NL2026214B1 - Mould container part and mould container press comprising such a mould container part - Google Patents

Abstract

The present invention relates to a mould container part, comprising: - one or more than one mould cavity for forming therein a green brick from clay, said mould cavity comprising a bottom and one or more than one side wall; and - Wherein at least a part of the bottom comprises one or more than one sliding plate that is slidable in a plane defined by said bottom between a filling state and a demoulding state to thereby promote the green brick formed in the mould cavity to be released therefrom in the demoulding state. The invention further relates to mould container press device, comprising such a mould container part.

Description

Mould container part and mould container press comprising such a mould container part The present invention relates to a mould container part, and to a mould container press, comprising such a mould container part.

In so-called mould container presses, to which the present invention relates, deformable clay is pressed in the mould cavities with great force, whereby a desired degree of filling of the mould cavity is achieved and the green brick obtains a desired shape. The green brick formed in the mould cavity is successively demoulded. i.e. release from the mould cavity, in order to be dried and fired.

In order to facilitate the release of the green bricks from the mould cavity, the mould cavities may be covered in sand prior to being filled with clay. The green brick will thereby have one or more than one sand-covered side. However, for some applications it may be undesirable for a green brick to have a sand-covered side, such as when a brick of the so-called waterstruck (German: Wasserstrich) type is being manufactured. Such waterstruck bricks must {5 have a smooth, levelled-off surface structure which is not covered with sand.

Different types of mould container presses exist, some comprising a chain conveyor, also referred to as mould chain, which is assembled from a large number of mutually connected mould containers parts. Each mould container part generally comprises a plurality of mould cavities in which the green bricks are formed. Ejectors are arranged in each mould cavity for the purpose of pressing the green brick from the respective mould cavity in a downward direction. During demoulding the opening of the respective mould cavity is directed downward, whereby the force of gravity contributes to the green brick releasing from the bottom.

Other types of mould container presses may apply mould container parts that are not connected to each other. Such mould container parts may be individually supported and moved in a circuit. An advantage of detached mould container parts is that they may be easily exchanged, allowing for swift changes in specific brick size, i.e. with different length, width and height dimensions. For example, the (Dutch) “Waal Formaat” (WF) has a height of 50 mm, “Vecht Formaat” has a height of 40 mm, and the “Waal Dik Formaat” (WDF) has a height of 65 mm. Other formats are for example the British Standard Brick size (BSB), the (German) Normal Format (NF) and the (German) Lang Format (LF), etcetera.

A disadvantage of detached mould container parts is related to the demoulding of green bricks out of the mould cavity. After all, it is very complicated to apply ejectors for actively pressing the green brick out of the mould cavity. During demoulding the opening of the respective mould cavity is directed downward, whereby the force of gravity in combination with a forced vibration of the mould container part together try to release the green brick from the mould cavity,

and in particular detach it from the bottom to which it regularly gets stuck, even when sand is applied.

As mentioned above, waterstruck bricks must have a smooth, levelled-off surface structure which is not covered with sand, and consequently the covering of the mould cavities with sand must be dispensed with in the manufacture of waterstruck bricks. As a result of this, demoulding of a waterstruck green brick formed in the mould cavity causes a significant risk that the green brick will remain stuck to the bottom of the mould cavity and loose not or only in part. The skilled person will however understand that the invention is related to demoulding of any type of green brick that may find some difficulty when demoulding, including sand or sawdust covered bricks. The invention is in particular relevant for any type of mould container part wherein the mould cavities lack an ejector as commonly used in mould chains.

Green bricks are formed of clay that is still relatively soft, and consequently problems during demoulding easily result in the green brick to become misshapen and unusable. An objective of the present invention is to provide a mould container part, that is improved relative to the prior art and wherein at least one of the above stated problems is obviated or alleviated.

Said objective is achieved with the mould container part according to claim 1 of the present invention, comprising: - one or more than one mould container for forming therein a green brick from clay, said mould container comprising a bottom and one or more than one side wall; and - wherein at least a part of the bottom comprises one or more than one sliding plate that is slidable in a plane defined by said bottom between a filling state and a demoulding state to thereby promote the green brick formed in the mould container to be released therefrom in the demoulding state.

The shear force that occurs when the sliding plate is slid sideward relative to the green brick facilitates the green brick to be released from the sliding plate, and consequently from the bottom. As soon as at least a large part of the green brick is released, the remaining part will easily follow due to gravity and/or additional vibrations.

