WO2005090714A1

WO2005090714A1 - Post

Info

Publication number: WO2005090714A1
Application number: PCT/AU2005/000337
Authority: WO
Inventors: Stuart Murray Dorey; Mario Casiero; Rodney John Granat
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-03-19
Filing date: 2005-03-11
Publication date: 2005-09-29
Anticipated expiration: 2006-09-19

Abstract

A post (1) comprising a thin walled elongate tubular element (3) having a substantially uniform cross-sectional shape, the cross-section being taken perpendicular to the length of the tubular element, wherein the cross-sectional shape of the tubular element comprises a main central region (14) joined by a neck region (6) to a laterally projecting lobe (5) having a greater maximum width than the minimum width (7) of the neck region, the area (14) of the main central region being substantially greater than the area (15) of the lobe.

Description

POST

Field of the Invention

This invention relates to a post. It relates particularly but not exclusively to a post which may be used for fencing or vineyard trellising.

Background to the Invention

Fence posts of various designs and sizes have been commonly used by farmers for a variety of purposes including trellising of vineyards, providing boundaries to separate their land from other properties, protecting their properties from stray animals and ensuring their own animals are retained within their own property boundaries.

Generally speaking, many of the post designs have been very successfully used for the variety of purposes for which they have been required. Nevertheless, as with any other item of commerce, there is always scope for alternative designs which may fulfil the needs of niche markets. Furthermore, there are clear financial advantages in providing alternative designs which ultimately result in a lower cost for the final product. This lower cost may be achieved in many ways e.g. by reduction in the cost of materials used, by reducing labour involved in manufacture and use of the posts, by reducing storage space required to house posts and by reducing costs of transport through reduction in transported volumes of posts.

The present invention seeks to provide a post which may give advantages in at least one of the categories mentioned above. Disclosure of the Invention

The invention provides in one aspect a post comprising a thin walled elongate tubular element having a substantially uniform cross-sectional shape, the cross-section being taken perpendicular to the length of the tubular element, wherein the cross-sectional shape of the tubular element comprises a main central region joined by a neck region to a laterally projecting lobe having a greater maximum width than the minimum width of the neck region, the area of the main central region being substantially greater than the area of the lobe.

The thin walled elongate tubular element may be formed of any material having sufficient strength and durability for the particular application required of the post. Thus, a range of materials may be suitable. Such materials may include any one or more of plastics, especially reinforced plastics, metals such as steel, aluminium, copper, zinc and any other structural metals and their alloys. Generally speaking however, it is anticipated that high tensile steel sheet will be the preferred material for the greater range of applications. The steel sheet may typically have a thickness between 0.6 and 6 mm. More preferably it may have a thickness between 0.9 and 2 mm.

Suitably, the post may be manufactured using an extrusion or roll forming process. Where the post is manufactured from steel sheet, it is anticipated that roll forming will be the most appropriate method of manufacture in a large proportion of cases. Roll forming has particular advantages in that the steel may be supplied in the form of a continuous ribbon of steel which can be unrolled from a reel. Thus, the posts can be readily produced as and when required by roll forming. The advantage of this approach is that a reel of steel ribbon does not take up much factory space as compared with the space which would be taken up by the finished roll formed posts. Furthermore, the ribbon of steel and roll forming machinery can be readily transported to a site where for example fencing may be erected and posts produced to order on the site. Such an approach has obvious savings with regard to transport costs, flexibility and ease of use. Where roll forming processes are used to produce the posts, it is anticipated that the roll forming will include overlapping the parallel edges of the ribbon of metal and bending them around each other so as to form a secure joint. For the purposes of this specification, this joint will be called a Pittsburgh joint.

An alternative roll forming process involving roll forming a tube of steel or other metal to the required shape may also be employed to produce posts.

The posts may be formed with a plurality of lobes. The plurality of lobes may be arranged so that they project in directions of 90° or 180° with respect to each other. Typically a post may be formed with between 1 and 4 lobes.

Thus for example, a corner post may be formed with two lobes projecting at 90° to each other. Generally speaking however, it is anticipated that a post with four lobes may typically be produced as the four lobes provides substantial flexibility.

As will be described hereinafter, the lobes can be used as a feature for attachment of clips which in turn may be used to attach other ancillary fencing devices such as wire, panels, boards and foot members.

