Patent Publication Number: US-8991792-B2

Title: Fence post and fence formed therefrom

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a fence post which may be installed in situations prone to rising water or flood, and also, to a fence formed using a plurality of such fence posts. 
     DESCRIPTION OF THE PRIOR ART 
     The reference to any prior art in the specification is not and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge. 
     In areas prone to flood, such as, but not limited to farms or other properties, it is not uncommon for fences on or around the farms or other properties to be substantially destroyed during floods and the like. 
     In such situations, not only does the water rise, but the water flow can sometimes be rapid in a direction from higher to lower ground, even on only slight inclines. Any debris, trees, shrubs, or other objects in the path of the moving and rising water is moved together with the flood waters as they travel. Such debris, trees, shrubs, and other objects tend to cause a considerable amount of damage when they contact any fixed item in their path. 
     Typically, when flood waters carrying debris, trees, shrubs, and other objects contact a fence in their pathway, the debris, trees, shrubs, and other objects become entangled in the fence. Depending upon the force of the flood waters, the fence may or may not withstand the forces exerted upon it by the debris, trees, shrubs, and other objects. In some situations, the debris and other matter is stalled by the fence, and after the flood waters recede, the debris and other matter is deposited along the fence line. In other situations, particularly in strong floods, the debris and other matter exerts such forces against the fence, that the fence typically gives way and breaks, allowing release of the debris and other matter. This situation is prone to be quite dangerous, especially where there has been significant build up of debris or other matter, as the debris or other matter is suddenly released and can cause quite a devastating effect on persons or objects downstream therefrom. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to overcome some of the problems experienced by prior art fencing, especially during floods or rising waters. 
     In one broad form, the present invention provides a fence post which is adapted to release from a substrate surface in the event of rising water or flood. 
     Preferably, at least a part of said fence post is adapted to float in the event of rising water or flood. 
     Also preferably, the fence post further includes an engaging mechanism at a first end thereof, which is adapted to release said first end of said fence post from said substrate surface in the event of rising water or flood. 
     Preferably, the fence post further includes a retaining mechanism at a second end thereof, which, when said engaging mechanism releases said first end of said fence post from said substrate surface, substantially retains said second end of said post at or near its pre-released position. 
     Preferably, said retaining mechanism permits transverse movement of said post in at least one dimension. 
     Also preferably, the engaging mechanism of the fence post further includes a latch which is adapted to float, such that, in the event of rising water or flood, said latch is moved from a first position in which said fence post is secured to said substrate surface, to a second position in which said fence post is no longer secured to said substrate surface. 
     Preferably, said engaging mechanism includes a buoyant portion which is adapted to substantially float to effect operation of said engaging mechanism. 
     Also preferably, said engaging mechanism include a float connected thereto, said float being formed at least partly of buoyant material, to effect operation of said engaging mechanism. 
     Also preferably, the engaging mechanism of the fence post further includes: 
     an anchor, having a substrate engaging end which is secured substantially below said substrate surface; and, 
     a latch engaging end which effectively enables said first end of said fence post to be secured to said substrate surface. 
     Preferably, said anchor is adapted to be received in a receiving mechanism, said receiving mechanism being anchored in said substrate surface. 
     Preferably, a body of said fence post is formed of hollow plastics or other lightweight floatable material. 
     Also preferably, said body of said fence post is shaped to be buoyant such that it assumes a substantially upright position when floating. 
     In a further broad form, the present invention provides a fence having a plurality of fence posts, at least one of said fence posts being a releasable fence post which is adapted to release from a substrate surface in the event of rising water or flood. 
     Preferably, each releasable fence post is adapted to float in the event of rising water or flood. 
     Also preferably, each releasable fence post includes an engaging mechanism at a first end thereof, which is adapted to release said first end of said releasable fence post from said substrate surface in the event of rising water or flood. 
     Also preferably, a retaining mechanism at a second end thereof, which, when said engaging mechanism releases said first end of said fence post from said substrate surface, substantially retains said second end of said post at or near its pre-released position. 
     The fence preferably also further includes: 
     a pair of spaced apart cable supports; and, 
     a cable spanning said cable supports in a manner such that it is spaced above a substrate surface; 
     whereby, said retaining mechanism of each releasable fence post engages said cable. 
