GB2591340A

GB2591340A - A cattle guard

Info

Publication number: GB2591340A
Application number: GB2019959.2A
Authority: GB
Inventors: Ray Nicholas
Original assignee: Ilecsys Group Ltd
Current assignee: Ilecsys Group Ltd
Priority date: 2019-12-18
Filing date: 2020-12-17
Publication date: 2021-07-28
Anticipated expiration: 2040-12-17
Also published as: GB2591340B; GB2590445A; GB202019959D0; GB201918737D0

Abstract

A cattle guard 1 comprises a frame having two opposed frame members 2, 3 and a plurality of parallel bars 6a to 6i extending and supported between the two opposed frame members 2, 3. Each bar 6a to 6i is rotatable between a guard position, where it is difficult to walk across and prevents cattle crossing and a walk position where the bars 6a to 6i are rotated to provide a walkway to permit authorised users to cross. The cattle guard arrangement permits authorised users to release the bars 6a to 6i from a locked guard position, or to lock the bars in the guard position, by operation of any one of two locking members 18, 19 located at opposite ends/sides of the cattle guard 1.

Description

A Cattle Guard The present invention relates a cattle guard and particularly, but not exclusively, to a cattle guard suitable for use on a railway.

One particular application of a cattle guard is for use on railways, to prevent cattle (or pedestrians) straying on to the railway off a crossing, for example off a road (level crossing). Such cattle guards are commonly used on the UK rail network and these normally comprise an array of parallel equally spaced pieces of wood, which are laid inside the rails and possibly to either side outside of the rails.

Each piece of wood is triangular in cross section with an apex of the triangle uppermost. The guard may typically be between one and three meters long and thus prevents cattle and most other large animals walking or jumping over and these also present an awkward obstacle for pedestrians to negotiate.

A significant advantage of the above type of cattle guard is that it is very simple to install and maintain and may last many tens of years without attention. One disadvantage however is that it may impede access to authorised rail workers, for whom a road crossing may otherwise provide easy access onto the railway to perform maintenance work or other necessary tasks.

It is an object of the present invention to provide an improved cattle guard.

According to the present invention there is provided a cattle guard comprising a frame having two opposed frame members and a plurality of parallel bars extending between the two opposed frame members, wherein: each end of each bar is rotatably supported by a respective frame member so that each bar may rotate about a respective longitudinal axis of rotation of that bar; each bar has a substantially planner surface which may be located uppermost by rotation of the bar and a nonplanar surface which may be located uppermost by rotation of the bar; and wherein the cattle guard further comprises a linkage mechanism connected to each of the bars and arranged to rotate the bars together between a walk position where the planar surfaces of each bar are uppermost and substantially coplanar, making it easier to walk over the cattle guard, and a guard position where the nonplanar surfaces are uppermost, making it more difficult to walk over the cattle guard, the cattle guard further comprising a locking means for locking the bars in a position where the planar and / or nonplanar surfaces are uppermost.

The provision of a cattle guard employing rotatable bars, such that a non-planar surface may be rotated uppermost, permits such a cattle guard to be switched to a "walk" position where it may provide a walkway permitting temporary access onto a railway line, for example, when access is required by an authorised user. The same cattle guard may however then to be reset to a "guard" position, by using locking means to lock the bars in the guard position, where the non-planar surfaces are uppermost.

A cattle guard in accordance with the present invention permits a temporary access to be provided across the cattle guard without the need to carry any planks or similar items to bridge the cattle guard.

In one embodiment each bar may be arranged to rotate about its axis of rotation between a first position, a second position and a third position, wherein: each bar has first and second planar surfaces joined at an apex, the apex defining the non-planar surface; in the first position the first planar surface of each bar is uppermost and substantially coplanar with the other first planar surfaces; in the third position the second planar surface of each bar is uppermost and substantially coplanar with the other first planar surfaces; and wherein in the second position intermediate the first and third positions the apex of each bar is uppermost.

The above arrangement may permit each bar to be square in section and rotated from a guard position, where an apex of the square section is uppermost, to a position where the bar has been rotated through 45°, either clockwise or anti-clockwise, to a position where a planar surface of each bar is uppermost to provide a substantially flat walkway.

The above arrangement is particularly advantageous where: the linkage mechanism comprises a first link member pivotally connected to each bar at a point above or below the axis of rotation of each bar and a second link member pivotally connected to each bar at a point above or below the axis of rotation of each bar; each link member is arranged to move substantially transversely relative to the axes of rotation of the bars, such as to cause the bars to rotate between their first, second and third positions; the link members have a first position, where the bars are in their first positions, a second position, where the bars are in their third positions and a third position, intermediate the first and second positions, where the bars are in their second positions; the locking means being arranged to lock the link members in their third positions.

In one embodiment, the locking means may comprise a first locking member arranged to move between first and second positions and located at or toward a first end or a first side of the cattle guard; and a second locking member arranged to move between first and second positions and located at or toward a second end or a second side of the cattle guard remote from the first end or first side of the cattle guard, and wherein: when in its first position the first locking member prevents the first link member moving to its first position but permits the second link member to move to its second position; when in its second position the first locking member prevents the second link member moving to its second position but permits the first link member to move to its first position; when in its first position the second locking member prevents the second link member moving to its first position but permits the first link member to move to its second position; and wherein when in its second position the second locking member prevents the first link member moving to its second position but permits the second link member to move to its first position, thus when the first and second locking members are both in their first positions, or are both in their second positions, the first and second link members and the are all held in their third positions.

More preferably, the two opposed frame members comprise a first frame member located to a first side of the cattle guard and a second frame member located to a second side of the cattle guard, wherein: the first link member is an upper link member located on the first side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; the second link member is a lower link member located on the first side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar; the first and second locking members are both located on the first side of the cattle guard, but at or towards opposite ends of the cattle guard.

A major advantage of the above arrangement is that it may permit the cattle guard to be approached from either end, or exited from either end, and the appropriate one of the first and second locking members operated to either release the bars from the guard position, or to lock the bars in the guard position, regardless of the position of the other locking member.

