NZ575847A

NZ575847A - Bogie for a mono-rail where the driven wheel acts on the side of the rail

Info

Publication number: NZ575847A
Application number: NZ57584710A
Authority: NZ
Inventors: Lindsay Mark Stephenson
Original assignee: Lindsay Mark Stephenson
Priority date: 2010-06-28
Filing date: 2010-06-28
Publication date: 2011-12-22

Abstract

A bogie (10) for running on a guide rail (12) is disclosed. The bogie (10) has a bogie frame (22) supported on a rail (12) by first (41), second (42) and third wheels (23) mounted to it. The first (41) and second wheels (42) are urged into contact against opposite sides of the guide rail (12). The third wheel (23) contacts an upward-facing support surface (13) of the guide rail, bearing the weight carried by the bogie. The first wheel (41) at least is driven by a motor (45) to move the bogie along the guide rail. The second wheel may be an idler or be also driven by a second motor (46).

Description

10059417680* ;No: 575847 Date: 27 March 2009 ;NEW ZEALAND PATENTS ACT, 1953 ;COMPLETE SPECIFICATION ;BOGIE AND CROWD GATE ;I, LINDSAY MARK STEPHENSON, a New Zealand citizen of 9/13 Scott Street, Rotorua, New Zealand, do hereby declare the invention for which we pray that a patent may be granted us, and the method by which it is to be performed, to be particularly described in and by the following statement: ;INTELLECTUAL PROPERTY OFFICE OF N.Z. ;2 8 JUN 2010 RECEIVED ;FIELD OF THE INVENTION ;The present invention relates to a bogie and to the bogie combined with a suspended 5 device, for example a crowd gate or a mixing device. The invention is particularly suited to handling stock animals. Such animals include dairy cows, dry stock, sheep and alpacas. ;In one specific application, two such bogies support opposite ends of a crowd gate spanning an animal marshalling yard. The bogies move the gate along the yard to urge the 10 animals held in the yard toward an exit end leading to an adjacent animal holding area, for example a milking station, another exit, or a collecting yard. In another specific application, two such bogies support opposite ends of a support beam from which mixing devices, for example oars, paddles, propellers, or pumps, are suspended. The bogie-mounted beam traverses the mixing devices through a fluid to be mixed or stirred, for 15 example water or effluent in a treatment pond. ;BACKGROUND TO THE INVENTION ;Wheeled bogies are used in devices that move along a guide-way such as a railway. One or 20 more bogies run on a guide or rail, or, more usually, a pair of guides or rails. In one common application, a railway coach or carriage is carried on a pair of bogies that run on two parallel rails. Each bogie has two pairs of flanged wheels. In each pair, the wheels share a common, and generally horizontal, axis of rotation. ;25 In another known bogie arrangement, two bogies support opposite ends of a crowd gate in an animal marshalling yard. Two horizontal U-shaped channels are mounted on the upper edges of the respective walls along two opposite sides of the yard. Each bogie has a pair of wheels which are spaced apart along, and run on the floor of, a respective one of the U-shaped channels. The axes of the wheels are horizontal and transverse to the channels. 30 The bogie wheels run between the upright flanges of the respective channel to retain the bogie on the channel. One of the wheels of each bogie may be driven by an electric motor through a reduction gearbox to move the crowd gate back and forth along the yard. ;2599487-3 ;Received at IPONZ 22 November 2010 ;In a further bogie arrangement, a motor-driven load-bearing support wheel rotates about a horizontal axis. The wheel runs along the upper surface of a guide rail. The bogie has two vertical axis idling rollers. The rail is held between the two idling rollers to keep the bogie on the rail. ;5 ;It is an object of the present invention to provide a bogie that either provides further improvements over the prior art or that at least provides the public with a useful choice. ;SUMMARY OF THE INVENTION ;10 ;In a first aspect, the present invention broadly relates to a bogie for running on a guide rail, the bogie comprising: ;a bogie frame; ;first, second and third wheels mounted to the bogie frame for rolling along the 15 guide rail when the bogie is running on the guide rail; and a drive motor; ;wherein the first wheel is adapted for applying a first contact force against a first side face of the guide rail when the bogie is running on the guide rail; ;20 the second wheel is adapted for applying a second contact force against a second side face of the guide rail when the bogie is running on the guide rail, the second side face of the guide rail being opposite the first side face of the guide rail; ;the third wheel is adapted for rolling along an upward-facing support surface of the guide rail and thereby bearing a weight carried by the bogie when the bogie is running on 25 the guide rail; and the drive motor is adapted for rotating the first wheel, and thereby moving the bogie along the guide rail when the bogie is on the rail. ;Preferably, the bogie comprises a second drive motor which is adapted for rotating the 30 second wheel, and thereby assisting in moving the bogie along the guide rail when the bogie is on the guide rail. ;Preferably, the second wheel is an idler wheel. Preferably, the third wheel is an idler wheel. ;3 ;Received at IPONZ 22 November 2010 ;Preferably the bogie comprises a fourth wheel which is adapted for rolling along the upward-facing support surface of the guide rail and thereby bearing a weight carried by the bogie when the bogie is running on the guide rail. Preferably, the fourth wheel is an idling wheel. ;5 ;Preferably, the bogie comprises: ;first and second further wheels mounted to the bogie frame for rolling along the guide rail when the bogie is running on the guide rail; ;wherein; ;10 the first further wheel is adapted so that a portion of its outer circumferential perimeter lies closely adjacent, or in contact with, the first side face of the guide rail when the bogie is running on the guide rail; and the second further wheel is adapted so that a portion of its outer circumferential perimeter lies closely adjacent, or in contact with, the second side face of the guide rail 15 when the bogie is running on the guide