AU2003231666A1 - Method of producing a textured building element - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: ERNEST REGINALD WELCH 159 Beechboro Road South Bayswater WA 6053 Australia Ernest Reginald WELCH Griffith Hack, Patent and Trade Mark Attorneys, 6th Floor, 256 Adelaide Terrace, Perth, Western Australia, 6000.

Standard Complete Specification for the invention entitled: Method of Producing a Textured Building Element Details of Associated Provisional Applications: Application No. 2002950784 dated 15 August 2002 The following is a full description of this invention, including the best method of performing it known to me:- "METHOD OF PRODUCING A TEXTURED BUILDING ELEMENT- Field of the Invention The present invention relates to a method of producing a building element such as a reconstituted limestone block having a preferred surface texture on one or more of the faces of the building element. The building element may be symmetrical or asymmetrical in shape and the surface texture may be applied to one or all of the surfaces thereof.

Background to the Invention Traditional building elements such as bricks and paving bricks used for retaining walls and the like have a surface texture that is consistent with the manufacturing process used to make the building element. For example, clay-fired bricks have a reasonably uniform porous surface texture partly due to the shape of the mould into which they are cast and partly due to the nature of the material as it solidifies and is subsequently heat-treated.

In recent times there has been a move towards providing more decorative building elements and materials for use as feature walls for gardens or outdoor entertainment areas and the like. A particularly popular product are blocks used for retaining walls in outdoor garden or entertainment areas made using limestone. Natural limestone is an expensive product that is extremely popular because of its unique surface texture. Many attempts have been made to produce reconstituted limestone blocks from a crushed limestone material mixed into a slurry and cast into moulds in an attempt to recreate the appearance of the surface texture of natural limestone.

However, a significant problem with traditional methods of casting building blocks using reconstituted limestone is that it has not previously been possible to apply the desired pattern to all of the faces of the block. This drawback is an outcome of the traditional method used to produce such blocks. This traditional method involves using a steel mould which has the desired pattern reproduced only in the base of the mould. The mould is filled with reconstituted limestone material provided in a slurry. A top may then be placed on the mould with the top also including the desired pattern.

The block so produced has the surface texture of the traditional limestone material provided only its base and the top surfaces.

The main reason why it has not been possible to apply a surface texture to the sides of the limestone block is that it is difficult to remove the patterned block from the steel mould without disturbing any such pattern applied to the surface. After casting, it is traditional to vibrate the mould to assist in removal of the limestone block from the mould. As the block from the mould, the surface texture applied to the top and/or bottom surfaces of the block becomes disturbed or damaged in some way.

An object of the present invention in at least one of its preferred embodiments is to provide a method of producing a building element with the preferred surface texture applied to one or more of the faces of that building element using a relatively simple moulding process.

Throughout this specification the term "comprising" is used inclusively, in the sense that there may be other features and/or steps included in the invention not expressly defined or comprehended in the features or steps subsequently defined or described. What such other features and/or steps may include will be apparent from the specification read as a whole.

Summary of the Invention According to one aspect of the present invention there is provided a method for moulding a textured building element, the method comprising the steps of: providing a mould having at least one removable mould element, the element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould; adding a settable composition to the mould to form a building element; allowing the settable compound to cure such that the corresponding face of the building element conforms with the arrangement of surface features of the at least one removable mould element; and, moving the at least one removable mould element away from the corresponding face of the building element to facilitate removal of the building element from the mould.

At least one removable mould element may be a side wall element and/or a top element.

Preferably, the at least one removable mould element is one of a plurality of removable mould elements for applying a preferred surface texture to a plurality of corresponding faces of the building element. Alternatively, the at least one removable mould element is one of a plurality of removable mould elements for applying a plurality of preferred surface textures to a plurality of corresponding faces of the building element.

Preferably, the method further comprises the step of assembling the mould from the plurality of removable mould elements.

Preferably, the step of assembling the mould comprises the step of folding the removable mould elements into a closed configuration suitable for moulding.

Preferably, the method further comprises the step of moving each of the plurality of removable mould elements away from the corresponding faces of the building element to facilitate removal of the building element from the mould.

The mould may be supported during the step of adding the settable composition and/or the step of allowing the settable composition to cure.

Preferably, the mould is supported by a frame. More preferably, the frame is provided with a locking means.