The cattle guard may alternatively comprise a first frame member located to a first side of the cattle guard and a second frame member located to a second side of the cattle guard, wherein: the first link member is an upper link member located on the first side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; the second link member is a lower link member located on the first side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar; the first locking member is located on the first side of the cattle guard, the cattle guard further comprising: a third link member which is an upper link member located on the second side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; and a forth link member which is a lower link member located on the second side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar, wherein: the second locking member is located on the second side of the cattle guard; when in its first position the second locking member prevents the second link member moving to its first position but permits the first link member to move to its second position by preventing the fourth link member moving to a first position while permitting the third first link member to move to a second position; and wherein when in its second position the second locking member prevents the first link member moving to its second position but permits the second link member to move to its first position by preventing the third link member moving to a second position while permitting the fourth link member to move to a first position.

The above arrangement may permit the first and second locking members to be arranged on diagonally opposed corners of the cattle guard, thus at two opposite sides and two opposition ends of the cattle guard, permitting the cattle guard to be installed with the bars either across or running along the intended direction of the walkway, while still permitting access to each locking member from either end of the walkway passing across the cattle guard.

Each locking member may be arranged to be raised or lowered, or to pivot, to block the path of a selected one of the two link members with which it is associated, providing a very simple and reliable mechanism for both locking and releasing the bars from either side or either end of the cattle guard.

Preferably, the cattle guard further comprises means for preventing access to the first and second locking members, or for locking the first and second locking members in one position. This may for example comprise a padlock or a locked housing, preventing unauthorised movement or access to the locking member or members.

Preferably, each bar has at least one stop on at least one end arranged to limit rotation of the bar and to partially bear any weight placed on the bar. In this manner, any forces placed on the bars by persons walking across it which may act to rotate the bar past its intended walk position, may enable the forces created to be supported locally rather than these being placed entirely on the linkage mechanism.

Preferably, the axis of rotation of each bar is offset below a longitudinal centreline of each bar, when each bar has its non-planar surface uppermost, such that when the bar is rotated so that a planar surface is uppermost, downward pressure applied to the upper planar surface prevents the bar rotating to a position where the non-planar surface is uppermost. In this manner, downward pressure applied on the upper surface effectively acts to urge the bar to a position in which it is retained, preventing the bar from rotating and thus providing a stable walkway to walk across.

Advantageously, the locking means may comprise first and second locking members at respective opposite sides, or respective opposite ends of the cattle guard, each locking member having a first position and a second position, wherein when the bars have their non-planner surfaces uppermost and are locked in position, moving either locking member from one of its positions to the other causes the bars to be released from the locked position, irrespective of the position of the other locking member and wherein, when the bars have their non-planner surfaces uppermost and are not locked in position, moving either locking member from one of its positions to the other causes the bars to be locked in position, irrespective of the position of the other locking member.

In any of the above embodiments it is preferable that the bars are arranged to be rotated by hand, avoiding the provision of any lever to rotate the bars, which may otherwise provide a potential obstacle to a passing train. This may also discourage attempted interference with the cattle guard by unauthorised users, by removing any obvious means of operating or tampering with the cattle guard.

In one embodiment, each bar may be formed from glass reinforced plastic so that it may be maintenance free for its intended life.

Where the cattle guard is to be employed on a railway line it is advantageous if it is dimensioned to fit between the rails of a railway line, with the two opposed frame members aligned perpendicular to the rails, for then the bars will run in the direction of the rails, in which direction they are more difficult to walk along when set in the guard position.

Two embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which like numerals are used to indicate like parts and of which: Figure 1 is a perspective view of a first embodiment of a cattle guard in accordance with the present invention in a "guard" position; Figure 2 is a perspective view of the cattle guard of Figure 1 but shown in a "walk" position; Figure 3 corresponds to Figure 1 but with frame members and a cover box removed to show the internal components when in the guard position of Figure 1; Figure 4 correspond to Figure 3 but shows the components in the walk position, as illustrated in Figure 2; Figure 5 is a partial perspective sectional view taken along the line V-V of Figure 3.

Figures 6A to 6C are end views of a bar of the cattle guard of Figures 1 to 4, shown rotated to different angles; Figure 7A is a side elevation of the first locking member; Figure 7B is a side elevation of the second locking member; Figures 8A to 8B, 9A to 9B, 10A to 10B and 11A to 11B show the locking members of Figures 7A and 7B in respective different positions during use of the cattle guard of Figure 1; Figure 12 is a perspective view of a second embodiment of a cattle guard in accordance with the present invention in a locked "guard" position; Figure 13 is a perspective view of the cattle guard of Figure 12 but shown in a locked "walk" position; Figure 14 corresponds to Figure 12, but with frame members removed to show the internal components when in the locked guard position of Figure 12; Figure 15 correspond to Figure 14 but shows the internal components in the locked walk position, illustrated in Figure 13; Figures 16A and 16B are end views of a bar of the cattle guard of Figures 12 to 15, shown rotated to different angles; Figures 17 and 18 are partial perspective sectional views along the line A -A of Figure 14 in the locked guard position; Figure 19 and 20 correspond to the partial perspective sectional views of Figures 17 and 18, but in a released guard position; and Figures 21 and 22 are partial perspective sectional views along the line B -B of Figure 14 in the released guard position of Figures 19 and 20.

Referring to Figure 1, this shows a cattle guard, indicated generally as 1, in accordance with the present invention. This comprises a first frame member 2 and a second frame member 3 both connected to first and second fixed end bars 4, 5, to form a square perimeter frame of the cattle guard 1. The fixed end bars 4 and 5 are both square section glass reinforced plastic (GRP) tube. Between the two fixed end bars 4 and 5 there are located, in this example, nine rotatable bars 6a to 6i, also formed of square section glass reinforced plastic tube. Each end of each rotatable bar 6a to 6i is supported by a respective one of the first and second frame members 2, 3 via a bearing mounted to a respective hole 7 in one of the first or second frame members 2, 3.

