AU670462B2 - Concrete fences and other articles simulating a wood texture or finish - Google Patents

Description

AUSTRALIA

Patents Act 1990 Invention Title:-k 3,i 'I1 P The following statement is a full description oif this invention, including the best mthod of performing it known to me:- This invention relates to fencing and other articles previously made of ::~timber and it refers particularly, but not exclusively, to a method of and :means for making concrete fencing, conprising posts and/or rails, and/or water troughs, and/or plant containers, and/or garden edging, and/or retaining walls, and/or bollards and so on (hereinafter referred to briefly V, as "fencing") so as to resemb~le wooden products (fencing) of the same character, and to the "fencing" made according to the method.

In the following description reference will be made to "fence post" but that term is to be deemed to include all such articles previously made of *ib. wood such as posts, rails, troughs, plant containers, garden edging, retaining walls, bollards, and so on.

For many years it was customary in country areas, in particular, of *9 Australia and some other parts of the world, to erect post-and-rail fences with the posts and rails made of wood, generally fairly roughly split fromn felled trees. However, as wood is prone to deterioration in a relatively short term such as 20 or 30 years it has become customnary to use other materials, such as steel, which provide for longer effective life and, therefore a utilitarian advantage, but an aesthetic loss.

It is an object of this invention to provide a method of and mans for making concrete fence posts (as herein defined) which will have the appearance of wooden fence posts, so as to combine the relatively long life of the concrete post with the favourable appearance of the wooden post.

Another object is to provide a method of and man-, for making concrete 2 fence posts, which will give the appearance of the previously-made spilt fence posts, differing from machine-made concrete fence posts as hitherto made.

A further object is to provide fence posts made of concrete which will have the appearance of wooden fence posts, even to the extent of the appearance of wood grain and of unevennes of construction or with variations from the straight-line appearance of concrete posts as hitherto made.

Accordin to aspect of the invention devised. _ith .thQsead her objects in mind there is provided a method of making/concrete fence posts (as herein defined) comprising the application to a wooden fence post, used as a pattern, of a suitable skin-forming paste or liquid such as a silicon rubber, a latex rubber or a polyurethane (hereinafter referred to generally as a rubber) having ability to pick up the grain and shape of the pattern and of being stripped from the pattern when dried to an adequate extent, drying (or permitting to dry) that skin-forming material, peeling if from the pattern, placing it in a oupport or housing having sufficient strength to support a concrete post to be formed within it, and applying to the interior of the formed rubber skin a sufficient quantity of concrete to form a concrete post. When the concrete has set the housing is opened, the formed concrete post is removed and the rubber skin is stripped from it.

Preferably, a colouring material is applied so as to give the concrete post an authentic colour. This may be done by applying a suitable colouring material to the interior surface of the formed skin and/or by applying r, colourant to the concrete mix and/or by applying a weather-resistant colouring material to the finished product.

The formed concrete post will have the shape of the pattern, the grain and surface roughness of the pattern and the colour of the natural wood.

The colourant applied to the interior of the rubber skin may be a coloured grout of the type used in setting tiles, or other grout, or a water or an oil-based paint suitable for use with concrete, as yellow ochre in colour, and the colourant applied to the finished product may be any suitable weather-resistant material of suitable colour.

The housing is preferably made of steel or other suitable metal, and may be made of hinged construction so that it may be opened to permit convenient removal of a formed concrete post. Thus, it may have two parts hingedly connected together, as at either of the ends, with locking means such as hasp and latch along the openable sides whereby the housing may be securely held in closed position. There may be means for holding the flexible rubber skin in it in correct position and one end may be open to -3 enable the concrete to be poured into it from that end. Alternatively, it may be trough-shaped with a flat, openabl e, side so that the concrete may be poured into it whilst it is in a horizontal position and the side then closed. In this case the rubber skin would also be closed with the side so as to encompass the concrete in the housing.

The finished concrete fence post may have applied to it a lacquer or other coating material, either clear or coloured, to provide a suitable finish to the article.