According to a preferred embodiment, the one or more than one sliding plate comprises one or more than one opening to define an aerator that is configured to selectively allow introduction of air between the bottom of the mould cavity and the green brick formed in the mould cavity in the demoulding state. Introduction of air between the bottom of the mould cavity and the green brick prevents a vacuum to occur and thereby further facilitates release of the green brick out of the mould cavity.

The invention further relates to a sliding plate of or for a mould container part according the invention and comprising one or more than one opening to define an aerator. The plurality of openings are preferably arranged at a longitudinal offset. This longitudinal offset corresponds to at least one of: a distance between two adjacent division walls that are arranged between adjacent mould cavities; and a distance between protrusions that are protruding from the bottom inward into two adjacent mould cavities.

The invention further relates to a mould container press, comprising a mould container part according to the invention, and an actuator for sliding the sliding plate between the filling state and the demoulding state.

Preferred embodiments are the subject of the dependent claims. The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, and in particular the aspects and features described in the attached dependent claims, may be an invention in its own right that is related to a different problem relative to the prior art. In the following description preferred embodiments of the present invention are further elucidated with reference to the drawing, in which: Figure 1 is a perspective view of a mould container press; Figure 2 is a perspective view of a mould container part according to the invention; Figures 3A and 3B are perspective view of a simplified mould container part, in a filing state and a demoulding state, respectively; Figures 4A to 4E are perspective views of successive steps of manufacturing green bricks; Figure 5 is a cross sectional perspective view of the mould container part; Figures 6A and 6B are top views of a mould container part according to a further embodiment having two sliding plates, shown in a filling state and a demoulding state, respectively; Figures 7A and 7B are top views of a mould container part according to a further embodiment, shown in a filling state and a demoulding state, respectively; and Figure 8 is a detailed perspective view of an actuator of a mould container press. The mould container press | shown in Figure | comprises a large number of detached mould container parts 2 that are moved forward in a (substantially square) circuit. The transport directions of the mould container parts 2 and the green bricks 3 after demoulding are indicated with arrows M and B, respectively. Filling station 4 comprises an input 5 for clay that is mixed in the filling station 4 and successively pressed with a press 6 into a mould container part 2 arranged in the circuit below the press 6. Alternatively, clay may be thrown into the mould cavities 7, e.g. by a cascade or by Hubert press, also known as a simulated hand moulding press. After the clay has been arranged in mould cavities 7, the mould cavities 7 are trimmed on their open upper side by a trimmer 8 to remove any clay extending out of the mould cavities 7 of the mould container part 2. Drying boards 9, which are stored in a drying board storage 10, are placed on top of the mould container parts 2, after which an assembly of the mould container part 2 and drying plate 9 are turned upside down by a turning device 11. After turning, the mould container part 2 is arranged above the drying board 9 onto which the green bricks 3 are to be placed in a demoulding step. To facilitate demoulding of the green bricks 3 out of the mould cavities 7, in the mould container part 2 may be exposed to vibrations with a vibrator 12. In combination with gravity, the green bricks 3 will demould. According to the present invention, the mould container press 1 applies improved mould IO container parts 2 that are configured to reduce the risk of green bricks 3 sticking to a bottom 13 of the mould cavities 7, which will be explained in more detail below.

After green bricks 3 have been released from the mould cavities 7 they are discharged on the drying boards 9 via a discharge conveyor 14 in direction B for further treatment, comprising of drying and firing of the green bricks 3. The now empty mould container parts 2 are moved forward in the circuit to pass a cleaning station 15, where they may be washed to remove any residue of clay left in the mould cavities 7. The mould container parts 2 are successively cleared of larger drops of water with a blower 16 and transported via segment 17 of the circuit. Dependent on the type of brick to be produced, an optional sanding station 18 may add sand to the bottom 13 and side walls 19 of the mould cavities 7. It is mentioned again that for e.g. waterstruck bricks, sand is not applied, thereby causing additional challenges during the demoulding step to which the improved mould container parts 2 according to the invention proposes a solution. In the final step, a further turning device 19 turns the mould container parts 2 again to have the mould cavities 7 facing upward again, ready to be filled by the filling station 4 and repeat the cycle.

