EP1775069A1

EP1775069A1 - A device for the artificial ageing of stones

Info

Publication number: EP1775069A1
Application number: EP05109599A
Authority: EP
Inventors: Willy Klaps
Original assignee: Klaps Invest
Current assignee: Klaps Invest
Priority date: 2005-10-14
Filing date: 2005-10-14
Publication date: 2007-04-18

Abstract

The present invention relates to a device (1) for the artificial ageing of substantially edged stones, the device (1) comprising a container (5) with a central volume (23) having an inlet opening (3) for receiving the stones to be aged and an outlet opening (13) for discharging stones which have been aged while moving through the internal volume of the container, which central volume (23) is delimited by at least one wall, the device (1) comprising means for moving the container to rock the stones to cause that the stones impact at least a part of the at least one wall and/or each other in view of knocking off pieces from at least one edge of the stones. The part of the at least one wall provided to be impacted by the stones (28) is at least partly made of an elastic material.

Description

The present invention relates to a device for the artificial ageing of substantially edged stones, the device comprising a container with a central volume having an inlet for receiving the stones to be aged and an outlet for discharging stones which have been aged while moving through the central volume of the container, which central volume is delimited by at least one wall, the device comprising means for moving the container to rock the stones to cause that the stones impact at least a part of the at least one wall and/or each other in view of knocking off pieces from at least one edge of the stones, according to the preamble of the first claim.
From EP-B-0.436.482 , a method is known for the artificial ageing of newly produced bricks of clay to be used in stead of recycled bricks originating from the demolition of old buildings or the facing bricks of historical or rustic facades. The artificial ageing is done to provide new materials with a more historical or rustic style. The artificially aged bricks are suitable for use in renovation of historical or rustic constructions. According to the method of EP-B-0.436.482 the bricks are fed to a drum, the inner wall of which is covered with obstacles and projections, immobilised on the inner wall of the drum. Both the drum, the obstacles and projections are generally made of steel. By rotating the drum, the bricks impact each other, the wall and the obstacles and projections present thereon for a predetermined period of time. After having been treated this way some mortar, plaster and/or water, is fed to the drum and the drum is rotated again. After having been processed in that way, the bricks all have different irregularities and encrustments of mortar and have the appearance of old or rustic bricks.
The device disclosed in EP-B-0.436.482 however has the disadvantage that the impact of the bricks with the wall causes a significant number of bricks to break into several pieces, which are unsuitable for further use in building constructions.
There is thus a need for a device with which the risk to breaking of stones may be reduced.
Accordingly, it is the object of the present invention to provide a device with which the risk to breaking of stones may be reduced.
This is achieved according to the present invention with a device showing the technical features of the characterising portion of the first claim.
Thereto, the part of the at least one wall provided to be impacted by the stones is at least partly made of an elastic material.
Preferably the whole part of the wall to be impacted by the stones is made of an elastic material.
The inventor has found that by using a container in which the part of the at least one wall provided to be impacted by the stones is at least partly made of an elastic material, the desired nature of ageing may be achieved. In particular, ageing may be achieved in the form of the wanted effect of knocking off small pieces from the edges and the corners of the stones inducing the desired rustic appearance.
The inventor has further found that the use of a container wherein the part to be impacted by the stones is made of an elastic material, permits significantly reducing the risk to the breaking of stones. Without wanting to be bound by any theory, the inventor believes that this effect may be attributed to the fact that through the elasticity of the wall the contact-time between the impacting stones, having a certain momentum, and the wall is prolonged. As a consequence, the resultant force exerted by the stones on the wall is reduced thus also reducing the resultant force of the wall on the stones as compared to the resultant force acting on stones with an equal momentum impacting a rigid wall. As a further consequence, the resultant force acting on stones impacting each other is also reduced as compared to stones impacting each other in a container comprising a rigid wall. This reduces the risk to breaking of the stones when they impact the wall as well as each other. These two effects contribute in reducing the risk to the breaking of stones during the ageing process. Besides this, the device of this invention has been found capable of providing a reproducible ageing of the stones, regardless of the nature of the material of the stones or their dimensions. This has up to now not been possible with the known prior art devices.