It is preferred that a silica fume concrete be used, and if desired reinforcing steel and, possible, polyethylene fibres may be incorporated in the concrete for strengthening purposes. If one or more reinforcing rods is/are to be incorporated in the concrete suitable mountings for the ends of the rods may be provided in the housing.

In the application of the invention to the production of a numrber or 40t5. concrete fence posts it is preferred that a number of different wooden posts be used as patterns, such as 10 or 12, so that the concrete fence posts made will not be identical. Similarly, a number of different wooden rails may be used as patterns so that, in the constructior, of a fence, not ee all the rails will be identical.

4U A. of course, in making a large quantity of the concrete fence posts the one wooden post my be used as a pattern for a substantial number of the V. concrete posts, and it may be that a rubber skin formed by the application of the liquid or paste to a wooden post may be used for the formation of a number of concrete fence posts. Similarly, the one wooden rail may be 5 used as a pattern for a substantial number of concrete rails.

If desired, the housing my be made as a multiple housing capable of being used f or the manuf acture of a number of articles at the one time, depending on the size of the articles to be made.

According to one exemiplary form of the invention, in the manufacture of rails to be used in making or restoring a fence, the overall length of each rail is 2.7 metres and they are of irregular cross-sectional shape (as is the case with roughly-split wooden rails) about 70irni x 250rmn in size. Each end of each rail is reduced in cross-section over the last 450nrm (approximately) to about 30mm x 150am in size so as to be able to fit into a slot of standard size in a supporting post.

The posts to be used to support such rails, in this exemiplary form of the invention, are about 1.8 metres overall in length and when mounted in post holes, will extend about 1.2 metres above the ground. A suitable cross-sectional size will be 150mm, x 200mm.

obviously, the moulds for the manuf acture of such rails and such posts are made large enough to hold them.

Of course, it is to be understood that the dimensions given above are merely by way of example and both the rails and the posts may be made larger or smaller, or other proportions, to suit particular requirements.

The rubber skin-forming materials I have found to be suitable are a cilicone rubber such as that produced by Dow Corning and sold under the brand name and number "SILASTIC R 3481", which is a mould-making agent with which is used a catalyst "Silastic 81" and a curing agent. That rubber takes about 30 minutes to set to a sufficient extent that it will retain the impression of the grain in the pattern but can be peeled off the pattern without difficulty.

a pre-vulcanised natural latex incorporating amnonia and poly acrylate thickener put out by R.L.T. Polymers Pty. Ltd., of Kilsyth, under the reference RL 18/3. This rubber takes somewhat longer to set to the 15. same extent, upwardly of 8 hours.

I a polyurethane rubber may be found to be satisfactory, such as that put out by British United Formulators Pty. Ltd., of Victoria, under the trade mark APTANE E637 which, I understand, should be mixed with polymeric diphenyl-methane di-isocyanate in the proportions of 100:25.

The selected rubber skin-forming material is applied as a fluid to a sample which is to be reproduced such as a wooden fencing post or a wooden fence rail and is allowed to set to an extent such that it will retain a clear impression of the shape of the pattern and of the grain of the wood, and the skin, so formed, is then peeled off the pattern. It is then placed in the appropriate mould so as to lie against the base, sides and in position to extend over the open top.

The reinforcing rods preferably, 4 mild steel rods of about 6rrM diameter, for each post or rail, which have been welded together at each end are then placed in the mould, with plastic wheels used to locate the rods in correct position and ensure that they are not in contact with the skin.

Those plastic wheels also act to hold the skin in position during the pouring of the concrete, which may done through a suitable hose from a pump.

In order to provide the colour-appearance of natural wood I have found it satisfactory to paint the finished product with a colourant such as that made by Bayer. However, I have also found that if a suitable colcuring material, suoh as a yellow ochre, is applied to the inner surface of the formed skin before the concrete is poured into the mould a very satisfactory colouring effect of the concrete product can be achieved. It may also be suitable to add a colouring material such as yellow ochre to the concrete mix before it is poured into the mould.

And, finally, to provide a finish and to highlight the depth of grain I have found it suitable to apply "BONDCRETE" polyvinyl acetate and/or "Black Ochre" brand of ochre colouring to the product, as by spraying or by brushing.

