The term "farm vehicle" is used to refer to any tractor, farm machine or any other vehicle whether engine propelled or not, which is used by personnel to perform works on or to travel through farms of one type or another. In the modern farm establishment, there is a constant need for the farmworker to move vehicles such as tractors and other machinery around the farm to carry out farm works and where stock is involved, to check on the well-being of the stock, the fencing, water supplies etc. Where the grazing of animals is required it is usual to divide the farmland up into a number of paddocks to facilitate grazing management and indeed stock separation. Electric fencing is used extensively for this task. There is then a problem for those travelling on farm vehicles around a farm since what they have to do is to use a gate, which may be either a specially constructed gate in the electric fence or is an existing gate into a conventionally fenced field. This involves dismounting, opening the gate, remounting and travelling through the gate on the farm vehicle, then dismounting the farm vehicle to close the gate and finally remounting the farm vehicle to depart into the field or paddock. Often gates are not closed defeating the purpose of having electric fencing. This nobody wants to do and the present invention is directed to overcoming the problem and to avoiding the problem that arises in too many instances of the farmworker neglecting to close the gate after himself or herself, or stock escaping through the opened gate before the machinery operator has an opportunity to dismount and close it

Various attempts have heretofore been made to address this problem. It is known for example to provide a gate for the electric fence composed of two fibreglass rods capable of carrying an electric current which are mounted on insulated hinges attached to gateposts at either side of the opening. These rods are held in a closed position by a spring-loaded mechanism integrated into the hinges. When a vehicle passes through these gateway it pushes the fibreglass rods apart and when the vehicle has passed through the rods are returned to a closed position by the spring mechanism. Because of wear related issues, failure of the hinge mechanism and the damage which the spring-loaded barrier rods cause to vehicles these electrified gates once popular are no longer to be seen in use on farms.

A similar type Electric Drive-Thru Gate is marketed by Farmand Ranch Depot Phoenix, Arazona. This gate relies on one long electrified fibreglass rod mounted on a complex type sprung hinge, which may necessitate constant maintenance A system sold under the brand name "The Pivotal Post ATV Gate" has been developed in the US. While this is a relatively efficient construction it has certain drawbacks in that in its simplest form it uses a "bungee" type rope and collapsible fencing post: its major drawback is that it requires somewhat of the order of an opening of 6 m or more.

A "bridge type cattle grid" has been developed in New Zealand. Unfortunately this device is both expensive and bulky and requires a good deal of excavation works to set it up

Because of the drawbacks with any of the current systems, people have reverted to the use of conventional steel gates or electric wire and insulated handles on a gate in the electric fencing. If they don't use such conventional gates or special electric fencing gates with insulated handles the farmworker sometimes dismounts from a slow moving farm vehicle to stand on the electric fence forcing the wire onto the ground while allowing the farm vehicle to pass over the electrified wire into the adjoining field where the farm worker re-mounts the tractor.

Obviously, this is not acceptable in the former case because it is time-consuming and in the latter case because of the extreme dangers involved. A further major problem is one of expense as none of the solutions proposed heretofore are inexpensive either from a capital provision aspect, a maintenance requirement, and efficiency aspect or indeed health and safety considerations. The present invention is directed towards providing an inexpensive maintenance free gateway that will overcome at least some of the aforesaid problems. Summary of thB invention.

According to the invention there is provided a farm vehicle gate for incorporation within an electrical fencing system comprising: a pair of spaced-apart posts; two metal member mounted vertically and insulated from the spaced-apart posts, the metal member and the spaced-apart posts defining an opening through which a farm vehicle can travel; means to connect the electrified elements of the electric fencing to two horizontal electrified plastic elements which form the gate barrier; and a vehicle gate in the form of two barrier member attached by hinges to the spaced-apart posts biased to a closed position and electrically connected to the electric fence to form, in effect, an extension of the electric fencing and means to allow a person driving farm machinery to pass through the gate without dismounting from the farm machine, whereby on driving through the gate the gate barriers closes behind the farm machine.

There are many ways in which the invention may be carried out. In one of its simplest there is provided two spaced apart wooden posts on each of which are mounted a vertical mild steel frame which is used to support the barrier. Both mild steel frames have the barrier pivotaiiy mounted to them enabling each barrier to lie across one half of the opening forming an extension of the electric fencing, Each barrier is supported in a horizontal position by double chain in the form of a V the upper part of which is fixed to the upper section of the frame and the lower part to the electrified barrier. ln another modification or improvement of the embodiment of the invention described above, a biasing means is provided to ensure that the tractor/farm vehicle gate closes after the barriers are released. In this embodiment a double chain suspended from a T piece fixed at the top of each frame is attached intermediate the free end of each barriers and its pivotal mounting whereby as the gate is opened by pushing the barriers away from their closed position, the barriers being attached to the chains is raised slightly such that when released the weight of the barriers causes the barriers to pivot gently back into a fixed closed position. Detailed description nf the invention

The invention will be more clearly understood from the following description of an embodiment thereof given by way of for example only with reference to the accompanying drawings in which:

Figure 1.a is a front view of an electric fence incorporating a farm vehicle gate according to the invention;

Figure 1 b is the same view but with a farm vehicle passing through the gate; Figure 2 is a detailed sectional view of the encircled portion of Figure 1 a identified by the reference letter A.

Referring to the drawings and initially to Figure 1.a thereof, there is provided a farm vehicle gate, indicated generally by the reference numeral 1. The farm vehicle gate 1 is mounted in an electric fencing system of the single wire type; the electric fence wires 2 on one side of the farm vehicle gate 1 and wires 27 on the other side of the farm vehicle gate 1 being illustrated. It will be appreciated the invention could be equally well used with a double electric fence wire system.

The farm vehicle gate 1 comprises a pair of spaced apart wooden posts 3 and 4 carrying mild steel uprights 5 and 6 respectively. The mild steel uprights, which are attached to, but insulated from the wooden stakes 3 and 4 by plastic membrane 18 and 34 and plastic collared steel screws, carry the hinges 19 and 9 and support chains 20, 29, 17 and 30 on which the gate barriers 10 and 11 constructed from plastic piping are mounted. Referring again to the drawings and specifically to Figure 2 there is illustrated the manner by which the double chains that support each gate barrier are attached to cross-member 33 mounted on the top of the steel uprights at 7 and 24 and from which the gate barrier is suspended at a single point 8 by the use of a steel collar and hook.

Referring again to the drawings and specifically to Figure 1.a, the electrified wires 2 and 27 are electrically connected to the steel uprights at 32 and 31 by insulated wiring 12 and 13 and thus to the chains and barriers. The electric current is then carried along the barrier using electrically conductive plastic/metal tape 16 wrapped around and fixed to the barrier at collar 21 and 8 and at ends 15 and 14

Mounted on the metal upright and again referring to Figure 1.a, are barrier bar 10 and 11. which are connected by metal link hinges 9 and 19 to the metal uprights 5 and 6 and suspended by chains 17, 30, 29 and 20 at the top of the steel uprights at points 7 and 24 , and 25 and 26, this allows traffic travel both way through gate The barrier bars carry electrically insulated collars towards the centre of each barrier at 22 and 23 for pedestrians and quad/atv drivers to grasp when opening gate

In operation, and prior to use of the farm vehicle gate 1 the barrier bars 10 and 11 lies across the opening between the posts 3 and 4 and act as an extension of the electric fencing.

Referring to Figure 1.b, when a farm worker or other person driving a farm vehicle approaches the farm vehicle gate 1 , the driver slows the vehicle and using the vehicle he/she pushes the barrier bars 10 and 11 apart at the opening and continues to drive through the opening without reversing

Again referring to Figure 1.b It will be appreciated that as the barrier bars 10 and 11 move away from the opening they are constrained by chains 20 and 30 mounted at the approach side of the gate, to rise. Accordingly, when released by the completion of the passage of a farm vehicle through the gate, the weight of the barrier bars 10 and 11 causes the barrier bars to return quickly to a fixed closed position across the opening between the poles 3 and 4 where they are held in position by chains 20 and 29, and 17 and 30 respectively

Again referring to Figure 1.b, when the farm vehicle is passing through the barrier in the opposite direction, chains 29 and 17 will be on the approach side and these will cause the barrier to rise slightly before it will be returned by gravity to the fixed closed position on completion of the passage of the farm vehicle through the gate

Referring to Figure lb and Figure 2, the use of two sets of equal length chains suspended at points 7 and 24, and 25 and 26 at about 20cm apart on a steel cross member, set at right angles to the barrier to form the support mechanism of each hinge system, ensures that the barrier bars 10 and 11 will return quickly and firmly, to the closed position and remain securely in this position.

It will be appreciated that the vehicle gate according to the invention could provide a conventional gate for cattle and other stock and could be adapted for wider or narrower openings. The terms "comprise" and "include" and any variations thereof required for grammatical reasons are to be considered as used interchangeably and to be accorded the widest possible interpretation.

The invention is not limited to the embodiments described above but may be varied in detail without departing from the scope of the invention.