AU2010101279A4 - Grid assembly - Google Patents

Description

P/00/012 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: "GRID ASSEMBLY" The following statement is a full description of this invention, including the best method of performing it known to us: 1 TITLE: GRID ASSEMBLY BACKGROUND OF THE INVENTION 1. Field of the Invention THIS INVENTION relates to a grid assembly. 5 The invention particularly relates, but is not limited to, a stock control grid assembly where the grid is hingedly mounted on a base frame; and a lifting mechanism is mountable on the base frame to assist in raising the grid to enable the cavity below the grid to be cleaned out. 2. Prior Art 10 Grid assemblies are commonly used to control the movement of stock (e.g. cattle, sheep, goats, horses or camels) between adjoining grazing areas or paddocks; while permitting unrestricted vehicle movement between the adjacent grazing areas or paddocks. The grid assemblies are typically provided in gaps in the fence-lines between adjacent grazing areas 15 or paddocks, and are usually associated with one or more gates which enable selective movement of the stock between the adjacent grazing areas or paddocks. If only gates are provided in the fence-lines, they must either be opened and closed each time a vehicle passes there-through; or the 20 gates must have (expensive / complicated) opening / closing mechanisms to allow the vehicles to drive over them. A typical grid assembly has a rectangular peripheral base frame, with side walls interconnecting end walls, where the base frame supports a grid having spaced-apart parallel grid bars laid transverse to the 25 direction of vehicular traffic over the grid assembly. The grid bars may be formed of steel bar or rod, or even light-weight railway irons; and may be supported by two or more bearers interconnecting the (longer) side walls of the base frame. The grid overlies a cavity defined at least in part by the base 30 frame; and most stock will not attempt to cross the cavity via the grid. However, particularly after long, dry periods, or prolonged drought, the dust and other rubbish blown into the cavity, e.g., by dust 2 storms, can reach the level of the grid. At this level, the stock do not see any cavity below the grid, and will walk across the grid to access the adjacent grazing area or paddock, especially if it contains better feed. SUMMARY OF THE PRESENT INVENTION 5 It is an object of the present invention to provide a grid assembly where the grid is hingedly mounted in a base frame to enable the grid to be raised for cleaning of the underlying cavity. It is a preferred object of the present invention to provide such a grid assembly which can be easily fabricated, transported, installed and/or 10 maintained. It is a further preferred object of the present invention to provide such a grid assembly with detachable wings which be detached for transport. It is a still further preferred object of the present invention to 15 provide a lifting mechanism, releasably engageable with the base frame, to enable the grid to be easily raised or lowered. Other preferred objects of the present invention will become apparent from the following description. In one aspect, the present invention resides in a grid assembly 20 including: a rectangular base frame having a pair of side walls interconnected by a pair of end walls; a grid, having a plurality of substantially-parallel, spaced, grid bars interconnected by a pair of end bars; and 25 a hinge mechanism hingedly interconnecting one end of the end bars to the base frame to enable the grid to be moved from a lowered, operational position to a raised, inoperational position. Preferably, the grid bars are interconnected by a plurality of substantially-parallel, spaced bearers which extend transversely thereto; and 30 inwardly-directed abutment faces on the side walls of the base frame are arranged to support respective ends of the bearers when the grid is in the lowered, operational position.