The concrete used in the manufacture of the fence posts may be 35% sand, stone and 20% cement, with the addition of a super plasticiser (a water reducer), at about 3 litres/metre of the concrete. The sizes of the sand and stone I have found to be satisfactory are: under Iln overall and about 6nm; and the cement Portland cement. To the concrete mix I prefer to add yellow ochre colourant so as to provide a desired natural-wood appearance to the finished product.

When the concrete has set to a sufficient extent the concrete post is removed from the housing or mould, and the rubber skin is stripped from the formed concrete product, which is then ready to be painted the naturalwood colour.

In some cases it may be found desirable to have the concrete articles, made according to this invention, of somewhat lighter weight and in those cases the articles may be made of lightweight concrete, as by adding aluminium powder to the concrete mix.

In the manufacture of a water trough a wooden water trough made of a tree stump may be used as the pattern and the skin-forming material applied to the inner and outer surfaces of it. The housing may be made an appropriated shape and construction as required to hold the formed skin and 35. to shape the required concrete trough.

I shall now refer to the accompanying illustrations which include views of moulds for use in the production of a fence rail and for the production of a fence post, as well as a plant container made in accordance with this invention. In these views: Fig. 1 is a vertical cross-sectional view through a mould for the making of rails; Fig. 2 shows a plan view of that mould; Fig. 3 depicts a side elevation of that mould; Fig. 4 is a vertical cross-sectional view through a mould for the making of posts; Fig. 5 shows a plan view of the mould depicted in Fig. 4; Fig. 6 is a side elevation of the mould shown in Figs. 4 and Fig. 7 is a perspective view of the plant container; and Fig. 8 is a vertical cross-sectional view through the plant container of Fig. 7.

'.6 The rail mould illusttated in Figs 1, 2 and 3 hasi a base 21 to which two sides 22,23 are attached by hinges so that they mry be closed to upstanding, substantially parallel position or lowered to a rnould-open position.

There are two end plates 24 which close the ends of the moulds, and latch mans 25 for locking the sides in closed position. Wooden wedges 25 may be inserted into' the end portions of the moulds so as to reduce the thickness of the opposite ends of the fence rail, In this simple form of a mould the formed rubber skin X may be placed so that it lies against or close to the inner walls of the two sides, the two ends and the base, leaving an open space into which the concrete mix may be poured.

The post mould illustrated in Figs. 4, 5 and 6, also has a base 31 with two sides 32, 33 hingedly connectl-ed to it at opposite sides, said sides being made to extend upwardly and inwardly, so that the mould is narrower at the top than at the bottom. The opposite ends 34 extend upwardly from the base and there are latch means for holding the sides in closed position. As it is necessary to provide each post with several openings to receive the ends of the fence rails there are cores 36 which are fastened to and extend upwardly from the base 31. These my be made of polystyrene or other suitable material.

As before, the formed rubber skin may be placed in the mould so that it lies against or close to the inner walls of the two sides, the two ends and the base.

In both cases the formed rubber skin may have a part to extend across the 3. top of the mould, and each mould may have a top part hingedly mounted on a side, so as to be capable of being closed down on to the top of the poured concrete mix, with adequate latch means to hold the top part in closed position.

of the end plates, in each of the mnoulds, has mountings for receiving and holding the ends of the reinforcing rods X which are placed in each mould after the rubber skin has been located therein and before the concrete mix is poured iii.

I now refer to Figjs. 7 and 8 which show a plant container node of concrete and made to have the appearance of natural wood. This article has a sump 41 in its lower part with a transverse wall 42 separating that stump from the upper opening 43 for receiving and holding the plant to be placed in the plant container. The sumip ray hold a quantity of water, which my incorporate a liquid fertilizer, and there in a filler tube 44 to enable the addition of water as required. A liquid gauge 45 my also be incorporated, and a numnber of wicks 45, an, of cotton are placed in openings 7 provided in the transverse wall 42 to act in drawing water by capillary action from the sump to maintain the soil in the upper portion of the container in a desirable degree of "wetness".In the foregoing description and in the appended claims the words "fence posts" or "fencing post" are to be deemed to refer to fence posts, fence rails, water troughs, plant containers, bollards, and all other such articles as have in the past been made of wood but which may now be made of concrete in accordance with this invention.