rail. Preferably, respective perimeter portions of the first and second further wheels are resiliently biased against the first and second side faces to respectively apply first and second further contact forces. Preferably, the first and second further wheels are rotatable about respective first and second substantially vertical further wheel axes, and at least one of the first and second further wheels is resiliently 20 biased to urge the first and second further wheel axes to move relative to one another and thereby provide the respective first and second further contact forces. ;Preferably, the opposite side faces of the guide rail are outward-facing. Preferably, respective perimeter portions of the first and second wheels are resiliently biased toward 25 one another to apply the respective first and second contact forces. Preferably, the first and second wheels are rotatable about respective substantially vertical first and second wheel axes, and at least one of the first and second wheels is resiliently biased to urge the vertical wheel axes closer to one another to thereby provide the respective first and second contact forces. ;30 ;Alternatively, the opposite side faces of the guide rail are inward-facing. Preferably, respective perimeter portions of the first and second wheels are resiliently biased away from one another to apply the respective first and second contact forces. Preferably, the first and second wheels are rotatable about respective substantially vertical first and 35 second wheel axes, and at least one of the first and second wheels is resiliently biased to ;4 ;Received at IPONZ 22 November 2010 ;urge the vertical wheel axes further apart to thereby provide the respective first and second contact forces. ;In some of the above preferences and alternatives of the first aspect of the invention, the 5 wheel axis of one of the first and second wheels may be fixed relative to the bogie frame. ;Preferably, one of the first and second wheels is mounted to the bogie frame by a link which is pivotably connected to the bogie frame, and the pivotable link is resiliently biased to urge the link to rotate about its pivot axis and thereby urge said one wheel against the 10 respective first or second side face of the guide rail. Preferably, the pivot axis is substantially vertical. Alternatively, the pivot axis is substantially horizontal. ;Alternatively, the first and second wheels are mounted to the bogie frame by respective links which are pivotably connected to the bogie frame, and each pivotable link is resiliently 15 biased to urge the respective link to rotate about its pivot axis and thereby urge the respective first or second wheel against the respective first or second side face of the guide rail. Preferably, the pivot axes of the pivotably connected links are substantially vertical. Alternatively, the pivot axes of the pivotably connected links are substantially horizontal. Preferably, the pivot axes of the pivotably connected links are mutually parallel and spaced 20 apart from one another. Alternatively, the pivot axes of the pivotably connected links are a common axis. ;Preferably, at least one of the first and second wheels comprises a resilient tyre, and a circumferential portion of the resilient tyre contacts the respective first or second side face 25 of the guide rail and is deformed to apply the respective first or second contact force. Preferably, the resilient tyre is a pneumatic tyre. ;Preferably, the first and second contact forces are derived from at least one spring and are applied respectively by the first and second wheels against the first and second side faces of 30 the guide rail. ;Preferably, the at least one spring is a helical compression spring. Alternatively, the at least one spring is a tension spring ;5 ;In a second aspect, the present invention broadly relates to an elongate barrier having opposite outer ends which are carried on respective bogies, wherein each bogie is the first aspect of the invention, or any of its preferences or alternatives as recited above. ;Preferably, the barrier is a crowd gate and the bogies run along respective guide rails at 5 opposite side walls of an animal marshalling yard. Preferably, the crowd gate is pivotably attached to the bogies, the crowd gate is reversibly movable between a gate raised position and a gate lowered position, and the weight of the crowd gate acts vertically downward between the bogies' first and fourth wheels for all positions of the crowd gate between the gate raised position and the gate lowered position. ;10 ;In a third aspect, the present invention broadly relates to an elongate beam having opposite outer ends which are carried on respective bogies, wherein each bogie is the first aspect of the invention, or any of its preferences or alternatives as recited above. Preferably, the bogies run along respective guide rails, the beam supports at least one agitating, stirring or ;15 mixing device, the beam spans across a volume of fluid that is situated between the guide rails and that is to be agitated, stirred or mixed by immersion of the at least one agitating, stirring or mixing device in the volume of fluid. ;The term 'comprising' as used in this specification means 'consisting at least in part of, that ;20 is to say when interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as 'comprise' and 'comprised' are to be interpreted in similar manner. ;25 The term 'bogie' as used in this specification denotes any form of wheeled carriage that can run along a rail, track or other guideway. It is anticipated that the rail, track or other guideway is laid out in a linear or circular configuration. A circular configuration is suitable where a circular yard is present. In this case the bogie is driven from a centre pole. ;30 In this specification, where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or sources of information is not to be construed as ;2599487-3 / ;an admission that such documents or sources of information in any jurisdiction are prior art, or form part of the common general knowledge in the art. ;The present invention may also be said broadly to consist in the parts, elements and 5 features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. ;10 ;BRIEF DESCRIPTION OF THE FIGURES ;Preferred forms of the device of the present invention will now be described with