Patent Application
20060288658
The invention relates to an apparatus for the artificial ageing of blocks, in particular concrete blocks, clinker bricks and natural stone blocks, according to the preamble of claim 1. The present invention also relates to a method for the artificial ageing of blocks according to the preamble of claim 34.
An apparatus of the generic type for ageing has been disclosed by DE 20 2004 020 206.9.
Blocks, for example, surfacing elements, facade elements, sand-lime blocks, concrete blocks, bricks or clinker bricks, natural stone blocks and the like, irrespective of their material condition, are often subjected to a subsequent treatment in order to lose their artificial appearance.
Freshly produced, set concrete blocks, in particular concrete paving blocks, are subjected to such a subsequent treatment especially frequently, in the course of which the surfaces and/or the edges are struck or broken in order to adapt the appearance to natural stone in this way. To this end, a relatively large number of concrete blocks are put into a rotary drum and “rumbled” there; the surfaces and edges of the blocks striking one another and the blocks thus treated leaving the drum in an “aged” state. Such an apparatus has been disclosed by DE-A 29 22 393.
During the treatment of the concrete blocks in a rotary drum, surfaces and edges which, for example when using the aged blocks, are not visible at all in a paving are also treated. To this extent, energy and time are needlessly wasted. Furthermore, it is necessary to put the treated concrete blocks leaving the rotary drum onto a pallet for dispatching in a regular arrangement, the amount of work and time which this involves being disproportionately high.
Sorting installations for sorting the blocks are known from the prior art, these sorting installations accordingly orienting the blocks and arranging them in a pallet form. Such sorting installations involve high procurement and operating costs and also take up a corresponding amount of space.
DE 36 21 276 C2 discloses a method in which concrete blocks are put onto a plate-like base in a single layer in a regular arrangement. The exposed surfaces and the adjoining exposed edges or essentially only the edges of the concrete blocks are then struck irregularly by way of a vibrating knocking or striking device.
Due to this method, a subsequent sorting device can be dispensed with, since the production layer is not changed. Before the treatment by the knocking or striking devices, the blocks are pushed together and oriented on the plate-like base, so that the blocks fit closely against one another and there is no longer any intermediate spaces between them. The striking tools of the striking device are arranged on a movable carriage which guides said striking tools across the surfaces of the blocks, so that the free surfaces of the blocks and those edges of the blocks lying at the top are struck by the striking tools.
A disadvantage with this method, however, is that the blocks aged in this way look artificially treated and not naturally aged. The use of the method of the generic publication does not result in ideal breaking of the edges of the blocks as is obtained by the rumbling of the blocks in a rotary drum.
Disclosed by EP 0 860 258 B2 is an apparatus and a method in which the blocks are arranged in one or two layers, preferably in their production layer, between two elements, preferably plates. In this case, the bottom plate, on which the concrete blocks rest, is in interaction with a vibrating device. The blocks are set in motion by the vibrating device so that they move back and forth between the plates. In the process, the blocks strike one another and also strike the top and the bottom plate as a result of which the edges on the top side and the underside are broken. In addition, the top sides and the undersides of the blocks are struck by the respectively assigned plates. The vertical side edges of the concrete blocks and the side faces are broken or struck by the respectively adjoining concrete blocks.
It has been found in tests that the breaking of the edges is all the poorer, the larger the block to be aged is. This results from the fact that the striking angle becomes all the smaller, the larger the block put between the plates is. The small striking angle results in unfavorable breaking of the edges.
As with the ageing method by way of the rotary drum, there is the disadvantage in this case that surfaces and edges of the blocks are treated which are possibly not visible at all, as a result of which energy and time are needlessly wasted. In addition, the requisite treatment time, in particular in the case of set concrete blocks, is long and the breaking of the edges is not ideal.
The generic publication DE 20 2004 020 206.9 discloses an apparatus for the artificial ageing of blocks in which the blocks (preferably in their production layer) are placed on a base, so that the surfaces to be treated and the adjoining edges of the blocks are exposed. By way of a magnet, freely movable striking bodies (of metal) are then applied to the surface to be treated. The base on which the blocks rest is set in vibration by way of a vibrating device. The blocks and the striking bodies are, therefore, set in motion relative to one another in such a way that the striking bodies act on the surfaces and the exposed edges of the blocks.
The apparatus disclosed by DE 20 2004 020 206.9 enables rapid and effective ageing of the top side of the blocks and the adjoining, exposed edges. The striking bodies randomly hit the surface of the blocks and, therefore, strike the latter irregularly, so that an optical effect is produced which corresponds to that of a naturally aged block.
According to the ageing process, the metallic striking bodies are lifted from the surface of the blocks again by the magnet by the latter being brought close to the blocks. The block layer can be removed and a new block layer can be fed. It is a disadvantage that the magnet to be used involves high costs. A further disadvantage is that downtimes occur due to the striking bodies being put down and picked up again by the magnet and these downtimes lead to longer cycle times.
The object of the present invention is, therefore, to improve the apparatus disclosed by the generic publication for the artificial ageing of blocks, in particular to develop an apparatus and a method which permits especially cost-effective and rapid ageing of blocks.
This object is achieved, according to the invention, by the apparatus as claimed in claim 1.
This object is also achieved, according to the invention, by the method as claimed in claim 34.
Owing to the fact that the striking bodies are movably fastened, but this fastening allows a movement of the striking bodies within a defined region of the surface of the blocks. This achieves the effect that, first, surfaces or the adjoining edges of the blocks continue to be struck irregularly and thus an optical effect is produced which corresponds to that of a naturally aged block and, second, a magnet for putting down the striking bodies and picking them up again from the surface can be dispensed with. By the initiation of vibrations, for example caused by a vibrating table which is arranged under the blocks, the blocks and the striking bodies are set in motion relative to one another in the manner as described in the generic publication so that the striking bodies act on the surfaces and the adjoining edges of the blocks.
According to the invention, the solution permits a plurality of variants for setting down the striking bodies and for removing them from the surfaces of the blocks and thus makes it possible to dispense with a hitherto required magnet in several ways. For example, in one embodiment, provision may be made for the retaining device on which the striking bodies are movably fastened to perform a lifting movement in order to be able to lift the striking bodies from the surface of the blocks or to feed them to said surface. The lifting of the striking bodies from an aged layer of blocks and the placing of the striking bodies again on a new layer of blocks to be aged can be carried out very quickly in this manner so that short cycle times can be maintained. The downtimes are markedly reduced compared with the prior art.
As the inventor has recognized, a special advantage of the solution according to the invention consists in the fact that lifting the striking bodies and setting them down again can be completely dispensed with. This is because the movable fastening or suspension of the striking bodies enables the apparatus according to the invention to be designed with a conveying device, for example in the form of a push rod or a conveying band, which pushes the blocks to be aged continuously or discontinuously through below the movably fastened striking bodies. The expression “continuous ageing” also refers to an interval during which the blocks are pushed through below the striking bodies with brief interruptions of 5 seconds, for example. In the process, the striking bodies, excited in a conventional manner by the initiated vibrations, act on so as to age the blocks. As already described, the movable and flexible fastening ensures that, first, the blocks are struck unevenly and that, second, the striking bodies can be prevented from traveling along with the blocks. The striking bodies in each case age the blocks which are located within the defined region available to them.
The defined region may be selected, for example, as a function of the number of striking bodies, the number of blocks and the speed of passage.
It has been found in this case that just a relatively small region within which the striking bodies are movable on the surface of the blocks is sufficient. This avoids a situation in which the striking bodies (on account of excessive mobility) can penetrate into the intermediate space between two blocks and possibly jam there.
According to the invention, provision may be made for the striking bodies to be arranged unevenly or irregularly on a retaining device, arranged transversely to the feed direction, both in the feed direction and transversely thereto so that the blocks are not aged evenly.
Furthermore, according to the invention, provision may be made for the striking bodies to be arranged in a plurality of rows transversely to the feed direction of the blocks in such way that the rows of striking bodies in each case span the blocks conveyed through. The ageing effect may in this case be varied by the number of rows of striking bodies below which the blocks have to pass through under a striking action of the striking bodies. Furthermore, the intensity of the ageing is determined by the speed of passage and by the initiated vibrations.
Due to the selection of a suitable number of rows with striking bodies, according to the invention, the apparatus can be integrated in the continuous process for producing blocks in a simple manner without this leading to a reduction in the cycle time. The blocks can pass through the apparatus of the generic type at the desired speed; the desired ageing effect being achieved by the number of rows of striking bodies. The striking bodies of a row may in each case preferably be arranged offset from an upstream or downstream row of striking bodies so that the surfaces of the blocks are uniformly treated. In principle, a non-uniformly aged appearance should certainly be produced, but this is obtained automatically by the movable fastening of the striking bodies. The offset arrangement reliably avoids a situation in which the blocks are increasingly struck (in a lasting manner) within a certain region due to the system. Provision may also be made in this respect for the distance between the rows to vary.