3 Preferably, the hinge mechanism includes: aligned holes at respective one ends of the end bars of the grid; and a hinge member, optionally of steel rod or hollow steel tube, 5 preferably having a locating flange adjacent one end thereof, and adapted to receive a releasable locating member at the other end, the hinge member being receivable in aligned holes in the base frame. Preferably, respective wings, having horizontal bars interconnected by at least a pair of posts, are provided for the grid assembly, 10 where the lower ends of the posts are operably engageable in (preferably outwardly inclined) sockets on the end walls of the base frame. Preferably, the lifting mechanism includes: a post having a lower portion receivably engageable in a substantially-vertical socket provided intermediate one of the side walls of 15 the base frame; a pulley or sheave rotatably mounted at the upper end of the post; an optional secondary pulley or sheave rotatably mounted intermediate the height of the post (on a side thereof spaced from the grid); 20 and; a cable, rope or like flexible tension means having one end connectable to the grid at a location spaced from the hinge mechanism, passing around the pulley or sheave (and the optional pulley or sheave), and the other connectable to a vehicle or winch operable to pull or release the 25 cable, rope or like tension means to enable the grid to be moved from the lowered, operational position, to the raised, inoperational position. Preferably, at least one safety arm, pivotally connected to the grid, is releasably engageable with the base frame when the grid is in the raised, inoperational position; and/or a safety chain on the post may secure 30 the grid to the post when the grid is in the raised, inoperational position. BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred 4 embodiments of the present invention will now be described with reference to the accompanying drawings in which: FIG. 1 is an isometric view of an embodiment of the grid assembly of the present invention, with the grid in the power, operable 5 position; FIG. 2 is an isometric view of the grid assembly, showing the lifting mechanism installed in position; FIG. 3 is an exploded view of the grid assembly, with the grid in the raised, inoperable position; 10 FIG. 4 is a sectional side view of the grid assembly; FIG. 5 is a detailed view, on an enlarged scale, of one end of the hinge mechanism; FIG. 6 is a sectional side view of the releasable attachment of the distal end of the safety arm to the base frame when the grid is in the 15 raided position; FIG. 7 is a sectional side view of the hinge member; FIG. 8 is an isometric view of the lifting mechanism; FIGS. 9 and 10 are respective front and side views thereof; and FIG. 11 is a perspective view showing the operation of the 20 lifting mechanism, with the grid in the raised, inoperable position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, the grid assembly 10, in accordance with the present invention, has a rectangular peripheral base frame 20, which at least partially defines the cavity 21 underlying the grid 40(to be hereinafter 25 described in more detail) when the grid assemblyl0 is installed. The base frame 20 has a pair of side walls 22, 23 interconnected by end walls 24, 25, the end walls being provided with drainage outlets 26. The side walls and end walls 22-25 are fabricated from I-section (i.e. universal beam) steel which may be suitably-coated or 30 otherwise-treated for corrosion resistance to maximize the life of the base frame 20. As illustrated more clearly in FIG. 5, a plurality of substantially 5 L-shaped brackets 27, 28 are welded within the inner faces of the side walls 22, 23, at spaced locations, and support substantially L-shaped plates 29, 30 which form supporting abutment faces 31, 32 for the grid 40. Lugs 33 on the end plates 29, 30 are provided with aligned 5 holes 34 to receive the hinge member 61 (to be hereinafter described in more detail). A pair of outwardly-inclined sockets 35 are provided on each end wall 24, 25 to receive the lower ends of respective posts 36 of wings 37 for the grid assembly 10. Each wing 37 has four horizontal rails 38 welded to 10 the posts 36 and terminated by respective end rails 39. The skilled addressee will appreciate that the wings 36 may be released from the base frame 20 to minimize the volume of the grid assembly 10 when packed for storage or transport. The grid 40 has a plurality of substantially parallel, spaced, grid 15 bars 41, fabricated from steel bar or RHS, and welded to respective end bars 42, 43; where each end bar 42, 43 has a distal end portion 44, 45 extending laterally from the adjacent grid bar 41. Respective hinge holes 47, 48 are provided, in alignment, in the distal end portions 44, 45 of the end bars 42, 43. 20 A plurality of bearers 49, e.g. of rolled RHS, are provided in substantially parallel, spaced arrangement, transverse to the grid bars 41, and welded thereto. The respective ends of the bearers 49 are supported by the abutment faces 31, 32 when the grid 40 is in its lowered, operational position (as illustrated in FIGS. 1 and 2). 25 The hinge mechanism 60 has a hinge member 61, illustrated in more detail in FIG. 7, with respective tubular end portions 62, 63 interconnected by a lighter-gauge intermediate portion 64. The hinge member 61 is received within the aligned holes 34 in the lugs 33 in the base frame 20. 30 One end portion 62 of the hinge member 61 is closed by a cylindrical plug 65; and a peripheral flange 66 around the one end portion 62 provides a locating stop.

6 An annular plug 67 is provided in the other end portion 63 of the hinge member 61, and has a screw-threaded bore 68 arranged to receive a removable stud 69, hinge restraint cap 70 and spring washer 71. The end portions 62, 63 of the hinge member 61 are 5 dimensioned to be received with a minimal working clearance within the aligned hinge holes 47, 48 in the end bars 42, 43 of the grid 40, where the end portions 62, 63 of the hinge member 61 are located by the peripheral flange 66 and the hinge restraint cap 70. The skilled addressee will appreciate that the hinge mechanism 10 60, interconnecting the grid 40 and the base frame 20, enables the grid 40 to be moved between a lowered, operational position, allowing the passage of vehicles (but not of stock), as illustrated in FIGS. 1 and 2; and a raised, inoperational position, as illustrated in FIG. 3, to provide access to the cavity 21, underlying the grid 40, so that any dust, dirt or rubbish built up in the 15 cavity 21may be removed. A pair of safety arms 50 are pivotally connected to respective outer faces of the end bars 42, 43 of the grid 40, and, as illustrated in FIG. 6, their distal ends 51 are releasably securable to fixed brackets 52 provided on the end walls 24, 25 of the base frame 20 by studs 53 received in lock-nuts 20 54, so that the grid 40 may be secured in the raised position while the cavity 21 is being cleaned. A lifting mechanism 80, illustrated in FIGS. 3, 8, 9, 10 and 11, is releasably mountable on the base frame 20, to provide a simple, yet efficient, method for raising or lowering the grid. 25 The lifting mechanism 80 has a post 81, which is substantially vertical in use, with a lower end portion 82 releasably receivable in a socket 83 welded to the outer-side of the side wall 22. A bracing plate 84, on the lower portion 82, extends downwardly of at least the upper portion of the side wall of the socket 83,and is terminated by a substantially horizontal abutment 30 face 85 arranged to engage the top face of the side wall 22 of the base frame 20. A collar 84A on the lower portion 82 of the post 81 engages the top rim of the socket 83.