     In yet a further broad form, the present invention provides a fence having: 
     a pair of spaced apart cable supports; 
     a cable spanning said cable supports in a manner such that it is spaced above a substrate surface; 
     at least one releasable post positioned between said cable supports, each releasable post including:
         engaging mechanism at a first end thereof, adapted to release said first end of said post from said substrate surface in the event of rising water or flood; and,   a retaining mechanism at a second end thereof, adapted to hold said second end of said post to said cable when said first end of said post is released from said substrate.       

     Preferably, said engaging mechanism includes a latch which is adapted to float, such that, in the event of rising water or flood, said latch is moved from a first position in which said fence post is secured to said substrate surface, to a second position in which said fence post is no longer secured to said substrate surface. 
     Preferably, said engaging mechanism includes a buoyant portion which is adapted to substantially float to effect operation of said engaging mechanism. 
     Also preferably, said engaging mechanism includes a float connected thereto, said float being formed at least partly of buoyant material, to effect operation of said engaging mechanism. 
     Also preferably, said engaging mechanism further includes an anchor, having a substrate engaging end which is secured substantially below said substrate surface, and, a latch engaging end which effectively enables said first end of said fence post to be secured to said substrate surface. 
     Preferably, each said anchor is adapted to be received in a receiving mechanism, each said receiving mechanism being anchored in said substrate surface. 
     Preferably, a body of each releasable fence post is formed of hollow plastics or other lightweight floatable material. 
     Also preferably, said body of each releasable fence post is shaped to be buoyant such that it assumes a substantially upright position when floating. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the following detailed description of preferred, but non-limiting embodiments thereof, described in connection with the accompanying drawings in which: 
         FIG. 1  ( a ) illustrates a perspective view of a first preferred embodiment of a fence post in accordance with the present invention; 
         FIG. 1(   b ) illustrates a top view of a first preferred embodiment of a fence post in accordance with the present invention; 
         FIGS. 2(   a ) to  2 ( e ) illustrate a second preferred embodiment of a fence post in accordance with the present invention,  FIG. 2(   a ) showing a first perspective view,  FIG. 2(   b ) showing a first side view,  FIG. 2(   c ) showing a second perspective view,  FIG. 2(   d ) showing a second side view, and  FIG. 2(   e ) showing a perspective view of a fence post installed in a substrate; 
         FIGS. 3(   a )(i) to  3 ( c )(ii) illustrate how the second embodiment of the fence post may be released,  FIG. 3(   a )(i) showing a perspective view of the fence post in a dry situation,  FIG. 3(   a )(ii) showing a side view of the fence post in a dry situation,  FIG. 3(   b )(i) illustrating a perspective view of the fence post in a situation where water is beginning to rise, and  FIG. 3(   b )(ii) illustrating a side view of the fence post in a situation where water is beginning to rise,  FIG. 3(   c )(i) illustrating a perspective view of the fence post in a situation of flood, and  FIG. 3(   c )(ii) illustrating a side view of the fence post in a situation of flood; 
         FIGS. 4(   a ) to  4 ( c ) illustrate a fence, including a plurality of fence posts of the second embodiment, installed in a dry riverbed situation,  FIG. 4(   a ) showing a perspective view,  FIG. 4(   b ) showing an enlarged portion of  FIG. 4(   a ), and  FIG. 4(   c ) showing a side view; 
       FIGS  5 ( a ) to  5 ( e ) illustrate a fence, comprising a plurality of fence posts of the second embodiment, installed in a riverbed situation wherein the waters in the riverbed are rising or flooding,  FIG. 5(   a ) showing a perspective view,  FIG. 5(   b ) showing an enlarged portion of  FIG. 5(   a ),  FIG. 5(   c ) showing a side view of an end portion of the fence,  FIG. 5(   d ) showing a side view of the fence, and  FIG. 5(   e ) also showing a side view of an end portion of the fence; 
