CUTTING DEVICE FOR CUTTING UNFIRED BRICKS AND METHOD FOR MANUFACTURING HAND-MOULDED FIRED BRICKS, SUCH AS STONE STRIPS

Abstract

 The present invention relates to a wire cutting device (1) for cutting unfired bricks, comprising a wire (2), displacement means (12, 13) for moving the wire (2) downwards through a horizontal unfired brick (10) and control means (13) for controlling this movement. In addition, the present invention relates to a method for manufacturing bricks, such as stone strips (14), comprising forming a hand-moulded brick (10), placing said hand-moulded brick (10) on a surface (11) and cutting it by means of a wire (2) which is moved downwards through the hand-moulded brick (10), cutting the hand-moulded brick (10) before firing.

Description

[0001] The present invention relates to a cutting device for cutting unfired bricks.
In addition, the present invention relates to a method for manufacturing hand-moulded fired bricks, such as for example stone strips.

[0002] Stone strips are mainly used for renovations, in which case the external insulation is installed and the façade is then finished with stone strips in order to give the façade the appearance of a classic façade made of bricks.

[0003] At present, such stone strips are usually made by sawing strips from one or from both sides of bricks. Also, strips of two sides adjoining each other at an angle are sawn off in this way to manufacture a corner stone strip.

[0004] Manufacturing stone strips in this way has a number of drawbacks and is also very laborious and expensive. Firstly, the stone strips have to be made from fired bricks.
The bricks from which the stone strips are sawn are firstly packaged after firing and then taken to the sawmill. There, they are unpacked again and manually arranged on the sawing machine. Subsequently, these bricks are sawn into stone strips and the resulting stone strips are repackaged.

[0005] Turning bricks into stone strips by sawing also requires a large amount of energy.

[0006] When sawing bricks into stone strips, there is usually also approximately 15% spoilage as a result of incorrect sawing or due to the strip breaking off during sawing.

[0007] The portion of such bricks from which the stone strip is sawn, is lost, or the recuperation thereof (crushing to stone rubble) is laborious and energy-consuming. Usually, only one single stone strip can be produced from one brick, as a result of which the largest portion of the material of such a brick is lost. This also means that the energy used to dry and fire this portion of the material which is lost will also be lost.

[0008] FR 3 007 683 describes a method to be able to produce two stone strips from one single brick, of which only one side was originally suitable to be the visible side, by giving a stone strip sawed off on the opposite side of the visible side of a brick an additional treatment in order to make it suitable as a visible side.

[0009] It is also known to manufacture special hollow bricks via the extrusion process from which stone strips can be sawn, in which less material is lost when sawing a stone strip off such a hollow brick due to the absence of the cavities, than when sawing stone strips from solid bricks.
GB 2 485 540 A describes how hand-moulded bricks and moulded fired bricks comprising a certain recess may be produced so as to be able to saw off stone strips while reducing the loss of material.

[0010] It is known from WO 2013/186566 A1 to cut, for a specific composition of brick material, a brick made from the latter before it is fired in order to produce a stone strip, so that the energy for the firing of the lost portion of material is no longer lost. However, the above-described solution is only suitable for bricks which show little plasticity in the unfired state, such as bricks which are produced by means of an extruder.
EP 2 826 608 A1 describes an alternative manufacturing method for directly manufacturing stone strips in a press, in which the brick material is cut to size by means of the press device. However, this method is only suitable for bricks which show little plasticity in the unfired state. Although in this case the aim is to achieve the appearance of a hand-moulded brick, such a method produces a stone strip with more flat walls than stone strips which are produced from hand-moulded bricks, so that it is not possible to achieve the same aesthetic effect.

[0011] In practice, hand-moulded fired brick stone strips are not manufactured directly, due to the fact that, on the one hand, because of the limited thickness of stone strips, it is not possible to produce hand-moulded stone strips directly in moulds.
For extruded bricks, directly manufacturing stone strips requires too large an investment to change over the manufacturing equipment for the proportion of stone strips to be manufactured compared to the proportion of bricks to be manufactured.

