GB2062048A

GB2062048A - Concrete fencing post

Info

Publication number: GB2062048A
Application number: GB7937235A
Authority: GB
Original assignee: Crossley A N
Current assignee: Crossley A N
Priority date: 1979-10-26
Filing date: 1979-10-26
Publication date: 1981-05-20

Abstract

The post is moulded from plastic concrete by filling a sleeve 1 of water- impermeable material, e.g. bituminous paper or plastics. The sleeve is sufficiently stiff to avoid enlargement of its cross sectional dimensions under lateral forces imposed thereon by the concrete filling before the latter sets, and the sleeve remains as part of the post, as a protective cover. The end of the sleeve may be fitted with a hollow cone 5. Reinforcing rods, e.g. 21, may be positioned against the interior surface of the sleeve. A steel band 25 may be fitted within the sleeve, at the top of the post. This increases impact resistance when the post is hammered into the ground. <IMAGE>

Description

SPECIFICATION Concrete fencing post The present invention relates to a concrete fencing post.

Such posts are known consisting of a moulding of concrete reinforced by longitudinally extending steel rods embedded in the concrete.

The known posts are not entirely satisfactory. In order to prevent corrosion of the reinforcing rods, they are of necessity embedded in the concrete and, in the case of fencing posts, this results in a significant reduction of the cross-section of the post which is effective against bending moments viz: the effective cross-section being less than the actual cross-section of the post by the crosssectional dimension of the concrete covering a reinforcing rod. Further, they cannot be pounded into the ground and require a hole to be dug in the ground to permit the erection of a post.

Further, there is no ready way in which the conventional posts could be adapted to permit them to be pounded into the ground; and their manner of production using rigid moulds is also inconvenient.

It is an object of the present invention to provide an improved method of moulding concrete posts.

It is also an object of the present invention to provide such a method which lends itself to the production of concrete posts in a form in which they can be pounded into the ground.

It is also an object of the present invention to provide an improved concrete post.

In the moulding of conventional concrete posts, the walls of the mould are substantially rigid to prevent deflection thereof by the weight of the concrete and the moulds are reusable, the moulding being separated from the mould after setting or, in the case where a stiff concrete mix is used, often partial setting of the concrete.

In the present invention a mould is used which remains a part of the post, the mould forming a water impermeable sleeve round the concrete moulding. The mould is suspended vertically or inclined to the horizontal with a constriction or stop being provided at its lower end, and is then filled with concrete. Thus, the moulding process is something in the nature of filling a bag; and the mould need only have sufficient stiffness for any given cross-sectional shape to prevent enlargement of the predetermined cross-section the post is to have, under the lateral forces exerted by the concrete filling of the mould. Thus, by using a circular cross-section, the mould may have a wall thickness of as little as or even less than 1 mm even with materials such as bituminous paper, and plastics as exemplified by P.V.C, polycarbonate and polystyrene.

The mould, therefore, is readily made such as to add little to the weight or cross-section of the concrete moulding; and because of the materials that may be employed to form the mould its cost is small in relation to the cost of conventional moulds. Further, the mould serves as a protective cover for the concrete and eliminates the need to use the concrete to protect any reinforcing rods employed.

This means that the rods can be used without any concrete cover i.e. to lie disposed between the exterior surface of the moulding and the interior surface of the mould, and this in turn makes it possible to reduce the cross-section of the concrete and thus reduce the amount of concrete and/or reinforcement used.

The sleeve formed by the mould also readily permits a pointed moulding e.g. of plastics material, to be attached to the bottom end of the post and, being given some means of protecting the upper end of the post against impact, thus permits the post to be pounded into the ground.

The protective means for the upper end of the post is conveniently provided by a band or coil of sufficient strength and stiffness to resist enlargement of its cross-section under the forces likely to be produced by pounding the top end surface of the post, e.g. with a sledge hammer, with sufficient force to drive the post into the ground. Preferably, the band or coil has a ratio of maximum cross-sectional dimension to axial length of 1:2.

The mould employed in the present invention reduces the labour requirment of conventional moulding and provides optimum curing conditions for the concrete.

The present invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an elevational sketch of apparatus for producing a post according to the invention, Figure 2 is a fragment showing the lower end of the post produced by the apparatus of Figure 1; and Figure 3 is like view of the upper end of the post fitted with a band.

Referring to the drawings, the apparatus comprises a mould 1 in the form of a sleeve of circular cross-section supported at its upper end in a hole in a support plate 3 by any convenient means. In the bottom end of the sleeve is fitted a hollow cone 5 having a hole 7 at the apex thereof, the apex being supported in a hole 9 in a lower support plate 11. Underlying the lower plate is a tray 13.

A hopper 1 5 for plastic concrete is positioned above the sleeve with the outlet 1 7 of the hopper positioned to deposit the concrete into the mould.

By this means, the sleeve and the cone are filled with concrete, which may be dense or lightweight; the hole 7 of the cone permitting air to escape from the mould. Any concrete falling through the hole is collected on the tray 1 3.

The concrete is then allowed to set to produce a concrete moulding with the sleeve and the cone integral therewith.

Reinforcing rods may be incorporated in the concrete, preferably being positioned against the interior surface of the mould. In the case of a moulding produced using the cone, the rods may be bent to protrude into the cone as shown in Figure 2, a reinforcing rod 21 being shown in broken line.

