AU729941B2 - Collapsible post system - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT COLLAPSIBLE POST SYSTEM The following statement is a full description of this invention, including the best method of performing it known to me: COLLAPSIBLE POST SYSTEM The present invention relates to types of posts and fences that are collapsible.

Other collapsible fence systems have the problem that they must be collapsed manually or rely on breakage of components to allow them to collapse leaving several posts remaining upright; all of these systems cannot readily be reerected to their original rigid upright position. Other types of fence designed to yield under the effect of a flood swing upwards from a top located pivot and are only resistant to floods which are not higher than the fence and also have the problem of leaving several upright posts exposed to damage by the flood. Other types of collapsible posts rely on some sort of removable pin to allow the post to pivot at the base, being non-automatic and difficult to collapse and re-erect.

15 Other types of collapsible fences as are developed for sporting enclosures and collapse when a person or persons applies force to the fence by pushing against it running into it, whereas the fence in this invention does not collapse under these circumstances but relies on activation of a release mechanism in a specific way to collapse the fence.

SThese problems are all overcome by the present invention described herein which provides a system of posts consisting of individual posts which may be joined by wires or other material to form a fence, the individual posts, post 2 system and fence being rigid in the upright position until a predetermined, widely 25 distributed load such as may be exerted by flood water is applied which then causes the individual posts, post system and fence to automatically collapse and lay down.

The post system and fence is capable of being re-erected by lifting the end bracing posts and may sometimes require some of the intermediate unbraced posts to be lifted, upon which the posts and fence automatically relocates to the original upright rigid position.

In one form of the invention, the post system comprising the fence consists of two different types of post; braced end support posts and intermediate unbraced p posts. The braced end support post is constructed to yield when a predetermined applied load is applied so that the whole assembly including the braced posts, the unbraced posts and the fence lies down.

io In its braced configuration the post assembly is caused to lay down when a tensional force is applied to a wire attached to a spring loaded pin causing it to release from the locked position, the post then rotating from the vertical to the horizontal position. The braced type post utilises a conventional post to support it, the conventional post having a socket made in the side to receive the spring- 15 loaded pin. The socket can be protected by a cover plate having a hole aligned with the socket. Two or more braced posts may be attached to one conventional post providing the capability of having changes of direction or junctions in the fence. The braced post may be made of any suitable rigid or semi-rigid material having any suitable cross-sectional shape and dimension and may have an anticorrosive coating.

The other type of post comprising the invention, the unbraced intermediate post, consists of a single rigid element attached to a supporting base or ground anchor by a pivot pin which is spring loaded, the shape of the post and anchor base 25 acting to present an initial resistance to an applied force at which point the spring mechanism allows the post to yield and lay down. The shape of the post is such that it also acts to relocate the post when it is brought back to the upright position. The post may be made of any suitable rigid or semi-rigid material having any suitable cross-sectional shape and dimension and may have an anticorrosive coating. A number of unbraced posts can be used to make a collapsible fence (which is not illustrated) without the need to use braced type posts, with end bracing provided if necessary by attaching the wires to a conventional type of post at the end of each span. The ability of this type of fence to collapse without stretching the wires can be improved by inserting an elastic section such as a spring in each wire.

In the unbraced post, the mechanism which provides the initial resistance to collapsing is not constrained to the use of a spring and may be performed by any other mechanism which provides an initial resistance before yielding and allowing the post to collapse.

In the form of the invention which represents its main application, the post system may have wires attached to enable operation as a collapsible fence. In this application, the wire which is used to activated the release of the sliding pin is run as a loose wire through holes in all the posts such that by its looseness it is not activated by animals or similar locally applied forces but may be tensioned by 15 the action of flood water causing release of a sliding pin which then allows the braced post(s) to collapse in unison with the unbraced posts in that span along with attached wires. The system can also be laid down by manually releasing the release pin and applying a force to some of the posts.

In another form of the invention, the post system can be utilised in a fence system which can be laid down in only a selected span when required by manually releasing the sliding pin and by applying either a manual or mechanical force to the fence causing it to lay down, thus providing a wide opening through S 2 which machinery or stock may pass.

In its applications as a collapsible fencing system, re-erection may be either by manual or mechanical means including a winching system utilising an erection wire or cable attached to the winch and run along the fence through holes in the posts.

