posts

Abstract

 A post (10) includes an anchor member (14) mounted in the ground, and an upper post member (18) spaced from the ground and mounted on an intermediate member (16) which extends into the anchor member.
Upon application of a force to the upper post member (18), the intermediate member (16) is arranged to deform or break prior to the upper post member (18) or anchor member (14) in order that the intermediate portion (16) can be quickly and cheaply replaced.
The height of the upper post member (18) can be adjusted by inserting a grooved pin (22) through the upper post member (18) and the selected pair of aligned holes (26) in the intermediate member.

Description

[0001] The present invention relates to posts.

[0002] In a known fence post, the post comprises a single elongate member, the lower portion of which is mounted in the ground and the remainder of which extends upwardly above the ground. When the fence post is broken or bent, such as occurs when excess bending moments or shear forces are applied to the post, -the complete post has to be replaced. This involves considerable expense and is a time consuming and troublesome operation, as the lower portion of the damaged post has to be removed from the ground, and the lower portion of a new post has to be inserted and anchored into the ground. The replacement of a post is even more complicated, if not virtually impossible where the lower portion of the post is anchored in concrete.

[0003] According to one aspect of the present invention, a post includes a replaceable substantially rigid intermediate portion the lower end of which is removably received in an anchorage and an upper post portion the lower region of which is mounted on the intermediate portion, the post being such that when a sufficient force is applied to the upper post portion in a direction transverse to its elongate extent, the intermediate portion is arranged to permanently deform or break prior to the upper post portion permanently deforming or breaking. When an excessive bending moment is applied to the post, the maximum bending moment occurs at the point where the post is no longer supported by, or held in the anchorage, i.e. at the point where the intermediate portion extends above the anchorage. Accordingly, the intermediate portion will tend to bend or break prior to the anchorage or upper post portion being damaged to the point where they can no longer be used. Thus the intermediate portion only of the fence post requires to be replaced, and this can be quickly effected by removing the upper post portion from the intermediate portion, removing the intermediate portion from the anchorage and replacing the damaged intermediate portion with a new intermediate portion. As only one component of the post has to be replaced, namely the intermediate portion, the post is extremely economical to repair.

[0004] The intermediate portion -may require less of a shear force or bending moment than the upper post potion to permanently deform or break to help ensure that it is the intermediate portion which will fail and require replacement in preference to the upper post portion.

[0005] The upper post portion may be arranged to be spaced from the anchorage to allow the intermediate portion alone to take the maximum bending force. The spacing of the upper post portion from the anchorage may be adjustable to allow the post to extend to different heights above the anchorage. The adjustable mounting of the upper post portion on the intermediate portion may comprise a pin arranged to extend through the upper post portion and the intermediate portion, the pin passing through a selected one of a series of spaced holes provided on either the upper post portion or the intermediate portion.

[0006] The upper post portion and the intermediate portion may be of generally rectangular, square or circular cross-section which may allow them to be quickly and easily manufactured.

[0007] The intermediate portion may extend within the upper post portion.

[0008] The anchorage may include an anchor portion within which the intermediate portion is removably received. Thus the anchor portion may not require to be replaced when the intermediate portion is to be replaced to further reduce the time and labour required to replace a damaged intermediate portion. Furthermore, where the anchor member is embedded in concrete, the difficult job of breaking up the concrete and replacing it by a fresh mix does not have to be undertaken when a damaged intermediate portion is being replaced.

[0009] The intermediate portion may rest on a base of the anchorage.

[0010] The lower portion of the upper post portion may be hollow and may be capable of receiving the upper portion of the intermediate member, and the upper portion of the anchor member may also be hollow and capable of receiving the lower portion of the intermediate member. Furthermore, the upper post portion may be a hollow elongate member of generally constant cross-section and the intermediate member may be a hollow elongate member of generally constant cross-section, as also may be the anchor portion.

[0011] The intermediate portion may be a close sliding fit within either the anchorage or the upper post portion, or both whereby the close sliding fit between the components allows the post to be generally stable with only a limited, if any, degree of relative movement being possible.

[0012] The invention may be carried into practice in various ways, but one embodiment will not be described by way of example and with reference to the accompanying figure which is a cross-section through a post mounted in the ground.