In Figure 1, the rotatable bars 6a to 6i are shown in a first guard position to enable the cattle guard to guard against cattle or other large animals walking across and to deter pedestrians from walking across it. In Figure 2, the cattle guard 1 of Figure 1 is shown with the rotatable bars 6a to 6i rotated through 45° so that a planar surface, or side, of each of the rotatable bars 6a to 6i is uppermost, placing the cattle guard 1 in a walk configuration, where it is relatively safe and easy for a pedestrian to walk over.

The cattle guard of Figures 1 and 2 comprise a number of link members connecting the rotatable bars 6a to 6i, so that they may all be rotated together, and two locking members which engage with the link members to enable the rotatable bars 6a to 6i to be either locked in the guard position of Figure 1, or to be released from the guard position of Figure 1. These are all described in detail later, but Figures 1 and 2 show secure housings 8 and 9 in which the locking members are located, each housing 8, 9 having a respective lockable cover 10 to prevent tampering with the locking mechanism and thus the rotatable bars 6a to 6i of the cattle guard 1.

Referring now to Figures 3, 4, these correspond to Figures 1 and 2 respectively, but omit the first and second frame members 2 and 3 and the secure housings 8 and 9. Figures 3 and 4 reveal how the rotatable bars 6a to 6i of the cattle guard 1 of Figure 1 are each connected at a first end to a first upper link member 11 and to a first lower link member 12, and at a second end to a second upper link member 13 and to a second lower link member 14.

Each of the rotatable bars 6a to 6i is pivotally connected to the upper link members 11 and 13 and the lower link members 12 and 14 at vertically separated points, such that rotation of one of the rotatable bars 6a to 6i clockwise, as shown in Figure 3, about a respective axes of rotation 17, causes rotation of all of the rotatable bars 6a to 6i, by displacing the upper link members 11 and 13 in the direction of the arrows 15, with the lower link members 12 and 14, being displaced in the directions of arrows 16, so that the rotatable bars 6a to 6i all adopt the position shown in Figure 4, placing the cattle guard in the walk configuration of Figure 2.

It will be appreciated that instead of one of the rotatable bars 6a to 6i of Figure 3 being rotated clockwise, it could equally have been rotated anti-clockwise, which would have again placed all the rotatable bars 6a to 6i in a second walk configuration, as will be described below with reference to Figures 6A to 6C.

Referring again to Figure 3, a first locking member 18 is provided at a first end and on a first side of the cattle guard 1. A second locking member 19 (just visible in Figure 4) is provided at a second end and on a second side of the cattle guard 1. The first locking member 18 is rotatable and may be moved to limit movement at any one time of one only of the first upper link member 11 and first lower link member 12. Similarly, the second locking members 19 is rotatable and may be moved to limit movement at any one time of one only of the second upper link member 13 and second lower link member 14. This is described in greater detail below with reference to Figures 7A to 11B.

Referring now to Figure 5, a perspective sectional view along the line V-V of Figure 3, (but including the first frame member 2 omitted from Figure 3), this shows that the first frame member 2 is a square C-shape in cross section, effectively providing a housing for the first upper link member 11 and the first lower link member 12. The upper link member 11 is seen to be supported by being pivotally connected by a pivot pin (not shown) to an end plate 20 of each of the rotatable bars 6a to 6i, at a point 21. Similarly, the lower link member 12 is supported by being pivotally connected to each end plate 20 of each of the rotatable bars 6a to 6i, at a second point 22, as can perhaps be more clearly seen with reference to Figures 6A.

With continued reference to Figures 5 and 6A, from these it can be seen how the rotatable bar 6a (and all the other rotatable bars 6b to 6i), is rotatably mounted by a bearing 23, in a bearing housing 24 secured to the end plate 20 of the rotatable bar 6a, to a spindle 25 mounted in a hole 7 in the first frame member 2.

With the exception of the rotating bars 6a and 6i, each of the other rotating bars 6b to 6h will have associated spindles 25 which are shorter and terminate substantially flush with an outer face of the respective first and second frame members 2, 3. However, in the case of rotating bars 6a and Si, one of their respective spindles 25 will have an extension portion on which the first locking member 18, or second locking member 19, are respectively mounted and free to rotate thereon, as shown in Figure 5.

With reference now to Figure 6A, this shows the two vertically separated connection points 21 and 22, in the end plate 20 of rotatable bar 6a, for pivotally engaging with respective upper and lower link members 11 and 12. A bearing 23 (one at each end of the rotatable bar 6a) mounted in bearing holder 24 fixed to the end plate 20, permits the rotatable bar 6a (and all the other rotatable bars 6b to 6i) to be rotated either clockwise, from the guard position shown in Figure 6A, to the walk position shown in Figure 6B, or rotated anti-clockwise to the walk position shown in Figure 6C. This rotation will occur around the axis of rotation 17 passing through the centre of the bearings 23, such that each of the rotatable bars 6a to 6i will either "fall" to the right as shown in Figure 6B and as represented by arrow 27, or fall to the left, as shown in Figure 6C and as represented by arrow 28. Thus, when unlocked from the guard position of Figure 6A, each bar 6a to 6i may rotate clockwise as shown in Figure 6B, or anti-clockwise as shown in Figure 6C, where each of the rotatable bars 6a to 6i will then be retained in place by gravity acting upon them and by the weight of a person walking across them.

The cattle guard 1 of Figures 1 and 2 may be arranged to be positioned between the two rails of a railway line with additional cattle guards having fixed bars, being placed outside of either rail, to effectively extend the cattle guard to beyond the width of a train, to a point where a fence or other vertical barrier may extend. Thus, in the guard configuration shown in Figure 1, the cattle guard 1 will prevent cattle walking across it along the railway line and deter pedestrians walking across the cattle guard 1.