An element of the post system in its mode as a fence is the triangular end bracing pieces which locks the fence in the upright position and permits the attachment of highly tensioned wires to the end braces. The wires are threaded through holes in the intermediate posts between the end braces. Tensioned wires, working together with the resistance of the individual posts provides a fence which offers substantial resistance tb any force applied at a point or points by a person or persons or stock. When such a force is -applied the fence resists the force and does not collapse even though there will be some deflection, however this deflection is insufficient to cause the loose release wire to become io taught as would be required to release the pins and allow the fence to collapse.

The fence can only be collapsed by a force specifically applied to the loose release wire and this does not occur when a force is applied to the highly tensioned wires by person/s or stock. This is because the resistance of the 15 highly tensioned wires arrests the movement resulting from the applied force before the loose wire becomes taught as is necessary to activate the release pins. There are two methods by which the fence can be collapsed. The first •to.

method is when the force from a flood is applied to the fence and the loose wire becomes taught and activates the release pins thus allowing the entire fence to collapse. The force applied by the flood to the loose wire will normally be provided by debris collecting on the wires however by attaching an object such as a length of polythene pipe to the loose wire, the force can be increased so as to ensure that the loose wire is triggered at the early stages of a flood when S.forces are low and so the fence collapses before large forces from the faster and 25 deeper flood waters that could cause the structure to break occur.

If impacted by a person or persons or by stock the post system in its form as a fence will not collapse either at the point or points of impact because of the system of highly tensioned wires attached to rigid end braces. The fence thus acts to retain people or stock when they apply a force to the fence.

In the second method, the fence can be triggered to collapse by manually pulling on the loose wire so as to release the pins while at the same time applying a force in the same direction to any other part of the fence. Upon so doing the whole fence will collapse in the direction of the force.

When the fence does collapse by the force of a flood or when manually triggered it does so as a whole (and not just in isolated sections) with the entire fence unit collapsing flat on the ground and remaining there. When collapsed the fence has no self re-erecting properties which would cause interference with the 1o passage of either a flood or stock over the fence and the fence must be purposely re-erected.

All of the above types of fences may be used in conjunction with conventional electrified fencing equipment.

In another form of the invention the unbraced post may be used in a mode unrelated to fencing as a means of providing a post which is collapsible when a force is applied in a direction which causes the pivot pin to rotate and release the spring mechanism which holds the post upright. In this mode the post is suitable for use in a number of post applications including for example a roadside guidepost or as a post for carrying a sign so that the post yields and can be reerected to the rigid upright position following impact.

The invention also comprises a special tool for use in driving in the base anchor 25 of the unbraced post and consists of a base to which are attached retaining guides which locate the tool on the top of the base anchor while driving it into the ground, the base of the tool thus minimising damage to the top of the base anchor during driving.

To assist with understanding the invention, reference will now be made to the accompanying drawings that show some examples of the invention.

6 In the drawings: Figure 1 shows the two types of post; braced post 1 and unbraced post 2 connected by tensioned wires 4 through holes in the posts to form a fence which is shown in its normal upright position. Wire 3 is the release wire that is also attached through holes in the posts but is at a low tension such that it is quite loose.

i0 Figure 2 shows the same arrangement of the posts to form a fence that is shown in its collapsed position lying on the ground. This drawing also shows how the unbraced posts can be attached to an ordinary wooden post 5 to form any number of spans between posts 5 to form a continuous fence. Figure 2 shows three unbraced posts in the first span however it is possible to use many more type 2 posts per span. As is used in conventional fencing "droppers" 6 may be added to provide increased rigidi;y.

.o Figure 3 provides greater detail of the type 1 post, showing how pin ib is free to Sslide through the frame of post 1 against the restraining action of spring ic which is retained by washer ld and retaining pin le. An arm attached to pin lb provides a handle for manual release and reinsertion of pin lb. Pin lb is shown in the locked position inserted into a socket 5a in post 5 which in shown as a conventional round wooden post but may be of other types. Socket 5a is shown protected by curved plate 5b attached around part of post 5 and having a corresponding hole to match socket 5a. The location of pin lb can be moved up or down according to the position of additional holes in the parallel upright members, and the position of hole 5a and plate 5b at post 5 may be varied to match the location of pin 1 b.

The frame of braced post 1 is anchored to post 5 by a pin If which is located in a tight fitting hole in post 5 and is free to rotate in tube lg fixed to the frame. Pin 1h is similarly free to rotate in tube ii which is fixed to the frame; pin 1h also passes through a hole in anchor stake la which may be fixed into the ground by concrete as shown or may be driven directly into the ground. Spacer tube lj is used to obtain the correct spacing to enable retractable pin lb to lock in and release from hole 5a, the length of lj being cut to suit. Pin lh may be secured by insertion any suitable stop such as a small pin at each end.