In a configuration of the solution, according to the invention, with a continuously working conveying device, it is sufficient if at least the striking bodies of a row are arranged in such a way that their defined regions cover the entire width of the blocks passing through under the striking bodies.
In principle, just one row of striking bodies or a few rows of striking bodies may be sufficient in order to age the blocks. However, as has been found in practice, this does not produce an optimum ageing appearance and also results in the speed of passage being relatively low.
According to the invention, in a configuration of the solution in which no continuously working conveying device is provided, provision may be made for the striking bodies to be fastened in such a way that the defined regions of the individual striking bodies together cover at least the entire surface of the blocks, preferably fed in layers.
During the discontinuous ageing, provision is made for the blocks to be fed in layers or as a unit to the region in which they are aged and for them to be aged in one operation, i.e., the blocks are not transported further until the ageing has been completed.
In a modification of the discontinuous ageing, a plurality of ageing stations to which the blocks are fed in succession may also be provided; the blocks being aged in the desired manner after they have passed through all the ageing stations.
In contrast to the discontinuous ageing, provision is made during the continuous ageing for the blocks to be transported constantly in the feed direction; that is to say, a layer or unit of blocks is not fed specifically to the ageing station or stations, but rather the process is a continuous process. This is also possible by feeding the blocks at intervals. To this end, the vibrating process need not be interrupted. In this case, the blocks are left in their position (no feed) for a relatively short period of time, e.g., 5 seconds, and are then transported further by a short distance. In tests, this has resulted in an advantageous ageing appearance without the blocks being struck increasingly due to the system.
According to the invention, provision may be made for the defined regions of the striking bodies to overlap.
The space which is predetermined by the movable fastening and in which the striking bodies can move is preferably to be selected in such a way that the striking bodies cannot penetrate into the intermediate space possibly forming between two blocks. According to the invention, provision is made in this case for the striking bodies to rest on the blocks in the rest state, that is to say, when no vibrations act on the blocks and the striking bodies.
However, it is also possible for the striking bodies to be arranged at a distance above the blocks. The blocks can, therefore, be transported through below the striking bodies without being scratched. A distance between the blocks and the striking bodies is possible without any problems, in particular in the case of thicker blocks, since the latter can be aged with a high amplitude and are thus pushed up accordingly. As has been found, a distance increases the ageing of the block edges and reduces the ageing of the block surface, a factor which may be advantageous depending on the application or the desired appearance.
With regard to especially effective ageing, however, it is appropriate if the striking bodies rest on the surface and, therefore, do not first have to overcome a distance (loss of striking energy). In particular during the ageing of thin blocks, which are aged only with a low amplitude on account of the risk of said blocks being rotated by the vibrations, contact between the striking bodies and the surface of the blocks is also appropriate in the rest state.
Provision may be made for the defined region within which the striking bodies can move on the surface of the blocks to correspond to a movement or deflection of the same of 5-40 mm, preferably 10 mm, in all directions. Under the assumption that the striking bodies are spherical and have a diameter of 40 mm, this would result in a circular defined region having a diameter of preferably 60 mm. The circumference or the horizontal cross-section of the striking bodies is, therefore, extended by 10 mm horizontally in all directions for reproducing the defined region.
It is advantageous if the striking bodies are fastened in such a way that they can perform a largely unrestricted lifting movement, resulting from the initiated vibrations.
In a constructive configuration of the invention, provision is made in this case for the retaining device on which the striking bodies are fastened to be arranged above the blocks. Here, the retaining device may constitute a plane or a pattern of retaining elements which extend in a plane-parallel manner to the surface of the blocks and are formed, for example, by a plurality of retaining rows running transversely to the direction of passage of the blocks. The striking bodies may be fastened to the retaining elements, via fastening members, which may be designed, for example as chains, ropes, rods or profile elements of varying form. The fastening members may be designed in various ways and should, at the same time, preferably ensure that the striking bodies can move as far as possible without restriction within the defined region and that, on the other hand, the striking bodies can carry out the lifting movement without considerable energy loss. The striking bodies are preferably each fastened individually to the retaining elements.