reference to the accompanying figures in which: ;15 ;Figure 1 shows a schematic side view of a preferred form of a bogie on one form of guide rail; ;Figure 2 shows a schematic top plan view of the bogie and guide rail of Figure 1; ;20 ;Figure 3 shows an end view of the bogie and a cross-section view of the guide rail as seen looking left at line 3-3' of Figures 1 and 2; ;Figure 4 shows a first transverse cross-sectional view of the bogie and guide rail, as 25 seen looking left at line 4-4' of Figures 1 and 2; ;Figure 5 shows a second transverse cross-sectional view of the bogie and guide rail, as seen looking left at line 5-5' of Figures 1 and 2; and ;30 Figure 6 shows a schematic top plan view of a portion of an animal marshalling yard with a crowd gate supported by a pair of bogies running on a pair of parallel rails. ;2599487-3 ;DETAILED DESCRIPTION OF PREFERRED FORMS OF THE INVENTION ;Figures 1 to 5 show various views of one preferred form of the present invention. A bogie 10 rides on a guideway or guide rail 12. The preferred form guide rail is in the form of a 5 universal beam (UB), a universal column (UC), a super light beam (SLB), or a rolled steel joist (RSJ). A length portion of the rail 12 is shown in Figure 1. ;The rail 12 has an I-shaped cross-section, as best seen in the cross-sections of Figures 3, 4 and 5. The rail has a generally horizontal upper flange 13, a generally horizontal lower 10 flange 14, and an upright intermediate web 15 extending generally vertically between the centre lines of the upper and lower flanges. The upper flange has a flat top surface 16 seen in Figure 2. ;The bogie comprises a frame formed from a steel box beam 22. The frame has a 15 rectangular cross-section as best seen in Figures 3 and 5. Two load-bearing support wheels 23, 24 are housed in respective opposite ends of the box beam 22. The support wheels rotate about respective generally horizontal axles 25, 26 which span between opposite vertical side walls 27, 28 of the box beam. The support wheels rotate freely, ie they are idler wheels that are not driven. ;20 ;Cut-outs 31, 32 (shown by broken lines in the top plan view of Figure 2) are formed in the bottom wall 33 of the box beam. A bottom portion of each support wheel 23, 24 extends through respective cut-outs 31, 32 to protrude below the underside of the box beam 22. This protrusion provides a clearance 35 (shown labelled in Figure 1) between the underside 25 of the box beam 22 and the flat top surface 16 of the rail 12 on which the support wheels bear. ;The upright intermediate web 15 of the beam 22 is pinched between two wheels or 'pinch' rollers 41, 42. These pinch rollers run on generally vertical shafts 43, 44 to roll along the 30 opposite outward-facing side faces of the intermediate web 15. The two pinch rollers are driven by respective first and second electric motors 45, 46 acting through respective first and second gearboxes 47, 48 from which the respective first and second vertical roller shafts 43, 44 extend. The gearboxes provide a reduction gearing so that the rotary shaft ;2599487-3 q ;speed is significantly less and the shaft torque correspondingly higher than provided by the electric motors. ;Each support wheel and each pinch roller is preferably fitted with a circumferential tyre. A 5 suitable tyre material is urethane which is cost-effective and provides reliable and quiet operation for movement of the bogie along the rail. The urethane pinch roller tyres provide sufficient traction to grip the rail and move the bogie along the rail, while allowing the bogie to slip if the bogie, or a gate or other device supported by the bogie, contacts an obstacle or is pushed forward or backward. This slippage limits or prevents damage to the 10 bogie or its components, for example the drive motors or gearboxes, and can reduce or prevent injury or harm to animals and people. ;The tyres fitted to the pinch rollers may be resilient so that when the tyre applies a contact force to a respective side of the guide rail, a portion of the tyre deforms. ;15 ;Each motor 45, 46 is attached to, and is supported by, the respective gearbox 47, 48. Each gearbox is attached to, and supported by, a respective L-shaped link or arm 51, 52 formed from plate steel. The two L-shaped arms 51, 52 are pivotably attached to the upper wall 53 of the box beam 22 by common vertical pivot shaft 54. The arms may be of other shapes. ;20 ;In an alternative arrangement, not shown, the pinch rollers rotate about respective vertical pivot shafts, in which case the pivot shafts are mutually parallel, but spaced apart, and can be located at respective sides of the box beam. ;25 As best seen in the side view of Figure 1, the proximal end, i.e. the pivot axis end, of lower L-shaped arm 52 is spaced above the top surface of the upper wall 53 of the box beam 22 by a lower steel spacing washer 55, and the proximal end, i.e. the pivot axis end, of upper L-shaped arm 51 is spaced above the top surface of the lower L-shaped arm 52 by an upper steel spacing washer 56. The pivot shaft 54 passes through central apertures in the 30 lower and upper spacing washers 55, 56. The lower and upper spacing washers 55, 56 are preferably secured to the respective lower and upper L-shaped arm 52, 51, for example by a small tack weld. ;2599487-3 ;9 ;As best seen in the side view of Figure 1 and in the end section views of Figures 3 and 4, the distal end, i.e. the non-pivot axis end, of lower L-shaped arm 52 is spaced from the top surface of the upper wall 53 of the box beam 22 by lower packing spacer 57, and the distal end, i.e. the non-pivot axis end, of upper L-shaped arm 51 is spaced from the top surface 5 of the lower L-shaped arm 52 by upper packing spacer 58. The lower and upper packing spacers 57, 58 are attached to respective outer ends of the lower and upper L-shaped arms 52, 51. ;The lower packing spacer 57 slides over the top surface of the upper wall 53 of the box 10 beam 22 when the lower L-shaped arm 52 rotates about the pivot shaft 54. The upper packing spacer 58 slides over the top surface of the lower L-shaped arm 52 when the upper and lower L-shaped arms 51, 52 rotate about the pivot shaft 54 relative to one another. ;The weight of the motors, gearboxes and rollers carried by the two L-shaped arms 51, 52 is 15 transferred through the corresponding packing