted and the complementary male plugs 9 move upward, reaching the level of the upper surface of the female mold part 7 for the expulsion of the molded tiles P.
The carriage 3 then moves the tray 4 above the complementary male plugs 9 and the belts 6, which are motionless, downstream of the recesses 8.
During the forward stroke, the pusher 27 moves away the tiles P formed by the press 2, while the brush 28 eliminates any residues of material of the cycle that has ended.
The complementary male plugs 9 are lowered in order to form the molding chambers 10, which are filled by the material M that falls from the tray 4; a first layer of material is thus formed.
The carriage 3, while keeping the male plugs 11 raised, is then retracted in order to place the downstream end of the belts 6 at the downstream edge of the chambers 10.
Starting from this configuration, the carriage 3 is made to retract at a controlled and variable speed, while the belts 6 are actuated with a variable motion; the material N deposited on them is thus gradually distributed inside the chambers 10 in order to form a second layer which is superimposed on the first one deposited earlier.
The carriage 3 then repositions itself at the feeder station, where the tray 4 and the belts 6 are prepared for the subsequent cycle while the male plugs 11 are lowered in order to press the tiles P.
If an auxiliary tray 26 is arranged in front of the belts 6, during the return stroke of the carriage 3 it is possible to deposit a third layer of material, which is superimposed on the second layer.
In practice it has been found that the described invention achieves the intended aim and objects, i.e. it reduces the time required for the double loading of the mold and speeds up the pressing cycle, accordingly increasing the hourly production rate.
The device according to the invention in fact allows to load the mold with two or more layers of material in just two strokes of the carriage, the loading means (tray, belts and auxiliary tray) being all supported by the same carriage, together with which they move rigidly.
The device according to the invention further allows to obtain simultaneously articles of different types and with different decorative effects, by providing, for each recess of the mold, a corresponding conveyor belt for loading and thanks to the possibility to deposit the material on said belts in a differentiated manner.
The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
All the details may further be replaced with other technically equivalent ones.
In practice, the materials employed, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.
The disclosures in Italian Patent Application No. MO2001A000007 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A method for loading material into a mold for pressing ceramic articles, characterized in that it comprises: depositing the material into a containment tray and on the upper portion of at least one motorized conveyor belt arranged in front of said tray; causing the simultaneous advancement of said tray and of said belt, which is kept stationary, above the mold, moving the tray so as to lie above the molding chambers of the mold and fill the chambers by gravity, forming a first layer of material; simultaneously retracting the tray and the stationary belt, and placing said belt at the downstream edge of said chambers; and causing the further retraction of the tray and of the belt, which is actuated so as to move, in order to release the material deposited on its upper portion into the chambers, so as to form a second layer which is superimposed on said first layer.
A device for loading material into a mold for pressing ceramic articles, characterized in that it comprises: a frame (T) which supports a carriage (3) with at least one tray (4) supported thereon, and at least one motorized conveyor belt (6) arranged in front of said tray (4), said carriage (3) being able to slide with a reciprocating rectilinear motion between a feeder station (13, 17) for feeding the material (M, N)into said tray (4) and onto the upper portion of said belt (6), and a loading station for loading the mold (7), in which said tray (4) is arranged above the molding chambers (10) of the mold (7) in order to fill the chambers (10) so as to constitute a first layer of material (M, N) and said belt (6) is kept stationary downstream of said chambers (10), the belt (6) being actuated so as to move during the retraction stroke of the carriage (3) for the release, into said chambers (10), of the material (M, N) deposited on said belt (6) so as to constitute a second layer superimposed on said first layer.
The device according to claim 2, characterized in that it comprises a plurality of said conveyor belts (6) arranged mutually side by side and parallel to each other, said belts (6) being adapted to load a corresponding plurality of compartments (10) of said mold (7).
The device according to one or more of the preceding claims, characterized in that said carriage (3) comprises an auxiliary tray (26) for containing said material (M, N), said auxiliary tray (26) being arranged in front of said at least one conveyor belt (6) and being adapted to release a third layer of material superimposed on said second layer during said retraction stroke of the carriage (3).
The device according to one or more of the preceding claims, characterized in that said feeder station comprises a first hopper (13) with controlled opening, which is adapted to fill said tray (4) with a predefined amount of material (M).
The device according to one or more of the preceding claims, characterized in that said first hopper (13) is provided with vibrating means, which are adapted to facilitate the fall of the material (M) contained therein into said tray (4).
The device according to one or more of the preceding claims, characterized in that said feeder station comprises a second hopper (17) with controlled opening, which is adapted to deposit the material (N) onto said upper portion of the belt (6).
The device according to one or more of the preceding claims, characterized in that said second hopper (17) comprises a plurality of internal partitions adapted to divide it into a plurality of separate portions for the differentiated distribution of said material (N) inside it, so as to obtain polychromatic effects.
The device according to one or more of the preceding claims, characterized in that said feeder station (13, 17) comprises a frame (20) for supporting a plurality of containers (19) which are arranged adjacent and above said second hopper (17), which is mounted so as to be slideable along a bar (21) that lies transversely to said device and is adapted to place said containers (19) at the portions of said second hopper (17).
The device according to one or more of the preceding claims, characterized in that said frame (20) comprises a plurality of longitudinal straight guides (23), along which said containers (19), associated with respective actuation means (24), can slide.
The device according to one or more of the preceding claims, characterized in that each one of said containers (19) has an outlet that is closed in a downward region by a motorized dosage roller (25).