The release wire 3 is shown having a tubular sleeve 3a which may be attached to the full length or part of the length of wire 3 to provide additional resistance to io flood water to assist in releasing pin lb. Holes 1k are for attachment of fence wires and may be at any suitable spacing.

Figure 4 provides details of unbraced post 2 with ground anchor 2a which is shown in the drawing having an additional optional ground thrust plate 2b attached. Post 2 is attached to 2a by pin 2c shown here as a bolt and nut with welds on the end of the bolt to prevent the removal of the nut. Pin 2c passes through spring 2d and thrust washers 2e. Wire attachment holes 2f may be at any suitable spacing to correspond with holes 1 k in post 1.

20 Figure 5 shows how post 2 may be modified for uses other than in a fence being 'i similar to post 2 except for main posts pieces 7 and 8 which are shown here as °a ~depicting a street sign and a roadside marker post respectively. Other parts numbered 2a, 2c, 2d are similar to those parts with the same numbering in i Figure 4.

S Figure 6 shows a tool for use in driving base anchor 2a of post 2 into the ground ooooi and consists of a steel driving plate 9 with attached retaining guides 9a which fit oooo° Sclosely over the end of 2a so that plate 9 can be struck by a driver with minimal °°oo° damage to the top of 2a.

Claims (12)

1. A permanently installed system of posts consisting of individual posts which are joined by wires, flexible or rigid material to form a fence, the posts, post system and fence being rigid in the upright position and acting as a retaining structure for stock or people and which is designed not to collapse should they apply a force to the fence structure as from stock pushing against it or people pushing or running into it, the structure only being able to be collapsed when a release mechanism is triggered either by a flood or manually upon which the io individual posts, post system and fence lays down flat on the ground as a total unit or span where it will so remain offering no resistance to a passing flood by attempting to self-erect, the individual posts, post system and fence is then capable of being raised which enables the posts to re-engage automatically in the original upright and rigid position.

2. The post system of claim 1 comprising a fence consisting of two different types of post; braced end support posts and intermediate unbraced posts (used in conjunction with conventional posts as supports for the braced posts) both types of post being constructed to yield when a predetermined applied load is S: 20 applied to a release wire by a flood or manually so that the whole assembly including the braced posts, the unbraced posts and the fence lays down, such release wire not being activated by the force of stock or people against the fence. 25

3. The post system and fence of claim 2 which can be caused to collapse manually by releasing a sliding pin in each on the braced type posts with the subsequent application of a manual or mechanical force to some of the posts to S similarly collapse the whole post system and fence so that animals stock or vehicles may be moved over the fence which is then acting as a gate.

4. The post system of claim 2 wherein the posts and attached wires are collapsed by the force of a flood which acts on a release wire to release a sliding pin in the braced posts which is then able to collapse from the force of the flood, together with the unbraced posts and wires of the fence.

The post system of claim 4 but having an attachment which increases the drag by the flood on the release wire by addition of a pipe sleeve over the release wire or by attachment of any type of drogue device to the release wire which may act at any angle to the line of the fence thus providing the capability of collapsing the io fence by the action of a flood which applies force to the fence at any angle to the alignment of the fence.

6. The post system of claim 4 but having an angled thrust plate or drogue device attached to some of the unbraced posts thus facilitating the collapse of the fence when subjected to forces from a flood acting at any angle to the line of the fence.

7. The post system of claims 1 to 6 but having a spring or other elastic material inserted in each of the wires which stretches to allow the fence to collapse without causing over-tensioning of the wires.

8. The post system of claim 1 to 7 wherein the arrangement and type of the wires are as used in high voltage electric stock fences and the fence is then capable of deterring stock by electrical stimulation. 25

9. The post system of claims 1 to 8 wherein the fence can be re-erected by a winching mechanism acting on a wire or cable running through several S collapsible posts and one or more conventional and permanently upright posts but fastened to one of the permanently upright posts. 30

10. An unbraced type post of claim 2 used as an individual, modified post in an application as a roadside post or sign, or any post which is capable of being collapsed by an applied force and able to be re-erected to its original upright, rigid position.

11. The post of claim 10 but having any other type of post attached to the collapsible mechanism which comprises the unbraced type of post.

12. A collapsible post and fence system substantially as described herein and with reference to the accompanying drawings. ROBERT IAN BELL 15 SEPTEMBER 1997 oooe oe ooeoe *oo oooo «oo oo** *ooo