spacers to the box beam, thereby reducing, and largely eliminating, the tendency for the arms to bend under the weight. ;Figures 1, 3 and 4 show an exaggerated space between the packing spacers 57, 58 and the respective surfaces over which they slide. Similarly, Figure 1 shows an exaggerated space 20 between the spacing washers 55 and 56 and the respective surfaces over which they slide when pivotally rotating about pivot shaft 54. These spaces are shown exaggerated in this specification for clarity of this description. ;A portion of each side wall 27, 28 of the box beam 22 is cut away to provide an aperture 61 25 (best seen in the side view of Figure 1) which extends completely through the box beam. The box beam bottom wall 33 at the aperture 61 is maintained, or is reinstated if cut away during formation of the aperture, to maintain the rigidity and strength of the bogie frame. The two gearboxes 47, 48 protrude into the aperture 61 from respective opposite sides of the box beam, as shown in Figure 4. ;30 ;A rectangular steel ceiling plate 66, seen in cross-section in Figure 4, is welded to the side walls 27, 28 of the box beam at the upper edges of the aperture 61 to form a generally horizontal ceiling in the aperture. ;2599487-3 ;10 ;The aperture 61 is provided with opposed walls by respective rectangular steel wall plates 67, 68, seen respectively in Figures 3 and 4. The upper edge of each rectangular wall plate 67, 68 is welded respectively to opposite end edges of the ceiling plate 66. A first vertical 5 side edge of each rectangular wall plate 67, 68 is welded to the box beam side wall 27 at respective sides of the aperture 61. A second vertical side edge of each rectangular wall plate 67, 68 is welded to the other box beam side wall 28 at respective sides of the aperture 61. The bottom edge of each rectangular wall plate 67, 68 is welded to the box beam bottom wall 33. These wall plates 67, 68 are generally vertical and strengthen the aperture 10 ceiling plate 66 and contribute to the strength and rigidity of the bogie frame box beam 22, particularly around the aperture 61. ;First and second spacing plates 62 are attached to the underside of the distal end, i.e. the non-pivot axis end, of the upper L-shaped arm 51. A first restraining plate 63 is attached 15 to the bottom ends of the first and second spacing plates 62. The first gearbox 47 is attached to the underside of the first restraining plate 63. The first restraining plate extends, generally horizontally, into the aperture 61 from one side of the box beam. ;Third and fourth spacing plates 64 are attached to the underside of the distal end, i.e. the 20 non-pivot axis end, of the lower L-shaped arm 52. A second restraining plate 65 is attached to the bottom ends of the third and fourth spacing plates 64. The second gearbox 48 is attached to the underside of the second restraining plate 65. The second restraining plate extends, generally horizontally, into the aperture 61 from the other side of the box beam. ;25 ;As best seen in Figures 3 and 4, the first and second spacing plates 62 are longer vertically than the third and fourth spacing plates 64, so that the two gear boxes 47, 48 supported from the respective upper and lower L-shaped arms 51, 52 are at the same height as each other. The respective pinch rollers 41, 42, being on similar length shafts 43, 44, are thereby 30 held at the same height as each other. ;The vertical length of the shorter third and fourth spacing plates 64 is selected so that the distance between the underside of the lower packing spacer 57 and the topside of the ;2599487-3 ;11 ;second restraining plate 65 is slighdy longer, for example by up to 3 mm, than the distance between the topside of the box beam upper wall 53 and the underside of the aperture ceiling plate 66. This provides for clearances, shown exaggerated for clarity in Figures 3 and 4, between these parts. ;5 ;The vertical length of the longer first and second spacing plates 62 is selected so that the distance between the underside of the upper packing spacer 58 and the topside of the first restraining plate 63 is slightly longer, for example by up to 3 mm, than the sum of the distance between the topside of the lower L-shape arm 52 and the underside of the 10 attached lower packing spacer 57, and the distance between the topside of the box beam upper wall 53 and the underside of the aperture ceiling plate 66. This provides for clearances, shown exaggerated for clarity in Figures 3 and 4, between these parts. ;This selection of the vertical lengths of the spacing plates 62, 64 provides a freely sliding 15 clearance between the respective packing spacers and restraining plates to permit the L- ;shaped arms to freely pivot while restraining the arms from excessive uplift from their rest positions, supported on the upper wall 53 of the box beam. This restraint maintains the pinch rollers at, or close to, a predetermined distance below the underside of the bogie frame. This restraint also helps resist the twisting of the arms that could be caused by 20 offset of the tensioned rod 73 above the pinch zone between the pinch rollers 41, 42. ;Two lugs 71, 72 are attached respectively to the first and second gearboxes 47, 48. A threaded rod 73 passes through the aperture 61 in the box beam 22 and also passes through respective apertures in the two lugs. A threaded nut 74, a pair of plain washers 75, 25 and a helical coil compression spring 76 (located between the two plain washers) are fitted to each end of the threaded rod. ;The two nuts are adjusted to compress the springs against the lugs, putting the rod under tension. The tension, acting through the lugs 71, 72, gearboxes 47, 48 and roller shafts 43, 30 44, resiliently biases the two pinch rollers 41, 42 toward one another to thereby grip the upright intermediate web 15 of the rail 12. Either of the nuts 74 can be rotated on the threaded rod 73 to adjust the contact or pinch pressure applied to the upright intermediate ;2599487-3 ;12 ;web 15 of the guide rail 12 by the two pinch rollers 41, 42. In an alternative arrangement, only one of the compression springs is used. ;In an alternative arrangement, not shown, the helical coil compression springs are omitted 5 and the resilience of tyres fitted to the pinch rollers provides resilient bias of the pinch rollers 41 and 42 against