The inventor has also found that the device of this invention is suitable for ageing stones made of a wide variety of materials, which may have a higher or smaller brittleness and sturdiness and stones made of softer and harder materials. The device of the present invention has been found suitable for ageing stones having widely varying dimensions, for example a width or height of a few centimetres to about 10cm-50cm or more and a length of 10cm-20cm to 100cm or even more. Moreover with the device of this invention a comparable ageing of the stones may be obtained regardless of their dimensions, the nature of the material of which they are made and/or physical properties. This is of interest for modern architecture where different types of stones are mixed in a construction or application and the apparent age of the different types of stones used in the construction may have to look comparable to reach the desired esthetical effect.
Another preferred embodiment is characterised in that the elastic part of the at least one wall comprises a plurality of zones of different elastic materials having a different elasticity. In this way the elasticity of the net can be adapted to the specific stones which are to be aged.
According to a preferred embodiment of the invention, the device of this invention is characterised in that the elastic part of the at least one wall comprises a net or mat with a plurality of meshes which are dimensioned such that they do not permit passing of the stones but do permit passing of debris originating from the impact. Due to the meshes dimensioned in this way the debris can be evacuated out of the container while being generated. In that way the risk that the debris contacts the stones or is impacted by the stones and the risk that the debris deposits on the stones may be diminished. This is of particular importance when batches of stones having different colours are successively passed through the device of this invention and deposition of debris of a different colour may give rise to unwanted colouring. Such colouring could harm the esthetical aspects of the final aged stones in addition to creating less reproducible ageing of the stones.
Preferably the net comprises a multiplicity of adjacent cables, every at least two adjacent cables being connected to each other at a plurality of positions in longitudinal direction of the cable by connecting means to form the meshes. The result is that the elastic part of the at least one wall is elastic in longitudinal and/or axial or transverse direction of the container, which permits to further reduce the risk to the breaking of stones and to improve the reproducibility of the ageing process.
Another preferred embodiment of the device of this invention is characterised in that the cables are tensioned and that the device comprises means for adjusting the tension of the cables in view of permitting to adjust the elasticity of the elastic part of the at least one wall in longitudinal and/or axial or transverse direction. The possibility of changing the tension of the cables, and thus the elasticity of the wall, renders the device suitable for the ageing of a broad range of stones, with varying dimensions, composition and/or physical properties, to provide a reproducible ageing even with long time intervals between successive batches and to control the extent to which the stones are aged in this process. An adaptable tension of the cables may be desirable to permit realising a comparable ageing of different types of stones, i.e. stones made of different materials and having different dimensions and/or physical properties.
A further preferred embodiment of the device of this invention is characterised in that the adjacent cables run substantially parallel to each other and extend in longitudinal direction of the container and the means for connecting the cables comprise a plurality of plates in a staggered position with respect to each other, the plates connecting at least two adjacent cables to each other. The staggered positioning provides a virtual uniform elasticity over the elastic wall.
Preferably the inner face of the container facing the central volume comprises at least one protrusion or driving element protruding from the wall, the driving element being dimensioned so as to cause the stones to tip over and tumble. In this way the likeliness that the stones impact both the wall and each other is ensured.
To cause tumbling and rocking of the stones, the device of this invention preferably comprises means for rotating the container about a rotation axis which extends in longitudinal direction of the container. Preferably the device of this invention also comprises means for adapting the rotation speed of the container. Rotating the container in stead of, for example, shaking the container back and forth, provides a continuous and uniform movement, with a minimum risk to the occurrence of instant chocks. The continuous movement permits achieving a more uniform and reproducible ageing of the stones. As the risk to the occurrence of instant chocks is reduced, the risk to breaking of the stones is also reduced. Preferably the device comprises means for adjusting the rotation speed as this permits adapting the movement of the container, and thus the intensity or force with which the stones impact each other and/or the wall, to the nature of the stones and to the envisaged extent of ageing. Thus a desired ageing of stones may be obtained regardless of the dimensions, nature and/or physical properties of the stones by changing the rotation speed of the container.