The clips for attachment to the lobes may have a clip body portion shaped so as to fit over the lobes. The clip body portion may include two forward projecting arms shaped so that they extend toward each other as they overlie the lobes to a configuration where they are separated by a distance less than the maximum width of the lobe.

The clips may be shaped so they can be telescoped onto the lopes or alternatively they may be formed of a resilient material which allows them to be press fitted onto the lobes. They may be constructed so as to provide an interference with the lobes.

The clips may be formed with a retaining projection joined to the body portion of the clip. The purpose of the retaining projection may be to secure ancillary fencing means to the post. For this purpose, the retaining projection may extend generally in a direction defined by the lengthwise dimension of the tubular element. The retaining projection may include a channel-shaped region for securing ancillary fencing items such as wire or a foot for the fence.

The clip may be secured to the post by a screw which extends through a least one of the clip body and retaining projection.

Suitably, the area of the lobe as defined by the region bounded by the lobe and a line joining the narrowest point of the neck is less than half the main central region of the post. In the majority of instances it is anticipated that the lobe will represent less than 1/8 of the main central region.

Brief Description of the Drawings

In order that the invention may be more fully understood there will now be described, by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where:

Figure 1 shows an isometric view of a post constructed in accordance with the invention;

Figure la shows an enlarged view of the circled region of Figure 1;

Figure 2 shows a cross-sectional view of an alternative post shape according to the invention;

Figure 3 shows a cross-sectional view of another alternative post shape according to the invention; Figure 4 shows a cross-sectional view of another alternative post shape according to the invention; Figure 5 shows a cross-sectional view of another alternative post shape according to the invention;

Figure 6 shows a cross-sectional view of another alternative post shape according to the invention;

Figure 7 shows a cross-sectional view of another alternative post shape according to the invention; Figure 8 shows a cross-sectional view of another alternative post shape according to the invention;

Figure 9 shows an isometric fragmentary view of a clip applied to a lobe of a post;

Figure 10 shows an isometric view of an alternative clip construction applied to a lobe;

Figure 11 shows an isometric view of a foot applied to a post;

Figure 12 shows an isometric view of a foot; and

Figure 13 shows an exploded / assembled view of an alternative foot construction applied to a post.

Description of the Preferred Embodiments and Other Examples of the Invention

The various elements identified by numerals in the drawing are listed in the following integer list.

Integer List

1 Post Tubular element

Wall

Lobe

Neck

Arrow

Rib

Central area region

Lobe area

Pittsburgh joint

Post

Tubular element

Lobe

Radiused corner

Post

Lobe

Wall

Rib

Post

Lobe

Radiused comer

Fence post

Lobe

Rib

Post

Lobe

Lobe Lobe

Lobe

Concave wall

Post

Lobe

Radiused corner

Convex wall

Post

Lobe

Convex wall

Fence Post

Lobe

Clip

Body portion

Projecting arm

Upturned end

Retaining projection

Screw

Hole

Channel

Wire

Post

Lobe

Clip

Projecting arm

Retaining projection

Screw

Wire 111 Post 112 Foot 113 Central aperture 120 Foot 121 Clip portion 122 Lateral pad 130 Post 131 Foot 132 Outer ring 133 Inner portion 134 Central opening 135 Clip 136 Screw 137 Retaining projection 138 Channel 140 End cup

Referring to Figures 1 and la of the drawings there is shown a post generally designated 1 in the form of a tubular element 3 having a wall 4 of suitable sheet material e.g. galvanized or colour bonded high tensile steel having a thickness of about 1.2 mm.

The tubular element may have been roll formed after unrolling a ribbon of steel from a reel. It may be cut to length before or after the roll forming step.

The tubular element includes a laterally projecting lobe 5 having a neck 7 which serves to provide a dove-tailed attachment to a clip which will be described hereinafter. The narrowest point of the neck shown by the arrow 7 for the purposes of this specification serves to define the demarcation between the lobe area 15 and central area region 14 of the main cross-sectional area of the tubular element.

The tubular element includes three formed ribs 10, 11, 12 arranged so that the three ribs and lobe project radially at 90° intervals. It is noted that the cross-sectional central area region extending into the ribs for the purposes of this specification are to be considered to form part of the area of the central area region.

As is shown more clearly in Figure la, the edges of the ribbon forming the tubular element are joined by overlapping and bending them over each other to lock them together. The particular form of overlapping shown in the drawing is known in the trade as a Pittsburgh joint and is identified by the reference numeral 18.