It is to be understood that modifications may be made in the method of making the fence posts, and the means employed may be changed as found necessary or desirable without departing from the ambit of the invention, the nature of which resides in the use of a material which will pick up from a timber pattern a representation of that pattern, including as far as possible the appearance of the grain of the timber, a suitable support for the skin so obtained and desirably, the application of a colourant to S provide a timber-like appearance to the concrete article formed in the S housing-held skin.

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Claims (15)

1. A method of making concrete fence posts including the steps of applying to a wooden fence post a suitable skin-forming paste or liquid having the ability to pick-up the grain and shape of the wooden pattern and of being stripped from the pattern when dried to an adequate extent, drying or permitting to dry that skin-forming material, peeling it from the pattern and placing it in a/supp6rt or housing having sufficient strength to support the concrete fence post to be formed within it, and applying to the intericr of the formed skin a sufficient quantity of concrete mix to form the concrete fence post.

2. A method of making concrete fence posts according to Claim 1 and including the additional steps of closing a lid of the support or housing and, with it, a part of the skin-forming material so that the concrete will be enclosed within the skin-forming material.

3. A method of making concrete fence posts according to Claim 1 or Claim 2 and including the additional step of placing at least one reinforcing rod in the support or housing before all the concrete is fed into the interior of the formed skin.

4. A method of making concrete fence posts according to Claim 3 wherein the at least one reinforcing rod extend from one end of the post to the other end,

5. A method of making concrete fence posts according to Claim 3 or 4 within there are a plurality of said reinforcing rods for each fence post and the opposite ends of the reinforcing rods are secured together, and said reinforcing rods are held in position by plastic wheels.

6. A method of making concrete fence posts according ts any one of the preceding claims and including the addition step of applying a colourant to the concrete so as to give the appearance of natural wood.

7. A method of making concrete fence posts according to Claim 6 wherein the colourant is applied to the concrete after the concrete has set,

8. A method of making concrete fence posts according to Claims 6 or 7 wherein the colourant is applied to the concrete mix before it is fed into the interior of the formed skin.

9. A method of making concrete fence posts according to any one of Claims 6, 7 or 8 wherein colourant is applied to the internal surface of the formed skin before the concrete mix is fed into the interior of the formed skin. method of making concrete fence posts according to any one of the preceding claims and including the additional step of removing the 9- concrete post from the support or housing after it has set, and of stripping the skin from the formed concrete post.

11.A method of making concrete fence posts according to any one of the preceding claims wherein the skin-forming paste or liquid is a silicone rubber.

12.A method of making concrete fence posts according to any one of the Claims 1 10 wherein the skin-forming paste or liquid is a latex rubber.

13.A method of making concrete fence posts according to any one of the Claims 1 10 wherein the skin-forming paste or liquid is a polyurethane rubber.

14.A concrete fence post made according to the method claimed in any one of the preceding claims. plant container made by the method defined in Claim 1 or 2 wherein said plant container has a sump or well in its lower part and a transverse wall above the sump providing an upper opening for the reception of a plant.

16.A plant container as claimed in Claim 15 wherein the transverse wall has at least one wick for conveyance of water from the sump or well to a plant placed in the upper opening. 17,A plant container constructed substantially as herein described with reference to Figs. 7 and 8 of the drawings. t* DATED THIS 18th day of NOVEMBER 1993. JAMES ALBERT EKBERG. *e e@ ABSTRACT O'- The invention provides a method of rmakingiconcrete fence posts, as herein defined, including the steps of applying to a wooden fence post a suitable skin-forming paste or liquid having the ability to pick up the shape and grain of the wooden fence post and of being stripped from the pattern when it has dried to an adequate' extent peeling the formed skin from the pattern and placing it in a support or housing for supporting the concrete fence post, and applying to t he intelior of thlt formed and suppol th d skin a sufficient quantity of concrete mix to form the concrete fence post. The invention also relates to the fence posts made according to the method. S.. **see S* 0 S 0 OS.. 0*

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