A mould container part 2 of the mould container press 1 is shown in Figure 2, and comprises {in this exemplary embodiment) a total of fourteen mould cavities 7 for forming therein a green brick 3 from clay. Each mould cavity 7 comprises a bottom 13 and one or more than one side wall 19. At least a part of the bottom 13 comprises one or more than one sliding plate 20 that is slidable back and forth as indicated by arrow S in a plane P defined by said bottom 13. The sliding plate 20 is slidable between a filling state (shown in Figure 2) and a demoulding state to thereby promote the green brick 3 formed in the mould cavity 7 to be released therefrom in the demoulding state. Sliding of sliding plate 20 results in a shear force between the green brick 3 and the sliding plate 20 of the bottom 13, thereby facilitating release of the green brick 3 ander influence of gravity (and optional vibrations caused by vibrator 12). The direction of demoulding a green brick 3 out of the mould cavity 7 is directed transverse to the sliding direction S of the sliding plate 20. Thus, moving sliding plate 20 in plane P defined by the bottom 13 results in a shear force that causes the green brick 3 to detach from said bottom 13 and move transverse relative to said bottom 13.

In order to provide a flat surface on the green brick 3, the sliding plate 20 is preferably arranged flush with the bottom 13, or alternatively forms the complete bottom 13.

5 The one or more than one sliding plate 20 preferably further comprises one or more than one opening 21 to define an aerator 22 that is configured to selectively allow introduction of air between the bottom 13 of the mould cavity 7 and the green brick 3 formed in the mould cavity 7 in the demoulding state. Introduction of air prevents a vacuum to occur and thereby further facilitates release of the green brick 3.

For illustrative purposes, the embodiments in the following Figures show relatively short mould containers parts 2 only comprising three mould cavities 7. The skilled person will however understand that the invention is not limited to any number of mould cavities 7 in a mould container part 2.

Also for illustrative purposes, various configurations of the one or more than one opening 21 in the sliding plate 20 are shown. Dependent on the type of green brick 3 to be formed, the shape. size and or configuration of the one or more than one opening 21 may be optimized. Contrary to the exemplary embodiment in the Figures, the one or more than one opening 21 in the multiple mould cavities 7 in one mould container part 2 are identical for a specific sliding plate 20. It is however conceivable that a sliding plate 20 may be exchangeable for another sliding plate 20 having different openings 21 optimized for a different type of green brick 3. For example, the one or more than one opening 21 may be a through hole or a slot. Alternatively, or additionally, the one or more than one opening 21 may be tapered. If clay, would accidentally get stuck in the one or more than one opening 21, drying thereof over time would cause the clay to shrink, after which it may be easily removed from the one or more than one opening 21, thereby taking away any blockage.

The mould container parts 2 may comprise optional protrusions 23, also referred to as frogs, protruding from the bottom 13 inward into the mould cavity 3. Such protrusions 23 allow material to be saved and also allow a reduction in time of the drying step and the firing step in the production process of the bricks. Especially interesting is that mould container parts 2 allow such protrusions 23 to be applied in the production of waterstruck bricks, i.e. without the use of sand to facilitate demoulding. Such material and energy-saving provisions are less / not always applicable in conventional production processes for the manufacture of waterstruck bricks, partially depending on the type of clay that is used. If material has to be saved in a conventional production process for waterstruck bricks, then this material may need to be actively removed from the green brick in an additional production step after forming of the green brick 3. The present invention proposes a solution wherein clay material and energy may be saved during production of waterstruck bricks, while also providing a solution to the additional challenges related to the demoulding of hard to demould green bricks, mainly when no sand can be applied in the mould cavities 7. As mentioned above, the one or more than one sliding plate 20 is slidable back and forth between a filling state (shown in Figure 3A) and a demoulding state (shown in Figure 3B).

In the filing state of Figure 3A, the one or more than one opening 21 in the one or more than one sliding plate 20 is covered by a at least one of a division wall 24 between adjacent mould cavities 7, and by an (optional) protrusion 23 that is protruding from the bottom 13 inward into the mould cavity 7. In this way, it is prevented that clay is forced in the one or more than one opening 21 when the press 6 of the filling station 4 forces clay into the mould cavities 7. Opposite surfaces of this division wall 24 define the side walls 19 of the adjacent mould cavities 7.

In the demoulding state of Figure 3B, the one or more than one sliding plate 20 is slid in the longitudinal direction of the mould container part 2, now exposing the one or more than one opening 21 and allowing air to flow there through. In this way, the one or more than one {5 opening 21 may function as an aerator 22.