[0013] In the figure, there is shown a post 10 mounted in the ground 12, the post 10 comprising an anchor member 14, an intermediate member 16 and an upper post member 18. The anchor member 14, intermediate member 16 and upper post member 18 are all hollow metal members of generally square cross-section. In an alternative embodiment, not shown, any or all of the hollow members may be generally circular in cross-section.

[0014] The intermediate member 16 extends into both the anchor member 14 and the upper post member 18 and is a close sliding fit therewith to generally prevent rocking or movement of upper post member 18 relative to the anchor member in a direction transverse to the longitudinal axis of the post. The intermediate member in fact extends along the whole length of the anchor member to rest on a base 20. In an alternative embodiment (not shown) the base is part of the anchor member 14 and comprises a plate extending across and beyond the bottom of the anchor member. The intermediate member need not necessarily rest on the base. Withdrawal of the intermediate member from the anchor member is prevented by a removable grooved pin 22 extending through aligned holes formed in both the intermediate member and the anchor member. The upper post member 18 is held above the ground by a removable grooved pin 24 extending through aligned holes in both the upper post member and the intermediate member. The intermediate member is formed with a series of aligned holes 26 along a portion of its length and the height of the upper post member relative to the ground may be varied by inserting the pin through the selected pair of aligned holes 26.

[0015] The illustrated post is a fence post, but it will be appreciated that the present invention is not limited to fence posts and includes any post.

[0016] The upper post member 18 is formed with an angled section 28 at its upper end. Wires are usually connected between the angled section of adjacent fence posts in order to deter people from scaling the fence, wire fixing lugs may be provided in the upper post portion. It has been found that the bending moment created by people on the fence post when they try and climb, or push against the fence causes the fence post to bend or break. It will be appreciated that the maximum bending moment on the post appears at the base of the post. In the post shown in the drawing, the intermediate section will be subject to this maximum bending moment, and as the cross- sectional area of the metal of the intermediate member is less than the other components of the post, and as the moment of inertia of the intermediate member is also less about an axis transverse to the post, it is the intermediate member that will fail first. If the post is subjected to an undue shear force, for instance by a vehicle reversing into the post, again it is the intermediate member that tends to fail first. All of the components in the post may be of galvanised metal.

[0017] In order to repair a post with a failed intermediate member, the pin 24 is removed from the upper post member and the intermediate member to allow the upper post member to be removed prior to removing the pin 22 from the anchor member to allow that part of the intermediate portion remaining to be removed. A replacement intermediate member is then included into the post by inserting the pins 22 and 24 through the components of the post. It may even be possible to leave the fence attached to the upper post member 18 when replacing the intermediate member 14 merely by lifting the upper post member, replacing the damaged intermediate member, and lowering the upper post member.

[0018] The anchor member 14 may be placed into a correspondingly shaped recess formed in the ground 12 or, alternatively, where the ground comprises concrete, the concrete can be cast around the anchor member.

Claims

1. A post (10) including a substantially rigid replaceable intermediate portion (16) the lower end of which is removably received in an anchorage (14), and an upper post portion (18) the lower region of which is mounted on the intermediate portion (16), the post being such that when a sufficient force is applied to the upper post portion (18) in a direction transverse to its elongate extend, the intermediate portion (16) is arranged to permanently deform or break prior to the upper post portion (18) deforming or breaking.

2. A post as claimed in Claim 1 in which the intermediate portion (16) requires less of a shear force than the upper post portion (18) to permanently deform or break.

3. A post as claimed in Claim 1 or 2 in which the intermediate portion (16) requires less of a bending moment than the upper post portion to permanently deform or break.

4. A post as claimed in any preceding claim in which the upper post portion (18) is arranged to be spaced from the anchorage.

5. A post as claimed in Claim 4 in which the spacing of the upper post portion (18) from the anchorage is adjustable.

6. A post as claimed in any preceding claim in which the upper post portion (18) and the intermediate portion (16) are of generally square cross-section.

7. A post as claimed in any preceding claim in which the intermediate potion (16) extends within the upper post portion (18).

8. A post as claimed in any preceding claim in which the anchorage includes an anchor portion (14) within which the intermediate portion (16) is removably received.

9. A post as claimed in any preceding claim in which the intermediate portion (14) rests on a base (20) of the anchorage.

10. A post as claimed in any preceding claim in which the intermediate portion (16) is a close fit with the upper post portion (18) and the anchorage.

Drawing