7 A top sheave 86 is rotatably mounted between a pair of spaced mounting plates 87 at the top of the post 81; while a secondary sheave 88 is rotatably mounted in a second pair of mounting plates 89 extending from an intermediate portion of the post 81 in a direction away from the grid 40. 5 As illustrated in FIG. 11, a cable 90 has a cable end 91 provided with a D-shackle 92, releasably connectable to a lifting bracket 93 on the centre bearer 49 (at its end spaced from the hinge mechanism 60). The cable 90 is arranged to pass over the top sheave 86, around the secondary sheave 88, and the other end of the cable 90 is connectable to a 10 vehicle or a winch (not shown), where the vehicle or winch are operable to pull or release the cable 90, to move thereby move the grid 40 between the lowered, operational position - as illustrated in FIG. 2 - and the raised, inoperational position - as illustrated in FIG. 11. A safety chain 94 has one end anchored via a coupling 95 to 15 the post 81, and can pass around an adjacent grid bar 41 of the grid 40, when the grid 40 is in the raised position, the free (other) end of the safety chain 94 being secured to the post 81 by the coupling 95 to prevent the grid 40 accidentally moving from the raised position to the lowered position. The skilled addressee will appreciate that the lifting mechanism 20 80 can be easily fitted, or released from, a grid assembly 10; and can be easily transported from site to site to enable simple, yet efficient, raising or lowering of the respective grids 40 of the grid assemblies 10 at those sites; while the safety arms 50 and/or the safety chain 94 can secure the grids 40 in their raised position while the respective cavities 21 are being cleaned. 25 In the embodiment illustrated, the grid 40 is shown as being hinged along its long edge. It will be readily apparent to the skilled addressee that, in certain applications, it may be preferable that the grids 40 are hinged along their short edges, i.e., hinged about an axis parallel to the end walls 24, 25 of the base frame 20. 30 The skilled addressee will appreciate that the materials, dimensions, sections and other design criteria of the components of the grid assemblies 10 may be varied to suit the particular intended applications for 8 the grid assemblies 10. By deleting the respective inclined sockets 35 on the end wall 24 of the base frame 20 of a first grid assembly 10 and on the end wall 25 of the base frame 20 of a second grid assembly 10, the first and second grid 5 assemblies 10 may have their base frames 20 laid, and secured together, end-to-end to span a longer cavity 21 than can be spanned by a single grid assembly 10. Joining - or connector plates or brackets can be e.g. bolted or welded to either or both base frames 20 for connection by bolts to the other base frame(s). While the connection could be via welding, this would require 10 the provision of welding equipment and an operator on-site. Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention. 15

Claims (5)

1. A grid assembly including: a rectangular base frame having a pair of side walls 5 interconnected by a pair of end walls; a grid, having a plurality of substantially-parallel, spaced, grid bars interconnected by a pair of end bars; and a hinge mechanism hingedly interconnecting one end of the end bars to the base frame to enable the grid to be moved from a lowered, 10 operational position to a raised, inoperational position.

2. A grid assembly as claimed in claim 1, wherein: the grid bars are interconnected by a plurality of substantially parallel, spaced bearers which extend transversely thereto; and inwardly-directed abutment faces on the side walls of the base 15 frame are arranged to support respective ends of the bearers when the grid is in the lowered, operational position.

3. A grid assembly as claimed in claim 1 or claim 2, wherein the hinge mechanism includes: aligned holes at respective one ends of the end bars of the 20 grid; and a hinge member, optionally of steel rod or hollow steel tube, having a locating flange adjacent one end thereof, and adapted to receive a releasable locating member at the other end, the hinge member being receivable in aligned holes in the base frame. 25

4. A grid assembly as claimed in any one of claims 1 to 3, and further including a lifting mechanism, the lifting mechanism including: a post, having a lower portion receivably engageable in a substantially-vertical socket provided intermediate one of the side walls of the base frame; 30 a pulley or sheave rotatably mounted at the upper end of the post; an optional secondary pulley or sheave rotatably mounted 10 intermediate the height of the post, on a side of the post spaced from the grid; and; a cable, rope or like flexible tension means having one end connectable to the grid at a location spaced from the hinge mechanism, 5 passing around the pulley or sheave (and the optional secondary pulley or sheave), and the other end connectable to a vehicle or winch, which is operable to pull or release the cable, rope or like flexible tension means to enable the grid to be moved from the lowered, operational position, to the raised, inoperational position. 10

5. A grid assembly as claimed in any one of claims 1 to 4, and further including: at least one safety arm, pivotally connected to the grid, being releasably engageable with the base frame when the grid is in the raised, inoperational position; and/or 15 a safety chain on the post to secure the grid to the post when the grid is in the raised, inoperational position. 20 25 30