Referring to Figure 2, the alternative post construction generally designated 20 comprises a tubular element 21 which may have been formed by extrusion although it is anticipated in the majority of cases, it will have been formed by a roll forming process using steel ribbon with the edges of the ribbon joined using a Pittsburgh joint 18 as shown in the drawing. Of course, if an extrusion process for forming the tubular element 21 is used, no such joint would be required.

In this Figure, there is only a single lobe 21 having a necked region so that apart from the lobe, the post has a generally square cross-sectional shape with three of the comers 24 of the square being radiused, the fourth comer of course being the lobe.

Referring to figure 3, the alternative cross-sectional shape of the post 30 shows two lobes 31, 32 extending at right angles to each other and two ribs 34, 35 also extending radially so that there is a lobe or rib at 90° radial intervals. The lobes and ribs are joined by wall sections 34 having a generally convex configuration.

In the alternative cross-sectional shape shown in Figure 4, the post 40 is provided with two lobes 41, 42 defining two comers of a generally square cross-section with two radiused corners 44.

The cross-sectional shapes shown in Figures 3 and 4 would generally be more suitable where they form corner posts for a fence or similar with the lobes providing dovetail attachment points for clips or other ancillary features of the fence. Referring to Figure 5, the fence post 50 includes three lobes 51, 52, 53 and a single rib 54 all joined by intermediate concave wall sections. This type of configuration may be used where a fence or trellis extends in three directions at right angles to each other from the post.

Similarly, the post 60 shown in Figure 6 in having four lobes 61, 62, 63, 64 joined by concave walls 65 might be used in situations where attachment to the post is required in four different directions. As a post having four lobes is the most flexible in terms of its capacity to provide interconnection with ancillary features along four sides of the post, it may be preferable to only manufacture four lobed posts for most scenarios to provide great flexibility.

In Figure 7 the post 70 includes three lobes 71, 72, 73 and a single radiused corner 74, the lobes and radiused comer being joined by convex wall sections 75. A post of this constmction would have similar application to that described with reference to Figure 5.

In Figure 8, the post 80 includes four lobes 81, 82, 83, 84 joined by convex wall sections 85. This is an alternative constmction to that described with reference to Figure 6 and would also have similar application to the post of Figure 6.

Referring to Figure 9, there is shown a fragmentary view of a post 90 having a lobe 91 fitted with a clip 92.

The clip which may be formed of any suitable material such as steel or plastic comprises a body portion 93 having two projecting arms 94 which fit in dovetail fashion over the lobe following the outline of the lobe. Suitably the arms give an interference fit with the lobe.

The projecting arms have upturned ends 95. A retaining projection 96 extends away from the body portion generally parallel to the length of the post. For additional restraint of the wire, the clip 92 can be held in place on the lobe by the screw 97 extending through the hole 98 in the body portion and into the lobe 91.

The channel portion 99 of the retaining projection is shaped so as to receive the wire 100 and hold it in place, the end of the retaining projection fitting against the outer wall of the lobe to trap the wire in the channel section.

In Figure 10, a post 101 having a lobe 102 is fitted with a clip 103 formed by bending wire into the shape where it has two projecting arms 104 and an upstanding retaining projection 105. A screw 106 passing through the retaining projection serves to hold the clip in place on the lobe and to trap the wire 107 in place in the manner illustrated.

Where the post needs to be driven into sandy soil, it may be necessary to provide the post with a foot to support the post against lateral movement and to prevent it being driven too far into the ground. Thus, in Figure 11 there is shown a post 111 surrounded by a circular foot 112 having a central aperture 113 conforming to the external outline of the post. The foot may be telescopically slid onto the post and held in place by a clip of the type described with reference to Figure 9. Thus, the retaining projection 96 having the enlarged portion provided by channel 99 may be installed on the post so as to prevent the foot 112 sliding up the post past the clip when it is driven into the ground. It is to be appreciated that the foot can be installed on the post before or after installation of the post in the ground.

An alternative foot 120 is shown in Figure 12. This includes a clip portion for fitting to the lobe of a post and a lateral pad. The foot may be secured to the post using a screw as described hereinbefore. The alternative foot design lends itself to retrofitting onto the post after the post has been in the ground for some time as the ground conditions could have changed since its installation.