When an authorised user with a key for unlocking the secure housings 8 or 9 approaches the cattle guard, from either end/side of the cattle guard 1, they may operate the appropriate locking means 18 or 19 to release the cattle guard 1 from the guard position shown in Figure 1 and rotate the rotatable bars 6a to 6i to the walk position shown in Figure 2, prior to crossing the cattle guard 1. Similarly, the cattle guard 1 permits the rotatable bars 6a to 6i to then be rotated to the position shown in Figure 1 and locked in place in the guard configuration of Figure 1, using either the first locking member 18 or second locking member 19, depending whether the user is at the opposite end/side of the cattle guard 1, or whether they have returned to the end/side they set out from. This dual end/side operation is made possible by the interaction between the first upper link 11, first lower link 12, second upper link 13, second lower link 14, first locking member 18, second locking member 19 and the rotatable bars 6a to 6i. This will now be described with reference to Figures; 7A and 7B; 8A and 8B; 9A and 9B; 10A and 10B; and 11A and 11B, where each pair of Figures is a snapshot in time showing the relative positions of all the above-mentioned components, with Figures 7A, 8A, 9A, 10A and 11A showing the first locking member 18, bearing the letter A, and Figures 7B, 8B, 9B, 10B and 11B indicating the position of the second locking member 19, bearing the letter B. Referring first to Figures 7A to 7B, these show rotatable bars 6a to 6i (represented by rotatable bars 6b and 6h) in the guard position, with an apex between two flat sides uppermost. In this position, the points 21 and 22, at which the end plate 20 is connected to the first upper link member 11 and the first lower link member 12, are aligned vertically, with the first upper link member 11 and first lower link member 12 arranged one above the other and with their respective ends aligned vertically, as shown in Figure 7A. Because those same rotatable bars 6a to 6b are also connected at their opposite ends to the second upper link member 13 and second lower link member 14, the second upper link member 13 and second lower link member 14 are also positioned as shown, with their respective ends aligned vertically, as shown in Figure 7B.

With the first locking member 18, raised as shown in Figure 7A, and the second locking member 19 raised, as shown in Figure 7B, the first upper link member 11 and second upper link member 13 are effectively locked in place by the first locking member 18 preventing the first upper link member 11 moving to the left, as shown in Figure 7A and the second locking member 19 preventing the second upper link member 13 moving to the left, as shown in Figure 7B (viewed from the opposite side to Figure 7A), thus preventing the upper points of connection with the rotatable bars 6a to 6i moving laterally and thus, by virtue of the axis of rotation 17 of each of the rotatable bars 6a to 6i being fixed relative to the first and second frame members 2 and 3 (not shown in Figure 7A and 7B), the rotatable bars 6a to 6i are locked in the guard configuration of Figure 1.

On approaching the cattle guard 1 and gaining access to the locking member 18 from a first side or first end of the cattle guard 1, a user may unlock the cattle guard by lowering the first locking member 18 from the position shown in Figure 7A, to the position shown in Figure 8A, while the second locking member 19, to which the user hasn't access due to it being at the opposite side/end of the cattle guard 1, remains in the raised position, as shown in Figure 8B. The user can then rotate one of the rotatable bars 6a to 6i, and thus rotate all the rotatable bars 6a to 6i, moving the first upper link member to the left in the direction of the arrow 29 shown in Figure 9A and thus causing the first lower link member 12 to move to the right, in the direction of arrow 30, as shown in Figure 9A. Thus, the second upper link member 13 and the second lower link member 14 on the opposite side move to the position shown in Figure 9B, as again represented by arrows 29 and respectively. If the user should now cross the cattle guard 1, which will now resemble the cattle guard as shown in Figure 2, where the rotatable bars 6a to 6i are held in the position shown by gravity, as previously discussed, and then return to the same side/ end they may then lock the rotatable bars 6a to 6i in the "guard" position, shown in Figure 1, by rotating the rotatable bars 6a to 6i to the position shown in Figures 8A and 8B and then raising the first locking member 18 to the position shown in Figure 7A, returning the cattle guard 1 back to its original locked guard configuration of Figures 7A and 7B.

If instead of returning to the first end or first side, the user alternatively proceeds across the cattle guard 1, while it is in the walk configuration shown in Figure 2, the user may then rotate the rotatable bars 6a to 6i, from the second end/side of the cattle guard 1, from the walk configuration of Figures 9A and 9B back to the guard position, as shown in Figure 10A. Here the user will have previously lowered the first locking member 18 to the position shown in Figure 10A (compare this with Figure 9A) and thus by lowering the second locking member 19 at the second end or second side, where the user is now located, to the position shown in Figure 10B, the first locking member 18 and the second locking member 19 will now lock the first lower link member 12 and second lower link member 14 in the positions shown in Figures 10A and 10B, by virtue of these two link members effectively being connected together via points 22 connecting them to common rotatable bars 6a to 6i and thus again lock the rotatable bars 6a to 6i in the guard position.

Once locked in the guard position shown in Figures 10A and 10B, if the user should again approach from the second side or second end they may then rotate the second locking member 19, to which they have access, from the position shown in Figure 10B to the position shown in Figure 7B, permitting the rotatable bars 6a to 6i to be rotated to the walk position shown in Figures 9A and 9B. The user may then again subsequently rotate the rotatable bars 6a to 6i back to the guard position of Figure 1 and lock them in that position by either raising the first locking member 18 from the position shown in Figure 10A to the position shown in Figure 7A or lowering the second locking member from the position shown in Figure 8B to the position shown in Figure 10B, depending which end or side they are at.

Referring backs to Figures 10A and 10B, this shows the position of the first locking member 18 and second locking member 19 when a user has exited the cattle guard 1 from the second end or second side, having locked it in place by operation of the second locking member 19 at the second end/side. If a second user should now approach the cattle guard 1 from the first end or first side, thus travelling in the same direction as the first user, they may raise the first locking member 18 from the position shown in Figure 10A to the position shown in Figure 7A and then rotate the rotatable bars 6a to 6i to the "walk" position shown in Figures 11A and 11B, for the second locking member 19 at the second end/ side being in the position shown in Figure 11B (compare this with Figure 10B) will permit the rotatable bars 6a to 6i to be rotated to the "walk" position shown in Figures 11A and 11B. The user may then leave the cattle guard 1 from the second end/side, rotate the bars 6a to 61 to the guard configuration and then lock them in place by raising the second lock member 19 from the position shown in Figure 10B to the position shown in Figure 11B.