Preferably, a or the removable mould element is flexible. More preferably, the step of moving a or the flexible removable mould element away further comprises the step of peeling each flexible mould element from each corresponding face of the building element.

Preferably, the flexible removable mould element(s) are formed from a single sheet of flexible material.

According to a second aspect of the present invention, there is provided a mould for forming a building element, the mould comprising at least one removable mould element, the mould element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould.

According to a third aspect of the present invention, there is provided a blank for a mould for forming a building element, the mould comprising at least one removable mould element, the mould element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould.

Brief Description of the Drawings In order to provide a better understanding of the present invention, a preferred embodiment of the method of producing a building element will now be described in detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 illustrates a mould for a symmetrical building element when configured into the closed position ready for moulding; Figure 2 illustrates the mould of Figure 1 configured into a substantially flat, open position; Figure 3 illustrates a side view of adjacent sidewall elements of the mould of Figure 1 showing a recessed foldable edge; Figure 4 illustrates a preferred embodiment of a supporting means for use with a mould having removable side elements; Figure 5 illustrates a mould for an asymmetrical building element, including locking means in a substantially flat open position; and Figure 6 illustrates the mould of Figure 5 once assembled in the closed position for moulding.

Detailed Description of the Preferred Embodiments With reference to Figure 1, there is provided a mould 10 for producing a building element configured into a closed position suitable for moulding. The mould comprises a plurality of mould elements, including a base 14 and side wall elements 16, 18, 20 and 22. When the mould 10 is configured into a substantially flat, open position as illustrated in Figure 2, each of the side wall elements 16, 18, 20 and 22 are provided with a plurality of surface features 30 arranged to produce preferred surface features on the corresponding external faces of the building element after moulding. The surface features 30 are provided on at least one portion of the face of the side wall elements 16, 18, 20 and 22 which is directed inwardly of the mould once the mould 10 is configured into the closed position for moulding.

The surface features 30 provided on the side wall elements 16, 18, 20 and 22 may be in the form of projections or recesses, depending on whether or not the desired surface texture being applied to the building element is in the form of depressions or projections respectively. A projection provided as a surface feature on a side wall element will result in a depression being provided in the corresponding face of the building element.

Each of the side wall elements 16, 18 20 and 22 are removable, i.e. they can be moved away from the building element after moulding. This can be done either by removing each side wall element in turn, for example by detaching a given side wall element from its adjacent side wall elements and the base, or by folding the side wall elements outwardly away from the building element.

The surface features 30 for any given side wall element 16, 18, 20 or 22 may be the same for each of the other side wall elements or may differ as depicted in Figure 2, by way of example only, with different surface features 30, 30' and etc being provided on the sidewall elements 16, 20 and 22 respectively. One or more of the sidewall elements may intentionally be left devoid of surface features.

Alternatively, it is possible for pairs of side wall elements to be provided with the same configuration of surface features 30, for example side wall elements 16 and 20, with an alternative configuration being provided on side wall elements 18 and 22, for example, or any combination thereof.

Once the mould 10 is assembled or swung into in a closed position as shown in Figure 1, the top 31 is open to allow filling of the mould with a settable composition, in this example a slurry of reconstructed limestone. Once filled to a desired height within the mould 10, the top 31 may be covered using a top element 32 applied to the mould 10 with the inwardly directed surface of the top element 32 also being provided with a plurality of surface features in a preferred configuration if desired. In this way it is possible for all of the faces of the building element to have a preferred surface texture on one face or indeed all of the faces of the building element.

The mould 10 may be constructed from a single piece of material. Alternatively, the top element 32 and side wall elements 16, 18, 20 and/or 22 may be detachable from the base 14. In this alternative embodiment, the sidewall elements may be removed from the building element after moulding of the element by detaching the sidewall elements 16, 18, 20 and 22 from the base 14.

When the mould 10 is constructed from a single piece of material, the sidewall elements 16, 18, 20 and 22 are foldably connected to the base 14 and thus be able to be swung away from the corresponding sides of the moulded building element when it is desired to remove the moulded building element from the mould As a further option, the mould 10 may be fabricated from a single sheet of, say, a plastic material that is scored or otherwise recessed along edges 56, 58, 60 and 62 respectively, as shown in Figure 3. The edges are recessed to allow repeatable foldability of the mould 10 along the edges 56, 58, 60 and 62. The depth of the recess is dependent on the selection of the particular flexible material used for construction of the mould and is merely that depth required to allow repeated bendability.