In a configuration of the apparatus, according to the invention, with a continuously working conveying device, provision may be made for means which lift at least a section of a block to be provided in the region through which the blocks pass under a striking action of the striking bodies so that the lifted section of the block projects in the direction of the striking bodies and is subjected to a more intense action of the striking bodies. The means may be designed, for example as prominences, over which the underside of the blocks are pushed on account of the feed movement (resulting from the conveying device). The prominences may preferably be of ramp-shaped design, so that the block travels up the ramp with at least one section and then drops down again or travels down said ramp again. Thus, as viewed in the feed direction, first the front region of the block is lifted and is thus subjected to a more intense action of the striking bodies, whereas subsequently the middle region and finally the rear region of the block projects in the direction of the striking bodies.
According to the invention, provision may be made for the prominences to be arranged in such a way that the blocks, with their underside, are pushed eccentrically over the prominences, as a result of which one side of the block (as viewed in the direction of passage) is in each case subjected to increased ageing. Provision is made in this case for each block to be lifted at least once on each side. In order to reduce the friction between the prominence and the underside of the block, provision may be made for the prominences to have rollers or to be designed as rollers. However, owing to the fact that the blocks are continuously lifted in this region anyway by the vibrating movement, the friction between the prominence and the block underside is not high in any case.
The means for lifting the blocks may also be designed in such a way as described in US-2002/0145224 A1.
Advantageous configurations and developments follow from the further subclaims. Two exemplary embodiments of the invention are explained in principle below with reference to the drawing. In the drawing:
According to the invention, any desired blocks, for example surfacing elements, facade elements, sand-lime blocks, concrete blocks, bricks or clinker bricks or natural stone blocks, can be aged irrespective of their material condition. The ageing of blocks 1 which are designed as concrete blocks will be explained below with reference to the exemplary embodiments. However, the invention is, of course, not restricted thereto.
The production of concrete blocks 1, in particular of concrete paving blocks, is sufficiently well known for which reason this will not be dealt with in any more detail below. The concrete blocks 1 leave the production plant generally in a production layer, i.e., in an arrangement in which the multiplicity of concrete blocks 1 are arranged next to one another in a single layer. Such a production layer is shown by way of example in
As can be seen from
With regard to the general principle of ageing with freely movable striking bodies 3, as can be seen from FIGS. 2 to 7, reference is made to DE 20 2004 020 206.9.
As can be seen from FIGS. 2 to 6, the surfaces 1a and the edges 1b adjoining the surfaces 1a of the blocks 1 are treated by striking bodies 3 which are essentially freely movable within a defined region 4 of the surface 1a of the blocks 1. To this end, the striking bodies 3 are movably fastened and arranged or suspended on a retaining device 5.
As can be seen in particular from
As can be seen from the Figures, the striking bodies 3 are freely movable both within the defined region 4 relative to the surface 1a and relative to one another. The striking bodies 3 may be made of any desired material. In the exemplary embodiment, provision is made for the striking bodies 3 to be made of carbide, metal or steel. Any desired shape of the striking bodies 3 may, likewise, be selected; it having proved to be advantageous for the striking bodies 3 to be of spherical, annular, polygonal, cylindrical or disk-shaped design. In the exemplary embodiment shown, the striking bodies 3 are essentially spherical, but are flattened on two opposite sides. This can be seen in detail in particular from
As can be seen when viewing
In the embodiment, provision is made for the striking bodies 3 of a row 7 to lie closely adjacent to one another, for example to be at a distance apart of 2 to 20 mm, preferably 5 to 10 mm.
Furthermore, provision is made in the exemplary embodiment for the retaining elements 7 or for the entire retaining device 5 to move during the striking action of the striking bodies 3 on the blocks 1. This assists irregular striking of the blocks 1 by the striking bodies 3. Provision is made in this case for an oscillating movement of the retaining elements 7, preferably in such a way that the retaining elements 7 are moved axially back and forth. This can be achieved from the design point of view with known means (e.g., an eccentric mounting or a randomly controlled pneumatic cylinder).
An alternative configuration of the fastening members 8 to that in FIGS. 2 to 4 is shown in
According to the embodiment shown in
In the exemplary embodiment, the fastening members 8 including the striking bodies 3 have a length of 200 mm. A length of 100 to 400 mm has generally proved to be advantageous.
As can be seen from
As can be seen from
According to the invention, provision may, likewise, be made for at least the row 7 of striking bodies 3 which is arranged in the inlet region, i.e., the row of striking bodies 3 which the blocks pass first when being introduced into the ageing region, to be inclined in the direction of passage (not shown). In terms of design, this may be effected in a similar manner to the inclination against the direction of passage. The advantage consists in the fact that jamming of the blocks 1 with the striking bodies 3 is avoided and the blocks 1 can, therefore, easily be fed. In an alternative embodiment (not shown), provision may also be made for all the striking bodies 3 to be inclined in the direction of passage in the rest position.