It will be observed from Figures 9A, 9B, 11A and 11B that the bearing housing 24, when the rotatable bars 6a to 6i are load bearing (either in the walk configuration of Figure 6B or the walk configuration of Figure 6C) will engage with respective lower and upper profiled edges of upper and lower link members 11 to 14 which will prevent over rotation of the associated rotatable bar 6a to 6i.

The invention, as described above with reference to the illustrated embodiment, permits the cattle guard 1 to be approached from either the first end/first side or the second end/second side and be set either to the locked guard position of Figure 1 or to one of the walk positions as illustrated in Figure 2, by operation of the nearest locking member 18 or 19, irrespective of the position of the locking member 19 or 18 at the opposite end or opposite side, to which the user will not have access.

Referring now to Figures 12 to 22 these illustrate a second embodiment of a cattle guard in accordance with the present invention, which is for the same purpose and functions in a similar manner to that of the above described first embodiment.

Referring to Figure 12, a cattle guard, indicated generally as 31, comprises a first C-shaped frame member 32 and a second C-shaped frame member 33, held together at their respective ends by fixed end bars 34 and 35, which thus form a rectangular frame with the C-shaped frame members 32 and 33. Between the end bars 34 and 35 are positioned six outer bars 36a to 36f and two shorter inner bars 36g and 36h.

All the bars 36a to 36h are formed of a rectangular box section glass reinforced plastic (GRP) tube, with the inner bars 36g and 36h being shorter to accommodate housings 37 and 38 (housing 38 is not seen in Figure 12). Each of the housings 37 and 38 has a lockable top cover 39, to prevent tampering with the components within the respective housings 37 and 38. The housings 37 and 38 are located "inboard" in this embodiment, to leave a flush end face on each side of the cattle guard, defined by the respective C-shaped frame members 32 and 33, which may then abut with an edge of a crossing across a railway, or similar.

The cattle guard is depicted in Figure 12 in a "guard" position, where each bar 36a to 36h is canted over at 300 and is retained in this position by the uppermost edge, as shown, of each outer bar 36a to 36f coming into contact with the underside of the top edge of each of the C-shaped frame members 32 and 33.

As will be explained in greater detail later, with reference to subsequent figures, each of the outer bars 36a to 36f is pivotally mounted to respective pairs of holes 43 in the first and second C-shaped frame member 32 and 33, so that all the bars 36a to 36h can be rotated together to the "walk" position shown in Figure 13. Thus, the cattle guard 31 may function in a very similar manner to the cattle guard 1 of the previously described embodiment.

Referring now to Figures 14 and 15, these correspond to Figures 12 and 13 respectively, but in Figures 14 and 15 the C-shaped frame members 32 and 33 have been omitted to show end plates 40 mounted in the end of the outer bars 36a to 36f. A bearing 41 is mounted by an associated bearing holder 42 to each respective end plate 40. The bearing holders 42 and thus each one of the outer bars 36a to 36f pivot on respective rods (not shown) which extend through each respective outer bar 36a to 36f, associated respective pairs of bearing 41 and into the holes 43 in the C-shaped frame members 32 and 33, where each rod is retained in place. The inner bars 36g and 36h are similarly arranged, as will be described later.

Figures 16a and 16b show an end plate 40 of a bar 36a in greater detail, where the bearing 41 can be seen to be held in place by the bearing holder 42, which bearing holder 42 is in turn is held in place by fastenings 44, securing the bearing 41 towards one corner of the end plate 40 of the bar 36a. At the opposite corner of the end plate 40, the end plate 40 extends beyond the periphery of the bar 36a to form a projecting lug 45.

Referring again now to Figures 14 and 15, the lugs 45 of each bar 36a to 36h are connected to link members 46 and 47, which connect the lugs 45 on each end of every bar 36a to 36h together. It is to be noted here that in Figure 14 the lugs 45 of the inner bars 36g and 36h are shown prior to connection to the link members 46 and 47, to which they will be connected by spacers, not shown.

Referring again to Figures 16A and 16B, these illustrate how any one bar, in this example outer bar 36a, may be rotated about an axis passing through the centre of the bearings 41, from the position shown in Figure 16A, through 30 degrees, to the position shown in Figure 16B, from the guard position of Figure 12 to the walk position of Figure 13.

From a comparison of Figure 13, showing a cattle guard in accordance with the second embodiment in the walk position, with that of Figure 2, showing a cattle guard 1 of the first embodiment also in a walk position, it will be seen that in these positions the rectangular profile of the bars 36a to 36h of the second embodiment enables a significant reduction in the spacing between adjacent bars to be achieved. For example, if each rectangular bar 36a to 36h of the second embodiment had a width of 120mm and a depth 60mm, then the spacing between adjacent bars, in the walk position, may be reduced to 20mm, while still providing sufficient spacing for the bars 36a to 36h to reliably swing unimpeded backwards and forwards between the guard position of Figure 12 and the walk position of Figure 13.

The rectangular cross section, instead of the square cross section of the previous embodiment, of each bar 36a to 36h, necessary to permit the bars 36a to 36h to be mounted more closely together, means that the lugs 45 are desirable to permit the link members 46 and 47 to be mounted relatively low in the cattle guard 31 and to avoid them fouling the respective housings 37 and 38 and the various components thereof, (to be subsequently described). In addition, the provision of the lugs 45 also ensures that as the any of the bars 36a to 36h approach the walk position, shown in Figure 15, urged to this position by movement of the link members 46 and 47, the vertical separation between the point at which each end plate 40 is connected to the link member by the respective lugs 45 and the position at which each end plate 40 is pivotally connected to the rod connecting it to the C-shaped frame members 32 and 33, ensures that lateral movement of the link members 46 and 47 results in a significant rotational force on each of the bars 36a to 36h, necessary to ensure reliable rotation of all of the bars 36a to 36h to the walk position.