the respective side faces of the web 15 of the guide rail. A pneumatic tyre can be used advantageously to maintain an adequate contact pressure on the guide rail while accommodating movement of the pinch roller axes. ;10 It will be appreciated that a tension spring could be used rather than a helical coil compression spring. ;A guide roller 81 runs on a generally vertical shaft 82 that is attached to the box beam 22 of the bogie frame. The guide roller rolls along one side face of the intermediate web 15 of 15 the rail 12. The guide roller is located toward the end of the bogie frame opposite the end near which the pinch rollers 23 and 24 are located. In one specific embodiment, where a pair of bogies are supporting opposite ends of a crowd gate that is approximately 15 metres long, the bogies have the guide roller located about 1.8 metres from the pinch rollers. In other embodiments the guide roller and the pinch rollers are spaced apart by other 20 distances, for example about 1.5 metres. ;The guide roller may be mounted at an alternative position on the opposite side of the bogie, as is shown in Figures 2 and 5 by broken lines. In some applications, a respective guide roller is fitted in each position, i.e. one on on each side of the rail. The guide rollers 25 are idler rollers which rotate freely but are at fixed locations relative to the bogie frame. ;The bogie 10 described above and shown in Figures 1 to 5 is generally paired with another like bogie and used to carry a load supported by the two bogies at respective points. For example, Figure 6 shows a schematic top plan view of a portion of one specific 30 embodiment in which a pair of bogies 110, 111 support opposite ends of a crowd gate 120 that spans across a yard 130 that is 8 to 15 metres wide. The bogies run on respective nominally-parallel rails 112, 113. The rails are nominally parallel but the spring biasing and pivotal mounting of the pinch rollers 41, 42 allows the bogies to successfully travel on rails ;2599487-3 ;13 ;that are off-parallel, i.e. are not exactly parallel. The rails are typically installed within a design tolerance of 5 mm from a nominal parallel spacing. In one preferred application, the gate spans across an animal marshalling area and the bogies move the gate along the yard to urge the animals held in the yard toward an exit end leading to an adjacent animal 5 holding area, for example a milking station, another exit, or a collecting yard. ;Each end of the crowd gate is pivotable suspended from a pair of spaced apart pivot points on a respective horizontal arm (not shown) that rigidly extends transversely to the frame of the respective bogie. In one preferred application, each bogie carries a winch drum driven 10 by a reversible motor. At each end of the gate, a line attached to a lower end of the gate is wound around the winch drum which is driven to move the gate between a substantially vertical lowered gate position and a substantially horizontal raised gate position. The weight of the crowd gate acts vertically downward between the load bearing support wheels of the two bogies for all positions of the crowd gate between the raised gate position and 15 the lowered gate position. ;In another application, the opposite ends of an elongate beam are carried on respective bogies as described above. The bogies run along respective guide rails. The beam supports at least one agitating, stirring or mixing device. The beam spans across a volume of fluid 20 that is situated between the guide rails and that is to be agitated, stirred or mixed by immersion of the at least one agitating, stirring or mixing device in the volume of fluid. The volume of fluid may be a waste water or effluent pond. The agitating, stirring or mixing device may be at least one oar, paddle, blade, propeller, or pump, or the like. ;25 The pivotal mounting of the pinch rollers 41, 42 on each bogie 110, 111 allows for up to ;30mm misalignment of each bogie on its rail, to accommodate distortions or displacements of the rails from their nominal parallel positions. With both bogies having both pinch rollers pivotally mounted, tolerances of up to at least 50mm in the distance between the rails can be accommodated without requiring a sliding joint between one or both bogies 30 and the gate. ;2599487-3 ;14 ;In. one alternative arrangement, not shown, the bogie has only one of the two pinch rollers pivotally mounted as described above. In this case the second pinch roller is fixed, for example mounted similarly to the guide roller described above. ;5 In another alternative arrangement, not shown, each pinch roller pivots about a generally horizontal axis. For example, each pinch roller, with its associated gearbox and motor, is attached to the distal lower end of a respective arm which rotates about a horizontal pivot shaft at the upper proximal end of the arm. The pivot shaft is preferably parallel to, and located above, the centreline of the box beam. ;10 ;The two pinch rollers may be carried on arms which rotate about a common pivot axis or about respective pivot axes. The respective axes may be spaced apart from one another. Alternatively, one pinch roller may be carried on a pivotable arm and the other pinch roller fixed relative to the bogie frame. ;15 ;When the pinch rollers 41, 42 are gripping the upright intermediate web 15 of the rail 12, an outer portion of each roller is located between the upper and lower flanges 13, 14 of the rail. Similarly, an outer portion of the guide roller (or guide rollers) is located between the upper and lower flanges 13, 14 of the rail. If the bogie 10, 110, 111 is lifted, an outer 20 portion of each pinch or guide roller abuts the underside of the upper flange 13 to limit upward movement and retain the bogie on the rail. ;The bogies 110, 111 are moved along the respective rails 112, 113 by powering the electric roller drive motors 45, 46 to rotate the rollers in opposite directions. The direction of the 25 bogie movement and the crowd gate 120 (in the directions of arrows A, B in Figure 6) along the rails 112, 113 can be reversed by reversing the direction of rotation of the two motors. ;The bogie 10 may have only one motor-driven pinch roller, the other pinch roller being an 30 idler roller. In this case, the idler pinch roller may be pivotally mounted and biased toward the driven