In the exemplary embodiments, provision is made for the blocks 1 to be conveyed through below the striking bodies 3, i.e., for said blocks to pass through the actual ageing region, by way of a conveying device 10. A plurality of different conveying devices 10 are known from the general prior art. For example, this may involve a band, belt or chain conveyor or the like. In the exemplary embodiment, the conveying device is designed as a chain conveyor 10 having a push rod 11 which pushes the blocks 1 over the base 2, i.e., in the actual ageing region, directly over the vibrating table. Furthermore, provision is made in the exemplary embodiment for the chain conveyor 10 to push the blocks 1 continuously through below the striking bodies 3. In this case, the speed of passage can be determined in connection with the overall production rate or the ageing result to be achieved.
Alternatively, provision may also be made for the chain conveyor 10 to merely push the blocks 1 to be aged, for example an entire production layer, into the intended position and for the blocks 1 not to be pushed forward during the ageing process (discontinuous conveying). After completion of the ageing process, i.e., once the striking bodies 3 have completed their striking action on the surfaces 1a and the adjoining edges 1b of the blocks 1 to the desired degree, the chain conveyor 10 can convey the blocks 1 further and introduce a new layer to the space which has become free.
The chain conveyor 10 is designed as a circulating conveying device. In the exemplary embodiment, the two tension chains of the chain conveyor 10 are guided outside the vibrating device 6 and their operability is, therefore, not impaired by vibrations. In principle, a multiplicity of design measures are conceivable in order to ensure that the chain conveyor 10 is not subjected to vibrations. The push rod 11, which is arranged between the two circulating chains of the chain conveyor 10, is at a distance from the vibrating table or the base 2 that ensures that the vibrating table or the base 2 does not come into contact with the push rod 11. The distance between the push rod and the top side of the base 2 or of the vibrating table must, therefore, be greater than the maximum oscillation of the vibrating table or of the base 2 in the direction of the push rod 11. As a rule, the vibrating table or the base 2 oscillates or moves by no more than at most 4 mm in the direction of the push rod 11, so that a distance of, for example, 10 mm is sufficient in order to ensure that the vibrating table or the base 2 does not touch the push rod 11 and the latter can, therefore, run smoothly and unimpeded. The distance between the push rod 11 and the top side of the vibrating table or the base 2 depends in this case on the peak-to-peak displacement or the intensity of the vibration.
In the exemplary embodiment, provision is made for the limit stops 12 to be isolated from the vibrating device 6, that is to say, they do not vibrate.
Simple design measures can ensure that the chain conveyor 10 conveys the push rod 11 in the direction of passage without the lateral limit stops 12 getting in the way. For example, the push rod 11 can be connected to the chain conveyor 10 below or above the lateral limit stops 12.
As shown in
As shown in
In principle, such ramps 13 can also be realized if the conveying device is designed as a band conveying device, the band having to run over the prominences 13 in this case. However, a design as a chain conveyor 10 having a push rod 11 has proved to be more advantageous for this purpose.
It is especially advantageous if the edges 1b of the blocks 1 are lifted. The means 13 may be designed in various ways, for example as projections, as extendable plungers according to US 2002/0145224 A1 or the like. It is, likewise, conceivable for the means 13 to be formed by a corrugated configuration of the base 2 or of the vibratory table.
The means 13 for lifting the blocks 1 at least in sections in such a way that the lifted part of the blocks 1 projects in the direction of the striking bodies 3 and is subjected to a more intense action of the striking bodies 3 may also be used independently of the inventive idea of movably fastening the striking bodies 3. For example, such a use is also possible in the apparatus according to DE 20 2004 020 206.9. During every treatment of blocks from above, owing to the fact that the blocks are lifted at least in sections, the treatment of this section can be intensified. A desired ageing result can, therefore, be achieved in a simple manner.
For reasons of clarity, the blocks 1 are shown in the non-vibrating state in
The distance, shown in
In an especially advantageous manner, the solution according to the invention is also suitable for the ageing of split blocks, which generally have an uneven surface or a surface provided with prominences and recesses. In this case, the split area of the block 1 is turned with its fracture surface toward the striking bodies 3.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 029 212.7 | Jun 2005 | DE | national |