In addition to the above, the location of the rotatable axis of each bar 36a to 36h towards an upper corner of that bar, also minimises the separation between an upper surface of each bar and the under surface of the upper edge of the C-shaped frame members 32 and 33, while still permitting the bars 36a to 36h to rotate between the guard position of Figure 12 and the walk position of Figure 13. In the embodiment shown in Figures 12 and 13, the distance between a top surface of each bar in the walk position of Figure 13 and the top edge of the C-shaped frame members 32 and 34 is only 18mm, significantly reducing the trip hazard relative to that of the previous embodiment.

In the cattle guard 31, of Figures 12 and 13, the outer bars 36a to 36f are only restrained from rotating between the walk and guard positions by the link members 46 and 47. The link members 46 and 47 are however arranged to be locked in both the walk and guard positions, (although in other embodiments it is possible that they could just be arranged to be locked only in the walk position), by being attached to the inner bars 36g and 36h, which inner bars 36g and 36h are arranged to be locked in place. This is achieved by the inner bars 36g and 36h being arranged to be locked in place at their ends to the housings 37 and 38.

In Figures 12 to 15, as in the corresponding figures of the previous embodiment, a relatively "short" version of the cattle guard 31 has been illustrated, such a short embodiment being selected to provide figures which may show the relevant detail to a relatively large scale. However, a typical application of such a cattle guard 31 would be on a railway line, where a cattle guard 31 may either border a level crossing, with one of the C-shaped frame members 32 or 33 forming an end of the cattle guard and abutting an edge of that crossing, or it could for example be aligned with a gap in a fence through which a railway passes, to stop animals crossing the fence by walking along the railway line. In either case, it is likely that the length of the cattle guard, in the direction of the bars 36a to 36h, would be greater than two metres and possibly the length of the bars 36a to 36f could be longer than the length of the C-shaped frame members 32 and 33.

Because the separation between the C-shaped frame members 32 and 33 needs to be sufficient to prevent animals, or people, leaping across the cattle guard 31, it is necessary that the locking mechanism be operable from each end of the cattle guard 31, so that the cattle guard, in a locked guard position, can be approached from either end, released from the guard position and placed in the walk position, locked in the walk position, crossed while locked in the walk position, released from the walk position, placed in the guard position and locked in the guard position, irrespective of from which end the cattle guard 31 is first approached. To enable this, a locking mechanism is provided which is operable from either of the housings 37 and 38, located at each respective end of the cattle guard 31 and the components and operation of this locking mechanism will now be described with reference to Figures 17 to 22.

With reference to Figure 17, this is a perspective sectional view along the line A-A of Figure 12, showing the nearest housing 38 (not seen in Figure 12, but opposite to housing 37) and the components associated with that housing 38 and 30 with the lockable top cover 39 removed.

In Figure 17, the C-shaped frame member 32 can be seen, however this portion of the C-shaped frame member has its top edge cutaway to provide an opening, normally covered by a lockable top cover 39 of Figure 12. The C-shaped frame member 32 defines, together with an L-shaped section 48, the housing 38 sitting on the inside face of the C-shaped frame member 32.

The housing 38, as can be seen from Figures 14 and 15, extends along a central section of the cattle guard 31, in which section the two inner bars 36g and 36h are accommodated. The inner bars 36g and 36h are the same as the previously described outer bars, 36a to 36f, except that they are shorter. Also, although they still have end plates 40 and bearings 41 located in the bearing holders 42, in the same manner as shown in Figures 16A and 16B, here rods 65 extending through the centre of the bearings 41, extend through respective holes in the inner walls of the housing 38, with the rods then extending into respective ones of end supports 50, 51, 52 and 53, which are bonded in respective C-shaped frame members 32 and 33.

Each of the inner bars 36g and 36h may be locked in place in either the guard position, shown in Figure 12, or the walk position, shown in Figure 13. It is the locking of the inner bars 36g and 36h in rotational position, in either the guard or walk positions, which locks each of the outer bars 36a to 36f in rotational position in either the guard position or walk position, by virtue of all the bars 36a to 36h being connected to the same two link members 46 and 47.

Both of the inner bars 36g and 36h are locked in either the walk or guard position by identical mechanisms, which will now be described with reference to the inner bar 36g, shown in Figures 17 to 22.

In Figure 17, the inner bar 36g is shown locked in the guard position, by locking pin 54 projecting through both a hole 55 in an inner face of the housing 38 and a corresponding hole 56 in the end plate 40 of the inner bar 36g. Pin 54 is urged into the position shown in Figures 17 by compression spring 57.

The pin 54 is attached to a first release plate 58, with the spring 57 and a corresponding spring associated with a corresponding pin, in turn associated with the inner bar 36h, acting to urge the first release plate 58 against the inner side of the housing 38, as shown in Figure 17.

At the opposite end of that same inner bar 36g, as shown in Figure 18, (also a perspective sectional view along the line A-A of Figure 14 but showing the housing 37), a similar locking pin 59 is attached to a steel plate 60 bonded to one face of a nylon bush 61, located inside the inner bar 36g. This locking pin 59 extends outwardly through the end plate 40 of the bar 36g and into a hole 62 in the inner face of the housing 37, thus locking this end of the bar 36g in the guard position, as shown.

Referring now to Figures 19 and 20, these correspond to Figures 17 and 18, but show the locking pins 54 and 59 in a release position and thus the bar 36g in an unlocked guard position, where it may then be rotated to the walk position of Figure 13.

