Indicator Post

Abstract

This invention relates to an indicator post comprising an elongate sheet of high strength engineering polymer (HSEP) material, the elongate sheet being resiliently bendable to enable the indicator post to revert upright after an impact. An associated reinforcement means attachable to a driveable portion of the indicator post is also disclosed.

Description

This application claims the benefit of Australian Application No. 2008905490 filed Oct. 23, 2008, the content of which is herein incorporated by reference.

TECHNICAL FIELD

The present invention relates to an indicator post. In a particular form, the present invention relates to a flexible indicator post suitable for indicating the position of an object or delineating a road, lane way or the like.

BACKGROUND

Indicator posts are commonly employed by road traffic authorities to visually indicate or delineate the location of roads, paths and lanes. Furthermore, indicator posts are often utilised by entities such as water authorities, fire protection authorities and mining companies to indicate the position or location of important assets such as pipelines, valves and drains.

Flexible indicator posts are used in those situations where a post is likely to suffer from numerous impacts from either vehicles or other objects. The principle behind these flexible posts is that upon impact they are able to flex and then subsequently return to a substantially upright position. In this manner, a flexible post is able to survive an impact unlike a standard rigid post which will either fracture or bend permanently. As such, flexible posts will tend to have a greater lifetime when compared to standard rigid posts resulting in reduced maintenance costs.

One example of a flexible indicator post is a roadside post that is formed of a single elongate sheet of spring steel. However, there are a number of serious disadvantages with these spring steel posts. One important disadvantage is that a spring steel post is likely to crease when subject to an impact such as a direct wheel over from a vehicle where the spring steel post is forced into a tight right angle bend thereby causing the spring steel to permanently deform. Another disadvantage is that a spring steel post must be coated to both prevent corrosion and to ensure that it stands out visually. In addition, a post formed of a single sheet of spring steel can cause a substantial amount of damage to a vehicle striking it and in the case of a motorcyclist, a spring steel post may form a safety hazard especially if the post is struck edge on. Furthermore, once a spring steel post has been damaged it cannot be easily recycled.

It is desirable to improve upon any one or more of the above identified shortcomings.

SUMMARY

In a first aspect the present invention accordingly provides an indicator post comprising an elongate sheet of high strength engineering polymer (HSEP) material, the elongate sheet resiliently bendable to enable the indicator post to revert upright after an impact.

In another form, the HSEP material is a UV stabilised extrudable polycarbonate.

In another form, the UV stabilised extrudable polycarbonate is selected from any one of Makrolon 3101, Panlite polycarbonate, Novarex polycarbonate, Carbine 8073 polycarbonate or any combination thereof.

In another form, the elongate sheet has a substantially arcuate sectional profile.

In another form, the elongate sheet has a substantially channel shaped profile.

In another form, the width is approximately between 40 mm and 140 mm.

In another form, the thickness is approximately between 1 mm and 6 mm.

In another form, the indicator post further includes ground engaging means to resist upward movement of the post after installation into the ground.

In another form, the indicator post further includes an installation depth indicator.

In another form, the indicator post further comprises a driveable base portion attached to the elongate sheet.

In another form, the driveable base portion includes a star picket section.

In another form, the indicator post includes reinforcement means to reinforce a drivable portion of the elongate sheet.

In another form, the reinforcement means substantially matches the shape of the drivable portion of the elongate sheet.

In another form, the reinforcement means comprises an elongate web portion attached to the elongate sheet.

In another form, the elongate web portion includes a tapered end.

In another form, the elongate sheet is formed of steel.

In another form, the indicator post is a roadside post.

In a second aspect, the present invention accordingly provides a reinforcement means for an indicator post, the reinforcement means being attached to a driveable portion of the indicator post to reinforce the driveable portion for driving into the ground.

In another form, the reinforcement means substantially matches the shape of the drivable portion of the indicator post.

