METHOD AND APPARATUS FOR MANUFACTURING CONCRETE ELEMENTS

Abstract: The object of the invention is a method for manufacturing concrete elements, in which method backing plates are transferred on a transferring device (1) to a conveyor (2), along which the backing plates are being moved, concrete is continuously fed by a feeding device (3) onto a backing plate in a compacting machine (4) which is situated near the said feeding device, fresh concrete is pressed into a desired shape in a compacting machine (4) and cut by a cutting device (5, 6) into desired sizes of concrete elements. With the present methods and equipment, it is not possible to manufacture sufficiently strong and variably shaped elements. In the method, according to the invention, reinforcing material is fed to the compacting machine from a reinforcing device (7) which is situated before the concrete feeding device (3).

Description: METHOD AND APPARATUS FOR MANUFACTURING CONCRETE ELEMENTS. The object of the invention is a method for manufacturing concrete elements. In this method, backing plates are transferred on a transferring device to a conveyor, along which the backing plates are being moved. By using a feeding device, concrete is continuously fed on to the backing plate in a compacting machine which is situated right next to the feeding device. The fresh concrete is pressed into the desired shape in a compacting machine and cut into desirable sizes of concrete elements by using a cutting device. Different kinds of concrete elements have been manufactured for a long time and many kinds of methods have been used in their manufacturing process. For the moment, amongst the most typical methods are: casting of concrete into a previously manufactured mould, compaction of concrete into a mould and pressing it in a form onto a fixed bed. The disadvantage of the previously known methods is the inflexibility of production and the periodicity of production essentially attached to them. It is not easy to change production to suit different kinds and/or different shapes of products such that their strength properties remain satisfactory. Much manual labour is needed in changing the shape of the final product and this is expensive. In addition, the equipments which are in use are large in size and usually require a great deal of production space. The aim of the invention is to bring forward a method for manufacturing concrete elements, such that, by the use of this method, disadvantages connected with present methods can be avoided. In particular, the aim of the invention is to bring forward a method for continuously and economically producing concrete elements which are sufficiently strong, variable in shape and have different kinds of structures. The aim of the invention is achieved with the method characterized in the following claims. In the method according to the invention, reinforcing material is fed from a reinforcing device, which is situated before a concrete feeding device, into concrete, which is fed from the feeding device to backing plates. As reinforcing material, any material suitable for this purpose can be used, like reinforcing bars or the equivalent. Reinforcing bars are favourably cut into suitable sizes according to the sizes of the elements to be manufactured, either before they are placed into the reinforcing device or they can be automatically cut continuously from a coil. By means of an automatic reinforcing device, concrete elements can obtain sufficient strength, and the structural properties of the concrete elements can be changed quickly and straightforwardly. In a favourable embodiment of the method according to the invention, the shapes of the inner parts of the compacting machine and the shapes of the surfaces of the backing plates are changed to obtain variably shaped concrete elements, the said surfaces of these backing plates being against the concrete element. The inner parts of the compacting machine can be detached from the compacting machine and changed. In this way, elements can be obtained which have different kinds of outer surface, side surfaces and inside part which are formed in the compacting machine. In addition, the shapes of the inside surfaces of the backing plates can be changed so that also the shape of this surface of the concrete element can be changed. Shaping parts can be fastened removably on the inside surfaces of the backing plates. Alternatively, several forming parts with different kinds of inside surface can be used and be changed when the shape of the element to be manufactured changes. By using cutting devices, extruded concrete which comes as a continuous casting can be cut into the desired sizes of elements. With the help of this method, elements can be produced either as individual pieces, small series or mass production series. The changes in the shapes and structures of the elements are easy to make and quick to do. The changes can also be done while production is in progress. In a favourable additional embodiment of the invention, a cast extruded concrete is cut by using a cutting device in a bevelled direction with respect to the moving direction of the conveyor. The extruded concrete can also be cut in a normal manner by using a cutting device which cuts perpendicularly. The place of cutting is the space between backing plates so that the backing plates do not obstruct the cutting. The backing plates can also in some embodiments be shaped so that they have places at which cutting can occur. With this method, concrete elements can be continuously cut into desired sizes and bevels. In the method according to this invention, backing plates and the elements on them are transferred favourably from the conveyor to a temporary store and, after a desired time, moved from the temporary store to an unloading station where the concrete elements are removed automatically from the backing plates. When using this method, the concrete elements are favourably transferred from the unloading station after a desired period of time to a surface treatment device where their surfaces are treated. For the surface treatment, one of generally known methods can be used as, for instance, polishing, sand or grain blasting. Elements can stay at the unloading station for a desired period of time so that they can be brought to the surface treatment at a certain degree of hardening, and thus one can influence the results of the surface