The manufacturing of green bricks 3 in the mould container part 2 according to the invention is now explained in more detail in Figures 4A-E, also relating to steps of the manufacturing process described in relation to the mould container press 1 shown in Figure 1.

In Figure 4A, clay is introduced into the mould cavities 7 of the mould container part 2, representing the step of the press 6 of the filling station 4 filling the mould cavities 7.

After trimming of the mould cavities 7 on their open upper side, excessive clay is removed, providing the situation shown in Figure 4B. With reference to the mould container press I in Figure 1, the situation of Figure 4B is present immediately downstream of trimmer 8. Green bricks 3 are now arranged in the mould cavities 7.

In Figure 4C, a drying board 9 is arranged on top of the mould container part 2. Successively, the assembly of the mould container part 2 and drying board 9 are turned upside down by a turning device 11. This step is schematically represented in Figure 4D.

In Figure 4D, which shows a bottom side of the mould container part 2, the one or more than one opening 21 in the one or more than one sliding plate 20 is still in the filling state, wherein the one or more than one opening 21 are covered — seen from the open side of the mould. cavities 7 — by one of the division walls 24 between adjacent mould cavities 7 (or by (optional) protrusions 23).

Although it is conceivable that the sliding plate 20 is a movable part of the bottom 13, the mould container part 2 in the shown embodiments comprises a bottom plate 26 having an opening 25 in the form of a slotted recess for receiving the sliding plate 20 therein. Such a bottom plate 26 may provide additional rigidity. The bottom plate 26 as such may then also comprise one or more than one opening 25 corresponding to the one or more than one opening 21 of the sliding plate 20. In the demoulding state, the openings 25 in the bottom plate 26 and the sliding plate 20 are aligned. Aeration only occurs when the openings 25, 21 are aligned, thereby allowing a controlled position of aeration that is not necessarily immediately present when the openings 21 in the sliding plate 20 emerge from behind a cover, such as a division wall 24 or a protrusion 23.

In Figure 4E, the one or more than one sliding plate 20 is slid in the direction S, thereby aligning the one or more than one opening 21 in the one or more than one sliding plate 20 with one or more than one opening 25 in the bottom plate 26.

The cross sectional perspective view shown in Figure 5 shows a cross section of a mould container part 2 corresponding to Figure 4D, wherein the one or more than one opening 21 in the one or more than one sliding plate 20 is covered by division walls 24 and protrusions 23. The green bricks 3 are still in the mould cavities 7.

A mould container part 2 having a sliding plate 20 may be provided in various configurations, as will now be explained using Figures 6A,B and 7A,B.

Preferably, the sliding plate 20 extends over at least two adjacent mould cavities 7, thereby allowing simultaneous control of aeration of multiple mould cavities 7 with a single sliding action of the sliding plate 20.

The middle part of the green brick 3 is most susceptible to get stuck in the mould cavity 7 during demoulding. If the mould cavities 7 have a rectangular shape, with a width smaller than a length thereof, and if the sliding plate is movable in a width direction of the mould cavities 7, the one or more than one opening 21 may be arranged along a longitudinal side of the green brick 3, thereby promoting an effective demoulding thereof.

Preferably, the sliding plate 20 extends in a longitudinal direction of the mould container part 2 and over a plurality of, and preferably all, mould cavities 7. If the sliding plate 20 extends over substantially the whole length of the mould container part 2, it may extend over a row of mould cavities 7 arranged therein. This preferred embodiment, wherein the width of the mould cavities 7 is arranged in the longitudinal direction of the mould container part, is the subject of Figures 2 — 6B.

The embodiment of Figures 6A, B is closely related to the embodiment shown in Figures 2-5B, but comprises two sliding plates 20 that are arranged next to each other and that are configured to be moved in opposite directions in the demoulding state (Figure 6B). The most important advantage of this embodiment is that the opposite sliding movement of both sliding plates 20 allows aeration to be provided on opposite sides of the mould cavity 7. In the shown embodiment, aeration may be provided on opposite longitudinal sides of the green brick 3, thereby further improving demoulding of said green brick 3 out of the mould cavity 7.

An alternative embodiment is shown in Figures 7A, B, wherein the sliding plate 20 is movable in the width direction of the mould cavities 7. However, now the mould cavities 7 are arranged with a length thereof in the longitudinal direction of the mould container part 2, and the sliding direction S is directed transverse to the longitudinal direction of the mould container part 2.