In another form, the reinforcement means comprises an elongate web portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention will be discussed with reference to the accompanying drawings wherein:

FIG. 1 is a front view of an indicator post according to a first illustrative embodiment of the present invention;

FIG. 2 is a bottom view of the indicator post as illustrated in FIG. 1;

FIG. 3 is a top view of the indicator post as illustrated in FIG. 1;

FIG. 4 is a side view of the indicator post as illustrated in FIG. 1;

FIG. 5 is a rear view of the indicator post as illustrated in FIG. 1;

FIG. 6 is a side view of the indicator post illustrated in FIG. 1 as installed in the ground;

FIG. 7 is a front view of an indicator post according to a second illustrative embodiment of the present invention;

FIG. 8 is a bottom view of the indicator post as illustrated in FIG. 7;

FIG. 9 is a top view of the indicator post as illustrated in FIG. 7;

FIG. 10 is a side view of the indicator post as illustrated in FIG. 7;

FIG. 11 is a rear view of the indicator post as illustrated in FIG. 7;

FIG. 12 is a side view of the indicator post illustrated in FIG. 7 as installed in the ground;

FIG. 13 is a front view of an indicator post according to a third illustrative embodiment of the present invention;

FIG. 14 is a bottom view of the indicator post as illustrated in FIG. 13;

FIG. 15 is a top view of the indicator post as illustrated in FIG. 13;

FIG. 16 is a side view of the indicator post as illustrated in FIG. 13;

FIG. 17 is a rear view of the indicator post as illustrated in FIG. 13;

FIG. 18 is a side view of the indicator post illustrated in FIG. 13 as installed in the ground; and

FIG. 19 is a series of sectional views of indicator posts in accordance with further embodiments of the present invention.

In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings.

TECHNICAL DESCRIPTION

Referring now to FIGS. 1 to 5, there is shown an indicator post 100 in accordance with a first illustrative embodiment of the present invention. Indicator post 100 includes an elongate sheet 110 of high strength engineering polymer (HSEP) such as a UV stabilised extrudable polycarbonate having high flexural and impact strength and high heat resistance. In this illustrative embodiment, elongated sheet is formed of Makrolon™ 3103 available from Bayer Material Sciences. Other examples of HSEP materials that are suitable include, but are not limited to, extrusion grade Panlite polycarbonate, Novarex polycarbonate or Carbine 8073 polycarbonate. As would be apparent to those skilled in the art, HSEP materials provide the important advantage of being generally recyclable.

Elongate sheet 110 has a generally channel shaped cross sectional profile comprising a central web portion 111 and two opposed angled portions 112 (as best seen in FIGS. 2 and 3) with a pair of longitudinally extending ribs 120 located at the boundary between the central web portion 111 and the angled portions 112.

Ribs 120 function to both stiffen elongate sheet 110 and to provide a longitudinally extending recessed portion 114, which at the top end of elongate sheet 110 provides a protected area for retro-reflective sheet portion 150. In this manner, retro-reflective sheeting 150 is shielded when indicator post 100 is struck by a vehicle and the top portion strikes the ground. Indicator post 100 includes a tapered end 140 coming to a point 141 which aids in the driving of the post 100 into the ground. While in this illustrative embodiment, the retro-reflective sheet portion is employed to enhance the visual indicating characteristics of indicator post 100, equally the top or other portion of post 100 may be coated with a suitable reflective coating or combination of coatings. Furthermore, elongate sheet 110 may be extruded in any desired colour unlike posts formed of spring steel which must be separately coated to improve their visibility.

The lower portion of indicator post 100 further includes an upwardly extending tongue 160 formed by punching a slot in elongate sheet 110 which upon installation of the post 100 into the ground functions to resists upward movement of the post 100. Other ground engaging means that may be employed include a retention rod which extends horizontally through an aperture in the post and anchoring devices which may be attached or fastened to post 100 which extend either horizontally or upwardly and function to resist upward movement of post 100.