With reference to Figure 19, this unlocked guard position may be achieved by unlocking and removing the appropriate top cover 39 of the cattle guard 31, and then pulling the first release plate 58 in the direction of the arrow 63, against the force of the springs 57, (only of one of which is shown), to pull the locking pin 54 out of engagement with the end plate 40 in the inner bar 36g. With reference now to Figure 20, at the other end of the bar 36g, as will be explained below, the nylon bush 61 moves in the direction of the arrow 64, pulling locking pin 59 out of engagement with the hole 62 in the housing 37.

With reference now to Figures 21 and 22, both partial perspective sectional views along the line B-B of Figure 12, these illustrate the mechanism by which movement of the first release plate 58, in the direction of the arrow 63 of Figure 19, causes the nylon bush 61 to move in the direction of the arrow 64 of Figure 20.

A rod 65 extends through the inner bar 36g, into both of the end supports 50 and 52. The rod 36g however has some movement backwards and forwards within both the fixed end supports 51 and 52, as will be appreciated from Figure 22, and the rod 65 is also free to slide through the bearings 41 at either end of the inner bar 36g. The rod 65 is however fixed in longitudinal position relative to the first release plate 61, of Figure 20, the nylon bush 61 and steel plate 60 of Figure 22 and also a second release plate 66, shown in Figure 22. The rod 65 is retained in place relative to each of these by having appropriate E-clips 67 engaging with circumferential grooves in the rod 65, in a conventional manner. Thus, a user moving the first release plate 63 in the direction of arrow 63 of Figure 21 will not only release the release pin 54, as shown in Figure 19, but will also draw the nylon bush 61 and steel plate 60 in the direction of the arrow 64 of Figure 20, releasing the pin 59 from the hole 56. This then permits any one of the bars 36a to 36h (and thus all the bars 36a to 36h) to be rotated to the walk position of Figure 13, where releasing the first release plate 58 will then cause locking pins 54 and 59 to engage with appropriate holes 68 and 69 in the end plates 40 (see Figure 19) and in the sides of the housings 37 and 38 (see Figure 12), to lock the bars 36a to 36h in the walk positions. Similarly, the release plate 58 may then again be pulled in the direction of arrow 63 of Figure 21, to again release the bars 36a to 36h from the locked walk position, to enable the bars 36a to 36h to be rotated back to the guard position, whereby releasing the first release plate 58 will cause the pins 54 and 59 to re-engage and lock the bars 36a to 36h back in the guard position.

As will be appreciated from a comparison on Figures 21 and 22, if the cattle guard 31 were to now to be approached from the opposite end (that of Figure 22), then instead of moving the first release plate 58 in the direction of arrow 63, a user could instead unlock and remove the appropriate top cover 39, to expose the second release plate 66 and then push the second release plate 66 in the direction of arrow 70, as shown in Figure 22 against both the force of the previously mentioned compression springs 57 and also tension springs 49, only one of which can be seen in Figures 18 and 20, which tension springs 49 act in tandem with the compression springs 57. This would again move the rod 65 and the first release plate 58 in the direction of the arrow 63 of Figure 21, again releasing the locking pins 58 and 59, permitting the bars 36a to 36h to be rotated to the desired position, before releasing the second release plate 66, to lock the bars 36a to 36h in that position.

Two embodiments of the present invention have been described by way of example only and it will be appreciated that many alternatives are possible which fall within the scope of the following claims. Particularly in respect of the first embodiment, it should be noted that the locking members disclosed could be on the same side, but at opposite ends of the cattle guard and both operate on the same pair of upper and lower link members.