pinch roller. Where the bogie is paired with another bogie, the second bogie may have both pinch rollers, or only one pinch roller, or neither pinch roller motor driven. A pair of bogies, each having a pair of pinch rollers, may have: ;2599487-3 ;15 ;• only a single driven pinch roller, ;• two driven pinch rollers (either in respective bogies or both in one bogie), ;• three driven pinch rollers, or ;• four driven pinch rollers. ;5 ;Where a bogie, used as one of a pair of bogies, has only a single driven pinch roller, the driven pinch roller may be located on either side of that bogie but is preferably located an outer side of that bogie, i.e. on the side of that bogie that is further from the other bogie. ;10 Where two bogies are used, a single guide roller may be provided on each bogie with the guide rollers mounted on opposite sides of the bogies. For example, a single guide roller would be provided on the left side of one bogie and a single guide roller would be provided on the right side of the other bogie. In an alternative arrangement, two guide rollers could be provided, with a guide roller on both sides of one bogie and no guide rollers on the 15 other bogie. In another arrangement, additional guide rollers can be used: for example, two guide rollers on both bogies. ;The guide rollers on a bogie may be fixed relative to the bogie frame, or one or both may be adjustably fixed, or resiliently biased against respective side faces of the guide rail on 20 which the bogie is running. ;The guide rollers maintain the alignment of the crowd gate: for example, generally perpendicular to the rails located on the side walls of the yard. In this case, neither a sensor monitoring the angle between the gate and the bogie, nor differential control of the speed 25 of the drive motors of the two bogies, is needed to maintain gate alignment across the yard. ;The guideway rail as described above has an I-shaped cross-section. A rail with a T-shaped cross-section could be used substantially identically. The bogie could also be used on rails having other cross-sectional shapes. For example, suitable rails include the following cross-30 sectional shapes. ;• C-shape cross-section, with a generally horizontal upper flange, a generally horizontal lower flange, and an upright intermediate web extending generally vertically between one side edge of the upper flange and one side edge of the lower ;2599487-3 ;16 ;flanges. The upright intermediate web is gripped between the two pinch rollers of the bogie. The bogie can run on the top of the C-shape with the support wheels rolling on the flat upward-facing top surface of the upper flange. Alternatively, the bogie could be modified to run substantially inside the C-shape with the support 5 wheels rolling on the flat upward-facing top surface of the lower flange. ;• Inverted L-shape cross-section, with a generally horizontal upper flange, and an upright web extending generally vertically downward from one side edge of the upper flange. The upright web is gripped between the two 'pinch' rollers of the bogie. The bogie runs on the top of the inverted L-shape with the support wheels ;10 rolling on the flat upward-facing top surface of the upper flange. ;• U-shape cross-section channel rail, with a generally horizontal bottom flange with an upright web extending generally vertically upward from each opposite side edge of the bottom flange. The bogie runs substantially inside the channel rail with the support wheels rolling on the flat upward-facing floor of the bottom flange. The ;15 two pinch rollers may lie outside the channel and grip the U-shape rail between the outer faces of the two upright webs. Alternatively, the two pinch rollers lie inside the channel and press outward against respective inside faces of the two upright webs. ;• O-shape circular or oval cross-section tube or rod. The outer side faces are ;20 gripped between the two 'pinch' rollers of the bogie. The support wheels roll on the upward-facing top surface of rod or tube. The outer circumference of each pinch roller and support wheel may be provided with a concave transverse cross-section to match the corresponding part of the cross-section of the rod or tube. ;25 The rails with I-shaped, T-shaped, C-shaped and inverted L-shaped cross-sections all have an upper flange which provides the advantage described above where portions of the pinch rollers are restrained below the upper flange to limit upward movement of the bogie off the rail. Where the support wheel runs on a lower flange and is located underneath an upper flange, for example where the rail has I-shaped or C-shaped cross-section, the support ;30 wheel is captive under the upper flange and restrains the bogie from excessive uplift. ;In the embodiment described above with reference to the figures, each pinch roller is mounted on a respective link or arm 51, 52 which is pivotably mounted to the bogie frame ;2599487-3 ;17 ;to rotate about a vertical axis. In an alternative arrangement, not shown in the figures, each pinch roller is mounted on a respective link or arm which is pivotably mounted to the bogie frame to rotate about a horizontal axis. The two arms may rotate about a common horizontal axis or may rotate about mutually parallel axes that are spaced apart from one 5 another. The horizontal axes are preferably parallel to, and preferably lying in, a vertical plane through the longitudinal centreline of the bogie frame. ;The bogie 10, and its use to support and carry one end of a crowd gate, as described above, is suitable for moving along a generally straight guiding rail. In this case, the axles 25, 26 of 10 the two load-bearing support wheels 23, 24 are mutually parallel, and the wheels aligned one directly behind the other so that the bogie tracks along the straight rail. ;However, the bogie may be adapted for moving along a curved rail by orienting the support wheel axles so that, although still horizontal, they are each parallel to the radii of 15 the curved rail at the point of contact of the respective wheel on the rail. Typically, the curved rail has a generally constant radius of curvature. ;The foregoing describes the invention including preferred forms thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be incorporated 20 within the scope hereof, as defined by the accompanying claims. ;2599487-3 ;18 *