Post 100 further includes a depth marker line 130 extending horizontally across the front face of elongate sheet 110 which functions as an installation depth indicator. In another illustrative embodiment, a second depth marker line is placed at the corresponding location on the rear of post 100, thereby facilitating installation of post 100 to the correct depth from either direction. Other examples of installation depth indicators include, but are not limited to, a depth marker hole comprising a single centrally located aperture located on the post at the height corresponding to the depth that the indicator post 100 is to be installed into the ground or a depth marker sticker or tag that is secured to the elongate sheet 110 by mechanical means and/or by an appropriate adhesive.

In this illustrative embodiment post 100 has a height of 1400 mm, a width of 100 mm and a thickness of 4.0 mm. The angle that angled portions 112 subtend with respect to web portion 111 is approximately 45 degrees. However, depending on the intended location and requirements, post 100 may range in height, thickness, width and channel angle as required. Some illustrative height ranges include, but are not limited to, less than 400 mm, 400 mm to 600 mm, 600 mm to 800 mm, 800 mm to 1000 mm, 1000 mm to 1200 mm, 1200 mm to 1400 mm, 1400 mm to 1600 mm, 1600 mm to 1800 mm, 1800 mm to 2000 mm and greater than 2000 mm.

Some illustrative thickness ranges include, but are not limited to, less than 1 mm, 1 mm to 1.5 mm, 1.5 mm to 2.0 mm, 2.5 mm to 3.0 mm, 3.5 mm to 4.0 mm, 4.5 mm to 5.0 mm, 5.0 mm to 5.5 mm, 5.5 mm to 6.0 mm and greater than 6.0 mm. Some illustrative width ranges include, but are not limited to, less than 40 mm, 40 mm to 60 mm, 60 mm to 80 mm, 80 mm to 100 mm, 100 mm to 120 mm, 120 mm to 140 mm and greater than 140 mm. Some illustrative channel angles include, but are not limited to, 0 degrees (i.e. substantially flat) to 20 degrees, 20 degrees to 40 degrees, 40 degrees to 60 degrees, 60 degrees to 80 degrees and greater than 80 degrees.

In one illustrative embodiment, the manufacturing process for indicator post 100 involves feeding granules of HSEP material into a plastic extruder which melts and extrudes the molten HSEP material through a die and then through an extrusion calibrator or sizing plate that forms and sets the post profile. The resultant extruded HSEP material is then fed through a cooling tank into a haul off or caterpillar drive which draws and pulls the cooled HSEP material from the cooling tank to form a continuous length of extruded HSEP material having the desired sectional profile. The cooled and extruded HSEP material then travels through a cutting device which cuts the extruded HSEP material into posts of the desired shape (e.g. a taper) and length.

Referring now to FIG. 6, there is shown indicator post 100 in operation. Indicator post 100 is installed in the ground 800 to the level of depth line marker 130. This installation may be accomplished in a number of different ways. In a first method of installing indicator post 100, a hole of larger size than the post may be dug or drilled to the suitable depth, post 100 is then deposited in the hole and the hole then refilled. In a second method of installing indicator post 100, a small pilot or lead hole is drilled into the ground 800 and post 100 may then be driven into the ground 800 either manually or by use of suitable pneumatic driving equipment. In a third method of instilling indicator post 100, the post may be driven into the ground 800 either manually or by pneumatic means without the use of a pilot hole.

In both the second and third methods of installation, the presence of tapered end 140 facilitates the installation of indicator post 100. In a fourth method of installing indicator post 100, a section of the ground 800 may be excavated and filled with a settable material such as concrete. Before the settable material sets, indicator post is deposited into the settable material in the upright position. As shown in FIG. 6, indicator post 100 when subject to an impact will resiliently bend and recover to revert upright after the impact. In those circumstances where indicator post 100 may subject to a tight right angle bend, such as where there is a direct wheel over by a vehicle, a recess may be formed in the ground immediately adjacent to the post to increase the bend radius at ground level.