Preferably the longitudinal axis of the container slants in relation to a horizontal plane and the device comprises means for adjusting this slope. Thus, no installation for transporting the stones through the container is required: the tumbling and the transport of the stones through the container is caused by gravity, the speed and thus the momentum of this downward motion is governed by the slope of the container. By providing the device of this invention with means for adapting this slope, the device may be adapted to the dimensions, nature and/or physical properties and the envisaged extent of ageing of the stones. The slope can for example be adjusted as to provide stones of different dimensions and/or physical properties with a comparable ageing.
Other details and advantages of the device according to the invention will become apparent from the enclosed figures and description of preferred embodiments of the invention.
Figure 1 shows a cross-section of the device according to the invention along the axial direction.
Figure 2 shows a cross-section of the device according to the invention in radial direction.
In the context of this application edged stones are stones comprising at least one edge. The exact dimensions, nature and/or physical properties of the edged stones are not critical to the invention as the device 1 comprises means for adapting the device 1 to these different types of stones as discussed below.
The preferred embodiment of the device 1 of this invention shown in figure 1 and 2 comprises a container 5 and a supporting frame 11. The container 5 is delimited by a circumferential wall 26, a top face 12 and a bottom face 24. The shape of the container 5 is not critical to the invention and may for example be cylindrical, substantially beam shaped, polygonal or any other shape considered suitable by a person skilled in the art. To ensure that the total surface of the circumferential wall 26 in radial direction can be used for the process of ageing of the stones, the container 5 is preferably substantially cylindrical. However, the shape of the container 5 is not critical to the invention and may be any shape considered suitable by a person skilled in the art, for example, cylindrical or rectangular, the shape of a polygone or any other shape.
As can be seen from figure 1, the container 5 may be enclosed in a cylindrical outer container 2. The second container may function to collect the debris originating from the ageing of the stones. The outer container 2 has been found to function as a noise isolator so that the noise produced in the course of the ageing process may be reduced to an acceptable level, for example approximate 105dB. The second container 2 may also function as a dust collector, reduce spreading of dust in the environment and facilitate collection and disposal of the debris and dust. The outer container 2 preferably comprises means for evacuating the debris, for example an opening 19 closed by a lid on the bottom end of the outer container. The shape of the outer container 2 is not critical to the invention and may be any shape considered suitable by a person skilled in the art, for example, cylindrical or rectangular, the shape of a polygone or any other suitable shape.
The device 1 comprises an inlet for feeding the stones in the container 5 and an outlet for removing aged stones. The inlet is preferably positioned on the top face or wall, for example an opening in the top face 3, while the outlet is preferably positioned on the bottom wall, and may comprise a bottom opening 13. The outlet may however also be provided in the circumferential wall 26, the outlet being in the vicinity of the bottom in the form of, for example, a plurality of holes along the circumference of the wall. The top opening 3 can be smaller or larger than the bottom opening 13 but its size is not critical to the invention.
To reduce the risk to breaking of the stones in the course of the ageing process at least part, preferably all, of the circumferential wall 26 of the container 5 to be impacted by the stones, is made of an elastic material.
A suitable example of an elastic wall is a net 29 or a mat. The wall may comprise a plurality of interconnected nets, which may be made of the same or a different material, having the same or a different elasticity. Thus a wall may be provided with varying elasticity. The net or mat comprises a plurality of meshes 9. These meshes 9 are dimensioned such that on the one hand debris and dust, formed during the ageing of the stones, can be evacuated while being generated in the container 5, but on the other hand the stones are prohibited from leaving the container 5. Such a net 29, or a mat satisfies the need for elasticity and has the advantage that the risk that stones impact the debris is minimised, so that unwanted colouring of the stones is prevented, when for example different batches of stone having different colours are successively passed through the container.
A net 29 may for example comprise a plurality of adjacent cables 15, chains, comprising series of connected rings or links, or even ropes. Preferably use is made of cables or chains which extend in the direction of the longitudinal axis 4 of the wall. However, the cables or chains may extend in radial direction as well.
The nature of the elastic material is not critical to the invention. Preferably the material is chosen such that its hardness is greater than the material of the stones, to achieve the desired ageing of the stones, for example ceramic material, fibres, composite or carbide materials or metal. Preferably however the elastic part 28 of the circumferential wall 26 is made of metal, more preferably steel because of its superior wear resistant properties.