The cone may be formed with an annular step 23 so as to fit into the bottom end of the sleeve.

The top end of the post (see Figure 3,) is fitted with a steel band 25, the wall 27 of which fits tightly around the top end portion of the post with the upper edge 29 being flush with the repective end surface of the post; the band being fitted within -the sleeve before it is filled with the concrete. The axial length of the band is preferably twice the diameter thereof.

The provision of the conical tip permits the post to be driven into the ground, for instance, by pounding the top end of the post with a sledge hammer; the metal band acting to protect the top end portion of the post to prevent break-up of the concrete under the force of the pounding. The steel band need only have a wall thickness of 1 mm or less, but greatly increases the impact resistance of the concrete.

The concrete filled hollow cone may be replaced by a solid wooden painted member e.g. a cone, again formed with an annular step to fit into the bottom end of the sleeve.

To facilitate the attachment of fencing wire to the post, it may be formed with wire loops anchored in the concrete with the loops being disposed at the exterior surface of the sleeve.

Alternatively, conventional separate wire ties may be used, and in this case, the sleeve may be moulded with a rib or projection in which the tie can bite when secured round the post to prevent the tie from slipping longitudinally on the post.

If the post is to be used with panel fencing, the sleeve may be formed with diametrically oppositely disposed longitudinal grooves to receive the respective edges of adjacent fencing panels.

The sleeve could also be formed with a longitudinal groove or recess axially to receive and radially to retain therein a wooden batten to which a fencing wire or panel could be fixed, e.g. by staples or nails.

Claims

1. A concrete fencing post comprising a water impermeable sleeve and an infilling of set concrete the internal cross-sectional dimensions of the sleeve generally conforming to those of the concrete infilling.

2. A post according to claim 1, wherein the sleeve is one formed of bituminous paper or of a plastics material.

3. A post according to claim 2, wherein the plastics material is P.V.C, polycarbonate or polystyrene.

4. A post according to any of the preceding claims, wherein the thickness of the sleeve is 1 mm or less.

5. A post according to any of the preceding claims, wherein the sleeve is of circular cross section.

6. A post according to any of the preceding claims, comprising a steal reinforcement rod.

7. A post according to claim 6, wherein the rod is positioned between the sleeve and the concrete infilling.

8. A post according to any of the preceding claims, wherein the post at one end thereof tapers to a point.

9. A post according to claim 8, wherein the pointed end is provided by a hollow member engaged within one end of the sleeve and filled with a terminal portion of the concrete infilling.

10. A post according to claim 8, wherein the pointed end is provided by a solid member secured to the post.

1 A post according to claim 8, 9 or 10, wherein at the opposite end, the post is provided with means to increase the impact resistance of the concrete.

12. A post according to claim 1 wherein said means comprises a band or coil located between the sleeve and the infilling and resistant to enlargement of its cross-section by impact forces imposed on the respective end face of the post.

13. A post according to claim 12, wherein the band or coil has a ratio of maximum cross-section of axial length of 1 :2.

14. A post according to any of the preceding claims, comprising wire loops anchored in the filling with the loops being disposed at the exterior of the sleeve and lying in alignment longitudinally of the post.

1 5. A post according to any of the preceding claims 1 to 13, wherein the sleeve is formed with a rib or projection to permit a tie wire to bite thereinto when secured to the post to avoid slipping of the tie wire longitudinally of the post.

16. A post according to any of preceding claims 1 to 13, wherein the post is formed with diametrically opposed longitudinal grooves to receive the respective edges of adjacent fencing panels.

17. A post according to any of the preceding claims 1 to 13, wherein the post is formed with a longitudinal groove or recess axially to receive and radially to retain therein a batten.

1 8. A concrete fencing post substantially as hereinbefore described with reference to the accompanying drawings.

19. A method of forming a concrete fencing post comprising moulding the concrete while in plastic condition by filling a water-impermeable sleeve disposed other than horizontally with the concrete; the internal cross-section of the sleeve delineating the external cross-section the moulding is to have; and the sleeve being sufficiently stiff to avoid enlargement of its crosssectional dimensions under the lateral forces imposed thereon by the concrete filling.

20. A method according to claim 19, wherein the sleeve is suspended vertically.

21. A method according to claim 19 or 20, wherein the cross-section of the sleeve is circular.

22. A method according to claims 19, 20, or 21, wherein a reinforcement rod is incorporated in the post.

23. A method according to claim 22, wherein the reinforcement rod is positioned against the inner surface of the sleeve before filling thereof.

24. A method according to any of preceding claims 19 to 21, wherein the sleeve is used together with a hollow tapered member engaged in the sleeve at one end thereof to mould the concrete filling to form a pointed end of the post.

25. A method according to claim 24, wherein means are positioned at the other end of the sleeve before filling thereof to increase the impact resistance of the concrete.

26. A method according to claim 25, wherein said means is a band or coil placed against the internal surface of the sleeve of sufficient strength to avoid enlargement of its cross-sectional dimensions under impact forces imposed on the respective end face of the post.

27. A method of forming a concrete fencing post, substantially as hereinbefore described with reference to the accompanying drawings.