Referring now to FIGS. 7 to 11, there is shown an indicator post 200 in accordance with a second illustrative embodiment of the present invention. As with the first embodiment, indicator post 200 includes an elongate sheet 110 of HSEP material which in this illustrative embodiment is formed from Makrolon™ 3103. Indicator post 200 also includes a driveable base portion 210 including a base attachment plate 240 welded to a star picket section 230 having a tapered end 240 and coming to a point 241. Star picket section 230 functions as a rigid insertion portion which is driven into the ground. In other embodiments, driveable base portion 210 may include a sharpened stake or a piece of a suitable rigid material having a channel or box section that may or may not include a tapered end. Base attachment plate 240 is attached to the bottom end of elongate sheet 110 by a series of rivets 220 but equally, driveable base portion 210 may be attached to elongate sheet 110 by other suitable attachments means such as by the use of an adhesive or other mechanical attachment means. Although in this illustrative embodiment, driveable base portion 210 has been utilised in combination with a HSEP material, equally driveable base portion 210 may be used with indicator posts formed of other materials.

Referring now to FIG. 12, there is shown indicator post 200 in operation. In this illustrative embodiment, indicator post 200 is installed in the ground to the level of the top edge 241 of attachment plate 240 which forms an installation depth indicator. As with indicator post 100 of the first illustrative embodiment, indicator post 200 may be installed in a number of different ways. However, the presence of driveable base portion 210 ensures that post 200 is more suitable to be directly driven into the ground 800. In one illustrative mode of installation, a jackhammer is employed to drive driveable base portion 210 by locating the end of a complementary tool inserted into the jackhammer into the notch 231 located at the top of star picket section 230. In this method of installation, the jackhammer is aligned substantially parallel and against the indicator post 200 as an installer drives star picket section 230 into the ground 800. Depending on the type of jackhammer, the indicator post 200 may be inserted through the handle of the jackhammer which will function to align and retain post 200 to the jackhammer to facilitate the installation process.

Referring now to FIGS. 13 to 17, there is shown an indicator post 300 in accordance with a third illustrative embodiment of the present invention. Indicator post 300 is directed to those situations where it is desirable to directly drive post 300 into a relatively hard surface such as a top layer of asphalt on a road or other compacted material and a substantially unitary post is required. In these situations, various materials such as PVC plastic and to a lesser extent HSEP material may not be suitably rigid to allow direct driveability into a hard surface. Indicator post 300 includes an elongate sheet 110 of HSEP material as described with reference to the first illustrative embodiment of the present invention and further includes reinforcement means 400 attached to a driveable portion 160 of elongate sheet 110 to reinforce this portion for driving into a surface.

In this illustrative embodiment, reinforcement means 400 includes an elongate web 410 formed of suitable rigid material such as galvanised steel having a thickness of 1 to 3 mm that is sized and shaped to sit in recessed portion 114 located between ribs 120 at the lower end of elongate sheet 110. Although in this illustrative embodiment, reinforcement means 400 is formed from galvanised steel, equally other rigid materials such as various type of steels, wood or rigid plastic materials may be employed.

Reinforcement means 400 is attached in this illustrative embodiment to the driveable portion of elongate sheet 110 by a series of spaced apart rivets 420 extending along the length of web 410. Equally however, reinforcement means 400 may be attached to the elongate sheet by other attachment means such as the use of bolts or attachment tags which are folded around and crimped onto elongate sheet 110. In another illustrative embodiment, reinforcement means may be formed as complementary shaped sleeve or cap which receives and is attached to the driveable portion of elongate sheet 110.