Claims

Received at IPONZ 22 November 2010 WHAT I CLAIM IS:

1. A bogie for running on a guide rail, the bogie comprising: a bogie frame; 5 first, second and third wheels mounted to the bogie frame for rolling along the guide rail when the bogie is running on the guide rail; and a drive motor; wherein the first wheel is adapted for applying a first contact force against a first side face of 10 the guide rail when the bogie is running on the guide rail; the second wheel is adapted for applying a second contact force against a second side face of the guide rail when the bogie is running on the guide rail, the second side face of the guide rail being opposite the first side face of the guide rail; the third wheel is adapted for rolling along an upward-facing support surface of the 15 guide rail and thereby bearing a weight carried by the bogie when the bogie is running on the guide rail; and the drive motor is adapted for rotating the first wheel, and thereby moving the bogie along the guide rail when the bogie is on the rail. 20

2. A bogie as claimed in claim 1, wherein the bogie comprises a second drive motor which is adapted for rotating the second wheel, and thereby assisting in moving the bogie along the guide rail when the bogie is on the guide rail.

3. A bogie as claimed in claim 1, wherein the second wheel is an idler wheel. 25

4. A bogie as claimed in claim 1, 2 or 3, wherein the third wheel is an idler wheel.

5. A bogie as claimed in any one of the preceding claims, wherein the bogie comprises a fourth wheel which is adapted for rolling along the upward-facing support surface of the 30 guide rail and thereby bearing a weight carried by the bogie when the bogie is running on the guide rail.

6. A bogie as claimed in claim 5, wherein the fourth wheel is an idling wheel. 19 Received at IPONZ 22 November 2010

7. A bogie as claimed in any one of the preceding claims, comprising: first and second further wheels mounted to the bogie frame for rolling along the guide rail when the bogie is running on the guide rail; wherein; 5 the first further wheel is adapted so that a portion of its outer circumferential perimeter lies closely adjacent, or in contact with, the first side face of the guide rail when the bogie is running on the guide rail; and the second further wheel is adapted so that a portion of its outer circumferential perimeter lies closely adjacent, or in contact with, the second side face of the guide rail 10 when the bogie is running on the guide rail.

8. A bogie as claimed in claim7, wherein respective perimeter portions of the first and second further wheels are resiliently biased against the first and second side faces to respectively apply first and second further contact forces. 15

9. A bogie as claimed in claim 8, wherein the first and second further wheels are rotatable about respective first and second substantially vertical further wheel axes, and at least one of the first and second further wheels is resiliently biased to urge the first and second further wheel axes to move relative to one another and thereby provide the 20 respective first and second further contact forces.