Best results are obtained when the material of construction of the mould is flexible enough to allow peeling of the side wall elements from the building element after moulding. The action of peeling reduces the potential for damage to the surface features 30 compared with the amount of damage to the surface features which may occur if an entire side wall element of rigid material is removed from the side of the building element in one action. Peeling allows for a gradual removal of the side wall and/or top elements at the interface between the projections or recesses provided in the surface features 30 and the corresponding recesses or projections provided in the side wall elements of the building element.

Peeling allows more gentle removal of the side wall elements 16, 18, 20 and 22 from the building element.

The building element may be produced using any settable composition suitable for construction including, but not limited to, clay, limestone, cement or concrete. All that is required of the settable compound is that it is able to flow into the depressions and/or around the projections, making up the plurality of surface features 30 provided on the side wall elements and/or the top and base to produce the desired surface texture on the corresponding surfaces of the building element. The settable composition would typically be provided as a slurry, but may also be added to the mould a dry mix to which water is subsequently added.

After the mould 10 is filled with the settable composition, sufficient time is allowed for the settable composition to cure or set to the point where removal of the top and/or side wall elements will not result in the building element collapsing under its own weight. It is not required that full setting of the settable compound occur before the sidewall elements are removed from the building element.

The mould when arranged in the closed position may be supported inside a supporting means 40, for example, a frame, as shown in Figure 4, which may be provided to resist the pressure exerted on the sidewall elements 16, 18, 20 and 22 by the weight of the settable composition inside the mould The supporting means 40 would typically be in the form of a steel box of substantially the same shape as the building element. The mould 10 is arranged into the closed position and inserted within the supporting means 40 prior to moulding. The inwardly directed surfaces of the side wall elements 16, 18, 20 and 22 are provided with a plurality of surface features 30, 30', 30", etc while the outwardly directed surfaces of the side wall elements 16, 18, 20 and 22 in contact with the support 40 may be substantially smooth.

This allows for easy removal of the mould 10 from the support following moulding.

In use, a mould 10 provided in a substantially flat open position as depicted in Figure 2 is arranged into the closed position shown in Figure 1 for moulding. The surface features 30, 30', 30", etc are directed inwardly of the mould The mould 10 is then inserted into a supporting means The mould is filled to the desired height with a settable composition depending on the required size of the -11building element. A top element 32 with or without additional surface features 30, 30', 30", etc is then placed on the exposed top surface of the settable composition to apply surface texture to the top surface as well, if desired.

After filling the mould with the settable composition, sufficient time is allowed for the settable composition to set such that the moulded building element is able to hold its own weight after filling of the mould with the settable composition, the mould may be vibrated or otherwise compacted to encourage the settable composition to conform with the shape of the surface features 30, 30', 30", etc.

After the settable composition has been allowed to sufficiently cure or set, the top and side wall elements are removed from the building element sequentially to reveal the surface texture on each of the corresponding faces of the building element.

As there is no requirement to slide the building element from the mould as is done in the prior art, the use of removable mould elements allows for building elements to be constructed having surface features provided on a plurality or indeed all of the faces.

Another advantage of the present invention is that an asymmetrical building element may be constructed with the desired surface features on a plurality of surfaces. Using prior art methods, it has not been possible to apply surface texture to the faces of an asymmetrical building element due to the fact that there is no requirement for lateral movement of the building element with respect to the mould during the step of removing the building element from the mould.

Figures 5 and 6 illustrate the use of the present invention -12for an asymmetrical building element.

The specific advantage of being able to provide an asymmetrical building element having a plurality of faces with the required surface texture is that such an element is able to be used in more configurations which makes it a more attractive product in the marketplace. The user has greater flexibility in the purchase of such asymmetrical building elements, as they are able to be positioned in any direction and still display the required surface texture for achieving the required aesthetic effect.

The asymmetrical mould of Figures 5 and 6 is provided with side wall elements 16, 18, 20, 22, 24 and 26, as well as a locking means 70. Once the mould 10 has been rearranged from the open position depicted in Figure 5 to the closed position depicted in Figure 6, the locking means 70 is used to assist in holding the sidewall elements 16, 18, 20, 22, 24 and 26 in the closed position. The locking means 70 serves the same function as the supporting frame 40 and may be used in conjunction with or as an alternative to the use of the supporting frame 40 for either a symmetrical or an asymmetrical building element.