Web 410 includes at the driveable end a taper 440 coming to a point 441 which substantially matches in shape the corresponding tapered portion 140 of elongate sheet 110, thereby reinforcing this region so that it is directly driveable into relatively hard surfaces. As would be appreciated by those skilled in the art, reinforcement means 400 may be applicable to all types of indicator posts formed from different materials which may require reinforcement to ensure driveability into relatively hard surfaces. While in this illustrative embodiment, reinforcement means 400 is shaped to substantially conform or match with the driveable portion 160 of elongate sheet 110, equally other shaped reinforcement means that function to reinforce the driveable portion 160 of elongate sheet 110 are contemplated to within the scope of the invention. In another illustrative embodiment, reinforcement means consists of reinforced edging that extends around the perimeter of the driveable portion of elongate sheet 110.

Referring now to FIG. 18, there is shown indicator post 300 in operation. Indicator post 300 is installed in the ground to the level of the top edge 430 of reinforcement means 400 which forms an installation depth indicator. As described previously, the presence of reinforcement means 400 facilitates the direct driving of post 300 into the ground 800 either manually or by pneumatic means without the use of a pilot hole.

Referring now to FIG. 19, there is shown a number of different indicator post cross sections or extruded sectional profiles that are contemplated to be within the scope of the present invention including, but not limited to, the ribbed channel shaped type cross sections 510, 515 as exemplified by the first, second and third embodiments described herein, a substantially arcuate cross section 520 (where the radius of curvature can vary from 50 mm to 300 mm), an arcuate cross section incorporating planar edge portions 525, a ribbed arcuate cross section 530, a generally planar cross section having a central broad rib and perpendicular edge portions 535 and a zigzag or concertina type cross section 540. In those situations where a reinforcement member 400 may be required it can be sized and shaped to substantially conform with the sectional profile of the indicator post.

It will be understood that the term “comprise” and any of its derivatives (e.g. comprises, comprising) as used in this specification is to be taken to be inclusive of features to which it refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied. The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

Although illustrative embodiments of the present invention have been described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiment disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.

Claims

1. An indicator post comprising an elongate sheet of high strength engineering polymer (HSEP) material, the elongate sheet being resiliently bendable to enable the indicator post to revert upright after an impact.

2. The indicator post of claim 1, wherein the HSEP material is a UV stabilised extrudable polycarbonate.

3. The indicator post of claim 1, wherein the UV stabilised extrudable polycarbonate is selected from any one of Makrolon 3101, Panlite polycarbonate, Novarex polycarbonate, Carbine 8073 polycarbonate or any combination thereof.

4. The indicator post of claim 1, wherein the elongate sheet has a substantially arcuate sectional profile.

5. The indicator post of claim 1, wherein the elongate sheet has a substantially channel shaped profile.

6. The indicator post of claim 1, wherein the width of the elongate sheet is approximately between 40 mm and 140 mm.

7. The indicator post of claim 1, wherein the thickness of the elongate sheet is approximately between 1 mm and 6 mm.

8. The indicator post of claim 1, further including ground engaging means to resist upward movement of the post after installation into the ground.

9. The indicator post of claim 1, further comprising an installation depth indicator.

10. The indicator post of claim 1, further comprising a driveable base portion attached to the elongate sheet.

11. The indicator post of claim 10, wherein the driveable base portion includes a star picket section.

12. The indicator post of claim 1, further comprising reinforcement means to reinforce a drivable portion of the elongate sheet.

13. The indicator post of claim 12, wherein the reinforcement means substantially matches the shape of the drivable portion of the elongate sheet.

14. The indicator post of claim 12, wherein the reinforcement means comprises an elongate web portion attached to the elongate sheet.

15. The indicator post of claim 14, wherein the elongate web portion includes a tapered end.

16. The indicator post of claim 14, wherein the elongate sheet is formed of steel.

17. The indicator post of claim 1, wherein the indicator post is a roadside post.

18. A reinforcement means for an indicator post, the reinforcement means being attached to a driveable portion of the indicator post to reinforce the driveable portion for driving into the ground.

19. The reinforcement means of claim 18, wherein the reinforcement means substantially matches the shape of the drivable portion of the indicator post.

20. The reinforcement means of claim 18, wherein the reinforcement means comprises an elongate web portion.