         FIGS. 6(   a ) to  6 ( f ) illustrate a third preferred embodiment of a fence post in accordance with the present invention,  FIG. 6(   a ) showing a first perspective view,  FIG. 6(   b ) showing a first side view,  FIG. 6(   c ) showing a second perspective view,  FIG. 6(   d ) showing a second side view, FIG  6 ( e ) showing a perspective view of the third embodiment installed in a substrate, and  FIG. 6(   f ) showing the first side view where the latch is in a position found prior to water rising; 
         FIGS. 7(   a )(i) to  7 ( c )(ii) illustrate how the third embodiment of the fence post may be released,  FIG. 7(   a )(i) showing a perspective view of the fence post in a dry river situation,  FIG. 7(   a )(ii) showing a side view of the fence post in a dry river situation,  FIG. 7(   b )(i) illustrating a perspective view of the fence post in a situation where water is beginning to rise,  FIG. 7(   b )(ii) illustrating a side view of the fence post in a situation where water is beginning to rise,  FIG. 7(   c )(i) illustrating the fence post in a situation of flood, and,  FIG. 7(   c )(ii) illustrating the fence post in a situation of flood; 
         FIGS. 8   a ) to  8 ( c ) illustrate a fence, including a plurality of fence posts of the third embodiment, installed in a dry riverbed situation,  FIG. 8(   a ) showing a perspective view,  FIG. 8(   b ) showing an enlarged portion of  FIG. 8(   a ), and  FIG. 8(   c ) showing a side view; and 
         FIGS. 9(   a ) to  9 ( e ) illustrate a fence, including a plurality of fence posts of the third embodiment, wherein the waters in a riverbed are rising or flooding,  FIG. 9(   a ) showing a perspective view,  FIG. 9(   b ) showing an enlarged portion of  FIG. 9(   a ),  FIG. 9(   c ) showing a side view of an end of the fence,  FIG. 9(   d ) showing a side view, and  FIG. 9(   e ) showing a side view of an end of the fence. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Throughout the drawings, like numerals will be used to identify similar features except where expressly otherwise indicated. 
       FIGS. 1 and 2  show two preferred embodiments of a fence post in accordance with the present invention. The fence post in accordance with the present invention is adapted to release from a substrate surface, in the event of rising water or flood. The fence post, generally designated by the numeral  1  includes an engaging mechanism  2  at a first end of the fence post  1 , which is adapted to release the first end  3  from a substrate surface  4  in the event of rising water or flood. 
     The fence post  1  further includes a retaining mechanism  5 , the second end of the fence post  1  which, when the engaging mechanism  2  releases the first end  3  of the fence post  1  from the substrate surface  4 , substantially retains the second end  6  at or near its pre-released position. 
     The retaining mechanism  5  therefore permits movement of the post  1  transverse to the longitudinal axis of the post  1  in at least one dimension, as will described hereafter. 
     The engaging mechanism  2  may be embodied in a variety of forms. Two examples are shown in  FIGS. 1 and 2 , but it will be appreciated by persons skilled in the art that the engaging mechanism  2  may be embodied in a variety of other forms. With reference to  FIG. 2 , the engaging mechanism  2  may include a latch arrangement  7  with a float, such that in the event of a flood or rising waters, the float  8  is adapted to pivot between the positions shown in  FIGS. 2   a  and  2   c , to release the latch  7  from the substrate surface  4  or an anchor  9  connected to the substrate surface  4 , to the position shown in  FIG. 2   c  in which the lower end  3  of the fence post  1  is no longer secured to the substrate surface anchor  9 . 
     The anchor  9  may have a substrate engaging end  10  which may be secured substantially below the substrate surface  4 , and a latch engaging end  11  which effectively enables the first end  3  of the fence post  1  to be secured to the substrate surface  4 . 
     The fence post  1  of the present invention may be formed of hollow plastics material, or other lightweight floatable material. In accordance with a preferred embodiment of the present invention, the body of the fence post  1  may be shaped to assume a substantially buoyant position when floating. For example, in  FIG. 1   b  is shown the profile of a typical fence post formed in accordance with the present invention, having lower surfaces  12  and  13  which are adapted to float atop the water, and upper surfaces  14  and  15 . The typical water surface might be located as shown by dashed line  16 . It will be appreciated by persons skilled in the art that a variety of other shapes may however be utilised in the fence post to achieve a similar purpose. 