[0012] It is an object of the present invention to provide a solution to the abovementioned problems, so that it becomes possible to manufacture stone strips in an economically viable way, using less energy and without a great loss of material or laborious ways of recovering material.

[0013] This object of the invention is achieved by providing a wire cutting device for cutting unfired bricks, comprising a wire for cutting these unfired bricks, tensioning means for keeping this wire tensioned between two ends, two wire holders for holding the wire between these ends, away from a straight line between these ends and at an intermediate distance from each other, damping means for resiliently mounting these wire holders on the cutting device, displacement means for moving the wire downwards through a horizontal unfired brick and control means for controlling this movement.

[0014] Until now, only sawing devices were known for sawing stone strips from hand-moulded bricks, by means of which the hand-moulded bricks could only be sawn after they had been fired.
Wire cutting devices were already known for extruded bricks by means of which the latter could be cut in the unfired state. However, these known wire cutting devices which are used to cut extruded bricks cannot be used to saw stone strips from hand-moulded bricks. In the unfired state, hand-moulded bricks are too mouldable for this purpose, as approximately 30% water is required to allow a hand-moulded brick to assume the shape of the mould.

[0015] By now providing such a wire cutting device with wire holders and damping means for resiliently mounting these wire holders on the cutting device, and by moving the wire downwards in a controlled manner with respect to a horizontal unfired brick, it was found that it is indeed possible to cut hand-moulded bricks in wet condition or (partly) dried condition, prior to the firing thereof.

[0016] By cutting stone strips from the hand-moulded bricks before they are fired, the excess material which remains after the cutting next to the stone strips can be recovered in an energetically and ecologically more advantageous manner. In this way, less energy is required to manufacture such stone strips. These stone strips are produced virtually without loss of material as the excess material can be recovered directly or in a much less laborious way than would be the case if the bricks were fired.

[0017] Obviously, a cutting device according to the present invention may also be used to cut stone strips from other types of bricks.
This cutting device may also be used, for example, to manufacture half bricks by cutting bricks in two in the unfired state.

[0018] In addition, using a cutting device according to the present invention, it is not only possible to cut through bricks entirely, but it is now for example also possible to partially cut bricks in the unfired state.
Cutting bricks partially is useful, for example, in cases where both solid and half bricks are required for the same building. Now, the half bricks are produced by sawing a solid brick in two at the building site or at a manufacturing plant for prefab walls. By cutting the bricks almost completely with a cutting device according to the present invention, these can be treated as standard bricks during the manufacturing process and can simply be divided into two halves after firing at the building site or at a manufacturing plant for prefab walls, for example by simply tapping these bricks with a trowel. The cutting depth is then preferably determined in such a way that the combination of the two halves remains a unit during handling in the factory, but that it is as easy as possible to separate them at the building site.

[0019] Said cutting device can easily be introduced in an existing line for manufacturing hand-moulded bricks, after the hand-moulded bricks have been formed in the moulds and have been demoulded. In this way, it also becomes possible to make these stone strips from the same batch of clay as, for example, solid bricks or bricks of different sizes. This offers a significant advantage with regard to renovations, in which bricks of different sizes having the same appearance are desired in order, on the one hand, to build new walls and, on the other hand, clad existing walls.

[0020] Due to the damping means, hand-moulded bricks can also be cut up, despite the arcuate shape of the drying slats on which the hand-moulded bricks are placed to dry.

[0021] By means of this cutting device, it is also possible to manufacture stone strips of larger sizes than is possible with the known production methods for manufacturing stone strips from hand-moulded bricks.
In addition, stone strips which are produced by means of this cutting device may be thinner than stone strips which are sawn from hand-moulded bricks in the fired state. A hand-moulded brick could also be made smaller, so that only two stone strips can be cut from it, without loss of material.