To realise the above-mentioned meshes 9, dimensioned as above-explained, two or more adjacent cables 15 or chains are mutually connected by connecting means 7. The connecting means 7 may be attached to two, three or more cables. In the preferred embodiment of the device 1 every two adjacent cables 15 are connected to each other. To improve the elasticity and uniformity of the elastic part of the wall 28, the connecting means 7 preferably extend mainly perpendicular to the cables and are preferably positioned equidistant along the length direction of the container 5. The connecting means 7 can be arranged in any possible way considered suitable by the person skilled in the art, for example in columns, but are by preference positioned in a staggered configuration to achieve that each time at least two adjacent cables are connected and connection over the whole surface of the net is achieved. The staggered positioning provides a uniform elasticity of the elastic wall. The connecting means 7 are preferably mounted immobile, but may be mobile and/or removable. The number of connecting means 7, in longitudinal and cross direction of the circumferential wall 26, may be the same or may vary on different parts of the wall to vary the elasticity of the wall, and can be adapted to the nature, dimensions and/or physical properties of the stones. The shape of the connecting means 7 is not critical to the invention and can be of any shape considered suitable by a person skilled in the art. Preferably however, the connecting means 7 comprise a plurality of plates 30, possibly with a sharp edge on the side of the inner volume 23 of the container 5. The connecting means may be made of the same material as the cables or of a different material, but are preferably made of the same material to preserve the homogeneity of the circumferential wall. Thus, preferably the connecting means 7 are made of metal, more preferably steel.
The face of the container 5 facing the central volume 23 preferably comprises at least one driving element causing the stones to rock and tumble through the container. The driving element may for example be positioned between the connecting means or be mounted onto them. The driving element may be connected to only one cable or to two or more cables although the connection to one single cable is preferred to preserve the elasticity of the circumferential wall. According to a preferred embodiment of the device 1 the driving element comprise barbs or protrusions 17 provided on the members connecting the cables, which cause the stones to tumble. When use is made of a polygonal shaped elastic wall, the presence of barbs or driving elements can be dispensed with.
Preferably the cables 15 run substantially parallel to each other. This however is not mandatory; the cables 15 can, for example, cross each other. The cables 15 preferably extend along the longitudinal axis 4 of the container 5 as is shown in figure 1, in particular parallel to the longitudinal axis 4 of the container 5, but can also extend otherwise, for example in radial direction or any other suitable direction having an angle with the longitudinal axis 4. It is however preferred that the cables 15 run along the direction of the longitudinal axis 4 as this facilitates the mounting of the cables and adjusting the tension of the cables 15 to the wanted effect of ageing and/or the dimensions, nature and/or physical properties, by pulling or loosening the cables 15 in the direction of the longitudinal axis 4 and/or by adapting the length of the connecting means 7, preferably the plates 30. The mounting in longitudinal direction is preferably achieved by suspended cables 15 between two rings: a first upper circular ring 6 on a first side of the container 5 in the vicinity of the top part of the circumferential wall 26 or the top part of the elastic part 28 of the circumferential wall 26, and a second bottom circular ring 16 on a second side of the container 5 opposite the first side, taken in longitudinal direction 4 of the container 5. The first 6 and second ring 16 are provided to be connected to opposite end parts of the cables 15. The cables extend a bit through these rings and thus end on the outer side of the cylinder formed by the net 29 and the circular rings 6,16 to maximise the length 27 of the elastic part of the wall.
The means for adjusting the tension of the cables 15 may be any means considered suitable by a person skilled in the art and may for example comprise a threaded rod, positioned behind the bottom ring 16 or in front of the upper ring 6. The tensioning of the cables 15 can be done manually or can be electrically, pneumatically or hydraulically controlled.
The result of the above-described connection and tensioning of the cables is that the elastic part of the at least one wall is elastic both in longitudinal and/or axial or transverse direction of the container, depending on its shape.
In the device 1 according to the invention the stones are aged by impacting the elastic wall 28 and each other. This process is caused by tumbling and rocking the stones in the container 5. Thereto the device of the invention preferably comprises means for moving the container 5, preferably means for rotating it around the longitudinal axis 4. Other ways of moving the container, for example shaking the container back and forth, horizontally and/or vertically, may be used as well but they have a discontinuous way of moving, increasing the risk for the stones to be broken and causing less reproducibly aged stones due to a non-uniform movement, involving the occurrence of instant chocks. Rotation of the container along its longitudinal axis may for example be achieved by mounting the first ring 6 and the second ring 16 on a roller bearing 14 so that the container 5 can be rotated around its longitudinal axis 4 by using a rotary engine. The rotation speed 25 is preferably adjustable to take account of the requested apparent age and/or the nature, dimensions and/or physical properties of the stones to be aged. Accordingly, if a comparable ageing of stones of different nature, dimensions and/or physical properties is required, the rotation speed 25 can likewise be adjusted so as to provide the particular type of ageing wanted.
The stones are fed to the container 5 through the inlet opening 3 and collected through the outlet opening 13. Transport of the stones throughout the container is achieved by positioning the container 5 in such a way that its longitudinal axis 4 slants in respect to the horizontal plane 21. This way the stones are pulled down by gravity so that they can be collected near the bottom of the container by the bottom opening 13. This way of working the stones permits operation in a continuous manner as well as a batch wise manner. By providing means for adjusting the slope 8 of the device 1, the residence time of the stones in the container 5 can be adjusted according to the required ageing and/or the nature, dimensions and/or physical properties of the stones to be aged. The slanting positioning may for example be achieved using means for tilting the container in relation to the supporting frame 11, or the whole of the container 5 and the supporting frame 11 can be tilted by a telescopic supporting stand 18, as represented in figure 1.
The process of the ageing of stones using the above-described device usually proceeds as follows. The stones are fed to the device 1 through inlet opening 3, the device 1 being tilted with a certain slope 8 in respect to the horizontal plane 21. The rotation of the container causes the stones to tumble and rock through the container 5 when they impact each other, the barbs 17, the driving elements, and/or the connecting means 7 of the container wall. By impacting the elastic part 28 of the at least one wall, and/or the other stones, pieces of stone are knocked off the edges and the corners, and the surface of the stones gets carved thus creating the rustic appearance of the stones. The stones are removed through the outlet 13, and are ready for further treatment, use in building constructions or can be subjected again to the ageing process depending on the wanted ageing effect and the result already obtained.
By suitably adapting the tension of the cables 15, the rotation speed 25, the slope 8 of the container 5 and the amount of barbs 17 and connecting means 7, the force with which the stones impact each other and the wall of the container and their residence time in the container may be adjusted to achieve the desired degree of ageing, while minimising the risk to breaking of the stones, regardless of nature of the materials of which the stones are made, their dimensions and/or physical properties. A person skilled in the art is capable of adjusting these parameters for each type of stone.
Length and/or diameter of the container 5 are not critical to the invention because the residence time can be controlled as well by the slope 8 of the longitudinal axis of the container and the rotation speed 25. Obviously the dimensions of the container 5 can be made smaller or larger when smaller or larger stones respectively are being used.
The process of this invention is suitable for the ageing of new, old or used stones, regardless of their dimensions and the nature of the material of which they are made. The process of this invention permits achieving a comparable and reproducible age for these stones if so desired or any degree of ageing envisaged. In case relatively new stones are used in the process of this invention, because the stones have not been subjected to the natural erosion and temperatures, the quality of the stones can still be guaranteed unlike recycled stones originating from, for example, the demolition of old buildings, while having exactly the same rustic appearance as the recycled stones. Because any type of stone can be processed with this device it is of particular interest for restoration or renovation purposes. When stones of matching nature, dimensions and/or physical properties are found they can be treated by the device of the present invention to obtain stones with a comparable age as the existing stones, but with a supreme quality. Construction is thus no longer bound to the supply of recycled stones found at a certain moment. To the contrary, stones of a broad spectrum of natures, dimensions and/or physical properties, in opposition to the state of the art, and the age of those stones can be chosen in advance for an acceptable price thus adding to the materials that can be used in construction.