The mould container press 1 shown in Figure 1 may further comprise an actuator 27 for sliding the sliding plate between the filling state and the demoulding state. An embodiment of such an actuator 27 is shown in Figure 8, comprising a drive 28 and an eccentrically arranged arm 29 configured to push the sliding plate 20 with a pusher 30. Such an actuator 27 is arranged downstream of the turning device 11 and preferably upstream of vibrator 12, and is configured to move the sliding plate from the filling state to the demoulding state.

A further actuator 27 that is configured to push the sliding plate back in the filling state may be arranged anywhere before the filling station 4. Preferably, this further actuator 27 is arranged downstream of the cleaning station 15, leaving the one or more than opening 21 exposed to allow them to be cleaned by the cleaning station 15.

The mould container press 1 may further comprise a blower / compressor 31 configured to introduce air under pressure between the bottom 13 of the mould cavity 7 and the green brick 3 formed in the mould cavity 7 in the demoulding state. This blower / compressor 31 may be integrated in the demoulding step wherein the dryer board 19 is separated from the mould container part 2.

Although they show preferred embodiments of the invention, the above described embodiments are intended only to illustrate the invention and not to limit in any way the scope of the invention. Accordingly, it should be understood that where features mentioned in the appended claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting on the scope of the claims. Furthermore, itis particularly noted that the skilled person can combine technical measures of the different embodiments. The scope of the invention is therefore defined solely by the following claims.

Claims (19)

Conclusions Mold container part, comprising: - one or more mold cavity for forming a clay mold therein, wherein the mold cavity comprises a bottom and one or more sidewalls; and - wherein at least a part of the bottom comprises one or more sliding plates which are slidable in a plane defined by the bottom between a filling state and an unmoulding state to thereby promote that the in the mold cavity molded green brick comes loose therefrom in the demoulding state. Mold container part according to claim 1, wherein the one or more than one sliding plate comprises one or more opening to define an aerator adapted to selectively introduce air in the demoulding state between the bottom of the mold cavity and the in the mold cavity. mold cavity to allow molded molding. 3. Mold container part according to claim | or 2, wherein the sliding plate extends over at least two adjacent mold cavities. Mold container part according to claims 2 and 3, wherein the one or more opening in the sliding plate is covered in the filling state by a partition wall between adjacent mold cavities. Mold container part according to at least one of claims 2-4, wherein the one or more opening in the sliding plate in the filling state is covered by a bulge extending from the bottom inwardly into the mold cavity. Mold container part according to at least one of the preceding claims, wherein the mold cavities have a rectangular shape, and wherein the sliding plate is movable in a width direction of the mold cavities. Mold container part according to at least one of the preceding claims, wherein the sliding plate extends in a longitudinal direction of the mold container part and over a plurality of mold cavities. Mold container part according to at least one of the preceding claims, wherein the sliding plate extends over substantially the entire length of the mold container part to extend over a row of mold cavities arranged therein. Mold container part according to at least one of claims 6-8, wherein the width of the mold cavities is arranged in the longitudinal direction of the mold container part. Mold container part according to at least one of the preceding claims, wherein the sliding plate is arranged flush with the bottom. Mold container part according to at least one of claims 2-10, wherein the one or more opening is a through hole or a slot. A mold container part according to at least one of claims 2-11, wherein the one or more than one opening is tapered. Mold container part according to at least one of claims 2-12, comprising two sliding plates which are arranged next to each other and which are adapted to be moved in opposite directions in the demoulding condition. Sliding plate of or for a mold container part according to any one of claims 2-13, comprising one or more opening to define an aerator. Sliding plate according to claim 14 of or for a mold container part according to any one of claims 3-13, wherein a plurality of openings are arranged at a longitudinal spacing from each other. Sliding plate according to claim 15, wherein the longitudinal spacing corresponds to at least one of: - a distance between two adjacent partition walls arranged between adjacent mold cavities: and - a distance between protrusions extending from the bottom inwardly into two adjacent mold cavities. 17. Mold container press, comprising: - a mold container part according to at least one of the preceding claims; and - an actuator for sliding the sliding plate between the filling state and the demoulding state. A mold mold press according to claim 17, further comprising a vibrator adapted to vibrate the mold container part in the demoulding condition, in which an open side of the one or more mold cavity is directed downwards. A molding press according to claim 17 or 18, further comprising a blower or compressor adapted to introduce, in the demoulding state, air under pressure between the bottom of the mold cavity and the green brick formed in the mold cavity.