[0022] In a specific embodiment, such a cutting device furthermore also comprises a support element to keep the wire between the wire holders.
A cutting device of this kind preferably also comprises damping means for resiliently mounting this support element on the cutting device.

[0023] If this support element is arranged in line with the wire holders, it is readily possible to ensure, in case of larger sized bricks and brick portions to be cut therefrom, such as for example stone strips, that the brick is cut through along the entire length. Such a support element can also advantageously be used with certain materials for producing bricks.

[0024] In addition, if the wire holders and the support element are arranged in a triangle, it is also possible to manufacture corner stone strips by using a cutting device according to the present invention. A straight line which extends through the first wire holder and the support element, at the location where these hold the wire, is then preferably at right angles to the straight line which extends through the support element and the second wire holder, at the location where these hold the wire.

[0025] The damping means of a cutting device according to the present invention are configured to ensure the wire is damped by means of the wire holders and the optional support element, with damping taking place in a direction at right angles to a straight line between the ends of this wire. To this end, these damping means may, more specifically, comprise at least one spring. These damping means are preferably chosen as a function of the clay mass to be cut.

[0026] The wire of a cutting device according to the present invention is preferably made from hardened steel. Other materials, such as for example plastic, could also be suitable.
Such a wire preferably has a diameter of between 0.1 mm and 1 mm and more preferably a diameter of approximately 0.35 mm. This diameter is preferably chosen as a function of the clay mass to be cut.

[0027] In a specific embodiment, a cutting device according to the present invention comprises a fixing element for retaining at least a part of a brick to be cut during cutting thereof. This fixing element is able to securely hold this part during the cutting process, so that it remains in the desired position with greater certainty and the dimensions of this part remain correct. Such a fixing element may be used, for example, when a brick is cut in half, to retain a half brick or when a stone strip is cut from a brick, to retain this stone strip.

[0028] The object of the invention is furthermore also achieved by providing a method for manufacturing bricks, such as stone strips, comprising producing a hand-moulded brick from clay or the like in a mould, wherein the hand-moulded brick is placed on a surface after demoulding and is at least partly cut by means of a wire which is moved downwards through the hand-moulded brick, prior to the clay or the like of this stone strip being fired, wherein the downward movement is damped.

[0029] This makes it possible to manufacture, for example, hand-moulded stone strips, half hand-moulded bricks or hand-moulded bricks which have been partly cut, etc. as said bricks.
The advantages of at least partly cutting hand-moulded bricks while they have not been fired yet have already been mentioned above.

[0030] With a method according to the present invention, the hand-moulded brick is preferably cut by means of an above-described cutting device according to the present invention.

[0031] Preferably, the wire of the cutting device is initially moved relatively quickly during the cutting of the hand-moulded brick and then relatively slowly.

[0032] In a specific method, water may be added at the location of the wire for cutting the hand-moulded brick, in order to limit sticking of the clay or the like to this wire in this way.

[0033] In a further specific method according to the present invention, the wire may be heated to cut the hand-moulded brick. Due to the fact that the unfired hand-moulded brick comprises such a large percentage of moisture, this heat will create steam around the wire during cutting which helps to limit sticking of the clay or the like to this wire. Preferably, the wire is heated to this end to between 200 °C and 300 °C.

[0034] In a particular method according to the present invention, a stone strip is cut from the hand-moulded brick before the clay or the like of this stone strip is fired.

[0035] In this case, it is possible to cut the hand-moulded brick after drying and before firing it. This makes it easier to cut the hand-moulded brick through at least partly.

[0036] Preferably, however, the stone strip is cut from the hand-moulded brick prior to the clay or the like of this stone strip being dried, since the excess material can then be recovered virtually directly and with the least energy loss in the manufacturing process for producing the hand-moulded bricks.

[0037] In a particularly preferred method according to the present invention, the excess clay or the like of the hand-moulded brick which remains next to the stone strip after the stone strip has been cut from the hand-moulded brick, is sucked off by means of a suction device:

• Either, this excess material is sucked up after the stone strip has dried. At that point in time, the excess material is easier to handle. In addition, in this way the bricks are incorporated in the same drying process as non-cut bricks. However, due to the absence of the excess material, the stone strips warp during drying. This then has to be remedied while firing them. This may be achieved, for example, by placing the bricks in such a manner during firing that they automatically straighten themselves out on account of the force of gravity.
• Or, the excess material is removed prior to the drying of the stone strip. This saves a significant amount of energy which would otherwise have been used for drying the piece of clay which will not be fired to completion. It also saves a significant amount of energy with regard to recovering this excess material. In addition, the stone strips in this case do not warp during drying.

[0038] Alternatively, the excess clay or the like could also be removed by blowing it away by means of a blowing device. This may likewise be carried out before or after drying of the stone strip, with the same advantages and drawbacks.

[0039] More specifically, in order to suck up the excess material using the suction device, a suction nozzle of the suction device can be moved to the excess clay or the like of the hand-moulded brick before cutting the stone strip from the hand-moulded brick, after which a vacuum is applied to this suction nozzle, after which the stone strip is cut from the hand-moulded brick, after which a greater vacuum is applied to the suction nozzle and after which the suction nozzle is moved away from the stone strip in order to remove this excess clay or the like. Preferably, an excess pressure is then applied to the suction nozzle in order to push the material out again.

[0040] With such a method, the suction nozzle for removing the excess clay or the like is preferably moved away from the stone strip at the same time as the wire after the stone strip has been cut from the hand-moulded brick.

[0041] According to a specific method according to the present invention, a corner stone strip is cut as a stone strip by means of an above-described cutting device according to the present invention, with wire holders and a support element being arranged in a triangle. During the further production process, this corner stone strip is then preferably placed with its comer facing down before firing. Both legs of this corner stone strip are in this case turned upwards.

[0042] The present invention will now be explained in more detail by means of the following detailed description of some preferred cutting devices and a preferred method for manufacturing stone strips according to the present invention. The sole aim of this description is to give illustrative examples and to indicate further advantages and particulars of the present invention and can therefore not be interpreted as limiting the area of application of the invention or of the patent lights defined in the claims.

[0043] Reference numerals are used in this detailed description to refer to the attached drawings, in which

• Fig. 1 shows a first embodiment of a cutting device according to the present invention in front view, arranged above an unfired brick;
• Fig. 2 shows the cutting device from Fig. 1 in side view, arranged above the unfired brick;
• Fig. 3 shows the unfired brick and the wire holders of the cutting device from Fig. 1 in top view;
• Fig. 4 shows the cutting device from Fig. 1 in front view, after the cutting of an unfired brick situated underneath, in which the excess material has been removed from the unfired brick;
• Fig. 5 shows the cutting device from Fig. 1 in side view, after the cutting of an unfired brick situated underneath, in which the excess material has been removed from the unfired brick;
• Fig. 6 shows the stone strips and the wire holders of the cutting device from Fig. 1 in top view, after the cutting of the unfired brick and the removal of the excess material from the unfired brick;
• Fig. 7 shows a second embodiment of a cutting device according to the present invention in front view, arranged above an unfired brick;
• Fig. 8 shows the cutting device from Fig. 7 in side view, arranged above the unfired brick;
• Fig. 9 shows the unfired brick, the wire holders and the support element of the cutting device from Fig. 7 in top view;
• Fig. 10 shows the cutting device from Fig. 7 in front view, after the cutting of an unfired brick situated underneath, in which the excess material has been removed from the unfired brick;
• Fig. 11 shows the cutting device from Fig. 7 in side view, after the cutting of the unfired brick situated underneath, in which the excess material has been removed from the unfired brick;
• Fig. 12 shows the corner stone strip and the wire holders and the support element of the cutting device from Fig. 1 in top view, after the cutting of the unfired brick and the removal of the excess material from the unfired brick.

[0044] The first cutting device (1) illustrated in Figs 1, 2, 4 and 5 is configured to cut two straight stone strips (14) from an unfired brick (10). To this end, two steel wires (2) are each attached and tensioned at their ends by means of two springs (3) in this first illustrated cutting device (1). Each wire (2) is kept at a distance from these springs (3) at a certain distance below these springs (3) between its ends by means of two wire holders (4, 6). These wires (2) are arranged virtually parallel to each other at a distance apart. If desired, a support element (8) may be provided between the wire holders (4, 6) in such an embodiment for cutting straight stone strips (14) which is arranged in line with the wire holders (4, 6) to keep the wire (2) between both wire holders (4, 6) in a straight line.

[0045] The second cutting device illustrated in Figs 7, 8, 10 and 11 is configured to cut a corner stone strip (14) from an unfired brick (10). To this end, a steel wire (2) is attached and tensioned by means of two springs (3) at its ends. By means of two wire holders (4, 6), this wire (2) is kept at a distance from these springs (3) at a certain distance below these springs (3) between its ends. The wire (2) is held between the wire holders (4, 6) at an angle by means of a support element (8), in such a way that a straight line which extends through the first wire holder (4) and the support element (8), at the location where these hold the wire (2), is virtually at right angles to the straight line which extends through the support element (8) and the second wire holder (6), at the location where these hold the wire (2).

[0046] The wire holders (4, 6) and the support element (8) of the illustrated embodiments are hydraulically damped and the wire holders (4, 6) are mounted resiliently on the cutting device (1) by means of springs (5).
The steel wire (2) is made from hardened steel and has a diameter of approximately 0.35 mm. The wires (2) have been shown thicker in order to make the figures clearer. Each of the cutting devices (1) comprise a linear motor (13) which is displaceably mounted on a frame (12) in order to move the framework (15) with the springs (3) mounted thereon, the wire holders (4, 6), the optional support element (8), the damping means (5) and the wire (2).

[0047] The cutting device (1) furthermore comprises a fixing element (9) for retaining stone strips (14) to be cut during cutting thereof.

[0048] In order to produce a stone strip (14) by means of these cutting devices (1), firstly, a hand-moulded brick (10) may be formed out of clay in a mould and demoulded. This hand-moulded brick (10) is placed on a drying board (11) and passed underneath the cutting device (1). The fixing element (9) is moved as far as up to the stone strip (14) or stone strips (14) to be cut, as can be seen in Figs 4, 5, 10 and 11. A suction nozzle of a suction device (not shown) is moved to the excess clay of the hand-moulded brick (10) which remains next to the stone strip (14) after the stone strip (14) has been cut from the hand-moulded brick (10). A vacuum is applied to this suction nozzle. Thereafter, the wire (2) is (or the wires (2) are) moved down by means of the linear motor (13) which moves the framework (15) in order to cut the hand-moulded brick (10) and thus cut the stone strip (14) or stone strips (14) from the hand-moulded brick (10), as can be seen in Figs 4, 5, 10 and 11. The linear motor (13) initially drives the wire (2)/wires (2) quickly and slower for the last few centimetres, to end on the drying board (11), with the movement being slowed down by means of the springs (5) and hydraulically. In this case, the wire (2) is thus initially moved more quickly and then more slowly, until it has completely cut through the hand-moulded brick (10) and the stone strip (14) or stone strips (14) has/have been formed. A still greater vacuum is then applied to the suction nozzle, so that the excess of clay partly ends up in the suction nozzle. Thereafter, both the suction nozzle and the wire (2) are moved upwards simultaneously. While the stone strip (14) is taken further on the drying board (11), the suction nozzle is moved further horizontally until it is situated above a conveyor belt and the vacuum in the suction nozzle is switched to overpressure to push the excess of clay out of the suction nozzle and carry it away using the conveyor belt. The pressure is then switched off and the suction nozzle is returned to an initial position. In the meantime, a subsequent formed hand-moulded brick (10) may have been positioned under the cutting device (1) by means of the drying board (11), in which case the abovementioned process is repeated. In this way, successive stone strips (14) may be cut from hand-moulded bricks (10) by means of the illustrated cutting devices (1) in a continuous process.

[0049] In order to also fire corner stone strips (14) which have been sawn from hand-moulded bricks (10) by means of the second illustrated cutting device (1) after they have been dried, they are preferably placed with their corner facing downwards before firing. In this case, both legs of these corner stone strips (14) are turned upwards.

Claims

1. Wire cutting device(1) for cutting unfired bricks (10), comprising a wire (2) for cutting said unfired bricks (10), tensioning means (3) for keeping said wire (2) tensioned between two ends, characterized in that the cutting device (1) comprises two wire holders (4, 6) for holding the wire (2) between said ends, away from a straight line between said ends and at an intermediate distance from each other, and damping means (5) for resiliently mounting said wire holders (4, 6) on the cutting device (1), comprises displacement means (12, 13) for moving the wire (2) downwards through a horizontal unfired brick (10) and comprises control means (13) for controlling said movement.

2. Cutting device (1) according to Claim 1, characterized in that said cutting device (1) comprises a support element (8) for keeping the wire (2) between the wire holders (4, 6).

3. Cutting device (1) according to Claim 2, characterized in that the cutting device (1) comprises damping means for resiliently mounting the support element (8) on the cutting device (1).

4. Cutting device (1) according to Claim 2 or 3, characterized in that the wire holders (4, 6) and the support element (8) are arranged in a triangle.

5. Cutting device (1) according to one of the preceding claims, characterized in that the damping means (5) comprise at least one spring (5).

6. Cutting device (1) according to one of the preceding claims, characterized in that the cutting device (1) comprises a fixing element (9) for retaining at least a part of a brick (10) to be cut when cutting the latter.

7. Method for manufacturing bricks, such as stone strips (11), comprising forming a hand-moulded brick (10) from clay or the like in a mould, characterized in that the hand-moulded brick (10) is placed on a surface (11) after demoulding and is at least partly cut by means of a wire (2) which is moved downwards through the hand-moulded brick (10), prior to the clay or the like being fired, wherein the downward movement is damped.

8. Method according to Claim 7, characterized in that the hand-moulded brick (10) is cut by means of a cutting device (1) according to one of Claims 1 to 6.

9. Method according to Claim 8, characterized in that the wire (2) of the cutting device (1) is initially moved relatively quickly during the cutting of the hand-moulded brick (10) and then relatively slowly.

10. Method according to one of the Claims 7 to 9, characterized in that a stone strip (14) is cut from the hand-moulded brick (10) before the clay or the like of said stone strip (14) is fired.

11. Method according to Claim 10, characterized in that the hand-moulded brick (10) is cut prior to the clay or the like being dried.

12. Method according to Claim 10 or 11, characterized in that the excess clay or the like of the hand-moulded brick (10) which remains next to the stone strip (14) after cutting the stone strip (14) from the hand-moulded brick (10) is sucked up by means of a suction device.

13. Method according to Claim 12, characterized in that a suction nozzle of the suction device is moved to the excess clay or the like of the hand-moulded brick (10) before cutting the stone strip (14) from the hand-moulded brick (10), in that a vacuum is applied to said suction nozzle, in that the stone strip (14) is cut from the hand-moulded brick (10), in that a greater vacuum is applied to the suction nozzle and in that the suction nozzle is moved away from the stone strip (11) in order to remove said excess clay or the like.

14. Method according to Claim 13, characterized in that after cutting the stone strip from the hand-moulded brick, the suction nozzle for removing the excess clay or the like and the wire (2) are moved away simultaneously from the stone strip.

15. Method according to one of Claims 11 to 14, characterized in that a corner stone strip (14) is cut as a stone strip (14) by means of a cutting device (1) according to Claim 4 and in that said corner stone strip (14) is placed with the corner facing down for firing.

Drawing