Claims

Claims 1. A cattle guard comprising a frame having two opposed frame members and a plurality of parallel bars extending between the two opposed frame members, 5 wherein: each end of each bar is rotatably supported by a respective frame member so that each bar may rotate about a respective longitudinal axis of rotation of that bar; each bar has a substantially planner surface which may be located uppermost by rotation of the bar and a nonplanar surface which may be located uppermost by rotation of the bar; and wherein the cattle guard further comprises a linkage mechanism connected to each of the bars and arranged to rotate the bars together between a walk position where the planar surfaces of each bar are uppermost and substantially coplanar, making it easier to walk over the cattle guard, and a guard position where the nonplanar surfaces are uppermost, making it more difficult to walk over the cattle guard, the cattle guard further comprising a locking means for locking the bars in a position where the planar and / or nonplanar surfaces are uppermost.
2. A cattle guard as claimed in Claim 1 wherein: each bar is arranged to rotate about its axis of rotation between a first position and a second position; each bar has first and second planar surfaces joined at an apex, the apex defining the non-planar surface; in the first position the first planar surface of each bar is uppermost and substantially coplanar with the other first planar surfaces, defining a walk position; and in the second position the apex of each bar is uppermost defining a guard position.
A cattle guard as claimed in Claim 1 or 2 wherein: each bar is arranged to rotate about its axis of rotation between a first position, a second position and a third position; in the first position the first planar surface of each bar is uppermost and substantially coplanar with the other first planar surfaces in a first walk position; in the third position the second planar surface of each bar is uppermost and substantially coplanar with the other first planar surfaces defining a second walk position; and wherein in the second position intermediate the first and third positions the apex of each bar is uppermost in the guard position.
4. A cattle guard as claimed in Claim 3 wherein: the linkage mechanism comprises a first link member pivotally connected to each bar at a point above or below the axis of rotation of each bar and a second link member pivotally connected to each bar at a point above or below the axis of rotation of each bar; each link member is arranged to move substantially transversely relative to the axes of rotation of the bars such as to cause the bars to rotate between their first, second and third positions; the link members having a first position, where the bars are in their first positions, a second position, where the bars are in their third positions and a third position, intermediate the first and second positions, where the bars are in their second positions; the locking means being arranged to lock the link members in their third positions.
5. A cattle guard as claimed in Claim 4 wherein the locking means comprises: a first locking member arranged to move between first and second positions and located at or toward a first end or a first side of the cattle guard; and a second locking member arranged to move between first and second positions and located at or toward a second end or second side of the cattle guard, remote from the first end or the first side of the cattle guard, and wherein: when in its first position the first locking member prevents the first link member moving to its first position but permits the second link member to move to its second position; when in its second position the first locking member prevents the second link member moving to its second position but permits the first link member to move to its first position; when in its first position the second locking member prevents the second link member moving to its first position but permits the first link member to move to its second position; and wherein when in its second position the second locking member prevents the first link member moving to its second position but permits the second link member to move to its first position, thus when the first and second locking members are both in their first positions, or are both in their second positions, the first and second link members are all held in their third positions.
6. A cattle guard as claimed in Claim 5 wherein the two opposed frame members comprise a first frame member located to a first side of the cattle guard and a second frame member located to a second side of the cattle guard, wherein: the first link member is an upper link member located on the first side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; the second link member is a lower link member located on the first side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar; the first and second locking members are both located on the first side of the cattle guard, but at or towards opposite end of the cattle guard.
7. A cattle guard as claimed in Claim 5 wherein the two opposed frame members comprise a first frame member located to a first side of the cattle guard and a second frame member located to a second side of the cattle guard, wherein: the first link member is an upper link member located on the first side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; the second link member is a lower link member located on the first side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar; the first locking member is located on the first side of the cattle guard, the cattle guard further comprising: a third link member which is an upper link member located on the second side of the cattle guard and pivotally connected to each bar at a point above the axis of rotation of each bar; and a fourth link member which is a lower link member located on the second side of the cattle guard and pivotally connected to each bar at a point below the axis of rotation of each bar, wherein: the second locking member is located on the second side of the cattle guard: when in its first position the second locking member prevents the second link member moving to its first position but permits the first link member to move to its second position by preventing the fourth link member moving to a first position while permitting the third first link member to move to a second position; and wherein when in its second position the second locking member prevents the first link member moving to its second position but permits the second link member to move to its first position by preventing the third link member moving to a second position while permitting the fourth link member to move to a first position.
8. A cattle guard as claimed in claim 5, 6 or 7 wherein each locking member is arranged to be raised or lowered, or to pivot, to block the path of a selected one of the two link members with which it is associated.
9. A cattle guard as claimed in any one of claims 5 to 8 further comprising means for preventing access to the first and second locking members, or for locking the first and second locking members in one position.
10. A cattle guard as claimed in any preceding claim wherein each bar has at least one stop on at least one end arranged to limit rotation of the bar and to partially bear any weight placed on the bar.
11. A cattle guard as claimed in any preceding claim wherein the axis of rotation of each bar is offset below a longitudinal centreline of each bar, when each bar has its non-planar surface uppermost, such that when the bar is rotated so that a planar surface is uppermost, downward pressure applied to the upper planar surface prevents the bar rotating to a position where the non-planar surface is uppermost.
12. A cattle guard as claimed in any preceding claim wherein the locking means comprises first and second locking members at respective opposite sides, or respective opposite ends of the cattle guard, each locking member having a first position and a second position, wherein when the bars have their non-planner surfaces uppermost and are locked in position, moving either locking member from one of its positions to the other causes the bars to be released from the locked position, irrespective of the position of the other locking member and wherein, when the bars have their non-planner surfaces uppermost and are not locked in position, moving either locking member from one of its positions to the other causes the bars to be locked in position, irrespective of the position of the other locking member.
13. A cattle guard as claimed in claim 1 or 2 wherein the locking mechanism extends to each frame member and can be accessed and operated from two position, one adjacent each frame member.
14. A cattle guard as claimed in claim 13 wherein one or more of the plurality of parallel bars are defined as primary bars, which are arranged to be rotationally locked in place in at least one rotational position directly by the locking mechanism; with the remainder of the plurality of parallel bars defined as secondary bars, which are arranged to be rotationally locked in place, indirectly, in at least one rotational position by the linkage mechanism locking them in the same position as the primary bars, wherein the locking mechanism comprises a locking member arranged to releasably engage between the primary bar and a component forming, or fixed relative to, a frame member.
15. A cattle guard as claimed in claim 14 wherein the locking member is a pin arranged to engage with an end plate of a primary bar.
16. A cattle guard as claimed in claim 14 or 15 wherein the locking mechanism 15 comprises two locking members arranged to releasably engage between respective ends of a primary bar and respective components forming, or fixed relative to, respective frame members.
17. A cattle guard as claimed in any one of claims 13 to 16 comprising a rod passing through at least one primary bar, which rod can move laterally to release at least one locking member.
18. A cattle guard as claimed in claim 17 comprising at least one locking member connected to the rod and arranged to be moved by the rod from a retracted position within a primary bar to an extended position where it extends from that primary bar to engage a component forming, or fixed relative to, a frame member.
19. A cattle guard as claimed in any one of claims 13 to 18 wherein the or each primary bar is shorter than the secondary bars and the cattle guard further comprises two housing, each extending in from a respective frame member, which housings are accommodated by the, or each, shorter primary bar, and wherein each housing comprises an actuator of the locking mechanism.
20. A cattle guard as claimed in any one of claims 13 to 19, when dependent on Claim 2, wherein the apex of at least some of the bars in the guard position engages with an underside of an upper lip of the frame members, which acts to restrain those bars from further rotation.
21. A cattle guard as claimed in any one of claims 13 to 20 wherein each of the plurality of bars has a non-square, rectangular cross section having two opposed outer planer major surfaces and two opposed outer planer minor surfaces, wherein, in the walk position one of the planer major surfaces is located uppermost.
22. A cattle guard as claimed in claim 21 wherein each of the plurality of bars has a rotational axis which is towards an uppermost corner of the rectangular profile when the bars are in the guard position and wherein, in the guard position, the plurality of bars are rotated through an angle of between 25 degrees and 35 degrees relative to their position when in the walk position.
23. A cattle guard as claimed in any preceding claim wherein the bars are arranged to be rotated by hand.
24. A cattle guard as claimed in any preceding claim wherein each bar is formed from glass reinforced plastic.
25. A cattle guard as claimed in any proceeding claim dimensioned to fit between the rails of a railway line with the two opposed frame members aligned with the rails.