       FIGS. 4 and 5  show a fence  17  formed of a plurality of fence posts  1  as hereinbefore described. The particular embodiment described in  FIGS. 4 and 5  is in a riverbed or similar situation, that is, of undulating terrain. The fence includes a pair of spaced-apart fixed posts acting as cable supports  18 . The support posts  18  are securely fastened to the substrate surface  4 . A cable  19 , which may be formed of wire rope or otherwise spans the support  18  such that it is spaced above the substrate surface  4 . Said cable  19 , engages each fence post at retaining mechanism  5 . A plurality of releasable posts  1  are positioned intermediate the cable supports  18 . Each releasable post  1  is formed as hereinbefore described, having an engaging mechanism  2  at a first end  3  thereof which is adapted to release the first end  3  of the post  1  from the substrate  4  in the event of a flood or raised water, and, a retaining mechanism  5  at a second end  6  thereof, adapted to hold the second end  6  of the post  1  to the cable  19  when the first end  3  of the post  1  is released from the substrate surface  4 . 
     Also as hereinbefore described each engaging mechanism  2  includes a latch  7  which is adapted to float such that in the event of a flood or raised water, the latch  7  is moved from a first position in which the fence post  1  is secured to the substrate  4 , to a second position in which the fence post  1  is no longer secured to the substrate  4 . This may be achieved using the anchor mechanism as hereinbefore described in relation to  FIG. 2 , which has a substrate engaging end  10  which is secured substantially below the substrate surface  4 , and a latch engaging end  11  which effectively enables a first end  3  of the fence post  1  to be secured to the substrate surface  4 . 
     Whilst  FIG. 4  shows the fence arrangement when the riverbed or substrate surface  4  is dry,  FIG. 5  shows a raised water level  20  showing the typical positioning of the fence  17  in such situation. As seen, when the water is flowing generally in the direction of arrow  20  the raised water level automatically disengages the lower ends  3  of posts  1  from the substrate surface  4 , and the fence effectively “floats” on the raised water surface  20 . As can been seen from  FIG. 5   a , each fence post  1  therefore “floats” allowing the water and any other debris contained therein to effectively pass under the fence. The “boat-like” shape of the fence posts maintain the fence in a consistent manner as shown in  FIG. 5   a  such that the fence wires  22  do not become entangled. As also shown in  FIG. 5 , due to the direction of flow  21 , the fence is shifted slightly downstream, but substantially maintains the fence in a consistent manner. As the water level recedes, the fence will likewise float down. The fence posts may therefore be easily reattached to the substrate using the latch once the water level has totally receded. 
     It will be appreciated that this arrangement results in the quick and easy repositioning of the fence after a flood situation rather than a whole new fence having to be effectively rebuilt. 
       FIGS. 6 and 7  illustrate an alternative preferred embodiment of the fence post in accordance with the present invention. In this version, the engaging mechanism  2  at the first end of each fence post  1  is adapted to be inserted in a respective complementary post receiver  23  which is anchored into the substrate surface. Each post receiver  23  has a tapered portion to receive the engaging portion  2  of the respective post  1 , and, a lip or the like therearound  24  to which the latch  7  may be engaged. A different version of a float  8  is shown in  FIGS. 6 and 7 , the float being secured to a rod or cable arrangement  24  which is itself adapted to undergo movement, being connected at it ends by latch  7  and arm  25 . It will therefore be appreciated that the arrangement formed by latch  7 , arm  25  and its interconnected members  24  and float  28  will be able to undergo pivotal movement from the position shown in  FIG. 6(   f ) to the position shown in  FIG. 6(   b ) as the water rises. This is further illustrated in  FIG. 7  as is the different arrangement of ground engaging portion. 
       FIGS. 8 and 9  show a fence  17  formed of a plurality of fence posts  1  as hereinbefore described, using the embodiment of fence posts as illustrated in  FIGS. 6 and 7 . Operation of the device is similar to that as hereinbefore described in relation to  FIGS. 4 and 5 . 
     It will be appreciated by persons skilled in the art that numerous variations and modifications will become apparent. For example, different types of latching mechanisms etc will be envisaged. The releasable posts, rather than being secured at their upper ends by a cable running therethrough, may alternatively be individually pivoted and secured to their own support posts. Such an arrangement might enable the automatic repositioning of the fence post after a flood situation without requiring manual assistance. 
     These and all other variations and modifications which become apparent to persons skilled in the art should be considered to fall within the spirit and scope of the invention as broadly herein before described and as hereinafter claimed.