treatment. In the following, the invention will be explained in more detail by referring to the attached drawing in which fig. 1 shows a schematic representation of a plan view of the production line, partly in cross-section and in this production line the method according to this invention has been applied, fig. 2 shows a side view of a production line according to fig. 1, and fig. 3 shows an elevated plan view of some embodiments of concrete elements which have been manufactured by using the method according to this invention. A production line or equipment according to figures 1 and 2 consists of a conveyor 2, several backing plates, a transferring device 1 for transferring backing plates to the conveyor, a reinforcing device 7, a concrete feeding device 3, a compacting machine 4, cutting devices 5 and 6, a temporary store 8, an unloading station 9 and a surface treatment device 10. The devices have been mentioned in the same order as they appear on the production line. All the devices have been placed sequentially in the immediate vicinity of the conveyor system. The production line is relatively small in size and does not require large production areas. As a conveyor system in this embodiment a circular chain conveyor is used but, in other embodiments, other conveyor systems which are suitable for the purpose can be used. The transferring device 1 for backing plates has been arranged to lift the backing plates at the level of the conveyor and to move the backing plate to rest on the conveyor. The reinforcing device 7 comprises steering apparatus which are used for feeding reinforcing bars on to certain places in the compacting machine, these reinforcing bars having been previously cut into suitable sizes. The concrete feeding device 3 is a continuous feeding device which, in this embodiment, is an upwards and downwards opening funnel-shaped device. Concrete is continuously fed into the feeding device, and this concrete flows partly on top of backing plates which are being moved underneath and partly on top of compaction devices 11 which belong to the compacting machine 4 which is in connection with the feeding device. The compacting machine 4 is used for producing the shape of the concrete element. The compaction devices are at least partly screw- shaped, longish devices which are partly underneath the feeding device. In addition, the device comprises inner parts of the compacting machine 12 which form the top and the side surfaces of concrete elements when concrete is being pressed against the inner surfaces. Correspondingly, the surfaces of the backing plate form the bottom surfaces of concrete elements. The compacting machine comprises several differently shaped inner parts which are removably fastened to it and several differently shaped surfaces of backing plates, which are facing against the concrete element. When concrete is being fed from the feeding device, the compaction devices are rotating and simultaneously pressing fresh concrete against the inside surfaces and the backing plate thus making the structure compact and producing the shape of the concrete element. By changing the shape of these compaction devices, either hollow-cored concrete elements or solid concrete elements can be manufactured. When cores are wanted in the element, a smooth extension of every compaction device forms the core of the desired size in the element. The inner parts of the compacting machine are changed according to the shapes of the element to be formed when production must be changed to an element of a different shape. Also the shape of the inside surface of the backing plates can be changed when production changes, this shape forming the other surface of the concrete element. This can be done either by changing the inside surface itself or by changing the shapes of the backing plates. At some distance from the compacting machine there is a cutting device 5 for cutting the extruded concrete in a perpendicular direction, and at a set distance from it there is another cutting device 6 for cutting the concrete element in a bevelled manner regarding the forward direction of the conveyor. As cutting devices in this embodiment are cross-cutting saws. The cross- cutting saw 5 is moved resting on a support which reaches over the conveyor. The cross-cutting saw 6 has been fastened reversibly to a support next to the conveyor so that its angle with respect to the conveyor system can be changed. When applying the method according to the invention, backing plates are moved on a transferring device 1 to a conveyor system 2 continuously one after another such that there remains a short distance between them. By using a concrete feeding device 3, concrete is continuously fed on to the top of the backing plate and, by using a compacting machine 4 and the backing plate, a desired shape can be formed on the concrete element. In case reinforcing material is needed, it is fed from a reinforcing device 3 into the concrete in the compacting machine. As the extruded concrete moves forward resting on the backing plates and the conveyor, it is cut by using a cutting device or cutting devices 5, 6 into elements of desired shapes and sizes. From the conveyor, the backing plates and the concrete elements on top of them are moved to a temporary store 8 where they can be stored in piles to await the next phase. By using transferring devices, the backing plates with their concrete elements are moved to an unfoading station 9 where the concrete elements are loosened from the backing plates. The concrete elements are transferred to a surface treatment device 10, and the backing plates are transferred back to the beginning of the production line or to a store. The surfaces of the concrete elements are treated in ' the surface treatment device in a desired manner. By applying the method according to the invention, sufficiently strong and variably shaped concrete elements can be manufactured continuously. According to figure 3, elements can be at least solid 13, hollow-cored 14, reinforced 15, non-reinforced, smooth 16 or profiled 17 in their surface and sides or bevelled 18 in different directions at their ends. Concrete elements can be manufactured either from normal concretes or from special lightweight concrete mixtures. The invention will not be limited to the described favourable embodiment but it may vary within the frame of the innovative idea formed by the claims.