The locking means 70 may take the form of inter-engaging tabs or any other commonly available releasable fastener.

Numerous variations and modifications will suggest themselves to persons skilled in the relevant art, in addition to those already described, without departing from the basic inventive concepts. All such variations and modifications are to be considered within the scope of the present invention, the nature of which is to be determined from the foregoing description and the appended claims.

Claims (29)

1. A method for moulding a textured building element, the method comprising the steps of: providing a mould having at least one removable mould element, the element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould; adding a settable composition to the mould to form a building element; allowing the settable compound to cure such that the corresponding face of the building element conforms with the arrangement of surface features of the at least one removable mould element; and, moving the at least one removable mould element away from the corresponding face of the building element to facilitate removal of the building element from the mould.

2. A method as defined in clam 1 wherein the at least one removable mould element is a side wall element.

3. A method as defined in clam 1 wherein the at least one removable mould element is a top element.

4. A method as defined in any one of the preceding claims, wherein the at least one removable mould element is one of a plurality of removable mould elements for applying a preferred surface texture to a plurality of corresponding faces of the building element.

A method as claimed in any one of claims 1 to 3, wherein the at least one removable mould element is one of a plurality of removable mould elements for applying a plurality of preferred surface textures to a plurality of corresponding -14- faces of the building element.

6. A method as claimed in claim 4 or 5 further comprising the step of assembling the mould from the plurality of removable mould elements.

7. A method as claimed in claim 6 wherein the step of assembling the mould comprises the step of folding the removable mould elements into a closed configuration suitable for moulding.

8. A method as defined in any one of claims 4 to 7 further comprising the step of moving each of the plurality of removable mould elements away from the corresponding faces of the building element to facilitate removal of the building element from the mould.

9. A method as defined in any one of the preceding claims further comprising the step of supporting the mould during the step of adding the settable composition.

A method as defined in any one of the preceding claims further comprising the step of supporting the mould during the step of allowing the settable composition to cure.

11. A method as defined in claim 9 or 10 wherein the mould is supported by a frame.

12. A method as defined in claim 11 wherein the frame is provided with a locking means.

13. A method as defined in any one of the preceding claims wherein a or the removable mould element is flexible.

14. A method as defined in claim 13 whereby the step of moving a or the flexible removable mould element away further comprising the step of peeling each flexible mould element from each corresponding face of the building element.

15. A method as defined in claim 13 or 14 wherein the flexible removable mould element(s) are formed from a single sheet of flexible material.

16. A mould for forming a building element, the mould comprising at least one removable mould element, the mould element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould.

17. A mould as defined in claim 16 wherein the at least one removable mould element is a side wall element.

18. A mould as defined in claim 16 wherein the at least one removable mould element is a top element.

19. A mould as defined in any one of the claims 16 to 18, wherein the at least one removable mould element is one of a plurality of removable mould elements for applying a preferred surface texture to a plurality of corresponding faces of the building element.

A mould as defined any one of claims 16 to 18, wherein the at least one removable mould element is one of a plurality of removable mould elements for applying a plurality of preferred surface textures to a plurality of corresponding faces of the building element.

21. A mould as defined in any one of claims 16 to 20 further comprising a supporting means. -16-

22. A mould as defined in claim 21 wherein the supporting means is a frame.

23. A mould as defined in claim 22 further comprising a locking means.

24. A mould as defined in any one of claims 16 to 23 wherein a or the removable mould element is flexible.

25. A mould as defined in claim 24 wherein the flexible removable mould elements are formed from a single sheet of flexible material.

26. A mould substantially as herein described with reference to and as illustrated in the accompanying drawings.

27. A method substantially as herein described with reference to and as illustrated in the accompanying drawings.

28. A textured building element produced in accordance with the method as claimed in any one of claims 1 to

29. A blank for a mould for forming a building element, the mould comprising at least one removable mould element, the mould element comprising an arrangement of surface features on an inwardly directed face to provide a preferred surface texture to a corresponding face of a building element when formed in the mould. Dated this 28th day of July 2003 ERNEST REGINALD WELCH By His Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia.