GATE IMPROVEMENTS

Abstract: This invention relates to a gate movable from an open position to a closed position wherein the gate includes a main barrier (3) and a movable extension (4) characterised in that the movable extension is open with respect to the main barrier when the gate is in the closed position, and the movable extension is closed with respect to the main barrier when the gate is in the open position.

Description: GATE IMPROVEMENTS TECHNICAL FIELD This invention relates to gate improvements. BACKGROUND ART Reference throughout the specification shall be made to use of the present invention in farm situations such as in dairy sheds. It should be appreciated however that the present invention can apply to other situations as well. The gates in dairy sheds must meet a number of requirements. The gates must: (a) be strong to withstand the pressure of cows bearing on them, (b) be simple to operate and maintain in a dirty environment, (c) provide either a real or deterrent barrier to cows when required, (d) allow ready exit of the cows through the gate when required, (e) be configured so that cows are unlikely to become entangled in the gate, (f) require minimal head room in which to operate so as to comply with the confines of a dairy shed, (g) close quick enough after the exit of one cow to prevent exit of the following cow. There have been many attempts to produce dairy gates which have these features - unfortunately these all have their problems. A typical dairy gate swings around the top pivot point. When the cows are to remain in the milking shed, the gate is left hanging downwards to prevent exit of the cows from the shed and into a race. To lift the gate, the farmer pulled a lever so the gate could be swung upwards allowing exit of the cows. However this initial form of dairy gate still did not meet all the previous requirements and in particular was slow to close and prevent the exit of following cows. An attempt to address these problems was made in New Zealand Patent No. 198795. This invention had a protrusion or "bump" at the bottom corner of the gate under the pivot point. This protrusion provided an extra barrier to cows when the gate was in the closed position. Allegedly the protrusion also assisted in exit of the cows through the gate by riding over the back of the cow when the gate was in the open position. However, this product also had problems. It is common for cows to become entangled between the protrusion, the rest of the gate and the frame on which the gate was hung. Further, the protrusion did not readily ride over the cows backs and instead made it more difficult for cows to exit the dairy shed. The primary problem however was that the gate required significant head room in which to operate to allow for the bump when the gate was raised. This meant that the design of some milking sheds was not suitable for the gate which therefore had limited application. It is an object of the present invention to address the above problems or at least provide the public with a useful choice. Further objects and advantages of the present invention will become apparent from the following description which is given by way of example only. DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a gate moveable from an open position to a closed position wherein the gate includes a main barrier and a moveable extension characterised in that the moveable extension is open with respect to the main barrier when the gate is in the closed position, and the moveable extension is closed with respect to the main barrier when the gate is in the open position. According to another aspect of the present invention there is provided a method of operating a gate from a closed position to an open position and back to a closed position wherein the gate comprises a main barrier and a movable extension, characterised by the steps of: a) to open the gate, swinging the main barrier upwards towards the movable extension, and b) stopping upwards movement of the movable extension with a stop, and c) ensuring that the main barrier is collapsed against the moveable extension when the gate is in the open position, and d) to close the gate, swinging the main barrier downwards along with the moveable extension, and e) catching the movable extension to ensure that it is open with respect to the main barrier when the gate is in the closed position. Reference throughout the specification shall now been made to use of the present invention in the dairy shed. Again, it should be appreciated that the present invention can be used in a variety of situations, not just agricultural ones. The gate can be moved from an open position to a closed position by a variety of means. For example the gate can be slid along rails, swung on hinges and so forth. However, in preferred embodiments the gate operates as do most dairy gates with a top pivot that allows the gate to swing downwards from an open position to a closed position to block entry into a race or other area. The construction of the main barrier may be similar to the construction of other gates in that it has a rigid steel frame with bars extending across the frame to strengthen the gate and present a barrier to cows. Again however it should be appreciated that other gate configurations may be used. The extension may come in a variety of forms. For example, the extension may concertina outwards along the plane of main barrier. In preferred embodiments however the extension pivots from the top (or near the top) of the main barrier, however it should be appreciated that other methods of fixing the extension may be used. In most cases, when the gate is in the closed position the sides of the main barrier are substantially vertical. Preferably, the extension is positioned on either of these sides. The applicant has recognised that the extension should be closed when the gate is in the open position. This is because generally there is limited ceiling height in milking sheds - which addresses one of the problems with the prior art. With this in mind, preferred embodiments of the present invention has the extension on the uppermost portion of the main barrier when the gate is in the open position. This position, in combination with the top pivoting of the gate in preferred embodiments, means that gravity can assist in moving the extension as required. For example, when the gate is in the open position, the extension may just collapse against the main barrier as a consequence of gravity. When the gate is descending from the open position to a closed position the extension may interact with a catch that holds the extension open in position as the main barrier travels downwards to the fully closed position. In some embodiments of the present invention there is provided a guide that assists in the opening and closing of the gate as a whole as well as the operation of the extension. The guide may come in a variety forms and one embodiment may be a set of runners along which the gate travels. However, in other embodiments the guide may be close-ended substantially vertical slot through which the gate can pass from open to closed position and vice versa. Regardless of whether there is a guide or not there may be a stop against which the extension can bear when the gate is in the open position. The stop may be at the top of the slot referred to previously. Preferably when the gate is fully opened the main barrier bears against the extension which bears against the stop causing the extension to be in its closed position. There may be a catch (which may be in the form of a stop, protrusion or whatever) that holds the extension as the gate travels from the closed position to the open position. In preferred embodiments there is no guide for the gate itself. Instead, there may be a top stop that prevents the gate from travelling too far vertically and a bottom catch which serves to hold the extension open when the gate is in the closed position. This configuration is in direct contrast to standard dairy gates which have a guide as previously described. The advantage of having no guide is that there is nothing in the way of the cows' heads when the gate opens. This lack of impedance leads to ready exit of the cows from the milking shed and is a sought after advantage. There may be provided a guide between the extension and the main barrier to ensure that the extension does not move significantly out of the plane of the main barrier. Again, the guide may take a variety of forms, for an example in the form of runners. In preferred embodiments however, the guide is a simple bracket which fits around a bar on the extension and a bar on the main barrier. This bracket is configured to allow the extension to slide with respect to the main barrier. There may be provided additional connections between the extension and the main barrier. For example, the extension may be relatively large in comparison to the main barrier and there is need for extra barriers to be provided to prevent cows from attempting to pass between the extension and the gate. It is envisioned that the extra barriers would be required if the gate was to be used as a "stand alone". In other embodiments however it is envisage that the gate may be used in conjunction with a secondary arm which also acts as an additional barrier. This arm may have various configurations but in some embodiments pivots away from the gate opening in the opposite direction to the main barrier when the gate is being opened and pivots towards the main barrier when the gate is being closed. The present invention may be made by a variety of materials which have the suitable strength required. In preferred embodiments however steel tubing is used. In preferred embodiments of the present invention there may be provided an additional feature that helps with the exit of cows through the open gate. This may be a provision of a kink in the side of the main barrier opposite to the extension. This kink can provide extra room for the head/back of the cow exiting. The kink may come in a variety of forms, perhaps a slight change in angle in the gate or maybe one side of the main barrier can be curved so as to provide the extra room desired. It can been seen that the use in extension has a number of advantages over the prior art. The extension provides an extra barrier to the exit of cows when the gate is in the closed position. The extension does not compromise the exit of cows when the gate is in the open position as a consequence of the extension closing up against the barrier. Minimal head room only is required to operate the gate. The present invention has a major advantage over the prior art in the amount of the clear space the cows have upon exiting through the gate opening. There is no "bump" or protrusion extending to the opening, there is no guide for the gate extending into the opening and the gate itself is narrow (giving maximum head clear space) as a consequence of the closable extension and the use of a secondary arm. BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view of the gate in accordance with one embodiment of the present invention in a closed position; and Figure 2 is a diagrammatic representation of the above gate in an open position. BEST MODES FOR CARRYING OUT THE INVENTION With respect to the figures there is illustrated a gate mechanism generally indicated by arrow 1. The gate mechanism 1 is mounted on frame 2 which is normally mounted in the exit of a milking shed. The gate mechanism 1 consists of a main barrier 3, an extension 4 and a secondary arm 5. The main barrier 3 is pivotally mounted at pivot point 6 with respect to the main frame 2. This allows the main barrier 3 to pivot from a closed position (see Figure 1) to an open position (see Figure 2). One particularly good feature about the main barrier 3 is that it only has three cross bars 7. The purpose of the cross bars 7 is to prevent the exit of cows or the trapping of cows heads with respect to the gate and to give the required gate strength across the span of the entire gate. Most gates need four cross bars to achieve this. However, in the present invention some of the gate span is provided by the extension 4, thus only three cross bars 7 are required. This cuts down on the weight of the gate making it easier to use and less expensive to manufacture. The extension 4 is a bar that is pivotally attached to pivot point 8 on the head plate 9 on the main gate 3. Bracket 10 ensures that the extension 4 remains substantially aligned with the plane of the main barrier 3. A plate 11 at the base of the barrier 3 (when in the closed position) interacts with the guide rod 12 at the base of the extension 4. This also ensures that the extension 4 remains substantially in the plane of gate 3. The secondary arm 5 is pivotally attached to a lever 14 which extends from the head plate 9 of the barrier 3. The secondary arm 5 provides an additional barrier to the exit of cows when the gate 3 is in the closed position. When the gate 3 is in the open position, the secondary arm 5 pivots away from the main barrier 3 to provide greater space for the cows to exit. To further aid in the exit of cows there is a provided a kink generally indicated by arrow 15 on the main barrier 3 opposite the extension 4. To operate the gate, lever 16 is pulled. In the closed position the main barrier 3, extension 4 and secondary arm 5 form a barrier to the exiting cows. The extension 4 is held open with respect to the gate 3 as a consequence of extension 4 catching on a bottom stop 17, (not clearly shown). Pulling the lever 16 causes both the secondary arm 5 and the main barrier 3 to pivot upwards away from the exit as defined by the frame 2. The main barrier 3 and extension 4 travels upwards. The extension 4 then stops on a top stop 18 which ensures that the gate cannot swing any higher. This also causes the extension 4 to abut the main barrier 3. That is, when in the open position the gate is effectively its smallest size. The gate is held in the open position as a consequence of the lever 16 being held by a catch or some other means. It can be seen that the absence of a guide for the gate, the use of a secondary arm and a gate which is narrower when in the open position as a consequence of the use of the extension provides a large clear space enabling cows to readily exit the dairy shed. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims: WHAT WE CLAIM IS: 1. A gate movable from an open position to a closed position wherein the gate includes a main barrier and a movable extension characterised in that the movable extension is open with respect to the main barrier when the gate is in the closed position, and the movable extension is closed with respect to the main barrier when the gate is in the open position. 2. A gate as claimed in claim 1 adapted for use in a dairy shed. 3. A gate as claimed in either claim 1 or claim 2 wherein the gate is pivoted from the top to swing downwards from an open position to a closed position. 4. A gate as claimed in any one of claims 1 to 3 wherein the main barrier has bars extending across the frame of the main barrier. 5. A gate as claimed in any one of claims 1 to 4 wherein the extension pivots from the top or near the top of the main barrier. 6. A gate as claimed in any one of claims 1 to 5 wherein the extension is positioned on the uppermost portion of the main barrier. 7. A gate as claimed in any one of claims 1 to 6 wherein the extension moves downwards as a consequence of gravity. 8. A gate as claimed in any one of claims 1 to 7 wherein the extension interacts with a catch which holds the extension open as the main barrier travels downwards to a closed position. 9. A gate as claimed in any one of claims 1 to 8 wherein there is included a stop against which the extension can bear when the gate is in the open position. 10. A gate as claimed in any one of claims 1 to 9 wherein there is provided a catch that can hold the extension as the gate travels from the closed position to the open position. 11. A gate as claimed in any one of claims 1 to 10 wherein there is provided a guide in the form of a bracket configured to allow the extension to slide with respect to the main barrier. 12. A gate as claimed in any one of claims 1 to 11 wherein there is provided a kink in the side of the main barrier opposite the extension. 13. A method of operating a gate from a closed position to an open position and back to a closed position wherein the gate comprises a main barrier and a movable extension, characterised by the steps of: a) to open the gate, swinging the main barrier upwards towards the movable extension, and b) stopping upwards movement of the movable extension with a stop, and c) ensuring that the main barrier is collapsed against the moveable extension when the gate is in the open position, and d) to close the gate, swinging the main barrier downwards along with the moveable extension, and e) catching the movable extension to ensure that it is open with respect to the main barrier when the gate is in the closed position. 14. A dairy shed incorporating a gate as claimed in any one of claims 1 to 12. 15. A gate substantially as herein described with reference to and as illustrated by the accompanying drawings. 16. A method of operating a gate substantially as herein described with reference to and as illustrated by the accompanying drawings. 17. A dairy shed substantially as herein described with reference to and as illustrated by the accompanying drawings.

Inventors: LEASK DAVID SAMUEL, LEASK, DAVID, SAMUEL
Applicants: LEASK CONSTRUCTION SERVICES LI, LEASK DAVID SAMUEL, LEASK CONSTRUCTION SERVICES LIMITED, LEASK, DAVID, SAMUEL
Application year: 1997
Main classification: A01K1
IPC codes: A01K1