10. A bogie as claimed in any one of the preceding claims, wherein the opposite side faces of the guide rail are outward-facing. 25

11. A bogie as claimed in claim 10, wherein respective perimeter portions of the first and second wheels are resiliently biased toward one another to apply the respective first and second contact forces.

12. A bogie as claimed in claim 10, wherein the first and second wheels are rotatable 30 about respective substantially vertical first and second wheel axes, and at least one of the first and second wheels is resiliently biased to urge the vertical wheel axes closer to one another to thereby provide the respective first and second contact forces.

13. A bogie as claimed in any one of claims 1-9, wherein the opposite side faces of the 35 guide rail are inward-facing. 20 Received at IPONZ 22 November 2010

14. A bogie as claimed in claim 13, wherein respective perimeter portions of the first and second wheels are resiliently biased away from one another to apply the respective first and second contact forces. 5

15. A bogie as claimed in claim 13, wherein the first and second wheels are rotatable about respective substantially vertical first and second wheel axes, and at least one of the first and second wheels is resiliently biased to urge the vertical wheel axes further apart to thereby provide the respective first and second contact forces. 10

16. A bogie as claimed in claim 12 or 15, wherein the wheel axis of one of the first and second wheels is fixed relative to the bogie frame.

17. A bogie as claimed in any one of the preceding claims, wherein one of the first and 15 second wheels is mounted to the bogie frame by a link which is pivotably connected to the bogie frame, and the pivotable link is resiliently biased to urge the link to rotate about its pivot axis and thereby urge said one wheel against the respective first or second side face of the guide rail. 20

18. A bogie as claimed in claim 17, wherein the pivot axis is substantially vertical.

19. A bogie as claimed in claim 17, wherein the pivot axis is substantially horizontal.

20. A bogie as claimed in any one of claims 1 to 15, wherein the first and second 25 wheels are mounted to the bogie frame by respective links which are pivotably connected to the bogie frame, and each pivotable link is resiliently biased to urge the respective link to rotate about its pivot axis and thereby urge the respective first or second wheel against the respective first or second side face of the guide rail. 30

21. A bogie as claimed in claim 20, wherein the pivot axes of the pivotably connected links are substantially vertical.

22. A bogie as claimed in claim 20, wherein the pivot axes of the pivotably connected links are substantially horizontal. 35

23. A bogie as claimed in claim 20, 21 or 22, wherein the pivot axes of the pivotably connected links are mutually parallel and spaced apart from one another. 21 Received at IPONZ 22 November 2010

24. A bogie as claimed in claim 20, 21 or 22, wherein the pivot axes of the pivotably connected links are a common axis.

25. A bogie as claimed in any one of the preceding claims, wherein at least one of the 5 first and second wheels comprises a resilient tyre, and a circumferential portion of the resilient tyre contacts the respective first or second side face of the guide rail and is deformed to apply the respective first or second contact force.

26. A bogie as claimed in claim 25, wherein the resilient tyre is a pneumatic tyre. 10

27. A bogie as claimed in any one of the preceding claims, wherein the first and second contact forces are derived from at least one spring and are applied respectively by the first and second wheels against the first and second side faces of the guide rail. 15

28. A bogie as claimed in claim 27, wherein the at least one spring is a helical compression spring.

29. A bogie as claimed in claim 27, wherein the at least one spring is a tension spring. 20

30. An elongate barrier having opposite outer ends which are carried on respective bogies, wherein each bogie is as claimed in any one of the preceding claims.

31. An elongate barrier as claimed in claim 30, wherein the barrier is a crowd gate and the bogies run along respective guide rails at opposite side walls of an animal marshalling 25 yard.

32. An elongate barrier as claimed in claim 31, when dependent on claims 5 and 6, wherein the crowd gate is pivotably attached to the bogies, the crowd gate is reversibly movable between a gate raised gate position and a gate lowered gate position, and the 30 weight of the crowd gate acts vertically downward between the bogies' first and fourth wheels for all positions of the crowd gate between the raised gate position and the lowered gate position. 22

33. An elongate beam having opposite outer ends which are carried on respective bogies, wherein each bogie is as claimed in any one of claims 1 to 28.

34. An elongate beam as claimed in claim 33, wherein the bogies run along respective 5 guide rails, the beam supports at least one agitating, stirring or mixing device, the beam spans across a volume of fluid that is situated between the guide rails and that is to be agitated, stirred or mixed by immersion of the at least one agitating, stirring or mixing device in the volume of fluid. 10

35. A bogie substantially as herein described with reference to, and/or as illustrated in, any one or more of the accompanying figures.

36. An elongate barrier having opposite outer ends which are carried on respective bogies, substantially as herein described with reference to, and/or as illustrated in, any one 15 or more of the accompanying figures.

37. An elongate beam having opposite outer ends which are carried on respective bogies, substantially as herein described with reference to, and/or as illustrated in, any one or more of the accompanying figures. 20 25 LINDSAY MARK STEPHENSON By the authorised agents A J Park Per 30 2 8 JUN 2010 RECEIVED 2599487-3 23