In Figure 13, there is shown a post 130 provided with a foot 131 formed of shaped wire or bar. The foot includes an outer ring 132 and an inner portion 133 shaped so as to allow the foot to be telescopically slid onto a post through its central opening 134 and to be secured with a clip 135 and screw 136.

The clip is substantially the same as the clip described with reference to Figure 9 with the retaining projection 137 having a channel 138 for retaining the wire forming the inner portion of the foot against the post.

The top of the post includes an end cap 140 which may be constructed with a skirt fitting over the top of the post or alternatively as a plug which nestles within and sits on top of the post.

One potential scenario for constmcting a fence using posts in accordance with the invention may comprise the following steps: (i) a vehicle loaded with roll forming equipment and a reel of high tensile steel ribbon is driven to a fencing construction site; (ii) posts are roll formed from the strip of high tensile steel at the site and cut to length. Clips may be applied to the post in this step in positions along the length of the post where wire must be retained and a foot is applied to each post (this step is optional depending on the nature of the soil) using a clip to retain the foot in place. At the same time, an end cap is placed on top of the post; (iii) the posts are driven into the ground at measured intervals using a whomper and clips are applied to the post if they have not already been applied in step (ii); (iv) wire is attached via the clips and strung between adjacent posts to produce the finished fence. (Note as an alternative to wire a fixing system for panels, boards or other material may be used. Where an electric fence is required the clips may be associated with an insulator for insulating the post from the electrical current in the wires.).

Whilst the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constractions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention.

It will be also understood that where the word "comprise", and variations such as "comprises" and "comprising", are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge in Australia.

Claims

1. A post comprising a thin walled elongate tubular element having a substantially uniform cross-sectional shape, the cross-section being taken perpendicular to the length of the tubular element, wherein the cross-sectional shape of the tubular element comprises a main central region joined by a neck region to a laterally projecting lobe having a greater maximum width than the minimum width of the neck region, the area of the main central region being substantially greater than the area of the lobe.

2. A post according to claim 1 comprising a clip having a clip body portion shaped so as to fit over the lobe, the clip body portion having two forward projecting arms shaped so as to extend towards each other as they overlie the lobe to a configuration where they are separated by a distance less than the maximum width of the lobe.

3. A post according to claim 1 wherein the tubular element comprises a roll formed sheet of steel having opposed generally parallel edges, and the generally parallel edges are joined by a Pittsburgh joint.

4. A post according to claim 2 wherein the clip comprises a retaining projection joined to the clip body portion, the retaining projection extending generally in a direction defined by the lengthwise dimension of the tubular element when the clip is secured to the lobe, the retaining projection being shaped so as to secure ancillary means extending generally perpendicular to the lengthwise dimension of the tubular element.

5. A fence comprising a plurality of posts as defined in claim 4 wherein the ancillary means comprise wire extending between adjacent posts.

6. A post according to claim 4 wherein the ancillary means comprise a foot extending laterally around the tubular element.

7. A post according to claim 4 wherein the retaining projection comprises a channel-shaped region for securing the ancillary means.

8. A post according to claim 2 comprising a screw for securing the clip to the tubular element, the screw extending through the clip body portion into the tubular element.

9. A post according to claim 4 comprising a screw for securing the clip to the tubular element, the screw extending through the retaining projection into the tubular element.

10. A post according to claim 1 wherein the area of the main central region is at least double the area of the lobe.

11. A post according to claim 3 wherein the metal sheet has a thickness between 0.6 and 6.0 mm.

12. A post according to claim 1 comprising a plurality of lobes arranged to project in directions at angles of 90° or 180° to each other.

13. A method of erecting a fence comprising, installing a plurality of posts according to claim 1 in the ground and attaching fencing material to extend between adjacent posts so that the fencing material is supported by the adjacent posts.

14. A method of erecting a fence according to claim 13 wherein the posts are manufactured at a site where a fence is being erected comprising the steps of, unrolling a continuous ribbon of steel from a roll, shaping the unrolled ribbon by a roll forming process to the profile required of the posts, joining opposed edges of the shaped ribbon with a Pittsburgh joint, cutting the shaped ribbon before or after roll forming to a desired length, erecting the posts formed and cut from the ribbon in the ground, securing a clip to the lobe of each post, and extending fencing material supported by the clip of each post between adjacent posts.

15. A method according to claim 14 wherein the fencing material comprises wire.