Claims: CLAIMS 1. A method for manufacturing concrete elements, in which method backing plates are transferred on a transferring device (1) to a conveyor (2), along which the backing plates are being moved, concrete is continuously fed by a feeding device (3) onto a backing plate in a compacting machine (4) which is situated near the feeding device, fresh concrete is pressed into a desired shape in a compacting machine (4) and cut by a cutting device (5, 6) into desirable sizes of concrete elements, c h a r a c t e r i z e d in that reinforcing material is fed to the compacting machine (4) from a reinforcing device (7) which is situated before the concrete feeding device (3). 2. A method according to claim 1, c h a r a c t e r i z e d in that the shapes of the inner parts of the compacting machine (12) and the shapes of the surfaces of the backing plates are changed to obtain variably shaped concrete elements, the said surfaces of these backing plates being against the concrete element. 3. A method according to claim 1 or claim 2, c h a r a ct e r i z ¬ e d in that the extruded concrete is cut by a cutting device (6) in a bevelled direction with respect to the forward direction of the conveyor system. 4. A method according to one of the claims 1-3, c h a r a ct e r ¬ i z e d in that from the conveyor (2) the backing plates and the elements are moved to a temporary store (8) and after a desired time, moved from the temporary store to an unloading station (9) where the concrete elements are loosened from the backing plates. 5. A method according to claim 4, c h a rac t e r i z e d in that the concrete elements are transferred from the unloading station after a desired time to a surface treatment device (10) where their surfaces are treated. 6. An apparatus for applying of the method according claim 1, to which apparatus belong a conveyor (2), severa backing plates, a near of the conveyor placed transferrin device (1) for transferring the backing plates to the con veyor, a feeding device (3) for feeding concrete onto backing plate, which is situated near it, a with the feedin device placed compacting machine (4) for pressing the conc rete mass and a cutting device (5, 6) for cutting the conc rete plate, c h a r a c t e r i z e d in that to th apparatus belongs a between the transferring device (3) an the feeding device (3) placed reinforcing device (7) fo feeding the reinforcing material to the compacting machin (4). 7. An apparatus according to claim 6, c ha r a cte r i z d in that to the apparatus belongs several variousl shaped inner parts (12), which are fastened removably on th compacting machine, and several variously shaped surfaces o backing plates which are against the concrete element. 8. An apparatus accoding to claim 6 or 7, c h a r a c t e r i z e in that to the apparatus belong a after the cutting device placed temperary store (8) and an unloading statio (9) for loosening the concrete elements from the backing plates. 9. An apparatus according to claim 8, ch a r a c te r i z¬ e in that to the apparatus belongs a surface treatment device (10) for treatment of the surfaces of the concrete elements. AMENDED CLAIMS [received by the International Bureau on 17 May 1993 (17.05.93); original claim 1 amended ; remaining claims unchanged (1 page)] 1. A method for manufacturing concrete elements, in which method backing plates are transferred on a transferring device (1) to a conveyor (2), along which the backing plates are being moved, concrete is continuosly fed by a feeding device (3) onto a backing plate in a compacting machine (4) which is situated near the feeding device, fresh concrete is pressed into a desired shape in a compacting machine (4) and cut by a cutting device (5, 6) into desirable sizes of concrete elements, c h a r a c t e r i z e d in that precut reinforcing material is fed to the compacting machine (4) from a reinforcing device (7) which is situated before the concrete feeding device ( 3 ) . 2. A method according to claim 1, c h a r a c t e r i z e d in that the shapes of the inner parts of the compacting machine (12) and the shapes of the surfaces of the backing plates are changed to obtain variably shaped concrete ele- ments, the said surfaces of these backing plates being against the concrete element. 3. A method according to claim 1 or claim 2, c h a r a c ¬ t e r i z e d in that the extruded concrete is cut by a cutting device (6) in a bevelled direction with respect to the forward direction of the conveyor system. 4. A method according to one of the claims 1-3, c h a ¬ r a c t e r i z e d in that from the conveyor (2) the backing plates and the elements are moved to a temporary store (8) and after a desired time, moved from the temporary store to an uncoading station (9) where the concrete ele¬ ments are loosened from the backing plates. 5. A method according to claim 4, c h a r a c t e r i z e d in that the concrete elements are transferred from the unlo¬ ading station after a desired time to a surface treatment device (10) where their surfaces are treated.

Inventors: MIKKOLA HEIKKI, TAMMINEN VESA, MIKKOLA, HEIKKI, TAMMINEN, VESA
Applicants: ACOTEC OY
Application year: 1992
Main classification: B28B5
IPC codes: B28B1, B28B5, B28B15, B28B23