The person skilled in the art is capable of determining an optimum between the number of stones, which decreases the effect of the elasticity, and the required elasticity in order to obtain the wanted effect of ageing of the stones.
The device and method/process of this invention are suitable for ageing stones of a wide variety of materials, for example bluestone, granite, clinkers, ceramic stones or any other material known to a person skilled in the art. Within the framework of the present invention, substantially edged stones designates stones having one or more edges. Such stones may be substantially block, beam or cubic shaped, be polygonal or any other edged shape known to the person skilled in the art.

Claims

A device (1) for the artificial ageing of substantially edged stones, the device (1) comprising a container (5) with a central volume (23) having an inlet opening (3) for receiving the stones to be aged and an outlet opening (13) for discharging stones which have been aged while moving through the internal volume of the container, which central volume (23) is delimited by at least one wall, the device (1) comprising means for moving the container to rock the stones to cause that the stones impact at least a part of the at least one wall and/or each other in view of knocking off pieces from at least one edge of the stones, characterised in that, the part of the at least one wall provided to be impacted by the stones (28) is at least partly made of an elastic material.
A device according to claim 1, characterised in that the elastic part (28) of the at least one wall is elastic in longitudinal and/or axial direction of the container (5).
A device according to any one of claims 1 or 2, characterised in that the elastic part (28) of the at least one wall comprises a plurality of zones of different elastic materials having a different elasticity.
A device according to any one of claims 1-3, characterised in that the elastic part (28) of the at least one wall comprises a net (29) or mat with a plurality of meshes (9) which are dimensioned such that they do not permit passing of the stones but do permit passing of debris originating from the impact.
A device according to claim 4, characterised in that the net (29) comprises a multiplicity of adjacent cables (15), every at least two adjacent cables (15) being connected to each other at a plurality of positions in longitudinal direction of the cable by connecting means (7) to form meshes (9) which are dimensioned such that they do not permit passing of the stones but do permit passing of debris originating from the impact.
A device according to claim 5, characterised in that the adjacent cables (15) run substantially parallel to each other and extend in longitudinal direction (4) of the container (5) and the means for connecting (7) the cables (15) comprise a plurality of plates (30) in a staggered position with respect to each other, the plates connecting at least two adjacent cables to each other.
A device as claimed in claim 5 or 6, characterised in that the cables (15) are tensioned and that the device comprises means (10) for adjusting the tension of the cables (15) in view of adjusting the elasticity of the elastic part (28) of the at least one wall in longitudinal and/or axial direction.
A device according to any one of claims 1 - 7, characterised in that the face of the container (5) facing the central volume (23) comprises at least one driving element, the driving element dimensioned so as to cause the stones to tip over and tumble.
A device as claimed in claim 8, characterised in that the driving element comprises at least one barb (17) provided on at least part of the plates (30), which barbs (17) are dimensioned such that they cause the stones to tip over and tumble.
A device as claimed in any one of claims 6 - 9, characterised in that the cables (15) and the plates (30) are made of metal, preferably steel.
A device as claimed in any one of claims 1 to 10, characterised in that the at least one wall to be impacted by the stones is a circumferential wall which is substantially cylindrically shaped.
A device as claimed in any one of claims 1 to 11, characterised in that the device (1) comprises means for rotating (14) the container (5) about a rotation axis which extends in longitudinal direction (4) of the container (5).
A device as claimed in claim 12, characterised in that the longitudinal axis of the container slants in relation to a horizontal plane (21), the device (1) comprising means for adjusting (18) this slope (8).
A device as claimed in any one of claims 1 to 13, characterised in that the container (5) is received in an outer container (2), having a substantially closed circumferential wall (26) surrounding at least the elastic part (28) of the wall of the first container (5).
A device as claimed in any one of claims 11 to 14, characterised in that the inlet opening (3) is provided in a top wall and the outlet opening (13) is provided in a bottom wall of the container (5).
A process for the artificial ageing of stones characterised in that at least one stone for the artificial ageing of stones is inserted into the central volume of the container (5) of the device (1) of any one of claims 1 to 15, while rotating the container (5).